ss: force check all set_metadata returns

lws_ss_set_metadata can fail... eg, due to transient OOM situation... if it does,
caller must take appropriate action like disconnect and retry.

So mark the api as requiring the result checking, and make sure all the
examples do it.

include/libwebsockets/lws-secure-streams.h

@@ -622,9 +622,10 @@ lws_ss_rideshare(struct lws_ss_handle *h);
  * name with the value of the metadata on the left.
  *
  * Return 0 if OK or nonzero if, eg, metadata name does not exist on the
- * streamtype.
+ * streamtype.  You must check the result of this, eg, transient OOM can cause
+ * these to fail and you should retry later.
  */
-LWS_VISIBLE LWS_EXTERN int
+LWS_VISIBLE LWS_EXTERN int LWS_WARN_UNUSED_RESULT
 lws_ss_set_metadata(struct lws_ss_handle *h, const char *name,
 		    const void *value, size_t len);
 

lib/secure-streams/protocols/ss-h1.c

@@ -962,29 +962,35 @@ malformed:
 #if defined(LWS_ROLE_H2)
 			m = lws_hdr_total_length(wsi, WSI_TOKEN_HTTP_COLON_METHOD);
 			if (m) {
-				lws_ss_set_metadata(h, "method",
+				if (lws_ss_set_metadata(h, "method",
 						    lws_hdr_simple_ptr(wsi,
-						     WSI_TOKEN_HTTP_COLON_METHOD), (unsigned int)m);
+						     WSI_TOKEN_HTTP_COLON_METHOD), (unsigned int)m))
+					return -1;
 				m = lws_hdr_total_length(wsi, WSI_TOKEN_HTTP_COLON_PATH);
-				lws_ss_set_metadata(h, "path",
+				if (lws_ss_set_metadata(h, "path",
 						    lws_hdr_simple_ptr(wsi,
-						     WSI_TOKEN_HTTP_COLON_PATH), (unsigned int)m);
+						     WSI_TOKEN_HTTP_COLON_PATH), (unsigned int)m))
+					return -1;
 			} else
 #endif
 			{
 				m = lws_hdr_total_length(wsi, WSI_TOKEN_GET_URI);
 				if (m) {
-					lws_ss_set_metadata(h, "path",
+					if (lws_ss_set_metadata(h, "path",
 							lws_hdr_simple_ptr(wsi,
-								WSI_TOKEN_GET_URI), (unsigned int)m);
-					lws_ss_set_metadata(h, "method", "GET", 3);
+								WSI_TOKEN_GET_URI), (unsigned int)m))
+						return -1;
+					if (lws_ss_set_metadata(h, "method", "GET", 3))
+						return -1;
 				} else {
 					m = lws_hdr_total_length(wsi, WSI_TOKEN_POST_URI);
 					if (m) {
-						lws_ss_set_metadata(h, "path",
+						if (lws_ss_set_metadata(h, "path",
 								lws_hdr_simple_ptr(wsi,
-									WSI_TOKEN_POST_URI), (unsigned int)m);
-						lws_ss_set_metadata(h, "method", "POST", 4);
+									WSI_TOKEN_POST_URI), (unsigned int)m))
+							return -1;
+						if (lws_ss_set_metadata(h, "method", "POST", 4))
+							return -1;
 					}
 				}
 			}

lib/secure-streams/secure-streams.c

@@ -1027,6 +1027,7 @@ late_bail:
 		lws_pt_lock(pt, __func__);
 		lws_dll2_remove(&h->list);
 		lws_pt_unlock(pt);
+		__lws_lc_untag(&h->lc);
 		lws_free(h);
 
 		return 1;

lib/secure-streams/system/auth-api.amazon.com/auth.c

@@ -54,7 +54,7 @@ static void
 lws_ss_sys_auth_api_amazon_com_kick(lws_sorted_usec_list_t *sul)
 {
 	struct lws_context *context = lws_container_of(sul, struct lws_context,
-							sul_api_amazon_com_kick);
+						       sul_api_amazon_com_kick);
 
 	lws_state_transition_steps(&context->mgr_system,
 				   LWS_SYSTATE_OPERATIONAL);
@@ -64,7 +64,7 @@ static void
 lws_ss_sys_auth_api_amazon_com_renew(lws_sorted_usec_list_t *sul)
 {
 	struct lws_context *context = lws_container_of(sul, struct lws_context,
-							sul_api_amazon_com);
+						       sul_api_amazon_com);
 
 	lws_ss_sys_auth_api_amazon_com(context);
 }
@@ -216,7 +216,8 @@ ss_api_amazon_auth_state(void *userobj, void *sh, lws_ss_constate_t state,
 
 	switch (state) {
 	case LWSSSCS_CREATING:
-        	lws_ss_set_metadata(m->ss, "ctype", "application/json", 16);
+        	if (lws_ss_set_metadata(m->ss, "ctype", "application/json", 16))
+        		return LWSSSSRET_DESTROY_ME;
 		/* fallthru */
 	case LWSSSCS_CONNECTING:
 		s = lws_system_blob_get_size(ab);

minimal-examples/secure-streams/minimal-secure-streams-hugeurl/minimal-secure-streams.c

@@ -281,7 +281,8 @@ myss_state(void *userobj, void *sh, lws_ss_constate_t state,
 
 		lws_hex_random(lws_ss_get_context(m->ss), hugeurl,
 			       hugeurl_size + 1);
-		lws_ss_set_metadata(m->ss, "hugearg", hugeurl, hugeurl_size);
+		if (lws_ss_set_metadata(m->ss, "hugearg", hugeurl, hugeurl_size))
+			return LWSSSSRET_DISCONNECT_ME;
 
 		return lws_ss_client_connect(m->ss);
 

minimal-examples/secure-streams/minimal-secure-streams-metadata/minimal-secure-streams.c

@@ -182,7 +182,9 @@ myss_state(void *userobj, void *sh, lws_ss_constate_t state,
 	case LWSSSCS_CREATING:
 		lwsl_notice("%s: CREATING: setting servername metadata to %s\n",
 				__func__, server_name_or_url);
-		lws_ss_set_metadata(m->ss, "servername", server_name_or_url, strlen(server_name_or_url));
+		if (lws_ss_set_metadata(m->ss, "servername", server_name_or_url,
+					strlen(server_name_or_url)))
+			return LWSSSSRET_DISCONNECT_ME;
 		return lws_ss_client_connect(m->ss);
 
 	case LWSSSCS_ALL_RETRIES_FAILED:

minimal-examples/secure-streams/minimal-secure-streams-post/minimal-secure-streams-post.c

@@ -345,9 +345,10 @@ myss_state(void *userobj, void *sh, lws_ss_constate_t state,
 		 * proxy to create the stream and it has been allowed.
 		 */
 
-		lws_ss_set_metadata(m->ss, "ctype",
+		if (lws_ss_set_metadata(m->ss, "ctype",
 				    "multipart/form-data;boundary=\"boundary\"",
-				    39);
+				    39))
+			return LWSSSSRET_DISCONNECT_ME;
 
 		/* provide a hint about the payload size */
 		m->pos = 0;

minimal-examples/secure-streams/minimal-secure-streams-server/ss-server.c

@@ -191,11 +191,13 @@ myss_srv_state(void *userobj, void *sh, lws_ss_constate_t state,
 		/*
 		 * ... it's going to be either text/html or multipart ...
 		 */
-		if (multipart)
-			lws_ss_set_metadata(m->ss, "mime",
-			   "multipart/form-data; boundary=aBoundaryString", 45);
-		else
-			lws_ss_set_metadata(m->ss, "mime", "text/html", 9);
+		if (multipart) {
+			if (lws_ss_set_metadata(m->ss, "mime",
+			   "multipart/form-data; boundary=aBoundaryString", 45))
+				return LWSSSSRET_DISCONNECT_ME;
+		} else
+			if (lws_ss_set_metadata(m->ss, "mime", "text/html", 9))
+				return LWSSSSRET_DISCONNECT_ME;
 		/*
 		 * ...it's going to be whatever size it is (and request tx)
 		 */

minimal-examples/secure-streams/minimal-secure-streams-testsfail/minimal-secure-streams-testsfail.c

@@ -660,7 +660,8 @@ fail:
 		if (curr_test->eom_pass) {
 			sl = (size_t)lws_snprintf(buf, sizeof(buf), "%u",
 					(unsigned int)curr_test->eom_pass);
-			lws_ss_set_metadata(m->ss, "amount", buf, sl);
+			if (lws_ss_set_metadata(m->ss, "amount", buf, sl))
+				return LWSSSSRET_DISCONNECT_ME;
 		}
 		return lws_ss_client_connect(m->ss);
 

minimal-examples/secure-streams/minimal-secure-streams/minimal-secure-streams.c

@@ -207,7 +207,7 @@ myss_rx(void *userobj, const uint8_t *buf, size_t len, int flags)
 		interrupted = 1;
 	}
 
-	return 0;
+	return LWSSSSRET_OK;
 }
 
 static lws_ss_state_return_t
@@ -232,11 +232,19 @@ myss_state(void *userobj, void *sh, lws_ss_constate_t state,
 
 	switch (state) {
 	case LWSSSCS_CREATING:
-		lws_ss_start_timeout(m->ss, timeout_ms);
-		lws_ss_set_metadata(m->ss, "uptag", "myuptag123", 10);
-		lws_ss_set_metadata(m->ss, "ctype", "myctype", 7);
 		return lws_ss_client_connect(m->ss);
 
+	case LWSSSCS_CONNECTING:
+		lws_ss_start_timeout(m->ss, timeout_ms);
+		if (lws_ss_set_metadata(m->ss, "uptag", "myuptag123", 10))
+			/* can fail, eg due to OOM, retry later if so */
+			return LWSSSSRET_DISCONNECT_ME;
+
+		if (lws_ss_set_metadata(m->ss, "ctype", "myctype", 7))
+			/* can fail, eg due to OOM, retry later if so */
+			return LWSSSSRET_DISCONNECT_ME;
+		break;
+
 	case LWSSSCS_ALL_RETRIES_FAILED:
 		/* if we're out of retries, we want to close the app and FAIL */
 		interrupted = 1;
@@ -257,7 +265,7 @@ myss_state(void *userobj, void *sh, lws_ss_constate_t state,
 		break;
 	}
 
-	return 0;
+	return LWSSSSRET_OK;
 }
 
 static int