diff options
Diffstat (limited to 'tools/testing/selftests/bpf/progs/test_xdp_dynptr.c')
| -rw-r--r-- | tools/testing/selftests/bpf/progs/test_xdp_dynptr.c | 256 |
1 files changed, 256 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/test_xdp_dynptr.c b/tools/testing/selftests/bpf/progs/test_xdp_dynptr.c new file mode 100644 index 000000000000..67a77944ef29 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_xdp_dynptr.c @@ -0,0 +1,256 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Meta */ +#include <stddef.h> +#include <string.h> +#include <stdbool.h> +#include <linux/bpf.h> +#include <linux/if_ether.h> +#include <linux/if_packet.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <linux/in.h> +#include <linux/udp.h> +#include <linux/tcp.h> +#include <linux/pkt_cls.h> +#include <sys/socket.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_endian.h> +#include "test_iptunnel_common.h" +#include "bpf_kfuncs.h" + +#define tcphdr_sz sizeof(struct tcphdr) +#define udphdr_sz sizeof(struct udphdr) +#define ethhdr_sz sizeof(struct ethhdr) +#define iphdr_sz sizeof(struct iphdr) +#define ipv6hdr_sz sizeof(struct ipv6hdr) + +struct { + __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); + __uint(max_entries, 256); + __type(key, __u32); + __type(value, __u64); +} rxcnt SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __uint(max_entries, MAX_IPTNL_ENTRIES); + __type(key, struct vip); + __type(value, struct iptnl_info); +} vip2tnl SEC(".maps"); + +static __always_inline void count_tx(__u32 protocol) +{ + __u64 *rxcnt_count; + + rxcnt_count = bpf_map_lookup_elem(&rxcnt, &protocol); + if (rxcnt_count) + *rxcnt_count += 1; +} + +static __always_inline int get_dport(void *trans_data, __u8 protocol) +{ + struct tcphdr *th; + struct udphdr *uh; + + switch (protocol) { + case IPPROTO_TCP: + th = (struct tcphdr *)trans_data; + return th->dest; + case IPPROTO_UDP: + uh = (struct udphdr *)trans_data; + return uh->dest; + default: + return 0; + } +} + +static __always_inline void set_ethhdr(struct ethhdr *new_eth, + const struct ethhdr *old_eth, + const struct iptnl_info *tnl, + __be16 h_proto) +{ + memcpy(new_eth->h_source, old_eth->h_dest, sizeof(new_eth->h_source)); + memcpy(new_eth->h_dest, tnl->dmac, sizeof(new_eth->h_dest)); + new_eth->h_proto = h_proto; +} + +static __always_inline int handle_ipv4(struct xdp_md *xdp, struct bpf_dynptr *xdp_ptr) +{ + __u8 eth_buffer[ethhdr_sz + iphdr_sz + ethhdr_sz]; + __u8 iph_buffer_tcp[iphdr_sz + tcphdr_sz]; + __u8 iph_buffer_udp[iphdr_sz + udphdr_sz]; + struct bpf_dynptr new_xdp_ptr; + struct iptnl_info *tnl; + struct ethhdr *new_eth; + struct ethhdr *old_eth; + struct iphdr *iph; + __u16 *next_iph; + __u16 payload_len; + struct vip vip = {}; + int dport; + __u32 csum = 0; + int i; + + __builtin_memset(eth_buffer, 0, sizeof(eth_buffer)); + __builtin_memset(iph_buffer_tcp, 0, sizeof(iph_buffer_tcp)); + __builtin_memset(iph_buffer_udp, 0, sizeof(iph_buffer_udp)); + + if (ethhdr_sz + iphdr_sz + tcphdr_sz > xdp->data_end - xdp->data) + iph = bpf_dynptr_slice(xdp_ptr, ethhdr_sz, iph_buffer_udp, sizeof(iph_buffer_udp)); + else + iph = bpf_dynptr_slice(xdp_ptr, ethhdr_sz, iph_buffer_tcp, sizeof(iph_buffer_tcp)); + + if (!iph) + return XDP_DROP; + + dport = get_dport(iph + 1, iph->protocol); + if (dport == -1) + return XDP_DROP; + + vip.protocol = iph->protocol; + vip.family = AF_INET; + vip.daddr.v4 = iph->daddr; + vip.dport = dport; + payload_len = bpf_ntohs(iph->tot_len); + + tnl = bpf_map_lookup_elem(&vip2tnl, &vip); + /* It only does v4-in-v4 */ + if (!tnl || tnl->family != AF_INET) + return XDP_PASS; + + if (bpf_xdp_adjust_head(xdp, 0 - (int)iphdr_sz)) + return