src/bin/lttng-sessiond/filter.c

   1 /*
   2  * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
   3  * Copyright (C) 2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License, version 2 only,
   7  * as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along
  15  * with this program; if not, write to the Free Software Foundation, Inc.,
  16  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  17  */
  18
  19 #define _GNU_SOURCE
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24 #include <urcu/list.h>
  25
  26 #include <common/error.h>
  27 #include <common/sessiond-comm/sessiond-comm.h>
  28
  29 #include "filter.h"
  30 #include "kernel.h"
  31 #include "ust-app.h"
  32 #include "trace-ust.h"
  33
  34 /*
  35  * Add UST context to event.
  36  */
  37 static int add_ufilter_to_event(struct ltt_ust_session *usess, int domain,
  38                 struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent,
  39                 struct lttng_filter_bytecode *bytecode)
  40 {
  41         int ret;
  42
  43         if (uevent->filter) {
  44                 ret = -EEXIST;
  45                 goto error;
  46         }
  47         /* Same layout. */
  48         uevent->filter = (struct lttng_ust_filter_bytecode *) bytecode;
  49         uevent->filter->seqnum = usess->filter_seq_num;
  50
  51         switch (domain) {
  52         case LTTNG_DOMAIN_UST:
  53                 ret = ust_app_set_filter_event_glb(usess, uchan, uevent,
  54                                                 bytecode);
  55                 if (ret < 0) {
  56                         goto error;
  57                 }
  58                 usess->filter_seq_num++;
  59                 break;
  60         default:
  61                 ret = -ENOSYS;
  62                 goto error;
  63         }
  64
  65         DBG("Filter UST added to event %s",uevent->attr.name);
  66
  67         return 0;
  68
  69 error:
  70         free(bytecode);
  71         return ret;
  72 }
  73
  74 /*
  75  * Add UST context to tracer.
  76  */
  77 int filter_ust_set(struct ltt_ust_session *usess, int domain,
  78                 struct lttng_filter_bytecode *bytecode, struct lttng_event *event,
  79                 char *channel_name)
  80 {
  81         int ret = LTTNG_OK, have_event = 0;
  82         struct lttng_ht_iter iter;
  83         struct lttng_ht *chan_ht;
  84         struct ltt_ust_channel *uchan = NULL;
  85         struct ltt_ust_event *uevent = NULL;
  86
  87         /*
  88          * Define which channel's hashtable to use from the domain or quit if
  89          * unknown domain.
  90          */
  91         switch (domain) {
  92         case LTTNG_DOMAIN_UST:
  93                 chan_ht = usess->domain_global.channels;
  94                 break;
  95 #if 0
  96         case LTTNG_DOMAIN_UST_EXEC_NAME:
  97         case LTTNG_DOMAIN_UST_PID:
  98         case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
  99 #endif
 100         default:
 101                 ret = LTTNG_ERR_UND;
 102                 goto error;
 103         }
 104
 105         /* Do we have a valid event. */
 106         if (event && event->name[0] != '\0') {
 107                 have_event = 1;
 108         }
 109
 110         /* Get UST channel if defined */
 111         if (strlen(channel_name) != 0) {
 112                 uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
 113                 if (uchan == NULL) {
 114                         ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
 115                         goto error;
 116                 }
 117         }
 118
 119         /* If UST channel specified and event name, get UST event ref */
 120         if (uchan && have_event) {
 121                 uevent = trace_ust_find_event(uchan->events, event->name, bytecode,
 122                                 event->loglevel);
 123                 if (uevent == NULL) {
 124                         ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
 125                         goto error;
 126                 }
 127         }
 128
 129         /* At this point, we have 4 possibilities */
 130
 131         if (uchan && uevent) {                          /* Add filter to event in channel */
 132                 ret = add_ufilter_to_event(usess, domain, uchan, uevent,
 133                                         bytecode);
 134         } else if (uchan && !have_event) {      /* Add filter to channel */
 135                 ERR("Cannot add filter to channel");
 136                 ret = LTTNG_ERR_FATAL;  /* not supported. */
 137                 goto error;
 138         } else if (!uchan && have_event) {      /* Add filter to event */
 139                 /* Add context to event without having the channel name */
 140                 cds_lfht_for_each_entry(chan_ht->ht, &iter.iter, uchan, node.node) {
 141                         uevent = trace_ust_find_event(uchan->events, event->name, bytecode,
 142                                         event->loglevel);
 143                         if (uevent != NULL) {
 144                                 ret = add_ufilter_to_event(usess, domain, uchan, uevent, bytecode);
 145                                 /*
 146                                  * LTTng UST does not allowed the same event to be registered
 147                                  * multiple time in different or the same channel. So, if we
 148                                  * found our event, we stop.
 149                                  */
 150                                 goto end;
 151                         }
 152                 }
 153                 ret = LTTNG_ERR_UST_EVENT_NOT_FOUND;
 154                 goto error;
 155         } else if (!uchan && !have_event) {     /* Add filter all events, all channels */
 156                 ERR("Cannot add filter to channel");
 157                 ret = LTTNG_ERR_FATAL;  /* not supported. */
 158                 goto error;
 159         }
 160
 161 end:
 162         /* Must handle both local internal error and UST code. */
 163         switch (ret) {
 164         case -EEXIST:
 165         case -LTTNG_UST_ERR_EXIST:
 166                 ret = LTTNG_ERR_FILTER_EXIST;
 167                 break;
 168         case -ENOMEM:
 169                 ret = LTTNG_ERR_FATAL;
 170                 break;
 171         case -EINVAL:
 172         case -LTTNG_UST_ERR_INVAL:
 173                 ret = LTTNG_ERR_FILTER_INVAL;
 174                 break;
 175         case -ENOSYS:
 176         case -LTTNG_UST_ERR_NOSYS:
 177                 ret = LTTNG_ERR_UNKNOWN_DOMAIN;
 178                 break;
 179         default:
 180                 ret = LTTNG_OK;
 181                 break;
 182         }
 183
 184 error:
 185         return ret;
 186 }