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Willy Tarreau92fb9832007-10-16 17:34:28 +02001/*
2 * UNIX SOCK_STREAM protocol layer (uxst)
3 *
Willy Tarreaueb472682010-05-28 18:46:57 +02004 * Copyright 2000-2010 Willy Tarreau <w@1wt.eu>
Willy Tarreau92fb9832007-10-16 17:34:28 +02005 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 *
11 */
12
13#include <ctype.h>
14#include <errno.h>
15#include <fcntl.h>
16#include <stdio.h>
17#include <stdlib.h>
18#include <string.h>
19#include <syslog.h>
20#include <time.h>
21
Willy Tarreau92fb9832007-10-16 17:34:28 +020022#include <sys/socket.h>
23#include <sys/stat.h>
24#include <sys/types.h>
25#include <sys/un.h>
26
Willy Tarreau4c7e4b72020-05-27 12:58:42 +020027#include <haproxy/api.h>
Willy Tarreau7ea393d2020-06-04 18:02:10 +020028#include <haproxy/connection.h>
Willy Tarreau8d366972020-05-27 16:10:29 +020029#include <haproxy/errors.h>
Willy Tarreaub2551052020-06-09 09:07:15 +020030#include <haproxy/fd.h>
Willy Tarreauf268ee82020-06-04 17:05:57 +020031#include <haproxy/global.h>
Willy Tarreau853b2972020-05-27 18:01:47 +020032#include <haproxy/list.h>
Willy Tarreau213e9902020-06-04 14:58:24 +020033#include <haproxy/listener.h>
Willy Tarreauaeed4a82020-06-04 22:01:04 +020034#include <haproxy/log.h>
Willy Tarreaub2551052020-06-09 09:07:15 +020035#include <haproxy/protocol.h>
Willy Tarreau18b7df72020-08-28 12:07:22 +020036#include <haproxy/sock.h>
Willy Tarreauf1725582020-08-28 15:30:11 +020037#include <haproxy/sock_unix.h>
Willy Tarreau92b4f132020-06-01 11:05:15 +020038#include <haproxy/time.h>
Willy Tarreaub2551052020-06-09 09:07:15 +020039#include <haproxy/tools.h>
Willy Tarreaud6788052020-05-27 15:59:00 +020040#include <haproxy/version.h>
Willy Tarreau92fb9832007-10-16 17:34:28 +020041
Willy Tarreau92fb9832007-10-16 17:34:28 +020042
Emeric Bruncf20bf12010-10-22 16:06:11 +020043static int uxst_bind_listener(struct listener *listener, char *errmsg, int errlen);
Olivier Houchardfdcb0072019-05-06 18:32:29 +020044static int uxst_connect_server(struct connection *conn, int flags);
Willy Tarreau9d5be5c2017-09-15 07:55:51 +020045static void uxst_add_listener(struct listener *listener, int port);
Willy Tarreau31794892017-09-15 07:59:31 +020046static int uxst_pause_listener(struct listener *l);
Willy Tarreaudabf2e22007-10-28 21:59:24 +010047
48/* Note: must not be declared <const> as its list will be overwritten */
49static struct protocol proto_unix = {
50 .name = "unix_stream",
Willy Tarreaub0254cb2020-09-04 08:07:11 +020051 .fam = &proto_fam_unix,
Willy Tarreaudabf2e22007-10-28 21:59:24 +010052 .sock_domain = PF_UNIX,
53 .sock_type = SOCK_STREAM,
54 .sock_prot = 0,
Willy Tarreaubbebbbf2012-05-07 21:22:09 +020055 .accept = &listener_accept,
Willy Tarreau47f48c42014-05-09 22:57:47 +020056 .connect = &uxst_connect_server,
Willy Tarreaub3580b12020-09-01 10:26:22 +020057 .listen = uxst_bind_listener,
Willy Tarreaudabf2e22007-10-28 21:59:24 +010058 .enable_all = enable_all_listeners,
59 .disable_all = disable_all_listeners,
Willy Tarreaufd0e0082014-07-07 21:07:51 +020060 .pause = uxst_pause_listener,
Willy Tarreau9d5be5c2017-09-15 07:55:51 +020061 .add = uxst_add_listener,
Willy Tarreaudabf2e22007-10-28 21:59:24 +010062 .listeners = LIST_HEAD_INIT(proto_unix.listeners),
63 .nb_listeners = 0,
64};
65
Willy Tarreau0108d902018-11-25 19:14:37 +010066INITCALL1(STG_REGISTER, protocol_register, &proto_unix);
67
Willy Tarreaudabf2e22007-10-28 21:59:24 +010068/********************************
69 * 1) low-level socket functions
70 ********************************/
71
72
Cyril Bonté1f5848a2010-11-14 17:03:19 +010073/********************************
74 * 2) listener-oriented functions
75 ********************************/
76
Cyril Bonté1f5848a2010-11-14 17:03:19 +010077/* This function creates a UNIX socket associated to the listener. It changes
78 * the state from ASSIGNED to LISTEN. The socket is NOT enabled for polling.
