[Asterisk-code-review] ARI: Detect duplicate channel IDs (asterisk[14])
Joshua Colp
asteriskteam at digium.com
Mon Oct 24 19:53:06 CDT 2016
Joshua Colp has submitted this change and it was merged. ( https://gerrit.asterisk.org/4154 )
Change subject: ARI: Detect duplicate channel IDs
......................................................................
ARI: Detect duplicate channel IDs
ARI and AMI allow for an explicit channel ID to be specified
when originating channels. Unfortunately, there is nothing in
place to prevent someone from using the same ID for multiple
channels. Further complicating things, adding ID validation to channel
allocation makes it impossible for ARI to discern why channel allocation
failed, resulting in a vague error code being returned.
The fix for this is to institute a new method for channel errors to be
discerned. The method mirrors errno, in that when an error occurs, the
caller can consult the channel errno value to determine what the error
was. This initial iteration of the feature only introduces "unknown" and
"channel ID exists" errors. However, it's possible to add more errors as
needed.
ARI uses this feature to determine why channel allocation failed and can
return a 409 error during origination to show that a channel with the
given ID already exists.
ASTERISK-26421
Change-Id: Ibba7ae68842dab6df0c2e9c45559208bc89d3d06
---
M include/asterisk/channel.h
M include/asterisk/channel_internal.h
M main/channel.c
M main/channel_internal_api.c
M res/ari/resource_channels.c
M res/res_ari_channels.c
M rest-api/api-docs/channels.json
7 files changed, 100 insertions(+), 6 deletions(-)
Approvals:
Kevin Harwell: Looks good to me, but someone else must approve
Anonymous Coward #1000019: Verified
Joshua Colp: Looks good to me, approved
diff --git a/include/asterisk/channel.h b/include/asterisk/channel.h
index 3293dd7..78db878 100644
--- a/include/asterisk/channel.h
+++ b/include/asterisk/channel.h
@@ -4649,4 +4649,16 @@
*/
int ast_channel_feature_hooks_replace(struct ast_channel *chan, struct ast_bridge_features *features);
+enum ast_channel_error {
+ /* Unable to determine what error occurred. */
+ AST_CHANNEL_ERROR_UNKNOWN,
+ /* Channel with this ID already exists */
+ AST_CHANNEL_ERROR_ID_EXISTS,
+};
+
+/*!
+ * \brief Get error code for latest channel operation.
+ */
+enum ast_channel_error ast_channel_errno(void);
+
#endif /* _ASTERISK_CHANNEL_H */
diff --git a/include/asterisk/channel_internal.h b/include/asterisk/channel_internal.h
index d1231b4..2316e2f 100644
--- a/include/asterisk/channel_internal.h
+++ b/include/asterisk/channel_internal.h
@@ -25,3 +25,5 @@
void ast_channel_internal_cleanup(struct ast_channel *chan);
int ast_channel_internal_setup_topics(struct ast_channel *chan);
+void ast_channel_internal_errno_set(enum ast_channel_error error);
+enum ast_channel_error ast_channel_internal_errno(void);
diff --git a/main/channel.c b/main/channel.c
index e2390ad..6e24ee6 100644
--- a/main/channel.c
+++ b/main/channel.c
@@ -770,6 +770,27 @@
static void ast_channel_destructor(void *obj);
static void ast_dummy_channel_destructor(void *obj);
+static int ast_channel_by_uniqueid_cb(void *obj, void *arg, void *data, int flags);
+
+static int does_id_conflict(const char *uniqueid)
+{
+ struct ast_channel *conflict;
+ int length = 0;
+
+ if (ast_strlen_zero(uniqueid)) {
+ return 0;
+ }
+
+ conflict = ast_channel_callback(ast_channel_by_uniqueid_cb, (char *) uniqueid, &length, OBJ_NOLOCK);
+ if (conflict) {
+ ast_log(LOG_ERROR, "Channel Unique ID '%s' already in use by channel %s(%p)\n",
+ uniqueid, ast_channel_name(conflict), conflict);
+ ast_channel_unref(conflict);
+ return 1;
+ }
+
+ return 0;
+}
/*! \brief Create a new channel structure */
static struct ast_channel * attribute_malloc __attribute__((format(printf, 15, 0)))
@@ -945,16 +966,33 @@
ast_channel_tech_set(tmp, &null_tech);
}
- ast_channel_internal_finalize(tmp);
-
- ast_atomic_fetchadd_int(&chancount, +1);
-
/* You might scream "locking inversion" at seeing this but it is actually perfectly fine.
* Since the channel was just created nothing can know about it yet or even acquire it.
