diff options
Diffstat (limited to '')
| -rw-r--r-- | dirmngr/dns.c | 11575 |
1 files changed, 11575 insertions, 0 deletions
diff --git a/dirmngr/dns.c b/dirmngr/dns.c new file mode 100644 index 0000000..25d839a --- /dev/null +++ b/dirmngr/dns.c @@ -0,0 +1,11575 @@ +/* ========================================================================== + * dns.c - Recursive, Reentrant DNS Resolver. + * -------------------------------------------------------------------------- + * Copyright (c) 2008, 2009, 2010, 2012-2016 William Ahern + * + * Permission is hereby granted, free of charge, to any person obtaining a + * copy of this software and associated documentation files (the + * "Software"), to deal in the Software without restriction, including + * without limitation the rights to use, copy, modify, merge, publish, + * distribute, sublicense, and/or sell copies of the Software, and to permit + * persons to whom the Software is furnished to do so, subject to the + * following conditions: + * + * The above copyright notice and this permission notice shall be included + * in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS + * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN + * NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, + * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR + * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE + * USE OR OTHER DEALINGS IN THE SOFTWARE. + * ========================================================================== + */ +#if HAVE_CONFIG_H +#include "config.h" +#elif !defined _GNU_SOURCE +#define _GNU_SOURCE 1 +#endif + +#include <limits.h> /* INT_MAX */ +#include <stdarg.h> /* va_list va_start va_end */ +#include <stddef.h> /* offsetof() */ +#ifdef _WIN32 +/* JW: This breaks our mingw build: #define uint32_t unsigned int */ +#else +#include <stdint.h> /* uint32_t */ +#endif +#include <stdlib.h> /* malloc(3) realloc(3) free(3) rand(3) random(3) arc4random(3) */ +#include <stdio.h> /* FILE fopen(3) fclose(3) getc(3) rewind(3) vsnprintf(3) */ +#include <string.h> /* memcpy(3) strlen(3) memmove(3) memchr(3) memcmp(3) strchr(3) strsep(3) strcspn(3) */ +#include <strings.h> /* strcasecmp(3) strncasecmp(3) */ +#include <ctype.h> /* isspace(3) isdigit(3) */ +#include <time.h> /* time_t time(2) difftime(3) */ +#include <signal.h> /* SIGPIPE sigemptyset(3) sigaddset(3) sigpending(2) sigprocmask(2) pthread_sigmask(3) sigtimedwait(2) */ +#include <errno.h> /* errno EINVAL ENOENT */ +#undef NDEBUG +#include <assert.h> /* assert(3) */ + +#if _WIN32 +#ifndef FD_SETSIZE +#define FD_SETSIZE 1024 +#endif +#include <winsock2.h> +#include <ws2tcpip.h> +typedef SOCKET socket_fd_t; +#define STDCALL __stdcall +#ifdef TIME_WITH_SYS_TIME +#include <sys/time.h> /* gettimeofday(2) */ +#endif +#else +typedef int socket_fd_t; +#define STDCALL +#include <sys/time.h> /* gettimeofday(2) */ +#include <sys/types.h> /* FD_SETSIZE socklen_t */ +#include <sys/select.h> /* FD_ZERO FD_SET fd_set select(2) */ +#include <sys/socket.h> /* AF_INET AF_INET6 AF_UNIX struct sockaddr struct sockaddr_in struct sockaddr_in6 socket(2) */ +#if defined(AF_UNIX) +#include <sys/un.h> /* struct sockaddr_un */ +#endif +#include <fcntl.h> /* F_SETFD F_GETFL F_SETFL O_NONBLOCK fcntl(2) */ +#include <unistd.h> /* _POSIX_THREADS gethostname(3) close(2) */ +#include <poll.h> /* POLLIN POLLOUT */ +#include <netinet/in.h> /* struct sockaddr_in struct sockaddr_in6 */ +#include <arpa/inet.h> /* inet_pton(3) inet_ntop(3) htons(3) ntohs(3) */ +#include <netdb.h> /* struct addrinfo */ +#endif + +#include "gpgrt.h" /* For GGPRT_GCC_VERSION */ +#include "dns.h" + + +/* + * C O M P I L E R V E R S I O N & F E A T U R E D E T E C T I O N + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#define DNS_GNUC_2VER(M, m, p) (((M) * 10000) + ((m) * 100) + (p)) +#define DNS_GNUC_PREREQ(M, m, p) (__GNUC__ > 0 && DNS_GNUC_2VER(__GNUC__, __GNUC_MINOR__, __GNUC_PATCHLEVEL__) >= DNS_GNUC_2VER((M), (m), (p))) + +#define DNS_MSC_2VER(M, m, p) ((((M) + 6) * 10000000) + ((m) * 1000000) + (p)) +#define DNS_MSC_PREREQ(M, m, p) (_MSC_VER_FULL > 0 && _MSC_VER_FULL >= DNS_MSC_2VER((M), (m), (p))) + +#define DNS_SUNPRO_PREREQ(M, m, p) (__SUNPRO_C > 0 && __SUNPRO_C >= 0x ## M ## m ## p) + +#if defined __has_builtin +#define dns_has_builtin(x) __has_builtin(x) +#else +#define dns_has_builtin(x) 0 +#endif + +#if defined __has_extension +#define dns_has_extension(x) __has_extension(x) +#else +#define dns_has_extension(x) 0 +#endif + +#ifndef HAVE___ASSUME +#define HAVE___ASSUME DNS_MSC_PREREQ(8,0,0) +#endif + +#ifndef HAVE___BUILTIN_TYPES_COMPATIBLE_P +#define HAVE___BUILTIN_TYPES_COMPATIBLE_P (DNS_GNUC_PREREQ(3,1,1) || __clang__) +#endif + +#ifndef HAVE___BUILTIN_UNREACHABLE +#define HAVE___BUILTIN_UNREACHABLE (DNS_GNUC_PREREQ(4,5,0) || dns_has_builtin(__builtin_unreachable)) +#endif + +#ifndef HAVE_PRAGMA_MESSAGE +#define HAVE_PRAGMA_MESSAGE (DNS_GNUC_PREREQ(4,4,0) || __clang__ || _MSC_VER) +#endif + + +/* + * C O M P I L E R A N N O T A T I O N S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#if __GNUC__ +#define DNS_NOTUSED __attribute__((unused)) +#define DNS_NORETURN __attribute__((noreturn)) +#else +#define DNS_NOTUSED +#define DNS_NORETURN +#endif + +#if __clang__ +#pragma clang diagnostic push +#pragma clang diagnostic ignored "-Wunused-parameter" +#pragma clang diagnostic ignored "-Wmissing-field-initializers" +#elif DNS_GNUC_PREREQ(4,6,0) +#pragma GCC diagnostic push +#pragma GCC diagnostic ignored "-Wunused-parameter" +#pragma GCC diagnostic ignored "-Wmissing-field-initializers" +#endif + + +/* + * S T A N D A R D M A C R O S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#if HAVE___BUILTIN_TYPES_COMPATIBLE_P +#define dns_same_type(a, b, def) __builtin_types_compatible_p(__typeof__ (a), __typeof__ (b)) +#else +#define dns_same_type(a, b, def) (def) +#endif +#define dns_isarray(a) (!dns_same_type((a), (&(a)[0]), 0)) +/* NB: "_" field silences Sun Studio "zero-sized struct/union" error diagnostic */ +#define dns_inline_assert(cond) ((void)(sizeof (struct { int:-!(cond); int _; }))) + +#if HAVE___ASSUME +#define dns_assume(cond) __assume(cond) +#elif HAVE___BUILTIN_UNREACHABLE +#define dns_assume(cond) do { if (!(cond)) __builtin_unreachable(); } while (0) +#else +#define dns_assume(cond) do { (void)(cond); } while (0) +#endif + +#ifndef lengthof +#define lengthof(a) (dns_inline_assert(dns_isarray(a)), (sizeof (a) / sizeof (a)[0])) +#endif + +#ifndef endof +#define endof(a) (dns_inline_assert(dns_isarray(a)), &(a)[lengthof((a))]) +#endif + + +/* + * M I S C E L L A N E O U S C O M P A T + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#if _WIN32 || _WIN64 +#define PRIuZ "Iu" +#else +#define PRIuZ "zu" +#endif + +#ifndef DNS_THREAD_SAFE +#if (defined _REENTRANT || defined _THREAD_SAFE) && _POSIX_THREADS > 0 +#define DNS_THREAD_SAFE 1 +#else +#define DNS_THREAD_SAFE 0 +#endif +#endif + +#ifndef HAVE__STATIC_ASSERT +#define HAVE__STATIC_ASSERT \ + (dns_has_extension(c_static_assert) || DNS_GNUC_PREREQ(4,6,0) || \ + __C11FEATURES__ || __STDC_VERSION__ >= 201112L) +#endif + +#ifndef HAVE_STATIC_ASSERT +#if DNS_GNUC_PREREQ(0,0,0) && !DNS_GNUC_PREREQ(4,6,0) +#define HAVE_STATIC_ASSERT 0 /* glibc doesn't check GCC version */ +#elif defined(static_assert) +#define HAVE_STATIC_ASSERT 1 +#else +#define HAVE_STATIC_ASSERT 0 +#endif +#endif + +#if HAVE_STATIC_ASSERT +#define dns_static_assert(cond, msg) static_assert(cond, msg) +#elif HAVE__STATIC_ASSERT +#define dns_static_assert(cond, msg) _Static_assert(cond, msg) +#else +#define dns_static_assert(cond, msg) extern char DNS_PP_XPASTE(dns_assert_, __LINE__)[sizeof (int[1 - 2*!(cond)])] +#endif + + +/* + * D E B U G M A C R O S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +int *dns_debug_p(void) { + static int debug; + + return &debug; +} /* dns_debug_p() */ + +#if DNS_DEBUG + +#undef DNS_DEBUG +#define DNS_DEBUG dns_debug + +#define DNS_SAY_(fmt, ...) \ + do { if (DNS_DEBUG > 0) fprintf(stderr, fmt "%.1s", __func__, __LINE__, __VA_ARGS__); } while (0) +#define DNS_SAY(...) DNS_SAY_("@@ (%s:%d) " __VA_ARGS__, "\n") +#define DNS_HAI DNS_SAY("HAI") + +#define DNS_SHOW_(P, fmt, ...) do { \ + if (DNS_DEBUG > 1) { \ + fprintf(stderr, "@@ BEGIN * * * * * * * * * * * *\n"); \ + fprintf(stderr, "@@ " fmt "%.0s\n", __VA_ARGS__); \ + dns_p_dump((P), stderr); \ + fprintf(stderr, "@@ END * * * * * * * * * * * * *\n\n"); \ + } \ +} while (0) + +#define DNS_SHOW(...) DNS_SHOW_(__VA_ARGS__, "") + +#else /* !DNS_DEBUG */ + +#undef DNS_DEBUG +#define DNS_DEBUG 0 + +#define DNS_SAY(...) +#define DNS_HAI +#define DNS_SHOW(...) + +#endif /* DNS_DEBUG */ + +#define DNS_CARP(...) DNS_SAY(__VA_ARGS__) + + +/* + * V E R S I O N R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +const char *dns_vendor(void) { + return DNS_VENDOR; +} /* dns_vendor() */ + + +int dns_v_rel(void) { + return DNS_V_REL; +} /* dns_v_rel() */ + + +int dns_v_abi(void) { + return DNS_V_ABI; +} /* dns_v_abi() */ + + +int dns_v_api(void) { + return DNS_V_API; +} /* dns_v_api() */ + + +/* + * E R R O R R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#ifndef EPROTO +# define EPROTO EPROTONOSUPPORT +#endif + +#if _WIN32 + +#define DNS_EINTR WSAEINTR +#define DNS_EINPROGRESS WSAEINPROGRESS +#define DNS_EISCONN WSAEISCONN +#define DNS_EWOULDBLOCK WSAEWOULDBLOCK +#define DNS_EALREADY WSAEALREADY +#define DNS_EAGAIN EAGAIN +#define DNS_ETIMEDOUT WSAETIMEDOUT + +#define dns_syerr() ((int)GetLastError()) +#define dns_soerr() ((int)WSAGetLastError()) + +#else + +#define DNS_EINTR EINTR +#define DNS_EINPROGRESS EINPROGRESS +#define DNS_EISCONN EISCONN +#define DNS_EWOULDBLOCK EWOULDBLOCK +#define DNS_EALREADY EALREADY +#define DNS_EAGAIN EAGAIN +#define DNS_ETIMEDOUT ETIMEDOUT + +#define dns_syerr() errno +#define dns_soerr() errno + +#endif + + +const char *dns_strerror(int error) { + switch (error) { + case DNS_ENOBUFS: + return "DNS packet buffer too small"; + case DNS_EILLEGAL: + return "Illegal DNS RR name or data"; + case DNS_EORDER: + return "Attempt to push RR out of section order"; + case DNS_ESECTION: + return "Invalid section specified"; + case DNS_EUNKNOWN: + return "Unknown DNS error"; + case DNS_EADDRESS: + return "Invalid textual address form"; + case DNS_ENOQUERY: + return "Bad execution state (missing query packet)"; + case DNS_ENOANSWER: + return "Bad execution state (missing answer packet)"; + case DNS_EFETCHED: + return "Answer already fetched"; + case DNS_ESERVICE: + return "The service passed was not recognized for the specified socket type"; + case DNS_ENONAME: + return "The name does not resolve for the supplied parameters"; + case DNS_EFAIL: + return "A non-recoverable error occurred when attempting to resolve the name"; + case DNS_ECONNFIN: + return "Connection closed"; + case DNS_EVERIFY: + return "Reply failed verification"; + default: + return strerror(error); + } /* switch() */ +} /* dns_strerror() */ + + +/* + * A T O M I C R O U T I N E S + * + * Use GCC's __atomic built-ins if possible. Unlike the __sync built-ins, we + * can use the preprocessor to detect API and, more importantly, ISA + * support. We want to avoid linking headaches where the API depends on an + * external library if the ISA (e.g. i386) doesn't support lockless + * operation. + * + * TODO: Support C11's atomic API. Although that may require some finesse + * with how we define some public types, such as dns_atomic_t and struct + * dns_resolv_conf. + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#ifndef HAVE___ATOMIC_FETCH_ADD +#ifdef __ATOMIC_RELAXED +#define HAVE___ATOMIC_FETCH_ADD 1 +#else +#define HAVE___ATOMIC_FETCH_ADD 0 +#endif +#endif + +#ifndef HAVE___ATOMIC_FETCH_SUB +#define HAVE___ATOMIC_FETCH_SUB HAVE___ATOMIC_FETCH_ADD +#endif + +#ifndef DNS_ATOMIC_FETCH_ADD +#if HAVE___ATOMIC_FETCH_ADD && __GCC_ATOMIC_LONG_LOCK_FREE == 2 +#define DNS_ATOMIC_FETCH_ADD(i) __atomic_fetch_add((i), 1, __ATOMIC_RELAXED) +#else +#pragma message("no atomic_fetch_add available") +#define DNS_ATOMIC_FETCH_ADD(i) ((*(i))++) +#endif +#endif + +#ifndef DNS_ATOMIC_FETCH_SUB +#if HAVE___ATOMIC_FETCH_SUB && __GCC_ATOMIC_LONG_LOCK_FREE == 2 +#define DNS_ATOMIC_FETCH_SUB(i) __atomic_fetch_sub((i), 1, __ATOMIC_RELAXED) +#else +#pragma message("no atomic_fetch_sub available") +#define DNS_ATOMIC_FETCH_SUB(i) ((*(i))--) +#endif +#endif + +static inline unsigned dns_atomic_fetch_add(dns_atomic_t *i) { + return DNS_ATOMIC_FETCH_ADD(i); +} /* dns_atomic_fetch_add() */ + + +static inline unsigned dns_atomic_fetch_sub(dns_atomic_t *i) { + return DNS_ATOMIC_FETCH_SUB(i); +} /* dns_atomic_fetch_sub() */ + + +/* + * C R Y P T O R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +/* + * P R N G + */ + +#ifndef DNS_RANDOM +#if defined(HAVE_ARC4RANDOM) \ + || defined(__OpenBSD__) \ + || defined(__FreeBSD__) \ + || defined(__NetBSD__) \ + || defined(__APPLE__) +#define DNS_RANDOM arc4random +#elif __linux +#define DNS_RANDOM random +#else +#define DNS_RANDOM rand +#endif +#endif + +#define DNS_RANDOM_arc4random 1 +#define DNS_RANDOM_random 2 +#define DNS_RANDOM_rand 3 +#define DNS_RANDOM_RAND_bytes 4 + +#define DNS_RANDOM_OPENSSL (DNS_RANDOM_RAND_bytes == DNS_PP_XPASTE(DNS_RANDOM_, DNS_RANDOM)) + +#if DNS_RANDOM_OPENSSL +#include <openssl/rand.h> +#endif + +static unsigned dns_random_(void) { +#if DNS_RANDOM_OPENSSL + unsigned r; + _Bool ok; + + ok = (1 == RAND_bytes((unsigned char *)&r, sizeof r)); + assert(ok && "1 == RAND_bytes()"); + + return r; +#else + return DNS_RANDOM(); +#endif +} /* dns_random_() */ + +dns_random_f **dns_random_p(void) { + static dns_random_f *random_f = &dns_random_; + + return &random_f; +} /* dns_random_p() */ + + +/* + * P E R M U T A T I O N G E N E R A T O R + */ + +#define DNS_K_TEA_KEY_SIZE 16 +#define DNS_K_TEA_BLOCK_SIZE 8 +#define DNS_K_TEA_CYCLES 32 +#define DNS_K_TEA_MAGIC 0x9E3779B9U + +struct dns_k_tea { + uint32_t key[DNS_K_TEA_KEY_SIZE / sizeof (uint32_t)]; + unsigned cycles; +}; /* struct dns_k_tea */ + + +static void dns_k_tea_init(struct dns_k_tea *tea, uint32_t key[], unsigned cycles) { + memcpy(tea->key, key, sizeof tea->key); + + tea->cycles = (cycles)? cycles : DNS_K_TEA_CYCLES; +} /* dns_k_tea_init() */ + + +static void dns_k_tea_encrypt(struct dns_k_tea *tea, uint32_t v[], uint32_t *w) { + uint32_t y, z, sum, n; + + y = v[0]; + z = v[1]; + sum = 0; + + for (n = 0; n < tea->cycles; n++) { + sum += DNS_K_TEA_MAGIC; + y += ((z << 4) + tea->key[0]) ^ (z + sum) ^ ((z >> 5) + tea->key[1]); + z += ((y << 4) + tea->key[2]) ^ (y + sum) ^ ((y >> 5) + tea->key[3]); + } + + w[0] = y; + w[1] = z; + + return /* void */; +} /* dns_k_tea_encrypt() */ + + +/* + * Permutation generator, based on a Luby-Rackoff Feistel construction. + * + * Specifically, this is a generic balanced Feistel block cipher using TEA + * (another block cipher) as the pseudo-random function, F. At best it's as + * strong as F (TEA), notwithstanding the seeding. F could be AES, SHA-1, or + * perhaps Bernstein's Salsa20 core; I am naively trying to keep things + * simple. + * + * The generator can create a permutation of any set of numbers, as long as + * the size of the set is an even power of 2. This limitation arises either + * out of an inherent property of balanced Feistel constructions, or by my + * own ignorance. I'll tackle an unbalanced construction after I wrap my + * head around Schneier and Kelsey's paper. + * + * CAVEAT EMPTOR. IANAC. + */ +#define DNS_K_PERMUTOR_ROUNDS 8 + +struct dns_k_permutor { + unsigned stepi, length, limit; + unsigned shift, mask, rounds; + + struct dns_k_tea tea; +}; /* struct dns_k_permutor */ + + +static inline unsigned dns_k_permutor_powof(unsigned n) { + unsigned m, i = 0; + + for (m = 1; m < n; m <<= 1, i++) + ;; + + return i; +} /* dns_k_permutor_powof() */ + +static void dns_k_permutor_init(struct dns_k_permutor *p, unsigned low, unsigned high) { + uint32_t key[DNS_K_TEA_KEY_SIZE / sizeof (uint32_t)]; + unsigned width, i; + + p->stepi = 0; + + p->length = (high - low) + 1; + p->limit = high; + + width = dns_k_permutor_powof(p->length); + width += width % 2; + + p->shift = width / 2; + p->mask = (1U << p->shift) - 1; + p->rounds = DNS_K_PERMUTOR_ROUNDS; + + for (i = 0; i < lengthof(key); i++) + key[i] = dns_random(); + + dns_k_tea_init(&p->tea, key, 0); + + return /* void */; +} /* dns_k_permutor_init() */ + + +static unsigned dns_k_permutor_F(struct dns_k_permutor *p, unsigned k, unsigned x) { + uint32_t in[DNS_K_TEA_BLOCK_SIZE / sizeof (uint32_t)], out[DNS_K_TEA_BLOCK_SIZE / sizeof (uint32_t)]; + + memset(in, '\0', sizeof in); + + in[0] = k; + in[1] = x; + + dns_k_tea_encrypt(&p->tea, in, out); + + return p->mask & out[0]; +} /* dns_k_permutor_F() */ + + +static unsigned dns_k_permutor_E(struct dns_k_permutor *p, unsigned n) { + unsigned l[2], r[2]; + unsigned i; + + i = 0; + l[i] = p->mask & (n >> p->shift); + r[i] = p->mask & (n >> 0); + + do { + l[(i + 1) % 2] = r[i % 2]; + r[(i + 1) % 2] = l[i % 2] ^ dns_k_permutor_F(p, i, r[i % 2]); + + i++; + } while (i < p->rounds - 1); + + return ((l[i % 2] & p->mask) << p->shift) | ((r[i % 2] & p->mask) << 0); +} /* dns_k_permutor_E() */ + + +DNS_NOTUSED static unsigned dns_k_permutor_D(struct dns_k_permutor *p, unsigned n) { + unsigned l[2], r[2]; + unsigned i; + + i = p->rounds - 1; + l[i % 2] = p->mask & (n >> p->shift); + r[i % 2] = p->mask & (n >> 0); + + do { + i--; + + r[i % 2] = l[(i + 1) % 2]; + l[i % 2] = r[(i + 1) % 2] ^ dns_k_permutor_F(p, i, l[(i + 1) % 2]); + } while (i > 0); + + return ((l[i % 2] & p->mask) << p->shift) | ((r[i % 2] & p->mask) << 0); +} /* dns_k_permutor_D() */ + + +static unsigned dns_k_permutor_step(struct dns_k_permutor *p) { + unsigned n; + + do { + n = dns_k_permutor_E(p, p->stepi++); + } while (n >= p->length); + + return n + (p->limit + 1 - p->length); +} /* dns_k_permutor_step() */ + + +/* + * Simple permutation box. Useful for shuffling rrsets from an iterator. + * Uses AES s-box to provide good diffusion. + * + * Seems to pass muster under runs test. + * + * $ for i in 0 1 2 3 4 5 6 7 8 9; do ./dns shuffle-16 > /tmp/out; done + * $ R -q -f /dev/stdin 2>/dev/null <<-EOF | awk '/p-value/{ print $8 }' + * library(lawstat) + * runs.test(scan(file="/tmp/out")) + * EOF + */ +static unsigned short dns_k_shuffle16(unsigned short n, unsigned s) { + static const unsigned char sbox[256] = + { 0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, + 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76, + 0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, + 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0, + 0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, + 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15, + 0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, + 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75, + 0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, + 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84, + 0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, + 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf, + 0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, + 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8, + 0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, + 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2, + 0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, + 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73, + 0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, + 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb, + 0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, + 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79, + 0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, + 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08, + 0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, + 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a, + 0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, + 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e, + 0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, + 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf, + 0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, + 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16 }; + unsigned char a, b; + unsigned i; + + a = 0xff & (n >> 0); + b = 0xff & (n >> 8); + + for (i = 0; i < 4; i++) { + a ^= 0xff & s; + a = sbox[a] ^ b; + b = sbox[b] ^ a; + s >>= 8; + } + + return ((0xff00 & (a << 8)) | (0x00ff & (b << 0))); +} /* dns_k_shuffle16() */ + +/* + * S T A T E M A C H I N E R O U T I N E S + * + * Application code should define DNS_SM_RESTORE and DNS_SM_SAVE, and the + * local variable pc. + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#define DNS_SM_ENTER \ + do { \ + static const int pc0 = __LINE__; \ + DNS_SM_RESTORE; \ + switch (pc0 + pc) { \ + case __LINE__: (void)0 + +#define DNS_SM_SAVE_AND_DO(do_statement) \ + do { \ + pc = __LINE__ - pc0; \ + DNS_SM_SAVE; \ + do_statement; \ + case __LINE__: (void)0; \ + } while (0) + +#define DNS_SM_YIELD(rv) \ + DNS_SM_SAVE_AND_DO(return (rv)) + +#define DNS_SM_EXIT \ + do { goto leave; } while (0) + +#define DNS_SM_LEAVE \ + leave: (void)0; \ + DNS_SM_SAVE_AND_DO(break); \ + } \ + } while (0) + +/* + * U T I L I T Y R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#define DNS_MAXINTERVAL 300 + +struct dns_clock { + time_t sample, elapsed; +}; /* struct dns_clock */ + +static void dns_begin(struct dns_clock *clk) { + clk->sample = time(0); + clk->elapsed = 0; +} /* dns_begin() */ + +static time_t dns_elapsed(struct dns_clock *clk) { + time_t curtime; + + if ((time_t)-1 == time(&curtime)) + return clk->elapsed; + + if (curtime > clk->sample) + clk->elapsed += (time_t)DNS_PP_MIN(difftime(curtime, clk->sample), DNS_MAXINTERVAL); + + clk->sample = curtime; + + return clk->elapsed; +} /* dns_elapsed() */ + + +DNS_NOTUSED static size_t dns_strnlen(const char *src, size_t m) { + size_t n = 0; + + while (*src++ && n < m) + ++n; + + return n; +} /* dns_strnlen() */ + + +DNS_NOTUSED static size_t dns_strnlcpy(char *dst, size_t lim, const char *src, size_t max) { + size_t len = dns_strnlen(src, max), n; + + if (lim > 0) { + n = DNS_PP_MIN(lim - 1, len); + memcpy(dst, src, n); + dst[n] = '\0'; + } + + return len; +} /* dns_strnlcpy() */ + + +#if (defined AF_UNIX && !defined _WIN32) +#define DNS_HAVE_SOCKADDR_UN 1 +#else +#define DNS_HAVE_SOCKADDR_UN 0 +#endif + +static size_t dns_af_len(int af) { + static const size_t table[AF_MAX] = { + [AF_INET6] = sizeof (struct sockaddr_in6), + [AF_INET] = sizeof (struct sockaddr_in), +#if DNS_HAVE_SOCKADDR_UN + [AF_UNIX] = sizeof (struct sockaddr_un), +#endif + }; + + return table[af]; +} /* dns_af_len() */ + +#define dns_sa_family(sa) (((struct sockaddr *)(sa))->sa_family) + +#define dns_sa_len(sa) dns_af_len(dns_sa_family(sa)) + + +#define DNS_SA_NOPORT &dns_sa_noport +static unsigned short dns_sa_noport; + +static unsigned short *dns_sa_port(int af, void *sa) { + switch (af) { + case AF_INET6: + return &((struct sockaddr_in6 *)sa)->sin6_port; + case AF_INET: + return &((struct sockaddr_in *)sa)->sin_port; + default: + return DNS_SA_NOPORT; + } +} /* dns_sa_port() */ + + +static void *dns_sa_addr(int af, const void *sa, socklen_t *size) { + switch (af) { + case AF_INET6: { + struct in6_addr *in6 = &((struct sockaddr_in6 *)sa)->sin6_addr; + + if (size) + *size = sizeof *in6; + + return in6; + } + case AF_INET: { + struct in_addr *in = &((struct sockaddr_in *)sa)->sin_addr; + + if (size) + *size = sizeof *in; + + return in; + } + default: + if (size) + *size = 0; + + return 0; + } +} /* dns_sa_addr() */ + + +#if DNS_HAVE_SOCKADDR_UN +#define DNS_SUNPATHMAX (sizeof ((struct sockaddr_un *)0)->sun_path) +#endif + +DNS_NOTUSED static void *dns_sa_path(void *sa, socklen_t *size) { + switch (dns_sa_family(sa)) { +#if DNS_HAVE_SOCKADDR_UN + case AF_UNIX: { + char *path = ((struct sockaddr_un *)sa)->sun_path; + + if (size) + *size = dns_strnlen(path, DNS_SUNPATHMAX); + + return path; + } +#endif + default: + if (size) + *size = 0; + + return NULL; + } +} /* dns_sa_path() */ + + +static int dns_sa_cmp(void *a, void *b) { + int cmp, af; + + if ((cmp = dns_sa_family(a) - dns_sa_family(b))) + return cmp; + + switch ((af = dns_sa_family(a))) { + case AF_INET: { + struct in_addr *a4, *b4; + + if ((cmp = htons(*dns_sa_port(af, a)) - htons(*dns_sa_port(af, b)))) + return cmp; + + a4 = dns_sa_addr(af, a, NULL); + b4 = dns_sa_addr(af, b, NULL); + + if (ntohl(a4->s_addr) < ntohl(b4->s_addr)) + return -1; + if (ntohl(a4->s_addr) > ntohl(b4->s_addr)) + return 1; + + return 0; + } + case AF_INET6: { + struct in6_addr *a6, *b6; + size_t i; + + if ((cmp = htons(*dns_sa_port(af, a)) - htons(*dns_sa_port(af, b)))) + return cmp; + + a6 = dns_sa_addr(af, a, NULL); + b6 = dns_sa_addr(af, b, NULL); + + /* XXX: do we need to use in6_clearscope()? */ + for (i = 0; i < sizeof a6->s6_addr; i++) { + if ((cmp = a6->s6_addr[i] - b6->s6_addr[i])) + return cmp; + } + + return 0; + } +#if DNS_HAVE_SOCKADDR_UN + case AF_UNIX: { + char a_path[DNS_SUNPATHMAX + 1], b_path[sizeof a_path]; + + dns_strnlcpy(a_path, sizeof a_path, dns_sa_path(a, NULL), DNS_SUNPATHMAX); + dns_strnlcpy(b_path, sizeof b_path, dns_sa_path(b, NULL), DNS_SUNPATHMAX); + + return strcmp(a_path, b_path); + } +#endif + default: + return -1; + } +} /* dns_sa_cmp() */ + + +#if _WIN32 +static int dns_inet_pton(int af, const void *src, void *dst) { + union { struct sockaddr_in sin; struct sockaddr_in6 sin6; } u; + int size_of_u = (int)sizeof u; + + u.sin.sin_family = af; + + if (0 != WSAStringToAddressA((void *)src, af, (void *)0, (struct sockaddr *)&u, &size_of_u)) + return -1; + + switch (af) { + case AF_INET6: + *(struct in6_addr *)dst = u.sin6.sin6_addr; + + return 1; + case AF_INET: + *(struct in_addr *)dst = u.sin.sin_addr; + + return 1; + default: + return 0; + } +} /* dns_inet_pton() */ + +static const char *dns_inet_ntop(int af, const void *src, void *dst, unsigned long lim) { + union { struct sockaddr_in sin; struct sockaddr_in6 sin6; } u; + + /* NOTE: WSAAddressToString will print .sin_port unless zeroed. */ + memset(&u, 0, sizeof u); + + u.sin.sin_family = af; + + switch (af) { + case AF_INET6: + u.sin6.sin6_addr = *(struct in6_addr *)src; + break; + case AF_INET: + u.sin.sin_addr = *(struct in_addr *)src; + + break; + default: + return 0; + } + + if (0 != WSAAddressToStringA((struct sockaddr *)&u, dns_sa_len(&u), (void *)0, dst, &lim)) + return 0; + + return dst; +} /* dns_inet_ntop() */ +#else +#define dns_inet_pton(...) inet_pton(__VA_ARGS__) +#define dns_inet_ntop(...) inet_ntop(__VA_ARGS__) +#endif + + +static dns_error_t dns_pton(int af, const void *src, void *dst) { + switch (dns_inet_pton(af, src, dst)) { + case 1: + return 0; + case -1: + return dns_soerr(); + default: + return DNS_EADDRESS; + } +} /* dns_pton() */ + + +static dns_error_t dns_ntop(int af, const void *src, void *dst, unsigned long lim) { + return (dns_inet_ntop(af, src, dst, lim))? 0 : dns_soerr(); +} /* dns_ntop() */ + + +size_t dns_strlcpy(char *dst, const char *src, size_t lim) { + char *d = dst; + char *e = &dst[lim]; + const char *s = src; + + if (d < e) { + do { + if ('\0' == (*d++ = *s++)) + return s - src - 1; + } while (d < e); + + d[-1] = '\0'; + } + + while (*s++ != '\0') + ;; + + return s - src - 1; +} /* dns_strlcpy() */ + + +size_t dns_strlcat(char *dst, const char *src, size_t lim) { + char *d = memchr(dst, '\0', lim); + char *e = &dst[lim]; + const char *s = src; + const char *p; + + if (d && d < e) { + do { + if ('\0' == (*d++ = *s++)) + return d - dst - 1; + } while (d < e); + + d[-1] = '\0'; + } + + p = s; + + while (*s++ != '\0') + ;; + + return lim + (s - p - 1); +} /* dns_strlcat() */ + + +static void *dns_reallocarray(void *p, size_t nmemb, size_t size, dns_error_t *error) { + void *rp; + + if (nmemb > 0 && SIZE_MAX / nmemb < size) { + *error = EOVERFLOW; + return NULL; + } + + if (!(rp = realloc(p, nmemb * size))) + *error = (errno)? errno : EINVAL; + + return rp; +} /* dns_reallocarray() */ + + +#if _WIN32 + +static char *dns_strsep(char **sp, const char *delim) { + char *p; + + if (!(p = *sp)) + return 0; + + *sp += strcspn(p, delim); + + if (**sp != '\0') { + **sp = '\0'; + ++*sp; + } else + *sp = NULL; + + return p; +} /* dns_strsep() */ + +#else +#define dns_strsep(...) strsep(__VA_ARGS__) +#endif + + +#if _WIN32 +#define strcasecmp(...) _stricmp(__VA_ARGS__) +#define strncasecmp(...) _strnicmp(__VA_ARGS__) +#endif + + +static inline _Bool dns_isalpha(unsigned char c) { + return isalpha(c); +} /* dns_isalpha() */ + +static inline _Bool dns_isdigit(unsigned char c) { + return isdigit(c); +} /* dns_isdigit() */ + +static inline _Bool dns_isalnum(unsigned char c) { + return isalnum(c); +} /* dns_isalnum() */ + +static inline _Bool dns_isspace(unsigned char c) { + return isspace(c); +} /* dns_isspace() */ + +static inline _Bool dns_isgraph(unsigned char c) { + return isgraph(c); +} /* dns_isgraph() */ + + +static int dns_poll(int fd, short events, int timeout) { + fd_set rset, wset; + struct timeval tv = { timeout, 0 }; + + if (!events) + return 0; + + if (fd < 0 || (unsigned)fd >= FD_SETSIZE) + return EINVAL; + + FD_ZERO(&rset); + FD_ZERO(&wset); + + if (events & DNS_POLLIN) + FD_SET(fd, &rset); + + if (events & DNS_POLLOUT) + FD_SET(fd, &wset); + + select(fd + 1, &rset, &wset, 0, (timeout >= 0)? &tv : NULL); + + return 0; +} /* dns_poll() */ + + +#if !_WIN32 +DNS_NOTUSED static int dns_sigmask(int how, const sigset_t *set, sigset_t *oset) { +#if DNS_THREAD_SAFE + return pthread_sigmask(how, set, oset); +#else + return (0 == sigprocmask(how, set, oset))? 0 : errno; +#endif +} /* dns_sigmask() */ +#endif + + +static size_t dns_send(int fd, const void *src, size_t len, int flags, dns_error_t *error) { + long n = send(fd, src, len, flags); + + if (n < 0) { + *error = dns_soerr(); + return 0; + } else { + *error = 0; + return n; + } +} /* dns_send() */ + +static size_t dns_recv(int fd, void *dst, size_t lim, int flags, dns_error_t *error) { + long n = recv(fd, dst, lim, flags); + + if (n < 0) { + *error = dns_soerr(); + return 0; + } else if (n == 0) { + *error = (lim > 0)? DNS_ECONNFIN : EINVAL; + return 0; + } else { + *error = 0; + return n; + } +} /* dns_recv() */ + +static size_t dns_send_nopipe(int fd, const void *src, size_t len, int flags, dns_error_t *_error) { +#if _WIN32 || !defined SIGPIPE || defined SO_NOSIGPIPE + return dns_send(fd, src, len, flags, _error); +#elif defined MSG_NOSIGNAL + return dns_send(fd, src, len, (flags|MSG_NOSIGNAL), _error); +#elif _POSIX_REALTIME_SIGNALS > 0 /* require sigtimedwait */ + /* + * SIGPIPE handling similar to the approach described in + * http://krokisplace.blogspot.com/2010/02/suppressing-sigpipe-in-library.html + */ + sigset_t pending, blocked, piped; + size_t count; + int error; + + sigemptyset(&pending); + sigpending(&pending); + + if (!sigismember(&pending, SIGPIPE)) { + sigemptyset(&piped); + sigaddset(&piped, SIGPIPE); + sigemptyset(&blocked); + + if ((error = dns_sigmask(SIG_BLOCK, &piped, &blocked))) + goto error; + } + + count = dns_send(fd, src, len, flags, &error); + + if (!sigismember(&pending, SIGPIPE)) { + int saved = error; + const struct timespec ts = { 0, 0 }; + + if (!count && error == EPIPE) { + while (-1 == sigtimedwait(&piped, NULL, &ts) && errno == EINTR) + ;; + } + + if ((error = dns_sigmask(SIG_SETMASK, &blocked, NULL))) + goto error; + + error = saved; + } + + *_error = error; + return count; +error: + *_error = error; + return 0; +#else +#error "unable to suppress SIGPIPE" + return dns_send(fd, src, len, flags, _error); +#endif +} /* dns_send_nopipe() */ + + +static dns_error_t dns_connect(int fd, const struct sockaddr *addr, socklen_t addrlen) { + if (0 != connect(fd, addr, addrlen)) + return dns_soerr(); + return 0; +} /* dns_connect() */ + + +#define DNS_FOPEN_STDFLAGS "rwabt+" + +static dns_error_t dns_fopen_addflag(char *dst, const char *src, size_t lim, int fc) { + char *p = dst, *pe = dst + lim; + + /* copy standard flags */ + while (*src && strchr(DNS_FOPEN_STDFLAGS, *src)) { + if (!(p < pe)) + return ENOMEM; + *p++ = *src++; + } + + /* append flag to standard flags */ + if (!(p < pe)) + return ENOMEM; + *p++ = fc; + + /* copy remaining mode string, including '\0' */ + do { + if (!(p < pe)) + return ENOMEM; + } while ((*p++ = *src++)); + + return 0; +} /* dns_fopen_addflag() */ + +static FILE *dns_fopen(const char *path, const char *mode, dns_error_t *_error) { + FILE *fp; + char mode_cloexec[32]; + int error; + + assert(path && mode && *mode); + if (!*path) { + error = EINVAL; + goto error; + } + +#if _WIN32 || _WIN64 + if ((error = dns_fopen_addflag(mode_cloexec, mode, sizeof mode_cloexec, 'N'))) + goto error; + if (!(fp = fopen(path, mode_cloexec))) + goto syerr; +#else + if ((error = dns_fopen_addflag(mode_cloexec, mode, sizeof mode_cloexec, 'e'))) + goto error; + if (!(fp = fopen(path, mode_cloexec))) { + if (errno != EINVAL) + goto syerr; + if (!(fp = fopen(path, mode))) + goto syerr; + } +#endif + + return fp; +syerr: + error = dns_syerr(); +error: + *_error = error; + + return NULL; +} /* dns_fopen() */ + + +struct dns_hxd_lines_i { + int pc; + size_t p; +}; + +#define DNS_SM_RESTORE \ + do { \ + pc = state->pc; \ + sp = src + state->p; \ + se = src + len; \ + } while (0) +#define DNS_SM_SAVE \ + do { \ + state->p = sp - src; \ + state->pc = pc; \ + } while (0) + +static size_t dns_hxd_lines(void *dst, size_t lim, const unsigned char *src, size_t len, struct dns_hxd_lines_i *state) { + static const unsigned char hex[] = "0123456789abcdef"; + static const unsigned char tmpl[] = " | |\n"; + unsigned char ln[sizeof tmpl]; + const unsigned char *sp, *se; + unsigned char *h, *g; + unsigned i, n; + int pc; + + DNS_SM_ENTER; + + while (sp < se) { + memcpy(ln, tmpl, sizeof ln); + + h = &ln[2]; + g = &ln[53]; + + for (n = 0; n < 2; n++) { + for (i = 0; i < 8 && se - sp > 0; i++, sp++) { + h[0] = hex[0x0f & (*sp >> 4)]; + h[1] = hex[0x0f & (*sp >> 0)]; + h += 3; + + *g++ = (dns_isgraph(*sp))? *sp : '.'; + } + + h++; + } + + n = dns_strlcpy(dst, (char *)ln, lim); + DNS_SM_YIELD(n); + } + + DNS_SM_EXIT; + DNS_SM_LEAVE; + + return 0; +} + +#undef DNS_SM_SAVE +#undef DNS_SM_RESTORE + +/* + * A R I T H M E T I C R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#define DNS_CHECK_OVERFLOW(error, r, f, ...) \ + do { \ + uintmax_t _r; \ + *(error) = f(&_r, __VA_ARGS__); \ + *(r) = _r; \ + } while (0) + +static dns_error_t dns_clamp_overflow(uintmax_t *r, uintmax_t n, uintmax_t clamp) { + if (n > clamp) { + *r = clamp; + return ERANGE; + } else { + *r = n; + return 0; + } +} /* dns_clamp_overflow() */ + +static dns_error_t dns_add_overflow(uintmax_t *r, uintmax_t a, uintmax_t b, uintmax_t clamp) { + if (~a < b) { + *r = DNS_PP_MIN(clamp, ~UINTMAX_C(0)); + return ERANGE; + } else { + return dns_clamp_overflow(r, a + b, clamp); + } +} /* dns_add_overflow() */ + +static dns_error_t dns_mul_overflow(uintmax_t *r, uintmax_t a, uintmax_t b, uintmax_t clamp) { + if (a > 0 && UINTMAX_MAX / a < b) { + *r = DNS_PP_MIN(clamp, ~UINTMAX_C(0)); + return ERANGE; + } else { + return dns_clamp_overflow(r, a * b, clamp); + } +} /* dns_mul_overflow() */ + +/* + * F I X E D - S I Z E D B U F F E R R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#define DNS_B_INIT(src, n) { \ + (unsigned char *)(src), \ + (unsigned char *)(src), \ + (unsigned char *)(src) + (n), \ +} + +#define DNS_B_FROM(src, n) DNS_B_INIT((src), (n)) +#define DNS_B_INTO(src, n) DNS_B_INIT((src), (n)) + +struct dns_buf { + const unsigned char *base; + unsigned char *p; + const unsigned char *pe; + dns_error_t error; + size_t overflow; +}; /* struct dns_buf */ + +static inline size_t +dns_b_tell(struct dns_buf *b) +{ + return b->p - b->base; +} + +static inline dns_error_t +dns_b_setoverflow(struct dns_buf *b, size_t n, dns_error_t error) +{ + b->overflow += n; + return b->error = error; +} + +DNS_NOTUSED static struct dns_buf * +dns_b_into(struct dns_buf *b, void *src, size_t n) +{ + *b = (struct dns_buf)DNS_B_INTO(src, n); + + return b; +} + +static dns_error_t +dns_b_putc(struct dns_buf *b, unsigned char uc) +{ + if (!