Wireguard: Use abstract unix sockets on Android

4 files changed, 30 insertions, 11 deletions

diff --git a/sysdep/unix/io.c b/sysdep/unix/io.c
index 3aba48d2..14bf99fe 100644
--- a/sysdep/unix/io.c
+++ b/sysdep/unix/io.c
@@ -1513,11 +1513,14 @@ sk_open_unix(sock *s, char *name)
 }
 
 int
-sk_connect_unix(sock *s, char *name)
+sk_connect_unix(sock *s, char *name, socklen_t namelen)
 {
   struct sockaddr_un sa;
   int fd;
 
+  if (namelen > sizeof(sa.sun_path))
+    return -1;
+
   /* We are sloppy during error (leak fd and not set s->err), but we die anyway */
 
   fd = socket(AF_UNIX, SOCK_STREAM, 0);
@@ -1528,10 +1531,11 @@ sk_connect_unix(sock *s, char *name)
     return -1;
 
   /* Path length checked in test_old_bird() */
+  memset(&sa, 0, sizeof(sa));
   sa.sun_family = AF_UNIX;
-  strcpy(sa.sun_path, name);
+  memcpy(sa.sun_path, name, namelen);
 
-  if (connect(fd, (struct sockaddr *) &sa, SUN_LEN(&sa)) < 0)
+  if (connect(fd, (struct sockaddr *) &sa, sizeof(sa.sun_family) + namelen) < 0)
     return -1;
 
   s->fd = fd;
diff --git a/sysdep/unix/unix.h b/sysdep/unix/unix.h
index 849e5947..a95e5c25 100644
--- a/sysdep/unix/unix.h
+++ b/sysdep/unix/unix.h
@@ -108,7 +108,7 @@ void io_loop(void);
 void io_log_dump(void);
 int sk_open_unix(struct birdsock *s, char *name);
 struct rfile *rf_open(struct pool *, const char *name, const char *mode);
-int sk_connect_unix(struct birdsock *s, char *name);
+int sk_connect_unix(struct birdsock *s, char *name, socklen_t namelen);
 void *rf_file(struct rfile *f);
 int rf_fileno(struct rfile *f);
 void test_old_bird(char *path);
diff --git a/sysdep/unix/wg_user.c b/sysdep/unix/wg_user.c
index db92ea8e..5d4d59a0 100644
--- a/sysdep/unix/wg_user.c
+++ b/sysdep/unix/wg_user.c
@@ -12,18 +12,32 @@
 #include "sysdep/linux/wireguard.h"
 
 static
-char *get_socket_path(const char *ifname, char *buf, uint size)
+socklen_t get_socket_path(const char *ifname, char *buf, uint size)
 {
-  bsnprintf(buf, size, SOCKET_PATH "%s.sock", ifname);
-  return buf;
+  int pos = 0;
+
+  if (size < 1)
+    return 0;
+
+#ifdef ANDROID
+  /* Abstract socket */
+  buf[pos++] = 0;
+#endif
+  bsnprintf(buf+pos, size-pos, SOCKET_PATH "%s.sock", ifname);
+  return pos + strlen(buf+pos);
 }
 
 bool wg_has_userspace(const char *ifname)
 {
   struct stat sb;
   char tmp[sizeof(struct sockaddr_un)];
+  socklen_t tmplen = get_socket_path(ifname, tmp, sizeof(tmp));
 
-  if (stat(get_socket_path(ifname, tmp, sizeof(tmp)), &sb) == 0)
+  if (tmplen > 0 && tmp[0] == 0)
+    /* System with abstract socket (Android) always use WireGuard's userspace
+       implementation. */
+    return true;
+  else if (stat(tmp, &sb) == 0)
     return (sb.st_mode & S_IFMT) == S_IFSOCK;
   else
     {
@@ -210,14 +224,13 @@ wg_user_set_device(struct pool *pool,
 		   struct wg_device *dev)
 {
   char path[sizeof(struct sockaddr_un)];
-
-  bsnprintf(path, sizeof(path), SOCKET_PATH "%s.sock", ifname);
+  socklen_t pathlen = get_socket_path(ifname, path, sizeof(path));
 
   struct birdsock *sock = sk_new(pool);
   sock->rx_hook = user_rx_hook;
   sock->tx_hook = user_tx_hook;
   sock->err_hook = user_err_hook;
-  int res = sk_connect_unix(sock, path);
+  int res = sk_connect_unix(sock, path, pathlen);
   DBG(L_TRACE "WG: socket %d %d %s", res, sock->fd, path);
   if (res < 0)
     {
diff --git a/sysdep/unix/wg_user.h b/sysdep/unix/wg_user.h
index a5e4251a..5bd9a41a 100644
--- a/sysdep/unix/wg_user.h
+++ b/sysdep/unix/wg_user.h
@@ -3,7 +3,9 @@
 
 #include "sysdep/config.h"
 
+#ifndef SOCKET_PATH
 #define SOCKET_PATH PATH_RUNSTATEDIR "/wireguard/"
+#endif /* SOCKET_PATH */
 
 struct pool;
 struct wg_device;