Fix: set FD_CLOEXEC on incoming FDs.

[lttng-ust.git] / liblttng-ust-comm / lttng-ust-comm.c

diff --git a/liblttng-ust-comm/lttng-ust-comm.c b/liblttng-ust-comm/lttng-ust-comm.c
index 9f2bdd5b3f80b650c04bbb6cb5ff37af74317880..814ccde17954b82200242e4ec03304907c2fac5c 100644 (file)
--- a/liblttng-ust-comm/lttng-ust-comm.c
+++ b/liblttng-ust-comm/lttng-ust-comm.c
@@ -107,6 +107,7 @@ int ustcomm_connect_unix_sock(const char *pathname, long timeout)
        /*
         * libust threads require the close-on-exec flag for all
         * resources so it does not leak file descriptors upon exec.
+        * SOCK_CLOEXEC is not used since it is linux specific.
         */
        fd = socket(PF_UNIX, SOCK_STREAM, 0);
        if (fd < 0) {
@@ -439,8 +440,6 @@ ssize_t ustcomm_send_fds_unix_sock(int sock, int *fds, size_t nb_fd)
 /*
  * Recv a message accompanied by fd(s) from a unix socket.
  *
- * Returns the size of received data, or negative error value.
- *
  * Expect at most "nb_fd" file descriptors. Returns the number of fd
  * actually received in nb_fd.
  * Returns -EPIPE on orderly shutdown.
@@ -454,6 +453,7 @@ ssize_t ustcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd)
        char recv_fd[CMSG_SPACE(sizeof_fds)];
        struct msghdr msg;
        char dummy;
+       int i;
 
        memset(&msg, 0, sizeof(msg));
 
@@ -509,8 +509,19 @@ ssize_t ustcomm_recv_fds_unix_sock(int sock, int *fds, size_t nb_fd)
                ret = -1;
                goto end;
        }
+
        memcpy(fds, CMSG_DATA(cmsg), sizeof_fds);
-       ret = sizeof_fds;
+
+       /* Set FD_CLOEXEC */
+       for (i = 0; i < nb_fd; i++) {
+               ret = fcntl(fds[i], F_SETFD, FD_CLOEXEC);
+               if (ret < 0) {
+                       PERROR("fcntl failed to set FD_CLOEXEC on fd %d",
+                              fds[i]);
+               }
+       }
+
+       ret = nb_fd;
 end:
        return ret;
 }