@@ -16,6 +16,7 @@ BPF_PROG(name, args)
struct sock_common {
unsigned char skc_state;
+ __u16 skc_num;
} __attribute__((preserve_access_index));
enum sk_pacing {
@@ -45,6 +46,10 @@ struct inet_connection_sock {
__u64 icsk_ca_priv[104 / sizeof(__u64)];
} __attribute__((preserve_access_index));
+struct request_sock {
+ struct sock_common __req_common;
+} __attribute__((preserve_access_index));
+
struct tcp_sock {
struct inet_connection_sock inet_conn;
new file mode 100644
@@ -0,0 +1,234 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+
+#define _GNU_SOURCE
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <sched.h>
+#include <linux/compiler.h>
+#include <bpf/libbpf.h>
+
+#include "network_helpers.h"
+#include "test_progs.h"
+#include "test_btf_skc_cls_ingress.skel.h"
+
+struct test_btf_skc_cls_ingress *skel;
+struct sockaddr_in6 srv_sa6;
+static __u32 duration;
+
+#define PROG_PIN_FILE "/sys/fs/bpf/btf_skc_cls_ingress"
+
+static int write_sysctl(const char *sysctl, const char *value)
+{
+ int fd, err, len;
+
+ fd = open(sysctl, O_WRONLY);
+ if (CHECK(fd == -1, "open sysctl", "open(%s): %s (%d)\n",
+ sysctl, strerror(errno), errno))
+ return -1;
+
+ len = strlen(value);
+ err = write(fd, value, len);
+ close(fd);
+ if (CHECK(err != len, "write sysctl",
+ "write(%s, %s, %d): err:%d %s (%d)\n",
+ sysctl, value, len, err, strerror(errno), errno))
+ return -1;
+
+ return 0;
+}
+
+static int prepare_netns(void)
+{
+ if (CHECK(unshare(CLONE_NEWNET), "create netns",
+ "unshare(CLONE_NEWNET): %s (%d)",
+ strerror(errno), errno))
+ return -1;
+
+ if (CHECK(system("ip link set dev lo up"),
+ "ip link set dev lo up", "failed\n"))
+ return -1;
+
+ if (CHECK(system("tc qdisc add dev lo clsact"),
+ "tc qdisc add dev lo clsact", "failed\n"))
+ return -1;
+
+ if (CHECK(system("tc filter add dev lo ingress bpf direct-action object-pinned " PROG_PIN_FILE),
+ "install tc cls-prog at ingress", "failed\n"))
+ return -1;
+
+ /* Ensure 20 bytes options (i.e. in total 40 bytes tcp header) for the
+ * bpf_tcp_gen_syncookie() helper.
+ */
+ if (write_sysctl("/proc/sys/net/ipv4/tcp_window_scaling", "1") ||
+ write_sysctl("/proc/sys/net/ipv4/tcp_timestamps", "1") ||
+ write_sysctl("/proc/sys/net/ipv4/tcp_sack", "1"))
+ return -1;
+
+ return 0;
+}
+
+static void reset_test(void)
+{
+ memset(&skel->bss->srv_sa6, 0, sizeof(skel->bss->srv_sa6));
+ skel->bss->listen_tp_sport = 0;
+ skel->bss->req_sk_sport = 0;
+ skel->bss->recv_cookie = 0;
+ skel->bss->gen_cookie = 0;
+ skel->bss->linum = 0;
+}
+
+static void print_err_line(void)
+{
+ if (skel->bss->linum)
+ printf("bpf prog error at line %u\n", skel->bss->linum);
+}
+
+static void test_conn(void)
+{
+ int listen_fd = -1, cli_fd = -1, err;
+ socklen_t addrlen = sizeof(srv_sa6);
+ int srv_port;
+
+ if (write_sysctl("/proc/sys/net/ipv4/tcp_syncookies", "1"))
+ return;
+
+ listen_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0);
+ if (CHECK_FAIL(listen_fd == -1))
+ return;
+
+ err = getsockname(listen_fd, (struct sockaddr *)&srv_sa6, &addrlen);
+ if (CHECK(err, "getsockname(listen_fd)", "err:%d errno:%d\n", err,
+ errno))
+ goto done;
+ memcpy(&skel->bss->srv_sa6, &srv_sa6, sizeof(srv_sa6));
+ srv_port = ntohs(srv_sa6.sin6_port);
+
+ cli_fd = connect_to_fd(listen_fd, 0);
+ if (CHECK_FAIL(cli_fd == -1))
+ goto done;
+
+ if (CHECK(skel->bss->listen_tp_sport != srv_port ||
+ skel->bss->req_sk_sport != srv_port,
+ "Unexpected sk src port",
+ "listen_tp_sport:%u req_sk_sport:%u expected:%u\n",
+ skel->bss->listen_tp_sport, skel->bss->req_sk_sport,
