1827886628ae6236e991251e6b1d8ecd9a5ab34c
1 /*
2 * SysDB - src/frontend/sock.c
3 * Copyright (C) 2013 Sebastian 'tokkee' Harl <sh@tokkee.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
17 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
28 #if HAVE_CONFIG_H
29 # include "config.h"
30 #endif /* HAVE_CONFIG_H */
32 #include "sysdb.h"
33 #include "core/object.h"
34 #include "frontend/connection-private.h"
35 #include "frontend/sock.h"
37 #include "utils/channel.h"
38 #include "utils/error.h"
39 #include "utils/llist.h"
40 #include "utils/os.h"
41 #include "utils/strbuf.h"
43 #include <assert.h>
44 #include <errno.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
50 #include <unistd.h>
52 #include <sys/time.h>
53 #include <sys/types.h>
54 #include <sys/select.h>
55 #include <sys/socket.h>
56 #include <sys/param.h>
57 #include <sys/un.h>
59 #ifdef HAVE_UCRED_H
60 # include <ucred.h>
61 #endif
62 #ifdef HAVE_SYS_UCRED_H
63 # include <sys/ucred.h>
64 #endif
66 #include <pwd.h>
68 #include <netdb.h>
69 #include <libgen.h>
70 #include <pthread.h>
72 /*
73 * private data types
74 */
76 typedef struct {
77 char *address;
78 int type;
80 int sock_fd;
81 int (*setup)(sdb_conn_t *, void *);
82 } listener_t;
84 typedef struct {
85 int type;
86 const char *prefix;
88 int (*open)(listener_t *);
89 void (*close)(listener_t *);
90 } fe_listener_impl_t;
92 struct sdb_fe_socket {
93 listener_t *listeners;
94 size_t listeners_num;
96 sdb_llist_t *open_connections;
98 /* channel used for communication between main
99 * and connection handler threads */
100 sdb_channel_t *chan;
101 };
103 /*
104 * connection management functions
105 */
107 static int
108 setup_unixsock(sdb_conn_t *conn, void __attribute__((unused)) *user_data)
109 {
110 uid_t uid;
112 struct passwd pw_entry;
113 struct passwd *result = NULL;
114 char buf[1024];
116 #ifdef SO_PEERCRED
117 struct ucred cred;
118 socklen_t len = sizeof(cred);
120 if (getsockopt(conn->fd, SOL_SOCKET, SO_PEERCRED, &cred, &len)
121 || (len != sizeof(cred))) {
122 char errbuf[1024];
123 sdb_log(SDB_LOG_ERR, "frontend: Failed to determine peer for "
124 "connection conn#%i: %s", conn->fd,
125 sdb_strerror(errno, errbuf, sizeof(errbuf)));
126 return -1;
127 }
128 uid = cred.uid;
129 #else /* SO_PEERCRED */
130 sdb_log(SDB_LOG_ERR, "frontend: Failed to determine peer for "
131 "connection conn#%i: operation not supported", conn->fd);
132 return -1;
133 #endif
135 memset(&pw_entry, 0, sizeof(pw_entry));
136 if (getpwuid_r(uid, &pw_entry, buf, sizeof(buf), &result) || (! result)
137 || (! (conn->username = strdup(result->pw_name)))) {
138 char errbuf[1024];
139 sdb_log(SDB_LOG_ERR, "frontend: Failed to determine peer for "
140 "connection conn#%i: %s", conn->fd,
141 sdb_strerror(errno, errbuf, sizeof(errbuf)));
142 return -1;
143 }
144 return 0;
145 } /* setup_unixsock */
147 static int
148 open_unixsock(listener_t *listener)
149 {
150 char *addr_copy;
151 char *base_dir;
152 struct sockaddr_un sa;
153 int status;
155 listener->sock_fd = socket(AF_UNIX, SOCK_STREAM, 0);
156 if (listener->sock_fd < 0) {
157 char buf[1024];
158 sdb_log(SDB_LOG_ERR, "frontend: Failed to open UNIX socket %s: %s",
159 listener->address, sdb_strerror(errno, buf, sizeof(buf)));
160 return -1;
161 }
163 memset(&sa, 0, sizeof(sa));
164 sa.sun_family = AF_UNIX;
165 strncpy(sa.sun_path, listener->address, sizeof(sa.sun_path));
167 addr_copy = strdup(listener->address);
168 if (! addr_copy) {
169 char errbuf[1024];
170 sdb_log(SDB_LOG_ERR, "frontend: strdup failed: %s",
171 sdb_strerror(errno, errbuf, sizeof(errbuf)));
172 return -1;
173 }
