03b0c7d03ecee91f63dff4317dc956c10130f7fc
[lttng-tools.git] / src / bin / lttng-sessiond / ust-consumer.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 modify
5 * it under the terms of the GNU General Public License, version 2 only,
6 * as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
16 */
17
18 #define _GNU_SOURCE
19 #include <errno.h>
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <unistd.h>
24
25 #include <common/common.h>
26 #include <common/consumer.h>
27 #include <common/defaults.h>
28 #include <common/sessiond-comm/sessiond-comm.h>
29
30 #include "ust-consumer.h"
31
32 /*
33 * Send all stream fds of UST channel to the consumer.
34 */
35 static int send_channel_streams(int sock,
36 struct ust_app_channel *uchan,
37 uid_t uid, gid_t gid)
38 {
39 int ret, fd;
40 struct lttcomm_consumer_msg lum;
41 struct ltt_ust_stream *stream, *tmp;
42
43 DBG("Sending streams of channel %s to UST consumer", uchan->name);
44
45 /* Send channel */
46 lum.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
47
48 /*
49 * We need to keep shm_fd open while we transfer the stream file
50 * descriptors to make sure this key stays unique within the
51 * session daemon. We can free the channel shm_fd without
52 * problem after we finished sending stream fds for that
53 * channel.
54 */
55 lum.u.channel.channel_key = uchan->obj->shm_fd;
56 lum.u.channel.max_sb_size = uchan->attr.subbuf_size;
57 lum.u.channel.mmap_len = uchan->obj->memory_map_size;
58 DBG("Sending channel %d to consumer", lum.u.channel.channel_key);
59 ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
60 if (ret < 0) {
61 PERROR("send consumer channel");
62 goto error;
63 }
64 fd = uchan->obj->shm_fd;
65 ret = lttcomm_send_fds_unix_sock(sock, &fd, 1);
66 if (ret < 0) {
67 PERROR("send consumer channel ancillary data");
68 goto error;
69 }
70
71 cds_list_for_each_entry_safe(stream, tmp, &uchan->streams.head, list) {
72 int fds[2];
73
74 if (!stream->obj->shm_fd) {
75 continue;
76 }
77 lum.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
78 lum.u.stream.channel_key = uchan->obj->shm_fd;
79 lum.u.stream.stream_key = stream->obj->shm_fd;
80 lum.u.stream.state = LTTNG_CONSUMER_ACTIVE_STREAM;
81 /*
82 * FIXME Hack alert! we force MMAP for now. Mixup
83 * between EVENT and UST enums elsewhere.
84 */
85 lum.u.stream.output = DEFAULT_UST_CHANNEL_OUTPUT;
86 lum.u.stream.mmap_len = stream->obj->memory_map_size;
87 lum.u.stream.uid = uid;
88 lum.u.stream.gid = gid;
89 strncpy(lum.u.stream.path_name, stream->pathname, PATH_MAX - 1);
90 lum.u.stream.path_name[PATH_MAX - 1] = '\0';
91 DBG("Sending stream %d to consumer", lum.u.stream.stream_key);
92 ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
93 if (ret < 0) {
94 PERROR("send consumer stream");
95 goto error;
96 }
97
98 fds[0] = stream->obj->shm_fd;
99 fds[1] = stream->obj->wait_fd;
100 ret = lttcomm_send_fds_unix_sock(sock, fds, 2);
101 if (ret < 0) {
102 PERROR("send consumer stream ancillary data");
103 goto error;
104 }
105 }
106
107 DBG("consumer channel streams sent");
108
109 return 0;
110
111 error:
112 return ret;
113 }
114
115 /*
116 * Send all stream fds of the UST session to the consumer.
117 */
118 int ust_consumer_send_session(int consumer_fd, struct ust_app_session *usess)
119 {
120 int ret = 0;
121 int sock = consumer_fd;
122 struct lttng_ht_iter iter;
123 struct lttcomm_consumer_msg lum;
124 struct ust_app_channel *ua_chan;
125
126 DBG("Sending metadata stream fd");
127
128 if (consumer_fd < 0) {
129 ERR("Consumer has negative file descriptor");
130 return -EINVAL;
131 }
132
133 if (usess->metadata->obj->shm_fd != 0) {
134 int fd;
135 int fds[2];
136
137 /* Send metadata channel fd */
138 lum.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
139 lum.u.channel.channel_key = usess->metadata->obj->shm_fd;
140 lum.u.channel.max_sb_size = usess->metadata->attr.subbuf_size;
141 lum.u.channel.mmap_len = usess->metadata->obj->memory_map_size;
142 DBG("Sending metadata channel %d to consumer", lum.u.channel.channel_key);
143 ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
144 if (ret < 0) {
145 PERROR("send consumer channel");
146 goto error;
147 }
148 fd = usess->metadata->obj->shm_fd;
149 ret = lttcomm_send_fds_unix_sock(sock, &fd, 1);
150 if (ret < 0) {
151 PERROR("send consumer metadata channel");
152 goto error;
153 }
154
155 /* Send metadata stream fd */
156 lum.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
157 lum.u.stream.channel_key = usess->metadata->obj->shm_fd;
158 lum.u.stream.stream_key = usess->metadata->stream_obj->shm_fd;
159 lum.u.stream.state = LTTNG_CONSUMER_ACTIVE_STREAM;
160 lum.u.stream.output = DEFAULT_UST_CHANNEL_OUTPUT;
161 lum.u.stream.mmap_len = usess->metadata->stream_obj->memory_map_size;
162 lum.u.stream.uid = usess->uid;
163 lum.u.stream.gid = usess->gid;
164 strncpy(lum.u.stream.path_name, usess->metadata->pathname, PATH_MAX - 1);
165 lum.u.stream.path_name[PATH_MAX - 1] = '\0';
166 DBG("Sending metadata stream %d to consumer", lum.u.stream.stream_key);
167 ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
168 if (ret < 0) {
169 PERROR("send consumer metadata stream");
170 goto error;
171 }
172 fds[0] = usess->metadata->stream_obj->shm_fd;
173 fds[1] = usess->metadata->stream_obj->wait_fd;
174 ret = lttcomm_send_fds_unix_sock(sock, fds, 2);
175 if (ret < 0) {
176 PERROR("send consumer stream");
177 goto error;
178 }
179 }
180
181 /* Send each channel fd streams of session */
182 rcu_read_lock();
183 cds_lfht_for_each_entry(usess->channels->ht, &iter.iter, ua_chan,
184 node.node) {
185 /*
186 * Indicate that the channel was not created on the tracer side so skip
187 * sending unexisting streams.
188 */
189 if (ua_chan->obj == NULL) {
190 continue;
191 }
192
193 ret = send_channel_streams(sock, ua_chan, usess->uid, usess->gid);
194 if (ret < 0) {
195 rcu_read_unlock();
196 goto error;
197 }
198 }
199 rcu_read_unlock();
200
201 DBG("consumer fds (metadata and channel streams) sent");
202
203 return 0;
204
205 error:
206 return ret;
207 }
This page took 0.048302 seconds and 3 git commands to generate.