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a75eb03b DM |
1 | /* |
2 | * Copyright 6WIND S.A., 2014 | |
3 | * | |
4 | * This work is licensed under the terms of the GNU GPL, version 2 or | |
5 | * (at your option) any later version. See the COPYING file in the | |
6 | * top-level directory. | |
7 | */ | |
8 | ||
ccd241b5 | 9 | #include "qemu/osdep.h" |
a75eb03b DM |
10 | #include <sys/socket.h> |
11 | #include <sys/un.h> | |
12 | ||
a75eb03b DM |
13 | #include "qemu/queue.h" |
14 | ||
15 | #include "ivshmem-client.h" | |
16 | ||
17 | /* log a message on stdout if verbose=1 */ | |
18 | #define IVSHMEM_CLIENT_DEBUG(client, fmt, ...) do { \ | |
19 | if ((client)->verbose) { \ | |
20 | printf(fmt, ## __VA_ARGS__); \ | |
21 | } \ | |
22 | } while (0) | |
23 | ||
24 | /* read message from the unix socket */ | |
25 | static int | |
f7a199b2 | 26 | ivshmem_client_read_one_msg(IvshmemClient *client, int64_t *index, int *fd) |
a75eb03b DM |
27 | { |
28 | int ret; | |
29 | struct msghdr msg; | |
30 | struct iovec iov[1]; | |
31 | union { | |
32 | struct cmsghdr cmsg; | |
33 | char control[CMSG_SPACE(sizeof(int))]; | |
34 | } msg_control; | |
35 | struct cmsghdr *cmsg; | |
36 | ||
37 | iov[0].iov_base = index; | |
38 | iov[0].iov_len = sizeof(*index); | |
39 | ||
40 | memset(&msg, 0, sizeof(msg)); | |
41 | msg.msg_iov = iov; | |
42 | msg.msg_iovlen = 1; | |
43 | msg.msg_control = &msg_control; | |
44 | msg.msg_controllen = sizeof(msg_control); | |
45 | ||
46 | ret = recvmsg(client->sock_fd, &msg, 0); | |
f7a199b2 | 47 | if (ret < sizeof(*index)) { |
a75eb03b DM |
48 | IVSHMEM_CLIENT_DEBUG(client, "cannot read message: %s\n", |
49 | strerror(errno)); | |
50 | return -1; | |
51 | } | |
52 | if (ret == 0) { | |
53 | IVSHMEM_CLIENT_DEBUG(client, "lost connection to server\n"); | |
54 | return -1; | |
55 | } | |
56 | ||
f7a199b2 | 57 | *index = GINT64_FROM_LE(*index); |
a75eb03b DM |
58 | *fd = -1; |
59 | ||
60 | for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) { | |
61 | ||
62 | if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)) || | |
63 | cmsg->cmsg_level != SOL_SOCKET || | |
64 | cmsg->cmsg_type != SCM_RIGHTS) { | |
65 | continue; | |
66 | } | |
67 | ||
68 | memcpy(fd, CMSG_DATA(cmsg), sizeof(*fd)); | |
69 | } | |
70 | ||
71 | return 0; | |
72 | } | |
73 | ||
74 | /* free a peer when the server advertises a disconnection or when the | |
75 | * client is freed */ | |
76 | static void | |
77 | ivshmem_client_free_peer(IvshmemClient *client, IvshmemClientPeer *peer) | |
78 | { | |
79 | unsigned vector; | |
80 | ||
81 | QTAILQ_REMOVE(&client->peer_list, peer, next); | |
82 | for (vector = 0; vector < peer->vectors_count; vector++) { | |
83 | close(peer->vectors[vector]); | |
84 | } | |
85 | ||
86 | g_free(peer); | |
87 | } | |
88 | ||
89 | /* handle message coming from server (new peer, new vectors) */ | |
90 | static int | |
91 | ivshmem_client_handle_server_msg(IvshmemClient *client) | |
92 | { | |
93 | IvshmemClientPeer *peer; | |
