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ebd04379 | 1 | /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
d59f11e1 | 2 | |
d59f11e1 | 3 | #include <errno.h> |
cf0fbc49 | 4 | #include <poll.h> |
d59f11e1 | 5 | #include <stddef.h> |
cf0fbc49 | 6 | #include <stdlib.h> |
d59f11e1 | 7 | #include <string.h> |
d59f11e1 | 8 | #include <sys/un.h> |
cf0fbc49 | 9 | #include <unistd.h> |
d59f11e1 | 10 | |
d02c6f54 YW |
11 | #include "sd-event.h" |
12 | ||
b5efdb8a | 13 | #include "alloc-util.h" |
4ff9bc2e | 14 | #include "errno-util.h" |
3ffd4af2 | 15 | #include "fd-util.h" |
f97b34a6 | 16 | #include "format-util.h" |
5cfa2c3d | 17 | #include "io-util.h" |
3ffd4af2 | 18 | #include "socket-util.h" |
7d68eb1b YW |
19 | #include "strxcpyx.h" |
20 | #include "udev-ctrl.h" | |
ef118d00 | 21 | #include "util.h" |
d59f11e1 | 22 | |
540f4669 | 23 | /* wire protocol magic must match */ |
912541b0 | 24 | #define UDEV_CTRL_MAGIC 0xdead1dea |
d59f11e1 | 25 | |
e0d61dac | 26 | typedef struct UdevCtrlMessageWire { |
912541b0 | 27 | char version[16]; |
14cb109d | 28 | unsigned magic; |
e0d61dac YW |
29 | UdevCtrlMessageType type; |
30 | UdevCtrlMessageValue value; | |
31 | } UdevCtrlMessageWire; | |
d59f11e1 | 32 | |
e0d61dac | 33 | struct UdevCtrl { |
8f71a0d1 | 34 | unsigned n_ref; |
912541b0 | 35 | int sock; |
d02c6f54 | 36 | int sock_connect; |
6421348d | 37 | union sockaddr_union saddr; |
912541b0 | 38 | socklen_t addrlen; |
481f24d1 | 39 | bool bound; |
481f24d1 YW |
40 | bool connected; |
41 | bool maybe_disconnected; | |
d02c6f54 YW |
42 | sd_event *event; |
43 | sd_event_source *event_source; | |
44 | sd_event_source *event_source_connect; | |
45 | udev_ctrl_handler_t callback; | |
46 | void *userdata; | |
d59f11e1 KS |
47 | }; |
48 | ||
e0d61dac | 49 | int udev_ctrl_new_from_fd(UdevCtrl **ret, int fd) { |
100bc5bf | 50 | _cleanup_close_ int sock = -1; |
e0d61dac | 51 | UdevCtrl *uctrl; |
912541b0 | 52 | |
100bc5bf | 53 | assert(ret); |
912541b0 KS |
54 | |
55 | if (fd < 0) { | |
100bc5bf YW |
56 | sock = socket(AF_LOCAL, SOCK_SEQPACKET|SOCK_NONBLOCK|SOCK_CLOEXEC, 0); |
57 | if (sock < 0) | |
58 | return log_error_errno(errno, "Failed to create socket: %m"); | |
912541b0 | 59 | } |
25568304 | 60 | |
e0d61dac | 61 | uctrl = new(UdevCtrl, 1); |
100bc5bf YW |
62 | if (!uctrl) |
63 | return -ENOMEM; | |
64 | ||
e0d61dac | 65 | *uctrl = (UdevCtrl) { |
100bc5bf YW |
66 | .n_ref = 1, |
67 | .sock = fd >= 0 ? fd : TAKE_FD(sock), | |
2f5b282a | 68 | .sock_connect = -1, |
100bc5bf YW |
69 | .bound = fd >= 0, |
70 | }; | |
71 | ||
44ed5214 LP |
72 | uctrl->saddr.un = (struct sockaddr_un) { |
73 | .sun_family = AF_UNIX, | |
74 | .sun_path = "/run/udev/control", | |
75 | }; | |
76 | ||
fc2fffe7 | 77 | uctrl->addrlen = SOCKADDR_UN_LEN(uctrl->saddr.un); |
fc1de713 | 78 | |
