url: protocol handler lookup tidy-up

- rename lookup to what it does
- use ARRAYSIZE instead of NULL check for end
- offer alternate lookup for 0-terminated strings

Closes #12216

lib/setopt.c

@@ -171,7 +171,7 @@ static CURLcode protocol2num(const char *str, curl_prot_t *val)
     str = strchr(str, ',');
     tlen = str? (size_t) (str - token): strlen(token);
     if(tlen) {
-      const struct Curl_handler *h = Curl_builtin_scheme(token, tlen);
+      const struct Curl_handler *h = Curl_getn_scheme_handler(token, tlen);
 
       if(!h)
         return CURLE_UNSUPPORTED_PROTOCOL;

lib/transfer.c

@@ -1640,7 +1640,7 @@ CURLcode Curl_follow(struct Curl_easy *data,
           return Curl_uc_to_curlcode(uc);
         }
 
-        p = Curl_builtin_scheme(scheme, CURL_ZERO_TERMINATED);
+        p = Curl_get_scheme_handler(scheme);
         if(p && (p->protocol != data->info.conn_protocol)) {
           infof(data, "Clear auth, redirects scheme from %s to %s",
                 data->info.conn_scheme, scheme);

lib/url.c

@@ -288,8 +288,6 @@ static const struct Curl_handler * const protocols[] = {
 #ifndef CURL_DISABLE_DICT
   &Curl_handler_dict,
 #endif
-
-  (struct Curl_handler *) NULL
 };
 
 void Curl_freeset(struct Curl_easy *data)
@@ -1607,20 +1605,23 @@ error:
   return NULL;
 }
 
-/* returns the handler if the given scheme is built-in */
-const struct Curl_handler *Curl_builtin_scheme(const char *scheme,
-                                               size_t schemelen)
+const struct Curl_handler *Curl_get_scheme_handler(const char *scheme)
 {
-  const struct Curl_handler * const *pp;
-  const struct Curl_handler *p;
+  return Curl_getn_scheme_handler(scheme, strlen(scheme));
+}
+
+/* returns the handler if the given scheme is built-in */
+const struct Curl_handler *Curl_getn_scheme_handler(const char *scheme,
+                                                    size_t len)
+{
+  size_t i;
   /* Scan protocol handler table and match against 'scheme'. The handler may
      be changed later when the protocol specific setup function is called. */
-  if(schemelen == CURL_ZERO_TERMINATED)
-    schemelen = strlen(scheme);
-  for(pp = protocols; (p = *pp) != NULL; pp++)
-    if(strncasecompare(p->scheme, scheme, schemelen) && !p->scheme[schemelen])
+  for(i = 0; i < ARRAYSIZE(protocols); ++i)
+    if(strncasecompare(protocols[i]->scheme, scheme, len) &&
+       !protocols[i]->scheme[len])
       /* Protocol found in table. */
-      return p;
+      return protocols[i];
   return NULL; /* not found */
 }
 
@@ -1629,8 +1630,7 @@ static CURLcode findprotocol(struct Curl_easy *data,
                              struct connectdata *conn,
                              const char *protostr)
 {
-  const struct Curl_handler *p = Curl_builtin_scheme(protostr,
-                                                     CURL_ZERO_TERMINATED);
+  const struct Curl_handler *p = Curl_get_scheme_handler(protostr);
 
   if(p && /* Protocol found in table. Check if allowed */
      (data->set.allowed_protocols & p->protocol)) {
@@ -1644,7 +1644,6 @@ static CURLcode findprotocol(struct Curl_easy *data,
     else {
       /* Perform setup complement if some. */
       conn->handler = conn->given = p;
-
       /* 'port' and 'remote_port' are set in setup_connection_internals() */
       return CURLE_OK;
     }

lib/url.h

@@ -46,8 +46,13 @@ CURLcode Curl_parse_login_details(const char *login, const size_t len,
                                   char **userptr, char **passwdptr,
                                   char **optionsptr);
 
