blob: 596be43d6c008a009d3dc7a1a0f6008001823234 [file] [log] [blame]
Willy Tarreau18b7df72020-08-28 12:07:22 +02001/*
2 * Generic code for native (BSD-compatible) sockets
3 *
4 * Copyright 2000-2020 Willy Tarreau <w@1wt.eu>
5 *
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
Willy Tarreauf1dc9f22020-10-15 09:21:31 +020013#define _GNU_SOURCE
Willy Tarreau18b7df72020-08-28 12:07:22 +020014#include <ctype.h>
15#include <errno.h>
16#include <fcntl.h>
17#include <stdio.h>
18#include <stdlib.h>
19#include <string.h>
20#include <time.h>
21
22#include <sys/param.h>
23#include <sys/socket.h>
24#include <sys/types.h>
25
Willy Tarreau42961742020-08-28 18:42:45 +020026#include <net/if.h>
27
Willy Tarreau18b7df72020-08-28 12:07:22 +020028#include <haproxy/api.h>
29#include <haproxy/connection.h>
Willy Tarreaua74cb382020-10-15 21:29:49 +020030#include <haproxy/listener.h>
Willy Tarreauf1dc9f22020-10-15 09:21:31 +020031#include <haproxy/log.h>
Willy Tarreau18b7df72020-08-28 12:07:22 +020032#include <haproxy/namespace.h>
33#include <haproxy/sock.h>
Willy Tarreau2d34a712020-08-28 16:49:41 +020034#include <haproxy/sock_inet.h>
Willy Tarreau18b7df72020-08-28 12:07:22 +020035#include <haproxy/tools.h>
36
Willy Tarreau063d47d2020-08-28 16:29:53 +020037/* the list of remaining sockets transferred from an older process */
38struct xfer_sock_list *xfer_sock_list = NULL;
Willy Tarreau18b7df72020-08-28 12:07:22 +020039
Willy Tarreauf1dc9f22020-10-15 09:21:31 +020040
41/* Accept an incoming connection from listener <l>, and return it, as well as
42 * a CO_AC_* status code into <status> if not null. Null is returned on error.
43 * <l> must be a valid listener with a valid frontend.
44 */
45struct connection *sock_accept_conn(struct listener *l, int *status)
46{
47#ifdef USE_ACCEPT4
48 static int accept4_broken;
49#endif
50 struct proxy *p = l->bind_conf->frontend;
Willy Tarreau344b8fc2020-10-15 09:43:31 +020051 struct connection *conn = NULL;
52 struct sockaddr_storage *addr = NULL;
Willy Tarreauf1dc9f22020-10-15 09:21:31 +020053 socklen_t laddr;
54 int ret;
55 int cfd;
56
Willy Tarreau344b8fc2020-10-15 09:43:31 +020057 if (!sockaddr_alloc(&addr, NULL, 0))
Willy Tarreauf1dc9f22020-10-15 09:21:31 +020058 goto fail_addr;
59
60 /* accept() will mark all accepted FDs O_NONBLOCK and the ones accepted
61 * in the master process as FD_CLOEXEC. It's not done for workers
62 * because 1) workers are not supposed to execute anything so there's
63 * no reason for uselessly slowing down everything, and 2) that would
64 * prevent us from implementing fd passing in the future.
65 */
66#ifdef USE_ACCEPT4
67 laddr = sizeof(*conn->src);
68
69 /* only call accept4() if it's known to be safe, otherwise fallback to
70 * the legacy accept() + fcntl().
71 */
72 if (unlikely(accept4_broken) ||
Willy Tarreau344b8fc2020-10-15 09:43:31 +020073 (((cfd = accept4(l->rx.fd, (struct sockaddr*)addr, &laddr,
Willy Tarreauf1dc9f22020-10-15 09:21:31 +020074 SOCK_NONBLOCK | (master ? SOCK_CLOEXEC : 0))) == -1) &&
75 (errno == ENOSYS || errno == EINVAL || errno == EBADF) &&
76 (accept4_broken = 1)))
77#endif
78 {
79 laddr = sizeof(*conn->src);
Willy Tarreau344b8fc2020-10-15 09:43:31 +020080 if ((cfd = accept(l->rx.fd, (struct sockaddr*)addr, &laddr)) != -1) {
Willy Tarreauf1dc9f22020-10-15 09:21:31 +020081 fcntl(cfd, F_SETFL, O_NONBLOCK);
82 if (master)
83 fcntl(cfd, F_SETFD, FD_CLOEXEC);
84 }
85 }
86
87 if (likely(cfd != -1)) {
88 /* Perfect, the connection was accepted */
Willy Tarreau344b8fc2020-10-15 09:43:31 +020089 conn = conn_new(&l->obj_type);
90 if (!conn)
91 goto fail_conn;
92
93 conn->src = addr;
Willy Tarreauf1dc9f22020-10-15 09:21:31 +020094 conn->handle.fd = cfd;
95 conn->flags |= CO_FL_ADDR_FROM_SET;
96 ret = CO_AC_DONE;
97 goto done;
98 }
99
100 /* error conditions below */
Willy Tarreau344b8fc2020-10-15 09:43:31 +0200101 sockaddr_free(&addr);
Willy Tarreauf1dc9f22020-10-15 09:21:31 +0200102
103 switch (errno) {
104 case EAGAIN:
105 ret = CO_AC_DONE; /* nothing more to accept */
106 if (fdtab[l->rx.fd].ev & (FD_POLL_HUP|FD_POLL_ERR)) {
107 /* the listening socket might have been disabled in a shared
108 * process and we're a collateral victim. We'll just pause for
109 * a while in case it comes back. In the mean time, we need to
110 * clear this sticky flag.
