cli: add timeout support for listen command
[project/ubus.git] / ubusd.c
1 /*
2  * Copyright (C) 2011-2014 Felix Fietkau <nbd@openwrt.org>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU Lesser General Public License version 2.1
6  * as published by the Free Software Foundation
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  */
13
14 #include <sys/socket.h>
15 #include <sys/stat.h>
16 #include <sys/uio.h>
17 #ifdef FreeBSD
18 #include <sys/param.h>
19 #endif
20 #include <syslog.h>
21 #include <signal.h>
22 #include <stdio.h>
23 #include <unistd.h>
24 #include <fcntl.h>
25
26 #include <libubox/blob.h>
27 #include <libubox/uloop.h>
28 #include <libubox/usock.h>
29 #include <libubox/list.h>
30
31 #include "ubusd.h"
32
33 static struct ubus_msg_buf *ubus_msg_ref(struct ubus_msg_buf *ub)
34 {
35         if (ub->refcount == ~0)
36                 return ubus_msg_new(ub->data, ub->len, false);
37
38         ub->refcount++;
39         return ub;
40 }
41
42 struct ubus_msg_buf *ubus_msg_new(void *data, int len, bool shared)
43 {
44         struct ubus_msg_buf *ub;
45         int buflen = sizeof(*ub);
46
47         if (!shared)
48                 buflen += len;
49
50         ub = calloc(1, buflen);
51         if (!ub)
52                 return NULL;
53
54         ub->fd = -1;
55
56         if (shared) {
57                 ub->refcount = ~0;
58                 ub->data = data;
59         } else {
60                 ub->refcount = 1;
61                 ub->data = (void *) (ub + 1);
62                 if (data)
63                         memcpy(ub + 1, data, len);
64         }
65
66         ub->len = len;
67         return ub;
68 }
69
70 void ubus_msg_free(struct ubus_msg_buf *ub)
71 {
72         switch (ub->refcount) {
73         case 1:
74         case ~0:
75                 if (ub->fd >= 0)
76                         close(ub->fd);
77
78                 free(ub);
79                 break;
80         default:
81                 ub->refcount--;
82                 break;
83         }
84 }
85
86 static int ubus_msg_writev(int fd, struct ubus_msg_buf *ub, int offset)
87 {
88         static struct iovec iov[2];
89         static struct {
90                 struct cmsghdr h;
91                 int fd;
92         } fd_buf = {
93                 .h = {
94                         .cmsg_len = sizeof(fd_buf),
95                         .cmsg_level = SOL_SOCKET,
96                         .cmsg_type = SCM_RIGHTS,
97                 },
98         };
99         struct msghdr msghdr = {
100                 .msg_iov = iov,
101                 .msg_iovlen = ARRAY_SIZE(iov),
102                 .msg_control = &fd_buf,
103                 .msg_controllen = sizeof(fd_buf),
104         };
105
106         fd_buf.fd = ub->fd;
107         if (ub->fd < 0) {
108                 msghdr.msg_control = NULL;
109                 msghdr.msg_controllen = 0;
110         }
111
112         if (offset < sizeof(ub->hdr)) {
113                 struct ubus_msghdr hdr;
114
115                 hdr.version = ub->hdr.version;
116                 hdr.type = ub->hdr.type;
117                 hdr.seq = cpu_to_be16(ub->hdr.seq);
118                 hdr.peer = cpu_to_be32(ub->hdr.peer);
119
120                 iov[0].iov_base = ((char *) &hdr) + offset;
121                 iov[0].iov_len = sizeof(hdr) - offset;
122                 iov[1].iov_base = (char *) ub->data;
123                 iov[1].iov_len = ub->len;
124
125                 return sendmsg(fd, &msghdr, 0);
126         } else {
127                 offset -= sizeof(ub->hdr);
128                 return write(fd, ((char *) ub->data) + offset, ub->len - offset);
129         }
130 }
131
132 static void ubus_msg_enqueue(struct ubus_client *cl, struct ubus_msg_buf *ub)
133 {
134         if (cl->tx_queue[cl->txq_tail])
135                 return;
136
137         cl->tx_queue[cl->txq_tail] = ubus_msg_ref(ub);
138         cl->txq_tail = (cl->txq_tail + 1) % ARRAY_SIZE(cl->tx_queue);
139 }
140
141 /* takes the msgbuf reference */
142 void ubus_msg_send(struct ubus_client *cl, struct ubus_msg_buf *ub, bool free)
143 {
144         int written;
145
146         if (ub->hdr.type != UBUS_MSG_MONITOR)
147                 ubusd_monitor_message(cl, ub, true);
148
149         if (!cl->tx_queue[cl->txq_cur]) {
150                 written = ubus_msg_writev(cl->sock.fd, ub, 0);
151                 if (written >= ub->len + sizeof(ub->hdr))
152                         goto out;
