[libvirt] [PATCH 1/2] socket: preserve real errno when socket/bind calls fail

[Daniel P. Berrangé]

When reporting socket/bind failures we want to ensure any fatal error
reported is as accurate as possible. We'll prefer reporting a bind()
errno over a socket() errno, because if socket() works but bind() fails
that is a more significant event.

Signed-off-by: Daniel P. Berrangé <berrange at redhat.com>
---
 src/rpc/virnetsocket.c | 24 ++++++++++++------------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/src/rpc/virnetsocket.c b/src/rpc/virnetsocket.c
index fee61ace60..8e04d61e98 100644
--- a/src/rpc/virnetsocket.c
+++ b/src/rpc/virnetsocket.c
@@ -310,8 +310,8 @@ int virNetSocketNewListenTCP(const char *nodename,
     struct addrinfo hints;
     int fd = -1;
     size_t i;
-    bool addrInUse = false;
-    bool familyNotSupported = false;
+    int socketErrno = 0;
+    int bindErrno = 0;
     virSocketAddr tmp_addr;
 
     *retsocks = NULL;
@@ -351,7 +351,7 @@ int virNetSocketNewListenTCP(const char *nodename,
         if ((fd = socket(runp->ai_family, runp->ai_socktype,
                          runp->ai_protocol)) < 0) {
             if (errno == EAFNOSUPPORT) {
-                familyNotSupported = true;
+                socketErrno = errno;
                 runp = runp->ai_next;
                 continue;
             }
@@ -386,7 +386,7 @@ int virNetSocketNewListenTCP(const char *nodename,
                 virReportSystemError(errno, "%s", _("Unable to bind to port"));
                 goto error;
             }
-            addrInUse = true;
+            bindErrno = errno;
             VIR_FORCE_CLOSE(fd);
             runp = runp->ai_next;
             continue;
@@ -409,14 +409,14 @@ int virNetSocketNewListenTCP(const char *nodename,
         fd = -1;
     }
 
-    if (nsocks == 0 && familyNotSupported) {
-        virReportSystemError(EAFNOSUPPORT, "%s", _("Unable to bind to port"));
-        goto error;
-    }
-
-    if (nsocks == 0 &&
-        addrInUse) {
-        virReportSystemError(EADDRINUSE, "%s", _("Unable to bind to port"));
+    if (nsocks == 0) {
+        if (bindErrno) {
+            virReportSystemError(bindErrno, "%s", _("Unable to bind to port"));
+        } else if (socketErrno) {
+            virReportSystemError(socketErrno, "%s", _("Unable to create socket"));
+        } else {
+            virReportError(VIR_ERR_INTERNAL_ERROR, "%s", _("No addresses to bind to"));
+        }
         goto error;
     }
 
-- 
2.17.1