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/sock.h"
33 #include "utils/channel.h"
34 #include "utils/llist.h"
36 #include <assert.h>
38 #include <errno.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
44 #include <unistd.h>
46 #include <fcntl.h>
48 #include <sys/time.h>
49 #include <sys/types.h>
50 #include <sys/select.h>
51 #include <sys/socket.h>
52 #include <sys/un.h>
54 #include <pthread.h>
56 /* name of connection objects */
57 #define CONN_FD_PREFIX "conn#"
58 #define CONN_FD_PLACEHOLDER "XXXXXXX"
60 /*
61 * private data types
62 */
64 typedef struct {
65 int fd;
66 struct sockaddr_storage client_addr;
67 socklen_t client_addr_len;
68 } connection_t;
70 typedef struct {
71 sdb_object_t super;
72 connection_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);
185 if (listener->address)
186 free(listener->address);
187 } /* listener_destroy */
189 static listener_t *
190 listener_create(sdb_fe_socket_t *sock, const char *address)
191 {
192 listener_t *listener;
193 int type;
195 type = get_type(address);
196 if (type < 0) {
197 sdb_log(SDB_LOG_ERR, "frontend: Unsupported address type specified "
198 "in listen address '%s'", address);
199 return NULL;
200 }
202 listener = realloc(sock->listeners,
203 sock->listeners_num * sizeof(*sock->listeners));
204 if (! listener) {
205 char buf[1024];
206 sdb_log(SDB_LOG_ERR, "frontend: Failed to allocate memory: %s",
207 sdb_strerror(errno, buf, sizeof(buf)));
208 return NULL;
209 }
211 sock->listeners = listener;
212 listener = sock->listeners + sock->listeners_num;
214 listener->sock_fd = -1;
215 listener->address = strdup(address);
216 if (! listener->address) {
217 char buf[1024];
218 sdb_log(SDB_LOG_ERR, "frontend: Failed to allocate memory: %s",
219 sdb_strerror(errno, buf, sizeof(buf)));
220 listener_destroy(listener);
221 return NULL;
222 }
223 listener->type = type;
225 if (listener_impls[type].opener(listener)) {
226 /* prints error */
227 listener_destroy(listener);
228 return NULL;
229 }
231 ++sock->listeners_num;
232 return listener;
233 } /* listener_create */
235 /*
236 * private data types
237 */
239 static int
240 connection_init(sdb_object_t *obj, va_list ap)
241 {
242 connection_t *conn;
243 int sock_fd;
244 int sock_fl;
246 assert(obj);
247 conn = &CONN(obj)->conn;
249 sock_fd = va_arg(ap, int);
251 conn->client_addr_len = sizeof(conn->client_addr);
252 conn->fd = accept(sock_fd, (struct sockaddr *)&conn->client_addr,
253 &conn->client_addr_len);
255 if (conn->fd < 0) {
256 char buf[1024];
257 sdb_log(SDB_LOG_ERR, "frontend: Failed to accept remote "
258 "connection: %s", sdb_strerror(errno,
259 buf, sizeof(buf)));
260 return -1;
261 }
263 if (conn->client_addr.ss_family != AF_UNIX) {
264 sdb_log(SDB_LOG_ERR, "frontend: Accepted connection using "
265 "unexpected family type %d", conn->client_addr.ss_family);
266 return -1;
267 }
269 sock_fl = fcntl(conn->fd, F_GETFL);
270 if (fcntl(conn->fd, F_SETFL, sock_fl | O_NONBLOCK)) {
271 char buf[1024];
272 sdb_log(SDB_LOG_ERR, "frontend: Failed to switch connection conn#%i "
273 "to non-blocking mode: %s", conn->fd,
274 sdb_strerror(errno, buf, sizeof(buf)));
275 return -1;
276 }
278 sdb_log(SDB_LOG_DEBUG, "frontend: Accepted connection on fd=%i",
279 conn->fd);
281 /* update the object name */
282 snprintf(obj->name + strlen(CONN_FD_PREFIX),
283 strlen(CONN_FD_PLACEHOLDER), "%i", conn->fd);
284 return 0;
285 } /* connection_init */
287 static void
288 connection_destroy(sdb_object_t *obj)
289 {
290 connection_t *conn;
