A previous commit described in this topic http://lore.kernel.org/bpf/20230523025618.113937-9-john.fastabend@gmail.com directly updated 'sk->copied_seq' in the tcp_eat_skb() function when the action of a BPF program was SK_REDIRECT. For other actions, like SK_PASS, the update logic for 'sk->copied_seq' was moved to tcp_bpf_recvmsg_parser() to ensure the accuracy of the 'fionread' feature.
That commit works for a single stream_verdict scenario, as it also modified 'sk_data_ready->sk_psock_verdict_data_ready->tcp_read_skb' to remove updating 'sk->copied_seq'.
However, for programs where both stream_parser and stream_verdict are active (strparser purpose), tcp_read_sock() was used instead of tcp_read_skb() (sk_data_ready->strp_data_ready->tcp_read_sock). tcp_read_sock() now still updates 'sk->copied_seq', leading to duplicated updates.
In summary, for strparser + SK_PASS, copied_seq is redundantly calculated in both tcp_read_sock() and tcp_bpf_recvmsg_parser().
The issue causes incorrect copied_seq calculations, which prevent correct data reads from the recv() interface in user-land.
Also we added test cases for bpf + strparser and separated them from sockmap_basic, as strparser has more encapsulation and parsing capabilities compared to sockmap.
--- V8 -> v9 https://lore.kernel.org/bpf/20250121050707.55523-1-mrpre@163.com/ Fixed some issues suggested by Jakub Sitnicki.
V7 -> V8 https://lore.kernel.org/bpf/20250116140531.108636-1-mrpre@163.com/ Avoid using add read_sock to psock. (Jakub Sitnicki) Avoid using warpper function to check whether strparser is supported.
V3 -> V7: https://lore.kernel.org/bpf/20250109094402.50838-1-mrpre@163.com/ https://lore.kernel.org/bpf/20241218053408.437295-1-mrpre@163.com/ Avoid introducing new proto_ops. (Jakub Sitnicki). Add more edge test cases for strparser + bpf. Fix patchwork fail of test cases code. Fix psock fetch without rcu lock. Move code of modifying to tcp_bpf.c.
V1 -> V3: https://lore.kernel.org/bpf/20241209152740.281125-1-mrpre@163.com/ Fix patchwork fail by adding Fixes tag. Save skb data offset for ENOMEM. (John Fastabend) ---
Jiayuan Chen (5): strparser: add read_sock callback bpf: fix wrong copied_seq calculation bpf: disable non stream socket for strparser selftests/bpf: fix invalid flag of recv() selftests/bpf: add strparser test for bpf
Documentation/networking/strparser.rst | 9 +- include/linux/skmsg.h | 2 + include/net/strparser.h | 2 + include/net/tcp.h | 8 + net/core/skmsg.c | 7 + net/core/sock_map.c | 5 +- net/ipv4/tcp.c | 29 +- net/ipv4/tcp_bpf.c | 36 ++ net/strparser/strparser.c | 11 +- .../selftests/bpf/prog_tests/sockmap_basic.c | 59 +-- .../selftests/bpf/prog_tests/sockmap_strp.c | 454 ++++++++++++++++++ .../selftests/bpf/progs/test_sockmap_strp.c | 53 ++ 12 files changed, 610 insertions(+), 65 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/sockmap_strp.c create mode 100644 tools/testing/selftests/bpf/progs/test_sockmap_strp.c
Added a new read_sock handler, allowing users to customize read operations instead of relying on the native socket's read_sock.
Signed-off-by: Jiayuan Chen mrpre@163.com --- Documentation/networking/strparser.rst | 9 ++++++++- include/net/strparser.h | 2 ++ net/strparser/strparser.c | 11 +++++++++-- 3 files changed, 19 insertions(+), 3 deletions(-)
diff --git a/Documentation/networking/strparser.rst b/Documentation/networking/strparser.rst index 6cab1f74ae05..7f623d1db72a 100644 --- a/Documentation/networking/strparser.rst +++ b/Documentation/networking/strparser.rst @@ -112,7 +112,7 @@ Functions Callbacks =========
-There are six callbacks: +There are seven callbacks:
::
@@ -182,6 +182,13 @@ There are six callbacks: the length of the message. skb->len - offset may be greater then full_len since strparser does not trim the skb.
