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networkd: don't consider deprecated or tentative addresses when determining operstate
[elogind.git] / src / udev / udev-ctrl.c
1 /*
2  * libudev - interface to udev device information
3  *
4  * Copyright (C) 2008 Kay Sievers <kay@vrfy.org>
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  */
11
12 #include <errno.h>
13 #include <stdio.h>
14 #include <stdlib.h>
15 #include <stddef.h>
16 #include <string.h>
17 #include <unistd.h>
18 #include <sys/types.h>
19 #include <sys/poll.h>
20 #include <sys/socket.h>
21 #include <sys/un.h>
22
23 #include "udev.h"
24
25 /* wire protocol magic must match */
26 #define UDEV_CTRL_MAGIC                                0xdead1dea
27
28 enum udev_ctrl_msg_type {
29         UDEV_CTRL_UNKNOWN,
30         UDEV_CTRL_SET_LOG_LEVEL,
31         UDEV_CTRL_STOP_EXEC_QUEUE,
32         UDEV_CTRL_START_EXEC_QUEUE,
33         UDEV_CTRL_RELOAD,
34         UDEV_CTRL_SET_ENV,
35         UDEV_CTRL_SET_CHILDREN_MAX,
36         UDEV_CTRL_PING,
37         UDEV_CTRL_EXIT,
38 };
39
40 struct udev_ctrl_msg_wire {
41         char version[16];
42         unsigned int magic;
43         enum udev_ctrl_msg_type type;
44         union {
45                 int intval;
46                 char buf[256];
47         };
48 };
49
50 struct udev_ctrl_msg {
51         int refcount;
52         struct udev_ctrl_connection *conn;
53         struct udev_ctrl_msg_wire ctrl_msg_wire;
54 };
55
56 struct udev_ctrl {
57         int refcount;
58         struct udev *udev;
59         int sock;
60         struct sockaddr_un saddr;
61         socklen_t addrlen;
62         bool bound;
63         bool cleanup_socket;
64         bool connected;
65 };
66
67 struct udev_ctrl_connection {
68         int refcount;
69         struct udev_ctrl *uctrl;
70         int sock;
71 };
72
73 struct udev_ctrl *udev_ctrl_new_from_fd(struct udev *udev, int fd) {
74         struct udev_ctrl *uctrl;
75         const int on = 1;
76
77         uctrl = new0(struct udev_ctrl, 1);
78         if (uctrl == NULL)
79                 return NULL;
80         uctrl->refcount = 1;
81         uctrl->udev = udev;
82
83         if (fd < 0) {
84                 uctrl->sock = socket(AF_LOCAL, SOCK_SEQPACKET|SOCK_NONBLOCK|SOCK_CLOEXEC, 0);
85                 if (uctrl->sock < 0) {
86                         log_error("error getting socket: %m");
87                         udev_ctrl_unref(uctrl);
88                         return NULL;
89                 }
90         } else {
91                 uctrl->bound = true;
92                 uctrl->sock = fd;
93         }
94         setsockopt(uctrl->sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
95
96         uctrl->saddr.sun_family = AF_LOCAL;
97         strscpy(uctrl->saddr.sun_path, sizeof(uctrl->saddr.sun_path), "/run/udev/control");
98         uctrl->addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(uctrl->saddr.sun_path);
99         return uctrl;
100 }
101
102 struct udev_ctrl *udev_ctrl_new(struct udev *udev) {
103         return udev_ctrl_new_from_fd(udev, -1);
104 }
105
106 int udev_ctrl_enable_receiving(struct udev_ctrl *uctrl) {
107         int err;
108
109         if (!uctrl->bound) {
110                 err = bind(uctrl->sock, (struct sockaddr *)&uctrl->saddr, uctrl->addrlen);
111                 if (err < 0 && errno == EADDRINUSE) {
112                         unlink(uctrl->saddr.sun_path);
113                         err = bind(uctrl->sock, (struct sockaddr *)&uctrl->saddr, uctrl->addrlen);
114                 }
115
116                 if (err < 0) {
117                         err = -errno;
118                         log_error("bind failed: %m");
119                         return err;
120                 }
121
122                 err = listen(uctrl->sock, 0);
123                 if (err < 0) {
124                         err = -errno;
125                         log_error("listen failed: %m");
126                         return err;
127                 }
128
129                 uctrl->bound = true;
130                 uctrl->cleanup_socket = true;
131         }
132         return 0;
133 }
134
135 struct udev *udev_ctrl_get_udev(struct udev_ctrl *uctrl) {
136         return uctrl->udev;
137 }
138
139 static struct udev_ctrl *udev_ctrl_ref(struct udev_ctrl *uctrl) {
140         if (uctrl == NULL)
141                 return NULL;
142         uctrl->refcount++;
143         return uctrl;
144 }
145
146 struct udev_ctrl *udev_ctrl_unref(struct udev_ctrl *uctrl) {
147         if (uctrl == NULL)
148                 return NULL;
149         uctrl->refcount--;
150         if (uctrl->refcount > 0)
151                 return uctrl;
152         if (uctrl->sock >= 0)
153                 close(uctrl->sock);
154         free(uctrl);
155         return NULL;
156 }
157
158 int udev_ctrl_cleanup(struct udev_ctrl *uctrl) {
159         if (uctrl == NULL)
160                 return 0;
161         if (uctrl->cleanup_socket)
162                 unlink(uctrl->saddr.sun_path);
163         return 0;
164 }
165
166 int udev_ctrl_get_fd(struct udev_ctrl *uctrl) {
167         if (uctrl == NULL)
168                 return -EINVAL;
169         return uctrl->sock;
170 }
171
172 struct udev_ctrl_connection *udev_ctrl_get_connection(struct udev_ctrl *uctrl) {
173         struct udev_ctrl_connection *conn;
174         struct ucred ucred = {};
175         const int on = 1;
176         int r;
177
178         conn = new(struct udev_ctrl_connection, 1);
179         if (conn == NULL)
180                 return NULL;
181         conn->refcount = 1;
182         conn->uctrl = uctrl;
183
184         conn->sock = accept4(uctrl->sock, NULL, NULL, SOCK_CLOEXEC|SOCK_NONBLOCK);
185         if (conn->sock < 0) {
186                 if (errno != EINTR)
187                         log_error("unable to receive ctrl connection: %m");
188                 goto err;
189         }
190
191         /* check peer credential of connection */
192         r = getpeercred(conn->sock, &ucred);
193         if (r < 0) {
194                 log_error("unable to receive credentials of ctrl connection: %s", strerror(-r));
195                 goto err;
196         }
197         if (ucred.uid > 0) {
198                 log_error("sender uid=%i, message ignored", ucred.uid);
199                 goto err;
200         }
201
202         /* enable receiving of the sender credentials in the messages */
203         setsockopt(conn->sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
204         udev_ctrl_ref(uctrl);
205         return conn;
206 err:
207         if (conn->sock >= 0)
208                 close(conn->sock);
209         free(conn);
210         return NULL;
211 }
212
213 struct udev_ctrl_connection *udev_ctrl_connection_ref(struct udev_ctrl_connection *conn) {
214         if (conn == NULL)
215                 return NULL;
216         conn->refcount++;
217         return conn;
218 }
219
220 struct udev_ctrl_connection *udev_ctrl_connection_unref(struct udev_ctrl_connection *conn) {
221         if (conn == NULL)
222                 return NULL;
223         conn->refcount--;
224         if (conn->refcount > 0)
225                 return conn;
226         if (conn->sock >= 0)
227                 close(conn->sock);
228         udev_ctrl_unref(conn->uctrl);
229         free(conn);
230         return NULL;
231 }
232
233 static int ctrl_send(struct udev_ctrl *uctrl, enum udev_ctrl_msg_type type, int intval, const char *buf, int timeout) {
234         struct udev_ctrl_msg_wire ctrl_msg_wire;
235         int err = 0;
236
237         memzero(&ctrl_msg_wire, sizeof(struct udev_ctrl_msg_wire));
238         strcpy(ctrl_msg_wire.version, "udev-" VERSION);
239         ctrl_msg_wire.magic = UDEV_CTRL_MAGIC;
240         ctrl_msg_wire.type = type;
241
242         if (buf != NULL)
243                 strscpy(ctrl_msg_wire.buf, sizeof(ctrl_msg_wire.buf), buf);
244         else
245                 ctrl_msg_wire.intval = intval;
246
247         if (!uctrl->connected) {
248                 if (connect(uctrl->sock, (struct sockaddr *)&uctrl->saddr, uctrl->addrlen) < 0) {
249                         err = -errno;
250                         goto out;
251                 }
252                 uctrl->connected = true;
253         }
254         if (send(uctrl->sock, &ctrl_msg_wire, sizeof(ctrl_msg_wire), 0) < 0) {
255                 err = -errno;
256                 goto out;
257         }
258
259         /* wait for peer message handling or disconnect */
260         for (;;) {
261                 struct pollfd pfd[1];
262                 int r;
263
264                 pfd[0].fd = uctrl->sock;
265                 pfd[0].events = POLLIN;
266                 r = poll(pfd, 1, timeout * MSEC_PER_SEC);
267                 if (r  < 0) {
268                         if (errno == EINTR)
269                                 continue;
270                         err = -errno;
271                         break;
272                 }
273
274                 if (r > 0 && pfd[0].revents & POLLERR) {
275                         err = -EIO;
276                         break;
277                 }
278
279                 if (r == 0)
280                         err = -ETIMEDOUT;
281                 break;
282         }
283 out:
284         return err;
285 }
286
287 int udev_ctrl_send_set_log_level(struct udev_ctrl *uctrl, int priority, int timeout) {
288         return ctrl_send(uctrl, UDEV_CTRL_SET_LOG_LEVEL, priority, NULL, timeout);
289 }
290
291 int udev_ctrl_send_stop_exec_queue(struct udev_ctrl *uctrl, int timeout) {
292         return ctrl_send(uctrl, UDEV_CTRL_STOP_EXEC_QUEUE, 0, NULL, timeout);
293 }
294
295 int udev_ctrl_send_start_exec_queue(struct udev_ctrl *uctrl, int timeout) {
296         return ctrl_send(uctrl, UDEV_CTRL_START_EXEC_QUEUE, 0, NULL, timeout);
297 }
298
299 int udev_ctrl_send_reload(struct udev_ctrl *uctrl, int timeout) {
300         return ctrl_send(uctrl, UDEV_CTRL_RELOAD, 0, NULL, timeout);
301 }
302
303 int udev_ctrl_send_set_env(struct udev_ctrl *uctrl, const char *key, int timeout) {
304         return ctrl_send(uctrl, UDEV_CTRL_SET_ENV, 0, key, timeout);
305 }
306
307 int udev_ctrl_send_set_children_max(struct udev_ctrl *uctrl, int count, int timeout) {
308         return ctrl_send(uctrl, UDEV_CTRL_SET_CHILDREN_MAX, count, NULL, timeout);
309 }
310
311 int udev_ctrl_send_ping(struct udev_ctrl *uctrl, int timeout) {
312         return ctrl_send(uctrl, UDEV_CTRL_PING, 0, NULL, timeout);
313 }
314
315 int udev_ctrl_send_exit(struct udev_ctrl *uctrl, int timeout) {
316         return ctrl_send(uctrl, UDEV_CTRL_EXIT, 0, NULL, timeout);
317 }
318
319 struct udev_ctrl_msg *udev_ctrl_receive_msg(struct udev_ctrl_connection *conn) {
320         struct udev_ctrl_msg *uctrl_msg;
321         ssize_t size;
322         struct cmsghdr *cmsg;
323         struct iovec iov;
324         char cred_msg[CMSG_SPACE(sizeof(struct ucred))];
325         struct msghdr smsg = {
326                 .msg_iov = &iov,
327                 .msg_iovlen = 1,
328                 .msg_control = cred_msg,
329                 .msg_controllen = sizeof(cred_msg),
330         };
331         struct ucred *cred;
332
333         uctrl_msg = new0(struct udev_ctrl_msg, 1);
334         if (uctrl_msg == NULL)
335                 return NULL;
336         uctrl_msg->refcount = 1;
337         uctrl_msg->conn = conn;
338         udev_ctrl_connection_ref(conn);
339
340         /* wait for the incoming message */
341         for (;;) {
342                 struct pollfd pfd[1];
343                 int r;
344
345                 pfd[0].fd = conn->sock;
346                 pfd[0].events = POLLIN;
347
348                 r = poll(pfd, 1, 10000);
349                 if (r  < 0) {
350                         if (errno == EINTR)
351                                 continue;
352                         goto err;
353                 } else if (r == 0) {
354                         log_error("timeout waiting for ctrl message");
355                         goto err;
356                 } else {
357                         if (!(pfd[0].revents & POLLIN)) {
358                                 log_error("ctrl connection error: %m");
359                                 goto err;
360                         }
361                 }
362
363                 break;
364         }
365
366         iov.iov_base = &uctrl_msg->ctrl_msg_wire;
367         iov.iov_len = sizeof(struct udev_ctrl_msg_wire);
368
369         size = recvmsg(conn->sock, &smsg, 0);
370         if (size <  0) {
371                 log_error("unable to receive ctrl message: %m");
372                 goto err;
373         }
374         cmsg = CMSG_FIRSTHDR(&smsg);
375         cred = (struct ucred *) CMSG_DATA(cmsg);
376
377         if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) {
378                 log_error("no sender credentials received, message ignored");
379                 goto err;
380         }
381
382         if (cred->uid != 0) {
383                 log_error("sender uid=%i, message ignored", cred->uid);
384                 goto err;
385         }
386
387         if (uctrl_msg->ctrl_msg_wire.magic != UDEV_CTRL_MAGIC) {
388                 log_error("message magic 0x%08x doesn't match, ignore it", uctrl_msg->ctrl_msg_wire.magic);
389                 goto err;
390         }
391
392         return uctrl_msg;
393 err:
394         udev_ctrl_msg_unref(uctrl_msg);
395         return NULL;
396 }
397
398 struct udev_ctrl_msg *udev_ctrl_msg_unref(struct udev_ctrl_msg *ctrl_msg) {
399         if (ctrl_msg == NULL)
400                 return NULL;
401         ctrl_msg->refcount--;
402         if (ctrl_msg->refcount > 0)
403                 return ctrl_msg;
404         udev_ctrl_connection_unref(ctrl_msg->conn);
405         free(ctrl_msg);
406         return NULL;
407 }
408
409 int udev_ctrl_get_set_log_level(struct udev_ctrl_msg *ctrl_msg) {
410         if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_SET_LOG_LEVEL)
411                 return ctrl_msg->ctrl_msg_wire.intval;
412         return -1;
413 }
414
415 int udev_ctrl_get_stop_exec_queue(struct udev_ctrl_msg *ctrl_msg) {
416         if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_STOP_EXEC_QUEUE)
417                 return 1;
418         return -1;
419 }
420
421 int udev_ctrl_get_start_exec_queue(struct udev_ctrl_msg *ctrl_msg) {
422         if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_START_EXEC_QUEUE)
423                 return 1;
424         return -1;
425 }
426
427 int udev_ctrl_get_reload(struct udev_ctrl_msg *ctrl_msg) {
428         if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_RELOAD)
429                 return 1;
430         return -1;
431 }
432
433 const char *udev_ctrl_get_set_env(struct udev_ctrl_msg *ctrl_msg) {
434         if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_SET_ENV)
435                 return ctrl_msg->ctrl_msg_wire.buf;
436         return NULL;
437 }
438
439 int udev_ctrl_get_set_children_max(struct udev_ctrl_msg *ctrl_msg) {
440         if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_SET_CHILDREN_MAX)
441                 return ctrl_msg->ctrl_msg_wire.intval;
442         return -1;
443 }
444
445 int udev_ctrl_get_ping(struct udev_ctrl_msg *ctrl_msg) {
446         if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_PING)
447                 return 1;
448         return -1;
449 }
450
451 int udev_ctrl_get_exit(struct udev_ctrl_msg *ctrl_msg) {
452         if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_EXIT)
453                 return 1;
454         return -1;
455 }