f7a199b2 | 94 | int64_t peer_id; |
a75eb03b DM |
95 | int ret, fd; |
96 | ||
97 | ret = ivshmem_client_read_one_msg(client, &peer_id, &fd); | |
98 | if (ret < 0) { | |
99 | return -1; | |
100 | } | |
101 | ||
102 | /* can return a peer or the local client */ | |
103 | peer = ivshmem_client_search_peer(client, peer_id); | |
104 | ||
105 | /* delete peer */ | |
106 | if (fd == -1) { | |
107 | ||
108 | if (peer == NULL || peer == &client->local) { | |
109 | IVSHMEM_CLIENT_DEBUG(client, "receive delete for invalid " | |
f7a199b2 | 110 | "peer %" PRId64 "\n", peer_id); |
a75eb03b DM |
111 | return -1; |
112 | } | |
113 | ||
f7a199b2 | 114 | IVSHMEM_CLIENT_DEBUG(client, "delete peer id = %" PRId64 "\n", peer_id); |
a75eb03b DM |
115 | ivshmem_client_free_peer(client, peer); |
116 | return 0; | |
117 | } | |
118 | ||
119 | /* new peer */ | |
120 | if (peer == NULL) { | |
121 | peer = g_malloc0(sizeof(*peer)); | |
122 | peer->id = peer_id; | |
123 | peer->vectors_count = 0; | |
124 | QTAILQ_INSERT_TAIL(&client->peer_list, peer, next); | |
f7a199b2 | 125 | IVSHMEM_CLIENT_DEBUG(client, "new peer id = %" PRId64 "\n", peer_id); |
a75eb03b DM |
126 | } |
127 | ||
128 | /* new vector */ | |
f7a199b2 MAL |
129 | IVSHMEM_CLIENT_DEBUG(client, " new vector %d (fd=%d) for peer id %" |
130 | PRId64 "\n", peer->vectors_count, fd, peer->id); | |
95204aa9 MAL |
131 | if (peer->vectors_count >= G_N_ELEMENTS(peer->vectors)) { |
132 | IVSHMEM_CLIENT_DEBUG(client, "Too many vectors received, failing"); | |
133 | return -1; | |
134 | } | |
135 | ||
a75eb03b DM |
136 | peer->vectors[peer->vectors_count] = fd; |
137 | peer->vectors_count++; | |
138 | ||
139 | return 0; | |
140 | } | |
141 | ||
142 | /* init a new ivshmem client */ | |
143 | int | |
144 | ivshmem_client_init(IvshmemClient *client, const char *unix_sock_path, | |
145 | IvshmemClientNotifCb notif_cb, void *notif_arg, | |
146 | bool verbose) | |
147 | { | |
148 | int ret; | |
149 | unsigned i; | |
150 | ||
151 | memset(client, 0, sizeof(*client)); | |
152 | ||
153 | ret = snprintf(client->unix_sock_path, sizeof(client->unix_sock_path), | |
154 | "%s", unix_sock_path); | |
155 | ||
156 | if (ret < 0 || ret >= sizeof(client->unix_sock_path)) { | |
157 | IVSHMEM_CLIENT_DEBUG(client, "could not copy unix socket path\n"); | |
158 | return -1; | |
159 | } | |
160 | ||
161 | for (i = 0; i < IVSHMEM_CLIENT_MAX_VECTORS; i++) { | |
162 | client->local.vectors[i] = -1; | |
163 | } | |
164 | ||
165 | QTAILQ_INIT(&client->peer_list); | |
166 | client->local.id = -1; | |
167 | ||
168 | client->notif_cb = notif_cb; | |
169 | client->notif_arg = notif_arg; | |
170 | client->verbose = verbose; | |
171 | client->shm_fd = -1; | |
172 | client->sock_fd = -1; | |
173 | ||
174 | return 0; | |
175 | } | |
176 | ||
177 | /* create and connect to the unix socket */ | |
178 | int | |
179 | ivshmem_client_connect(IvshmemClient *client) | |
180 | { | |
7e47061d | 181 | struct sockaddr_un s_un; |
a75eb03b | 182 | int fd, ret; |
