Fix flush buffer after wait quiescent
[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",
8c0faa1d
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",
7753dea8
MD
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",
2bdd86d4
MD
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",
3b25d04d 95 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_EVENT_EXIST) ] = "UST event already exist",
be4f0921 96 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_EVENT_NOT_FOUND)] = "UST event not found",
ae357384 97 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_CONTEXT_EXIST)] = "UST context already exist",
3bd1e081
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98 [ LTTCOMM_ERR_INDEX(CONSUMERD_COMMAND_SOCK_READY) ] = "consumerd command socket ready",
99 [ LTTCOMM_ERR_INDEX(CONSUMERD_SUCCESS_RECV_FD) ] = "consumerd success on receiving fds",
100 [ LTTCOMM_ERR_INDEX(CONSUMERD_ERROR_RECV_FD) ] = "consumerd error on receiving fds",
f2fc6720 101 [ LTTCOMM_ERR_INDEX(CONSUMERD_ERROR_RECV_CMD) ] = "consumerd error on receiving command",
3bd1e081
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102 [ LTTCOMM_ERR_INDEX(CONSUMERD_POLL_ERROR) ] = "consumerd error in polling thread",
103 [ LTTCOMM_ERR_INDEX(CONSUMERD_POLL_NVAL) ] = "consumerd polling on closed fd",
104 [ LTTCOMM_ERR_INDEX(CONSUMERD_POLL_HUP) ] = "consumerd all fd hung up",
105 [ LTTCOMM_ERR_INDEX(CONSUMERD_EXIT_SUCCESS) ] = "consumerd exiting normally",
106 [ LTTCOMM_ERR_INDEX(CONSUMERD_EXIT_FAILURE) ] = "consumerd exiting on error",
107 [ LTTCOMM_ERR_INDEX(CONSUMERD_OUTFD_ERROR) ] = "consumerd error opening the tracefile",
108 [ LTTCOMM_ERR_INDEX(CONSUMERD_SPLICE_EBADF) ] = "consumerd splice EBADF",
109 [ LTTCOMM_ERR_INDEX(CONSUMERD_SPLICE_EINVAL) ] = "consumerd splice EINVAL",
110 [ LTTCOMM_ERR_INDEX(CONSUMERD_SPLICE_ENOMEM) ] = "consumerd splice ENOMEM",
111 [ LTTCOMM_ERR_INDEX(CONSUMERD_SPLICE_ESPIPE) ] = "consumerd splice ESPIPE",
d65106b1 112 [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_EVENT) ] = "Event not found",
fac6795d
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113};
114
115/*
917216f6
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116 * Return ptr to string representing a human readable error code from the
117 * lttcomm_return_code enum.
fac6795d 118 *
917216f6 119 * These code MUST be negative in other to treat that as an error value.
fac6795d
DG
120 */
121const char *lttcomm_get_readable_code(enum lttcomm_return_code code)
122{
123 int tmp_code = -code;
124
125 if (tmp_code >= LTTCOMM_OK && tmp_code < LTTCOMM_NR) {
126 return lttcomm_readable_code[LTTCOMM_ERR_INDEX(tmp_code)];
127 }
128
129 return "Unknown error code";
130}
131
132/*
917216f6 133 * Connect to unix socket using the path name.
fac6795d
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134 */
135int lttcomm_connect_unix_sock(const char *pathname)
136{
686204ab
MD
137 struct sockaddr_un sun;
138 int fd;
a8afeb4a 139 int ret;
fac6795d 140
686204ab 141 fd = socket(PF_UNIX, SOCK_STREAM, 0);
fac6795d
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142 if (fd < 0) {
143 perror("socket");
a8afeb4a 144 ret = fd;
fac6795d
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145 goto error;
146 }
147
686204ab
MD
148 memset(&sun, 0, sizeof(sun));
149 sun.sun_family = AF_UNIX;
150 strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
99497cd0 151 sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
fac6795d 152
686204ab
MD
153 ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun));
154 if (ret < 0) {
a8afeb4a 155 /*
917216f6
DG
156 * Don't print message on connect error, because connect is used in
157 * normal execution to detect if sessiond is alive.
a8afeb4a
MD
158 */
159 goto error_connect;
686204ab 160 }
fac6795d 161
686204ab 162 return fd;
fac6795d 163
a8afeb4a
MD
164error_connect:
165 close(fd);
fac6795d 166error:
a8afeb4a 167 return ret;
fac6795d
DG
168}
169
170/*
917216f6
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171 * Do an accept(2) on the sock and return the new file descriptor. The socket
172 * MUST be bind(2) before.
