xdp: T2666: switch to example code provided by xdp-tutorial

1 files changed, 0 insertions, 202 deletions

diff --git a/src/ebpf/xdp_router.c b/src/ebpf/xdp_router.c
deleted file mode 100644
index 4fb5c7cb1..000000000
--- a/src/ebpf/xdp_router.c
+++ /dev/null
@@ -1,202 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-
-// Code thankfully copied from:
-// https://medium.com/swlh/building-a-xdp-express-data-path-based-peering-router-20db4995da66
-
-#include <linux/bpf.h>
-#include <linux/if_ether.h>
-#include <linux/in.h>
-#include <linux/ip.h>
-#include <linux/ipv6.h>
-#include <linux/udp.h>
-#include <linux/socket.h>
-
-#include <bpf/bpf_endian.h>
-#include <bpf/bpf_helpers.h>
-
-#include <stdint.h>
-
-#ifndef XDP_ACTION_MAX
-#define XDP_ACTION_MAX (XDP_REDIRECT + 1)
-#endif
-
-#ifndef memcpy
-#define memcpy(dest, src, n) __builtin_memcpy((dest), (src), (n))
-#endif
-
-#ifndef AF_INET
-#define AF_INET 2
-#endif
-
-#ifndef AF_INET6
-#define AF_INET6 10
-#endif
-
-#ifndef IPV6_FLOWINFO_MASK
-#define IPV6_FLOWINFO_MASK bpf_htonl(0x0FFFFFFF)
-#endif
-
-/* This is the data record stored in the map */
-struct datarec {
-	__u64 rx_packets;
-	__u64 rx_bytes;
-};
-
-/* Keeps stats per (enum) xdp_action */
-struct bpf_map_def SEC("maps") xdp_stats_map = {
-	.type        = BPF_MAP_TYPE_PERCPU_ARRAY,
-	.key_size    = sizeof(__u32),
-	.value_size  = sizeof(struct datarec),
-	.max_entries = XDP_ACTION_MAX,
-};
-
-struct bpf_map_def SEC("maps") tx_port = {
-	.type = BPF_MAP_TYPE_DEVMAP,
-	.key_size = sizeof(int),
-	.value_size = sizeof(int),
-	.max_entries = 256,
-};
-
-/* from include/net/ip.h */
-static __always_inline int ip_decrease_ttl(struct iphdr *iph)
-{
-	__u32 check = iph->check;
-	check += bpf_htons(0x0100);
-	iph->check = (__u16)(check + (check >= 0xFFFF));
-	return --iph->ttl;
-}
-
-static __always_inline
-__u32 xdp_stats_record_action(struct xdp_md *ctx, __u32 action)
-{
-	if (action >= XDP_ACTION_MAX)
-		return XDP_ABORTED;
-
-	/* Lookup in kernel BPF-side return pointer to actual data record */
-	struct datarec *rec = bpf_map_lookup_elem(&xdp_stats_map, &action);
-	if (!rec)
-		return XDP_ABORTED;
-
-	/* BPF_MAP_TYPE_PERCPU_ARRAY returns a data record specific to current
-	 * CPU and XDP hooks runs under Softirq, which makes it safe to update
-	 * without atomic operations.
