1 /* $OpenBSD: ftp-proxy.c,v 1.13 2006/12/30 13:24:00 camield Exp $ */
4 * Copyright (c) 2004, 2005 Camiel Dobbelaar, <cd@sentia.nl>
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
19 #include <sys/cdefs.h>
20 __FBSDID("$FreeBSD$");
22 #include <sys/queue.h>
23 #include <sys/types.h>
25 #include <sys/resource.h>
26 #include <sys/socket.h>
29 #include <net/pfvar.h>
30 #include <netinet/in.h>
31 #include <arpa/inet.h>
50 #define CONNECT_TIMEOUT 30
53 #define MAX_LOGLINE 300
55 #define TCP_BACKLOG 10
57 #define CHROOT_DIR "/var/empty"
58 #define NOPRIV_USER "proxy"
60 /* pfctl standard NAT range. */
61 #define PF_NAT_PROXY_PORT_LOW 50001
62 #define PF_NAT_PROXY_PORT_HIGH 65535
64 #define sstosa(ss) ((struct sockaddr *)(ss))
66 enum { CMD_NONE = 0, CMD_PORT, CMD_EPRT, CMD_PASV, CMD_EPSV };
70 struct sockaddr_storage client_ss;
71 struct sockaddr_storage proxy_ss;
72 struct sockaddr_storage server_ss;
73 struct sockaddr_storage orig_server_ss;
74 struct bufferevent *client_bufev;
75 struct bufferevent *server_bufev;
85 LIST_ENTRY(session) entry;
88 LIST_HEAD(, session) sessions = LIST_HEAD_INITIALIZER(sessions);
90 void client_error(struct bufferevent *, short, void *);
91 int client_parse(struct session *s);
92 int client_parse_anon(struct session *s);
93 int client_parse_cmd(struct session *s);
94 void client_read(struct bufferevent *, void *);
96 void end_session(struct session *);
97 int exit_daemon(void);
98 int getline(char *, size_t *);
99 void handle_connection(const int, short, void *);
100 void handle_signal(int, short, void *);
101 struct session * init_session(void);
102 void logmsg(int, const char *, ...);
103 u_int16_t parse_port(int);
104 u_int16_t pick_proxy_port(void);
105 void proxy_reply(int, struct sockaddr *, u_int16_t);
106 void server_error(struct bufferevent *, short, void *);
107 int server_parse(struct session *s);
108 void server_read(struct bufferevent *, void *);
109 const char *sock_ntop(struct sockaddr *);
112 char linebuf[MAX_LINE + 1];
115 char ntop_buf[NTOP_BUFS][INET6_ADDRSTRLEN];
117 struct sockaddr_storage fixed_server_ss, fixed_proxy_ss;
118 char *fixed_server, *fixed_server_port, *fixed_proxy, *listen_ip, *listen_port,
120 int anonymous_only, daemonize, id_count, ipv6_mode, loglevel, max_sessions,
121 rfc_mode, session_count, timeout, verbose;
122 extern char *__progname;
125 client_error(struct bufferevent *bufev, short what, void *arg)
127 struct session *s = arg;
129 if (what & EVBUFFER_EOF)
130 logmsg(LOG_INFO, "#%d client close", s->id);
131 else if (what == (EVBUFFER_ERROR | EVBUFFER_READ))
132 logmsg(LOG_ERR, "#%d client reset connection", s->id);
133 else if (what & EVBUFFER_TIMEOUT)
134 logmsg(LOG_ERR, "#%d client timeout", s->id);
135 else if (what & EVBUFFER_WRITE)
136 logmsg(LOG_ERR, "#%d client write error: %d", s->id, what);
138 logmsg(LOG_ERR, "#%d abnormal client error: %d", s->id, what);
144 client_parse(struct session *s)
146 /* Reset any previous command. */
150 /* Commands we are looking for are at least 4 chars long. */
154 if (linebuf[0] == 'P' || linebuf[0] == 'p' ||
155 linebuf[0] == 'E' || linebuf[0] == 'e')
156 return (client_parse_cmd(s));
158 if (anonymous_only && (linebuf[0] == 'U' || linebuf[0] == 'u'))
159 return (client_parse_anon(s));