fac6795d
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173 */
174int lttcomm_accept_unix_sock(int sock)
175{
176 int new_fd;
177 struct sockaddr_un sun;
178 socklen_t len = 0;
179
180 /* Blocking call */
181 new_fd = accept(sock, (struct sockaddr *) &sun, &len);
182 if (new_fd < 0) {
183 perror("accept");
184 goto error;
185 }
186
187 return new_fd;
188
189error:
190 return -1;
191}
192
193/*
917216f6
DG
194 * Creates a AF_UNIX local socket using pathname bind the socket upon creation
195 * and return the fd.
fac6795d
DG
196 */
197int lttcomm_create_unix_sock(const char *pathname)
198{
199 struct sockaddr_un sun;
200 int fd;
201 int ret = -1;
202
203 /* Create server socket */
204 if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
205 perror("socket");
206 goto error;
207 }
208
209 memset(&sun, 0, sizeof(sun));
210 sun.sun_family = AF_UNIX;
99497cd0
MD
211 strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
212 sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
fac6795d 213
7d8234d9
MD
214 /* Unlink the old file if present */
215 (void) unlink(pathname);
fac6795d
DG
216 ret = bind(fd, (struct sockaddr *) &sun, sizeof(sun));
217 if (ret < 0) {
218 perror("bind");
219 goto error;
220 }
221
222 return fd;
223
224error:
225 return ret;
226}
227
228/*
f158a754 229 * Make the socket listen using LTTNG_SESSIOND_COMM_MAX_LISTEN.
fac6795d
DG
230 */
231int lttcomm_listen_unix_sock(int sock)
232{
233 int ret;
234
f158a754 235 ret = listen(sock, LTTNG_SESSIOND_COMM_MAX_LISTEN);
fac6795d
DG
236 if (ret < 0) {
237 perror("listen");
238 }
239
240 return ret;
241}
242
243/*
917216f6
DG
244 * Receive data of size len in put that data into the buf param. Using recvmsg
245 * API.
fac6795d 246 *
917216f6 247 * Return the size of received data.
fac6795d
DG
248 */
249ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len)
250{
159c7ff4 251 struct msghdr msg = { 0 };
fac6795d
DG
252 struct iovec iov[1];
253 ssize_t ret = -1;
254
fac6795d
DG
255 iov[0].iov_base = buf;
256 iov[0].iov_len = len;
257 msg.msg_iov = iov;
258 msg.msg_iovlen = 1;
259
260 ret = recvmsg(sock, &msg, 0);
261 if (ret < 0) {
262 perror("recvmsg");
263 }
264
265 return ret;
266}
267
268/*
917216f6 269 * Send buf data of size len. Using sendmsg API.
fac6795d 270 *
917216f6 271 * Return the size of sent data.
fac6795d
DG
272 */
273ssize_t lttcomm_send_unix_sock(int sock, void *buf, size_t len)
274{
159c7ff4 275 struct msghdr msg = { 0 };
fac6795d
DG
276 struct iovec iov[1];
277 ssize_t ret = -1;
278
fac6795d
DG
279 iov[0].iov_base = buf;
280 iov[0].iov_len = len;
281 msg.msg_iov = iov;
282 msg.msg_iovlen = 1;
283
284 ret = sendmsg(sock, &msg, 0);
285 if (ret < 0) {
286 perror("sendmsg");
287 }
288
289 return ret;
290}
87378cf5
DG
291
292/*
917216f6 293 * Shutdown cleanly a unix socket.
87378cf5
DG
294 */
295int lttcomm_close_unix_sock(int sock)
296{
297 int ret;
298
299 /* Shutdown receptions and transmissions */
300 ret = shutdown(sock, SHUT_RDWR);
301 if (ret < 0) {
302 perror("shutdown");
303 }
304
305 return ret;
306}
8c0faa1d
DG
307
308/*
3bd1e081
MD
309 * Send a message accompanied by fd(s) over a unix socket.
310 *
311 * Returns the size of data sent, or negative error value.