+ srv_port))
+ goto done;
+
+ if (CHECK(skel->bss->gen_cookie || skel->bss->recv_cookie,
+ "Unexpected syncookie states",
+ "gen_cookie:%u recv_cookie:%u\n",
+ skel->bss->gen_cookie, skel->bss->recv_cookie))
+ goto done;
+
+ CHECK(skel->bss->linum, "bpf prog detected error", "at line %u\n",
+ skel->bss->linum);
+
+done:
+ if (listen_fd != -1)
+ close(listen_fd);
+ if (cli_fd != -1)
+ close(cli_fd);
+}
+
+static void test_syncookie(void)
+{
+ int listen_fd = -1, cli_fd = -1, err;
+ socklen_t addrlen = sizeof(srv_sa6);
+ int srv_port;
+
+ /* Enforce syncookie mode */
+ if (write_sysctl("/proc/sys/net/ipv4/tcp_syncookies", "2"))
+ return;
+
+ listen_fd = start_server(AF_INET6, SOCK_STREAM, "::1", 0, 0);
+ if (CHECK_FAIL(listen_fd == -1))
+ return;
+
+ err = getsockname(listen_fd, (struct sockaddr *)&srv_sa6, &addrlen);
+ if (CHECK(err, "getsockname(listen_fd)", "err:%d errno:%d\n", err,
+ errno))
+ goto done;
+ memcpy(&skel->bss->srv_sa6, &srv_sa6, sizeof(srv_sa6));
+ srv_port = ntohs(srv_sa6.sin6_port);
+
+ cli_fd = connect_to_fd(listen_fd, 0);
+ if (CHECK_FAIL(cli_fd == -1))
+ goto done;
+
+ if (CHECK(skel->bss->listen_tp_sport != srv_port,
+ "Unexpected tp src port",
+ "listen_tp_sport:%u expected:%u\n",
+ skel->bss->listen_tp_sport, srv_port))
+ goto done;
+
+ if (CHECK(skel->bss->req_sk_sport,
+ "Unexpected req_sk src port",
+ "req_sk_sport:%u expected:0\n",
+ skel->bss->req_sk_sport))
+ goto done;
+
+ if (CHECK(!skel->bss->gen_cookie ||
+ skel->bss->gen_cookie != skel->bss->recv_cookie,
+ "Unexpected syncookie states",
+ "gen_cookie:%u recv_cookie:%u\n",
+ skel->bss->gen_cookie, skel->bss->recv_cookie))
+ goto done;
+
+ CHECK(skel->bss->linum, "bpf prog detected error", "at line %u\n",
+ skel->bss->linum);
+
+done:
+ if (listen_fd != -1)
+ close(listen_fd);
+ if (cli_fd != -1)
+ close(cli_fd);
+}
+
+struct test {
+ const char *desc;
+ void (*run)(void);
+};
+
+#define DEF_TEST(name) { #name, test_##name }
+static struct test tests[] = {
+ DEF_TEST(conn),
+ DEF_TEST(syncookie),
+};
+
+void test_btf_skc_cls_ingress(void)
+{
+ int i, err;
+
+ skel = test_btf_skc_cls_ingress__open_and_load();
+ if (CHECK(!skel, "test_btf_skc_cls_ingress__open_and_load", "failed\n"))
+ return;
+
+ err = bpf_program__pin(skel->progs.cls_ingress, PROG_PIN_FILE);
+ if (CHECK(err, "bpf_program__pin",
+ "cannot pin bpf prog to %s. err:%d\n", PROG_PIN_FILE, err)) {
+ test_btf_skc_cls_ingress__destroy(skel);
+ return;
+ }
+
+ for (i = 0; i < ARRAY_SIZE(tests); i++) {
+ if (!test__start_subtest(tests[i].desc))
+ continue;
+
+ if (prepare_netns())
+ break;
+
+ tests[i].run();
+
+ print_err_line();
+ reset_test();
+ }
+
+ bpf_program__unpin(skel->progs.cls_ingress, PROG_PIN_FILE);
+ test_btf_skc_cls_ingress__destroy(skel);
+}
new file mode 100644
@@ -0,0 +1,174 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2020 Facebook */
+
+#include <string.h>
+#include <errno.h>
+#include <netinet/in.h>
+#include <linux/stddef.h>
+#include <linux/bpf.h>
+#include <linux/ipv6.h>
+#include <linux/tcp.h>
+#include <linux/if_ether.h>
+#include <linux/pkt_cls.h>
+
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+#include "bpf_tcp_helpers.h"
+
+struct sockaddr_in6 srv_sa6 = {};
+__u16 listen_tp_sport = 0;
+__u16 req_sk_sport = 0;
+__u32 recv_cookie = 0;
+__u32 gen_cookie = 0;
+__u32 linum = 0;
+
+#define LOG() ({ if (!linum) linum = __LINE__; })
+
+static void test_syncookie_helper(struct ipv6hdr *ip6h, struct tcphdr *th,
+ struct tcp_sock *tp,
+ struct __sk_buff *skb)
+{