292 assert(obj);
293 conn = &CONN(obj)->conn;
295 close(conn->fd);
296 conn->fd = -1;
297 } /* connection_destroy */
299 static sdb_type_t connection_type = {
300 /* size = */ sizeof(connection_obj_t),
301 /* init = */ connection_init,
302 /* destroy = */ connection_destroy,
303 };
305 /*
306 * connection handler functions
307 */
309 /* returns negative value on error, 0 on EOF, number of packets else */
310 static int
311 connection_read(int fd)
312 {
313 int n = 0;
315 while (42) {
316 int32_t cmd;
317 ssize_t status;
319 errno = 0;
320 status = read(fd, &cmd, sizeof(cmd));
321 if (status < 0) {
322 if ((errno == EAGAIN) || (errno == EWOULDBLOCK))
323 return n + 1;
324 return (int)status;
325 }
326 else if (! status) /* EOF */
327 return 0;
329 /* XXX */
330 sdb_log(SDB_LOG_DEBUG, "frontend: read command %i from fd=%i",
331 cmd, fd);
332 ++n;
333 }
335 return n + 1;
336 } /* connection_read */
338 static void *
339 connection_handler(void *data)
340 {
341 sdb_fe_socket_t *sock = data;
343 assert(sock);
345 while (42) {
346 struct timespec timeout = { 0, 500000000 }; /* .5 seconds */
347 connection_obj_t *conn;
348 int status;
350 errno = 0;
351 status = sdb_channel_select(sock->chan, /* read */ NULL, &conn,
352 /* write */ NULL, NULL, &timeout);
353 if (status) {
354 char buf[1024];
356 if (errno == ETIMEDOUT)
357 continue;
358 if (errno == EBADF) /* channel shut down */
359 break;
361 sdb_log(SDB_LOG_ERR, "frontend: Failed to read from channel: %s",
362 sdb_strerror(errno, buf, sizeof(buf)));
363 continue;
364 }
366 /* XXX */
367 sdb_log(SDB_LOG_INFO, "frontend: Data available on connection fd=%i\n",
368 conn->conn.fd);
369 }
370 return NULL;
371 } /* connection_handler */
373 static int
374 connection_accept(sdb_fe_socket_t *sock, listener_t *listener)
375 {
376 sdb_object_t *obj;
378 /* the placeholder will be replaced with the accepted file
379 * descriptor when initializing the object */
380 obj = sdb_object_create(CONN_FD_PREFIX CONN_FD_PLACEHOLDER,
381 connection_type, listener->sock_fd);
382 if (! obj)
383 return -1;
385 if (sdb_llist_append(sock->open_connections, obj)) {
386 sdb_log(SDB_LOG_ERR, "frontend: Failed to append "
387 "connection %s to list of open connections",
388 obj->name);
389 sdb_object_deref(obj);
390 return -1;
391 }
393 /* hand ownership over to the list */
394 sdb_object_deref(obj);
395 return 0;
396 } /* connection_accept */
398 /*
399 * public API
400 */
402 sdb_fe_socket_t *
403 sdb_fe_sock_create(void)
404 {
405 sdb_fe_socket_t *sock;
407 sock = calloc(1, sizeof(*sock));
408 if (! sock)
409 return NULL;
411 sock->open_connections = sdb_llist_create();
412 if (! sock->open_connections) {
413 sdb_fe_sock_destroy(sock);
414 return NULL;
415 }
416 return sock;
417 } /* sdb_fe_sock_create */
419 void
420 sdb_fe_sock_destroy(sdb_fe_socket_t *sock)
421 {
422 size_t i;
424 if (! sock)
425 return;
427 for (i = 0; i < sock->listeners_num; ++i) {
428 listener_destroy(sock->listeners + i);
429 }
430 if (sock->listeners)
431 free(sock->listeners);
432 sock->listeners = NULL;
434 sdb_llist_destroy(sock->open_connections);
435 sock->open_connections = NULL;
436 free(sock);
437 } /* sdb_fe_sock_destroy */
439 int
440 sdb_fe_sock_add_listener(sdb_fe_socket_t *sock, const char *address)
441 {
442 listener_t *listener;
444 if ((! sock) || (! address))
445 return -1;
447 listener = listener_create(sock, address);
448 if (! listener)
449 return -1;
450 return 0;
451 } /* sdb_fe_sock_add_listener */
453 int