174 base_dir = dirname(addr_copy);
176 /* ensure that the directory exists */
177 if (sdb_mkdir_all(base_dir, 0777)) {
178 char errbuf[1024];
179 sdb_log(SDB_LOG_ERR, "frontend: Failed to create directory '%s': %s",
180 base_dir, sdb_strerror(errno, errbuf, sizeof(errbuf)));
181 free(addr_copy);
182 return -1;
183 }
184 free(addr_copy);
186 if (unlink(listener->address) && (errno != ENOENT)) {
187 char errbuf[1024];
188 sdb_log(SDB_LOG_WARNING, "frontend: Failed to remove stale UNIX "
189 "socket %s: %s", listener->address,
190 sdb_strerror(errno, errbuf, sizeof(errbuf)));
191 }
193 status = bind(listener->sock_fd, (struct sockaddr *)&sa, sizeof(sa));
194 if (status) {
195 char buf[1024];
196 sdb_log(SDB_LOG_ERR, "frontend: Failed to bind to UNIX socket %s: %s",
197 listener->address, sdb_strerror(errno, buf, sizeof(buf)));
198 return -1;
199 }
201 listener->setup = setup_unixsock;
202 return 0;
203 } /* open_unixsock */
205 static void
206 close_unixsock(listener_t *listener)
207 {
208 assert(listener);
210 if (! listener->address)
211 return;
213 if (listener->sock_fd >= 0)
214 close(listener->sock_fd);
215 listener->sock_fd = -1;
217 unlink(listener->address);
218 } /* close_unixsock */
220 static int
221 open_tcp(listener_t *listener)
222 {
223 struct addrinfo *ai, *ai_list = NULL;
224 int status;
226 assert(listener);
228 if ((status = sdb_resolve(SDB_NET_TCP, listener->address, &ai_list))) {
229 sdb_log(SDB_LOG_ERR, "frontend: Failed to resolve '%s': %s",
230 listener->address, gai_strerror(status));
231 return -1;
232 }
234 for (ai = ai_list; ai != NULL; ai = ai->ai_next) {
235 char errbuf[1024];
236 int reuse = 1;
238 listener->sock_fd = socket(ai->ai_family,
239 ai->ai_socktype, ai->ai_protocol);
240 if (listener->sock_fd < 0) {
241 sdb_log(SDB_LOG_ERR, "frontend: Failed to open socket for %s: %s",
242 listener->address,
243 sdb_strerror(errno, errbuf, sizeof(errbuf)));
244 continue;
245 }
247 if (setsockopt(listener->sock_fd, SOL_SOCKET, SO_REUSEADDR,
248 &reuse, sizeof(reuse)) < 0) {
249 sdb_log(SDB_LOG_ERR, "frontend: Failed to set socket option: %s",
250 sdb_strerror(errno, errbuf, sizeof(errbuf)));
251 close(listener->sock_fd);
252 listener->sock_fd = -1;
253 continue;
254 }
256 if (bind(listener->sock_fd, ai->ai_addr, ai->ai_addrlen) < 0) {
257 char host[1024], port[32];
258 getnameinfo(ai->ai_addr, ai->ai_addrlen, host, sizeof(host),
259 port, sizeof(port), NI_NUMERICHOST | NI_NUMERICSERV);
260 sdb_log(SDB_LOG_ERR, "frontend: Failed to bind to %s:%s: %s",
261 host, port, sdb_strerror(errno, errbuf, sizeof(errbuf)));
262 close(listener->sock_fd);
263 listener->sock_fd = -1;
264 continue;
265 }
266 break;
267 }
268 freeaddrinfo(ai_list);
270 if (listener->sock_fd < 0)
271 return -1;
272 return 0;
273 } /* open_tcp */
275 static void
276 close_tcp(listener_t *listener)
277 {
278 assert(listener);
280 if (listener->sock_fd >= 0)
281 close(listener->sock_fd);
282 listener->sock_fd = -1;
283 } /* close_tcp */
285 /*
286 * private variables
287 */
289 /* the enum has to be sorted the same as the implementations array
290 * to ensure that the type may be used as index into the array */
291 enum {
292 LISTENER_TCP = 0, /* this is the default */
293 LISTENER_UNIXSOCK,
294 };
295 static fe_listener_impl_t listener_impls[] = {
296 { LISTENER_TCP, "tcp", open_tcp, close_tcp },
297 { LISTENER_UNIXSOCK, "unix", open_unixsock, close_unixsock },
298 };
300 /*
301 * private helper functions
302 */
304 static int
305 listener_listen(listener_t *listener)
306 {
307 assert(listener);
309 /* try to reopen */
310 if (listener->sock_fd < 0)