8c0faa1d 312 */
3bd1e081 313ssize_t lttcomm_send_fds_unix_sock(int sock, int *fds, size_t nb_fd)
8c0faa1d 314{
159c7ff4 315 struct msghdr msg = { 0 };
8c0faa1d
DG
316 struct cmsghdr *cmptr;
317 struct iovec iov[1];
318 ssize_t ret = -1;
319 unsigned int sizeof_fds = nb_fd * sizeof(int);
320 char tmp[CMSG_SPACE(sizeof_fds)];
3bd1e081 321 char dummy = 0;
8c0faa1d 322
3bd1e081
MD
323 if (nb_fd > LTTCOMM_MAX_SEND_FDS)
324 return -EINVAL;
8c0faa1d
DG
325
326 msg.msg_control = (caddr_t)tmp;
327 msg.msg_controllen = CMSG_LEN(sizeof_fds);
328
329 cmptr = CMSG_FIRSTHDR(&msg);
8c0faa1d
DG
330 cmptr->cmsg_level = SOL_SOCKET;
331 cmptr->cmsg_type = SCM_RIGHTS;
159c7ff4 332 cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
8c0faa1d 333 memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
159c7ff4
MD
334 /* Sum of the length of all control messages in the buffer: */
335 msg.msg_controllen = cmptr->cmsg_len;
8c0faa1d 336
3bd1e081
MD
337 iov[0].iov_base = &dummy;
338 iov[0].iov_len = 1;
8c0faa1d
DG
339 msg.msg_iov = iov;
340 msg.msg_iovlen = 1;
341
342 ret = sendmsg(sock, &msg, 0);
343 if (ret < 0) {
344 perror("sendmsg");
345 }
8c0faa1d
DG
346 return ret;
347}
09de5c68
DG
348
349/*
3bd1e081 350 * Recv a message accompanied by fd(s) from a unix socket.
09de5c68 351 *
3bd1e081
MD
352 * Returns the size of received data, or negative error value.
353 *
354 * Expect at most "nb_fd" file descriptors. Returns the number of fd
355 * actually received in nb_fd.
09de5c68 356 */
3bd1e081 357ssize_t lttcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd)
09de5c68
DG
358{
359 struct iovec iov[1];
3bd1e081 360 ssize_t ret = 0;
09de5c68 361 struct cmsghdr *cmsg;
3bd1e081
MD
362 size_t sizeof_fds = nb_fd * sizeof(int);
363 char recv_fd[CMSG_SPACE(sizeof_fds)];
09de5c68 364 struct msghdr msg = { 0 };
3bd1e081 365 char dummy;
09de5c68
DG
366
367 /* Prepare to receive the structures */
3bd1e081
MD
368 iov[0].iov_base = &dummy;
369 iov[0].iov_len = 1;
09de5c68
DG
370 msg.msg_iov = iov;
371 msg.msg_iovlen = 1;
372 msg.msg_control = recv_fd;
373 msg.msg_controllen = sizeof(recv_fd);
374
375 ret = recvmsg(sock, &msg, 0);
376 if (ret < 0) {
377 perror("recvmsg fds");
378 goto end;
379 }
3bd1e081
MD
380 if (ret != 1) {
381 fprintf(stderr, "Error: Received %zd bytes, expected %d\n",
382 ret, 1);
383 goto end;
384 }
385 if (msg.msg_flags & MSG_CTRUNC) {
386 fprintf(stderr, "Error: Control message truncated.\n");
387 ret = -1;
09de5c68
DG
388 goto end;
389 }
09de5c68
DG
390 cmsg = CMSG_FIRSTHDR(&msg);
391 if (!cmsg) {
3bd1e081 392 fprintf(stderr, "Error: Invalid control message header\n");
09de5c68
DG
393 ret = -1;
394 goto end;
395 }
09de5c68 396 if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS) {
3bd1e081 397 fprintf(stderr, "Didn't received any fd\n");
09de5c68
DG
398 ret = -1;
399 goto end;
400 }
3bd1e081
MD
401 if (cmsg->cmsg_len != CMSG_LEN(sizeof_fds)) {
402 fprintf(stderr, "Error: Received %zu bytes of ancillary data, expected %zu\n",
403 cmsg->cmsg_len, CMSG_LEN(sizeof_fds));
404 ret = -1;
405 goto end;
09de5c68 406 }
3bd1e081
MD
407 memcpy(fds, CMSG_DATA(cmsg), sizeof_fds);
408 ret = sizeof_fds;
09de5c68
DG
409end:
410 return ret;
411}
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