111 */
112 _HA_ATOMIC_AND(&fdtab[l->rx.fd].ev, ~(FD_POLL_HUP|FD_POLL_ERR));
113 ret = CO_AC_PAUSE;
114 }
115 fd_cant_recv(l->rx.fd);
116 break;
117
118 case EINVAL:
119 /* might be trying to accept on a shut fd (eg: soft stop) */
120 ret = CO_AC_PAUSE;
121 break;
122
123 case EINTR:
124 case ECONNABORTED:
125 ret = CO_AC_RETRY;
126 break;
127
128 case ENFILE:
129 if (p)
130 send_log(p, LOG_EMERG,
131 "Proxy %s reached system FD limit (maxsock=%d). Please check system tunables.\n",
132 p->id, global.maxsock);
133 ret = CO_AC_PAUSE;
134 break;
135
136 case EMFILE:
137 if (p)
138 send_log(p, LOG_EMERG,
139 "Proxy %s reached process FD limit (maxsock=%d). Please check 'ulimit-n' and restart.\n",
140 p->id, global.maxsock);
141 ret = CO_AC_PAUSE;
142 break;
143
144 case ENOBUFS:
145 case ENOMEM:
146 if (p)
147 send_log(p, LOG_EMERG,
148 "Proxy %s reached system memory limit (maxsock=%d). Please check system tunables.\n",
149 p->id, global.maxsock);
150 ret = CO_AC_PAUSE;
151 break;
152
153 default:
154 /* unexpected result, let's give up and let other tasks run */
155 ret = CO_AC_YIELD;
156 }
157 done:
158 if (status)
159 *status = ret;
160 return conn;
161
Willy Tarreauf1dc9f22020-10-15 09:21:31 +0200162 fail_conn:
Willy Tarreau344b8fc2020-10-15 09:43:31 +0200163 sockaddr_free(&addr);
Remi Tricot-Le Breton25dd0ad2021-01-14 15:26:24 +0100164 /* The accept call already succeeded by the time we try to allocate the connection,
165 * we need to close it in case of failure. */
166 close(cfd);
Willy Tarreau344b8fc2020-10-15 09:43:31 +0200167 fail_addr:
Willy Tarreauf1dc9f22020-10-15 09:21:31 +0200168 ret = CO_AC_PAUSE;
169 goto done;
170}
171
Willy Tarreau18b7df72020-08-28 12:07:22 +0200172/* Create a socket to connect to the server in conn->dst (which MUST be valid),
173 * using the configured namespace if needed, or the one passed by the proxy
174 * protocol if required to do so. It ultimately calls socket() or socketat()
175 * and returns the FD or error code.
176 */
177int sock_create_server_socket(struct connection *conn)
178{
179 const struct netns_entry *ns = NULL;
180
181#ifdef USE_NS
182 if (objt_server(conn->target)) {
183 if (__objt_server(conn->target)->flags & SRV_F_USE_NS_FROM_PP)
184 ns = conn->proxy_netns;
185 else
186 ns = __objt_server(conn->target)->netns;
187 }
188#endif
189 return my_socketat(ns, conn->dst->ss_family, SOCK_STREAM, 0);
190}
191
Willy Tarreaua4380b22020-11-04 13:59:04 +0100192/* Enables receiving on receiver <rx> once already bound. */
Willy Tarreaue70c7972020-09-25 19:00:01 +0200193void sock_enable(struct receiver *rx)
194{
Willy Tarreaua4380b22020-11-04 13:59:04 +0100195 if (rx->flags & RX_F_BOUND)
196 fd_want_recv_safe(rx->fd);
Willy Tarreaue70c7972020-09-25 19:00:01 +0200197}
198
Willy Tarreaua4380b22020-11-04 13:59:04 +0100199/* Disables receiving on receiver <rx> once already bound. */
Willy Tarreaue70c7972020-09-25 19:00:01 +0200200void sock_disable(struct receiver *rx)
201{
Willy Tarreaua4380b22020-11-04 13:59:04 +0100202 if (rx->flags & RX_F_BOUND)
Willy Tarreaue70c7972020-09-25 19:00:01 +0200203 fd_stop_recv(rx->fd);
204}
205
Willy Tarreauf58b8db2020-10-09 16:32:08 +0200206/* stops, unbinds and possibly closes the FD associated with receiver rx */
207void sock_unbind(struct receiver *rx)
208{
209 /* There are a number of situations where we prefer to keep the FD and
210 * not to close it (unless we're stopping, of course):
211 * - worker process unbinding from a worker's FD with socket transfer enabled => keep
212 * - master process unbinding from a master's inherited FD => keep
213 * - master process unbinding from a master's FD => close
Willy Tarreau22ccd5e2020-11-03 18:38:05 +0100214 * - master process unbinding from a worker's inherited FD => keep
Willy Tarreauf58b8db2020-10-09 16:32:08 +0200215 * - master process unbinding from a worker's FD => close
216 * - worker process unbinding from a master's FD => close
217 * - worker process unbinding from a worker's FD => close
218 */
219 if (rx->flags & RX_F_BOUND)
220 rx->proto->rx_disable(rx);
221
222 if (!stopping && !master &&
223 !(rx->flags & RX_F_MWORKER) &&
224 (global.tune.options & GTUNE_SOCKET_TRANSFER))
225 return;
226
227 if (!stopping && master &&
Willy Tarreauf58b8db2020-10-09 16:32:08 +0200228 rx->flags & RX_F_INHERITED)
229 return;
230
231 rx->flags &= ~RX_F_BOUND;
232 if (rx->fd != -1)
233 fd_delete(rx->fd);
234 rx->fd = -1;
235}
236
Willy Tarreau18b7df72020-08-28 12:07:22 +0200237/*
238 * Retrieves the source address for the socket <fd>, with <dir> indicating
239 * if we're a listener (=0) or an initiator (!=0). It returns 0 in case of
240 * success, -1 in case of error. The socket's source address is stored in
241 * <sa> for <salen> bytes.
