From ed842faeb2bd49256f00485402f3113205f91d30 Mon Sep 17 00:00:00 2001 From: Roopa Prabhu Date: Fri, 6 Oct 2017 22:12:39 -0700 Subject: bridge: suppress nd pkts on BR_NEIGH_SUPPRESS ports This patch avoids flooding and proxies ndisc packets for BR_NEIGH_SUPPRESS ports. Signed-off-by: Roopa Prabhu Signed-off-by: David S. Miller --- net/bridge/br_arp_nd_proxy.c | 249 +++++++++++++++++++++++++++++++++++++++++++ net/bridge/br_device.c | 11 ++ net/bridge/br_input.c | 11 ++ net/bridge/br_private.h | 3 + 4 files changed, 274 insertions(+) diff --git a/net/bridge/br_arp_nd_proxy.c b/net/bridge/br_arp_nd_proxy.c index a79c1824e163..2cf7716254be 100644 --- a/net/bridge/br_arp_nd_proxy.c +++ b/net/bridge/br_arp_nd_proxy.c @@ -21,6 +21,9 @@ #include #include #include +#if IS_ENABLED(CONFIG_IPV6) +#include +#endif #include "br_private.h" @@ -218,3 +221,249 @@ void br_do_proxy_suppress_arp(struct sk_buff *skb, struct net_bridge *br, } } #endif + +#if IS_ENABLED(CONFIG_IPV6) +struct nd_msg *br_is_nd_neigh_msg(struct sk_buff *skb, struct nd_msg *msg) +{ + struct nd_msg *m; + + m = skb_header_pointer(skb, skb_network_offset(skb) + + sizeof(struct ipv6hdr), sizeof(*msg), msg); + if (!m) + return NULL; + + if (m->icmph.icmp6_code != 0 || + (m->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION && + m->icmph.icmp6_type != NDISC_NEIGHBOUR_ADVERTISEMENT)) + return NULL; + + return m; +} + +static void br_nd_send(struct net_bridge *br, struct net_bridge_port *p, + struct sk_buff *request, struct neighbour *n, + __be16 vlan_proto, u16 vlan_tci, struct nd_msg *ns) +{ + struct net_device *dev = request->dev; + struct net_bridge_vlan_group *vg; + struct sk_buff *reply; + struct nd_msg *na; + struct ipv6hdr *pip6; + int na_olen = 8; /* opt hdr + ETH_ALEN for target */ + int ns_olen; + int i, len; + u8 *daddr; + u16 pvid; + + if (!dev) + return; + + len = LL_RESERVED_SPACE(dev) + sizeof(struct ipv6hdr) + + sizeof(*na) + na_olen + dev->needed_tailroom; + + reply = alloc_skb(len, GFP_ATOMIC); + if (!reply) + return; + + reply->protocol = htons(ETH_P_IPV6); + reply->dev = dev; + skb_reserve(reply, LL_RESERVED_SPACE(dev)); + skb_push(reply, sizeof(struct ethhdr)); + skb_set_mac_header(reply, 0); + + daddr = eth_hdr(request)->h_source; + + /* Do we need option processing ? */ + ns_olen = request->len - (skb_network_offset(request) + + sizeof(struct ipv6hdr)) - sizeof(*ns); + for (i = 0; i < ns_olen - 1; i += (ns->opt[i + 1] << 3)) { + if (ns->opt[i] == ND_OPT_SOURCE_LL_ADDR) { + daddr = ns->opt + i + sizeof(struct nd_opt_hdr); + break; + } + } + + /* Ethernet header */ + ether_addr_copy(eth_hdr(reply)->h_dest, daddr); + ether_addr_copy(eth_hdr(reply)->h_source, n->ha); + eth_hdr(reply)->h_proto = htons(ETH_P_IPV6); + reply->protocol = htons(ETH_P_IPV6); + + skb_pull(reply, sizeof(struct ethhdr)); + skb_set_network_header(reply, 0); + skb_put(reply, sizeof(struct ipv6hdr)); + + /* IPv6 header */ + pip6 = ipv6_hdr(reply); + memset(pip6, 0, sizeof(struct ipv6hdr)); + pip6->version = 6; + pip6->priority = ipv6_hdr(request)->priority; + pip6->nexthdr = IPPROTO_ICMPV6; + pip6->hop_limit = 255; + pip6->daddr = ipv6_hdr(request)->saddr; + pip6->saddr = *(struct in6_addr *)n->primary_key; + + skb_pull(reply, sizeof(struct ipv6hdr)); + skb_set_transport_header(reply, 0); + + na = (struct nd_msg *)skb_put(reply, sizeof(*na) + na_olen); + + /* Neighbor Advertisement */ + memset(na, 0, sizeof(*na) + na_olen); + na->icmph.icmp6_type = NDISC_NEIGHBOUR_ADVERTISEMENT; + na->icmph.icmp6_router = 0; /* XXX: should be 1 ? */ + na->icmph.icmp6_override = 1; + na->icmph.icmp6_solicited = 1; + na->target = ns->target; + ether_addr_copy(&na->opt[2], n->ha); + na->opt[0] = ND_OPT_TARGET_LL_ADDR; + na->opt[1] = na_olen >> 3; + + na->icmph.icmp6_cksum = csum_ipv6_magic(&pip6->saddr, + &pip6->daddr, + sizeof(*na) + na_olen, + IPPROTO_ICMPV6, + csum_partial(na, sizeof(*na) + na_olen, 0)); + + pip6->payload_len = htons(sizeof(*na) + na_olen); + + skb_push(reply, sizeof(struct ipv6hdr)); + skb_push(reply, sizeof(struct ethhdr)); + + reply->ip_summed = CHECKSUM_UNNECESSARY; + + if (p) + vg = nbp_vlan_group_rcu(p); + else + vg = br_vlan_group_rcu(br); + pvid = br_get_pvid(vg); + if (pvid == (vlan_tci & VLAN_VID_MASK)) + vlan_tci = 0; + + if (vlan_tci) + __vlan_hwaccel_put_tag(reply, vlan_proto, vlan_tci); + + netdev_dbg(dev, "nd send dev %s dst %pI6 dst_hw %pM src %pI6 src_hw %pM\n", + dev->name, &pip6->daddr, daddr, &pip6->saddr, n->ha); + + if (p) { + dev_queue_xmit(reply); + } else { + skb_reset_mac_header(reply); + __skb_pull(reply, skb_network_offset(reply)); + reply->ip_summed = CHECKSUM_UNNECESSARY; + reply->pkt_type = PACKET_HOST; + + netif_rx_ni(reply); + } +} + +static int br_chk_addr_ip6(struct net_device *dev, void *data) +{ + struct in6_addr *addr = (struct in6_addr *)data; + + if (ipv6_chk_addr(dev_net(dev), addr, dev, 0)) + return 1; + + return 0; +} + +static bool br_is_local_ip6(struct net_device *dev, struct in6_addr *addr) + +{ + if (br_chk_addr_ip6(dev, addr)) + return true; + + /* check if ip is configured on upper dev */ + if (netdev_walk_all_upper_dev_rcu(dev, br_chk_addr_ip6, addr)) + return true; + + return false; +} + +void br_do_suppress_nd(struct sk_buff *skb, struct net_bridge *br, + u16 vid, struct net_bridge_port *p, struct nd_msg *msg) +{ + struct net_device *dev = br->dev; + struct net_device *vlandev = NULL; + struct in6_addr *saddr, *daddr; + struct ipv6hdr *iphdr; + struct neighbour *n; + + BR_INPUT_SKB_CB(skb)->proxyarp_replied = false; + + if (p && (p->flags & BR_NEIGH_SUPPRESS)) + return; + + if (msg->icmph.icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT && + !msg->icmph.icmp6_solicited) { + /* prevent flooding to neigh suppress ports */ + BR_INPUT_SKB_CB(skb)->proxyarp_replied = true; + return; + } + + if (msg->icmph.icmp6_type != NDISC_NEIGHBOUR_SOLICITATION) + return; + + iphdr = ipv6_hdr(skb); + saddr = &iphdr->saddr; + daddr = &iphdr->daddr; + + if (ipv6_addr_any(saddr) || !ipv6_addr_cmp(saddr, daddr)) { + /* prevent flooding to neigh suppress ports */ + BR_INPUT_SKB_CB(skb)->proxyarp_replied = true; + return; + } + + if (vid != 0) { + /* build neigh table lookup on the vlan device */ + vlandev = __vlan_find_dev_deep_rcu(br->dev, skb->vlan_proto, + vid); + if (!vlandev) + return; + } else { + vlandev = dev; + } + + if (br_is_local_ip6(vlandev, &msg->target)) { + /* its our own ip, so don't proxy reply + * and don't forward to arp suppress ports + */ + BR_INPUT_SKB_CB(skb)->proxyarp_replied = true; + return; + } + + n = neigh_lookup(ipv6_stub->nd_tbl, &msg->target, vlandev); + if (n) { + struct net_bridge_fdb_entry *f; + + if (!