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Diffstat (limited to 'openbsd-compat/getrrsetbyname.c')
| -rw-r--r-- | openbsd-compat/getrrsetbyname.c | 615 |
1 files changed, 615 insertions, 0 deletions
diff --git a/openbsd-compat/getrrsetbyname.c b/openbsd-compat/getrrsetbyname.c new file mode 100644 index 0000000..73de5e9 --- /dev/null +++ b/openbsd-compat/getrrsetbyname.c @@ -0,0 +1,615 @@ +/* $OpenBSD: getrrsetbyname.c,v 1.11 2007/10/11 18:36:41 jakob Exp $ */ + +/* + * Copyright (c) 2001 Jakob Schlyter. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. + * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF + * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +/* + * Portions Copyright (c) 1999-2001 Internet Software Consortium. + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM + * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL + * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, + * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING + * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, + * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION + * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +/* OPENBSD ORIGINAL: lib/libc/net/getrrsetbyname.c */ + +#include "includes.h" + +#if !defined (HAVE_GETRRSETBYNAME) && !defined (HAVE_LDNS) + +#include <stdlib.h> +#include <string.h> + +#include <netinet/in.h> +#include <arpa/inet.h> + +#include "getrrsetbyname.h" + +#if defined(HAVE_DECL_H_ERRNO) && !HAVE_DECL_H_ERRNO +extern int h_errno; +#endif + +/* We don't need multithread support here */ +#ifdef _THREAD_PRIVATE +# undef _THREAD_PRIVATE +#endif +#define _THREAD_PRIVATE(a,b,c) (c) + +#ifndef HAVE__RES_EXTERN +struct __res_state _res; +#endif + +/* Necessary functions and macros */ + +/* + * Inline versions of get/put short/long. Pointer is advanced. + * + * These macros demonstrate the property of C whereby it can be + * portable or it can be elegant but rarely both. + */ + +#ifndef INT32SZ +# define INT32SZ 4 +#endif +#ifndef INT16SZ +# define INT16SZ 2 +#endif + +#ifndef GETSHORT +#define GETSHORT(s, cp) { \ + u_char *t_cp = (u_char *)(cp); \ + (s) = ((u_int16_t)t_cp[0] << 8) \ + | ((u_int16_t)t_cp[1]) \ + ; \ + (cp) += INT16SZ; \ +} +#endif + +#ifndef GETLONG +#define GETLONG(l, cp) { \ + u_char *t_cp = (u_char *)(cp); \ + (l) = ((u_int32_t)t_cp[0] << 24) \ + | ((u_int32_t)t_cp[1] << 16) \ + | ((u_int32_t)t_cp[2] << 8) \ + | ((u_int32_t)t_cp[3]) \ + ; \ + (cp) += INT32SZ; \ +} +#endif + +/* + * If the system doesn't have _getshort/_getlong or that are not exactly what + * we need then use local replacements, avoiding name collisions. + */ +#if !defined(HAVE__GETSHORT) || !defined(HAVE__GETLONG) || \ + !defined(HAVE_DECL__GETSHORT) || HAVE_DECL__GETSHORT == 0 || \ + !defined(HAVE_DECL__GETLONG) || HAVE_DECL__GETLONG == 0 +# ifdef _getshort +# undef _getshort +# endif +# ifdef _getlong +# undef _getlong +# endif +# define _getshort(x) (_ssh_compat_getshort(x)) +# define _getlong(x) (_ssh_compat_getlong(x)) +/* + * Routines to insert/extract short/long's. + */ +static u_int16_t +_getshort(const u_char *msgp) +{ + u_int16_t u; + + GETSHORT(u, msgp); + return (u); +} + +static u_int32_t +_getlong(const u_char *msgp) +{ + u_int32_t u; + + GETLONG(u, msgp); + return (u); +} +#endif /* missing _getshort/_getlong */ + +/* ************** */ + +#define ANSWER_BUFFER_SIZE 0xffff + +struct dns_query { + char *name; + u_int16_t type; + u_int16_t class; + struct dns_query *next; +}; + +struct dns_rr { + char *name; + u_int16_t type; + u_int16_t class; + u_int16_t ttl; + u_int16_t size; + void *rdata; + struct dns_rr *next; +}; + +struct dns_response { + HEADER header; + struct dns_query *query; + struct dns_rr *answer; + struct dns_rr *authority; + struct dns_rr *additional; +}; + +static struct dns_response *parse_dns_response(const u_char *, int); +static struct dns_query *parse_dns_qsection(const u_char *, int, + const u_char **, int); +static struct dns_rr *parse_dns_rrsection(const u_char *, int, const u_char **, + int); + +static void free_dns_query(struct dns_query *); +static void free_dns_rr(struct dns_rr *); +static void free_dns_response(struct dns_response *); + +static int count_dns_rr(struct dns_rr *, u_int16_t, u_int16_t); + +int +getrrsetbyname(const char *hostname, unsigned int rdclass, + unsigned int rdtype, unsigned int flags, + struct rrsetinfo **res) +{ + struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res); + int result; + struct rrsetinfo *rrset = NULL; + struct dns_response *response = NULL; + struct dns_rr *rr; + struct rdatainfo *rdata; + int length; + unsigned int index_ans, index_sig; + u_char answer[ANSWER_BUFFER_SIZE]; + + /* check for invalid class and type */ + if (rdclass > 0xffff || rdtype > 0xffff) { + result = ERRSET_INVAL; + goto fail; + } + + /* don't allow queries of class or type ANY */ + if (rdclass == 0xff || rdtype == 0xff) { + result = ERRSET_INVAL; + goto fail; + } + + /* don't allow flags yet, unimplemented */ + if (flags) { + result = ERRSET_INVAL; + goto fail; + } + + /* initialize resolver */ + if ((_resp->options & RES_INIT) == 0 && res_init() == -1) { + result = ERRSET_FAIL; + goto fail; + } + +#ifdef DEBUG + _resp->options |= RES_DEBUG; +#endif /* DEBUG */ + +#ifdef RES_USE_DNSSEC + /* turn on DNSSEC if EDNS0 is configured */ + if (_resp->options & RES_USE_EDNS0) + _resp->options |= RES_USE_DNSSEC; +#endif /* RES_USE_DNSEC */ + + /* make query */ + length = res_query(hostname, (signed int) rdclass, (signed int) rdtype, + answer, sizeof(answer)); + if (length < 0) { + switch(h_errno) { + case HOST_NOT_FOUND: + result = ERRSET_NONAME; + goto fail; + case NO_DATA: + result = ERRSET_NODATA; + goto fail; + default: + result = ERRSET_FAIL; + goto fail; + } + } + + /* parse result */ + response = parse_dns_response(answer, length); + if (response == NULL) { + result = ERRSET_FAIL; + goto fail; + } + + if (response->header.qdcount != 1) { + result = ERRSET_FAIL; + goto fail; + } + + /* initialize rrset */ + rrset = calloc(1, sizeof(struct rrsetinfo)); + if (rrset == NULL) { + result = ERRSET_NOMEMORY; + goto fail; + } + rrset->rri_rdclass = response->query->class; + rrset->rri_rdtype = response->query->type; + rrset->rri_ttl = response->answer->ttl; + rrset->rri_nrdatas = response->header.ancount; + +#ifdef HAVE_HEADER_AD + /* check for authenticated data */ + if (response->header.ad == 1) + rrset->rri_flags |= RRSET_VALIDATED; +#endif + + /* copy name from answer section */ + rrset->rri_name = strdup(response->answer->name); + if (rrset->rri_name == NULL) { + result = ERRSET_NOMEMORY; + goto fail; + } + + /* count