(b->p < b->pe)) + return dns_b_setoverflow(b, 1, DNS_ENOBUFS); + + *b->p++ = uc; + + return 0; +} + +static dns_error_t +dns_b_pputc(struct dns_buf *b, unsigned char uc, size_t p) +{ + size_t pe = b->pe - b->base; + if (pe <= p) + return dns_b_setoverflow(b, p - pe + 1, DNS_ENOBUFS); + + *((unsigned char *)b->base + p) = uc; + + return 0; +} + +static inline dns_error_t +dns_b_put16(struct dns_buf *b, uint16_t u) +{ + return dns_b_putc(b, u >> 8), dns_b_putc(b, u >> 0); +} + +static inline dns_error_t +dns_b_pput16(struct dns_buf *b, uint16_t u, size_t p) +{ + if (dns_b_pputc(b, u >> 8, p) || dns_b_pputc(b, u >> 0, p + 1)) + return b->error; + + return 0; +} + +DNS_NOTUSED static inline dns_error_t +dns_b_put32(struct dns_buf *b, uint32_t u) +{ + return dns_b_putc(b, u >> 24), dns_b_putc(b, u >> 16), + dns_b_putc(b, u >> 8), dns_b_putc(b, u >> 0); +} + +static dns_error_t +dns_b_put(struct dns_buf *b, const void *src, size_t len) +{ + size_t n = DNS_PP_MIN((size_t)(b->pe - b->p), len); + + memcpy(b->p, src, n); + b->p += n; + + if (n < len) + return dns_b_setoverflow(b, len - n, DNS_ENOBUFS); + + return 0; +} + +static dns_error_t +dns_b_puts(struct dns_buf *b, const void *src) +{ + return dns_b_put(b, src, strlen(src)); +} + +DNS_NOTUSED static inline dns_error_t +dns_b_fmtju(struct dns_buf *b, const uintmax_t u, const unsigned width) +{ + size_t digits, padding, overflow; + uintmax_t r; + unsigned char *tp, *te, tc; + + digits = 0; + r = u; + do { + digits++; + r /= 10; + } while (r); + + padding = width - DNS_PP_MIN(digits, width); + overflow = (digits + padding) - DNS_PP_MIN((size_t)(b->pe - b->p), (digits + padding)); + + while (padding--) { + dns_b_putc(b, '0'); + } + + digits = 0; + tp = b->p; + r = u; + do { + if (overflow < ++digits) + dns_b_putc(b, '0' + (r % 10)); + r /= 10; + } while (r); + + te = b->p; + while (tp < te) { + tc = *--te; + *te = *tp; + *tp++ = tc; + } + + return b->error; +} + +static void +dns_b_popc(struct dns_buf *b) +{ + if (b->overflow && !--b->overflow) + b->error = 0; + if (b->p > b->base) + b->p--; +} + +static inline const char * +dns_b_tolstring(struct dns_buf *b, size_t *n) +{ + if (b->p < b->pe) { + *b->p = '\0'; + *n = b->p - b->base; + + return (const char *)b->base; + } else if (b->p > b->base) { + if (b->p[-1] != '\0') { + dns_b_setoverflow(b, 1, DNS_ENOBUFS); + b->p[-1] = '\0'; + } + *n = &b->p[-1] - b->base; + + return (const char *)b->base; + } else { + *n = 0; + + return ""; + } +} + +static inline const char * +dns_b_tostring(struct dns_buf *b) +{ + size_t n; + return dns_b_tolstring(b, &n); +} + +static inline size_t +dns_b_strlen(struct dns_buf *b) +{ + size_t n; + dns_b_tolstring(b, &n); + return n; +} + +static inline size_t +dns_b_strllen(struct dns_buf *b) +{ + size_t n = dns_b_strlen(b); + return n + b->overflow; +} + +DNS_NOTUSED static const struct dns_buf * +dns_b_from(const struct dns_buf *b, const void *src, size_t n) +{ + *(struct dns_buf *)b = (struct dns_buf)DNS_B_FROM(src, n); + + return b; +} + +static inline int +dns_b_getc(const struct dns_buf *_b, const int eof) +{ + struct dns_buf *b = (struct dns_buf *)_b; + + if (!(b->p < b->pe)) + return dns_b_setoverflow(b, 1, DNS_EILLEGAL), eof; + + return *b->p++; +} + +static inline intmax_t +dns_b_get16(const struct dns_buf *b, const intmax_t eof) +{ + intmax_t n; + + n = (dns_b_getc(b, 0) << 8); + n |= (dns_b_getc(b, 0) << 0); + + return (!b->overflow)? n : eof; +} + +DNS_NOTUSED static inline intmax_t +dns_b_get32(const struct dns_buf *b, const intmax_t eof) +{ + intmax_t n; + + n = (dns_b_get16(b, 0) << 16); + n |= (dns_b_get16(b, 0) << 0); + + return (!b->overflow)? n : eof; +} + +static inline dns_error_t +dns_b_move(struct dns_buf *dst, const struct dns_buf *_src, size_t n) +{ + struct dns_buf *src = (struct dns_buf *)_src; + size_t src_n = DNS_PP_MIN((size_t)(src->pe - src->p), n); + size_t src_r = n - src_n; + + dns_b_put(dst, src->p, src_n); + src->p += src_n; + + if (src_r) + return dns_b_setoverflow(src, src_r, DNS_EILLEGAL); + + return dst->error; +} + +/* + * T I M E R O U T I N E S + * + * Most functions still rely on the older time routines defined in the + * utility routines section, above. + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#define DNS_TIME_C(n) UINT64_C(n) +#define DNS_TIME_INF (~DNS_TIME_C(0)) + +typedef uint64_t dns_time_t; +typedef dns_time_t dns_microseconds_t; + +static dns_error_t dns_time_add(dns_time_t *r, dns_time_t a, dns_time_t b) { + int error; + DNS_CHECK_OVERFLOW(&error, r, dns_add_overflow, a, b, DNS_TIME_INF); + return error; +} + +static dns_error_t dns_time_mul(dns_time_t *r, dns_time_t a, dns_time_t b) { + int error; + DNS_CHECK_OVERFLOW(&error, r, dns_mul_overflow, a, b, DNS_TIME_INF); + return error; +} + +static dns_error_t dns_time_diff(dns_time_t *r, dns_time_t a, dns_time_t b) { + if (a < b) { + *r = DNS_TIME_C(0); + return ERANGE; + } else { + *r = a - b; + return 0; + } +} + +static dns_microseconds_t dns_ts2us(const struct timespec *ts, _Bool rup) { + if (ts) { + dns_time_t sec = DNS_PP_MAX(0, ts->tv_sec); + dns_time_t nsec = DNS_PP_MAX(0, ts->tv_nsec); + dns_time_t usec = nsec / 1000; + dns_microseconds_t r; + + if (rup && nsec % 1000 > 0) + usec++; + dns_time_mul(&r, sec, DNS_TIME_C(1000000)); + dns_time_add(&r, r, usec); + + return r; + } else { + return DNS_TIME_INF; + } +} /* dns_ts2us() */ + +static struct timespec *dns_tv2ts(struct timespec *ts, const struct timeval *tv) { + if (tv) { + ts->tv_sec = tv->tv_sec; + ts->tv_nsec = tv->tv_usec * 1000; + + return ts; + } else { + return NULL; + } +} /* dns_tv2ts() */ + +static size_t dns_utime_print(void *_dst, size_t lim, dns_microseconds_t us) { + struct dns_buf dst = DNS_B_INTO(_dst, lim); + + dns_b_fmtju(&dst, us / 1000000, 1); + dns_b_putc(&dst, '.'); + dns_b_fmtju(&dst, us % 1000000, 6); + + return dns_b_strllen(&dst); +} /* dns_utime_print() */ + +/* + * P A C K E T R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +unsigned dns_p_count(struct dns_packet *P, enum dns_section section) { + unsigned count; + + switch (section) { + case DNS_S_QD: + return ntohs(dns_header(P)->qdcount); + case DNS_S_AN: + return ntohs(dns_header(P)->ancount); + case DNS_S_NS: + return ntohs(dns_header(P)->nscount); + case DNS_S_AR: + return ntohs(dns_header(P)->arcount); + default: + count = 0; + + if (section & DNS_S_QD) + count += ntohs(dns_header(P)->qdcount); + if (section & DNS_S_AN) + count += ntohs(dns_header(P)->ancount); + if (section & DNS_S_NS) + count += ntohs(dns_header(P)->nscount); + if (section & DNS_S_AR) + count += ntohs(dns_header(P)->arcount); + + return count; + } +} /* dns_p_count() */ + + +struct dns_packet *dns_p_init(struct dns_packet *P, size_t size) { + if (!P) + return 0; + + assert(size >= offsetof(struct dns_packet, data) + 12); + + memset(P, 0, sizeof *P); + P->size = size - offsetof(struct dns_packet, data); + P->end = 12; + + memset(P->data, '\0', 12); + + return P; +} /* dns_p_init() */ + + +static struct dns_packet *dns_p_reset(struct dns_packet *P) { + return dns_p_init(P, offsetof(struct dns_packet, data) + P->size); +} /* dns_p_reset() */ + + +static unsigned short dns_p_qend(struct dns_packet *P) { + unsigned short qend = 12; + unsigned i, count = dns_p_count(P, DNS_S_QD); + + for (i = 0; i < count && qend < P->end; i++) { + if (P->end == (qend = dns_d_skip(qend, P))) + goto invalid; + + if (P->end - qend < 4) + goto invalid; + + qend += 4; + } + + return DNS_PP_MIN(qend, P->end); +invalid: + return P->end; +} /* dns_p_qend() */ + + +struct dns_packet *dns_p_make(size_t len, int *error) { + struct dns_packet *P; + size_t size = dns_p_calcsize(len); + + if (!(P = dns_p_init(malloc(size), size))) + *error = dns_syerr(); + + return P; +} /* dns_p_make() */ + + +static void dns_p_free(struct dns_packet *P) { + free(P); +} /* dns_p_free() */ + + +/* convience routine to free any existing packet before storing new packet */ +static struct dns_packet *dns_p_setptr(struct dns_packet **dst, struct dns_packet *src) { + dns_p_free(*dst); + + *dst = src; + + return src; +} /* dns_p_setptr() */ + + +static struct dns_packet *dns_p_movptr(struct dns_packet **dst, struct dns_packet **src) { + dns_p_setptr(dst, *src); + + *src = NULL; + + return *dst; +} /* dns_p_movptr() */ + + +int dns_p_grow(struct dns_packet **P) { + struct dns_packet *tmp; + size_t size; + int error; + + if (!*P) { + if (!(*P = dns_p_make(DNS_P_QBUFSIZ, &error))) + return error; + + return 0; + } + + size = dns_p_sizeof(*P); + size |= size >> 1; + size |= size >> 2; + size |= size >> 4; + size |= size >> 8; + size++; + + if (size > 65536) + return DNS_ENOBUFS; + + if (!(tmp = realloc(*P, dns_p_calcsize(size)))) + return dns_syerr(); + + tmp->size = size; + *P = tmp; + + return 0; +} /* dns_p_grow() */ + + +struct dns_packet *dns_p_copy(struct dns_packet *P, const struct dns_packet *P0) { + if (!P) + return 0; + + P->end = DNS_PP_MIN(P->size, P0->end); + + memcpy(P->data, P0->data, P->end); + + return P; +} /* dns_p_copy() */ + + +struct dns_packet *dns_p_merge(struct dns_packet *A, enum dns_section Amask, struct dns_packet *B, enum dns_section Bmask, int *error_) { + size_t bufsiz = DNS_PP_MIN(65535, ((A)? A->end : 0) + ((B)? B->end : 0)); + struct dns_packet *M; + enum dns_section section; + struct dns_rr rr, mr; + int error, copy; + + if (!A && B) { + A = B; + Amask = Bmask; + B = 0; + } + +merge: + if (!(M = dns_p_make(bufsiz, &error))) + goto error; + + for (section = DNS_S_QD; (DNS_S_ALL & section); section <<= 1) { + if (A && (section & Amask)) { + dns_rr_foreach(&rr, A, .section = section) { + if ((error = dns_rr_copy(M, &rr, A))) + goto error; + } + } + + if (B && (section & Bmask)) { + dns_rr_foreach(&rr, B, .section = section) { + copy = 1; + + dns_rr_foreach(&mr, M, .type = rr.type, .section = DNS_S_ALL) { + if (!(copy = dns_rr_cmp(&rr, B, &mr, M))) + break; + } + + if (copy && (error = dns_rr_copy(M, &rr, B))) + goto error; + } + } + } + + return M; +error: + dns_p_setptr(&M, NULL); + + if (error == DNS_ENOBUFS && bufsiz < 65535) { + bufsiz = DNS_PP_MIN(65535, bufsiz * 2); + + goto merge; + } + + *error_ = error; + + return 0; +} /* dns_p_merge() */ + + +static unsigned short dns_l_skip(unsigned short, const unsigned char *, size_t); + +void dns_p_dictadd(struct dns_packet *P, unsigned short dn) { + unsigned short lp, lptr, i; + + lp = dn; + + while (lp < P->end) { + if (0xc0 == (0xc0 & P->data[lp]) && P->end - lp >= 2 && lp != dn) { + lptr = ((0x3f & P->data[lp + 0]) << 8) + | ((0xff & P->data[lp + 1]) << 0); + + for (i = 0; i < lengthof(P->dict) && P->dict[i]; i++) { + if (P->dict[i] == lptr) { + P->dict[i] = dn; + + return; + } + } + } + + lp = dns_l_skip(lp, P->data, P->end); + } + + for (i = 0; i < lengthof(P->dict); i++) { + if (!P->dict[i]) { + P->dict[i] = dn; + + break; + } + } +} /* dns_p_dictadd() */ + + +static inline uint16_t +plus1_ns (uint16_t count_net) +{ + uint16_t count = ntohs (count_net); + + count++; + return htons (count); +} + +int dns_p_push(struct dns_packet *P, enum dns_section section, const void *dn, size_t dnlen, enum dns_type type, enum dns_class class, unsigned ttl, const void *any) { + size_t end = P->end; + int error; + + if ((error = dns_d_push(P, dn, dnlen))) + goto error; + + if (P->size - P->end < 4) + goto nobufs; + + P->data[P->end++] = 0xff & (type >> 8); + P->data[P->end++] = 0xff & (type >> 0); + + P->data[P->end++] = 0xff & (class >> 8); + P->data[P->end++] = 0xff & (class >> 0); + + if (section == DNS_S_QD) + goto update; + + if (P->size - P->end < 6) + goto nobufs; + + if (type != DNS_T_OPT) + ttl = DNS_PP_MIN(ttl, 0x7fffffffU); + P->data[P->end++] = ttl >> 24; + P->data[P->end++] = ttl >> 16; + P->data[P->end++] = ttl >> 8; + P->data[P->end++] = ttl >> 0; + + if ((error = dns_any_push(P, (union dns_any *)any, type))) + goto error; + +update: + switch (section) { + case DNS_S_QD: + if (dns_p_count(P, DNS_S_AN|DNS_S_NS|DNS_S_AR)) + goto order; + + if (!P->memo.qd.base && (error = dns_p_study(P))) + goto error; + + dns_header(P)->qdcount = plus1_ns (dns_header(P)->qdcount); + + P->memo.qd.end = P->end; + P->memo.an.base = P->end; + P->memo.an.end = P->end; + P->memo.ns.base = P->end; + P->memo.ns.end = P->end; + P->memo.ar.base = P->end; + P->memo.ar.end = P->end; + + break; + case DNS_S_AN: + if (dns_p_count(P, DNS_S_NS|DNS_S_AR)) + goto order; + + if (!P->memo.an.base && (error = dns_p_study(P))) + goto error; + + dns_header(P)->ancount = plus1_ns (dns_header(P)->ancount); + + P->memo.an.end = P->end; + P->memo.ns.base = P->end; + P->memo.ns.end = P->end; + P->memo.ar.base = P->end; + P->memo.ar.end = P->end; + + break; + case DNS_S_NS: + if (dns_p_count(P, DNS_S_AR)) + goto order; + + if (!P->memo.ns.base && (error = dns_p_study(P))) + goto error; + + dns_header(P)->nscount = plus1_ns (dns_header(P)->nscount); + + P->memo.ns.end = P->end; + P->memo.ar.base = P->end; + P->memo.ar.end = P->end; + + break; + case DNS_S_AR: + if (!P->memo.ar.base && (error = dns_p_study(P))) + goto error; + + dns_header(P)->arcount = plus1_ns (dns_header(P)->arcount); + + P->memo.ar.end = P->end; + + if (type == DNS_T_OPT && !P->memo.opt.p) { + P->memo.opt.p = end; + P->memo.opt.maxudp = class; + P->memo.opt.ttl = ttl; + } + + break; + default: + error = DNS_ESECTION; + + goto error; + } /* switch() */ + + return 0; +nobufs: + error = DNS_ENOBUFS; + + goto error; +order: + error = DNS_EORDER; + + goto error; +error: + P->end = end; + + return error; +} /* dns_p_push() */ + +#define DNS_SM_RESTORE do { pc = state->pc; error = state->error; } while (0) +#define DNS_SM_SAVE do { state->error = error; state->pc = pc; } while (0) + +struct dns_p_lines_i { + int pc; + enum dns_section section; + struct dns_rr rr; + int error; +}; + +static size_t dns_p_lines_fmt(void *dst, size_t lim, dns_error_t *_error, const char *fmt, ...) { + va_list ap; + int error = 0, n; + + va_start(ap, fmt); + if ((n = vsnprintf(dst, lim, fmt, ap)) < 0) + error = errno; + va_end(ap); + + *_error = error; + return DNS_PP_MAX(n, 0); +} /* dns_p_lines_fmt() */ + +#define DNS_P_LINE(...) \ + do { \ + len = dns_p_lines_fmt(dst, lim, &error, __VA_ARGS__); \ + if (len == 0 && error) \ + goto error; \ + DNS_SM_YIELD(len); \ + } while (0) + +static size_t dns_p_lines(void *dst, size_t lim, dns_error_t *_error, struct dns_packet *P, struct dns_rr_i *I, struct dns_p_lines_i *state) { + int error, pc; + size_t len; + char __dst[DNS_STRMAXLEN + 1] = { 0 }; + + *_error = 0; + + DNS_SM_ENTER; + + DNS_P_LINE(";; [HEADER]\n"); + DNS_P_LINE(";; qid : %d\n", ntohs(dns_header(P)->qid)); + DNS_P_LINE(";; qr : %s(%d)\n", (dns_header(P)->qr)? "RESPONSE" : "QUERY", dns_header(P)->qr); + DNS_P_LINE(";; opcode : %s(%d)\n", dns_stropcode(dns_header(P)->opcode), dns_header(P)->opcode); + DNS_P_LINE(";; aa : %s(%d)\n", (dns_header(P)->aa)? "AUTHORITATIVE" : "NON-AUTHORITATIVE", dns_header(P)->aa); + DNS_P_LINE(";; tc : %s(%d)\n", (dns_header(P)->tc)? "TRUNCATED" : "NOT-TRUNCATED", dns_header(P)->tc); + DNS_P_LINE(";; rd : %s(%d)\n", (dns_header(P)->rd)? "RECURSION-DESIRED" : "RECURSION-NOT-DESIRED", dns_header(P)->rd); + DNS_P_LINE(";; ra : %s(%d)\n", (dns_header(P)->ra)? "RECURSION-ALLOWED" : "RECURSION-NOT-ALLOWED", dns_header(P)->ra); + DNS_P_LINE(";; rcode : %s(%d)\n", dns_strrcode(dns_p_rcode(P)), dns_p_rcode(P)); + + while (dns_rr_grep(&state->rr, 1, I, P, &error)) { + if (state->section != state->rr.section) { + DNS_P_LINE("\n"); + DNS_P_LINE(";; [%s:%d]\n", dns_strsection(state->rr.section, __dst), dns_p_count(P, state->rr.section)); + } + + if (!(len = dns_rr_print(dst, lim, &state->rr, P, &error))) + goto error; + dns_strlcat(dst, "\n", lim); + DNS_SM_YIELD(len + 1); + + state->section = state->rr.section; + } + + if (error) + goto error; + + DNS_SM_EXIT; +error: + for (;;) { + *_error = error; + DNS_SM_YIELD(0); + } + + DNS_SM_LEAVE; + + *_error = 0; + return 0; +} /* dns_p_lines() */ + +#undef DNS_P_LINE +#undef DNS_SM_SAVE +#undef DNS_SM_RESTORE + +static void dns_p_dump3(struct dns_packet *P, struct dns_rr_i *I, FILE *fp) { + struct dns_p_lines_i lines = { 0 }; + char line[sizeof (union dns_any) * 2]; + size_t len; + int error; + + while ((len = dns_p_lines(line, sizeof line, &error, P, I, &lines))) { + if (len < sizeof line) { + fwrite(line, 1, len, fp); + } else { + fwrite(line, 1, sizeof line - 1, fp); + fputc('\n', fp); + } + } +} /* dns_p_dump3() */ + + +void dns_p_dump(struct dns_packet *P, FILE *fp) { + struct dns_rr_i I_instance = { 0 }; + dns_p_dump3(P, &I_instance, fp); +} /* dns_p_dump() */ + + +static void dns_s_unstudy(struct dns_s_memo *m) + { m->base = 0; m->end = 0; } + +static void dns_m_unstudy(struct dns_p_memo *m) { + dns_s_unstudy(&m->qd); + dns_s_unstudy(&m->an); + dns_s_unstudy(&m->ns); + dns_s_unstudy(&m->ar); + m->opt.p = 0; + m->opt.maxudp = 0; + m->opt.ttl = 0; +} /* dns_m_unstudy() */ + +static int dns_s_study(struct dns_s_memo *m, enum dns_section section, unsigned short base, struct dns_packet *P) { + unsigned short count, rp; + + count = dns_p_count(P, section); + + for (rp = base; count && rp < P->end; count--) + rp = dns_rr_skip(rp, P); + + m->base = base; + m->end = rp; + + return 0; +} /* dns_s_study() */ + +static int dns_m_study(struct dns_p_memo *m, struct dns_packet *P) { + struct dns_rr rr; + int error; + + if ((error = dns_s_study(&m->qd, DNS_S_QD, 12, P))) + goto error; + if ((error = dns_s_study(&m->an, DNS_S_AN, m->qd.end, P))) + goto error; + if ((error = dns_s_study(&m->ns, DNS_S_NS, m->an.end, P))) + goto error; + if ((error = dns_s_study(&m->ar, DNS_S_AR, m->ns.end, P))) + goto error; + + m->opt.p = 0; + m->opt.maxudp = 0; + m->opt.ttl = 0; + dns_rr_foreach(&rr, P, .type = DNS_T_OPT, .section = DNS_S_AR) { + m->opt.p = rr.dn.p; + m->opt.maxudp = rr.class; + m->opt.ttl = rr.ttl; + break; + } + + return 0; +error: + dns_m_unstudy(m); + + return error; +} /* dns_m_study() */ + +int dns_p_study(struct dns_packet *P) { + return dns_m_study(&P->memo, P); +} /* dns_p_study() */ + + +enum dns_rcode dns_p_rcode(struct dns_packet *P) { + return 0xfff & ((P->memo.opt.ttl >> 20) | dns_header(P)->rcode); +} /* dns_p_rcode() */ + + +/* + * Q U E R Y P A C K E T R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#define DNS_Q_RD 0x1 /* recursion desired */ +#define DNS_Q_EDNS0 0x2 /* include OPT RR */ + +static dns_error_t +dns_q_make2(struct dns_packet **_Q, const char *qname, size_t qlen, enum dns_type qtype, enum dns_class qclass, int qflags) +{ + struct dns_packet *Q = NULL; + int error; + + if (dns_p_movptr(&Q, _Q)) { + dns_p_reset(Q); + } else if (!(Q = dns_p_make(DNS_P_QBUFSIZ, &error))) { + goto error; + } + + if ((error = dns_p_push(Q, DNS_S_QD, qname, qlen, qtype, qclass, 0, 0))) + goto error; + + dns_header(Q)->rd = !!(qflags & DNS_Q_RD); + + if (qflags & DNS_Q_EDNS0) { + struct dns_opt opt = DNS_OPT_INIT(&opt); + + opt.version = 0; /* RFC 6891 version */ + opt.maxudp = 4096; + + if ((error = dns_p_push(Q, DNS_S_AR, ".", 1, DNS_T_OPT, dns_opt_class(&opt), dns_opt_ttl(&opt), &opt))) + goto error; + } + + *_Q = Q; + + return 0; +error: + dns_p_free(Q); + + return error; +} + +static dns_error_t +dns_q_make(struct dns_packet **Q, const char *qname, enum dns_type qtype, enum dns_class qclass, int qflags) +{ + return dns_q_make2(Q, qname, strlen(qname), qtype, qclass, qflags); +} + +static dns_error_t +dns_q_remake(struct dns_packet **Q, int qflags) +{ + char qname[DNS_D_MAXNAME + 1]; + size_t qlen; + struct dns_rr rr; + int error; + + assert(Q && *Q); + if ((error = dns_rr_parse(&rr, 12, *Q))) + return error; + if (!(qlen = dns_d_expand(qname, sizeof qname, rr.dn.p, *Q, &error))) + return error; + if (qlen >= sizeof qname) + return DNS_EILLEGAL; + return dns_q_make2(Q, qname, qlen, rr.type, rr.class, qflags); +} + +/* + * D O M A I N N A M E R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +#ifndef DNS_D_MAXPTRS +#define DNS_D_MAXPTRS 127 /* Arbitrary; possible, valid depth is something like packet size / 2 + fudge. */ +#endif + +static size_t dns_l_expand(unsigned char *dst, size_t lim, unsigned short src, unsigned short *nxt, const unsigned char *data, size_t end) { + unsigned short len; + unsigned nptrs = 0; + +retry: + if (src >= end) + goto invalid; + + switch (0x03 & (data[src] >> 6)) { + case 0x00: + len = (0x3f & (data[src++])); + + if (end - src < len) + goto invalid; + + if (lim > 0) { + memcpy(dst, &data[src], DNS_PP_MIN(lim, len)); + + dst[DNS_PP_MIN(lim - 1, len)] = '\0'; + } + + *nxt = src + len; + + return len; + case 0x01: + goto invalid; + case 0x02: + goto invalid; + case 0x03: + if (++nptrs > DNS_D_MAXPTRS) + goto invalid; + + if (end - src < 2) + goto invalid; + + src = ((0x3f & data[src + 0]) << 8) + | ((0xff & data[src + 1]) << 0); + + goto retry; + } /* switch() */ + + /* NOT REACHED */ +invalid: + *nxt = end; + + return 0; +} /* dns_l_expand() */ + + +static unsigned short dns_l_skip(unsigned short src, const unsigned char *data, size_t end) { + unsigned short len; + + if (src >= end) + goto invalid; + + switch (0x03 & (data[src] >> 6)) { + case 0x00: + len = (0x3f & (data[src++])); + + if (end - src < len) + goto invalid; + + return (len)? src + len : end; + case 0x01: + goto invalid; + case 0x02: + goto invalid; + case 0x03: + return end; + } /* switch() */ + + /* NOT REACHED */ +invalid: + return end; +} /* dns_l_skip() */ + + +static _Bool dns_d_isanchored(const void *_src, size_t len) { + const unsigned char *src = _src; + return len > 0 && src[len - 1] == '.'; +} /* dns_d_isanchored() */ + + +static size_t dns_d_ndots(const void *_src, size_t len) { + const unsigned char *p = _src, *pe = p + len; + size_t ndots = 0; + + while ((p = memchr(p, '.', pe - p))) { + ndots++; + p++; + } + + return ndots; +} /* dns_d_ndots() */ + + +static size_t dns_d_trim(void *dst_, size_t lim, const void *src_, size_t len, int flags) { + unsigned char *dst = dst_; + const unsigned char *src = src_; + size_t dp = 0, sp = 0; + int lc; + + /* trim any leading dot(s) */ + while (sp < len && src[sp] == '.') + sp++; + + for (lc = 0; sp < len; lc = src[sp++]) { + /* trim extra dot(s) */ + if (src[sp] == '.' && lc == '.') + continue; + + if (dp < lim) + dst[dp] = src[sp]; + + dp++; + } + + if ((flags & DNS_D_ANCHOR) && lc != '.') { + if (dp < lim) + dst[dp] = '.'; + + dp++; + } + + if (lim > 0) + dst[DNS_PP_MIN(dp, lim - 1)] = '\0'; + + return dp; +} /* dns_d_trim() */ + + +char *dns_d_init(void *dst, size_t lim, const void *src, size_t len, int flags) { + if (flags & DNS_D_TRIM) { + dns_d_trim(dst, lim, src, len, flags); + } if (flags & DNS_D_ANCHOR) { + dns_d_anchor(dst, lim, src, len); + } else { + memmove(dst, src, DNS_PP_MIN(lim, len)); + + if (lim > 0) + ((char *)dst)[DNS_PP_MIN(len, lim - 1)] = '\0'; + } + + return dst; +} /* dns_d_init() */ + + +size_t dns_d_anchor(void *dst, size_t lim, const void *src, size_t len) { + if (len == 0) + return 0; + + memmove(dst, src, DNS_PP_MIN(lim, len)); + + if (((const char *)src)[len - 1] != '.') { + if (len < lim) + ((char *)dst)[len] = '.'; + len++; + } + + if (lim > 0) + ((char *)dst)[DNS_PP_MIN(lim - 1, len)] = '\0'; + + return len; +} /* dns_d_anchor() */ + + +size_t dns_d_cleave(void *dst, size_t lim, const void *src, size_t len) { + const char *dot; + + /* XXX: Skip any leading dot. Handles cleaving root ".". */ + if (len == 0 || !(dot = memchr((const char *)src + 1, '.', len - 1))) + return 0; + + len -= dot - (const char *)src; + + /* XXX: Unless root, skip the label's trailing dot. */ + if (len > 1) { + src = ++dot; + len--; + } else + src = dot; + + memmove(dst, src, DNS_PP_MIN(lim, len)); + + if (lim > 0) + ((char *)dst)[DNS_PP_MIN(lim - 1, len)] = '\0'; + + return len; +} /* dns_d_cleave() */ + + +size_t dns_d_comp(void *dst_, size_t lim, const void *src_, size_t len, struct dns_packet *P, int *error) { + struct { unsigned char *b; size_t p, x; } dst, src; + unsigned char ch = '.'; + + dst.b = dst_; + dst.p = 0; + dst.x = 1; + + src.b = (unsigned char *)src_; + src.p = 0; + src.x = 0; + + while (src.x < len) { + ch = src.b[src.x]; + + if (ch == '.') { + if (dst.p < lim) + dst.b[dst.p] = (0x3f & (src.x - src.p)); + + dst.p = dst.x++; + src.p = ++src.x; + } else { + if (dst.x < lim) + dst.b[dst.x] = ch; + + dst.x++; + src.x++; + } + } /* while() */ + + if (src.x > src.p) { + if (dst.p < lim) + dst.b[dst.p] = (0x3f & (src.x - src.p)); + + dst.p = dst.x; + } + + if (dst.p > 1) { + if (dst.p < lim) + dst.b[dst.p] = 0x00; + + dst.p++; + } + +#if 1 + if (dst.p < lim) { + struct { unsigned char label[DNS_D_MAXLABEL + 1]; size_t len; unsigned short p, x, y; } a, b; + unsigned i; + + a.p = 0; + + while ((a.len = dns_l_expand(a.label, sizeof a.label, a.p, &a.x, dst.b, lim))) { + for (i = 0; i < lengthof(P->dict) && P->dict[i]; i++) { + b.p = P->dict[i]; + + while ((b.len = dns_l_expand(b.label, sizeof b.label, b.p, &b.x, P->data, P->end))) { + a.y = a.x; + b.y = b.x; + + while (a.len && b.len && 0 == strcasecmp((char *)a.label, (char *)b.label)) { + a.len = dns_l_expand(a.label, sizeof a.label, a.y, &a.y, dst.b, lim); + b.len = dns_l_expand(b.label, sizeof b.label, b.y, &b.y, P->data, P->end); + } + + if (a.len == 0 && b.len == 0 && b.p <= 0x3fff) { + dst.b[a.p++] = 0xc0 + | (0x3f & (b.p >> 8)); + dst.b[a.p++] = (0xff & (b.p >> 0)); + + /* silence static analyzers */ + dns_assume(a.p > 0); + + return a.p; + } + + b.p = b.x; + } /* while() */ + } /* for() */ + + a.p = a.x; + } /* while() */ + } /* if () */ +#endif + + if (!dst.p) + *error = DNS_EILLEGAL; + + return dst.p; +} /* dns_d_comp() */ + + +unsigned short dns_d_skip(unsigned short src, struct dns_packet *P) { + unsigned short len; + + while (src < P->end) { + switch (0x03 & (P->data[src] >> 6)) { + case 0x00: /* FOLLOWS */ + len = (0x3f & P->data[src++]); + + if (0 == len) { +/* success ==> */ return src; + } else if (P->end - src > len) { + src += len; + + break; + } else + goto invalid; + + /* NOT REACHED */ + case 0x01: /* RESERVED */ + goto invalid; + case 0x02: /* RESERVED */ + goto invalid; + case 0x03: /* POINTER */ + if (P->end - src < 2) + goto invalid; + + src += 2; + +/* success ==> */ return src; + } /* switch() */ + } /* while() */ + +invalid: + return P->end; +} /* dns_d_skip() */ + + +#include <stdio.h> + +size_t dns_d_expand(void *dst, size_t lim, unsigned short src, struct dns_packet *P, int *error) { + size_t dstp = 0; + unsigned nptrs = 0; + unsigned char len; + + while (src < P->end) { + switch ((0x03 & (P->data[src] >> 6))) { + case 0x00: /* FOLLOWS */ + len = (0x3f & P->data[src]); + + if (0 == len) { + if (dstp == 0) { + if (dstp < lim) + ((unsigned char *)dst)[dstp] = '.'; + + dstp++; + } + + /* NUL terminate */ + if (lim > 0) + ((unsigned char *)dst)[DNS_PP_MIN(dstp, lim - 1)] = '\0'; + +/* success ==> */ return dstp; + } + + src++; + + if (P->end - src < len) + goto toolong; + + if (dstp < lim) + memcpy(&((unsigned char *)dst)[dstp], &P->data[src], DNS_PP_MIN(len, lim - dstp)); + + src += len; + dstp += len; + + if (dstp < lim) + ((unsigned char *)dst)[dstp] = '.'; + + dstp++; + + nptrs = 0; + + continue; + case 0x01: /* RESERVED */ + goto reserved; + case 0x02: /* RESERVED */ + goto reserved; + case 0x03: /* POINTER */ + if (++nptrs > DNS_D_MAXPTRS) + goto toolong; + + if (P->end - src < 2) + goto toolong; + + src = ((0x3f & P->data[src + 0]) << 8) + | ((0xff & P->data[src + 1]) << 0); + + continue; + } /* switch() */ + } /* while() */ + +toolong: + *error = DNS_EILLEGAL; + + if (lim > 0) + ((unsigned char *)dst)[DNS_PP_MIN(dstp, lim - 1)] = '\0'; + + return 0; +reserved: + *error = DNS_EILLEGAL; + + if (lim > 0) + ((unsigned char *)dst)[DNS_PP_MIN(dstp, lim - 1)] = '\0'; + + return 0; +} /* dns_d_expand() */ + + +int dns_d_push(struct dns_packet *P, const void *dn, size_t len) { + size_t lim = P->size - P->end; + unsigned dp = P->end; + int error = DNS_EILLEGAL; /* silence compiler */ + + len = dns_d_comp(&P->data[dp], lim, dn, len, P, &error); + + if (len == 0) + return error; + if (len > lim) + return DNS_ENOBUFS; + + P->end += len; + + dns_p_dictadd(P, dp); + + return 0; +} /* dns_d_push() */ + + +size_t dns_d_cname(void *dst, size_t lim, const void *dn, size_t len, struct dns_packet *P, int *error_) { + char host[DNS_D_MAXNAME + 1]; + struct dns_rr_i i; + struct dns_rr rr; + unsigned depth; + int error; + + if (sizeof host <= dns_d_anchor(host, sizeof host, dn, len)) + { error = ENAMETOOLONG; goto error; } + + for (depth = 0; depth < 7; depth++) { + memset(&i, 0, sizeof i); + i.section = DNS_S_ALL & ~DNS_S_QD; + i.name = host; + i.type = DNS_T_CNAME; + + if (!dns_rr_grep(&rr, 1, &i, P, &error)) + break; + + if ((error = dns_cname_parse((struct dns_cname *)host, &rr, P))) + goto error; + } + + return dns_strlcpy(dst, host, lim); +error: + *error_ = error; + + return 0; +} /* dns_d_cname() */ + + +/* + * R E S O U R C E R E C O R D R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +int dns_rr_copy(struct dns_packet *P, struct dns_rr *rr, struct dns_packet *Q) { + unsigned char dn[DNS_D_MAXNAME + 1]; + union dns_any any; + size_t len; + int error; + + if (!(len = dns_d_expand(dn, sizeof dn, rr->dn.p, Q, &error))) + return error; + else if (len >= sizeof dn) + return DNS_EILLEGAL; + + if (rr->section != DNS_S_QD && (error = dns_any_parse(dns_any_init(&any, sizeof any), rr, Q))) + return error; + + return dns_p_push(P, rr->section, dn, len, rr->type, rr->class, rr->ttl, &any); +} /* dns_rr_copy() */ + + +int dns_rr_parse(struct dns_rr *rr, unsigned short src, struct dns_packet *P) { + unsigned short p = src; + + if (src >= P->end) + goto invalid; + + rr->dn.p = p; + rr->dn.len = (p = dns_d_skip(p, P)) - rr->dn.p; + + if (P->end - p < 4) + goto invalid; + + rr->type = ((0xff & P->data[p + 0]) << 8) + | ((0xff & P->data[p + 1]) << 0); + + rr->class = ((0xff & P->data[p + 2]) << 8) + | ((0xff & P->data[p + 3]) << 0); + + p += 4; + + if (src < dns_p_qend(P)) { + rr->section = DNS_S_QUESTION; + + rr->ttl = 0; + rr->rd.p = 0; + rr->rd.len = 0; + + return 0; + } + + if (P->end - p < 4) + goto invalid; + + rr->ttl = ((0xff & P->data[p + 0]) << 24) + | ((0xff & P->data[p + 1]) << 16) + | ((0xff & P->data[p + 2]) << 8) + | ((0xff & P->data[p + 3]) << 0); + if (rr->type != DNS_T_OPT) + rr->ttl = DNS_PP_MIN(rr->ttl, 0x7fffffffU); + + p += 4; + + if (P->end - p < 2) + goto invalid; + + rr->rd.len = ((0xff & P->data[p + 0]) << 8) + | ((0xff & P->data[p + 1]) << 0); + rr->rd.p = p + 2; + + p += 2; + + if (P->end - p < rr->rd.len) + goto invalid; + + return 0; +invalid: + return DNS_EILLEGAL; +} /* dns_rr_parse() */ + + +static unsigned short dns_rr_len(const unsigned short src, struct dns_packet *P) { + unsigned short rp, rdlen; + + rp = dns_d_skip(src, P); + + if (P->end - rp < 4) + return P->end - src; + + rp += 4; /* TYPE, CLASS */ + + if (rp <= dns_p_qend(P)) + return rp - src; + + if (P->end - rp < 6) + return P->end - src; + + rp += 6; /* TTL, RDLEN */ + + rdlen = ((0xff & P->data[rp - 2]) << 8) + | ((0xff & P->data[rp - 1]) << 0); + + if (P->end - rp < rdlen) + return P->end - src; + + rp += rdlen; + + return rp - src; +} /* dns_rr_len() */ + + +unsigned short dns_rr_skip(unsigned short src, struct dns_packet *P) { + return src + dns_rr_len(src, P); +} /* dns_rr_skip() */ + + +static enum dns_section dns_rr_section(unsigned short src, struct dns_packet *P) { + enum dns_section section; + unsigned count, index; + unsigned short rp; + + if (src >= P->memo.qd.base && src < P->memo.qd.end) + return DNS_S_QD; + if (src >= P->memo.an.base && src < P->memo.an.end) + return DNS_S_AN; + if (src >= P->memo.ns.base && src < P->memo.ns.end) + return DNS_S_NS; + if (src >= P->memo.ar.base && src < P->memo.ar.end) + return DNS_S_AR; + + /* NOTE: Possibly bad memoization. Try it the hard-way. */ + + for (rp = 12, index = 0; rp < src && rp < P->end; index++) + rp = dns_rr_skip(rp, P); + + section = DNS_S_QD; + count = dns_p_count(P, section); + + while (index >= count && section <= DNS_S_AR) { + section <<= 1; + count += dns_p_count(P, section); + } + + return DNS_S_ALL & section; +} /* dns_rr_section() */ + + +static enum dns_type dns_rr_type(unsigned short src, struct dns_packet *P) { + struct dns_rr rr; + int error; + + if ((error = dns_rr_parse(&rr, src, P))) + return 0; + + return rr.type; +} /* dns_rr_type() */ + + +int dns_rr_cmp(struct dns_rr *r0, struct dns_packet *P0, struct dns_rr *r1, struct dns_packet *P1) { + char host0[DNS_D_MAXNAME + 1], host1[DNS_D_MAXNAME + 1]; + union dns_any any0, any1; + int cmp, error; + size_t len; + + if ((cmp = r0->type - r1->type)) + return cmp; + + if ((cmp = r0->class - r1->class)) + return cmp; + + /* + * FIXME: Do label-by-label comparison to handle illegally long names? + */ + + if (!(len = dns_d_expand(host0, sizeof host0, r0->dn.p, P0, &error)) + || len >= sizeof host0) + return -1; + + if (!