nbd-server: treat accept errors as non-fatal

On Sun, Jun 24, 2012 at 01:31:28AM +0200, Wouter Verhelst wrote:
> On Fri, Jun 22, 2012 at 01:40:48AM +0400, Dmitry V. Levin wrote:
> > In most cases, an error returned by accept system call is a network
> > error, which should not terminate the whole nbd-server.
>
> Yes, that's a leftover from the days when nbd-server ran in
> one-process-per-export mode (i.e., the 2.7 days). Oops.

Then there is at least one more issue of this kind:

>From a2e158154fd743fb039e0823736774804a9645ac Mon Sep 17 00:00:00 2001
From: "Dmitry V. Levin" <ldv@altlinux.org>
Date: Sun, 24 Jun 2012 22:40:54 +0000
Subject: [PATCH] nbd-server: treat getpeername errors as non-fatal

In most cases, an error returned by getpeername system call is a network
error, which should not terminate the whole nbd-server.

diff --git a/nbd-server.c b/nbd-server.c
index fc5ae2d..49822a7 100644 (file)
--- a/nbd-server.c
+++ b/nbd-server.c
@@ -2055,8 +2055,9 @@ void serveconnection(CLIENT *client) {
  * @param client information about the client. The IP address in human-readable
  * format will be written to a new char* buffer, the address of which will be
  * stored in client->clientname.
+ * @return: 0 - OK, -1 - failed.
  **/
-void set_peername(int net, CLIENT *client) {
+int set_peername(int net, CLIENT *client) {
        struct sockaddr_storage addrin;
        struct sockaddr_storage netaddr;
        struct sockaddr_in  *netaddr4 = NULL;
@@ -2071,13 +2072,15 @@ void set_peername(int net, CLIENT *client) {
        int e;
        int shift;
 
-       if (getpeername(net, (struct sockaddr *) &addrin, &addrinlen) < 0)
-               err("getpeername failed: %m");
+       if (getpeername(net, (struct sockaddr *) &addrin, &addrinlen) < 0) {
+               msg2(LOG_INFO, "getpeername failed: %m");
+               return -1;
+       }
 
        if((e = getnameinfo((struct sockaddr *)&addrin, addrinlen,
                        peername, sizeof (peername), NULL, 0, NI_NUMERICHOST))) {
                msg3(LOG_INFO, "getnameinfo failed: %s", gai_strerror(e));
-               freeaddrinfo(ai);
+               return -1;
        }
 
        memset(&hints, '\0', sizeof (hints));
@@ -2087,7 +2090,7 @@ void set_peername(int net, CLIENT *client) {
        if(e != 0) {
                msg3(LOG_INFO, "getaddrinfo failed: %s", gai_strerror(e));
                freeaddrinfo(ai);
-               return;
+               return -1;
        }
 
        switch(client->server->virtstyle) {
@@ -2145,6 +2148,7 @@ void set_peername(int net, CLIENT *client) {
        msg4(LOG_INFO, "connect from %s, assigned file is %s", 
             peername, client->exportname);
        client->clientname=g_strdup(peername);
+       return 0;
 }
 
 /**
@@ -2181,7 +2185,9 @@ handle_connection(GArray *servers, int net, SERVER *serve, CLIENT *client)
                client->net=net;
                client->transactionlogfd = -1;
        }
-       set_peername(net, client);
+       if (set_peername(net, client)) {
+               goto handle_connection_out;
+       }
        if (!authorized_client(client)) {
                msg2(LOG_INFO,"Unauthorized client") ;
                goto handle_connection_out;
@@ -2626,7 +2632,8 @@ int main(int argc, char *argv[]) {
                        client->server=serve;
                        client->net=-1;
                        client->exportsize=OFFT_MAX;
-                       set_peername(0,client);
+                       if (set_peername(0, client))
+                               exit(EXIT_FAILURE);
                        serveconnection(client);
                        return 0;
                }