selftests/bpf: add a test for basic XDP functionality
add C test for xdp_adjust_head(), packet rewrite and map lookups Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Alexei Starovoitov
committed by
David S. Miller
David S. Miller
parent
6882804c91
commit
8d48f5e427
236
tools/testing/selftests/bpf/test_xdp.c
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236
tools/testing/selftests/bpf/test_xdp.c
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/* Copyright (c) 2016,2017 Facebook
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of version 2 of the GNU General Public
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* License as published by the Free Software Foundation.
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*/
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#include <stddef.h>
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#include <string.h>
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#include <linux/bpf.h>
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#include <linux/if_ether.h>
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#include <linux/if_packet.h>
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#include <linux/ip.h>
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#include <linux/ipv6.h>
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#include <linux/in.h>
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#include <linux/udp.h>
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#include <linux/tcp.h>
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#include <linux/pkt_cls.h>
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#include <sys/socket.h>
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#include "bpf_helpers.h"
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#include "test_iptunnel_common.h"
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#define htons __builtin_bswap16
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#define ntohs __builtin_bswap16
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int _version SEC("version") = 1;
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struct bpf_map_def SEC("maps") rxcnt = {
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.type = BPF_MAP_TYPE_PERCPU_ARRAY,
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.key_size = sizeof(__u32),
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.value_size = sizeof(__u64),
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.max_entries = 256,
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};
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struct bpf_map_def SEC("maps") vip2tnl = {
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.type = BPF_MAP_TYPE_HASH,
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.key_size = sizeof(struct vip),
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.value_size = sizeof(struct iptnl_info),
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.max_entries = MAX_IPTNL_ENTRIES,
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};
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static __always_inline void count_tx(__u32 protocol)
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{
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__u64 *rxcnt_count;
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rxcnt_count = bpf_map_lookup_elem(&rxcnt, &protocol);
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if (rxcnt_count)
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*rxcnt_count += 1;
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}
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static __always_inline int get_dport(void *trans_data, void *data_end,
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__u8 protocol)
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{
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struct tcphdr *th;
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struct udphdr *uh;
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switch (protocol) {
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case IPPROTO_TCP:
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th = (struct tcphdr *)trans_data;
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if (th + 1 > data_end)
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return -1;
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return th->dest;
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case IPPROTO_UDP:
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uh = (struct udphdr *)trans_data;
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if (uh + 1 > data_end)
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return -1;
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return uh->dest;
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default:
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return 0;
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}
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}
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static __always_inline void set_ethhdr(struct ethhdr *new_eth,
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const struct ethhdr *old_eth,
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const struct iptnl_info *tnl,
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__be16 h_proto)
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{
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memcpy(new_eth->h_source, old_eth->h_dest, sizeof(new_eth->h_source));
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memcpy(new_eth->h_dest, tnl->dmac, sizeof(new_eth->h_dest));
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new_eth->h_proto = h_proto;
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}
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static __always_inline int handle_ipv4(struct xdp_md *xdp)
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{
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void *data_end = (void *)(long)xdp->data_end;
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void *data = (void *)(long)xdp->data;
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struct iptnl_info *tnl;
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struct ethhdr *new_eth;
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struct ethhdr *old_eth;
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struct iphdr *iph = data + sizeof(struct ethhdr);
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__u16 *next_iph;
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__u16 payload_len;
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struct vip vip = {};
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int dport;
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__u32 csum = 0;
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int i;
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if (iph + 1 > data_end)
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return XDP_DROP;
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dport = get_dport(iph + 1, data_end, iph->protocol);
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if (dport == -1)
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return XDP_DROP;
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vip.protocol = iph->protocol;
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vip.family = AF_INET;
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vip.daddr.v4 = iph->daddr;
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vip.dport = dport;
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payload_len = ntohs(iph->tot_len);
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tnl = bpf_map_lookup_elem(&vip2tnl, &vip);
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/* It only does v4-in-v4 */
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if (!tnl || tnl->family != AF_INET)
