[network-manager-libreswan] service: check fcntl() return values

[Lubomir Rintel <lkundrak src gnome org>]

commit 28edbc133f786ae208167ce525017066df81dd01
Author: Lubomir Rintel <lkundrak v3 sk>
Date:   Tue Mar 8 13:38:16 2016 +0100

    service: check fcntl() return values
    
    CID 59905 (#2 of 4): Unchecked return value from library (CHECKED_RETURN)
    6. check_return: Calling fcntl(stdout_pipe[0], 4, 0x800 | md) without
    checking return value. This library function may fail and return an error
    code.

 src/nm-libreswan-service.c |   98 ++++++++++++++++++++++++++++++++++---------
 1 files changed, 77 insertions(+), 21 deletions(-)
---
diff --git a/src/nm-libreswan-service.c b/src/nm-libreswan-service.c
index 1228d65..c076f08 100644
--- a/src/nm-libreswan-service.c
+++ b/src/nm-libreswan-service.c
@@ -706,14 +706,83 @@ spawn_pty (NMLibreswanPlugin *self,
            const char *progname,
            ...)
 {
-       int pty_master_fd, md;
+       int pty_master_fd = 0;
        int stdout_pipe[2], stderr_pipe[2];
        pid_t child_pid;
        struct termios termios_flags;
        va_list ap;
        GPtrArray *argv;
        char *cmdline, *arg;
+       int ret;
 
+       /* The pipes */
+       pipe (stderr_pipe);
+       pipe (stdout_pipe);
+
+       /* Set the parent pipes non-blocking, so we can read big buffers
+        * in the callback without having to use FIONREAD
+        * to make sure the callback doesn't block.
+        */
+       ret = fcntl (stdout_pipe[0], F_GETFL);
+       if (ret == -1) {
+               g_set_error (error, NM_VPN_PLUGIN_ERROR, NM_VPN_PLUGIN_ERROR_LAUNCH_FAILED,
+                            "PTY spawn: F_GETFL on stdout failed (%d): %s",
+                            errno, g_strerror (errno));
+               goto badpipes;
+       }
+       ret = fcntl (stdout_pipe[0], F_SETFL, O_NONBLOCK | ret);
+       if (ret == -1) {
+               g_set_error (error, NM_VPN_PLUGIN_ERROR, NM_VPN_PLUGIN_ERROR_LAUNCH_FAILED,
+                            "PTY spawn: F_SETFL on stdout failed (%d): %s",
+                            errno, g_strerror (errno));
+               goto badpipes;
+       }
+       ret = fcntl (stderr_pipe[0], F_GETFL);
+       if (ret == -1) {
+               g_set_error (error, NM_VPN_PLUGIN_ERROR, NM_VPN_PLUGIN_ERROR_LAUNCH_FAILED,
+                            "PTY spawn: F_GETFL on stderr failed (%d): %s",
+                            errno, g_strerror (errno));
+               goto badpipes;
+       }
+       ret = fcntl (stderr_pipe[0], F_SETFL, O_NONBLOCK | ret);
+       if (ret == -1) {
+               g_set_error (error, NM_VPN_PLUGIN_ERROR, NM_VPN_PLUGIN_ERROR_LAUNCH_FAILED,
+                            "PTY spawn: F_SETFL on stderr failed (%d): %s",
+                            errno, g_strerror (errno));
+               goto badpipes;
+       }
+
+       /* Disable buffering of child writes */
+       ret = fcntl (stdout_pipe[1], F_GETFL);
+       if (ret == -1) {
+               g_set_error (error, NM_VPN_PLUGIN_ERROR, NM_VPN_PLUGIN_ERROR_LAUNCH_FAILED,
+                            "PTY spawn: F_GETFL on child stdout failed (%d): %s",
+                            errno, g_strerror (errno));
+               goto badpipes;
+       }
+       ret = fcntl (stdout_pipe[1], F_SETFL, O_SYNC | ret);
+       if (ret == -1) {
+               g_set_error (error, NM_VPN_PLUGIN_ERROR, NM_VPN_PLUGIN_ERROR_LAUNCH_FAILED,
+                            "PTY spawn: F_SETFL on child stdout failed (%d): %s",
+                            errno, g_strerror (errno));
+               goto badpipes;
+       }
+       ret = fcntl (stderr_pipe[1], F_GETFL);
+       if (ret == -1) {
+               g_set_error (error, NM_VPN_PLUGIN_ERROR, NM_VPN_PLUGIN_ERROR_LAUNCH_FAILED,
+                            "PTY spawn: F_GETFL on child stderr failed (%d): %s",
+                            errno, g_strerror (errno));
+               goto badpipes;
+       }
+       ret = fcntl (stderr_pipe[1], F_SETFL, O_SYNC | ret);
+       if (ret == -1) {
+               g_set_error (error, NM_VPN_PLUGIN_ERROR, NM_VPN_PLUGIN_ERROR_LAUNCH_FAILED,
+                            "PTY spawn: F_SETFL on child stderr failed (%d): %s",
+                            errno, g_strerror (errno));
+               goto badpipes;
+       }
+
+       /* The command line arguments */
        argv = g_ptr_array_sized_new (10);
        g_ptr_array_add (argv, (char *) progname);
 
@@ -729,10 +798,6 @@ spawn_pty (NMLibreswanPlugin *self,
                g_free (cmdline);
        }
 
-       /* The pipes */
-       pipe (stderr_pipe);
-       pipe (stdout_pipe);
-
        /* Fork the command */
        child_pid = forkpty (&pty_master_fd, NULL, NULL, NULL);
        if (child_pid == 0) {
@@ -747,11 +812,6 @@ spawn_pty (NMLibreswanPlugin *self,
                close (stderr_pipe[0]);
                close (stdout_pipe[0]);
 
-               if ((md = fcntl (stdout_pipe[1], F_GETFL)) != -1)
-                       fcntl (stdout_pipe[1], F_SETFL, O_SYNC | md);
-               if ((md = fcntl (stderr_pipe[1], F_GETFL)) != -1)
-                       fcntl (stderr_pipe[1], F_SETFL, O_SYNC | md);
-
                /* Ensure output is untranslated */
                setenv ("LC_ALL", "C", 1);
                setenv ("LANG", "C", 1);
@@ -777,17 +837,6 @@ spawn_pty (NMLibreswanPlugin *self,
        }
        g_ptr_array_free (argv, TRUE);
 
-       /*  Set pipes non-blocking, so we can read big buffers
-        *  in the callback without having to use FIONREAD
-        *  to make sure the callback doesn't block.
-        */
-       if ((md = fcntl (stdout_pipe[0], F_GETFL)) != -1)
-               fcntl (stdout_pipe[0], F_SETFL, O_NONBLOCK | md);
-       if ((md = fcntl (stderr_pipe[0], F_GETFL)) != -1)
-               fcntl (stderr_pipe[0], F_SETFL, O_NONBLOCK | md);
-       if ((md = fcntl (pty_master_fd, F_GETFL)) != -1)
-               fcntl (pty_master_fd, F_SETFL, O_NONBLOCK | md);
-
        tcgetattr (pty_master_fd, &termios_flags);
        cfmakeraw (&termios_flags);
        cfsetospeed (&termios_flags, __MAX_BAUD);
@@ -804,6 +853,13 @@ spawn_pty (NMLibreswanPlugin *self,
 
        block_quit (self);
        return TRUE;
+
+badpipes:
+       close (stderr_pipe[0]);
+       close (stdout_pipe[0]);
+       close (stderr_pipe[1]);
+       close (stdout_pipe[1]);
+       return FALSE;
 }
 
 /****************************************************************/