exec: unwatch and close sockets exactly once

diff --git a/backends/exec.c b/backends/exec.c
index fe3271905a101a3b23f721d915c55a093dd41ccc..a5313534c2e705aa35f4db10cd6f8fddc7391ea4 100644 (file)
--- a/backends/exec.c
+++ b/backends/exec.c
@@ -82,21 +82,18 @@ err_pipe1:
 static void
 send_stdin(netresolve_backend_t resolver, struct priv_exec *priv)
 {
-       ssize_t size;
-
-       if (priv->inbuf.start == priv->inbuf.end) {
-               netresolve_backend_watch_fd(resolver, priv->infd, 0);
-               return;
-       }
-       size = write(priv->infd, priv->inbuf.start, priv->inbuf.end - priv->inbuf.start);
-       if (size <= 0) {
-               abort();
+       if (priv->inbuf.start != priv->inbuf.end) {
+               ssize_t size = write(priv->infd, priv->inbuf.start, priv->inbuf.end - priv->inbuf.start);
+               if (size > 0) {
+                       priv->inbuf.start += size;
+                       return;
+               }
                debug("write failed: %s", strerror(errno));
-               netresolve_backend_failed(resolver);
-               return;
        }
-       priv->inbuf.start += size;
-       return;
+
+       netresolve_backend_watch_fd(resolver, priv->infd, 0);
+       close(priv->infd);
+       priv->infd = -1;
 }
 
 static bool
@@ -174,6 +171,9 @@ start(netresolve_backend_t resolver, char **settings)
 {
        struct priv_exec *priv = netresolve_backend_new_priv(resolver, sizeof *priv);
 
+       priv->infd = -1;
+       priv->outfd = -1;
+
        if (!priv || !start_subprocess(settings, &priv->pid, &priv->infd, &priv->outfd)) {
                netresolve_backend_failed(resolver);
                return;
@@ -212,10 +212,14 @@ cleanup(netresolve_backend_t resolver)
 {
        struct priv_exec *priv = netresolve_backend_get_priv(resolver);
 
-       netresolve_backend_watch_fd(resolver, priv->infd, 0);
-       netresolve_backend_watch_fd(resolver, priv->outfd, 0);
-       close(priv->infd);
-       close(priv->outfd);
+       if (priv->infd != -1) {
+               netresolve_backend_watch_fd(resolver, priv->infd, 0);
+               close(priv->infd);
+       }
+       if (priv->outfd != -1) {
+               netresolve_backend_watch_fd(resolver, priv->outfd, 0);
+               close(priv->outfd);
+       }
        /* TODO: Implement proper child handling. */
        kill(priv->pid, SIGKILL);
        free(priv->inbuf.buffer);