1 /* $OpenBSD: sftp-server.c,v 1.73 2007/05/17 07:55:29 djm Exp $ */
3 * Copyright (c) 2000-2004 Markus Friedl. All rights reserved.
5 * Permission to use, copy, modify, and distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
20 #include <sys/types.h>
21 #include <sys/param.h>
23 #ifdef HAVE_SYS_TIME_H
24 # include <sys/time.h>
46 #include "sftp-common.h"
49 #define get_int64() buffer_get_int64(&iqueue);
50 #define get_int() buffer_get_int(&iqueue);
51 #define get_string(lenp) buffer_get_string(&iqueue, lenp);
54 LogLevel log_level = SYSLOG_LEVEL_ERROR;
57 struct passwd *pw = NULL;
58 char *client_addr = NULL;
60 /* input and output queue */
64 /* Version of client */
67 /* portable attributes, etc. */
69 typedef struct Stat Stat;
78 errno_to_portable(int unixerrno)
90 ret = SSH2_FX_NO_SUCH_FILE;
95 ret = SSH2_FX_PERMISSION_DENIED;
99 ret = SSH2_FX_BAD_MESSAGE;
102 ret = SSH2_FX_FAILURE;
109 flags_from_portable(int pflags)
113 if ((pflags & SSH2_FXF_READ) &&
114 (pflags & SSH2_FXF_WRITE)) {
116 } else if (pflags & SSH2_FXF_READ) {
118 } else if (pflags & SSH2_FXF_WRITE) {
121 if (pflags & SSH2_FXF_CREAT)
123 if (pflags & SSH2_FXF_TRUNC)
125 if (pflags & SSH2_FXF_EXCL)
131 string_from_portable(int pflags)
133 static char ret[128];
137 #define PAPPEND(str) { \
139 strlcat(ret, ",", sizeof(ret)); \
140 strlcat(ret, str, sizeof(ret)); \
143 if (pflags & SSH2_FXF_READ)
145 if (pflags & SSH2_FXF_WRITE)
147 if (pflags & SSH2_FXF_CREAT)
149 if (pflags & SSH2_FXF_TRUNC)
151 if (pflags & SSH2_FXF_EXCL)
160 return decode_attrib(&iqueue);
165 typedef struct Handle Handle;
171 u_int64_t bytes_read, bytes_write;
187 for (i = 0; i < sizeof(handles)/sizeof(Handle); i++)
188 handles[i].use = HANDLE_UNUSED;
192 handle_new(int use, const char *name, int fd, DIR *dirp)
196 for (i = 0; i < sizeof(handles)/sizeof(Handle); i++) {
197 if (handles[i].use == HANDLE_UNUSED) {
198 handles[i].use = use;
199 handles[i].dirp = dirp;
201 handles[i].name = xstrdup(name);
202 handles[i].bytes_read = handles[i].bytes_write = 0;
210 handle_is_ok(int i, int type)
212 return i >= 0 && (u_int)i < sizeof(handles)/sizeof(Handle) &&
213 handles[i].use == type;
217 handle_to_string(int handle, char **stringp, int *hlenp)
219 if (stringp == NULL || hlenp == NULL)
221 *stringp = xmalloc(sizeof(int32_t));
222 put_u32(*stringp, handle);
223 *hlenp = sizeof(int32_t);
228 handle_from_string(const char *handle, u_int hlen)
232 if (hlen != sizeof(int32_t))
234 val = get_u32(handle);
235 if (handle_is_ok(val, HANDLE_FILE) ||
236 handle_is_ok(val, HANDLE_DIR))
242 handle_to_name(int handle)
244 if (handle_is_ok(handle, HANDLE_DIR)||
245 handle_is_ok(handle, HANDLE_FILE))
246 return handles[handle].name;
251 handle_to_dir(int handle)
253 if (handle_is_ok(handle, HANDLE_DIR))
254 return handles[handle].dirp;
259 handle_to_fd(int handle)
261 if (handle_is_ok(handle, HANDLE_FILE))
262 return handles[handle].fd;
267 handle_update_read(int handle, ssize_t bytes)
269 if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0)
270 handles[handle].bytes_read += bytes;
274 handle_update_write(int handle, ssize_t bytes)
276 if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0)
277 handles[handle].bytes_write += bytes;
281 handle_bytes_read(int handle)
283 if (handle_is_ok(handle, HANDLE_FILE))
284 return (handles[handle].bytes_read);
289 handle_bytes_write(int handle)
291 if (handle_is_ok(handle, HANDLE_FILE))
292 return (handles[handle].bytes_write);
297 handle_close(int handle)
301 if (handle_is_ok(handle, HANDLE_FILE)) {
302 ret = close(handles[handle].fd);
