31e43de102b924a789889be0e2d5284c0fee85b8
[lttng-tools.git] / liblttng-sessiond-comm / lttng-sessiond-comm.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the Free
7 * Software Foundation; only version 2 of the License.
8 *
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
16 * Place - Suite 330, Boston, MA 02111-1307, USA.
17 */
18
19 #define _GNU_SOURCE
20 #include <assert.h>
21 #include <limits.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <sys/socket.h>
26 #include <sys/stat.h>
27 #include <sys/types.h>
28 #include <sys/un.h>
29 #include <unistd.h>
30 #include <errno.h>
31
32 #include <lttng-sessiond-comm.h>
33
34 /*
35 * Human readable error message.
36 */
37 static const char *lttcomm_readable_code[] = {
38 [ LTTCOMM_ERR_INDEX(LTTCOMM_OK) ] = "Success",
39 [ LTTCOMM_ERR_INDEX(LTTCOMM_ERR) ] = "Unknown error",
40 [ LTTCOMM_ERR_INDEX(LTTCOMM_UND) ] = "Undefined command",
41 [ LTTCOMM_ERR_INDEX(LTTCOMM_NOT_IMPLEMENTED) ] = "Not implemented",
42 [ LTTCOMM_ERR_INDEX(LTTCOMM_UNKNOWN_DOMAIN) ] = "Unknown tracing domain",
43 [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_SESSION) ] = "No session found",
44 [ LTTCOMM_ERR_INDEX(LTTCOMM_LIST_FAIL) ] = "Unable to list traceable apps",
45 [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_APPS) ] = "No traceable apps found",
46 [ LTTCOMM_ERR_INDEX(LTTCOMM_SESS_NOT_FOUND) ] = "Session name not found",
47 [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_TRACE) ] = "No trace found",
48 [ LTTCOMM_ERR_INDEX(LTTCOMM_FATAL) ] = "Fatal error of the session daemon",
49 [ LTTCOMM_ERR_INDEX(LTTCOMM_CREATE_FAIL) ] = "Create trace failed",
50 [ LTTCOMM_ERR_INDEX(LTTCOMM_START_FAIL) ] = "Start trace failed",
51 [ LTTCOMM_ERR_INDEX(LTTCOMM_STOP_FAIL) ] = "Stop trace failed",
52 [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_TRACEABLE) ] = "App is not traceable",
53 [ LTTCOMM_ERR_INDEX(LTTCOMM_SELECT_SESS) ] = "A session MUST be selected",
54 [ LTTCOMM_ERR_INDEX(LTTCOMM_EXIST_SESS) ] = "Session name already exist",
55 [ LTTCOMM_ERR_INDEX(LTTCOMM_CONNECT_FAIL) ] = "Unable to connect to Unix socket",
56 [ LTTCOMM_ERR_INDEX(LTTCOMM_APP_NOT_FOUND) ] = "Application not found",
57 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_NA) ] = "Kernel tracer not available",
58 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_EVENT_EXIST) ] = "Kernel event already exists",
59 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_SESS_FAIL) ] = "Kernel create session failed",
60 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CHAN_FAIL) ] = "Kernel create channel failed",
61 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CHAN_NOT_FOUND) ] = "Kernel channel not found",
62 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CHAN_DISABLE_FAIL) ] = "Disable kernel channel failed",
63 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CHAN_ENABLE_FAIL) ] = "Enable kernel channel failed",
64 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CONTEXT_FAIL) ] = "Add kernel context failed",
65 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_ENABLE_FAIL) ] = "Enable kernel event failed",
66 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_DISABLE_FAIL) ] = "Disable kernel event failed",
67 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_META_FAIL) ] = "Opening metadata failed",
68 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_START_FAIL) ] = "Starting kernel trace failed",
69 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_STOP_FAIL) ] = "Stoping kernel trace failed",
70 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CONSUMER_FAIL) ] = "Kernel consumer start failed",
71 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_STREAM_FAIL) ] = "Kernel create stream failed",
72 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_DIR_FAIL) ] = "Kernel trace directory creation failed",
73 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_DIR_EXIST) ] = "Kernel trace directory already exist",
