src/bin/lttng-sessiond/kernel-consumer.c

   1 /*
   2  * Copyright (C) 2012 - David Goulet <dgoulet@efficios.com>
   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, version 2 only, as
   6  * published by the Free Software Foundation.
   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., 51
  15  * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  16  */
  17
  18 #define _GNU_SOURCE
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <sys/stat.h>
  23 #include <unistd.h>
  24
  25 #include <common/common.h>
  26 #include <common/defaults.h>
  27
  28 #include "consumer.h"
  29 #include "kernel-consumer.h"
  30
  31 /*
  32  * Sending a single channel to the consumer with command ADD_CHANNEL.
  33  */
  34 int kernel_consumer_add_channel(int sock, struct ltt_kernel_channel *channel)
  35 {
  36         int ret;
  37         struct lttcomm_consumer_msg lkm;
  38
  39         /* Safety net */
  40         assert(channel);
  41
  42         DBG("Kernel consumer adding channel %s to kernel consumer",
  43                         channel->channel->name);
  44
  45         /* Prep channel message structure */
  46         consumer_init_channel_comm_msg(&lkm,
  47                         LTTNG_CONSUMER_ADD_CHANNEL,
  48                         channel->fd,
  49                         channel->channel->attr.subbuf_size,
  50                         0, /* Kernel */
  51                         channel->channel->name,
  52                         channel->stream_count);
  53
  54         ret = consumer_send_channel(sock, &lkm);
  55         if (ret < 0) {
  56                 goto error;
  57         }
  58
  59 error:
  60         return ret;
  61 }
  62
  63 /*
  64  * Sending metadata to the consumer with command ADD_CHANNEL and ADD_STREAM.
  65  */
  66 int kernel_consumer_add_metadata(int sock, struct ltt_kernel_session *session)
  67 {
  68         int ret;
  69         char tmp_path[PATH_MAX];
  70         const char *pathname;
  71         struct lttcomm_consumer_msg lkm;
  72         struct consumer_output *consumer;
  73
  74         /* Safety net */
  75         assert(session);
  76         assert(session->consumer);
  77
  78         DBG("Sending metadata %d to kernel consumer", session->metadata_stream_fd);
  79
  80         /* Get consumer output pointer */
  81         consumer = session->consumer;
  82
  83         /* Get the right path name destination */
  84         if (consumer->type == CONSUMER_DST_LOCAL) {
  85                 /* Set application path to the destination path */
  86                 ret = snprintf(tmp_path, sizeof(tmp_path), "%s/%s",
  87                                 consumer->dst.trace_path, consumer->subdir);
  88                 if (ret < 0) {
  89                         PERROR("snprintf metadata path");
  90                         goto error;
  91                 }
  92                 pathname = tmp_path;
  93
  94                 /* Create directory */
  95                 ret = run_as_mkdir_recursive(pathname, S_IRWXU | S_IRWXG,
  96                                 session->uid, session->gid);
  97                 if (ret < 0) {
  98                         if (ret != -EEXIST) {
  99                                 ERR("Trace directory creation error");
 100                                 goto error;
 101                         }
 102                 }
 103                 DBG3("Kernel local consumer tracefile path: %s", pathname);
 104         } else {
 105                 ret = snprintf(tmp_path, sizeof(tmp_path), "%s", consumer->subdir);
 106                 if (ret < 0) {
 107                         PERROR("snprintf metadata path");
 108                         goto error;
 109                 }
 110                 pathname = tmp_path;
 111                 DBG3("Kernel network consumer subdir path: %s", pathname);
 112         }
 113
 114         /* Prep channel message structure */
 115         consumer_init_channel_comm_msg(&lkm,
 116                         LTTNG_CONSUMER_ADD_CHANNEL,
 117                         session->metadata->fd,
 118                         session->metadata->conf->attr.subbuf_size,
 119                         0, /* for kernel */
 120                         "metadata",
 121                         1);
 122
 123         ret = consumer_send_channel(sock, &lkm);
 124         if (ret < 0) {
 125                 goto error;
 126         }
 127
 128         /* Prep stream message structure */
 129         consumer_init_stream_comm_msg(&lkm,
 130                         LTTNG_CONSUMER_ADD_STREAM,
 131                         session->metadata->fd,
 132                         session->metadata_stream_fd,
 133                         LTTNG_CONSUMER_ACTIVE_STREAM,
 134                         DEFAULT_KERNEL_CHANNEL_OUTPUT,
 135                         0, /* Kernel */
 136                         session->uid,
 137                         session->gid,
 138                         consumer->net_seq_index,
 139                         1, /* Metadata flag set */
 140                         "metadata",
 141                         pathname);
 142
 143         /* Send stream and file descriptor */
 144         ret = consumer_send_stream(sock, consumer, &lkm,
 145                         &session->metadata_stream_fd, 1);
 146         if (ret < 0) {
 147                 goto error;
 148         }
 149
 150 error:
 151         return ret;
 152 }
 153
 154 /*
 155  * Sending a single stream to the consumer with command ADD_STREAM.
 156  */
 157 int kernel_consumer_add_stream(int sock, struct ltt_kernel_channel *channel,
 158                 struct ltt_kernel_stream *stream, struct ltt_kernel_session *session)
 159 {
 160         int ret;
 161         char tmp_path[PATH_MAX];
 162         const char *pathname;
 163         struct lttcomm_consumer_msg lkm;
 164         struct consumer_output *consumer;
 165
 166         assert(channel);
 167         assert(stream);
 168         assert(session);
 169         assert(session->consumer);
 170
 171         DBG("Sending stream %d of channel %s to kernel consumer",
 172                         stream->fd, channel->channel->name);
 173
 174         /* Get consumer output pointer */
 175         consumer = session->consumer;
 176
 177         /* Get the right path name destination */
 178         if (consumer->type == CONSUMER_DST_LOCAL) {
 179                 /* Set application path to the destination path */
 180                 ret = snprintf(tmp_path, sizeof(tmp_path), "%s/%s",
 181                                 consumer->dst.trace_path, consumer->subdir);
 182                 if (ret < 0) {
 183                         PERROR("snprintf stream path");
 184                         goto error;
 185                 }
 186                 pathname = tmp_path;
 187                 DBG3("Kernel local consumer tracefile path: %s", pathname);
 188         } else {
 189                 ret = snprintf(tmp_path, sizeof(tmp_path), "%s", consumer->subdir);
 190                 if (ret < 0) {
 191                         PERROR("snprintf stream path");
 192                         goto error;
 193                 }
 194                 pathname = tmp_path;
 195                 DBG3("Kernel network consumer subdir path: %s", pathname);
 196         }
 197
 198         /* Prep stream consumer message */
 199         consumer_init_stream_comm_msg(&lkm, LTTNG_CONSUMER_ADD_STREAM,
 200                         channel->fd,
 201                         stream->fd,
 202                         stream->state,
 203                         channel->channel->attr.output,
 204                         0, /* Kernel */
 205                         session->uid,
 206                         session->gid,
 207                         consumer->net_seq_index,
 208                         0, /* Metadata flag unset */
 209                         stream->name,
 210                         pathname);
 211
 212         /* Send stream and file descriptor */
 213         ret = consumer_send_stream(sock, consumer, &lkm, &stream->fd, 1);
 214         if (ret < 0) {
 215                 goto error;
 216         }
 217
 218 error:
 219         return ret;
 220 }
 221
 222 /*
 223  * Send all stream fds of kernel channel to the consumer.
 224  */
 225 int kernel_consumer_send_channel_stream(int sock,
 226                 struct ltt_kernel_channel *channel, struct ltt_kernel_session *session)
 227 {
 228         int ret;
 229         struct ltt_kernel_stream *stream;
 230
 231         /* Safety net */
 232         assert(channel);
 233         assert(session);
 234         assert(session->consumer);
 235
 236         /* Bail out if consumer is disabled */
 237         if (!session->consumer->enabled) {
 238                 ret = LTTNG_OK;
 239                 goto error;
 240         }
 241
 242         DBG("Sending streams of channel %s to kernel consumer",
 243                         channel->channel->name);
 244
 245         ret = kernel_consumer_add_channel(sock, channel);
 246         if (ret < 0) {
 247                 goto error;
 248         }
 249
 250         /* Send streams */
 251         cds_list_for_each_entry(stream, &channel->stream_list.head, list) {
 252                 if (!stream->fd) {
 253                         continue;
 254                 }
 255
 256                 /* Add stream on the kernel consumer side. */
 257                 ret = kernel_consumer_add_stream(sock, channel, stream, session);
 258                 if (ret < 0) {
 259                         goto error;
 260                 }
 261         }
 262
 263 error:
 264         return ret;
 265 }
 266
 267 /*
 268  * Send all stream fds of the kernel session to the consumer.
 269  */
 270 int kernel_consumer_send_session(int sock, struct ltt_kernel_session *session)
 271 {
 272         int ret;
 273         struct ltt_kernel_channel *chan;
 274
 275         /* Safety net */
 276         assert(session);
 277         assert(session->consumer);
 278
 279         /* Bail out if consumer is disabled */
 280         if (!session->consumer->enabled) {
 281                 ret = LTTNG_OK;
 282                 goto error;
 283         }
 284
 285         DBG("Sending session stream to kernel consumer");
 286
 287         if (session->metadata_stream_fd >= 0) {
 288                 ret = kernel_consumer_add_metadata(sock, session);
 289                 if (ret < 0) {
 290                         goto error;
 291                 }
 292
 293                 /* Flag that at least the metadata has been sent to the consumer. */
 294                 session->consumer_fds_sent = 1;
 295         }
 296
 297         /* Send channel and streams of it */
 298         cds_list_for_each_entry(chan, &session->channel_list.head, list) {
 299                 ret = kernel_consumer_send_channel_stream(sock, chan, session);
 300                 if (ret < 0) {
 301                         goto error;
 302                 }
 303         }
 304
 305         DBG("Kernel consumer FDs of metadata and channel streams sent");
 306
 307         return 0;
 308
 309 error:
 310         return ret;
 311 }