165 client_parse_anon(struct session *s)
167 if (strcasecmp("USER ftp\r\n", linebuf) != 0 &&
168 strcasecmp("USER anonymous\r\n", linebuf) != 0) {
169 snprintf(linebuf, sizeof linebuf,
170 "500 Only anonymous FTP allowed\r\n");
171 logmsg(LOG_DEBUG, "#%d proxy: %s", s->id, linebuf);
173 /* Talk back to the client ourself. */
174 linelen = strlen(linebuf);
175 bufferevent_write(s->client_bufev, linebuf, linelen);
177 /* Clear buffer so it's not sent to the server. */
186 client_parse_cmd(struct session *s)
188 if (strncasecmp("PASV", linebuf, 4) == 0)
190 else if (strncasecmp("PORT ", linebuf, 5) == 0)
192 else if (strncasecmp("EPSV", linebuf, 4) == 0)
194 else if (strncasecmp("EPRT ", linebuf, 5) == 0)
199 if (ipv6_mode && (s->cmd == CMD_PASV || s->cmd == CMD_PORT)) {
200 logmsg(LOG_CRIT, "PASV and PORT not allowed with IPv6");
204 if (s->cmd == CMD_PORT || s->cmd == CMD_EPRT) {
205 s->port = parse_port(s->cmd);
206 if (s->port < MIN_PORT) {
207 logmsg(LOG_CRIT, "#%d bad port in '%s'", s->id,
211 s->proxy_port = pick_proxy_port();
212 proxy_reply(s->cmd, sstosa(&s->proxy_ss), s->proxy_port);
213 logmsg(LOG_DEBUG, "#%d proxy: %s", s->id, linebuf);
220 client_read(struct bufferevent *bufev, void *arg)
222 struct session *s = arg;
223 size_t buf_avail, read;
227 buf_avail = sizeof s->cbuf - s->cbuf_valid;
228 read = bufferevent_read(bufev, s->cbuf + s->cbuf_valid,
230 s->cbuf_valid += read;
232 while ((n = getline(s->cbuf, &s->cbuf_valid)) > 0) {
233 logmsg(LOG_DEBUG, "#%d client: %s", s->id, linebuf);
234 if (!client_parse(s)) {
238 bufferevent_write(s->server_bufev, linebuf, linelen);
242 logmsg(LOG_ERR, "#%d client command too long or not"
247 } while (read == buf_avail);
255 pw = getpwnam(NOPRIV_USER);
260 if (chroot(CHROOT_DIR) != 0 || chdir("/") != 0 ||
261 setgroups(1, &pw->pw_gid) != 0 ||
262 setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) != 0 ||
263 setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) != 0)
270 end_session(struct session *s)
274 logmsg(LOG_INFO, "#%d ending session", s->id);
276 if (s->client_fd != -1)
278 if (s->server_fd != -1)
282 bufferevent_free(s->client_bufev);
284 bufferevent_free(s->server_bufev);
286 /* Remove rulesets by commiting empty ones. */
288 if (prepare_commit(s->id) == -1)
290 else if (do_commit() == -1) {
295 logmsg(LOG_ERR, "#%d pf rule removal failed: %s", s->id,
298 LIST_REMOVE(s, entry);
306 struct session *s, *next;
309 LIST_FOREACH_SAFE(s, &sessions, entry, next) {
311 for (s = LIST_FIRST(&sessions); s != LIST_END(&sessions); s = next) {
312 next = LIST_NEXT(s, entry);
327 getline(char *buf, size_t *valid)
331 if (*valid > MAX_LINE)
334 /* Copy to linebuf while searching for a newline. */
335 for (i = 0; i < *valid; i++) {
344 /* No newline found. */
353 linebuf[linelen] = '\0';
356 /* Move leftovers to the start. */
358 bcopy(buf + linelen, buf, *valid);
360 return ((int)linelen);
364 handle_connection(const int listen_fd, short event, void *ev)
366 struct sockaddr_storage tmp_ss;
367 struct sockaddr *client_sa, *server_sa, *fixed_server_sa;
368 struct sockaddr *client_to_proxy_sa, *proxy_to_server_sa;
371 int client_fd, fc, on;
374 * We _must_ accept the connection, otherwise libevent will keep
375 * coming back, and we will chew up all CPU.