(len = dns_d_expand(host1, sizeof host1, r1->dn.p, P1, &error)) + || len >= sizeof host1) + return 1; + + if ((cmp = strcasecmp(host0, host1))) + return cmp; + + if (DNS_S_QD & (r0->section | r1->section)) { + if (r0->section == r1->section) + return 0; + + return (r0->section == DNS_S_QD)? -1 : 1; + } + + if ((error = dns_any_parse(&any0, r0, P0))) + return -1; + + if ((error = dns_any_parse(&any1, r1, P1))) + return 1; + + return dns_any_cmp(&any0, r0->type, &any1, r1->type); +} /* dns_rr_cmp() */ + + +static _Bool dns_rr_exists(struct dns_rr *rr0, struct dns_packet *P0, struct dns_packet *P1) { + struct dns_rr rr1; + + dns_rr_foreach(&rr1, P1, .section = rr0->section, .type = rr0->type) { + if (0 == dns_rr_cmp(rr0, P0, &rr1, P1)) + return 1; + } + + return 0; +} /* dns_rr_exists() */ + + +static unsigned short dns_rr_offset(struct dns_rr *rr) { + return rr->dn.p; +} /* dns_rr_offset() */ + + +static _Bool dns_rr_i_match(struct dns_rr *rr, struct dns_rr_i *i, struct dns_packet *P) { + if (i->section && !(rr->section & i->section)) + return 0; + + if (i->type && rr->type != i->type && i->type != DNS_T_ALL) + return 0; + + if (i->class && rr->class != i->class && i->class != DNS_C_ANY) + return 0; + + if (i->name) { + char dn[DNS_D_MAXNAME + 1]; + size_t len; + int error; + + if (!(len = dns_d_expand(dn, sizeof dn, rr->dn.p, P, &error)) + || len >= sizeof dn) + return 0; + + if (0 != strcasecmp(dn, i->name)) + return 0; + } + + if (i->data && i->type && rr->section > DNS_S_QD) { + union dns_any rd; + int error; + + if ((error = dns_any_parse(&rd, rr, P))) + return 0; + + if (0 != dns_any_cmp(&rd, rr->type, i->data, i->type)) + return 0; + } + + return 1; +} /* dns_rr_i_match() */ + + +static unsigned short dns_rr_i_start(struct dns_rr_i *i, struct dns_packet *P) { + unsigned short rp; + struct dns_rr r0, rr; + int error; + + if ((i->section & DNS_S_QD) && P->memo.qd.base) + rp = P->memo.qd.base; + else if ((i->section & DNS_S_AN) && P->memo.an.base) + rp = P->memo.an.base; + else if ((i->section & DNS_S_NS) && P->memo.ns.base) + rp = P->memo.ns.base; + else if ((i->section & DNS_S_AR) && P->memo.ar.base) + rp = P->memo.ar.base; + else + rp = 12; + + for (; rp < P->end; rp = dns_rr_skip(rp, P)) { + if ((error = dns_rr_parse(&rr, rp, P))) + continue; + + rr.section = dns_rr_section(rp, P); + + if (!dns_rr_i_match(&rr, i, P)) + continue; + + r0 = rr; + + goto lower; + } + + return P->end; +lower: + if (i->sort == &dns_rr_i_packet) + return dns_rr_offset(&r0); + + while ((rp = dns_rr_skip(rp, P)) < P->end) { + if ((error = dns_rr_parse(&rr, rp, P))) + continue; + + rr.section = dns_rr_section(rp, P); + + if (!dns_rr_i_match(&rr, i, P)) + continue; + + if (i->sort(&rr, &r0, i, P) < 0) + r0 = rr; + } + + return dns_rr_offset(&r0); +} /* dns_rr_i_start() */ + + +static unsigned short dns_rr_i_skip(unsigned short rp, struct dns_rr_i *i, struct dns_packet *P) { + struct dns_rr r0, r1, rr; + int error; + + if ((error = dns_rr_parse(&r0, rp, P))) + return P->end; + + r0.section = dns_rr_section(rp, P); + + rp = (i->sort == &dns_rr_i_packet)? dns_rr_skip(rp, P) : 12; + + for (; rp < P->end; rp = dns_rr_skip(rp, P)) { + if ((error = dns_rr_parse(&rr, rp, P))) + continue; + + rr.section = dns_rr_section(rp, P); + + if (!dns_rr_i_match(&rr, i, P)) + continue; + + if (i->sort(&rr, &r0, i, P) <= 0) + continue; + + r1 = rr; + + goto lower; + } + + return P->end; +lower: + if (i->sort == &dns_rr_i_packet) + return dns_rr_offset(&r1); + + while ((rp = dns_rr_skip(rp, P)) < P->end) { + if ((error = dns_rr_parse(&rr, rp, P))) + continue; + + rr.section = dns_rr_section(rp, P); + + if (!dns_rr_i_match(&rr, i, P)) + continue; + + if (i->sort(&rr, &r0, i, P) <= 0) + continue; + + if (i->sort(&rr, &r1, i, P) >= 0) + continue; + + r1 = rr; + } + + return dns_rr_offset(&r1); +} /* dns_rr_i_skip() */ + + +int dns_rr_i_packet(struct dns_rr *a, struct dns_rr *b, struct dns_rr_i *i, struct dns_packet *P) { + (void)i; + (void)P; + + return (int)a->dn.p - (int)b->dn.p; +} /* dns_rr_i_packet() */ + + +int dns_rr_i_order(struct dns_rr *a, struct dns_rr *b, struct dns_rr_i *i, struct dns_packet *P) { + int cmp; + + (void)i; + + if ((cmp = a->section - b->section)) + return cmp; + + if (a->type != b->type) + return (int)a->dn.p - (int)b->dn.p; + + return dns_rr_cmp(a, P, b, P); +} /* dns_rr_i_order() */ + + +int dns_rr_i_shuffle(struct dns_rr *a, struct dns_rr *b, struct dns_rr_i *i, struct dns_packet *P) { + int cmp; + + (void)i; + (void)P; + + while (!i->state.regs[0]) + i->state.regs[0] = dns_random(); + + if ((cmp = a->section - b->section)) + return cmp; + + return dns_k_shuffle16(a->dn.p, i->state.regs[0]) - dns_k_shuffle16(b->dn.p, i->state.regs[0]); +} /* dns_rr_i_shuffle() */ + + +void dns_rr_i_init(struct dns_rr_i *i) { + static const struct dns_rr_i i_initializer; + + i->state = i_initializer.state; + i->saved = i->state; +} /* dns_rr_i_init() */ + + +unsigned dns_rr_grep(struct dns_rr *rr, unsigned lim, struct dns_rr_i *i, struct dns_packet *P, int *error_) { + unsigned count = 0; + int error; + + switch (i->state.exec) { + case 0: + if (!i->sort) + i->sort = &dns_rr_i_packet; + + i->state.next = dns_rr_i_start(i, P); + i->state.exec++; + + /* FALL THROUGH */ + case 1: + while (count < lim && i->state.next < P->end) { + if ((error = dns_rr_parse(rr, i->state.next, P))) + goto error; + + rr->section = dns_rr_section(i->state.next, P); + + rr++; + count++; + i->state.count++; + + i->state.next = dns_rr_i_skip(i->state.next, i, P); + } /* while() */ + + break; + } /* switch() */ + + return count; +error: + if (error_) + *error_ = error; + + return count; +} /* dns_rr_grep() */ + + +size_t dns_rr_print(void *_dst, size_t lim, struct dns_rr *rr, struct dns_packet *P, int *_error) { + struct dns_buf dst = DNS_B_INTO(_dst, lim); + union dns_any any; + size_t n; + int error; + char __dst[DNS_STRMAXLEN + 1] = { 0 }; + + if (rr->section == DNS_S_QD) + dns_b_putc(&dst, ';'); + + if (!(n = dns_d_expand(any.ns.host, sizeof any.ns.host, rr->dn.p, P, &error))) + goto error; + dns_b_put(&dst, any.ns.host, DNS_PP_MIN(n, sizeof any.ns.host - 1)); + + if (rr->section != DNS_S_QD) { + dns_b_putc(&dst, ' '); + dns_b_fmtju(&dst, rr->ttl, 0); + } + + dns_b_putc(&dst, ' '); + dns_b_puts(&dst, dns_strclass(rr->class, __dst)); + dns_b_putc(&dst, ' '); + dns_b_puts(&dst, dns_strtype(rr->type, __dst)); + + if (rr->section == DNS_S_QD) + goto epilog; + + dns_b_putc(&dst, ' '); + + if ((error = dns_any_parse(dns_any_init(&any, sizeof any), rr, P))) + goto error; + + n = dns_any_print(dst.p, dst.pe - dst.p, &any, rr->type); + dst.p += DNS_PP_MIN(n, (size_t)(dst.pe - dst.p)); +epilog: + return dns_b_strllen(&dst); +error: + *_error = error; + + return 0; +} /* dns_rr_print() */ + + +int dns_a_parse(struct dns_a *a, struct dns_rr *rr, struct dns_packet *P) { + unsigned long addr; + + if (rr->rd.len != 4) + return DNS_EILLEGAL; + + addr = ((0xffU & P->data[rr->rd.p + 0]) << 24) + | ((0xffU & P->data[rr->rd.p + 1]) << 16) + | ((0xffU & P->data[rr->rd.p + 2]) << 8) + | ((0xffU & P->data[rr->rd.p + 3]) << 0); + + a->addr.s_addr = htonl(addr); + + return 0; +} /* dns_a_parse() */ + + +int dns_a_push(struct dns_packet *P, struct dns_a *a) { + unsigned long addr; + + if (P->size - P->end < 6) + return DNS_ENOBUFS; + + P->data[P->end++] = 0x00; + P->data[P->end++] = 0x04; + + addr = ntohl(a->addr.s_addr); + + P->data[P->end++] = 0xffU & (addr >> 24); + P->data[P->end++] = 0xffU & (addr >> 16); + P->data[P->end++] = 0xffU & (addr >> 8); + P->data[P->end++] = 0xffU & (addr >> 0); + + return 0; +} /* dns_a_push() */ + + +size_t dns_a_arpa(void *_dst, size_t lim, const struct dns_a *a) { + struct dns_buf dst = DNS_B_INTO(_dst, lim); + unsigned long octets = ntohl(a->addr.s_addr); + unsigned i; + + for (i = 0; i < 4; i++) { + dns_b_fmtju(&dst, 0xff & octets, 0); + dns_b_putc(&dst, '.'); + octets >>= 8; + } + + dns_b_puts(&dst, "in-addr.arpa."); + + return dns_b_strllen(&dst); +} /* dns_a_arpa() */ + + +int dns_a_cmp(const struct dns_a *a, const struct dns_a *b) { + if (ntohl(a->addr.s_addr) < ntohl(b->addr.s_addr)) + return -1; + if (ntohl(a->addr.s_addr) > ntohl(b->addr.s_addr)) + return 1; + + return 0; +} /* dns_a_cmp() */ + + +size_t dns_a_print(void *dst, size_t lim, struct dns_a *a) { + char addr[INET_ADDRSTRLEN + 1] = "0.0.0.0"; + + dns_inet_ntop(AF_INET, &a->addr, addr, sizeof addr); + + return dns_strlcpy(dst, addr, lim); +} /* dns_a_print() */ + + +int dns_aaaa_parse(struct dns_aaaa *aaaa, struct dns_rr *rr, struct dns_packet *P) { + if (rr->rd.len != sizeof aaaa->addr.s6_addr) + return DNS_EILLEGAL; + + memcpy(aaaa->addr.s6_addr, &P->data[rr->rd.p], sizeof aaaa->addr.s6_addr); + + return 0; +} /* dns_aaaa_parse() */ + + +int dns_aaaa_push(struct dns_packet *P, struct dns_aaaa *aaaa) { + if (P->size - P->end < 2 + sizeof aaaa->addr.s6_addr) + return DNS_ENOBUFS; + + P->data[P->end++] = 0x00; + P->data[P->end++] = 0x10; + + memcpy(&P->data[P->end], aaaa->addr.s6_addr, sizeof aaaa->addr.s6_addr); + + P->end += sizeof aaaa->addr.s6_addr; + + return 0; +} /* dns_aaaa_push() */ + + +int dns_aaaa_cmp(const struct dns_aaaa *a, const struct dns_aaaa *b) { + unsigned i; + int cmp; + + for (i = 0; i < lengthof(a->addr.s6_addr); i++) { + if ((cmp = (a->addr.s6_addr[i] - b->addr.s6_addr[i]))) + return cmp; + } + + return 0; +} /* dns_aaaa_cmp() */ + + +size_t dns_aaaa_arpa(void *_dst, size_t lim, const struct dns_aaaa *aaaa) { + static const unsigned char hex[16] = "0123456789abcdef"; + struct dns_buf dst = DNS_B_INTO(_dst, lim); + unsigned nyble; + int i, j; + + for (i = sizeof aaaa->addr.s6_addr - 1; i >= 0; i--) { + nyble = aaaa->addr.s6_addr[i]; + + for (j = 0; j < 2; j++) { + dns_b_putc(&dst, hex[0x0f & nyble]); + dns_b_putc(&dst, '.'); + nyble >>= 4; + } + } + + dns_b_puts(&dst, "ip6.arpa."); + + return dns_b_strllen(&dst); +} /* dns_aaaa_arpa() */ + + +size_t dns_aaaa_print(void *dst, size_t lim, struct dns_aaaa *aaaa) { + char addr[INET6_ADDRSTRLEN + 1] = "::"; + + dns_inet_ntop(AF_INET6, &aaaa->addr, addr, sizeof addr); + + return dns_strlcpy(dst, addr, lim); +} /* dns_aaaa_print() */ + + +int dns_mx_parse(struct dns_mx *mx, struct dns_rr *rr, struct dns_packet *P) { + size_t len; + int error; + + if (rr->rd.len < 3) + return DNS_EILLEGAL; + + mx->preference = (0xff00 & (P->data[rr->rd.p + 0] << 8)) + | (0x00ff & (P->data[rr->rd.p + 1] << 0)); + + if (!(len = dns_d_expand(mx->host, sizeof mx->host, rr->rd.p + 2, P, &error))) + return error; + else if (len >= sizeof mx->host) + return DNS_EILLEGAL; + + return 0; +} /* dns_mx_parse() */ + + +int dns_mx_push(struct dns_packet *P, struct dns_mx *mx) { + size_t end, len; + int error; + + if (P->size - P->end < 5) + return DNS_ENOBUFS; + + end = P->end; + P->end += 2; + + P->data[P->end++] = 0xff & (mx->preference >> 8); + P->data[P->end++] = 0xff & (mx->preference >> 0); + + if ((error = dns_d_push(P, mx->host, strlen(mx->host)))) + goto error; + + len = P->end - end - 2; + + P->data[end + 0] = 0xff & (len >> 8); + P->data[end + 1] = 0xff & (len >> 0); + + return 0; +error: + P->end = end; + + return error; +} /* dns_mx_push() */ + + +int dns_mx_cmp(const struct dns_mx *a, const struct dns_mx *b) { + int cmp; + + if ((cmp = a->preference - b->preference)) + return cmp; + + return strcasecmp(a->host, b->host); +} /* dns_mx_cmp() */ + + +size_t dns_mx_print(void *_dst, size_t lim, struct dns_mx *mx) { + struct dns_buf dst = DNS_B_INTO(_dst, lim); + + dns_b_fmtju(&dst, mx->preference, 0); + dns_b_putc(&dst, ' '); + dns_b_puts(&dst, mx->host); + + return dns_b_strllen(&dst); +} /* dns_mx_print() */ + + +size_t dns_mx_cname(void *dst, size_t lim, struct dns_mx *mx) { + return dns_strlcpy(dst, mx->host, lim); +} /* dns_mx_cname() */ + + +int dns_ns_parse(struct dns_ns *ns, struct dns_rr *rr, struct dns_packet *P) { + size_t len; + int error; + + if (!(len = dns_d_expand(ns->host, sizeof ns->host, rr->rd.p, P, &error))) + return error; + else if (len >= sizeof ns->host) + return DNS_EILLEGAL; + + return 0; +} /* dns_ns_parse() */ + + +int dns_ns_push(struct dns_packet *P, struct dns_ns *ns) { + size_t end, len; + int error; + + if (P->size - P->end < 3) + return DNS_ENOBUFS; + + end = P->end; + P->end += 2; + + if ((error = dns_d_push(P, ns->host, strlen(ns->host)))) + goto error; + + len = P->end - end - 2; + + P->data[end + 0] = 0xff & (len >> 8); + P->data[end + 1] = 0xff & (len >> 0); + + return 0; +error: + P->end = end; + + return error; +} /* dns_ns_push() */ + + +int dns_ns_cmp(const struct dns_ns *a, const struct dns_ns *b) { + return strcasecmp(a->host, b->host); +} /* dns_ns_cmp() */ + + +size_t dns_ns_print(void *dst, size_t lim, struct dns_ns *ns) { + return dns_strlcpy(dst, ns->host, lim); +} /* dns_ns_print() */ + + +size_t dns_ns_cname(void *dst, size_t lim, struct dns_ns *ns) { + return dns_strlcpy(dst, ns->host, lim); +} /* dns_ns_cname() */ + + +int dns_cname_parse(struct dns_cname *cname, struct dns_rr *rr, struct dns_packet *P) { + return dns_ns_parse((struct dns_ns *)cname, rr, P); +} /* dns_cname_parse() */ + + +int dns_cname_push(struct dns_packet *P, struct dns_cname *cname) { + return dns_ns_push(P, (struct dns_ns *)cname); +} /* dns_cname_push() */ + + +int dns_cname_cmp(const struct dns_cname *a, const struct dns_cname *b) { + return strcasecmp(a->host, b->host); +} /* dns_cname_cmp() */ + + +size_t dns_cname_print(void *dst, size_t lim, struct dns_cname *cname) { + return dns_ns_print(dst, lim, (struct dns_ns *)cname); +} /* dns_cname_print() */ + + +size_t dns_cname_cname(void *dst, size_t lim, struct dns_cname *cname) { + return dns_strlcpy(dst, cname->host, lim); +} /* dns_cname_cname() */ + + +int dns_soa_parse(struct dns_soa *soa, struct dns_rr *rr, struct dns_packet *P) { + struct { void *dst; size_t lim; } dn[] = + { { soa->mname, sizeof soa->mname }, + { soa->rname, sizeof soa->rname } }; + unsigned *ts[] = + { &soa->serial, &soa->refresh, &soa->retry, &soa->expire, &soa->minimum }; + unsigned short rp; + unsigned i, j, n; + int error; + + /* MNAME / RNAME */ + if ((rp = rr->rd.p) >= P->end) + return DNS_EILLEGAL; + + for (i = 0; i < lengthof(dn); i++) { + if (!(n = dns_d_expand(dn[i].dst, dn[i].lim, rp, P, &error))) + return error; + else if (n >= dn[i].lim) + return DNS_EILLEGAL; + + if ((rp = dns_d_skip(rp, P)) >= P->end) + return DNS_EILLEGAL; + } + + /* SERIAL / REFRESH / RETRY / EXPIRE / MINIMUM */ + for (i = 0; i < lengthof(ts); i++) { + for (j = 0; j < 4; j++, rp++) { + if (rp >= P->end) + return DNS_EILLEGAL; + + *ts[i] <<= 8; + *ts[i] |= (0xff & P->data[rp]); + } + } + + return 0; +} /* dns_soa_parse() */ + + +int dns_soa_push(struct dns_packet *P, struct dns_soa *soa) { + void *dn[] = { soa->mname, soa->rname }; + unsigned ts[] = { (0xffffffff & soa->serial), + (0x7fffffff & soa->refresh), + (0x7fffffff & soa->retry), + (0x7fffffff & soa->expire), + (0xffffffff & soa->minimum) }; + unsigned i, j; + size_t end, len; + int error; + + end = P->end; + + if ((P->end += 2) >= P->size) + goto toolong; + + /* MNAME / RNAME */ + for (i = 0; i < lengthof(dn); i++) { + if ((error = dns_d_push(P, dn[i], strlen(dn[i])))) + goto error; + } + + /* SERIAL / REFRESH / RETRY / EXPIRE / MINIMUM */ + for (i = 0; i < lengthof(ts); i++) { + if ((P->end += 4) >= P->size) + goto toolong; + + for (j = 1; j <= 4; j++) { + P->data[P->end - j] = (0xff & ts[i]); + ts[i] >>= 8; + } + } + + len = P->end - end - 2; + P->data[end + 0] = (0xff & (len >> 8)); + P->data[end + 1] = (0xff & (len >> 0)); + + return 0; +toolong: + error = DNS_ENOBUFS; + + /* FALL THROUGH */ +error: + P->end = end; + + return error; +} /* dns_soa_push() */ + + +int dns_soa_cmp(const struct dns_soa *a, const struct dns_soa *b) { + int cmp; + + if ((cmp = strcasecmp(a->mname, b->mname))) + return cmp; + + if ((cmp = strcasecmp(a->rname, b->rname))) + return cmp; + + if (a->serial > b->serial) + return -1; + else if (a->serial < b->serial) + return 1; + + if (a->refresh > b->refresh) + return -1; + else if (a->refresh < b->refresh) + return 1; + + if (a->retry > b->retry) + return -1; + else if (a->retry < b->retry) + return 1; + + if (a->expire > b->expire) + return -1; + else if (a->expire < b->expire) + return 1; + + if (a->minimum > b->minimum) + return -1; + else if (a->minimum < b->minimum) + return 1; + + return 0; +} /* dns_soa_cmp() */ + + +size_t dns_soa_print(void *_dst, size_t lim, struct dns_soa *soa) { + struct dns_buf dst = DNS_B_INTO(_dst, lim); + + dns_b_puts(&dst, soa->mname); + dns_b_putc(&dst, ' '); + dns_b_puts(&dst, soa->rname); + dns_b_putc(&dst, ' '); + dns_b_fmtju(&dst, soa->serial, 0); + dns_b_putc(&dst, ' '); + dns_b_fmtju(&dst, soa->refresh, 0); + dns_b_putc(&dst, ' '); + dns_b_fmtju(&dst, soa->retry, 0); + dns_b_putc(&dst, ' '); + dns_b_fmtju(&dst, soa->expire, 0); + dns_b_putc(&dst, ' '); + dns_b_fmtju(&dst, soa->minimum, 0); + + return dns_b_strllen(&dst); +} /* dns_soa_print() */ + + +int dns_srv_parse(struct dns_srv *srv, struct dns_rr *rr, struct dns_packet *P) { + unsigned short rp; + unsigned i; + size_t n; + int error; + + memset(srv, '\0', sizeof *srv); + + rp = rr->rd.p; + + if (rr->rd.len < 7) + return DNS_EILLEGAL; + + for (i = 0; i < 2; i++, rp++) { + srv->priority <<= 8; + srv->priority |= (0xff & P->data[rp]); + } + + for (i = 0; i < 2; i++, rp++) { + srv->weight <<= 8; + srv->weight |= (0xff & P->data[rp]); + } + + for (i = 0; i < 2; i++, rp++) { + srv->port <<= 8; + srv->port |= (0xff & P->data[rp]); + } + + if (!(n = dns_d_expand(srv->target, sizeof srv->target, rp, P, &error))) + return error; + else if (n >= sizeof srv->target) + return DNS_EILLEGAL; + + return 0; +} /* dns_srv_parse() */ + + +int dns_srv_push(struct dns_packet *P, struct dns_srv *srv) { + size_t end, len; + int error; + + end = P->end; + + if (P->size - P->end < 2) + goto toolong; + + P->end += 2; + + if (P->size - P->end < 6) + goto toolong; + + P->data[P->end++] = 0xff & (srv->priority >> 8); + P->data[P->end++] = 0xff & (srv->priority >> 0); + + P->data[P->end++] = 0xff & (srv->weight >> 8); + P->data[P->end++] = 0xff & (srv->weight >> 0); + + P->data[P->end++] = 0xff & (srv->port >> 8); + P->data[P->end++] = 0xff & (srv->port >> 0); + + if (0 == (len = dns_d_comp(&P->data[P->end], P->size - P->end, srv->target, strlen(srv->target), P, &error))) + goto error; + else if (P->size - P->end < len) + goto toolong; + + P->end += len; + + if (P->end > 65535) + goto toolong; + + len = P->end - end - 2; + + P->data[end + 0] = 0xff & (len >> 8); + P->data[end + 1] = 0xff & (len >> 0); + + return 0; +toolong: + error = DNS_ENOBUFS; + + /* FALL THROUGH */ +error: + P->end = end; + + return error; +} /* dns_srv_push() */ + + +int dns_srv_cmp(const struct dns_srv *a, const struct dns_srv *b) { + int cmp; + + if ((cmp = a->priority - b->priority)) + return cmp; + + /* + * FIXME: We need some sort of random seed to implement the dynamic + * weighting required by RFC 2782. + */ + if ((cmp = a->weight - b->weight)) + return cmp; + + if ((cmp = a->port - b->port)) + return cmp; + + return strcasecmp(a->target, b->target); +} /* dns_srv_cmp() */ + + +size_t dns_srv_print(void *_dst, size_t lim, struct dns_srv *srv) { + struct dns_buf dst = DNS_B_INTO(_dst, lim); + + dns_b_fmtju(&dst, srv->priority, 0); + dns_b_putc(&dst, ' '); + dns_b_fmtju(&dst, srv->weight, 0); + dns_b_putc(&dst, ' '); + dns_b_fmtju(&dst, srv->port, 0); + dns_b_putc(&dst, ' '); + dns_b_puts(&dst, srv->target); + + return dns_b_strllen(&dst); +} /* dns_srv_print() */ + + +size_t dns_srv_cname(void *dst, size_t lim, struct dns_srv *srv) { + return dns_strlcpy(dst, srv->target, lim); +} /* dns_srv_cname() */ + + +unsigned int dns_opt_ttl(const struct dns_opt *opt) { + unsigned int ttl = 0; + + ttl |= (0xffU & opt->rcode) << 24; + ttl |= (0xffU & opt->version) << 16; + ttl |= (0xffffU & opt->flags) << 0; + + return ttl; +} /* dns_opt_ttl() */ + + +unsigned short dns_opt_class(const struct dns_opt *opt) { + return opt->maxudp; +} /* dns_opt_class() */ + + +struct dns_opt *dns_opt_init(struct dns_opt *opt, size_t size) { + assert(size >= offsetof(struct dns_opt, data)); + + opt->size = size - offsetof(struct dns_opt, data); + opt->len = 0; + + opt->rcode = 0; + opt->version = 0; + opt->maxudp = 0; + + return opt; +} /* dns_opt_init() */ + + +static union dns_any *dns_opt_initany(union dns_any *any, size_t size) { + return dns_opt_init(&any->opt, size), any; +} /* dns_opt_initany() */ + + +int dns_opt_parse(struct dns_opt *opt, struct dns_rr *rr, struct dns_packet *P) { + const struct dns_buf src = DNS_B_FROM(&P->data[rr->rd.p], rr->rd.len); + struct dns_buf dst = DNS_B_INTO(opt->data, opt->size); + int error; + + opt->rcode = 0xfff & ((rr->ttl >> 20) | dns_header(P)->rcode); + opt->version = 0xff & (rr->ttl >> 16); + opt->flags = 0xffff & rr->ttl; + opt->maxudp = 0xffff & rr->class; + + while (src.p < src.pe) { + int code, len; + + if (-1 == (code = dns_b_get16(&src, -1))) + return src.error; + if (-1 == (len = dns_b_get16(&src, -1))) + return src.error; + + switch (code) { + default: + dns_b_put16(&dst, code); + dns_b_put16(&dst, len); + if ((error = dns_b_move(&dst, &src, len))) + return error; + break; + } + } + + return 0; +} /* dns_opt_parse() */ + + +int dns_opt_push(struct dns_packet *P, struct dns_opt *opt) { + const struct dns_buf src = DNS_B_FROM(opt->data, opt->len); + struct dns_buf dst = DNS_B_INTO(&P->data[P->end], (P->size - P->end)); + int error; + + /* rdata length (see below) */ + if ((error = dns_b_put16(&dst, 0))) + goto error; + + /* ... push known options here */ + + /* push opaque option data */ + if ((error = dns_b_move(&dst, &src, (size_t)(src.pe - src.p)))) + goto error; + + /* rdata length */ + if ((error = dns_b_pput16(&dst, dns_b_tell(&dst) - 2, 0))) + goto error; + +#if !DNS_DEBUG_OPT_FORMERR + P->end += dns_b_tell(&dst); +#endif + + return 0; +error: + return error; +} /* dns_opt_push() */ + + +int dns_opt_cmp(const struct dns_opt *a, const struct dns_opt *b) { + (void)a; + (void)b; + + return -1; +} /* dns_opt_cmp() */ + + +size_t dns_opt_print(void *_dst, size_t lim, struct dns_opt *opt) { + struct dns_buf dst = DNS_B_INTO(_dst, lim); + size_t p; + + dns_b_putc(&dst, '"'); + + for (p = 0; p < opt->len; p++) { + dns_b_putc(&dst, '\\'); + dns_b_fmtju(&dst, opt->data[p], 3); + } + + dns_b_putc(&dst, '"'); + + return dns_b_strllen(&dst); +} /* dns_opt_print() */ + + +int dns_ptr_parse(struct dns_ptr *ptr, struct dns_rr *rr, struct dns_packet *P) { + return dns_ns_parse((struct dns_ns *)ptr, rr, P); +} /* dns_ptr_parse() */ + + +int dns_ptr_push(struct dns_packet *P, struct dns_ptr *ptr) { + return dns_ns_push(P, (struct dns_ns *)ptr); +} /* dns_ptr_push() */ + + +size_t dns_ptr_qname(void *dst, size_t lim, int af, void *addr) { + switch (af) { + case AF_INET6: + return dns_aaaa_arpa(dst, lim, addr); + case AF_INET: + return dns_a_arpa(dst, lim, addr); + default: { + struct dns_a a; + a.addr.s_addr = INADDR_NONE; + return dns_a_arpa(dst, lim, &a); + } + } +} /* dns_ptr_qname() */ + + +int dns_ptr_cmp(const struct dns_ptr *a, const struct dns_ptr *b) { + return strcasecmp(a->host, b->host); +} /* dns_ptr_cmp() */ + + +size_t dns_ptr_print(void *dst, size_t lim, struct dns_ptr *ptr) { + return dns_ns_print(dst, lim, (struct dns_ns *)ptr); +} /* dns_ptr_print() */ + + +size_t dns_ptr_cname(void *dst, size_t lim, struct dns_ptr *ptr) { + return dns_strlcpy(dst, ptr->host, lim); +} /* dns_ptr_cname() */ + + +int dns_sshfp_parse(struct dns_sshfp *fp, struct dns_rr *rr, struct dns_packet *P) { + unsigned p = rr->rd.p, pe = rr->rd.p + rr->rd.len; + + if (pe - p < 2) + return DNS_EILLEGAL; + + fp->algo = P->data[p++]; + fp->type = P->data[p++]; + + switch (fp->type) { + case DNS_SSHFP_SHA1: + if (pe - p < sizeof fp->digest.sha1) + return DNS_EILLEGAL; + + memcpy(fp->digest.sha1, &P->data[p], sizeof fp->digest.sha1); + + break; + default: + break; + } /* switch() */ + + return 0; +} /* dns_sshfp_parse() */ + + +int dns_sshfp_push(struct dns_packet *P, struct dns_sshfp *fp) { + unsigned p = P->end, pe = P->size, n; + + if (pe - p < 4) + return DNS_ENOBUFS; + + p += 2; + P->data[p++] = 0xff & fp->algo; + P->data[p++] = 0xff & fp->type; + + switch (fp->type) { + case DNS_SSHFP_SHA1: + if (pe - p < sizeof fp->digest.sha1) + return DNS_ENOBUFS; + + memcpy(&P->data[p], fp->digest.sha1, sizeof fp->digest.sha1); + p += sizeof fp->digest.sha1; + + break; + default: + return DNS_EILLEGAL; + } /* switch() */ + + n = p - P->end - 2; + P->data[P->end++] = 0xff & (n >> 8); + P->data[P->end++] = 0xff & (n >> 0); + P->end = p; + + return 0; +} /* dns_sshfp_push() */ + + +int dns_sshfp_cmp(const struct dns_sshfp *a, const struct dns_sshfp *b) { + int cmp; + + if ((cmp = a->algo - b->algo) || (cmp = a->type - b->type)) + return cmp; + + switch (a->type) { + case DNS_SSHFP_SHA1: + return memcmp(a->digest.sha1, b->digest.sha1, sizeof a->digest.sha1); + default: + return 0; + } /* switch() */ + + /* NOT REACHED */ +} /* dns_sshfp_cmp() */ + + +size_t dns_sshfp_print(void *_dst, size_t lim, struct dns_sshfp *fp) { + static const unsigned char hex[16] = "0123456789abcdef"; + struct dns_buf dst = DNS_B_INTO(_dst, lim); + size_t i; + + dns_b_fmtju(&dst, fp->algo, 0); + dns_b_putc(&dst, ' '); + dns_b_fmtju(&dst, fp->type, 0); + dns_b_putc(&dst, ' '); + + switch (fp->type) { + case DNS_SSHFP_SHA1: + for (i = 0; i < sizeof fp->digest.sha1; i++) { + dns_b_putc(&dst, hex[0x0f & (fp->digest.sha1[i] >> 4)]); + dns_b_putc(&dst, hex[0x0f & (fp->digest.sha1[i] >> 0)]); + } + + break; + default: + dns_b_putc(&dst, '0'); + + break; + } /* switch() */ + + return dns_b_strllen(&dst); +} /* dns_sshfp_print() */ + + +struct dns_txt *dns_txt_init(struct dns_txt *txt, size_t size) { + assert(size > offsetof(struct dns_txt, data)); + + txt->size = size - offsetof(struct dns_txt, data); + txt->len = 0; + + return txt; +} /* dns_txt_init() */ + + +static union dns_any *dns_txt_initany(union dns_any *any, size_t size) { + /* NB: union dns_any is already initialized as struct dns_txt */ + (void)size; + return any; +} /* dns_txt_initany() */ + + +int dns_txt_parse(struct dns_txt *txt, struct dns_rr *rr, struct dns_packet *P) { + struct { unsigned char *b; size_t p, end; } dst, src; + unsigned n; + + dst.b = txt->data; + dst.p = 0; + dst.end = txt->size; + + src.b = P->data; + src.p = rr->rd.p; + src.end = src.p + rr->rd.len; + + while (src.p < src.end) { + n = 0xff & P->data[src.p++]; + + if (src.end - src.p < n || dst.end - dst.p < n) + return DNS_EILLEGAL; + + memcpy(&dst.b[dst.p], &src.b[src.p], n); + + dst.p += n; + src.p += n; + } + + txt->len = dst.p; + + return 0; +} /* dns_txt_parse() */ + + +int dns_txt_push(struct dns_packet *P, struct dns_txt *txt) { + struct { unsigned char *b; size_t p, end; } dst, src; + unsigned n; + + dst.b = P->data; + dst.p = P->end; + dst.end = P->size; + + src.b = txt->data; + src.p = 0; + src.end = txt->len; + + if (dst.end - dst.p < 2) + return DNS_ENOBUFS; + + n = txt->len + ((txt->len + 254) / 255); + + dst.b[dst.p++] = 0xff & (n >> 8); + dst.b[dst.p++] = 0xff & (n >> 0); + + while (src.p < src.end) { + n = DNS_PP_MIN(255, src.end - src.p); + + if (dst.p >= dst.end) + return DNS_ENOBUFS; + + dst.b[dst.p++] = n; + + if (dst.end - dst.p < n) + return DNS_ENOBUFS; + + memcpy(&dst.b[dst.p], &src.b[src.p], n); + + dst.p += n; + src.p += n; + } + + P->end = dst.p; + + return 0; +} /* dns_txt_push() */ + + +int dns_txt_cmp(const struct dns_txt *a, const struct dns_txt *b) { + (void)a; + (void)b; + + return -1; +} /* dns_txt_cmp() */ + + +size_t dns_txt_print(void *_dst, size_t lim, struct dns_txt *txt) { + struct dns_buf src = DNS_B_FROM(txt->data, txt->len); + struct dns_buf dst = DNS_B_INTO(_dst, lim); + unsigned i; + + if (src.p < src.pe) { + do { + dns_b_putc(&dst, '"'); + + for (i = 0; i < 256 && src.p < src.pe; i++, src.p++) { + if (*src.p < 32 || *src.p > 126 || *src.p == '"' || *src.p == '\\') { + dns_b_putc(&dst, '\\'); + dns_b_fmtju(&dst, *src.p, 3); + } else { + dns_b_putc(&dst, *src.p); + } + } + + dns_b_putc(&dst, '"'); + dns_b_putc(&dst, ' '); + } while (src.p < src.pe); + + dns_b_popc(&dst); + } else { + dns_b_putc(&dst, '"'); + dns_b_putc(&dst, '"'); + } + + return dns_b_strllen(&dst); +} /* dns_txt_print() */ + + +/* Some of the function pointers of DNS_RRTYPES are initialized with + * slighlly different functions, thus we can't use prototypes. */ +DNS_PRAGMA_PUSH +#if __clang__ +#pragma clang diagnostic ignored "-Wstrict-prototypes" +#elif DNS_GNUC_PREREQ(4,6,0) +#pragma GCC diagnostic ignored "-Wstrict-prototypes" +#endif + +static const struct dns_rrtype { + enum dns_type type; + const char *name; + union dns_any *(*init)(union dns_any *, size_t); + int (*parse)(); + int (*push)(); + int (*cmp)(); + size_t (*print)(); + size_t (*cname)(); +} dns_rrtypes[] = { + { DNS_T_A, "A", 0, &dns_a_parse, &dns_a_push, &dns_a_cmp, &dns_a_print, 0, }, + { DNS_T_AAAA, "AAAA", 0, &dns_aaaa_parse, &dns_aaaa_push, &dns_aaaa_cmp, &dns_aaaa_print, 0, }, + { DNS_T_MX, "MX", 0, &dns_mx_parse, &dns_mx_push, &dns_mx_cmp, &dns_mx_print, &dns_mx_cname, }, + { DNS_T_NS, "NS", 0, &dns_ns_parse, &dns_ns_push, &dns_ns_cmp, &dns_ns_print, &dns_ns_cname, }, + { DNS_T_CNAME, "CNAME", 0, &dns_cname_parse, &dns_cname_push, &dns_cname_cmp, &dns_cname_print, &dns_cname_cname, }, + { DNS_T_SOA, "SOA", 0, &dns_soa_parse, &dns_soa_push, &dns_soa_cmp, &dns_soa_print, 0, }, + { DNS_T_SRV, "SRV", 0, &dns_srv_parse, &dns_srv_push, &dns_srv_cmp, &dns_srv_print, &dns_srv_cname, }, + { DNS_T_OPT, "OPT", &dns_opt_initany, &dns_opt_parse, &dns_opt_push, &dns_opt_cmp, &dns_opt_print, 0, }, + { DNS_T_PTR, "PTR", 0, &dns_ptr_parse, &dns_ptr_push, &dns_ptr_cmp, &dns_ptr_print, &dns_ptr_cname, }, + { DNS_T_TXT, "TXT", &dns_txt_initany, &dns_txt_parse, &dns_txt_push, &dns_txt_cmp, &dns_txt_print, 0, }, + { DNS_T_SPF, "SPF", &dns_txt_initany, &dns_txt_parse, &dns_txt_push, &dns_txt_cmp, &dns_txt_print, 0, }, + { DNS_T_SSHFP, "SSHFP", 0, &dns_sshfp_parse, &dns_sshfp_push, &dns_sshfp_cmp, &dns_sshfp_print, 0, }, + { DNS_T_AXFR, "AXFR", 0, 0, 0, 0, 0, 0, }, +}; /* dns_rrtypes[] */ + +DNS_PRAGMA_POP /*(-Wstrict-prototypes)*/ + + + +static const struct dns_rrtype *dns_rrtype(enum dns_type type) { + const struct dns_rrtype *t; + + for (t = dns_rrtypes; t < endof(dns_rrtypes); t++) { + if (t->type == type && t->parse) { + return t; + } + } + + return NULL; +} /* dns_rrtype() */ + + +union dns_any *dns_any_init(union dns_any *any, size_t size) { + dns_static_assert(dns_same_type(any->txt, any->rdata, 1), "unexpected rdata type"); + return (union dns_any *)dns_txt_init(&any->rdata, size); +} /* dns_any_init() */ + + +static size_t dns_any_sizeof(union dns_any *any) { + dns_static_assert(dns_same_type(any->txt, any->rdata, 1), "unexpected rdata type"); + return offsetof(struct dns_txt, data) + any->rdata.size; +} /* dns_any_sizeof() */ + +static union dns_any *dns_any_reinit(union dns_any *any, const struct dns_rrtype *t) { + return (t->init)? t->init(any, dns_any_sizeof(any)) : any; +} /* dns_any_reinit() */ + +int dns_any_parse(union dns_any *any, struct dns_rr *rr, struct dns_packet *P) { + const struct dns_rrtype *t; + + if ((t = dns_rrtype(rr->type))) + return t->parse(dns_any_reinit(any, t), rr, P); + + if (rr->rd.len > any->rdata.size) + return DNS_EILLEGAL; + + memcpy(any->rdata.data, &P->data[rr->rd.p], rr->rd.len); + any->rdata.len = rr->rd.len; + + return 0; +} /* dns_any_parse() */ + + +int dns_any_push(struct dns_packet *P, union dns_any *any, enum dns_type type) { + const struct dns_rrtype *t; + + if ((t = dns_rrtype(type))) + return t->push(P, any); + + if (P->size - P->end < any->rdata.len + 2) + return DNS_ENOBUFS; + + P->data[P->end++] = 0xff & (any->rdata.len >> 8); + P->data[P->end++] = 0xff & (any->rdata.len >> 0); + + memcpy(&P->data[P->end], any->rdata.data, any->rdata.len); + P->end += any->rdata.len; + + return 0; +} /* dns_any_push() */ + + +int dns_any_cmp(const union dns_any *a, enum dns_type x, const union dns_any *b, enum dns_type y) { + const struct dns_rrtype *t; + int cmp; + + if ((cmp = x - y)) + return cmp; + + if ((t = dns_rrtype(x))) + return t->cmp(a, b); + + return -1; +} /* dns_any_cmp() */ + + +size_t dns_any_print(void *_dst, size_t lim, union dns_any *any, enum dns_type type) { + const struct dns_rrtype *t; + struct dns_buf src, dst; + + if ((t = dns_rrtype(type))) + return t->print(_dst, lim, any); + + dns_b_from(&src, any->rdata.data, any->rdata.len); + dns_b_into(&dst, _dst, lim); + + dns_b_putc(&dst, '"'); + + while (src.p < src.pe) { + dns_b_putc(&dst, '\\'); + dns_b_fmtju(&dst, *src.p++, 3); + } + + dns_b_putc(&dst, '"'); + + return dns_b_strllen(&dst); +} /* dns_any_print() */ + + +size_t dns_any_cname(void *dst, size_t lim, union dns_any *any, enum dns_type type) { + const struct dns_rrtype *t; + + if ((t = dns_rrtype(type)) && t->cname) + return t->cname(dst, lim, any); + + return 0; +} /* dns_any_cname() */ + + +/* + * E V E N T T R A C I N G R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ +#include <float.h> /* DBL_MANT_DIG */ +#include <inttypes.h> /* PRIu64 */ + +/* for default trace ID generation try to fit in lua_Number, usually double */ +#define DNS_TRACE_ID_BITS DNS_PP_MIN(DBL_MANT_DIG, (sizeof (dns_trace_id_t) * CHAR_BIT)) /* assuming FLT_RADIX == 2 */ +#define DNS_TRACE_ID_MASK (((DNS_TRACE_ID_C(1) << (DNS_TRACE_ID_BITS - 1)) - 1) | (DNS_TRACE_ID_C(1) << (DNS_TRACE_ID_BITS - 1))) +#define DNS_TRACE_ID_PRI PRIu64 + +static inline dns_trace_id_t dns_trace_mkid(void) { + dns_trace_id_t id = 0; + unsigned r; /* return type of dns_random() */ + const size_t id_bit = sizeof id * CHAR_BIT; + const size_t r_bit = sizeof r * CHAR_BIT; + + for (size_t n = 0; n < id_bit; n += r_bit) { + r = dns_random(); + id <<= r_bit; + id |= r; + } + + return DNS_TRACE_ID_MASK & id; +} + +struct dns_trace { + dns_atomic_t refcount; + + FILE *fp; + dns_trace_id_t id; + + struct { + struct dns_trace_cname { + char host[DNS_D_MAXNAME + 1]; + struct sockaddr_storage addr; + } base[4]; + size_t p; + } cnames; +}; + +static void dns_te_initname(struct sockaddr_storage *ss, int fd, int (* STDCALL f)(socket_fd_t, struct sockaddr *, socklen_t *)) { + socklen_t n = sizeof *ss; + + if (0 != f(fd, (struct sockaddr *)ss, &n)) + goto unspec; + + if (n > sizeof *ss) + goto unspec; + + return; +unspec: + memset(ss, '\0', sizeof *ss); + ss->ss_family = AF_UNSPEC; +} + +static void dns_te_initnames(struct sockaddr_storage *local, struct sockaddr_storage *remote, int fd) { + dns_te_initname(local, fd, &getsockname); + dns_te_initname(remote, fd, &getpeername); +} + +static struct dns_trace_event *dns_te_init(struct dns_trace_event *te, int type) { + /* NB: silence valgrind */ + memset(te, '\0', offsetof(struct dns_trace_event, data)); + te->type = type; + return te; +} + +int dns_trace_abi(void) { + return DNS_TRACE_ABI; +} + +struct dns_trace *dns_trace_open(FILE *fp, dns_error_t *error) { + static const struct dns_trace trace_initializer = { .refcount = 1 }; + struct dns_trace *trace; + + if (!