Create all trace directories and files with client user credentials
[lttng-tools.git] / 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 it
5 * under the terms of the GNU General Public License as published by the Free
6 * Software Foundation; only version 2 of the License.
7 *
8 * This program is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
15 * Place - Suite 330, Boston, MA 02111-1307, 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 <lttngerr.h>
26 #include <lttng-share.h>
27 #include <lttng-sessiond-comm.h>
28 #include <lttng/lttng-consumer.h>
29
30 #include "hashtable.h"
31 #include "ust-consumer.h"
32
33 /*
34 * Send all stream fds of UST channel to the consumer.
35 */
36 static int send_channel_streams(int sock,
37 struct ust_app_channel *uchan,
38 uid_t uid, gid_t gid)
39 {
40 int ret, fd;
41 struct lttcomm_consumer_msg lum;
42 struct ltt_ust_stream *stream, *tmp;
43
44 DBG("Sending streams of channel %s to UST consumer", uchan->name);
45
46 /* Send channel */
47 lum.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
48
49 /*
50 * We need to keep shm_fd open while we transfer the stream file
51 * descriptors to make sure this key stays unique within the
52 * session daemon. We can free the channel shm_fd without
53 * problem after we finished sending stream fds for that
54 * channel.
55 */
56 lum.u.channel.channel_key = uchan->obj->shm_fd;
57 lum.u.channel.max_sb_size = uchan->attr.subbuf_size;
58 lum.u.channel.mmap_len = uchan->obj->memory_map_size;
59 DBG("Sending channel %d to consumer", lum.u.channel.channel_key);
60 ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
61 if (ret < 0) {
62 perror("send consumer channel");
63 goto error;
64 }
65 fd = uchan->obj->shm_fd;
66 ret = lttcomm_send_fds_unix_sock(sock, &fd, 1);
67 if (ret < 0) {
68 perror("send consumer channel ancillary data");
69 goto error;
70 }
71
72 cds_list_for_each_entry_safe(stream, tmp, &uchan->streams.head, list) {
73 int fds[2];
74
75 if (!stream->obj->shm_fd) {
76 continue;
77 }
78 lum.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
79 lum.u.stream.channel_key = uchan->obj->shm_fd;
80 lum.u.stream.stream_key = stream->obj->shm_fd;
81 lum.u.stream.state = LTTNG_CONSUMER_ACTIVE_STREAM;
82 /*
83 * FIXME Hack alert! we force MMAP for now. Mixup
84 * between EVENT and UST enums elsewhere.
85 */
86 lum.u.stream.output = DEFAULT_UST_CHANNEL_OUTPUT;
87 lum.u.stream.mmap_len = stream->obj->memory_map_size;
88 lum.u.stream.uid = uid;
89 lum.u.stream.gid = gid;
90 strncpy(lum.u.stream.path_name, stream->pathname, PATH_MAX - 1);
91 lum.u.stream.path_name[PATH_MAX - 1] = '\0';
92 DBG("Sending stream %d to consumer", lum.u.stream.stream_key);
93 ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
94 if (ret < 0) {
95 perror("send consumer stream");
96 goto error;
97 }
98
99 fds[0] = stream->obj->shm_fd;
100 fds[1] = stream->obj->wait_fd;
101 ret = lttcomm_send_fds_unix_sock(sock, fds, 2);
102 if (ret < 0) {
103 perror("send consumer stream ancillary data");
104 goto error;
105 }
106 }
107
108 DBG("consumer channel streams sent");
109
110 return 0;
111
112 error:
113 return ret;
114 }
115
116 /*
117 * Send all stream fds of the UST session to the consumer.
118 */
119 int ust_consumer_send_session(int consumer_fd, struct ust_app_session *usess)
120 {
121 int ret = 0;
122 int sock = consumer_fd;
123 struct cds_lfht_iter iter;
124 struct cds_lfht_node *node;
125 struct lttcomm_consumer_msg lum;
126 struct ust_app_channel *uchan;
127
128 DBG("Sending metadata stream fd");
129
130 if (consumer_fd < 0) {
131 ERR("Consumer has negative file descriptor");
132 return -EINVAL;
133 }
134
135 if (usess->metadata->obj->shm_fd != 0) {
136 int fd;
137 int fds[2];
138
139 /* Send metadata channel fd */
140 lum.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
141 lum.u.channel.channel_key = usess->metadata->obj->shm_fd;
142 lum.u.channel.max_sb_size = usess->metadata->attr.subbuf_size;
143 lum.u.channel.mmap_len = usess->metadata->obj->memory_map_size;
144 DBG("Sending metadata channel %d to consumer", lum.u.channel.channel_key);
145 ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
146 if (ret < 0) {
147 perror("send consumer channel");
148 goto error;
149 }
150 fd = usess->metadata->obj->shm_fd;
151 ret = lttcomm_send_fds_unix_sock(sock, &fd, 1);
152 if (ret < 0) {
153 perror("send consumer metadata channel");
154 goto error;
155 }
156
157 /* Send metadata stream fd */
158 lum.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
159 lum.u.stream.channel_key = usess->metadata->obj->shm_fd;
160 lum.u.stream.stream_key = usess->metadata->stream_obj->shm_fd;
161 lum.u.stream.state = LTTNG_CONSUMER_ACTIVE_STREAM;
162 lum.u.stream.output = DEFAULT_UST_CHANNEL_OUTPUT;
163 lum.u.stream.mmap_len = usess->metadata->stream_obj->memory_map_size;
164 lum.u.stream.uid = usess->uid;
165 lum.u.stream.gid = usess->gid;
166 strncpy(lum.u.stream.path_name, usess->metadata->pathname, PATH_MAX - 1);
167 lum.u.stream.path_name[PATH_MAX - 1] = '\0';
168 DBG("Sending metadata stream %d to consumer", lum.u.stream.stream_key);
169 ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
170 if (ret < 0) {
171 perror("send consumer metadata stream");
172 goto error;
173 }
174 fds[0] = usess->metadata->stream_obj->shm_fd;
175 fds[1] = usess->metadata->stream_obj->wait_fd;
176 ret = lttcomm_send_fds_unix_sock(sock, fds, 2);
177 if (ret < 0) {
178 perror("send consumer stream");
179 goto error;
180 }
181 }
182
183 /* Send each channel fd streams of session */
184 rcu_read_lock();
185 hashtable_get_first(usess->channels, &iter);
186 while ((node = hashtable_iter_get_node(&iter)) != NULL) {
187 uchan = caa_container_of(node, struct ust_app_channel, node);
188
189 ret = send_channel_streams(sock, uchan, usess->uid,
190 usess->gid);
191 if (ret < 0) {
192 rcu_read_unlock();
193 goto error;
194 }
195 hashtable_get_next(usess->channels, &iter);
196 }
197 rcu_read_unlock();
198
199 DBG("consumer fds (metadata and channel streams) sent");
200
201 return 0;
202
203 error:
204 return ret;
205 }
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