MINOR: backend: Get client dst address to set the server's one only if needful

In alloc_dst_address(), the client destination address must only be
retrieved when we are sure to use it. Most of time, this save a syscall to
getsockname(). It is not a bugfix in itself. But it revealed a bug in the
QUIC part. The CO_FL_ADDR_TO_SET flag is not set when the destination
address is create for anew quic client connection.

diff --git a/src/backend.c b/src/backend.c
index 27cb58833fb307e4346bd9aca3790b665f3b6d7b..2d2c0d6e093d4373de623fa80ceca2e1d236b596 100644 (file)
--- a/src/backend.c
+++ b/src/backend.c
@@ -846,18 +846,18 @@ static int alloc_dst_address(struct sockaddr_storage **ss,
 
                **ss = srv->addr;
                set_host_port(*ss, srv->svc_port);
-               dst = si_dst(&s->si[0]);
-               if (!is_addr(*ss) && dst) {
+               if (!is_addr(*ss)) {
                        /* if the server has no address, we use the same address
                         * the client asked, which is handy for remapping ports
                         * locally on multiple addresses at once. Nothing is done
                         * for AF_UNIX addresses.
                         */
-                       if (dst->ss_family == AF_INET) {
+                       dst = si_dst(&s->si[0]);
+                       if (dst && dst->ss_family == AF_INET) {
                                ((struct sockaddr_in *)*ss)->sin_family = AF_INET;
                                ((struct sockaddr_in *)*ss)->sin_addr =
                                  ((struct sockaddr_in *)dst)->sin_addr;
-                       } else if (dst->ss_family == AF_INET6) {
+                       } else if (dst && dst->ss_family == AF_INET6) {
                                ((struct sockaddr_in6 *)*ss)->sin6_family = AF_INET6;
                                ((struct sockaddr_in6 *)*ss)->sin6_addr =
                                  ((struct sockaddr_in6 *)dst)->sin6_addr;
@@ -866,15 +866,18 @@ static int alloc_dst_address(struct sockaddr_storage **ss,
 
                /* if this server remaps proxied ports, we'll use
                 * the port the client connected to with an offset. */
-               if ((srv->flags & SRV_F_MAPPORTS) && dst) {
+               if ((srv->flags & SRV_F_MAPPORTS)) {
                        int base_port;
 
-                       /* First, retrieve the port from the incoming connection */
-                       base_port = get_host_port(dst);
+                       dst = si_dst(&s->si[0]);
+                       if (dst) {
+                               /* First, retrieve the port from the incoming connection */
+                               base_port = get_host_port(dst);
 
-                       /* Second, assign the outgoing connection's port */
-                       base_port += get_host_port(*ss);
-                       set_host_port(*ss, base_port);
+                               /* Second, assign the outgoing connection's port */
+                               base_port += get_host_port(*ss);
+                               set_host_port(*ss, base_port);
+                       }
                }
        }
        else if (s->be->options & PR_O_DISPATCH) {
@@ -885,12 +888,12 @@ static int alloc_dst_address(struct sockaddr_storage **ss,
                **ss = s->be->dispatch_addr;
        }
        else if ((s->be->options & PR_O_TRANSP)) {
-               dst = si_dst(&s->si[0]);
-               if (!dst || !sockaddr_alloc(ss, NULL, 0))
+               if (!sockaddr_alloc(ss, NULL, 0))
                        return SRV_STATUS_INTERNAL;
 
                /* in transparent mode, use the original dest addr if no dispatch specified */
-               if ((dst->ss_family == AF_INET || dst->ss_family == AF_INET6))
+               dst = si_dst(&s->si[0]);
+               if (dst && (dst->ss_family == AF_INET || dst->ss_family == AF_INET6))
                        **ss = *dst;
        }
        else {