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return XDP_PASS;
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if (bpf_xdp_adjust_head(xdp, 0 - (int)sizeof(struct iphdr)))
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return XDP_DROP;
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data = (void *)(long)xdp->data;
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data_end = (void *)(long)xdp->data_end;
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new_eth = data;
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iph = data + sizeof(*new_eth);
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old_eth = data + sizeof(*iph);
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if (new_eth + 1 > data_end ||
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old_eth + 1 > data_end ||
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iph + 1 > data_end)
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return XDP_DROP;
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set_ethhdr(new_eth, old_eth, tnl, htons(ETH_P_IP));
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iph->version = 4;
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iph->ihl = sizeof(*iph) >> 2;
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iph->frag_off = 0;
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iph->protocol = IPPROTO_IPIP;
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iph->check = 0;
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iph->tos = 0;
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iph->tot_len = htons(payload_len + sizeof(*iph));
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iph->daddr = tnl->daddr.v4;
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iph->saddr = tnl->saddr.v4;
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iph->ttl = 8;
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next_iph = (__u16 *)iph;
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#pragma clang loop unroll(full)
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for (i = 0; i < sizeof(*iph) >> 1; i++)
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csum += *next_iph++;
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iph->check = ~((csum & 0xffff) + (csum >> 16));
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count_tx(vip.protocol);
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return XDP_TX;
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}
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static __always_inline int handle_ipv6(struct xdp_md *xdp)
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{
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void *data_end = (void *)(long)xdp->data_end;
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void *data = (void *)(long)xdp->data;
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struct iptnl_info *tnl;
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struct ethhdr *new_eth;
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struct ethhdr *old_eth;
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struct ipv6hdr *ip6h = data + sizeof(struct ethhdr);
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__u16 payload_len;
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struct vip vip = {};
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int dport;
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if (ip6h + 1 > data_end)
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return XDP_DROP;
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dport = get_dport(ip6h + 1, data_end, ip6h->nexthdr);
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if (dport == -1)
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return XDP_DROP;
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vip.protocol = ip6h->nexthdr;
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vip.family = AF_INET6;
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memcpy(vip.daddr.v6, ip6h->daddr.s6_addr32, sizeof(vip.daddr));
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vip.dport = dport;
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payload_len = ip6h->payload_len;
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tnl = bpf_map_lookup_elem(&vip2tnl, &vip);
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/* It only does v6-in-v6 */
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if (!tnl || tnl->family != AF_INET6)
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return XDP_PASS;
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if (bpf_xdp_adjust_head(xdp, 0 - (int)sizeof(struct ipv6hdr)))
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return XDP_DROP;
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data = (void *)(long)xdp->data;
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data_end = (void *)(long)xdp->data_end;
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new_eth = data;
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ip6h = data + sizeof(*new_eth);
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old_eth = data + sizeof(*ip6h);
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if (new_eth + 1 > data_end || old_eth + 1 > data_end ||
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ip6h + 1 > data_end)
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return XDP_DROP;
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set_ethhdr(new_eth, old_eth, tnl, htons(ETH_P_IPV6));
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ip6h->version = 6;
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ip6h->priority = 0;
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memset(ip6h->flow_lbl, 0, sizeof(ip6h->flow_lbl));
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ip6h->payload_len = htons(ntohs(payload_len) + sizeof(*ip6h));
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ip6h->nexthdr = IPPROTO_IPV6;
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ip6h->hop_limit = 8;
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memcpy(ip6h->saddr.s6_addr32, tnl->saddr.v6, sizeof(tnl->saddr.v6));
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memcpy(ip6h->daddr.s6_addr32, tnl->daddr.v6, sizeof(tnl->daddr.v6));
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count_tx(vip.protocol);
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return XDP_TX;
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}
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SEC("xdp_tx_iptunnel")
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int _xdp_tx_iptunnel(struct xdp_md *xdp)
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{
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void *data_end = (void *)(long)xdp->data_end;
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void *data = (void *)(long)xdp->data;
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struct ethhdr *eth = data;
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__u16 h_proto;
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if (eth + 1 > data_end)
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return XDP_DROP;
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h_proto = eth->h_proto;
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if (h_proto == htons(ETH_P_IP))
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return handle_ipv4(xdp);
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else if (h_proto == htons(ETH_P_IPV6))
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return handle_ipv6(xdp);
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else
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return XDP_DROP;
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}
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char _license[] SEC("license") = "GPL";
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