f7a199b2 | 183 | int64_t tmp; |
a75eb03b DM |
184 | |
185 | IVSHMEM_CLIENT_DEBUG(client, "connect to client %s\n", | |
186 | client->unix_sock_path); | |
187 | ||
188 | client->sock_fd = socket(AF_UNIX, SOCK_STREAM, 0); | |
189 | if (client->sock_fd < 0) { | |
190 | IVSHMEM_CLIENT_DEBUG(client, "cannot create socket: %s\n", | |
191 | strerror(errno)); | |
192 | return -1; | |
193 | } | |
194 | ||
7e47061d DC |
195 | s_un.sun_family = AF_UNIX; |
196 | ret = snprintf(s_un.sun_path, sizeof(s_un.sun_path), "%s", | |
a75eb03b | 197 | client->unix_sock_path); |
7e47061d | 198 | if (ret < 0 || ret >= sizeof(s_un.sun_path)) { |
a75eb03b DM |
199 | IVSHMEM_CLIENT_DEBUG(client, "could not copy unix socket path\n"); |
200 | goto err_close; | |
201 | } | |
202 | ||
7e47061d DC |
203 | if (connect(client->sock_fd, (struct sockaddr *)&s_un, sizeof(s_un)) < 0) { |
204 | IVSHMEM_CLIENT_DEBUG(client, "cannot connect to %s: %s\n", s_un.sun_path, | |
a75eb03b DM |
205 | strerror(errno)); |
206 | goto err_close; | |
207 | } | |
208 | ||
5105b1d8 DM |
209 | /* first, we expect a protocol version */ |
210 | if (ivshmem_client_read_one_msg(client, &tmp, &fd) < 0 || | |
211 | (tmp != IVSHMEM_PROTOCOL_VERSION) || fd != -1) { | |
212 | IVSHMEM_CLIENT_DEBUG(client, "cannot read from server\n"); | |
213 | goto err_close; | |
214 | } | |
215 | ||
216 | /* then, we expect our index + a fd == -1 */ | |
a75eb03b DM |
217 | if (ivshmem_client_read_one_msg(client, &client->local.id, &fd) < 0 || |
218 | client->local.id < 0 || fd != -1) { | |
5105b1d8 | 219 | IVSHMEM_CLIENT_DEBUG(client, "cannot read from server (2)\n"); |
a75eb03b DM |
220 | goto err_close; |
221 | } | |
f7a199b2 | 222 | IVSHMEM_CLIENT_DEBUG(client, "our_id=%" PRId64 "\n", client->local.id); |
a75eb03b DM |
223 | |
224 | /* now, we expect shared mem fd + a -1 index, note that shm fd | |
225 | * is not used */ | |
226 | if (ivshmem_client_read_one_msg(client, &tmp, &fd) < 0 || | |
227 | tmp != -1 || fd < 0) { | |
228 | if (fd >= 0) { | |
229 | close(fd); | |
230 | } | |
5105b1d8 | 231 | IVSHMEM_CLIENT_DEBUG(client, "cannot read from server (3)\n"); |
a75eb03b DM |
232 | goto err_close; |
233 | } | |
234 | client->shm_fd = fd; | |
235 | IVSHMEM_CLIENT_DEBUG(client, "shm_fd=%d\n", fd); | |
236 | ||
237 | return 0; | |
238 | ||
239 | err_close: | |
240 | close(client->sock_fd); | |
241 | client->sock_fd = -1; | |
242 | return -1; | |
243 | } | |
244 | ||
245 | /* close connection to the server, and free all peer structures */ | |
246 | void | |
247 | ivshmem_client_close(IvshmemClient *client) | |
248 | { | |
249 | IvshmemClientPeer *peer; | |
250 | unsigned i; | |
251 | ||
252 | IVSHMEM_CLIENT_DEBUG(client, "close client\n"); | |
253 | ||
254 | while ((peer = QTAILQ_FIRST(&client->peer_list)) != NULL) { | |
255 | ivshmem_client_free_peer(client, peer); | |
256 | } | |
257 | ||
258 | close(client->shm_fd); | |
259 | client->shm_fd = -1; | |
260 | close(client->sock_fd); | |
261 | client->sock_fd = -1; | |
262 | client->local.id = -1; | |