Willy Tarreau8ab505b2013-01-24 01:41:38 +010079 * The return value is composed from ERR_NONE, ERR_RETRYABLE and ERR_FATAL. It
80 * may return a warning or an error message in <errmsg> if the message is at
81 * most <errlen> bytes long (including '\0'). Note that <errmsg> may be NULL if
82 * <errlen> is also zero.
Willy Tarreau92fb9832007-10-16 17:34:28 +020083 */
Cyril Bonté1f5848a2010-11-14 17:03:19 +010084static int uxst_bind_listener(struct listener *listener, char *errmsg, int errlen)
Willy Tarreau92fb9832007-10-16 17:34:28 +020085{
Willy Tarreaucd5e5ea2020-09-02 17:21:02 +020086 int fd, err;
87 int ready;
Willy Tarreau40aa0702013-03-10 23:51:38 +010088 socklen_t ready_len;
Willy Tarreaucd5e5ea2020-09-02 17:21:02 +020089 char *msg = NULL;
Willy Tarreau92fb9832007-10-16 17:34:28 +020090
Willy Tarreau3c5efa22014-07-07 18:36:45 +020091 err = ERR_NONE;
92
Cyril Bonté1f5848a2010-11-14 17:03:19 +010093 /* ensure we never return garbage */
Willy Tarreau8ab505b2013-01-24 01:41:38 +010094 if (errlen)
Cyril Bonté1f5848a2010-11-14 17:03:19 +010095 *errmsg = 0;
96
97 if (listener->state != LI_ASSIGNED)
98 return ERR_NONE; /* already bound */
Willy Tarreau0b915012020-09-01 10:47:07 +020099
Willy Tarreauad33acf2020-09-02 18:40:02 +0200100 if (!(listener->rx.flags & RX_F_BOUND)) {
101 msg = "receiving socket not bound";
102 goto uxst_return;
Willy Tarreau92fb9832007-10-16 17:34:28 +0200103 }
104
Willy Tarreaucd5e5ea2020-09-02 17:21:02 +0200105 fd = listener->rx.fd;
Willy Tarreaue6ad2b12007-10-18 12:45:54 +0200106
Willy Tarreau40aa0702013-03-10 23:51:38 +0100107 ready = 0;
108 ready_len = sizeof(ready);
109 if (getsockopt(fd, SOL_SOCKET, SO_ACCEPTCONN, &ready, &ready_len) == -1)
110 ready = 0;
111
Willy Tarreaucd5e5ea2020-09-02 17:21:02 +0200112 if (!ready && /* only listen if not already done by external process */
Willy Tarreaue2711c72019-02-27 15:39:41 +0100113 listen(fd, listener_backlog(listener)) < 0) {
Willy Tarreau3c5efa22014-07-07 18:36:45 +0200114 err |= ERR_FATAL | ERR_ALERT;
Willy Tarreaub40dc942010-11-07 12:10:51 +0100115 msg = "cannot listen to UNIX socket";
Willy Tarreaucd5e5ea2020-09-02 17:21:02 +0200116 goto uxst_close_return;
Willy Tarreau92fb9832007-10-16 17:34:28 +0200117 }
118
Willy Tarreaudabf2e22007-10-28 21:59:24 +0100119 /* the socket is now listening */
Willy Tarreaudabf2e22007-10-28 21:59:24 +0100120 listener->state = LI_LISTEN;
Willy Tarreau3c5efa22014-07-07 18:36:45 +0200121 return err;
122
Willy Tarreaucd5e5ea2020-09-02 17:21:02 +0200123 uxst_close_return:
Cyril Bonté1f5848a2010-11-14 17:03:19 +0100124 close(fd);
Willy Tarreauad33acf2020-09-02 18:40:02 +0200125 uxst_return:
Willy Tarreau40aa0702013-03-10 23:51:38 +0100126 if (msg && errlen) {
Willy Tarreaucd5e5ea2020-09-02 17:21:02 +0200127 const char *path = ((struct sockaddr_un *)&listener->rx.addr)->sun_path;