377 client_sa = sstosa(&tmp_ss);
378 len = sizeof(struct sockaddr_storage);
379 if ((client_fd = accept(listen_fd, client_sa, &len)) < 0) {
380 logmsg(LOG_CRIT, "accept failed: %s", strerror(errno));
384 /* Refuse connection if the maximum is reached. */
385 if (session_count >= max_sessions) {
386 logmsg(LOG_ERR, "client limit (%d) reached, refusing "
387 "connection from %s", max_sessions, sock_ntop(client_sa));
392 /* Allocate session and copy back the info from the accept(). */
395 logmsg(LOG_CRIT, "init_session failed");
399 s->client_fd = client_fd;
400 memcpy(sstosa(&s->client_ss), client_sa, client_sa->sa_len);
402 /* Cast it once, and be done with it. */
403 client_sa = sstosa(&s->client_ss);
404 server_sa = sstosa(&s->server_ss);
405 client_to_proxy_sa = sstosa(&tmp_ss);
406 proxy_to_server_sa = sstosa(&s->proxy_ss);
407 fixed_server_sa = sstosa(&fixed_server_ss);
409 /* Log id/client early to ease debugging. */
410 logmsg(LOG_DEBUG, "#%d accepted connection from %s", s->id,
411 sock_ntop(client_sa));
414 * Find out the real server and port that the client wanted.
416 len = sizeof(struct sockaddr_storage);
417 if ((getsockname(s->client_fd, client_to_proxy_sa, &len)) < 0) {
418 logmsg(LOG_CRIT, "#%d getsockname failed: %s", s->id,
422 if (server_lookup(client_sa, client_to_proxy_sa, server_sa) != 0) {
423 logmsg(LOG_CRIT, "#%d server lookup failed (no rdr?)", s->id);
427 memcpy(sstosa(&s->orig_server_ss), server_sa,
429 memcpy(server_sa, fixed_server_sa, fixed_server_sa->sa_len);
432 /* XXX: check we are not connecting to ourself. */
435 * Setup socket and connect to server.
437 if ((s->server_fd = socket(server_sa->sa_family, SOCK_STREAM,
439 logmsg(LOG_CRIT, "#%d server socket failed: %s", s->id,
443 if (fixed_proxy && bind(s->server_fd, sstosa(&fixed_proxy_ss),
444 fixed_proxy_ss.ss_len) != 0) {
445 logmsg(LOG_CRIT, "#%d cannot bind fixed proxy address: %s",
446 s->id, strerror(errno));
450 /* Use non-blocking connect(), see CONNECT_TIMEOUT below. */
451 if ((fc = fcntl(s->server_fd, F_GETFL)) == -1 ||
452 fcntl(s->server_fd, F_SETFL, fc | O_NONBLOCK) == -1) {
453 logmsg(LOG_CRIT, "#%d cannot mark socket non-blocking: %s",
454 s->id, strerror(errno));
457 if (connect(s->server_fd, server_sa, server_sa->sa_len) < 0 &&
458 errno != EINPROGRESS) {
459 logmsg(LOG_CRIT, "#%d proxy cannot connect to server %s: %s",
460 s->id, sock_ntop(server_sa), strerror(errno));
464 len = sizeof(struct sockaddr_storage);
465 if ((getsockname(s->server_fd, proxy_to_server_sa, &len)) < 0) {
466 logmsg(LOG_CRIT, "#%d getsockname failed: %s", s->id,
471 logmsg(LOG_INFO, "#%d FTP session %d/%d started: client %s to server "
472 "%s via proxy %s ", s->id, session_count, max_sessions,
473 sock_ntop(client_sa), sock_ntop(server_sa),
474 sock_ntop(proxy_to_server_sa));
476 /* Keepalive is nice, but don't care if it fails. */
478 setsockopt(s->client_fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&on,
480 setsockopt(s->server_fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&on,
484 * Setup buffered events.