303 handles[handle].use = HANDLE_UNUSED;
304 xfree(handles[handle].name);
305 } else if (handle_is_ok(handle, HANDLE_DIR)) {
306 ret = closedir(handles[handle].dirp);
307 handles[handle].use = HANDLE_UNUSED;
308 xfree(handles[handle].name);
316 handle_log_close(int handle, char *emsg)
318 if (handle_is_ok(handle, HANDLE_FILE)) {
319 logit("%s%sclose \"%s\" bytes read %llu written %llu",
320 emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ",
321 handle_to_name(handle),
322 (unsigned long long)handle_bytes_read(handle),
323 (unsigned long long)handle_bytes_write(handle));
325 logit("%s%sclosedir \"%s\"",
326 emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ",
327 handle_to_name(handle));
332 handle_log_exit(void)
336 for (i = 0; i < sizeof(handles)/sizeof(Handle); i++)
337 if (handles[i].use != HANDLE_UNUSED)
338 handle_log_close(i, "forced");
348 handle = get_string(&hlen);
350 val = handle_from_string(handle, hlen);
360 int mlen = buffer_len(m);
362 buffer_put_int(&oqueue, mlen);
363 buffer_append(&oqueue, buffer_ptr(m), mlen);
364 buffer_consume(m, mlen);
368 status_to_message(u_int32_t status)
370 const char *status_messages[] = {
371 "Success", /* SSH_FX_OK */
372 "End of file", /* SSH_FX_EOF */
373 "No such file", /* SSH_FX_NO_SUCH_FILE */
374 "Permission denied", /* SSH_FX_PERMISSION_DENIED */
375 "Failure", /* SSH_FX_FAILURE */
376 "Bad message", /* SSH_FX_BAD_MESSAGE */
377 "No connection", /* SSH_FX_NO_CONNECTION */
378 "Connection lost", /* SSH_FX_CONNECTION_LOST */
379 "Operation unsupported", /* SSH_FX_OP_UNSUPPORTED */
380 "Unknown error" /* Others */
382 return (status_messages[MIN(status,SSH2_FX_MAX)]);
386 send_status(u_int32_t id, u_int32_t status)
390 debug3("request %u: sent status %u", id, status);
391 if (log_level > SYSLOG_LEVEL_VERBOSE ||
392 (status != SSH2_FX_OK && status != SSH2_FX_EOF))
393 logit("sent status %s", status_to_message(status));
395 buffer_put_char(&msg, SSH2_FXP_STATUS);
396 buffer_put_int(&msg, id);
397 buffer_put_int(&msg, status);
399 buffer_put_cstring(&msg, status_to_message(status));
400 buffer_put_cstring(&msg, "");
406 send_data_or_handle(char type, u_int32_t id, const char *data, int dlen)
411 buffer_put_char(&msg, type);
412 buffer_put_int(&msg, id);
413 buffer_put_string(&msg, data, dlen);
419 send_data(u_int32_t id, const char *data, int dlen)
421 debug("request %u: sent data len %d", id, dlen);
422 send_data_or_handle(SSH2_FXP_DATA, id, data, dlen);
426 send_handle(u_int32_t id, int handle)
431 handle_to_string(handle, &string, &hlen);
432 debug("request %u: sent handle handle %d", id, handle);
433 send_data_or_handle(SSH2_FXP_HANDLE, id, string, hlen);
438 send_names(u_int32_t id, int count, const Stat *stats)
444 buffer_put_char(&msg, SSH2_FXP_NAME);
445 buffer_put_int(&msg, id);
446 buffer_put_int(&msg, count);
447 debug("request %u: sent names count %d", id, count);
448 for (i = 0; i < count; i++) {
449 buffer_put_cstring(&msg, stats[i].name);
450 buffer_put_cstring(&msg, stats[i].long_name);
451 encode_attrib(&msg, &stats[i].attrib);
458 send_attrib(u_int32_t id, const Attrib *a)
462 debug("request %u: sent attrib have 0x%x", id, a->flags);
464 buffer_put_char(&msg, SSH2_FXP_ATTRS);
465 buffer_put_int(&msg, id);
466 encode_attrib(&msg, a);
479 verbose("received client version %d", version);
481 buffer_put_char(&msg, SSH2_FXP_VERSION);
482 buffer_put_int(&msg, SSH2_FILEXFER_VERSION);
490 u_int32_t id, pflags;
493 int handle, fd, flags, mode, status = SSH2_FX_FAILURE;
496 name = get_string(NULL);
