Merge branch 'master' of git://git.lttng.org/lttng-tools
[lttng-tools.git] / liblttng-sessiond-comm / lttng-sessiond-comm.c
CommitLineData
826d496d 1/*
917216f6
DG
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
fac6795d 4 *
917216f6
DG
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.
fac6795d 8 *
917216f6
DG
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.
fac6795d 13 *
917216f6
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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.
fac6795d
DG
17 */
18
19#define _GNU_SOURCE
1e307fab 20#include <assert.h>
fac6795d
DG
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>
3bd1e081 30#include <errno.h>
fac6795d 31
e88129fc 32#include <lttng-sessiond-comm.h>
fac6795d
DG
33
34/*
35 * Human readable error message.
36 */
37static 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",
7d29a247
DG
41 [ LTTCOMM_ERR_INDEX(LTTCOMM_NOT_IMPLEMENTED) ] = "Not implemented",
42 [ LTTCOMM_ERR_INDEX(LTTCOMM_UNKNOWN_DOMAIN) ] = "Unknown tracing domain",
fac6795d
DG
43 [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_SESSION) ] = "No session found",
44 [ LTTCOMM_ERR_INDEX(LTTCOMM_LIST_FAIL) ] = "Unable to list traceable apps",
e065084a 45 [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_APPS) ] = "No traceable apps found",
f3ed775e 46 [ LTTCOMM_ERR_INDEX(LTTCOMM_SESS_NOT_FOUND) ] = "Session name not found",
ce3d728c 47 [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_TRACE) ] = "No trace found",
ca95a216 48 [ LTTCOMM_ERR_INDEX(LTTCOMM_FATAL) ] = "Fatal error of the session daemon",
df0da139 49 [ LTTCOMM_ERR_INDEX(LTTCOMM_CREATE_FAIL) ] = "Create trace failed",
379473d2 50 [ LTTCOMM_ERR_INDEX(LTTCOMM_START_FAIL) ] = "Start trace failed",
520ff687 51 [ LTTCOMM_ERR_INDEX(LTTCOMM_STOP_FAIL) ] = "Stop trace failed",
379473d2
DG
52 [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_TRACEABLE) ] = "App is not traceable",
53 [ LTTCOMM_ERR_INDEX(LTTCOMM_SELECT_SESS) ] = "A session MUST be selected",
27673bb6 54 [ LTTCOMM_ERR_INDEX(LTTCOMM_EXIST_SESS) ] = "Session name already exist",
d9800920 55 [ LTTCOMM_ERR_INDEX(LTTCOMM_CONNECT_FAIL) ] = "Unable to connect to Unix socket",
2b0bf864 56 [ LTTCOMM_ERR_INDEX(LTTCOMM_APP_NOT_FOUND) ] = "Application not found",
20fe2104 57 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_NA) ] = "Kernel tracer not available",
7d29a247 58 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_EVENT_EXIST) ] = "Kernel event already exists",
20fe2104
DG
59 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_SESS_FAIL) ] = "Kernel create session failed",
60 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CHAN_FAIL) ] = "Kernel create channel failed",
f3ed775e 61 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CHAN_NOT_FOUND) ] = "Kernel channel not found",
26cc6b4e 62 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CHAN_DISABLE_FAIL) ] = "Disable kernel channel failed",
d36b8583 63 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CHAN_ENABLE_FAIL) ] = "Enable kernel channel failed",
d65106b1 64 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CONTEXT_FAIL) ] = "Add kernel context failed",
f34daff7
DG
65 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_ENABLE_FAIL) ] = "Enable kernel event failed",
66 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_DISABLE_FAIL) ] = "Disable kernel event failed",
aaf26714 67 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_META_FAIL) ] = "Opening metadata failed",
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DG
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",
84291629 74 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_NO_SESSION) ] = "No kernel session found",
2ef84c95 75 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_LIST_FAIL) ] = "Listing kernel events failed",
0177d773 76 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_SESS_FAIL) ] = "UST create session failed",
2b0bf864 77 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_CHAN_FAIL) ] = "UST create channel failed",
f6a9efaa 78 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_CHAN_EXIST) ] = "UST channel already exist",
2bdd86d4
MD
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",
3bd1e081
MD
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",
f2fc6720 97 [ LTTCOMM_ERR_INDEX(CONSUMERD_ERROR_RECV_CMD) ] = "consumerd error on receiving command",
3bd1e081
MD
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",
d65106b1 108 [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_EVENT) ] = "Event not found",
fac6795d
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109};
110
111/*
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112 * Return ptr to string representing a human readable error code from the
113 * lttcomm_return_code enum.
fac6795d 114 *
917216f6 115 * These code MUST be negative in other to treat that as an error value.
fac6795d
DG
116 */
117const 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/*
917216f6 129 * Connect to unix socket using the path name.
fac6795d
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130 */
131int lttcomm_connect_unix_sock(const char *pathname)
132{
686204ab
MD
133 struct sockaddr_un sun;
134 int fd;
a8afeb4a 135 int ret;
fac6795d 136
686204ab 137 fd = socket(PF_UNIX, SOCK_STREAM, 0);
fac6795d
DG
138 if (fd < 0) {
139 perror("socket");
a8afeb4a 140 ret = fd;
fac6795d
DG
141 goto error;
142 }
143
686204ab
MD
144 memset(&sun, 0, sizeof(sun));
145 sun.sun_family = AF_UNIX;
146 strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
99497cd0 147 sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
fac6795d 148
686204ab
MD
149 ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun));
150 if (ret < 0) {
a8afeb4a 151 /*
917216f6
DG
152 * Don't print message on connect error, because connect is used in
153 * normal execution to detect if sessiond is alive.