74 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_NO_SESSION) ] = "No kernel session found",
75 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_LIST_FAIL) ] = "Listing kernel events failed",
76 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_SESS_FAIL) ] = "UST create session failed",
77 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_CHAN_FAIL) ] = "UST create channel failed",
78 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_CHAN_EXIST) ] = "UST channel already exist",
79 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_CHAN_NOT_FOUND) ] = "UST channel not found",
80 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_CHAN_DISABLE_FAIL) ] = "Disable UST channel failed",
81 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_CHAN_ENABLE_FAIL) ] = "Enable UST channel failed",
82 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_CONTEXT_FAIL) ] = "Add UST context failed",
83 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_ENABLE_FAIL) ] = "Enable UST event failed",
84 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_DISABLE_FAIL) ] = "Disable UST event failed",
85 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_META_FAIL) ] = "Opening metadata failed",
86 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_START_FAIL) ] = "Starting UST trace failed",
87 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_STOP_FAIL) ] = "Stoping UST trace failed",
88 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_CONSUMER64_FAIL) ] = "64-bit UST consumer start failed",
89 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_CONSUMER32_FAIL) ] = "32-bit UST consumer start failed",
90 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_STREAM_FAIL) ] = "UST create stream failed",
91 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_DIR_FAIL) ] = "UST trace directory creation failed",
92 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_DIR_EXIST) ] = "UST trace directory already exist",
93 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_NO_SESSION) ] = "No UST session found",
94 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_LIST_FAIL) ] = "Listing UST events failed",
95 [ LTTCOMM_ERR_INDEX(CONSUMERD_COMMAND_SOCK_READY) ] = "consumerd command socket ready",
96 [ LTTCOMM_ERR_INDEX(CONSUMERD_SUCCESS_RECV_FD) ] = "consumerd success on receiving fds",
97 [ LTTCOMM_ERR_INDEX(CONSUMERD_ERROR_RECV_FD) ] = "consumerd error on receiving fds",
98 [ LTTCOMM_ERR_INDEX(CONSUMERD_ERROR_RECV_CMD) ] = "consumerd error on receiving command",
99 [ LTTCOMM_ERR_INDEX(CONSUMERD_POLL_ERROR) ] = "consumerd error in polling thread",
100 [ LTTCOMM_ERR_INDEX(CONSUMERD_POLL_NVAL) ] = "consumerd polling on closed fd",
101 [ LTTCOMM_ERR_INDEX(CONSUMERD_POLL_HUP) ] = "consumerd all fd hung up",
102 [ LTTCOMM_ERR_INDEX(CONSUMERD_EXIT_SUCCESS) ] = "consumerd exiting normally",
103 [ LTTCOMM_ERR_INDEX(CONSUMERD_EXIT_FAILURE) ] = "consumerd exiting on error",
104 [ LTTCOMM_ERR_INDEX(CONSUMERD_OUTFD_ERROR) ] = "consumerd error opening the tracefile",
105 [ LTTCOMM_ERR_INDEX(CONSUMERD_SPLICE_EBADF) ] = "consumerd splice EBADF",
106 [ LTTCOMM_ERR_INDEX(CONSUMERD_SPLICE_EINVAL) ] = "consumerd splice EINVAL",
107 [ LTTCOMM_ERR_INDEX(CONSUMERD_SPLICE_ENOMEM) ] = "consumerd splice ENOMEM",
108 [ LTTCOMM_ERR_INDEX(CONSUMERD_SPLICE_ESPIPE) ] = "consumerd splice ESPIPE",
109 [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_EVENT) ] = "Event not found",
110 };
111
112 /*
113 * Return ptr to string representing a human readable error code from the
114 * lttcomm_return_code enum.
115 *
116 * These code MUST be negative in other to treat that as an error value.
117 */
118 const char *lttcomm_get_readable_code(enum lttcomm_return_code code)
119 {
120 int tmp_code = -code;
121
122 if (tmp_code >= LTTCOMM_OK && tmp_code < LTTCOMM_NR) {
123 return lttcomm_readable_code[LTTCOMM_ERR_INDEX(tmp_code)];
124 }
125
126 return "Unknown error code";
127 }
128
129 /*
130 * Connect to unix socket using the path name.
