properly handle return codes
[project/procd.git] / plug / hotplug.c
1 /*
2 * Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
3 * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU Lesser General Public License version 2.1
7 * as published by the Free Software Foundation
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 */
14
15 #include <sys/stat.h>
16 #include <sys/socket.h>
17 #include <sys/types.h>
18
19 #include <linux/types.h>
20 #include <linux/netlink.h>
21
22 #include <libubox/blobmsg_json.h>
23 #include <libubox/json_script.h>
24 #include <libubox/uloop.h>
25 #include <json-c/json.h>
26
27 #include <fcntl.h>
28 #include <unistd.h>
29 #include <stdlib.h>
30 #include <libgen.h>
31
32 #include "../procd.h"
33
34 #include "hotplug.h"
35
36 #define HOTPLUG_WAIT 500
37
38 struct cmd_queue {
39 struct list_head list;
40
41 struct blob_attr *msg;
42 struct blob_attr *data;
43 void (*handler)(struct blob_attr *msg, struct blob_attr *data);
44 };
45
46 static LIST_HEAD(cmd_queue);
47 static struct uloop_process queue_proc;
48 static struct uloop_timeout last_event;
49 static struct blob_buf b;
50 static char *rule_file;
51 static struct blob_buf script;
52
53 static char *hotplug_msg_find_var(struct blob_attr *msg, const char *name)
54 {
55 struct blob_attr *cur;
56 int rem;
57
58 blobmsg_for_each_attr(cur, msg, rem) {
59 if (blobmsg_type(cur) != BLOBMSG_TYPE_STRING)
60 continue;
61
62 if (strcmp(blobmsg_name(cur), name) != 0)
63 continue;
64
65 return blobmsg_data(cur);
66 }
67
68 return NULL;
69 }
70
71 static void mkdir_p(char *dir)
72 {
73 char *l = strrchr(dir, '/');
74
75 if (l) {
76 *l = '\0';
77 mkdir_p(dir);
78 *l = '/';
79 mkdir(dir, 0755);
80 }
81 }
82
83 static void handle_makedev(struct blob_attr *msg, struct blob_attr *data)
84 {
85 unsigned int oldumask = umask(0);
86 static struct blobmsg_policy mkdev_policy[2] = {
87 { .type = BLOBMSG_TYPE_STRING },
88 { .type = BLOBMSG_TYPE_STRING },
89 };
90 struct blob_attr *tb[2];
91 char *minor = hotplug_msg_find_var(msg, "MINOR");
92 char *major = hotplug_msg_find_var(msg, "MAJOR");
93 char *subsystem = hotplug_msg_find_var(msg, "SUBSYSTEM");
94
95 blobmsg_parse_array(mkdev_policy, 2, tb, blobmsg_data(data), blobmsg_data_len(data));
96 if (tb[0] && tb[1] && minor && major && subsystem) {
97 mode_t m = S_IFCHR;
98 char *d = strdup(blobmsg_get_string(tb[0]));
99
100 d = dirname(d);
101 mkdir_p(d);
102 free(d);
103
104 if (!strcmp(subsystem, "block"))
105 m = S_IFBLK;
106 mknod(blobmsg_get_string(tb[0]),
107 m | strtoul(blobmsg_data(tb[1]), NULL, 8),
108 makedev(atoi(major), atoi(minor)));
109 }
110 umask(oldumask);
111 }
112
113 static void handle_rm(struct blob_attr *msg, struct blob_attr *data)
114 {
115 static struct blobmsg_policy rm_policy = {
116 .type = BLOBMSG_TYPE_STRING,
117 };
118 struct blob_attr *tb;
119
120 blobmsg_parse_array(&rm_policy, 1, &tb, blobmsg_data(data), blobmsg_data_len(data));
121 if (tb)
