Re: [PATCH bpf-next 2/2] selftests/bpf: Test that SO_REUSEPORT can be used with sk_assign helper
From: Martin KaFai Lau
Date: Thu May 25 2023 - 20:07:15 EST
On 5/25/23 1:19 AM, Lorenz Bauer wrote:
diff --git a/tools/testing/selftests/bpf/network_helpers.c b/tools/testing/selftests/bpf/network_helpers.c
index a105c0cd008a..8a33bcea97de 100644
--- a/tools/testing/selftests/bpf/network_helpers.c
+++ b/tools/testing/selftests/bpf/network_helpers.c
@@ -423,6 +423,9 @@ struct nstoken *open_netns(const char *name)
void close_netns(struct nstoken *token)
{
+ if (!token)
+ return;
+1. :)
+
ASSERT_OK(setns(token->orig_netns_fd, CLONE_NEWNET), "setns");
close(token->orig_netns_fd);
free(token);
diff --git a/tools/testing/selftests/bpf/prog_tests/assign_reuse.c b/tools/testing/selftests/bpf/prog_tests/assign_reuse.c
new file mode 100644
index 000000000000..2cb9bb591e71
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/assign_reuse.c
@@ -0,0 +1,280 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2023 Isovalent */
+#include <uapi/linux/if_link.h>
+#include <test_progs.h>
+
+#include <netinet/tcp.h>
+#include <netinet/udp.h>
+
+#include "network_helpers.h"
+#include "test_assign_reuse.skel.h"
+
+#define NS_TEST "assign_reuse"
+#define LOOPBACK 1
+#define PORT 4443
+
+static int attach_reuseport(int sock_fd, int prog_fd)
+{
+ return setsockopt(sock_fd, SOL_SOCKET, SO_ATTACH_REUSEPORT_EBPF,
+ &prog_fd, sizeof(prog_fd));
+}
+
+static socklen_t inetaddr_len(const struct sockaddr_storage *addr)
+{
+ return addr->ss_family == AF_INET ? sizeof(struct sockaddr_in) :
+ addr->ss_family == AF_INET6 ? sizeof(struct sockaddr_in6) :
+ 0;
+}
+
+static bool is_ipv6(const char *ip)
+{
+ return !!strchr(ip, ':');
+}
+
+static int make_socket(int sotype, const char *ip, int port,
+ struct sockaddr_storage *addr)
+{
+ struct timeval timeo = { .tv_usec = 500000 /* 500 ms */ };
+ int family = is_ipv6(ip) ? AF_INET6 : AF_INET;
+ int ret, fd;
+
+ ret = make_sockaddr(family, ip, port, addr, NULL);
+ if (!ASSERT_OK(ret, "make_sockaddr"))
+ return -1;
+ fd = socket(addr->ss_family, sotype, 0);
+ if (!ASSERT_GE(fd, 0, "socket"))
+ return -1;
+ ret = setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &timeo, sizeof(timeo));
+ if (!ASSERT_OK(ret, "sndtimeo")) {
+ close(fd);
+ return -1;
+ }
+ ret = setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &timeo, sizeof(timeo));
+ if (!ASSERT_OK(ret, "rcvtimeo")) {
+ close(fd);
+ return -1;
+ }
+ return fd;
+}
+
+static int create_server(int sotype, const char *ip, int port, int prog_fd)
+{
+ struct sockaddr_storage addr = {};
+ const int one = 1;
+ int ret, fd;
+
+ fd = make_socket(sotype, ip, port, &addr);
+ if (fd < 0)
+ return -1;
+ if (sotype == SOCK_STREAM) {
+ ret = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one,
+ sizeof(one));
+ if (!ASSERT_OK(ret, "reuseaddr"))
+ goto cleanup;
+ }
+ if (prog_fd >= 0) {
+ ret = setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &one,
+ sizeof(one));
+ if (!ASSERT_OK(ret, "reuseport"))
+ goto cleanup;
+ ret = attach_reuseport(fd, prog_fd);
+ if (!ASSERT_OK(ret, "attach_reuseport"))
+ goto cleanup;
+ }
+ ret = bind(fd, (void *)&addr, inetaddr_len(&addr));
+ if (!ASSERT_OK(ret, "bind"))
+ goto cleanup;
+ if (sotype == SOCK_STREAM) {
+ ret = listen(fd, SOMAXCONN);
+ if (!ASSERT_OK(ret, "listen"))
+ goto cleanup;
+ }
+ return fd;
+cleanup:
+ close(fd);
+ return -1;
+}
+
+static int create_client(int sotype, const char *ip, int port)
+{
+ struct sockaddr_storage addr = {};
+ int ret, fd;
+
+ fd = make_socket(sotype, ip, port, &addr);
+ if (fd < 0)
+ return -1;
+ ret = connect(fd, (void *)&addr, inetaddr_len(&addr));
+ if (ret)
+ goto cleanup;
+ return fd;
+cleanup:
+ close(fd);
+ return -1;
+}
I believe a lot of the above can be done by start_reuseport_server() and
connect_to_fd() from network_helpers.c.
