From 8d48f5e427923fa6f6482c716082d310b7f3bcd5 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Thu, 30 Mar 2017 21:45:42 -0700 Subject: [PATCH] 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 Acked-by: Daniel Borkmann Acked-by: Martin KaFai Lau Signed-off-by: David S. Miller --- tools/testing/selftests/bpf/Makefile | 2 +- .../selftests/bpf/test_iptunnel_common.h | 37 +++ tools/testing/selftests/bpf/test_progs.c | 58 +++++ tools/testing/selftests/bpf/test_xdp.c | 236 ++++++++++++++++++ 4 files changed, 332 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/bpf/test_iptunnel_common.h create mode 100644 tools/testing/selftests/bpf/test_xdp.c diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index ff68c9419a67..76cbe1d42dda 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -6,7 +6,7 @@ LDLIBS += -lcap -lelf TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test_progs -TEST_GEN_FILES = test_pkt_access.o +TEST_GEN_FILES = test_pkt_access.o test_xdp.o TEST_PROGS := test_kmod.sh diff --git a/tools/testing/selftests/bpf/test_iptunnel_common.h b/tools/testing/selftests/bpf/test_iptunnel_common.h new file mode 100644 index 000000000000..e4cd252a1b20 --- /dev/null +++ b/tools/testing/selftests/bpf/test_iptunnel_common.h @@ -0,0 +1,37 @@ +/* Copyright (c) 2016 Facebook + * + * 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. + */ +#ifndef _TEST_IPTNL_COMMON_H +#define _TEST_IPTNL_COMMON_H + +#include + +#define MAX_IPTNL_ENTRIES 256U + +struct vip { + union { + __u32 v6[4]; + __u32 v4; + } daddr; + __u16 dport; + __u16 family; + __u8 protocol; +}; + +struct iptnl_info { + union { + __u32 v6[4]; + __u32 v4; + } saddr; + union { + __u32 v6[4]; + __u32 v4; + } daddr; + __u16 family; + __u8 dmac[6]; +}; + +#endif diff --git a/tools/testing/selftests/bpf/test_progs.c b/tools/testing/selftests/bpf/test_progs.c index 1d9a310e71e5..defcb273242e 100644 --- a/tools/testing/selftests/bpf/test_progs.c +++ b/tools/testing/selftests/bpf/test_progs.c @@ -27,6 +27,7 @@ typedef __u16 __sum16; #include #include #include +#include "test_iptunnel_common.h" #define _htons __builtin_bswap16 @@ -100,6 +101,20 @@ static int bpf_prog_load(const char *file, enum bpf_prog_type type, return 0; } +static int bpf_find_map(const char *test, struct bpf_object *obj, + const char *name) +{ + struct bpf_map *map; + + map = bpf_object__find_map_by_name(obj, name); + if (!map) { + printf("%s:FAIL:map '%s' not found\n", test, name); + error_cnt++; + return -1; + } + return bpf_map__fd(map); +} + static void test_pkt_access(void) { const char *file = "./test_pkt_access.o"; @@ -125,6 +140,48 @@ static void test_pkt_access(void) bpf_object__close(obj); } +static void test_xdp(void) +{ + struct vip key4 = {.protocol = 6, .family = AF_INET}; + struct vip key6 = {.protocol = 6, .family = AF_INET6}; + struct iptnl_info value4 = {.family = AF_INET}; + struct iptnl_info value6 = {.family = AF_INET6}; + const char *file = "./test_xdp.o"; + struct bpf_object *obj; + char buf[128]; + struct ipv6hdr *iph6 = (void *)buf + sizeof(struct ethhdr); + struct iphdr *iph = (void *)buf + sizeof(struct ethhdr); + __u32 duration, retval, size; + int err, prog_fd, map_fd; + + err = bpf_prog_load(file, BPF_PROG_TYPE_XDP, &obj, &prog_fd); + if (err) + return; + + map_fd = bpf_find_map(__func__, obj, "vip2tnl"); + if (map_fd < 0) + goto out; + bpf_map_update_elem(map_fd, &key4, &value4, 0); + bpf_map_update_elem(map_fd, &key6, &value6, 0); + + err = bpf_prog_test_run(prog_fd, 1, &pkt_v4, sizeof(pkt_v4), + buf, &size, &retval, &duration); + + CHECK(err || errno || retval != XDP_TX || size != 74 || + iph->protocol != IPPROTO_IPIP, "ipv4", + "err %d errno %d retval %d size %d\n", + err, errno, retval, size); + + err = bpf_prog_test_run(prog_fd, 1, &pkt_v6, sizeof(pkt_v6), + buf, &size, &retval, &duration); + CHECK(err || errno || retval != XDP_TX || size != 114 || + iph6->nexthdr != IPPROTO_IPV6, "ipv6", + "err %d errno %d retval %d size %d\n", + err, errno, retval, size); +out: + bpf_object__close(obj); +} + int main(void) { struct rlimit rinf = { RLIM_INFINITY, RLIM_INFINITY }; @@ -132,6 +189,7 @@ int