/* $OpenBSD: misc.c,v 1.113 2017/08/18 05:48:04 djm Exp $ */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. * Copyright (c) 2005,2006 Damien Miller. 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. */ #include "includes.h" #include #include #include #include #include #include #include #include #ifdef HAVE_LIBGEN_H # include #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef HAVE_PATHS_H # include #include #endif #ifdef SSH_TUN_OPENBSD #include #endif #include "xmalloc.h" #include "misc.h" #include "log.h" #include "ssh.h" #include "sshbuf.h" #include "ssherr.h" #include "uidswap.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; } /* set/unset filedescriptor to non-blocking */ int set_nonblock(int fd) { int val; val = fcntl(fd, F_GETFL); if (val < 0) { 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 < 0) { 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)); } /* Characters considered whitespace in strsep calls. */ #define WHITESPACE " \t\r\n" #define QUOTE "\"" /* return next token in configuration line */ char * strdelim(char **s) { char *old; int wspace = 0; if (*s == NULL) return NULL; old = *s; *s = strpbrk(*s, 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 (*s[0] == '=') wspace = 1; *s[0] = '\0'; /* Skip any extra whitespace after first token */ *s += strspn(*s + 1, WHITESPACE) + 1; if (*s[0] == '=' && !wspace) *s += strspn(*s + 1, WHITESPACE) + 1; return (old); } 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); #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) { long long port; const char *errstr; port = strtonum(s, 0, 65535, &errstr); if (errstr != NULL) return -1; return (int)port; } 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: * 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. */ long convtime(const char *s) { long total, secs, multiplier = 1; 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 == LONG_MIN || secs == LONG_MAX)) || secs < 0) return -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 >= LONG_MAX / multiplier) return -1; secs *= multiplier; if (total >= LONG_MAX - secs) return -1; total += secs; if (total < 0) return -1; p = endp; } return total; } /* * 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) < 0) 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 delimiter, if one was found. * If this is the last field, *cp is set to NULL. */ char * hpdelim(char **cp) { 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 '/': *s = '\0'; /* terminate */ *cp = s + 1; break; default: return NULL; } return old; } 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[: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 = strchr(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; } /* 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("addargs: argument too long"); nalloc = args->nalloc; if (args->list == NULL) { nalloc = 32; args->num = 0; } 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("replacearg: argument too long"); if (which >= args->num) fatal("replacearg: 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->list != NULL) { 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*. */ char * tilde_expand_filename(const char *filename, uid_t uid) { const char *path, *sep; char user[128], *ret; struct passwd *pw; u_int len, slash; if (*filename != '~') return (xstrdup(filename)); filename++; path = strchr(filename, '/'); if (path != NULL && path > filename) { /* ~user/path */ slash = path - filename; if (slash > sizeof(user) - 1) fatal("tilde_expand_filename: ~username too long"); memcpy(user, filename, slash); user[slash] = '\0'; if ((pw = getpwnam(user)) == NULL) fatal("tilde_expand_filename: No such user %s", user); } else if ((pw = getpwuid(uid)) == NULL) /* ~/path */ fatal("tilde_expand_filename: No such uid %ld", (long)uid); /* Make sure directory has a trailing '/' */ len = strlen(pw->pw_dir); if (len == 0 || pw->pw_dir[len - 1] != '/') sep = "/"; else sep = ""; /* Skip leading '/' from specified path */ if (path != NULL) filename = path + 1; if (xasprintf(&ret, "%s%s%s", pw->pw_dir, sep, filename) >= PATH_MAX) fatal("tilde_expand_filename: Path too long"); return (ret); } /* * Expand a string with a set of %[char] escapes. 