a8afeb4a
MD
154 */
155 goto error_connect;
686204ab 156 }
fac6795d 157
686204ab 158 return fd;
fac6795d 159
a8afeb4a
MD
160error_connect:
161 close(fd);
fac6795d 162error:
a8afeb4a 163 return ret;
fac6795d
DG
164}
165
166/*
917216f6
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167 * Do an accept(2) on the sock and return the new file descriptor. The socket
168 * MUST be bind(2) before.
fac6795d
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169 */
170int 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
185error:
186 return -1;
187}
188
189/*
917216f6
DG
190 * Creates a AF_UNIX local socket using pathname bind the socket upon creation
191 * and return the fd.
fac6795d
DG
192 */
193int 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;
99497cd0
MD
207 strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
208 sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
fac6795d 209
7d8234d9
MD
210 /* Unlink the old file if present */
211 (void) unlink(pathname);
fac6795d
DG
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
220error:
221 return ret;
222}
223
224/*
f158a754 225 * Make the socket listen using LTTNG_SESSIOND_COMM_MAX_LISTEN.
fac6795d
DG
226 */
227int lttcomm_listen_unix_sock(int sock)
228{
229 int ret;
230
f158a754 231 ret = listen(sock, LTTNG_SESSIOND_COMM_MAX_LISTEN);
fac6795d
DG
232 if (ret < 0) {
233 perror("listen");
234 }
235
236 return ret;
237}
238
239/*
917216f6
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240 * Receive data of size len in put that data into the buf param. Using recvmsg
241 * API.
fac6795d 242 *
917216f6 243 * Return the size of received data.
fac6795d
DG
244 */
245ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len)
246{
159c7ff4 247 struct msghdr msg = { 0 };
fac6795d
DG
248 struct iovec iov[1];
249 ssize_t ret = -1;
250
fac6795d
DG
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/*
917216f6 265 * Send buf data of size len. Using sendmsg API.
fac6795d 266 *
917216f6 267 * Return the size of sent data.
fac6795d
DG
268 */
269ssize_t lttcomm_send_unix_sock(int sock, void *buf, size_t len)
270{
159c7ff4 271 struct msghdr msg = { 0 };
fac6795d
DG
272 struct iovec iov[1];
273 ssize_t ret = -1;
274
fac6795d
DG
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}
87378cf5
DG
287
288/*
917216f6 289 * Shutdown cleanly a unix socket.
87378cf5
DG
290 */
291int 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}
8c0faa1d
DG
303
304/*
3bd1e081
MD
305 * Send a message accompanied by fd(s) over a unix socket.
306 *
307 * Returns the size of data sent, or negative error value.
8c0faa1d 308 */
3bd1e081 309ssize_t lttcomm_send_fds_unix_sock(int sock, int *fds, size_t nb_fd)
8c0faa1d 310{
159c7ff4 311 struct msghdr msg = { 0 };
8c0faa1d
DG
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)];
3bd1e081 317 char dummy = 0;
8c0faa1d 318
3bd1e081
MD
319 if (nb_fd > LTTCOMM_MAX_SEND_FDS)
320 return -EINVAL;
8c0faa1d
DG
321
322 msg.msg_control = (caddr_t)tmp;
323 msg.msg_controllen = CMSG_LEN(sizeof_fds);
324
325 cmptr = CMSG_FIRSTHDR(&msg);
8c0faa1d
DG
326 cmptr->cmsg_level = SOL_SOCKET;
327 cmptr->cmsg_type = SCM_RIGHTS;
159c7ff4 328 cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
8c0faa1d 329 memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
159c7ff4
MD
330 /* Sum of the length of all control messages in the buffer: */
331 msg.msg_controllen = cmptr->cmsg_len;
8c0faa1d 332
3bd1e081
MD
333 iov[0].iov_base = &dummy;
334 iov[0].iov_len = 1;
8c0faa1d
DG
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 }
8c0faa1d
DG
342 return ret;
343}
09de5c68
DG
344
345/*
3bd1e081 346 * Recv a message accompanied by fd(s) from a unix socket.
09de5c68 347 *
3bd1e081
MD
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.
09de5c68 352 */
3bd1e081 353ssize_t lttcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd)
09de5c68
DG
354{
355 struct iovec iov[1];
3bd1e081 356 ssize_t ret = 0;
09de5c68 357 struct cmsghdr *cmsg;
3bd1e081
MD
358 size_t sizeof_fds = nb_fd * sizeof(int);
359 char recv_fd[CMSG_SPACE(sizeof_fds)];
09de5c68 360 struct msghdr msg = { 0 };
3bd1e081 361 char dummy;
09de5c68
DG
362
363 /* Prepare to receive the structures */
3bd1e081
MD
364 iov[0].iov_base = &dummy;
365 iov[0].iov_len = 1;
09de5c68
DG
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 }
3bd1e081
MD
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;
09de5c68
DG
384 goto end;
385 }
09de5c68
DG
386 cmsg = CMSG_FIRSTHDR(&msg);
387 if (!cmsg) {
3bd1e081 388 fprintf(stderr, "Error: Invalid control message header\n");
09de5c68
DG
389 ret = -1;
390 goto end;
391 }
09de5c68 392 if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS) {
3bd1e081 393 fprintf(stderr, "Didn't received any fd\n");
09de5c68
DG
394 ret = -1;
395 goto end;
396 }
3bd1e081
MD
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;
09de5c68 402 }
3bd1e081
MD
403 memcpy(fds, CMSG_DATA(cmsg), sizeof_fds);
404 ret = sizeof_fds;
09de5c68
DG
405end:
406 return ret;
407}
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