Multiple fixes when cleaning app and UST sessions
[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_CONSUMER_FAIL) ] = "UST consumer start failed",
89 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_STREAM_FAIL) ] = "UST create stream failed",
90 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_DIR_FAIL) ] = "UST trace directory creation failed",
91 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_DIR_EXIST) ] = "UST trace directory already exist",
92 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_NO_SESSION) ] = "No UST session found",
93 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_LIST_FAIL) ] = "Listing UST events failed",
94 [ LTTCOMM_ERR_INDEX(CONSUMERD_COMMAND_SOCK_READY) ] = "consumerd command socket ready",
95 [ LTTCOMM_ERR_INDEX(CONSUMERD_SUCCESS_RECV_FD) ] = "consumerd success on receiving fds",
96 [ LTTCOMM_ERR_INDEX(CONSUMERD_ERROR_RECV_FD) ] = "consumerd error on receiving fds",
97 [ LTTCOMM_ERR_INDEX(CONSUMERD_ERROR_RECV_CMD) ] = "consumerd error on receiving command",
98 [ LTTCOMM_ERR_INDEX(CONSUMERD_POLL_ERROR) ] = "consumerd error in polling thread",
99 [ LTTCOMM_ERR_INDEX(CONSUMERD_POLL_NVAL) ] = "consumerd polling on closed fd",
100 [ LTTCOMM_ERR_INDEX(CONSUMERD_POLL_HUP) ] = "consumerd all fd hung up",
101 [ LTTCOMM_ERR_INDEX(CONSUMERD_EXIT_SUCCESS) ] = "consumerd exiting normally",
102 [ LTTCOMM_ERR_INDEX(CONSUMERD_EXIT_FAILURE) ] = "consumerd exiting on error",
103 [ LTTCOMM_ERR_INDEX(CONSUMERD_OUTFD_ERROR) ] = "consumerd error opening the tracefile",
104 [ LTTCOMM_ERR_INDEX(CONSUMERD_SPLICE_EBADF) ] = "consumerd splice EBADF",
105 [ LTTCOMM_ERR_INDEX(CONSUMERD_SPLICE_EINVAL) ] = "consumerd splice EINVAL",
106 [ LTTCOMM_ERR_INDEX(CONSUMERD_SPLICE_ENOMEM) ] = "consumerd splice ENOMEM",
107 [ LTTCOMM_ERR_INDEX(CONSUMERD_SPLICE_ESPIPE) ] = "consumerd splice ESPIPE",
108 [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_EVENT) ] = "Event not found",
109 };
110
111 /*
112 * Return ptr to string representing a human readable error code from the
113 * lttcomm_return_code enum.
114 *
115 * These code MUST be negative in other to treat that as an error value.
116 */
117 const char *lttcomm_get_readable_code(enum lttcomm_return_code code)
118 {
119 int tmp_code = -code;
120
121 if (tmp_code >= LTTCOMM_OK && tmp_code < LTTCOMM_NR) {
122 return lttcomm_readable_code[LTTCOMM_ERR_INDEX(tmp_code)];
123 }
124
125 return "Unknown error code";
126 }
127
128 /*
129 * Connect to unix socket using the path name.
130 */
131 int lttcomm_connect_unix_sock(const char *pathname)
132 {
133 struct sockaddr_un sun;
134 int fd;
135 int ret;
136
137 fd = socket(PF_UNIX, SOCK_STREAM, 0);
138 if (fd < 0) {
139 perror("socket");
140 ret = fd;
141 goto error;
142 }
143
144 memset(&sun, 0, sizeof(sun));
145 sun.sun_family = AF_UNIX;
146 strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
147 sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
148
149 ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun));
150 if (ret < 0) {
151 /*
152 * Don't print message on connect error, because connect is used in
153 * normal execution to detect if sessiond is alive.
154 */
155 goto error_connect;
156 }
157
158 return fd;
159
160 error_connect:
161 close(fd);
162 error:
163 return ret;
164 }
165
166 /*
167 * Do an accept(2) on the sock and return the new file descriptor. The socket
168 * MUST be bind(2) before.
169 */
170 int lttcomm_accept_unix_sock(int sock)
171 {
172 int new_fd;
173 struct sockaddr_un sun;
174 socklen_t len = 0;
175
176 /* Blocking call */
177 new_fd = accept(sock, (struct sockaddr *) &sun, &len);
178 if (new_fd < 0) {
179 perror("accept");
180 goto error;
181 }
182
183 return new_fd;
184
185 error:
186 return -1;
187 }
188
189 /*
190 * Creates a AF_UNIX local socket using pathname bind the socket upon creation
191 * and return the fd.
192 */
193 int lttcomm_create_unix_sock(const char *pathname)
194 {
195 struct sockaddr_un sun;
196 int fd;
197 int ret = -1;
198
199 /* Create server socket */
200 if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
201 perror("socket");
202 goto error;
203 }
204
205 memset(&sun, 0, sizeof(sun));
206 sun.sun_family = AF_UNIX;
207 strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
208 sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
209
210 /* Unlink the old file if present */
211 (void) unlink(pathname);
212 ret = bind(fd, (struct sockaddr *) &sun, sizeof(sun));
213 if (ret < 0) {
214 perror("bind");
215 goto error;
216 }
217
218 return fd;
219
220 error:
221 return ret;
222 }
223
224 /*
225 * Make the socket listen using LTTNG_SESSIOND_COMM_MAX_LISTEN.