*/
ast_channel_lock(tmp);
- ao2_link(channels, tmp);
+ ao2_lock(channels);
+
+ if (assignedids && (does_id_conflict(assignedids->uniqueid) || does_id_conflict(assignedids->uniqueid2))) {
+ ast_channel_internal_errno_set(AST_CHANNEL_ERROR_ID_EXISTS);
+ ao2_unlock(channels);
+ /* This is a bit unorthodox, but we can't just call ast_channel_stage_snapshot_done()
+ * because that will result in attempting to publish the channel snapshot. That causes
+ * badness in some places, such as CDRs. So we need to manually clear the flag on the
+ * channel that says that a snapshot is being cleared.
+ */
+ ast_clear_flag(ast_channel_flags(tmp), AST_FLAG_SNAPSHOT_STAGE);
+ ast_channel_unlock(tmp);
+ return ast_channel_unref(tmp);
+ }
+
+ ast_channel_internal_finalize(tmp);
+
+ ast_atomic_fetchadd_int(&chancount, +1);
+
+ ao2_link_flags(channels, tmp, OBJ_NOLOCK);
+
+ ao2_unlock(channels);
if (endpoint) {
ast_endpoint_add_channel(endpoint, tmp);
@@ -10842,3 +10880,8 @@
{
return channel_feature_hooks_set_full(chan, features, 1);
}
+
+enum ast_channel_error ast_channel_errno(void)
+{
+ return ast_channel_internal_errno();
+}
diff --git a/main/channel_internal_api.c b/main/channel_internal_api.c
index d94b267..3c156d4 100644
--- a/main/channel_internal_api.c
+++ b/main/channel_internal_api.c
@@ -1661,3 +1661,25 @@
return 0;
}
+
+AST_THREADSTORAGE(channel_errno);
+
+void ast_channel_internal_errno_set(enum ast_channel_error error)
+{
+ enum ast_channel_error *error_code = ast_threadstorage_get(&channel_errno, sizeof(*error_code));
+ if (!error_code) {
+ return;
+ }
+
+ *error_code = error;
+}
+
+enum ast_channel_error ast_channel_internal_errno(void)
+{
+ enum ast_channel_error *error_code = ast_threadstorage_get(&channel_errno, sizeof(*error_code));
+ if (!error_code) {
+ return AST_CHANNEL_ERROR_UNKNOWN;
+ }
+
+ return *error_code;
+}
diff --git a/res/ari/resource_channels.c b/res/ari/resource_channels.c
index 35b7572..89c9d7f 100644
--- a/res/ari/resource_channels.c
+++ b/res/ari/resource_channels.c
@@ -1228,7 +1228,12 @@
}
if (ast_dial_prerun(dial, other, format_cap)) {
- ast_ari_response_alloc_failed(response);
+ if (ast_channel_errno() == AST_CHANNEL_ERROR_ID_EXISTS) {
+ ast_ari_response_error(response, 409, "Conflict",
+ "Channel with given unique ID already exists");
+ } else {
+ ast_ari_response_alloc_failed(response);
+ }
ast_dial_destroy(dial);
ast_free(origination);
ast_channel_cleanup(other);
diff --git a/res/res_ari_channels.c b/res/res_ari_channels.c
index 25da17d..b7c088c 100644
--- a/res/res_ari_channels.c
+++ b/res/res_ari_channels.c
@@ -253,6 +253,7 @@
case 500: /* Internal Server Error */
case 501: /* Not Implemented */
case 400: /* Invalid parameters for originating a channel. */
+ case 409: /* Channel with given unique ID already exists. */
is_valid = 1;
break;
default:
@@ -615,6 +616,7 @@
case 500: /* Internal Server Error */
case 501: /* Not Implemented */
case 400: /* Invalid parameters for originating a channel. */
+ case 409: /* Channel with given unique ID already exists. */
is_valid = 1;
break;
default:
diff --git a/rest-api/api-docs/channels.json b/rest-api/api-docs/channels.json
index 75feeb1..522cc00 100644
--- a/rest-api/api-docs/channels.json
+++ b/rest-api/api-docs/channels.json
@@ -142,6 +142,10 @@
{
"code": 400,
"reason": "Invalid parameters for originating a channel."
+ },
+ {
+ "code": 409,
+ "reason": "Channel with given unique ID already exists."
}
]
}
@@ -368,6 +372,10 @@
{
"code": 400,
"reason": "Invalid parameters for originating a channel."
+ },
+ {
+ "code": 409,
+ "reason": "Channel with given unique ID already exists."
}
]
--
To view, visit https://gerrit.asterisk.org/4154
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Gerrit-MessageType: merged
Gerrit-Change-Id: Ibba7ae68842dab6df0c2e9c45559208bc89d3d06
Gerrit-PatchSet: 3
Gerrit-Project: asterisk
Gerrit-Branch: 14
Gerrit-Owner: Mark Michelson <mmichelson at digium.com>
Gerrit-Reviewer: Anonymous Coward #1000019
Gerrit-Reviewer: Joshua Colp <jcolp at digium.com>
Gerrit-Reviewer: Kevin Harwell <kharwell at digium.com>
Gerrit-Reviewer: Mark Michelson <mmichelson at digium.com>
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