497 pflags = get_int(); /* portable flags */
498 debug3("request %u: open flags %d", id, pflags);
500 flags = flags_from_portable(pflags);
501 mode = (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ? a->perm : 0666;
502 logit("open \"%s\" flags %s mode 0%o",
503 name, string_from_portable(pflags), mode);
504 fd = open(name, flags, mode);
506 status = errno_to_portable(errno);
508 handle = handle_new(HANDLE_FILE, name, fd, NULL);
512 send_handle(id, handle);
516 if (status != SSH2_FX_OK)
517 send_status(id, status);
525 int handle, ret, status = SSH2_FX_FAILURE;
528 handle = get_handle();
529 debug3("request %u: close handle %u", id, handle);
530 handle_log_close(handle, NULL);
531 ret = handle_close(handle);
532 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
533 send_status(id, status);
541 int handle, fd, ret, status = SSH2_FX_FAILURE;
545 handle = get_handle();
549 debug("request %u: read \"%s\" (handle %d) off %llu len %d",
550 id, handle_to_name(handle), handle, (unsigned long long)off, len);
551 if (len > sizeof buf) {
553 debug2("read change len %d", len);
555 fd = handle_to_fd(handle);
557 if (lseek(fd, off, SEEK_SET) < 0) {
558 error("process_read: seek failed");
559 status = errno_to_portable(errno);
561 ret = read(fd, buf, len);
563 status = errno_to_portable(errno);
564 } else if (ret == 0) {
565 status = SSH2_FX_EOF;
567 send_data(id, buf, ret);
569 handle_update_read(handle, ret);
573 if (status != SSH2_FX_OK)
574 send_status(id, status);
583 int handle, fd, ret, status = SSH2_FX_FAILURE;
587 handle = get_handle();
589 data = get_string(&len);
591 debug("request %u: write \"%s\" (handle %d) off %llu len %d",
592 id, handle_to_name(handle), handle, (unsigned long long)off, len);
593 fd = handle_to_fd(handle);
595 if (lseek(fd, off, SEEK_SET) < 0) {
596 status = errno_to_portable(errno);
597 error("process_write: seek failed");
600 ret = write(fd, data, len);
602 error("process_write: write failed");
603 status = errno_to_portable(errno);
604 } else if ((size_t)ret == len) {
606 handle_update_write(handle, ret);
608 debug2("nothing at all written");
612 send_status(id, status);
617 process_do_stat(int do_lstat)
623 int ret, status = SSH2_FX_FAILURE;
626 name = get_string(NULL);
627 debug3("request %u: %sstat", id, do_lstat ? "l" : "");
628 verbose("%sstat name \"%s\"", do_lstat ? "l" : "", name);
629 ret = do_lstat ? lstat(name, &st) : stat(name, &st);
631 status = errno_to_portable(errno);
633 stat_to_attrib(&st, &a);
637 if (status != SSH2_FX_OK)
638 send_status(id, status);
660 int fd, ret, handle, status = SSH2_FX_FAILURE;
663 handle = get_handle();
664 debug("request %u: fstat \"%s\" (handle %u)",
665 id, handle_to_name(handle), handle);
666 fd = handle_to_fd(handle);
668 ret = fstat(fd, &st);
670 status = errno_to_portable(errno);
672 stat_to_attrib(&st, &a);
677 if (status != SSH2_FX_OK)
678 send_status(id, status);
681 static struct timeval *
682 attrib_to_tv(const Attrib *a)
684 static struct timeval tv[2];
686 tv[0].tv_sec = a->atime;
688 tv[1].tv_sec = a->mtime;
694 process_setstat(void)
699 int status = SSH2_FX_OK, ret;
702 name = get_string(NULL);
704 debug("request %u: setstat name \"%s\"", id, name);
705 if (a->flags & SSH2_FILEXFER_ATTR_SIZE) {
706 logit("set \"%s\" size %llu",
707 name, (unsigned long long)a->size);
708 ret = truncate(name, a->size);
710 status = errno_to_portable(errno);
712 if (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
713 logit("set \"%s\" mode %04o", name, a->perm);
714 ret = chmod(name, a->perm & 0777);
