src/bin/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
   5  * it under the terms of the GNU General Public License, version 2 only,
   6  * as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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 <common/common.h>
  26 #include <common/consumer.h>
  27 #include <common/defaults.h>
  28 #include <common/sessiond-comm/sessiond-comm.h>
  29
  30 #include "ust-consumer.h"
  31
  32 /*
  33  * Send all stream fds of UST channel to the consumer.
  34  */
  35 static int send_channel_streams(int sock,
  36                 struct ust_app_channel *uchan,
  37                 uid_t uid, gid_t gid)
  38 {
  39         int ret;
  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 while we transfer the stream file
  50          * descriptors to make sure this key stays unique within the
  51          * session daemon. We can free the channel shm_fd without
  52          * problem after we finished sending stream fds for that
  53          * channel.
  54          */
  55         lum.u.channel.channel_key = uchan->obj->shm_fd;
  56         lum.u.channel.max_sb_size = uchan->attr.subbuf_size;
  57         lum.u.channel.mmap_len = uchan->obj->memory_map_size;
  58         DBG("Sending channel %d to consumer", lum.u.channel.channel_key);
  59         ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
  60         if (ret < 0) {
  61                 PERROR("send consumer channel");
  62                 goto error;
  63         }
  64
  65         DBG("Sending channel shm path: %s\n", uchan->obj->shm_path);
  66         ret = lttcomm_send_string(sock,
  67                                   uchan->obj->shm_path,
  68                                   strlen(uchan->obj->shm_path));
  69         if (ret < 0) {
  70                 PERROR("send consumer channel shm path");
  71                 goto error;
  72         }
  73
  74         cds_list_for_each_entry_safe(stream, tmp, &uchan->streams.head, list) {
  75
  76                 if (!stream->obj->shm_fd) {
  77                         continue;
  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                 /*
  84                  * FIXME Hack alert! we force MMAP for now. Mixup
  85                  * between EVENT and UST enums elsewhere.
  86                  */
  87                 lum.u.stream.output = DEFAULT_UST_CHANNEL_OUTPUT;
  88                 lum.u.stream.mmap_len = stream->obj->memory_map_size;
  89                 lum.u.stream.uid = uid;
  90                 lum.u.stream.gid = gid;
  91                 strncpy(lum.u.stream.path_name, stream->pathname, PATH_MAX - 1);
  92                 lum.u.stream.path_name[PATH_MAX - 1] = '\0';
  93                 DBG("Sending stream %d to consumer", lum.u.stream.stream_key);
  94                 ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
  95                 if (ret < 0) {
  96                         PERROR("send consumer stream");
  97                         goto error;
  98                 }
  99
 100                 DBG("Sending stream shm path: %s\n", stream->obj->shm_path);
 101                 ret = lttcomm_send_string(sock,
 102                                           stream->obj->shm_path,
 103                                           strlen(stream->obj->shm_path));
 104                 if (ret < 0) {
 105                         PERROR("send consumer stream shm path");
 106                         goto error;
 107                 }
 108
 109                 DBG("Sending stream wait pipe path: %s\n", stream->obj->wait_pipe_path);
 110                 ret = lttcomm_send_string(sock,
 111                                           stream->obj->wait_pipe_path,
 112                                           strlen(stream->obj->wait_pipe_path));
 113
 114                 if (ret < 0) {
 115                         PERROR("send consumer stream wait pipe path");
 116                         goto error;
 117                 }
 118         }
 119
 120         DBG("consumer channel streams sent");
 121
 122         return 0;
 123
 124 error:
 125         return ret;
 126 }
 127
 128 /*
 129  * Send all stream fds of the UST session to the consumer.
 130  */
 131 int ust_consumer_send_session(int consumer_fd, struct ust_app_session *usess)
 132 {
 133         int ret = 0;
 134         int sock = consumer_fd;
 135         struct lttng_ht_iter iter;
 136         struct lttcomm_consumer_msg lum;
 137         struct ust_app_channel *ua_chan;
 138
 139         DBG("Sending metadata stream fd");
 140
 141         if (consumer_fd < 0) {
 142                 ERR("Consumer has negative file descriptor");
 143                 return -EINVAL;
 144         }
 145
 146         if (usess->metadata->obj->shm_fd != 0) {
 147                 /* Send metadata channel fd */
 148                 lum.cmd_type = LTTNG_CONSUMER_ADD_CHANNEL;
 149                 lum.u.channel.channel_key = usess->metadata->obj->shm_fd;
 150                 lum.u.channel.max_sb_size = usess->metadata->attr.subbuf_size;
 151                 lum.u.channel.mmap_len = usess->metadata->obj->memory_map_size;
 152                 DBG("Sending metadata channel %d to consumer", lum.u.channel.channel_key);
 153                 ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
 154                 if (ret < 0) {
 155                         PERROR("send consumer channel");
 156                         goto error;
 157                 }
 158
 159                 DBG("Sending metadata channel shm path: %s\n", usess->metadata->obj->shm_path);
 160                 ret = lttcomm_send_string(sock,
 161                                           usess->metadata->obj->shm_path,
 162                                           strlen(usess->metadata->obj->shm_path));
 163                 if (ret < 0) {
 164                         PERROR("send consumer metadata channel");
 165                         goto error;
 166                 }
 167
 168                 /* Send metadata stream fd */
 169                 lum.cmd_type = LTTNG_CONSUMER_ADD_STREAM;
 170                 lum.u.stream.channel_key = usess->metadata->obj->shm_fd;
 171                 lum.u.stream.stream_key = usess->metadata->stream_obj->shm_fd;
 172                 lum.u.stream.state = LTTNG_CONSUMER_ACTIVE_STREAM;
 173                 lum.u.stream.output = DEFAULT_UST_CHANNEL_OUTPUT;
 174                 lum.u.stream.mmap_len = usess->metadata->stream_obj->memory_map_size;
 175                 lum.u.stream.uid = usess->uid;
 176                 lum.u.stream.gid = usess->gid;
 177                 strncpy(lum.u.stream.path_name, usess->metadata->pathname, PATH_MAX - 1);
 178                 lum.u.stream.path_name[PATH_MAX - 1] = '\0';
 179                 DBG("Sending metadata stream %d to consumer", lum.u.stream.stream_key);
 180                 ret = lttcomm_send_unix_sock(sock, &lum, sizeof(lum));
 181                 if (ret < 0) {
 182                         PERROR("send consumer metadata stream");
 183                         goto error;
 184                 }
 185
 186                 DBG("Sending metadata stream shm path: %s\n",
 187                     usess->metadata->stream_obj->shm_path);
 188                 ret = lttcomm_send_string(sock,
 189                                           usess->metadata->stream_obj->shm_path,
 190                                           strlen(usess->metadata->stream_obj->shm_path));
 191
 192                 if (ret < 0) {
 193                         PERROR("send consumer shm stream");
 194                         goto error;
 195                 }
 196
 197                 DBG("Sending metadata stream wait pipe path: %s\n",
 198                     usess->metadata->stream_obj->wait_pipe_path);
 199                 ret = lttcomm_send_string(sock,
 200                                           usess->metadata->stream_obj->wait_pipe_path,
 201                                           strlen(usess->metadata->stream_obj->wait_pipe_path));
 202
 203                 if (ret < 0) {
 204                         PERROR("send consumer shm stream");
 205                         goto error;
 206                 }
 207
 208         }
 209
 210         /* Send each channel fd streams of session */
 211         rcu_read_lock();
 212         cds_lfht_for_each_entry(usess->channels->ht, &iter.iter, ua_chan,
 213                         node.node) {
 214                 /*
 215                  * Indicate that the channel was not created on the tracer side so skip
 216                  * sending unexisting streams.
 217                  */
 218                 if (ua_chan->obj == NULL) {
 219                         continue;
 220                 }
 221
 222                 ret = send_channel_streams(sock, ua_chan, usess->uid, usess->gid);
 223                 if (ret < 0) {
 224                         rcu_read_unlock();
 225                         goto error;
 226                 }
 227         }
 228         rcu_read_unlock();
 229
 230         DBG("consumer fds (metadata and channel streams) sent");
 231
 232         return 0;
 233
 234 error:
 235         return ret;
 236 }