131 */
132 int lttcomm_connect_unix_sock(const char *pathname)
133 {
134 struct sockaddr_un sun;
135 int fd;
136 int ret;
137
138 fd = socket(PF_UNIX, SOCK_STREAM, 0);
139 if (fd < 0) {
140 perror("socket");
141 ret = fd;
142 goto error;
143 }
144
145 memset(&sun, 0, sizeof(sun));
146 sun.sun_family = AF_UNIX;
147 strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
148 sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
149
150 ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun));
151 if (ret < 0) {
152 /*
153 * Don't print message on connect error, because connect is used in
154 * normal execution to detect if sessiond is alive.
155 */
156 goto error_connect;
157 }
158
159 return fd;
160
161 error_connect:
162 close(fd);
163 error:
164 return ret;
165 }
166
167 /*
168 * Do an accept(2) on the sock and return the new file descriptor. The socket
169 * MUST be bind(2) before.
170 */
171 int lttcomm_accept_unix_sock(int sock)
172 {
173 int new_fd;
174 struct sockaddr_un sun;
175 socklen_t len = 0;
176
177 /* Blocking call */
178 new_fd = accept(sock, (struct sockaddr *) &sun, &len);
179 if (new_fd < 0) {
180 perror("accept");
181 goto error;
182 }
183
184 return new_fd;
185
186 error:
187 return -1;
188 }
189
190 /*
191 * Creates a AF_UNIX local socket using pathname bind the socket upon creation
192 * and return the fd.
193 */
194 int lttcomm_create_unix_sock(const char *pathname)
195 {
196 struct sockaddr_un sun;
197 int fd;
198 int ret = -1;
199
200 /* Create server socket */
201 if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
202 perror("socket");
203 goto error;
204 }
205
206 memset(&sun, 0, sizeof(sun));
207 sun.sun_family = AF_UNIX;
208 strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
209 sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
210
211 /* Unlink the old file if present */
212 (void) unlink(pathname);
213 ret = bind(fd, (struct sockaddr *) &sun, sizeof(sun));
214 if (ret < 0) {
215 perror("bind");
216 goto error;
217 }
218
219 return fd;
220
221 error:
222 return ret;
223 }
224
225 /*
226 * Make the socket listen using LTTNG_SESSIOND_COMM_MAX_LISTEN.
227 */
228 int lttcomm_listen_unix_sock(int sock)
229 {
230 int ret;
231
232 ret = listen(sock, LTTNG_SESSIOND_COMM_MAX_LISTEN);
233 if (ret < 0) {
234 perror("listen");
235 }
236
237 return ret;
238 }
239
240 /*
241 * Receive data of size len in put that data into the buf param. Using recvmsg
242 * API.
243 *
244 * Return the size of received data.
245 */
246 ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len)
247 {
248 struct msghdr msg = { 0 };
249 struct iovec iov[1];
250 ssize_t ret = -1;
251
252 iov[0].iov_base = buf;
253 iov[0].iov_len = len;
254 msg.msg_iov = iov;
255 msg.msg_iovlen = 1;
256
257 ret = recvmsg(sock, &msg, 0);
258 if (ret < 0) {
259 perror("recvmsg");
260 }
261
262 return ret;
263 }
264
265 /*
266 * Send buf data of size len. Using sendmsg API.
267 *
268 * Return the size of sent data.
269 */
270 ssize_t lttcomm_send_unix_sock(int sock, void *buf, size_t len)
271 {
272 struct msghdr msg = { 0 };
273 struct iovec iov[1];
274 ssize_t ret = -1;
275
276 iov[0].iov_base = buf;
277 iov[0].iov_len = len;
278 msg.msg_iov = iov;
279 msg.msg_iovlen = 1;
280
281 ret = sendmsg(sock, &msg, 0);
282 if (ret < 0) {
283 perror("sendmsg");
284 }
285
286 return ret;
287 }
288
289 /*
290 * Shutdown cleanly a unix socket.