486 s->client_bufev = bufferevent_new(s->client_fd, &client_read, NULL,
488 if (s->client_bufev == NULL) {
489 logmsg(LOG_CRIT, "#%d bufferevent_new client failed", s->id);
492 bufferevent_settimeout(s->client_bufev, timeout, 0);
493 bufferevent_enable(s->client_bufev, EV_READ | EV_TIMEOUT);
495 s->server_bufev = bufferevent_new(s->server_fd, &server_read, NULL,
497 if (s->server_bufev == NULL) {
498 logmsg(LOG_CRIT, "#%d bufferevent_new server failed", s->id);
501 bufferevent_settimeout(s->server_bufev, CONNECT_TIMEOUT, 0);
502 bufferevent_enable(s->server_bufev, EV_READ | EV_TIMEOUT);
511 handle_signal(int sig, short event, void *arg)
514 * Signal handler rules don't apply, libevent decouples for us.
517 logmsg(LOG_ERR, "%s exiting on signal %d", __progname, sig);
528 s = calloc(1, sizeof(struct session));
539 s->client_bufev = NULL;
540 s->server_bufev = NULL;
544 LIST_INSERT_HEAD(&sessions, s, entry);
551 logmsg(int pri, const char *message, ...)
558 va_start(ap, message);
561 /* syslog does its own vissing. */
562 vsyslog(pri, message, ap);
564 char buf[MAX_LOGLINE];
565 char visbuf[2 * MAX_LOGLINE];
567 /* We don't care about truncation. */
568 vsnprintf(buf, sizeof buf, message, ap);
570 /* XXX: strnvis might be nice to have */
572 MIN((sizeof(visbuf) / 4) - 1, strlen(buf)),
573 VIS_CSTYLE | VIS_NL);
575 strnvis(visbuf, buf, sizeof visbuf, VIS_CSTYLE | VIS_NL);
577 fprintf(stderr, "%s\n", visbuf);
584 main(int argc, char *argv[])
587 struct addrinfo hints, *res;
588 struct event ev, ev_sighup, ev_sigint, ev_sigterm;
589 int ch, error, listenfd, on;
597 fixed_server_port = "21";
600 listen_port = "8021";
601 loglevel = LOG_NOTICE;
608 /* Other initialization. */
612 while ((ch = getopt(argc, argv, "6Aa:b:D:dm:P:p:q:R:rt:v")) != -1) {
621 fixed_proxy = optarg;
627 loglevel = strtonum(optarg, LOG_EMERG, LOG_DEBUG,
630 errx(1, "loglevel %s", errstr);
636 max_sessions = strtonum(optarg, 1, 500, &errstr);
638 errx(1, "max sessions %s", errstr);
641 fixed_server_port = optarg;
644 listen_port = optarg;
647 if (strlen(optarg) >= PF_QNAME_SIZE)
648 errx(1, "queuename too long");
652 fixed_server = optarg;
658 timeout = strtonum(optarg, 0, 86400, &errstr);
660 errx(1, "timeout %s", errstr);
672 if (listen_ip == NULL)
673 listen_ip = ipv6_mode ? "::1" : "127.0.0.1";
675 /* Check for root to save the user from cryptic failure messages. */
677 errx(1, "needs to start as root");
679 /* Raise max. open files limit to satisfy max. sessions. */
680 rlp.rlim_cur = rlp.rlim_max = (2 * max_sessions) + 10;
681 if (setrlimit(RLIMIT_NOFILE, &rlp) == -1)
685 memset(&hints, 0, sizeof hints);
686 hints.ai_flags = AI_NUMERICHOST;
687 hints.ai_family = ipv6_mode ? AF_INET6 : AF_INET;
688 hints.ai_socktype = SOCK_STREAM;
689 error = getaddrinfo(fixed_proxy, NULL, &hints, &res);
691 errx(1, "getaddrinfo fixed proxy address failed: %s",
692 gai_strerror(error));
693 memcpy(&fixed_proxy_ss, res->ai_addr, res->ai_addrlen);
694 logmsg(LOG_INFO, "using %s to connect to servers",
695 sock_ntop(sstosa(&fixed_proxy_ss)));
700 memset(&hints, 0, sizeof hints);