242 */
243int sock_get_src(int fd, struct sockaddr *sa, socklen_t salen, int dir)
244{
245 if (dir)
246 return getsockname(fd, sa, &salen);
247 else
248 return getpeername(fd, sa, &salen);
249}
250
251/*
252 * Retrieves the original destination address for the socket <fd>, with <dir>
253 * indicating if we're a listener (=0) or an initiator (!=0). It returns 0 in
254 * case of success, -1 in case of error. The socket's source address is stored
255 * in <sa> for <salen> bytes.
256 */
257int sock_get_dst(int fd, struct sockaddr *sa, socklen_t salen, int dir)
258{
259 if (dir)
260 return getpeername(fd, sa, &salen);
261 else
262 return getsockname(fd, sa, &salen);
263}
264
Willy Tarreau42961742020-08-28 18:42:45 +0200265/* Try to retrieve exported sockets from worker at CLI <unixsocket>. These
266 * ones will be placed into the xfer_sock_list for later use by function
267 * sock_find_compatible_fd(). Returns 0 on success, -1 on failure.
268 */
269int sock_get_old_sockets(const char *unixsocket)
270{
271 char *cmsgbuf = NULL, *tmpbuf = NULL;
272 int *tmpfd = NULL;
273 struct sockaddr_un addr;
274 struct cmsghdr *cmsg;
275 struct msghdr msghdr;
276 struct iovec iov;
277 struct xfer_sock_list *xfer_sock = NULL;
278 struct timeval tv = { .tv_sec = 1, .tv_usec = 0 };
279 int sock = -1;
280 int ret = -1;
281 int ret2 = -1;
282 int fd_nb;
283 int got_fd = 0;
284 int cur_fd = 0;
285 size_t maxoff = 0, curoff = 0;
286
287 memset(&msghdr, 0, sizeof(msghdr));
288 cmsgbuf = malloc(CMSG_SPACE(sizeof(int)) * MAX_SEND_FD);
289 if (!cmsgbuf) {
290 ha_warning("Failed to allocate memory to send sockets\n");
291 goto out;
292 }
293
294 sock = socket(PF_UNIX, SOCK_STREAM, 0);
295 if (sock < 0) {
296 ha_warning("Failed to connect to the old process socket '%s'\n", unixsocket);
297 goto out;
298 }
299
300 strncpy(addr.sun_path, unixsocket, sizeof(addr.sun_path) - 1);
301 addr.sun_path[sizeof(addr.sun_path) - 1] = 0;
302 addr.sun_family = PF_UNIX;
303
304 ret = connect(sock, (struct sockaddr *)&addr, sizeof(addr));
305 if (ret < 0) {
306 ha_warning("Failed to connect to the old process socket '%s'\n", unixsocket);
307 goto out;
308 }
309
310 setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, (void *)&tv, sizeof(tv));
311 iov.iov_base = &fd_nb;
312 iov.iov_len = sizeof(fd_nb);
313 msghdr.msg_iov = &iov;
314 msghdr.msg_iovlen = 1;
315
316 if (send(sock, "_getsocks\n", strlen("_getsocks\n"), 0) != strlen("_getsocks\n")) {
317 ha_warning("Failed to get the number of sockets to be transferred !\n");
318 goto out;
319 }
320
321 /* First, get the number of file descriptors to be received */
322 if (recvmsg(sock, &msghdr, MSG_WAITALL) != sizeof(fd_nb)) {
323 ha_warning("Failed to get the number of sockets to be transferred !\n");
324 goto out;
325 }
326
327 if (fd_nb == 0) {
328 ret2 = 0;
329 goto out;
330 }
331
332 tmpbuf = malloc(fd_nb * (1 + MAXPATHLEN + 1 + IFNAMSIZ + sizeof(int)));
333 if (tmpbuf == NULL) {
334 ha_warning("Failed to allocate memory while receiving sockets\n");
335 goto out;
336 }
337
338 tmpfd = malloc(fd_nb * sizeof(int));
339 if (tmpfd == NULL) {
340 ha_warning("Failed to allocate memory while receiving sockets\n");
341 goto out;
342 }
343
344 msghdr.msg_control = cmsgbuf;
345 msghdr.msg_controllen = CMSG_SPACE(sizeof(int)) * MAX_SEND_FD;
