Fix enable-event for UST events
[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(LTTCOMM_UST_EVENT_EXIST) ] = "UST event already exist",
96 [ LTTCOMM_ERR_INDEX(CONSUMERD_COMMAND_SOCK_READY) ] = "consumerd command socket ready",
97 [ LTTCOMM_ERR_INDEX(CONSUMERD_SUCCESS_RECV_FD) ] = "consumerd success on receiving fds",
98 [ LTTCOMM_ERR_INDEX(CONSUMERD_ERROR_RECV_FD) ] = "consumerd error on receiving fds",
99 [ LTTCOMM_ERR_INDEX(CONSUMERD_ERROR_RECV_CMD) ] = "consumerd error on receiving command",
100 [ LTTCOMM_ERR_INDEX(CONSUMERD_POLL_ERROR) ] = "consumerd error in polling thread",
101 [ LTTCOMM_ERR_INDEX(CONSUMERD_POLL_NVAL) ] = "consumerd polling on closed fd",
102 [ LTTCOMM_ERR_INDEX(CONSUMERD_POLL_HUP) ] = "consumerd all fd hung up",
103 [ LTTCOMM_ERR_INDEX(CONSUMERD_EXIT_SUCCESS) ] = "consumerd exiting normally",
104 [ LTTCOMM_ERR_INDEX(CONSUMERD_EXIT_FAILURE) ] = "consumerd exiting on error",
105 [ LTTCOMM_ERR_INDEX(CONSUMERD_OUTFD_ERROR) ] = "consumerd error opening the tracefile",
106 [ LTTCOMM_ERR_INDEX(CONSUMERD_SPLICE_EBADF) ] = "consumerd splice EBADF",
107 [ LTTCOMM_ERR_INDEX(CONSUMERD_SPLICE_EINVAL) ] = "consumerd splice EINVAL",
108 [ LTTCOMM_ERR_INDEX(CONSUMERD_SPLICE_ENOMEM) ] = "consumerd splice ENOMEM",
109 [ LTTCOMM_ERR_INDEX(CONSUMERD_SPLICE_ESPIPE) ] = "consumerd splice ESPIPE",
110 [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_EVENT) ] = "Event not found",
111 };
112
113 /*
114 * Return ptr to string representing a human readable error code from the
115 * lttcomm_return_code enum.
116 *
117 * These code MUST be negative in other to treat that as an error value.
118 */
119 const char *lttcomm_get_readable_code(enum lttcomm_return_code code)
120 {
121 int tmp_code = -code;
122
123 if (tmp_code >= LTTCOMM_OK && tmp_code < LTTCOMM_NR) {
124 return lttcomm_readable_code[LTTCOMM_ERR_INDEX(tmp_code)];
125 }
126
127 return "Unknown error code";
128 }
129
130 /*
131 * Connect to unix socket using the path name.
132 */
133 int lttcomm_connect_unix_sock(const char *pathname)
134 {
135 struct sockaddr_un sun;
136 int fd;
137 int ret;
138
139 fd = socket(PF_UNIX, SOCK_STREAM, 0);
140 if (fd < 0) {
141 perror("socket");
142 ret = fd;
143 goto error;
144 }
145
146 memset(&sun, 0, sizeof(sun));
147 sun.sun_family = AF_UNIX;
148 strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
149 sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
150
151 ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun));
152 if (ret < 0) {
153 /*
154 * Don't print message on connect error, because connect is used in
155 * normal execution to detect if sessiond is alive.
156 */
157 goto error_connect;
158 }
159
160 return fd;
161
162 error_connect:
163 close(fd);
164 error:
165 return ret;
166 }
167
168 /*
169 * Do an accept(2) on the sock and return the new file descriptor. The socket
170 * MUST be bind(2) before.
171 */
172 int lttcomm_accept_unix_sock(int sock)
173 {
174 int new_fd;
175 struct sockaddr_un sun;
176 socklen_t len = 0;
177
178 /* Blocking call */
179 new_fd = accept(sock, (struct sockaddr *) &sun, &len);
180 if (new_fd < 0) {
181 perror("accept");
182 goto error;
183 }
184
185 return new_fd;
186
187 error:
188 return -1;
189 }
190
191 /*
192 * Creates a AF_UNIX local socket using pathname bind the socket upon creation
193 * and return the fd.
194 */
195 int lttcomm_create_unix_sock(const char *pathname)
196 {
197 struct sockaddr_un sun;
198 int fd;
199 int ret = -1;
200
201 /* Create server socket */
202 if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
203 perror("socket");
204 goto error;
205 }
206
207 memset(&sun, 0, sizeof(sun));
208 sun.sun_family = AF_UNIX;
209 strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
210 sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
211
212 /* Unlink the old file if present */
213 (void) unlink(pathname);
214 ret = bind(fd, (struct sockaddr *) &sun, sizeof(sun));
215 if (ret < 0) {
216 perror("bind");
217 goto error;
218 }
219
220 return fd;
221
222 error:
223 return ret;
224 }
225
226 /*
227 * Make the socket listen using LTTNG_SESSIOND_COMM_MAX_LISTEN.
228 */
229 int lttcomm_listen_unix_sock(int sock)
230 {
231 int ret;
232
233 ret = listen(sock, LTTNG_SESSIOND_COMM_MAX_LISTEN);
234 if (ret < 0) {
235 perror("listen");
236 }
237
238 return ret;
239 }
240
241 /*
242 * Receive data of size len in put that data into the buf param. Using recvmsg
243 * API.
