uuidd: Fix warn_unused_result warnings from gcc

Fixed a potential bug caused by partial returns from the write system
call (especially possible for network connections).

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/misc/uuidd.c b/misc/uuidd.c
index 3a855bc..e2d3656 100644 (file)
--- a/misc/uuidd.c
+++ b/misc/uuidd.c
@@ -78,7 +78,7 @@ static void create_daemon(void)
        open("/dev/null", O_RDWR);
        open("/dev/null", O_RDWR);
 
-       chdir("/");
+       if (chdir("/")) {}      /* Silence warn_unused_result warning */
        (void) setsid();
        euid = geteuid();
        if (setreuid(euid, euid) < 0)
@@ -105,6 +105,25 @@ static int read_all(int fd, char *buf, size_t count)
        return c;
 }
 
+static int write_all(int fd, char *buf, size_t count)
+{
+       ssize_t ret;
+       int c = 0;
+
+       while (count > 0) {
+               ret = write(fd, buf, count);
+               if (ret < 0) {
+                       if ((errno == EAGAIN) || (errno == EINTR))
+                               continue;
+                       return -1;
+               }
+               count -= ret;
+               buf += ret;
+               c += ret;
+       }
+       return c;
+}
+
 static const char *cleanup_pidfile, *cleanup_socket;
 
 static void terminate_intr(int signo CODE_ATTR((unused)))
@@ -161,7 +180,7 @@ static int call_daemon(const char *socket_path, int op, char *buf,
                op_len += sizeof(int);
        }
 
-       ret = write(s, op_buf, op_len);
+       ret = write_all(s, op_buf, op_len);
        if (ret < op_len) {
                if (err_context)
                        *err_context = _("write");
@@ -291,9 +310,9 @@ static void server_loop(const char *socket_path, const char *pidfile_path,
        signal(SIGALRM, terminate_intr);
        signal(SIGPIPE, SIG_IGN);
 
-       sprintf(reply_buf, "%d\n", getpid());
-       ftruncate(fd_pidfile, 0);
-       write(fd_pidfile, reply_buf, strlen(reply_buf));
+       sprintf(reply_buf, "%8d\n", getpid());
+       if (ftruncate(fd_pidfile, 0)) {} /* Silence warn_unused_result */
+       write_all(fd_pidfile, reply_buf, strlen(reply_buf));
        if (fd_pidfile > 1)
                close(fd_pidfile); /* Unlock the pid file */
 
@@ -393,8 +412,8 @@ static void server_loop(const char *socket_path, const char *pidfile_path,
                                printf(_("Invalid operation %d\n"), op);
                        goto shutdown_socket;
                }
-               write(ns, &reply_len, sizeof(reply_len));
-               write(ns, reply_buf, reply_len);
+               write_all(ns, (char *) &reply_len, sizeof(reply_len));
+               write_all(ns, reply_buf, reply_len);
        shutdown_socket:
                close(ns);
        }