unix: fix wrong MAC of uv_interface_address

fix a wrong `if` in `uv_interface_address` about MAC.

Fixes: nodejs/node#13581
PR-URL: #1375
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Santiago Gimeno <santiago.gimeno@gmail.com>

src/unix/bsd-ifaddrs.c

@@ -31,11 +31,18 @@
 #include <net/if_dl.h>
 #endif
 
-static int uv__ifaddr_exclude(struct ifaddrs *ent) {
+static int uv__ifaddr_exclude(struct ifaddrs *ent, int exclude_type) {
   if (!((ent->ifa_flags & IFF_UP) && (ent->ifa_flags & IFF_RUNNING)))
     return 1;
   if (ent->ifa_addr == NULL)
     return 1;
+  /*
+   * If `exclude_type` is `UV__EXCLUDE_IFPHYS`, just see whether `sa_family`
+   * equals to `AF_LINK` or not. Otherwise, the result depends on the operation
+   * system with `AF_LINK` or `PF_INET`.
+   */
+  if (exclude_type == UV__EXCLUDE_IFPHYS)
+    return (ent->ifa_addr->sa_family != AF_LINK);
 #if defined(__APPLE__) || defined(__FreeBSD__) || defined(__DragonFly__)
   /*
    * On BSD getifaddrs returns information related to the raw underlying
@@ -63,7 +70,7 @@ int uv_interface_addresses(uv_interface_address_t** addresses, int* count) {
 
   /* Count the number of interfaces */
   for (ent = addrs; ent != NULL; ent = ent->ifa_next) {
-    if (uv__ifaddr_exclude(ent))
+    if (uv__ifaddr_exclude(ent, UV__EXCLUDE_IFADDR))
       continue;
     (*count)++;
   }
@@ -78,7 +85,7 @@ int uv_interface_addresses(uv_interface_address_t** addresses, int* count) {
   address = *addresses;
 
   for (ent = addrs; ent != NULL; ent = ent->ifa_next) {
-    if (uv__ifaddr_exclude(ent))
+    if (uv__ifaddr_exclude(ent, UV__EXCLUDE_IFADDR))
       continue;
 
     address->name = uv__strdup(ent->ifa_name);
@@ -102,7 +109,7 @@ int uv_interface_addresses(uv_interface_address_t** addresses, int* count) {
 
   /* Fill in physical addresses for each interface */
   for (ent = addrs; ent != NULL; ent = ent->ifa_next) {
-    if (uv__ifaddr_exclude(ent))
+    if (uv__ifaddr_exclude(ent, UV__EXCLUDE_IFPHYS))
       continue;
 
     address = *addresses;

src/unix/internal.h

@@ -151,6 +151,12 @@ enum {
   UV_LOOP_BLOCK_SIGPROF = 1
 };
 
+/* flags of excluding ifaddr */
+enum {
+  UV__EXCLUDE_IFPHYS,
+  UV__EXCLUDE_IFADDR
+};
+
 typedef enum {
   UV_CLOCK_PRECISE = 0,  /* Use the highest resolution clock available. */
   UV_CLOCK_FAST = 1      /* Use the fastest clock with <= 1ms granularity. */

src/unix/linux-core.c

@@ -837,7 +837,7 @@ void uv_free_cpu_info(uv_cpu_info_t* cpu_infos, int count) {
   uv__free(cpu_infos);
 }
 
-static int uv__ifaddr_exclude(struct ifaddrs *ent) {
+static int uv__ifaddr_exclude(struct ifaddrs *ent, int exclude_type) {
   if (!((ent->ifa_flags & IFF_UP) && (ent->ifa_flags & IFF_RUNNING)))
     return 1;
   if (ent->ifa_addr == NULL)
@@ -847,8 +847,8 @@ static int uv__ifaddr_exclude(struct ifaddrs *ent) {
    * devices. We're not interested in this information yet.
    */
   if (ent->ifa_addr->sa_family == PF_PACKET)
-    return 1;
-  return 0;
+    return exclude_type;
+  return !exclude_type;
 }
 
 int uv_interface_addresses(uv_interface_address_t** addresses,
@@ -869,7 +869,7 @@ int uv_interface_addresses(uv_interface_address_t** addresses,
 
   /* Count the number of interfaces */
   for (ent = addrs; ent != NULL; ent = ent->ifa_next) {
-    if (uv__ifaddr_exclude(ent))
+    if (uv__ifaddr_exclude(ent, UV__EXCLUDE_IFADDR))
       continue;
 
     (*count)++;
@@ -887,7 +887,7 @@ int uv_interface_addresses(uv_interface_address_t** addresses,
   address = *addresses;
 
   for (ent = addrs; ent != NULL; ent = ent->ifa_next) {
-    if (uv__ifaddr_exclude(ent))
+    if (uv__ifaddr_exclude(ent, UV__EXCLUDE_IFADDR))
       continue;
 
     address->name = uv__strdup(ent->ifa_name);
@@ -911,7 +911,7 @@ int uv_interface_addresses(uv_interface_address_t** addresses,
 
   /* Fill in physical addresses for each interface */
   for (ent = addrs; ent != NULL; ent = ent->ifa_next) {
-    if (uv__ifaddr_exclude(ent))
+    if (uv__ifaddr_exclude(ent, UV__EXCLUDE_IFPHYS))
       continue;
 
     address = *addresses;