From 0905beec9f52caf2c7065a8a88c08bc370850710 Mon Sep 17 00:00:00 2001 From: Stanislav Fomichev Date: Mon, 22 Apr 2019 08:55:50 -0700 Subject: selftests/bpf: run flow dissector tests in skb-less mode Export last_dissection map from flow dissector and use a known place in tun driver to trigger BPF flow dissection. Signed-off-by: Stanislav Fomichev Signed-off-by: Daniel Borkmann --- tools/testing/selftests/bpf/flow_dissector_load.c | 2 +- tools/testing/selftests/bpf/flow_dissector_load.h | 16 +++- .../selftests/bpf/prog_tests/flow_dissector.c | 102 ++++++++++++++++++++- tools/testing/selftests/bpf/progs/bpf_flow.c | 79 ++++++++++------ 4 files changed, 165 insertions(+), 34 deletions(-) (limited to 'tools/testing/selftests') diff --git a/tools/testing/selftests/bpf/flow_dissector_load.c b/tools/testing/selftests/bpf/flow_dissector_load.c index 7136ab9ffa73..3fd83b9dc1bf 100644 --- a/tools/testing/selftests/bpf/flow_dissector_load.c +++ b/tools/testing/selftests/bpf/flow_dissector_load.c @@ -26,7 +26,7 @@ static void load_and_attach_program(void) struct bpf_object *obj; ret = bpf_flow_load(&obj, cfg_path_name, cfg_section_name, - cfg_map_name, &prog_fd); + cfg_map_name, NULL, &prog_fd, NULL); if (ret) error(1, 0, "bpf_flow_load %s", cfg_path_name); diff --git a/tools/testing/selftests/bpf/flow_dissector_load.h b/tools/testing/selftests/bpf/flow_dissector_load.h index 41dd6959feb0..eeb48b6fc827 100644 --- a/tools/testing/selftests/bpf/flow_dissector_load.h +++ b/tools/testing/selftests/bpf/flow_dissector_load.h @@ -9,10 +9,12 @@ static inline int bpf_flow_load(struct bpf_object **obj, const char *path, const char *section_name, const char *map_name, - int *prog_fd) + const char *keys_map_name, + int *prog_fd, + int *keys_fd) { struct bpf_program *prog, *main_prog; - struct bpf_map *prog_array; + struct bpf_map *prog_array, *keys; int prog_array_fd; int ret, fd, i; @@ -37,6 +39,16 @@ static inline int bpf_flow_load(struct bpf_object **obj, if (prog_array_fd < 0) return ret; + if (keys_map_name && keys_fd) { + keys = bpf_object__find_map_by_name(*obj, keys_map_name); + if (!keys) + return -1; + + *keys_fd = bpf_map__fd(keys); + if (*keys_fd < 0) + return -1; + } + i = 0; bpf_object__for_each_program(prog, *obj) { fd = bpf_program__fd(prog); diff --git a/tools/testing/selftests/bpf/prog_tests/flow_dissector.c b/tools/testing/selftests/bpf/prog_tests/flow_dissector.c index 126319f9a97c..51758a0ca55e 100644 --- a/tools/testing/selftests/bpf/prog_tests/flow_dissector.c +++ b/tools/testing/selftests/bpf/prog_tests/flow_dissector.c @@ -1,5 +1,8 @@ // SPDX-License-Identifier: GPL-2.0 #include +#include +#include +#include #define CHECK_FLOW_KEYS(desc, got, expected) \ CHECK_ATTR(memcmp(&got, &expected, sizeof(got)) != 0, \ @@ -140,13 +143,73 @@ struct test tests[] = { }, }; +static int create_tap(const char *ifname) +{ + struct ifreq ifr = { + .ifr_flags = IFF_TAP | IFF_NO_PI | IFF_NAPI | IFF_NAPI_FRAGS, + }; + int fd, ret; + + strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name)); + + fd = open("/dev/net/tun", O_RDWR); + if (fd < 0) + return -1; + + ret = ioctl(fd, TUNSETIFF, &ifr); + if (ret) + return -1; + + return fd; +} + +static int tx_tap(int fd, void *pkt, size_t len) +{ + struct iovec iov[] = { + { + .iov_len = len, + .iov_base = pkt, + }, + }; + return writev(fd, iov, ARRAY_SIZE(iov)); +} + +static int ifup(const char *ifname) +{ + struct ifreq ifr = {}; + int sk, ret; + + strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name)); + + sk = socket(PF_INET, SOCK_DGRAM, 0); + if (sk < 0) + return -1; + + ret = ioctl(sk, SIOCGIFFLAGS, &ifr); + if (ret) { + close(sk); + return -1; + } + + ifr.ifr_flags |= IFF_UP; + ret = ioctl(sk, SIOCSIFFLAGS, &ifr); + if (ret) { + close(sk); + return -1; + } + + close(sk); + return 0; +} + void test_flow_dissector(void) { + int i, err, prog_fd, keys_fd = -1, tap_fd; struct bpf_object *obj; - int i, err, prog_fd; + __u32 duration = 0; err = bpf_flow_load(&obj, "./bpf_flow.o", "flow_dissector", - "jmp_table", &prog_fd); + "jmp_table", "last_dissection", &prog_fd, &keys_fd); if (err) { error_cnt++; return; @@ -171,5 +234,40 @@ void test_flow_dissector(void) CHECK_FLOW_KEYS(tests[i].name, flow_keys, tests[i].keys); } + /* Do the same tests but for skb-less flow dissector. + * We use a known path in the net/tun driver that calls + * eth_get_headlen and we manually export bpf_flow_keys + * via BPF map in this case. + * + * Note, that since eth_get_headlen operates on a L2 level, + * we adjust exported nhoff/thoff by ETH_HLEN. + */ + + err = bpf_prog_attach(prog_fd, 0, BPF_FLOW_DISSECTOR, 0); + CHECK(err, "bpf_prog_attach", "err %d errno %d", err, errno); + + tap_fd = create_tap("tap0"); + CHECK(tap_fd < 0, "create_tap", "tap_fd %d errno %d", tap_fd, errno); + err = ifup("tap0"); + CHECK(err, "ifup", "err %d errno %d", err, errno); + + for (i = 0; i < ARRAY_SIZE(tests); i++) { + struct bpf_flow_keys flow_keys = {}; + struct bpf_prog_test_run_attr tattr = {}; + __u32 key = 0; + + err = tx_tap(tap_fd, &tests[i].pkt, sizeof(tests[i].pkt)); + CHECK(err < 0, "tx_tap", "err %d errno %d", err, errno); + + err = bpf_map_lookup_elem(keys_fd, &key, &flow_keys); + CHECK_ATTR(err, tests[i].name, "bpf_map_lookup_elem %d\n", err); + + flow_keys.nhoff -= ETH_HLEN; + flow_keys.thoff -= ETH_HLEN; + + CHECK_ATTR(err, tests[i].name, "skb-less err %d\n", err); + CHECK_FLOW_KEYS(tests[i].name, flow_keys, tests[i].keys); + } + bpf_object__close(obj); } diff --git a/tools/testing/selftests/bpf/progs/bpf_flow.c b/tools/testing/selftests/bpf/progs/bpf_flow.c index 75b17cada539..81ad9a0b29d0 100644 --- a/tools/testing/selftests/bpf/progs/bpf_flow.c +++ b/tools/testing/selftests/bpf/progs/bpf_flow.c @@ -64,6 +64,25 @@ struct bpf_map_def SEC("maps") jmp_table = { .max_entries = 8 }; +struct bpf_map_def SEC("maps") last_dissection = { + .type = BPF_MAP_TYPE_ARRAY, + .key_size = sizeof(__u32), + .value_size = sizeof(struct bpf_flow_keys), + .max_entries = 1, +}; + +static __always_inline int export_flow_keys(struct bpf_flow_keys *keys, + int ret) +{ + struct bpf_flow_keys *val; + __u32 key = 0; + + val = bpf_map_lookup_elem(&last_dissection, &key); + if (val) + memcpy(val, keys, sizeof(*val)); + return ret; +} + static __always_inline void *bpf_flow_dissect_get_header(struct __sk_buff *skb, __u16 hdr_size, void *buffer) @@ -109,10 +128,10 @@ static __always_inline int parse_eth_proto(struct __sk_buff *skb, __be16 proto) break; default: /* Protocol not supported */ - return BPF_DROP; + return export_flow_keys(keys, BPF_DROP); } - return BPF_DROP; + return export_flow_keys(keys, BPF_DROP); } SEC("flow_dissector") @@ -139,8 +158,8 @@ static __always_inline int parse_ip_proto(struct __sk_buff *skb, __u8 proto) case IPPROTO_ICMP: icmp = bpf_flow_dissect_get_header(skb, sizeof(*icmp), &_icmp); if (!icmp) - return BPF_DROP; - return BPF_OK; + return export_flow_keys(keys, BPF_DROP); + return export_flow_keys(keys, BPF_OK); case IPPROTO_IPIP: keys->is_encap = true; return parse_eth_proto(skb, bpf_htons(ETH_P_IP)); @@ -150,11 +169,11 @@ static __always_inline int parse_ip_proto(struct __sk_buff *skb, __u8 proto) case IPPROTO_GRE: gre = bpf_flow_dissect_get_header(skb, sizeof(*gre), &_gre); if (!gre) - return BPF_DROP; + return export_flow_keys(keys, BPF_DROP); if (bpf_htons(gre->flags & GRE_VERSION)) /* Only inspect standard GRE packets with version 0 */ - return BPF_OK; + return export_flow_keys(keys, BPF_OK); keys->thoff += sizeof(*gre); /* Step over GRE Flags and Proto */ if (GRE_IS_CSUM(gre->flags)) @@ -170,7 +189,7 @@ static __always_inline int parse_ip_proto(struct __sk_buff *skb, __u8 proto) eth = bpf_flow_dissect_get_header(skb, sizeof(*eth), &_eth); if (!eth) - return BPF_DROP; + return export_flow_keys(keys, BPF_DROP); keys->thoff += sizeof(*eth); @@ -181,31 +200,31 @@ static __always_inline int parse_ip_proto(struct __sk_buff *skb, __u8 proto) case IPPROTO_TCP: tcp = bpf_flow_dissect_get_header(skb, sizeof(*tcp), &_tcp); if (!tcp) - return BPF_DROP; + return export_flow_keys(keys, BPF_DROP); if (tcp->doff < 5) - return BPF_DROP; + return export_flow_keys(keys, BPF_DROP); if ((__u8 *)tcp + (tcp->doff << 2) > data_end) - return BPF_DROP; + return export_flow_keys(keys, BPF_DROP); keys->sport = tcp->source; keys->dport = tcp->dest; - return BPF_OK; + return export_flow_keys(keys, BPF_OK); case IPPROTO_UDP: case IPPROTO_UDPLITE: udp = bpf_flow_dissect_get_header(skb, sizeof(*udp), &_udp); if (!udp) - return BPF_DROP; + return export_flow_keys(keys, BPF_DROP); keys->sport = udp->source; keys->dport = udp->dest; - return BPF_OK; + return export_flow_keys(keys, BPF_OK); default: - return BPF_DROP; + return export_flow_keys(keys, BPF_DROP); } - return BPF_DROP; + return export_flow_keys(keys, BPF_DROP); } static __always_inline int parse_ipv6_proto(struct __sk_buff *skb, __u8 nexthdr) @@ -225,7 +244,7 @@ static __always_inline int parse_ipv6_proto(struct __sk_buff *skb, __u8 nexthdr) return parse_ip_proto(skb, nexthdr); } - return BPF_DROP; + return export_flow_keys(keys, BPF_DROP); } PROG(IP)(struct __sk_buff *skb) @@ -238,11 +257,11 @@ PROG(IP)(struct __sk_buff *skb) iph = bpf_flow_dissect_get_header(skb, sizeof(*iph), &_iph); if (!iph) - return BPF_DROP; + return export_flow_keys(keys, BPF_DROP); /* IP header cannot be smaller than 20 bytes */ if (iph->ihl < 5) - return BPF_DROP; + return export_flow_keys(keys, BPF_DROP); keys->addr_proto = ETH_P_IP; keys->ipv4_src = iph->saddr; @@ -250,7 +269,7 @@ PROG(IP)(struct __sk_buff *skb) keys->thoff += iph->ihl << 2; if (data + keys->thoff > data_end) - return BPF_DROP; + return export_flow_keys(keys, BPF_DROP); if (iph->frag_off & bpf_htons(IP_MF | IP_OFFSET)) { keys->is_frag = true; @@ -264,7 +283,7 @@ PROG(IP)(struct __sk_buff *skb) } if (done) - return BPF_OK; + return export_flow_keys(keys, BPF_OK); return parse_ip_proto(skb, iph->protocol); } @@ -276,7 +295,7 @@ PROG(IPV6)(struct __sk_buff *skb) ip6h = bpf_flow_dissect_get_header(skb, sizeof(*ip6h), &_ip6h); if (!ip6h) - return BPF_DROP; + return export_flow_keys(keys, BPF_DROP); keys->addr_proto = ETH_P_IPV6; memcpy(&keys->ipv6_src, &ip6h->saddr, 2*sizeof(ip6h->saddr)); @@ -288,11 +307,12 @@ PROG(IPV6)(struct __sk_buff *skb) PROG(IPV6OP)(struct __sk_buff *skb) { + struct bpf_flow_keys *keys = skb->flow_keys; struct ipv6_opt_hdr *ip6h, _ip6h; ip6h = bpf_flow_dissect_get_header(skb, sizeof(*ip6h), &_ip6h); if (!ip6h) - return BPF_DROP; + return export_flow_keys(keys, BPF_DROP); /* hlen is in 8-octets and does not include the first 8 bytes * of the header @@ -309,7 +329,7 @@ PROG(IPV6FR)(struct __sk_buff *skb) fragh = bpf_flow_dissect_get_header(skb, sizeof(*fragh), &_fragh); if (!fragh) - return BPF_DROP; + return export_flow_keys(keys, BPF_DROP); keys->thoff += sizeof(*fragh); keys->is_frag = true; @@ -321,13 +341,14 @@ PROG(IPV6FR)(struct __sk_buff *skb) PROG(MPLS)(struct __sk_buff *skb) { + struct bpf_flow_keys *keys = skb->flow_keys; struct mpls_label *mpls, _mpls; mpls = bpf_flow_dissect_get_header(skb, sizeof(*mpls), &_mpls); if (!mpls) - return BPF_DROP; + return export_flow_keys(keys, BPF_DROP); - return BPF_OK; + return export_flow_keys(keys, BPF_OK); } PROG(VLAN)(struct __sk_buff *skb) @@ -339,10 +360,10 @@ PROG(VLAN)(struct __sk_buff *skb) if (keys->n_proto == bpf_htons(ETH_P_8021AD)) { vlan = bpf_flow_dissect_get_header(skb, sizeof(*vlan), &_vlan); if (!vlan) - return BPF_DROP; + return export_flow_keys(keys, BPF_DROP); if (vlan->h_vlan_encapsulated_proto != bpf_htons(ETH_P_8021Q)) - return BPF_DROP; + return export_flow_keys(keys, BPF_DROP); keys->nhoff += sizeof(*vlan); keys->thoff += sizeof(*vlan); @@ -350,14 +371,14 @@ PROG(VLAN)(struct __sk_buff *skb) vlan = bpf_flow_dissect_get_header(skb, sizeof(*vlan), &_vlan); if (!vlan) - return BPF_DROP; + return export_flow_keys(keys, BPF_DROP); keys->nhoff += sizeof(*vlan); keys->thoff += sizeof(*vlan); /* Only allow 8021AD + 8021Q double tagging and no triple tagging.*/ if (vlan->h_vlan_encapsulated_proto == bpf_htons(ETH_P_8021AD) || vlan->h_vlan_encapsulated_proto == bpf_htons(ETH_P_8021Q)) - return BPF_DROP; + return export_flow_keys(keys, BPF_DROP); keys->n_proto = vlan->h_vlan_encapsulated_proto; return parse_eth_proto(skb, vlan->h_vlan_encapsulated_proto); -- cgit v1.2.3-59-g8ed1b