-const struct Curl_handler *Curl_builtin_scheme(const char *scheme,
-                                               size_t schemelen);
+/* Get protocol handler for a URI scheme
+ * @param scheme URI scheme, case-insensitive
+ * @return NULL of handler not found
+ */
+const struct Curl_handler *Curl_get_scheme_handler(const char *scheme);
+const struct Curl_handler *Curl_getn_scheme_handler(const char *scheme,
+                                                    size_t len);
 
 #define CURL_DEFAULT_PROXY_PORT 1080 /* default proxy port unless specified */
 #define CURL_DEFAULT_HTTPS_PROXY_PORT 443 /* default https proxy port unless

lib/urlapi.c

@@ -446,7 +446,7 @@ static CURLUcode parse_hostname_login(struct Curl_URL *u,
 
   /* if this is a known scheme, get some details */
   if(u->scheme)
-    h = Curl_builtin_scheme(u->scheme, CURL_ZERO_TERMINATED);
+    h = Curl_get_scheme_handler(u->scheme);
 
   /* We could use the login information in the URL so extract it. Only parse
      options if the handler says we should. Note that 'h' might be NULL! */
@@ -1129,7 +1129,7 @@ static CURLUcode parseurl(const char *url, CURLU *u, unsigned int flags)
       }
 
       schemep = schemebuf;
-      if(!Curl_builtin_scheme(schemep, CURL_ZERO_TERMINATED) &&
+      if(!Curl_get_scheme_handler(schemep) &&
          !(flags & CURLU_NON_SUPPORT_SCHEME)) {
         result = CURLUE_UNSUPPORTED_SCHEME;
         goto fail;
@@ -1447,8 +1447,7 @@ CURLUcode curl_url_get(const CURLU *u, CURLUPart what,
     if(!ptr && (flags & CURLU_DEFAULT_PORT) && u->scheme) {
       /* there's no stored port number, but asked to deliver
          a default one for the scheme */
-      const struct Curl_handler *h =
-        Curl_builtin_scheme(u->scheme, CURL_ZERO_TERMINATED);
+      const struct Curl_handler *h = Curl_get_scheme_handler(u->scheme);
       if(h) {
         msnprintf(portbuf, sizeof(portbuf), "%u", h->defport);
         ptr = portbuf;
@@ -1457,8 +1456,7 @@ CURLUcode curl_url_get(const CURLU *u, CURLUPart what,
     else if(ptr && u->scheme) {
       /* there is a stored port number, but ask to inhibit if
          it matches the default one for the scheme */
-      const struct Curl_handler *h =
-        Curl_builtin_scheme(u->scheme, CURL_ZERO_TERMINATED);
+      const struct Curl_handler *h = Curl_get_scheme_handler(u->scheme);
       if(h && (h->defport == u->portnum) &&
          (flags & CURLU_NO_DEFAULT_PORT))
         ptr = NULL;
@@ -1503,7 +1501,7 @@ CURLUcode curl_url_get(const CURLU *u, CURLUPart what,
       else
         return CURLUE_NO_SCHEME;
 
-      h = Curl_builtin_scheme(scheme, CURL_ZERO_TERMINATED);
+      h = Curl_get_scheme_handler(scheme);
       if(!port && (flags & CURLU_DEFAULT_PORT)) {
         /* there's no stored port number, but asked to deliver
            a default one for the scheme */
@@ -1743,9 +1741,8 @@ CURLUcode curl_url_set(CURLU *u, CURLUPart what,
     if((plen > MAX_SCHEME_LEN) || (plen < 1))
       /* too long or too short */
       return CURLUE_BAD_SCHEME;
-    if(!(flags & CURLU_NON_SUPPORT_SCHEME) &&
-       /* verify that it is a fine scheme */
-       !Curl_builtin_scheme(part, CURL_ZERO_TERMINATED))
+   /* verify that it is a fine scheme */
+    if(!(flags & CURLU_NON_SUPPORT_SCHEME) && !Curl_get_scheme_handler(part))
       return CURLUE_UNSUPPORTED_SCHEME;
     storep = &u->scheme;
     urlencode = FALSE; /* never */