-	 */
-	rec->rx_packets++;
-	rec->rx_bytes += (ctx->data_end - ctx->data);
-
-	return action;
-}
-
-/* xdp_router is the name of the xdp program */
-SEC("prog")
-int xdp_router_func(struct xdp_md *ctx)
-{
-	/* this is the packet context*/
-	void *data_end = (void *)(long)ctx->data_end;
-	void *data = (void *)(long)ctx->data;
-	struct bpf_fib_lookup fib_params = {};
-	struct ethhdr *eth = data;
-	struct ipv6hdr *ip6h;
-	struct iphdr *iph;
-	__u16 h_proto;
-	__u64 nh_off;
-	int rc;
-	/* default action is to pass */
-	int action = XDP_PASS;
-
-	nh_off = sizeof(*eth);
-	if (data + nh_off > data_end) {
-		action = XDP_DROP;
-		goto out;
-	}
-
-	/* determine if this is IP4 or IPv6 by looking at the Ethernet protocol field */
-	h_proto = eth->h_proto;
-	if (h_proto == bpf_htons(ETH_P_IP)) {
-		/* IPv4 part of the code */
-		iph = data + nh_off;
-
-		if (iph + 1 > data_end) {
-			action = XDP_DROP;
-			goto out;
-		}
-		/* as a real router, we need to check the TTL to prevent never ending loops*/
-		if (iph->ttl <= 1)
-			goto out;
-
-		/* populate the fib_params fields to prepare for the lookup */
-		fib_params.family	= AF_INET;
-		fib_params.tos		= iph->tos;
-		fib_params.l4_protocol	= iph->protocol;
-		fib_params.sport	= 0;
-		fib_params.dport	= 0;
-		fib_params.tot_len	= bpf_ntohs(iph->tot_len);
-		fib_params.ipv4_src	= iph->saddr;
-		fib_params.ipv4_dst	= iph->daddr;
-	} else if (h_proto == bpf_htons(ETH_P_IPV6)) {
-		/* IPv6 part of the code */
-		struct in6_addr *src = (struct in6_addr *) fib_params.ipv6_src;
-		struct in6_addr *dst = (struct in6_addr *) fib_params.ipv6_dst;
-
-		ip6h = data + nh_off;
-		if (ip6h + 1 > data_end) {
-			action = XDP_DROP;
-			goto out;
-		}
-		/* as a real router, we need to check the TTL to prevent never ending loops*/
-		if (ip6h->hop_limit <= 1)
-			goto out;
-
-		/* populate the fib_params fields to prepare for the lookup */
-		fib_params.family	= AF_INET6;
-		fib_params.flowinfo	= *(__be32 *) ip6h & IPV6_FLOWINFO_MASK;
-		fib_params.l4_protocol	= ip6h->nexthdr;
-		fib_params.sport	= 0;
-		fib_params.dport	= 0;
-		fib_params.tot_len	= bpf_ntohs(ip6h->payload_len);
-		*src			= ip6h->saddr;
-		*dst			= ip6h->daddr;
-	} else {
-		goto out;
-	}
-
-	fib_params.ifindex = ctx->ingress_ifindex;
-
-	/* this is where the FIB lookup happens. If the lookup is successful */
-	/* it will populate the fib_params.ifindex with the egress interface index */
-
-	rc = bpf_fib_lookup(ctx, &fib_params, sizeof(fib_params), 0);
-	switch (rc) {
-	case BPF_FIB_LKUP_RET_SUCCESS:         /* lookup successful */
-		   /* we are a router, so we need to decrease the ttl */
-		if (h_proto == bpf_htons(ETH_P_IP))
-			ip_decrease_ttl(iph);
-		else if (h_proto == bpf_htons(ETH_P_IPV6))
-			ip6h->hop_limit--;
-		/* set the correct new source and destionation mac addresses */
-		/* can be found in fib_params.dmac and fib_params.smac */
-		memcpy(eth->h_dest, fib_params.dmac, ETH_ALEN);
-		memcpy(eth->h_source, fib_params.smac, ETH_ALEN);
-		/* and done, now we set the action to bpf_redirect_map with fib_params.ifindex which is the egress port as paramater */
-		action = bpf_redirect_map(&tx_port, fib_params.ifindex, 0);
-		break;
-	case BPF_FIB_LKUP_RET_BLACKHOLE:    /* dest is blackholed; can be dropped */
-	case BPF_FIB_LKUP_RET_UNREACHABLE:  /* dest is unreachable; can be dropped */
-	case BPF_FIB_LKUP_RET_PROHIBIT:     /* dest not allowed; can be dropped */
-		action = XDP_DROP;
-		break;
-	case BPF_FIB_LKUP_RET_NOT_FWDED:    /* packet is not forwarded */
-	case BPF_FIB_LKUP_RET_FWD_DISABLED: /* fwding is not enabled on ingress */
-	case BPF_FIB_LKUP_RET_UNSUPP_LWT:   /* fwd requires encapsulation */
-	case BPF_FIB_LKUP_RET_NO_NEIGH:     /* no neighbor entry for nh */
-	case BPF_FIB_LKUP_RET_FRAG_NEEDED:  /* fragmentation required to fwd */
-		/* PASS */
-		break;
-	}
-
-out:
-	/* and done, update stats and return action */
-	return xdp_stats_record_action(ctx, action);
-}
-
-char _license[] SEC("license") = "GPL";