226 */
227 int lttcomm_listen_unix_sock(int sock)
228 {
229 int ret;
230
231 ret = listen(sock, LTTNG_SESSIOND_COMM_MAX_LISTEN);
232 if (ret < 0) {
233 perror("listen");
234 }
235
236 return ret;
237 }
238
239 /*
240 * Receive data of size len in put that data into the buf param. Using recvmsg
241 * API.
242 *
243 * Return the size of received data.
244 */
245 ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len)
246 {
247 struct msghdr msg = { 0 };
248 struct iovec iov[1];
249 ssize_t ret = -1;
250
251 iov[0].iov_base = buf;
252 iov[0].iov_len = len;
253 msg.msg_iov = iov;
254 msg.msg_iovlen = 1;
255
256 ret = recvmsg(sock, &msg, 0);
257 if (ret < 0) {
258 perror("recvmsg");
259 }
260
261 return ret;
262 }
263
264 /*
265 * Send buf data of size len. Using sendmsg API.
266 *
267 * Return the size of sent data.
268 */
269 ssize_t lttcomm_send_unix_sock(int sock, void *buf, size_t len)
270 {
271 struct msghdr msg = { 0 };
272 struct iovec iov[1];
273 ssize_t ret = -1;
274
275 iov[0].iov_base = buf;
276 iov[0].iov_len = len;
277 msg.msg_iov = iov;
278 msg.msg_iovlen = 1;
279
280 ret = sendmsg(sock, &msg, 0);
281 if (ret < 0) {
282 perror("sendmsg");
283 }
284
285 return ret;
286 }
287
288 /*
289 * Shutdown cleanly a unix socket.
290 */
291 int lttcomm_close_unix_sock(int sock)
292 {
293 int ret;
294
295 /* Shutdown receptions and transmissions */
296 ret = shutdown(sock, SHUT_RDWR);
297 if (ret < 0) {
298 perror("shutdown");
299 }
300
301 return ret;
302 }
303
304 /*
305 * Send a message accompanied by fd(s) over a unix socket.
306 *
307 * Returns the size of data sent, or negative error value.
308 */
309 ssize_t lttcomm_send_fds_unix_sock(int sock, int *fds, size_t nb_fd)
310 {
311 struct msghdr msg = { 0 };
312 struct cmsghdr *cmptr;
313 struct iovec iov[1];
314 ssize_t ret = -1;
315 unsigned int sizeof_fds = nb_fd * sizeof(int);
316 char tmp[CMSG_SPACE(sizeof_fds)];
317 char dummy = 0;
318
319 if (nb_fd > LTTCOMM_MAX_SEND_FDS)
320 return -EINVAL;
321
322 msg.msg_control = (caddr_t)tmp;
323 msg.msg_controllen = CMSG_LEN(sizeof_fds);
324
325 cmptr = CMSG_FIRSTHDR(&msg);
326 cmptr->cmsg_level = SOL_SOCKET;
327 cmptr->cmsg_type = SCM_RIGHTS;
328 cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
329 memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
330 /* Sum of the length of all control messages in the buffer: */
331 msg.msg_controllen = cmptr->cmsg_len;
332
333 iov[0].iov_base = &dummy;
334 iov[0].iov_len = 1;
335 msg.msg_iov = iov;
336 msg.msg_iovlen = 1;
337
338 ret = sendmsg(sock, &msg, 0);
339 if (ret < 0) {
340 perror("sendmsg");
341 }
342 return ret;
343 }
344
345 /*
346 * Recv a message accompanied by fd(s) from a unix socket.
347 *
348 * Returns the size of received data, or negative error value.
349 *
350 * Expect at most "nb_fd" file descriptors. Returns the number of fd
351 * actually received in nb_fd.
352 */
353 ssize_t lttcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd)
354 {
355 struct iovec iov[1];
356 ssize_t ret = 0;
357 struct cmsghdr *cmsg;
358 size_t sizeof_fds = nb_fd * sizeof(int);
359 char recv_fd[CMSG_SPACE(sizeof_fds)];
360 struct msghdr msg = { 0 };
361 char dummy;
362
363 /* Prepare to receive the structures */
364 iov[0].iov_base = &dummy;
365 iov[0].iov_len = 1;
366 msg.msg_iov = iov;
367 msg.msg_iovlen = 1;
368 msg.msg_control = recv_fd;
369 msg.msg_controllen = sizeof(recv_fd);
370
371 ret = recvmsg(sock, &msg, 0);
372 if (ret < 0) {
373 perror("recvmsg fds");
374 goto end;
375 }
376 if (ret != 1) {
377 fprintf(stderr, "Error: Received %zd bytes, expected %d\n",
378 ret, 1);
379 goto end;
380 }
381 if (msg.msg_flags & MSG_CTRUNC) {
382 fprintf(stderr, "Error: Control message truncated.\n");
383 ret = -1;
384 goto end;
385 }
386 cmsg = CMSG_FIRSTHDR(&msg);
387 if (!cmsg) {
388 fprintf(stderr, "Error: Invalid control message header\n");
389 ret = -1;
390 goto end;
391 }
392 if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS) {
393 fprintf(stderr, "Didn't received any fd\n");
394 ret = -1;
395 goto end;
396 }
397 if (cmsg->cmsg_len != CMSG_LEN(sizeof_fds)) {
398 fprintf(stderr, "Error: Received %zu bytes of ancillary data, expected %zu\n",
399 cmsg->cmsg_len, CMSG_LEN(sizeof_fds));
400 ret = -1;
401 goto end;
402 }
403 memcpy(fds, CMSG_DATA(cmsg), sizeof_fds);
404 ret = sizeof_fds;
405 end:
406 return ret;
407 }
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