From 99d2baa2cab0706d89beff596f997d4e3a1c833f Mon Sep 17 00:00:00 2001 From: Susant Sahani Date: Thu, 4 Aug 2016 19:30:58 +0530 Subject: [PATCH] networkd: add support to configure NOARP/ARP for interface (#3854) https://lists.freedesktop.org/archives/systemd-devel/2016-August/037268.html --- man/systemd.network.xml | 11 +++++ src/network/networkd-link.c | 63 ++++++++++++++++++++++++ src/network/networkd-network-gperf.gperf | 1 + src/network/networkd-network.c | 1 + src/network/networkd-network.h | 1 + 5 files changed, 77 insertions(+) diff --git a/man/systemd.network.xml b/man/systemd.network.xml index 4541a55490..c332cd7bdc 100644 --- a/man/systemd.network.xml +++ b/man/systemd.network.xml @@ -212,6 +212,17 @@ below 1280 (the minimum MTU for IPv6) it will automatically be increased to this value. + + ARP= + + A boolean. Enables or disables the ARP (low-level Address Resolution Protocol) + for this interface. Defaults to unset, which means that the kernel default will be used. + For example, disabling ARP is useful when creating multiple MACVLAN or VLAN virtual + interfaces atop a single lower-level physical interface, which will then only serve as a + link/"bridge" device aggregating traffic to the same physical link and not participate in + the network otherwise. + + diff --git a/src/network/networkd-link.c b/src/network/networkd-link.c index 99784b0ebe..3e10ab1e04 100644 --- a/src/network/networkd-link.c +++ b/src/network/networkd-link.c @@ -1314,6 +1314,65 @@ int link_set_mtu(Link *link, uint32_t mtu) { return 0; } +static int set_flags_handler(sd_netlink *rtnl, sd_netlink_message *m, void *userdata) { + _cleanup_link_unref_ Link *link = userdata; + int r; + + assert(m); + assert(link); + assert(link->ifname); + + if (IN_SET(link->state, LINK_STATE_FAILED, LINK_STATE_LINGER)) + return 1; + + r = sd_netlink_message_get_errno(m); + if (r < 0) + log_link_warning_errno(link, r, "Could not set link flags: %m"); + + return 1; +} + +static int link_set_flags(Link *link) { + _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL; + unsigned ifi_change = 0; + unsigned ifi_flags = 0; + int r; + + assert(link); + assert(link->manager); + assert(link->manager->rtnl); + + if (link->flags & IFF_LOOPBACK) + return 0; + + if (!link->network) + return 0; + + if (link->network->arp < 0) + return 0; + + r = sd_rtnl_message_new_link(link->manager->rtnl, &req, RTM_SETLINK, link->ifindex); + if (r < 0) + return log_link_error_errno(link, r, "Could not allocate RTM_SETLINK message: %m"); + + if (link->network->arp >= 0) { + ifi_change |= IFF_NOARP; + ifi_flags |= IFF_NOARP; + } + + r = sd_rtnl_message_link_set_flags(req, ifi_flags, ifi_change); + if (r < 0) + return log_link_error_errno(link, r, "Could not set link flags: %m"); + + r = sd_netlink_call_async(link->manager->rtnl, req, set_flags_handler, link, 0, NULL); + if (r < 0) + return log_link_error_errno(link, r, "Could not send rtnetlink message: %m"); + + link_ref(link); + + return 0; +} + static int link_set_bridge(Link *link) { _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL; int r; @@ -2411,6 +2470,10 @@ static int link_configure(Link *link) { if (r < 0) return r; + r = link_set_flags(link); + if (r < 0) + return r; + if (link_ipv4ll_enabled(link)) { r = ipv4ll_configure(link); if (r < 0) diff --git a/src/network/networkd-network-gperf.gperf b/src/network/networkd-network-gperf.gperf index 5172a7b5e9..19adac66b8 100644 --- a/src/network/networkd-network-gperf.gperf +++ b/src/network/networkd-network-gperf.gperf @@ -28,6 +28,7 @@ Match.KernelCommandLine, config_parse_net_condition, Match.Architecture, config_parse_net_condition, CONDITION_ARCHITECTURE, offsetof(Network, match_arch) Link.MACAddress, config_parse_hwaddr, 0, offsetof(Network, mac) Link.MTUBytes, config_parse_iec_size, 0, offsetof(Network, mtu) +Link.ARP, config_parse_tristate, 0, offsetof(Network, arp) Network.Description, config_parse_string, 0, offsetof(Network, description) Network.Bridge, config_parse_netdev, 0, offsetof(Network, bridge) Network.Bond, config_parse_netdev, 0, offsetof(Network, bond) diff --git a/src/network/networkd-network.c b/src/network/networkd-network.c index 2b764d4f24..17bbe5de9f 100644 --- a/src/network/networkd-network.c +++ b/src/network/networkd-network.c @@ -134,6 +134,7 @@ static int network_load_one(Manager *manager, const char *filename) { network->ipv6_hop_limit = -1; network->duid.type = _DUID_TYPE_INVALID; network->proxy_arp = -1; + network->arp = -1; network->ipv6_accept_ra_use_dns = true; r = config_parse(NULL, filename, file, diff --git a/src/network/networkd-network.h b/src/network/networkd-network.h index 08ee939faa..7c0bdc1e4a 100644 --- a/src/network/networkd-network.h +++ b/src/network/networkd-network.h @@ -171,6 +171,7 @@ struct Network { struct ether_addr *mac; unsigned mtu; + int arp; uint32_t iaid; DUID duid;