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 #include "sysdb.h"
29 #include "core/error.h"
30 #include "core/object.h"
31 #include "frontend/connection.h"
32 #include "frontend/sock.h"
34 #include "utils/channel.h"
35 #include "utils/llist.h"
36 #include "utils/strbuf.h"
38 #include <assert.h>
39 #include <errno.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
45 #include <unistd.h>
47 #include <fcntl.h>
49 #include <sys/time.h>
50 #include <sys/types.h>
51 #include <sys/select.h>
52 #include <sys/socket.h>
53 #include <sys/un.h>
55 #include <pthread.h>
57 /* name of connection objects */
58 #define CONN_FD_PREFIX "conn#"
59 #define CONN_FD_PLACEHOLDER "XXXXXXX"
61 /*
62 * private data types
63 */
65 typedef struct {
66 sdb_object_t super;
68 /* connection and client information */
69 struct sockaddr_storage client_addr;
70 socklen_t client_addr_len;
72 sdb_conn_t conn;
73 } connection_obj_t;
74 #define CONN(obj) ((connection_obj_t *)(obj))
76 typedef struct {
77 char *address;
78 int type;
80 int sock_fd;
81 } listener_t;
83 typedef struct {
84 int type;
85 const char *prefix;
87 int (*opener)(listener_t *);
88 } fe_listener_impl_t;
90 struct sdb_fe_socket {
91 listener_t *listeners;
92 size_t listeners_num;
94 sdb_llist_t *open_connections;
96 /* channel used for communication between main
97 * and connection handler threads */
98 sdb_channel_t *chan;
99 };
101 /*
102 * connection management functions
103 */
105 static int
106 open_unix_sock(listener_t *listener)
107 {
108 struct sockaddr_un sa;
109 int status;
111 listener->sock_fd = socket(AF_UNIX, SOCK_STREAM, 0);
112 if (listener->sock_fd < 0) {
113 char buf[1024];
114 sdb_log(SDB_LOG_ERR, "frontend: Failed to open UNIX socket %s: %s",
115 listener->address, sdb_strerror(errno, buf, sizeof(buf)));
116 return -1;
117 }
119 memset(&sa, 0, sizeof(sa));
120 sa.sun_family = AF_UNIX;
121 strncpy(sa.sun_path, listener->address + strlen("unix:"),
122 sizeof(sa.sun_path));
124 status = bind(listener->sock_fd, (struct sockaddr *)&sa, sizeof(sa));
125 if (status) {
126 char buf[1024];
127 sdb_log(SDB_LOG_ERR, "frontend: Failed to bind to UNIX socket %s: %s",
128 listener->address, sdb_strerror(errno, buf, sizeof(buf)));
129 return -1;
130 }
131 return 0;
132 } /* open_unix_sock */
134 /*
135 * private variables
136 */
138 /* the enum has to be sorted the same as the implementations array
139 * to ensure that the type may be used as index into the array */
140 enum {
141 LISTENER_UNIXSOCK = 0,
142 };
143 static fe_listener_impl_t listener_impls[] = {
144 { LISTENER_UNIXSOCK, "unix", open_unix_sock },
145 };
147 /*
148 * private helper functions
149 */
151 static int
152 get_type(const char *address)
153 {
154 char *sep;
155 size_t len;
156 size_t i;
158 sep = strchr(address, (int)':');
159 if (! sep)
160 return -1;
162 assert(sep > address);
163 len = (size_t)(sep - address);
165 for (i = 0; i < SDB_STATIC_ARRAY_LEN(listener_impls); ++i) {
166 fe_listener_impl_t *impl = listener_impls + i;
168 if (!strncmp(address, impl->prefix, len)) {
169 assert(impl->type == (int)i);
170 return impl->type;
171 }
172 }
173 return -1;
174 } /* get_type */
176 static void
177 listener_destroy(listener_t *listener)
178 {
179 if (! listener)
180 return;
182 if (listener->sock_fd >= 0)
183 close(listener->sock_fd);
184 listener->sock_fd = -1;
186 if (listener->address)
187 free(listener->address);
188 } /* listener_destroy */
190 static listener_t *
191 listener_create(sdb_fe_socket_t *sock, const char *address)
192 {