346 iov.iov_len = MAX_SEND_FD * (1 + MAXPATHLEN + 1 + IFNAMSIZ + sizeof(int));
347
348 do {
349 int ret3;
350
351 iov.iov_base = tmpbuf + curoff;
352
353 ret = recvmsg(sock, &msghdr, 0);
354
355 if (ret == -1 && errno == EINTR)
356 continue;
357
358 if (ret <= 0)
359 break;
360
361 /* Send an ack to let the sender know we got the sockets
362 * and it can send some more
363 */
364 do {
365 ret3 = send(sock, &got_fd, sizeof(got_fd), 0);
366 } while (ret3 == -1 && errno == EINTR);
367
368 for (cmsg = CMSG_FIRSTHDR(&msghdr); cmsg != NULL; cmsg = CMSG_NXTHDR(&msghdr, cmsg)) {
369 if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) {
370 size_t totlen = cmsg->cmsg_len - CMSG_LEN(0);
371
372 if (totlen / sizeof(int) + got_fd > fd_nb) {
373 ha_warning("Got to many sockets !\n");
374 goto out;
375 }
376
377 /*
378 * Be paranoid and use memcpy() to avoid any
379 * potential alignment issue.
380 */
381 memcpy(&tmpfd[got_fd], CMSG_DATA(cmsg), totlen);
382 got_fd += totlen / sizeof(int);
383 }
384 }
385 curoff += ret;
386 } while (got_fd < fd_nb);
387
388 if (got_fd != fd_nb) {
389 ha_warning("We didn't get the expected number of sockets (expecting %d got %d)\n",
390 fd_nb, got_fd);
391 goto out;
392 }
393
394 maxoff = curoff;
395 curoff = 0;
396
397 for (cur_fd = 0; cur_fd < got_fd; cur_fd++) {
398 int fd = tmpfd[cur_fd];
399 socklen_t socklen;
400 int val;
401 int len;
402
403 xfer_sock = calloc(1, sizeof(*xfer_sock));
404 if (!xfer_sock) {
405 ha_warning("Failed to allocate memory in get_old_sockets() !\n");
406 break;
407 }
408 xfer_sock->fd = -1;
409
410 socklen = sizeof(xfer_sock->addr);
411 if (getsockname(fd, (struct sockaddr *)&xfer_sock->addr, &socklen) != 0) {
412 ha_warning("Failed to get socket address\n");
413 free(xfer_sock);
414 xfer_sock = NULL;
415 continue;
416 }
417
418 if (curoff >= maxoff) {
419 ha_warning("Inconsistency while transferring sockets\n");
420 goto out;
421 }
422
423 len = tmpbuf[curoff++];
424 if (len > 0) {
425 /* We have a namespace */
426 if (curoff + len > maxoff) {
427 ha_warning("Inconsistency while transferring sockets\n");
428 goto out;
429 }
430 xfer_sock->namespace = malloc(len + 1);
431 if (!xfer_sock->namespace) {
432 ha_warning("Failed to allocate memory while transferring sockets\n");
433 goto out;
434 }
435 memcpy(xfer_sock->namespace, &tmpbuf[curoff], len);
436 xfer_sock->namespace[len] = 0;
437 xfer_sock->ns_namelen = len;
438 curoff += len;
439 }
440
441 if (curoff >= maxoff) {
442 ha_warning("Inconsistency while transferring sockets\n");
443 goto out;
444 }
445
446 len = tmpbuf[curoff++];
447 if (len > 0) {
448 /* We have an interface */
449 if (curoff + len > maxoff) {
450 ha_warning("Inconsistency while transferring sockets\n");
451 goto out;
452 }
453 xfer_sock->iface = malloc(len + 1);
454 if (!xfer_sock->iface) {
455 ha_warning("Failed to allocate memory while transferring sockets\n");
456 goto out;
457 }
458 memcpy(xfer_sock->iface, &tmpbuf[curoff], len);
459 xfer_sock->iface[len] = 0;
460 xfer_sock->if_namelen = len;
461 curoff += len;
462 }
463
464 if (curoff + sizeof(int) > maxoff) {
465 ha_warning("Inconsistency while transferring sockets\n");
466 goto out;
467 }
468
469 /* we used to have 32 bits of listener options here but we don't
470 * use them anymore.
