int
main(int argc, char **argv)
{
struct passwd *user_pw;
ssh_malloc_init(); /* must be called before any mallocs */
/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
sanitise_stdfd();
if ((user_pw = getpwuid(getuid())) == NULL) {
fprintf(stderr, "No user found for uid %lu\n",
(u_long)getuid());
return 1;
}
return (sftp_server_main(argc, argv, user_pw));
}
int
sftp_server_main(int argc, char **argv, struct passwd *user_pw)
{
fd_set *rset, *wset;
int i, r, in, out, max, ch, skipargs = 0, log_stderr = 0;
ssize_t len, olen, set_size;
SyslogFacility log_facility = SYSLOG_FACILITY_AUTH;
char *cp, *homedir = NULL, buf[4*4096];
long mask;
extern char *optarg;
extern char *__progname;
ssh_malloc_init(); /* must be called before any mallocs */
__progname = ssh_get_progname(argv[0]);
log_init(__progname, log_level, log_facility, log_stderr);
pw = pwcopy(user_pw);
while (!skipargs && (ch = getopt(argc, argv,
"d:f:l:P:p:Q:u:cehR")) != -1) {
switch (ch) {
case 'Q':
if (strcasecmp(optarg, "requests") != 0) {
fprintf(stderr, "Invalid query type\n");
exit(1);
}
for (i = 0; handlers[i].handler != NULL; i++)
printf("%s\n", handlers[i].name);
for (i = 0; extended_handlers[i].handler != NULL; i++)
printf("%s\n", extended_handlers[i].name);
exit(0);
break;
case 'R':
readonly = 1;
break;
case 'c':
/*
* Ignore all arguments if we are invoked as a
* shell using "sftp-server -c command"
*/
skipargs = 1;
break;
case 'e':
log_stderr = 1;
break;
case 'l':
log_level = log_level_number(optarg);
if (log_level == SYSLOG_LEVEL_NOT_SET)
error("Invalid log level \"%s\"", optarg);
break;
case 'f':
log_facility = log_facility_number(optarg);
if (log_facility == SYSLOG_FACILITY_NOT_SET)
error("Invalid log facility \"%s\"", optarg);
break;
case 'd':
cp = tilde_expand_filename(optarg, user_pw->pw_uid);
homedir = percent_expand(cp, "d", user_pw->pw_dir,
"u", user_pw->pw_name, (char *)NULL);
free(cp);
break;
case 'p':
if (request_whitelist != NULL)
fatal("Permitted requests already set");
request_whitelist = xstrdup(optarg);
break;
case 'P':
if (request_blacklist != NULL)
fatal("Refused requests already set");
request_blacklist = xstrdup(optarg);
break;
case 'u':
errno = 0;
mask = strtol(optarg, &cp, 8);
if (mask < 0 || mask > 0777 || *cp != '\0' ||
cp == optarg || (mask == 0 && errno != 0))
fatal("Invalid umask \"%s\"", optarg);
(void)umask((mode_t)mask);
break;
case 'h':
default:
sftp_server_usage();
}
}
log_init(__progname, log_level, log_facility, log_stderr);
#if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE)
/*
* On Linux, we should try to avoid making /proc/self/{mem,maps}
* available to the user so that sftp access doesn't automatically
* imply arbitrary code execution access that will break
* restricted configurations.
*/
if (prctl(PR_SET_DUMPABLE, 0) != 0)
fatal("unable to make the process undumpable");
#endif /* defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE) */
/* Drop any fine-grained privileges we don't need */
platform_pledge_sftp_server();
if ((cp = getenv("SSH_CONNECTION")) != NULL) {
client_addr = xstrdup(cp);
if ((cp = strchr(client_addr, ' ')) == NULL) {
error("Malformed SSH_CONNECTION variable: \"%s\"",
getenv("SSH_CONNECTION"));
sftp_server_cleanup_exit(255);
}
*cp = '\0';
} else
client_addr = xstrdup("UNKNOWN");
logit("session opened for local user %s from [%s]",
pw->pw_name, client_addr);
in = STDIN_FILENO;
out = STDOUT_FILENO;
#ifdef HAVE_CYGWIN
setmode(in, O_BINARY);
setmode(out, O_BINARY);
#endif
max = 0;
if (in > max)
max = in;
if (out > max)
max = out;
if ((iqueue = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
if ((oqueue = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
rset = xcalloc(howmany(max + 1, NFDBITS), sizeof(fd_mask));
wset = xcalloc(howmany(max + 1, NFDBITS), sizeof(fd_mask));
if (homedir != NULL) {
if (chdir(homedir) != 0) {
error("chdir to \"%s\" failed: %s", homedir,
strerror(errno));
}
}
set_size = howmany(max + 1, NFDBITS) * sizeof(fd_mask);
for (;;) {
memset(rset, 0, set_size);
memset(wset, 0, set_size);
/*
* Ensure that we can read a full buffer and handle
* the worst-case length packet it can generate,
* otherwise apply backpressure by stopping reads.