193 listener_t *listener;
194 int type;
196 type = get_type(address);
197 if (type < 0) {
198 sdb_log(SDB_LOG_ERR, "frontend: Unsupported address type specified "
199 "in listen address '%s'", address);
200 return NULL;
201 }
203 listener = realloc(sock->listeners,
204 sock->listeners_num * sizeof(*sock->listeners));
205 if (! listener) {
206 char buf[1024];
207 sdb_log(SDB_LOG_ERR, "frontend: Failed to allocate memory: %s",
208 sdb_strerror(errno, buf, sizeof(buf)));
209 return NULL;
210 }
212 sock->listeners = listener;
213 listener = sock->listeners + sock->listeners_num;
215 listener->sock_fd = -1;
216 listener->address = strdup(address);
217 if (! listener->address) {
218 char buf[1024];
219 sdb_log(SDB_LOG_ERR, "frontend: Failed to allocate memory: %s",
220 sdb_strerror(errno, buf, sizeof(buf)));
221 listener_destroy(listener);
222 return NULL;
223 }
224 listener->type = type;
226 if (listener_impls[type].opener(listener)) {
227 /* prints error */
228 listener_destroy(listener);
229 return NULL;
230 }
232 ++sock->listeners_num;
233 return listener;
234 } /* listener_create */
236 static int
237 listener_listen(listener_t *listener)
238 {
239 assert(listener);
241 /* try to reopen */
242 if (listener->sock_fd < 0)
243 if (listener_impls[listener->type].opener(listener))
244 return -1;
245 assert(listener->sock_fd >= 0);
247 if (listen(listener->sock_fd, /* backlog = */ 32)) {
248 char buf[1024];
249 sdb_log(SDB_LOG_ERR, "frontend: Failed to listen on socket %s: %s",
250 listener->address, sdb_strerror(errno, buf, sizeof(buf)));
251 return -1;
252 }
253 return 0;
254 } /* listener_listen */
256 static void
257 listener_close(listener_t *listener)
258 {
259 assert(listener);
261 if (listener->sock_fd < 0)
262 return;
264 close(listener->sock_fd);
265 listener->sock_fd = -1;
266 } /* listener_close */
268 static void
269 socket_close(sdb_fe_socket_t *sock)
270 {
271 size_t i;
273 assert(sock);
274 for (i = 0; i < sock->listeners_num; ++i)
275 listener_close(sock->listeners + i);
276 } /* socket_close */
278 /*
279 * private data types
280 */
282 static int
283 connection_init(sdb_object_t *obj, va_list ap)
284 {
285 connection_obj_t *conn;
286 int sock_fd;
287 int sock_fl;
289 assert(obj);
290 conn = CONN(obj);
292 sock_fd = va_arg(ap, int);
294 if (sdb_connection_init(&CONN(obj)->conn))
295 return -1;
297 conn->client_addr_len = sizeof(conn->client_addr);
298 conn->conn.fd = accept(sock_fd, (struct sockaddr *)&conn->client_addr,
299 &conn->client_addr_len);
301 if (conn->conn.fd < 0) {
302 char buf[1024];
303 sdb_log(SDB_LOG_ERR, "frontend: Failed to accept remote "
304 "connection: %s", sdb_strerror(errno,
305 buf, sizeof(buf)));
306 return -1;
307 }
309 if (conn->client_addr.ss_family != AF_UNIX) {
310 sdb_log(SDB_LOG_ERR, "frontend: Accepted connection using "
311 "unexpected family type %d", conn->client_addr.ss_family);
312 return -1;
313 }
315 sock_fl = fcntl(conn->conn.fd, F_GETFL);
316 if (fcntl(conn->conn.fd, F_SETFL, sock_fl | O_NONBLOCK)) {
317 char buf[1024];
318 sdb_log(SDB_LOG_ERR, "frontend: Failed to switch connection conn#%i "
319 "to non-blocking mode: %s", conn->conn.fd,
320 sdb_strerror(errno, buf, sizeof(buf)));
321 return -1;
322 }
324 sdb_log(SDB_LOG_DEBUG, "frontend: Accepted connection on fd=%i",
325 conn->conn.fd);
327 /* update the object name */
328 snprintf(obj->name + strlen(CONN_FD_PREFIX),
329 strlen(CONN_FD_PLACEHOLDER), "%i", conn->conn.fd);
330 return 0;
331 } /* connection_init */
333 static void
334 connection_destroy(sdb_object_t *obj)