(trace = malloc(sizeof *trace))) + goto syerr; + + *trace = trace_initializer; + + if (fp) { + trace->fp = fp; + } else if (!(fp = tmpfile())) { + goto syerr; + } + + trace->id = dns_trace_mkid(); + + return trace; +syerr: + *error = dns_syerr(); + + dns_trace_close(trace); + + return NULL; +} /* dns_trace_open() */ + +void dns_trace_close(struct dns_trace *trace) { + if (!trace || 1 != dns_trace_release(trace)) + return; + + if (trace->fp) + fclose(trace->fp); + free(trace); +} /* dns_trace_close() */ + +dns_refcount_t dns_trace_acquire(struct dns_trace *trace) { + return dns_atomic_fetch_add(&trace->refcount); +} /* dns_trace_acquire() */ + +static struct dns_trace *dns_trace_acquire_p(struct dns_trace *trace) { + return (trace)? dns_trace_acquire(trace), trace : NULL; +} /* dns_trace_acquire_p() */ + +dns_refcount_t dns_trace_release(struct dns_trace *trace) { + return dns_atomic_fetch_sub(&trace->refcount); +} /* dns_trace_release() */ + +dns_trace_id_t dns_trace_id(struct dns_trace *trace) { + return trace->id; +} /* dns_trace_id() */ + +dns_trace_id_t dns_trace_setid(struct dns_trace *trace, dns_trace_id_t id) { + trace->id = (id)? id : dns_trace_mkid(); + return trace->id; +} /* dns_trace_setid() */ + +struct dns_trace_event *dns_trace_get(struct dns_trace *trace, struct dns_trace_event **tp, dns_error_t *error) { + return dns_trace_fget(tp, trace->fp, error); +} /* dns_trace_get() */ + +dns_error_t dns_trace_put(struct dns_trace *trace, const struct dns_trace_event *te, const void *data, size_t datasize) { + return dns_trace_fput(te, data, datasize, trace->fp); +} /* dns_trace_put() */ + +struct dns_trace_event *dns_trace_tag(struct dns_trace *trace, struct dns_trace_event *te) { + struct timeval tv; + + te->id = trace->id; + gettimeofday(&tv, NULL); + dns_tv2ts(&te->ts, &tv); + te->abi = DNS_TRACE_ABI; + + return te; +} /* dns_trace_tag() */ + +static dns_error_t dns_trace_tag_and_put(struct dns_trace *trace, struct dns_trace_event *te, const void *data, size_t datasize) { + return dns_trace_put(trace, dns_trace_tag(trace, te), data, datasize); +} /* dns_trace_tag_and_put() */ + +struct dns_trace_event *dns_trace_fget(struct dns_trace_event **tp, FILE *fp, dns_error_t *error) { + const size_t headsize = offsetof(struct dns_trace_event, data); + struct dns_trace_event tmp, *te; + size_t n; + + errno = 0; + if (!(n = fread(&tmp, 1, headsize, fp))) + goto none; + if (n < offsetof(struct dns_trace_event, data)) + goto some; + + if (!(te = realloc(*tp, DNS_PP_MAX(headsize, tmp.size)))) { + *error = errno; + return NULL; + } + + *tp = te; + memcpy(te, &tmp, offsetof(struct dns_trace_event, data)); + + if (dns_te_datasize(te)) { + errno = 0; + if (!(n = fread(te->data, 1, dns_te_datasize(te), fp))) + goto none; + if (n < dns_te_datasize(te)) + goto some; + } + + return te; +none: + *error = (ferror(fp))? errno : 0; + return NULL; +some: + *error = 0; + return NULL; +} + +dns_error_t dns_trace_fput(const struct dns_trace_event *te, const void *data, size_t datasize, FILE *fp) { + size_t headsize = offsetof(struct dns_trace_event, data); + struct dns_trace_event tmp; + + memcpy(&tmp, te, headsize); + tmp.size = headsize + datasize; + + /* NB: ignore seek error as fp might not point to a regular file */ + (void)fseek(fp, 0, SEEK_END); + + if (fwrite(&tmp, 1, headsize, fp) < headsize) + return errno; + if (data) + if (fwrite(data, 1, datasize, fp) < datasize) + return errno; + if (fflush(fp)) + return errno; + + return 0; +} + +static void dns_trace_setcname(struct dns_trace *trace, const char *host, const struct sockaddr *addr) { + struct dns_trace_cname *cname; + if (!trace || !trace->fp) + return; + + cname = &trace->cnames.base[trace->cnames.p]; + dns_strlcpy(cname->host, host, sizeof cname->host); + memcpy(&cname->addr, addr, DNS_PP_MIN(dns_sa_len(addr), sizeof cname->addr)); + + trace->cnames.p = (trace->cnames.p + 1) % lengthof(trace->cnames.base); +} + +static const char *dns_trace_cname(struct dns_trace *trace, const struct sockaddr *addr) { + if (!trace || !trace->fp) + return NULL; + + /* NB: start search from the write cursor to */ + for (const struct dns_trace_cname *cname = trace->cnames.base; cname < endof(trace->cnames.base); cname++) { + if (0 == dns_sa_cmp((struct sockaddr *)addr, (struct sockaddr *)&cname->addr)) + return cname->host; + } + + return NULL; +} + +static void dns_trace_res_submit(struct dns_trace *trace, const char *qname, enum dns_type qtype, enum dns_class qclass, int error) { + struct dns_trace_event te; + if (!trace || !trace->fp) + return; + + dns_te_init(&te, DNS_TE_RES_SUBMIT); + dns_strlcpy(te.res_submit.qname, qname, sizeof te.res_submit.qname); + te.res_submit.qtype = qtype; + te.res_submit.qclass = qclass; + te.res_submit.error = error; + dns_trace_tag_and_put(trace, &te, NULL, 0); +} + +static void dns_trace_res_fetch(struct dns_trace *trace, const struct dns_packet *packet, int error) { + struct dns_trace_event te; + const void *data; + size_t datasize; + if (!trace || !trace->fp) + return; + + dns_te_init(&te, DNS_TE_RES_FETCH); + data = (packet)? packet->data : NULL; + datasize = (packet)? packet->end : 0; + te.res_fetch.error = error; + dns_trace_tag_and_put(trace, &te, data, datasize); +} + +static void dns_trace_so_submit(struct dns_trace *trace, const struct dns_packet *packet, const struct sockaddr *haddr, int error) { + struct dns_trace_event te; + const char *cname; + if (!trace || !trace->fp) + return; + + dns_te_init(&te, DNS_TE_SO_SUBMIT); + memcpy(&te.so_submit.haddr, haddr, DNS_PP_MIN(dns_sa_len(haddr), sizeof te.so_submit.haddr)); + if ((cname = dns_trace_cname(trace, haddr))) + dns_strlcpy(te.so_submit.hname, cname, sizeof te.so_submit.hname); + te.so_submit.error = error; + dns_trace_tag_and_put(trace, &te, packet->data, packet->end); +} + +static void dns_trace_so_verify(struct dns_trace *trace, const struct dns_packet *packet, int error) { + struct dns_trace_event te; + if (!trace || !trace->fp) + return; + + dns_te_init(&te, DNS_TE_SO_VERIFY); + te.so_verify.error = error; + dns_trace_tag_and_put(trace, &te, packet->data, packet->end); +} + +static void dns_trace_so_fetch(struct dns_trace *trace, const struct dns_packet *packet, int error) { + struct dns_trace_event te; + const void *data; + size_t datasize; + if (!trace || !trace->fp) + return; + + dns_te_init(&te, DNS_TE_SO_FETCH); + data = (packet)? packet->data : NULL; + datasize = (packet)? packet->end : 0; + te.so_fetch.error = error; + dns_trace_tag_and_put(trace, &te, data, datasize); +} + +static void dns_trace_sys_connect(struct dns_trace *trace, int fd, int socktype, const struct sockaddr *dst, int error) { + struct dns_trace_event te; + if (!trace || !trace->fp) + return; + + dns_te_init(&te, DNS_TE_SYS_CONNECT); + dns_te_initname(&te.sys_connect.src, fd, &getsockname); + memcpy(&te.sys_connect.dst, dst, DNS_PP_MIN(dns_sa_len(dst), sizeof te.sys_connect.dst)); + te.sys_connect.socktype = socktype; + te.sys_connect.error = error; + dns_trace_tag_and_put(trace, &te, NULL, 0); +} + +static void dns_trace_sys_send(struct dns_trace *trace, int fd, int socktype, const void *data, size_t datasize, int error) { + struct dns_trace_event te; + if (!trace || !trace->fp) + return; + + dns_te_init(&te, DNS_TE_SYS_SEND); + dns_te_initnames(&te.sys_send.src, &te.sys_send.dst, fd); + te.sys_send.socktype = socktype; + te.sys_send.error = error; + dns_trace_tag_and_put(trace, &te, data, datasize); +} + +static void dns_trace_sys_recv(struct dns_trace *trace, int fd, int socktype, const void *data, size_t datasize, int error) { + struct dns_trace_event te; + if (!trace || !trace->fp) + return; + + dns_te_init(&te, DNS_TE_SYS_RECV); + dns_te_initnames(&te.sys_recv.dst, &te.sys_recv.src, fd); + te.sys_recv.socktype = socktype; + te.sys_recv.error = error; + dns_trace_tag_and_put(trace, &te, data, datasize); +} + +static dns_error_t dns_trace_dump_packet(struct dns_trace *trace, const char *prefix, const unsigned char *data, size_t datasize, FILE *fp) { + struct dns_packet *packet = NULL; + char *line = NULL, *p; + size_t size = 1, skip = 0; + struct dns_rr_i records; + struct dns_p_lines_i lines; + size_t len, count; + int error; + + if (!(packet = dns_p_make(datasize, &error))) + goto error; + + memcpy(packet->data, data, datasize); + packet->end = datasize; + (void)dns_p_study(packet); +resize: + if (!(p = dns_reallocarray(line, size, 2, &error))) + goto error; + line = p; + size *= 2; + + memset(&records, 0, sizeof records); + memset(&lines, 0, sizeof lines); + count = 0; + + while ((len = dns_p_lines(line, size, &error, packet, &records, &lines))) { + if (!(len < size)) { + skip = count; + goto resize; + } else if (skip <= count) { + fputs(prefix, fp); + fwrite(line, 1, len, fp); + } + count++; + } + + if (error) + goto error; + + error = 0; +error: + free(line); + dns_p_free(packet); + + return error; +} + +static dns_error_t dns_trace_dump_data(struct dns_trace *trace, const char *prefix, const unsigned char *data, size_t datasize, FILE *fp) { + struct dns_hxd_lines_i lines = { 0 }; + char line[128]; + size_t len; + + while ((len = dns_hxd_lines(line, sizeof line, data, datasize, &lines))) { + if (len >= sizeof line) + return EOVERFLOW; /* shouldn't be possible */ + fputs(prefix, fp); + fwrite(line, 1, len, fp); + } + + return 0; +} + +static dns_error_t dns_trace_dump_addr(struct dns_trace *trace, const char *prefix, const struct sockaddr_storage *ss, FILE *fp) { + const void *addr; + const char *path; + socklen_t len; + int error; + + if ((addr = dns_sa_addr(ss->ss_family, (struct sockaddr *)ss, NULL))) { + char ip[INET6_ADDRSTRLEN + 1]; + + if ((error = dns_ntop(ss->ss_family, addr, ip, sizeof ip))) + return error; + fprintf(fp, "%s%s\n", prefix, ip); + } else if ((path = dns_sa_path((struct sockaddr *)ss, &len))) { + fprintf(fp, "%sunix:%.*s", prefix, (int)len, path); + } else { + return EINVAL; + } + + return 0; +} + +static dns_error_t dns_trace_dump_meta(struct dns_trace *trace, const char *prefix, const struct dns_trace_event *te, dns_microseconds_t elapsed, FILE *fp) { + char time_s[48], elapsed_s[48]; + + dns_utime_print(time_s, sizeof time_s, dns_ts2us(&te->ts, 0)); + dns_utime_print(elapsed_s, sizeof elapsed_s, elapsed); + + fprintf(fp, "%sid: %"DNS_TRACE_ID_PRI"\n", prefix, te->id); + fprintf(fp, "%sts: %s (%s)\n", prefix, time_s, elapsed_s); + fprintf(fp, "%sabi: 0x%x (0x%x)\n", prefix, te->abi, DNS_TRACE_ABI); + return 0; +} + +static dns_error_t dns_trace_dump_error(struct dns_trace *trace, const char *prefix, int error, FILE *fp) { + fprintf(fp, "%s%d (%s)\n", prefix, error, (error)? dns_strerror(error) : "none"); + return 0; +} + +dns_error_t dns_trace_dump(struct dns_trace *trace, FILE *fp) { + struct dns_trace_event *te = NULL; + struct { + dns_trace_id_t id; + dns_microseconds_t begin, elapsed; + } state = { 0 }; + int error; + char __dst[DNS_STRMAXLEN + 1] = { 0 }; + + if (!trace || !trace->fp) + return EINVAL; + + if (0 != fseek(trace->fp, 0, SEEK_SET)) + goto syerr; + + while (dns_trace_fget(&te, trace->fp, &error)) { + size_t datasize = dns_te_datasize(te); + const unsigned char *data = (datasize)? te->data : NULL; + + if (state.id != te->id) { + state.id = te->id; + state.begin = dns_ts2us(&te->ts, 0); + } + dns_time_diff(&state.elapsed, dns_ts2us(&te->ts, 0), state.begin); + + switch(te->type) { + case DNS_TE_RES_SUBMIT: + fprintf(fp, "dns_res_submit:\n"); + dns_trace_dump_meta(trace, " ", te, state.elapsed, fp); + fprintf(fp, " qname: %s\n", te->res_submit.qname); + fprintf(fp, " qtype: %s\n", dns_strtype(te->res_submit.qtype, __dst)); + fprintf(fp, " qclass: %s\n", dns_strclass(te->res_submit.qclass, __dst)); + dns_trace_dump_error(trace, " error: ", te->res_submit.error, fp); + break; + case DNS_TE_RES_FETCH: + fprintf(fp, "dns_res_fetch:\n"); + dns_trace_dump_meta(trace, " ", te, state.elapsed, fp); + dns_trace_dump_error(trace, " error: ", te->res_fetch.error, fp); + + if (data) { + fprintf(fp, " packet: |\n"); + if ((error = dns_trace_dump_packet(trace, " ", data, datasize, fp))) + goto error; + fprintf(fp, " data: |\n"); + if ((error = dns_trace_dump_data(trace, " ", data, datasize, fp))) + goto error; + } + + break; + case DNS_TE_SO_SUBMIT: + fprintf(fp, "dns_so_submit:\n"); + dns_trace_dump_meta(trace, " ", te, state.elapsed, fp); + fprintf(fp, " hname: %s\n", te->so_submit.hname); + dns_trace_dump_addr(trace, " haddr: ", &te->so_submit.haddr, fp); + dns_trace_dump_error(trace, " error: ", te->so_submit.error, fp); + + if (data) { + fprintf(fp, " packet: |\n"); + if ((error = dns_trace_dump_packet(trace, " ", data, datasize, fp))) + goto error; + fprintf(fp, " data: |\n"); + if ((error = dns_trace_dump_data(trace, " ", data, datasize, fp))) + goto error; + } + + break; + case DNS_TE_SO_VERIFY: + fprintf(fp, "dns_so_verify:\n"); + dns_trace_dump_meta(trace, " ", te, state.elapsed, fp); + dns_trace_dump_error(trace, " error: ", te->so_verify.error, fp); + + if (data) { + fprintf(fp, " packet: |\n"); + if ((error = dns_trace_dump_packet(trace, " ", data, datasize, fp))) + goto error; + fprintf(fp, " data: |\n"); + if ((error = dns_trace_dump_data(trace, " ", data, datasize, fp))) + goto error; + } + + break; + case DNS_TE_SO_FETCH: + fprintf(fp, "dns_so_fetch:\n"); + dns_trace_dump_meta(trace, " ", te, state.elapsed, fp); + dns_trace_dump_error(trace, " error: ", te->so_fetch.error, fp); + + if (data) { + fprintf(fp, " packet: |\n"); + if ((error = dns_trace_dump_packet(trace, " ", data, datasize, fp))) + goto error; + fprintf(fp, " data: |\n"); + if ((error = dns_trace_dump_data(trace, " ", data, datasize, fp))) + goto error; + } + + break; + case DNS_TE_SYS_CONNECT: { + int socktype = te->sys_connect.socktype; + fprintf(fp, "dns_sys_connect:\n"); + dns_trace_dump_meta(trace, " ", te, state.elapsed, fp); + dns_trace_dump_addr(trace, " src: ", &te->sys_connect.src, fp); + dns_trace_dump_addr(trace, " dst: ", &te->sys_connect.dst, fp); + fprintf(fp, " socktype: %d (%s)\n", socktype, ((socktype == SOCK_STREAM)? "SOCK_STREAM" : (socktype == SOCK_DGRAM)? "SOCK_DGRAM" : "?")); + dns_trace_dump_error(trace, " error: ", te->sys_connect.error, fp); + + break; + } + case DNS_TE_SYS_SEND: { + int socktype = te->sys_send.socktype; + fprintf(fp, "dns_sys_send:\n"); + dns_trace_dump_meta(trace, " ", te, state.elapsed, fp); + dns_trace_dump_addr(trace, " src: ", &te->sys_send.src, fp); + dns_trace_dump_addr(trace, " dst: ", &te->sys_send.dst, fp); + fprintf(fp, " socktype: %d (%s)\n", socktype, ((socktype == SOCK_STREAM)? "SOCK_STREAM" : (socktype == SOCK_DGRAM)? "SOCK_DGRAM" : "?")); + dns_trace_dump_error(trace, " error: ", te->sys_send.error, fp); + + if (data) { + fprintf(fp, " data: |\n"); + if ((error = dns_trace_dump_data(trace, " ", data, datasize, fp))) + goto error; + } + + break; + } + case DNS_TE_SYS_RECV: { + int socktype = te->sys_recv.socktype; + fprintf(fp, "dns_sys_recv:\n"); + dns_trace_dump_meta(trace, " ", te, state.elapsed, fp); + dns_trace_dump_addr(trace, " src: ", &te->sys_recv.src, fp); + dns_trace_dump_addr(trace, " dst: ", &te->sys_recv.dst, fp); + fprintf(fp, " socktype: %d (%s)\n", socktype, ((socktype == SOCK_STREAM)? "SOCK_STREAM" : (socktype == SOCK_DGRAM)? "SOCK_DGRAM" : "?")); + dns_trace_dump_error(trace, " error: ", te->sys_recv.error, fp); + + if (data) { + fprintf(fp, " data: |\n"); + if ((error = dns_trace_dump_data(trace, " ", data, datasize, fp))) + goto error; + } + + break; + } + default: + fprintf(fp, "unknown(0x%.2x):\n", te->type); + dns_trace_dump_meta(trace, " ", te, state.elapsed, fp); + + if (data) { + fprintf(fp, " data: |\n"); + if ((error = dns_trace_dump_data(trace, " ", data, datasize, fp))) + goto error; + } + + break; + } + } + + goto epilog; +syerr: + error = errno; +error: + (void)0; +epilog: + free(te); + + return error; +} + +/* + * H O S T S R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +struct dns_hosts { + struct dns_hosts_entry { + char host[DNS_D_MAXNAME + 1]; + char arpa[73 + 1]; + + int af; + + union { + struct in_addr a4; + struct in6_addr a6; + } addr; + + _Bool alias; + + struct dns_hosts_entry *next; + } *head, **tail; + + dns_atomic_t refcount; +}; /* struct dns_hosts */ + + +struct dns_hosts *dns_hosts_open(int *error) { + static const struct dns_hosts hosts_initializer = { .refcount = 1 }; + struct dns_hosts *hosts; + + if (!(hosts = malloc(sizeof *hosts))) + goto syerr; + + *hosts = hosts_initializer; + + hosts->tail = &hosts->head; + + return hosts; +syerr: + *error = dns_syerr(); + + free(hosts); + + return 0; +} /* dns_hosts_open() */ + + +void dns_hosts_close(struct dns_hosts *hosts) { + struct dns_hosts_entry *ent, *xnt; + + if (!hosts || 1 != dns_hosts_release(hosts)) + return; + + for (ent = hosts->head; ent; ent = xnt) { + xnt = ent->next; + + free(ent); + } + + free(hosts); + + return; +} /* dns_hosts_close() */ + + +dns_refcount_t dns_hosts_acquire(struct dns_hosts *hosts) { + return dns_atomic_fetch_add(&hosts->refcount); +} /* dns_hosts_acquire() */ + + +dns_refcount_t dns_hosts_release(struct dns_hosts *hosts) { + return dns_atomic_fetch_sub(&hosts->refcount); +} /* dns_hosts_release() */ + + +struct dns_hosts *dns_hosts_mortal(struct dns_hosts *hosts) { + if (hosts) + dns_hosts_release(hosts); + + return hosts; +} /* dns_hosts_mortal() */ + + +struct dns_hosts *dns_hosts_local(int *error_) { + struct dns_hosts *hosts; + int error; + + if (!(hosts = dns_hosts_open(&error))) + goto error; + + if ((error = dns_hosts_loadpath(hosts, "/etc/hosts"))) + goto error; + + return hosts; +error: + *error_ = error; + + dns_hosts_close(hosts); + + return 0; +} /* dns_hosts_local() */ + + +#define dns_hosts_issep(ch) (dns_isspace(ch)) +#define dns_hosts_iscom(ch) ((ch) == '#' || (ch) == ';') + +int dns_hosts_loadfile(struct dns_hosts *hosts, FILE *fp) { + struct dns_hosts_entry ent; + char word[DNS_PP_MAX(INET6_ADDRSTRLEN, DNS_D_MAXNAME) + 1]; + unsigned wp, wc, skip; + int ch, error; + + rewind(fp); + + do { + memset(&ent, '\0', sizeof ent); + wc = 0; + skip = 0; + + do { + memset(word, '\0', sizeof word); + wp = 0; + + while (EOF != (ch = fgetc(fp)) && ch != '\n') { + skip |= !!dns_hosts_iscom(ch); + + if (skip) + continue; + + if (dns_hosts_issep(ch)) + break; + + if (wp < sizeof word - 1) + word[wp] = ch; + wp++; + } + + if (!wp) + continue; + + wc++; + + switch (wc) { + case 0: + break; + case 1: + ent.af = (strchr(word, ':'))? AF_INET6 : AF_INET; + skip = (1 != dns_inet_pton(ent.af, word, &ent.addr)); + + break; + default: + if (!wp) + break; + + dns_d_anchor(ent.host, sizeof ent.host, word, wp); + + if ((error = dns_hosts_insert(hosts, ent.af, &ent.addr, ent.host, (wc > 2)))) + return error; + + break; + } /* switch() */ + } while (ch != EOF && ch != '\n'); + } while (ch != EOF); + + return 0; +} /* dns_hosts_loadfile() */ + + +int dns_hosts_loadpath(struct dns_hosts *hosts, const char *path) { + FILE *fp; + int error; + + if (!(fp = dns_fopen(path, "rt", &error))) + return error; + + error = dns_hosts_loadfile(hosts, fp); + + fclose(fp); + + return error; +} /* dns_hosts_loadpath() */ + + +int dns_hosts_dump(struct dns_hosts *hosts, FILE *fp) { + struct dns_hosts_entry *ent, *xnt; + char addr[INET6_ADDRSTRLEN + 1]; + unsigned i; + + for (ent = hosts->head; ent; ent = xnt) { + xnt = ent->next; + + dns_inet_ntop(ent->af, &ent->addr, addr, sizeof addr); + + fputs(addr, fp); + + for (i = strlen(addr); i < INET_ADDRSTRLEN; i++) + fputc(' ', fp); + + fputc(' ', fp); + + fputs(ent->host, fp); + fputc('\n', fp); + } + + return 0; +} /* dns_hosts_dump() */ + + +int dns_hosts_insert(struct dns_hosts *hosts, int af, const void *addr, const void *host, _Bool alias) { + struct dns_hosts_entry *ent; + int error; + + if (!(ent = malloc(sizeof *ent))) + goto syerr; + + dns_d_anchor(ent->host, sizeof ent->host, host, strlen(host)); + + switch ((ent->af = af)) { + case AF_INET6: + memcpy(&ent->addr.a6, addr, sizeof ent->addr.a6); + + dns_aaaa_arpa(ent->arpa, sizeof ent->arpa, addr); + + break; + case AF_INET: + memcpy(&ent->addr.a4, addr, sizeof ent->addr.a4); + + dns_a_arpa(ent->arpa, sizeof ent->arpa, addr); + + break; + default: + error = EINVAL; + + goto error; + } /* switch() */ + + ent->alias = alias; + + ent->next = 0; + *hosts->tail = ent; + hosts->tail = &ent->next; + + return 0; +syerr: + error = dns_syerr(); +error: + free(ent); + + return error; +} /* dns_hosts_insert() */ + + +struct dns_packet *dns_hosts_query(struct dns_hosts *hosts, struct dns_packet *Q, int *error_) { + union { unsigned char b[dns_p_calcsize((512))]; struct dns_packet p; } P_instance = { 0 }; + struct dns_packet *P = dns_p_init(&P_instance.p, 512); + struct dns_packet *A = 0; + struct dns_rr rr; + struct dns_hosts_entry *ent; + int error, af; + char qname[DNS_D_MAXNAME + 1]; + size_t qlen; + + if ((error = dns_rr_parse(&rr, 12, Q))) + goto error; + + if (!(qlen = dns_d_expand(qname, sizeof qname, rr.dn.p, Q, &error))) + goto error; + else if (qlen >= sizeof qname) + goto toolong; + + if ((error = dns_p_push(P, DNS_S_QD, qname, qlen, rr.type, rr.class, 0, 0))) + goto error; + + switch (rr.type) { + case DNS_T_PTR: + for (ent = hosts->head; ent; ent = ent->next) { + if (ent->alias || 0 != strcasecmp(qname, ent->arpa)) + continue; + + if ((error = dns_p_push(P, DNS_S_AN, qname, qlen, rr.type, rr.class, 0, ent->host))) + goto error; + } + + break; + case DNS_T_AAAA: + af = AF_INET6; + + goto loop; + case DNS_T_A: + af = AF_INET; + +loop: for (ent = hosts->head; ent; ent = ent->next) { + if (ent->af != af || 0 != strcasecmp(qname, ent->host)) + continue; + + if ((error = dns_p_push(P, DNS_S_AN, qname, qlen, rr.type, rr.class, 0, &ent->addr))) + goto error; + } + + break; + default: + break; + } /* switch() */ + + + if (!(A = dns_p_copy(dns_p_make(P->end, &error), P))) + goto error; + + return A; +toolong: + error = DNS_EILLEGAL; +error: + *error_ = error; + + dns_p_free(A); + + return 0; +} /* dns_hosts_query() */ + + +/* + * R E S O L V . C O N F R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +struct dns_resolv_conf *dns_resconf_open(int *error) { + static const struct dns_resolv_conf resconf_initializer = { + .lookup = "bf", + .family = { AF_INET, AF_INET6 }, + .options = { .ndots = 1, .timeout = 5, .attempts = 2, .tcp = DNS_RESCONF_TCP_ENABLE, }, + .iface = { .ss_family = AF_INET }, + }; + struct dns_resolv_conf *resconf; + struct sockaddr_in *sin; + + if (!(resconf = malloc(sizeof *resconf))) + goto syerr; + + *resconf = resconf_initializer; + + sin = (struct sockaddr_in *)&resconf->nameserver[0]; + sin->sin_family = AF_INET; + sin->sin_addr.s_addr = INADDR_ANY; + sin->sin_port = htons(53); +#if defined(SA_LEN) + sin->sin_len = sizeof *sin; +#endif + + if (0 != gethostname(resconf->search[0], sizeof resconf->search[0])) + goto syerr; + + /* + * If gethostname() returned a string without any label + * separator, then search[0][0] should be NUL. + */ + if (strchr (resconf->search[0], '.')) { + dns_d_anchor(resconf->search[0], sizeof resconf->search[0], resconf->search[0], strlen(resconf->search[0])); + dns_d_cleave(resconf->search[0], sizeof resconf->search[0], resconf->search[0], strlen(resconf->search[0])); + } else { + memset (resconf->search[0], 0, sizeof resconf->search[0]); + } + + dns_resconf_acquire(resconf); + + return resconf; +syerr: + *error = dns_syerr(); + + free(resconf); + + return 0; +} /* dns_resconf_open() */ + + +void dns_resconf_close(struct dns_resolv_conf *resconf) { + if (!resconf || 1 != dns_resconf_release(resconf)) + return /* void */; + + free(resconf); +} /* dns_resconf_close() */ + + +dns_refcount_t dns_resconf_acquire(struct dns_resolv_conf *resconf) { + return dns_atomic_fetch_add(&resconf->_.refcount); +} /* dns_resconf_acquire() */ + + +dns_refcount_t dns_resconf_release(struct dns_resolv_conf *resconf) { + return dns_atomic_fetch_sub(&resconf->_.refcount); +} /* dns_resconf_release() */ + + +struct dns_resolv_conf *dns_resconf_mortal(struct dns_resolv_conf *resconf) { + if (resconf) + dns_resconf_release(resconf); + + return resconf; +} /* dns_resconf_mortal() */ + + +struct dns_resolv_conf *dns_resconf_local(int *error_) { + struct dns_resolv_conf *resconf; + int error; + + if (!(resconf = dns_resconf_open(&error))) + goto error; + + if ((error = dns_resconf_loadpath(resconf, "/etc/resolv.conf"))) { + /* + * NOTE: Both the glibc and BIND9 resolvers ignore a missing + * /etc/resolv.conf, defaulting to a nameserver of + * 127.0.0.1. See also dns_hints_insert_resconf, and the + * default initialization of nameserver[0] in + * dns_resconf_open. + */ + if (error != ENOENT) + goto error; + } + + if ((error = dns_nssconf_loadpath(resconf, "/etc/nsswitch.conf"))) { + if (error != ENOENT) + goto error; + } + + return resconf; +error: + *error_ = error; + + dns_resconf_close(resconf); + + return 0; +} /* dns_resconf_local() */ + + +struct dns_resolv_conf *dns_resconf_root(int *error) { + struct dns_resolv_conf *resconf; + + if ((resconf = dns_resconf_local(error))) + resconf->options.recurse = 1; + + return resconf; +} /* dns_resconf_root() */ + + +static time_t dns_resconf_timeout(const struct dns_resolv_conf *resconf) { + return (time_t)DNS_PP_MIN(INT_MAX, resconf->options.timeout); +} /* dns_resconf_timeout() */ + + +enum dns_resconf_keyword { + DNS_RESCONF_NAMESERVER, + DNS_RESCONF_DOMAIN, + DNS_RESCONF_SEARCH, + DNS_RESCONF_LOOKUP, + DNS_RESCONF_FILE, + DNS_RESCONF_BIND, + DNS_RESCONF_CACHE, + DNS_RESCONF_FAMILY, + DNS_RESCONF_INET4, + DNS_RESCONF_INET6, + DNS_RESCONF_OPTIONS, + DNS_RESCONF_EDNS0, + DNS_RESCONF_NDOTS, + DNS_RESCONF_TIMEOUT, + DNS_RESCONF_ATTEMPTS, + DNS_RESCONF_ROTATE, + DNS_RESCONF_RECURSE, + DNS_RESCONF_SMART, + DNS_RESCONF_TCP, + DNS_RESCONF_TCPx, + DNS_RESCONF_INTERFACE, + DNS_RESCONF_ZERO, + DNS_RESCONF_ONE, + DNS_RESCONF_ENABLE, + DNS_RESCONF_ONLY, + DNS_RESCONF_DISABLE, +}; /* enum dns_resconf_keyword */ + +static enum dns_resconf_keyword dns_resconf_keyword(const char *word) { + static const char *words[] = { + [DNS_RESCONF_NAMESERVER] = "nameserver", + [DNS_RESCONF_DOMAIN] = "domain", + [DNS_RESCONF_SEARCH] = "search", + [DNS_RESCONF_LOOKUP] = "lookup", + [DNS_RESCONF_FILE] = "file", + [DNS_RESCONF_BIND] = "bind", + [DNS_RESCONF_CACHE] = "cache", + [DNS_RESCONF_FAMILY] = "family", + [DNS_RESCONF_INET4] = "inet4", + [DNS_RESCONF_INET6] = "inet6", + [DNS_RESCONF_OPTIONS] = "options", + [DNS_RESCONF_EDNS0] = "edns0", + [DNS_RESCONF_ROTATE] = "rotate", + [DNS_RESCONF_RECURSE] = "recurse", + [DNS_RESCONF_SMART] = "smart", + [DNS_RESCONF_TCP] = "tcp", + [DNS_RESCONF_INTERFACE] = "interface", + [DNS_RESCONF_ZERO] = "0", + [DNS_RESCONF_ONE] = "1", + [DNS_RESCONF_ENABLE] = "enable", + [DNS_RESCONF_ONLY] = "only", + [DNS_RESCONF_DISABLE] = "disable", + }; + unsigned i; + + for (i = 0; i < lengthof(words); i++) { + if (words[i] && 0 == strcasecmp(words[i], word)) + return i; + } + + if (0 == strncasecmp(word, "ndots:", sizeof "ndots:" - 1)) + return DNS_RESCONF_NDOTS; + + if (0 == strncasecmp(word, "timeout:", sizeof "timeout:" - 1)) + return DNS_RESCONF_TIMEOUT; + + if (0 == strncasecmp(word, "attempts:", sizeof "attempts:" - 1)) + return DNS_RESCONF_ATTEMPTS; + + if (0 == strncasecmp(word, "tcp:", sizeof "tcp:" - 1)) + return DNS_RESCONF_TCPx; + + return -1; +} /* dns_resconf_keyword() */ + + +/** OpenBSD-style "[1.2.3.4]:53" nameserver syntax */ +int dns_resconf_pton(struct sockaddr_storage *ss, const char *src) { + struct { char buf[128], *p; } addr = { "", addr.buf }; + unsigned short port = 0; + int ch, af = AF_INET, error; + + memset(ss, 0, sizeof *ss); + while ((ch = *src++)) { + switch (ch) { + case ' ': + /* FALL THROUGH */ + case '\t': + break; + case '[': + break; + case ']': + while ((ch = *src++)) { + if (dns_isdigit(ch)) { + port *= 10; + port += ch - '0'; + } + } + + goto inet; + case ':': + af = AF_INET6; + + /* FALL THROUGH */ + default: + if (addr.p < endof(addr.buf) - 1) + *addr.p++ = ch; + + break; + } /* switch() */ + } /* while() */ +inet: + + if ((error = dns_pton(af, addr.buf, dns_sa_addr(af, ss, NULL)))) + return error; + + port = (!port)? 53 : port; + *dns_sa_port(af, ss) = htons(port); + dns_sa_family(ss) = af; + + return 0; +} /* dns_resconf_pton() */ + +#define dns_resconf_issep(ch) (dns_isspace(ch) || (ch) == ',') +#define dns_resconf_iscom(ch) ((ch) == '#' || (ch) == ';') + +int dns_resconf_loadfile(struct dns_resolv_conf *resconf, FILE *fp) { + unsigned sa_count = 0; + char words[6][DNS_D_MAXNAME + 1]; + unsigned wp, wc, i, j, n; + int ch, error; + + rewind(fp); + + do { + memset(words, '\0', sizeof words); + wp = 0; + wc = 0; + + while (EOF != (ch = getc(fp)) && ch != '\n') { + if (dns_resconf_issep(ch)) { + if (wp > 0) { + wp = 0; + + if (++wc >= lengthof(words)) + goto skip; + } + } else if (dns_resconf_iscom(ch)) { +skip: + do { + ch = getc(fp); + } while (ch != EOF && ch != '\n'); + + break; + } else if (wp < sizeof words[wc] - 1) { + words[wc][wp++] = ch; + } else { + wp = 0; /* drop word */ + goto skip; + } + } + + if (wp > 0) + wc++; + + if (wc < 2) + continue; + + switch (dns_resconf_keyword(words[0])) { + case DNS_RESCONF_NAMESERVER: + if (sa_count >= lengthof(resconf->nameserver)) + continue; + + if ((error = dns_resconf_pton(&resconf->nameserver[sa_count], words[1]))) + continue; + + sa_count++; + + break; + case DNS_RESCONF_DOMAIN: + case DNS_RESCONF_SEARCH: + memset(resconf->search, '\0', sizeof resconf->search); + + for (i = 1, j = 0; i < wc && j < lengthof(resconf->search); i++, j++) + if (words[i][0] == '.') { + /* Ignore invalid search spec. */ + j--; + } else { + dns_d_anchor(resconf->search[j], sizeof resconf->search[j], words[i], strlen(words[i])); + } + + break; + case DNS_RESCONF_LOOKUP: + for (i = 1, j = 0; i < wc && j < lengthof(resconf->lookup); i++) { + switch (dns_resconf_keyword(words[i])) { + case DNS_RESCONF_FILE: + resconf->lookup[j++] = 'f'; + + break; + case DNS_RESCONF_BIND: + resconf->lookup[j++] = 'b'; + + break; + case DNS_RESCONF_CACHE: + resconf->lookup[j++] = 'c'; + + break; + default: + break; + } /* switch() */ + } /* for() */ + + break; + case DNS_RESCONF_FAMILY: + for (i = 1, j = 0; i < wc && j < lengthof(resconf->family); i++) { + switch (dns_resconf_keyword(words[i])) { + case DNS_RESCONF_INET4: + resconf->family[j++] = AF_INET; + + break; + case DNS_RESCONF_INET6: + resconf->family[j++] = AF_INET6; + + break; + default: + break; + } + } + + break; + case DNS_RESCONF_OPTIONS: + for (i = 1; i < wc; i++) { + switch (dns_resconf_keyword(words[i])) { + case DNS_RESCONF_EDNS0: + resconf->options.edns0 = 1; + + break; + case DNS_RESCONF_NDOTS: + for (j = sizeof "ndots:" - 1, n = 0; dns_isdigit(words[i][j]); j++) { + n *= 10; + n += words[i][j] - '0'; + } /* for() */ + + resconf->options.ndots = n; + + break; + case DNS_RESCONF_TIMEOUT: + for (j = sizeof "timeout:" - 1, n = 0; dns_isdigit(words[i][j]); j++) { + n *= 10; + n += words[i][j] - '0'; + } /* for() */ + + resconf->options.timeout = n; + + break; + case DNS_RESCONF_ATTEMPTS: + for (j = sizeof "attempts:" - 1, n = 0; dns_isdigit(words[i][j]); j++) { + n *= 10; + n += words[i][j] - '0'; + } /* for() */ + + resconf->options.attempts = n; + + break; + case DNS_RESCONF_ROTATE: + resconf->options.rotate = 1; + + break; + case DNS_RESCONF_RECURSE: + resconf->options.recurse = 1; + + break; + case DNS_RESCONF_SMART: + resconf->options.smart = 1; + + break; + case DNS_RESCONF_TCP: + resconf->options.tcp = DNS_RESCONF_TCP_ONLY; + + break; + case DNS_RESCONF_TCPx: + switch (dns_resconf_keyword(&words[i][sizeof "tcp:" - 1])) { + case DNS_RESCONF_ENABLE: + resconf->options.tcp = DNS_RESCONF_TCP_ENABLE; + + break; + case DNS_RESCONF_ONE: + case DNS_RESCONF_ONLY: + resconf->options.tcp = DNS_RESCONF_TCP_ONLY; + + break; + case DNS_RESCONF_ZERO: + case DNS_RESCONF_DISABLE: + resconf->options.tcp = DNS_RESCONF_TCP_DISABLE; + + break; + default: + break; + } /* switch() */ + + break; + default: + break; + } /* switch() */ + } /* for() */ + + break; + case DNS_RESCONF_INTERFACE: + for (i = 0, n = 0; dns_isdigit(words[2][i]); i++) { + n *= 10; + n += words[2][i] - '0'; + } + + dns_resconf_setiface(resconf, words[1], n); + + break; + default: + break; + } /* switch() */ + } while (ch != EOF); + + return 0; +} /* dns_resconf_loadfile() */ + + +int dns_resconf_loadpath(struct dns_resolv_conf *resconf, const char *path) { + FILE *fp; + int error; + + if (!(fp = dns_fopen(path, "rt", &error))) + return error; + + error = dns_resconf_loadfile(resconf, fp); + + fclose(fp); + + return error; +} /* dns_resconf_loadpath() */ + + +struct dns_anyconf { + char *token[16]; + unsigned count; + char buffer[1024], *tp, *cp; +}; /* struct dns_anyconf */ + + +static void dns_anyconf_reset(struct dns_anyconf *cf) { + cf->count = 0; + cf->tp = cf->cp = cf->buffer; +} /* dns_anyconf_reset() */ + + +static int dns_anyconf_push(struct dns_anyconf *cf) { + if (!(cf->cp < endof(cf->buffer) && cf->count < lengthof(cf->token))) + return ENOMEM; + + *cf->cp++ = '\0'; + cf->token[cf->count++] = cf->tp; + cf->tp = cf->cp; + + return 0; +} /* dns_anyconf_push() */ + + +static void dns_anyconf_pop(struct dns_anyconf *cf) { + if (cf->count > 0) { + --cf->count; + cf->tp = cf->cp = cf->token[cf->count]; + cf->token[cf->count] = 0; + } +} /* dns_anyconf_pop() */ + + +static int dns_anyconf_addc(struct dns_anyconf *cf, int ch) { + if (!(cf->cp < endof(cf->buffer))) + return ENOMEM; + + *cf->cp++ = ch; + + return 0; +} /* dns_anyconf_addc() */ + + +static _Bool dns_anyconf_match(const char *pat, int mc) { + _Bool match; + int pc; + + if (*pat == '^') { + match = 0; + ++pat; + } else { + match = 1; + } + + while ((pc = *(const unsigned char *)pat++)) { + switch (pc) { + case '%': + if (!