+ :: + + int (*read_sock)(struct strparser *strp, read_descriptor_t *desc, + sk_read_actor_t recv_actor); + + The read_sock callback is used by strparser instead of + sock->ops->read_sock, if provided. ::
int (*read_sock_done)(struct strparser *strp, int err); diff --git a/include/net/strparser.h b/include/net/strparser.h index 41e2ce9e9e10..0a83010b3a64 100644 --- a/include/net/strparser.h +++ b/include/net/strparser.h @@ -43,6 +43,8 @@ struct strparser; struct strp_callbacks { int (*parse_msg)(struct strparser *strp, struct sk_buff *skb); void (*rcv_msg)(struct strparser *strp, struct sk_buff *skb); + int (*read_sock)(struct strparser *strp, read_descriptor_t *desc, + sk_read_actor_t recv_actor); int (*read_sock_done)(struct strparser *strp, int err); void (*abort_parser)(struct strparser *strp, int err); void (*lock)(struct strparser *strp); diff --git a/net/strparser/strparser.c b/net/strparser/strparser.c index 8299ceb3e373..95696f42647e 100644 --- a/net/strparser/strparser.c +++ b/net/strparser/strparser.c @@ -347,7 +347,10 @@ static int strp_read_sock(struct strparser *strp) struct socket *sock = strp->sk->sk_socket; read_descriptor_t desc;
- if (unlikely(!sock || !sock->ops || !sock->ops->read_sock)) + if (unlikely(!sock || !sock->ops)) + return -EBUSY; + + if (unlikely(!strp->cb.read_sock && !sock->ops->read_sock)) return -EBUSY;
desc.arg.data = strp; @@ -355,7 +358,10 @@ static int strp_read_sock(struct strparser *strp) desc.count = 1; /* give more than one skb per call */
/* sk should be locked here, so okay to do read_sock */ - sock->ops->read_sock(strp->sk, &desc, strp_recv); + if (strp->cb.read_sock) + strp->cb.read_sock(strp, &desc, strp_recv); + else + sock->ops->read_sock(strp->sk, &desc, strp_recv);
desc.error = strp->cb.read_sock_done(strp, desc.error);
@@ -468,6 +474,7 @@ int strp_init(struct strparser *strp, struct sock *sk, strp->cb.unlock = cb->unlock ? : strp_sock_unlock; strp->cb.rcv_msg = cb->rcv_msg; strp->cb.parse_msg = cb->parse_msg; + strp->cb.read_sock = cb->read_sock; strp->cb.read_sock_done = cb->read_sock_done ? : default_read_sock_done; strp->cb.abort_parser = cb->abort_parser ? : strp_abort_strp;
On Wed, Jan 22, 2025 at 06:09 PM +08, Jiayuan Chen wrote:
Added a new read_sock handler, allowing users to customize read operations instead of relying on the native socket's read_sock.
Signed-off-by: Jiayuan Chen mrpre@163.com
Reviewed-by: Jakub Sitnicki jakub@cloudflare.com
'sk->copied_seq' was updated in the tcp_eat_skb() function when the action of a BPF program was SK_REDIRECT. For other actions, like SK_PASS, the update logic for 'sk->copied_seq' was moved to tcp_bpf_recvmsg_parser() to ensure the accuracy of the 'fionread' feature.
It works for a single stream_verdict scenario, as it also modified sk_data_ready->sk_psock_verdict_data_ready->tcp_read_skb to remove updating 'sk->copied_seq'.
However, for programs where both stream_parser and stream_verdict are active (strparser purpose), tcp_read_sock() was used instead of tcp_read_skb() (sk_data_ready->strp_data_ready->tcp_read_sock). tcp_read_sock() now still updates 'sk->copied_seq', leading to duplicate updates.
In summary, for strparser + SK_PASS, copied_seq is redundantly calculated in both tcp_read_sock() and tcp_bpf_recvmsg_parser().
The issue causes incorrect copied_seq calculations, which prevent correct data reads from the recv() interface in user-land.
We do not want to add new proto_ops to implement a new version of tcp_read_sock, as this would introduce code complexity [1].
We could have added noack and copied_seq to desc, and then called ops->read_sock. However, unfortunately, other modules didn’t fully initialize desc to zero. So, for now, we are directly calling tcp_read_sock_noack() in tcp_bpf.c.
[1]: https://lore.kernel.org/bpf/20241218053408.437295-1-mrpre@163.com Fixes: e5c6de5fa025 ("bpf, sockmap: Incorrectly handling copied_seq") Suggested-by: Jakub Sitnicki jakub@cloudflare.com Signed-off-by: Jiayuan Chen mrpre@163.com --- include/linux/skmsg.h | 2 ++ include/net/tcp.h | 8 ++++++++ net/core/skmsg.c | 7 +++++++ net/ipv4/tcp.c | 29 ++++++++++++++++++++++++----- net/ipv4/tcp_bpf.c | 36 ++++++++++++++++++++++++++++++++++++ 5 files changed, 77 insertions(+), 5 deletions(-)
diff --git a/include/linux/skmsg.h b/include/linux/skmsg.h index 2cbe0c22a32f..0b9095a281b8 100644 --- a/include/linux/skmsg.h +++ b/include/linux/skmsg.h @@ -91,6 +91,8 @@ struct sk_psock { struct sk_psock_progs progs; #if IS_ENABLED(CONFIG_BPF_STREAM_PARSER) struct strparser strp; + u32 copied_seq; + u32 ingress_bytes; #endif struct sk_buff_head ingress_skb; struct list_head ingress_msg; diff --git a/include/net/tcp.h b/include/net/tcp.h index e9b37b76e894..06affc653247 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -729,6 +729,9 @@ void tcp_get_info(struct sock *, struct tcp_info *); /* Read 'sendfile()'-style from a TCP socket */ int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, sk_read_actor_t recv_actor); +int tcp_read_sock_noack(struct sock *sk, read_descriptor_t *desc, + sk_read_actor_t recv_actor, bool noack, + u32 *copied_seq); int tcp_read_skb(struct sock *sk, skb_read_actor_t recv_actor); struct sk_buff *tcp_recv_skb(struct sock *sk, u32 seq, u32 *off); void tcp_read_done(struct sock *sk, size_t len); @@ -2599,6 +2602,11 @@ struct sk_psock; #ifdef CONFIG_BPF_SYSCALL int tcp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore); void tcp_bpf_clone(const struct sock *sk, struct sock *newsk); +#ifdef CONFIG_BPF_STREAM_PARSER +struct strparser; +int tcp_bpf_strp_read_sock(struct strparser *strp, read_descriptor_t *desc, + sk_read_actor_t recv_actor); +#endif /* CONFIG_BPF_STREAM_PARSER */ #endif /* CONFIG_BPF_SYSCALL */