335 {
336 assert(obj);
337 sdb_connection_close(&CONN(obj)->conn);
338 } /* connection_destroy */
340 static sdb_type_t connection_type = {
341 /* size = */ sizeof(connection_obj_t),
342 /* init = */ connection_init,
343 /* destroy = */ connection_destroy,
344 };
346 /*
347 * connection handler functions
348 */
350 static void *
351 connection_handler(void *data)
352 {
353 sdb_fe_socket_t *sock = data;
355 assert(sock);
357 while (42) {
358 struct timespec timeout = { 0, 500000000 }; /* .5 seconds */
359 connection_obj_t *conn;
360 int status;
362 errno = 0;
363 status = sdb_channel_select(sock->chan, /* read */ NULL, &conn,
364 /* write */ NULL, NULL, &timeout);
365 if (status) {
366 char buf[1024];
368 if (errno == ETIMEDOUT)
369 continue;
370 if (errno == EBADF) /* channel shut down */
371 break;
373 sdb_log(SDB_LOG_ERR, "frontend: Failed to read from channel: %s",
374 sdb_strerror(errno, buf, sizeof(buf)));
375 continue;
376 }
378 status = (int)sdb_connection_read(&conn->conn);
379 if (status <= 0) {
380 /* error or EOF -> close connection */
381 sdb_object_deref(SDB_OBJ(conn));
382 continue;
383 }
385 /* return the connection to the main loop */
386 if (sdb_llist_append(sock->open_connections, SDB_OBJ(conn))) {
387 sdb_log(SDB_LOG_ERR, "frontend: Failed to re-append "
388 "connection %s to list of open connections",
389 SDB_OBJ(conn)->name);
390 }
392 /* pass ownership back to list; or destroy in case of an error */
393 sdb_object_deref(SDB_OBJ(conn));
394 }
395 return NULL;
396 } /* connection_handler */
398 static int
399 connection_accept(sdb_fe_socket_t *sock, listener_t *listener)
400 {
401 sdb_object_t *obj;
403 /* the placeholder will be replaced with the accepted file
404 * descriptor when initializing the object */
405 obj = sdb_object_create(CONN_FD_PREFIX CONN_FD_PLACEHOLDER,
406 connection_type, listener->sock_fd);
407 if (! obj)
408 return -1;
410 if (sdb_llist_append(sock->open_connections, obj)) {
411 sdb_log(SDB_LOG_ERR, "frontend: Failed to append "
412 "connection %s to list of open connections",
413 obj->name);
414 sdb_object_deref(obj);
415 return -1;
416 }
418 /* hand ownership over to the list */
419 sdb_object_deref(obj);
420 return 0;
421 } /* connection_accept */
423 static int
424 socket_handle_incoming(sdb_fe_socket_t *sock,
425 fd_set *ready, fd_set *exceptions)
426 {
427 sdb_llist_iter_t *iter;
428 size_t i;
430 for (i = 0; i < sock->listeners_num; ++i) {
431 listener_t *listener = sock->listeners + i;
432 if (FD_ISSET(listener->sock_fd, ready))
433 if (connection_accept(sock, listener))
434 continue;
435 }
437 iter = sdb_llist_get_iter(sock->open_connections);
438 if (! iter) {
439 sdb_log(SDB_LOG_ERR, "frontend: Failed to acquire iterator "
440 "for open connections");
441 return -1;
442 }
444 while (sdb_llist_iter_has_next(iter)) {
445 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
447 if (FD_ISSET(CONN(obj)->conn.fd, exceptions))
448 sdb_log(SDB_LOG_INFO, "Exception on fd %d",
449 CONN(obj)->conn.fd);
451 if (FD_ISSET(CONN(obj)->conn.fd, ready)) {
452 sdb_llist_iter_remove_current(iter);
453 sdb_channel_write(sock->chan, &obj);
454 }
455 }
456 sdb_llist_iter_destroy(iter);
457 return 0;
458 } /* socket_handle_incoming */
460 /*
461 * public API
462 */
464 sdb_fe_socket_t *
465 sdb_fe_sock_create(void)
466 {
467 sdb_fe_socket_t *sock;
469 sock = calloc(1, sizeof(*sock));
470 if (! sock)
471 return NULL;
473 sock->open_connections = sdb_llist_create();
474 if (! sock->open_connections) {
475 sdb_fe_sock_destroy(sock);
