resolv: Fully initialize struct mmsghdr in send_dg [BZ #23037]

(cherry picked from commit 583a27d525ae189bdfaa6784021b92a9a1dae12e)

diff --git a/ChangeLog b/ChangeLog
index 27753462facf1a8d500992087a4719d341ede0e2..2a080bd816e37b153735057fcb2616c98997b8a1 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2018-04-09  Florian Weimer  <fweimer@redhat.com>
+
+       [BZ #23037]
+       * resolv/res_send.c (send_dg): Use designated initializers instead
+       of assignment to zero-initialize other fields of struct mmsghdr.
+
 2018-04-06  Andreas Schwab  <schwab@linux-m68k.org>
 
        * manual/charset.texi (Converting a Character): Fix typo.

diff --git a/resolv/res_send.c b/resolv/res_send.c
index 7debf143f7c26a98f02700a6ebdc1fd9a49538d0..9e9541789b2e6eab77d7aaf083c61a8d73948072 100644 (file)
--- a/resolv/res_send.c
+++ b/resolv/res_send.c
@@ -1157,25 +1157,27 @@ send_dg(res_state statp,
                if (have_sendmmsg >= 0 && nwritten == 0 && buf2 != NULL
                    && !single_request)
                  {
-                   struct iovec iov[2];
-                   struct mmsghdr reqs[2];
-                   reqs[0].msg_hdr.msg_name = NULL;
-                   reqs[0].msg_hdr.msg_namelen = 0;
-                   reqs[0].msg_hdr.msg_iov = &iov[0];
-                   reqs[0].msg_hdr.msg_iovlen = 1;
-                   iov[0].iov_base = (void *) buf;
-                   iov[0].iov_len = buflen;
-                   reqs[0].msg_hdr.msg_control = NULL;
-                   reqs[0].msg_hdr.msg_controllen = 0;
-
-                   reqs[1].msg_hdr.msg_name = NULL;
-                   reqs[1].msg_hdr.msg_namelen = 0;
-                   reqs[1].msg_hdr.msg_iov = &iov[1];
-                   reqs[1].msg_hdr.msg_iovlen = 1;
-                   iov[1].iov_base = (void *) buf2;
-                   iov[1].iov_len = buflen2;
-                   reqs[1].msg_hdr.msg_control = NULL;
-                   reqs[1].msg_hdr.msg_controllen = 0;
+                   struct iovec iov =
+                     { .iov_base = (void *) buf, .iov_len = buflen };
+                   struct iovec iov2 =
+                     { .iov_base = (void *) buf2, .iov_len = buflen2 };
+                   struct mmsghdr reqs[2] =
+                     {
+                       {
+                         .msg_hdr =
+                           {
+                             .msg_iov = &iov,
+                             .msg_iovlen = 1,
+                           },
+                       },
+                       {
+                         .msg_hdr =
+                           {
+                             .msg_iov = &iov2,
+                             .msg_iovlen = 1,
+                           }
+                       },
+                     };
 
                    int ndg = __sendmmsg (pfd[0].fd, reqs, 2, MSG_NOSIGNAL);
                    if (__glibc_likely (ndg == 2))