311 if (listener_impls[listener->type].open(listener))
312 return -1;
313 assert(listener->sock_fd >= 0);
315 if (listen(listener->sock_fd, /* backlog = */ 32)) {
316 char buf[1024];
317 sdb_log(SDB_LOG_ERR, "frontend: Failed to listen on socket %s: %s",
318 listener->address, sdb_strerror(errno, buf, sizeof(buf)));
319 return -1;
320 }
321 return 0;
322 } /* listener_listen */
324 static void
325 listener_close(listener_t *listener)
326 {
327 assert(listener);
329 if (listener_impls[listener->type].close)
330 listener_impls[listener->type].close(listener);
332 if (listener->sock_fd >= 0)
333 close(listener->sock_fd);
334 listener->sock_fd = -1;
335 } /* listener_close */
337 static int
338 get_type(const char *address)
339 {
340 char *sep;
341 size_t len;
342 size_t i;
344 if (*address == '/')
345 return LISTENER_UNIXSOCK;
346 sep = strchr(address, (int)':');
347 if (! sep)
348 return listener_impls[0].type;
350 assert(sep > address);
351 len = (size_t)(sep - address);
353 for (i = 0; i < SDB_STATIC_ARRAY_LEN(listener_impls); ++i) {
354 fe_listener_impl_t *impl = listener_impls + i;
356 if (!strncmp(address, impl->prefix, len)) {
357 assert(impl->type == (int)i);
358 return impl->type;
359 }
360 }
361 return -1;
362 } /* get_type */
364 static void
365 listener_destroy(listener_t *listener)
366 {
367 if (! listener)
368 return;
370 listener_close(listener);
372 if (listener->address)
373 free(listener->address);
374 listener->address = NULL;
375 } /* listener_destroy */
377 static listener_t *
378 listener_create(sdb_fe_socket_t *sock, const char *address)
379 {
380 listener_t *listener;
381 size_t len;
382 int type;
384 type = get_type(address);
385 if (type < 0) {
386 sdb_log(SDB_LOG_ERR, "frontend: Unsupported address type specified "
387 "in listen address '%s'", address);
388 return NULL;
389 }
391 listener = realloc(sock->listeners,
392 (sock->listeners_num + 1) * sizeof(*sock->listeners));
393 if (! listener) {
394 char buf[1024];
395 sdb_log(SDB_LOG_ERR, "frontend: Failed to allocate memory: %s",
396 sdb_strerror(errno, buf, sizeof(buf)));
397 return NULL;
398 }
400 sock->listeners = listener;
401 listener = sock->listeners + sock->listeners_num;
403 len = strlen(listener_impls[type].prefix);
404 if ((! strncmp(address, listener_impls[type].prefix, len))
405 && (address[len] == ':'))
406 address += strlen(listener_impls[type].prefix) + 1;
408 listener->sock_fd = -1;
409 listener->address = strdup(address);
410 if (! listener->address) {
411 char buf[1024];
412 sdb_log(SDB_LOG_ERR, "frontend: Failed to allocate memory: %s",
413 sdb_strerror(errno, buf, sizeof(buf)));
414 listener_destroy(listener);
415 return NULL;
416 }
417 listener->type = type;
418 listener->setup = NULL;
420 if (listener_impls[type].open(listener)) {
421 /* prints error */
422 listener_destroy(listener);
423 return NULL;
424 }
426 ++sock->listeners_num;
427 return listener;
428 } /* listener_create */
430 static void
431 socket_clear(sdb_fe_socket_t *sock)
432 {
433 size_t i;
435 assert(sock);
436 for (i = 0; i < sock->listeners_num; ++i)
437 listener_destroy(sock->listeners + i);
438 if (sock->listeners)
439 free(sock->listeners);
440 sock->listeners = NULL;
441 sock->listeners_num = 0;
442 } /* socket_clear */
444 static void
445 socket_close(sdb_fe_socket_t *sock)
446 {
447 size_t i;
449 assert(sock);
450 for (i = 0; i < sock->listeners_num; ++i)
451 listener_close(sock->listeners + i);
452 } /* socket_close */
454 /*
455 * connection handler functions
456 */
458 static void *
459 connection_handler(void *data)
460 {
461 sdb_fe_socket_t *sock = data;
463 assert(sock);
465 while (42) {