(n->nud_state & NUD_VALID)) { + neigh_release(n); + return; + } + + f = br_fdb_find_rcu(br, n->ha, vid); + if (f) { + bool replied = false; + + if (f->dst && (f->dst->flags & BR_NEIGH_SUPPRESS)) { + if (vid != 0) + br_nd_send(br, p, skb, n, + skb->vlan_proto, + skb_vlan_tag_get(skb), msg); + else + br_nd_send(br, p, skb, n, 0, 0, msg); + replied = true; + } + + /* If we have replied or as long as we know the + * mac, indicate to NEIGH_SUPPRESS ports that we + * have replied + */ + if (replied || br->neigh_suppress_enabled) + BR_INPUT_SKB_CB(skb)->proxyarp_replied = true; + } + neigh_release(n); + } +} +#endif diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c index eb30c6a274c3..28bb22186fa0 100644 --- a/net/bridge/br_device.c +++ b/net/bridge/br_device.c @@ -69,6 +69,17 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) eth->h_proto == htons(ETH_P_RARP)) && br->neigh_suppress_enabled) { br_do_proxy_suppress_arp(skb, br, vid, NULL); + } else if (IS_ENABLED(CONFIG_IPV6) && + skb->protocol == htons(ETH_P_IPV6) && + br->neigh_suppress_enabled && + pskb_may_pull(skb, sizeof(struct ipv6hdr) + + sizeof(struct nd_msg)) && + ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) { + struct nd_msg *msg, _msg; + + msg = br_is_nd_neigh_msg(skb, &_msg); + if (msg) + br_do_suppress_nd(skb, br, vid, NULL, msg); } dest = eth_hdr(skb)->h_dest; diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c index 4b8d2ec2fa23..a096d3e189da 100644 --- a/net/bridge/br_input.c +++ b/net/bridge/br_input.c @@ -119,6 +119,17 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb (skb->protocol == htons(ETH_P_ARP) || skb->protocol == htons(ETH_P_RARP))) { br_do_proxy_suppress_arp(skb, br, vid, p); + } else if (IS_ENABLED(CONFIG_IPV6) && + skb->protocol == htons(ETH_P_IPV6) && + br->neigh_suppress_enabled && + pskb_may_pull(skb, sizeof(struct ipv6hdr) + + sizeof(struct nd_msg)) && + ipv6_hdr(skb)->nexthdr == IPPROTO_ICMPV6) { + struct nd_msg *msg, _msg; + + msg = br_is_nd_neigh_msg(skb, &_msg); + if (msg) + br_do_suppress_nd(skb, br, vid, p, msg); } switch (pkt_type) { diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index 4e6b25be14d0..fa0039f44818 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -1144,4 +1144,7 @@ static inline void br_switchdev_frame_unmark(struct sk_buff *skb) void br_recalculate_neigh_suppress_enabled(struct net_bridge *br); void br_do_proxy_suppress_arp(struct sk_buff *skb, struct net_bridge *br, u16 vid, struct net_bridge_port *p); +void br_do_suppress_nd(struct sk_buff *skb, struct net_bridge *br, + u16 vid, struct net_bridge_port *p, struct nd_msg *msg); +struct nd_msg *br_is_nd_neigh_msg(struct sk_buff *skb, struct nd_msg *m); #endif -- cgit v1.2.3-59-g8ed1b