#ifdef CONFIG_INET diff --git a/net/core/skmsg.c b/net/core/skmsg.c index 61f3f3d4e528..0ddc4c718833 100644 --- a/net/core/skmsg.c +++ b/net/core/skmsg.c @@ -549,6 +549,9 @@ static int sk_psock_skb_ingress_enqueue(struct sk_buff *skb, return num_sge; }
+#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER) + psock->ingress_bytes += len; +#endif copied = len; msg->sg.start = 0; msg->sg.size = copied; @@ -1144,6 +1147,10 @@ int sk_psock_init_strp(struct sock *sk, struct sk_psock *psock) if (!ret) sk_psock_set_state(psock, SK_PSOCK_RX_STRP_ENABLED);
+ if (sk_is_tcp(sk)) { + psock->strp.cb.read_sock = tcp_bpf_strp_read_sock; + psock->copied_seq = tcp_sk(sk)->copied_seq; + } return ret; }
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 0d704bda6c41..285678d8ce07 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1565,12 +1565,13 @@ EXPORT_SYMBOL(tcp_recv_skb); * or for 'peeking' the socket using this routine * (although both would be easy to implement). */ -int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, - sk_read_actor_t recv_actor) +static int __tcp_read_sock(struct sock *sk, read_descriptor_t *desc, + sk_read_actor_t recv_actor, bool noack, + u32 *copied_seq) { struct sk_buff *skb; struct tcp_sock *tp = tcp_sk(sk); - u32 seq = tp->copied_seq; + u32 seq = *copied_seq; u32 offset; int copied = 0;
@@ -1624,9 +1625,12 @@ int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, tcp_eat_recv_skb(sk, skb); if (!desc->count) break; - WRITE_ONCE(tp->copied_seq, seq); + WRITE_ONCE(*copied_seq, seq); } - WRITE_ONCE(tp->copied_seq, seq); + WRITE_ONCE(*copied_seq, seq); + + if (noack) + goto out;
tcp_rcv_space_adjust(sk);
@@ -1635,10 +1639,25 @@ int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, tcp_recv_skb(sk, seq, &offset); tcp_cleanup_rbuf(sk, copied); } +out: return copied; } + +int tcp_read_sock(struct sock *sk, read_descriptor_t *desc, + sk_read_actor_t recv_actor) +{ + return __tcp_read_sock(sk, desc, recv_actor, false, + &tcp_sk(sk)->copied_seq); +} EXPORT_SYMBOL(tcp_read_sock);
+int tcp_read_sock_noack(struct sock *sk, read_descriptor_t *desc, + sk_read_actor_t recv_actor, bool noack, + u32 *copied_seq) +{ + return __tcp_read_sock(sk, desc, recv_actor, noack, copied_seq); +} + int tcp_read_skb(struct sock *sk, skb_read_actor_t recv_actor) { struct sk_buff *skb; diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c index 47f65b1b70ca..ba581785adb4 100644 --- a/net/ipv4/tcp_bpf.c +++ b/net/ipv4/tcp_bpf.c @@ -646,6 +646,42 @@ static int tcp_bpf_assert_proto_ops(struct proto *ops) ops->sendmsg == tcp_sendmsg ? 0 : -ENOTSUPP; }
+#if IS_ENABLED(CONFIG_BPF_STREAM_PARSER) +int tcp_bpf_strp_read_sock(struct strparser *strp, read_descriptor_t *desc, + sk_read_actor_t recv_actor) +{ + struct sock *sk = strp->sk; + struct sk_psock *psock; + struct tcp_sock *tp; + int copied = 0; + + tp = tcp_sk(sk); + rcu_read_lock(); + psock = sk_psock(sk); + if (WARN_ON_ONCE(!psock)) { + desc->error = -EINVAL; + goto out; + } + + psock->ingress_bytes = 0; + copied = tcp_read_sock_noack(sk, desc, recv_actor, true, + &psock->copied_seq); + if (copied < 0) + goto out; + /* recv_actor may redirect skb to another socket (SK_REDIRECT) or + * just put skb into ingress queue of current socket (SK_PASS). + * For SK_REDIRECT, we need to ack the frame immediately but for + * SK_PASS, we want to delay the ack until tcp_bpf_recvmsg_parser(). + */ + tp->copied_seq = psock->copied_seq - psock->ingress_bytes; + tcp_rcv_space_adjust(sk); + __tcp_cleanup_rbuf(sk, copied - psock->ingress_bytes); +out: + rcu_read_unlock(); + return copied; +} +#endif /* CONFIG_BPF_STREAM_PARSER */ + int tcp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore) { int family = sk->sk_family == AF_INET6 ? TCP_BPF_IPV6 : TCP_BPF_IPV4;
On Wed, Jan 22, 2025 at 06:09 PM +08, Jiayuan Chen wrote:
'sk->copied_seq' was updated in the tcp_eat_skb() function when the action of a BPF program was SK_REDIRECT. For other actions, like SK_PASS, the update logic for 'sk->copied_seq' was moved to tcp_bpf_recvmsg_parser() to ensure the accuracy of the 'fionread' feature.
It works for a single stream_verdict scenario, as it also modified sk_data_ready->sk_psock_verdict_data_ready->tcp_read_skb to remove updating 'sk->copied_seq'.
However, for programs where both stream_parser and stream_verdict are active (strparser purpose), tcp_read_sock() was used instead of tcp_read_skb() (sk_data_ready->strp_data_ready->tcp_read_sock). tcp_read_sock() now still updates 'sk->copied_seq', leading to duplicate updates.
