Update and fix UST register and session creation
[lttng-tools.git] / liblttng-sessiond-comm / lttng-sessiond-comm.c
1 /*
2 * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; only version 2
7 * of the License.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple 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
31 #include <lttng-sessiond-comm.h>
32
33 /*
34 * Human readable error message.
35 */
36 static const char *lttcomm_readable_code[] = {
37 [ LTTCOMM_ERR_INDEX(LTTCOMM_OK) ] = "Success",
38 [ LTTCOMM_ERR_INDEX(LTTCOMM_ERR) ] = "Unknown error",
39 [ LTTCOMM_ERR_INDEX(LTTCOMM_UND) ] = "Undefined command",
40 [ LTTCOMM_ERR_INDEX(LTTCOMM_NOT_IMPLEMENTED) ] = "Not implemented",
41 [ LTTCOMM_ERR_INDEX(LTTCOMM_UNKNOWN_DOMAIN) ] = "Unknown tracing domain",
42 [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_SESSION) ] = "No session found",
43 [ LTTCOMM_ERR_INDEX(LTTCOMM_LIST_FAIL) ] = "Unable to list traceable apps",
44 [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_APPS) ] = "No traceable apps found",
45 [ LTTCOMM_ERR_INDEX(LTTCOMM_SESS_NOT_FOUND) ] = "Session name not found",
46 [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_TRACE) ] = "No trace found",
47 [ LTTCOMM_ERR_INDEX(LTTCOMM_FATAL) ] = "Fatal error of the session daemon",
48 [ LTTCOMM_ERR_INDEX(LTTCOMM_CREATE_FAIL) ] = "Create trace failed",
49 [ LTTCOMM_ERR_INDEX(LTTCOMM_START_FAIL) ] = "Start trace failed",
50 [ LTTCOMM_ERR_INDEX(LTTCOMM_STOP_FAIL) ] = "Stop trace failed",
51 [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_TRACEABLE) ] = "App is not traceable",
52 [ LTTCOMM_ERR_INDEX(LTTCOMM_SELECT_SESS) ] = "A session MUST be selected",
53 [ LTTCOMM_ERR_INDEX(LTTCOMM_EXIST_SESS) ] = "Session name already exist",
54 [ LTTCOMM_ERR_INDEX(LTTCOMM_CONNECT_FAIL) ] = "Unable to connect to Unix socket",
55 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_NA) ] = "Kernel tracer not available",
56 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_EVENT_EXIST) ] = "Kernel event already exists",
57 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_SESS_FAIL) ] = "Kernel create session failed",
58 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CHAN_FAIL) ] = "Kernel create channel failed",
59 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CHAN_NOT_FOUND) ] = "Kernel channel not found",
60 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CHAN_DISABLE_FAIL) ] = "Disable kernel channel failed",
61 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CHAN_ENABLE_FAIL) ] = "Enable kernel channel failed",
62 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CONTEXT_FAIL) ] = "Add kernel context failed",
63 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_ENABLE_FAIL) ] = "Enable kernel event failed",
64 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_DISABLE_FAIL) ] = "Disable kernel event failed",
65 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_META_FAIL) ] = "Opening metadata failed",
66 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_START_FAIL) ] = "Starting kernel trace failed",
67 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_STOP_FAIL) ] = "Stoping kernel trace failed",
68 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_CONSUMER_FAIL) ] = "Kernel consumer start failed",
69 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_STREAM_FAIL) ] = "Kernel create stream failed",
70 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_DIR_FAIL) ] = "Kernel trace directory creation failed",
71 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_DIR_EXIST) ] = "Kernel trace directory already exist",