716 status = errno_to_portable(errno);
718 if (a->flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
722 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
724 logit("set \"%s\" modtime %s", name, buf);
725 ret = utimes(name, attrib_to_tv(a));
727 status = errno_to_portable(errno);
729 if (a->flags & SSH2_FILEXFER_ATTR_UIDGID) {
730 logit("set \"%s\" owner %lu group %lu", name,
731 (u_long)a->uid, (u_long)a->gid);
732 ret = chown(name, a->uid, a->gid);
734 status = errno_to_portable(errno);
736 send_status(id, status);
741 process_fsetstat(void)
746 int status = SSH2_FX_OK;
749 handle = get_handle();
751 debug("request %u: fsetstat handle %d", id, handle);
752 fd = handle_to_fd(handle);
754 status = SSH2_FX_FAILURE;
756 char *name = handle_to_name(handle);
758 if (a->flags & SSH2_FILEXFER_ATTR_SIZE) {
759 logit("set \"%s\" size %llu",
760 name, (unsigned long long)a->size);
761 ret = ftruncate(fd, a->size);
763 status = errno_to_portable(errno);
765 if (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
766 logit("set \"%s\" mode %04o", name, a->perm);
768 ret = fchmod(fd, a->perm & 0777);
770 ret = chmod(name, a->perm & 0777);
773 status = errno_to_portable(errno);
775 if (a->flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
779 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
781 logit("set \"%s\" modtime %s", name, buf);
783 ret = futimes(fd, attrib_to_tv(a));
785 ret = utimes(name, attrib_to_tv(a));
788 status = errno_to_portable(errno);
790 if (a->flags & SSH2_FILEXFER_ATTR_UIDGID) {
791 logit("set \"%s\" owner %lu group %lu", name,
792 (u_long)a->uid, (u_long)a->gid);
794 ret = fchown(fd, a->uid, a->gid);
796 ret = chown(name, a->uid, a->gid);
799 status = errno_to_portable(errno);
802 send_status(id, status);
806 process_opendir(void)
810 int handle, status = SSH2_FX_FAILURE;
814 path = get_string(NULL);
815 debug3("request %u: opendir", id);
816 logit("opendir \"%s\"", path);
817 dirp = opendir(path);
819 status = errno_to_portable(errno);
821 handle = handle_new(HANDLE_DIR, path, 0, dirp);
825 send_handle(id, handle);
830 if (status != SSH2_FX_OK)
831 send_status(id, status);
836 process_readdir(void)
845 handle = get_handle();
846 debug("request %u: readdir \"%s\" (handle %d)", id,
847 handle_to_name(handle), handle);
848 dirp = handle_to_dir(handle);
849 path = handle_to_name(handle);
850 if (dirp == NULL || path == NULL) {
851 send_status(id, SSH2_FX_FAILURE);
854 char pathname[MAXPATHLEN];
856 int nstats = 10, count = 0, i;
858 stats = xcalloc(nstats, sizeof(Stat));
859 while ((dp = readdir(dirp)) != NULL) {
860 if (count >= nstats) {
862 stats = xrealloc(stats, nstats, sizeof(Stat));
865 snprintf(pathname, sizeof pathname, "%s%s%s", path,
866 strcmp(path, "/") ? "/" : "", dp->d_name);
867 if (lstat(pathname, &st) < 0)
869 stat_to_attrib(&st, &(stats[count].attrib));
870 stats[count].name = xstrdup(dp->d_name);
871 stats[count].long_name = ls_file(dp->d_name, &st, 0);
873 /* send up to 100 entries in one message */
874 /* XXX check packet size instead */
879 send_names(id, count, stats);
880 for (i = 0; i < count; i++) {
881 xfree(stats[i].name);
882 xfree(stats[i].long_name);
885 send_status(id, SSH2_FX_EOF);
896 int status = SSH2_FX_FAILURE;
900 name = get_string(NULL);
901 debug3("request %u: remove", id);
902 logit("remove name \"%s\"", name);
904 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
905 send_status(id, status);
915 int ret, mode, status = SSH2_FX_FAILURE;
918 name = get_string(NULL);
920 mode = (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ?