In summary, for strparser + SK_PASS, copied_seq is redundantly calculated in both tcp_read_sock() and tcp_bpf_recvmsg_parser().
The issue causes incorrect copied_seq calculations, which prevent correct data reads from the recv() interface in user-land.
We do not want to add new proto_ops to implement a new version of tcp_read_sock, as this would introduce code complexity [1].
We could have added noack and copied_seq to desc, and then called ops->read_sock. However, unfortunately, other modules didn’t fully initialize desc to zero. So, for now, we are directly calling tcp_read_sock_noack() in tcp_bpf.c.
Fixes: e5c6de5fa025 ("bpf, sockmap: Incorrectly handling copied_seq") Suggested-by: Jakub Sitnicki jakub@cloudflare.com Signed-off-by: Jiayuan Chen mrpre@163.com
I'm happy with how this turned out, but let's run it by Eric.
Reviewed-by: Jakub Sitnicki jakub@cloudflare.com
Currently, only TCP supports strparser, but sockmap doesn't intercept non-TCP connections to attach strparser. For example, with UDP, although the read/write handlers are replaced, strparser is not executed due to the lack of a read_sock operation.
Furthermore, in udp_bpf_recvmsg(), it checks whether the psock has data, and if not, it falls back to the native UDP read interface, making UDP + strparser appear to read correctly. According to its commit history, this behavior is unexpected.
Moreover, since UDP lacks the concept of streams, we intercept it directly.
Fixes: 1fa1fe8ff161 ("bpf, sockmap: Test shutdown() correctly exits epoll and recv()=0") Signed-off-by: Jiayuan Chen mrpre@163.com --- net/core/sock_map.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/net/core/sock_map.c b/net/core/sock_map.c index f1b9b3958792..3b0f59d9b4db 100644 --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -303,7 +303,10 @@ static int sock_map_link(struct bpf_map *map, struct sock *sk)
write_lock_bh(&sk->sk_callback_lock); if (stream_parser && stream_verdict && !psock->saved_data_ready) { - ret = sk_psock_init_strp(sk, psock); + if (sk_is_tcp(sk)) + ret = sk_psock_init_strp(sk, psock); + else + ret = -EOPNOTSUPP; if (ret) { write_unlock_bh(&sk->sk_callback_lock); sk_psock_put(sk, psock);
On Wed, Jan 22, 2025 at 06:09 PM +08, Jiayuan Chen wrote:
Currently, only TCP supports strparser, but sockmap doesn't intercept non-TCP connections to attach strparser. For example, with UDP, although the read/write handlers are replaced, strparser is not executed due to the lack of a read_sock operation.
Furthermore, in udp_bpf_recvmsg(), it checks whether the psock has data, and if not, it falls back to the native UDP read interface, making UDP + strparser appear to read correctly. According to its commit history, this behavior is unexpected.
Moreover, since UDP lacks the concept of streams, we intercept it directly.
Fixes: 1fa1fe8ff161 ("bpf, sockmap: Test shutdown() correctly exits epoll and recv()=0") Signed-off-by: Jiayuan Chen mrpre@163.com
Acked-by: Jakub Sitnicki jakub@cloudflare.com
SOCK_NONBLOCK flag is only effective during socket creation, not during recv. Use MSG_DONTWAIT instead.
Signed-off-by: Jiayuan Chen mrpre@163.com --- tools/testing/selftests/bpf/prog_tests/sockmap_basic.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c index 884ad87783d5..0c51b7288978 100644 --- a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c +++ b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c @@ -522,8 +522,8 @@ static void test_sockmap_skb_verdict_shutdown(void) if (!ASSERT_EQ(err, 1, "epoll_wait(fd)")) goto out_close;
- n = recv(c1, &b, 1, SOCK_NONBLOCK); - ASSERT_EQ(n, 0, "recv_timeout(fin)"); + n = recv(c1, &b, 1, MSG_DONTWAIT); + ASSERT_EQ(n, 0, "recv(fin)"); out_close: close(c1); close(p1); @@ -628,7 +628,7 @@ static void test_sockmap_skb_verdict_fionread(bool pass_prog) ASSERT_EQ(avail, expected, "ioctl(FIONREAD)"); /* On DROP test there will be no data to read */ if (pass_prog) { - recvd = recv_timeout(c1, &buf, sizeof(buf), SOCK_NONBLOCK, IO_TIMEOUT_SEC); + recvd = recv_timeout(c1, &buf, sizeof(buf), MSG_DONTWAIT, IO_TIMEOUT_SEC); ASSERT_EQ(recvd, sizeof(buf), "recv_timeout(c0)"); }
On Wed, Jan 22, 2025 at 06:09 PM +08, Jiayuan Chen wrote:
SOCK_NONBLOCK flag is only effective during socket creation, not during recv. Use MSG_DONTWAIT instead.
Signed-off-by: Jiayuan Chen mrpre@163.com
Acked-by: Jakub Sitnicki jakub@cloudflare.com
Add test cases for bpf + strparser and separated them from sockmap_basic, as strparser has more encapsulation and parsing capabilities compared to standard sockmap.
