make sure that all error paths are correctly handled in asr_run_sync()

and that the result is always properly set when the functions returns.
fix issues spotted by claudio@.

ok claudio@

diff --git a/lib/libc/asr/asr.c b/lib/libc/asr/asr.c
index d5601e5..c73c985 100644 (file)
--- a/lib/libc/asr/asr.c
+++ b/lib/libc/asr/asr.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: asr.c,v 1.57 2017/02/27 10:44:46 jca Exp $    */
+/*     $OpenBSD: asr.c,v 1.58 2018/02/06 13:00:48 eric Exp $   */
 /*
  * Copyright (c) 2010-2012 Eric Faurot <eric@openbsd.org>
  *
@@ -165,32 +165,47 @@ DEF_WEAK(asr_run);
 /*
  * Same as above, but run in a loop that handles the fd conditions result.
  */
+
+static int
+poll_intrsafe(struct pollfd *fds, nfds_t nfds, int timeout)
+{
+       struct timespec pollstart, pollend, elapsed;
+       int r;
+
+       if (clock_gettime(CLOCK_MONOTONIC, &pollstart))
+               return -1;
+
+       while ((r = poll(fds, 1, timeout)) == -1 && errno == EINTR) {
+               if (clock_gettime(CLOCK_MONOTONIC, &pollend))
+                       return -1;
+               timespecsub(&pollend, &pollstart, &elapsed);
+               timeout -= elapsed.tv_sec * 1000 + elapsed.tv_nsec / 1000000;
+               if (timeout < 1)
+                       return 0;
+       }
+
+       return r;
+}
+
 int
 asr_run_sync(struct asr_query *as, struct asr_result *ar)
 {
        struct pollfd    fds[1];
-       struct timespec  pollstart, pollend, elapsed;
-       int              timeout, r, p, saved_errno = errno;
+       int              r, saved_errno = errno;
 
        while ((r = asr_run(as, ar)) == ASYNC_COND) {
                fds[0].fd = ar->ar_fd;
                fds[0].events = (ar->ar_cond == ASR_WANT_READ) ? POLLIN:POLLOUT;
 
-               timeout = ar->ar_timeout;
-       again:
-               if (clock_gettime(CLOCK_MONOTONIC, &pollstart))
-                       break;
-               p = poll(fds, 1, timeout);
-               if (p == -1 && errno == EINTR) {
-                       if (clock_gettime(CLOCK_MONOTONIC, &pollend))
-                               break;
-
-                       timespecsub(&pollend, &pollstart, &elapsed);
-                       timeout -= (elapsed.tv_sec * 1000) +
-                           (elapsed.tv_nsec / 1000000);
-                       if (timeout < 1)
-                               break;
-                       goto again;
+               if (poll_intrsafe(fds, 1, ar->ar_timeout) == -1) {
+                       memset(ar, 0, sizeof(*ar));
+                       ar->ar_errno = errno;
+                       ar->ar_h_errno = NETDB_INTERNAL;
+                       ar->ar_gai_errno = EAI_SYSTEM;
+                       ar->ar_rrset_errno = NETDB_INTERNAL;
+                       _asr_async_free(as);
+                       errno = saved_errno;
+                       return ASYNC_DONE;
                }
 
                /*