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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 14:40:04 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 14:40:04 +0000 |
commit | 25505898530a333011f4fd5cbc841ad6b26c089c (patch) | |
tree | 333a33fdd60930bcccc3f177ed9467d535e9bac6 /misc.c | |
parent | Initial commit. (diff) | |
download | openssh-upstream.tar.xz openssh-upstream.zip |
Adding upstream version 1:9.2p1.upstream/1%9.2p1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'misc.c')
-rw-r--r-- | misc.c | 2917 |
1 files changed, 2917 insertions, 0 deletions
@@ -0,0 +1,2917 @@ +/* $OpenBSD: misc.c,v 1.180 2023/01/06 02:37:04 djm Exp $ */ +/* + * Copyright (c) 2000 Markus Friedl. All rights reserved. + * Copyright (c) 2005-2020 Damien Miller. All rights reserved. + * Copyright (c) 2004 Henning Brauer <henning@openbsd.org> + * + * 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 THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR 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. + */ + + +#include "includes.h" + +#include <sys/types.h> +#include <sys/ioctl.h> +#include <sys/socket.h> +#include <sys/stat.h> +#include <sys/time.h> +#include <sys/wait.h> +#include <sys/un.h> + +#include <limits.h> +#ifdef HAVE_LIBGEN_H +# include <libgen.h> +#endif +#ifdef HAVE_POLL_H +#include <poll.h> +#endif +#include <signal.h> +#include <stdarg.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <time.h> +#include <unistd.h> + +#include <netinet/in.h> +#include <netinet/in_systm.h> +#include <netinet/ip.h> +#include <netinet/tcp.h> +#include <arpa/inet.h> + +#include <ctype.h> +#include <errno.h> +#include <fcntl.h> +#include <netdb.h> +#ifdef HAVE_PATHS_H +# include <paths.h> +#include <pwd.h> +#include <grp.h> +#endif +#ifdef SSH_TUN_OPENBSD +#include <net/if.h> +#endif + +#include "xmalloc.h" +#include "misc.h" +#include "log.h" +#include "ssh.h" +#include "sshbuf.h" +#include "ssherr.h" +#include "platform.h" + +/* remove newline at end of string */ +char * +chop(char *s) +{ + char *t = s; + while (*t) { + if (*t == '\n' || *t == '\r') { + *t = '\0'; + return s; + } + t++; + } + return s; + +} + +/* remove whitespace from end of string */ +void +rtrim(char *s) +{ + size_t i; + + if ((i = strlen(s)) == 0) + return; + for (i--; i > 0; i--) { + if (isspace((unsigned char)s[i])) + s[i] = '\0'; + } +} + +/* set/unset filedescriptor to non-blocking */ +int +set_nonblock(int fd) +{ + int val; + + val = fcntl(fd, F_GETFL); + if (val == -1) { + error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); + return (-1); + } + if (val & O_NONBLOCK) { + debug3("fd %d is O_NONBLOCK", fd); + return (0); + } + debug2("fd %d setting O_NONBLOCK", fd); + val |= O_NONBLOCK; + if (fcntl(fd, F_SETFL, val) == -1) { + debug("fcntl(%d, F_SETFL, O_NONBLOCK): %s", fd, + strerror(errno)); + return (-1); + } + return (0); +} + +int +unset_nonblock(int fd) +{ + int val; + + val = fcntl(fd, F_GETFL); + if (val == -1) { + error("fcntl(%d, F_GETFL): %s", fd, strerror(errno)); + return (-1); + } + if (!(val & O_NONBLOCK)) { + debug3("fd %d is not O_NONBLOCK", fd); + return (0); + } + debug("fd %d clearing O_NONBLOCK", fd); + val &= ~O_NONBLOCK; + if (fcntl(fd, F_SETFL, val) == -1) { + debug("fcntl(%d, F_SETFL, ~O_NONBLOCK): %s", + fd, strerror(errno)); + return (-1); + } + return (0); +} + +const char * +ssh_gai_strerror(int gaierr) +{ + if (gaierr == EAI_SYSTEM && errno != 0) + return strerror(errno); + return gai_strerror(gaierr); +} + +/* disable nagle on socket */ +void +set_nodelay(int fd) +{ + int opt; + socklen_t optlen; + + optlen = sizeof opt; + if (getsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, &optlen) == -1) { + debug("getsockopt TCP_NODELAY: %.100s", strerror(errno)); + return; + } + if (opt == 1) { + debug2("fd %d is TCP_NODELAY", fd); + return; + } + opt = 1; + debug2("fd %d setting TCP_NODELAY", fd); + if (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof opt) == -1) + error("setsockopt TCP_NODELAY: %.100s", strerror(errno)); +} + +/* Allow local port reuse in TIME_WAIT */ +int +set_reuseaddr(int fd) +{ + int on = 1; + + if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) { + error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno)); + return -1; + } + return 0; +} + +/* Get/set routing domain */ +char * +get_rdomain(int fd) +{ +#if defined(HAVE_SYS_GET_RDOMAIN) + return sys_get_rdomain(fd); +#elif defined(__OpenBSD__) + int rtable; + char *ret; + socklen_t len = sizeof(rtable); + + if (getsockopt(fd, SOL_SOCKET, SO_RTABLE, &rtable, &len) == -1) { + error("Failed to get routing domain for fd %d: %s", + fd, strerror(errno)); + return NULL; + } + xasprintf(&ret, "%d", rtable); + return ret; +#else /* defined(__OpenBSD__) */ + return NULL; +#endif +} + +int +set_rdomain(int fd, const char *name) +{ +#if defined(HAVE_SYS_SET_RDOMAIN) + return sys_set_rdomain(fd, name); +#elif defined(__OpenBSD__) + int rtable; + const char *errstr; + + if (name == NULL) + return 0; /* default table */ + + rtable = (int)strtonum(name, 0, 255, &errstr); + if (errstr != NULL) { + /* Shouldn't happen */ + error("Invalid routing domain \"%s\": %s", name, errstr); + return -1; + } + if (setsockopt(fd, SOL_SOCKET, SO_RTABLE, + &rtable, sizeof(rtable)) == -1) { + error("Failed to set routing domain %d on fd %d: %s", + rtable, fd, strerror(errno)); + return -1; + } + return 0; +#else /* defined(__OpenBSD__) */ + error("Setting routing domain is not supported on this platform"); + return -1; +#endif +} + +int +get_sock_af(int fd) +{ + struct sockaddr_storage to; + socklen_t tolen = sizeof(to); + + memset(&to, 0, sizeof(to)); + if (getsockname(fd, (struct sockaddr *)&to, &tolen) == -1) + return -1; +#ifdef IPV4_IN_IPV6 + if (to.ss_family == AF_INET6 && + IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&to)->sin6_addr)) + return AF_INET; +#endif + return to.ss_family; +} + +void +set_sock_tos(int fd, int tos) +{ +#ifndef IP_TOS_IS_BROKEN + int af; + + switch ((af = get_sock_af(fd))) { + case -1: + /* assume not a socket */ + break; + case AF_INET: +# ifdef IP_TOS + debug3_f("set socket %d IP_TOS 0x%02x", fd, tos); + if (setsockopt(fd, IPPROTO_IP, IP_TOS, + &tos, sizeof(tos)) == -1) { + error("setsockopt socket %d IP_TOS %d: %s", + fd, tos, strerror(errno)); + } +# endif /* IP_TOS */ + break; + case AF_INET6: +# ifdef IPV6_TCLASS + debug3_f("set socket %d IPV6_TCLASS 0x%02x", fd, tos); + if (setsockopt(fd, IPPROTO_IPV6, IPV6_TCLASS, + &tos, sizeof(tos)) == -1) { + error("setsockopt socket %d IPV6_TCLASS %d: %s", + fd, tos, strerror(errno)); + } +# endif /* IPV6_TCLASS */ + break; + default: + debug2_f("unsupported socket family %d", af); + break; + } +#endif /* IP_TOS_IS_BROKEN */ +} + +/* + * Wait up to *timeoutp milliseconds for events on fd. Updates + * *timeoutp with time remaining. + * Returns 0 if fd ready or -1 on timeout or error (see errno). + */ +static int +waitfd(int fd, int *timeoutp, short events) +{ + struct pollfd pfd; + struct timeval t_start; + int oerrno, r; + + pfd.fd = fd; + pfd.events = events; + for (; *timeoutp >= 0;) { + monotime_tv(&t_start); + r = poll(&pfd, 1, *timeoutp); + oerrno = errno; + ms_subtract_diff(&t_start, timeoutp); + errno = oerrno; + if (r > 0) + return 0; + else if (r == -1 && errno != EAGAIN && errno != EINTR) + return -1; + else if (r == 0) + break; + } + /* timeout */ + errno = ETIMEDOUT; + return -1; +} + +/* + * Wait up to *timeoutp milliseconds for fd to be readable. Updates + * *timeoutp with time remaining. + * Returns 0 if fd ready or -1 on timeout or error (see errno). + */ +int +waitrfd(int fd, int *timeoutp) { + return waitfd(fd, timeoutp, POLLIN); +} + +/* + * Attempt a non-blocking connect(2) to the specified address, waiting up to + * *timeoutp milliseconds for the connection to complete. If the timeout is + * <=0, then wait indefinitely. + * + * Returns 0 on success or -1 on failure. + */ +int +timeout_connect(int sockfd, const struct sockaddr *serv_addr, + socklen_t addrlen, int *timeoutp) +{ + int optval = 0; + socklen_t optlen = sizeof(optval); + + /* No timeout: just do a blocking connect() */ + if (timeoutp == NULL || *timeoutp <= 0) + return