From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Date: Mon, 22 Mar 2021 14:01:55 +0000 (-0400)
Subject: Validate match of all session channel's UUID
X-Git-Tag: v2.13.0-rc1~236
X-Git-Url: https://git.lttng.org./?a=commitdiff_plain;h=9daacd1a32798bcef31f13cf45a3aab25bdc67af;p=lttng-ust.git

Validate match of all session channel's UUID

Add a validation at channel creation to ensure that the uuid of all
channels created within a session match.

Note that we still need to keep a copy of the uuid field in the channel
private data at this stage, because the consumer daemon creates channels
with a NULL session pointer.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Change-Id: I3490bab8879ffa66bc1e19559b0a1a60d33d605b
---

diff --git a/liblttng-ust/lttng-events.c b/liblttng-ust/lttng-events.c
index 9c65dc45..70e2f3a9 100644
--- a/liblttng-ust/lttng-events.c
+++ b/liblttng-ust/lttng-events.c
@@ -2019,3 +2019,21 @@ void lttng_ust_context_set_event_notifier_group_provider(const char *name,
 			abort();
 	}
 }
+
+int lttng_ust_session_uuid_validate(struct lttng_ust_session *session,
+		unsigned char *uuid)
+{
+	if (!session)
+		return 0;
+	/* Compare UUID with session. */
+	if (session->priv->uuid_set) {
+		if (memcmp(session->priv->uuid, uuid, LTTNG_UST_UUID_LEN)) {
+			return -1;
+		}
+	} else {
+		memcpy(session->priv->uuid, uuid, LTTNG_UST_UUID_LEN);
+		session->priv->uuid_set = true;
+	}
+	return 0;
+
+}
diff --git a/liblttng-ust/lttng-ust-abi.c b/liblttng-ust/lttng-ust-abi.c
index 53ca5dbe..af2a47dc 100644
--- a/liblttng-ust/lttng-ust-abi.c
+++ b/liblttng-ust/lttng-ust-abi.c
@@ -502,6 +502,11 @@ int lttng_abi_map_channel(int session_objd,
 		goto alloc_error;
 	}
 
+	if (lttng_ust_session_uuid_validate(session, lttng_chan_config->uuid)) {
+		ret = -EINVAL;
+		goto uuid_error;
+	}
+
 	/* Lookup transport name */
 	switch (type) {
 	case LTTNG_UST_ABI_CHAN_PER_CPU:
@@ -578,6 +583,7 @@ int lttng_abi_map_channel(int session_objd,
 	/* error path after channel was created */
 objd_error:
 notransport:
+uuid_error:
 alloc_error:
 	channel_destroy(chan, channel_handle, 0);
 	lttng_ust_free_channel_common(lttng_chan_buf->parent);
diff --git a/liblttng-ust/ust-events-internal.h b/liblttng-ust/ust-events-internal.h
index 6ade956e..f6ab27a2 100644
--- a/liblttng-ust/ust-events-internal.h
+++ b/liblttng-ust/ust-events-internal.h
@@ -332,6 +332,9 @@ struct lttng_ust_session_private {
 	struct lttng_ust_enum_ht enums_ht;	/* ht of enumerations */
 	struct cds_list_head enums_head;
 	struct lttng_ust_ctx *ctx;		/* contexts for filters. */
+
+	unsigned char uuid[LTTNG_UST_UUID_LEN];	/* Trace session unique ID */
+	bool uuid_set;				/* Is uuid set ? */
 };
 
 struct lttng_enum {
@@ -893,4 +896,8 @@ int lttng_ust_interpret_event_filter(struct lttng_ust_event_common *event,
 		const char *interpreter_stack_data,
 		void *filter_ctx);
 
+__attribute__((visibility("hidden")))
+int lttng_ust_session_uuid_validate(struct lttng_ust_session *session,
+		unsigned char *uuid);
+
 #endif /* _LTTNG_UST_EVENTS_INTERNAL_H */