bpf: Add test_sock_fields for skb->sk and bpf_tcp_sock

This patch adds a C program to show the usage on
skb->sk and bpf_tcp_sock.

Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Martin KaFai Lau 2019-02-09 23:22:28 -08:00 committed by Alexei Starovoitov
parent fb47d1d931
commit e0b27b3f97
4 changed files with 487 additions and 2 deletions

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@ -23,7 +23,7 @@ TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test
test_align test_verifier_log test_dev_cgroup test_tcpbpf_user \
test_sock test_btf test_sockmap test_lirc_mode2_user get_cgroup_id_user \
test_socket_cookie test_cgroup_storage test_select_reuseport test_section_names \
test_netcnt test_tcpnotify_user
test_netcnt test_tcpnotify_user test_sock_fields
BPF_OBJ_FILES = \
test_xdp_redirect.o test_xdp_meta.o sockmap_parse_prog.o \
@ -35,7 +35,8 @@ BPF_OBJ_FILES = \
sendmsg4_prog.o sendmsg6_prog.o test_lirc_mode2_kern.o \
get_cgroup_id_kern.o socket_cookie_prog.o test_select_reuseport_kern.o \
test_skb_cgroup_id_kern.o bpf_flow.o netcnt_prog.o test_xdp_vlan.o \
xdp_dummy.o test_map_in_map.o test_spin_lock.o test_map_lock.o
xdp_dummy.o test_map_in_map.o test_spin_lock.o test_map_lock.o \
test_sock_fields_kern.o
# Objects are built with default compilation flags and with sub-register
# code-gen enabled.
@ -111,6 +112,7 @@ $(OUTPUT)/test_progs: trace_helpers.c
$(OUTPUT)/get_cgroup_id_user: cgroup_helpers.c
$(OUTPUT)/test_cgroup_storage: cgroup_helpers.c
$(OUTPUT)/test_netcnt: cgroup_helpers.c
$(OUTPUT)/test_sock_fields: cgroup_helpers.c
.PHONY: force

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@ -176,6 +176,10 @@ static void (*bpf_spin_lock)(struct bpf_spin_lock *lock) =
(void *) BPF_FUNC_spin_lock;
static void (*bpf_spin_unlock)(struct bpf_spin_lock *lock) =
(void *) BPF_FUNC_spin_unlock;
static struct bpf_sock *(*bpf_sk_fullsock)(struct bpf_sock *sk) =
(void *) BPF_FUNC_sk_fullsock;
static struct bpf_tcp_sock *(*bpf_tcp_sock)(struct bpf_sock *sk) =
(void *) BPF_FUNC_tcp_sock;
/* llvm builtin functions that eBPF C program may use to
* emit BPF_LD_ABS and BPF_LD_IND instructions

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@ -0,0 +1,327 @@
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2019 Facebook */
#include <sys/socket.h>
#include <sys/epoll.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <bpf/bpf.h>
#include <bpf/libbpf.h>
#include "cgroup_helpers.h"
enum bpf_array_idx {
SRV_IDX,
CLI_IDX,
__NR_BPF_ARRAY_IDX,
};
#define CHECK(condition, tag, format...) ({ \
int __ret = !!(condition); \
if (__ret) { \
printf("%s(%d):FAIL:%s ", __func__, __LINE__, tag); \
printf(format); \
printf("\n"); \
exit(-1); \
} \
})
#define TEST_CGROUP "/test-bpf-sock-fields"
#define DATA "Hello BPF!"
