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, *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 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_safe(stream, tmp, &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                 /*
  79                  * FIXME Hack alert! we force MMAP for now. Mixup
  80                  * between EVENT and UST enums elsewhere.
  81                  */
  82                 lum.u.stream.output = DEFAULT_UST_CHANNEL_OUTPUT;
  83                 lum.u.stream.mmap_len = stream->obj->memory_map_size;
  84                 strncpy(lum.u.stream.path_name, stream->pathname, PATH_MAX - 1);
  85                 lum.u.stream.path_name[PATH_MAX - 1] = '\0';
  86                 DBG("Sending stream %d to consumer", lum.u.stream.stream_key);
  87                 ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
  88                 if (ret < 0) {
  89                         perror("send consumer stream");
  90                         goto error;
  91                 }
  92
  93                 fds[0] = stream->obj->shm_fd;
  94                 fds[1] = stream->obj->wait_fd;
  95                 ret = lttcomm_send_fds_unix_sock(sock, fds, 2);
  96                 if (ret < 0) {
  97                         perror("send consumer stream ancillary data");
  98                         goto error;
  99                 }
 100
 101                 /*
 102                  * We release the stream object here, as we have passed
 103                  * it to the consumer.
 104                  */
 105                 /* Ensure we don't let the app know (sock = -1). */
 106                 ustctl_release_object(-1, stream->obj);
 107                 cds_list_del(&stream->list);
 108                 free(stream);
 109         }
 110         /* Ensure we don't let the app know (sock = -1). */
 111         ustctl_release_object(-1, uchan->obj);
 112
 113         DBG("consumer channel streams sent");
 114
 115         return 0;
 116
 117 error:
 118         return ret;
 119 }
 120
 121 /*
 122  * Send all stream fds of the UST session to the consumer.
 123  */
 124 int ust_consumer_send_session(int consumer_fd, struct ust_app_session *usess)
 125 {
 126         int ret = 0;
 127         int sock = consumer_fd;
 128         struct cds_lfht_iter iter;
 129         struct cds_lfht_node *node;
 130         struct lttcomm_consumer_msg lum;
 131         struct ust_app_channel *uchan;
 132
 133         DBG("Sending metadata stream fd");
 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                 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                 /* Metadata fds passed to consumer, release them. */
 180                 /* Ensure we don't let the app know (sock = -1). */
 181                 ustctl_release_object(-1, usess->metadata->stream_obj);
 182                 ustctl_release_object(-1, usess->metadata->obj);
 183         }
 184
 185         /* Send each channel fd streams of session */
 186         rcu_read_lock();
 187         hashtable_get_first(usess->channels, &iter);
 188         while ((node = hashtable_iter_get_node(&iter)) != NULL) {
 189                 uchan = caa_container_of(node, struct ust_app_channel, node);
 190
 191                 ret = send_channel_streams(sock, uchan);
 192                 if (ret < 0) {
 193                         rcu_read_unlock();
 194                         goto error;
 195                 }
 196                 hashtable_get_next(usess->channels, &iter);
 197         }
 198         rcu_read_unlock();
 199
 200         DBG("consumer fds (metadata and channel streams) sent");
 201
 202         return 0;
 203
 204 error:
 205         return ret;
 206 }