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 cds_lfht_iter iter;
  42         struct cds_lfht_node *node;
  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 to make sure this key stays unique within
  51          * the session daemon.
  52          */
  53         lum.u.channel.channel_key = uchan->obj->shm_fd;
  54         lum.u.channel.max_sb_size = uchan->attr.subbuf_size;
  55         lum.u.channel.mmap_len = uchan->obj->memory_map_size;
  56         DBG("Sending channel %d to consumer", lum.u.channel.channel_key);
  57         ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
  58         if (ret < 0) {
  59                 perror("send consumer channel");
  60                 goto error;
  61         }
  62         fd = uchan->obj->shm_fd;
  63         ret = lttcomm_send_fds_unix_sock(sock, &fd, 1);
  64         if (ret < 0) {
  65                 perror("send consumer channel ancillary data");
  66                 goto error;
  67         }
  68
  69         rcu_read_lock();
  70         hashtable_get_first(uchan->streams, &iter);
  71         while ((node = hashtable_iter_get_node(&iter)) != NULL) {
  72                 struct ltt_ust_stream *stream =
  73                                 caa_container_of(node, struct ltt_ust_stream, node);
  74                 int fds[2];
  75
  76                 if (!stream->obj->shm_fd) {
  77                         goto next;
  78                 }
  79                 lum.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
  80                 lum.u.stream.channel_key = uchan->obj->shm_fd;
  81                 lum.u.stream.stream_key = stream->obj->shm_fd;
  82                 lum.u.stream.state = LTTNG_CONSUMER_ACTIVE_STREAM;
  83                 lum.u.stream.output = uchan->attr.output;
  84                 lum.u.stream.mmap_len = stream->obj->memory_map_size;
  85                 strncpy(lum.u.stream.path_name, stream->pathname, PATH_MAX - 1);
  86                 lum.u.stream.path_name[PATH_MAX - 1] = '\0';
  87                 DBG("Sending stream %d to consumer", lum.u.stream.stream_key);
  88                 ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
  89                 if (ret < 0) {
  90                         perror("send consumer stream");
  91                         goto error;
  92                 }
  93
  94                 fds[0] = stream->obj->shm_fd;
  95                 fds[1] = stream->obj->wait_fd;
  96                 ret = lttcomm_send_fds_unix_sock(sock, fds, 2);
  97                 if (ret < 0) {
  98                         perror("send consumer stream ancillary data");
  99                         goto error;
 100                 }
 101
 102 next:
 103                 hashtable_get_next(uchan->streams, &iter);
 104         }
 105         rcu_read_unlock();
 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 cds_lfht_iter iter;
 123         struct cds_lfht_node *node;
 124         struct lttcomm_consumer_msg lum;
 125         struct ust_app_channel *uchan;
 126
 127         DBG("Sending metadata stream fd");
 128
 129         if (usess->metadata->obj->shm_fd != 0) {
 130                 int fd;
 131                 int fds[2];
 132
 133                 /* Send metadata channel fd */
 134                 lum.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
 135                 lum.u.channel.channel_key = usess->metadata->obj->shm_fd;
 136                 lum.u.channel.max_sb_size = usess->metadata->attr.subbuf_size;
 137                 lum.u.channel.mmap_len = 0;     /* for kernel */
 138                 DBG("Sending metadata channel %d to consumer", lum.u.channel.channel_key);
 139                 ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
 140                 if (ret < 0) {
 141                         perror("send consumer channel");
 142                         goto error;
 143                 }
 144                 fd = usess->metadata->obj->shm_fd;
 145                 ret = lttcomm_send_fds_unix_sock(sock, &fd, 1);
 146                 if (ret < 0) {
 147                         perror("send consumer metadata channel");
 148                         goto error;
 149                 }
 150
 151                 /* Send metadata stream fd */
 152                 lum.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
 153                 lum.u.stream.channel_key = usess->metadata->obj->shm_fd;
 154                 lum.u.stream.stream_key = usess->metadata->stream_obj->shm_fd;
 155                 lum.u.stream.state = LTTNG_CONSUMER_ACTIVE_STREAM;
 156                 lum.u.stream.output = DEFAULT_UST_CHANNEL_OUTPUT;
 157                 lum.u.stream.mmap_len = usess->metadata->stream_obj->memory_map_size;
 158                 strncpy(lum.u.stream.path_name, usess->metadata->pathname, PATH_MAX - 1);
 159                 lum.u.stream.path_name[PATH_MAX - 1] = '\0';
 160                 DBG("Sending metadata stream %d to consumer", lum.u.stream.stream_key);
 161                 ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
 162                 if (ret < 0) {
 163                         perror("send consumer metadata stream");
 164                         goto error;
 165                 }
 166                 fds[0] = usess->metadata->stream_obj->shm_fd;
 167                 fds[1] = usess->metadata->stream_obj->wait_fd;
 168                 ret = lttcomm_send_fds_unix_sock(sock, fds, 2);
 169                 if (ret < 0) {
 170                         perror("send consumer stream");
 171                         goto error;
 172                 }
 173         }
 174
 175         /* Send each channel fd streams of session */
 176         rcu_read_lock();
 177         hashtable_get_first(usess->channels, &iter);
 178         while ((node = hashtable_iter_get_node(&iter)) != NULL) {
 179                 uchan = caa_container_of(node, struct ust_app_channel, node);
 180
 181                 ret = send_channel_streams(sock, uchan);
 182                 if (ret < 0) {
 183                         goto error;
 184                 }
 185                 hashtable_get_next(usess->channels, &iter);
 186         }
 187         rcu_read_unlock();
 188
 189         DBG("consumer fds (metadata and channel streams) sent");
 190
 191         return 0;
 192
 193 error:
 194         return ret;
 195 }