128 snprintf(errmsg, errlen, "%s [%s]", msg, path);
Willy Tarreau40aa0702013-03-10 23:51:38 +0100129 }
Willy Tarreau3c5efa22014-07-07 18:36:45 +0200130 return err;
Willy Tarreaudabf2e22007-10-28 21:59:24 +0100131}
132
Willy Tarreau32282382017-09-15 07:44:44 +0200133/* Add <listener> to the list of unix stream listeners (port is ignored). The
134 * listener's state is automatically updated from LI_INIT to LI_ASSIGNED.
135 * The number of listeners for the protocol is updated.
Willy Tarreaudaacf362019-07-24 16:45:02 +0200136 *
137 * Must be called with proto_lock held.
138 *
Willy Tarreaudabf2e22007-10-28 21:59:24 +0100139 */
Willy Tarreau9d5be5c2017-09-15 07:55:51 +0200140static void uxst_add_listener(struct listener *listener, int port)
Willy Tarreaudabf2e22007-10-28 21:59:24 +0100141{
142 if (listener->state != LI_INIT)
143 return;
144 listener->state = LI_ASSIGNED;
Willy Tarreaub7436612020-08-28 19:51:44 +0200145 listener->rx.proto = &proto_unix;
146 LIST_ADDQ(&proto_unix.listeners, &listener->rx.proto_list);
Willy Tarreaudabf2e22007-10-28 21:59:24 +0100147 proto_unix.nb_listeners++;
148}
149
Willy Tarreaufd0e0082014-07-07 21:07:51 +0200150/* Pause a listener. Returns < 0 in case of failure, 0 if the listener
151 * was totally stopped, or > 0 if correctly paused. Nothing is done for
152 * plain unix sockets since currently it's the new process which handles
153 * the renaming. Abstract sockets are completely unbound.
154 */
Willy Tarreau31794892017-09-15 07:59:31 +0200155static int uxst_pause_listener(struct listener *l)
Willy Tarreaufd0e0082014-07-07 21:07:51 +0200156{
Willy Tarreau37159062020-08-27 07:48:42 +0200157 if (((struct sockaddr_un *)&l->rx.addr)->sun_path[0])
Willy Tarreaufd0e0082014-07-07 21:07:51 +0200158 return 1;
159
Christopher Faulet510c0d62018-03-16 10:04:47 +0100160 /* Listener's lock already held. Call lockless version of
161 * unbind_listener. */
162 do_unbind_listener(l, 1);
Willy Tarreaufd0e0082014-07-07 21:07:51 +0200163 return 0;
164}
165
Willy Tarreau47f48c42014-05-09 22:57:47 +0200166
167/*
168 * This function initiates a UNIX connection establishment to the target assigned
Willy Tarreauca9f5a92019-07-17 16:40:37 +0200169 * to connection <conn> using (si->{target,dst}). The source address is ignored
Willy Tarreau47f48c42014-05-09 22:57:47 +0200170 * and will be selected by the system. conn->target may point either to a valid
171 * server or to a backend, depending on conn->target. Only OBJ_TYPE_PROXY and
172 * OBJ_TYPE_SERVER are supported. The <data> parameter is a boolean indicating
173 * whether there are data waiting for being sent or not, in order to adjust data
174 * write polling and on some platforms. The <delack> argument is ignored.