153
154                 if (written < 0)
155                         written = 0;
156
157                 cl->txq_ofs = written;
158
159                 /* get an event once we can write to the socket again */
160                 uloop_fd_add(&cl->sock, ULOOP_READ | ULOOP_WRITE | ULOOP_EDGE_TRIGGER);
161         }
162         ubus_msg_enqueue(cl, ub);
163
164 out:
165         if (free)
166                 ubus_msg_free(ub);
167 }
168
169 static struct ubus_msg_buf *ubus_msg_head(struct ubus_client *cl)
170 {
171         return cl->tx_queue[cl->txq_cur];
172 }
173
174 static void ubus_msg_dequeue(struct ubus_client *cl)
175 {
176         struct ubus_msg_buf *ub = ubus_msg_head(cl);
177
178         if (!ub)
179                 return;
180
181         ubus_msg_free(ub);
182         cl->txq_ofs = 0;
183         cl->tx_queue[cl->txq_cur] = NULL;
184         cl->txq_cur = (cl->txq_cur + 1) % ARRAY_SIZE(cl->tx_queue);
185 }
186
187 static void handle_client_disconnect(struct ubus_client *cl)
188 {
189         while (ubus_msg_head(cl))
190                 ubus_msg_dequeue(cl);
191
192         ubusd_monitor_disconnect(cl);
193         ubusd_proto_free_client(cl);
194         if (cl->pending_msg_fd >= 0)
195                 close(cl->pending_msg_fd);
196         uloop_fd_delete(&cl->sock);
197         close(cl->sock.fd);
198         free(cl);
199 }
200
201 static void client_cb(struct uloop_fd *sock, unsigned int events)
202 {
203         struct ubus_client *cl = container_of(sock, struct ubus_client, sock);
204         struct ubus_msg_buf *ub;
205         static struct iovec iov;
206         static struct {
207                 struct cmsghdr h;
208                 int fd;
209         } fd_buf = {
210                 .h = {
211                         .cmsg_type = SCM_RIGHTS,
212                         .cmsg_level = SOL_SOCKET,
213                         .cmsg_len = sizeof(fd_buf),
214                 }
215         };
216         struct msghdr msghdr = {
217                 .msg_iov = &iov,
218                 .msg_iovlen = 1,
219         };
220
221         /* first try to tx more pending data */
222         while ((ub = ubus_msg_head(cl))) {
223                 int written;
224
225                 written = ubus_msg_writev(sock->fd, ub, cl->txq_ofs);
226                 if (written < 0) {
227                         switch(errno) {
228                         case EINTR:
229                         case EAGAIN:
230                                 break;
231                         default:
232                                 goto disconnect;
233                         }
234                         break;
235                 }
236
237                 cl->txq_ofs += written;
238                 if (cl->txq_ofs < ub->len + sizeof(ub->hdr))
239                         break;
240
241                 ubus_msg_dequeue(cl);
242         }
243
244         /* prevent further ULOOP_WRITE events if we don't have data
245          * to send anymore */
246         if (!ubus_msg_head(cl) && (events & ULOOP_WRITE))
247                 uloop_fd_add(sock, ULOOP_READ | ULOOP_EDGE_TRIGGER);
248
249 retry:
250         if (!sock->eof && cl->pending_msg_offset < sizeof(cl->hdrbuf)) {
251                 int offset = cl->pending_msg_offset;
252                 int bytes;
253
254                 fd_buf.fd = -1;
255
256                 iov.iov_base = ((char *) &cl->hdrbuf) + offset;
257                 iov.iov_len = sizeof(cl->hdrbuf) - offset;
258
259                 if (cl->pending_msg_fd < 0) {
260                         msghdr.msg_control = &fd_buf;
261                         msghdr.msg_controllen = sizeof(fd_buf);
262                 } else {
263                         msghdr.msg_control = NULL;
264                         msghdr.msg_controllen = 0;
265                 }
266
267                 bytes = recvmsg(sock->fd, &msghdr, 0);
268                 if (bytes < 0)
269                         goto out;
270
271                 if (fd_buf.fd >= 0)
272                         cl->pending_msg_fd = fd_buf.fd;
273
274                 cl->pending_msg_offset += bytes;
275                 if (cl->pending_msg_offset < sizeof(cl->hdrbuf))
276                         goto out;
277
278                 if (blob_pad_len(&cl->hdrbuf.data) > UBUS_MAX_MSGLEN)
279                         goto disconnect;
280
281                 cl->pending_msg = ubus_msg_new(NULL, blob_raw_len(&cl->hdrbuf.data), false);