921 a->perm & 0777 : 0777;
922 debug3("request %u: mkdir", id);
923 logit("mkdir name \"%s\" mode 0%o", name, mode);
924 ret = mkdir(name, mode);
925 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
926 send_status(id, status);
938 name = get_string(NULL);
939 debug3("request %u: rmdir", id);
940 logit("rmdir name \"%s\"", name);
942 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
943 send_status(id, status);
948 process_realpath(void)
950 char resolvedname[MAXPATHLEN];
955 path = get_string(NULL);
956 if (path[0] == '\0') {
960 debug3("request %u: realpath", id);
961 verbose("realpath \"%s\"", path);
962 if (realpath(path, resolvedname) == NULL) {
963 send_status(id, errno_to_portable(errno));
966 attrib_clear(&s.attrib);
967 s.name = s.long_name = resolvedname;
968 send_names(id, 1, &s);
977 char *oldpath, *newpath;
982 oldpath = get_string(NULL);
983 newpath = get_string(NULL);
984 debug3("request %u: rename", id);
985 logit("rename old \"%s\" new \"%s\"", oldpath, newpath);
986 status = SSH2_FX_FAILURE;
987 if (lstat(oldpath, &sb) == -1)
988 status = errno_to_portable(errno);
989 else if (S_ISREG(sb.st_mode)) {
990 /* Race-free rename of regular files */
991 if (link(oldpath, newpath) == -1) {
992 if (errno == EOPNOTSUPP
993 #ifdef LINK_OPNOTSUPP_ERRNO
994 || errno == LINK_OPNOTSUPP_ERRNO
1000 * fs doesn't support links, so fall back to
1001 * stat+rename. This is racy.
1003 if (stat(newpath, &st) == -1) {
1004 if (rename(oldpath, newpath) == -1)
1006 errno_to_portable(errno);
1008 status = SSH2_FX_OK;
1011 status = errno_to_portable(errno);
1013 } else if (unlink(oldpath) == -1) {
1014 status = errno_to_portable(errno);
1015 /* clean spare link */
1018 status = SSH2_FX_OK;
1019 } else if (stat(newpath, &sb) == -1) {
1020 if (rename(oldpath, newpath) == -1)
1021 status = errno_to_portable(errno);
1023 status = SSH2_FX_OK;
1025 send_status(id, status);
1031 process_readlink(void)
1035 char buf[MAXPATHLEN];
1039 path = get_string(NULL);
1040 debug3("request %u: readlink", id);
1041 verbose("readlink \"%s\"", path);
1042 if ((len = readlink(path, buf, sizeof(buf) - 1)) == -1)
1043 send_status(id, errno_to_portable(errno));
1048 attrib_clear(&s.attrib);
1049 s.name = s.long_name = buf;
1050 send_names(id, 1, &s);
1056 process_symlink(void)
1059 char *oldpath, *newpath;
1063 oldpath = get_string(NULL);
1064 newpath = get_string(NULL);
1065 debug3("request %u: symlink", id);
1066 logit("symlink old \"%s\" new \"%s\"", oldpath, newpath);
1067 /* this will fail if 'newpath' exists */
1068 ret = symlink(oldpath, newpath);
1069 status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1070 send_status(id, status);
1076 process_extended(void)
1082 request = get_string(NULL);
1083 send_status(id, SSH2_FX_OP_UNSUPPORTED); /* MUST */
1087 /* stolen from ssh-agent */
1098 buf_len = buffer_len(&iqueue);
1100 return; /* Incomplete message. */
1101 cp = buffer_ptr(&iqueue);
1102 msg_len = get_u32(cp);
1103 if (msg_len > SFTP_MAX_MSG_LENGTH) {
1104 error("bad message from %s local user %s",
1105 client_addr, pw->pw_name);
1108 if (buf_len < msg_len + 4)
1110 buffer_consume(&iqueue, 4);
1112 type = buffer_get_char(&iqueue);
1120 case SSH2_FXP_CLOSE:
1126 case SSH2_FXP_WRITE:
1129 case SSH2_FXP_LSTAT:
1132 case SSH2_FXP_FSTAT:
1135 case SSH2_FXP_SETSTAT:
1138 case SSH2_FXP_FSETSTAT:
1141 case SSH2_FXP_OPENDIR:
1144 case SSH2_FXP_READDIR:
1147 case SSH2_FXP_REMOVE:
1150 case SSH2_FXP_MKDIR:
1153 case SSH2_FXP_RMDIR:
1156 case SSH2_FXP_REALPATH:
1162 case SSH2_FXP_RENAME:
1165 case SSH2_FXP_READLINK:
1168 case SSH2_FXP_SYMLINK:
1171 case SSH2_FXP_EXTENDED:
1175 error("Unknown message %d", type);
1178 /* discard the remaining bytes from the current packet */
1179 if (buf_len < buffer_len(&iqueue))
1180 fatal("iqueue grew unexpectedly");
1181 consumed = buf_len - buffer_len(&iqueue);
1182 if (msg_len < consumed)
1183 fatal("msg_len %d < consumed %d", msg_len, consumed);
1184 if (msg_len > consumed)
1185 buffer_consume(&iqueue, msg_len - consumed);
1188 /* Cleanup handler that logs active handles upon normal exit */
1192 if (pw != NULL && client_addr != NULL) {
1194 logit("session closed for local user %s from [%s]",
1195 pw->pw_name, client_addr);
1203 extern char *__progname;
1206 "usage: %s [-he] [-l log_level] [-f log_facility]\n", __progname);
1211 main(int argc, char **argv)
1213 fd_set *rset, *wset;
1214 int in, out, max, ch, skipargs = 0, log_stderr = 0;
1215 ssize_t len, olen, set_size;
1216 SyslogFacility log_facility = SYSLOG_FACILITY_AUTH;
1217 char *cp, buf[4*4096];
1219 extern char *optarg;
1220 extern char *__progname;
1222 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1225 __progname = ssh_get_progname(argv[0]);
1226 log_init(__progname, log_level, log_facility, log_stderr);
1228 while (!skipargs && (ch = getopt(argc, argv, "C:f:l:che")) != -1) {
1232 * Ignore all arguments if we are invoked as a
1233 * shell using "sftp-server -c command"
1241 log_level = log_level_number(optarg);
1242 if (log_level == SYSLOG_LEVEL_NOT_SET)
1243 error("Invalid log level \"%s\"", optarg);
1246 log_facility = log_facility_number(optarg);
1247 if (log_level == SYSLOG_FACILITY_NOT_SET)
1248 error("Invalid log facility \"%s\"", optarg);
1256 log_init(__progname, log_level, log_facility, log_stderr);
1258 if ((cp = getenv("SSH_CONNECTION")) != NULL) {
1259 client_addr = xstrdup(cp);
1260 if ((cp = strchr(client_addr, ' ')) == NULL)
1261 fatal("Malformed SSH_CONNECTION variable: \"%s\"",
1262 getenv("SSH_CONNECTION"));
1265 client_addr = xstrdup("UNKNOWN");
1267 if ((pw = getpwuid(getuid())) == NULL)
1268 fatal("No user found for uid %lu", (u_long)getuid());
1271 logit("session opened for local user %s from [%s]",
1272 pw->pw_name, client_addr);
1276 in = dup(STDIN_FILENO);
1277 out = dup(STDOUT_FILENO);
1280 setmode(in, O_BINARY);
1281 setmode(out, O_BINARY);
1290 buffer_init(&iqueue);
1291 buffer_init(&oqueue);
1293 set_size = howmany(max + 1, NFDBITS) * sizeof(fd_mask);
1294 rset = (fd_set *)xmalloc(set_size);
1295 wset = (fd_set *)xmalloc(set_size);
1298 memset(rset, 0, set_size);
1299 memset(wset, 0, set_size);
1302 * Ensure that we can read a full buffer and handle
1303 * the worst-case length packet it can generate,
1304 * otherwise apply backpressure by stopping reads.
1306 if (buffer_check_alloc(&iqueue, sizeof(buf)) &&
1307 buffer_check_alloc(&oqueue, SFTP_MAX_MSG_LENGTH))
1310 olen = buffer_len(&oqueue);
1314 if (select(max+1, rset, wset, NULL, NULL) < 0) {
1317 error("select: %s", strerror(errno));
1321 /* copy stdin to iqueue */
1322 if (FD_ISSET(in, rset)) {
1323 len = read(in, buf, sizeof buf);
1327 } else if (len < 0) {
1328 error("read: %s", strerror(errno));
1331 buffer_append(&iqueue, buf, len);
1334 /* send oqueue to stdout */
1335 if (FD_ISSET(out, wset)) {
1336 len = write(out, buffer_ptr(&oqueue), olen);
1338 error("write: %s", strerror(errno));
1341 buffer_consume(&oqueue, len);
1346 * Process requests from client if we can fit the results
1347 * into the output buffer, otherwise stop processing input
1348 * and let the output queue drain.
1350 if (buffer_check_alloc(&oqueue, SFTP_MAX_MSG_LENGTH))