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, fd;
  40         struct lttcomm_consumer_msg lum;
  41         struct ltt_ust_stream *stream;
  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 to make sure this key stays unique within
  50          * the session daemon.
  51          */
  52         lum.u.channel.channel_key = uchan->obj->shm_fd;
  53         lum.u.channel.max_sb_size = uchan->attr.subbuf_size;
  54         lum.u.channel.mmap_len = uchan->obj->memory_map_size;
  55         DBG("Sending channel %d to consumer", lum.u.channel.channel_key);
  56         ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
  57         if (ret < 0) {
  58                 perror("send consumer channel");
  59                 goto error;
  60         }
  61         fd = uchan->obj->shm_fd;
  62         ret = lttcomm_send_fds_unix_sock(sock, &fd, 1);
  63         if (ret < 0) {
  64                 perror("send consumer channel ancillary data");
  65                 goto error;
  66         }
  67
  68         cds_list_for_each_entry(stream, &uchan->streams.head, list) {
  69                 int fds[2];
  70
  71                 if (!stream->obj->shm_fd) {
  72                         continue;
  73                 }
  74                 lum.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
  75                 lum.u.stream.channel_key = uchan->obj->shm_fd;
  76                 lum.u.stream.stream_key = stream->obj->shm_fd;
  77                 lum.u.stream.state = LTTNG_CONSUMER_ACTIVE_STREAM;
  78                 lum.u.stream.output = uchan->attr.output;
  79                 lum.u.stream.mmap_len = stream->obj->memory_map_size;
  80                 strncpy(lum.u.stream.path_name, stream->pathname, PATH_MAX - 1);
  81                 lum.u.stream.path_name[PATH_MAX - 1] = '\0';
  82                 DBG("Sending stream %d to consumer", lum.u.stream.stream_key);
  83                 ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
  84                 if (ret < 0) {
  85                         perror("send consumer stream");
  86                         goto error;
  87                 }
  88
  89                 fds[0] = stream->obj->shm_fd;
  90                 fds[1] = stream->obj->wait_fd;
  91                 ret = lttcomm_send_fds_unix_sock(sock, fds, 2);
  92                 if (ret < 0) {
  93                         perror("send consumer stream ancillary data");
  94                         goto error;
  95                 }
  96         }
  97
  98         DBG("consumer channel streams sent");
  99
 100         return 0;
 101
 102 error:
 103         return ret;
 104 }
 105
 106 /*
 107  * Send all stream fds of the UST session to the consumer.
 108  */
 109 int ust_consumer_send_session(int consumer_fd, struct ust_app_session *usess)
 110 {
 111         int ret = 0;
 112         int sock = consumer_fd;
 113         struct cds_lfht_iter iter;
 114         struct cds_lfht_node *node;
 115         struct lttcomm_consumer_msg lum;
 116         struct ust_app_channel *uchan;
 117
 118         DBG("Sending metadata stream fd");
 119
 120         if (usess->metadata->obj->shm_fd != 0) {
 121                 int fd;
 122                 int fds[2];
 123
 124                 /* Send metadata channel fd */
 125                 lum.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
 126                 lum.u.channel.channel_key = usess->metadata->obj->shm_fd;
 127                 lum.u.channel.max_sb_size = usess->metadata->attr.subbuf_size;
 128                 lum.u.channel.mmap_len = usess->metadata->obj->memory_map_size;
 129                 DBG("Sending metadata channel %d to consumer", lum.u.channel.channel_key);
 130                 ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
 131                 if (ret < 0) {
 132                         perror("send consumer channel");
 133                         goto error;
 134                 }
 135                 fd = usess->metadata->obj->shm_fd;
 136                 ret = lttcomm_send_fds_unix_sock(sock, &fd, 1);
 137                 if (ret < 0) {
 138                         perror("send consumer metadata channel");
 139                         goto error;
 140                 }
 141
 142                 /* Send metadata stream fd */
 143                 lum.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
 144                 lum.u.stream.channel_key = usess->metadata->obj->shm_fd;
 145                 lum.u.stream.stream_key = usess->metadata->stream_obj->shm_fd;
 146                 lum.u.stream.state = LTTNG_CONSUMER_ACTIVE_STREAM;
 147                 lum.u.stream.output = DEFAULT_UST_CHANNEL_OUTPUT;
 148                 lum.u.stream.mmap_len = usess->metadata->stream_obj->memory_map_size;
 149                 strncpy(lum.u.stream.path_name, usess->metadata->pathname, PATH_MAX - 1);
 150                 lum.u.stream.path_name[PATH_MAX - 1] = '\0';
 151                 DBG("Sending metadata stream %d to consumer", lum.u.stream.stream_key);
 152                 ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
 153                 if (ret < 0) {
 154                         perror("send consumer metadata stream");
 155                         goto error;
 156                 }
 157                 fds[0] = usess->metadata->stream_obj->shm_fd;
 158                 fds[1] = usess->metadata->stream_obj->wait_fd;
 159                 ret = lttcomm_send_fds_unix_sock(sock, fds, 2);
 160                 if (ret < 0) {
 161                         perror("send consumer stream");
 162                         goto error;
 163                 }
 164         }
 165
 166         /* Send each channel fd streams of session */
 167         rcu_read_lock();
 168         hashtable_get_first(usess->channels, &iter);
 169         while ((node = hashtable_iter_get_node(&iter)) != NULL) {
 170                 uchan = caa_container_of(node, struct ust_app_channel, node);
 171
 172                 ret = send_channel_streams(sock, uchan);
 173                 if (ret < 0) {
 174                         goto error;
 175                 }
 176                 hashtable_get_next(usess->channels, &iter);
 177         }
 178         rcu_read_unlock();
 179
 180         DBG("consumer fds (metadata and channel streams) sent");
 181
 182         return 0;
 183
 184 error:
 185         return ret;
 186 }