Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 189 insertions, 0 deletions

diff --git a/samples/bpf/xdp_router_ipv4.bpf.c b/samples/bpf/xdp_router_ipv4.bpf.c
new file mode 100644
index 000000000..0643330d1
--- /dev/null
+++ b/samples/bpf/xdp_router_ipv4.bpf.c
@@ -0,0 +1,189 @@
+/* Copyright (C) 2017 Cavium, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License
+ * as published by the Free Software Foundation.
+ */
+
+#include "vmlinux.h"
+#include "xdp_sample.bpf.h"
+#include "xdp_sample_shared.h"
+
+#define ETH_ALEN	6
+#define ETH_P_8021Q	0x8100
+#define ETH_P_8021AD	0x88A8
+
+struct trie_value {
+	__u8 prefix[4];
+	__be64 value;
+	int ifindex;
+	int metric;
+	__be32 gw;
+};
+
+/* Key for lpm_trie */
+union key_4 {
+	u32 b32[2];
+	u8 b8[8];
+};
+
+struct arp_entry {
+	__be64 mac;
+	__be32 dst;
+};
+
+struct direct_map {
+	struct arp_entry arp;
+	int ifindex;
+	__be64 mac;
+};
+
+/* Map for trie implementation */
+struct {
+	__uint(type, BPF_MAP_TYPE_LPM_TRIE);
+	__uint(key_size, 8);
+	__uint(value_size, sizeof(struct trie_value));
+	__uint(max_entries, 50);
+	__uint(map_flags, BPF_F_NO_PREALLOC);
+} lpm_map SEC(".maps");
+
+/* Map for ARP table */
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, __be32);
+	__type(value, __be64);
+	__uint(max_entries, 50);
+} arp_table SEC(".maps");
+
+/* Map to keep the exact match entries in the route table */
+struct {
+	__uint(type, BPF_MAP_TYPE_HASH);
+	__type(key, __be32);
+	__type(value, struct direct_map);
+	__uint(max_entries, 50);
+} exact_match SEC(".maps");
+
+struct {
+	__uint(type, BPF_MAP_TYPE_DEVMAP);
+	__uint(key_size, sizeof(int));
+	__uint(value_size, sizeof(int));
+	__uint(max_entries, 100);
+} tx_port SEC(".maps");
+
+SEC("xdp")
+int xdp_router_ipv4_prog(struct xdp_md *ctx)
+{
+	void *data_end = (void *)(long)ctx->data_end;
+	void *data = (void *)(long)ctx->data;
+	struct ethhdr *eth = data;
+	u64 nh_off = sizeof(*eth);
+	struct datarec *rec;
+	__be16 h_proto;
+	u32 key = 0;
+
+	rec = bpf_map_lookup_elem(&rx_cnt, &key);
+	if (rec)
+		NO_TEAR_INC(rec->processed);
+
+	if (data + nh_off > data_end)
+		goto drop;
+
+	h_proto = eth->h_proto;
+	if (h_proto == bpf_htons(ETH_P_8021Q) ||
+	    h_proto == bpf_htons(ETH_P_8021AD)) {
+		struct vlan_hdr *vhdr;
+
+		vhdr = data + nh_off;
+		nh_off += sizeof(struct vlan_hdr);
+		if (data + nh_off > data_end)
+			goto drop;
+
+		h_proto = vhdr->h_vlan_encapsulated_proto;
+	}
+
+	switch (bpf_ntohs(h_proto)) {
+	case ETH_P_ARP:
+		if (rec)
+			NO_TEAR_INC(rec->xdp_pass);
+		return XDP_PASS;
+	case ETH_P_IP: {
+		struct iphdr *iph = data + nh_off;
+		struct direct_map *direct_entry;
+		__be64 *dest_mac, *src_mac;
+		int forward_to;
+
+		if (iph + 1 > data_end)
+			goto drop;
+
+		direct_entry = bpf_map_lookup_elem(&exact_match, &iph->daddr);
+
+		/* Check for exact match, this would give a faster lookup */
+		if (direct_entry && direct_entry->mac &&
+		    direct_entry->arp.mac) {
+			src_mac = &direct_entry->mac;
+			dest_mac = &direct_entry->arp.mac;
+			forward_to = direct_entry->ifindex;
+		} else {
+			struct trie_value *prefix_value;
+			union key_4 key4;
+
+			/* Look up in the trie for lpm */
+			key4.b32[0] = 32;
+			key4.b8[4] = iph->daddr & 0xff;
+			key4.b8[5] = (iph->daddr >> 8) & 0xff;
+			key4.b8[6] = (iph->daddr >> 16) & 0xff;
+			key4.b8[7] = (iph->daddr >> 24) & 0xff;
+
+			prefix_value = bpf_map_lookup_elem(&lpm_map, &key4);
+			if (!prefix_value)
+				goto drop;
+
+			forward_to = prefix_value->ifindex;
+			src_mac = &prefix_value->value;
+			if (!src_mac)
+				goto drop;
+
+			dest_mac = bpf_map_lookup_elem(&arp_table, &iph->daddr);
+			if (!dest_mac) {
+				if (!prefix_value->gw)
+					goto drop;
+
+				dest_mac = bpf_map_lookup_elem(&arp_table,
+							       &prefix_value->gw);
+				if (!dest_mac) {
+					/* Forward the packet to the kernel in
+					 * order to trigger ARP discovery for
+					 * the default gw.
+					 */
+					if (rec)
+						NO_TEAR_INC(rec->xdp_pass);
+					return XDP_PASS;
+				}
+			}
+		}
+
+		if (src_mac && dest_mac) {
+			int ret;
+
+			__builtin_memcpy(eth->h_dest, dest_mac, ETH_ALEN);
+			__builtin_memcpy(eth->h_source, src_mac, ETH_ALEN);
+
+			ret = bpf_redirect_map(&tx_port, forward_to, 0);
+			if (ret == XDP_REDIRECT) {
+				if (rec)
+					NO_TEAR_INC(rec->xdp_redirect);
+				return ret;
+			}
+		}
+	}
+	default:
+		break;
+	}
+drop:
+	if (rec)
+		NO_TEAR_INC(rec->xdp_drop);
+
+	return XDP_DROP;
+}
+
+char _license[] SEC("license") = "GPL";