100bc5bf YW |
79 | *ret = TAKE_PTR(uctrl); |
80 | return 0; | |
d59f11e1 KS |
81 | } |
82 | ||
e0d61dac | 83 | int udev_ctrl_enable_receiving(UdevCtrl *uctrl) { |
53bba2fb | 84 | assert(uctrl); |
912541b0 | 85 | |
53bba2fb YW |
86 | if (uctrl->bound) |
87 | return 0; | |
912541b0 | 88 | |
bdb492b2 YW |
89 | (void) sockaddr_un_unlink(&uctrl->saddr.un); |
90 | if (bind(uctrl->sock, &uctrl->saddr.sa, uctrl->addrlen) < 0) | |
53bba2fb YW |
91 | return log_error_errno(errno, "Failed to bind udev control socket: %m"); |
92 | ||
93 | if (listen(uctrl->sock, 0) < 0) | |
94 | return log_error_errno(errno, "Failed to listen udev control socket: %m"); | |
95 | ||
96 | uctrl->bound = true; | |
912541b0 | 97 | return 0; |
d59f11e1 KS |
98 | } |
99 | ||
e0d61dac | 100 | static void udev_ctrl_disconnect(UdevCtrl *uctrl) { |
d02c6f54 YW |
101 | if (!uctrl) |
102 | return; | |
103 | ||
9612da36 | 104 | uctrl->event_source_connect = sd_event_source_disable_unref(uctrl->event_source_connect); |
d02c6f54 YW |
105 | uctrl->sock_connect = safe_close(uctrl->sock_connect); |
106 | } | |
107 | ||
e0d61dac | 108 | static UdevCtrl *udev_ctrl_free(UdevCtrl *uctrl) { |
8f71a0d1 | 109 | assert(uctrl); |
35927d13 | 110 | |
d02c6f54 YW |
111 | udev_ctrl_disconnect(uctrl); |
112 | ||
9612da36 | 113 | sd_event_source_disable_unref(uctrl->event_source); |
8f71a0d1 | 114 | safe_close(uctrl->sock); |
d02c6f54 YW |
115 | |
116 | sd_event_unref(uctrl->event); | |
8f71a0d1 | 117 | return mfree(uctrl); |
d59f11e1 KS |
118 | } |
119 | ||
e0d61dac | 120 | DEFINE_TRIVIAL_REF_UNREF_FUNC(UdevCtrl, udev_ctrl, udev_ctrl_free); |
d59f11e1 | 121 | |
e0d61dac | 122 | int udev_ctrl_attach_event(UdevCtrl *uctrl, sd_event *event) { |
d02c6f54 YW |
123 | int r; |
124 | ||
125 | assert_return(uctrl, -EINVAL); | |
126 | assert_return(!uctrl->event, -EBUSY); | |
127 | ||
128 | if (event) | |
129 | uctrl->event = sd_event_ref(event); | |
130 | else { | |
131 | r = sd_event_default(&uctrl->event); | |
132 | if (r < 0) | |
133 | return r; | |
134 | } | |
135 | ||
136 | return 0; | |
d59f11e1 KS |
137 | } |
138 | ||
e0d61dac | 139 | sd_event_source *udev_ctrl_get_event_source(UdevCtrl *uctrl) { |
d02c6f54 YW |
140 | assert(uctrl); |
141 | ||
142 | return uctrl->event_source; | |
143 | } | |
144 | ||
e0d61dac | 145 | static void udev_ctrl_disconnect_and_listen_again(UdevCtrl *uctrl) { |
d02c6f54 YW |
146 | udev_ctrl_disconnect(uctrl); |
147 | udev_ctrl_unref(uctrl); | |
148 | (void) sd_event_source_set_enabled(uctrl->event_source, SD_EVENT_ON); | |
75db809a | 149 | /* We don't return NULL here because uctrl is not freed */ |
d02c6f54 YW |
150 | } |
151 | ||
e0d61dac | 152 | DEFINE_TRIVIAL_CLEANUP_FUNC_FULL(UdevCtrl*, udev_ctrl_disconnect_and_listen_again, NULL); |
d02c6f54 YW |
153 | |
