/* $OpenBSD: misc.c,v 1.64 2006/08/03 03:34:42 deraadt 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 <sys/types.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/param.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <errno.h>
#include <fcntl.h>
#ifdef HAVE_PATHS_H
# include <paths.h>
#include <pwd.h>
#endif
#ifdef SSH_TUN_OPENBSD
#include <net/if.h>
#endif
#include "xmalloc.h"
#include "misc.h"
#include "log.h"
#include "ssh.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, 0);
if (val < 0) {
error("fcntl(%d, F_GETFL, 0): %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, 0);
if (val < 0) {
error("fcntl(%d, F_GETFL, 0): %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);
}
/* 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';
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);
copy->pw_gecos = xstrdup(pw->pw_gecos);
copy->pw_uid = pw->pw_uid;
copy->pw_gid = pw->pw_gid;
#ifdef HAVE_PW_EXPIRE_IN_PASSWD
copy->pw_expire = pw->pw_expire;
#endif
#ifdef HAVE_PW_CHANGE_IN_PASSWD
copy->pw_change = pw->pw_change;
#endif
#ifdef HAVE_PW_CLASS_IN_PASSWD
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 0 if invalid.
*/
int
a2port(const char *s)
{
long port;
char *endp;
errno = 0;
port = strtol(s, &endp, 0);
if (s == endp || *endp != '\0' ||
(errno == ERANGE && (port == LONG_MIN || port == LONG_MAX)) ||
port <= 0 || port > 65535)
return 0;
return 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) {
xfree(sp);
return (a2tun(s, NULL));
}
ep[0] = '\0'; ep++;
*remote = a2tun(ep, NULL);
tun = a2tun(sp, NULL);
xfree(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.
*/
long
convtime(const char *s)
{
long total, secs;
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':
secs *= MINUTES;
break;
case 'h':
case 'H':
secs *= HOURS;
break;
case 'd':
case 'D':
secs *= DAYS;
break;
case 'w':
case 'W':
secs *= WEEKS;
break;
default:
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 (0);
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 (0);
}
return (0);
}
/* 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 = xrealloc(args->list, 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);
xfree(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++)
xfree(args->list[i]);
xfree(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;
char user[128], ret[MAXPATHLEN];
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 %d", uid);
if (strlcpy(ret, pw->pw_dir, sizeof(ret)) >= sizeof(ret))
fatal("tilde_expand_filename: Path too long");
/* Make sure directory has a trailing '/' */
len = strlen(pw->pw_dir);
if ((len == 0 || pw->pw_dir[len - 1] != '/') &&
strlcat(ret, "/", sizeof(ret)) >= sizeof(ret))
fatal("tilde_expand_filename: Path too long");
/* Skip leading '/' from specified path */
if (path != NULL)
filename = path + 1;
if (strlcat(ret, filename, sizeof(ret)) >= sizeof(ret))
fatal("tilde_expand_filename: Path too long");
return (xstrdup(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
struct {
const char *key;
const char *repl;
} keys[EXPAND_MAX_KEYS];
u_int num_keys, i, j;
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("percent_expand: NULL replacement");
}
va_end(ap);
if (num_keys >= EXPAND_MAX_KEYS)
fatal("percent_expand: too many keys");
/* Expand string */
*buf = '\0';
for (i = 0; *string != '\0'; string++) {
if (*string != '%') {
append:
buf[i++] = *string;
if (i >= sizeof(buf))
fatal("percent_expand: string too long");
buf[i] = '\0';
continue;
}
string++;
if (*string == '%')
goto append;
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("percent_expand: string too long");
break;
}
}
if (j >= num_keys)
fatal("percent_expand: unknown key %%%c", *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) {
(*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;
/* Open the tunnel device */
if (tun <= SSH_TUNID_MAX) {
snprintf(name, sizeof(name), "/dev/tun%d", tun);
fd = open(name, O_RDWR);
} else if (tun == SSH_TUNID_ANY) {
for (tun = 100; tun >= 0; tun--) {
snprintf(name, sizeof(name), "/dev/tun%d", 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 failed: %s", __func__, name, strerror(errno));
return (-1);
}
debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
/* Set the tunnel device operation mode */
snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "tun%d", tun);
if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
goto failed;
if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1)
goto failed;
/* Set interface mode */
ifr.ifr_flags &= ~IFF_UP;
if (mode == SSH_TUNMODE_ETHERNET)
ifr.ifr_flags |= IFF_LINK0;
else
ifr.ifr_flags &= ~IFF_LINK0;
if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
goto failed;
/* Bring interface up */
ifr.ifr_flags |= IFF_UP;
if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
goto failed;
close(sock);
return (fd);
failed:
if (fd >= 0)
close(fd);
if (sock >= 0)
close(sock);
debug("%s: failed to set %s mode %d: %s", __func__, name,
mode, strerror(errno));
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", strerror(errno));
exit(1);
}
while (++dupfd <= 2) {
/* Only clobber closed fds */
if (fcntl(dupfd, F_GETFL, 0) >= 0)
continue;
if (dup2(nullfd, dupfd) == -1) {
fprintf(stderr, "dup2: %s", strerror(errno));
exit(1);
}
}
if (nullfd > 2)
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_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_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;
}
