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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /net/bridge/br_input.c
parentInitial commit. (diff)
downloadlinux-upstream/5.10.209.tar.xz
linux-upstream/5.10.209.zip
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'net/bridge/br_input.c')
-rw-r--r--net/bridge/br_input.c389
1 files changed, 389 insertions, 0 deletions
diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
new file mode 100644
index 000000000..52dd0708f
--- /dev/null
+++ b/net/bridge/br_input.c
@@ -0,0 +1,389 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Handle incoming frames
+ * Linux ethernet bridge
+ *
+ * Authors:
+ * Lennert Buytenhek <buytenh@gnu.org>
+ */
+
+#include <linux/slab.h>
+#include <linux/kernel.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/netfilter_bridge.h>
+#ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
+#include <net/netfilter/nf_queue.h>
+#endif
+#include <linux/neighbour.h>
+#include <net/arp.h>
+#include <net/dsa.h>
+#include <linux/export.h>
+#include <linux/rculist.h>
+#include "br_private.h"
+#include "br_private_tunnel.h"
+
+static int
+br_netif_receive_skb(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+ br_drop_fake_rtable(skb);
+ return netif_receive_skb(skb);
+}
+
+static int br_pass_frame_up(struct sk_buff *skb)
+{
+ struct net_device *indev, *brdev = BR_INPUT_SKB_CB(skb)->brdev;
+ struct net_bridge *br = netdev_priv(brdev);
+ struct net_bridge_vlan_group *vg;
+ struct pcpu_sw_netstats *brstats = this_cpu_ptr(br->stats);
+
+ u64_stats_update_begin(&brstats->syncp);
+ brstats->rx_packets++;
+ brstats->rx_bytes += skb->len;
+ u64_stats_update_end(&brstats->syncp);
+
+ vg = br_vlan_group_rcu(br);
+
+ /* Reset the offload_fwd_mark because there could be a stacked
+ * bridge above, and it should not think this bridge it doing
+ * that bridge's work forwarding out its ports.
+ */
+ br_switchdev_frame_unmark(skb);
+
+ /* Bridge is just like any other port. Make sure the
+ * packet is allowed except in promisc modue when someone
+ * may be running packet capture.
+ */
+ if (!(brdev->flags & IFF_PROMISC) &&
+ !br_allowed_egress(vg, skb)) {
+ kfree_skb(skb);
+ return NET_RX_DROP;
+ }
+
+ indev = skb->dev;
+ skb->dev = brdev;
+ skb = br_handle_vlan(br, NULL, vg, skb);
+ if (!skb)
+ return NET_RX_DROP;
+ /* update the multicast stats if the packet is IGMP/MLD */
+ br_multicast_count(br, NULL, skb, br_multicast_igmp_type(skb),
+ BR_MCAST_DIR_TX);
+
+ return NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN,
+ dev_net(indev), NULL, skb, indev, NULL,
+ br_netif_receive_skb);
+}
+
+/* note: already called with rcu_read_lock */
+int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+ struct net_bridge_port *p = br_port_get_rcu(skb->dev);
+ enum br_pkt_type pkt_type = BR_PKT_UNICAST;
+ struct net_bridge_fdb_entry *dst = NULL;
+ struct net_bridge_mdb_entry *mdst;
+ bool local_rcv, mcast_hit = false;
+ struct net_bridge *br;
+ u16 vid = 0;
+ u8 state;
+
+ if (!p || p->state == BR_STATE_DISABLED)
+ goto drop;
+
+ state = p->state;
+ if (!br_allowed_ingress(p->br, nbp_vlan_group_rcu(p), skb, &vid,
+ &state))
+ goto out;
+
+ nbp_switchdev_frame_mark(p, skb);
+
+ /* insert into forwarding database after filtering to avoid spoofing */
+ br = p->br;
+ if (p->flags & BR_LEARNING)
+ br_fdb_update(br, p, eth_hdr(skb)->h_source, vid, 0);
+
+ local_rcv = !!(br->dev->flags & IFF_PROMISC);
+ if (is_multicast_ether_addr(eth_hdr(skb)->h_dest)) {