476 return NULL;
477 }
478 return sock;
479 } /* sdb_fe_sock_create */
481 void
482 sdb_fe_sock_destroy(sdb_fe_socket_t *sock)
483 {
484 size_t i;
486 if (! sock)
487 return;
489 for (i = 0; i < sock->listeners_num; ++i) {
490 listener_destroy(sock->listeners + i);
491 }
492 if (sock->listeners)
493 free(sock->listeners);
494 sock->listeners = NULL;
496 sdb_llist_destroy(sock->open_connections);
497 sock->open_connections = NULL;
498 free(sock);
499 } /* sdb_fe_sock_destroy */
501 int
502 sdb_fe_sock_add_listener(sdb_fe_socket_t *sock, const char *address)
503 {
504 listener_t *listener;
506 if ((! sock) || (! address))
507 return -1;
509 listener = listener_create(sock, address);
510 if (! listener)
511 return -1;
512 return 0;
513 } /* sdb_fe_sock_add_listener */
515 int
516 sdb_fe_sock_listen_and_serve(sdb_fe_socket_t *sock, sdb_fe_loop_t *loop)
517 {
518 fd_set sockets;
519 int max_listen_fd = 0;
520 size_t i;
522 /* XXX: make the number of threads configurable */
523 pthread_t handler_threads[5];
525 if ((! sock) || (! sock->listeners_num) || (! loop) || sock->chan)
526 return -1;
528 FD_ZERO(&sockets);
529 for (i = 0; i < sock->listeners_num; ++i) {
530 listener_t *listener = sock->listeners + i;
532 if (listener_listen(listener)) {
533 socket_close(sock);
534 return -1;
535 }
537 FD_SET(listener->sock_fd, &sockets);
538 if (listener->sock_fd > max_listen_fd)
539 max_listen_fd = listener->sock_fd;
540 }
542 sock->chan = sdb_channel_create(1024, sizeof(connection_obj_t *));
543 if (! sock->chan) {
544 socket_close(sock);
545 return -1;
546 }
548 memset(&handler_threads, 0, sizeof(handler_threads));
549 /* XXX: error handling */
550 for (i = 0; i < SDB_STATIC_ARRAY_LEN(handler_threads); ++i)
551 pthread_create(&handler_threads[i], /* attr = */ NULL,
552 connection_handler, /* arg = */ sock);
554 while (loop->do_loop) {
555 struct timeval timeout = { 1, 0 }; /* one second */
556 sdb_llist_iter_t *iter;
558 int max_fd = max_listen_fd;
559 fd_set ready;
560 fd_set exceptions;
561 int n;
563 FD_ZERO(&ready);
564 FD_ZERO(&exceptions);
566 ready = sockets;
568 iter = sdb_llist_get_iter(sock->open_connections);
569 if (! iter) {
570 sdb_log(SDB_LOG_ERR, "frontend: Failed to acquire iterator "
571 "for open connections");
572 break;
573 }
575 while (sdb_llist_iter_has_next(iter)) {
576 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
577 FD_SET(CONN(obj)->conn.fd, &ready);
578 FD_SET(CONN(obj)->conn.fd, &exceptions);
580 if (CONN(obj)->conn.fd > max_fd)
581 max_fd = CONN(obj)->conn.fd;
582 }
583 sdb_llist_iter_destroy(iter);
585 errno = 0;
586 n = select(max_fd + 1, &ready, NULL, &exceptions, &timeout);
587 if (n < 0) {
588 char buf[1024];
590 if (errno == EINTR)
591 continue;
593 sdb_log(SDB_LOG_ERR, "frontend: Failed to monitor sockets: %s",
594 sdb_strerror(errno, buf, sizeof(buf)));
595 break;
596 }
597 else if (! n)
598 continue;
600 /* handle new and open connections */
601 if (socket_handle_incoming(sock, &ready, &exceptions))
602 break;
603 }
605 socket_close(sock);
607 sdb_log(SDB_LOG_INFO, "frontend: Waiting for connection handler threads "
608 "to terminate");
609 if (! sdb_channel_shutdown(sock->chan))
610 for (i = 0; i < SDB_STATIC_ARRAY_LEN(handler_threads); ++i)
611 pthread_join(handler_threads[i], NULL);
612 /* else: we tried our best; let the operating system clean up */
614 sdb_channel_destroy(sock->chan);
615 sock->chan = NULL;
616 return 0;
617 } /* sdb_fe_sock_listen_and_server */
619 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */