liblttng-ust/lttng-filter.c

   1 /*
   2  * lttng-filter.c
   3  *
   4  * LTTng UST filter code.
   5  *
   6  * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; only
  11  * version 2.1 of the License.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #include <errno.h>
  24 #include <stdio.h>
  25 #include <helper.h>
  26 #include <lttng/ust-events.h>
  27
  28 static
  29 int lttng_filter_interpret_bytecode(void *filter_data,
  30                 const char *filter_stack_data)
  31 {
  32         /* TODO */
  33         return 0;
  34 }
  35
  36 static
  37 int _lttng_filter_event_link_bytecode(struct ltt_event *event,
  38                 struct lttng_ust_filter_bytecode *filter_bytecode)
  39 {
  40         if (!filter_bytecode)
  41                 return 0;
  42
  43         event->filter = lttng_filter_interpret_bytecode;
  44         /* TODO */
  45         /* event->filter_data = ; */
  46         return 0;
  47 }
  48
  49 void lttng_filter_event_link_bytecode(struct ltt_event *event,
  50                 struct lttng_ust_filter_bytecode *filter_bytecode)
  51 {
  52         int ret;
  53
  54         ret = _lttng_filter_event_link_bytecode(event, event->filter_bytecode);
  55         if (ret) {
  56                 fprintf(stderr, "[lttng filter] error linking event bytecode\n");
  57         }
  58 }
  59
  60 /*
  61  * Link bytecode to all events for a wildcard. Skips events that already
  62  * have a bytecode linked.
  63  * We do not set each event's filter_bytecode field, because they do not
  64  * own the filter_bytecode: the wildcard owns it.
  65  */
  66 void lttng_filter_wildcard_link_bytecode(struct session_wildcard *wildcard)
  67 {
  68         struct ltt_event *event;
  69         int ret;
  70
  71         if (!wildcard->filter_bytecode)
  72                 return;
  73
  74         cds_list_for_each_entry(event, &wildcard->events, wildcard_list) {
  75                 if (event->filter)
  76                         continue;
  77                 ret = _lttng_filter_event_link_bytecode(event,
  78                                 wildcard->filter_bytecode);
  79                 if (ret) {
  80                         fprintf(stderr, "[lttng filter] error linking wildcard bytecode\n");
  81                 }
  82
  83         }
  84         return;
  85 }
  86
  87 /*
  88  * Need to attach filter to an event before starting tracing for the
  89  * session.
  90  */
  91 int lttng_filter_event_attach_bytecode(struct ltt_event *event,
  92                 struct lttng_ust_filter_bytecode *filter_bytecode)
  93 {
  94         struct lttng_ust_filter_bytecode *bc;
  95
  96         if (event->chan->session->been_active)
  97                 return -EPERM;
  98         if (event->filter_bytecode)
  99                 return -EEXIST;
 100
 101         bc = zmalloc(sizeof(struct lttng_ust_filter_bytecode)
 102                         + filter_bytecode->len);
 103         if (!bc)
 104                 return -ENOMEM;
 105         event->filter_bytecode = bc;
 106         return 0;
 107 }
 108
 109 /*
 110  * Need to attach filter to a wildcard before starting tracing for the
 111  * session.
 112  */
 113 int lttng_filter_wildcard_attach_bytecode(struct session_wildcard *wildcard,
 114                 struct lttng_ust_filter_bytecode *filter_bytecode)
 115 {
 116         struct lttng_ust_filter_bytecode *bc;
 117
 118         if (wildcard->chan->session->been_active)
 119                 return -EPERM;
 120         if (wildcard->filter_bytecode)
 121                 return -EEXIST;
 122
 123         bc = zmalloc(sizeof(struct lttng_ust_filter_bytecode)
 124                         + filter_bytecode->len);
 125         if (!bc)
 126                 return -ENOMEM;
 127         wildcard->filter_bytecode = bc;
 128         return 0;
 129 }