| /* |
| * Handle bridge arp/nd proxy/suppress |
| * |
| * Copyright (C) 2017 Cumulus Networks |
| * Copyright (c) 2017 Roopa Prabhu <roopa@cumulusnetworks.com> |
| * |
| * Authors: |
| * Roopa Prabhu <roopa@cumulusnetworks.com> |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/netdevice.h> |
| #include <linux/etherdevice.h> |
| #include <linux/neighbour.h> |
| #include <net/arp.h> |
| #include <linux/if_vlan.h> |
| #include <linux/inetdevice.h> |
| #include <net/addrconf.h> |
| #include <net/ipv6_stubs.h> |
| #if IS_ENABLED(CONFIG_IPV6) |
| #include <net/ip6_checksum.h> |
| #endif |
| |
| #include "br_private.h" |
| |
| void br_recalculate_neigh_suppress_enabled(struct net_bridge *br) |
| { |
| struct net_bridge_port *p; |
| bool neigh_suppress = false; |
| |
| list_for_each_entry(p, &br->port_list, list) { |
| if (p->flags & BR_NEIGH_SUPPRESS) { |
| neigh_suppress = true; |
| break; |
| } |
| } |
| |
| br_opt_toggle(br, BROPT_NEIGH_SUPPRESS_ENABLED, neigh_suppress); |
| } |
| |
| #if IS_ENABLED(CONFIG_INET) |
| static void br_arp_send(struct net_bridge *br, struct net_bridge_port *p, |
| struct net_device *dev, __be32 dest_ip, __be32 src_ip, |
| const unsigned char *dest_hw, |
| const unsigned char *src_hw, |
| const unsigned char *target_hw, |
| __be16 vlan_proto, u16 vlan_tci) |
| { |
| struct net_bridge_vlan_group *vg; |
| struct sk_buff *skb; |
| u16 pvid; |
| |
| netdev_dbg(dev, "arp send dev %s dst %pI4 dst_hw %pM src %pI4 src_hw %pM\n", |
| dev->name, &dest_ip, dest_hw, &src_ip, src_hw); |
| |
| if (!vlan_tci) { |
| arp_send(ARPOP_REPLY, ETH_P_ARP, dest_ip, dev, src_ip, |
| dest_hw, src_hw, target_hw); |
| return; |
| } |
| |
| skb = arp_create(ARPOP_REPLY, ETH_P_ARP, dest_ip, dev, src_ip, |
| dest_hw, src_hw, target_hw); |
| if (!skb) |
| return; |
| |
| 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(skb, vlan_proto, vlan_tci); |
| |
| if (p) { |
| arp_xmit(skb); |
| } else { |
| skb_reset_mac_header(skb); |
| __skb_pull(skb, skb_network_offset(skb)); |
| skb->ip_summed = CHECKSUM_UNNECESSARY; |
| skb->pkt_type = PACKET_HOST; |
| |
| netif_rx_ni(skb); |
| } |
| } |
| |
| static int br_chk_addr_ip(struct net_device *dev, void *data) |
| { |
| __be32 ip = *(__be32 *)data; |
| struct in_device *in_dev; |
| __be32 addr = 0; |
| |
| in_dev = __in_dev_get_rcu(dev); |
| if (in_dev) |
| addr = inet_confirm_addr(dev_net(dev), in_dev, 0, ip, |
| RT_SCOPE_HOST); |
| |
| if (addr == ip) |
| return 1; |
| |
| return 0; |
| } |
| |
| static bool br_is_local_ip(struct net_device *dev, __be32 ip) |
| { |
| if (br_chk_addr_ip(dev, &ip)) |
| return true; |
| |
| /* check if ip is configured on upper dev */ |
| if (netdev_walk_all_upper_dev_rcu(dev, br_chk_addr_ip, &ip)) |
| return true; |
| |
| return false; |
| } |
| |
| void br_do_proxy_suppress_arp(struct sk_buff *skb, struct net_bridge *br, |
| u16 vid, struct net_bridge_port *p) |
| { |
| struct net_device *dev = br->dev; |
| struct net_device *vlandev = dev; |
| struct neighbour *n; |
| struct arphdr *parp; |
| u8 *arpptr, *sha; |
| __be32 sip, tip; |
| |
| BR_INPUT_SKB_CB(skb)->proxyarp_replied = 0; |
| |
| if ((dev->flags & IFF_NOARP) || |
| !pskb_may_pull(skb, arp_hdr_len(dev))) |
| return; |
| |
| parp = arp_hdr(skb); |
| |
| if (parp->ar_pro != htons(ETH_P_IP) || |
| parp->ar_hln != dev->addr_len || |
| parp->ar_pln != 4) |
| return; |
| |
| arpptr = (u8 *)parp + sizeof(struct arphdr); |
| sha = arpptr; |
| arpptr += dev->addr_len; /* sha */ |
| memcpy(&sip, arpptr, sizeof(sip)); |
| arpptr += sizeof(sip); |
| arpptr += dev->addr_len; /* tha */ |
| memcpy(&tip, arpptr, sizeof(tip)); |
| |
| if (ipv4_is_loopback(tip) || |
| ipv4_is_multicast(tip)) |
| return; |
| |
| if (br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED)) { |
| if (p && (p->flags & BR_NEIGH_SUPPRESS)) |
| return; |
| if (ipv4_is_zeronet(sip) || sip == tip) { |
| /* prevent flooding to neigh suppress ports */ |
| BR_INPUT_SKB_CB(skb)->proxyarp_replied = 1; |
| return; |
| } |
| } |
| |
| if (parp->ar_op != htons(ARPOP_REQUEST)) |
| return; |
| |
| if (vid != 0) { |
| vlandev = __vlan_find_dev_deep_rcu(br->dev, skb->vlan_proto, |
| vid); |
| if (!vlandev) |
| return; |
| } |
| |
| if (br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED) && |
| br_is_local_ip(vlandev, tip)) { |
| /* its our local ip, so don't proxy reply |
| * and don't forward to neigh suppress ports |
| */ |
| BR_INPUT_SKB_CB(skb)->proxyarp_replied = 1; |
| return; |
| } |
| |
| n = neigh_lookup(&arp_tbl, &tip, 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 ((p && (p->flags & BR_PROXYARP)) || |
| (f->dst && (f->dst->flags & (BR_PROXYARP_WIFI | |
| BR_NEIGH_SUPPRESS)))) { |
| if (!vid) |
| br_arp_send(br, p, skb->dev, sip, tip, |
| sha, n->ha, sha, 0, 0); |
| else |
| br_arp_send(br, p, skb->dev, sip, tip, |
| sha, n->ha, sha, |
| skb->vlan_proto, |
| skb_vlan_tag_get(skb)); |
| replied = true; |
| } |
| |
| /* If we have replied or as long as we know the |
| * mac, indicate to arp replied |
| */ |
| if (replied || |
| br_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED)) |
| BR_INPUT_SKB_CB(skb)->proxyarp_replied = 1; |
| } |
| |
| neigh_release(n); |
| } |
| } |
| #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 = (n->flags & NTF_ROUTER) ? 1 : 0; |
| 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 = 0; |
| |
| 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 = 1; |
| 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 = 1; |
| 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 = 1; |
| 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_opt_get(br, BROPT_NEIGH_SUPPRESS_ENABLED)) |
| BR_INPUT_SKB_CB(skb)->proxyarp_replied = 1; |
| } |
| neigh_release(n); |
| } |
| } |
| #endif |