Commit 89382c3d authored by Knut Omang's avatar Knut Omang Committed by Daniel P. Berrangé
Browse files

sockets: factor out a new try_bind() function 



A refactoring step to prepare for the problem
exposed by the test-listen test in the previous commit.

Simplify and reorganize the IPv6 specific extra
measures and move it out of the for loop to increase
code readability. No semantic changes.

Signed-off-by: default avatarKnut Omang <knut.omang@oracle.com>
Reviewed-by: default avatarDaniel P. Berrange <berrange@redhat.com>
Signed-off-by: default avatarDaniel P. Berrange <berrange@redhat.com>
parent 79b2a13a

util/qemu-sockets.c

+39 −30
Original line number Diff line number Diff line
@@ -149,6 +149,44 @@ int inet_ai_family_from_address(InetSocketAddress *addr, 
    return PF_UNSPEC;

}



static int try_bind(int socket, InetSocketAddress *saddr, struct addrinfo *e)

{

#ifndef IPV6_V6ONLY

    return bind(socket, e->ai_addr, e->ai_addrlen);

#else

    /*

     * Deals with first & last cases in matrix in comment

     * for inet_ai_family_from_address().

     */

    int v6only =

        ((!saddr->has_ipv4 && !saddr->has_ipv6) ||

         (saddr->has_ipv4 && saddr->ipv4 &&

          saddr->has_ipv6 && saddr->ipv6)) ? 0 : 1;

    int stat;



 rebind:

    if (e->ai_family == PF_INET6) {

        qemu_setsockopt(socket, IPPROTO_IPV6, IPV6_V6ONLY, &v6only,

                        sizeof(v6only));

    }



    stat = bind(socket, e->ai_addr, e->ai_addrlen);

    if (!stat) {

        return 0;

    }



    /* If we got EADDRINUSE from an IPv6 bind & v6only is unset,

     * it could be that the IPv4 port is already claimed, so retry

     * with v6only set

     */

    if (e->ai_family == PF_INET6 && errno == EADDRINUSE && !v6only) {

        v6only = 1;

        goto rebind;

    }

    return stat;

#endif

}



static int inet_listen_saddr(InetSocketAddress *saddr,

                             int port_offset,

                             bool update_addr,
@@ -228,39 +266,10 @@ static int inet_listen_saddr(InetSocketAddress *saddr, 
        port_min = inet_getport(e);

        port_max = saddr->has_to ? saddr->to + port_offset : port_min;

        for (p = port_min; p <= port_max; p++) {

#ifdef IPV6_V6ONLY

            /*

             * Deals with first & last cases in matrix in comment

             * for inet_ai_family_from_address().

             */

            int v6only =

                ((!saddr->has_ipv4 && !saddr->has_ipv6) ||

                 (saddr->has_ipv4 && saddr->ipv4 &&

                  saddr->has_ipv6 && saddr->ipv6)) ? 0 : 1;

#endif

            inet_setport(e, p);

#ifdef IPV6_V6ONLY

        rebind:

            if (e->ai_family == PF_INET6) {

                qemu_setsockopt(slisten, IPPROTO_IPV6, IPV6_V6ONLY, &v6only,

                                sizeof(v6only));

            }

#endif

            if (bind(slisten, e->ai_addr, e->ai_addrlen) == 0) {

            if (try_bind(slisten, saddr, e) >= 0) {

                goto listen;

            }



#ifdef IPV6_V6ONLY

            /* If we got EADDRINUSE from an IPv6 bind & V6ONLY is unset,

             * it could be that the IPv4 port is already claimed, so retry

             * with V6ONLY set

             */

            if (e->ai_family == PF_INET6 && errno == EADDRINUSE && !v6only) {

                v6only = 1;

                goto rebind;

            }

#endif



            if (p == port_max) {

                if (!e->ai_next) {

                    error_setg_errno(errp, errno, "Failed to bind socket");