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. */ char * percent_expand(const char *string, ...) { #define EXPAND_MAX_KEYS 16 u_int num_keys, i, j; struct { const char *key; const char *repl; } keys[EXPAND_MAX_KEYS]; char buf[4096]; va_list ap; /* Gather keys */ va_start(ap, string); 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("%s: NULL replacement", __func__); } if (num_keys == EXPAND_MAX_KEYS && va_arg(ap, char *) != NULL) fatal("%s: too many keys", __func__); va_end(ap); /* Expand string */ *buf = '\0'; for (i = 0; *string != '\0'; string++) { if (*string != '%') { append: buf[i++] = *string; if (i >= sizeof(buf)) fatal("%s: string too long", __func__); buf[i] = '\0'; continue; } string++; /* %% case */ if (*string == '%') goto append; if (*string == '\0') fatal("%s: invalid format", __func__); for (j = 0; j < num_keys; j++) { if (strchr(keys[j].key, *string) != NULL) { i = strlcat(buf, keys[j].repl, sizeof(buf)); if (i >= sizeof(buf)) fatal("%s: string too long", __func__); break; } } if (j >= num_keys) fatal("%s: unknown key %%%c", __func__, *string); } return (xstrdup(buf)); #undef EXPAND_MAX_KEYS } /* * Read an entire line from a public key file into a static buffer, discarding * lines that exceed the buffer size. Returns 0 on success, -1 on failure. */ int read_keyfile_line(FILE *f, const char *filename, char *buf, size_t bufsz, u_long *lineno) { while (fgets(buf, bufsz, f) != NULL) { if (buf[0] == '\0') continue; (*lineno)++; if (buf[strlen(buf) - 1] == '\n' || feof(f)) { return 0; } else { debug("%s: %s line %lu exceeds size limit", __func__, filename, *lineno); /* discard remainder of line */ while (fgetc(f) != '\n' && !feof(f)) ; /* nothing */ } } return -1; } int tun_open(int tun, int mode) { #if defined(CUSTOM_SYS_TUN_OPEN) return (sys_tun_open(tun, mode)); #elif defined(SSH_TUN_OPENBSD) struct ifreq ifr; char name[100]; int fd = -1, sock; const char *tunbase = "tun"; 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("%s: invalid tunnel %u", __func__, tun); return -1; } if (fd < 0) { debug("%s: %s open: %s", __func__, name, strerror(errno)); return -1; } debug("%s: %s mode %d fd %d", __func__, 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("%s: get interface %s flags: %s", __func__, 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("%s: activate interface %s: %s", __func__, ifr.ifr_name, strerror(errno)); goto failed; } } 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); } 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; gettimeofday(&finish, NULL); timersub(&finish, start, &diff); *ms -= (diff.tv_sec * 1000) + (diff.tv_usec / 1000); } void ms_to_timeval(struct timeval *tv, int ms) { if (ms < 0) ms = 0; tv->tv_sec = ms / 1000; tv->tv_usec = (ms % 1000) * 1000; } time_t monotime(void) { #if defined(HAVE_CLOCK_GETTIME) && \ (defined(CLOCK_MONOTONIC) || defined(CLOCK_BOOTTIME)) struct timespec ts; static int gettime_failed = 0; if (!gettime_failed) { #if defined(CLOCK_BOOTTIME) if (clock_gettime(CLOCK_BOOTTIME, &ts) == 0) return (ts.tv_sec); #endif #if defined(CLOCK_MONOTONIC) if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0) return (ts.tv_sec); #endif debug3("clock_gettime: %s", strerror(errno)); gettime_failed = 1; } #endif /* HAVE_CLOCK_GETTIME && (CLOCK_MONOTONIC || CLOCK_BOOTTIME */ return time(NULL); } double monotime_double(void) { #if defined(HAVE_CLOCK_GETTIME) && \ (defined(CLOCK_MONOTONIC) || defined(CLOCK_BOOTTIME)) struct timespec ts; static int gettime_failed = 0; if (!gettime_failed) { #if defined(CLOCK_BOOTTIME) if (clock_gettime(CLOCK_BOOTTIME, &ts) == 0) return (ts.tv_sec + (double)ts.tv_nsec / 1000000000); #endif #if defined(CLOCK_MONOTONIC) if (clock_gettime(CLOCK_MONOTONIC, &ts) == 0) return (ts.tv_sec + (double)ts.tv_nsec / 1000000000); #endif debug3("clock_gettime: %s", strerror(errno)); gettime_failed = 1; } #endif /* HAVE_CLOCK_GETTIME && (CLOCK_MONOTONIC || CLOCK_BOOTTIME */ return (double)time(NULL); } void bandwidth_limit_init(struct bwlimit *bw, u_int64_t kbps, size_t buflen) { bw->buflen = buflen; bw->rate = kbps; bw->thresh = bw->rate; 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; if (!timerisset(&bw->bwstart)) { gettimeofday(&bw->bwstart, NULL); return; } bw->lamt += read_len; if (bw->lamt < bw->thresh) return; gettimeofday(&bw->bwend, NULL); 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; gettimeofday(&bw->bwstart, NULL); } /* 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("%s: template string too short", __func__); } 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 }, { "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("%s: \"%s\" too long for Unix domain socket", __func__, path); errno = ENAMETOOLONG; return -1; } sock = socket(PF_UNIX, SOCK_STREAM, 0); if (sock < 0) { saved_errno = errno; error("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)) < 0) { saved_errno = errno; error("bind: %.100s", strerror(errno)); close(sock); error("%s: cannot bind to path: %s", __func__, path); errno = saved_errno; return -1; } if (listen(sock, backlog) < 0) { saved_errno = errno; error("listen: %.100s", strerror(errno)); close(sock); unlink(path); error("%s: cannot listen on path: %s", __func__, 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 bind to specified port by specified user is permitted */ int bind_permitted(int port, uid_t uid) { if (port < IPPORT_RESERVED && uid != 0) return 0; 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 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; /* Start of a token */ quote = 0; if (s[i] == '\\' && (s[i + 1] == '\'' || s[i + 1] == '\"' || s[i + 1] == '\\')) i++; else if (s[i] == '\'' || s[i] == '"') quote = s[i++]; 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] == '\\') { 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] == quote) break; /* done */ 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("%s: sshbuf_new failed", __func__); 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("%s: sshbuf_put_u8: %s", __func__, ssh_err(r)); } 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("%s: buffer error: %s", __func__, ssh_err(r)); } if ((ret = malloc(sshbuf_len(buf) + 1)) == NULL) fatal("%s: malloc failed", __func__); memcpy(ret, sshbuf_ptr(buf), sshbuf_len(buf)); ret[sshbuf_len(buf)] = '\0'; sshbuf_free(buf); sshbuf_free(arg); return ret; } /* * Runs command in a subprocess wuth 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, struct passwd *pw, const char *command, int ac, char **av, FILE **child, u_int flags) { FILE *f = NULL; struct stat st; int fd, devnull, p[2], i; pid_t pid; char *cp, errmsg[512]; u_int envsize; char **child_env; if (child != NULL) *child = NULL; debug3("%s: %s command \"%s\" running as %s (flags 0x%x)", __func__, tag, command, pw->pw_name, flags); /* Check consistency */ if ((flags & SSH_SUBPROCESS_STDOUT_DISCARD) != 0 && (flags & SSH_SUBPROCESS_STDOUT_CAPTURE) != 0) { error("%s: inconsistent flags", __func__); return 0; } if (((flags & SSH_SUBPROCESS_STDOUT_CAPTURE) == 0) != (child == NULL)) { error("%s: inconsistent flags/output", __func__); return 0; } /* * If executing an explicit binary, then verify the it exists * and appears safe-ish to execute */ if (*av[0] != '/') { error("%s path is not absolute", tag); return 0; } temporarily_use_uid(pw); if (stat(av[0], &st) < 0) { error("Could not stat %s \"%s\": %s", tag, av[0], strerror(errno)); restore_uid(); return 0; } if (safe_path(av[0], &st, NULL, 0, errmsg, sizeof(errmsg)) != 0) { error("Unsafe %s \"%s\": %s", tag, av[0], errmsg); restore_uid(); return 0; } /* Prepare to keep the child's stdout if requested */ if (pipe(p) != 0) { error("%s: pipe: %s", tag, strerror(errno)); restore_uid(); return 0; } restore_uid(); 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. */ envsize = 5; child_env = xcalloc(sizeof(*child_env), envsize); child_set_env(&child_env, &envsize, "PATH", _PATH_STDPATH); child_set_env(&child_env, &envsize, "USER", pw->pw_name); child_set_env(&child_env, &envsize, "LOGNAME", pw->pw_name); child_set_env(&child_env, &envsize, "HOME", pw->pw_dir); if ((cp = getenv("LANG")) != NULL) child_set_env(&child_env, &envsize, "LANG", cp); for (i = 0; i < NSIG; i++) 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); /* Don't use permanently_set_uid() here to avoid fatal() */ if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) != 0) { 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) != 0) { 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); } execve(av[0], av, child_env); error("%s exec \"%s\": %s", tag, 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("%s: %s pid %ld", __func__, tag, (long)pid); if (child != NULL) *child = f; return pid; } /* 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) < 0 || (!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) < 0) { 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. */ env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1); snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value); }