(pc = *(const unsigned char *)pat++)) + return !match; + + switch (pc) { + case 'a': + if (dns_isalpha(mc)) + return match; + break; + case 'd': + if (dns_isdigit(mc)) + return match; + break; + case 'w': + if (dns_isalnum(mc)) + return match; + break; + case 's': + if (dns_isspace(mc)) + return match; + break; + default: + if (mc == pc) + return match; + break; + } /* switch() */ + + break; + default: + if (mc == pc) + return match; + break; + } /* switch() */ + } /* while() */ + + return !match; +} /* dns_anyconf_match() */ + + +static int dns_anyconf_peek(FILE *fp) { + int ch; + ch = getc(fp); + ungetc(ch, fp); + return ch; +} /* dns_anyconf_peek() */ + + +static size_t dns_anyconf_skip(const char *pat, FILE *fp) { + size_t count = 0; + int ch; + + while (EOF != (ch = getc(fp))) { + if (dns_anyconf_match(pat, ch)) { + count++; + continue; + } + + ungetc(ch, fp); + + break; + } + + return count; +} /* dns_anyconf_skip() */ + + +static size_t dns_anyconf_scan(struct dns_anyconf *cf, const char *pat, FILE *fp, int *error) { + size_t len; + int ch; + + while (EOF != (ch = getc(fp))) { + if (dns_anyconf_match(pat, ch)) { + if ((*error = dns_anyconf_addc(cf, ch))) + return 0; + + continue; + } else { + ungetc(ch, fp); + + break; + } + } + + if ((len = cf->cp - cf->tp)) { + if ((*error = dns_anyconf_push(cf))) + return 0; + + return len; + } else { + *error = 0; + + return 0; + } +} /* dns_anyconf_scan() */ + + +DNS_NOTUSED static void dns_anyconf_dump(struct dns_anyconf *cf, FILE *fp) { + unsigned i; + + fprintf(fp, "tokens:"); + + for (i = 0; i < cf->count; i++) { + fprintf(fp, " %s", cf->token[i]); + } + + fputc('\n', fp); +} /* dns_anyconf_dump() */ + + +enum dns_nssconf_keyword { + DNS_NSSCONF_INVALID = 0, + DNS_NSSCONF_HOSTS = 1, + DNS_NSSCONF_SUCCESS, + DNS_NSSCONF_NOTFOUND, + DNS_NSSCONF_UNAVAIL, + DNS_NSSCONF_TRYAGAIN, + DNS_NSSCONF_CONTINUE, + DNS_NSSCONF_RETURN, + DNS_NSSCONF_FILES, + DNS_NSSCONF_DNS, + DNS_NSSCONF_MDNS, + + DNS_NSSCONF_LAST, +}; /* enum dns_nssconf_keyword */ + +static enum dns_nssconf_keyword dns_nssconf_keyword(const char *word) { + static const char *list[] = { + [DNS_NSSCONF_HOSTS] = "hosts", + [DNS_NSSCONF_SUCCESS] = "success", + [DNS_NSSCONF_NOTFOUND] = "notfound", + [DNS_NSSCONF_UNAVAIL] = "unavail", + [DNS_NSSCONF_TRYAGAIN] = "tryagain", + [DNS_NSSCONF_CONTINUE] = "continue", + [DNS_NSSCONF_RETURN] = "return", + [DNS_NSSCONF_FILES] = "files", + [DNS_NSSCONF_DNS] = "dns", + [DNS_NSSCONF_MDNS] = "mdns", + }; + unsigned i; + + for (i = 1; i < lengthof(list); i++) { + if (list[i] && 0 == strcasecmp(list[i], word)) + return i; + } + + return DNS_NSSCONF_INVALID; +} /* dns_nssconf_keyword() */ + + +static enum dns_nssconf_keyword dns_nssconf_c2k(int ch) { + static const char map[] = { + ['S'] = DNS_NSSCONF_SUCCESS, + ['N'] = DNS_NSSCONF_NOTFOUND, + ['U'] = DNS_NSSCONF_UNAVAIL, + ['T'] = DNS_NSSCONF_TRYAGAIN, + ['C'] = DNS_NSSCONF_CONTINUE, + ['R'] = DNS_NSSCONF_RETURN, + ['f'] = DNS_NSSCONF_FILES, + ['F'] = DNS_NSSCONF_FILES, + ['d'] = DNS_NSSCONF_DNS, + ['D'] = DNS_NSSCONF_DNS, + ['b'] = DNS_NSSCONF_DNS, + ['B'] = DNS_NSSCONF_DNS, + ['m'] = DNS_NSSCONF_MDNS, + ['M'] = DNS_NSSCONF_MDNS, + }; + + return (ch >= 0 && ch < (int)lengthof(map))? map[ch] : DNS_NSSCONF_INVALID; +} /* dns_nssconf_c2k() */ + + +DNS_PRAGMA_PUSH +DNS_PRAGMA_QUIET + +static int dns_nssconf_k2c(int k) { + static const char map[DNS_NSSCONF_LAST] = { + [DNS_NSSCONF_SUCCESS] = 'S', + [DNS_NSSCONF_NOTFOUND] = 'N', + [DNS_NSSCONF_UNAVAIL] = 'U', + [DNS_NSSCONF_TRYAGAIN] = 'T', + [DNS_NSSCONF_CONTINUE] = 'C', + [DNS_NSSCONF_RETURN] = 'R', + [DNS_NSSCONF_FILES] = 'f', + [DNS_NSSCONF_DNS] = 'b', + [DNS_NSSCONF_MDNS] = 'm', + }; + + return (k >= 0 && k < (int)lengthof(map))? (map[k]? map[k] : '?') : '?'; +} /* dns_nssconf_k2c() */ + +static const char *dns_nssconf_k2s(int k) { + static const char *const map[DNS_NSSCONF_LAST] = { + [DNS_NSSCONF_SUCCESS] = "SUCCESS", + [DNS_NSSCONF_NOTFOUND] = "NOTFOUND", + [DNS_NSSCONF_UNAVAIL] = "UNAVAIL", + [DNS_NSSCONF_TRYAGAIN] = "TRYAGAIN", + [DNS_NSSCONF_CONTINUE] = "continue", + [DNS_NSSCONF_RETURN] = "return", + [DNS_NSSCONF_FILES] = "files", + [DNS_NSSCONF_DNS] = "dns", + [DNS_NSSCONF_MDNS] = "mdns", + }; + + return (k >= 0 && k < (int)lengthof(map))? (map[k]? map[k] : "") : ""; +} /* dns_nssconf_k2s() */ + +DNS_PRAGMA_POP + + +int dns_nssconf_loadfile(struct dns_resolv_conf *resconf, FILE *fp) { + enum dns_nssconf_keyword source, status, action; + char lookup[sizeof resconf->lookup] = "", *lp; + struct dns_anyconf cf; + size_t i; + int error; + + while (!feof(fp) && !ferror(fp)) { + dns_anyconf_reset(&cf); + + dns_anyconf_skip("%s", fp); + + if (!dns_anyconf_scan(&cf, "%w_", fp, &error)) + goto nextent; + + if (DNS_NSSCONF_HOSTS != dns_nssconf_keyword(cf.token[0])) + goto nextent; + + dns_anyconf_pop(&cf); + + if (!dns_anyconf_skip(": \t", fp)) + goto nextent; + + *(lp = lookup) = '\0'; + + while (dns_anyconf_scan(&cf, "%w_", fp, &error)) { + dns_anyconf_skip(" \t", fp); + + if ('[' == dns_anyconf_peek(fp)) { + dns_anyconf_skip("[! \t", fp); + + while (dns_anyconf_scan(&cf, "%w_", fp, &error)) { + dns_anyconf_skip("= \t", fp); + if (!dns_anyconf_scan(&cf, "%w_", fp, &error)) { + dns_anyconf_pop(&cf); /* discard status */ + dns_anyconf_skip("^#;]\n", fp); /* skip to end of criteria */ + break; + } + dns_anyconf_skip(" \t", fp); + } + + dns_anyconf_skip("] \t", fp); + } + + if ((size_t)(endof(lookup) - lp) < cf.count + 1) /* +1 for '\0' */ + goto nextsrc; + + source = dns_nssconf_keyword(cf.token[0]); + + switch (source) { + case DNS_NSSCONF_DNS: + case DNS_NSSCONF_MDNS: + case DNS_NSSCONF_FILES: + *lp++ = dns_nssconf_k2c(source); + break; + default: + goto nextsrc; + } + + for (i = 1; i + 1 < cf.count; i += 2) { + status = dns_nssconf_keyword(cf.token[i]); + action = dns_nssconf_keyword(cf.token[i + 1]); + + switch (status) { + case DNS_NSSCONF_SUCCESS: + case DNS_NSSCONF_NOTFOUND: + case DNS_NSSCONF_UNAVAIL: + case DNS_NSSCONF_TRYAGAIN: + *lp++ = dns_nssconf_k2c(status); + break; + default: + continue; + } + + switch (action) { + case DNS_NSSCONF_CONTINUE: + case DNS_NSSCONF_RETURN: + break; + default: + action = (status == DNS_NSSCONF_SUCCESS) + ? DNS_NSSCONF_RETURN + : DNS_NSSCONF_CONTINUE; + break; + } + + *lp++ = dns_nssconf_k2c(action); + } +nextsrc: + *lp = '\0'; + dns_anyconf_reset(&cf); + } +nextent: + dns_anyconf_skip("^\n", fp); + } + + if (*lookup) + strncpy(resconf->lookup, lookup, sizeof resconf->lookup); + + return 0; +} /* dns_nssconf_loadfile() */ + + +int dns_nssconf_loadpath(struct dns_resolv_conf *resconf, const char *path) { + FILE *fp; + int error; + + if (!(fp = dns_fopen(path, "rt", &error))) + return error; + + error = dns_nssconf_loadfile(resconf, fp); + + fclose(fp); + + return error; +} /* dns_nssconf_loadpath() */ + + +struct dns_nssconf_source { + enum dns_nssconf_keyword source, success, notfound, unavail, tryagain; +}; /* struct dns_nssconf_source */ + +typedef unsigned dns_nssconf_i; + +static inline int dns_nssconf_peek(const struct dns_resolv_conf *resconf, dns_nssconf_i state) { + return (state < lengthof(resconf->lookup) && resconf->lookup[state])? resconf->lookup[state] : 0; +} /* dns_nssconf_peek() */ + +static _Bool dns_nssconf_next(struct dns_nssconf_source *src, const struct dns_resolv_conf *resconf, dns_nssconf_i *state) { + int source, status, action; + + src->source = DNS_NSSCONF_INVALID; + src->success = DNS_NSSCONF_RETURN; + src->notfound = DNS_NSSCONF_CONTINUE; + src->unavail = DNS_NSSCONF_CONTINUE; + src->tryagain = DNS_NSSCONF_CONTINUE; + + while ((source = dns_nssconf_peek(resconf, *state))) { + source = dns_nssconf_c2k(source); + ++*state; + + switch (source) { + case DNS_NSSCONF_FILES: + case DNS_NSSCONF_DNS: + case DNS_NSSCONF_MDNS: + src->source = source; + break; + default: + continue; + } + + while ((status = dns_nssconf_peek(resconf, *state)) && (action = dns_nssconf_peek(resconf, *state + 1))) { + status = dns_nssconf_c2k(status); + action = dns_nssconf_c2k(action); + + switch (action) { + case DNS_NSSCONF_RETURN: + case DNS_NSSCONF_CONTINUE: + break; + default: + goto done; + } + + switch (status) { + case DNS_NSSCONF_SUCCESS: + src->success = action; + break; + case DNS_NSSCONF_NOTFOUND: + src->notfound = action; + break; + case DNS_NSSCONF_UNAVAIL: + src->unavail = action; + break; + case DNS_NSSCONF_TRYAGAIN: + src->tryagain = action; + break; + default: + goto done; + } + + *state += 2; + } + + break; + } +done: + return src->source != DNS_NSSCONF_INVALID; +} /* dns_nssconf_next() */ + + +static int dns_nssconf_dump_status(int status, int action, unsigned *count, FILE *fp) { + switch (status) { + case DNS_NSSCONF_SUCCESS: + if (action == DNS_NSSCONF_RETURN) + return 0; + break; + default: + if (action == DNS_NSSCONF_CONTINUE) + return 0; + break; + } + + fputc(' ', fp); + + if (!*count) + fputc('[', fp); + + fprintf(fp, "%s=%s", dns_nssconf_k2s(status), dns_nssconf_k2s(action)); + + ++*count; + + return 0; +} /* dns_nssconf_dump_status() */ + + +int dns_nssconf_dump(struct dns_resolv_conf *resconf, FILE *fp) { + struct dns_nssconf_source src; + dns_nssconf_i i = 0; + + fputs("hosts:", fp); + + while (dns_nssconf_next(&src, resconf, &i)) { + unsigned n = 0; + + fprintf(fp, " %s", dns_nssconf_k2s(src.source)); + + dns_nssconf_dump_status(DNS_NSSCONF_SUCCESS, src.success, &n, fp); + dns_nssconf_dump_status(DNS_NSSCONF_NOTFOUND, src.notfound, &n, fp); + dns_nssconf_dump_status(DNS_NSSCONF_UNAVAIL, src.unavail, &n, fp); + dns_nssconf_dump_status(DNS_NSSCONF_TRYAGAIN, src.tryagain, &n, fp); + + if (n) + fputc(']', fp); + } + + fputc('\n', fp); + + return 0; +} /* dns_nssconf_dump() */ + + +int dns_resconf_setiface(struct dns_resolv_conf *resconf, const char *addr, unsigned short port) { + int af = (strchr(addr, ':'))? AF_INET6 : AF_INET; + int error; + + memset(&resconf->iface, 0, sizeof (struct sockaddr_storage)); + if ((error = dns_pton(af, addr, dns_sa_addr(af, &resconf->iface, NULL)))) + return error; + + *dns_sa_port(af, &resconf->iface) = htons(port); + resconf->iface.ss_family = af; + + return 0; +} /* dns_resconf_setiface() */ + + +#define DNS_SM_RESTORE \ + do { \ + pc = 0xff & (*state >> 0); \ + srchi = 0xff & (*state >> 8); \ + ndots = 0xff & (*state >> 16); \ + } while (0) + +#define DNS_SM_SAVE \ + do { \ + *state = ((0xff & pc) << 0) \ + | ((0xff & srchi) << 8) \ + | ((0xff & ndots) << 16); \ + } while (0) + +size_t dns_resconf_search(void *dst, size_t lim, const void *qname, size_t qlen, struct dns_resolv_conf *resconf, dns_resconf_i_t *state) { + unsigned pc, srchi, ndots, len; + + DNS_SM_ENTER; + + /* if FQDN then return as-is and finish */ + if (dns_d_isanchored(qname, qlen)) { + len = dns_d_anchor(dst, lim, qname, qlen); + DNS_SM_YIELD(len); + DNS_SM_EXIT; + } + + ndots = dns_d_ndots(qname, qlen); + + if (ndots >= resconf->options.ndots) { + len = dns_d_anchor(dst, lim, qname, qlen); + DNS_SM_YIELD(len); + } + + while (srchi < lengthof(resconf->search) && resconf->search[srchi][0]) { + struct dns_buf buf = DNS_B_INTO(dst, lim); + const char *dn = resconf->search[srchi++]; + + dns_b_put(&buf, qname, qlen); + dns_b_putc(&buf, '.'); + dns_b_puts(&buf, dn); + if (!dns_d_isanchored(dn, strlen(dn))) + dns_b_putc(&buf, '.'); + len = dns_b_strllen(&buf); + DNS_SM_YIELD(len); + } + + if (ndots < resconf->options.ndots) { + len = dns_d_anchor(dst, lim, qname, qlen); + DNS_SM_YIELD(len); + } + + DNS_SM_LEAVE; + + return dns_strlcpy(dst, "", lim); +} /* dns_resconf_search() */ + +#undef DNS_SM_SAVE +#undef DNS_SM_RESTORE + + +int dns_resconf_dump(struct dns_resolv_conf *resconf, FILE *fp) { + unsigned i; + int af; + + for (i = 0; i < lengthof(resconf->nameserver) && (af = resconf->nameserver[i].ss_family) != AF_UNSPEC; i++) { + char addr[INET6_ADDRSTRLEN + 1] = "[INVALID]"; + unsigned short port; + + dns_inet_ntop(af, dns_sa_addr(af, &resconf->nameserver[i], NULL), addr, sizeof addr); + port = ntohs(*dns_sa_port(af, &resconf->nameserver[i])); + + if (port == 53) + fprintf(fp, "nameserver %s\n", addr); + else + fprintf(fp, "nameserver [%s]:%hu\n", addr, port); + } + + + fprintf(fp, "search"); + + for (i = 0; i < lengthof(resconf->search) && resconf->search[i][0]; i++) + fprintf(fp, " %s", resconf->search[i]); + + fputc('\n', fp); + + + fputs("; ", fp); + dns_nssconf_dump(resconf, fp); + + fprintf(fp, "lookup"); + + for (i = 0; i < lengthof(resconf->lookup) && resconf->lookup[i]; i++) { + switch (resconf->lookup[i]) { + case 'b': + fprintf(fp, " bind"); break; + case 'f': + fprintf(fp, " file"); break; + case 'c': + fprintf(fp, " cache"); break; + } + } + + fputc('\n', fp); + + + fprintf(fp, "options ndots:%u timeout:%u attempts:%u", resconf->options.ndots, resconf->options.timeout, resconf->options.attempts); + + if (resconf->options.edns0) + fprintf(fp, " edns0"); + if (resconf->options.rotate) + fprintf(fp, " rotate"); + if (resconf->options.recurse) + fprintf(fp, " recurse"); + if (resconf->options.smart) + fprintf(fp, " smart"); + + switch (resconf->options.tcp) { + case DNS_RESCONF_TCP_ENABLE: + break; + case DNS_RESCONF_TCP_ONLY: + fprintf(fp, " tcp"); + break; + case DNS_RESCONF_TCP_SOCKS: + fprintf(fp, " tcp:socks"); + break; + case DNS_RESCONF_TCP_DISABLE: + fprintf(fp, " tcp:disable"); + break; + } + + fputc('\n', fp); + + + if ((af = resconf->iface.ss_family) != AF_UNSPEC) { + char addr[INET6_ADDRSTRLEN + 1] = "[INVALID]"; + + dns_inet_ntop(af, dns_sa_addr(af, &resconf->iface, NULL), addr, sizeof addr); + + fprintf(fp, "interface %s %hu\n", addr, ntohs(*dns_sa_port(af, &resconf->iface))); + } + + return 0; +} /* dns_resconf_dump() */ + + +/* + * H I N T S E R V E R R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +struct dns_hints_soa { + unsigned char zone[DNS_D_MAXNAME + 1]; + + struct { + struct sockaddr_storage ss; + unsigned priority; + } addrs[16]; + + unsigned count; + + struct dns_hints_soa *next; +}; /* struct dns_hints_soa */ + + +struct dns_hints { + dns_atomic_t refcount; + + struct dns_hints_soa *head; +}; /* struct dns_hints */ + + +struct dns_hints *dns_hints_open(struct dns_resolv_conf *resconf, int *error) { + static const struct dns_hints H_initializer; + struct dns_hints *H; + + (void)resconf; + + if (!(H = malloc(sizeof *H))) + goto syerr; + + *H = H_initializer; + + dns_hints_acquire(H); + + return H; +syerr: + *error = dns_syerr(); + + free(H); + + return 0; +} /* dns_hints_open() */ + + +void dns_hints_close(struct dns_hints *H) { + struct dns_hints_soa *soa, *nxt; + + if (!H || 1 != dns_hints_release(H)) + return /* void */; + + for (soa = H->head; soa; soa = nxt) { + nxt = soa->next; + + free(soa); + } + + free(H); + + return /* void */; +} /* dns_hints_close() */ + + +dns_refcount_t dns_hints_acquire(struct dns_hints *H) { + return dns_atomic_fetch_add(&H->refcount); +} /* dns_hints_acquire() */ + + +dns_refcount_t dns_hints_release(struct dns_hints *H) { + return dns_atomic_fetch_sub(&H->refcount); +} /* dns_hints_release() */ + + +struct dns_hints *dns_hints_mortal(struct dns_hints *hints) { + if (hints) + dns_hints_release(hints); + + return hints; +} /* dns_hints_mortal() */ + + +struct dns_hints *dns_hints_local(struct dns_resolv_conf *resconf, int *error_) { + struct dns_hints *hints = 0; + int error; + + if (resconf) + dns_resconf_acquire(resconf); + else if (!(resconf = dns_resconf_local(&error))) + goto error; + + if (!(hints = dns_hints_open(resconf, &error))) + goto error; + + error = 0; + + if (0 == dns_hints_insert_resconf(hints, ".", resconf, &error) && error) + goto error; + + dns_resconf_close(resconf); + + return hints; +error: + *error_ = error; + + dns_resconf_close(resconf); + dns_hints_close(hints); + + return 0; +} /* dns_hints_local() */ + + +struct dns_hints *dns_hints_root(struct dns_resolv_conf *resconf, int *error_) { + static const struct { + int af; + char addr[INET6_ADDRSTRLEN]; + } root_hints[] = { + { AF_INET, "198.41.0.4" }, /* A.ROOT-SERVERS.NET. */ + { AF_INET6, "2001:503:ba3e::2:30" }, /* A.ROOT-SERVERS.NET. */ + { AF_INET, "192.228.79.201" }, /* B.ROOT-SERVERS.NET. */ + { AF_INET6, "2001:500:84::b" }, /* B.ROOT-SERVERS.NET. */ + { AF_INET, "192.33.4.12" }, /* C.ROOT-SERVERS.NET. */ + { AF_INET6, "2001:500:2::c" }, /* C.ROOT-SERVERS.NET. */ + { AF_INET, "199.7.91.13" }, /* D.ROOT-SERVERS.NET. */ + { AF_INET6, "2001:500:2d::d" }, /* D.ROOT-SERVERS.NET. */ + { AF_INET, "192.203.230.10" }, /* E.ROOT-SERVERS.NET. */ + { AF_INET, "192.5.5.241" }, /* F.ROOT-SERVERS.NET. */ + { AF_INET6, "2001:500:2f::f" }, /* F.ROOT-SERVERS.NET. */ + { AF_INET, "192.112.36.4" }, /* G.ROOT-SERVERS.NET. */ + { AF_INET, "128.63.2.53" }, /* H.ROOT-SERVERS.NET. */ + { AF_INET6, "2001:500:1::803f:235" }, /* H.ROOT-SERVERS.NET. */ + { AF_INET, "192.36.148.17" }, /* I.ROOT-SERVERS.NET. */ + { AF_INET6, "2001:7FE::53" }, /* I.ROOT-SERVERS.NET. */ + { AF_INET, "192.58.128.30" }, /* J.ROOT-SERVERS.NET. */ + { AF_INET6, "2001:503:c27::2:30" }, /* J.ROOT-SERVERS.NET. */ + { AF_INET, "193.0.14.129" }, /* K.ROOT-SERVERS.NET. */ + { AF_INET6, "2001:7FD::1" }, /* K.ROOT-SERVERS.NET. */ + { AF_INET, "199.7.83.42" }, /* L.ROOT-SERVERS.NET. */ + { AF_INET6, "2001:500:3::42" }, /* L.ROOT-SERVERS.NET. */ + { AF_INET, "202.12.27.33" }, /* M.ROOT-SERVERS.NET. */ + { AF_INET6, "2001:DC3::35" }, /* M.ROOT-SERVERS.NET. */ + }; + struct dns_hints *hints = 0; + struct sockaddr_storage ss; + unsigned i; + int error, af; + + if (!(hints = dns_hints_open(resconf, &error))) + goto error; + + for (i = 0; i < lengthof(root_hints); i++) { + af = root_hints[i].af; + + memset(&ss, 0, sizeof ss); + if ((error = dns_pton(af, root_hints[i].addr, dns_sa_addr(af, &ss, NULL)))) + goto error; + + *dns_sa_port(af, &ss) = htons(53); + ss.ss_family = af; + + if ((error = dns_hints_insert(hints, ".", (struct sockaddr *)&ss, 1))) + goto error; + } + + return hints; +error: + *error_ = error; + + dns_hints_close(hints); + + return 0; +} /* dns_hints_root() */ + + +static struct dns_hints_soa *dns_hints_fetch(struct dns_hints *H, const char *zone) { + struct dns_hints_soa *soa; + + for (soa = H->head; soa; soa = soa->next) { + if (0 == strcasecmp(zone, (char *)soa->zone)) + return soa; + } + + return 0; +} /* dns_hints_fetch() */ + + +int dns_hints_insert(struct dns_hints *H, const char *zone, const struct sockaddr *sa, unsigned priority) { + static const struct dns_hints_soa soa_initializer; + struct dns_hints_soa *soa; + unsigned i; + + if (!(soa = dns_hints_fetch(H, zone))) { + if (!(soa = malloc(sizeof *soa))) + return dns_syerr(); + *soa = soa_initializer; + dns_strlcpy((char *)soa->zone, zone, sizeof soa->zone); + + soa->next = H->head; + H->head = soa; + } + + i = soa->count % lengthof(soa->addrs); + + memcpy(&soa->addrs[i].ss, sa, dns_sa_len(sa)); + + soa->addrs[i].priority = DNS_PP_MAX(1, priority); + + if (soa->count < lengthof(soa->addrs)) + soa->count++; + + return 0; +} /* dns_hints_insert() */ + + +static _Bool dns_hints_isinaddr_any(const void *sa) { + struct in_addr *addr; + + if (dns_sa_family(sa) != AF_INET) + return 0; + + addr = dns_sa_addr(AF_INET, sa, NULL); + return addr->s_addr == htonl(INADDR_ANY); +} + +unsigned dns_hints_insert_resconf(struct dns_hints *H, const char *zone, const struct dns_resolv_conf *resconf, int *error_) { + unsigned i, n, p; + int error; + + for (i = 0, n = 0, p = 1; i < lengthof(resconf->nameserver) && resconf->nameserver[i].ss_family != AF_UNSPEC; i++, n++) { + union { struct sockaddr_in sin; } tmp; + struct sockaddr *ns; + + /* + * dns_resconf_open initializes nameserver[0] to INADDR_ANY. + * + * Traditionally the semantics of 0.0.0.0 meant the default + * interface, which evolved to mean the loopback interface. + * See comment block preceding resolv/res_init.c:res_init in + * glibc 2.23. As of 2.23, glibc no longer translates + * 0.0.0.0 despite the code comment, but it does default to + * 127.0.0.1 when no nameservers are present. + * + * BIND9 as of 9.10.3 still translates 0.0.0.0 to 127.0.0.1. + * See lib/lwres/lwconfig.c:lwres_create_addr and the + * convert_zero flag. 127.0.0.1 is also the default when no + * nameservers are present. + */ + if (dns_hints_isinaddr_any(&resconf->nameserver[i])) { + memcpy(&tmp.sin, &resconf->nameserver[i], sizeof tmp.sin); + tmp.sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK); + ns = (struct sockaddr *)&tmp.sin; + } else { + ns = (struct sockaddr *)&resconf->nameserver[i]; + } + + if ((error = dns_hints_insert(H, zone, ns, p))) + goto error; + + p += !resconf->options.rotate; + } + + return n; +error: + *error_ = error; + + return n; +} /* dns_hints_insert_resconf() */ + + +static int dns_hints_i_cmp(unsigned a, unsigned b, struct dns_hints_i *i, struct dns_hints_soa *soa) { + int cmp; + + if ((cmp = soa->addrs[a].priority - soa->addrs[b].priority)) + return cmp; + + return dns_k_shuffle16(a, i->state.seed) - dns_k_shuffle16(b, i->state.seed); +} /* dns_hints_i_cmp() */ + + +static unsigned dns_hints_i_start(struct dns_hints_i *i, struct dns_hints_soa *soa) { + unsigned p0, p; + + p0 = 0; + + for (p = 1; p < soa->count; p++) { + if (dns_hints_i_cmp(p, p0, i, soa) < 0) + p0 = p; + } + + return p0; +} /* dns_hints_i_start() */ + + +static unsigned dns_hints_i_skip(unsigned p0, struct dns_hints_i *i, struct dns_hints_soa *soa) { + unsigned pZ, p; + + for (pZ = 0; pZ < soa->count; pZ++) { + if (dns_hints_i_cmp(pZ, p0, i, soa) > 0) + goto cont; + } + + return soa->count; +cont: + for (p = pZ + 1; p < soa->count; p++) { + if (dns_hints_i_cmp(p, p0, i, soa) <= 0) + continue; + + if (dns_hints_i_cmp(p, pZ, i, soa) >= 0) + continue; + + pZ = p; + } + + + return pZ; +} /* dns_hints_i_skip() */ + + +static struct dns_hints_i *dns_hints_i_init(struct dns_hints_i *i, struct dns_hints *hints) { + static const struct dns_hints_i i_initializer; + struct dns_hints_soa *soa; + + i->state = i_initializer.state; + + do { + i->state.seed = dns_random(); + } while (0 == i->state.seed); + + if ((soa = dns_hints_fetch(hints, i->zone))) { + i->state.next = dns_hints_i_start(i, soa); + } + + return i; +} /* dns_hints_i_init() */ + + +unsigned dns_hints_grep(struct sockaddr **sa, socklen_t *sa_len, unsigned lim, struct dns_hints_i *i, struct dns_hints *H) { + struct dns_hints_soa *soa; + unsigned n; + + if (!(soa = dns_hints_fetch(H, i->zone))) + return 0; + + n = 0; + + while (i->state.next < soa->count && n < lim) { + *sa = (struct sockaddr *)&soa->addrs[i->state.next].ss; + *sa_len = dns_sa_len(*sa); + + sa++; + sa_len++; + n++; + + i->state.next = dns_hints_i_skip(i->state.next, i, soa); + } + + return n; +} /* dns_hints_grep() */ + + +struct dns_packet *dns_hints_query(struct dns_hints *hints, struct dns_packet *Q, int *error_) { + union { unsigned char b[dns_p_calcsize((512))]; struct dns_packet p; } P_instance = { 0 }; + struct dns_packet *A, *P; + struct dns_rr rr; + char zone[DNS_D_MAXNAME + 1]; + size_t zlen; + struct dns_hints_i i; + struct sockaddr *sa; + socklen_t slen; + int error; + struct dns_rr_i I_instance = { 0 }; + + I_instance.section = DNS_S_QUESTION; + + if (!dns_rr_grep(&rr, 1, &I_instance, Q, &error)) + goto error; + + if (!(zlen = dns_d_expand(zone, sizeof zone, rr.dn.p, Q, &error))) + goto error; + else if (zlen >= sizeof zone) + goto toolong; + + P = dns_p_init(&P_instance.p, 512); + dns_header(P)->qr = 1; + + if ((error = dns_rr_copy(P, &rr, Q))) + goto error; + + if ((error = dns_p_push(P, DNS_S_AUTHORITY, ".", strlen("."), DNS_T_NS, DNS_C_IN, 0, "hints.local."))) + goto error; + + do { + i.zone = zone; + + dns_hints_i_init(&i, hints); + + while (dns_hints_grep(&sa, &slen, 1, &i, hints)) { + int af = sa->sa_family; + int rtype = (af == AF_INET6)? DNS_T_AAAA : DNS_T_A; + + if ((error = dns_p_push(P, DNS_S_ADDITIONAL, "hints.local.", strlen("hints.local."), rtype, DNS_C_IN, 0, dns_sa_addr(af, sa, NULL)))) + goto error; + } + } while ((zlen = dns_d_cleave(zone, sizeof zone, zone, zlen))); + + if (!(A = dns_p_copy(dns_p_make(P->end, &error), P))) + goto error; + + return A; +toolong: + error = DNS_EILLEGAL; +error: + *error_ = error; + + return 0; +} /* dns_hints_query() */ + + +/** ugly hack to support specifying ports other than 53 in resolv.conf. */ +static unsigned short dns_hints_port(struct dns_hints *hints, int af, void *addr) { + struct dns_hints_soa *soa; + void *addrsoa; + socklen_t addrlen; + unsigned short port; + unsigned i; + + for (soa = hints->head; soa; soa = soa->next) { + for (i = 0; i < soa->count; i++) { + if (af != soa->addrs[i].ss.ss_family) + continue; + + if (!(addrsoa = dns_sa_addr(af, &soa->addrs[i].ss, &addrlen))) + continue; + + if (memcmp(addr, addrsoa, addrlen)) + continue; + + port = *dns_sa_port(af, &soa->addrs[i].ss); + + return (port)? port : htons(53); + } + } + + return htons(53); +} /* dns_hints_port() */ + + +int dns_hints_dump(struct dns_hints *hints, FILE *fp) { + struct dns_hints_soa *soa; + char addr[INET6_ADDRSTRLEN]; + unsigned i; + int af, error; + + for (soa = hints->head; soa; soa = soa->next) { + fprintf(fp, "ZONE \"%s\"\n", soa->zone); + + for (i = 0; i < soa->count; i++) { + af = soa->addrs[i].ss.ss_family; + + if ((error = dns_ntop(af, dns_sa_addr(af, &soa->addrs[i].ss, NULL), addr, sizeof addr))) + return error; + + fprintf(fp, "\t(%d) [%s]:%hu\n", (int)soa->addrs[i].priority, addr, ntohs(*dns_sa_port(af, &soa->addrs[i].ss))); + } + } + + return 0; +} /* dns_hints_dump() */ + + +/* + * C A C H E R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +static dns_refcount_t dns_cache_acquire(struct dns_cache *cache) { + return dns_atomic_fetch_add(&cache->_.refcount); +} /* dns_cache_acquire() */ + + +static dns_refcount_t dns_cache_release(struct dns_cache *cache) { + return dns_atomic_fetch_sub(&cache->_.refcount); +} /* dns_cache_release() */ + + +static struct dns_packet *dns_cache_query(struct dns_packet *query, struct dns_cache *cache, int *error) { + (void)query; + (void)cache; + (void)error; + + return NULL; +} /* dns_cache_query() */ + + +static int dns_cache_submit(struct dns_packet *query, struct dns_cache *cache) { + (void)query; + (void)cache; + + return 0; +} /* dns_cache_submit() */ + + +static int dns_cache_check(struct dns_cache *cache) { + (void)cache; + + return 0; +} /* dns_cache_check() */ + + +static struct dns_packet *dns_cache_fetch(struct dns_cache *cache, int *error) { + (void)cache; + (void)error; + + return NULL; +} /* dns_cache_fetch() */ + + +static int dns_cache_pollfd(struct dns_cache *cache) { + (void)cache; + + return -1; +} /* dns_cache_pollfd() */ + + +static short dns_cache_events(struct dns_cache *cache) { + (void)cache; + + return 0; +} /* dns_cache_events() */ + + +static void dns_cache_clear(struct dns_cache *cache) { + (void)cache; + + return; +} /* dns_cache_clear() */ + + +struct dns_cache *dns_cache_init(struct dns_cache *cache) { + static const struct dns_cache c_init = { + .acquire = &dns_cache_acquire, + .release = &dns_cache_release, + .query = &dns_cache_query, + .submit = &dns_cache_submit, + .check = &dns_cache_check, + .fetch = &dns_cache_fetch, + .pollfd = &dns_cache_pollfd, + .events = &dns_cache_events, + .clear = &dns_cache_clear, + ._ = { .refcount = 1, }, + }; + + *cache = c_init; + + return cache; +} /* dns_cache_init() */ + + +void dns_cache_close(struct dns_cache *cache) { + if (cache) + cache->release(cache); +} /* dns_cache_close() */ + + +/* + * S O C K E T R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +static void dns_socketclose(int *fd, const struct dns_options *opts) { + if (opts && opts->closefd.cb) + opts->closefd.cb(fd, opts->closefd.arg); + + if (*fd != -1) { +#if _WIN32 + closesocket(*fd); +#else + close(*fd); +#endif + *fd = -1; + } +} /* dns_socketclose() */ + + +#ifndef HAVE_IOCTLSOCKET +#define HAVE_IOCTLSOCKET (_WIN32 || _WIN64) +#endif + +#ifndef HAVE_SOCK_CLOEXEC +#ifdef SOCK_CLOEXEC +#define HAVE_SOCK_CLOEXEC 1 +#else +#define HAVE_SOCK_CLOEXEC 0 +#endif +#endif + +#ifndef HAVE_SOCK_NONBLOCK +#ifdef SOCK_NONBLOCK +#define HAVE_SOCK_NONBLOCK 1 +#else +#define HAVE_SOCK_NONBLOCK 0 +#endif +#endif + +#define DNS_SO_MAXTRY 7 + +static int dns_socket(struct sockaddr *local, int type, int *error_) { + int fd = -1, flags, error; +#if defined FIONBIO + unsigned long opt; +#endif + + flags = 0; +#if HAVE_SOCK_CLOEXEC + flags |= SOCK_CLOEXEC; +#endif +#if HAVE_SOCK_NONBLOCK + flags |= SOCK_NONBLOCK; +#endif + if (-1 == (fd = socket(local->sa_family, type|flags, 0))) + goto soerr; + +#if defined F_SETFD && !HAVE_SOCK_CLOEXEC + if (-1 == fcntl(fd, F_SETFD, 1)) + goto syerr; +#endif + +#if defined O_NONBLOCK && !HAVE_SOCK_NONBLOCK + if (-1 == (flags = fcntl(fd, F_GETFL))) + goto syerr; + if (-1 == fcntl(fd, F_SETFL, flags | O_NONBLOCK)) + goto syerr; +#elif defined FIONBIO && HAVE_IOCTLSOCKET + opt = 1; + if (0 != ioctlsocket(fd, FIONBIO, &opt)) + goto soerr; +#endif + +#if defined SO_NOSIGPIPE + if (type != SOCK_DGRAM) { + const int v = 1; + if (0 != setsockopt(fd, SOL_SOCKET, SO_NOSIGPIPE, &v, sizeof (int))) + goto soerr; + } +#endif + + if (local->sa_family != AF_INET && local->sa_family != AF_INET6) + return fd; + + if (type != SOCK_DGRAM) + return fd; + +#define LEAVE_SELECTION_OF_PORT_TO_KERNEL +#if !defined(LEAVE_SELECTION_OF_PORT_TO_KERNEL) + /* + * FreeBSD, Linux, OpenBSD, OS X, and Solaris use random ports by + * default. Though the ephemeral range is quite small on OS X + * (49152-65535 on 10.10) and Linux (32768-60999 on 4.4.0, Ubuntu + * Xenial). See also RFC 6056. + * + * TODO: Optionally rely on the kernel to select a random port. + */ + if (*dns_sa_port(local->sa_family, local) == 0) { + struct sockaddr_storage tmp; + unsigned i, port; + + memcpy(&tmp, local, dns_sa_len(local)); + + for (i = 0; i < DNS_SO_MAXTRY; i++) { + port = 1025 + (dns_random() % 64510); + + *dns_sa_port(tmp.ss_family, &tmp) = htons(port); + + if (0 == bind(fd, (struct sockaddr *)&tmp, dns_sa_len(&tmp))) + return fd; + } + + /* NB: continue to next bind statement */ + } +#endif + + if (0 == bind(fd, local, dns_sa_len(local))) + return fd; + + /* FALL THROUGH */ +soerr: + error = dns_soerr(); + + goto error; +#if (defined F_SETFD && !HAVE_SOCK_CLOEXEC) || (defined O_NONBLOCK && !HAVE_SOCK_NONBLOCK) +syerr: + error = dns_syerr(); + + goto error; +#endif +error: + *error_ = error; + + dns_socketclose(&fd, NULL); + + return -1; +} /* dns_socket() */ + + +enum { + DNS_SO_UDP_INIT = 1, + DNS_SO_UDP_CONN, + DNS_SO_UDP_SEND, + DNS_SO_UDP_RECV, + DNS_SO_UDP_DONE, + + DNS_SO_TCP_INIT, + DNS_SO_TCP_CONN, + DNS_SO_TCP_SEND, + DNS_SO_TCP_RECV, + DNS_SO_TCP_DONE, + + DNS_SO_SOCKS_INIT, + DNS_SO_SOCKS_CONN, + DNS_SO_SOCKS_HELLO_SEND, + DNS_SO_SOCKS_HELLO_RECV, + DNS_SO_SOCKS_AUTH_SEND, + DNS_SO_SOCKS_AUTH_RECV, + DNS_SO_SOCKS_REQUEST_PREPARE, + DNS_SO_SOCKS_REQUEST_SEND, + DNS_SO_SOCKS_REQUEST_RECV, + DNS_SO_SOCKS_REQUEST_RECV_V6, + DNS_SO_SOCKS_HANDSHAKE_DONE, +}; + +struct dns_socket { + struct dns_options opts; + + int udp; + int tcp; + + int *old; + unsigned onum, olim; + + int type; + + struct sockaddr_storage local, remote; + + struct dns_k_permutor qids; + + struct dns_stat stat; + + struct dns_trace *trace; + + /* + * NOTE: dns_so_reset() zeroes everything from here down. + */ + int state; + + unsigned short qid; + char qname[DNS_D_MAXNAME + 1]; + size_t qlen; + enum dns_type qtype; + enum dns_class qclass; + + struct dns_packet *query; + size_t qout; + + /* During a SOCKS handshake the query is temporarily stored + * here. */ + struct dns_packet *query_backup; + + struct dns_clock elapsed; + + struct dns_packet *answer; + size_t alen, apos; +}; /* struct dns_socket */ + + +/* + * NOTE: Actual closure delayed so that kqueue(2) and epoll(2) callers have + * a chance to recognize a state change after installing a persistent event + * and where sequential descriptors with the same integer value returned + * from _pollfd() would be ambiguous. See dns_so_closefds(). + */ +static int dns_so_closefd(struct dns_socket *so, int *fd) { + int error; + + if (*fd == -1) + return 0; + + if (so->opts.closefd.cb) { + if ((error = so->opts.closefd.cb(fd, so->opts.closefd.arg))) { + return error; + } else if (*fd == -1) + return 0; + } + + if (!(so->onum < so->olim)) { + unsigned olim = DNS_PP_MAX(4, so->olim * 2); + void *old; + + if (!(old = realloc(so->old, sizeof so->old[0] * olim))) + return dns_syerr(); + + so->old = old; + so->olim = olim; + } + + so->old[so->onum++] = *fd; + *fd = -1; + + return 0; +} /* dns_so_closefd() */ + + +#define DNS_SO_CLOSE_UDP 0x01 +#define DNS_SO_CLOSE_TCP 0x02 +#define DNS_SO_CLOSE_OLD 0x04 +#define DNS_SO_CLOSE_ALL (DNS_SO_CLOSE_UDP|DNS_SO_CLOSE_TCP|DNS_SO_CLOSE_OLD) + +static void dns_so_closefds(struct dns_socket *so, int which) { + if (DNS_SO_CLOSE_UDP & which) + dns_socketclose(&so->udp, &so->opts); + if (DNS_SO_CLOSE_TCP & which) + dns_socketclose(&so->tcp, &so->opts); + if (DNS_SO_CLOSE_OLD & which) { + unsigned i; + for (i = 0; i < so->onum; i++) + dns_socketclose(&so->old[i], &so->opts); + so->onum = 0; + free(so->old); + so->old = 0; + so->olim = 0; + } +} /* dns_so_closefds() */ + + +static void dns_so_destroy(struct dns_socket *); + +static struct dns_socket *dns_so_init(struct dns_socket *so, const struct sockaddr *local, int type, const struct dns_options *opts, int *error) { + static const struct dns_socket so_initializer = { .opts = DNS_OPTS_INITIALIZER, .udp = -1, .tcp = -1, }; + + *so = so_initializer; + so->type = type; + + if (opts) + so->opts = *opts; + + if (local) + memcpy(&so->local, local, dns_sa_len(local)); + + if (-1 == (so->udp = dns_socket((struct sockaddr *)&so->local, SOCK_DGRAM, error))) + goto error; + + dns_k_permutor_init(&so->qids, 1, 65535); + + return so; +error: + dns_so_destroy(so); + + return 0; +} /* dns_so_init() */ + + +struct dns_socket *dns_so_open(const struct sockaddr *local, int type, const struct dns_options *opts, int *error) { + struct dns_socket *so; + + if (!(so = malloc(sizeof *so))) + goto syerr; + + if (!dns_so_init(so, local, type, opts, error)) + goto error; + + return so; +syerr: + *error = dns_syerr(); +error: + dns_so_close(so); + + return 0; +} /* dns_so_open() */ + + +static void dns_so_destroy(struct dns_socket *so) { + dns_so_reset(so); + dns_so_closefds(so, DNS_SO_CLOSE_ALL); + dns_trace_close(so->trace); +} /* dns_so_destroy() */ + + +void dns_so_close(struct dns_socket *so) { + if (!so) + return; + + dns_so_destroy(so); + + free(so); +} /* dns_so_close() */ + + +void dns_so_reset(struct dns_socket *so) { + dns_p_setptr(&so->answer, NULL); + + memset(&so->state, '\0', sizeof *so - offsetof(struct dns_socket, state)); +} /* dns_so_reset() */ + + +unsigned short dns_so_mkqid(struct dns_socket *so) { + return dns_k_permutor_step(&so->qids); +} /* dns_so_mkqid() */ + + +#define DNS_SO_MINBUF 768 + +static int dns_so_newanswer(struct dns_socket *so, size_t len) { + size_t size = offsetof(struct dns_packet, data) + DNS_PP_MAX(len, DNS_SO_MINBUF); + void *p; + + if (!(p = realloc(so->answer, size))) + return dns_syerr(); + + so->answer = dns_p_init(p, size); + + return 0; +} /* dns_so_newanswer() */ + + +int dns_so_submit(struct dns_socket *so, struct dns_packet *Q, struct sockaddr *host) { + struct dns_rr rr; + int error = DNS_EUNKNOWN; + + dns_so_reset(so); + + if ((error = dns_rr_parse(&rr, 12, Q))) + goto error; + + if (!