commit 212a5c5b3bf2a8b5915e6ae151a104f3ae30bbd2
author Joshua Conner <joshconner@google.com> Fri Jan 18 09:41:40 2019 -0800
committer CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org> Fri Jan 18 23:39:48 2019 +0000
tree 20c95a1b4e33e18dd9afd64fa24f4c427319014b
parent 5c4a92a12f796cddc36f1b18ce7dddeb6494251e

[netprotocol] Remove spurious errors

When querying for devices, don't print an error for every interface
failure. Instead, print an error if *all* interfaces fail.

ZX-3244
PT-89

Test: Ran fx shell and fx traceutil on a system that was failing
      with symptoms described in bugs.
Change-Id: I6af656a4fcf8ce485fcccf7832f27445d51c206a

system/host/netprotocol/netprotocol.c

diff --git a/system/host/netprotocol/netprotocol.c b/system/host/netprotocol/netprotocol.c
index dda3774..e87fbe7 100644
--- a/system/host/netprotocol/netprotocol.c
+++ b/system/host/netprotocol/netprotocol.c
@@ -91,6 +91,8 @@
         return -1;
     }
 
+    bool success = false;
+
     for (; ifa != NULL; ifa = ifa->ifa_next) {
         if (ifa->ifa_addr == NULL) {
             continue;
@@ -102,21 +104,25 @@
         if (in6->sin6_scope_id == 0) {
             continue;
         }
-        if (ifname && ifname[0] != 0 && strcmp(ifname, ifa->ifa_name))
+        if (ifname && ifname[0] != 0 && strcmp(ifname, ifa->ifa_name)) {
             continue;
+        }
         // printf("tx %s (sid=%d)\n", ifa->ifa_name, in6->sin6_scope_id);
         size_t sz = sizeof(nbmsg) + hostname_len;
         addr.sin6_scope_id = in6->sin6_scope_id;
 
         ssize_t r = sendto(socket, &m, sz, 0,
                            (struct sockaddr*)&addr, sizeof(addr));
-        if (r < 0) {
-            fprintf(stderr, "error: sendto: %s\n", strerror(errno));
-        } else if ((size_t)r != sz) {
-            fprintf(stderr, "error: sendto: short count %zu != %zu\n", r, sz);
+        if ((r >= 0) && (size_t)r == sz) {
+            success = true;
         }
     }
 
+    if (!success) {
+        fprintf(stderr, "error: failed to find interface for sending query\n");
+        return -1;
+    }
+
     return 0;
 }