sysmocom
/
asterisk
11
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

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
This commit is contained in:
George Joseph 2019-08-20 12:04:56 -06:00
parent ff180a5bfc
commit f82d0b74fd
1 changed files with 18 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

23
res/res_ari.c
View File

@ -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;
}
}