(send_vc): Fix use of unaligned address. Properly handle partial reads.

diff --git a/resolv/res_send.c b/resolv/res_send.c
index 3130f64..59cdc21 100644 (file)
--- a/resolv/res_send.c
+++ b/resolv/res_send.c
@@ -734,11 +734,11 @@ send_vc(res_state statp,
         */
        int recvresp1 = 0;
        int recvresp2 = buf2 == NULL;
- read_len:
-       cp = ans;
        uint16_t rlen16;
+ read_len:
+       cp = (u_char *)&rlen16;
        len = sizeof(rlen16);
-       while ((n = TEMP_FAILURE_RETRY (read(statp->_vcsock, &rlen16,
+       while ((n = TEMP_FAILURE_RETRY (read(statp->_vcsock, cp,
                                             (int)len))) > 0) {
                cp += n;
                if ((len -= n) <= 0)
@@ -778,8 +778,16 @@ send_vc(res_state statp,
                        /* No buffer allocated for the first
                           reply.  We can try to use the rest
                           of the user-provided buffer.  */
+#ifdef _STRING_ARCH_unaligned
                        *anssizp2 = orig_anssizp - resplen;
                        *ansp2 = *ansp + resplen;
+#else
+                       int aligned_resplen
+                         = ((resplen + __alignof__ (HEADER) - 1)
+                            & (__alignof__ (HEADER) - 1));
+                       *anssizp2 = orig_anssizp - aligned_resplen;
+                       *ansp2 = *ansp + aligned_resplen;
+#endif
                } else {
                        /* The first reply did not fit into the
                           user-provided buffer.  Maybe the second