454 sdb_fe_sock_listen_and_serve(sdb_fe_socket_t *sock, sdb_fe_loop_t *loop)
455 {
456 fd_set sockets;
457 int max_listen_fd = 0;
458 size_t i;
460 /* XXX: make the number of threads configurable */
461 pthread_t handler_threads[5];
463 if ((! sock) || (! sock->listeners_num) || (! loop))
464 return -1;
466 FD_ZERO(&sockets);
468 for (i = 0; i < sock->listeners_num; ++i) {
469 listener_t *listener = sock->listeners + i;
471 if (listen(listener->sock_fd, /* backlog = */ 32)) {
472 char buf[1024];
473 sdb_log(SDB_LOG_ERR, "frontend: Failed to listen on socket %s: %s",
474 listener->address, sdb_strerror(errno, buf, sizeof(buf)));
475 return -1;
476 }
478 FD_SET(listener->sock_fd, &sockets);
479 if (listener->sock_fd > max_listen_fd)
480 max_listen_fd = listener->sock_fd;
481 }
483 sock->chan = sdb_channel_create(1024, sizeof(connection_obj_t *));
484 if (! sock->chan)
485 return -1;
487 memset(&handler_threads, 0, sizeof(handler_threads));
488 /* XXX: error handling */
489 for (i = 0; i < SDB_STATIC_ARRAY_LEN(handler_threads); ++i)
490 pthread_create(&handler_threads[i], /* attr = */ NULL,
491 connection_handler, /* arg = */ sock);
493 while (loop->do_loop) {
494 fd_set ready;
495 fd_set exceptions;
496 int max_fd;
497 int n;
499 struct timeval timeout = { 1, 0 }; /* one second */
500 sdb_llist_iter_t *iter;
502 FD_ZERO(&ready);
503 FD_ZERO(&exceptions);
505 ready = sockets;
507 max_fd = max_listen_fd;
509 iter = sdb_llist_get_iter(sock->open_connections);
510 if (! iter) {
511 sdb_log(SDB_LOG_ERR, "frontend: Failed to acquire iterator "
512 "for open connections");
513 return -1;
514 }
516 while (sdb_llist_iter_has_next(iter)) {
517 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
518 FD_SET(CONN(obj)->conn.fd, &ready);
519 FD_SET(CONN(obj)->conn.fd, &exceptions);
521 if (CONN(obj)->conn.fd > max_fd)
522 max_fd = CONN(obj)->conn.fd;
523 }
524 sdb_llist_iter_destroy(iter);
526 errno = 0;
527 n = select(max_fd + 1, &ready, NULL, &exceptions, &timeout);
528 if (n < 0) {
529 char buf[1024];
531 if (errno == EINTR)
532 continue;
534 sdb_log(SDB_LOG_ERR, "frontend: Failed to monitor sockets: %s",
535 sdb_strerror(errno, buf, sizeof(buf)));
536 return -1;
537 }
539 if (! n)
540 continue;
542 for (i = 0; i < sock->listeners_num; ++i) {
543 listener_t *listener = sock->listeners + i;
544 if (FD_ISSET(listener->sock_fd, &ready))
545 if (connection_accept(sock, listener))
546 continue;
547 }
549 iter = sdb_llist_get_iter(sock->open_connections);
550 if (! iter) {
551 sdb_log(SDB_LOG_ERR, "frontend: Failed to acquire iterator "
552 "for open connections");
553 return -1;
554 }
556 while (sdb_llist_iter_has_next(iter)) {
557 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
559 if (FD_ISSET(CONN(obj)->conn.fd, &exceptions))
560 sdb_log(SDB_LOG_INFO, "Exception on fd %d",
561 CONN(obj)->conn.fd);
563 if (FD_ISSET(CONN(obj)->conn.fd, &ready)) {
564 sdb_log(SDB_LOG_INFO, "Data on fd %d", CONN(obj)->conn.fd);
565 sdb_llist_iter_remove_current(iter);
566 sdb_channel_write(sock->chan, &obj);
567 }
568 }
569 sdb_llist_iter_destroy(iter);
570 }
572 sdb_log(SDB_LOG_INFO, "frontend: Waiting for connection handler threads "
573 "to terminate");
574 if (! sdb_channel_shutdown(sock->chan))
575 for (i = 0; i < SDB_STATIC_ARRAY_LEN(handler_threads); ++i)
576 pthread_join(handler_threads[i], NULL);
577 /* else: we tried our best; let the operating system clean up */
578 return 0;
579 } /* sdb_fe_sock_listen_and_server */
581 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */