From 82aed1dee6c5ea8ce122c20712b9778b656ee9e6 Mon Sep 17 00:00:00 2001 From: Luca Boccassi Date: Wed, 6 Apr 2016 17:15:39 +0100 Subject: [PATCH 1/4] Problem: zmq_bind IPv4 fallback still tries IPv6 Solution: if opening an IPv6 TCP socket fails because IPv6 is not available, try to open an IPv4 socket instead when creating and binding a TCP endpoint. --- src/tcp_listener.cpp | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/src/tcp_listener.cpp b/src/tcp_listener.cpp index 05171b35..be9ab7d8 100644 --- a/src/tcp_listener.cpp +++ b/src/tcp_listener.cpp @@ -173,13 +173,13 @@ int zmq::tcp_listener_t::set_address (const char *addr_) #endif // IPv6 address family not supported, try automatic downgrade to IPv4. - if (address.family () == AF_INET6 + if (s == -1 && address.family () == AF_INET6 && errno == EAFNOSUPPORT && options.ipv6) { - rc = address.resolve (addr_, true, true); + rc = address.resolve (addr_, true, false); if (rc != 0) return rc; - s = ::socket (address.family (), SOCK_STREAM, IPPROTO_TCP); + s = open_socket (AF_INET, SOCK_STREAM, IPPROTO_TCP); } #ifdef ZMQ_HAVE_WINDOWS From 1e87d9252782423885f569a789714966c237b61f Mon Sep 17 00:00:00 2001 From: Luca Boccassi Date: Thu, 7 Apr 2016 13:15:41 +0100 Subject: [PATCH 2/4] Problem: zmq_connect (TCP) has no IPv4 fallback Solution: if opening an IPv6 TCP socket fails because IPv6 is not available, try to open an IPv4 socket instead when creating and connecting a TCP endpoint. --- src/tcp_connecter.cpp | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/src/tcp_connecter.cpp b/src/tcp_connecter.cpp index fdbc45c2..75c049e9 100644 --- a/src/tcp_connecter.cpp +++ b/src/tcp_connecter.cpp @@ -235,6 +235,21 @@ int zmq::tcp_connecter_t::open () // Create the socket. s = open_socket (tcp_addr->family (), SOCK_STREAM, IPPROTO_TCP); + + // IPv6 address family not supported, try automatic downgrade to IPv4. + if (s == -1 && tcp_addr->family () == AF_INET6 + && errno == EAFNOSUPPORT + && options.ipv6) { + rc = addr->resolved.tcp_addr->resolve ( + addr->address.c_str (), false, false); + if (rc != 0) { + delete addr->resolved.tcp_addr; + addr->resolved.tcp_addr = NULL; + return -1; + } + s = open_socket (AF_INET, SOCK_STREAM, IPPROTO_TCP); + } + #ifdef ZMQ_HAVE_WINDOWS if (s == INVALID_SOCKET) { errno = wsa_error_to_errno (WSAGetLastError ()); From 1a1abe3d5eacd3aa8bc50219383f532e39c080b6 Mon Sep 17 00:00:00 2001 From: Luca Boccassi Date: Thu, 7 Apr 2016 13:17:08 +0100 Subject: [PATCH 3/4] Problem: redundant Windows errno conversion Solution: in the Windows-specific ifdef in tcp_listener set_address, check for error and set errno only after the IPv4 fallback has failed too, to avoid setting errno when the socket creation succeeds through the fallback. --- src/tcp_listener.cpp | 4 ---- 1 file changed, 4 deletions(-) diff --git a/src/tcp_listener.cpp b/src/tcp_listener.cpp index be9ab7d8..4e283c95 100644 --- a/src/tcp_listener.cpp +++ b/src/tcp_listener.cpp @@ -167,10 +167,6 @@ int zmq::tcp_listener_t::set_address (const char *addr_) // Create a listening socket. s = open_socket (address.family (), SOCK_STREAM, IPPROTO_TCP); -#ifdef ZMQ_HAVE_WINDOWS - if (s == INVALID_SOCKET) - errno = wsa_error_to_errno (WSAGetLastError ()); -#endif // IPv6 address family not supported, try automatic downgrade to IPv4. if (s == -1 && address.family () == AF_INET6 From 6d92d263e13fd00c5170274f8dd4ab92d8324cb5 Mon Sep 17 00:00:00 2001 From: Luca Boccassi Date: Thu, 7 Apr 2016 17:10:52 +0100 Subject: [PATCH 4/4] Update NEWS for fix #1887 --- NEWS | 2 ++ 1 file changed, 2 insertions(+) diff --git a/NEWS b/NEWS index 7576ba07..11f6dcb0 100644 --- a/NEWS +++ b/NEWS @@ -17,6 +17,8 @@ * Fixed #1877 - Avoid terminating connections prematurely +* Fixed #1887 - zmq_bind IPv4 fallback still tries IPv6 + 0MQ version 4.1.4 stable, released on 2015/12/18 ================================================