471 */
472 curoff += sizeof(int);
473
474 /* determine the foreign status directly from the socket itself */
475 if (sock_inet_is_foreign(fd, xfer_sock->addr.ss_family))
Willy Tarreaua2c17872020-08-28 19:09:19 +0200476 xfer_sock->options |= SOCK_XFER_OPT_FOREIGN;
Willy Tarreau42961742020-08-28 18:42:45 +0200477
Willy Tarreau9dbb6c42020-08-28 19:20:23 +0200478 socklen = sizeof(val);
479 if (getsockopt(fd, SOL_SOCKET, SO_TYPE, &val, &socklen) == 0 && val == SOCK_DGRAM)
480 xfer_sock->options |= SOCK_XFER_OPT_DGRAM;
481
Willy Tarreau42961742020-08-28 18:42:45 +0200482#if defined(IPV6_V6ONLY)
483 /* keep only the v6only flag depending on what's currently
484 * active on the socket, and always drop the v4v6 one.
485 */
486 socklen = sizeof(val);
487 if (xfer_sock->addr.ss_family == AF_INET6 &&
488 getsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &val, &socklen) == 0 && val > 0)
Willy Tarreaua2c17872020-08-28 19:09:19 +0200489 xfer_sock->options |= SOCK_XFER_OPT_V6ONLY;
Willy Tarreau42961742020-08-28 18:42:45 +0200490#endif
491
492 xfer_sock->fd = fd;
493 if (xfer_sock_list)
494 xfer_sock_list->prev = xfer_sock;
495 xfer_sock->next = xfer_sock_list;
496 xfer_sock->prev = NULL;
497 xfer_sock_list = xfer_sock;
498 xfer_sock = NULL;
499 }
500
501 ret2 = 0;
502out:
503 /* If we failed midway make sure to close the remaining
504 * file descriptors
505 */
506 if (tmpfd != NULL && cur_fd < got_fd) {
507 for (; cur_fd < got_fd; cur_fd++) {
508 close(tmpfd[cur_fd]);
509 }
510 }
511
512 free(tmpbuf);
513 free(tmpfd);
514 free(cmsgbuf);
515
516 if (sock != -1)
517 close(sock);
518
519 if (xfer_sock) {
520 free(xfer_sock->namespace);
521 free(xfer_sock->iface);
522 if (xfer_sock->fd != -1)
523 close(xfer_sock->fd);
524 free(xfer_sock);
525 }
526 return (ret2);
527}
528
Willy Tarreauc049c0d2020-09-01 15:20:52 +0200529/* When binding the receivers, check if a socket has been sent to us by the
Willy Tarreau2d34a712020-08-28 16:49:41 +0200530 * previous process that we could reuse, instead of creating a new one. Note
531 * that some address family-specific options are checked on the listener and
532 * on the socket. Typically for AF_INET and AF_INET6, we check for transparent
533 * mode, and for AF_INET6 we also check for "v4v6" or "v6only". The reused
534 * socket is automatically removed from the list so that it's not proposed
535 * anymore.
536 */
Willy Tarreauc049c0d2020-09-01 15:20:52 +0200537int sock_find_compatible_fd(const struct receiver *rx)
Willy Tarreau2d34a712020-08-28 16:49:41 +0200538{
539 struct xfer_sock_list *xfer_sock = xfer_sock_list;
Willy Tarreaua2c17872020-08-28 19:09:19 +0200540 int options = 0;
Willy Tarreau2d34a712020-08-28 16:49:41 +0200541 int if_namelen = 0;
542 int ns_namelen = 0;
543 int ret = -1;
544
Willy Tarreauf1f66092020-09-04 08:15:31 +0200545 if (!rx->proto->fam->addrcmp)
Willy Tarreau2d34a712020-08-28 16:49:41 +0200546 return -1;
547
Willy Tarreauc049c0d2020-09-01 15:20:52 +0200548 if (rx->proto->sock_type == SOCK_DGRAM)
Willy Tarreau9dbb6c42020-08-28 19:20:23 +0200549 options |= SOCK_XFER_OPT_DGRAM;
550
Willy Tarreauc049c0d2020-09-01 15:20:52 +0200551 if (rx->settings->options & RX_O_FOREIGN)
Willy Tarreaua2c17872020-08-28 19:09:19 +0200552 options |= SOCK_XFER_OPT_FOREIGN;
553
Willy Tarreauc049c0d2020-09-01 15:20:52 +0200554 if (rx->addr.ss_family == AF_INET6) {
Willy Tarreau2d34a712020-08-28 16:49:41 +0200555 /* Prepare to match the v6only option against what we really want. Note
556 * that sadly the two options are not exclusive to each other and that
557 * v6only is stronger than v4v6.