(so->qlen = dns_d_expand(so->qname, sizeof so->qname, rr.dn.p, Q, &error))) + goto error; + /* + * NOTE: Don't bail if expansion is too long; caller may be + * intentionally sending long names. However, we won't be able to + * verify it on return. + */ + + so->qtype = rr.type; + so->qclass = rr.class; + + if ((error = dns_so_newanswer(so, (Q->memo.opt.maxudp)? Q->memo.opt.maxudp : DNS_SO_MINBUF))) + goto syerr; + + memcpy(&so->remote, host, dns_sa_len(host)); + + so->query = Q; + so->qout = 0; + + dns_begin(&so->elapsed); + + if (dns_header(so->query)->qid == 0) + dns_header(so->query)->qid = dns_so_mkqid(so); + + so->qid = dns_header(so->query)->qid; + so->state = (so->opts.socks_host && so->opts.socks_host->ss_family) ? DNS_SO_SOCKS_INIT : + (so->type == SOCK_STREAM)? DNS_SO_TCP_INIT : DNS_SO_UDP_INIT; + + so->stat.queries++; + dns_trace_so_submit(so->trace, Q, host, 0); + + return 0; +syerr: + error = dns_syerr(); +error: + dns_so_reset(so); + dns_trace_so_submit(so->trace, Q, host, error); + return error; +} /* dns_so_submit() */ + + +static int dns_so_verify(struct dns_socket *so, struct dns_packet *P) { + char qname[DNS_D_MAXNAME + 1]; + size_t qlen; + struct dns_rr rr; + int error = -1; + + if (P->end < 12) + goto reject; + + if (so->qid != dns_header(P)->qid) + goto reject; + + if (!dns_p_count(P, DNS_S_QD)) + goto reject; + + if (0 != dns_rr_parse(&rr, 12, P)) + goto reject; + + if (rr.type != so->qtype || rr.class != so->qclass) + goto reject; + + if (!(qlen = dns_d_expand(qname, sizeof qname, rr.dn.p, P, &error))) + goto error; + else if (qlen >= sizeof qname || qlen != so->qlen) + goto reject; + + if (0 != strcasecmp(so->qname, qname)) + goto reject; + + dns_trace_so_verify(so->trace, P, 0); + + return 0; +reject: + error = DNS_EVERIFY; +error: + DNS_SHOW(P, "rejecting packet (%s)", dns_strerror(error)); + dns_trace_so_verify(so->trace, P, error); + + return error; +} /* dns_so_verify() */ + + +static _Bool dns_so_tcp_keep(struct dns_socket *so) { + struct sockaddr_storage remote; + socklen_t l = sizeof remote; + + if (so->tcp == -1) + return 0; + + if (0 != getpeername(so->tcp, (struct sockaddr *)&remote, &l)) + return 0; + + return 0 == dns_sa_cmp(&remote, &so->remote); +} /* dns_so_tcp_keep() */ + + +/* Convenience functions for sending non-DNS data. */ + +/* Set up everything for sending LENGTH octets. Returns the buffer + for the data. */ +static unsigned char *dns_so_tcp_send_buffer(struct dns_socket *so, size_t length) { + /* Skip the length octets, we are not doing DNS. */ + so->qout = 2; + so->query->end = length; + return so->query->data; +} + +/* Set up everything for receiving LENGTH octets. */ +static void dns_so_tcp_recv_expect(struct dns_socket *so, size_t length) { + /* Skip the length octets, we are not doing DNS. */ + so->apos = 2; + so->alen = length; +} + +/* Returns the buffer containing the received data. */ +static unsigned char *dns_so_tcp_recv_buffer(struct dns_socket *so) { + return so->answer->data; +} + + + +#if GPGRT_GCC_VERSION >= 80000 +# pragma GCC diagnostic push +# pragma GCC diagnostic ignored "-Warray-bounds" +#elif defined __clang__ +# pragma clang diagnostic push +# pragma clang diagnostic ignored "-Warray-bounds" +#endif + +static int dns_so_tcp_send(struct dns_socket *so) { + unsigned char *qsrc; + size_t qend; + int error; + size_t n; + + so->query->data[-2] = 0xff & (so->query->end >> 8); + so->query->data[-1] = 0xff & (so->query->end >> 0); + + qend = so->query->end + 2; + + while (so->qout < qend) { + qsrc = &so->query->data[-2] + so->qout; + n = dns_send_nopipe(so->tcp, (void *)qsrc, qend - so->qout, 0, &error); + dns_trace_sys_send(so->trace, so->tcp, SOCK_STREAM, qsrc, n, error); + if (error) + return error; + so->qout += n; + so->stat.tcp.sent.bytes += n; + } + + so->stat.tcp.sent.count++; + + return 0; +} /* dns_so_tcp_send() */ + + +static int dns_so_tcp_recv(struct dns_socket *so) { + unsigned char *asrc; + size_t aend, alen, n; + int error; + + aend = so->alen + 2; + + while (so->apos < aend) { + asrc = &so->answer->data[-2]; + + n = dns_recv(so->tcp, (void *)&asrc[so->apos], aend - so->apos, 0, &error); + dns_trace_sys_recv(so->trace, so->tcp, SOCK_STREAM, &asrc[so->apos], n, error); + if (error) + return error; + + so->apos += n; + so->stat.tcp.rcvd.bytes += n; + + if (so->alen == 0 && so->apos >= 2) { + alen = ((0xff & so->answer->data[-2]) << 8) + | ((0xff & so->answer->data[-1]) << 0); + + if ((error = dns_so_newanswer(so, alen))) + return error; + + so->alen = alen; + aend = alen + 2; + } + } + + so->answer->end = so->alen; + so->stat.tcp.rcvd.count++; + + return 0; +} /* dns_so_tcp_recv() */ + +#if GPGRT_GCC_VERSION >= 80000 +# pragma GCC diagnostic pop +#elif __clang__ +# pragma clang diagnostic pop +#endif + + +int dns_so_check(struct dns_socket *so) { + int error; + size_t n; + unsigned char *buffer; + +retry: + switch (so->state) { + case DNS_SO_UDP_INIT: + if (so->remote.ss_family != so->local.ss_family) { + /* Family mismatch. Reinitialize. */ + if ((error = dns_so_closefd(so, &so->udp))) + goto error; + if ((error = dns_so_closefd(so, &so->tcp))) + goto error; + + /* If the user supplied an interface + statement, that is gone now. Sorry. */ + memset(&so->local, 0, sizeof so->local); + so->local.ss_family = so->remote.ss_family; + + if (-1 == (so->udp = dns_socket((struct sockaddr *)&so->local, SOCK_DGRAM, &error))) + goto error; + } + + so->state++; /* FALL THROUGH */ + case DNS_SO_UDP_CONN: + udp_connect_retry: + error = dns_connect(so->udp, (struct sockaddr *)&so->remote, dns_sa_len(&so->remote)); + dns_trace_sys_connect(so->trace, so->udp, SOCK_DGRAM, (struct sockaddr *)&so->remote, error); + + /* Linux returns EINVAL when address was bound to + localhost and it's external IP address now. */ + if (error == EINVAL) { + struct sockaddr unspec_addr; + memset (&unspec_addr, 0, sizeof unspec_addr); + unspec_addr.sa_family = AF_UNSPEC; + connect(so->udp, &unspec_addr, sizeof unspec_addr); + goto udp_connect_retry; + } else if (error == ECONNREFUSED) + /* Error for previous socket operation may + be reserverd asynchronously. */ + goto udp_connect_retry; + + if (error) + goto error; + + so->state++; /* FALL THROUGH */ + case DNS_SO_UDP_SEND: + n = dns_send(so->udp, (void *)so->query->data, so->query->end, 0, &error); + dns_trace_sys_send(so->trace, so->udp, SOCK_DGRAM, so->query->data, n, error); + if (error) + goto error; + + so->stat.udp.sent.bytes += n; + so->stat.udp.sent.count++; + + so->state++; /* FALL THROUGH */ + case DNS_SO_UDP_RECV: + n = dns_recv(so->udp, (void *)so->answer->data, so->answer->size, 0, &error); + dns_trace_sys_recv(so->trace, so->udp, SOCK_DGRAM, so->answer->data, n, error); + if (error) + goto error; + + so->answer->end = n; + so->stat.udp.rcvd.bytes += n; + so->stat.udp.rcvd.count++; + + if ((error = dns_so_verify(so, so->answer))) + goto trash; + + so->state++; /* FALL THROUGH */ + case DNS_SO_UDP_DONE: + if (!dns_header(so->answer)->tc || so->type == SOCK_DGRAM) + return 0; + + so->state++; /* FALL THROUGH */ + case DNS_SO_TCP_INIT: + if (so->remote.ss_family != so->local.ss_family) { + /* Family mismatch. Reinitialize. */ + if ((error = dns_so_closefd(so, &so->udp))) + goto error; + if ((error = dns_so_closefd(so, &so->tcp))) + goto error; + + /* If the user supplied an interface + statement, that is gone now. Sorry. */ + memset(&so->local, 0, sizeof so->local); + so->local.ss_family = so->remote.ss_family; + } + + if (dns_so_tcp_keep(so)) { + so->state = DNS_SO_TCP_SEND; + + goto retry; + } + + if ((error = dns_so_closefd(so, &so->tcp))) + goto error; + + if (-1 == (so->tcp = dns_socket((struct sockaddr *)&so->local, SOCK_STREAM, &error))) + goto error; + + so->state++; /* FALL THROUGH */ + case DNS_SO_TCP_CONN: + error = dns_connect(so->tcp, (struct sockaddr *)&so->remote, dns_sa_len(&so->remote)); + dns_trace_sys_connect(so->trace, so->tcp, SOCK_STREAM, (struct sockaddr *)&so->remote, error); + if (error && error != DNS_EISCONN) + goto error; + + so->state++; /* FALL THROUGH */ + case DNS_SO_TCP_SEND: + if ((error = dns_so_tcp_send(so))) + goto error; + + so->state++; /* FALL THROUGH */ + case DNS_SO_TCP_RECV: + if ((error = dns_so_tcp_recv(so))) + goto error; + + so->state++; /* FALL THROUGH */ + case DNS_SO_TCP_DONE: + /* close unless DNS_RESCONF_TCP_ONLY (see dns_res_tcp2type) */ + if (so->type != SOCK_STREAM) { + if ((error = dns_so_closefd(so, &so->tcp))) + goto error; + } + + if ((error = dns_so_verify(so, so->answer))) + goto error; + + return 0; + case DNS_SO_SOCKS_INIT: + if ((error = dns_so_closefd(so, &so->tcp))) + goto error; + + if (-1 == (so->tcp = dns_socket((struct sockaddr *)&so->local, SOCK_STREAM, &error))) + goto error; + + so->state++; /* FALL THROUGH */ + case DNS_SO_SOCKS_CONN: { + unsigned char method; + + error = dns_connect(so->tcp, (struct sockaddr *)so->opts.socks_host, dns_sa_len(so->opts.socks_host)); + dns_trace_sys_connect(so->trace, so->tcp, SOCK_STREAM, (struct sockaddr *)so->opts.socks_host, error); + if (error && error != DNS_EISCONN) + goto error; + + /* We need to do a handshake with the SOCKS server, + * but the query is already in the buffer. Move it + * out of the way. */ + dns_p_movptr(&so->query_backup, &so->query); + + /* Create a new buffer for the handshake. */ + dns_p_grow(&so->query); + + /* Negotiate method. */ + buffer = dns_so_tcp_send_buffer(so, 3); + buffer[0] = 5; /* RFC-1928 VER field. */ + buffer[1] = 1; /* NMETHODS */ + if (so->opts.socks_user) + method = 2; /* Method: username/password authentication. */ + else + method = 0; /* Method: No authentication required. */ + buffer[2] = method; + + so->state++; + } /* FALL THROUGH */ + case DNS_SO_SOCKS_HELLO_SEND: + if ((error = dns_so_tcp_send(so))) + goto error; + + dns_so_tcp_recv_expect(so, 2); + so->state++; /* FALL THROUGH */ + case DNS_SO_SOCKS_HELLO_RECV: { + unsigned char method; + + if ((error = dns_so_tcp_recv(so))) + goto error; + + buffer = dns_so_tcp_recv_buffer(so); + method = so->opts.socks_user ? 2 : 0; + if (buffer[0] != 5 || buffer[1] != method) { + /* Socks server returned wrong version or does + not support our requested method. */ + error = ENOTSUP; /* Fixme: Is there a better errno? */ + goto error; + } + + if (method == 0) { + /* No authentication, go ahead and send the + request. */ + so->state = DNS_SO_SOCKS_REQUEST_PREPARE; + goto retry; + } + + /* Prepare username/password sub-negotiation. */ + if (! so->opts.socks_password) { + error = EINVAL; /* No password given. */ + goto error; + } else { + size_t buflen, ulen, plen; + + ulen = strlen(so->opts.socks_user); + plen = strlen(so->opts.socks_password); + if (!ulen || ulen > 255 || !plen || plen > 255) { + error = EINVAL; /* Credentials too long or too short. */ + goto error; + } + + buffer = dns_so_tcp_send_buffer(so, 3 + ulen + plen); + buffer[0] = 1; /* VER of the sub-negotiation. */ + buffer[1] = (unsigned char) ulen; + buflen = 2; + memcpy (buffer+buflen, so->opts.socks_user, ulen); + buflen += ulen; + buffer[buflen++] = (unsigned char) plen; + memcpy (buffer+buflen, so->opts.socks_password, plen); + } + + so->state++; + } /* FALL THROUGH */ + case DNS_SO_SOCKS_AUTH_SEND: + if ((error = dns_so_tcp_send(so))) + goto error; + + /* Skip the two length octets, and receive two octets. */ + dns_so_tcp_recv_expect(so, 2); + + so->state++; /* FALL THROUGH */ + case DNS_SO_SOCKS_AUTH_RECV: + if ((error = dns_so_tcp_recv(so))) + goto error; + + buffer = dns_so_tcp_recv_buffer(so); + if (buffer[0] != 1) { + /* SOCKS server returned wrong version. */ + error = EPROTO; + goto error; + } + if (buffer[1]) { + /* SOCKS server denied access. */ + error = EACCES; + goto error; + } + + so->state++; /* FALL THROUGH */ + case DNS_SO_SOCKS_REQUEST_PREPARE: + /* Send request details (rfc-1928, 4). */ + buffer = dns_so_tcp_send_buffer(so, so->remote.ss_family == AF_INET6 ? 22 : 10); + buffer[0] = 5; /* VER */ + buffer[1] = 1; /* CMD = CONNECT */ + buffer[2] = 0; /* RSV */ + if (so->remote.ss_family == AF_INET6) { + struct sockaddr_in6 *addr_in6 = (struct sockaddr_in6 *)&so->remote; + + buffer[3] = 4; /* ATYP = IPv6 */ + memcpy (buffer+ 4, &addr_in6->sin6_addr.s6_addr, 16); /* DST.ADDR */ + memcpy (buffer+20, &addr_in6->sin6_port, 2); /* DST.PORT */ + } else { + struct sockaddr_in *addr_in = (struct sockaddr_in *)&so->remote; + + buffer[3] = 1; /* ATYP = IPv4 */ + memcpy (buffer+4, &addr_in->sin_addr.s_addr, 4); /* DST.ADDR */ + memcpy (buffer+8, &addr_in->sin_port, 2); /* DST.PORT */ + } + + so->state++; /* FALL THROUGH */ + case DNS_SO_SOCKS_REQUEST_SEND: + if ((error = dns_so_tcp_send(so))) + goto error; + + /* Expect ten octets. This is the length of the + * response assuming a IPv4 address is used. */ + dns_so_tcp_recv_expect(so, 10); + so->state++; /* FALL THROUGH */ + case DNS_SO_SOCKS_REQUEST_RECV: + if ((error = dns_so_tcp_recv(so))) + goto error; + + buffer = dns_so_tcp_recv_buffer(so); + if (buffer[0] != 5 || buffer[2] != 0) { + /* Socks server returned wrong version or the + reserved field is not zero. */ + error = EPROTO; + goto error; + } + if (buffer[1]) { + switch (buffer[1]) { + case 0x01: /* general SOCKS server failure. */ + error = ENETDOWN; + break; + case 0x02: /* connection not allowed by ruleset. */ + error = EACCES; + break; + case 0x03: /* Network unreachable */ + error = ENETUNREACH; + break; + case 0x04: /* Host unreachable */ + error = EHOSTUNREACH; + break; + case 0x05: /* Connection refused */ + error = ECONNREFUSED; + break; + case 0x06: /* TTL expired */ + error = ETIMEDOUT; + break; + case 0x08: /* Address type not supported */ + error = EPROTONOSUPPORT; + break; + case 0x07: /* Command not supported */ + default: + error = ENOTSUP; /* Fixme: Is there a better error? */ + break; + } + goto error; + } + + if (buffer[3] == 1) { + /* This was indeed an IPv4 address. */ + so->state = DNS_SO_SOCKS_HANDSHAKE_DONE; + goto retry; + } + + if (buffer[3] != 4) { + error = ENOTSUP; + goto error; + } + + /* Expect receive twelve octets. This accounts for + * the remaining bytes assuming an IPv6 address is + * used. */ + dns_so_tcp_recv_expect(so, 12); + so->state++; /* FALL THROUGH */ + case DNS_SO_SOCKS_REQUEST_RECV_V6: + if ((error = dns_so_tcp_recv(so))) + goto error; + + so->state++; /* FALL THROUGH */ + case DNS_SO_SOCKS_HANDSHAKE_DONE: + /* We have not way to store the actual address used by + * the server. Then again, we don't really care. */ + + /* Restore the query. */ + dns_p_movptr(&so->query, &so->query_backup); + + /* Reset cursors. */ + so->qout = 0; + so->apos = 0; + so->alen = 0; + + /* SOCKS handshake is done. Proceed with the + * lookup. */ + so->state = DNS_SO_TCP_SEND; + goto retry; + default: + error = DNS_EUNKNOWN; + + goto error; + } /* switch() */ + +trash: + DNS_CARP("discarding packet"); + goto retry; +error: + switch (error) { + case DNS_EINTR: + goto retry; + case DNS_EINPROGRESS: + /* FALL THROUGH */ + case DNS_EALREADY: + /* FALL THROUGH */ +#if DNS_EWOULDBLOCK != DNS_EAGAIN + case DNS_EWOULDBLOCK: + /* FALL THROUGH */ +#endif + error = DNS_EAGAIN; + + break; + } /* switch() */ + + return error; +} /* dns_so_check() */ + + +struct dns_packet *dns_so_fetch(struct dns_socket *so, int *error) { + struct dns_packet *answer; + + switch (so->state) { + case DNS_SO_UDP_DONE: + case DNS_SO_TCP_DONE: + answer = so->answer; + so->answer = 0; + dns_trace_so_fetch(so->trace, answer, 0); + + return answer; + default: + *error = DNS_EUNKNOWN; + dns_trace_so_fetch(so->trace, NULL, *error); + + return 0; + } +} /* dns_so_fetch() */ + + +struct dns_packet *dns_so_query(struct dns_socket *so, struct dns_packet *Q, struct sockaddr *host, int *error_) { + struct dns_packet *A; + int error; + + if (!so->state) { + if ((error = dns_so_submit(so, Q, host))) + goto error; + } + + if ((error = dns_so_check(so))) + goto error; + + if (!(A = dns_so_fetch(so, &error))) + goto error; + + dns_so_reset(so); + + return A; +error: + *error_ = error; + + return 0; +} /* dns_so_query() */ + + +time_t dns_so_elapsed(struct dns_socket *so) { + return dns_elapsed(&so->elapsed); +} /* dns_so_elapsed() */ + + +void dns_so_clear(struct dns_socket *so) { + dns_so_closefds(so, DNS_SO_CLOSE_OLD); +} /* dns_so_clear() */ + + +static int dns_so_events2(struct dns_socket *so, enum dns_events type) { + int events = 0; + + switch (so->state) { + case DNS_SO_UDP_CONN: + case DNS_SO_UDP_SEND: + events |= DNS_POLLOUT; + + break; + case DNS_SO_UDP_RECV: + events |= DNS_POLLIN; + + break; + case DNS_SO_TCP_CONN: + case DNS_SO_TCP_SEND: + events |= DNS_POLLOUT; + + break; + case DNS_SO_TCP_RECV: + events |= DNS_POLLIN; + + break; + } /* switch() */ + + switch (type) { + case DNS_LIBEVENT: + return DNS_POLL2EV(events); + default: + return events; + } /* switch() */ +} /* dns_so_events2() */ + + +int dns_so_events(struct dns_socket *so) { + return dns_so_events2(so, so->opts.events); +} /* dns_so_events() */ + + +int dns_so_pollfd(struct dns_socket *so) { + switch (so->state) { + case DNS_SO_UDP_CONN: + case DNS_SO_UDP_SEND: + case DNS_SO_UDP_RECV: + return so->udp; + case DNS_SO_TCP_CONN: + case DNS_SO_TCP_SEND: + case DNS_SO_TCP_RECV: + return so->tcp; + } /* switch() */ + + return -1; +} /* dns_so_pollfd() */ + + +int dns_so_poll(struct dns_socket *so, int timeout) { + return dns_poll(dns_so_pollfd(so), dns_so_events2(so, DNS_SYSPOLL), timeout); +} /* dns_so_poll() */ + + +const struct dns_stat *dns_so_stat(struct dns_socket *so) { + return &so->stat; +} /* dns_so_stat() */ + + +struct dns_trace *dns_so_trace(struct dns_socket *so) { + return so->trace; +} /* dns_so_trace() */ + + +void dns_so_settrace(struct dns_socket *so, struct dns_trace *trace) { + struct dns_trace *otrace = so->trace; + so->trace = dns_trace_acquire_p(trace); + dns_trace_close(otrace); +} /* dns_so_settrace() */ + + +/* + * R E S O L V E R R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +enum dns_res_state { + DNS_R_INIT, + DNS_R_GLUE, + DNS_R_SWITCH, /* (B)IND, (F)ILE, (C)ACHE */ + + DNS_R_FILE, /* Lookup in local hosts database */ + + DNS_R_CACHE, /* Lookup in application cache */ + DNS_R_SUBMIT, + DNS_R_CHECK, + DNS_R_FETCH, + + DNS_R_BIND, /* Lookup in the network */ + DNS_R_SEARCH, + DNS_R_HINTS, + DNS_R_ITERATE, + DNS_R_FOREACH_NS, + DNS_R_RESOLV0_NS, /* Prologue: Setup next frame and recurse */ + DNS_R_RESOLV1_NS, /* Epilog: Inspect answer */ + DNS_R_FOREACH_A, + DNS_R_QUERY_A, + DNS_R_FOREACH_AAAA, + DNS_R_QUERY_AAAA, + DNS_R_CNAME0_A, + DNS_R_CNAME1_A, + + DNS_R_FINISH, + DNS_R_SMART0_A, + DNS_R_SMART1_A, + DNS_R_DONE, + DNS_R_SERVFAIL, +}; /* enum dns_res_state */ + + +#define DNS_R_MAXDEPTH 8 +#define DNS_R_ENDFRAME (DNS_R_MAXDEPTH - 1) + +struct dns_resolver { + struct dns_socket so; + + struct dns_resolv_conf *resconf; + struct dns_hosts *hosts; + struct dns_hints *hints; + struct dns_cache *cache; + struct dns_trace *trace; + + dns_atomic_t refcount; + + /* Reset zeroes everything below here. */ + + char qname[DNS_D_MAXNAME + 1]; + size_t qlen; + + enum dns_type qtype; + enum dns_class qclass; + + struct dns_clock elapsed; + + dns_resconf_i_t search; + + struct dns_rr_i smart; + + struct dns_packet *nodata; /* answer if nothing better */ + + unsigned sp; + + struct dns_res_frame { + enum dns_res_state state; + + int error; + int which; /* (B)IND, (F)ILE; index into resconf->lookup */ + int qflags; + + unsigned attempts; + + struct dns_packet *query, *answer, *hints; + + struct dns_rr_i hints_i, hints_j; + struct dns_rr hints_ns, ans_cname; + } stack[DNS_R_MAXDEPTH]; +}; /* struct dns_resolver */ + + +static int dns_res_tcp2type(int tcp) { + switch (tcp) { + case DNS_RESCONF_TCP_ONLY: + case DNS_RESCONF_TCP_SOCKS: + return SOCK_STREAM; + case DNS_RESCONF_TCP_DISABLE: + return SOCK_DGRAM; + default: + return 0; + } +} /* dns_res_tcp2type() */ + +struct dns_resolver *dns_res_open(struct dns_resolv_conf *resconf, struct dns_hosts *hosts, struct dns_hints *hints, struct dns_cache *cache, const struct dns_options *opts, int *_error) { + static const struct dns_resolver R_initializer + = { .refcount = 1, }; + struct dns_resolver *R = 0; + int type, error; + + /* + * Grab ref count early because the caller may have passed us a mortal + * reference, and we want to do the right thing if we return early + * from an error. + */ + if (resconf) + dns_resconf_acquire(resconf); + if (hosts) + dns_hosts_acquire(hosts); + if (hints) + dns_hints_acquire(hints); + if (cache) + dns_cache_acquire(cache); + + /* + * Don't try to load it ourselves because a NULL object might be an + * error from, say, dns_resconf_root(), and loading + * dns_resconf_local() by default would create undesirable surpises. + */ + if (!resconf || !hosts || !hints) { + if (!*_error) + *_error = EINVAL; + goto _error; + } + + if (!(R = malloc(sizeof *R))) + goto syerr; + + *R = R_initializer; + type = dns_res_tcp2type(resconf->options.tcp); + + if (!dns_so_init(&R->so, (struct sockaddr *)&resconf->iface, type, opts, &error)) + goto error; + + R->resconf = resconf; + R->hosts = hosts; + R->hints = hints; + R->cache = cache; + + return R; +syerr: + error = dns_syerr(); +error: + *_error = error; +_error: + dns_res_close(R); + + dns_resconf_close(resconf); + dns_hosts_close(hosts); + dns_hints_close(hints); + dns_cache_close(cache); + + return 0; +} /* dns_res_open() */ + + +struct dns_resolver *dns_res_stub(const struct dns_options *opts, int *error) { + struct dns_resolv_conf *resconf = 0; + struct dns_hosts *hosts = 0; + struct dns_hints *hints = 0; + struct dns_resolver *res = 0; + + if (!(resconf = dns_resconf_local(error))) + goto epilog; + + if (!(hosts = dns_hosts_local(error))) + goto epilog; + + if (!(hints = dns_hints_local(resconf, error))) + goto epilog; + + if (!(res = dns_res_open(resconf, hosts, hints, NULL, opts, error))) + goto epilog; + +epilog: + dns_resconf_close(resconf); + dns_hosts_close(hosts); + dns_hints_close(hints); + + return res; +} /* dns_res_stub() */ + + +static void dns_res_frame_destroy(struct dns_resolver *R, struct dns_res_frame *frame) { + (void)R; + + dns_p_setptr(&frame->query, NULL); + dns_p_setptr(&frame->answer, NULL); + dns_p_setptr(&frame->hints, NULL); +} /* dns_res_frame_destroy() */ + + +static void dns_res_frame_init(struct dns_resolver *R, struct dns_res_frame *frame) { + memset(frame, '\0', sizeof *frame); + + /* + * NB: Can be invoked from dns_res_open, before R->resconf has been + * initialized. + */ + if (R->resconf) { + if (!R->resconf->options.recurse) + frame->qflags |= DNS_Q_RD; + if (R->resconf->options.edns0) + frame->qflags |= DNS_Q_EDNS0; + } +} /* dns_res_frame_init() */ + + +static void dns_res_frame_reset(struct dns_resolver *R, struct dns_res_frame *frame) { + dns_res_frame_destroy(R, frame); + dns_res_frame_init(R, frame); +} /* dns_res_frame_reset() */ + + +static dns_error_t dns_res_frame_prepare(struct dns_resolver *R, struct dns_res_frame *F, const char *qname, enum dns_type qtype, enum dns_class qclass) { + struct dns_packet *P = NULL; + + if (!(F < endof(R->stack))) + return DNS_EUNKNOWN; + + dns_p_movptr(&P, &F->query); + dns_res_frame_reset(R, F); + dns_p_movptr(&F->query, &P); + + return dns_q_make(&F->query, qname, qtype, qclass, F->qflags); +} /* dns_res_frame_prepare() */ + + +void dns_res_reset(struct dns_resolver *R) { + unsigned i; + + dns_so_reset(&R->so); + dns_p_setptr(&R->nodata, NULL); + + for (i = 0; i < lengthof(R->stack); i++) + dns_res_frame_destroy(R, &R->stack[i]); + + memset(&R->qname, '\0', sizeof *R - offsetof(struct dns_resolver, qname)); + + for (i = 0; i < lengthof(R->stack); i++) + dns_res_frame_init(R, &R->stack[i]); +} /* dns_res_reset() */ + + +void dns_res_close(struct dns_resolver *R) { + if (!R || 1 < dns_res_release(R)) + return; + + dns_res_reset(R); + + dns_so_destroy(&R->so); + + dns_hints_close(R->hints); + dns_hosts_close(R->hosts); + dns_resconf_close(R->resconf); + dns_cache_close(R->cache); + dns_trace_close(R->trace); + + free(R); +} /* dns_res_close() */ + + +dns_refcount_t dns_res_acquire(struct dns_resolver *R) { + return dns_atomic_fetch_add(&R->refcount); +} /* dns_res_acquire() */ + + +dns_refcount_t dns_res_release(struct dns_resolver *R) { + return dns_atomic_fetch_sub(&R->refcount); +} /* dns_res_release() */ + + +struct dns_resolver *dns_res_mortal(struct dns_resolver *res) { + if (res) + dns_res_release(res); + return res; +} /* dns_res_mortal() */ + + +static struct dns_packet *dns_res_merge(struct dns_packet *P0, struct dns_packet *P1, int *error_) { + size_t bufsiz = P0->end + P1->end; + struct dns_packet *P[3] = { P0, P1, 0 }; + struct dns_rr rr[3]; + int error, copy, i; + enum dns_section section; + +retry: + if (!(P[2] = dns_p_make(bufsiz, &error))) + goto error; + + dns_rr_foreach(&rr[0], P[0], .section = DNS_S_QD) { + if ((error = dns_rr_copy(P[2], &rr[0], P[0]))) + goto error; + } + + for (section = DNS_S_AN; (DNS_S_ALL & section); section <<= 1) { + for (i = 0; i < 2; i++) { + dns_rr_foreach(&rr[i], P[i], .section = section) { + copy = 1; + + dns_rr_foreach(&rr[2], P[2], .type = rr[i].type, .section = (DNS_S_ALL & ~DNS_S_QD)) { + if (0 == dns_rr_cmp(&rr[i], P[i], &rr[2], P[2])) { + copy = 0; + + break; + } + } + + if (copy && (error = dns_rr_copy(P[2], &rr[i], P[i]))) { + if (error == DNS_ENOBUFS && bufsiz < 65535) { + dns_p_setptr(&P[2], NULL); + + bufsiz = DNS_PP_MAX(65535, bufsiz * 2); + + goto retry; + } + + goto error; + } + } /* foreach(rr) */ + } /* foreach(packet) */ + } /* foreach(section) */ + + return P[2]; +error: + *error_ = error; + + dns_p_free(P[2]); + + return 0; +} /* dns_res_merge() */ + + +static struct dns_packet *dns_res_glue(struct dns_resolver *R, struct dns_packet *Q) { + union { unsigned char b[dns_p_calcsize((512))]; struct dns_packet p; } P_instance = { 0 }; + struct dns_packet *P = dns_p_init(&P_instance.p, 512); + char qname[DNS_D_MAXNAME + 1]; + size_t qlen; + enum dns_type qtype; + struct dns_rr rr; + unsigned sp; + int error; + + if (!(qlen = dns_d_expand(qname, sizeof qname, 12, Q, &error)) + || qlen >= sizeof qname) + return 0; + + if (!(qtype = dns_rr_type(12, Q))) + return 0; + + if ((error = dns_p_push(P, DNS_S_QD, qname, strlen(qname), qtype, DNS_C_IN, 0, 0))) + return 0; + + for (sp = 0; sp <= R->sp; sp++) { + if (!R->stack[sp].answer) + continue; + + dns_rr_foreach(&rr, R->stack[sp].answer, .name = qname, .type = qtype, .section = (DNS_S_ALL & ~DNS_S_QD)) { + rr.section = DNS_S_AN; + + if ((error = dns_rr_copy(P, &rr, R->stack[sp].answer))) + return 0; + } + } + + if (dns_p_count(P, DNS_S_AN) > 0) + goto copy; + + /* Otherwise, look for a CNAME */ + for (sp = 0; sp <= R->sp; sp++) { + if (!R->stack[sp].answer) + continue; + + dns_rr_foreach(&rr, R->stack[sp].answer, .name = qname, .type = DNS_T_CNAME, .section = (DNS_S_ALL & ~DNS_S_QD)) { + rr.section = DNS_S_AN; + + if ((error = dns_rr_copy(P, &rr, R->stack[sp].answer))) + return 0; + } + } + + if (!dns_p_count(P, DNS_S_AN)) + return 0; + +copy: + return dns_p_copy(dns_p_make(P->end, &error), P); +} /* dns_res_glue() */ + + +/* + * Sort NS records by three criteria: + * + * 1) Whether glue is present. + * 2) Whether glue record is original or of recursive lookup. + * 3) Randomly shuffle records which share the above criteria. + * + * NOTE: Assumes only NS records passed, AND ASSUMES no new NS records will + * be added during an iteration. + * + * FIXME: Only groks A glue, not AAAA glue. + */ +static int dns_res_nameserv_cmp(struct dns_rr *a, struct dns_rr *b, struct dns_rr_i *i, struct dns_packet *P) { + _Bool glued[2] = { 0 }; + struct dns_rr x = { 0 }, y = { 0 }; + struct dns_ns ns; + int cmp, error; + + if (!(error = dns_ns_parse(&ns, a, P))) { + struct dns_rr_i I_instance = { 0 }; + + I_instance.section = (DNS_S_ALL & ~DNS_S_QD); + I_instance.name = ns.host; + I_instance.type = DNS_T_A; + glued[0] = !!dns_rr_grep(&x, 1, &I_instance, P, &error); + } + if (!(error = dns_ns_parse(&ns, b, P))) { + struct dns_rr_i I_instance = { 0 }; + + I_instance.section = (DNS_S_ALL & ~DNS_S_QD); + I_instance.name = ns.host; + I_instance.type = DNS_T_A; + glued[1] = !!dns_rr_grep(&y, 1, &I_instance, P, &error); + } + if ((cmp = glued[1] - glued[0])) { + return cmp; + } else if ((cmp = (dns_rr_offset(&y) < i->args[0]) - (dns_rr_offset(&x) < i->args[0]))) { + return cmp; + } else { + return dns_rr_i_shuffle(a, b, i, P); + } +} /* dns_res_nameserv_cmp() */ + + +#define dgoto(sp, i) \ + do { R->stack[(sp)].state = (i); goto exec; } while (0) + +static int dns_res_exec(struct dns_resolver *R) { + struct dns_res_frame *F; + struct dns_packet *P; + union { + char host[DNS_D_MAXNAME + 1]; + char name[DNS_D_MAXNAME + 1]; + struct dns_ns ns; + struct dns_cname cname; + } u; + size_t len; + struct dns_rr rr; + int error; + +exec: + + F = &R->stack[R->sp]; + + switch (F->state) { + case DNS_R_INIT: + F->state++; /* FALL THROUGH */ + case DNS_R_GLUE: + if (R->sp == 0) + dgoto(R->sp, DNS_R_SWITCH); + + if (!F->query) + goto noquery; + + if (!(F->answer = dns_res_glue(R, F->query))) + dgoto(R->sp, DNS_R_SWITCH); + + if (!(len = dns_d_expand(u.name, sizeof u.name, 12, F->query, &error))) + goto error; + else if (len >= sizeof u.name) + goto toolong; + + dns_rr_foreach(&rr, F->answer, .name = u.name, .type = dns_rr_type(12, F->query), .section = DNS_S_AN) { + dgoto(R->sp, DNS_R_FINISH); + } + + dns_rr_foreach(&rr, F->answer, .name = u.name, .type = DNS_T_CNAME, .section = DNS_S_AN) { + F->ans_cname = rr; + + dgoto(R->sp, DNS_R_CNAME0_A); + } + + F->state++; + case DNS_R_SWITCH: + while (F->which < (int)sizeof R->resconf->lookup && R->resconf->lookup[F->which]) { + switch (R->resconf->lookup[F->which++]) { + case 'b': case 'B': + dgoto(R->sp, DNS_R_BIND); + case 'f': case 'F': + dgoto(R->sp, DNS_R_FILE); + case 'c': case 'C': + if (R->cache) + dgoto(R->sp, DNS_R_CACHE); + + break; + default: + break; + } + } + + /* + * FIXME: Examine more closely whether our logic is correct + * and DNS_R_SERVFAIL is the correct default response. + * + * Case 1: We got here because we never got an answer on the + * wire. All queries timed-out and we reached maximum + * attempts count. See DNS_R_FOREACH_NS. In that case + * DNS_R_SERVFAIL is the correct state, unless we want to + * return DNS_ETIMEDOUT. + * + * Case 2: We were a stub resolver and got an unsatisfactory + * answer (empty ANSWER section) which caused us to jump + * back to DNS_R_SEARCH and ultimately to DNS_R_SWITCH. We + * return the answer returned from the wire, which we + * stashed in R->nodata. + * + * Case 3: We reached maximum attempts count as in case #1, + * but never got an authoritative response which caused us + * to short-circuit. See end of DNS_R_QUERY_A case. We + * should probably prepare R->nodata as in case #2. + */ + if (R->sp == 0 && R->nodata) { /* XXX: can we just return nodata regardless? */ + dns_p_movptr(&F->answer, &R->nodata); + dgoto(R->sp, DNS_R_FINISH); + } + + dgoto(R->sp, DNS_R_SERVFAIL); + case DNS_R_FILE: + if (R->sp > 0) { + if (!dns_p_setptr(&F->answer, dns_hosts_query(R->hosts, F->query, &error))) + goto error; + + if (dns_p_count(F->answer, DNS_S_AN) > 0) + dgoto(R->sp, DNS_R_FINISH); + + dns_p_setptr(&F->answer, NULL); + } else { + R->search = 0; + + while ((len = dns_resconf_search(u.name, sizeof u.name, R->qname, R->qlen, R->resconf, &R->search))) { + if ((error = dns_q_make2(&F->query, u.name, len, R->qtype, R->qclass, F->qflags))) + goto error; + + if (!dns_p_setptr(&F->answer, dns_hosts_query(R->hosts, F->query, &error))) + goto error; + + if (dns_p_count(F->answer, DNS_S_AN) > 0) + dgoto(R->sp, DNS_R_FINISH); + + dns_p_setptr(&F->answer, NULL); + } + } + + dgoto(R->sp, DNS_R_SWITCH); + case DNS_R_CACHE: + error = 0; + + if (!F->query && (error = dns_q_make(&F->query, R->qname, R->qtype, R->qclass, F->qflags))) + goto error; + + if (dns_p_setptr(&F->answer, R->cache->query(F->query, R->cache, &error))) { + if (dns_p_count(F->answer, DNS_S_AN) > 0) + dgoto(R->sp, DNS_R_FINISH); + + dns_p_setptr(&F->answer, NULL); + + dgoto(R->sp, DNS_R_SWITCH); + } else if (error) + goto error; + + F->state++; /* FALL THROUGH */ + case DNS_R_SUBMIT: + if ((error = R->cache->submit(F->query, R->cache))) + goto error; + + F->state++; /* FALL THROUGH */ + case DNS_R_CHECK: + if ((error = R->cache->check(R->cache))) + goto error; + + F->state++; /* FALL THROUGH */ + case DNS_R_FETCH: + error = 0; + + if (dns_p_setptr(&F->answer, R->cache->fetch(R->cache, &error))) { + if (dns_p_count(F->answer, DNS_S_AN) > 0) + dgoto(R->sp, DNS_R_FINISH); + + dns_p_setptr(&F->answer, NULL); + + dgoto(R->sp, DNS_R_SWITCH); + } else if (error) + goto error; + + dgoto(R->sp, DNS_R_SWITCH); + case DNS_R_BIND: + if (R->sp > 0) { + if (!F->query) + goto noquery; + + dgoto(R->sp, DNS_R_HINTS); + } + + R->search = 0; + + F->state++; /* FALL THROUGH */ + case DNS_R_SEARCH: + /* + * XXX: We probably should only apply the domain search + * algorithm if R->sp == 0. + */ + if (!(len = dns_resconf_search(u.name, sizeof u.name, R->qname, R->qlen, R->resconf, &R->search))) + dgoto(R->sp, DNS_R_SWITCH); + + if ((error = dns_q_make2(&F->query, u.name, len, R->qtype, R->qclass, F->qflags))) + goto error; + + F->state++; /* FALL THROUGH */ + case DNS_R_HINTS: + if (!dns_p_setptr(&F->hints, dns_hints_query(R->hints, F->query, &error))) + goto error; + + F->state++; /* FALL THROUGH */ + case DNS_R_ITERATE: + dns_rr_i_init(&F->hints_i); + + F->hints_i.section = DNS_S_AUTHORITY; + F->hints_i.type = DNS_T_NS; + F->hints_i.sort = &dns_res_nameserv_cmp; + F->hints_i.args[0] = F->hints->end; + + F->state++; /* FALL THROUGH */ + case DNS_R_FOREACH_NS: + dns_rr_i_save(&F->hints_i); + + /* Load our next nameserver host. */ + if (!dns_rr_grep(&F->hints_ns, 1, &F->hints_i, F->hints, &error)) { + if (++F->attempts < R->resconf->options.attempts) + dgoto(R->sp, DNS_R_ITERATE); + + dgoto(R->sp, DNS_R_SWITCH); + } + + dns_rr_i_init(&F->hints_j); + + /* Assume there are glue records */ + dgoto(R->sp, DNS_R_FOREACH_A); + case DNS_R_RESOLV0_NS: + /* Have we reached our max depth? */ + if (&F[1] >= endof(R->stack)) + dgoto(R->sp, DNS_R_FOREACH_NS); + + if ((error = dns_ns_parse(&u.ns, &F->hints_ns, F->hints))) + goto error; + if ((error = dns_res_frame_prepare(R, &F[1], u.ns.host, DNS_T_A, DNS_C_IN))) + goto error; + + F->state++; + + dgoto(++R->sp, DNS_R_INIT); + case DNS_R_RESOLV1_NS: + if (!