175 *
176 * Note that a pending send_proxy message accounts for data.
177 *
178 * It can return one of :
Willy Tarreaue7dff022015-04-03 01:14:29 +0200179 * - SF_ERR_NONE if everything's OK
180 * - SF_ERR_SRVTO if there are no more servers
181 * - SF_ERR_SRVCL if the connection was refused by the server
182 * - SF_ERR_PRXCOND if the connection has been limited by the proxy (maxconn)
183 * - SF_ERR_RESOURCE if a system resource is lacking (eg: fd limits, ports, ...)
184 * - SF_ERR_INTERNAL for any other purely internal errors
Tim Düsterhus4896c442016-11-29 02:15:19 +0100185 * Additionally, in the case of SF_ERR_RESOURCE, an emergency log will be emitted.
Willy Tarreau47f48c42014-05-09 22:57:47 +0200186 *
Willy Tarreaue7dff022015-04-03 01:14:29 +0200187 * The connection's fd is inserted only when SF_ERR_NONE is returned, otherwise
Willy Tarreau47f48c42014-05-09 22:57:47 +0200188 * it's invalid and the caller has nothing to do.
189 */
Olivier Houchardfdcb0072019-05-06 18:32:29 +0200190static int uxst_connect_server(struct connection *conn, int flags)
Willy Tarreau47f48c42014-05-09 22:57:47 +0200191{
192 int fd;
193 struct server *srv;
194 struct proxy *be;
195
Willy Tarreau47f48c42014-05-09 22:57:47 +0200196 switch (obj_type(conn->target)) {
197 case OBJ_TYPE_PROXY:
198 be = objt_proxy(conn->target);
199 srv = NULL;
200 break;
201 case OBJ_TYPE_SERVER:
202 srv = objt_server(conn->target);
203 be = srv->proxy;
204 break;
205 default:
206 conn->flags |= CO_FL_ERROR;
Willy Tarreaue7dff022015-04-03 01:14:29 +0200207 return SF_ERR_INTERNAL;
Willy Tarreau47f48c42014-05-09 22:57:47 +0200208 }
209
Willy Tarreau585744b2017-08-24 14:31:19 +0200210 if ((fd = conn->handle.fd = socket(PF_UNIX, SOCK_STREAM, 0)) == -1) {
Willy Tarreau47f48c42014-05-09 22:57:47 +0200211 qfprintf(stderr, "Cannot get a server socket.\n");
212
213 if (errno == ENFILE) {
214 conn->err_code = CO_ER_SYS_FDLIM;
215 send_log(be, LOG_EMERG,
Willy Tarreauc5532ac2018-01-29 15:06:04 +0100216 "Proxy %s reached system FD limit (maxsock=%d). Please check system tunables.\n",
217 be->id, global.maxsock);
Willy Tarreau47f48c42014-05-09 22:57:47 +0200218 }
219 else if (errno == EMFILE) {
220 conn->err_code = CO_ER_PROC_FDLIM;
221 send_log(be, LOG_EMERG,
Willy Tarreauc5532ac2018-01-29 15:06:04 +0100222 "Proxy %s reached process FD limit (maxsock=%d). Please check 'ulimit-n' and restart.\n",
223 be->id, global.maxsock);
Willy Tarreau47f48c42014-05-09 22:57:47 +0200224 }
225 else if (errno == ENOBUFS || errno == ENOMEM) {
226 conn->err_code = CO_ER_SYS_MEMLIM;
227 send_log(be, LOG_EMERG,
Willy Tarreauc5532ac2018-01-29 15:06:04 +0100228 "Proxy %s reached system memory limit (maxsock=%d). Please check system tunables.\n",
229 be->id, global.maxsock);
Willy Tarreau47f48c42014-05-09 22:57:47 +0200230 }
231 else if (errno == EAFNOSUPPORT || errno == EPROTONOSUPPORT) {
232 conn->err_code = CO_ER_NOPROTO;
233 }
234 else
235 conn->err_code = CO_ER_SOCK_ERR;
236
237 /* this is a resource error */
238 conn->flags |= CO_FL_ERROR;
Willy Tarreaue7dff022015-04-03 01:14:29 +0200239 return SF_ERR_RESOURCE;
Willy Tarreau47f48c42014-05-09 22:57:47 +0200240 }
241
242 if (fd >= global.maxsock) {
243 /* do not log anything there, it's a normal condition when this option
244 * is used to serialize connections to a server !