72 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_NO_SESSION) ] = "No kernel session found",
73 [ LTTCOMM_ERR_INDEX(LTTCOMM_KERN_LIST_FAIL) ] = "Listing kernel events failed",
74 [ LTTCOMM_ERR_INDEX(LTTCOMM_UST_SESS_FAIL) ] = "UST create session failed",
75 [ LTTCOMM_ERR_INDEX(KCONSUMERD_COMMAND_SOCK_READY) ] = "Kconsumerd command socket ready",
76 [ LTTCOMM_ERR_INDEX(KCONSUMERD_SUCCESS_RECV_FD) ] = "Kconsumerd success on receiving fds",
77 [ LTTCOMM_ERR_INDEX(KCONSUMERD_ERROR_RECV_FD) ] = "Kconsumerd error on receiving fds",
78 [ LTTCOMM_ERR_INDEX(KCONSUMERD_POLL_ERROR) ] = "Kconsumerd error in polling thread",
79 [ LTTCOMM_ERR_INDEX(KCONSUMERD_POLL_NVAL) ] = "Kconsumerd polling on closed fd",
80 [ LTTCOMM_ERR_INDEX(KCONSUMERD_POLL_HUP) ] = "Kconsumerd all fd hung up",
81 [ LTTCOMM_ERR_INDEX(KCONSUMERD_EXIT_SUCCESS) ] = "Kconsumerd exiting normally",
82 [ LTTCOMM_ERR_INDEX(KCONSUMERD_EXIT_FAILURE) ] = "Kconsumerd exiting on error",
83 [ LTTCOMM_ERR_INDEX(KCONSUMERD_OUTFD_ERROR) ] = "Kconsumerd error opening the tracefile",
84 [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_EBADF) ] = "Kconsumerd splice EBADF",
85 [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_EINVAL) ] = "Kconsumerd splice EINVAL",
86 [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_ENOMEM) ] = "Kconsumerd splice ENOMEM",
87 [ LTTCOMM_ERR_INDEX(KCONSUMERD_SPLICE_ESPIPE) ] = "Kconsumerd splice ESPIPE",
88 [ LTTCOMM_ERR_INDEX(LTTCOMM_NO_EVENT) ] = "Event not found",
89 };
90
91 /*
92 * lttcom_get_readable_code
93 *
94 * Return ptr to string representing a human readable
95 * error code from the lttcomm_return_code enum.
96 *
97 * These code MUST be negative in other to treat that
98 * as an error value.
99 */
100 const char *lttcomm_get_readable_code(enum lttcomm_return_code code)
101 {
102 int tmp_code = -code;
103
104 if (tmp_code >= LTTCOMM_OK && tmp_code < LTTCOMM_NR) {
105 return lttcomm_readable_code[LTTCOMM_ERR_INDEX(tmp_code)];
106 }
107
108 return "Unknown error code";
109 }
110
111 /*
112 * lttcomm_connect_unix_sock
113 *
114 * Connect to unix socket using the path name.
115 */
116 int lttcomm_connect_unix_sock(const char *pathname)
117 {
118 struct sockaddr_un sun;
119 int fd;
120 int ret;
121
122 fd = socket(PF_UNIX, SOCK_STREAM, 0);
123 if (fd < 0) {
124 perror("socket");
125 ret = fd;
126 goto error;
127 }
128
129 memset(&sun, 0, sizeof(sun));
130 sun.sun_family = AF_UNIX;
131 strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
132 sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
133
134 ret = connect(fd, (struct sockaddr *) &sun, sizeof(sun));
135 if (ret < 0) {
136 /*
137 * Don't print message on connect error, because connect
138 * is used in normal execution to detect if sessiond is
139 * alive.
140 */
141 goto error_connect;
142 }
143
144 return fd;
145
146 error_connect:
147 close(fd);
148 error:
149 return ret;
150 }
151
152 /*
153 * lttcomm_accept_unix_sock
154 *
155 * Do an accept(2) on the sock and return the
156 * new file descriptor. The socket MUST be bind(2) before.
157 */
158 int lttcomm_accept_unix_sock(int sock)
159 {
160 int new_fd;
161 struct sockaddr_un sun;
162 socklen_t len = 0;
163
164 /* Blocking call */
165 new_fd = accept(sock, (struct sockaddr *) &sun, &len);
166 if (new_fd < 0) {
167 perror("accept");
168 goto error;
169 }
170
171 return new_fd;
172
173 error:
174 return -1;
175 }
176
177 /*
178 * lttcomm_create_unix_sock
179 *
180 * Creates a AF_UNIX local socket using pathname
181 * bind the socket upon creation and return the fd.