+ /* by definition the broadcast is also a multicast address */
+ if (is_broadcast_ether_addr(eth_hdr(skb)->h_dest)) {
+ pkt_type = BR_PKT_BROADCAST;
+ local_rcv = true;
+ } else {
+ pkt_type = BR_PKT_MULTICAST;
+ if (br_multicast_rcv(br, p, skb, vid))
+ goto drop;
+ }
+ }
+
+ if (state == BR_STATE_LEARNING)
+ goto drop;
+
+ BR_INPUT_SKB_CB(skb)->brdev = br->dev;
+ BR_INPUT_SKB_CB(skb)->src_port_isolated = !!(p->flags & BR_ISOLATED);
+
+ if (IS_ENABLED(CONFIG_INET) &&
+ (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_opt_get(br, BROPT_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) {
+ case BR_PKT_MULTICAST:
+ mdst = br_mdb_get(br, skb, vid);
+ if ((mdst || BR_INPUT_SKB_CB_MROUTERS_ONLY(skb)) &&
+ br_multicast_querier_exists(br, eth_hdr(skb))) {
+ if ((mdst && mdst->host_joined) ||
+ br_multicast_is_router(br)) {
+ local_rcv = true;
+ DEV_STATS_INC(br->dev, multicast);
+ }
+ mcast_hit = true;
+ } else {
+ local_rcv = true;
+ DEV_STATS_INC(br->dev, multicast);
+ }
+ break;
+ case BR_PKT_UNICAST:
+ dst = br_fdb_find_rcu(br, eth_hdr(skb)->h_dest, vid);
+ default:
+ break;
+ }
+
+ if (dst) {
+ unsigned long now = jiffies;
+
+ if (test_bit(BR_FDB_LOCAL, &dst->flags))
+ return br_pass_frame_up(skb);
+
+ if (now != dst->used)
+ dst->used = now;
+ br_forward(dst->dst, skb, local_rcv, false);
+ } else {
+ if (!mcast_hit)
+ br_flood(br, skb, pkt_type, local_rcv, false);
+ else
+ br_multicast_flood(mdst, skb, local_rcv, false);
+ }
+
+ if (local_rcv)
+ return br_pass_frame_up(skb);
+
+out:
+ return 0;
+drop:
+ kfree_skb(skb);
+ goto out;
+}
+EXPORT_SYMBOL_GPL(br_handle_frame_finish);
+
+static void __br_handle_local_finish(struct sk_buff *skb)
+{
+ struct net_bridge_port *p = br_port_get_rcu(skb->dev);
+ u16 vid = 0;
+
+ /* check if vlan is allowed, to avoid spoofing */
+ if ((p->flags & BR_LEARNING) &&
+ nbp_state_should_learn(p) &&
+ !br_opt_get(p->br, BROPT_NO_LL_LEARN) &&
+ br_should_learn(p, skb, &vid))
+ br_fdb_update(p->br, p, eth_hdr(skb)->h_source, vid, 0);
+}
+
+/* note: already called with rcu_read_lock */
+static int br_handle_local_finish(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+ __br_handle_local_finish(skb);
+
+ /* return 1 to signal the okfn() was called so it's ok to use the skb */
+ return 1;
+}
+
+static int nf_hook_bridge_pre(struct sk_buff *skb, struct sk_buff **pskb)
+{
+#ifdef CONFIG_NETFILTER_FAMILY_BRIDGE
+ struct nf_hook_entries *e = NULL;
+ struct nf_hook_state state;
+ unsigned int verdict, i;
+ struct net *net;
+ int ret;
+
+ net = dev_net(skb->dev);
+#ifdef HAVE_JUMP_LABEL
+ if (!static_key_false(&nf_hooks_needed[NFPROTO_BRIDGE][NF_BR_PRE_ROUTING]))
+ goto frame_finish;
+#endif
+
+ e = rcu_dereference(net->nf.hooks_bridge[NF_BR_PRE_ROUTING]);
+ if (!e)
+ goto frame_finish;
+
+ nf_hook_state_init(&state, NF_BR_PRE_ROUTING,
+ NFPROTO_BRIDGE, skb->dev, NULL, NULL,
+ net, br_handle_frame_finish);
+
+ for (i = 0; i < e->num_hook_entries; i++) {
+ verdict = nf_hook_entry_hookfn(&e->hooks[i], skb, &state);
+ switch (verdict & NF_VERDICT_MASK) {
+ case NF_ACCEPT:
+ if (BR_INPUT_SKB_CB(skb)->br_netfilter_broute) {
+ *pskb = skb;
+ return RX_HANDLER_PASS;
+ }
+ break;
+ case NF_DROP:
+ kfree_skb(skb);
+ return RX_HANDLER_CONSUMED;
+ case NF_QUEUE:
+ ret = nf_queue(skb, &state, i, verdict);
+ if (ret == 1)
+ continue;
+ return RX_HANDLER_CONSUMED;
+ default: /* STOLEN */
+ return RX_HANDLER_CONSUMED;
+ }
+ }
+frame_finish:
+ net = dev_net(skb->dev);
+ br_handle_frame_finish(net, NULL, skb);
+#else