558 */
Willy Tarreauc049c0d2020-09-01 15:20:52 +0200559 if ((rx->settings->options & RX_O_V6ONLY) ||
560 (sock_inet6_v6only_default && !(rx->settings->options & RX_O_V4V6)))
Willy Tarreaua2c17872020-08-28 19:09:19 +0200561 options |= SOCK_XFER_OPT_V6ONLY;
Willy Tarreau2d34a712020-08-28 16:49:41 +0200562 }
Willy Tarreau2d34a712020-08-28 16:49:41 +0200563
Willy Tarreauc049c0d2020-09-01 15:20:52 +0200564 if (rx->settings->interface)
565 if_namelen = strlen(rx->settings->interface);
Willy Tarreau2d34a712020-08-28 16:49:41 +0200566#ifdef USE_NS
Willy Tarreauc049c0d2020-09-01 15:20:52 +0200567 if (rx->settings->netns)
568 ns_namelen = rx->settings->netns->name_len;
Willy Tarreau2d34a712020-08-28 16:49:41 +0200569#endif
570
571 while (xfer_sock) {
Willy Tarreaua2c17872020-08-28 19:09:19 +0200572 if ((options == xfer_sock->options) &&
Willy Tarreau2d34a712020-08-28 16:49:41 +0200573 (if_namelen == xfer_sock->if_namelen) &&
574 (ns_namelen == xfer_sock->ns_namelen) &&
Willy Tarreauc049c0d2020-09-01 15:20:52 +0200575 (!if_namelen || strcmp(rx->settings->interface, xfer_sock->iface) == 0) &&
Willy Tarreau2d34a712020-08-28 16:49:41 +0200576#ifdef USE_NS
Willy Tarreauc049c0d2020-09-01 15:20:52 +0200577 (!ns_namelen || strcmp(rx->settings->netns->node.key, xfer_sock->namespace) == 0) &&
Willy Tarreau2d34a712020-08-28 16:49:41 +0200578#endif
Willy Tarreauf1f66092020-09-04 08:15:31 +0200579 rx->proto->fam->addrcmp(&xfer_sock->addr, &rx->addr) == 0)
Willy Tarreau2d34a712020-08-28 16:49:41 +0200580 break;
581 xfer_sock = xfer_sock->next;
582 }
583
584 if (xfer_sock != NULL) {
585 ret = xfer_sock->fd;
586 if (xfer_sock == xfer_sock_list)
587 xfer_sock_list = xfer_sock->next;
588 if (xfer_sock->prev)
589 xfer_sock->prev->next = xfer_sock->next;
590 if (xfer_sock->next)
591 xfer_sock->next->prev = xfer_sock->prev;
592 free(xfer_sock->iface);
593 free(xfer_sock->namespace);
594 free(xfer_sock);
595 }
596 return ret;
597}
598
Willy Tarreau5ced3e82020-10-13 17:06:12 +0200599/* Tests if the receiver supports accepting connections. Returns positive on
600 * success, 0 if not possible, negative if the socket is non-recoverable. The
601 * rationale behind this is that inherited FDs may be broken and that shared
602 * FDs might have been paused by another process.
603 */
Willy Tarreau7d053e42020-10-15 09:19:43 +0200604int sock_accepting_conn(const struct receiver *rx)
Willy Tarreau5ced3e82020-10-13 17:06:12 +0200605{
606 int opt_val = 0;
607 socklen_t opt_len = sizeof(opt_val);
608
609 if (getsockopt(rx->fd, SOL_SOCKET, SO_ACCEPTCONN, &opt_val, &opt_len) == -1)
610 return -1;
611
612 return opt_val;
613}
614
Willy Tarreaua74cb382020-10-15 21:29:49 +0200615/* This is the FD handler IO callback for stream sockets configured for
616 * accepting incoming connections. It's a pass-through to listener_accept()
617 * which will iterate over the listener protocol's accept_conn() function.
618 * The FD's owner must be a listener.
619 */
620void sock_accept_iocb(int fd)
621{
622 struct listener *l = fdtab[fd].owner;
623
624 if (!l)
625 return;
626
Willy Tarreaub4daeeb2020-11-04 14:58:36 +0100627 BUG_ON(!!master != !!(l->rx.flags & RX_F_MWORKER));
Willy Tarreaua74cb382020-10-15 21:29:49 +0200628 listener_accept(l);
629}
630
Willy Tarreaude471c42020-12-08 15:50:56 +0100631/* This completes the initialization of connection <conn> by inserting its FD
632 * into the fdtab, associating it with the regular connection handler. It will
633 * be bound to the current thread only. This call cannot fail.
634 */
635void sock_conn_ctrl_init(struct connection *conn)
636{
Willy Tarreau586f71b2020-12-11 15:54:36 +0100637 fd_insert(conn->handle.fd, conn, sock_conn_iocb, tid_bit);
Willy Tarreaude471c42020-12-08 15:50:56 +0100638}
639
640/* This completes the release of connection <conn> by removing its FD from the
641 * fdtab and deleting it. The connection must not use the FD anymore past this
642 * point. The FD may be modified in the connection.
643 */
644void sock_conn_ctrl_close(struct connection *conn)
645{
646 fd_delete(conn->handle.fd);
647 conn->handle.fd = DEAD_FD_MAGIC;
648}
649
Willy Tarreau586f71b2020-12-11 15:54:36 +0100650/* This is the callback which is set when a connection establishment is pending
651 * and we have nothing to send. It may update the FD polling status to indicate
652 * !READY. It returns 0 if it fails in a fatal way or needs to poll to go
653 * further, otherwise it returns non-zero and removes the CO_FL_WAIT_L4_CONN
654 * flag from the connection's flags. In case of error, it sets CO_FL_ERROR and
655 * leaves the error code in errno.