122 unlink(blobmsg_data(tb));
123 }
124
125 static void handle_exec(struct blob_attr *msg, struct blob_attr *data)
126 {
127 char *argv[8];
128 struct blob_attr *cur;
129 int rem, fd;
130 int i = 0;
131
132 blobmsg_for_each_attr(cur, msg, rem)
133 setenv(blobmsg_name(cur), blobmsg_data(cur), 1);
134
135 blobmsg_for_each_attr(cur, data, rem) {
136 argv[i] = blobmsg_data(cur);
137 i++;
138 if (i == 7)
139 break;
140 }
141
142 if (debug < 3) {
143 fd = open("/dev/null", O_RDWR);
144 if (fd > -1) {
145 dup2(fd, STDIN_FILENO);
146 dup2(fd, STDOUT_FILENO);
147 dup2(fd, STDERR_FILENO);
148 if (fd > STDERR_FILENO)
149 close(fd);
150 }
151 }
152
153 if (i > 0) {
154 argv[i] = NULL;
155 execvp(argv[0], &argv[0]);
156 }
157 exit(-1);
158 }
159
160 static void handle_firmware(struct blob_attr *msg, struct blob_attr *data)
161 {
162 char *dir = blobmsg_get_string(blobmsg_data(data));
163 char *file = hotplug_msg_find_var(msg, "FIRMWARE");
164 char *dev = hotplug_msg_find_var(msg, "DEVPATH");
165 struct stat s = { 0 };
166 char *path, loadpath[256], syspath[256];
167 int fw, src, load, len;
168 static char buf[4096];
169
170 DEBUG(2, "Firmware request for %s/%s\n", dir, file);
171
172 if (!file || !dir || !dev) {
173 ERROR("Request for unknown firmware %s/%s\n", dir, file);
174 exit(-1);
175 }
176
177 path = alloca(strlen(dir) + strlen(file) + 2);
178 sprintf(path, "%s/%s", dir, file);
179
180 if (stat(path, &s)) {
181 ERROR("Could not find firmware %s\n", path);
182 src = -1;
183 s.st_size = 0;
184 goto send_to_kernel;
185 }
186
187 src = open(path, O_RDONLY);
188 if (src < 0) {
189 ERROR("Failed to open %s\n", path);
190 s.st_size = 0;
191 goto send_to_kernel;
192 }
193
194 send_to_kernel:
195 snprintf(loadpath, sizeof(loadpath), "/sys/%s/loading", dev);
196 load = open(loadpath, O_WRONLY);
197 if (!load) {
198 ERROR("Failed to open %s\n", loadpath);
199 exit(-1);
200 }
201 if (write(load, "1", 1) == -1) {
202 ERROR("Failed to write to %s\n", loadpath);
203 exit(-1);
204 }
205 close(load);
206
207 snprintf(syspath, sizeof(syspath), "/sys/%s/data", dev);
208 fw = open(syspath, O_WRONLY);
209 if (fw < 0) {
210 ERROR("Failed to open %s\n", syspath);
211 exit(-1);
212 }
213
214 len = s.st_size;
215 while (len) {
216 len = read(src, buf, sizeof(buf));
217 if (len <= 0)
218 break;
219
220 if (write(fw, buf, len) == -1) {
221 ERROR("failed to write firmware file %s/%s to %s\n", dir, file, dev);
222 break;
223 }
224 }
225
226 if (src >= 0)
227 close(src);
228 close(fw);
229
230 load = open(loadpath, O_WRONLY);
231 if (write(load, "0", 1) == -1)
232 ERROR("failed to write to %s\n", loadpath);
233 close(load);
234
235 DEBUG(2, "Done loading %s\n", path);
236
237 exit(-1);
238 }
239
240 static struct cmd_handler {
241 char *name;
242 int atomic;
243 void (*handler)(struct blob_attr *msg, struct blob_attr *data);
244 } handlers[] = {
245 {
246 .name = "makedev",
247 .atomic = 1,
248 .handler = handle_makedev,
249 }, {
250 .name = "rm",