701 hints.ai_family = ipv6_mode ? AF_INET6 : AF_INET;
702 hints.ai_socktype = SOCK_STREAM;
703 error = getaddrinfo(fixed_server, fixed_server_port, &hints,
706 errx(1, "getaddrinfo fixed server address failed: %s",
707 gai_strerror(error));
708 memcpy(&fixed_server_ss, res->ai_addr, res->ai_addrlen);
709 logmsg(LOG_INFO, "using fixed server %s",
710 sock_ntop(sstosa(&fixed_server_ss)));
714 /* Setup listener. */
715 memset(&hints, 0, sizeof hints);
716 hints.ai_flags = AI_NUMERICHOST | AI_PASSIVE;
717 hints.ai_family = ipv6_mode ? AF_INET6 : AF_INET;
718 hints.ai_socktype = SOCK_STREAM;
719 error = getaddrinfo(listen_ip, listen_port, &hints, &res);
721 errx(1, "getaddrinfo listen address failed: %s",
722 gai_strerror(error));
723 if ((listenfd = socket(res->ai_family, SOCK_STREAM, IPPROTO_TCP)) == -1)
724 errx(1, "socket failed");
726 if (setsockopt(listenfd, SOL_SOCKET, SO_REUSEADDR, (void *)&on,
728 err(1, "setsockopt failed");
729 if (bind(listenfd, (struct sockaddr *)res->ai_addr,
730 (socklen_t)res->ai_addrlen) != 0)
731 err(1, "bind failed");
732 if (listen(listenfd, TCP_BACKLOG) != 0)
733 err(1, "listen failed");
737 init_filter(qname, verbose);
740 if (daemon(0, 0) == -1)
741 err(1, "cannot daemonize");
742 openlog(__progname, LOG_PID | LOG_NDELAY, LOG_DAEMON);
745 /* Use logmsg for output from here on. */
748 logmsg(LOG_ERR, "cannot drop privileges: %s", strerror(errno));
754 /* Setup signal handler. */
755 signal(SIGPIPE, SIG_IGN);
756 signal_set(&ev_sighup, SIGHUP, handle_signal, NULL);
757 signal_set(&ev_sigint, SIGINT, handle_signal, NULL);
758 signal_set(&ev_sigterm, SIGTERM, handle_signal, NULL);
759 signal_add(&ev_sighup, NULL);
760 signal_add(&ev_sigint, NULL);
761 signal_add(&ev_sigterm, NULL);
763 event_set(&ev, listenfd, EV_READ | EV_PERSIST, handle_connection, &ev);
764 event_add(&ev, NULL);
766 logmsg(LOG_NOTICE, "listening on %s port %s", listen_ip, listen_port);
771 logmsg(LOG_ERR, "event_dispatch error: %s", strerror(errno));
781 unsigned int port, v[6];
785 /* Find the last space or left-parenthesis. */
786 for (p = linebuf + linelen; p > linebuf; p--)
787 if (*p == ' ' || *p == '(')
794 n = sscanf(p, " %u,%u,%u,%u,%u,%u", &v[0], &v[1], &v[2],
795 &v[3], &v[4], &v[5]);
796 if (n == 6 && v[0] < 256 && v[1] < 256 && v[2] < 256 &&
797 v[3] < 256 && v[4] < 256 && v[5] < 256)
798 return ((v[4] << 8) | v[5]);
801 n = sscanf(p, "(%u,%u,%u,%u,%u,%u)", &v[0], &v[1], &v[2],
802 &v[3], &v[4], &v[5]);
803 if (n == 6 && v[0] < 256 && v[1] < 256 && v[2] < 256 &&
804 v[3] < 256 && v[4] < 256 && v[5] < 256)
805 return ((v[4] << 8) | v[5]);
808 n = sscanf(p, "(|||%u|)", &port);
809 if (n == 1 && port < 65536)
813 n = sscanf(p, " |1|%u.%u.%u.%u|%u|", &v[0], &v[1], &v[2],
815 if (n == 5 && v[0] < 256 && v[1] < 256 && v[2] < 256 &&
816 v[3] < 256 && port < 65536)
818 n = sscanf(p, " |2|%*[a-fA-F0-9:]|%u|", &port);
819 if (n == 1 && port < 65536)
830 pick_proxy_port(void)
832 /* Random should be good enough for avoiding port collisions. */
833 return (IPPORT_HIFIRSTAUTO + (arc4random() %
834 (IPPORT_HILASTAUTO - IPPORT_HIFIRSTAUTO)));
