[network-manager-libreswan] service: add missing error checking

[Lubomir Rintel <lkundrak src gnome org>]

commit 120f6ba840cd195d09bbb9ae5abc86ff61761bed
Author: Lubomir Rintel <lkundrak v3 sk>
Date:   Fri Mar 18 15:43:04 2016 +0100

    service: add missing error checking
    
    Fixes compiler warnings.

 src/nm-libreswan-service.c |   34 +++++++++++++++++++++++++++-------
 1 files changed, 27 insertions(+), 7 deletions(-)
---
diff --git a/src/nm-libreswan-service.c b/src/nm-libreswan-service.c
index ffaf192..156db7f 100644
--- a/src/nm-libreswan-service.c
+++ b/src/nm-libreswan-service.c
@@ -724,8 +724,20 @@ spawn_pty (NMLibreswanPlugin *self,
        int ret;
 
        /* The pipes */
-       pipe (stderr_pipe);
-       pipe (stdout_pipe);
+       if (pipe (stdout_pipe) == -1) {
+               g_set_error (error, NM_VPN_PLUGIN_ERROR, NM_VPN_PLUGIN_ERROR_LAUNCH_FAILED,
+                            "PTY spawn: failed to create a stdout pipe (%d): %s",
+                            errno, g_strerror (errno));
+               return FALSE;
+       }
+       if (pipe (stderr_pipe) == -1) {
+               g_set_error (error, NM_VPN_PLUGIN_ERROR, NM_VPN_PLUGIN_ERROR_LAUNCH_FAILED,
+                            "PTY spawn: failed to create a stderr pipe (%d): %s",
+                            errno, g_strerror (errno));
+               close (stdout_pipe[0]);
+               close (stdout_pipe[1]);
+               return FALSE;
+       }
 
        /* Set the parent pipes non-blocking, so we can read big buffers
         * in the callback without having to use FIONREAD
@@ -811,10 +823,14 @@ spawn_pty (NMLibreswanPlugin *self,
        if (child_pid == 0) {
                /* in the child */
 
-               close (2);
-               dup (stderr_pipe[1]);
-               close (1);
-               dup (stdout_pipe[1]);
+               if (dup2 (stdout_pipe[1], 1) == -1) {
+                       g_error ("PTY spawn: cannot dup stdout (%d): %s.", errno, g_strerror (errno));
+                       _exit (-1);
+               }
+               if (dup2 (stderr_pipe[1], 2) == -1) {
+                       g_error ("PTY spawn: cannot dup stderr (%d): %s.", errno, g_strerror (errno));
+                       _exit (-1);
+               }
 
                /* Close unnecessary pipes */
                close (stderr_pipe[0]);
@@ -825,7 +841,11 @@ spawn_pty (NMLibreswanPlugin *self,
                setenv ("LANG", "C", 1);
 
                execv (argv->pdata[0], (char * const*) argv->pdata);
-               g_error ("PTY spawn: cannot exec '%s'", (char *) argv->pdata[0]);
+
+               /* This is probably a rather futile attempt to produce an error message
+                * as it goes to the piped stderr. */
+               g_error ("PTY spawn: cannot exec '%s' (%d): %s", (char *) argv->pdata[0],
+                        errno, g_strerror (errno));
                _exit (-1);
        }