#define DATA_LEN sizeof(DATA)
static struct sockaddr_in6 srv_sa6, cli_sa6;
static int linum_map_fd;
static int addr_map_fd;
static int tp_map_fd;
static int sk_map_fd;
static __u32 srv_idx = SRV_IDX;
static __u32 cli_idx = CLI_IDX;
static void init_loopback6(struct sockaddr_in6 *sa6)
{
memset(sa6, 0, sizeof(*sa6));
sa6->sin6_family = AF_INET6;
sa6->sin6_addr = in6addr_loopback;
}
static void print_sk(const struct bpf_sock *sk)
{
char src_ip4[24], dst_ip4[24];
char src_ip6[64], dst_ip6[64];
inet_ntop(AF_INET, &sk->src_ip4, src_ip4, sizeof(src_ip4));
inet_ntop(AF_INET6, &sk->src_ip6, src_ip6, sizeof(src_ip6));
inet_ntop(AF_INET, &sk->dst_ip4, dst_ip4, sizeof(dst_ip4));
inet_ntop(AF_INET6, &sk->dst_ip6, dst_ip6, sizeof(dst_ip6));
printf("state:%u bound_dev_if:%u family:%u type:%u protocol:%u mark:%u priority:%u "
"src_ip4:%x(%s) src_ip6:%x:%x:%x:%x(%s) src_port:%u "
"dst_ip4:%x(%s) dst_ip6:%x:%x:%x:%x(%s) dst_port:%u\n",
sk->state, sk->bound_dev_if, sk->family, sk->type, sk->protocol,
sk->mark, sk->priority,
sk->src_ip4, src_ip4,
sk->src_ip6[0], sk->src_ip6[1], sk->src_ip6[2], sk->src_ip6[3],
src_ip6, sk->src_port,
sk->dst_ip4, dst_ip4,
sk->dst_ip6[0], sk->dst_ip6[1], sk->dst_ip6[2], sk->dst_ip6[3],
dst_ip6, ntohs(sk->dst_port));
}
static void print_tp(const struct bpf_tcp_sock *tp)
{
printf("snd_cwnd:%u srtt_us:%u rtt_min:%u snd_ssthresh:%u rcv_nxt:%u "
"snd_nxt:%u snd:una:%u mss_cache:%u ecn_flags:%u "
"rate_delivered:%u rate_interval_us:%u packets_out:%u "
"retrans_out:%u total_retrans:%u segs_in:%u data_segs_in:%u "
"segs_out:%u data_segs_out:%u lost_out:%u sacked_out:%u "
"bytes_received:%llu bytes_acked:%llu\n",
tp->snd_cwnd, tp->srtt_us, tp->rtt_min, tp->snd_ssthresh,
tp->rcv_nxt, tp->snd_nxt, tp->snd_una, tp->mss_cache,
tp->ecn_flags, tp->rate_delivered, tp->rate_interval_us,
tp->packets_out, tp->retrans_out, tp->total_retrans,
tp->segs_in, tp->data_segs_in, tp->segs_out,
tp->data_segs_out, tp->lost_out, tp->sacked_out,
tp->bytes_received, tp->bytes_acked);
}
static void check_result(void)
{
struct bpf_tcp_sock srv_tp, cli_tp;
struct bpf_sock srv_sk, cli_sk;
__u32 linum, idx0 = 0;
int err;
err = bpf_map_lookup_elem(linum_map_fd, &idx0, &linum);
CHECK(err == -1, "bpf_map_lookup_elem(linum_map_fd)",
"err:%d errno:%d", err, errno);
err = bpf_map_lookup_elem(sk_map_fd, &srv_idx, &srv_sk);
CHECK(err == -1, "bpf_map_lookup_elem(sk_map_fd, &srv_idx)",
"err:%d errno:%d", err, errno);
err = bpf_map_lookup_elem(tp_map_fd, &srv_idx, &srv_tp);
CHECK(err == -1, "bpf_map_lookup_elem(tp_map_fd, &srv_idx)",
"err:%d errno:%d", err, errno);
err = bpf_map_lookup_elem(sk_map_fd, &cli_idx, &cli_sk);
CHECK(err == -1, "bpf_map_lookup_elem(sk_map_fd, &cli_idx)",
"err:%d errno:%d", err, errno);
err = bpf_map_lookup_elem(tp_map_fd, &cli_idx, &cli_tp);
CHECK(err == -1, "bpf_map_lookup_elem(tp_map_fd, &cli_idx)",
"err:%d errno:%d", err, errno);
printf("srv_sk: ");
print_sk(&srv_sk);
printf("\n");
printf("cli_sk: ");
print_sk(&cli_sk);
printf("\n");
printf("srv_tp: ");
print_tp(&srv_tp);
printf("\n");
printf("cli_tp: ");
print_tp(&cli_tp);
printf("\n");
CHECK(srv_sk.state == 10 ||
!srv_sk.state ||
srv_sk.family != AF_INET6 ||
srv_sk.protocol != IPPROTO_TCP ||
memcmp(srv_sk.src_ip6, &in6addr_loopback,
sizeof(srv_sk.src_ip6)) ||
memcmp(srv_sk.dst_ip6, &in6addr_loopback,
sizeof(srv_sk.dst_ip6)) ||
srv_sk.src_port != ntohs(srv_sa6.sin6_port) ||
srv_sk.dst_port != cli_sa6.sin6_port,
"Unexpected srv_sk", "Check srv_sk output. linum:%u", linum);
CHECK(cli_sk.state == 10 ||
!cli_sk.state ||
cli_sk.family != AF_INET6 ||
cli_sk.protocol != IPPROTO_TCP ||
memcmp(cli_sk.src_ip6, &in6addr_loopback,
sizeof(cli_sk.src_ip6)) ||
memcmp(cli_sk.dst_ip6, &in6addr_loopback,
sizeof(cli_sk.dst_ip6)) ||
cli_sk.src_port != ntohs(cli_sa6.sin6_port) ||
cli_sk.dst_port != srv_sa6.sin6_port,
"Unexpected cli_sk", "Check cli_sk output. linum:%u", linum);
CHECK(srv_tp.data_segs_out != 1 ||
srv_tp.data_segs_in ||
srv_tp.snd_cwnd != 10 ||
srv_tp.total_retrans ||
srv_tp.bytes_acked != DATA_LEN,
"Unexpected srv_tp", "Check srv_tp output. linum:%u", linum);
CHECK(cli_tp.data_segs_out ||
cli_tp.data_segs_in != 1 ||
cli_tp.snd_cwnd != 10 ||
cli_tp.total_retrans ||
cli_tp.bytes_received != DATA_LEN,
"Unexpected cli_tp", "Check cli_tp output. linum:%u", linum);
}
static void test(void)
{
int listen_fd, cli_fd, accept_fd, epfd, err;
struct epoll_event ev;
socklen_t addrlen;
addrlen = sizeof(struct sockaddr_in6);
ev.events = EPOLLIN;
epfd = epoll_create(1);
CHECK(epfd == -1, "epoll_create()", "epfd:%d errno:%d", epfd, errno);
/* Prepare listen_fd */
listen_fd = socket(AF_INET6, SOCK_STREAM | SOCK_NONBLOCK, 0);
CHECK(listen_fd == -1, "socket()", "listen_fd:%d errno:%d",
listen_fd, errno);
init_loopback6(&srv_sa6);
err = bind(listen_fd, (struct sockaddr *)&srv_sa6, sizeof(srv_sa6));
CHECK(err, "bind(listen_fd)", "err:%d errno:%d", err, errno);
err = getsockname(listen_fd, (struct sockaddr *)&srv_sa6, &addrlen);
CHECK(err, "getsockname(listen_fd)", "err:%d errno:%d", err, errno);
err = listen(listen_fd, 1);
CHECK(err, "listen(listen_fd)", "err:%d errno:%d", err, errno);
/* Prepare cli_fd */
cli_fd = socket(AF_INET6, SOCK_STREAM | SOCK_NONBLOCK, 0);
CHECK(cli_fd == -1, "socket()", "cli_fd:%d errno:%d", cli_fd, errno);
init_loopback6(&cli_sa6);
err = bind(cli_fd, (struct sockaddr *)&cli_sa6, sizeof(cli_sa6));
CHECK(err, "bind(cli_fd)", "err:%d errno:%d", err, errno);
err = getsockname(cli_fd, (struct sockaddr *)&cli_sa6, &addrlen);
CHECK(err, "getsockname(cli_fd)", "err:%d errno:%d",
err, errno);
/* Update addr_map with srv_sa6 and cli_sa6 */
err = bpf_map_update_elem(addr_map_fd, &srv_idx, &srv_sa6, 0);
CHECK(err, "map_update", "err:%d errno:%d", err, errno);
err = bpf_map_update_elem(addr_map_fd, &cli_idx, &cli_sa6, 0);
CHECK(err, "map_update", "err:%d errno:%d", err, errno);
/* Connect from cli_sa6 to srv_sa6 */
err = connect(cli_fd, (struct sockaddr *)&srv_sa6, addrlen);
printf("srv_sa6.sin6_port:%u cli_sa6.sin6_port:%u\n\n",
ntohs(srv_sa6.sin6_port), ntohs(cli_sa6.sin6_port));
CHECK(err && errno != EINPROGRESS,
"connect(cli_fd)", "err:%d errno:%d", err, errno);
ev.data.fd = listen_fd;
err = epoll_ctl(epfd, EPOLL_CTL_ADD, listen_fd, &ev);
CHECK(err, "epoll_ctl(EPOLL_CTL_ADD, listen_fd)", "err:%d errno:%d",
err, errno);
/* Accept the connection */
/* Have some timeout in accept(listen_fd). Just in case. */
err = epoll_wait(epfd, &ev, 1, 1000);
CHECK(err != 1 || ev.data.fd != listen_fd,
"epoll_wait(listen_fd)",
"err:%d errno:%d ev.data.fd:%d listen_fd:%d",
err, errno, ev.data.fd, listen_fd);
accept_fd = accept(listen_fd, NULL, NULL);
CHECK(accept_fd == -1, "accept(listen_fd)", "accept_fd:%d errno:%d",
accept_fd, errno);
close(listen_fd);
/* Send some data from accept_fd to cli_fd */
err = send(accept_fd, DATA, DATA_LEN, 0);
CHECK(err != DATA_LEN, "send(accept_fd)", "err:%d errno:%d",
err, errno);
/* Have some timeout in recv(cli_fd). Just in case. */
ev.data.fd = cli_fd;
err = epoll_ctl(epfd, EPOLL_CTL_ADD, cli_fd, &ev);
CHECK(err, "epoll_ctl(EPOLL_CTL_ADD, cli_fd)", "err:%d errno:%d",
err, errno);
err = epoll_wait(epfd, &ev, 1, 1000);
CHECK(err != 1 || ev.data.fd != cli_fd,
"epoll_wait(cli_fd)", "err:%d errno:%d ev.data.fd:%d cli_fd:%d",
err, errno, ev.data.fd, cli_fd);
err = recv(cli_fd, NULL, 0, MSG_TRUNC);
CHECK(err, "recv(cli_fd)", "err:%d errno:%d", err, errno);
close(epfd);
close(accept_fd);
close(cli_fd);
check_result();
}
int main(int argc, char **argv)
{
struct bpf_prog_load_attr attr = {
.file = "test_sock_fields_kern.o",
.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
.expected_attach_type = BPF_CGROUP_INET_EGRESS,
};
int cgroup_fd, prog_fd, err;
struct bpf_object *obj;
struct bpf_map *map;
err = setup_cgroup_environment();
CHECK(err, "setup_cgroup_environment()", "err:%d errno:%d",
err, errno);
atexit(cleanup_cgroup_environment);
/* Create a cgroup, get fd, and join it */
cgroup_fd = create_and_get_cgroup(TEST_CGROUP);
CHECK(cgroup_fd == -1, "create_and_get_cgroup()",
"cgroup_fd:%d errno:%d", cgroup_fd, errno);
err = join_cgroup(TEST_CGROUP);
CHECK(err, "join_cgroup", "err:%d errno:%d", err, errno);
err = bpf_prog_load_xattr(&attr, &obj, &prog_fd);
CHECK(err, "bpf_prog_load_xattr()", "err:%d", err);
err = bpf_prog_attach(prog_fd, cgroup_fd, BPF_CGROUP_INET_EGRESS, 0);
CHECK(err == -1, "bpf_prog_attach(CPF_CGROUP_INET_EGRESS)",
"err:%d errno%d", err, errno);
close(cgroup_fd);
map = bpf_object__find_map_by_name(obj, "addr_map");
CHECK(!map, "cannot find addr_map", "(null)");
addr_map_fd = bpf_map__fd(map);
map = bpf_object__find_map_by_name(obj, "sock_result_map");
CHECK(!map, "cannot find sock_result_map", "(null)");
sk_map_fd = bpf_map__fd(map);
map = bpf_object__find_map_by_name(obj, "tcp_sock_result_map");
CHECK(!map, "cannot find tcp_sock_result_map", "(null)");
tp_map_fd = bpf_map__fd(map);
map = bpf_object__find_map_by_name(obj, "linum_map");
CHECK(!map, "cannot find linum_map", "(null)");
linum_map_fd = bpf_map__fd(map);
test();
bpf_object__close(obj);
cleanup_cgroup_environment();
printf("PASS\n");
return 0;
}

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@ -0,0 +1,152 @@
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2019 Facebook */
#include <linux/bpf.h>
#include <netinet/in.h>
#include <stdbool.h>
#include "bpf_helpers.h"
#include "bpf_endian.h"
enum bpf_array_idx {
SRV_IDX,
CLI_IDX,
__NR_BPF_ARRAY_IDX,
};
struct bpf_map_def SEC("maps") addr_map = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(__u32),
.value_size = sizeof(struct sockaddr_in6),
.max_entries = __NR_BPF_ARRAY_IDX,
};