838 proxy_reply(int cmd, struct sockaddr *sa, u_int16_t port)
844 r = snprintf(linebuf, sizeof linebuf,
845 "PORT %s,%u,%u\r\n", sock_ntop(sa), port / 256,
849 r = snprintf(linebuf, sizeof linebuf,
850 "227 Entering Passive Mode (%s,%u,%u)\r\n", sock_ntop(sa),
851 port / 256, port % 256);
854 if (sa->sa_family == AF_INET)
855 r = snprintf(linebuf, sizeof linebuf,
856 "EPRT |1|%s|%u|\r\n", sock_ntop(sa), port);
857 else if (sa->sa_family == AF_INET6)
858 r = snprintf(linebuf, sizeof linebuf,
859 "EPRT |2|%s|%u|\r\n", sock_ntop(sa), port);
862 r = snprintf(linebuf, sizeof linebuf,
863 "229 Entering Extended Passive Mode (|||%u|)\r\n", port);
867 if (r < 0 || r >= sizeof linebuf) {
868 logmsg(LOG_ERR, "proxy_reply failed: %d", r);
875 if (cmd == CMD_PORT || cmd == CMD_PASV) {
876 /* Replace dots in IP address with commas. */
877 for (i = 0; i < linelen; i++)
878 if (linebuf[i] == '.')
884 server_error(struct bufferevent *bufev, short what, void *arg)
886 struct session *s = arg;
888 if (what & EVBUFFER_EOF)
889 logmsg(LOG_INFO, "#%d server close", s->id);
890 else if (what == (EVBUFFER_ERROR | EVBUFFER_READ))
891 logmsg(LOG_ERR, "#%d server refused connection", s->id);
892 else if (what & EVBUFFER_WRITE)
893 logmsg(LOG_ERR, "#%d server write error: %d", s->id, what);
894 else if (what & EVBUFFER_TIMEOUT)
895 logmsg(LOG_NOTICE, "#%d server timeout", s->id);
897 logmsg(LOG_ERR, "#%d abnormal server error: %d", s->id, what);
903 server_parse(struct session *s)
905 struct sockaddr *client_sa, *orig_sa, *proxy_sa, *server_sa;
908 if (s->cmd == CMD_NONE || linelen < 4 || linebuf[0] != '2')
912 * The pf rules below do quite some NAT rewriting, to keep up
913 * appearances. Points to keep in mind:
914 * 1) The client must think it's talking to the real server,
915 * for both control and data connections. Transparently.
916 * 2) The server must think that the proxy is the client.
917 * 3) Source and destination ports are rewritten to minimize
918 * port collisions, to aid security (some systems pick weak
919 * ports) or to satisfy RFC requirements (source port 20).
922 /* Cast this once, to make code below it more readable. */
923 client_sa = sstosa(&s->client_ss);
924 server_sa = sstosa(&s->server_ss);
925 proxy_sa = sstosa(&s->proxy_ss);
927 /* Fixed server: data connections must appear to come
928 from / go to the original server, not the fixed one. */
929 orig_sa = sstosa(&s->orig_server_ss);
931 /* Server not fixed: orig_server == server. */
932 orig_sa = sstosa(&s->server_ss);
935 if ((s->cmd == CMD_PASV && strncmp("227 ", linebuf, 4) == 0) ||
936 (s->cmd == CMD_EPSV && strncmp("229 ", linebuf, 4) == 0)) {
937 s->port = parse_port(s->cmd);
938 if (s->port < MIN_PORT) {
939 logmsg(LOG_CRIT, "#%d bad port in '%s'", s->id,
943 s->proxy_port = pick_proxy_port();
944 logmsg(LOG_INFO, "#%d passive: client to server port %d"
945 " via port %d", s->id, s->port, s->proxy_port);
947 if (prepare_commit(s->id) == -1)
951 proxy_reply(s->cmd, orig_sa, s->proxy_port);
952 logmsg(LOG_DEBUG, "#%d proxy: %s", s->id, linebuf);
954 /* rdr from $client to $orig_server port $proxy_port -> $server