182 */
183 int lttcomm_create_unix_sock(const char *pathname)
184 {
185 struct sockaddr_un sun;
186 int fd;
187 int ret = -1;
188
189 /* Create server socket */
190 if ((fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) {
191 perror("socket");
192 goto error;
193 }
194
195 memset(&sun, 0, sizeof(sun));
196 sun.sun_family = AF_UNIX;
197 strncpy(sun.sun_path, pathname, sizeof(sun.sun_path));
198 sun.sun_path[sizeof(sun.sun_path) - 1] = '\0';
199
200 /* Unlink the old file if present */
201 (void) unlink(pathname);
202 ret = bind(fd, (struct sockaddr *) &sun, sizeof(sun));
203 if (ret < 0) {
204 perror("bind");
205 goto error;
206 }
207
208 return fd;
209
210 error:
211 return ret;
212 }
213
214 /*
215 * lttcomm_listen_unix_sock
216 *
217 * Make the socket listen using MAX_LISTEN.
218 */
219 int lttcomm_listen_unix_sock(int sock)
220 {
221 int ret;
222
223 ret = listen(sock, MAX_LISTEN);
224 if (ret < 0) {
225 perror("listen");
226 }
227
228 return ret;
229 }
230
231 /*
232 * lttcomm_recv_unix_sock
233 *
234 * Receive data of size len in put that data into
235 * the buf param. Using recvmsg API.
236 * Return the size of received data.
237 */
238 ssize_t lttcomm_recv_unix_sock(int sock, void *buf, size_t len)
239 {
240 struct msghdr msg = { 0 };
241 struct iovec iov[1];
242 ssize_t ret = -1;
243
244 iov[0].iov_base = buf;
245 iov[0].iov_len = len;
246 msg.msg_iov = iov;
247 msg.msg_iovlen = 1;
248
249 ret = recvmsg(sock, &msg, 0);
250 if (ret < 0) {
251 perror("recvmsg");
252 }
253
254 return ret;
255 }
256
257 /*
258 * lttcomm_send_unix_sock
259 *
260 * Send buf data of size len. Using sendmsg API.
261 * Return the size of sent data.
262 */
263 ssize_t lttcomm_send_unix_sock(int sock, void *buf, size_t len)
264 {
265 struct msghdr msg = { 0 };
266 struct iovec iov[1];
267 ssize_t ret = -1;
268
269 iov[0].iov_base = buf;
270 iov[0].iov_len = len;
271 msg.msg_iov = iov;
272 msg.msg_iovlen = 1;
273
274 ret = sendmsg(sock, &msg, 0);
275 if (ret < 0) {
276 perror("sendmsg");
277 }
278
279 return ret;
280 }
281
282 /*
283 * lttcomm_close_unix_sock
284 *
285 * Shutdown cleanly a unix socket.
286 */
287 int lttcomm_close_unix_sock(int sock)
288 {
289 int ret;
290
291 /* Shutdown receptions and transmissions */
292 ret = shutdown(sock, SHUT_RDWR);
293 if (ret < 0) {
294 perror("shutdown");
295 }
296
297 return ret;
298 }
299
300 /*
301 * lttcomm_send_fds_unix_sock
302 *
303 * Send multiple fds on a unix socket.
304 */
305 ssize_t lttcomm_send_fds_unix_sock(int sock, void *buf, int *fds, size_t nb_fd, size_t len)
306 {
307 struct msghdr msg = { 0 };
308 struct cmsghdr *cmptr;
309 struct iovec iov[1];
310 ssize_t ret = -1;
311 unsigned int sizeof_fds = nb_fd * sizeof(int);
312 char tmp[CMSG_SPACE(sizeof_fds)];
313
314 /*
315 * Note: the consumerd receiver only supports receiving one FD per
316 * message.
317 */
318 assert(nb_fd == 1);
319
320 msg.msg_control = (caddr_t)tmp;
321 msg.msg_controllen = CMSG_LEN(sizeof_fds);
322
323 cmptr = CMSG_FIRSTHDR(&msg);
324 cmptr->cmsg_level = SOL_SOCKET;
325 cmptr->cmsg_type = SCM_RIGHTS;
326 cmptr->cmsg_len = CMSG_LEN(sizeof_fds);
327 memcpy(CMSG_DATA(cmptr), fds, sizeof_fds);
328 /* Sum of the length of all control messages in the buffer: */
329 msg.msg_controllen = cmptr->cmsg_len;
330
331 iov[0].iov_base = buf;
332 iov[0].iov_len = len;
333 msg.msg_iov = iov;
334 msg.msg_iovlen = 1;
335
336 ret = sendmsg(sock, &msg, 0);
337 if (ret < 0) {
338 perror("sendmsg");
339 }
340
341 return ret;
342 }
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