245 */
Christopher Faulet767a84b2017-11-24 16:50:31 +0100246 ha_alert("socket(): not enough free sockets. Raise -n argument. Giving up.\n");
Willy Tarreau47f48c42014-05-09 22:57:47 +0200247 close(fd);
248 conn->err_code = CO_ER_CONF_FDLIM;
249 conn->flags |= CO_FL_ERROR;
Willy Tarreaue7dff022015-04-03 01:14:29 +0200250 return SF_ERR_PRXCOND; /* it is a configuration limit */
Willy Tarreau47f48c42014-05-09 22:57:47 +0200251 }
252
253 if (fcntl(fd, F_SETFL, O_NONBLOCK) == -1) {
254 qfprintf(stderr,"Cannot set client socket to non blocking mode.\n");
255 close(fd);
256 conn->err_code = CO_ER_SOCK_ERR;
257 conn->flags |= CO_FL_ERROR;
Willy Tarreaue7dff022015-04-03 01:14:29 +0200258 return SF_ERR_INTERNAL;
Willy Tarreau47f48c42014-05-09 22:57:47 +0200259 }
260
William Lallemandc03eb012018-11-27 12:02:37 +0100261 if (master == 1 && (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1)) {
262 ha_alert("Cannot set CLOEXEC on client socket.\n");
263 close(fd);
264 conn->err_code = CO_ER_SOCK_ERR;
265 conn->flags |= CO_FL_ERROR;
266 return SF_ERR_INTERNAL;
267 }
268
Willy Tarreau47f48c42014-05-09 22:57:47 +0200269 /* if a send_proxy is there, there are data */
Olivier Houchardfdcb0072019-05-06 18:32:29 +0200270 if (conn->send_proxy_ofs)
271 flags |= CONNECT_HAS_DATA;
Willy Tarreau47f48c42014-05-09 22:57:47 +0200272
273 if (global.tune.server_sndbuf)
274 setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &global.tune.server_sndbuf, sizeof(global.tune.server_sndbuf));
275
276 if (global.tune.server_rcvbuf)
277 setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &global.tune.server_rcvbuf, sizeof(global.tune.server_rcvbuf));
278
Willy Tarreauca9f5a92019-07-17 16:40:37 +0200279 if (connect(fd, (struct sockaddr *)conn->dst, get_addr_len(conn->dst)) == -1) {
Willy Tarreau94841792017-01-25 14:27:38 +0100280 if (errno == EINPROGRESS || errno == EALREADY) {
Willy Tarreau7bb21532014-05-10 09:48:28 +0200281 conn->flags |= CO_FL_WAIT_L4_CONN;
282 }
Willy Tarreau94841792017-01-25 14:27:38 +0100283 else if (errno == EISCONN) {
284 conn->flags &= ~CO_FL_WAIT_L4_CONN;
285 }
Willy Tarreau7bb21532014-05-10 09:48:28 +0200286 else if (errno == EAGAIN || errno == EADDRINUSE || errno == EADDRNOTAVAIL) {
Willy Tarreau47f48c42014-05-09 22:57:47 +0200287 char *msg;
288 if (errno == EAGAIN || errno == EADDRNOTAVAIL) {
Lukas Tribus9f256d42016-01-26 20:33:14 +0100289 msg = "can't connect to destination unix socket, check backlog size on the server";
Willy Tarreau47f48c42014-05-09 22:57:47 +0200290 conn->err_code = CO_ER_FREE_PORTS;
291 }
292 else {
293 msg = "local address already in use";
294 conn->err_code = CO_ER_ADDR_INUSE;
295 }