263 | for (i = 0; i < IVSHMEM_CLIENT_MAX_VECTORS; i++) { | |
264 | close(client->local.vectors[i]); | |
265 | client->local.vectors[i] = -1; | |
266 | } | |
267 | client->local.vectors_count = 0; | |
268 | } | |
269 | ||
270 | /* get the fd_set according to the unix socket and peer list */ | |
271 | void | |
272 | ivshmem_client_get_fds(const IvshmemClient *client, fd_set *fds, int *maxfd) | |
273 | { | |
274 | int fd; | |
275 | unsigned vector; | |
276 | ||
277 | FD_SET(client->sock_fd, fds); | |
278 | if (client->sock_fd >= *maxfd) { | |
279 | *maxfd = client->sock_fd + 1; | |
280 | } | |
281 | ||
282 | for (vector = 0; vector < client->local.vectors_count; vector++) { | |
283 | fd = client->local.vectors[vector]; | |
284 | FD_SET(fd, fds); | |
285 | if (fd >= *maxfd) { | |
286 | *maxfd = fd + 1; | |
287 | } | |
288 | } | |
289 | } | |
290 | ||
291 | /* handle events from eventfd: just print a message on notification */ | |
292 | static int | |
293 | ivshmem_client_handle_event(IvshmemClient *client, const fd_set *cur, int maxfd) | |
294 | { | |
295 | IvshmemClientPeer *peer; | |
296 | uint64_t kick; | |
297 | unsigned i; | |
298 | int ret; | |
299 | ||
300 | peer = &client->local; | |
301 | ||
302 | for (i = 0; i < peer->vectors_count; i++) { | |
303 | if (peer->vectors[i] >= maxfd || !FD_ISSET(peer->vectors[i], cur)) { | |
304 | continue; | |
305 | } | |
306 | ||
307 | ret = read(peer->vectors[i], &kick, sizeof(kick)); | |
308 | if (ret < 0) { | |
309 | return ret; | |
310 | } | |
311 | if (ret != sizeof(kick)) { | |
312 | IVSHMEM_CLIENT_DEBUG(client, "invalid read size = %d\n", ret); | |
313 | errno = EINVAL; | |
314 | return -1; | |
315 | } | |
316 | IVSHMEM_CLIENT_DEBUG(client, "received event on fd %d vector %d: %" | |
317 | PRIu64 "\n", peer->vectors[i], i, kick); | |
318 | if (client->notif_cb != NULL) { | |
319 | client->notif_cb(client, peer, i, client->notif_arg); | |
320 | } | |
321 | } | |
322 | ||
323 | return 0; | |
324 | } | |
325 | ||
326 | /* read and handle new messages on the given fd_set */ | |
327 | int | |
328 | ivshmem_client_handle_fds(IvshmemClient *client, fd_set *fds, int maxfd) | |
329 | { | |
330 | if (client->sock_fd < maxfd && FD_ISSET(client->sock_fd, fds) && | |
331 | ivshmem_client_handle_server_msg(client) < 0 && errno != EINTR) { | |
332 | IVSHMEM_CLIENT_DEBUG(client, "ivshmem_client_handle_server_msg() " | |
333 | "failed\n"); | |
334 | return -1; | |
335 | } else if (ivshmem_client_handle_event(client, fds, maxfd) < 0 && | |
336 | errno != EINTR) { | |
337 | IVSHMEM_CLIENT_DEBUG(client, "ivshmem_client_handle_event() failed\n"); | |
338 | return -1; | |
339 | } | |
340 | ||
341 | return 0; | |
342 | } | |
343 | ||
344 | /* send a notification on a vector of a peer */ | |
345 | int | |
346 | ivshmem_client_notify(const IvshmemClient *client, | |
347 | const IvshmemClientPeer *peer, unsigned vector) | |
348 | { | |
349 | uint64_t kick; | |
350 | int fd; | |
351 | ||
352 | if (vector >= peer->vectors_count) { | |
f7a199b2 | 353 | IVSHMEM_CLIENT_DEBUG(client, "invalid vector %u on peer %" PRId64 "\n", |
a75eb03b DM |
354 | vector, peer->id); |
355 | return -1; | |
356 | } | |
357 | fd = peer->vectors[vector]; | |
f7a199b2 MAL |
358 | IVSHMEM_CLIENT_DEBUG(client, "notify peer %" PRId64 |
359 | " on vector %d, fd %d\n", peer->id, vector, fd); | |
a75eb03b DM |
360 | |
361 | kick = 1; | |
362 | if (write(fd, &kick, sizeof(kick)) != sizeof(kick)) { | |
363 | fprintf(stderr, "could not write to %d: %s\n", peer->vectors[vector], | |
364 | strerror(errno)); | |
365 | return -1; | |
366 | } | |
367 | return 0; | |
368 | } | |
369 | ||
370 | /* send a notification to all vectors of a peer */ | |
371 | int | |
372 | ivshmem_client_notify_all_vects(const IvshmemClient *client, | |
373 | const IvshmemClientPeer *peer) | |
374 | { | |
375 | unsigned vector; | |
376 | int ret = 0; | |
377 | ||
378 | for (vector = 0; vector < peer->vectors_count; vector++) { | |
379 | if (ivshmem_client_notify(client, peer, vector) < 0) { | |
380 | ret = -1; | |
381 | } | |
382 | } | |
383 | ||
384 | return ret; | |
385 | } | |
386 | ||
387 | /* send a notification to all peers */ | |
388 | int | |
389 | ivshmem_client_notify_broadcast(const IvshmemClient *client) | |
390 | { | |
391 | IvshmemClientPeer *peer; | |
392 | int ret = 0; | |
393 | ||
394 | QTAILQ_FOREACH(peer, &client->peer_list, next) { | |
395 | if (ivshmem_client_notify_all_vects(client, peer) < 0) { | |
396 | ret = -1; | |
397 | } | |
398 | } | |
399 | ||
400 | return ret; | |
401 | } | |
402 | ||
403 | /* lookup peer from its id */ | |
404 | IvshmemClientPeer * | |
f7a199b2 | 405 | ivshmem_client_search_peer(IvshmemClient *client, int64_t peer_id) |
a75eb03b DM |
406 | { |
407 | IvshmemClientPeer *peer; | |
408 | ||
409 | if (peer_id == client->local.id) { | |
410 | return &client->local; | |
411 | } | |
412 | ||
413 | QTAILQ_FOREACH(peer, &client->peer_list, next) { | |
414 | if (peer->id == peer_id) { | |
415 | return peer; | |
416 | } | |
417 | } | |
418 | return NULL; | |
419 | } | |
420 | ||
421 | /* dump our info, the list of peers their vectors on stdout */ | |
422 | void | |
423 | ivshmem_client_dump(const IvshmemClient *client) | |
424 | { | |
425 | const IvshmemClientPeer *peer; | |
426 | unsigned vector; | |
427 | ||
428 | /* dump local infos */ | |
429 | peer = &client->local; | |
f7a199b2 | 430 | printf("our_id = %" PRId64 "\n", peer->id); |
a75eb03b DM |
431 | for (vector = 0; vector < peer->vectors_count; vector++) { |
432 | printf(" vector %d is enabled (fd=%d)\n", vector, | |
433 | peer->vectors[vector]); | |
434 | } | |
435 | ||
436 | /* dump peers */ | |
437 | QTAILQ_FOREACH(peer, &client->peer_list, next) { | |
f7a199b2 | 438 | printf("peer_id = %" PRId64 "\n", peer->id); |
a75eb03b DM |
439 | |
440 | for (vector = 0; vector < peer->vectors_count; vector++) { | |
441 | printf(" vector %d is enabled (fd=%d)\n", vector, | |
442 | peer->vectors[vector]); | |
443 | } | |
444 | } | |
445 | } |