154 | static int udev_ctrl_connection_event_handler(sd_event_source *s, int fd, uint32_t revents, void *userdata) { | |
e0d61dac YW |
155 | _cleanup_(udev_ctrl_disconnect_and_listen_againp) UdevCtrl *uctrl = NULL; |
156 | UdevCtrlMessageWire msg_wire; | |
157 | struct iovec iov = IOVEC_MAKE(&msg_wire, sizeof(UdevCtrlMessageWire)); | |
fb29cdbe | 158 | CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct ucred))) control; |
d02c6f54 YW |
159 | struct msghdr smsg = { |
160 | .msg_iov = &iov, | |
161 | .msg_iovlen = 1, | |
fb29cdbe LP |
162 | .msg_control = &control, |
163 | .msg_controllen = sizeof(control), | |
d02c6f54 YW |
164 | }; |
165 | struct cmsghdr *cmsg; | |
166 | struct ucred *cred; | |
167 | ssize_t size; | |
168 | ||
169 | assert(userdata); | |
170 | ||
171 | /* When UDEV_CTRL_EXIT is received, manager unref udev_ctrl object. | |
172 | * To avoid the object freed, let's increment the refcount. */ | |
173 | uctrl = udev_ctrl_ref(userdata); | |
174 | ||
175 | size = next_datagram_size_fd(fd); | |
176 | if (size < 0) | |
177 | return log_error_errno(size, "Failed to get size of message: %m"); | |
178 | if (size == 0) | |
179 | return 0; /* Client disconnects? */ | |
180 | ||
3691bcf3 LP |
181 | size = recvmsg_safe(fd, &smsg, 0); |
182 | if (size == -EINTR) | |
d02c6f54 | 183 | return 0; |
3691bcf3 LP |
184 | if (size < 0) |
185 | return log_error_errno(size, "Failed to receive ctrl message: %m"); | |
d02c6f54 YW |
186 | |
187 | cmsg_close_all(&smsg); | |
188 | ||
189 | cmsg = CMSG_FIRSTHDR(&smsg); | |
190 | ||
191 | if (!cmsg || cmsg->cmsg_type != SCM_CREDENTIALS) { | |
192 | log_error("No sender credentials received, ignoring message"); | |
193 | return 0; | |
194 | } | |
195 | ||
196 | cred = (struct ucred *) CMSG_DATA(cmsg); | |
197 | ||
198 | if (cred->uid != 0) { | |
199 | log_error("Invalid sender uid "UID_FMT", ignoring message", cred->uid); | |
200 | return 0; | |
201 | } | |
202 | ||
203 | if (msg_wire.magic != UDEV_CTRL_MAGIC) { | |
204 | log_error("Message magic 0x%08x doesn't match, ignoring message", msg_wire.magic); | |
205 | return 0; | |
206 | } | |
207 | ||
78467aeb YW |
208 | if (msg_wire.type == _UDEV_CTRL_END_MESSAGES) |
209 | return 0; | |
210 | ||
d02c6f54 YW |
211 | if (uctrl->callback) |
212 | (void) uctrl->callback(uctrl, msg_wire.type, &msg_wire.value, uctrl->userdata); | |
213 | ||
78467aeb YW |
214 | /* Do not disconnect and wait for next message. */ |
215 | uctrl = udev_ctrl_unref(uctrl); | |
d02c6f54 YW |
216 | return 0; |
217 | } | |
218 | ||
219 | static int udev_ctrl_event_handler(sd_event_source *s, int fd, uint32_t revents, void *userdata) { | |
e0d61dac | 220 | UdevCtrl *uctrl = userdata; |
d02c6f54 YW |
221 | _cleanup_close_ int sock = -1; |
222 | struct ucred ucred; | |
eff05270 | 223 | int r; |
912541b0 | 224 | |
d02c6f54 | 225 | assert(uctrl); |
912541b0 | 226 | |
d02c6f54 YW |
227 | sock = accept4(fd, NULL, NULL, SOCK_CLOEXEC|SOCK_NONBLOCK); |
228 | if (sock < 0) { | |
4ff9bc2e LP |
229 | if (ERRNO_IS_ACCEPT_AGAIN(errno)) |
230 | return 0; | |
231 | ||
232 | return log_error_errno(errno, "Failed to accept ctrl connection: %m"); | |
912541b0 KS |
233 | } |
234 | ||
235 | /* check peer credential of connection */ | |
d02c6f54 | 236 | r = getpeercred(sock, &ucred); |
eff05270 | 237 | if (r < 0) { |
572909a3 | 238 | log_error_errno(r, "Failed to receive credentials of ctrl connection: %m"); |
d02c6f54 | 239 | return 0; |
912541b0 | 240 | } |
d02c6f54 | 241 | |
912541b0 | 242 | if (ucred.uid > 0) { |
d02c6f54 YW |
243 | log_error("Invalid sender uid "UID_FMT", closing connection", ucred.uid); |
244 | return 0; | |
912541b0 KS |
245 | } |
246 | ||
247 | /* enable receiving of the sender credentials in the messages */ | |
d02c6f54 | 248 | r = setsockopt_int(sock, SOL_SOCKET, SO_PASSCRED, true); |
4bbdff75 | 249 | if (r < 0) |
d02c6f54 | 250 | log_warning_errno(r, "Failed to set SO_PASSCRED, ignoring: %m"); |
4bbdff75 | 251 | |
d02c6f54 YW |
252 | r = sd_event_add_io(uctrl->event, &uctrl->event_source_connect, sock, EPOLLIN, udev_ctrl_connection_event_handler, uctrl); |
253 | if (r < 0) { | |
254 | log_error_errno(r, "Failed to create event source for udev control connection: %m"); | |
255 | return 0; | |
256 | } | |
257 | ||
258 | (void) sd_event_source_set_description(uctrl->event_source_connect, "udev-ctrl-connection"); | |
ff2c503d | 259 | |
d02c6f54 YW |
260 | /* Do not accept multiple connection. */ |
261 | (void) sd_event_source_set_enabled(uctrl->event_source, SD_EVENT_OFF); | |
35927d13 | 262 | |
d02c6f54 YW |
263 | uctrl->sock_connect = TAKE_FD(sock); |
264 | return 0; | |
ff2c503d KS |
265 | } |
266 | ||
e0d61dac | 267 | int udev_ctrl_start(UdevCtrl *uctrl, udev_ctrl_handler_t callback, void *userdata) { |
d02c6f54 YW |
268 | int r; |
269 | ||
270 | assert(uctrl); | |
271 | ||
272 | if (!uctrl->event) { | |
273 | r = udev_ctrl_attach_event(uctrl, NULL); | |
274 | if (r < 0) | |
275 | return r; | |
276 | } | |
277 | ||
278 | r = udev_ctrl_enable_receiving(uctrl); | |
279 | if (r < 0) | |
280 | return r; | |
281 | ||
282 | uctrl->callback = callback; | |
283 | uctrl->userdata = userdata; | |
284 | ||
285 | r = sd_event_add_io(uctrl->event, &uctrl->event_source, uctrl->sock, EPOLLIN, udev_ctrl_event_handler, uctrl); | |
286 | if (r < 0) | |
287 | return r; | |
288 | ||
289 | (void) sd_event_source_set_description(uctrl->event_source, "udev-ctrl"); | |
290 | ||
291 | return 0; | |
292 | } | |
8f71a0d1 | 293 | |
f9da11ef | 294 | int udev_ctrl_send(UdevCtrl *uctrl, UdevCtrlMessageType type, const void *data) { |
e0d61dac | 295 | UdevCtrlMessageWire ctrl_msg_wire = { |
b9da6a09 ZJS |
296 | .version = "udev-" STRINGIFY(PROJECT_VERSION), |
297 | .magic = UDEV_CTRL_MAGIC, | |
298 | .type = type, | |
299 | }; | |
912541b0 | 300 | |
78467aeb YW |
301 | if (uctrl->maybe_disconnected) |
302 | return -ENOANO; /* to distinguish this from other errors. */ | |
303 | ||
f9da11ef YW |
304 | if (type == UDEV_CTRL_SET_ENV) { |
305 | assert(data); | |
306 | strscpy(ctrl_msg_wire.value.buf, sizeof(ctrl_msg_wire.value.buf), data); | |
307 | } else if (IN_SET(type, UDEV_CTRL_SET_LOG_LEVEL, UDEV_CTRL_SET_CHILDREN_MAX)) | |
308 | ctrl_msg_wire.value.intval = PTR_TO_INT(data); | |
912541b0 KS |
309 | |
310 | if (!uctrl->connected) { | |
b9da6a09 ZJS |
311 | if (connect(uctrl->sock, &uctrl->saddr.sa, uctrl->addrlen) < 0) |
312 | return -errno; | |
912541b0 KS |
313 | uctrl->connected = true; |
314 | } | |
78467aeb | 315 | |
b9da6a09 ZJS |
316 | if (send(uctrl->sock, &ctrl_msg_wire, sizeof(ctrl_msg_wire), 0) < 0) |
317 | return -errno; | |
912541b0 | 318 | |
78467aeb YW |
319 | if (type == UDEV_CTRL_EXIT) |
320 | uctrl->maybe_disconnected = true; | |
d59f11e1 | 321 | |
78467aeb | 322 | return 0; |
ff2c503d KS |
323 | } |
324 | ||
e0d61dac | 325 | int udev_ctrl_wait(UdevCtrl *uctrl, usec_t timeout) { |
9612da36 | 326 | _cleanup_(sd_event_source_disable_unrefp) sd_event_source *source_io = NULL, *source_timeout = NULL; |
78467aeb | 327 | int r; |
d59f11e1 | 328 | |
78467aeb | 329 | assert(uctrl); |
d59f11e1 | 330 | |
78467aeb YW |
331 | if (uctrl->sock < 0) |
332 | return 0; | |
333 | if (!uctrl->connected) | |
334 | return 0; | |
d59f11e1 | 335 | |
78467aeb | 336 | if (!uctrl->maybe_disconnected) { |
f9da11ef | 337 | r = udev_ctrl_send(uctrl, _UDEV_CTRL_END_MESSAGES, NULL); |
78467aeb YW |
338 | if (r < 0) |
339 | return r; | |
340 | } | |
d59f11e1 | 341 | |
78467aeb YW |
342 | if (timeout == 0) |
343 | return 0; | |
344 | ||
345 | if (!uctrl->event) { | |
346 | r = udev_ctrl_attach_event(uctrl, NULL); | |
347 | if (r < 0) | |
348 | return r; | |
349 | } | |
350 | ||
cbda8bd5 | 351 | r = sd_event_add_io(uctrl->event, &source_io, uctrl->sock, EPOLLIN, NULL, INT_TO_PTR(0)); |
78467aeb YW |
352 | if (r < 0) |
353 | return r; | |
354 | ||
60ccab09 | 355 | (void) sd_event_source_set_description(source_io, "udev-ctrl-wait-io"); |
78467aeb YW |
356 | |
357 | if (timeout != USEC_INFINITY) { | |
39cf0351 LP |
358 | r = sd_event_add_time_relative( |
359 | uctrl->event, &source_timeout, clock_boottime_or_monotonic(), | |
360 | timeout, | |
361 | 0, NULL, INT_TO_PTR(-ETIMEDOUT)); | |
78467aeb YW |
362 | if (r < 0) |
363 | return r; | |
364 | ||
f6e8ba81 | 365 | (void) sd_event_source_set_description(source_timeout, "udev-ctrl-wait-timeout"); |
78467aeb | 366 | } |
d59f11e1 | 367 | |
78467aeb | 368 | return sd_event_loop(uctrl->event); |
bb38678e | 369 | } |