main(void) setrlimit(RLIMIT_MEMLOCK, &rinf); test_pkt_access(); + test_xdp(); printf("Summary: %d PASSED, %d FAILED\n", pass_cnt, error_cnt); return 0; diff --git a/tools/testing/selftests/bpf/test_xdp.c b/tools/testing/selftests/bpf/test_xdp.c new file mode 100644 index 000000000000..9a33b038cb31 --- /dev/null +++ b/tools/testing/selftests/bpf/test_xdp.c @@ -0,0 +1,236 @@ +/* Copyright (c) 2016,2017 Facebook + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "bpf_helpers.h" +#include "test_iptunnel_common.h" + +#define htons __builtin_bswap16 +#define ntohs __builtin_bswap16 +int _version SEC("version") = 1; + +struct bpf_map_def SEC("maps") rxcnt = { + .type = BPF_MAP_TYPE_PERCPU_ARRAY, + .key_size = sizeof(__u32), + .value_size = sizeof(__u64), + .max_entries = 256, +}; + +struct bpf_map_def SEC("maps") vip2tnl = { + .type = BPF_MAP_TYPE_HASH, + .key_size = sizeof(struct vip), + .value_size = sizeof(struct iptnl_info), + .max_entries = MAX_IPTNL_ENTRIES, +}; + +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, void *data_end, + __u8 protocol) +{ + struct tcphdr *th; + struct udphdr *uh; + + switch (protocol) { + case IPPROTO_TCP: + th = (struct tcphdr *)trans_data; + if (th + 1 > data_end) + return -1; + return th->dest; + case IPPROTO_UDP: + uh = (struct udphdr *)trans_data; + if (uh + 1 > data_end) + return -1; + 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) +{ + void *data_end = (void *)(long)xdp->data_end; + void *data = (void *)(long)xdp->data; + struct iptnl_info *tnl; + struct ethhdr *new_eth; + struct ethhdr *old_eth; + struct iphdr *iph = data + sizeof(struct ethhdr); + __u16 *next_iph; + __u16 payload_len; + struct vip vip = {}; + int dport; + __u32 csum = 0; + int i; + + if (iph + 1 > data_end) + return XDP_DROP; + + dport = get_dport(iph + 1, data_end, 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 = 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)sizeof(struct iphdr))) + return XDP_DROP; + + data = (void *)(long)xdp->data; + data_end = (void *)(long)xdp->data_end; + + new_eth = data; + iph = data + sizeof(*new_eth); + old_eth = data + sizeof(*iph); + + if (new_eth + 1 > data_end || + old_eth + 1 > data_end || + iph + 1 > data_end) + return XDP_DROP; + + set_ethhdr(new_eth, old_eth, tnl, htons(ETH_P_IP)); + + iph->version = 4; + iph->ihl = sizeof(*iph) >> 2; + iph->frag_off = 0; + iph->protocol = IPPROTO_IPIP; + iph->check = 0; + iph->tos = 0; + iph->tot_len = htons(payload_len + sizeof(*iph)); + iph->daddr = tnl->daddr.v4; + iph->saddr = tnl->saddr.v4; + iph->ttl = 8; + + next_iph = (__u16 *)iph; +#pragma clang loop unroll(full) + for (i = 0; i < sizeof(*iph) >> 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) +{ + void *data_end = (void *)(long)xdp->data_end; + void *data = (void *)(long)xdp->data; + struct iptnl_info *tnl; + struct ethhdr *new_eth; + struct ethhdr *old_eth; + struct ipv6hdr *ip6h = data + sizeof(struct ethhdr); + __u16 payload_len; + struct vip vip = {}; + int dport; + + if (ip6h + 1 > data_end) + return XDP_DROP; + + dport = get_dport(ip6h + 1, data_end, 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)sizeof(struct ipv6hdr))) + return XDP_DROP; + + data = (void *)(long)xdp->data; + data_end = (void *)(long)xdp->data_end; + + new_eth = data; + ip6h = data + sizeof(*new_eth); + old_eth = data + sizeof(*ip6h); + + if (new_eth + 1 > data_end || old_eth + 1 > data_end || + ip6h + 1 > data_end) + return XDP_DROP; + + set_ethhdr(new_eth, old_eth, tnl, htons(ETH_P_IPV6)); + + ip6h->version = 6; + ip6h->priority = 0; + memset(ip6h->flow_lbl, 0, sizeof(ip6h->flow_lbl)); + ip6h->payload_len = htons(ntohs(payload_len) + sizeof(*ip6h)); + 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_tx_iptunnel") +int _xdp_tx_iptunnel(struct xdp_md *xdp) +{ + void *data_end = (void *)(long)xdp->data_end; + void *data = (void *)(long)xdp->data; + struct ethhdr *eth = data; + __u16 h_proto; + + if (eth + 1 > data_end) + return XDP_DROP; + + h_proto = eth->h_proto; + + if (h_proto == htons(ETH_P_IP)) + return handle_ipv4(xdp); + else if (h_proto == htons(ETH_P_IPV6)) + + return handle_ipv6(xdp); + else + return XDP_DROP; +} + +char _license[] SEC("license") = "GPL"; -- 2.20.1