+ br_handle_frame_finish(dev_net(skb->dev), NULL, skb);
+#endif
+ return RX_HANDLER_CONSUMED;
+}
+
+/*
+ * Return NULL if skb is handled
+ * note: already called with rcu_read_lock
+ */
+static rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
+{
+ struct net_bridge_port *p;
+ struct sk_buff *skb = *pskb;
+ const unsigned char *dest = eth_hdr(skb)->h_dest;
+
+ if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
+ return RX_HANDLER_PASS;
+
+ if (!is_valid_ether_addr(eth_hdr(skb)->h_source))
+ goto drop;
+
+ skb = skb_share_check(skb, GFP_ATOMIC);
+ if (!skb)
+ return RX_HANDLER_CONSUMED;
+
+ memset(skb->cb, 0, sizeof(struct br_input_skb_cb));
+
+ p = br_port_get_rcu(skb->dev);
+ if (p->flags & BR_VLAN_TUNNEL) {
+ if (br_handle_ingress_vlan_tunnel(skb, p,
+ nbp_vlan_group_rcu(p)))
+ goto drop;
+ }
+
+ if (unlikely(is_link_local_ether_addr(dest))) {
+ u16 fwd_mask = p->br->group_fwd_mask_required;
+
+ /*
+ * See IEEE 802.1D Table 7-10 Reserved addresses
+ *
+ * Assignment Value
+ * Bridge Group Address 01-80-C2-00-00-00
+ * (MAC Control) 802.3 01-80-C2-00-00-01
+ * (Link Aggregation) 802.3 01-80-C2-00-00-02
+ * 802.1X PAE address 01-80-C2-00-00-03
+ *
+ * 802.1AB LLDP 01-80-C2-00-00-0E
+ *
+ * Others reserved for future standardization
+ */
+ fwd_mask |= p->group_fwd_mask;
+ switch (dest[5]) {
+ case 0x00: /* Bridge Group Address */
+ /* If STP is turned off,
+ then must forward to keep loop detection */
+ if (p->br->stp_enabled == BR_NO_STP ||
+ fwd_mask & (1u << dest[5]))
+ goto forward;
+ *pskb = skb;
+ __br_handle_local_finish(skb);
+ return RX_HANDLER_PASS;
+
+ case 0x01: /* IEEE MAC (Pause) */
+ goto drop;
+
+ case 0x0E: /* 802.1AB LLDP */
+ fwd_mask |= p->br->group_fwd_mask;
+ if (fwd_mask & (1u << dest[5]))
+ goto forward;
+ *pskb = skb;
+ __br_handle_local_finish(skb);
+ return RX_HANDLER_PASS;
+
+ default:
+ /* Allow selective forwarding for most other protocols */
+ fwd_mask |= p->br->group_fwd_mask;
+ if (fwd_mask & (1u << dest[5]))
+ goto forward;
+ }
+
+ /* The else clause should be hit when nf_hook():
+ * - returns < 0 (drop/error)
+ * - returns = 0 (stolen/nf_queue)
+ * Thus return 1 from the okfn() to signal the skb is ok to pass
+ */
+ if (NF_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN,
+ dev_net(skb->dev), NULL, skb, skb->dev, NULL,
+ br_handle_local_finish) == 1) {
+ return RX_HANDLER_PASS;
+ } else {
+ return RX_HANDLER_CONSUMED;
+ }
+ }
+
+ if (unlikely(br_mrp_process(p, skb)))
+ return RX_HANDLER_PASS;
+
+forward:
+ switch (p->state) {
+ case BR_STATE_FORWARDING:
+ case BR_STATE_LEARNING:
+ if (ether_addr_equal(p->br->dev->dev_addr, dest))
+ skb->pkt_type = PACKET_HOST;
+
+ return nf_hook_bridge_pre(skb, pskb);
+ default:
+drop:
+ kfree_skb(skb);
+ }
+ return RX_HANDLER_CONSUMED;
+}
+
+/* This function has no purpose other than to appease the br_port_get_rcu/rtnl
+ * helpers which identify bridged ports according to the rx_handler installed
+ * on them (so there _needs_ to be a bridge rx_handler even if we don't need it
+ * to do anything useful). This bridge won't support traffic to/from the stack,
+ * but only hardware bridging. So return RX_HANDLER_PASS so we don't steal
+ * frames from the ETH_P_XDSA packet_type handler.
+ */
+static rx_handler_result_t br_handle_frame_dummy(struct sk_buff **pskb)
+{
+ return RX_HANDLER_PASS;
+}
+
+rx_handler_func_t *br_get_rx_handler(const struct net_device *dev)
+{
+ if (netdev_uses_dsa(dev))
+ return br_handle_frame_dummy;
+
+ return br_handle_frame;
+}