296
297 qfprintf(stderr,"Connect() failed for backend %s: %s.\n", be->id, msg);
298 close(fd);
299 send_log(be, LOG_ERR, "Connect() failed for backend %s: %s.\n", be->id, msg);
300 conn->flags |= CO_FL_ERROR;
Willy Tarreaue7dff022015-04-03 01:14:29 +0200301 return SF_ERR_RESOURCE;
Willy Tarreau47f48c42014-05-09 22:57:47 +0200302 }
303 else if (errno == ETIMEDOUT) {
304 close(fd);
305 conn->err_code = CO_ER_SOCK_ERR;
306 conn->flags |= CO_FL_ERROR;
Willy Tarreaue7dff022015-04-03 01:14:29 +0200307 return SF_ERR_SRVTO;
Willy Tarreau47f48c42014-05-09 22:57:47 +0200308 }
309 else { // (errno == ECONNREFUSED || errno == ENETUNREACH || errno == EACCES || errno == EPERM)
310 close(fd);
311 conn->err_code = CO_ER_SOCK_ERR;
312 conn->flags |= CO_FL_ERROR;
Willy Tarreaue7dff022015-04-03 01:14:29 +0200313 return SF_ERR_SRVCL;
Willy Tarreau47f48c42014-05-09 22:57:47 +0200314 }
315 }
Willy Tarreau7bb21532014-05-10 09:48:28 +0200316 else {
317 /* connect() already succeeded, which is quite usual for unix
Willy Tarreau94841792017-01-25 14:27:38 +0100318 * sockets. Let's avoid a second connect() probe to complete it.
Willy Tarreau7bb21532014-05-10 09:48:28 +0200319 */
320 conn->flags &= ~CO_FL_WAIT_L4_CONN;
Willy Tarreau7bb21532014-05-10 09:48:28 +0200321 }
Willy Tarreau47f48c42014-05-09 22:57:47 +0200322
323 conn->flags |= CO_FL_ADDR_TO_SET;
324
325 /* Prepare to send a few handshakes related to the on-wire protocol. */
326 if (conn->send_proxy_ofs)
327 conn->flags |= CO_FL_SEND_PROXY;
328
329 conn_ctrl_init(conn); /* registers the FD */
Willy Tarreau7bb21532014-05-10 09:48:28 +0200330 fdtab[fd].linger_risk = 0; /* no need to disable lingering */
Willy Tarreau47f48c42014-05-09 22:57:47 +0200331
Willy Tarreau4c69cff2020-03-04 16:38:00 +0100332 if (conn->flags & CO_FL_WAIT_L4_CONN) {
333 fd_want_send(fd);
334 fd_cant_send(fd);
Willy Tarreau8dbd1a22020-07-31 08:59:09 +0200335 fd_cant_recv(fd);
Willy Tarreau4c69cff2020-03-04 16:38:00 +0100336 }
Willy Tarreauccf3f6d2019-09-05 17:05:05 +0200337
Willy Tarreau47f48c42014-05-09 22:57:47 +0200338 if (conn_xprt_init(conn) < 0) {
Willy Tarreau8c829012017-10-05 18:02:11 +0200339 conn_full_close(conn);
Willy Tarreau47f48c42014-05-09 22:57:47 +0200340 conn->flags |= CO_FL_ERROR;
Willy Tarreaue7dff022015-04-03 01:14:29 +0200341 return SF_ERR_RESOURCE;
Willy Tarreau47f48c42014-05-09 22:57:47 +0200342 }
343
Willy Tarreaue7dff022015-04-03 01:14:29 +0200344 return SF_ERR_NONE; /* connection is OK */
Willy Tarreau47f48c42014-05-09 22:57:47 +0200345}
346
Willy Tarreau92fb9832007-10-16 17:34:28 +0200347/*
348 * Local variables:
349 * c-indent-level: 8
350 * c-basic-offset: 8
351 * End:
352 */