+ if (th->syn) {
+ __s64 mss_cookie;
+ void *data_end;
+
+ data_end = (void *)(long)(skb->data_end);
+
+ if (th->doff * 4 != 40) {
+ LOG();
+ return;
+ }
+
+ if ((void *)th + 40 > data_end) {
+ LOG();
+ return;
+ }
+
+ mss_cookie = bpf_tcp_gen_syncookie(tp, ip6h, sizeof(*ip6h),
+ th, 40);
+ if (mss_cookie < 0) {
+ if (mss_cookie != -ENOENT)
+ LOG();
+ } else {
+ gen_cookie = (__u32)mss_cookie;
+ }
+ } else if (gen_cookie) {
+ /* It was in cookie mode */
+ int ret = bpf_tcp_check_syncookie(tp, ip6h, sizeof(*ip6h),
+ th, sizeof(*th));
+
+ if (ret < 0) {
+ if (ret != -ENOENT)
+ LOG();
+ } else {
+ recv_cookie = bpf_ntohl(th->ack_seq) - 1;
+ }
+ }
+}
+
+static int handle_ip6_tcp(struct ipv6hdr *ip6h, struct __sk_buff *skb)
+{
+ struct bpf_sock_tuple *tuple;
+ struct bpf_sock *bpf_skc;
+ unsigned int tuple_len;
+ struct tcphdr *th;
+ void *data_end;
+
+ data_end = (void *)(long)(skb->data_end);
+
+ th = (struct tcphdr *)(ip6h + 1);
+ if (th + 1 > data_end)
+ return TC_ACT_OK;
+
+ /* Is it the testing traffic? */
+ if (th->dest != srv_sa6.sin6_port)
+ return TC_ACT_OK;
+
+ tuple_len = sizeof(tuple->ipv6);
+ tuple = (struct bpf_sock_tuple *)&ip6h->saddr;
+ if ((void *)tuple + tuple_len > data_end) {
+ LOG();
+ return TC_ACT_OK;
+ }
+
+ bpf_skc = bpf_skc_lookup_tcp(skb, tuple, tuple_len,
+ BPF_F_CURRENT_NETNS, 0);
+ if (!bpf_skc) {
+ LOG();
+ return TC_ACT_OK;
+ }
+
+ if (bpf_skc->state == BPF_TCP_NEW_SYN_RECV) {
+ struct request_sock *req_sk;
+
+ req_sk = (struct request_sock *)bpf_skc_to_tcp_request_sock(bpf_skc);
+ if (!req_sk) {
+ LOG();
+ goto release;
+ }
+
+ if (bpf_sk_assign(skb, req_sk, 0)) {
+ LOG();
+ goto release;
+ }
+
+ req_sk_sport = req_sk->__req_common.skc_num;
+
+ bpf_sk_release(req_sk);
+ return TC_ACT_OK;
+ } else if (bpf_skc->state == BPF_TCP_LISTEN) {
+ struct tcp_sock *tp;
+
+ tp = bpf_skc_to_tcp_sock(bpf_skc);
+ if (!tp) {
+ LOG();
+ goto release;
+ }
+
+ if (bpf_sk_assign(skb, tp, 0)) {
+ LOG();
+ goto release;
+ }
+
+ listen_tp_sport = tp->inet_conn.icsk_inet.sk.__sk_common.skc_num;
+
+ test_syncookie_helper(ip6h, th, tp, skb);
+ bpf_sk_release(tp);
+ return TC_ACT_OK;
+ }
+
+ if (bpf_sk_assign(skb, bpf_skc, 0))
+ LOG();
+
+release:
+ bpf_sk_release(bpf_skc);
+ return TC_ACT_OK;
+}
+
+SEC("classifier/ingress")
+int cls_ingress(struct __sk_buff *skb)
+{
+ struct ipv6hdr *ip6h;
+ struct ethhdr *eth;
+ void *data_end;
+
+ data_end = (void *)(long)(skb->data_end);
+
+ eth = (struct ethhdr *)(long)(skb->data);
+ if (eth + 1 > data_end)
+ return TC_ACT_OK;
+
+ if (eth->h_proto != bpf_htons(ETH_P_IPV6))
+ return TC_ACT_OK;
+
+ ip6h = (struct ipv6hdr *)(eth + 1);
+ if (ip6h + 1 > data_end)
+ return TC_ACT_OK;
+
+ if (ip6h->nexthdr == IPPROTO_TCP)
+ return handle_ip6_tcp(ip6h, skb);
+
+ return TC_ACT_OK;
+}
+
+char _license[] SEC("license") = "GPL";
This patch attaches a classifier prog to the ingress filter. It exercises the following helpers with different socket pointer types in different logical branches: 1. bpf_sk_release() 2. bpf_sk_assign() 3. bpf_skc_to_tcp_request_sock(), bpf_skc_to_tcp_sock() 4. bpf_tcp_gen_syncookie, bpf_tcp_check_syncookie Signed-off-by: Martin KaFai Lau <kafai@fb.com> --- tools/testing/selftests/bpf/bpf_tcp_helpers.h | 5 + .../bpf/prog_tests/btf_skc_cls_ingress.c | 234 ++++++++++++++++++ .../bpf/progs/test_btf_skc_cls_ingress.c | 174 +++++++++++++ 3 files changed, 413 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/btf_skc_cls_ingress.c create mode 100644 tools/testing/selftests/bpf/progs/test_btf_skc_cls_ingress.c