244 *
245 * Return the size of received data.
246 */
247 ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len)
248 {
249 struct msghdr msg = { 0 };
250 struct iovec iov[1];
251 ssize_t ret = -1;
252
253 iov[0].iov_base = buf;
254 iov[0].iov_len = len;
255 msg.msg_iov = iov;
256 msg.msg_iovlen = 1;
257
258 ret = recvmsg(sock, &msg, 0);
259 if (ret < 0) {
260 perror("recvmsg");
261 }
262
263 return ret;
264 }
265
266 /*
267 * Send buf data of size len. Using sendmsg API.
268 *
269 * Return the size of sent data.
270 */
271 ssize_t lttcomm_send_unix_sock(int sock, void *buf, size_t len)
272 {
273 struct msghdr msg = { 0 };
274 struct iovec iov[1];
275 ssize_t ret = -1;
276
277 iov[0].iov_base = buf;
278 iov[0].iov_len = len;
279 msg.msg_iov = iov;
280 msg.msg_iovlen = 1;
281
282 ret = sendmsg(sock, &msg, 0);
283 if (ret < 0) {
284 perror("sendmsg");
285 }
286
287 return ret;
288 }
289
290 /*
291 * Shutdown cleanly a unix socket.
292 */
293 int lttcomm_close_unix_sock(int sock)
294 {
295 int ret;
296
297 /* Shutdown receptions and transmissions */
298 ret = shutdown(sock, SHUT_RDWR);
299 if (ret < 0) {
300 perror("shutdown");
301 }
302
303 return ret;
304 }
305
306 /*
307 * Send a message accompanied by fd(s) over a unix socket.
308 *
309 * Returns the size of data sent, or negative error value.
310 */
311 ssize_t lttcomm_send_fds_unix_sock(int sock, int *fds, size_t nb_fd)
312 {
313 struct msghdr msg = { 0 };
314 struct cmsghdr *cmptr;
315 struct iovec iov[1];
316 ssize_t ret = -1;
317 unsigned int sizeof_fds = nb_fd * sizeof(int);
318 char tmp[CMSG_SPACE(sizeof_fds)];
319 char dummy = 0;
320
321 if (nb_fd > LTTCOMM_MAX_SEND_FDS)
322 return -EINVAL;
323
324 msg.msg_control = (caddr_t)tmp;
325 msg.msg_controllen = CMSG_LEN(sizeof_fds);
326
327 cmptr = CMSG_FIRSTHDR(&msg);
328 cmptr->cmsg_level = SOL_SOCKET;
329 cmptr->cmsg_type = SCM_RIGHTS;
330 cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
331 memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
332 /* Sum of the length of all control messages in the buffer: */
333 msg.msg_controllen = cmptr->cmsg_len;
334
335 iov[0].iov_base = &dummy;
336 iov[0].iov_len = 1;
337 msg.msg_iov = iov;
338 msg.msg_iovlen = 1;
339
340 ret = sendmsg(sock, &msg, 0);
341 if (ret < 0) {
342 perror("sendmsg");
343 }
344 return ret;
345 }
346
347 /*
348 * Recv a message accompanied by fd(s) from a unix socket.
349 *
350 * Returns the size of received data, or negative error value.
351 *
352 * Expect at most "nb_fd" file descriptors. Returns the number of fd
353 * actually received in nb_fd.
354 */
355 ssize_t lttcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd)
356 {
357 struct iovec iov[1];
358 ssize_t ret = 0;
359 struct cmsghdr *cmsg;
360 size_t sizeof_fds = nb_fd * sizeof(int);
361 char recv_fd[CMSG_SPACE(sizeof_fds)];
362 struct msghdr msg = { 0 };
363 char dummy;
364
365 /* Prepare to receive the structures */
366 iov[0].iov_base = &dummy;
367 iov[0].iov_len = 1;
368 msg.msg_iov = iov;
369 msg.msg_iovlen = 1;
370 msg.msg_control = recv_fd;
371 msg.msg_controllen = sizeof(recv_fd);
372
373 ret = recvmsg(sock, &msg, 0);
374 if (ret < 0) {
375 perror("recvmsg fds");
376 goto end;
377 }
378 if (ret != 1) {
379 fprintf(stderr, "Error: Received %zd bytes, expected %d\n",
380 ret, 1);
381 goto end;
382 }
383 if (msg.msg_flags & MSG_CTRUNC) {
384 fprintf(stderr, "Error: Control message truncated.\n");
385 ret = -1;
386 goto end;
387 }
388 cmsg = CMSG_FIRSTHDR(&msg);
389 if (!cmsg) {
390 fprintf(stderr, "Error: Invalid control message header\n");
391 ret = -1;
392 goto end;
393 }
394 if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS) {
395 fprintf(stderr, "Didn't received any fd\n");
396 ret = -1;
397 goto end;
398 }
399 if (cmsg->cmsg_len != CMSG_LEN(sizeof_fds)) {
400 fprintf(stderr, "Error: Received %zu bytes of ancillary data, expected %zu\n",
401 cmsg->cmsg_len, CMSG_LEN(sizeof_fds));
402 ret = -1;
403 goto end;
404 }
405 memcpy(fds, CMSG_DATA(cmsg), sizeof_fds);
406 ret = sizeof_fds;
407 end:
408 return ret;
409 }
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