656 */
657int sock_conn_check(struct connection *conn)
658{
659 struct sockaddr_storage *addr;
660 int fd = conn->handle.fd;
661
662 if (conn->flags & CO_FL_ERROR)
663 return 0;
664
665 if (!conn_ctrl_ready(conn))
666 return 0;
667
668 if (!(conn->flags & CO_FL_WAIT_L4_CONN))
669 return 1; /* strange we were called while ready */
670
671 if (!fd_send_ready(fd))
672 return 0;
673
674 /* Here we have 2 cases :
675 * - modern pollers, able to report ERR/HUP. If these ones return any
676 * of these flags then it's likely a failure, otherwise it possibly
677 * is a success (i.e. there may have been data received just before
678 * the error was reported).
679 * - select, which doesn't report these and with which it's always
680 * necessary either to try connect() again or to check for SO_ERROR.
681 * In order to simplify everything, we double-check using connect() as
682 * soon as we meet either of these delicate situations. Note that
683 * SO_ERROR would clear the error after reporting it!
684 */
685 if (cur_poller.flags & HAP_POLL_F_ERRHUP) {
686 /* modern poller, able to report ERR/HUP */
687 if ((fdtab[fd].ev & (FD_POLL_IN|FD_POLL_ERR|FD_POLL_HUP)) == FD_POLL_IN)
688 goto done;
689 if ((fdtab[fd].ev & (FD_POLL_OUT|FD_POLL_ERR|FD_POLL_HUP)) == FD_POLL_OUT)
690 goto done;
691 if (!(fdtab[fd].ev & (FD_POLL_ERR|FD_POLL_HUP)))
692 goto wait;
693 /* error present, fall through common error check path */
694 }
695
696 /* Use connect() to check the state of the socket. This has the double
697 * advantage of *not* clearing the error (so that health checks can
698 * still use getsockopt(SO_ERROR)) and giving us the following info :
699 * - error
700 * - connecting (EALREADY, EINPROGRESS)
701 * - connected (EISCONN, 0)
702 */
703 addr = conn->dst;
704 if ((conn->flags & CO_FL_SOCKS4) && obj_type(conn->target) == OBJ_TYPE_SERVER)
705 addr = &objt_server(conn->target)->socks4_addr;
706
707 if (connect(fd, (const struct sockaddr *)addr, get_addr_len(addr)) == -1) {
708 if (errno == EALREADY || errno == EINPROGRESS)
709 goto wait;
710
711 if (errno && errno != EISCONN)
712 goto out_error;
713 }
714
715 done:
716 /* The FD is ready now, we'll mark the connection as complete and
717 * forward the event to the transport layer which will notify the
718 * data layer.
719 */
720 conn->flags &= ~CO_FL_WAIT_L4_CONN;
721 fd_may_send(fd);
722 fd_cond_recv(fd);
723 errno = 0; // make health checks happy
724 return 1;
725
726 out_error:
727 /* Write error on the file descriptor. Report it to the connection
728 * and disable polling on this FD.
729 */
730 fdtab[fd].linger_risk = 0;
731 conn->flags |= CO_FL_ERROR | CO_FL_SOCK_RD_SH | CO_FL_SOCK_WR_SH;
732 fd_stop_both(fd);
733 return 0;
734
735 wait:
736 fd_cant_send(fd);
737 fd_want_send(fd);
738 return 0;
739}
740
741/* I/O callback for fd-based connections. It calls the read/write handlers
742 * provided by the connection's sock_ops, which must be valid.
743 */
744void sock_conn_iocb(int fd)
745{
746 struct connection *conn = fdtab[fd].owner;
747 unsigned int flags;
748 int need_wake = 0;
749
750 if (unlikely(!conn)) {
751 activity[tid].conn_dead++;
752 return;
753 }
754
755 flags = conn->flags & ~CO_FL_ERROR; /* ensure to call the wake handler upon error */
756
757 if (unlikely(conn->flags & CO_FL_WAIT_L4_CONN) &&
758 ((fd_send_ready(fd) && fd_send_active(fd)) ||
759 (fd_recv_ready(fd) && fd_recv_active(fd)))) {
760 /* Still waiting for a connection to establish and nothing was
761 * attempted yet to probe the connection. this will clear the
762 * CO_FL_WAIT_L4_CONN flag on success.
763 */
764 if (!sock_conn_check(conn))
765 goto leave;
766 need_wake = 1;
767 }
768
769 if (fd_send_ready(fd) && fd_send_active(fd)) {
770 /* force reporting of activity by clearing the previous flags :
771 * we'll have at least ERROR or CONNECTED at the end of an I/O,
772 * both of which will be detected below.
773 */
774 flags = 0;
775 if (conn->subs && conn->subs->events & SUB_RETRY_SEND) {
776 need_wake = 0; // wake will be called after this I/O
777 tasklet_wakeup(conn->subs->tasklet);
778 conn->subs->events &= ~SUB_RETRY_SEND;
779 if (!conn->subs->events)
780 conn->subs = NULL;
781 }
782 fd_stop_send(fd);
783 }
784
785 /* The data transfer starts here and stops on error and handshakes. Note
786 * that we must absolutely test conn->xprt at each step in case it suddenly
787 * changes due to a quick unexpected close().
