1// SPDX-License-Identifier: GPL-2.0
  2
  3#include <vmlinux.h>
  4#include "xdp_metadata.h"
  5#include <bpf/bpf_helpers.h>
  6#include <bpf/bpf_endian.h>
  7
  8struct {
  9	__uint(type, BPF_MAP_TYPE_XSKMAP);
 10	__uint(max_entries, 256);
 11	__type(key, __u32);
 12	__type(value, __u32);
 13} xsk SEC(".maps");
 14
 15__u64 pkts_skip = 0;
 16__u64 pkts_fail = 0;
 17__u64 pkts_redir = 0;
 18
 19extern int bpf_xdp_metadata_rx_timestamp(const struct xdp_md *ctx,
 20					 __u64 *timestamp) __ksym;
 21extern int bpf_xdp_metadata_rx_hash(const struct xdp_md *ctx, __u32 *hash,
 22				    enum xdp_rss_hash_type *rss_type) __ksym;
 23extern int bpf_xdp_metadata_rx_vlan_tag(const struct xdp_md *ctx,
 24					__be16 *vlan_proto,
 25					__u16 *vlan_tci) __ksym;
 26
 27SEC("xdp.frags")
 28int rx(struct xdp_md *ctx)
 29{
 30	void *data, *data_meta, *data_end;
 31	struct ipv6hdr *ip6h = NULL;
 32	struct udphdr *udp = NULL;
 33	struct iphdr *iph = NULL;
 34	struct xdp_meta *meta;
 35	struct ethhdr *eth;
 36	int err;
 37
 38	data = (void *)(long)ctx->data;
 39	data_end = (void *)(long)ctx->data_end;
 40	eth = data;
 41
 42	if (eth + 1 < data_end && (eth->h_proto == bpf_htons(ETH_P_8021AD) ||
 43				   eth->h_proto == bpf_htons(ETH_P_8021Q)))
 44		eth = (void *)eth + sizeof(struct vlan_hdr);
 45
 46	if (eth + 1 < data_end && eth->h_proto == bpf_htons(ETH_P_8021Q))
 47		eth = (void *)eth + sizeof(struct vlan_hdr);
 48
 49	if (eth + 1 < data_end) {
 50		if (eth->h_proto == bpf_htons(ETH_P_IP)) {
 51			iph = (void *)(eth + 1);
 52			if (iph + 1 < data_end && iph->protocol == IPPROTO_UDP)
 53				udp = (void *)(iph + 1);
 54		}
 55		if (eth->h_proto == bpf_htons(ETH_P_IPV6)) {
 56			ip6h = (void *)(eth + 1);
 57			if (ip6h + 1 < data_end && ip6h->nexthdr == IPPROTO_UDP)
 58				udp = (void *)(ip6h + 1);
 59		}
 60		if (udp && udp + 1 > data_end)
 61			udp = NULL;
 62	}
 63
 64	if (!udp) {
 65		__sync_add_and_fetch(&pkts_skip, 1);
 66		return XDP_PASS;
 67	}
 68
 69	/* Forwarding UDP:9091 to AF_XDP */
 70	if (udp->dest != bpf_htons(9091)) {
 71		__sync_add_and_fetch(&pkts_skip, 1);
 72		return XDP_PASS;
 73	}
 74
 75	err = bpf_xdp_adjust_meta(ctx, -(int)sizeof(struct xdp_meta));
 76	if (err) {
 77		__sync_add_and_fetch(&pkts_fail, 1);
 78		return XDP_PASS;
 79	}
 80
 81	data = (void *)(long)ctx->data;
 82	data_meta = (void *)(long)ctx->data_meta;
 83	meta = data_meta;
 84
 85	if (meta + 1 > data) {
 86		__sync_add_and_fetch(&pkts_fail, 1);
 87		return XDP_PASS;
 88	}
 89
 90	meta->hint_valid = 0;
 91
 92	meta->xdp_timestamp = bpf_ktime_get_tai_ns();
 93	err = bpf_xdp_metadata_rx_timestamp(ctx, &meta->rx_timestamp);
 94	if (err)
 95		meta->rx_timestamp_err = err;
 96	else
 97		meta->hint_valid |= XDP_META_FIELD_TS;
 98
 99	err = bpf_xdp_metadata_rx_hash(ctx, &meta->rx_hash,
100				       &meta->rx_hash_type);
101	if (err)
102		meta->rx_hash_err = err;
103	else
104		meta->hint_valid |= XDP_META_FIELD_RSS;
105
106	err = bpf_xdp_metadata_rx_vlan_tag(ctx, &meta->rx_vlan_proto,
107					   &meta->rx_vlan_tci);
108	if (err)
109		meta->rx_vlan_tag_err = err;
110	else
111		meta->hint_valid |= XDP_META_FIELD_VLAN_TAG;
112
113	__sync_add_and_fetch(&pkts_redir, 1);
114	return bpf_redirect_map(&xsk, ctx->rx_queue_index, XDP_PASS);
115}
116
117char _license[] SEC("license") = "GPL";