[ ... ]
+void serial_test_assign_reuse(void)
Remove "serial_" .
+{
+ struct nstoken *tok = NULL;
+
+ SYS(out, "ip netns add %s", NS_TEST);
+ SYS(cleanup, "ip -net %s link set dev lo up", NS_TEST);
+
+ tok = open_netns(NS_TEST);
+ if (!ASSERT_OK_PTR(tok, "netns token"))
+ return;
+
+ if (test__start_subtest("tcpv4"))
+ run_assign_reuse(SOCK_STREAM, "127.0.0.1", PORT);
+ if (test__start_subtest("tcpv6"))
+ run_assign_reuse(SOCK_STREAM, "::1", PORT);
+ if (test__start_subtest("udpv4"))
+ run_assign_reuse(SOCK_DGRAM, "127.0.0.1", PORT);
+ if (test__start_subtest("udpv6"))
+ run_assign_reuse(SOCK_DGRAM, "::1", PORT);
+
+cleanup:
+ close_netns(tok);
+ SYS_NOFAIL("ip netns delete %s", NS_TEST);
+out:
+ return;
+}
diff --git a/tools/testing/selftests/bpf/progs/test_assign_reuse.c b/tools/testing/selftests/bpf/progs/test_assign_reuse.c
new file mode 100644
index 000000000000..c83e870b2612
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/test_assign_reuse.c
@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2023 Isovalent */
+#include <stdbool.h>
+#include <linux/bpf.h>
+#include <linux/if_ether.h>
+#include <linux/in.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/tcp.h>
+#include <linux/udp.h>
+#include <bpf/bpf_endian.h>
+#include <bpf/bpf_helpers.h>
+#include <linux/pkt_cls.h>
+
+char LICENSE[] SEC("license") = "GPL";
+
+__u64 sk_cookie_seen;
+__u64 reuseport_executed;
+union {
+ struct tcphdr tcp;
+ struct udphdr udp;
+} headers;
+
+const volatile __u16 dest_port;
+
+struct {
+ __uint(type, BPF_MAP_TYPE_SOCKMAP);
+ __uint(max_entries, 1);
+ __type(key, __u32);
+ __type(value, __u64);
+} sk_map SEC(".maps");
+
+SEC("sk_reuseport")
+int reuse_accept(struct sk_reuseport_md *ctx)
+{
+ reuseport_executed++;
+
+ if (ctx->ip_protocol == IPPROTO_TCP) {
+ if (ctx->data + sizeof(headers.tcp) > ctx->data_end)
+ return SK_DROP;
+
+ if (__builtin_memcmp(&headers.tcp, ctx->data, sizeof(headers.tcp)) != 0)
+ return SK_DROP;
+ } else if (ctx->ip_protocol == IPPROTO_UDP) {
+ if (ctx->data + sizeof(headers.udp) > ctx->data_end)
+ return SK_DROP;
+
+ if (__builtin_memcmp(&headers.udp, ctx->data, sizeof(headers.udp)) != 0)
+ return SK_DROP;
+ } else {
+ return SK_DROP;
+ }
+
+ sk_cookie_seen = bpf_get_socket_cookie(ctx->sk);
+ return SK_PASS;
+}
+
+SEC("sk_reuseport")
+int reuse_drop(struct sk_reuseport_md *ctx)
+{
+ reuseport_executed++;
+ sk_cookie_seen = 0;
+ return SK_DROP;
+}
+
+static inline int
nit. inline is no longer a must. Same for a few functions below.
+assign_sk(struct __sk_buff *skb)
+{
+ int zero = 0, ret = 0;
+ struct bpf_sock *sk;
+
+ sk = bpf_map_lookup_elem(&sk_map, &zero);
+ if (!sk)
+ return TC_ACT_SHOT;
+ ret = bpf_sk_assign(skb, sk, 0);
+ bpf_sk_release(sk);
+ return ret ? TC_ACT_SHOT : TC_ACT_OK;
+}
+