*/
if ((r = sshbuf_check_reserve(iqueue, sizeof(buf))) == 0 &&
(r = sshbuf_check_reserve(oqueue,
SFTP_MAX_MSG_LENGTH)) == 0)
FD_SET(in, rset);
else if (r != SSH_ERR_NO_BUFFER_SPACE)
fatal("%s: sshbuf_check_reserve failed: %s",
__func__, ssh_err(r));
olen = sshbuf_len(oqueue);
if (olen > 0)
FD_SET(out, wset);
if (select(max+1, rset, wset, NULL, NULL) < 0) {
if (errno == EINTR)
continue;
error("select: %s", strerror(errno));
sftp_server_cleanup_exit(2);
}
/* copy stdin to iqueue */
if (FD_ISSET(in, rset)) {
len = read(in, buf, sizeof buf);
if (len == 0) {
debug("read eof");
sftp_server_cleanup_exit(0);
} else if (len < 0) {
error("read: %s", strerror(errno));
sftp_server_cleanup_exit(1);
} else if ((r = sshbuf_put(iqueue, buf, len)) != 0) {
fatal("%s: buffer error: %s",
__func__, ssh_err(r));
}
}
/* send oqueue to stdout */
if (FD_ISSET(out, wset)) {
len = write(out, sshbuf_ptr(oqueue), olen);
if (len < 0) {
error("write: %s", strerror(errno));
sftp_server_cleanup_exit(1);
} else if ((r = sshbuf_consume(oqueue, len)) != 0) {
fatal("%s: buffer error: %s",
__func__, ssh_err(r));
}
}
/*
* Process requests from client if we can fit the results
* into the output buffer, otherwise stop processing input
* and let the output queue drain.
*/
r = sshbuf_check_reserve(oqueue, SFTP_MAX_MSG_LENGTH);
if (r == 0)
process();
else if (r != SSH_ERR_NO_BUFFER_SPACE)
fatal("%s: sshbuf_check_reserve: %s",
__func__, ssh_err(r));
}
}
int
main(int argc, char **argv)
{
int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
int opt, fopt_count = 0, j;
char *tname, *cp, *line = NULL;
size_t linesize = 0;
FILE *fp;
extern int optind;
extern char *optarg;
ssh_malloc_init(); /* must be called before any mallocs */
TAILQ_INIT(&tq);
/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
sanitise_stdfd();
if (argc <= 1)
usage();
while ((opt = getopt(argc, argv, "cDHv46p:T:t:f:")) != -1) {
switch (opt) {
case 'H':
hash_hosts = 1;
break;
case 'c':
get_cert = 1;
break;
case 'D':
print_sshfp = 1;
break;
case 'p':
ssh_port = a2port(optarg);
if (ssh_port <= 0) {
fprintf(stderr, "Bad port '%s'\n", optarg);
exit(1);
}
break;
case 'T':
timeout = convtime(optarg);
if (timeout == -1 || timeout == 0) {
fprintf(stderr, "Bad timeout '%s'\n", optarg);
usage();
}
break;
case 'v':
if (!debug_flag) {
debug_flag = 1;
log_level = SYSLOG_LEVEL_DEBUG1;
}
else if (log_level < SYSLOG_LEVEL_DEBUG3)
log_level++;
else
fatal("Too high debugging level.");
break;
case 'f':
if (strcmp(optarg, "-") == 0)
optarg = NULL;
argv[fopt_count++] = optarg;
break;
case 't':
get_keytypes = 0;
tname = strtok(optarg, ",");
while (tname) {
int type = sshkey_type_from_name(tname);
switch (type) {
case KEY_DSA:
get_keytypes |= KT_DSA;
break;
case KEY_ECDSA:
get_keytypes |= KT_ECDSA;
break;
case KEY_RSA:
get_keytypes |= KT_RSA;
break;
case KEY_ED25519:
get_keytypes |= KT_ED25519;
break;
case KEY_XMSS:
get_keytypes |= KT_XMSS;
break;
case KEY_UNSPEC:
default:
fatal("Unknown key type \"%s\"", tname);
}
tname = strtok(NULL, ",");
}
break;
case '4':
IPv4or6 = AF_INET;
break;
case '6':
IPv4or6 = AF_INET6;
break;
case '?':
default:
usage();
}
}
if (optind == argc && !fopt_count)
usage();
log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
maxfd = fdlim_get(1);
if (maxfd < 0)
fatal("%s: fdlim_get: bad value", __progname);
if (maxfd > MAXMAXFD)
maxfd = MAXMAXFD;
if (MAXCON <= 0)
fatal("%s: not enough file descriptors", __progname);
if (maxfd > fdlim_get(0))
fdlim_set(maxfd);
fdcon = xcalloc(maxfd, sizeof(con));
read_wait_nfdset = howmany(maxfd, NFDBITS);
read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
for (j = 0; j < fopt_count; j++) {
if (argv[j] == NULL)
fp = stdin;
else if ((fp = fopen(argv[j], "r")) == NULL)
fatal("%s: %s: %s", __progname, argv[j],
strerror(errno));
while (getline(&line, &linesize, fp) != -1) {
/* Chomp off trailing whitespace and comments */
if ((cp = strchr(line, '#')) == NULL)
cp = line + strlen(line) - 1;
while (cp >= line) {
if (*cp == ' ' || *cp == '\t' ||
*cp == '\n' || *cp == '#')
*cp-- = '\0';
else
break;
}
/* Skip empty lines */
if (*line == '\0')
continue;
do_host(line);
}
if (ferror(fp))
fatal("%s: %s: %s", __progname, argv[j],
strerror(errno));
fclose(fp);
}
free(line);
while (optind < argc)
do_host(argv[optind++]);
while (ncon > 0)
conloop();
return found_one ? 0 : 1;
}