466 struct timespec timeout = { 0, 500000000 }; /* .5 seconds */
467 sdb_conn_t *conn;
468 int status;
470 errno = 0;
471 status = sdb_channel_select(sock->chan, /* read */ NULL, &conn,
472 /* write */ NULL, NULL, &timeout);
473 if (status) {
474 char buf[1024];
476 if (errno == ETIMEDOUT)
477 continue;
478 if (errno == EBADF) /* channel shut down */
479 break;
481 sdb_log(SDB_LOG_ERR, "frontend: Failed to read from channel: %s",
482 sdb_strerror(errno, buf, sizeof(buf)));
483 continue;
484 }
486 status = (int)sdb_connection_handle(conn);
487 if (status <= 0) {
488 /* error or EOF -> close connection */
489 sdb_object_deref(SDB_OBJ(conn));
490 continue;
491 }
493 /* return the connection to the main loop */
494 if (sdb_llist_append(sock->open_connections, SDB_OBJ(conn))) {
495 sdb_log(SDB_LOG_ERR, "frontend: Failed to re-append "
496 "connection %s to list of open connections",
497 SDB_OBJ(conn)->name);
498 }
500 /* pass ownership back to list; or destroy in case of an error */
501 sdb_object_deref(SDB_OBJ(conn));
502 }
503 return NULL;
504 } /* connection_handler */
506 static int
507 connection_accept(sdb_fe_socket_t *sock, listener_t *listener)
508 {
509 sdb_object_t *obj;
510 int status;
512 obj = SDB_OBJ(sdb_connection_accept(listener->sock_fd,
513 listener->setup, NULL));
514 if (! obj)
515 return -1;
517 status = sdb_llist_append(sock->open_connections, obj);
518 if (status)
519 sdb_log(SDB_LOG_ERR, "frontend: Failed to append "
520 "connection %s to list of open connections",
521 obj->name);
523 /* hand ownership over to the list; or destroy in case of an error */
524 sdb_object_deref(obj);
525 return status;
526 } /* connection_accept */
528 static int
529 socket_handle_incoming(sdb_fe_socket_t *sock,
530 fd_set *ready, fd_set *exceptions)
531 {
532 sdb_llist_iter_t *iter;
533 size_t i;
535 for (i = 0; i < sock->listeners_num; ++i) {
536 listener_t *listener = sock->listeners + i;
537 if (FD_ISSET(listener->sock_fd, ready))
538 if (connection_accept(sock, listener))
539 continue;
540 }
542 iter = sdb_llist_get_iter(sock->open_connections);
543 if (! iter) {
544 sdb_log(SDB_LOG_ERR, "frontend: Failed to acquire iterator "
545 "for open connections");
546 return -1;
547 }
549 while (sdb_llist_iter_has_next(iter)) {
550 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
552 if (FD_ISSET(CONN(obj)->fd, exceptions)) {
553 sdb_log(SDB_LOG_INFO, "Exception on fd %d",
554 CONN(obj)->fd);
555 /* close the connection */
556 sdb_llist_iter_remove_current(iter);
557 sdb_object_deref(obj);
558 continue;
559 }
561 if (FD_ISSET(CONN(obj)->fd, ready)) {
562 sdb_llist_iter_remove_current(iter);
563 sdb_channel_write(sock->chan, &obj);
564 }
565 }
566 sdb_llist_iter_destroy(iter);
567 return 0;
568 } /* socket_handle_incoming */
570 /*
571 * public API
572 */
574 sdb_fe_socket_t *
575 sdb_fe_sock_create(void)
576 {
577 sdb_fe_socket_t *sock;
579 sock = calloc(1, sizeof(*sock));
580 if (! sock)
581 return NULL;
583 sock->open_connections = sdb_llist_create();
584 if (! sock->open_connections) {
585 sdb_fe_sock_destroy(sock);
586 return NULL;
587 }
588 return sock;
589 } /* sdb_fe_sock_create */
591 void
592 sdb_fe_sock_destroy(sdb_fe_socket_t *sock)
593 {
594 if (! sock)
595 return;
597 socket_clear(sock);
599 sdb_llist_destroy(sock->open_connections);
600 sock->open_connections = NULL;
601 free(sock);
602 } /* sdb_fe_sock_destroy */
604 int
605 sdb_fe_sock_add_listener(sdb_fe_socket_t *sock, const char *address)
606 {
607 listener_t *listener;
609 if ((! sock) || (! address))
610 return -1;
612 listener = listener_create(sock, address);
