Implement filter bytecode support in lttng-session, and parse filter string

[lttng-tools.git] / src / bin / lttng-sessiond / filter.c

diff --git a/src/bin/lttng-sessiond/filter.c b/src/bin/lttng-sessiond/filter.c
new file mode 100644 (file)
index 0000000..e012cb8
--- /dev/null
+++ b/src/bin/lttng-sessiond/filter.c
@@ -0,0 +1,178 @@
+/*
+ * Copyright (C) 2011 - David Goulet <david.goulet@polymtl.ca>
+ * Copyright (C) 2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2 only,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <urcu/list.h>
+
+#include <common/error.h>
+#include <common/sessiond-comm/sessiond-comm.h>
+
+#include "filter.h"
+#include "kernel.h"
+#include "ust-app.h"
+#include "trace-ust.h"
+
+/*
+ * Add UST context to event.
+ */
+static int add_ufilter_to_event(struct ltt_ust_session *usess, int domain,
+               struct ltt_ust_channel *uchan, struct ltt_ust_event *uevent,
+               struct lttng_filter_bytecode *bytecode)
+{
+       int ret;
+
+       if (uevent->filter) {
+               ret = -EEXIST;
+               goto error;
+       }
+       /* Same layout. */
+       uevent->filter = (struct lttng_ust_filter_bytecode *) bytecode;
+
+       switch (domain) {
+       case LTTNG_DOMAIN_UST:
+               ret = ust_app_set_filter_event_glb(usess, uchan, uevent,
+                                               bytecode);
+               if (ret < 0) {
+                       goto error;
+               }
+               break;
+       default:
+               ret = -ENOSYS;
+               goto error;
+       }
+
+       DBG("Filter UST added to event %s",uevent->attr.name);
+
+       return 0;
+
+error:
+       free(bytecode);
+       return ret;
+}
+
+/*
+ * Add UST context to tracer.
+ */
+int filter_ust_set(struct ltt_ust_session *usess, int domain,
+               struct lttng_filter_bytecode *bytecode, char *event_name,
+               char *channel_name)
+{
+       int ret = LTTCOMM_OK, have_event = 0;
+       struct lttng_ht_iter iter;
+       struct lttng_ht *chan_ht;
+       struct ltt_ust_channel *uchan = NULL;
+       struct ltt_ust_event *uevent = NULL;
+
+       /*
+        * Define which channel's hashtable to use from the domain or quit if
+        * unknown domain.
+        */
+       switch (domain) {
+       case LTTNG_DOMAIN_UST:
+               chan_ht = usess->domain_global.channels;
+               break;
+#if 0
+       case LTTNG_DOMAIN_UST_EXEC_NAME:
+       case LTTNG_DOMAIN_UST_PID:
+       case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
+#endif
+       default:
+               ret = LTTCOMM_UND;
+               goto error;
+       }
+
+       /* Do we have an event name */
+       if (strlen(event_name) != 0) {
+               have_event = 1;
+       }
+
+       /* Get UST channel if defined */
+       if (strlen(channel_name) != 0) {
+               uchan = trace_ust_find_channel_by_name(chan_ht, channel_name);
+               if (uchan == NULL) {
+                       ret = LTTCOMM_UST_CHAN_NOT_FOUND;
+                       goto error;
+               }
+       }
+
+       /* If UST channel specified and event name, get UST event ref */
+       if (uchan && have_event) {
+               uevent = trace_ust_find_event_by_name(uchan->events, event_name);
+               if (uevent == NULL) {
+                       ret = LTTCOMM_UST_EVENT_NOT_FOUND;
+                       goto error;
+               }
+       }
+
+       /* At this point, we have 4 possibilities */
+
+       if (uchan && uevent) {                          /* Add filter to event in channel */
+               ret = add_ufilter_to_event(usess, domain, uchan, uevent,
+                                       bytecode);
+       } else if (uchan && !have_event) {      /* Add filter to channel */
+               ERR("Cannot add filter to channel");
+               ret = LTTCOMM_FATAL;    /* not supported. */
+               goto error;
+       } else if (!uchan && have_event) {      /* Add filter to event */
+               /* Add context to event without having the channel name */
+               cds_lfht_for_each_entry(chan_ht->ht, &iter.iter, uchan, node.node) {
+                       uevent = trace_ust_find_event_by_name(uchan->events, event_name);
+                       if (uevent != NULL) {
+                               ret = add_ufilter_to_event(usess, domain, uchan, uevent, bytecode);
+                               /*
+                                * LTTng UST does not allowed the same event to be registered
+                                * multiple time in different or the same channel. So, if we
+                                * found our event, we stop.
+                                */
+                               goto end;
+                       }
+               }
+               ret = LTTCOMM_UST_EVENT_NOT_FOUND;
+               goto error;
+       } else if (!uchan && !have_event) {     /* Add filter all events, all channels */
+               ERR("Cannot add filter to channel");
+               ret = LTTCOMM_FATAL;    /* not supported. */
+               goto error;
+       }
+
+end:
+       switch (ret) {
+       case -EEXIST:
+               ret = LTTCOMM_FILTER_EXIST;
+               break;
+       case -ENOMEM:
+               ret = LTTCOMM_FATAL;
+               break;
+       case -EINVAL:
+               ret = LTTCOMM_FILTER_INVAL;
+               break;
+       case -ENOSYS:
+               ret = LTTCOMM_UNKNOWN_DOMAIN;
+               break;
+       default:
+               ret = LTTCOMM_OK;
+               break;
+       }
+
+error:
+       return ret;
+}