788 */
789 if (fd_recv_ready(fd) && fd_recv_active(fd)) {
790 /* force reporting of activity by clearing the previous flags :
791 * we'll have at least ERROR or CONNECTED at the end of an I/O,
792 * both of which will be detected below.
793 */
794 flags = 0;
795 if (conn->subs && conn->subs->events & SUB_RETRY_RECV) {
796 need_wake = 0; // wake will be called after this I/O
797 tasklet_wakeup(conn->subs->tasklet);
798 conn->subs->events &= ~SUB_RETRY_RECV;
799 if (!conn->subs->events)
800 conn->subs = NULL;
801 }
802 fd_stop_recv(fd);
803 }
804
805 leave:
806 /* we may have to finish to install a mux or to wake it up based on
807 * what was just done above. It may kill the connection so we have to
808 * be prpared not to use it anymore.
809 */
810 if (conn_notify_mux(conn, flags, need_wake) < 0)
811 return;
812
813 /* commit polling changes in case of error.
814 * WT: it seems that the last case where this could still be relevant
815 * is if a mux wake function above report a connection error but does
816 * not stop polling. Shouldn't we enforce this into the mux instead of
817 * having to deal with this ?
818 */
819 if (unlikely(conn->flags & CO_FL_ERROR)) {
820 if (conn_ctrl_ready(conn))
821 fd_stop_both(fd);
822 }
823}
824
Willy Tarreau427c8462020-12-11 16:19:12 +0100825/* Drains possibly pending incoming data on the file descriptor attached to the
826 * connection. This is used to know whether we need to disable lingering on
827 * close. Returns non-zero if it is safe to close without disabling lingering,
828 * otherwise zero.
829 */
830int sock_drain(struct connection *conn)
831{
832 int turns = 2;
833 int fd = conn->handle.fd;
834 int len;
835
836 if (fdtab[fd].ev & (FD_POLL_ERR|FD_POLL_HUP))
837 goto shut;
838
839 if (!fd_recv_ready(fd))
840 return 0;
841
842 /* no drain function defined, use the generic one */
843
844 while (turns) {
845#ifdef MSG_TRUNC_CLEARS_INPUT
846 len = recv(fd, NULL, INT_MAX, MSG_DONTWAIT | MSG_NOSIGNAL | MSG_TRUNC);
847 if (len == -1 && errno == EFAULT)
848#endif
849 len = recv(fd, trash.area, trash.size, MSG_DONTWAIT | MSG_NOSIGNAL);
850
851 if (len == 0)
852 goto shut;
853
854 if (len < 0) {
855 if (errno == EAGAIN) {
856 /* connection not closed yet */
857 fd_cant_recv(fd);
858 break;
859 }
860 if (errno == EINTR) /* oops, try again */
861 continue;
862 /* other errors indicate a dead connection, fine. */
863 goto shut;
864 }
865 /* OK we read some data, let's try again once */
866 turns--;
867 }
868
869 /* some data are still present, give up */
870 return 0;
871
872 shut:
873 /* we're certain the connection was shut down */
874 fdtab[fd].linger_risk = 0;
875 return 1;
876}
877
Willy Tarreau472125b2020-12-11 17:02:50 +0100878/* Checks the connection's FD for readiness of events <event_type>, which may
879 * only be a combination of SUB_RETRY_RECV and SUB_RETRY_SEND. Those which are
880 * ready are returned. The ones that are not ready are enabled. The caller is
881 * expected to do what is needed to handle ready events and to deal with
882 * subsequent wakeups caused by the requested events' readiness.
883 */
884int sock_check_events(struct connection *conn, int event_type)
885{
886 int ret = 0;
887
888 if (event_type & SUB_RETRY_RECV) {
889 if (fd_recv_ready(conn->handle.fd))
890 ret |= SUB_RETRY_RECV;
891 else
892 fd_want_recv(conn->handle.fd);
893 }
894
895 if (event_type & SUB_RETRY_SEND) {
896 if (fd_send_ready(conn->handle.fd))
897 ret |= SUB_RETRY_SEND;
898 else
899 fd_want_send(conn->handle.fd);
900 }
901
902 return ret;
903}
904
905/* Ignore readiness events from connection's FD for events of types <event_type>
906 * which may only be a combination of SUB_RETRY_RECV and SUB_RETRY_SEND.
907 */
908void sock_ignore_events(struct connection *conn, int event_type)
909{
910 if (event_type & SUB_RETRY_RECV)
911 fd_stop_recv(conn->handle.fd);
912
913 if (event_type & SUB_RETRY_SEND)
914 fd_stop_send(conn->handle.fd);
915}
916
Willy Tarreau18b7df72020-08-28 12:07:22 +0200917/*
918 * Local variables:
919 * c-indent-level: 8
920 * c-basic-offset: 8
921 * End:
922 */