251 .atomic = 1,
252 .handler = handle_rm,
253 }, {
254 .name = "exec",
255 .handler = handle_exec,
256 }, {
257 .name = "load-firmware",
258 .handler = handle_firmware,
259 },
260 };
261
262 static void queue_next(void)
263 {
264 struct cmd_queue *c;
265
266 if (queue_proc.pending || list_empty(&cmd_queue))
267 return;
268
269 c = list_first_entry(&cmd_queue, struct cmd_queue, list);
270
271 queue_proc.pid = fork();
272 if (!queue_proc.pid) {
273 uloop_done();
274 c->handler(c->msg, c->data);
275 exit(0);
276 }
277
278 list_del(&c->list);
279 free(c);
280
281 if (queue_proc.pid <= 0) {
282 queue_next();
283 return;
284 }
285
286 uloop_process_add(&queue_proc);
287
288 DEBUG(4, "Launched hotplug exec instance, pid=%d\n", (int) queue_proc.pid);
289 }
290
291 static void queue_proc_cb(struct uloop_process *c, int ret)
292 {
293 DEBUG(4, "Finished hotplug exec instance, pid=%d\n", (int) c->pid);
294
295 queue_next();
296 }
297
298 static void queue_add(struct cmd_handler *h, struct blob_attr *msg, struct blob_attr *data)
299 {
300 struct cmd_queue *c = NULL;
301 struct blob_attr *_msg, *_data;
302
303 c = calloc_a(sizeof(struct cmd_queue),
304 &_msg, blob_pad_len(msg),
305 &_data, blob_pad_len(data),
306 NULL);
307
308 c->msg = _msg;
309 c->data = _data;
310
311 if (!c)
312 return;
313
314 memcpy(c->msg, msg, blob_pad_len(msg));
315 memcpy(c->data, data, blob_pad_len(data));
316 c->handler = h->handler;
317 list_add_tail(&c->list, &cmd_queue);
318 queue_next();
319 }
320
321 static const char* rule_handle_var(struct json_script_ctx *ctx, const char *name, struct blob_attr *vars)
322 {
323 const char *str, *sep;
324
325 if (!strcmp(name, "DEVICENAME") || !strcmp(name, "DEVNAME")) {
326 str = json_script_find_var(ctx, vars, "DEVPATH");
327 if (!str)
328 return NULL;
329
330 sep = strrchr(str, '/');
331 if (sep)
332 return sep + 1;
333
334 return str;
335 }
336
337 return NULL;
338 }
339
340 static struct json_script_file *
341 rule_handle_file(struct json_script_ctx *ctx, const char *name)
342 {
343 json_object *obj;
344
345 obj = json_object_from_file((char*)name);
346 if (!obj)
347 return NULL;
348
349 blob_buf_init(&script, 0);
350 blobmsg_add_json_element(&script, "", obj);
351
352 return json_script_file_from_blobmsg(name, blob_data(script.head), blob_len(script.head));
353 }
354
355 static void rule_handle_command(struct json_script_ctx *ctx, const char *name,
356 struct blob_attr *data, struct blob_attr *vars)
357 {
358 struct blob_attr *cur;
359 int rem, i;
360
361 if (debug > 3) {
362 DEBUG(4, "Command: %s", name);
363 blobmsg_for_each_attr(cur, data, rem)
364 DEBUG(4, " %s", (char *) blobmsg_data(cur));
365 DEBUG(4, "\n");
366
367 DEBUG(4, "Message:");
368 blobmsg_for_each_attr(cur, vars, rem)
369 DEBUG(4, " %s=%s", blobmsg_name(cur), (char *) blobmsg_data(cur));
370 DEBUG(4, "\n");
371 }
372
373 for (i = 0; i < ARRAY_SIZE(handlers); i++)
374 if (!strcmp(handlers[i].name, name)) {
