wol: add interface binding to context

Author: lws-team

include/libwebsockets/lws-context-vhost.h

@@ -967,6 +967,11 @@ struct lws_context_creation_info {
 	 * zero.
 	 */
 
+#if defined(LWS_WITH_NETWORK)
+	const char		*wol_if;
+	/**< CONTEXT: NULL, or interface name to bind outgoing WOL packet to */
+#endif
+
 	/* Add new things just above here ---^
 	 * This is part of the ABI, don't needlessly break compatibility
 	 *

lib/core-net/wol.c

@@ -25,21 +25,34 @@
 #include "private-lib-core.h"
 
 int
-lws_wol(struct lws_context *ctx, const char *ip_or_NULL, uint8_t *mac_6_bytes)
+lws_wol(struct lws_context *cx, const char *ip_or_NULL, uint8_t *mac_6_bytes)
 {
         int n, m, ofs = 0, fd, optval = 1, ret = 1;
         uint8_t pkt[17 * ETHER_ADDR_LEN];
         struct sockaddr_in addr;
 
         fd = (int)(intptr_t)socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
         if (fd < 0) {
-                lwsl_cx_err(ctx, "failed to open UDP, errno %d\n", errno);
+                lwsl_cx_err(cx, "failed to open UDP, errno %d\n", errno);
                 goto bail;
         }
 
+#if defined(__linux__)
+	if (cx->wol_if) {
+		struct ifreq ifr;
+
+		memset(&ifr, 0, sizeof(ifr));
+		snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), cx->wol_if);
+		if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, (void *)&ifr, sizeof(ifr)) < 0) {
+			lwsl_cx_err(cx, "failed to BINDTODEVICE, errno %d\n", errno);
+	                goto bail;
+	        }
+	}
+#endif
+
         if (setsockopt(fd, SOL_SOCKET, SO_BROADCAST,
                         (char *)&optval, sizeof(optval)) < 0) {
-                lwsl_cx_err(ctx, "failed to set broadcast, errno %d\n", errno);
+                lwsl_cx_err(cx, "failed to set broadcast, errno %d\n", errno);
                 goto bail;
         }
 
@@ -59,19 +72,19 @@ lws_wol(struct lws_context *ctx, const char *ip_or_NULL, uint8_t *mac_6_bytes)
 
 	if (!inet_pton(AF_INET, ip_or_NULL ? ip_or_NULL : "255.255.255.255",
 				      &addr.sin_addr)) {
-                lwsl_cx_err(ctx, "failed to convert to ipv4 broadcast ads, errno %d\n",
+                lwsl_cx_err(cx, "failed to convert to ipv4 broadcast ads, errno %d\n",
                                  errno);
                 goto bail;
         }
 
-        lwsl_cx_notice(ctx, "Sending WOL to %02X:%02X:%02X:%02X:%02X:%02X %s\n",
+        lwsl_cx_notice(cx, "Sending WOL to %02X:%02X:%02X:%02X:%02X:%02X %s '%s'\n",
                 mac_6_bytes[0], mac_6_bytes[1], mac_6_bytes[2], mac_6_bytes[3],
-                mac_6_bytes[4], mac_6_bytes[5], ip_or_NULL ? ip_or_NULL : "");
+                mac_6_bytes[4], mac_6_bytes[5], ip_or_NULL ? ip_or_NULL : "", cx->wol_if);
 
 	/* arg2 is normally const void *, on mingw it's const char * */
         if (sendto(fd, (const char *)pkt, sizeof(pkt), 0, (struct sockaddr *)&addr,
                         sizeof(addr)) < 0) {
-                lwsl_cx_err(ctx, "failed to sendto broadcast ads, errno %d\n",
+                lwsl_cx_err(cx, "failed to sendto broadcast ads, errno %d\n",
                                  errno);
                 goto bail;
         }

lib/core/context.c

@@ -665,6 +665,7 @@ lws_create_context(const struct lws_context_creation_info *info)
 #if defined(LWS_WITH_NETWORK)
 	context->event_loop_ops = plev->ops;
 	context->us_wait_resolution = us_wait_resolution;
+	context->wol_if = info->wol_if;
 #if defined(LWS_WITH_TLS_JIT_TRUST)
 	{
 		struct lws_cache_creation_info ci;

lib/core/private-lib-core.h

@@ -635,6 +635,8 @@ struct lws_context {
 	lws_ss_handle_t			* ota_ss;	/* opaque to platform */
 #endif
 
+	const char			*wol_if;
+
 /*
  * <====== LWS_WITH_NETWORK end
  */

minimal-examples-lowlevel/raw/minimal-raw-wol/minimal-raw-wol.c

@@ -15,7 +15,7 @@ int main(int argc, const char **argv)
 {
        struct lws_context_creation_info info;
        struct lws_context *ctx;
-       const char *p, *ip = NULL;
+       const char *p, *ip = NULL, *wol_if = NULL;
        uint8_t mac[LWS_ETHER_ADDR_LEN];
        int ret = 1;
 
@@ -25,8 +25,12 @@ int main(int argc, const char **argv)
 	if ((p = lws_cmdline_option(argc, argv, "-ip")))
 		ip = p;
 
+	if ((p = lws_cmdline_option(argc, argv, "-i")))
+		wol_if = p;
+
+
 	if (argc < 2) {
-		lwsl_user("lws-minimal-raw-wol XX:XX:XX:XX:XX:XX [-ip interface IP]\n");
+		lwsl_user("lws-minimal-raw-wol XX:XX:XX:XX:XX:XX [-ip interface IP] [-i interface name]\n");
 		goto bail1;
 	}
 
@@ -35,6 +39,8 @@ int main(int argc, const char **argv)
 		goto bail1;
 	}
 
+	info.wol_if = wol_if;
+
 	ctx = lws_create_context(&info);
 	if (!ctx) {
 		lwsl_err("lws init failed\n");