From 8da4e28a81e46eb1e5be0702849e1304fce2764f Mon Sep 17 00:00:00 2001
From: George Joseph <gjoseph@digium.com>
Date: Tue, 20 Aug 2019 12:04:56 -0600
Subject: [PATCH] res_ari.c: Prefer exact handler match over wildcard
Given the following request path and 2 handler paths...
Request: /channels/externalMedia
Handler: /channels/{channelId} "wildcard"
Handler: /channels/externalmedia "non-wildcard"
...if /channels/externalMedia was registered as a handler after
/channels/{channelId} as shown above, the request would automatically
match the wildcard handler and attempt to parse "externalMedia" into
the channelId variable which isn't what was intended. It'd work
if the non-wildard entry was defined in rest-api/api-docs/channels.json
before the wildcard entry but that makes the json files
order-dependent which isn't a good thing.
To combat this issue, the search loop saves any wildcard match but
continues looking for exact matches at the same level. If it finds
one, it's used. If it hasn't found an exact match at the end of
the current level, the wildcard is used. Regardless, after
searching the current level, the wildcard is cleared so it won't
accidentally match for a different object or a higher level.
BTW, it's currently not possible for more than 1 wildcard entry
to be defined for a level. For instance, there couldn't be:
Handler: /channels/{channelId}
Handler: /channels/{channelName}
We wouldn't know which one to match.
Change-Id: I574aa3cbe4249c92c30f74b9b40e750e9002f925
---
res/res_ari.c | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)
diff --git a/res/res_ari.c b/res/res_ari.c
index ee4a00ed7d..682d3e931b 100644
--- a/res/res_ari.c
+++ b/res/res_ari.c
@@ -495,6 +495,7 @@ void ast_ari_invoke(struct ast_tcptls_session_instance *ser,
{
RAII_VAR(struct stasis_rest_handlers *, root, NULL, ao2_cleanup);
struct stasis_rest_handlers *handler;
+ struct stasis_rest_handlers *wildcard_handler = NULL;
RAII_VAR(struct ast_variable *, path_vars, NULL, ast_variables_destroy);
char *path = ast_strdupa(uri);
char *path_segment;
@@ -503,37 +504,49 @@ void ast_ari_invoke(struct ast_tcptls_session_instance *ser,
root = handler = get_root_handler();
ast_assert(root != NULL);
+ ast_debug(3, "Finding handler for %s\n", path);
+
while ((path_segment = strsep(&path, "/")) && (strlen(path_segment) > 0)) {
struct stasis_rest_handlers *found_handler = NULL;
int i;
ast_uri_decode(path_segment, ast_uri_http_legacy);
- ast_debug(3, "Finding handler for %s\n", path_segment);
+ ast_debug(3, " Finding handler for %s\n", path_segment);
for (i = 0; found_handler == NULL && i < handler->num_children; ++i) {
struct stasis_rest_handlers *child = handler->children[i];
- ast_debug(3, " Checking %s\n", child->path_segment);
if (child->is_wildcard) {
/* Record the path variable */
struct ast_variable *path_var = ast_variable_new(child->path_segment, path_segment, __FILE__);
path_var->next = path_vars;
path_vars = path_var;
- found_handler = child;
+ wildcard_handler = child;
+ ast_debug(3, " Checking %s %s: Matched wildcard.\n", handler->path_segment, child->path_segment);
+
} else if (strcmp(child->path_segment, path_segment) == 0) {
found_handler = child;
+ ast_debug(3, " Checking %s %s: Explicit match with %s\n", handler->path_segment, child->path_segment, path_segment);
+ } else {
+ ast_debug(3, " Checking %s %s: Didn't match %s\n", handler->path_segment, child->path_segment, path_segment);
}
}
+ if (!found_handler && wildcard_handler) {
+ ast_debug(3, " No explicit handler found for %s. Using wildcard %s.\n",
+ path_segment, wildcard_handler->path_segment);
+ found_handler = wildcard_handler;
+ wildcard_handler = NULL;
+ }
+
if (found_handler == NULL) {
/* resource not found */
- ast_debug(3, " Handler not found\n");
+ ast_debug(3, " Handler not found for %s\n", path_segment);
ast_ari_response_error(
response, 404, "Not Found",
"Resource not found");
return;
} else {
- ast_debug(3, " Got it!\n");
handler = found_handler;
}
}
--
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