struct bpf_map_def SEC("maps") sock_result_map = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(__u32),
.value_size = sizeof(struct bpf_sock),
.max_entries = __NR_BPF_ARRAY_IDX,
};
struct bpf_map_def SEC("maps") tcp_sock_result_map = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(__u32),
.value_size = sizeof(struct bpf_tcp_sock),
.max_entries = __NR_BPF_ARRAY_IDX,
};
struct bpf_map_def SEC("maps") linum_map = {
.type = BPF_MAP_TYPE_ARRAY,
.key_size = sizeof(__u32),
.value_size = sizeof(__u32),
.max_entries = 1,
};
static bool is_loopback6(__u32 *a6)
{
return !a6[0] && !a6[1] && !a6[2] && a6[3] == bpf_htonl(1);
}
static void skcpy(struct bpf_sock *dst,
const struct bpf_sock *src)
{
dst->bound_dev_if = src->bound_dev_if;
dst->family = src->family;
dst->type = src->type;
dst->protocol = src->protocol;
dst->mark = src->mark;
dst->priority = src->priority;
dst->src_ip4 = src->src_ip4;
dst->src_ip6[0] = src->src_ip6[0];
dst->src_ip6[1] = src->src_ip6[1];
dst->src_ip6[2] = src->src_ip6[2];
dst->src_ip6[3] = src->src_ip6[3];
dst->src_port = src->src_port;
dst->dst_ip4 = src->dst_ip4;
dst->dst_ip6[0] = src->dst_ip6[0];
dst->dst_ip6[1] = src->dst_ip6[1];
dst->dst_ip6[2] = src->dst_ip6[2];
dst->dst_ip6[3] = src->dst_ip6[3];
dst->dst_port = src->dst_port;
dst->state = src->state;
}
static void tpcpy(struct bpf_tcp_sock *dst,
const struct bpf_tcp_sock *src)
{
dst->snd_cwnd = src->snd_cwnd;
dst->srtt_us = src->srtt_us;
dst->rtt_min = src->rtt_min;
dst->snd_ssthresh = src->snd_ssthresh;
dst->rcv_nxt = src->rcv_nxt;
dst->snd_nxt = src->snd_nxt;
dst->snd_una = src->snd_una;
dst->mss_cache = src->mss_cache;
dst->ecn_flags = src->ecn_flags;
dst->rate_delivered = src->rate_delivered;
dst->rate_interval_us = src->rate_interval_us;
dst->packets_out = src->packets_out;
dst->retrans_out = src->retrans_out;
dst->total_retrans = src->total_retrans;
dst->segs_in = src->segs_in;
dst->data_segs_in = src->data_segs_in;
dst->segs_out = src->segs_out;
dst->data_segs_out = src->data_segs_out;
dst->lost_out = src->lost_out;
dst->sacked_out = src->sacked_out;
dst->bytes_received = src->bytes_received;
dst->bytes_acked = src->bytes_acked;
}
#define RETURN { \
linum = __LINE__; \
bpf_map_update_elem(&linum_map, &idx0, &linum, 0); \
return 1; \
}
SEC("cgroup_skb/egress")
int read_sock_fields(struct __sk_buff *skb)
{
__u32 srv_idx = SRV_IDX, cli_idx = CLI_IDX, idx;
struct sockaddr_in6 *srv_sa6, *cli_sa6;
struct bpf_tcp_sock *tp, *tp_ret;
struct bpf_sock *sk, *sk_ret;
__u32 linum, idx0 = 0;
sk = skb->sk;
if (!sk || sk->state == 10)
RETURN;
sk = bpf_sk_fullsock(sk);
if (!sk || sk->family != AF_INET6 || sk->protocol != IPPROTO_TCP ||
!is_loopback6(sk->src_ip6))
RETURN;
tp = bpf_tcp_sock(sk);
if (!tp)
RETURN;
srv_sa6 = bpf_map_lookup_elem(&addr_map, &srv_idx);
cli_sa6 = bpf_map_lookup_elem(&addr_map, &cli_idx);
if (!srv_sa6 || !cli_sa6)
RETURN;
if (sk->src_port == bpf_ntohs(srv_sa6->sin6_port))
idx = srv_idx;
else if (sk->src_port == bpf_ntohs(cli_sa6->sin6_port))
idx = cli_idx;
else
RETURN;
sk_ret = bpf_map_lookup_elem(&sock_result_map, &idx);
tp_ret = bpf_map_lookup_elem(&tcp_sock_result_map, &idx);
if (!sk_ret || !tp_ret)
RETURN;
skcpy(sk_ret, sk);
tpcpy(tp_ret, tp);
RETURN;
}
char _license[] SEC("license") = "GPL";