(len = dns_d_expand(u.host, sizeof u.host, 12, F[1].query, &error))) + goto error; + else if (len >= sizeof u.host) + goto toolong; + + dns_rr_foreach(&rr, F[1].answer, .name = u.host, .type = DNS_T_A, .section = (DNS_S_ALL & ~DNS_S_QD)) { + rr.section = DNS_S_AR; + + if ((error = dns_rr_copy(F->hints, &rr, F[1].answer))) + goto error; + + dns_rr_i_rewind(&F->hints_i); /* Now there's glue. */ + } + + dgoto(R->sp, DNS_R_FOREACH_NS); + case DNS_R_FOREACH_A: { + struct dns_a a; + struct sockaddr_in sin; + + /* + * NOTE: Iterator initialized in DNS_R_FOREACH_NS because + * this state is re-entrant, but we need to reset + * .name to a valid pointer each time. + */ + if ((error = dns_ns_parse(&u.ns, &F->hints_ns, F->hints))) + goto error; + + F->hints_j.name = u.ns.host; + F->hints_j.type = DNS_T_A; + F->hints_j.section = DNS_S_ALL & ~DNS_S_QD; + + if (!dns_rr_grep(&rr, 1, &F->hints_j, F->hints, &error)) { + if (!dns_rr_i_count(&F->hints_j)) { + /* Check if we have in fact servers + with an IPv6 address. */ + dns_rr_i_init(&F->hints_j); + F->hints_j.name = u.ns.host; + F->hints_j.type = DNS_T_AAAA; + F->hints_j.section = DNS_S_ALL & ~DNS_S_QD; + if (dns_rr_grep(&rr, 1, &F->hints_j, F->hints, &error)) { + /* We do. Reinitialize + iterator and handle it. */ + dns_rr_i_init(&F->hints_j); + dgoto(R->sp, DNS_R_FOREACH_AAAA); + } + + dgoto(R->sp, DNS_R_RESOLV0_NS); + } + + dgoto(R->sp, DNS_R_FOREACH_NS); + } + + if ((error = dns_a_parse(&a, &rr, F->hints))) + goto error; + + memset(&sin, '\0', sizeof sin); /* NB: silence valgrind */ + sin.sin_family = AF_INET; + sin.sin_addr = a.addr; + if (R->sp == 0) + sin.sin_port = dns_hints_port(R->hints, AF_INET, &sin.sin_addr); + else + sin.sin_port = htons(53); + + if (DNS_DEBUG) { + char addr[INET_ADDRSTRLEN + 1]; + dns_a_print(addr, sizeof addr, &a); + dns_header(F->query)->qid = dns_so_mkqid(&R->so); + DNS_SHOW(F->query, "ASKING: %s/%s @ DEPTH: %u)", u.ns.host, addr, R->sp); + } + + dns_trace_setcname(R->trace, u.ns.host, (struct sockaddr *)&sin); + + if ((error = dns_so_submit(&R->so, F->query, (struct sockaddr *)&sin))) + goto error; + + F->state++; + } /* FALL THROUGH */ + case DNS_R_QUERY_A: + if (dns_so_elapsed(&R->so) >= dns_resconf_timeout(R->resconf)) + dgoto(R->sp, DNS_R_FOREACH_A); + + error = dns_so_check(&R->so); + if (R->so.state != DNS_SO_SOCKS_CONN && error == ECONNREFUSED) + dgoto(R->sp, DNS_R_FOREACH_A); + else if (error) + goto error; + + if (!dns_p_setptr(&F->answer, dns_so_fetch(&R->so, &error))) + goto error; + + if (DNS_DEBUG) { + DNS_SHOW(F->answer, "ANSWER @ DEPTH: %u)", R->sp); + } + + if (dns_p_rcode(F->answer) == DNS_RC_FORMERR || + dns_p_rcode(F->answer) == DNS_RC_NOTIMP || + dns_p_rcode(F->answer) == DNS_RC_BADVERS) { + /* Temporarily disable EDNS0 and try again. */ + if (F->qflags & DNS_Q_EDNS0) { + F->qflags &= ~DNS_Q_EDNS0; + if ((error = dns_q_remake(&F->query, F->qflags))) + goto error; + + dgoto(R->sp, DNS_R_FOREACH_A); + } + } + + if ((error = dns_rr_parse(&rr, 12, F->query))) + goto error; + + if (!(len = dns_d_expand(u.name, sizeof u.name, rr.dn.p, F->query, &error))) + goto error; + else if (len >= sizeof u.name) + goto toolong; + + dns_rr_foreach(&rr, F->answer, .section = DNS_S_AN, .name = u.name, .type = rr.type) { + dgoto(R->sp, DNS_R_FINISH); /* Found */ + } + + dns_rr_foreach(&rr, F->answer, .section = DNS_S_AN, .name = u.name, .type = DNS_T_CNAME) { + F->ans_cname = rr; + + dgoto(R->sp, DNS_R_CNAME0_A); + } + + /* + * XXX: The condition here should probably check whether + * R->sp == 0, because DNS_R_SEARCH runs regardless of + * options.recurse. See DNS_R_BIND. + */ + if (!R->resconf->options.recurse) { + /* Make first answer our tentative answer */ + if (!R->nodata) + dns_p_movptr(&R->nodata, &F->answer); + + dgoto(R->sp, DNS_R_SEARCH); + } + + dns_rr_foreach(&rr, F->answer, .section = DNS_S_NS, .type = DNS_T_NS) { + dns_p_movptr(&F->hints, &F->answer); + + dgoto(R->sp, DNS_R_ITERATE); + } + + /* XXX: Should this go further up? */ + if (dns_header(F->answer)->aa) + dgoto(R->sp, DNS_R_FINISH); + + /* XXX: Should we copy F->answer to R->nodata? */ + + dgoto(R->sp, DNS_R_FOREACH_A); + case DNS_R_FOREACH_AAAA: { + struct dns_aaaa aaaa; + struct sockaddr_in6 sin6; + + /* + * NOTE: Iterator initialized in DNS_R_FOREACH_NS because + * this state is re-entrant, but we need to reset + * .name to a valid pointer each time. + */ + if ((error = dns_ns_parse(&u.ns, &F->hints_ns, F->hints))) + goto error; + + F->hints_j.name = u.ns.host; + F->hints_j.type = DNS_T_AAAA; + F->hints_j.section = DNS_S_ALL & ~DNS_S_QD; + + if (!dns_rr_grep(&rr, 1, &F->hints_j, F->hints, &error)) { + if (!dns_rr_i_count(&F->hints_j)) { + /* Check if we have in fact servers + with an IPv4 address. */ + dns_rr_i_init(&F->hints_j); + F->hints_j.name = u.ns.host; + F->hints_j.type = DNS_T_A; + F->hints_j.section = DNS_S_ALL & ~DNS_S_QD; + if (dns_rr_grep(&rr, 1, &F->hints_j, F->hints, &error)) { + /* We do. Reinitialize + iterator and handle it. */ + dns_rr_i_init(&F->hints_j); + dgoto(R->sp, DNS_R_FOREACH_A); + } + + dgoto(R->sp, DNS_R_RESOLV0_NS); + } + + dgoto(R->sp, DNS_R_FOREACH_NS); + } + + if ((error = dns_aaaa_parse(&aaaa, &rr, F->hints))) + goto error; + + memset(&sin6, '\0', sizeof sin6); /* NB: silence valgrind */ + sin6.sin6_family = AF_INET6; + sin6.sin6_addr = aaaa.addr; + if (R->sp == 0) + sin6.sin6_port = dns_hints_port(R->hints, AF_INET, &sin6.sin6_addr); + else + sin6.sin6_port = htons(53); + + if (DNS_DEBUG) { + char addr[INET6_ADDRSTRLEN + 1]; + dns_aaaa_print(addr, sizeof addr, &aaaa); + dns_header(F->query)->qid = dns_so_mkqid(&R->so); + DNS_SHOW(F->query, "ASKING: %s/%s @ DEPTH: %u)", u.ns.host, addr, R->sp); + } + + dns_trace_setcname(R->trace, u.ns.host, (struct sockaddr *)&sin6); + + if ((error = dns_so_submit(&R->so, F->query, (struct sockaddr *)&sin6))) + goto error; + + F->state++; + } /* FALL THROUGH */ + case DNS_R_QUERY_AAAA: + if (dns_so_elapsed(&R->so) >= dns_resconf_timeout(R->resconf)) + dgoto(R->sp, DNS_R_FOREACH_AAAA); + + error = dns_so_check(&R->so); + if (error == ECONNREFUSED) + dgoto(R->sp, DNS_R_FOREACH_AAAA); + else if (error) + goto error; + + if (!dns_p_setptr(&F->answer, dns_so_fetch(&R->so, &error))) + goto error; + + if (DNS_DEBUG) { + DNS_SHOW(F->answer, "ANSWER @ DEPTH: %u)", R->sp); + } + + if (dns_p_rcode(F->answer) == DNS_RC_FORMERR || + dns_p_rcode(F->answer) == DNS_RC_NOTIMP || + dns_p_rcode(F->answer) == DNS_RC_BADVERS) { + /* Temporarily disable EDNS0 and try again. */ + if (F->qflags & DNS_Q_EDNS0) { + F->qflags &= ~DNS_Q_EDNS0; + if ((error = dns_q_remake(&F->query, F->qflags))) + goto error; + + dgoto(R->sp, DNS_R_FOREACH_AAAA); + } + } + + if ((error = dns_rr_parse(&rr, 12, F->query))) + goto error; + + if (!(len = dns_d_expand(u.name, sizeof u.name, rr.dn.p, F->query, &error))) + goto error; + else if (len >= sizeof u.name) + goto toolong; + + dns_rr_foreach(&rr, F->answer, .section = DNS_S_AN, .name = u.name, .type = rr.type) { + dgoto(R->sp, DNS_R_FINISH); /* Found */ + } + + dns_rr_foreach(&rr, F->answer, .section = DNS_S_AN, .name = u.name, .type = DNS_T_CNAME) { + F->ans_cname = rr; + + dgoto(R->sp, DNS_R_CNAME0_A); + } + + /* + * XXX: The condition here should probably check whether + * R->sp == 0, because DNS_R_SEARCH runs regardless of + * options.recurse. See DNS_R_BIND. + */ + if (!R->resconf->options.recurse) { + /* Make first answer our tentative answer */ + if (!R->nodata) + dns_p_movptr(&R->nodata, &F->answer); + + dgoto(R->sp, DNS_R_SEARCH); + } + + dns_rr_foreach(&rr, F->answer, .section = DNS_S_NS, .type = DNS_T_NS) { + dns_p_movptr(&F->hints, &F->answer); + + dgoto(R->sp, DNS_R_ITERATE); + } + + /* XXX: Should this go further up? */ + if (dns_header(F->answer)->aa) + dgoto(R->sp, DNS_R_FINISH); + + /* XXX: Should we copy F->answer to R->nodata? */ + + dgoto(R->sp, DNS_R_FOREACH_AAAA); + case DNS_R_CNAME0_A: + if (&F[1] >= endof(R->stack)) + dgoto(R->sp, DNS_R_FINISH); + + if ((error = dns_cname_parse(&u.cname, &F->ans_cname, F->answer))) + goto error; + if ((error = dns_res_frame_prepare(R, &F[1], u.cname.host, dns_rr_type(12, F->query), DNS_C_IN))) + goto error; + + F->state++; + + dgoto(++R->sp, DNS_R_INIT); + case DNS_R_CNAME1_A: + if (!(P = dns_res_merge(F->answer, F[1].answer, &error))) + goto error; + + dns_p_setptr(&F->answer, P); + + dgoto(R->sp, DNS_R_FINISH); + case DNS_R_FINISH: + if (!F->answer) + goto noanswer; + + if (!R->resconf->options.smart || R->sp > 0) + dgoto(R->sp, DNS_R_DONE); + + R->smart.section = DNS_S_AN; + R->smart.type = R->qtype; + + dns_rr_i_init(&R->smart); + + F->state++; /* FALL THROUGH */ + case DNS_R_SMART0_A: + if (&F[1] >= endof(R->stack)) + dgoto(R->sp, DNS_R_DONE); + + while (dns_rr_grep(&rr, 1, &R->smart, F->answer, &error)) { + union { + struct dns_ns ns; + struct dns_mx mx; + struct dns_srv srv; + } rd; + const char *qname; + enum dns_type qtype; + enum dns_class qclass; + + switch (rr.type) { + case DNS_T_NS: + if ((error = dns_ns_parse(&rd.ns, &rr, F->answer))) + goto error; + + qname = rd.ns.host; + qtype = DNS_T_A; + qclass = DNS_C_IN; + + break; + case DNS_T_MX: + if ((error = dns_mx_parse(&rd.mx, &rr, F->answer))) + goto error; + + qname = rd.mx.host; + qtype = DNS_T_A; + qclass = DNS_C_IN; + + break; + case DNS_T_SRV: + if ((error = dns_srv_parse(&rd.srv, &rr, F->answer))) + goto error; + + qname = rd.srv.target; + qtype = DNS_T_A; + qclass = DNS_C_IN; + + break; + default: + continue; + } /* switch() */ + + if ((error = dns_res_frame_prepare(R, &F[1], qname, qtype, qclass))) + goto error; + + F->state++; + + dgoto(++R->sp, DNS_R_INIT); + } /* while() */ + + /* + * NOTE: SMTP specification says to fallback to A record. + * + * XXX: Should we add a mock MX answer? + */ + if (R->qtype == DNS_T_MX && R->smart.state.count == 0) { + if ((error = dns_res_frame_prepare(R, &F[1], R->qname, DNS_T_A, DNS_C_IN))) + goto error; + + R->smart.state.count++; + F->state++; + + dgoto(++R->sp, DNS_R_INIT); + } + + dgoto(R->sp, DNS_R_DONE); + case DNS_R_SMART1_A: + if (!F[1].answer) + goto noanswer; + + /* + * FIXME: For CNAME chains (which are typically illegal in + * this context), we should rewrite the record host name + * to the original smart qname. All the user cares about + * is locating that A/AAAA record. + */ + dns_rr_foreach(&rr, F[1].answer, .section = DNS_S_AN, .type = DNS_T_A) { + rr.section = DNS_S_AR; + + if (dns_rr_exists(&rr, F[1].answer, F->answer)) + continue; + + while ((error = dns_rr_copy(F->answer, &rr, F[1].answer))) { + if (error != DNS_ENOBUFS) + goto error; + if ((error = dns_p_grow(&F->answer))) + goto error; + } + } + + dgoto(R->sp, DNS_R_SMART0_A); + case DNS_R_DONE: + if (!F->answer) + goto noanswer; + + if (R->sp > 0) + dgoto(--R->sp, F[-1].state); + + break; + case DNS_R_SERVFAIL: + if (!dns_p_setptr(&F->answer, dns_p_make(DNS_P_QBUFSIZ, &error))) + goto error; + + dns_header(F->answer)->qr = 1; + dns_header(F->answer)->rcode = DNS_RC_SERVFAIL; + + if ((error = dns_p_push(F->answer, DNS_S_QD, R->qname, strlen(R->qname), R->qtype, R->qclass, 0, 0))) + goto error; + + dgoto(R->sp, DNS_R_DONE); + default: + error = EINVAL; + + goto error; + } /* switch () */ + + return 0; +noquery: + error = DNS_ENOQUERY; + + goto error; +noanswer: + error = DNS_ENOANSWER; + + goto error; +toolong: + error = DNS_EILLEGAL; + + /* FALL THROUGH */ +error: + return error; +} /* dns_res_exec() */ + +#undef goto + + +void dns_res_clear(struct dns_resolver *R) { + switch (R->stack[R->sp].state) { + case DNS_R_CHECK: + R->cache->clear(R->cache); + break; + default: + dns_so_clear(&R->so); + break; + } +} /* dns_res_clear() */ + + +static int dns_res_events2(struct dns_resolver *R, enum dns_events type) { + int events; + + switch (R->stack[R->sp].state) { + case DNS_R_CHECK: + events = R->cache->events(R->cache); + + return (type == DNS_LIBEVENT)? DNS_POLL2EV(events) : events; + default: + return dns_so_events2(&R->so, type); + } +} /* dns_res_events2() */ + + +int dns_res_events(struct dns_resolver *R) { + return dns_res_events2(R, R->so.opts.events); +} /* dns_res_events() */ + + +int dns_res_pollfd(struct dns_resolver *R) { + switch (R->stack[R->sp].state) { + case DNS_R_CHECK: + return R->cache->pollfd(R->cache); + default: + return dns_so_pollfd(&R->so); + } +} /* dns_res_pollfd() */ + + +time_t dns_res_timeout(struct dns_resolver *R) { + time_t elapsed; + + switch (R->stack[R->sp].state) { +#if 0 + case DNS_R_QUERY_AAAA: +#endif + case DNS_R_QUERY_A: + elapsed = dns_so_elapsed(&R->so); + + if (elapsed <= dns_resconf_timeout(R->resconf)) + return R->resconf->options.timeout - elapsed; + + break; + default: + break; + } /* switch() */ + + /* + * NOTE: We're not in a pollable state, or the user code hasn't + * called dns_res_check properly. The calling code is probably + * broken. Put them into a slow-burn pattern. + */ + return 1; +} /* dns_res_timeout() */ + + +time_t dns_res_elapsed(struct dns_resolver *R) { + return dns_elapsed(&R->elapsed); +} /* dns_res_elapsed() */ + + +int dns_res_poll(struct dns_resolver *R, int timeout) { + return dns_poll(dns_res_pollfd(R), dns_res_events2(R, DNS_SYSPOLL), timeout); +} /* dns_res_poll() */ + + +int dns_res_submit2(struct dns_resolver *R, const char *qname, size_t qlen, enum dns_type qtype, enum dns_class qclass) { + dns_res_reset(R); + + /* Don't anchor; that can conflict with searchlist generation. */ + dns_d_init(R->qname, sizeof R->qname, qname, (R->qlen = qlen), 0); + + R->qtype = qtype; + R->qclass = qclass; + + dns_begin(&R->elapsed); + + dns_trace_res_submit(R->trace, R->qname, R->qtype, R->qclass, 0); + + return 0; +} /* dns_res_submit2() */ + + +int dns_res_submit(struct dns_resolver *R, const char *qname, enum dns_type qtype, enum dns_class qclass) { + return dns_res_submit2(R, qname, strlen(qname), qtype, qclass); +} /* dns_res_submit() */ + + +int dns_res_check(struct dns_resolver *R) { + int error; + + if (R->stack[0].state != DNS_R_DONE) { + if ((error = dns_res_exec(R))) + return error; + } + + return 0; +} /* dns_res_check() */ + + +struct dns_packet *dns_res_fetch(struct dns_resolver *R, int *_error) { + struct dns_packet *P = NULL; + int error; + + if (R->stack[0].state != DNS_R_DONE) { + error = DNS_EUNKNOWN; + goto error; + } + + if (!dns_p_movptr(&P, &R->stack[0].answer)) { + error = DNS_EFETCHED; + goto error; + } + + dns_trace_res_fetch(R->trace, P, 0); + + return P; +error: + *_error = error; + dns_trace_res_fetch(R->trace, NULL, error); + return NULL; +} /* dns_res_fetch() */ + + +static struct dns_packet *dns_res_fetch_and_study(struct dns_resolver *R, int *_error) { + struct dns_packet *P = NULL; + int error; + + if (!(P = dns_res_fetch(R, &error))) + goto error; + if ((error = dns_p_study(P))) + goto error; + + return P; +error: + *_error = error; + + dns_p_free(P); + + return NULL; +} /* dns_res_fetch_and_study() */ + + +struct dns_packet *dns_res_query(struct dns_resolver *res, const char *qname, enum dns_type qtype, enum dns_class qclass, int timeout, int *error_) { + int error; + + if ((error = dns_res_submit(res, qname, qtype, qclass))) + goto error; + + while ((error = dns_res_check(res))) { + if (dns_res_elapsed(res) > timeout) + error = DNS_ETIMEDOUT; + + if (error != DNS_EAGAIN) + goto error; + + if ((error = dns_res_poll(res, 1))) + goto error; + } + + return dns_res_fetch(res, error_); +error: + *error_ = error; + + return 0; +} /* dns_res_query() */ + + +const struct dns_stat *dns_res_stat(struct dns_resolver *res) { + return dns_so_stat(&res->so); +} /* dns_res_stat() */ + + +void dns_res_sethints(struct dns_resolver *res, struct dns_hints *hints) { + dns_hints_acquire(hints); /* acquire first in case same hints object */ + dns_hints_close(res->hints); + res->hints = hints; +} /* dns_res_sethints() */ + + +struct dns_trace *dns_res_trace(struct dns_resolver *res) { + return res->trace; +} /* dns_res_trace() */ + + +void dns_res_settrace(struct dns_resolver *res, struct dns_trace *trace) { + struct dns_trace *otrace = res->trace; + res->trace = dns_trace_acquire_p(trace); + dns_trace_close(otrace); + dns_so_settrace(&res->so, trace); +} /* dns_res_settrace() */ + + +/* + * A D D R I N F O R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +struct dns_addrinfo { + struct addrinfo hints; + struct dns_resolver *res; + struct dns_trace *trace; + + char qname[DNS_D_MAXNAME + 1]; + enum dns_type qtype; + unsigned short qport, port; + + struct { + unsigned long todo; + int state; + int atype; + enum dns_type qtype; + } af; + + struct dns_packet *answer; + struct dns_packet *glue; + + struct dns_rr_i i, g; + struct dns_rr rr; + + char cname[DNS_D_MAXNAME + 1]; + char i_cname[DNS_D_MAXNAME + 1], g_cname[DNS_D_MAXNAME + 1]; + + int g_depth; + + int state; + int found; + + struct dns_stat st; +}; /* struct dns_addrinfo */ + + +#define DNS_AI_AFMAX 32 +#define DNS_AI_AF2INDEX(af) (1UL << ((af) - 1)) + +static inline unsigned long dns_ai_af2index(int af) { + dns_static_assert(dns_same_type(unsigned long, DNS_AI_AF2INDEX(1), 1), "internal type mismatch"); + dns_static_assert(dns_same_type(unsigned long, ((struct dns_addrinfo *)0)->af.todo, 1), "internal type mismatch"); + + return (af > 0 && af <= DNS_AI_AFMAX)? DNS_AI_AF2INDEX(af) : 0; +} + +static int dns_ai_setaf(struct dns_addrinfo *ai, int af, int qtype) { + ai->af.atype = af; + ai->af.qtype = qtype; + + ai->af.todo &= ~dns_ai_af2index(af); + + return af; +} /* dns_ai_setaf() */ + +#define DNS_SM_RESTORE \ + do { pc = 0xff & (ai->af.state >> 0); i = 0xff & (ai->af.state >> 8); } while (0) +#define DNS_SM_SAVE \ + do { ai->af.state = ((0xff & pc) << 0) | ((0xff & i) << 8); } while (0) + +static int dns_ai_nextaf(struct dns_addrinfo *ai) { + int i, pc; + + dns_static_assert(AF_UNSPEC == 0, "AF_UNSPEC constant not 0"); + dns_static_assert(AF_INET <= DNS_AI_AFMAX, "AF_INET constant too large"); + dns_static_assert(AF_INET6 <= DNS_AI_AFMAX, "AF_INET6 constant too large"); + + DNS_SM_ENTER; + + if (ai->res) { + /* + * NB: On OpenBSD, at least, the types of entries resolved + * is the intersection of the /etc/resolv.conf families and + * the families permitted by the .ai_type hint. So if + * /etc/resolv.conf has "family inet4" and .ai_type + * is AF_INET6, then the address ::1 will return 0 entries + * even if AI_NUMERICHOST is specified in .ai_flags. + */ + while (i < (int)lengthof(ai->res->resconf->family)) { + int af = ai->res->resconf->family[i++]; + + if (af == AF_UNSPEC) { + DNS_SM_EXIT; + } else if (af < 0 || af > DNS_AI_AFMAX) { + continue; + } else if (!(DNS_AI_AF2INDEX(af) & ai->af.todo)) { + continue; + } else if (af == AF_INET) { + DNS_SM_YIELD(dns_ai_setaf(ai, AF_INET, DNS_T_A)); + } else if (af == AF_INET6) { + DNS_SM_YIELD(dns_ai_setaf(ai, AF_INET6, DNS_T_AAAA)); + } + } + } else { + /* + * NB: If we get here than AI_NUMERICFLAGS should be set and + * order shouldn't matter. + */ + if (DNS_AI_AF2INDEX(AF_INET) & ai->af.todo) + DNS_SM_YIELD(dns_ai_setaf(ai, AF_INET, DNS_T_A)); + if (DNS_AI_AF2INDEX(AF_INET6) & ai->af.todo) + DNS_SM_YIELD(dns_ai_setaf(ai, AF_INET6, DNS_T_AAAA)); + } + + DNS_SM_LEAVE; + + return dns_ai_setaf(ai, AF_UNSPEC, 0); +} /* dns_ai_nextaf() */ + +#undef DNS_SM_RESTORE +#undef DNS_SM_SAVE + +static enum dns_type dns_ai_qtype(struct dns_addrinfo *ai) { + return (ai->qtype)? ai->qtype : ai->af.qtype; +} /* dns_ai_qtype() */ + +/* JW: This is not defined on mingw. */ +#ifndef AI_NUMERICSERV +#define AI_NUMERICSERV 0 +#endif + +static dns_error_t dns_ai_parseport(unsigned short *port, const char *serv, const struct addrinfo *hints) { + const char *cp = serv; + unsigned long n = 0; + + while (*cp >= '0' && *cp <= '9' && n < 65536) { + n *= 10; + n += *cp++ - '0'; + } + + if (*cp == '\0') { + if (cp == serv || n >= 65536) + return DNS_ESERVICE; + + *port = n; + + return 0; + } + + if (hints->ai_flags & AI_NUMERICSERV) + return DNS_ESERVICE; + + /* TODO: try getaddrinfo(NULL, serv, { .ai_flags = AI_NUMERICSERV }) */ + + return DNS_ESERVICE; +} /* dns_ai_parseport() */ + + +struct dns_addrinfo *dns_ai_open(const char *host, const char *serv, enum dns_type qtype, const struct addrinfo *hints, struct dns_resolver *res, int *_error) { + static const struct dns_addrinfo ai_initializer; + struct dns_addrinfo *ai; + int error; + + if (res) { + dns_res_acquire(res); + } else if (!(hints->ai_flags & AI_NUMERICHOST)) { + /* + * NOTE: it's assumed that *_error is set from a previous + * API function call, such as dns_res_stub(). Should change + * this semantic, but it's applied elsewhere, too. + */ + if (!*_error) + *_error = EINVAL; + return NULL; + } + + if (!(ai = malloc(sizeof *ai))) + goto syerr; + + *ai = ai_initializer; + ai->hints = *hints; + + ai->res = res; + res = NULL; + + if (sizeof ai->qname <= dns_strlcpy(ai->qname, host, sizeof ai->qname)) + { error = ENAMETOOLONG; goto error; } + + ai->qtype = qtype; + ai->qport = 0; + + if (serv && (error = dns_ai_parseport(&ai->qport, serv, hints))) + goto error; + ai->port = ai->qport; + + /* + * FIXME: If an explicit A or AAAA record type conflicts with + * .ai_family or with resconf.family (i.e. AAAA specified but + * AF_INET6 not in interection of .ai_family and resconf.family), + * then what? + */ + switch (ai->qtype) { + case DNS_T_A: + ai->af.todo = DNS_AI_AF2INDEX(AF_INET); + break; + case DNS_T_AAAA: + ai->af.todo = DNS_AI_AF2INDEX(AF_INET6); + break; + default: /* 0, MX, SRV, etc */ + switch (ai->hints.ai_family) { + case AF_UNSPEC: + ai->af.todo = DNS_AI_AF2INDEX(AF_INET) | DNS_AI_AF2INDEX(AF_INET6); + break; + case AF_INET: + ai->af.todo = DNS_AI_AF2INDEX(AF_INET); + break; + case AF_INET6: + ai->af.todo = DNS_AI_AF2INDEX(AF_INET6); + break; + default: + break; + } + } + + return ai; +syerr: + error = dns_syerr(); +error: + *_error = error; + + dns_ai_close(ai); + dns_res_close(res); + + return NULL; +} /* dns_ai_open() */ + + +void dns_ai_close(struct dns_addrinfo *ai) { + if (!ai) + return; + + dns_res_close(ai->res); + dns_trace_close(ai->trace); + + if (ai->answer != ai->glue) + dns_p_free(ai->glue); + + dns_p_free(ai->answer); + free(ai); +} /* dns_ai_close() */ + + +static int dns_ai_setent(struct addrinfo **ent, union dns_any *any, enum dns_type type, struct dns_addrinfo *ai) { + union u { + struct sockaddr_in sin; + struct sockaddr_in6 sin6; + struct sockaddr_storage ss; + } addr; + const char *cname; + size_t clen; + + switch (type) { + case DNS_T_A: + memset(&addr.sin, '\0', sizeof addr.sin); + + addr.sin.sin_family = AF_INET; + addr.sin.sin_port = htons(ai->port); + + memcpy(&addr.sin.sin_addr, any, sizeof addr.sin.sin_addr); + + break; + case DNS_T_AAAA: + memset(&addr.sin6, '\0', sizeof addr.sin6); + + addr.sin6.sin6_family = AF_INET6; + addr.sin6.sin6_port = htons(ai->port); + + memcpy(&addr.sin6.sin6_addr, any, sizeof addr.sin6.sin6_addr); + + break; + default: + return EINVAL; + } /* switch() */ + + if (ai->hints.ai_flags & AI_CANONNAME) { + cname = (*ai->cname)? ai->cname : ai->qname; + clen = strlen(cname); + } else { + cname = NULL; + clen = 0; + } + + if (!(*ent = malloc(sizeof **ent + dns_sa_len(&addr) + ((ai->hints.ai_flags & AI_CANONNAME)? clen + 1 : 0)))) + return dns_syerr(); + + memset(*ent, '\0', sizeof **ent); + + (*ent)->ai_family = addr.ss.ss_family; + (*ent)->ai_socktype = ai->hints.ai_socktype; + (*ent)->ai_protocol = ai->hints.ai_protocol; + + (*ent)->ai_addr = memcpy((unsigned char *)*ent + sizeof **ent, &addr, dns_sa_len(&addr)); + (*ent)->ai_addrlen = dns_sa_len(&addr); + + if (ai->hints.ai_flags & AI_CANONNAME) + (*ent)->ai_canonname = memcpy((unsigned char *)*ent + sizeof **ent + dns_sa_len(&addr), cname, clen + 1); + + ai->found++; + + return 0; +} /* dns_ai_setent() */ + + +enum dns_ai_state { + DNS_AI_S_INIT, + DNS_AI_S_NEXTAF, + DNS_AI_S_NUMERIC, + DNS_AI_S_SUBMIT, + DNS_AI_S_CHECK, + DNS_AI_S_FETCH, + DNS_AI_S_FOREACH_I, + DNS_AI_S_INIT_G, + DNS_AI_S_ITERATE_G, + DNS_AI_S_FOREACH_G, + DNS_AI_S_SUBMIT_G, + DNS_AI_S_CHECK_G, + DNS_AI_S_FETCH_G, + DNS_AI_S_DONE, +}; /* enum dns_ai_state */ + +#define dns_ai_goto(which) do { ai->state = (which); goto exec; } while (0) + +int dns_ai_nextent(struct addrinfo **ent, struct dns_addrinfo *ai) { + struct dns_packet *ans, *glue; + struct dns_rr rr; + char qname[DNS_D_MAXNAME + 1]; + union dns_any any; + size_t qlen, clen; + int error; + + *ent = 0; + +exec: + + switch (ai->state) { + case DNS_AI_S_INIT: + ai->state++; /* FALL THROUGH */ + case DNS_AI_S_NEXTAF: + if (!dns_ai_nextaf(ai)) + dns_ai_goto(DNS_AI_S_DONE); + + ai->state++; /* FALL THROUGH */ + case DNS_AI_S_NUMERIC: + if (1 == dns_inet_pton(AF_INET, ai->qname, &any.a)) { + if (ai->af.atype == AF_INET) { + ai->state = DNS_AI_S_NEXTAF; + return dns_ai_setent(ent, &any, DNS_T_A, ai); + } else { + dns_ai_goto(DNS_AI_S_NEXTAF); + } + } + + if (1 == dns_inet_pton(AF_INET6, ai->qname, &any.aaaa)) { + if (ai->af.atype == AF_INET6) { + ai->state = DNS_AI_S_NEXTAF; + return dns_ai_setent(ent, &any, DNS_T_AAAA, ai); + } else { + dns_ai_goto(DNS_AI_S_NEXTAF); + } + } + + if (ai->hints.ai_flags & AI_NUMERICHOST) + dns_ai_goto(DNS_AI_S_NEXTAF); + + ai->state++; /* FALL THROUGH */ + case DNS_AI_S_SUBMIT: + assert(ai->res); + + if ((error = dns_res_submit(ai->res, ai->qname, dns_ai_qtype(ai), DNS_C_IN))) + return error; + + ai->state++; /* FALL THROUGH */ + case DNS_AI_S_CHECK: + if ((error = dns_res_check(ai->res))) + return error; + + ai->state++; /* FALL THROUGH */ + case DNS_AI_S_FETCH: + if (!(ans = dns_res_fetch_and_study(ai->res, &error))) + return error; + if (ai->glue != ai->answer) + dns_p_free(ai->glue); + ai->glue = dns_p_movptr(&ai->answer, &ans); + + /* Search generator may have changed the qname. */ + if (!(qlen = dns_d_expand(qname, sizeof qname, 12, ai->answer, &error))) + return error; + else if (qlen >= sizeof qname) + return DNS_EILLEGAL; + if (!dns_d_cname(ai->cname, sizeof ai->cname, qname, qlen, ai->answer, &error)) + return error; + + dns_strlcpy(ai->i_cname, ai->cname, sizeof ai->i_cname); + dns_rr_i_init(&ai->i); + ai->i.section = DNS_S_AN; + ai->i.name = ai->i_cname; + ai->i.type = dns_ai_qtype(ai); + ai->i.sort = &dns_rr_i_order; + + ai->state++; /* FALL THROUGH */ + case DNS_AI_S_FOREACH_I: + if (!dns_rr_grep(&rr, 1, &ai->i, ai->answer, &error)) + dns_ai_goto(DNS_AI_S_NEXTAF); + + if ((error = dns_any_parse(&any, &rr, ai->answer))) + return error; + + ai->port = ai->qport; + + switch (rr.type) { + case DNS_T_A: + case DNS_T_AAAA: + return dns_ai_setent(ent, &any, rr.type, ai); + default: + if (!(clen = dns_any_cname(ai->cname, sizeof ai->cname, &any, rr.type))) + dns_ai_goto(DNS_AI_S_FOREACH_I); + + /* + * Find the "real" canonical name. Some authorities + * publish aliases where an RFC defines a canonical + * name. We trust that the resolver followed any + * CNAME chains on it's own, regardless of whether + * the "smart" option is enabled. + */ + if (!dns_d_cname(ai->cname, sizeof ai->cname, ai->cname, clen, ai->answer, &error)) + return error; + + if (rr.type == DNS_T_SRV) + ai->port = any.srv.port; + + break; + } /* switch() */ + + ai->state++; /* FALL THROUGH */ + case DNS_AI_S_INIT_G: + ai->g_depth = 0; + + ai->state++; /* FALL THROUGH */ + case DNS_AI_S_ITERATE_G: + dns_strlcpy(ai->g_cname, ai->cname, sizeof ai->g_cname); + dns_rr_i_init(&ai->g); + ai->g.section = DNS_S_ALL & ~DNS_S_QD; + ai->g.name = ai->g_cname; + ai->g.type = ai->af.qtype; + + ai->state++; /* FALL THROUGH */ + case DNS_AI_S_FOREACH_G: + if (!dns_rr_grep(&rr, 1, &ai->g, ai->glue, &error)) { + if (dns_rr_i_count(&ai->g) > 0) + dns_ai_goto(DNS_AI_S_FOREACH_I); + else + dns_ai_goto(DNS_AI_S_SUBMIT_G); + } + + if ((error = dns_any_parse(&any, &rr, ai->glue))) + return error; + + return dns_ai_setent(ent, &any, rr.type, ai); + case DNS_AI_S_SUBMIT_G: + { + struct dns_rr_i I_instance = { 0 }; + + I_instance.section = DNS_S_QD; + I_instance.name = ai->g.name; + I_instance.type = ai->g.type; + /* skip if already queried */ + if (dns_rr_grep(&rr, 1, &I_instance, ai->glue, &error)) + dns_ai_goto(DNS_AI_S_FOREACH_I); + /* skip if we recursed (CNAME chains should have been handled in the resolver) */ + if (++ai->g_depth > 1) + dns_ai_goto(DNS_AI_S_FOREACH_I); + + if ((error = dns_res_submit(ai->res, ai->g.name, ai->g.type, DNS_C_IN))) + return error; + + ai->state++; + } /* FALL THROUGH */ + case DNS_AI_S_CHECK_G: + if ((error = dns_res_check(ai->res))) + return error; + + ai->state++; /* FALL THROUGH */ + case DNS_AI_S_FETCH_G: + if (!(ans = dns_res_fetch_and_study(ai->res, &error))) + return error; + + glue = dns_p_merge(ai->glue, DNS_S_ALL, ans, DNS_S_ALL, &error); + dns_p_setptr(&ans, NULL); + if (!glue) + return error; + + if (ai->glue != ai->answer) + dns_p_free(ai->glue); + ai->glue = glue; + + if (!dns_d_cname(ai->cname, sizeof ai->cname, ai->g.name, strlen(ai->g.name), ai->glue, &error)) + dns_ai_goto(DNS_AI_S_FOREACH_I); + + dns_ai_goto(DNS_AI_S_ITERATE_G); + case DNS_AI_S_DONE: + if (ai->found) { + return ENOENT; /* TODO: Just return 0 */ + } else if (ai->answer) { + switch (dns_p_rcode(ai->answer)) { + case DNS_RC_NOERROR: + /* FALL THROUGH */ + case DNS_RC_NXDOMAIN: + return DNS_ENONAME; + default: + return DNS_EFAIL; + } + } else { + return DNS_EFAIL; + } + default: + return EINVAL; + } /* switch() */ +} /* dns_ai_nextent() */ + + +time_t dns_ai_elapsed(struct dns_addrinfo *ai) { + return (ai->res)? dns_res_elapsed(ai->res) : 0; +} /* dns_ai_elapsed() */ + + +void dns_ai_clear(struct dns_addrinfo *ai) { + if (ai->res) + dns_res_clear(ai->res); +} /* dns_ai_clear() */ + + +int dns_ai_events(struct dns_addrinfo *ai) { + return (ai->res)? dns_res_events(ai->res) : 0; +} /* dns_ai_events() */ + + +int dns_ai_pollfd(struct dns_addrinfo *ai) { + return (ai->res)? dns_res_pollfd(ai->res) : -1; +} /* dns_ai_pollfd() */ + + +time_t dns_ai_timeout(struct dns_addrinfo *ai) { + return (ai->res)? dns_res_timeout(ai->res) : 0; +} /* dns_ai_timeout() */ + + +int dns_ai_poll(struct dns_addrinfo *ai, int timeout) { + return (ai->res)? dns_res_poll(ai->res, timeout) : 0; +} /* dns_ai_poll() */ + + +size_t dns_ai_print(void *_dst, size_t lim, struct addrinfo *ent, struct dns_addrinfo *ai) { + struct dns_buf dst = DNS_B_INTO(_dst, lim); + char addr[DNS_PP_MAX(INET_ADDRSTRLEN, INET6_ADDRSTRLEN) + 1]; + char __dst[DNS_STRMAXLEN + 1] = { 0 }; + + dns_b_puts(&dst, "[ "); + dns_b_puts(&dst, ai->qname); + dns_b_puts(&dst, " IN "); + if (ai->qtype) { + dns_b_puts(&dst, dns_strtype(ai->qtype, __dst)); + } else if (ent->ai_family == AF_INET) { + dns_b_puts(&dst, dns_strtype(DNS_T_A, __dst)); + } else if (ent->ai_family == AF_INET6) { + dns_b_puts(&dst, dns_strtype(DNS_T_AAAA, __dst)); + } else { + dns_b_puts(&dst, "0"); + } + dns_b_puts(&dst, " ]\n"); + + dns_b_puts(&dst, ".ai_family = "); + switch (ent->ai_family) { + case AF_INET: + dns_b_puts(&dst, "AF_INET"); + break; + case AF_INET6: + dns_b_puts(&dst, "AF_INET6"); + break; + default: + dns_b_fmtju(&dst, ent->ai_family, 0); + break; + } + dns_b_putc(&dst, '\n'); + + dns_b_puts(&dst, ".ai_socktype = "); + switch (ent->ai_socktype) { + case SOCK_STREAM: + dns_b_puts(&dst, "SOCK_STREAM"); + break; + case SOCK_DGRAM: + dns_b_puts(&dst, "SOCK_DGRAM"); + break; + default: + dns_b_fmtju(&dst, ent->ai_socktype, 0); + break; + } + dns_b_putc(&dst, '\n'); + + dns_inet_ntop(dns_sa_family(ent->ai_addr), dns_sa_addr(dns_sa_family(ent->ai_addr), ent->ai_addr, NULL), addr, sizeof addr); + dns_b_puts(&dst, ".ai_addr = ["); + dns_b_puts(&dst, addr); + dns_b_puts(&dst, "]:"); + dns_b_fmtju(&dst, ntohs(*dns_sa_port(dns_sa_family(ent->ai_addr), ent->ai_addr)), 0); + dns_b_putc(&dst, '\n'); + + dns_b_puts(&dst, ".ai_canonname = "); + dns_b_puts(&dst, (ent->ai_canonname)? ent->ai_canonname : "[NULL]"); + dns_b_putc(&dst, '\n'); + + return dns_b_strllen(&dst); +} /* dns_ai_print() */ + + +const struct dns_stat *dns_ai_stat(struct dns_addrinfo *ai) { + return (ai->res)? dns_res_stat(ai->res) : &ai->st; +} /* dns_ai_stat() */ + + +struct dns_trace *dns_ai_trace(struct dns_addrinfo *ai) { + return ai->trace; +} /* dns_ai_trace() */ + + +void dns_ai_settrace(struct dns_addrinfo *ai, struct dns_trace *trace) { + struct dns_trace *otrace = ai->trace; + ai->trace = dns_trace_acquire_p(trace); + dns_trace_close(otrace); + if (ai->res) + dns_res_settrace(ai->res, trace); +} /* dns_ai_settrace() */ + + +/* + * M I S C E L L A N E O U S R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ + +static const struct { + char name[16]; + enum dns_section type; +} dns_sections[] = { + { "QUESTION", DNS_S_QUESTION }, + { "QD", DNS_S_QUESTION }, + { "ANSWER", DNS_S_ANSWER }, + { "AN", DNS_S_ANSWER }, + { "AUTHORITY", DNS_S_AUTHORITY }, + { "NS", DNS_S_AUTHORITY }, + { "ADDITIONAL", DNS_S_ADDITIONAL }, + { "AR", DNS_S_ADDITIONAL }, +}; + +const char *(dns_strsection)(enum dns_section section, char *_dst) { + struct dns_buf dst = DNS_B_INTO(_dst, DNS_STRMAXLEN + 1); + unsigned i; + + for (i = 0; i < lengthof(dns_sections); i++) { + if (dns_sections[i].type & section) { + dns_b_puts(&dst, dns_sections[i].name); + section &= ~dns_sections[i].type; + if (section) + dns_b_putc(&dst, '|'); + } + } + + if (section || dst.p == dst.base) + dns_b_fmtju(&dst, (0xffff & section), 0); + + return dns_b_tostring(&dst); +} /* dns_strsection() */ + + +enum dns_section dns_isection(const char *src) { + enum dns_section section = 0; + char sbuf[128]; + char *name, *next; + unsigned i; + + dns_strlcpy(sbuf, src, sizeof sbuf); + next = sbuf; + + while ((name = dns_strsep(&next, "|+, \t"))) { + for (i = 0; i < lengthof(dns_sections); i++) { + if (!strcasecmp(dns_sections[i].name, name)) { + section |= dns_sections[i].type; + break; + } + } + } + + return section; +} /* dns_isection() */ + + +static const struct { + char name[8]; + enum dns_class type; +} dns_classes[] = { + { "IN", DNS_C_IN }, +}; + +const char *(dns_strclass)(enum dns_class type, char *_dst) { + struct dns_buf dst = DNS_B_INTO(_dst, DNS_STRMAXLEN + 1); + unsigned i; + + for (i = 0; i < lengthof(dns_classes); i++) { + if (dns_classes[i].type == type) { + dns_b_puts(&dst, dns_classes[i].name); + break; + } + } + + if (dst.p == dst.base) + dns_b_fmtju(&dst, (0xffff & type), 0); + + return dns_b_tostring(&dst); +} /* dns_strclass() */ + + +enum dns_class dns_iclass(const char *name) { + unsigned i, class; + + for (i = 0; i < lengthof(dns_classes); i++) { + if (!strcasecmp(dns_classes[i].name, name)) + return dns_classes[i].type; + } + + class = 0; + while (dns_isdigit(*name)) { + class *= 10; + class += *name++ - '0'; + } + + return DNS_PP_MIN(class, 0xffff); +} /* dns_iclass() */ + + +const char *(dns_strtype)(enum dns_type type, char *_dst) { + struct dns_buf dst = DNS_B_INTO(_dst, DNS_STRMAXLEN + 1); + unsigned i; + + for (i = 0; i < lengthof(dns_rrtypes); i++) { + if (dns_rrtypes[i].type == type) { + dns_b_puts(&dst, dns_rrtypes[i].name); + break; + } + } + + if (dst.p == dst.base) + dns_b_fmtju(&dst, (0xffff & type), 0); + + return dns_b_tostring(&dst); +} /* dns_strtype() */ + + +enum dns_type dns_itype(const char *name) { + unsigned i, type; + + for (i = 0; i < lengthof(dns_rrtypes); i++) { + if (!strcasecmp(dns_rrtypes[i].name, name)) + return dns_rrtypes[i].type; + } + + type = 0; + while (dns_isdigit(*name)) { + type *= 10; + type += *name++ - '0'; + } + + return DNS_PP_MIN(type, 0xffff); +} /* dns_itype() */ + + +static char dns_opcodes[16][16] = { + [DNS_OP_QUERY] = "QUERY", + [DNS_OP_IQUERY] = "IQUERY", + [DNS_OP_STATUS] = "STATUS", + [DNS_OP_NOTIFY] = "NOTIFY", + [DNS_OP_UPDATE] = "UPDATE", +}; + +static const char *dns__strcode(int code, volatile char *dst, size_t lim) { + char _tmp[48] = ""; + struct dns_buf tmp; + size_t p; + + assert(lim > 0); + dns_b_fmtju(dns_b_into(&tmp, _tmp, DNS_PP_MIN(sizeof _tmp, lim - 1)), code, 0); + + /* copy downwards so first byte is copied last (see below) */ + p = (size_t)(tmp.p - tmp.base); + dst[p] = '\0'; + while (p--) + dst[p] = _tmp[p]; + + return (const char *)dst; +} + +const char *dns_stropcode(enum dns_opcode opcode) { + opcode = (unsigned)opcode % lengthof(dns_opcodes); + + if ('\0' == dns_opcodes[opcode][0]) + return dns__strcode(opcode, dns_opcodes[opcode], sizeof dns_opcodes[opcode]); + + return dns_opcodes[opcode]; +} /* dns_stropcode() */ + + +enum dns_opcode dns_iopcode(const char *name) { + unsigned opcode; + + for (opcode = 0; opcode < lengthof(dns_opcodes); opcode++) { + if (!strcasecmp(name, dns_opcodes[opcode])) + return opcode; + } + + opcode = 0; + while (dns_isdigit(*name)) { + opcode *= 10; + opcode += *name++ - '0'; + } + + return DNS_PP_MIN(opcode, 0x0f); +} /* dns_iopcode() */ + + +static char dns_rcodes[32][16] = { + [DNS_RC_NOERROR] = "NOERROR", + [DNS_RC_FORMERR] = "FORMERR", + [DNS_RC_SERVFAIL] = "SERVFAIL", + [DNS_RC_NXDOMAIN] = "NXDOMAIN", + [DNS_RC_NOTIMP] = "NOTIMP", + [DNS_RC_REFUSED] = "REFUSED", + [DNS_RC_YXDOMAIN] = "YXDOMAIN", + [DNS_RC_YXRRSET] = "YXRRSET", + [DNS_RC_NXRRSET] = "NXRRSET", + [DNS_RC_NOTAUTH] = "NOTAUTH", + [DNS_RC_NOTZONE] = "NOTZONE", + /* EDNS(0) extended RCODEs ... */ + [DNS_RC_BADVERS] = "BADVERS", +}; + +const char *dns_strrcode(enum dns_rcode rcode) { + rcode = (unsigned)rcode % lengthof(dns_rcodes); + + if ('\0' == dns_rcodes[rcode][0]) + return dns__strcode(rcode, dns_rcodes[rcode], sizeof dns_rcodes[rcode]); + + return dns_rcodes[rcode]; +} /* dns_strrcode() */ + + +enum dns_rcode dns_ircode(const char *name) { + unsigned rcode; + + for (rcode = 0; rcode < lengthof(dns_rcodes); rcode++) { + if (!strcasecmp(name, dns_rcodes[rcode])) + return rcode; + } + + rcode = 0; + while (dns_isdigit(*name)) { + rcode *= 10; + rcode += *name++ - '0'; + } + + return DNS_PP_MIN(rcode, 0xfff); +} /* dns_ircode() */ + + + +/* + * C O M M A N D - L I N E / R E G R E S S I O N R O U T I N E S + * + * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ +#if DNS_MAIN + +#include <stdarg.h> +#include <stdlib.h> +#include <stdio.h> + +#include <ctype.h> + +#if _WIN32 +#include <getopt.h> +#endif + +#if !