static const char *TAG = "httpd_uri";
+
+/**
+ * @brief Test if a URI matches the given template.
+ *
+ * Template may end with "?" to make the previous character optional (typically a slash),
+ * "*" for a wildcard match, and "?*" to make the previous character optional, and if present,
+ * allow anything to follow.
+ *
+ * Example:
+ * - * matches everything
+ * - /foo/? matches /foo and /foo/
+ * - /foo/\* (sans the backslash) matches /foo/ and /foo/bar, but not /foo or /fo
+ * - /foo/?* or /foo/\*? (sans the backslash) matches /foo/, /foo/bar, and also /foo, but not /foox or /fo
+ *
+ * The special characters "?" and "*" anywhere else in the template will be taken literally.
+ *
+ * @param[in] template - URI template (pattern)
+ * @param[in] uri - tested URI
+ * @param[in] template - how many characters of the URI buffer to test
+ * (there may be trailing query string etc.)
+ *
+ * @return true if a match was found
+ */
+static bool uri_matches(const char *template, const char *uri, const unsigned int len)
+{
+ const size_t tpl_len = strlen(template);
+ size_t exact_match_chars = tpl_len;
+
+ /* Check for trailing question mark and asterisk */
+ const char last = (const char) (tpl_len > 0 ? template[tpl_len - 1] : 0);
+ const char prevlast = (const char) (tpl_len > 1 ? template[tpl_len - 2] : 0);
+ const bool asterisk = last == '*' || (prevlast == '*' && last == '?');
+ const bool quest = last == '?' || (prevlast == '?' && last == '*');
+
+ /* abort in cases such as "?" with no preceding character (invalid template) */
+ if (exact_match_chars < asterisk + quest*2) return false;
+ /* account for special characters and the optional character if "?" is used */
+ exact_match_chars -= asterisk + quest*2;
+
+ if (len < exact_match_chars) return false;
+
+ if (!quest) {
+ if (!asterisk && len != exact_match_chars) {
+ /* no special characters and different length - strncmp would return false */
+ return false;
+ }
+ /* asterisk allows arbitrary trailing characters, we ignore these using
+ * exact_match_chars as the length limit */
+ return 0 == strncmp(template, uri, exact_match_chars);
+ } else {
+ /* question mark present */
+ if (len > exact_match_chars && template[exact_match_chars] != uri[exact_match_chars]) {
+ /* the optional character is present, but different */
+ return false;
+ }
+ if (0 != strncmp(template, uri, exact_match_chars)) {
+ /* the mandatory part differs */
+ return false;
+ }
+ /* Now we know the URI is longer than the required part of template,
+ * the mandatory part matches, and if the optional character is present, it is correct.
+ * Match is OK if we have asterisk, i.e. any trailing characters are OK, or if
+ * there are no characters beyond the optional character. */
+ return asterisk || len <= exact_match_chars + 1;
+ }
+}
+
static int httpd_find_uri_handler(struct httpd_data *hd,
const char* uri,
httpd_method_t method)
if (hd->hd_calls[i]) {
ESP_LOGD(TAG, LOG_FMT("[%d] = %s"), i, hd->hd_calls[i]->uri);
if ((hd->hd_calls[i]->method == method) && // First match methods
- (strcmp(hd->hd_calls[i]->uri, uri) == 0)) { // Then match uri strings
+ uri_matches(hd->hd_calls[i]->uri, uri, strlen(uri))) { // Then match uri strings
return i;
}
}
for (int i = 0; i < hd->config.max_uri_handlers; i++) {
if (hd->hd_calls[i]) {
ESP_LOGD(TAG, LOG_FMT("[%d] = %s"), i, hd->hd_calls[i]->uri);
- if ((strlen(hd->hd_calls[i]->uri) == uri_len) && // First match uri length
- (strncmp(hd->hd_calls[i]->uri, uri, uri_len) == 0)) { // Then match uri strings
- if (hd->hd_calls[i]->method == method) { // Finally match methods
+ if (uri_matches(hd->hd_calls[i]->uri, uri, uri_len)) {
+ if (hd->hd_calls[i]->method == method) { // Match methods
return hd->hd_calls[i];
}
/* URI found but method not allowed.