291 */
292 int lttcomm_close_unix_sock(int sock)
293 {
294 int ret;
295
296 /* Shutdown receptions and transmissions */
297 ret = shutdown(sock, SHUT_RDWR);
298 if (ret < 0) {
299 perror("shutdown");
300 }
301
302 return ret;
303 }
304
305 /*
306 * Send a message accompanied by fd(s) over a unix socket.
307 *
308 * Returns the size of data sent, or negative error value.
309 */
310 ssize_t lttcomm_send_fds_unix_sock(int sock, int *fds, size_t nb_fd)
311 {
312 struct msghdr msg = { 0 };
313 struct cmsghdr *cmptr;
314 struct iovec iov[1];
315 ssize_t ret = -1;
316 unsigned int sizeof_fds = nb_fd * sizeof(int);
317 char tmp[CMSG_SPACE(sizeof_fds)];
318 char dummy = 0;
319
320 if (nb_fd > LTTCOMM_MAX_SEND_FDS)
321 return -EINVAL;
322
323 msg.msg_control = (caddr_t)tmp;
324 msg.msg_controllen = CMSG_LEN(sizeof_fds);
325
326 cmptr = CMSG_FIRSTHDR(&msg);
327 cmptr->cmsg_level = SOL_SOCKET;
328 cmptr->cmsg_type = SCM_RIGHTS;
329 cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
330 memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
331 /* Sum of the length of all control messages in the buffer: */
332 msg.msg_controllen = cmptr->cmsg_len;
333
334 iov[0].iov_base = &dummy;
335 iov[0].iov_len = 1;
336 msg.msg_iov = iov;
337 msg.msg_iovlen = 1;
338
339 ret = sendmsg(sock, &msg, 0);
340 if (ret < 0) {
341 perror("sendmsg");
342 }
343 return ret;
344 }
345
346 /*
347 * Recv a message accompanied by fd(s) from a unix socket.
348 *
349 * Returns the size of received data, or negative error value.
350 *
351 * Expect at most "nb_fd" file descriptors. Returns the number of fd
352 * actually received in nb_fd.
353 */
354 ssize_t lttcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd)
355 {
356 struct iovec iov[1];
357 ssize_t ret = 0;
358 struct cmsghdr *cmsg;
359 size_t sizeof_fds = nb_fd * sizeof(int);
360 char recv_fd[CMSG_SPACE(sizeof_fds)];
361 struct msghdr msg = { 0 };
362 char dummy;
363
364 /* Prepare to receive the structures */
365 iov[0].iov_base = &dummy;
366 iov[0].iov_len = 1;
367 msg.msg_iov = iov;
368 msg.msg_iovlen = 1;
369 msg.msg_control = recv_fd;
370 msg.msg_controllen = sizeof(recv_fd);
371
372 ret = recvmsg(sock, &msg, 0);
373 if (ret < 0) {
374 perror("recvmsg fds");
375 goto end;
376 }
377 if (ret != 1) {
378 fprintf(stderr, "Error: Received %zd bytes, expected %d\n",
379 ret, 1);
380 goto end;
381 }
382 if (msg.msg_flags & MSG_CTRUNC) {
383 fprintf(stderr, "Error: Control message truncated.\n");
384 ret = -1;
385 goto end;
386 }
387 cmsg = CMSG_FIRSTHDR(&msg);
388 if (!cmsg) {
389 fprintf(stderr, "Error: Invalid control message header\n");
390 ret = -1;
391 goto end;
392 }
393 if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS) {
394 fprintf(stderr, "Didn't received any fd\n");
395 ret = -1;
396 goto end;
397 }
398 if (cmsg->cmsg_len != CMSG_LEN(sizeof_fds)) {
399 fprintf(stderr, "Error: Received %zu bytes of ancillary data, expected %zu\n",
400 cmsg->cmsg_len, CMSG_LEN(sizeof_fds));
401 ret = -1;
402 goto end;
403 }
404 memcpy(fds, CMSG_DATA(cmsg), sizeof_fds);
405 ret = sizeof_fds;
406 end:
407 return ret;
408 }
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