connect(sockfd, serv_addr, addrlen); + + set_nonblock(sockfd); + for (;;) { + if (connect(sockfd, serv_addr, addrlen) == 0) { + /* Succeeded already? */ + unset_nonblock(sockfd); + return 0; + } else if (errno == EINTR) + continue; + else if (errno != EINPROGRESS) + return -1; + break; + } + + if (waitfd(sockfd, timeoutp, POLLIN | POLLOUT) == -1) + return -1; + + /* Completed or failed */ + if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &optval, &optlen) == -1) { + debug("getsockopt: %s", strerror(errno)); + return -1; + } + if (optval != 0) { + errno = optval; + return -1; + } + unset_nonblock(sockfd); + return 0; +} + +/* Characters considered whitespace in strsep calls. */ +#define WHITESPACE " \t\r\n" +#define QUOTE "\"" + +/* return next token in configuration line */ +static char * +strdelim_internal(char **s, int split_equals) +{ + char *old; + int wspace = 0; + + if (*s == NULL) + return NULL; + + old = *s; + + *s = strpbrk(*s, + split_equals ? WHITESPACE QUOTE "=" : WHITESPACE QUOTE); + if (*s == NULL) + return (old); + + if (*s[0] == '\"') { + memmove(*s, *s + 1, strlen(*s)); /* move nul too */ + /* Find matching quote */ + if ((*s = strpbrk(*s, QUOTE)) == NULL) { + return (NULL); /* no matching quote */ + } else { + *s[0] = '\0'; + *s += strspn(*s + 1, WHITESPACE) + 1; + return (old); + } + } + + /* Allow only one '=' to be skipped */ + if (split_equals && *s[0] == '=') + wspace = 1; + *s[0] = '\0'; + + /* Skip any extra whitespace after first token */ + *s += strspn(*s + 1, WHITESPACE) + 1; + if (split_equals && *s[0] == '=' && !wspace) + *s += strspn(*s + 1, WHITESPACE) + 1; + + return (old); +} + +/* + * Return next token in configuration line; splts on whitespace or a + * single '=' character. + */ +char * +strdelim(char **s) +{ + return strdelim_internal(s, 1); +} + +/* + * Return next token in configuration line; splts on whitespace only. + */ +char * +strdelimw(char **s) +{ + return strdelim_internal(s, 0); +} + +struct passwd * +pwcopy(struct passwd *pw) +{ + struct passwd *copy = xcalloc(1, sizeof(*copy)); + + copy->pw_name = xstrdup(pw->pw_name); + copy->pw_passwd = xstrdup(pw->pw_passwd == NULL ? "*" : pw->pw_passwd); +#ifdef HAVE_STRUCT_PASSWD_PW_GECOS + copy->pw_gecos = xstrdup(pw->pw_gecos); +#endif + copy->pw_uid = pw->pw_uid; + copy->pw_gid = pw->pw_gid; +#ifdef HAVE_STRUCT_PASSWD_PW_EXPIRE + copy->pw_expire = pw->pw_expire; +#endif +#ifdef HAVE_STRUCT_PASSWD_PW_CHANGE + copy->pw_change = pw->pw_change; +#endif +#ifdef HAVE_STRUCT_PASSWD_PW_CLASS + copy->pw_class = xstrdup(pw->pw_class); +#endif + copy->pw_dir = xstrdup(pw->pw_dir); + copy->pw_shell = xstrdup(pw->pw_shell); + return copy; +} + +/* + * Convert ASCII string to TCP/IP port number. + * Port must be >=0 and <=65535. + * Return -1 if invalid. + */ +int +a2port(const char *s) +{ + struct servent *se; + long long port; + const char *errstr; + + port = strtonum(s, 0, 65535, &errstr); + if (errstr == NULL) + return (int)port; + if ((se = getservbyname(s, "tcp")) != NULL) + return ntohs(se->s_port); + return -1; +} + +int +a2tun(const char *s, int *remote) +{ + const char *errstr = NULL; + char *sp, *ep; + int tun; + + if (remote != NULL) { + *remote = SSH_TUNID_ANY; + sp = xstrdup(s); + if ((ep = strchr(sp, ':')) == NULL) { + free(sp); + return (a2tun(s, NULL)); + } + ep[0] = '\0'; ep++; + *remote = a2tun(ep, NULL); + tun = a2tun(sp, NULL); + free(sp); + return (*remote == SSH_TUNID_ERR ? *remote : tun); + } + + if (strcasecmp(s, "any") == 0) + return (SSH_TUNID_ANY); + + tun = strtonum(s, 0, SSH_TUNID_MAX, &errstr); + if (errstr != NULL) + return (SSH_TUNID_ERR); + + return (tun); +} + +#define SECONDS 1 +#define MINUTES (SECONDS * 60) +#define HOURS (MINUTES * 60) +#define DAYS (HOURS * 24) +#define WEEKS (DAYS * 7) + +/* + * Convert a time string into seconds; format is + * a sequence of: + * time[qualifier] + * + * Valid time qualifiers are: + * <none> seconds + * s|S seconds + * m|M minutes + * h|H hours + * d|D days + * w|W weeks + * + * Examples: + * 90m 90 minutes + * 1h30m 90 minutes + * 2d 2 days + * 1w 1 week + * + * Return -1 if time string is invalid. + */ +int +convtime(const char *s) +{ + long total, secs, multiplier; + const char *p; + char *endp; + + errno = 0; + total = 0; + p = s; + + if (p == NULL || *p == '\0') + return -1; + + while (*p) { + secs = strtol(p, &endp, 10); + if (p == endp || + (errno == ERANGE && (secs == INT_MIN || secs == INT_MAX)) || + secs < 0) + return -1; + + multiplier = 1; + switch (*endp++) { + case '\0': + endp--; + break; + case 's': + case 'S': + break; + case 'm': + case 'M': + multiplier = MINUTES; + break; + case 'h': + case 'H': + multiplier = HOURS; + break; + case 'd': + case 'D': + multiplier = DAYS; + break; + case 'w': + case 'W': + multiplier = WEEKS; + break; + default: + return -1; + } + if (secs > INT_MAX / multiplier) + return -1; + secs *= multiplier; + if (total > INT_MAX - secs) + return -1; + total += secs; + if (total < 0) + return -1; + p = endp; + } + + return total; +} + +#define TF_BUFS 8 +#define TF_LEN 9 + +const char * +fmt_timeframe(time_t t) +{ + char *buf; + static char tfbuf[TF_BUFS][TF_LEN]; /* ring buffer */ + static int idx = 0; + unsigned int sec, min, hrs, day; + unsigned long long week; + + buf = tfbuf[idx++]; + if (idx == TF_BUFS) + idx = 0; + + week = t; + + sec = week % 60; + week /= 60; + min = week % 60; + week /= 60; + hrs = week % 24; + week /= 24; + day = week % 7; + week /= 7; + + if (week > 0) + snprintf(buf, TF_LEN, "%02lluw%01ud%02uh", week, day, hrs); + else if (day > 0) + snprintf(buf, TF_LEN, "%01ud%02uh%02um", day, hrs, min); + else + snprintf(buf, TF_LEN, "%02u:%02u:%02u", hrs, min, sec); + + return (buf); +} + +/* + * Returns a standardized host+port identifier string. + * Caller must free returned string. + */ +char * +put_host_port(const char *host, u_short port) +{ + char *hoststr; + + if (port == 0 || port == SSH_DEFAULT_PORT) + return(xstrdup(host)); + if (asprintf(&hoststr, "[%s]:%d", host, (int)port) == -1) + fatal("put_host_port: asprintf: %s", strerror(errno)); + debug3("put_host_port: %s", hoststr); + return hoststr; +} + +/* + * Search for next delimiter between hostnames/addresses and ports. + * Argument may be modified (for termination). + * Returns *cp if parsing succeeds. + * *cp is set to the start of the next field, if one was found. + * The delimiter char, if present, is stored in delim. + * If this is the last field, *cp is set to NULL. + */ +char * +hpdelim2(char **cp, char *delim) +{ + char *s, *old; + + if (cp == NULL || *cp == NULL) + return NULL; + + old = s = *cp; + if (*s == '[') { + if ((s = strchr(s, ']')) == NULL) + return NULL; + else + s++; + } else if ((s = strpbrk(s, ":/")) == NULL) + s = *cp + strlen(*cp); /* skip to end (see first case below) */ + + switch (*s) { + case '\0': + *cp = NULL; /* no more fields*/ + break; + + case ':': + case '/': + if (delim != NULL) + *delim = *s; + *s = '\0'; /* terminate */ + *cp = s + 1; + break; + + default: + return NULL; + } + + return old; +} + +/* The common case: only accept colon as delimiter. */ +char * +hpdelim(char **cp) +{ + char *r, delim = '\0'; + + r = hpdelim2(cp, &delim); + if (delim == '/') + return NULL; + return r; +} + +char * +cleanhostname(char *host) +{ + if (*host == '[' && host[strlen(host) - 1] == ']') { + host[strlen(host) - 1] = '\0'; + return (host + 1); + } else + return host; +} + +char * +colon(char *cp) +{ + int flag = 0; + + if (*cp == ':') /* Leading colon is part of file name. */ + return NULL; + if (*cp == '[') + flag = 1; + + for (; *cp; ++cp) { + if (*cp == '@' && *(cp+1) == '[') + flag = 1; + if (*cp == ']' && *(cp+1) == ':' && flag) + return (cp+1); + if (*cp == ':' && !flag) + return (cp); + if (*cp == '/') + return NULL; + } + return NULL; +} + +/* + * Parse a [user@]host:[path] string. + * Caller must free returned user, host and path. + * Any of the pointer return arguments may be NULL (useful for syntax checking). + * If user was not specified then *userp will be set to NULL. + * If host was not specified then *hostp will be set to NULL. + * If path was not specified then *pathp will be set to ".". + * Returns 0 on success, -1 on failure. + */ +int +parse_user_host_path(const char *s, char **userp, char **hostp, char **pathp) +{ + char *user = NULL, *host = NULL, *path = NULL; + char *sdup, *tmp; + int ret = -1; + + if (userp != NULL) + *userp = NULL; + if (hostp != NULL) + *hostp = NULL; + if (pathp != NULL) + *pathp = NULL; + + sdup = xstrdup(s); + + /* Check for remote syntax: [user@]host:[path] */ + if ((tmp = colon(sdup)) == NULL) + goto out; + + /* Extract optional path */ + *tmp++ = '\0'; + if (*tmp == '\0') + tmp = "."; + path = xstrdup(tmp); + + /* Extract optional user and mandatory host */ + tmp = strrchr(sdup, '@'); + if (tmp != NULL) { + *tmp++ = '\0'; + host = xstrdup(cleanhostname(tmp)); + if (*sdup != '\0') + user = xstrdup(sdup); + } else { + host = xstrdup(cleanhostname(sdup)); + user = NULL; + } + + /* Success */ + if (userp != NULL) { + *userp = user; + user = NULL; + } + if (hostp != NULL) { + *hostp = host; + host = NULL; + } + if (pathp != NULL) { + *pathp = path; + path = NULL; + } + ret = 0; +out: + free(sdup); + free(user); + free(host); + free(path); + return ret; +} + +/* + * Parse a [user@]host[:port] string. + * Caller must free returned user and host. + * Any of the pointer return arguments may be NULL (useful for syntax checking). + * If user was not specified then *userp will be set to NULL. + * If port was not specified then *portp will be -1. + * Returns 0 on success, -1 on failure. + */ +int +parse_user_host_port(const char *s, char **userp, char **hostp, int *portp) +{ + char *sdup, *cp, *tmp; + char *user = NULL, *host = NULL; + int port = -1, ret = -1; + + if (userp != NULL) + *userp = NULL; + if (hostp != NULL) + *hostp = NULL; + if (portp != NULL) + *portp = -1; + + if ((sdup = tmp = strdup(s)) == NULL) + return -1; + /* Extract optional username */ + if ((cp = strrchr(tmp, '@')) != NULL) { + *cp = '\0'; + if (*tmp == '\0') + goto out; + if ((user = strdup(tmp)) == NULL) + goto out; + tmp = cp + 1; + } + /* Extract mandatory hostname */ + if ((cp = hpdelim(&tmp)) == NULL || *cp == '\0') + goto out; + host = xstrdup(cleanhostname(cp)); + /* Convert and verify optional port */ + if (tmp != NULL && *tmp != '\0') { + if ((port = a2port(tmp)) <= 0) + goto out; + } + /* Success */ + if (userp != NULL) { + *userp = user; + user = NULL; + } + if (hostp != NULL) { + *hostp = host; + host = NULL; + } + if (portp != NULL) + *portp = port; + ret = 0; + out: + free(sdup); + free(user); + free(host); + return ret; +} + +/* + * Converts a two-byte hex string to decimal. + * Returns the decimal value or -1 for invalid input. + */ +static int +hexchar(const char *s) +{ + unsigned char result[2]; + int i; + + for (i = 0; i < 2; i++) { + if (s[i] >= '0' && s[i] <= '9') + result[i] = (unsigned char)(s[i] - '0'); + else if (s[i] >= 'a' && s[i] <= 'f') + result[i] = (unsigned char)(s[i] - 'a') + 10; + else if (s[i] >= 'A' && s[i] <= 'F') + result[i] = (unsigned char)(s[i] - 'A') + 10; + else + return -1; + } + return (result[0] << 4) | result[1]; +} + +/* + * Decode an url-encoded string. + * Returns a newly allocated string on success or NULL on failure. + */ +static char * +urldecode(const char *src) +{ + char *ret, *dst; + int ch; + + ret = xmalloc(strlen(src) + 1); + for (dst = ret; *src != '\0'; src++) { + switch (*src) { + case '+': + *dst++ = ' '; + break; + case '%': + if (!isxdigit((unsigned char)src[1]) || + !isxdigit((unsigned char)src[2]) || + (ch = hexchar(src + 1)) == -1) { + free(ret); + return NULL; + } + *dst++ = ch; + src += 2; + break; + default: + *dst++ = *src; + break; + } + } + *dst = '\0'; + + return ret; +} + +/* + * Parse an (scp|ssh|sftp)://[user@]host[:port][/path] URI. + * See https://tools.ietf.org/html/draft-ietf-secsh-scp-sftp-ssh-uri-04 + * Either user or path may be url-encoded (but not host or port). + * Caller must free returned user, host and path. + * Any of the pointer return arguments may be NULL (useful for syntax checking) + * but the scheme must always be specified. + * If user was not specified then *userp will be set to NULL. + * If port was not specified then *portp will be -1. + * If path was not specified then *pathp will be set to NULL. + * Returns 0 on success, 1 if non-uri/wrong scheme, -1 on error/invalid uri. + */ +int +parse_uri(const char *scheme, const char *uri, char **userp, char **hostp, + int *portp, char **pathp) +{ + char *uridup, *cp, *tmp, ch; + char *user = NULL, *host = NULL, *path = NULL; + int port = -1, ret = -1; + size_t len; + + len = strlen(scheme); + if (strncmp(uri, scheme, len) != 0 || strncmp(uri + len, "://", 3) != 0) + return 1; + uri += len + 3; + + if (userp != NULL) + *userp = NULL; + if (hostp != NULL) + *hostp = NULL; + if (portp != NULL) + *portp = -1; + if (pathp != NULL) + *pathp = NULL; + + uridup = tmp = xstrdup(uri); + + /* Extract optional ssh-info (username + connection params) */ + if ((cp = strchr(tmp, '@')) != NULL) { + char *delim; + + *cp = '\0'; + /* Extract username and connection params */ + if ((delim = strchr(tmp, ';')) != NULL) { + /* Just ignore connection params for now */ + *delim = '\0'; + } + if (*tmp == '\0') { + /* Empty username */ + goto out; + } + if ((user = urldecode(tmp)) == NULL) + goto out; + tmp = cp + 1; + } + + /* Extract mandatory hostname */ + if ((cp = hpdelim2(&tmp, &ch)) == NULL || *cp == '\0') + goto out; + host = xstrdup(cleanhostname(cp)); + if (!valid_domain(host, 0, NULL)) + goto out; + + if (tmp != NULL && *tmp != '\0') { + if (ch == ':') { + /* Convert and verify port. */ + if ((cp = strchr(tmp, '/')) != NULL) + *cp = '\0'; + if ((port = a2port(tmp)) <= 0) + goto out; + tmp = cp ? cp + 1 : NULL; + } + if (tmp != NULL && *tmp != '\0') { + /* Extract optional path */ + if ((path = urldecode(tmp)) == NULL) + goto out; + } + } + + /* Success */ + if (userp != NULL) { + *userp = user; + user = NULL; + } + if (hostp != NULL) { + *hostp = host; + host = NULL; + } + if (portp != NULL) + *portp = port; + if (pathp != NULL) { + *pathp = path; + path = NULL; + } + ret = 0; + out: + free(uridup); + free(user); + free(host); + free(path); + return ret; +} + +/* function to assist building execv() arguments */ +void +addargs(arglist *args, char *fmt, ...) +{ + va_list ap; + char *cp; + u_int nalloc; + int r; + + va_start(ap, fmt); + r = vasprintf(&cp, fmt, ap); + va_end(ap); + if (r == -1) + fatal_f("argument too long"); + + nalloc = args->nalloc; + if (args->list == NULL) { + nalloc = 32; + args->num = 0; + } else if (args->num > (256 * 1024)) + fatal_f("too many arguments"); + else if (args->num >= args->nalloc) + fatal_f("arglist corrupt"); + else if (args->num+2 >= nalloc) + nalloc *= 2; + + args->list = xrecallocarray(args->list, args->nalloc, + nalloc, sizeof(char *)); + args->nalloc = nalloc; + args->list[args->num++] = cp; + args->list[args->num] = NULL; +} + +void +replacearg(arglist *args, u_int which, char *fmt, ...) +{ + va_list ap; + char *cp; + int r; + + va_start(ap, fmt); + r = vasprintf(&cp, fmt, ap); + va_end(ap); + if (r == -1) + fatal_f("argument too long"); + if (args->list == NULL || args->num >= args->nalloc) + fatal_f("arglist corrupt"); + + if (which >= args->num) + fatal_f("tried to replace invalid arg %d >= %d", + which, args->num); + free(args->list[which]); + args->list[which] = cp; +} + +void +freeargs(arglist *args) +{ + u_int i; + + if (args == NULL) + return; + if (args->list != NULL && args->num < args->nalloc) { + for (i = 0; i < args->num; i++) + free(args->list[i]); + free(args->list); + } + args->nalloc = args->num = 0; + args->list = NULL; +} + +/* + * Expands tildes in the file name. Returns data allocated by xmalloc. + * Warning: this calls getpw*. + */ +int +tilde_expand(const char *filename, uid_t uid, char **retp) +{ + char *ocopy = NULL, *copy, *s = NULL; + const char *path = NULL, *user = NULL; + struct passwd *pw; + size_t len; + int ret = -1, r, slash; + + *retp = NULL; + if (*filename != '~') { + *retp = xstrdup(filename); + return 0; + } + ocopy = copy = xstrdup(filename + 1); + + if (*copy == '\0') /* ~ */ + path = NULL; + else if (*copy == '/') { + copy += strspn(copy, "/"); + if (*copy == '\0') + path = NULL; /* ~/ */ + else + path = copy; /* ~/path */ + } else { + user = copy; + if ((path = strchr(copy, '/')) != NULL) { + copy[path - copy] = '\0'; + path++; + path += strspn(path, "/"); + if (*path == '\0') /* ~user/ */ + path = NULL; + /* else ~user/path */ + } + /* else ~user */ + } + if (user != NULL) { + if ((pw = getpwnam(user)) == NULL) { + error_f("No such user %s", user); + goto out; + } + } else if ((pw = getpwuid(uid)) == NULL) { + error_f("No such uid %ld", (long)uid); + goto out; + } + + /* Make sure directory has a trailing '/' */ + slash = (len = strlen(pw->pw_dir)) == 0 || pw->pw_dir[len - 1] != '/'; + + if ((r = xasprintf(&s, "%s%s%s", pw->pw_dir, + slash ? "/" : "", path != NULL ? path : "")) <= 0) { + error_f("xasprintf failed"); + goto out; + } + if (r >= PATH_MAX) { + error_f("Path too long"); + goto out; + } + /* success */ + ret = 0; + *retp = s; + s = NULL; + out: + free(s); + free(ocopy); + return ret; +} + +char * +tilde_expand_filename(const char *filename, uid_t uid) +{ + char *ret; + + if (tilde_expand(filename, uid, &ret) != 0) + cleanup_exit(255); + return ret; +} + +/* + * Expand a string with a set of %[char] escapes and/or ${ENVIRONMENT} + * substitutions. A number of escapes may be specified as + * (char *escape_chars, char *replacement) pairs. The list must be terminated + * by a NULL escape_char. Returns replaced string in memory allocated by + * xmalloc which the caller must free. + */ +static char * +vdollar_percent_expand(int *parseerror, int dollar, int percent, + const char *string, va_list ap) +{ +#define EXPAND_MAX_KEYS 16 + u_int num_keys = 0, i; + struct { + const char *key; + const char *repl; + } keys[EXPAND_MAX_KEYS]; + struct sshbuf *buf; + int r, missingvar = 0; + char *ret = NULL, *var, *varend, *val; + size_t len; + + if ((buf = sshbuf_new()) == NULL) + fatal_f("sshbuf_new failed"); + if (parseerror == NULL) + fatal_f("null parseerror arg"); + *parseerror = 1; + + /* Gather keys if we're doing percent expansion. */ + if (percent) { + for (num_keys = 0; num_keys < EXPAND_MAX_KEYS; num_keys++) { + keys[num_keys].key = va_arg(ap, char *); + if (keys[num_keys].key == NULL) + break; + keys[num_keys].repl = va_arg(ap, char *); + if (keys[num_keys].repl == NULL) { + fatal_f("NULL replacement for token %s", + keys[num_keys].key); + } + } + if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL) + fatal_f("too many keys"); + if (num_keys == 0) + fatal_f("percent expansion without token list"); + } + + /* Expand string */ + for (i = 0; *string != '\0'; string++) { + /* Optionally process ${ENVIRONMENT} expansions. */ + if (dollar && string[0] == '$' && string[1] == '{') { + string += 2; /* skip over '${' */ + if ((varend = strchr(string, '}')) == NULL) { + error_f("environment variable '%s' missing " + "closing '}'", string); + goto out; + } + len = varend - string; + if (len == 0) { + error_f("zero-length environment variable"); + goto out; + } + var = xmalloc(len + 1); + (void)strlcpy(var, string, len + 1); + if ((val = getenv(var)) == NULL) { + error_f("env var ${%s} has no value", var); + missingvar = 1; + } else { + debug3_f("expand ${%s} -> '%s'", var, val); + if ((r = sshbuf_put(buf, val, strlen(val))) !=0) + fatal_fr(r, "sshbuf_put ${}"); + } + free(var); + string += len; + continue; + } + + /* + * Process percent expansions if we have a list of TOKENs. + * If we're not doing percent expansion everything just gets + * appended here. + */ + if (*string != '%' || !percent) { + append: + if ((r = sshbuf_put_u8(buf, *string)) != 0) + fatal_fr(r, "sshbuf_put_u8 %%"); + continue; + } + string++; + /* %% case */ + if (*string == '%') + goto append; + if (*string == '\0') { + error_f("invalid format"); + goto out; + } + for (i = 0; i < num_keys; i++) { + if (strchr(keys[i].key, *string) != NULL) { + if ((r = sshbuf_put(buf, keys[i].repl, + strlen(keys[i].repl))) != 0) + fatal_fr(r, "sshbuf_put %%-repl"); + break; + } + } + if (i >= num_keys) { + error_f("unknown key %%%c", *string); + goto out; + } + } + if (!missingvar && (ret = sshbuf_dup_string(buf)) == NULL) + fatal_f("sshbuf_dup_string failed"); + *parseerror = 0; + out: + sshbuf_free(buf); + return *parseerror ? NULL : ret; +#undef EXPAND_MAX_KEYS +} + +/* + * Expand only environment variables. + * Note that although this function is variadic like the other similar + * functions, any such arguments will be unused. + */ + +char * +dollar_expand(int *parseerr, const char *string, ...) +{ + char *ret; + int err; + va_list ap; + + va_start(ap, string); + ret = vdollar_percent_expand(&err, 1, 0, string, ap); + va_end(ap); + if (parseerr != NULL) + *parseerr = err; + return ret; +} + +/* + * Returns expanded string or NULL if a specified environment variable is + * not defined, or calls fatal if the string is invalid. + */ +char * +percent_expand(const char *string, ...) +{ + char *ret; + int err; + va_list ap; + + va_start(ap, string); + ret = vdollar_percent_expand(&err, 0, 1, string, ap); + va_end(ap); + if (err) + fatal_f("failed"); + return ret; +} + +/* + * Returns expanded string or NULL if a specified environment variable is + * not defined, or calls fatal if the string is invalid. + */ +char * +percent_dollar_expand(const char *string, ...) +{ + char *ret; + int err; + va_list ap; + + va_start(ap, string); + ret = vdollar_percent_expand(&err, 1, 1, string, ap); + va_end(ap); + if (err) + fatal_f("failed"); + return ret; +} + +int +tun_open(int tun, int mode, char **ifname) +{ +#if defined(CUSTOM_SYS_TUN_OPEN) + return (sys_tun_open(tun, mode, ifname)); +#elif defined(SSH_TUN_OPENBSD) + struct ifreq ifr; + char name[100]; + int fd = -1, sock; + const char *tunbase = "tun"; + + if (ifname != NULL) + *ifname = NULL; + + if (mode == SSH_TUNMODE_ETHERNET) + tunbase = "tap"; + + /* Open the tunnel device */ + if (tun <= SSH_TUNID_MAX) { + snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun); + fd = open(name, O_RDWR); + } else if (tun == SSH_TUNID_ANY) { + for (tun = 100; tun >= 0; tun--) { + snprintf(name, sizeof(name), "/dev/%s%d", + tunbase, tun); + if ((fd = open(name, O_RDWR)) >= 0) + break; + } + } else { + debug_f("invalid tunnel %u", tun); + return -1; + } + + if (fd == -1) { + debug_f("%s open: %s", name, strerror(errno)); + return -1; + } + + debug_f("%s mode %d fd %d", name, mode, fd); + + /* Bring interface up if it is not already */ + snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun); + if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) + goto failed; + + if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1) { + debug_f("get interface %s flags: %s", ifr.ifr_name, + strerror(errno)); + goto failed; + } + + if (!(ifr.ifr_flags & IFF_UP)) { + ifr.ifr_flags |= IFF_UP; + if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1) { + debug_f("activate interface %s: %s", ifr.ifr_name, + strerror(errno)); + goto failed; + } + } + + if (ifname != NULL) + *ifname = xstrdup(ifr.ifr_name); + + close(sock); + return fd; + + failed: + if (fd >= 0) + close(fd); + if (sock >= 0) + close(sock); + return -1; +#else + error("Tunnel interfaces are not supported on this platform"); + return (-1); +#endif +} + +void +sanitise_stdfd(void) +{ + int nullfd, dupfd; + + if ((nullfd = dupfd = open(_PATH_DEVNULL, O_RDWR)) == -1) { + fprintf(stderr, "Couldn't open /dev/null: %s\n", + strerror(errno)); + exit(1); + } + while (++dupfd <= STDERR_FILENO) { + /* Only populate closed fds. */ + if (fcntl(dupfd, F_GETFL) == -1 && errno == EBADF) { + if (dup2(nullfd, dupfd) == -1) { + fprintf(stderr, "dup2: %s\n", strerror(errno)); + exit(1); + } + } + } + if (nullfd > STDERR_FILENO) + close(nullfd); +} + +char * +tohex(const void *vp, size_t l) +{ + const u_char *p = (const u_char *)vp; + char b[3], *r; + size_t i, hl; + + if (l > 65536) + return xstrdup("tohex: length > 65536"); + + hl = l * 2 + 1; + r = xcalloc(1, hl); + for (i = 0; i < l; i++) { + snprintf(b, sizeof(b), "%02x", p[i]); + strlcat(r, b, hl); + } + return (r); +} + +/* + * Extend string *sp by the specified format. If *sp is not NULL (or empty), + * then the separator 'sep' will be prepended before the formatted arguments. + * Extended strings are heap allocated. + */ +void +xextendf(char **sp, const char *sep, const char *fmt, ...) +{ + va_list ap; + char *tmp1, *tmp2; + + va_start(ap, fmt); + xvasprintf(&tmp1, fmt, ap); + va_end(ap); + + if (*sp == NULL || **sp == '\0') { + free(*sp); + *sp = tmp1; + return; + } + xasprintf(&tmp2, "%s%s%s", *sp, sep == NULL ? "" : sep, tmp1); + free(tmp1); + free(*sp); + *sp = tmp2; +} + + +u_int64_t +get_u64(const void *vp) +{ + const u_char *p = (const u_char *)vp; + u_int64_t v; + + v = (u_int64_t)p[0] << 56; + v |= (u_int64_t)p[1] << 48; + v |= (u_int64_t)p[2] << 40; + v |= (u_int64_t)p[3] << 32; + v |= (u_int64_t)p[4] << 24; + v |= (u_int64_t)p[5] << 16; + v |= (u_int64_t)p[6] << 8; + v |= (u_int64_t)p[7]; + + return (v); +} + +u_int32_t +get_u32(const void *vp) +{ + const u_char *p = (const u_char *)vp; + u_int32_t v; + + v = (u_int32_t)p[0] << 24; + v |= (u_int32_t)p[1] << 16; + v |= (u_int32_t)p[2] << 8; + v |= (u_int32_t)p[3]; + + return (v); +} + +u_int32_t +get_u32_le(const void *vp) +{ + const u_char *p = (const u_char *)vp; + u_int32_t v; + + v = (u_int32_t)p[0]; + v |= (u_int32_t)p[1] << 8; + v |= (u_int32_t)p[2] << 16; + v |= (u_int32_t)p[3] << 24; + + return (v); +} + +u_int16_t +get_u16(const void *vp) +{ + const u_char *p = (const u_char *)vp; + u_int16_t v; + + v = (u_int16_t)p[0] << 8; + v |= (u_int16_t)p[1]; + + return (v); +} + +void +put_u64(void *vp, u_int64_t v) +{ + u_char *p = (u_char *)vp; + + p[0] = (u_char)(v >> 56) & 0xff; + p[1] = (u_char)(v >> 48) & 0xff; + p[2] = (u_char)(v >> 40) & 0xff; + p[3] = (u_char)(v >> 32) & 0xff; + p[4] = (u_char)(v >> 24) & 0xff; + p[5] = (u_char)(v >> 16) & 0xff; + p[6] = (u_char)(v >> 8) & 0xff; + p[7] = (u_char)v & 0xff; +} + +void +put_u32(void *vp, u_int32_t v) +{ + u_char *p = (u_char *)vp; + + p[0] = (u_char)(v >> 24) & 0xff; + p[1] = (u_char)(v >> 16) & 0xff; + p[2] = (u_char)(v >> 8) & 0xff; + p[3] = (u_char)v & 0xff; +} + +void +put_u32_le(void *vp, u_int32_t v) +{ + u_char *p = (u_char *)vp; + + p[0] = (u_char)v & 0xff; + p[1] = (u_char)(v >> 8) & 0xff; + p[2] = (u_char)(v >> 16) & 0xff; + p[3] = (u_char)(v >> 24) & 0xff; +} + +void +put_u16(void *vp, u_int16_t v) +{ + u_char *p = (u_char *)vp; + + p[0] = (u_char)(v >> 8) & 0xff; + p[1] = (u_char)v & 0xff; +} + +void +ms_subtract_diff(struct timeval *start, int *ms) +{ + struct timeval diff, finish; + + monotime_tv(&finish); + timersub(&finish, start, &diff); + *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000); +} + +void +ms_to_timespec(struct timespec *ts, int ms) +{ + if (ms < 0) + ms = 0; + ts->tv_sec = ms / 1000; + ts->tv_nsec = (ms % 1000) * 1000 * 1000; +} + +void +monotime_ts(struct timespec *ts) +{ + struct timeval tv; +#if defined(HAVE_CLOCK_GETTIME) && (defined(CLOCK_BOOTTIME) || \ + defined(CLOCK_MONOTONIC) || defined(CLOCK_REALTIME)) + static int gettime_failed = 0; + + if (!gettime_failed) { +# ifdef CLOCK_BOOTTIME + if (clock_gettime(CLOCK_BOOTTIME, ts) == 0) + return; +# endif /* CLOCK_BOOTTIME */ +# ifdef CLOCK_MONOTONIC + if (clock_gettime(CLOCK_MONOTONIC, ts) == 0) + return; +# endif /* CLOCK_MONOTONIC */ +# ifdef CLOCK_REALTIME + /* Not monotonic, but we're almost out of options here. */ + if (clock_gettime(CLOCK_REALTIME, ts) == 0) + return; +# endif /* CLOCK_REALTIME */ + debug3("clock_gettime: %s", strerror(errno)); + gettime_failed = 1; + } +#endif /* HAVE_CLOCK_GETTIME && (BOOTTIME || MONOTONIC || REALTIME) */ + gettimeofday(&tv, NULL); + ts->tv_sec = tv.tv_sec; + ts->tv_nsec = (long)tv.tv_usec * 1000; +} + +void +monotime_tv(struct timeval *tv) +{ + struct timespec ts; + + monotime_ts(&ts); + tv->tv_sec = ts.tv_sec; + tv->tv_usec = ts.tv_nsec / 1000; +} + +time_t +monotime(void) +{ + struct timespec ts; + + monotime_ts(&ts); + return ts.tv_sec; +} + +double +monotime_double(void) +{ + struct timespec ts; + + monotime_ts(&ts); + return ts.tv_sec + ((double)ts.tv_nsec / 1000000000); +} + +void +bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen) +{ + bw->buflen = buflen; + bw->rate = kbps; + bw->thresh = buflen; + bw->lamt = 0; + timerclear(&bw->bwstart); + timerclear(&bw->bwend); +} + +/* Callback from read/write loop to insert bandwidth-limiting delays */ +void +bandwidth_limit(struct bwlimit *bw, size_t read_len) +{ + u_int64_t waitlen; + struct timespec ts, rm; + + bw->lamt += read_len; + if (!timerisset(&bw->bwstart)) { + monotime_tv(&bw->bwstart); + return; + } + if (bw->lamt < bw->thresh) + return; + + monotime_tv(&bw->bwend); + timersub(&bw->bwend, &bw->bwstart, &bw->bwend); + if (!timerisset(&bw->bwend)) + return; + + bw->lamt *= 8; + waitlen = (double)1000000L * bw->lamt / bw->rate; + + bw->bwstart.tv_sec = waitlen / 1000000L; + bw->bwstart.tv_usec = waitlen % 1000000L; + + if (timercmp(&bw->bwstart, &bw->bwend, >)) { + timersub(&bw->bwstart, &bw->bwend, &bw->bwend); + + /* Adjust the wait time */ + if (bw->bwend.tv_sec) { + bw->thresh /= 2; + if (bw->thresh < bw->buflen / 4) + bw->thresh = bw->buflen / 4; + } else if (bw->bwend.tv_usec < 10000) { + bw->thresh *= 2; + if (bw->thresh > bw->buflen * 8) + bw->thresh = bw->buflen * 8; + } + + TIMEVAL_TO_TIMESPEC(&bw->bwend, &ts); + while (nanosleep(&ts, &rm) == -1) { + if (errno != EINTR) + break; + ts = rm; + } + } + + bw->lamt = 0; + monotime_tv(&bw->bwstart); +} + +/* Make a template filename for mk[sd]temp() */ +void +mktemp_proto(char *s, size_t len) +{ + const char *tmpdir; + int r; + + if ((tmpdir = getenv("TMPDIR")) != NULL) { + r = snprintf(s, len, "%s/ssh-XXXXXXXXXXXX", tmpdir); + if (r > 0 && (size_t)r < len) + return; + } + r = snprintf(s, len, "/tmp/ssh-XXXXXXXXXXXX"); + if (r < 0 || (size_t)r >= len) + fatal_f("template string too short"); +} + +static const struct { + const char *name; + int value; +} ipqos[] = { + { "none", INT_MAX }, /* can't use 0 here; that's CS0 */ + { "af11", IPTOS_DSCP_AF11 }, + { "af12", IPTOS_DSCP_AF12 }, + { "af13", IPTOS_DSCP_AF13 }, + { "af21", IPTOS_DSCP_AF21 }, + { "af22", IPTOS_DSCP_AF22 }, + { "af23", IPTOS_DSCP_AF23 }, + { "af31", IPTOS_DSCP_AF31 }, + { "af32", IPTOS_DSCP_AF32 }, + { "af33", IPTOS_DSCP_AF33 }, + { "af41", IPTOS_DSCP_AF41 }, + { "af42", IPTOS_DSCP_AF42 }, + { "af43", IPTOS_DSCP_AF43 }, + { "cs0", IPTOS_DSCP_CS0 }, + { "cs1", IPTOS_DSCP_CS1 }, + { "cs2", IPTOS_DSCP_CS2 }, + { "cs3", IPTOS_DSCP_CS3 }, + { "cs4", IPTOS_DSCP_CS4 }, + { "cs5", IPTOS_DSCP_CS5 }, + { "cs6", IPTOS_DSCP_CS6 }, + { "cs7", IPTOS_DSCP_CS7 }, + { "ef", IPTOS_DSCP_EF }, + { "le", IPTOS_DSCP_LE }, + { "lowdelay", IPTOS_LOWDELAY }, + { "throughput", IPTOS_THROUGHPUT }, + { "reliability", IPTOS_RELIABILITY }, + { NULL, -1 } +}; + +int +parse_ipqos(const char *cp) +{ + u_int i; + char *ep; + long val; + + if (cp == NULL) + return -1; + for (i = 0; ipqos[i].name != NULL; i++) { + if (strcasecmp(cp, ipqos[i].name) == 0) + return ipqos[i].value; + } + /* Try parsing as an integer */ + val = strtol(cp, &ep, 0); + if (*cp == '\0' || *ep != '\0' || val < 0 || val > 255) + return -1; + return val; +} + +const char * +iptos2str(int iptos) +{ + int i; + static char iptos_str[sizeof "0xff"]; + + for (i = 0; ipqos[i].name != NULL; i++) { + if (ipqos[i].value == iptos) + return ipqos[i].name; + } + snprintf(iptos_str, sizeof iptos_str, "0x%02x", iptos); + return iptos_str; +} + +void +lowercase(char *s) +{ + for (; *s; s++) + *s = tolower((u_char)*s); +} + +int +unix_listener(const char *path, int backlog, int unlink_first) +{ + struct sockaddr_un sunaddr; + int saved_errno, sock; + + memset(&sunaddr, 0, sizeof(sunaddr)); + sunaddr.sun_family = AF_UNIX; + if (strlcpy(sunaddr.sun_path, path, + sizeof(sunaddr.sun_path)) >= sizeof(sunaddr.sun_path)) { + error_f("path \"%s\" too long for Unix domain socket", path); + errno = ENAMETOOLONG; + return -1; + } + + sock = socket(PF_UNIX, SOCK_STREAM, 0); + if (sock == -1) { + saved_errno = errno; + error_f("socket: %.100s", strerror(errno)); + errno = saved_errno; + return -1; + } + if (unlink_first == 1) { + if (unlink(path) != 0 && errno != ENOENT) + error("unlink(%s): %.100s", path, strerror(errno)); + } + if (bind(sock, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) == -1) { + saved_errno = errno; + error_f("cannot bind to path %s: %s", path, strerror(errno)); + close(sock); + errno = saved_errno; + return -1; + } + if (listen(sock, backlog) == -1) { + saved_errno = errno; + error_f("cannot listen on path %s: %s", path, strerror(errno)); + close(sock); + unlink(path); + errno = saved_errno; + return -1; + } + return sock; +} + +void +sock_set_v6only(int s) +{ +#if defined(IPV6_V6ONLY) && !defined(__OpenBSD__) + int on = 1; + + debug3("%s: set socket %d IPV6_V6ONLY", __func__, s); + if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) == -1) + error("setsockopt IPV6_V6ONLY: %s", strerror(errno)); +#endif +} + +/* + * Compares two strings that maybe be NULL. Returns non-zero if strings + * are both NULL or are identical, returns zero otherwise. + */ +static int +strcmp_maybe_null(const char *a, const char *b) +{ + if ((a == NULL && b != NULL) || (a != NULL && b == NULL)) + return 0; + if (a != NULL && strcmp(a, b) != 0) + return 0; + return 1; +} + +/* + * Compare two forwards, returning non-zero if they are identical or + * zero otherwise. + */ +int +forward_equals(const struct Forward *a, const struct Forward *b) +{ + if (strcmp_maybe_null(a->listen_host, b->listen_host) == 0) + return 0; + if (a->listen_port != b->listen_port) + return 0; + if (strcmp_maybe_null(a->listen_path, b->listen_path) == 0) + return 0; + if (strcmp_maybe_null(a->connect_host, b->connect_host) == 0) + return 0; + if (a->connect_port != b->connect_port) + return 0; + if (strcmp_maybe_null(a->connect_path, b->connect_path) == 0) + return 0; + /* allocated_port and handle are not checked */ + return 1; +} + +/* returns 1 if process is already daemonized, 0 otherwise */ +int +daemonized(void) +{ + int fd; + + if ((fd = open(_PATH_TTY, O_RDONLY | O_NOCTTY)) >= 0) { + close(fd); + return 0; /* have controlling terminal */ + } + if (getppid() != 1) + return 0; /* parent is not init */ + if (getsid(0) != getpid()) + return 0; /* not session leader */ + debug3("already daemonized"); + return 1; +} + +/* + * Splits 's' into an argument vector. Handles quoted string and basic + * escape characters (\\, \", \'). Caller must free the argument vector + * and its members. + */ +int +argv_split(const char *s, int *argcp, char ***argvp, int terminate_on_comment) +{ + int r = SSH_ERR_INTERNAL_ERROR; + int argc = 0, quote, i, j; + char *arg, **argv = xcalloc(1, sizeof(*argv)); + + *argvp = NULL; + *argcp = 0; + + for (i = 0; s[i] != '\0'; i++) { + /* Skip leading whitespace */ + if (s[i] == ' ' || s[i] == '\t') + continue; + if (terminate_on_comment && s[i] == '#') + break; + /* Start of a token */ + quote = 0; + + argv = xreallocarray(argv, (argc + 2), sizeof(*argv)); + arg = argv[argc++] = xcalloc(1, strlen(s + i) + 1); + argv[argc] = NULL; + + /* Copy the token in, removing escapes */ + for (j = 0; s[i] != '\0'; i++) { + if (s[i] == '\\') { + if (s[i + 1] == '\'' || + s[i + 1] == '\"' || + s[i + 1] == '\\' || + (quote == 0 && s[i + 1] == ' ')) { + i++; /* Skip '\' */ + arg[j++] = s[i]; + } else { + /* Unrecognised escape */ + arg[j++] = s[i]; + } + } else if (quote == 0 && (s[i] == ' ' || s[i] == '\t')) + break; /* done */ + else if (quote == 0 && (s[i] == '\"' || s[i] == '\'')) + quote = s[i]; /* quote start */ + else if (quote != 0 && s[i] == quote) + quote = 0; /* quote end */ + else + arg[j++] = s[i]; + } + if (s[i] == '\0') { + if (quote != 0) { + /* Ran out of string looking for close quote */ + r = SSH_ERR_INVALID_FORMAT; + goto out; + } + break; + } + } + /* Success */ + *argcp = argc; + *argvp = argv; + argc = 0; + argv = NULL; + r = 0; + out: + if (argc != 0 && argv != NULL) { + for (i = 0; i < argc; i++) + free(argv[i]); + free(argv); + } + return r; +} + +/* + * Reassemble an argument vector into a string, quoting and escaping as + * necessary. Caller must free returned string. + */ +char * +argv_assemble(int argc, char **argv) +{ + int i, j, ws, r; + char c, *ret; + struct sshbuf *buf, *arg; + + if ((buf = sshbuf_new()) == NULL || (arg = sshbuf_new()) == NULL) + fatal_f("sshbuf_new failed"); + + for (i = 0; i < argc; i++) { + ws = 0; + sshbuf_reset(arg); + for (j = 0; argv[i][j] != '\0'; j++) { + r = 0; + c = argv[i][j]; + switch (c) { + case ' ': + case '\t': + ws = 1; + r = sshbuf_put_u8(arg, c); + break; + case '\\': + case '\'': + case '"': + if ((r = sshbuf_put_u8(arg, '\\')) != 0) + break; + /* FALLTHROUGH */ + default: + r = sshbuf_put_u8(arg, c); + break; + } + if (r != 0) + fatal_fr(r, "sshbuf_put_u8"); + } + if ((i != 0 && (r = sshbuf_put_u8(buf, ' ')) != 0) || + (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0) || + (r = sshbuf_putb(buf, arg)) != 0 || + (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0)) + fatal_fr(r, "assemble"); + } + if ((ret = malloc(sshbuf_len(buf) + 1)) == NULL) + fatal_f("malloc failed"); + memcpy(ret, sshbuf_ptr(buf), sshbuf_len(buf)); + ret[sshbuf_len(buf)] = '\0'; + sshbuf_free(buf); + sshbuf_free(arg); + return ret; +} + +char * +argv_next(int *argcp, char ***argvp) +{ + char *ret = (*argvp)[0]; + + if (*argcp > 0 && ret != NULL) { + (*argcp)--; + (*argvp)++; + } + return ret; +} + +void +argv_consume(int *argcp) +{ + *argcp = 0; +} + +void +argv_free(char **av, int ac) +{ + int i; + + if (av == NULL) + return; + for (i = 0; i < ac; i++) + free(av[i]); + free(av); +} + +/* Returns 0 if pid exited cleanly, non-zero otherwise */ +int +exited_cleanly(pid_t pid, const char *tag, const char *cmd, int quiet) +{ + int status; + + while (waitpid(pid, &status, 0) == -1) { + if (errno != EINTR) { + error("%s waitpid: %s", tag, strerror(errno)); + return -1; + } + } + if (WIFSIGNALED(status)) { + error("%s %s exited on signal %d", tag, cmd, WTERMSIG(status)); + return -1; + } else if (WEXITSTATUS(status) != 0) { + do_log2(quiet ? SYSLOG_LEVEL_DEBUG1 : SYSLOG_LEVEL_INFO, + "%s %s failed, status %d", tag, cmd, WEXITSTATUS(status)); + return -1; + } + return 0; +} + +/* + * Check a given path for security. This is defined as all components + * of the path to the file must be owned by either the owner of + * of the file or root and no directories must be group or world writable. + * + * XXX Should any specific check be done for sym links ? + * + * Takes a file name, its stat information (preferably from fstat() to + * avoid races), the uid of the expected owner, their home directory and an + * error buffer plus max size as arguments. + * + * Returns 0 on success and -1 on failure + */ +int +safe_path(const char *name, struct stat *stp, const char *pw_dir, + uid_t uid, char *err, size_t errlen) +{ + char buf[PATH_MAX], homedir[PATH_MAX]; + char *cp; + int comparehome = 0; + struct stat st; + + if (realpath(name, buf) == NULL) { + snprintf(err, errlen, "realpath %s failed: %s", name, + strerror(errno)); + return -1; + } + if (pw_dir != NULL && realpath(pw_dir, homedir) != NULL) + comparehome = 1; + + if (!S_ISREG(stp->st_mode)) { + snprintf(err, errlen, "%s is not a regular file", buf); + return -1; + } + if ((!platform_sys_dir_uid(stp->st_uid) && stp->st_uid != uid) || + (stp->st_mode & 022) != 0) { + snprintf(err, errlen, "bad ownership or modes for file %s", + buf); + return -1; + } + + /* for each component of the canonical path, walking upwards */ + for (;;) { + if ((cp = dirname(buf)) == NULL) { + snprintf(err, errlen, "dirname() failed"); + return -1; + } + strlcpy(buf, cp, sizeof(buf)); + + if (stat(buf, &st) == -1 || + (!platform_sys_dir_uid(st.st_uid) && st.st_uid != uid) || + (st.st_mode & 022) != 0) { + snprintf(err, errlen, + "bad ownership or modes for directory %s", buf); + return -1; + } + + /* If are past the homedir then we can stop */ + if (comparehome && strcmp(homedir, buf) == 0) + break; + + /* + * dirname should always complete with a "/" path, + * but we can be paranoid and check for "." too + */ + if ((strcmp("/", buf) == 0) || (strcmp(".", buf) == 0)) + break; + } + return 0; +} + +/* + * Version of safe_path() that accepts an open file descriptor to + * avoid races. + * + * Returns 0 on success and -1 on failure + */ +int +safe_path_fd(int fd, const char *file, struct passwd *pw, + char *err, size_t errlen) +{ + struct stat st; + + /* check the open file to avoid races */ + if (fstat(fd, &st) == -1) { + snprintf(err, errlen, "cannot stat file %s: %s", + file, strerror(errno)); + return -1; + } + return safe_path(file, &st, pw->pw_dir, pw->pw_uid, err, errlen); +} + +/* + * Sets