_WIN32 +#include <err.h> +#endif + + +struct { + struct { + const char *path[8]; + unsigned count; + } resconf, nssconf, hosts, cache; + + const char *qname; + enum dns_type qtype; + + int (*sort)(); + + const char *trace; + + int verbose; + + struct { + struct dns_resolv_conf *resconf; + struct dns_hosts *hosts; + struct dns_trace *trace; + } memo; + + struct sockaddr_storage socks_host; + const char *socks_user; + const char *socks_password; +} MAIN = { + .sort = &dns_rr_i_packet, +}; + + +static void hexdump(const unsigned char *src, size_t len, FILE *fp) { + struct dns_hxd_lines_i lines = { 0 }; + char line[128]; + + while (dns_hxd_lines(line, sizeof line, src, len, &lines)) { + fputs(line, fp); + } +} /* hexdump() */ + + +DNS_NORETURN static void panic(const char *fmt, ...) { + va_list ap; + + va_start(ap, fmt); + +#if _WIN32 + vfprintf(stderr, fmt, ap); + + exit(EXIT_FAILURE); +#else + verrx(EXIT_FAILURE, fmt, ap); +#endif +} /* panic() */ + +#define panic_(fn, ln, fmt, ...) \ + panic(fmt "%0s", (fn), (ln), __VA_ARGS__) +#define panic(...) \ + panic_(__func__, __LINE__, "(%s:%d) " __VA_ARGS__, "") + + +static void *grow(unsigned char *p, size_t size) { + void *tmp; + + if (!(tmp = realloc(p, size))) + panic("realloc(%"PRIuZ"): %s", size, dns_strerror(errno)); + + return tmp; +} /* grow() */ + + +static size_t add(size_t a, size_t b) { + if (~a < b) + panic("%"PRIuZ" + %"PRIuZ": integer overflow", a, b); + + return a + b; +} /* add() */ + + +static size_t append(unsigned char **dst, size_t osize, const void *src, size_t len) { + size_t size = add(osize, len); + + *dst = grow(*dst, size); + memcpy(*dst + osize, src, len); + + return size; +} /* append() */ + + +static size_t slurp(unsigned char **dst, size_t osize, FILE *fp, const char *path) { + size_t size = osize; + unsigned char buf[1024]; + size_t count; + + while ((count = fread(buf, 1, sizeof buf, fp))) + size = append(dst, size, buf, count); + + if (ferror(fp)) + panic("%s: %s", path, dns_strerror(errno)); + + return size; +} /* slurp() */ + + +static struct dns_resolv_conf *resconf(void) { + struct dns_resolv_conf **resconf = &MAIN.memo.resconf; + const char *path; + unsigned i; + int error; + + if (*resconf) + return *resconf; + + if (!(*resconf = dns_resconf_open(&error))) + panic("dns_resconf_open: %s", dns_strerror(error)); + + if (!MAIN.resconf.count) + MAIN.resconf.path[MAIN.resconf.count++] = "/etc/resolv.conf"; + + for (i = 0; i < MAIN.resconf.count; i++) { + path = MAIN.resconf.path[i]; + + if (0 == strcmp(path, "-")) + error = dns_resconf_loadfile(*resconf, stdin); + else + error = dns_resconf_loadpath(*resconf, path); + + if (error) + panic("%s: %s", path, dns_strerror(error)); + } + + for (i = 0; i < MAIN.nssconf.count; i++) { + path = MAIN.nssconf.path[i]; + + if (0 == strcmp(path, "-")) + error = dns_nssconf_loadfile(*resconf, stdin); + else + error = dns_nssconf_loadpath(*resconf, path); + + if (error) + panic("%s: %s", path, dns_strerror(error)); + } + + if (!MAIN.nssconf.count) { + path = "/etc/nsswitch.conf"; + + if (!(error = dns_nssconf_loadpath(*resconf, path))) + MAIN.nssconf.path[MAIN.nssconf.count++] = path; + else if (error != ENOENT) + panic("%s: %s", path, dns_strerror(error)); + } + + return *resconf; +} /* resconf() */ + + +static struct dns_hosts *hosts(void) { + struct dns_hosts **hosts = &MAIN.memo.hosts; + const char *path; + unsigned i; + int error; + + if (*hosts) + return *hosts; + + if (!MAIN.hosts.count) { + MAIN.hosts.path[MAIN.hosts.count++] = "/etc/hosts"; + + /* Explicitly test dns_hosts_local() */ + if (!(*hosts = dns_hosts_local(&error))) + panic("%s: %s", "/etc/hosts", dns_strerror(error)); + + return *hosts; + } + + if (!(*hosts = dns_hosts_open(&error))) + panic("dns_hosts_open: %s", dns_strerror(error)); + + for (i = 0; i < MAIN.hosts.count; i++) { + path = MAIN.hosts.path[i]; + + if (0 == strcmp(path, "-")) + error = dns_hosts_loadfile(*hosts, stdin); + else + error = dns_hosts_loadpath(*hosts, path); + + if (error) + panic("%s: %s", path, dns_strerror(error)); + } + + return *hosts; +} /* hosts() */ + + +#if DNS_CACHE +#include "cache.h" + +static struct dns_cache *cache(void) { + static struct cache *cache; + const char *path; + unsigned i; + int error; + + if (cache) + return cache_resi(cache); + if (!MAIN.cache.count) + return NULL; + + if (!(cache = cache_open(&error))) + panic("%s: %s", MAIN.cache.path[0], dns_strerror(error)); + + for (i = 0; i < MAIN.cache.count; i++) { + path = MAIN.cache.path[i]; + + if (!strcmp(path, "-")) { + if ((error = cache_loadfile(cache, stdin, NULL, 0))) + panic("%s: %s", path, dns_strerror(error)); + } else if ((error = cache_loadpath(cache, path, NULL, 0))) + panic("%s: %s", path, dns_strerror(error)); + } + + return cache_resi(cache); +} /* cache() */ +#else +static struct dns_cache *cache(void) { return NULL; } +#endif + + +static struct dns_trace *trace(const char *mode) { + static char omode[64] = ""; + struct dns_trace **trace = &MAIN.memo.trace; + FILE *fp; + int error; + + if (*trace && 0 == strcmp(omode, mode)) + return *trace; + if (!MAIN.trace) + return NULL; + + if (!(fp = fopen(MAIN.trace, mode))) + panic("%s: %s", MAIN.trace, strerror(errno)); + dns_trace_close(*trace); + if (!(*trace = dns_trace_open(fp, &error))) + panic("%s: %s", MAIN.trace, dns_strerror(error)); + dns_strlcpy(omode, mode, sizeof omode); + + return *trace; +} + + +static void print_packet(struct dns_packet *P, FILE *fp) { + struct dns_rr_i I_instance = { 0 }; + I.sort = MAIN.sort; + dns_p_dump3(P, &I, fp); + + if (MAIN.verbose > 2) + hexdump(P->data, P->end, fp); +} /* print_packet() */ + + +static int parse_packet(int argc DNS_NOTUSED, char *argv[] DNS_NOTUSED) { + union { unsigned char b[dns_p_calcsize((512))]; struct dns_packet p; } P_instance = { 0 }; + union { unsigned char b[dns_p_calcsize((512))]; struct dns_packet p; } Q_instance = { 0 }; + struct dns_packet *P = dns_p_init(&P_instance.p, 512); + struct dns_packet *Q = dns_p_init(&Q_instance.p, 512); + enum dns_section section; + struct dns_rr rr; + int error; + union dns_any any; + char pretty[sizeof any * 2]; + size_t len; + char __dst[DNS_STRMAXLEN + 1] = { 0 }; + + P->end = fread(P->data, 1, P->size, stdin); + + fputs(";; [HEADER]\n", stdout); + fprintf(stdout, ";; qr : %s(%d)\n", (dns_header(P)->qr)? "RESPONSE" : "QUERY", dns_header(P)->qr); + fprintf(stdout, ";; opcode : %s(%d)\n", dns_stropcode(dns_header(P)->opcode), dns_header(P)->opcode); + fprintf(stdout, ";; aa : %s(%d)\n", (dns_header(P)->aa)? "AUTHORITATIVE" : "NON-AUTHORITATIVE", dns_header(P)->aa); + fprintf(stdout, ";; tc : %s(%d)\n", (dns_header(P)->tc)? "TRUNCATED" : "NOT-TRUNCATED", dns_header(P)->tc); + fprintf(stdout, ";; rd : %s(%d)\n", (dns_header(P)->rd)? "RECURSION-DESIRED" : "RECURSION-NOT-DESIRED", dns_header(P)->rd); + fprintf(stdout, ";; ra : %s(%d)\n", (dns_header(P)->ra)? "RECURSION-ALLOWED" : "RECURSION-NOT-ALLOWED", dns_header(P)->ra); + fprintf(stdout, ";; rcode : %s(%d)\n", dns_strrcode(dns_p_rcode(P)), dns_p_rcode(P)); + + section = 0; + + dns_rr_foreach(&rr, P, .sort = MAIN.sort) { + if (section != rr.section) + fprintf(stdout, "\n;; [%s:%d]\n", dns_strsection(rr.section, __dst), dns_p_count(P, rr.section)); + + if ((len = dns_rr_print(pretty, sizeof pretty, &rr, P, &error))) + fprintf(stdout, "%s\n", pretty); + + dns_rr_copy(Q, &rr, P); + + section = rr.section; + } + + fputs("; ; ; ; ; ; ; ;\n\n", stdout); + + section = 0; + +#if 0 + dns_rr_foreach(&rr, Q, .name = "ns8.yahoo.com.") { +#else + char _p[DNS_D_MAXNAME + 1] = { 0 }; + const char *dn = "ns8.yahoo.com"; + char *_name = dns_d_init(_p, sizeof _p, dn, strlen (dn), DNS_D_ANCHOR); + struct dns_rr rrset[32]; + struct dns_rr_i I_instance = { 0 }; + struct dns_rr_i *rri = &I; + unsigned rrcount = dns_rr_grep(rrset, lengthof(rrset), rri, Q, &error); + + I.name = _name; + I.sort = MAIN.sort; + for (unsigned i = 0; i < rrcount; i++) { + rr = rrset[i]; +#endif + if (section != rr.section) + fprintf(stdout, "\n;; [%s:%d]\n", dns_strsection(rr.section, __dst), dns_p_count(Q, rr.section)); + + if ((len = dns_rr_print(pretty, sizeof pretty, &rr, Q, &error))) + fprintf(stdout, "%s\n", pretty); + + section = rr.section; + } + + if (MAIN.verbose > 1) { + fprintf(stderr, "orig:%"PRIuZ"\n", P->end); + hexdump(P->data, P->end, stdout); + + fprintf(stderr, "copy:%"PRIuZ"\n", Q->end); + hexdump(Q->data, Q->end, stdout); + } + + return 0; +} /* parse_packet() */ + + +static int parse_domain(int argc, char *argv[]) { + char _p[DNS_D_MAXNAME + 1] = { 0 }; + char *dn; + + dn = (argc > 1)? argv[1] : "f.l.google.com"; + + printf("[%s]\n", dn); + + dn = dns_d_init(_p, sizeof _p, dn, strlen (dn), DNS_D_ANCHOR); + + do { + puts(dn); + } while (dns_d_cleave(dn, strlen(dn) + 1, dn, strlen(dn))); + + return 0; +} /* parse_domain() */ + + +static int trim_domain(int argc, char **argv) { + for (argc--, argv++; argc > 0; argc--, argv++) { + char name[DNS_D_MAXNAME + 1]; + + dns_d_trim(name, sizeof name, *argv, strlen(*argv), DNS_D_ANCHOR); + + puts(name); + } + + return 0; +} /* trim_domain() */ + + +static int expand_domain(int argc, char *argv[]) { + unsigned short rp = 0; + unsigned char *src = NULL; + unsigned char *dst; + struct dns_packet *pkt; + size_t lim = 0, len; + int error; + + if (argc > 1) + rp = atoi(argv[1]); + + len = slurp(&src, 0, stdin, "-"); + + if (!(pkt = dns_p_make(len, &error))) + panic("malloc(%"PRIuZ"): %s", len, dns_strerror(error)); + + memcpy(pkt->data, src, len); + pkt->end = len; + + lim = 1; + dst = grow(NULL, lim); + + while (lim <= (len = dns_d_expand(dst, lim, rp, pkt, &error))) { + lim = add(len, 1); + dst = grow(dst, lim); + } + + if (!len) + panic("expand: %s", dns_strerror(error)); + + fwrite(dst, 1, len, stdout); + fflush(stdout); + + free(src); + free(dst); + free(pkt); + + return 0; +} /* expand_domain() */ + + +static int show_resconf(int argc DNS_NOTUSED, char *argv[] DNS_NOTUSED) { + unsigned i; + + resconf(); /* load it */ + + fputs("; SOURCES\n", stdout); + + for (i = 0; i < MAIN.resconf.count; i++) + fprintf(stdout, "; %s\n", MAIN.resconf.path[i]); + + for (i = 0; i < MAIN.nssconf.count; i++) + fprintf(stdout, "; %s\n", MAIN.nssconf.path[i]); + + fputs(";\n", stdout); + + dns_resconf_dump(resconf(), stdout); + + return 0; +} /* show_resconf() */ + + +static int show_nssconf(int argc DNS_NOTUSED, char *argv[] DNS_NOTUSED) { + unsigned i; + + resconf(); + + fputs("# SOURCES\n", stdout); + + for (i = 0; i < MAIN.resconf.count; i++) + fprintf(stdout, "# %s\n", MAIN.resconf.path[i]); + + for (i = 0; i < MAIN.nssconf.count; i++) + fprintf(stdout, "# %s\n", MAIN.nssconf.path[i]); + + fputs("#\n", stdout); + + dns_nssconf_dump(resconf(), stdout); + + return 0; +} /* show_nssconf() */ + + +static int show_hosts(int argc DNS_NOTUSED, char *argv[] DNS_NOTUSED) { + unsigned i; + + hosts(); + + fputs("# SOURCES\n", stdout); + + for (i = 0; i < MAIN.hosts.count; i++) + fprintf(stdout, "# %s\n", MAIN.hosts.path[i]); + + fputs("#\n", stdout); + + dns_hosts_dump(hosts(), stdout); + + return 0; +} /* show_hosts() */ + + +static int query_hosts(int argc, char *argv[]) { + union { unsigned char b[dns_p_calcsize((512))]; struct dns_packet p; } Q_instance = { 0 }; + struct dns_packet *Q = dns_p_init(&Q_instance.p, 512); + struct dns_packet *A; + char qname[DNS_D_MAXNAME + 1]; + size_t qlen; + int error; + + if (!MAIN.qname) + MAIN.qname = (argc > 1)? argv[1] : "localhost"; + if (!MAIN.qtype) + MAIN.qtype = DNS_T_A; + + hosts(); + + if (MAIN.qtype == DNS_T_PTR && !strstr(MAIN.qname, "arpa")) { + union { struct in_addr a; struct in6_addr a6; } addr; + int af = (strchr(MAIN.qname, ':'))? AF_INET6 : AF_INET; + + if ((error = dns_pton(af, MAIN.qname, &addr))) + panic("%s: %s", MAIN.qname, dns_strerror(error)); + + qlen = dns_ptr_qname(qname, sizeof qname, af, &addr); + } else + qlen = dns_strlcpy(qname, MAIN.qname, sizeof qname); + + if ((error = dns_p_push(Q, DNS_S_QD, qname, qlen, MAIN.qtype, DNS_C_IN, 0, 0))) + panic("%s: %s", qname, dns_strerror(error)); + + if (!(A = dns_hosts_query(hosts(), Q, &error))) + panic("%s: %s", qname, dns_strerror(error)); + + print_packet(A, stdout); + + free(A); + + return 0; +} /* query_hosts() */ + + +static int search_list(int argc, char *argv[]) { + const char *qname = (argc > 1)? argv[1] : "f.l.google.com"; + unsigned long i = 0; + char name[DNS_D_MAXNAME + 1]; + + printf("[%s]\n", qname); + + while (dns_resconf_search(name, sizeof name, qname, strlen(qname), resconf(), &i)) + puts(name); + + return 0; +} /* search_list() */ + + +static int permute_set(int argc, char *argv[]) { + unsigned lo, hi, i; + struct dns_k_permutor p; + + hi = (--argc > 0)? atoi(argv[argc]) : 8; + lo = (--argc > 0)? atoi(argv[argc]) : 0; + + fprintf(stderr, "[%u .. %u]\n", lo, hi); + + dns_k_permutor_init(&p, lo, hi); + + for (i = lo; i <= hi; i++) + fprintf(stdout, "%u\n", dns_k_permutor_step(&p)); +// printf("%u -> %u -> %u\n", i, dns_k_permutor_E(&p, i), dns_k_permutor_D(&p, dns_k_permutor_E(&p, i))); + + return 0; +} /* permute_set() */ + + +static int shuffle_16(int argc, char *argv[]) { + unsigned n, r; + + if (--argc > 0) { + n = 0xffff & atoi(argv[argc]); + r = (--argc > 0)? (unsigned)atoi(argv[argc]) : dns_random(); + + fprintf(stdout, "%hu\n", dns_k_shuffle16(n, r)); + } else { + r = dns_random(); + + for (n = 0; n < 65536; n++) + fprintf(stdout, "%hu\n", dns_k_shuffle16(n, r)); + } + + return 0; +} /* shuffle_16() */ + + +static int dump_random(int argc, char *argv[]) { + unsigned char b[32]; + unsigned i, j, n, r; + + n = (argc > 1)? atoi(argv[1]) : 32; + + while (n) { + i = 0; + + do { + r = dns_random(); + + for (j = 0; j < sizeof r && i < n && i < sizeof b; i++, j++) { + b[i] = 0xff & r; + r >>= 8; + } + } while (i < n && i < sizeof b); + + hexdump(b, i, stdout); + + n -= i; + } + + return 0; +} /* dump_random() */ + + +static int send_query(int argc, char *argv[]) { + union { unsigned char b[dns_p_calcsize((512))]; struct dns_packet p; } Q_instance = { 0 }; + struct dns_packet *A, *Q = dns_p_init(&Q_instance.p, 512); + char host[INET6_ADDRSTRLEN + 1]; + struct sockaddr_storage ss; + struct dns_socket *so; + int error, type; + struct dns_options opts = { 0 }; + char __dst[DNS_STRMAXLEN + 1] = { 0 }; + + memset(&ss, 0, sizeof ss); + if (argc > 1) { + ss.ss_family = (strchr(argv[1], ':'))? AF_INET6 : AF_INET; + + if ((error = dns_pton(ss.ss_family, argv[1], dns_sa_addr(ss.ss_family, &ss, NULL)))) + panic("%s: %s", argv[1], dns_strerror(error)); + + *dns_sa_port(ss.ss_family, &ss) = htons(53); + } else + memcpy(&ss, &resconf()->nameserver[0], dns_sa_len(&resconf()->nameserver[0])); + + if (!dns_inet_ntop(ss.ss_family, dns_sa_addr(ss.ss_family, &ss, NULL), host, sizeof host)) + panic("bad host address, or none provided"); + + if (!MAIN.qname) + MAIN.qname = "ipv6.google.com"; + if (!MAIN.qtype) + MAIN.qtype = DNS_T_AAAA; + + if ((error = dns_p_push(Q, DNS_S_QD, MAIN.qname, strlen(MAIN.qname), MAIN.qtype, DNS_C_IN, 0, 0))) + panic("dns_p_push: %s", dns_strerror(error)); + + dns_header(Q)->rd = 1; + + if (strstr(argv[0], "udp")) + type = SOCK_DGRAM; + else if (strstr(argv[0], "tcp")) + type = SOCK_STREAM; + else + type = dns_res_tcp2type(resconf()->options.tcp); + + fprintf(stderr, "querying %s for %s IN %s\n", host, MAIN.qname, dns_strtype(MAIN.qtype, __dst)); + + if (!(so = dns_so_open((struct sockaddr *)&resconf()->iface, type, &opts, &error))) + panic("dns_so_open: %s", dns_strerror(error)); + + while (!(A = dns_so_query(so, Q, (struct sockaddr *)&ss, &error))) { + if (error != DNS_EAGAIN) + panic("dns_so_query: %s (%d)", dns_strerror(error), error); + if (dns_so_elapsed(so) > 10) + panic("query timed-out"); + + dns_so_poll(so, 1); + } + + print_packet(A, stdout); + + dns_so_close(so); + + return 0; +} /* send_query() */ + + +static int print_arpa(int argc, char *argv[]) { + const char *ip = (argc > 1)? argv[1] : "::1"; + int af = (strchr(ip, ':'))? AF_INET6 : AF_INET; + union { struct in_addr a4; struct in6_addr a6; } addr; + char host[DNS_D_MAXNAME + 1]; + + if (1 != dns_inet_pton(af, ip, &addr) || 0 == dns_ptr_qname(host, sizeof host, af, &addr)) + panic("%s: invalid address", ip); + + fprintf(stdout, "%s\n", host); + + return 0; +} /* print_arpa() */ + + +static int show_hints(int argc, char *argv[]) { + struct dns_hints *(*load)(struct dns_resolv_conf *, int *); + const char *which, *how, *who; + struct dns_hints *hints; + int error; + + which = (argc > 1)? argv[1] : "local"; + how = (argc > 2)? argv[2] : "plain"; + who = (argc > 3)? argv[3] : "google.com"; + + load = (0 == strcmp(which, "local")) + ? &dns_hints_local + : &dns_hints_root; + + if (!(hints = load(resconf(), &error))) + panic("%s: %s", argv[0], dns_strerror(error)); + + if (0 == strcmp(how, "plain")) { + dns_hints_dump(hints, stdout); + } else { + union { unsigned char b[dns_p_calcsize((512))]; struct dns_packet p; } P_instance = { 0 }; + struct dns_packet *query, *answer; + + query = dns_p_init(&P_instance.p, 512); + + if ((error = dns_p_push(query, DNS_S_QUESTION, who, strlen(who), DNS_T_A, DNS_C_IN, 0, 0))) + panic("%s: %s", who, dns_strerror(error)); + + if (!(answer = dns_hints_query(hints, query, &error))) + panic("%s: %s", who, dns_strerror(error)); + + print_packet(answer, stdout); + + free(answer); + } + + dns_hints_close(hints); + + return 0; +} /* show_hints() */ + + +static int resolve_query(int argc DNS_NOTUSED, char *argv[]) { + _Bool recurse = !!strstr(argv[0], "recurse"); + struct dns_hints *(*hints)() = (recurse)? &dns_hints_root : &dns_hints_local; + struct dns_resolver *R; + struct dns_packet *ans; + const struct dns_stat *st; + int error; + struct dns_options opts = { 0 }; + + opts.socks_host = &MAIN.socks_host; + opts.socks_user = MAIN.socks_user; + opts.socks_password = MAIN.socks_password; + + if (!MAIN.qname) + MAIN.qname = "www.google.com"; + if (!MAIN.qtype) + MAIN.qtype = DNS_T_A; + + resconf()->options.recurse = recurse; + + if (!(R = dns_res_open(resconf(), hosts(), dns_hints_mortal(hints(resconf(), &error)), cache(), + &opts, &error))) + panic("%s: %s", MAIN.qname, dns_strerror(error)); + + dns_res_settrace(R, trace("w+b")); + + if ((error = dns_res_submit(R, MAIN.qname, MAIN.qtype, DNS_C_IN))) + panic("%s: %s", MAIN.qname, dns_strerror(error)); + + while ((error = dns_res_check(R))) { + if (error != DNS_EAGAIN) + panic("dns_res_check: %s (%d)", dns_strerror(error), error); + if (dns_res_elapsed(R) > 30) + panic("query timed-out"); + + dns_res_poll(R, 1); + } + + ans = dns_res_fetch(R, &error); + print_packet(ans, stdout); + free(ans); + + st = dns_res_stat(R); + putchar('\n'); + printf(";; queries: %"PRIuZ"\n", st->queries); + printf(";; udp sent: %"PRIuZ" in %"PRIuZ" bytes\n", st->udp.sent.count, st->udp.sent.bytes); + printf(";; udp rcvd: %"PRIuZ" in %"PRIuZ" bytes\n", st->udp.rcvd.count, st->udp.rcvd.bytes); + printf(";; tcp sent: %"PRIuZ" in %"PRIuZ" bytes\n", st->tcp.sent.count, st->tcp.sent.bytes); + printf(";; tcp rcvd: %"PRIuZ" in %"PRIuZ" bytes\n", st->tcp.rcvd.count, st->tcp.rcvd.bytes); + + dns_res_close(R); + + return 0; +} /* resolve_query() */ + + +static int resolve_addrinfo(int argc DNS_NOTUSED, char *argv[]) { + _Bool recurse = !!strstr(argv[0], "recurse"); + struct dns_hints *(*hints)() = (recurse)? &dns_hints_root : &dns_hints_local; + struct dns_resolver *res = NULL; + struct dns_addrinfo *ai = NULL; + struct addrinfo ai_hints = { .ai_family = PF_UNSPEC, .ai_socktype = SOCK_STREAM, .ai_flags = AI_CANONNAME }; + struct addrinfo *ent; + char pretty[512]; + int error; + struct dns_options opts = { 0 }; + + if (!MAIN.qname) + MAIN.qname = "www.google.com"; + /* NB: MAIN.qtype of 0 means obey hints.ai_family */ + + resconf()->options.recurse = recurse; + + if (!(res = dns_res_open(resconf(), hosts(), dns_hints_mortal(hints(resconf(), &error)), cache(), &opts, &error))) + panic("%s: %s", MAIN.qname, dns_strerror(error)); + + if (!(ai = dns_ai_open(MAIN.qname, "80", MAIN.qtype, &ai_hints, res, &error))) + panic("%s: %s", MAIN.qname, dns_strerror(error)); + + dns_ai_settrace(ai, trace("w+b")); + + do { + switch (error = dns_ai_nextent(&ent, ai)) { + case 0: + dns_ai_print(pretty, sizeof pretty, ent, ai); + + fputs(pretty, stdout); + + free(ent); + + break; + case ENOENT: + break; + case DNS_EAGAIN: + if (dns_ai_elapsed(ai) > 30) + panic("query timed-out"); + + dns_ai_poll(ai, 1); + + break; + default: + panic("dns_ai_nextent: %s (%d)", dns_strerror(error), error); + } + } while (error != ENOENT); + + dns_res_close(res); + dns_ai_close(ai); + + return 0; +} /* resolve_addrinfo() */ + + +static int dump_trace(int argc DNS_NOTUSED, char *argv[]) { + int error; + + if (!MAIN.trace) + panic("no trace file specified"); + + if ((error = dns_trace_dump(trace("r"), stdout))) + panic("dump_trace: %s", dns_strerror(error)); + + return 0; +} /* dump_trace() */ + + +static int echo_port(int argc DNS_NOTUSED, char *argv[] DNS_NOTUSED) { + union { + struct sockaddr sa; + struct sockaddr_in sin; + } port; + int fd; + + memset(&port, 0, sizeof port); + port.sin.sin_family = AF_INET; + port.sin.sin_port = htons(5354); + port.sin.sin_addr.s_addr = inet_addr("127.0.0.1"); + + if (-1 == (fd = socket(PF_INET, SOCK_DGRAM, 0))) + panic("socket: %s", strerror(errno)); + + if (0 != bind(fd, &port.sa, sizeof port.sa)) + panic("127.0.0.1:5353: %s", dns_strerror(errno)); + + for (;;) { + union { unsigned char b[dns_p_calcsize((512))]; struct dns_packet p; } P_instance = { 0 }; + struct dns_packet *pkt = dns_p_init(&P_instance.p, 512); + struct sockaddr_storage ss; + socklen_t slen = sizeof ss; + ssize_t count; +#if defined(MSG_WAITALL) /* MinGW issue */ + int rflags = MSG_WAITALL; +#else + int rflags = 0; +#endif + + count = recvfrom(fd, (char *)pkt->data, pkt->size, rflags, (struct sockaddr *)&ss, &slen); + + if (!count || count < 0) + panic("recvfrom: %s", strerror(errno)); + + pkt->end = count; + + dns_p_dump(pkt, stdout); + + (void)sendto(fd, (char *)pkt->data, pkt->end, 0, (struct sockaddr *)&ss, slen); + } + + return 0; +} /* echo_port() */ + + +static int isection(int argc, char *argv[]) { + char __dst[DNS_STRMAXLEN + 1] = { 0 }; + const char *name = (argc > 1)? argv[1] : ""; + int type; + + type = dns_isection(name); + name = dns_strsection(type, __dst); + + printf("%s (%d)\n", name, type); + + return 0; +} /* isection() */ + + +static int iclass(int argc, char *argv[]) { + char __dst[DNS_STRMAXLEN + 1] = { 0 }; + const char *name = (argc > 1)? argv[1] : ""; + int type; + + type = dns_iclass(name); + name = dns_strclass(type, __dst); + + printf("%s (%d)\n", name, type); + + return 0; +} /* iclass() */ + + +static int itype(int argc, char *argv[]) { + char __dst[DNS_STRMAXLEN + 1] = { 0 }; + const char *name = (argc > 1)? argv[1] : ""; + int type; + + type = dns_itype(name); + name = dns_strtype(type, __dst); + + printf("%s (%d)\n", name, type); + + return 0; +} /* itype() */ + + +static int iopcode(int argc, char *argv[]) { + const char *name = (argc > 1)? argv[1] : ""; + int type; + + type = dns_iopcode(name); + name = dns_stropcode(type); + + printf("%s (%d)\n", name, type); + + return 0; +} /* iopcode() */ + + +static int ircode(int argc, char *argv[]) { + const char *name = (argc > 1)? argv[1] : ""; + int type; + + type = dns_ircode(name); + name = dns_strrcode(type); + + printf("%s (%d)\n", name, type); + + return 0; +} /* ircode() */ + + +#define SIZE1(x) { DNS_PP_STRINGIFY(x), sizeof (x) } +#define SIZE2(x, ...) SIZE1(x), SIZE1(__VA_ARGS__) +#define SIZE3(x, ...) SIZE1(x), SIZE2(__VA_ARGS__) +#define SIZE4(x, ...) SIZE1(x), SIZE3(__VA_ARGS__) +#define SIZE(...) DNS_PP_CALL(DNS_PP_XPASTE(SIZE, DNS_PP_NARG(__VA_ARGS__)), __VA_ARGS__) + +static int sizes(int argc DNS_NOTUSED, char *argv[] DNS_NOTUSED) { + static const struct { const char *name; size_t size; } type[] = { + SIZE(struct dns_header, struct dns_packet, struct dns_rr, struct dns_rr_i), + SIZE(struct dns_a, struct dns_aaaa, struct dns_mx, struct dns_ns), + SIZE(struct dns_cname, struct dns_soa, struct dns_ptr, struct dns_srv), + SIZE(struct dns_sshfp, struct dns_txt, union dns_any), + SIZE(struct dns_resolv_conf, struct dns_hosts, struct dns_hints, struct dns_hints_i), + SIZE(struct dns_options, struct dns_socket, struct dns_resolver, struct dns_addrinfo), + SIZE(struct dns_cache), SIZE(size_t), SIZE(void *), SIZE(long) + }; + unsigned i, max; + + for (i = 0, max = 0; i < lengthof(type); i++) + max = DNS_PP_MAX(max, strlen(type[i].name)); + + for (i = 0; i < lengthof(type); i++) + printf("%*s : %"PRIuZ"\n", max, type[i].name, type[i].size); + + return 0; +} /* sizes() */ + + +static const struct { const char *cmd; int (*run)(); const char *help; } cmds[] = { + { "parse-packet", &parse_packet, "parse binary packet from stdin" }, + { "parse-domain", &parse_domain, "anchor and iteratively cleave domain" }, + { "trim-domain", &trim_domain, "trim and anchor domain name" }, + { "expand-domain", &expand_domain, "expand domain at offset NN in packet from stdin" }, + { "show-resconf", &show_resconf, "show resolv.conf data" }, + { "show-hosts", &show_hosts, "show hosts data" }, + { "show-nssconf", &show_nssconf, "show nsswitch.conf data" }, + { "query-hosts", &query_hosts, "query A, AAAA or PTR in hosts data" }, + { "search-list", &search_list, "generate query search list from domain" }, + { "permute-set", &permute_set, "generate random permutation -> (0 .. N or N .. M)" }, + { "shuffle-16", &shuffle_16, "simple 16-bit permutation" }, + { "dump-random", &dump_random, "generate random bytes" }, + { "send-query", &send_query, "send query to host" }, + { "send-query-udp", &send_query, "send udp query to host" }, + { "send-query-tcp", &send_query, "send tcp query to host" }, + { "print-arpa", &print_arpa, "print arpa. zone name of address" }, + { "show-hints", &show_hints, "print hints: show-hints [local|root] [plain|packet]" }, + { "resolve-stub", &resolve_query, "resolve as stub resolver" }, + { "resolve-recurse", &resolve_query, "resolve as recursive resolver" }, + { "addrinfo-stub", &resolve_addrinfo, "resolve through getaddrinfo clone" }, + { "addrinfo-recurse", &resolve_addrinfo, "resolve through getaddrinfo clone" }, +/* { "resolve-nameinfo", &resolve_query, "resolve as recursive resolver" }, */ + { "dump-trace", &dump_trace, "dump the contents of a trace file" }, + { "echo", &echo_port, "server echo mode, for nmap fuzzing" }, + { "isection", &isection, "parse section string" }, + { "iclass", &iclass, "parse class string" }, + { "itype", &itype, "parse type string" }, + { "iopcode", &iopcode, "parse opcode string" }, + { "ircode", &ircode, "parse rcode string" }, + { "sizes", &sizes, "print data structure sizes" }, +}; + + +static void print_usage(const char *progname, FILE *fp) { + static const char *usage = + " [OPTIONS] COMMAND [ARGS]\n" + " -c PATH Path to resolv.conf\n" + " -n PATH Path to nsswitch.conf\n" + " -l PATH Path to local hosts\n" + " -z PATH Path to zone cache\n" + " -q QNAME Query name\n" + " -t QTYPE Query type\n" + " -s HOW Sort records\n" + " -S ADDR Address of SOCKS server to use\n" + " -P PORT Port of SOCKS server to use\n" + " -A USER:PASSWORD Credentials for the SOCKS server\n" + " -f PATH Path to trace file\n" + " -v Be more verbose (-vv show packets; -vvv hexdump packets)\n" + " -V Print version info\n" + " -h Print this usage message\n" + "\n"; + unsigned i, n, m; + + fputs(progname, fp); + fputs(usage, fp); + + for (i = 0, m = 0; i < lengthof(cmds); i++) { + if (strlen(cmds[i].cmd) > m) + m = strlen(cmds[i].cmd); + } + + for (i = 0; i < lengthof(cmds); i++) { + fprintf(fp, " %s ", cmds[i].cmd); + + for (n = strlen(cmds[i].cmd); n < m; n++) + putc(' ', fp); + + fputs(cmds[i].help, fp); + putc('\n', fp); + } + + fputs("\nReport bugs to William Ahern <william@25thandClement.com>\n", fp); +} /* print_usage() */ + + +static void print_version(const char *progname, FILE *fp) { + fprintf(fp, "%s (dns.c) %.8X\n", progname, dns_v_rel()); + fprintf(fp, "vendor %s\n", dns_vendor()); + fprintf(fp, "release %.8X\n", dns_v_rel()); + fprintf(fp, "abi %.8X\n", dns_v_abi()); + fprintf(fp, "api %.8X\n", dns_v_api()); +} /* print_version() */ + + +static void main_exit(void) { + dns_trace_close(MAIN.memo.trace); + MAIN.memo.trace = NULL; + dns_hosts_close(MAIN.memo.hosts); + MAIN.memo.hosts = NULL; + dns_resconf_close(MAIN.memo.resconf); + MAIN.memo.resconf = NULL; +} /* main_exit() */ + +int main(int argc, char **argv) { + extern int optind; + extern char *optarg; + const char *progname = argv[0]; + unsigned i; + int ch; + + atexit(&main_exit); + + while (-1 != (ch = getopt(argc, argv, "q:t:c:n:l:z:s:S:P:A:f:vVh"))) { + switch (ch) { + case 'c': + assert(MAIN.resconf.count < lengthof(MAIN.resconf.path)); + + MAIN.resconf.path[MAIN.resconf.count++] = optarg; + + break; + case 'n': + assert(MAIN.nssconf.count < lengthof(MAIN.nssconf.path)); + + MAIN.nssconf.path[MAIN.nssconf.count++] = optarg; + + break; + case 'l': + assert(MAIN.hosts.count < lengthof(MAIN.hosts.path)); + + MAIN.hosts.path[MAIN.hosts.count++] = optarg; + + break; + case 'z': + assert(MAIN.cache.count < lengthof(MAIN.cache.path)); + + MAIN.cache.path[MAIN.cache.count++] = optarg; + + break; + case 'q': + MAIN.qname = optarg; + + break; + case 't': + for (i = 0; i < lengthof(dns_rrtypes); i++) { + if (0 == strcasecmp(dns_rrtypes[i].name, optarg)) + { MAIN.qtype = dns_rrtypes[i].type; break; } + } + + if (MAIN.qtype) + break; + + for (i = 0; dns_isdigit(optarg[i]); i++) { + MAIN.qtype *= 10; + MAIN.qtype += optarg[i] - '0'; + } + + if (!MAIN.qtype) + panic("%s: invalid query type", optarg); + + break; + case 's': + if (0 == strcasecmp(optarg, "packet")) + MAIN.sort = &dns_rr_i_packet; + else if (0 == strcasecmp(optarg, "shuffle")) + MAIN.sort = &dns_rr_i_shuffle; + else if (0 == strcasecmp(optarg, "order")) + MAIN.sort = &dns_rr_i_order; + else + panic("%s: invalid sort method", optarg); + + break; + case 'S': { + dns_error_t error; + struct dns_resolv_conf *conf = resconf(); + conf->options.tcp = DNS_RESCONF_TCP_SOCKS; + + MAIN.socks_host.ss_family = (strchr(optarg, ':')) ? AF_INET6 : AF_INET; + if ((error = dns_pton(MAIN.socks_host.ss_family, optarg, + dns_sa_addr(MAIN.socks_host.ss_family, + &MAIN.socks_host, NULL)))) + panic("%s: %s", optarg, dns_strerror(error)); + + *dns_sa_port(MAIN.socks_host.ss_family, &MAIN.socks_host) = htons(1080); + + break; + } + case 'P': + if (! MAIN.socks_host.ss_family) + panic("-P without prior -S"); + *dns_sa_port(MAIN.socks_host.ss_family, &MAIN.socks_host) = htons(atoi(optarg)); + + break; + case 'A': { + char *password; + if (! MAIN.socks_host.ss_family) + panic("-A without prior -S"); + if (! (password = strchr(optarg, ':'))) + panic("Usage: -A USER:PASSWORD"); + *password = 0; + password += 1; + MAIN.socks_user = optarg; + MAIN.socks_password = password; + break; + } + case 'f': + MAIN.trace = optarg; + + break; + case 'v': + dns_debug = ++MAIN.verbose; + + break; + case 'V': + print_version(progname, stdout); + + return 0; + case 'h': + print_usage(progname, stdout); + + return 0; + default: + print_usage(progname, stderr); + + return EXIT_FAILURE; + } /* switch() */ + } /* while() */ + + argc -= optind; + argv += optind; + + for (i = 0; i < lengthof(cmds) && argv[0]; i++) { + if (0 == strcmp(cmds[i].cmd, argv[0])) + return cmds[i].run(argc, argv); + } + + print_usage(progname, stderr); + + return EXIT_FAILURE; +} /* main() */ + + +#endif /* DNS_MAIN */ + + +/* + * pop file-scoped compiler annotations + */ +#if __clang__ +#pragma clang diagnostic pop +#elif DNS_GNUC_PREREQ(4,6,0) +#pragma GCC diagnostic pop +#endif |