From: Gert Doering Date: Tue, 15 Sep 2020 09:41:01 +0000 (+0200) Subject: Fix netbits setting (in TAP mode) for IPv6 on Windows. X-Git-Tag: v2.6_beta1~695 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=81b6a7e75b343e324a44b4476c89c596d7b6c74b;p=thirdparty%2Fopenvpn.git Fix netbits setting (in TAP mode) for IPv6 on Windows. For TUN interfaces, the IPv6 address needs to be configured with "address/128" and a local subnet route is needed, pointing to our fake gateway fe80::8. There is no ethernet headers or ND outside the tun/tap interface, so anything but fe80::8 is not resolvable. For TAP interfaces, the proper subnet mask (netbits) must be configured, and no connected route to "our local host address" must be configured, to make make IPv6 ND work inside the local subnet. Our code was nicely consistent in doing the same thing in tun.c ("gui/openvpn running with admin privileges") and in the requests to the interactive service ("gui running with user privs"). Fix in both places. On tun close, symmetric to addition, remove the on-link subnet route only for "tun" interfaces. Address removal works without specifying netbits. While at it, extend do_address_service() to actually log both IPv4 and IPv6 addresses requested via it. Tested on Win10/64. v2: - change logging to use D_IFCONFIG - fix whitespace on "?" operator Reported-By: Laurent Fasnacht Reported-By: Klara Mall Trac: #1054 Signed-off-by: Gert Doering Acked-by: Lev Stipakov Message-Id: <20200915094101.86470-1-gert@greenie.muc.de> URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg21008.html Signed-off-by: Gert Doering --- diff --git a/src/openvpn/errlevel.h b/src/openvpn/errlevel.h index e448fc370..5663f8414 100644 --- a/src/openvpn/errlevel.h +++ b/src/openvpn/errlevel.h @@ -91,6 +91,7 @@ #define D_OSBUF LOGLEV(3, 43, 0) /* show socket/tun/tap buffer sizes */ #define D_PS_PROXY LOGLEV(3, 44, 0) /* messages related to --port-share option */ #define D_PF_INFO LOGLEV(3, 45, 0) /* packet filter informational messages */ +#define D_IFCONFIG LOGLEV(3, 0, 0) /* show ifconfig info (don't mute) */ #define D_SHOW_PARMS LOGLEV(4, 50, 0) /* show all parameters on program initiation */ #define D_SHOW_OCC LOGLEV(4, 51, 0) /* show options compatibility string */ diff --git a/src/openvpn/tun.c b/src/openvpn/tun.c index 651cb8717..ef9f173c8 100644 --- a/src/openvpn/tun.c +++ b/src/openvpn/tun.c @@ -115,11 +115,17 @@ do_address_service(const bool add, const short family, const struct tuntap *tt) { addr.address.ipv4.s_addr = htonl(tt->local); addr.prefix_len = netmask_to_netbits2(tt->adapter_netmask); + msg(D_IFCONFIG, "INET address service: %s %s/%d", + add ? "add" : "remove", + print_in_addr_t(tt->local, 0, &gc), addr.prefix_len); } else { addr.address.ipv6 = tt->local_ipv6; - addr.prefix_len = tt->netbits_ipv6; + addr.prefix_len = (tt->type == DEV_TYPE_TUN) ? 128 : tt->netbits_ipv6; + msg(D_IFCONFIG, "INET6 address service: %s %s/%d", + add ? "add" : "remove", + print_in6_addr(tt->local_ipv6, 0, &gc), addr.prefix_len); } if (!send_msg_iservice(pipe, &addr, sizeof(addr), &ack, "TUN")) @@ -1088,24 +1094,36 @@ do_ifconfig_ipv6(struct tuntap *tt, const char *ifname, int tun_mtu, else if (tt->options.msg_channel) { do_address_service(true, AF_INET6, tt); - add_route_connected_v6_net(tt, es); + if (tt->type == DEV_TYPE_TUN) + { + add_route_connected_v6_net(tt, es); + } do_dns_service(true, AF_INET6, tt); do_set_mtu_service(tt, AF_INET6, tun_mtu); } else { /* example: netsh interface ipv6 set address interface=42 - * 2001:608:8003::d store=active + * 2001:608:8003::d/bits store=active */ char iface[64]; + /* in TUN mode, we only simulate a subnet, so the interface + * is configured with /128 + a route to fe80::8. In TAP mode, + * the correct netbits must be set, and no on-link route + */ + int netbits = (tt->type == DEV_TYPE_TUN) ? 128 : tt->netbits_ipv6; + openvpn_snprintf(iface, sizeof(iface), "interface=%lu", tt->adapter_index); - argv_printf(&argv, "%s%s interface ipv6 set address %s %s store=active", + argv_printf(&argv, "%s%s interface ipv6 set address %s %s/%d store=active", get_win_sys_path(), NETSH_PATH_SUFFIX, iface, - ifconfig_ipv6_local); + ifconfig_ipv6_local, netbits); netsh_command(&argv, 4, M_FATAL); - add_route_connected_v6_net(tt, es); + if (tt->type == DEV_TYPE_TUN) + { + add_route_connected_v6_net(tt, es); + } /* set ipv6 dns servers if any are specified */ netsh_set_dns6_servers(tt->options.dns6, tt->options.dns6_len, ifname); windows_set_mtu(tt->adapter_index, AF_INET6, tun_mtu); @@ -6688,7 +6706,7 @@ netsh_delete_address_dns(const struct tuntap *tt, bool ipv6, struct gc_arena *gc netsh_command(&argv, 1, M_WARN); } - if (ipv6) + if (ipv6 && tt->type == DEV_TYPE_TUN) { delete_route_connected_v6_net(tt); }