956 if (add_rdr(s->id, client_sa, orig_sa, s->proxy_port,
957 server_sa, s->port) == -1)
960 /* nat from $client to $server port $port -> $proxy */
961 if (add_nat(s->id, client_sa, server_sa, s->port, proxy_sa,
962 PF_NAT_PROXY_PORT_LOW, PF_NAT_PROXY_PORT_HIGH) == -1)
965 /* pass in from $client to $server port $port */
966 if (add_filter(s->id, PF_IN, client_sa, server_sa,
970 /* pass out from $proxy to $server port $port */
971 if (add_filter(s->id, PF_OUT, proxy_sa, server_sa,
977 if ((s->cmd == CMD_PORT || s->cmd == CMD_EPRT) &&
978 strncmp("200 ", linebuf, 4) == 0) {
979 logmsg(LOG_INFO, "#%d active: server to client port %d"
980 " via port %d", s->id, s->port, s->proxy_port);
982 if (prepare_commit(s->id) == -1)
986 /* rdr from $server to $proxy port $proxy_port -> $client port
988 if (add_rdr(s->id, server_sa, proxy_sa, s->proxy_port,
989 client_sa, s->port) == -1)
992 /* nat from $server to $client port $port -> $orig_server port
994 if (rfc_mode && s->cmd == CMD_PORT) {
995 /* Rewrite sourceport to RFC mandated 20. */
996 if (add_nat(s->id, server_sa, client_sa, s->port,
997 orig_sa, 20, 20) == -1)
1000 /* Let pf pick a source port from the standard range. */
1001 if (add_nat(s->id, server_sa, client_sa, s->port,
1002 orig_sa, PF_NAT_PROXY_PORT_LOW,
1003 PF_NAT_PROXY_PORT_HIGH) == -1)
1007 /* pass in from $server to $client port $port */
1008 if (add_filter(s->id, PF_IN, server_sa, client_sa, s->port) ==
1012 /* pass out from $orig_server to $client port $port */
1013 if (add_filter(s->id, PF_OUT, orig_sa, client_sa, s->port) ==
1018 /* Commit rules if they were prepared. */
1019 if (prepared && (do_commit() == -1)) {
1022 /* One more try if busy. */
1024 if (do_commit() == -1)
1035 logmsg(LOG_CRIT, "#%d pf operation failed: %s", s->id, strerror(errno));
1042 server_read(struct bufferevent *bufev, void *arg)
1044 struct session *s = arg;
1045 size_t buf_avail, read;
1048 bufferevent_settimeout(bufev, timeout, 0);
1051 buf_avail = sizeof s->sbuf - s->sbuf_valid;
1052 read = bufferevent_read(bufev, s->sbuf + s->sbuf_valid,
1054 s->sbuf_valid += read;
1056 while ((n = getline(s->sbuf, &s->sbuf_valid)) > 0) {
1057 logmsg(LOG_DEBUG, "#%d server: %s", s->id, linebuf);
1058 if (!server_parse(s)) {
1062 bufferevent_write(s->client_bufev, linebuf, linelen);
1066 logmsg(LOG_ERR, "#%d server reply too long or not"
1071 } while (read == buf_avail);
1075 sock_ntop(struct sockaddr *sa)
1079 /* Cycle to next buffer. */
1080 n = (n + 1) % NTOP_BUFS;
1081 ntop_buf[n][0] = '\0';
1083 if (sa->sa_family == AF_INET) {
1084 struct sockaddr_in *sin = (struct sockaddr_in *)sa;
1086 return (inet_ntop(AF_INET, &sin->sin_addr, ntop_buf[n],
1087 sizeof ntop_buf[0]));
1090 if (sa->sa_family == AF_INET6) {
1091 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sa;
1093 return (inet_ntop(AF_INET6, &sin6->sin6_addr, ntop_buf[n],
1094 sizeof ntop_buf[0]));
1103 fprintf(stderr, "usage: %s [-6Adrv] [-a address] [-b address]"
1104 " [-D level] [-m maxsessions]\n [-P port]"
1105 " [-p port] [-q queue] [-R address] [-t timeout]\n", __progname);