613 if (! listener)
614 return -1;
615 return 0;
616 } /* sdb_fe_sock_add_listener */
618 void
619 sdb_fe_sock_clear_listeners(sdb_fe_socket_t *sock)
620 {
621 if (! sock)
622 return;
624 socket_clear(sock);
625 } /* sdb_fe_sock_clear_listeners */
627 int
628 sdb_fe_sock_listen_and_serve(sdb_fe_socket_t *sock, sdb_fe_loop_t *loop)
629 {
630 fd_set sockets;
631 int max_listen_fd = 0;
632 size_t i;
634 pthread_t handler_threads[loop->num_threads];
635 size_t num_threads;
637 if ((! sock) || (! sock->listeners_num) || sock->chan
638 || (! loop) || (loop->num_threads <= 0))
639 return -1;
641 if (! loop->do_loop)
642 return 0;
644 FD_ZERO(&sockets);
645 for (i = 0; i < sock->listeners_num; ++i) {
646 listener_t *listener = sock->listeners + i;
648 if (listener_listen(listener)) {
649 socket_close(sock);
650 return -1;
651 }
653 FD_SET(listener->sock_fd, &sockets);
654 if (listener->sock_fd > max_listen_fd)
655 max_listen_fd = listener->sock_fd;
656 }
658 sock->chan = sdb_channel_create(1024, sizeof(sdb_conn_t *));
659 if (! sock->chan) {
660 socket_close(sock);
661 return -1;
662 }
664 sdb_log(SDB_LOG_INFO, "frontend: Starting %zu connection "
665 "handler thread%s managing %zu listener%s",
666 loop->num_threads, loop->num_threads == 1 ? "" : "s",
667 sock->listeners_num, sock->listeners_num == 1 ? "" : "s");
669 num_threads = loop->num_threads;
670 memset(&handler_threads, 0, sizeof(handler_threads));
671 for (i = 0; i < num_threads; ++i) {
672 errno = 0;
673 if (pthread_create(&handler_threads[i], /* attr = */ NULL,
674 connection_handler, /* arg = */ sock)) {
675 char errbuf[1024];
676 sdb_log(SDB_LOG_ERR, "frontend: Failed to create "
677 "connection handler thread: %s",
678 sdb_strerror(errno, errbuf, sizeof(errbuf)));
679 num_threads = i;
680 break;
681 }
682 }
684 while (loop->do_loop && num_threads) {
685 struct timeval timeout = { 1, 0 }; /* one second */
686 sdb_llist_iter_t *iter;
688 int max_fd = max_listen_fd;
689 fd_set ready;
690 fd_set exceptions;
691 int n;
693 FD_ZERO(&ready);
694 FD_ZERO(&exceptions);
696 ready = sockets;
698 iter = sdb_llist_get_iter(sock->open_connections);
699 if (! iter) {
700 sdb_log(SDB_LOG_ERR, "frontend: Failed to acquire iterator "
701 "for open connections");
702 break;
703 }
705 while (sdb_llist_iter_has_next(iter)) {
706 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
708 if (CONN(obj)->fd < 0) {
709 sdb_llist_iter_remove_current(iter);
710 sdb_object_deref(obj);
711 continue;
712 }
714 FD_SET(CONN(obj)->fd, &ready);
715 FD_SET(CONN(obj)->fd, &exceptions);
717 if (CONN(obj)->fd > max_fd)
718 max_fd = CONN(obj)->fd;
719 }
720 sdb_llist_iter_destroy(iter);
722 errno = 0;
723 n = select(max_fd + 1, &ready, NULL, &exceptions, &timeout);
724 if (n < 0) {
725 char buf[1024];
727 if (errno == EINTR)
728 continue;
730 sdb_log(SDB_LOG_ERR, "frontend: Failed to monitor sockets: %s",
731 sdb_strerror(errno, buf, sizeof(buf)));
732 break;
733 }
734 else if (! n)
735 continue;
737 /* handle new and open connections */
738 if (socket_handle_incoming(sock, &ready, &exceptions))
739 break;
740 }
742 socket_close(sock);
744 sdb_log(SDB_LOG_INFO, "frontend: Waiting for connection handler threads "
745 "to terminate");
746 if (! sdb_channel_shutdown(sock->chan))
747 for (i = 0; i < num_threads; ++i)
748 pthread_join(handler_threads[i], NULL);
749 /* else: we tried our best; let the operating system clean up */
751 sdb_channel_destroy(sock->chan);
752 sock->chan = NULL;
754 if (! num_threads)
755 return -1;
756 return 0;
757 } /* sdb_fe_sock_listen_and_server */
759 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */