diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 2d6b8de35c449..90b4aeca2596a 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -61,11 +61,13 @@ static u64 mptcp_wnd_end(const struct mptcp_sock *msk) static const struct proto_ops *mptcp_fallback_tcp_ops(const struct sock *sk) { + unsigned short family = READ_ONCE(sk->sk_family); + #if IS_ENABLED(CONFIG_MPTCP_IPV6) - if (sk->sk_prot == &tcpv6_prot) + if (family == AF_INET6) return &inet6_stream_ops; #endif - WARN_ON_ONCE(sk->sk_prot != &tcp_prot); + WARN_ON_ONCE(family != AF_INET); return &inet_stream_ops; } diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index e8325890a3223..af707ce0f6244 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -2144,6 +2144,10 @@ void __init mptcp_subflow_init(void) tcp_prot_override = tcp_prot; tcp_prot_override.release_cb = tcp_release_cb_override; tcp_prot_override.diag_destroy = tcp_abort_override; +#ifdef CONFIG_BPF_SYSCALL + /* Disable sockmap processing for subflows */ + tcp_prot_override.psock_update_sk_prot = NULL; +#endif #if IS_ENABLED(CONFIG_MPTCP_IPV6) /* In struct mptcp_subflow_request_sock, we assume the TCP request sock @@ -2180,6 +2184,10 @@ void __init mptcp_subflow_init(void) tcpv6_prot_override = tcpv6_prot; tcpv6_prot_override.release_cb = tcp_release_cb_override; tcpv6_prot_override.diag_destroy = tcp_abort_override; +#ifdef CONFIG_BPF_SYSCALL + /* Disable sockmap processing for subflows */ + tcpv6_prot_override.psock_update_sk_prot = NULL; +#endif #endif mptcp_diag_subflow_init(&subflow_ulp_ops); diff --git a/tools/testing/selftests/bpf/prog_tests/mptcp.c b/tools/testing/selftests/bpf/prog_tests/mptcp.c index f8eb7f9d4fd20..b976fe6263434 100644 --- a/tools/testing/selftests/bpf/prog_tests/mptcp.c +++ b/tools/testing/selftests/bpf/prog_tests/mptcp.c @@ -6,11 +6,14 @@ #include #include #include +#include #include "cgroup_helpers.h" #include "network_helpers.h" +#include "socket_helpers.h" #include "mptcp_sock.skel.h" #include "mptcpify.skel.h" #include "mptcp_subflow.skel.h" +#include "mptcp_sockmap.skel.h" #define NS_TEST "mptcp_ns" #define ADDR_1 "10.0.1.1" @@ -436,6 +439,142 @@ static void test_subflow(void) close(cgroup_fd); } +/* Test sockmap on MPTCP server handling non-mp-capable clients. */ +static void test_sockmap_with_mptcp_fallback(struct mptcp_sockmap *skel) +{ + int listen_fd = -1, client_fd1 = -1, client_fd2 = -1; + int server_fd1 = -1, server_fd2 = -1, sent, recvd; + char snd[9] = "123456789"; + char rcv[10]; + + /* start server with MPTCP enabled */ + listen_fd = start_mptcp_server(AF_INET, NULL, 0, 0); + if (!ASSERT_OK_FD(listen_fd, "sockmap-fb:start_mptcp_server")) + return; + + skel->bss->trace_port = ntohs(get_socket_local_port(listen_fd)); + skel->bss->sk_index = 0; + /* create client without MPTCP enabled */ + client_fd1 = connect_to_fd_opts(listen_fd, NULL); + if (!ASSERT_OK_FD(client_fd1, "sockmap-fb:connect_to_fd")) + goto end; + + server_fd1 = xaccept_nonblock(listen_fd, NULL, NULL); + skel->bss->sk_index = 1; + client_fd2 = connect_to_fd_opts(listen_fd, NULL); + if (!ASSERT_OK_FD(client_fd2, "sockmap-fb:connect_to_fd")) + goto end; + + server_fd2 = xaccept_nonblock(listen_fd, NULL, NULL); + /* test normal redirect behavior: data sent by client_fd1 can be + * received by client_fd2 + */ + skel->bss->redirect_idx = 1; + sent = xsend(client_fd1, snd, sizeof(snd), 0); + if (!ASSERT_EQ(sent, sizeof(snd), "sockmap-fb:xsend(client_fd1)")) + goto end; + + /* try to recv more bytes to avoid truncation check */ + recvd = recv_timeout(client_fd2, rcv, sizeof(rcv), MSG_DONTWAIT, 2); + if (!ASSERT_EQ(recvd, sizeof(snd), "sockmap-fb:recv(client_fd2)")) + goto end; + +end: + if (client_fd1 >= 0) + close(client_fd1); + if (client_fd2 >= 0) + close(client_fd2); + if (server_fd1 >= 0) + close(server_fd1); + if (server_fd2 >= 0) + close(server_fd2); + close(listen_fd); +} + +/* Test sockmap rejection of MPTCP sockets - both server and client sides. */ +static void test_sockmap_reject_mptcp(struct mptcp_sockmap *skel) +{ + int listen_fd = -1, server_fd = -1, client_fd1 = -1; + int err, zero = 0; + + /* start server with MPTCP enabled */ + listen_fd = start_mptcp_server(AF_INET, NULL, 0, 0); + if (!ASSERT_OK_FD(listen_fd, "start_mptcp_server")) + return; + + skel->bss->trace_port = ntohs(get_socket_local_port(listen_fd)); + skel->bss->sk_index = 0; + /* create client with MPTCP enabled */ + client_fd1 = connect_to_fd(listen_fd, 0); + if (!ASSERT_OK_FD(client_fd1, "connect_to_fd client_fd1")) + goto end; + + /* bpf_sock_map_update() called from sockops should reject MPTCP sk */ + if (!ASSERT_EQ(skel->bss->helper_ret, -EOPNOTSUPP, "should reject")) + goto end; + + server_fd = xaccept_nonblock(listen_fd, NULL, NULL); + err = bpf_map_update_elem(bpf_map__fd(skel->maps.sock_map), + &zero, &server_fd, BPF_NOEXIST); + if (!ASSERT_EQ(err, -EOPNOTSUPP, "server should be disallowed")) + goto end; + + /* MPTCP client should also be disallowed */ + err = bpf_map_update_elem(bpf_map__fd(skel->maps.sock_map), + &zero, &client_fd1, BPF_NOEXIST); + if (!ASSERT_EQ(err, -EOPNOTSUPP, "client should be disallowed")) + goto end; +end: + if (client_fd1 >= 0) + close(client_fd1); + if (server_fd >= 0) + close(server_fd); + close(listen_fd); +} + +static void test_mptcp_sockmap(void) +{ + struct mptcp_sockmap *skel; + struct netns_obj *netns; + int cgroup_fd, err; + + cgroup_fd = test__join_cgroup("/mptcp_sockmap"); + if (!ASSERT_OK_FD(cgroup_fd, "join_cgroup: mptcp_sockmap")) + return; + + skel = mptcp_sockmap__open_and_load(); + if (!ASSERT_OK_PTR(skel, "skel_open_load: mptcp_sockmap")) + goto close_cgroup; + + skel->links.mptcp_sockmap_inject = + bpf_program__attach_cgroup(skel->progs.mptcp_sockmap_inject, cgroup_fd); + if (!ASSERT_OK_PTR(skel->links.mptcp_sockmap_inject, "attach sockmap")) + goto skel_destroy; + + err = bpf_prog_attach(bpf_program__fd(skel->progs.mptcp_sockmap_redirect), + bpf_map__fd(skel->maps.sock_map), + BPF_SK_SKB_STREAM_VERDICT, 0); + if (!ASSERT_OK(err, "bpf_prog_attach stream verdict")) + goto skel_destroy; + + netns = netns_new(NS_TEST, true); + if (!ASSERT_OK_PTR(netns, "netns_new: mptcp_sockmap")) + goto skel_destroy; + + if (endpoint_init("subflow") < 0) + goto close_netns; + + test_sockmap_with_mptcp_fallback(skel); + test_sockmap_reject_mptcp(skel); + +close_netns: + netns_free(netns); +skel_destroy: + mptcp_sockmap__destroy(skel); +close_cgroup: + close(cgroup_fd); +} + void test_mptcp(void) { if (test__start_subtest("base")) @@ -444,4 +583,6 @@ void test_mptcp(void) test_mptcpify(); if (test__start_subtest("subflow")) test_subflow(); + if (test__start_subtest("sockmap")) + test_mptcp_sockmap(); } diff --git a/tools/testing/selftests/bpf/progs/mptcp_sockmap.c b/tools/testing/selftests/bpf/progs/mptcp_sockmap.c new file mode 100644 index 0000000000000..d4eef0cbadb9f --- /dev/null +++ b/tools/testing/selftests/bpf/progs/mptcp_sockmap.c @@ -0,0 +1,43 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "bpf_tracing_net.h" + +char _license[] SEC("license") = "GPL"; + +int sk_index; +int redirect_idx; +int trace_port; +int helper_ret; +struct { + __uint(type, BPF_MAP_TYPE_SOCKMAP); + __uint(key_size, sizeof(__u32)); + __uint(value_size, sizeof(__u32)); + __uint(max_entries, 100); +} sock_map SEC(".maps"); + +SEC("sockops") +int mptcp_sockmap_inject(struct bpf_sock_ops *skops) +{ + struct bpf_sock *sk; + + /* only accept specified connection */ + if (skops->local_port != trace_port || + skops->op != BPF_SOCK_OPS_PASSIVE_ESTABLISHED_CB) + return 1; + + sk = skops->sk; + if (!sk) + return 1; + + /* update sk handler */ + helper_ret = bpf_sock_map_update(skops, &sock_map, &sk_index, BPF_NOEXIST); + + return 1; +} + +SEC("sk_skb/stream_verdict") +int mptcp_sockmap_redirect(struct __sk_buff *skb) +{ + /* redirect skb to the sk under sock_map[redirect_idx] */ + return bpf_sk_redirect_map(skb, &sock_map, redirect_idx, 0); +}