the value of the given variable in the environment. If the variable + * already exists, its value is overridden. + */ +void +child_set_env(char ***envp, u_int *envsizep, const char *name, + const char *value) +{ + char **env; + u_int envsize; + u_int i, namelen; + + if (strchr(name, '=') != NULL) { + error("Invalid environment variable \"%.100s\"", name); + return; + } + + /* + * If we're passed an uninitialized list, allocate a single null + * entry before continuing. + */ + if (*envp == NULL && *envsizep == 0) { + *envp = xmalloc(sizeof(char *)); + *envp[0] = NULL; + *envsizep = 1; + } + + /* + * Find the slot where the value should be stored. If the variable + * already exists, we reuse the slot; otherwise we append a new slot + * at the end of the array, expanding if necessary. + */ + env = *envp; + namelen = strlen(name); + for (i = 0; env[i]; i++) + if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=') + break; + if (env[i]) { + /* Reuse the slot. */ + free(env[i]); + } else { + /* New variable. Expand if necessary. */ + envsize = *envsizep; + if (i >= envsize - 1) { + if (envsize >= 1000) + fatal("child_set_env: too many env vars"); + envsize += 50; + env = (*envp) = xreallocarray(env, envsize, sizeof(char *)); + *envsizep = envsize; + } + /* Need to set the NULL pointer at end of array beyond the new slot. */ + env[i + 1] = NULL; + } + + /* Allocate space and format the variable in the appropriate slot. */ + /* XXX xasprintf */ + env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); + snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); +} + +/* + * Check and optionally lowercase a domain name, also removes trailing '.' + * Returns 1 on success and 0 on failure, storing an error message in errstr. + */ +int +valid_domain(char *name, int makelower, const char **errstr) +{ + size_t i, l = strlen(name); + u_char c, last = '\0'; + static char errbuf[256]; + + if (l == 0) { + strlcpy(errbuf, "empty domain name", sizeof(errbuf)); + goto bad; + } + if (!isalpha((u_char)name[0]) && !isdigit((u_char)name[0])) { + snprintf(errbuf, sizeof(errbuf), "domain name \"%.100s\" " + "starts with invalid character", name); + goto bad; + } + for (i = 0; i < l; i++) { + c = tolower((u_char)name[i]); + if (makelower) + name[i] = (char)c; + if (last == '.' && c == '.') { + snprintf(errbuf, sizeof(errbuf), "domain name " + "\"%.100s\" contains consecutive separators", name); + goto bad; + } + if (c != '.' && c != '-' && !isalnum(c) && + c != '_') /* technically invalid, but common */ { + snprintf(errbuf, sizeof(errbuf), "domain name " + "\"%.100s\" contains invalid characters", name); + goto bad; + } + last = c; + } + if (name[l - 1] == '.') + name[l - 1] = '\0'; + if (errstr != NULL) + *errstr = NULL; + return 1; +bad: + if (errstr != NULL) + *errstr = errbuf; + return 0; +} + +/* + * Verify that a environment variable name (not including initial '$') is + * valid; consisting of one or more alphanumeric or underscore characters only. + * Returns 1 on valid, 0 otherwise. + */ +int +valid_env_name(const char *name) +{ + const char *cp; + + if (name[0] == '\0') + return 0; + for (cp = name; *cp != '\0'; cp++) { + if (!isalnum((u_char)*cp) && *cp != '_') + return 0; + } + return 1; +} + +const char * +atoi_err(const char *nptr, int *val) +{ + const char *errstr = NULL; + long long num; + + if (nptr == NULL || *nptr == '\0') + return "missing"; + num = strtonum(nptr, 0, INT_MAX, &errstr); + if (errstr == NULL) + *val = (int)num; + return errstr; +} + +int +parse_absolute_time(const char *s, uint64_t *tp) +{ + struct tm tm; + time_t tt; + char buf[32], *fmt; + const char *cp; + size_t l; + int is_utc = 0; + + *tp = 0; + + l = strlen(s); + if (l > 1 && strcasecmp(s + l - 1, "Z") == 0) { + is_utc = 1; + l--; + } else if (l > 3 && strcasecmp(s + l - 3, "UTC") == 0) { + is_utc = 1; + l -= 3; + } + /* + * POSIX strptime says "The application shall ensure that there + * is white-space or other non-alphanumeric characters between + * any two conversion specifications" so arrange things this way. + */ + switch (l) { + case 8: /* YYYYMMDD */ + fmt = "%Y-%m-%d"; + snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2s", s, s + 4, s + 6); + break; + case 12: /* YYYYMMDDHHMM */ + fmt = "%Y-%m-%dT%H:%M"; + snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s", + s, s + 4, s + 6, s + 8, s + 10); + break; + case 14: /* YYYYMMDDHHMMSS */ + fmt = "%Y-%m-%dT%H:%M:%S"; + snprintf(buf, sizeof(buf), "%.4s-%.2s-%.2sT%.2s:%.2s:%.2s", + s, s + 4, s + 6, s + 8, s + 10, s + 12); + break; + default: + return SSH_ERR_INVALID_FORMAT; + } + + memset(&tm, 0, sizeof(tm)); + if ((cp = strptime(buf, fmt, &tm)) == NULL || *cp != '\0') + return SSH_ERR_INVALID_FORMAT; + if (is_utc) { + if ((tt = timegm(&tm)) < 0) + return SSH_ERR_INVALID_FORMAT; + } else { + if ((tt = mktime(&tm)) < 0) + return SSH_ERR_INVALID_FORMAT; + } + /* success */ + *tp = (uint64_t)tt; + return 0; +} + +/* On OpenBSD time_t is int64_t which is long long. */ +/* #define SSH_TIME_T_MAX LLONG_MAX */ + +void +format_absolute_time(uint64_t t, char *buf, size_t len) +{ + time_t tt = t > SSH_TIME_T_MAX ? SSH_TIME_T_MAX : t; + struct tm tm; + + localtime_r(&tt, &tm); + strftime(buf, len, "%Y-%m-%dT%H:%M:%S", &tm); +} + +/* check if path is absolute */ +int +path_absolute(const char *path) +{ + return (*path == '/') ? 1 : 0; +} + +void +skip_space(char **cpp) +{ + char *cp; + + for (cp = *cpp; *cp == ' ' || *cp == '\t'; cp++) + ; + *cpp = cp; +} + +/* authorized_key-style options parsing helpers */ + +/* + * Match flag 'opt' in *optsp, and if allow_negate is set then also match + * 'no-opt'. Returns -1 if option not matched, 1 if option matches or 0 + * if negated option matches. + * If the option or negated option matches, then *optsp is updated to + * point to the first character after the option. + */ +int +opt_flag(const char *opt, int allow_negate, const char **optsp) +{ + size_t opt_len = strlen(opt); + const char *opts = *optsp; + int negate = 0; + + if (allow_negate && strncasecmp(opts, "no-", 3) == 0) { + opts += 3; + negate = 1; + } + if (strncasecmp(opts, opt, opt_len) == 0) { + *optsp = opts + opt_len; + return negate ? 0 : 1; + } + return -1; +} + +char * +opt_dequote(const char **sp, const char **errstrp) +{ + const char *s = *sp; + char *ret; + size_t i; + + *errstrp = NULL; + if (*s != '"') { + *errstrp = "missing start quote"; + return NULL; + } + s++; + if ((ret = malloc(strlen((s)) + 1)) == NULL) { + *errstrp = "memory allocation failed"; + return NULL; + } + for (i = 0; *s != '\0' && *s != '"';) { + if (s[0] == '\\' && s[1] == '"') + s++; + ret[i++] = *s++; + } + if (*s == '\0') { + *errstrp = "missing end quote"; + free(ret); + return NULL; + } + ret[i] = '\0'; + s++; + *sp = s; + return ret; +} + +int +opt_match(const char **opts, const char *term) +{ + if (strncasecmp((*opts), term, strlen(term)) == 0 && + (*opts)[strlen(term)] == '=') { + *opts += strlen(term) + 1; + return 1; + } + return 0; +} + +void +opt_array_append2(const char *file, const int line, const char *directive, + char ***array, int **iarray, u_int *lp, const char *s, int i) +{ + + if (*lp >= INT_MAX) + fatal("%s line %d: Too many %s entries", file, line, directive); + + if (iarray != NULL) { + *iarray = xrecallocarray(*iarray, *lp, *lp + 1, + sizeof(**iarray)); + (*iarray)[*lp] = i; + } + + *array = xrecallocarray(*array, *lp, *lp + 1, sizeof(**array)); + (*array)[*lp] = xstrdup(s); + (*lp)++; +} + +void +opt_array_append(const char *file, const int line, const char *directive, + char ***array, u_int *lp, const char *s) +{ + opt_array_append2(file, line, directive, array, NULL, lp, s, 0); +} + +sshsig_t +ssh_signal(int signum, sshsig_t handler) +{ + struct sigaction sa, osa; + + /* mask all other signals while in handler */ + memset(&sa, 0, sizeof(sa)); + sa.sa_handler = handler; + sigfillset(&sa.sa_mask); +#if defined(SA_RESTART) && !defined(NO_SA_RESTART) + if (signum != SIGALRM) + sa.sa_flags = SA_RESTART; +#endif + if (sigaction(signum, &sa, &osa) == -1) { + debug3("sigaction(%s): %s", strsignal(signum), strerror(errno)); + return SIG_ERR; + } + return osa.sa_handler; +} + +int +stdfd_devnull(int do_stdin, int do_stdout, int do_stderr) +{ + int devnull, ret = 0; + + if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { + error_f("open %s: %s", _PATH_DEVNULL, + strerror(errno)); + return -1; + } + if ((do_stdin && dup2(devnull, STDIN_FILENO) == -1) || + (do_stdout && dup2(devnull, STDOUT_FILENO) == -1) || + (do_stderr && dup2(devnull, STDERR_FILENO) == -1)) { + error_f("dup2: %s", strerror(errno)); + ret = -1; + } + if (devnull > STDERR_FILENO) + close(devnull); + return ret; +} + +/* + * Runs command in a subprocess with a minimal environment. + * Returns pid on success, 0 on failure. + * The child stdout and stderr maybe captured, left attached or sent to + * /dev/null depending on the contents of flags. + * "tag" is prepended to log messages. + * NB. "command" is only used for logging; the actual command executed is + * av[0]. + */ +pid_t +subprocess(const char *tag, const char *command, + int ac, char **av, FILE **child, u_int flags, + struct passwd *pw, privdrop_fn *drop_privs, privrestore_fn *restore_privs) +{ + FILE *f = NULL; + struct stat st; + int fd, devnull, p[2], i; + pid_t pid; + char *cp, errmsg[512]; + u_int nenv = 0; + char **env = NULL; + + /* If dropping privs, then must specify user and restore function */ + if (drop_privs != NULL && (pw == NULL || restore_privs == NULL)) { + error("%s: inconsistent arguments", tag); /* XXX fatal? */ + return 0; + } + if (pw == NULL && (pw = getpwuid(getuid())) == NULL) { + error("%s: no user for current uid", tag); + return 0; + } + if (child != NULL) + *child = NULL; + + debug3_f("%s command \"%s\" running as %s (flags 0x%x)", + tag, command, pw->pw_name, flags); + + /* Check consistency */ + if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && + (flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) { + error_f("inconsistent flags"); + return 0; + } + if (((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) != (child == NULL)) { + error_f("inconsistent flags/output"); + return 0; + } + + /* + * If executing an explicit binary, then verify the it exists + * and appears safe-ish to execute + */ + if (!path_absolute(av[0])) { + error("%s path is not absolute", tag); + return 0; + } + if (drop_privs != NULL) + drop_privs(pw); + if (stat(av[0], &st) == -1) { + error("Could not stat %s \"%s\": %s", tag, + av[0], strerror(errno)); + goto restore_return; + } + if ((flags & SSH_SUBPROCESS_UNSAFE_PATH) == 0 && + safe_path(av[0], &st, NULL, 0, errmsg, sizeof(errmsg)) != 0) { + error("Unsafe %s \"%s\": %s", tag, av[0], errmsg); + goto restore_return; + } + /* Prepare to keep the child's stdout if requested */ + if (pipe(p) == -1) { + error("%s: pipe: %s", tag, strerror(errno)); + restore_return: + if (restore_privs != NULL) + restore_privs(); + return 0; + } + if (restore_privs != NULL) + restore_privs(); + + switch ((pid = fork())) { + case -1: /* error */ + error("%s: fork: %s", tag, strerror(errno)); + close(p[0]); + close(p[1]); + return 0; + case 0: /* child */ + /* Prepare a minimal environment for the child. */ + if ((flags & SSH_SUBPROCESS_PRESERVE_ENV) == 0) { + nenv = 5; + env = xcalloc(sizeof(*env), nenv); + child_set_env(&env, &nenv, "PATH", _PATH_STDPATH); + child_set_env(&env, &nenv, "USER", pw->pw_name); + child_set_env(&env, &nenv, "LOGNAME", pw->pw_name); + child_set_env(&env, &nenv, "HOME", pw->pw_dir); + if ((cp = getenv("LANG")) != NULL) + child_set_env(&env, &nenv, "LANG", cp); + } + + for (i = 1; i < NSIG; i++) + ssh_signal(i, SIG_DFL); + + if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { + error("%s: open %s: %s", tag, _PATH_DEVNULL, + strerror(errno)); + _exit(1); + } + if (dup2(devnull, STDIN_FILENO) == -1) { + error("%s: dup2: %s", tag, strerror(errno)); + _exit(1); + } + + /* Set up stdout as requested; leave stderr in place for now. */ + fd = -1; + if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) + fd = p[1]; + else if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0) + fd = devnull; + if (fd != -1 && dup2(fd, STDOUT_FILENO) == -1) { + error("%s: dup2: %s", tag, strerror(errno)); + _exit(1); + } + closefrom(STDERR_FILENO + 1); + + if (geteuid() == 0 && + initgroups(pw->pw_name, pw->pw_gid) == -1) { + error("%s: initgroups(%s, %u): %s", tag, + pw->pw_name, (u_int)pw->pw_gid, strerror(errno)); + _exit(1); + } + if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) == -1) { + error("%s: setresgid %u: %s", tag, (u_int)pw->pw_gid, + strerror(errno)); + _exit(1); + } + if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) == -1) { + error("%s: setresuid %u: %s", tag, (u_int)pw->pw_uid, + strerror(errno)); + _exit(1); + } + /* stdin is pointed to /dev/null at this point */ + if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && + dup2(STDIN_FILENO, STDERR_FILENO) == -1) { + error("%s: dup2: %s", tag, strerror(errno)); + _exit(1); + } + if (env != NULL) + execve(av[0], av, env); + else + execv(av[0], av); + error("%s %s \"%s\": %s", tag, env == NULL ? "execv" : "execve", + command, strerror(errno)); + _exit(127); + default: /* parent */ + break; + } + + close(p[1]); + if ((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) + close(p[0]); + else if ((f = fdopen(p[0], "r")) == NULL) { + error("%s: fdopen: %s", tag, strerror(errno)); + close(p[0]); + /* Don't leave zombie child */ + kill(pid, SIGTERM); + while (waitpid(pid, NULL, 0) == -1 && errno == EINTR) + ; + return 0; + } + /* Success */ + debug3_f("%s pid %ld", tag, (long)pid); + if (child != NULL) + *child = f; + return pid; +} + +const char * +lookup_env_in_list(const char *env, char * const *envs, size_t nenvs) +{ + size_t i, envlen; + + envlen = strlen(env); + for (i = 0; i < nenvs; i++) { + if (strncmp(envs[i], env, envlen) == 0 && + envs[i][envlen] == '=') { + return envs[i] + envlen + 1; + } + } + return NULL; +} + +const char * +lookup_setenv_in_list(const char *env, char * const *envs, size_t nenvs) +{ + char *name, *cp; + const char *ret; + + name = xstrdup(env); + if ((cp = strchr(name, '=')) == NULL) { + free(name); + return NULL; /* not env=val */ + } + *cp = '\0'; + ret = lookup_env_in_list(name, envs, nenvs); + free(name); + return ret; +} + +/* + * Helpers for managing poll(2)/ppoll(2) timeouts + * Will remember the earliest deadline and return it for use in poll/ppoll. + */ + +/* Initialise a poll/ppoll timeout with an indefinite deadline */ +void +ptimeout_init(struct timespec *pt) +{ + /* + * Deliberately invalid for ppoll(2). + * Will be converted to NULL in ptimeout_get_tspec() later. + */ + pt->tv_sec = -1; + pt->tv_nsec = 0; +} + +/* Specify a poll/ppoll deadline of at most 'sec' seconds */ +void +ptimeout_deadline_sec(struct timespec *pt, long sec) +{ + if (pt->tv_sec == -1 || pt->tv_sec >= sec) { + pt->tv_sec = sec; + pt->tv_nsec = 0; + } +} + +/* Specify a poll/ppoll deadline of at most 'p' (timespec) */ +static void +ptimeout_deadline_tsp(struct timespec *pt, struct timespec *p) +{ + if (pt->tv_sec == -1 || timespeccmp(pt, p, >=)) + *pt = *p; +} + +/* Specify a poll/ppoll deadline of at most 'ms' milliseconds */ +void +ptimeout_deadline_ms(struct timespec *pt, long ms) +{ + struct timespec p; + + p.tv_sec = ms / 1000; + p.tv_nsec = (ms % 1000) * 1000000; + ptimeout_deadline_tsp(pt, &p); +} + +/* Specify a poll/ppoll deadline at wall clock monotime 'when' */ +void +ptimeout_deadline_monotime(struct timespec *pt, time_t when) +{ + struct timespec now, t; + + t.tv_sec = when; + t.tv_nsec = 0; + monotime_ts(&now); + + if (timespeccmp(&now, &t, >=)) + ptimeout_deadline_sec(pt, 0); + else { + timespecsub(&t, &now, &t); + ptimeout_deadline_tsp(pt, &t); + } +} + +/* Get a poll(2) timeout value in milliseconds */ +int +ptimeout_get_ms(struct timespec *pt) +{ + if (pt->tv_sec == -1) + return -1; + if (pt->tv_sec >= (INT_MAX - (pt->tv_nsec / 1000000)) / 1000) + return INT_MAX; + return (pt->tv_sec * 1000) + (pt->tv_nsec / 1000000); +} + +/* Get a ppoll(2) timeout value as a timespec pointer */ +struct timespec * +ptimeout_get_tsp(struct timespec *pt) +{ + return pt->tv_sec == -1 ? NULL : pt; +} + +/* Returns non-zero if a timeout has been set (i.e. is not indefinite) */ +int +ptimeout_isset(struct timespec *pt) +{ + return pt->tv_sec != -1; +} |