Support compile with clang on BSD

A couple of changes to make the code compile on BSD systems with clang

src/server.c

@@ -211,10 +211,11 @@ int dqlite_node_set_bind_address(dqlite_node *t, const char *address)
  len += sizeof(sa_family_t);
  addr = (struct sockaddr *)&addr_un;
  }
- fd = socket(domain, SOCK_STREAM | SOCK_CLOEXEC, 0);
+ fd = socket(domain, SOCK_STREAM, 0);
  if (fd == -1) {
  return DQLITE_ERROR;
  }
+ fcntl(fd, O_CLOEXEC);
  if (domain == AF_INET) {
  int reuse = 1;
  rv = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
@@ -431,10 +432,20 @@ static void listenCb(uv_stream_t *listener, int status)
 
  /* We accept unix socket connections only from the same process. */
  if (listener->type == UV_NAMED_PIPE) {
+ int fd = stream->io_watcher.fd;
+#if defined(__FreeBSD__) || defined(__APPLE__)
+ pid_t pid = -1;
+ socklen_t len = sizeof(pid);
+ rv = getsockopt(fd, SOL_SOCKET, LOCAL_PEERPID, &pid, &len);
+ if (rv != 0) {
+ goto err;
+ }
+ if (pid != getpid()) {
+ goto err;
+ }
+#else
  struct ucred cred;
  socklen_t len;
- int fd;
- fd = stream->io_watcher.fd;
  len = sizeof cred;
  rv = getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &cred, &len);
  if (rv != 0) {
@@ -443,6 +454,7 @@ static void listenCb(uv_stream_t *listener, int status)
  if (cred.pid != getpid()) {
  goto err;
  }
+#endif
  }
 
  conn = sqlite3_malloc(sizeof *conn);