XDP_DROP; + + bpf_dynptr_from_xdp(xdp, 0, &new_xdp_ptr); + new_eth = bpf_dynptr_slice_rdwr(&new_xdp_ptr, 0, eth_buffer, sizeof(eth_buffer)); + if (!new_eth) + return XDP_DROP; + + iph = (struct iphdr *)(new_eth + 1); + old_eth = (struct ethhdr *)(iph + 1); + + set_ethhdr(new_eth, old_eth, tnl, bpf_htons(ETH_P_IP)); + + if (new_eth == eth_buffer) + bpf_dynptr_write(&new_xdp_ptr, 0, eth_buffer, sizeof(eth_buffer), 0); + + iph->version = 4; + iph->ihl = iphdr_sz >> 2; + iph->frag_off = 0; + iph->protocol = IPPROTO_IPIP; + iph->check = 0; + iph->tos = 0; + iph->tot_len = bpf_htons(payload_len + iphdr_sz); + iph->daddr = tnl->daddr.v4; + iph->saddr = tnl->saddr.v4; + iph->ttl = 8; + + next_iph = (__u16 *)iph; + for (i = 0; i < iphdr_sz >> 1; i++) + csum += *next_iph++; + + iph->check = ~((csum & 0xffff) + (csum >> 16)); + + count_tx(vip.protocol); + + return XDP_TX; +} + +static __always_inline int handle_ipv6(struct xdp_md *xdp, struct bpf_dynptr *xdp_ptr) +{ + __u8 eth_buffer[ethhdr_sz + ipv6hdr_sz + ethhdr_sz]; + __u8 ip6h_buffer_tcp[ipv6hdr_sz + tcphdr_sz]; + __u8 ip6h_buffer_udp[ipv6hdr_sz + udphdr_sz]; + struct bpf_dynptr new_xdp_ptr; + struct iptnl_info *tnl; + struct ethhdr *new_eth; + struct ethhdr *old_eth; + struct ipv6hdr *ip6h; + __u16 payload_len; + struct vip vip = {}; + int dport; + + __builtin_memset(eth_buffer, 0, sizeof(eth_buffer)); + __builtin_memset(ip6h_buffer_tcp, 0, sizeof(ip6h_buffer_tcp)); + __builtin_memset(ip6h_buffer_udp, 0, sizeof(ip6h_buffer_udp)); + + if (ethhdr_sz + iphdr_sz + tcphdr_sz > xdp->data_end - xdp->data) + ip6h = bpf_dynptr_slice(xdp_ptr, ethhdr_sz, ip6h_buffer_udp, sizeof(ip6h_buffer_udp)); + else + ip6h = bpf_dynptr_slice(xdp_ptr, ethhdr_sz, ip6h_buffer_tcp, sizeof(ip6h_buffer_tcp)); + + if (!ip6h) + return XDP_DROP; + + dport = get_dport(ip6h + 1, ip6h->nexthdr); + if (dport == -1) + return XDP_DROP; + + vip.protocol = ip6h->nexthdr; + vip.family = AF_INET6; + memcpy(vip.daddr.v6, ip6h->daddr.s6_addr32, sizeof(vip.daddr)); + vip.dport = dport; + payload_len = ip6h->payload_len; + + tnl = bpf_map_lookup_elem(&vip2tnl, &vip); + /* It only does v6-in-v6 */ + if (!tnl || tnl->family != AF_INET6) + return XDP_PASS; + + if (bpf_xdp_adjust_head(xdp, 0 - (int)ipv6hdr_sz)) + return XDP_DROP; + + bpf_dynptr_from_xdp(xdp, 0, &new_xdp_ptr); + new_eth = bpf_dynptr_slice_rdwr(&new_xdp_ptr, 0, eth_buffer, sizeof(eth_buffer)); + if (!new_eth) + return XDP_DROP; + + ip6h = (struct ipv6hdr *)(new_eth + 1); + old_eth = (struct ethhdr *)(ip6h + 1); + + set_ethhdr(new_eth, old_eth, tnl, bpf_htons(ETH_P_IPV6)); + + if (new_eth == eth_buffer) + bpf_dynptr_write(&new_xdp_ptr, 0, eth_buffer, sizeof(eth_buffer), 0); + + ip6h->version = 6; + ip6h->priority = 0; + memset(ip6h->flow_lbl, 0, sizeof(ip6h->flow_lbl)); + ip6h->payload_len = bpf_htons(bpf_ntohs(payload_len) + ipv6hdr_sz); + ip6h->nexthdr = IPPROTO_IPV6; + ip6h->hop_limit = 8; + memcpy(ip6h->saddr.s6_addr32, tnl->saddr.v6, sizeof(tnl->saddr.v6)); + memcpy(ip6h->daddr.s6_addr32, tnl->daddr.v6, sizeof(tnl->daddr.v6)); + + count_tx(vip.protocol); + + return XDP_TX; +} + +SEC("xdp") +int _xdp_tx_iptunnel(struct xdp_md *xdp) +{ + __u8 buffer[ethhdr_sz]; + struct bpf_dynptr ptr; + struct ethhdr *eth; + __u16 h_proto; + + __builtin_memset(buffer, 0, sizeof(buffer)); + + bpf_dynptr_from_xdp(xdp, 0, &ptr); + eth = bpf_dynptr_slice(&ptr, 0, buffer, sizeof(buffer)); + if (!eth) + return XDP_DROP; + + h_proto = eth->h_proto; + + if (h_proto == bpf_htons(ETH_P_IP)) + return handle_ipv4(xdp, &ptr); + else if (h_proto == bpf_htons(ETH_P_IPV6)) + + return handle_ipv6(xdp, &ptr); + else + return XDP_DROP; +} + +char _license[] SEC("license") = "GPL"; |