answers */ + rrset->rri_nrdatas = count_dns_rr(response->answer, rrset->rri_rdclass, + rrset->rri_rdtype); + rrset->rri_nsigs = count_dns_rr(response->answer, rrset->rri_rdclass, + T_RRSIG); + + /* allocate memory for answers */ + rrset->rri_rdatas = calloc(rrset->rri_nrdatas, + sizeof(struct rdatainfo)); + if (rrset->rri_rdatas == NULL) { + result = ERRSET_NOMEMORY; + goto fail; + } + + /* allocate memory for signatures */ + if (rrset->rri_nsigs > 0) { + rrset->rri_sigs = calloc(rrset->rri_nsigs, sizeof(struct rdatainfo)); + if (rrset->rri_sigs == NULL) { + result = ERRSET_NOMEMORY; + goto fail; + } + } + + /* copy answers & signatures */ + for (rr = response->answer, index_ans = 0, index_sig = 0; + rr; rr = rr->next) { + + rdata = NULL; + + if (rr->class == rrset->rri_rdclass && + rr->type == rrset->rri_rdtype) + rdata = &rrset->rri_rdatas[index_ans++]; + + if (rr->class == rrset->rri_rdclass && + rr->type == T_RRSIG) + rdata = &rrset->rri_sigs[index_sig++]; + + if (rdata) { + rdata->rdi_length = rr->size; + rdata->rdi_data = malloc(rr->size); + + if (rdata->rdi_data == NULL) { + result = ERRSET_NOMEMORY; + goto fail; + } + memcpy(rdata->rdi_data, rr->rdata, rr->size); + } + } + free_dns_response(response); + + *res = rrset; + return (ERRSET_SUCCESS); + +fail: + if (rrset != NULL) + freerrset(rrset); + if (response != NULL) + free_dns_response(response); + return (result); +} + +void +freerrset(struct rrsetinfo *rrset) +{ + u_int16_t i; + + if (rrset == NULL) + return; + + if (rrset->rri_rdatas) { + for (i = 0; i < rrset->rri_nrdatas; i++) { + if (rrset->rri_rdatas[i].rdi_data == NULL) + break; + free(rrset->rri_rdatas[i].rdi_data); + } + free(rrset->rri_rdatas); + } + + if (rrset->rri_sigs) { + for (i = 0; i < rrset->rri_nsigs; i++) { + if (rrset->rri_sigs[i].rdi_data == NULL) + break; + free(rrset->rri_sigs[i].rdi_data); + } + free(rrset->rri_sigs); + } + + if (rrset->rri_name) + free(rrset->rri_name); + free(rrset); +} + +/* + * DNS response parsing routines + */ +static struct dns_response * +parse_dns_response(const u_char *answer, int size) +{ + struct dns_response *resp; + const u_char *cp; + + /* allocate memory for the response */ + resp = calloc(1, sizeof(*resp)); + if (resp == NULL) + return (NULL); + + /* initialize current pointer */ + cp = answer; + + /* copy header */ + memcpy(&resp->header, cp, HFIXEDSZ); + cp += HFIXEDSZ; + + /* fix header byte order */ + resp->header.qdcount = ntohs(resp->header.qdcount); + resp->header.ancount = ntohs(resp->header.ancount); + resp->header.nscount = ntohs(resp->header.nscount); + resp->header.arcount = ntohs(resp->header.arcount); + + /* there must be at least one query */ + if (resp->header.qdcount < 1) { + free_dns_response(resp); + return (NULL); + } + + /* parse query section */ + resp->query = parse_dns_qsection(answer, size, &cp, + resp->header.qdcount); + if (resp->header.qdcount && resp->query == NULL) { + free_dns_response(resp); + return (NULL); + } + + /* parse answer section */ + resp->answer = parse_dns_rrsection(answer, size, &cp, + resp->header.ancount); + if (resp->header.ancount && resp->answer == NULL) { + free_dns_response(resp); + return (NULL); + } + + /* parse authority section */ + resp->authority = parse_dns_rrsection(answer, size, &cp, + resp->header.nscount); + if (resp->header.nscount && resp->authority == NULL) { + free_dns_response(resp); + return (NULL); + } + + /* parse additional section */ + resp->additional = parse_dns_rrsection(answer, size, &cp, + resp->header.arcount); + if (resp->header.arcount && resp->additional == NULL) { + free_dns_response(resp); + return (NULL); + } + + return (resp); +} + +static struct dns_query * +parse_dns_qsection(const u_char *answer, int size, const u_char **cp, int count) +{ + struct dns_query *head, *curr, *prev; + int i, length; + char name[MAXDNAME]; + + for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) { + + /* allocate and initialize struct */ + curr = calloc(1, sizeof(struct dns_query)); + if (curr == NULL) { + free_dns_query(head); + return (NULL); + } + if (head == NULL) + head = curr; + if (prev != NULL) + prev->next = curr; + + /* name */ + length = dn_expand(answer, answer + size, *cp, name, + sizeof(name)); + if (length < 0) { + free_dns_query(head); + return (NULL); + } + curr->name = strdup(name); + if (curr->name == NULL) { + free_dns_query(head); + return (NULL); + } + *cp += length; + + /* type */ + curr->type = _getshort(*cp); + *cp += INT16SZ; + + /* class */ + curr->class = _getshort(*cp); + *cp += INT16SZ; + } + + return (head); +} + +static struct dns_rr * +parse_dns_rrsection(const u_char *answer, int size, const u_char **cp, + int count) +{ + struct dns_rr *head, *curr, *prev; + int i, length; + char name[MAXDNAME]; + + for (i = 1, head = NULL, prev = NULL; i <= count; i++, prev = curr) { + + /* allocate and initialize struct */ + curr = calloc(1, sizeof(struct dns_rr)); + if (curr == NULL) { + free_dns_rr(head); + return (NULL); + } + if (head == NULL) + head = curr; + if (prev != NULL) + prev->next = curr; + + /* name */ + length = dn_expand(answer, answer + size, *cp, name, + sizeof(name)); + if (length < 0) { + free_dns_rr(head); + return (NULL); + } + curr->name = strdup(name); + if (curr->name == NULL) { + free_dns_rr(head); + return (NULL); + } + *cp += length; + + /* type */ + curr->type = _getshort(*cp); + *cp += INT16SZ; + + /* class */ + curr->class = _getshort(*cp); + *cp += INT16SZ; + + /* ttl */ + curr->ttl = _getlong(*cp); + *cp += INT32SZ; + + /* rdata size */ + curr->size = _getshort(*cp); + *cp += INT16SZ; + + /* rdata itself */ + curr->rdata = malloc(curr->size); + if (curr->rdata == NULL) { + free_dns_rr(head); + return (NULL); + } + memcpy(curr->rdata, *cp, curr->size); + *cp += curr->size; + } + + return (head); +} + +static void +free_dns_query(struct dns_query *p) +{ + if (p == NULL) + return; + + if (p->name) + free(p->name); + free_dns_query(p->next); + free(p); +} + +static void +free_dns_rr(struct dns_rr *p) +{ + if (p == NULL) + return; + + if (p->name) + free(p->name); + if (p->rdata) + free(p->rdata); + free_dns_rr(p->next); + free(p); +} + +static void +free_dns_response(struct dns_response *p) +{ + if (p == NULL) + return; + + free_dns_query(p->query); + free_dns_rr(p->answer); + free_dns_rr(p->authority); + free_dns_rr(p->additional); + free(p); +} + +static int +count_dns_rr(struct dns_rr *p, u_int16_t class, u_int16_t type) +{ + int n = 0; + + while(p) { + if (p->class == class && p->type == type) + n++; + p = p->next; + } + + return (n); +} + +#endif /* !defined (HAVE_GETRRSETBYNAME) && !defined (HAVE_LDNS) */ |