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 {
  39         int ret, fds[2];
  40         struct ltt_ust_stream *stream;
  41         struct lttcomm_consumer_msg lum;
  42         struct cds_lfht_iter iter;
  43         struct cds_lfht_node *node;
  44
  45         DBG("Sending streams of channel %s to UST consumer", uchan->name);
  46
  47         /* Send channel */
  48         lum.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
  49
  50         /*
  51          * We need to keep shm_fd open to make sure this key stays unique within
  52          * the session daemon.
  53          */
  54         lum.u.channel.channel_key = uchan->obj->shm_fd;
  55         lum.u.channel.max_sb_size = uchan->attr.subbuf_size;
  56         lum.u.channel.mmap_len = uchan->obj->memory_map_size;
  57         DBG("Sending channel %d to consumer", lum.u.channel.channel_key);
  58         ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
  59         if (ret < 0) {
  60                 perror("send consumer channel");
  61                 goto error;
  62         }
  63         fds[0] = uchan->obj->shm_fd;
  64         fds[1] = uchan->obj->wait_fd;
  65         ret = lttcomm_send_fds_unix_sock(sock, fds, 2);
  66         if (ret < 0) {
  67                 perror("send consumer channel ancillary data");
  68                 goto error;
  69         }
  70
  71
  72         rcu_read_lock();
  73         hashtable_get_first(uchan->streams, &iter);
  74         while ((node = hashtable_iter_get_node(&iter)) != NULL) {
  75                 stream = caa_container_of(node, struct ltt_ust_stream, node);
  76
  77                 int fds[2];
  78
  79                 if (!stream->obj->shm_fd) {
  80                         goto next;
  81                 }
  82
  83                 lum.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
  84                 lum.u.stream.channel_key = uchan->obj->shm_fd;
  85                 lum.u.stream.stream_key = stream->obj->shm_fd;
  86                 lum.u.stream.state = LTTNG_CONSUMER_ACTIVE_STREAM;
  87                 lum.u.stream.output = uchan->attr.output;
  88                 lum.u.stream.mmap_len = stream->obj->memory_map_size;
  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 next:
 107                 hashtable_get_next(uchan->streams, &iter);
 108         }
 109         rcu_read_unlock();
 110
 111         DBG("consumer channel streams sent");
 112
 113         return 0;
 114
 115 error:
 116         return ret;
 117 }
 118
 119 /*
 120  * Send all stream fds of the UST session to the consumer.
 121  */
 122 int ust_consumer_send_session(int consumer_fd, struct ust_app_session *usess)
 123 {
 124         int ret = 0;
 125         int sock = consumer_fd;
 126         struct cds_lfht_iter iter;
 127         struct cds_lfht_node *node;
 128         struct lttcomm_consumer_msg lum;
 129         struct ust_app_channel *uchan;
 130
 131         DBG("Sending metadata stream fd");
 132
 133         if (usess->metadata->obj->shm_fd != 0) {
 134                 int fds[2];
 135
 136                 /* Send metadata channel fd */
 137                 lum.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
 138                 lum.u.channel.channel_key = usess->metadata->obj->shm_fd;
 139                 lum.u.channel.max_sb_size = usess->metadata->attr.subbuf_size;
 140                 lum.u.channel.mmap_len = 0;     /* for kernel */
 141                 DBG("Sending metadata channel %d to consumer", lum.u.stream.stream_key);
 142                 ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
 143                 if (ret < 0) {
 144                         perror("send consumer channel");
 145                         goto error;
 146                 }
 147                 fds[0] = usess->metadata->obj->shm_fd;
 148                 fds[1] = usess->metadata->obj->wait_fd;
 149                 ret = lttcomm_send_fds_unix_sock(sock, fds, 2);
 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                 strncpy(lum.u.stream.path_name, usess->metadata->pathname, PATH_MAX - 1);
 163                 lum.u.stream.path_name[PATH_MAX - 1] = '\0';
 164                 DBG("Sending metadata stream %d to consumer", lum.u.stream.stream_key);
 165                 ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
 166                 if (ret < 0) {
 167                         perror("send consumer metadata stream");
 168                         goto error;
 169                 }
 170                 fds[0] = usess->metadata->stream_obj->shm_fd;
 171                 fds[1] = usess->metadata->stream_obj->wait_fd;
 172                 ret = lttcomm_send_fds_unix_sock(sock, fds, 2);
 173                 if (ret < 0) {
 174                         perror("send consumer stream");
 175                         goto error;
 176                 }
 177         }
 178
 179         /* Send each channel fd streams of session */
 180         rcu_read_lock();
 181         hashtable_get_first(usess->channels, &iter);
 182         while ((node = hashtable_iter_get_node(&iter)) != NULL) {
 183                 uchan = caa_container_of(node, struct ust_app_channel, node);
 184
 185                 ret = send_channel_streams(sock, uchan);
 186                 if (ret < 0) {
 187                         goto error;
 188                 }
 189                 hashtable_get_next(usess->channels, &iter);
 190         }
 191         rcu_read_unlock();
 192
 193         DBG("consumer fds (metadata and channel streams) sent");
 194
 195         return 0;
 196
 197 error:
 198         return ret;
 199 }