375 if (handlers[i].atomic)
376 handlers[i].handler(vars, data);
377 else
378 queue_add(&handlers[i], vars, data);
379 break;
380 }
381
382 if (last_event.cb)
383 uloop_timeout_set(&last_event, HOTPLUG_WAIT);
384 }
385
386 static void rule_handle_error(struct json_script_ctx *ctx, const char *msg,
387 struct blob_attr *context)
388 {
389 char *s;
390
391 s = blobmsg_format_json(context, false);
392 ERROR("ERROR: %s in block: %s\n", msg, s);
393 free(s);
394 }
395
396 static struct json_script_ctx jctx = {
397 .handle_var = rule_handle_var,
398 .handle_error = rule_handle_error,
399 .handle_command = rule_handle_command,
400 .handle_file = rule_handle_file,
401 };
402
403 static void hotplug_handler_debug(struct blob_attr *data)
404 {
405 char *str;
406
407 if (debug < 3)
408 return;
409
410 str = blobmsg_format_json(data, true);
411 DEBUG(3, "%s\n", str);
412 free(str);
413 }
414
415 static void hotplug_handler(struct uloop_fd *u, unsigned int ev)
416 {
417 int i = 0;
418 static char buf[4096];
419 int len = recv(u->fd, buf, sizeof(buf), MSG_DONTWAIT);
420 void *index;
421 if (len < 1)
422 return;
423
424 blob_buf_init(&b, 0);
425 index = blobmsg_open_table(&b, NULL);
426 while (i < len) {
427 int l = strlen(buf + i) + 1;
428 char *e = strstr(&buf[i], "=");
429
430 if (e) {
431 *e = '\0';
432 blobmsg_add_string(&b, &buf[i], &e[1]);
433 }
434 i += l;
435 }
436 blobmsg_close_table(&b, index);
437 hotplug_handler_debug(b.head);
438 json_script_run(&jctx, rule_file, blob_data(b.head));
439 }
440
441 static struct uloop_fd hotplug_fd = {
442 .cb = hotplug_handler,
443 };
444
445 void hotplug_last_event(uloop_timeout_handler handler)
446 {
447 last_event.cb = handler;
448 if (handler)
449 uloop_timeout_set(&last_event, HOTPLUG_WAIT);
450 else
451 uloop_timeout_cancel(&last_event);
452 }
453
454 void hotplug(char *rules)
455 {
456 struct sockaddr_nl nls;
457 int nlbufsize = 512 * 1024;
458
459 rule_file = strdup(rules);
460 memset(&nls,0,sizeof(struct sockaddr_nl));
461 nls.nl_family = AF_NETLINK;
462 nls.nl_pid = getpid();
463 nls.nl_groups = -1;
464
465 if ((hotplug_fd.fd = socket(PF_NETLINK, SOCK_DGRAM | SOCK_CLOEXEC, NETLINK_KOBJECT_UEVENT)) == -1) {
466 ERROR("Failed to open hotplug socket: %s\n", strerror(errno));
467 exit(1);
468 }
469 if (bind(hotplug_fd.fd, (void *)&nls, sizeof(struct sockaddr_nl))) {
470 ERROR("Failed to bind hotplug socket: %s\n", strerror(errno));
471 exit(1);
472 }
473
474 if (setsockopt(hotplug_fd.fd, SOL_SOCKET, SO_RCVBUFFORCE, &nlbufsize, sizeof(nlbufsize)))
475 ERROR("Failed to resize receive buffer: %s\n", strerror(errno));
476
477 json_script_init(&jctx);
478 queue_proc.cb = queue_proc_cb;
479 uloop_fd_add(&hotplug_fd, ULOOP_READ);
480 }
481
482 int hotplug_run(char *rules)
483 {
484 uloop_init();
485 hotplug(rules);
486 uloop_run();
487
488 return 0;
489 }
490
491 void hotplug_shutdown(void)
492 {
493 uloop_fd_delete(&hotplug_fd);
494 close(hotplug_fd.fd);
495 }