From 89382c3de5bc2250b1dad1c42c1f73d5ec6febda Mon Sep 17 00:00:00 2001 From: Knut Omang Date: Mon, 7 Aug 2017 12:58:40 +0200 Subject: 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: Knut Omang Reviewed-by: Daniel P. Berrange Signed-off-by: Daniel P. Berrange --- util/qemu-sockets.c | 69 ++++++++++++++++++++++++++++++----------------------- 1 file changed, 39 insertions(+), 30 deletions(-) (limited to 'util') diff --git a/util/qemu-sockets.c b/util/qemu-sockets.c index d149383bb9..211ebadcec 100644 --- a/util/qemu-sockets.c +++ b/util/qemu-sockets.c @@ -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"); -- cgit v1.2.3-55-g7522