282                 if (!cl->pending_msg)
283                         goto disconnect;
284
285                 cl->hdrbuf.hdr.seq = be16_to_cpu(cl->hdrbuf.hdr.seq);
286                 cl->hdrbuf.hdr.peer = be32_to_cpu(cl->hdrbuf.hdr.peer);
287
288                 memcpy(&cl->pending_msg->hdr, &cl->hdrbuf.hdr, sizeof(cl->hdrbuf.hdr));
289                 memcpy(cl->pending_msg->data, &cl->hdrbuf.data, sizeof(cl->hdrbuf.data));
290         }
291
292         ub = cl->pending_msg;
293         if (ub) {
294                 int offset = cl->pending_msg_offset - sizeof(ub->hdr);
295                 int len = blob_raw_len(ub->data) - offset;
296                 int bytes = 0;
297
298                 if (len > 0) {
299                         bytes = read(sock->fd, (char *) ub->data + offset, len);
300                         if (bytes <= 0)
301                                 goto out;
302                 }
303
304                 if (bytes < len) {
305                         cl->pending_msg_offset += bytes;
306                         goto out;
307                 }
308
309                 /* accept message */
310                 ub->fd = cl->pending_msg_fd;
311                 cl->pending_msg_fd = -1;
312                 cl->pending_msg_offset = 0;
313                 cl->pending_msg = NULL;
314                 ubusd_monitor_message(cl, ub, false);
315                 ubusd_proto_receive_message(cl, ub);
316                 goto retry;
317         }
318
319 out:
320         if (!sock->eof || ubus_msg_head(cl))
321                 return;
322
323 disconnect:
324         handle_client_disconnect(cl);
325 }
326
327 static bool get_next_connection(int fd)
328 {
329         struct ubus_client *cl;
330         int client_fd;
331
332         client_fd = accept(fd, NULL, 0);
333         if (client_fd < 0) {
334                 switch (errno) {
335                 case ECONNABORTED:
336                 case EINTR:
337                         return true;
338                 default:
339                         return false;
340                 }
341         }
342
343         cl = ubusd_proto_new_client(client_fd, client_cb);
344         if (cl)
345                 uloop_fd_add(&cl->sock, ULOOP_READ | ULOOP_EDGE_TRIGGER);
346         else
347                 close(client_fd);
348
349         return true;
350 }
351
352 static void server_cb(struct uloop_fd *fd, unsigned int events)
353 {
354         bool next;
355
356         do {
357                 next = get_next_connection(fd->fd);
358         } while (next);
359 }
360
361 static struct uloop_fd server_fd = {
362         .cb = server_cb,
363 };
364
365 static int usage(const char *progname)
366 {
367         fprintf(stderr, "Usage: %s [<options>]\n"
368                 "Options: \n"
369                 "  -A <path>:           Set the path to ACL files\n"
370                 "  -s <socket>:         Set the unix domain socket to listen on\n"
371                 "\n", progname);
372         return 1;
373 }
374
375 static void sighup_handler(int sig)
376 {
377         ubusd_acl_load();
378 }
379
380 int main(int argc, char **argv)
381 {
382         const char *ubus_socket = UBUS_UNIX_SOCKET;
383         int ret = 0;
384         int ch;
385
386         signal(SIGPIPE, SIG_IGN);
387         signal(SIGHUP, sighup_handler);
388
389         openlog("ubusd", LOG_PID, LOG_DAEMON);
390         uloop_init();
391
392         while ((ch = getopt(argc, argv, "A:s:")) != -1) {
393                 switch (ch) {
394                 case 's':
395                         ubus_socket = optarg;
396                         break;
397                 case 'A':
398                         ubusd_acl_dir = optarg;
399                         break;
400                 default:
401                         return usage(argv[0]);
402                 }
403         }
404
405         unlink(ubus_socket);
406         umask(0111);
407         server_fd.fd = usock(USOCK_UNIX | USOCK_SERVER | USOCK_NONBLOCK, ubus_socket, NULL);
408         if (server_fd.fd < 0) {
409                 perror("usock");
410                 ret = -1;
411                 goto out;
412         }
413         uloop_fd_add(&server_fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
414         ubusd_acl_load();
415
416         uloop_run();
417         unlink(ubus_socket);
418
419 out:
420         uloop_done();
421         return ret;
422 }