Signed-off-by: Jiayuan Chen mrpre@163.com --- .../selftests/bpf/prog_tests/sockmap_basic.c | 53 -- .../selftests/bpf/prog_tests/sockmap_strp.c | 454 ++++++++++++++++++ .../selftests/bpf/progs/test_sockmap_strp.c | 53 ++ 3 files changed, 507 insertions(+), 53 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/sockmap_strp.c create mode 100644 tools/testing/selftests/bpf/progs/test_sockmap_strp.c
diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c index 0c51b7288978..f8953455db29 100644 --- a/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c +++ b/tools/testing/selftests/bpf/prog_tests/sockmap_basic.c @@ -531,57 +531,6 @@ static void test_sockmap_skb_verdict_shutdown(void) test_sockmap_pass_prog__destroy(skel); }
-static void test_sockmap_stream_pass(void) -{ - int zero = 0, sent, recvd; - int verdict, parser; - int err, map; - int c = -1, p = -1; - struct test_sockmap_pass_prog *pass = NULL; - char snd[256] = "0123456789"; - char rcv[256] = "0"; - - pass = test_sockmap_pass_prog__open_and_load(); - verdict = bpf_program__fd(pass->progs.prog_skb_verdict); - parser = bpf_program__fd(pass->progs.prog_skb_parser); - map = bpf_map__fd(pass->maps.sock_map_rx); - - err = bpf_prog_attach(parser, map, BPF_SK_SKB_STREAM_PARSER, 0); - if (!ASSERT_OK(err, "bpf_prog_attach stream parser")) - goto out; - - err = bpf_prog_attach(verdict, map, BPF_SK_SKB_STREAM_VERDICT, 0); - if (!ASSERT_OK(err, "bpf_prog_attach stream verdict")) - goto out; - - err = create_pair(AF_INET, SOCK_STREAM, &c, &p); - if (err) - goto out; - - /* sk_data_ready of 'p' will be replaced by strparser handler */ - err = bpf_map_update_elem(map, &zero, &p, BPF_NOEXIST); - if (!ASSERT_OK(err, "bpf_map_update_elem(p)")) - goto out_close; - - /* - * as 'prog_skb_parser' return the original skb len and - * 'prog_skb_verdict' return SK_PASS, the kernel will just - * pass it through to original socket 'p' - */ - sent = xsend(c, snd, sizeof(snd), 0); - ASSERT_EQ(sent, sizeof(snd), "xsend(c)"); - - recvd = recv_timeout(p, rcv, sizeof(rcv), SOCK_NONBLOCK, - IO_TIMEOUT_SEC); - ASSERT_EQ(recvd, sizeof(rcv), "recv_timeout(p)"); - -out_close: - close(c); - close(p); - -out: - test_sockmap_pass_prog__destroy(pass); -}
static void test_sockmap_skb_verdict_fionread(bool pass_prog) { @@ -1101,8 +1050,6 @@ void test_sockmap_basic(void) test_sockmap_progs_query(BPF_SK_SKB_VERDICT); if (test__start_subtest("sockmap skb_verdict shutdown")) test_sockmap_skb_verdict_shutdown(); - if (test__start_subtest("sockmap stream parser and verdict pass")) - test_sockmap_stream_pass(); if (test__start_subtest("sockmap skb_verdict fionread")) test_sockmap_skb_verdict_fionread(true); if (test__start_subtest("sockmap skb_verdict fionread on drop")) diff --git a/tools/testing/selftests/bpf/prog_tests/sockmap_strp.c b/tools/testing/selftests/bpf/prog_tests/sockmap_strp.c new file mode 100644 index 000000000000..621b3b71888e --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/sockmap_strp.c @@ -0,0 +1,454 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <error.h> +#include <netinet/tcp.h> +#include <test_progs.h> +#include "sockmap_helpers.h" +#include "test_skmsg_load_helpers.skel.h" +#include "test_sockmap_strp.skel.h" + +#define STRP_PKT_HEAD_LEN 4 +#define STRP_PKT_BODY_LEN 6 +#define STRP_PKT_FULL_LEN (STRP_PKT_HEAD_LEN + STRP_PKT_BODY_LEN) + +static const char packet[STRP_PKT_FULL_LEN] = "head+body\0"; +static const int test_packet_num = 100; + +/* Current implementation of tcp_bpf_recvmsg_parser() invokes data_ready + * with sk held if an skb exists in sk_receive_queue. Then for the + * data_ready implementation of strparser, it will delay the read + * operation if sk is held and EAGAIN is returned. + */ +static int sockmap_strp_consume_pre_data(int p) +{ + int recvd; + bool retried = false; + char rcv[10]; + +retry: + errno = 0; + recvd = recv_timeout(p, rcv, sizeof(rcv), 0, 1); + if (recvd < 0 && errno == EAGAIN && retried == false) { + /* On the first call, EAGAIN will certainly be returned. + * A 1-second wait is enough for the workqueue to finish. + */ + sleep(1); + retried = true; + goto retry; + } + + if (!ASSERT_EQ(recvd, STRP_PKT_FULL_LEN, "recv error or truncated data") || + !ASSERT_OK(memcmp(packet, rcv, STRP_PKT_FULL_LEN), + "data mismatch")) + return -1; + return 0; +} + +static struct test_sockmap_strp *sockmap_strp_init(int *out_map, bool pass, + bool need_parser) +{ + struct test_sockmap_strp *strp = NULL; + int verdict, parser; + int err; + + strp = test_sockmap_strp__open_and_load(); + *out_map = bpf_map__fd(strp->maps.sock_map); + + if (need_parser) + parser = bpf_program__fd(strp->progs.prog_skb_parser_partial); + else + parser = bpf_program__fd(strp->progs.prog_skb_parser); + + if (pass) + verdict = bpf_program__fd(strp->progs.prog_skb_verdict_pass); + else + verdict = bpf_program__fd(strp->progs.prog_skb_verdict); + + err = bpf_prog_attach(parser, *out_map, BPF_SK_SKB_STREAM_PARSER, 0); + if (!ASSERT_OK(err, "bpf_prog_attach stream parser")) + goto err; + + err = bpf_prog_attach(verdict, *out_map, BPF_SK_SKB_STREAM_VERDICT, 0); + if (!ASSERT_OK(err, "bpf_prog_attach stream verdict")) + goto err; + + return strp; +err: + test_sockmap_strp__destroy(strp); + return NULL; +} + +/* Dispatch packets to different socket by packet size: + * + * ------ ------ + * | pkt4 || pkt1 |... > remote socket + * ------ ------ / ------ ------ + * | pkt8 | pkt7 |... + * ------ ------ \ ------ ------ + * | pkt3 || pkt2 |... > local socket + * ------ ------ + */ +static void test_sockmap_strp_dispatch_pkt(int family, int sotype) +{ + int i, j, zero = 0, one = 1, recvd; + int err, map; + int c0 = -1, p0 = -1, c1 = -1, p1 = -1; + struct test_sockmap_strp *strp = NULL; + int test_cnt = 6; + char rcv[10]; + struct { + char data[7]; + int data_len; + int send_cnt; + int *receiver; + } send_dir[2] = { + /* data expected to deliver to local */ + {"llllll", 6, 0, &p0}, + /* data expected to deliver to remote */ + {"rrrrr", 5, 0, &c1} + }; + + strp = sockmap_strp_init(&map, false, false); + if (!ASSERT_TRUE(strp, "sockmap_strp_init")) + return; + + err = create_socket_pairs(family, sotype, &c0, &c1, &p0, &p1); + if (!ASSERT_OK(err, "create_socket_pairs()")) + goto out; + + err = bpf_map_update_elem(map, &zero, &p0, BPF_NOEXIST); + if (!ASSERT_OK(err, "bpf_map_update_elem(p0)")) + goto out_close; + + err = bpf_map_update_elem(map, &one, &p1, BPF_NOEXIST); + if (!ASSERT_OK(err, "bpf_map_update_elem(p1)")) + goto out_close; + + err = setsockopt(c1, IPPROTO_TCP, TCP_NODELAY, &zero, sizeof(zero)); + if (!ASSERT_OK(err, "setsockopt(TCP_NODELAY)")) + goto out_close; + + /* deliver data with data size greater than 5 to local */ + strp->data->verdict_max_size = 5; + + for (i = 0; i < test_cnt; i++) { + int d = i % 2; + + xsend(c0, send_dir[d].data, send_dir[d].data_len, 0); + send_dir[d].send_cnt++; + } + + for (i = 0; i < 2; i++) { + for (j = 0; j < send_dir[i].send_cnt; j++) { + int expected = send_dir[i].data_len; + + recvd = recv_timeout(*send_dir[i].receiver, rcv, + expected, MSG_DONTWAIT, + IO_TIMEOUT_SEC); + if (!ASSERT_EQ(recvd, expected, "recv_timeout()")) + goto out_close; + if (!ASSERT_OK(memcmp(send_dir[i].data, rcv, recvd), + "data mismatch")) + goto out_close; + } + } +out_close: + close(c0); + close(c1); + close(p0); + close(p1); +out: + test_sockmap_strp__destroy(strp); +} + +/* We have multiple packets in one skb + * ------------ ------------ ------------ + * | packet1 | packet2 | ... + * ------------ ------------ ------------ + */ +static void test_sockmap_strp_multiple_pkt(int family, int sotype) +{ + int i, zero = 0; + int sent, recvd, total; + int err, map; + int c = -1, p = -1; + struct test_sockmap_strp *strp = NULL; + char *snd = NULL, *rcv = NULL; + + strp = sockmap_strp_init(&map, true, true); + if (!ASSERT_TRUE(strp, "sockmap_strp_init")) + return; + + err = create_pair(family, sotype, &c, &p); + if (err) + goto out; + + err = bpf_map_update_elem(map, &zero, &p, BPF_NOEXIST); + if (!ASSERT_OK(err, "bpf_map_update_elem(zero, p)")) + goto out_close; + + /* construct multiple packets in one buffer */ + total = test_packet_num * STRP_PKT_FULL_LEN; + snd = malloc(total); + rcv = malloc(total + 1); + if (!ASSERT_TRUE(snd, "malloc(snd)") || + !ASSERT_TRUE(rcv, "malloc(rcv)")) + goto out_close; + + for (i = 0; i < test_packet_num; i++) { + memcpy(snd + i * STRP_PKT_FULL_LEN, + packet, STRP_PKT_FULL_LEN); + } + + sent = xsend(c, snd, total, 0); + if (!ASSERT_EQ(sent, total, "xsend(c)")) + goto out_close; + + /* try to recv one more byte to avoid truncation check */ + recvd = recv_timeout(p, rcv, total + 1, MSG_DONTWAIT, IO_TIMEOUT_SEC); + if (!ASSERT_EQ(recvd, total, "recv(rcv)")) + goto out_close; + + /* we sent TCP segment with multiple encapsulation + * then check whether packets are handled correctly + */ + if (!ASSERT_OK(memcmp(snd, rcv, total), "data mismatch")) + goto out_close; + +out_close: + close(c); + close(p); + if (snd) + free(snd); + if (rcv) + free(rcv); +out: + test_sockmap_strp__destroy(strp); +} + +/* Test strparser with partial read */ +static void test_sockmap_strp_partial_read(int family, int sotype) +{ + int zero = 0, recvd, off; + int err, map; + int c = -1, p = -1; + struct test_sockmap_strp *strp = NULL; + char rcv[STRP_PKT_FULL_LEN + 1] = "0"; + + strp = sockmap_strp_init(&map, true, true); + if (!ASSERT_TRUE(strp, "sockmap_strp_init")) + return; + + err = create_pair(family, sotype, &c, &p); + if (err) + goto out; + + /* sk_data_ready of 'p' will be replaced by strparser handler */ + err = bpf_map_update_elem(map, &zero, &p, BPF_NOEXIST); + if (!ASSERT_OK(err, "bpf_map_update_elem(zero, p)")) + goto out_close; + + /* 1.1 send partial head, 1 byte header left */ + off = STRP_PKT_HEAD_LEN - 1; + xsend(c, packet, off, 0); + recvd = recv_timeout(p, rcv, sizeof(rcv), MSG_DONTWAIT, 1); + if (!ASSERT_EQ(-1, recvd, "partial head sent, expected no data")) + goto out_close; + + /* 1.2 send remaining head and body */ + xsend(c, packet + off, STRP_PKT_FULL_LEN - off, 0); + recvd = recv_timeout(p, rcv, sizeof(rcv), MSG_DONTWAIT, IO_TIMEOUT_SEC); + if (!ASSERT_EQ(recvd, STRP_PKT_FULL_LEN, "expected full data")) + goto out_close; + + /* 2.1 send partial head, 1 byte header left */ + off = STRP_PKT_HEAD_LEN - 1; + xsend(c, packet, off, 0); + + /* 2.2 send remaining head and partial body, 1 byte body left */ + xsend(c, packet + off, STRP_PKT_FULL_LEN - off - 1, 0); + off = STRP_PKT_FULL_LEN - 1; + recvd = recv_timeout(p, rcv, sizeof(rcv), MSG_DONTWAIT, 1); + if (!ASSERT_EQ(-1, recvd, "partial body sent, expected no data")) + goto out_close; + + /* 2.3 send remaining body */ + xsend(c, packet + off, STRP_PKT_FULL_LEN - off, 0); + recvd = recv_timeout(p, rcv, sizeof(rcv), MSG_DONTWAIT, IO_TIMEOUT_SEC); + if (!ASSERT_EQ(recvd, STRP_PKT_FULL_LEN, "expected full data")) + goto out_close; + +out_close: + close(c); + close(p); + +out: + test_sockmap_strp__destroy(strp); +} + +/* Test simple socket read/write with strparser + FIONREAD */ +static void test_sockmap_strp_pass(int family, int sotype, bool fionread) +{ + int zero = 0, pkt_size = STRP_PKT_FULL_LEN, sent, recvd, avail; + int err, map; + int c = -1, p = -1; + int test_cnt = 10, i; + struct test_sockmap_strp *strp = NULL; + char rcv[STRP_PKT_FULL_LEN + 1] = "0"; + + strp = sockmap_strp_init(&map, true, true); + if (!ASSERT_TRUE(strp, "sockmap_strp_init")) + return; + + err = create_pair(family, sotype, &c, &p); + if (err) + goto out; + + /* inject some data before bpf process, it should be read + * correctly because we check sk_receive_queue in + * tcp_bpf_recvmsg_parser(). + */ + sent = xsend(c, packet, pkt_size, 0); + if (!ASSERT_EQ(sent, pkt_size, "xsend(pre-data)")) + goto out_close; + + /* sk_data_ready of 'p' will be replaced by strparser handler */ + err = bpf_map_update_elem(map, &zero, &p, BPF_NOEXIST); + if (!ASSERT_OK(err, "bpf_map_update_elem(p)")) + goto out_close; + + /* consume previous data we injected */ + if (sockmap_strp_consume_pre_data(p)) + goto out_close; + + /* Previously, we encountered issues such as deadlocks and + * sequence errors that resulted in the inability to read + * continuously. Therefore, we perform multiple iterations + * of testing here. + */ + for (i = 0; i < test_cnt; i++) { + sent = xsend(c, packet, pkt_size, 0); + if (!ASSERT_EQ(sent, pkt_size, "xsend(c)")) + goto out_close; + + recvd = recv_timeout(p, rcv, sizeof(rcv), MSG_DONTWAIT, + IO_TIMEOUT_SEC); + if (!ASSERT_EQ(recvd, pkt_size, "recv_timeout(p)") || + !ASSERT_OK(memcmp(packet, rcv, pkt_size), + "memcmp, data mismatch")) + goto out_close; + } + + if (fionread) { + sent = xsend(c, packet, pkt_size, 0); + if (!ASSERT_EQ(sent, pkt_size, "second xsend(c)")) + goto out_close; + + err = ioctl(p, FIONREAD, &avail); + if (!ASSERT_OK(err, "ioctl(FIONREAD) error") || + !ASSERT_EQ(avail, pkt_size, "ioctl(FIONREAD)")) + goto out_close; + + recvd = recv_timeout(p, rcv, sizeof(rcv), MSG_DONTWAIT, + IO_TIMEOUT_SEC); + if (!ASSERT_EQ(recvd, pkt_size, "second recv_timeout(p)") || + !ASSERT_OK(memcmp(packet, rcv, pkt_size), + "second memcmp, data mismatch")) + goto out_close; + } + +out_close: + close(c); + close(p); + +out: + test_sockmap_strp__destroy(strp); +} + +/* Test strparser with verdict mode */ +static void test_sockmap_strp_verdict(int family, int sotype) +{ + int zero = 0, one = 1, sent, recvd, off; + int err, map; + int c0 = -1, p0 = -1, c1 = -1, p1 = -1; + struct test_sockmap_strp *strp = NULL; + char rcv[STRP_PKT_FULL_LEN + 1] = "0"; + + strp = sockmap_strp_init(&map, false, true); + if (!ASSERT_TRUE(strp, "sockmap_strp_init")) + return; + + /* We simulate a reverse proxy server. + * When p0 receives data from c0, we forward it to c1. + * From c1's perspective, it will consider this data + * as being sent by p1. + */ + err = create_socket_pairs(family, sotype, &c0, &c1, &p0, &p1); + if (!ASSERT_OK(err, "create_socket_pairs()")) + goto out; + + err = bpf_map_update_elem(map, &zero, &p0, BPF_NOEXIST); + if (!ASSERT_OK(err, "bpf_map_update_elem(p0)")) + goto out_close; + + err = bpf_map_update_elem(map, &one, &p1, BPF_NOEXIST); + if (!ASSERT_OK(err, "bpf_map_update_elem(p1)")) + goto out_close; + + sent = xsend(c0, packet, STRP_PKT_FULL_LEN, 0); + if (!ASSERT_EQ(sent, STRP_PKT_FULL_LEN, "xsend(c0)")) + goto out_close; + + recvd = recv_timeout(c1, rcv, sizeof(rcv), MSG_DONTWAIT, + IO_TIMEOUT_SEC); + if (!ASSERT_EQ(recvd, STRP_PKT_FULL_LEN, "recv_timeout(c1)") || + !ASSERT_OK(memcmp(packet, rcv, STRP_PKT_FULL_LEN), + "received data does not match the sent data")) + goto out_close; + + /* send again to ensure the stream is functioning correctly. */ + sent = xsend(c0, packet, STRP_PKT_FULL_LEN, 0); + if (!ASSERT_EQ(sent, STRP_PKT_FULL_LEN, "second xsend(c0)")) + goto out_close; + + /* partial read */ + off = STRP_PKT_FULL_LEN / 2; + recvd = recv_timeout(c1, rcv, off, MSG_DONTWAIT, + IO_TIMEOUT_SEC); + recvd += recv_timeout(c1, rcv + off, sizeof(rcv) - off, MSG_DONTWAIT, + IO_TIMEOUT_SEC); + + if (!ASSERT_EQ(recvd, STRP_PKT_FULL_LEN, "partial recv_timeout(c1)") || + !ASSERT_OK(memcmp(packet, rcv, STRP_PKT_FULL_LEN), + "partial received data does not match the sent data")) + goto out_close; + +out_close: + close(c0); + close(c1); + close(p0); + close(p1); +out: + test_sockmap_strp__destroy(strp); +} + +void test_sockmap_strp(void) +{ + if (test__start_subtest("sockmap strp tcp pass")) + test_sockmap_strp_pass(AF_INET, SOCK_STREAM, false); + if (test__start_subtest("sockmap strp tcp v6 pass")) + test_sockmap_strp_pass(AF_INET6, SOCK_STREAM, false); + if (test__start_subtest("sockmap strp tcp pass fionread")) + test_sockmap_strp_pass(AF_INET, SOCK_STREAM, true); + if (test__start_subtest("sockmap strp tcp v6 pass fionread")) + test_sockmap_strp_pass(AF_INET6, SOCK_STREAM, true); + if (test__start_subtest("sockmap strp tcp verdict")) + test_sockmap_strp_verdict(AF_INET, SOCK_STREAM); + if (test__start_subtest("sockmap strp tcp v6 verdict")) + test_sockmap_strp_verdict(AF_INET6, SOCK_STREAM); + if (test__start_subtest("sockmap strp tcp partial read")) + test_sockmap_strp_partial_read(AF_INET, SOCK_STREAM); + if (test__start_subtest("sockmap strp tcp multiple packets")) + test_sockmap_strp_multiple_pkt(AF_INET, SOCK_STREAM); + if (test__start_subtest("sockmap strp tcp dispatch")) + test_sockmap_strp_dispatch_pkt(AF_INET, SOCK_STREAM); +} diff --git a/tools/testing/selftests/bpf/progs/test_sockmap_strp.c b/tools/testing/selftests/bpf/progs/test_sockmap_strp.c new file mode 100644 index 000000000000..dde3d5bec515 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_sockmap_strp.c @@ -0,0 +1,53 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/bpf.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_endian.h> +int verdict_max_size = 10000; +struct { + __uint(type, BPF_MAP_TYPE_SOCKMAP); + __uint(max_entries, 20); + __type(key, int); + __type(value, int); +} sock_map SEC(".maps"); + +SEC("sk_skb/stream_verdict") +int prog_skb_verdict(struct __sk_buff *skb) +{ + __u32 one = 1; + + if (skb->len > verdict_max_size) + return SK_PASS; + + return bpf_sk_redirect_map(skb, &sock_map, one, 0); +} + +SEC("sk_skb/stream_verdict") +int prog_skb_verdict_pass(struct __sk_buff *skb) +{ + return SK_PASS; +} + +SEC("sk_skb/stream_parser") +int prog_skb_parser(struct __sk_buff *skb) +{ + return skb->len; +} + +SEC("sk_skb/stream_parser") +int prog_skb_parser_partial(struct __sk_buff *skb) +{ + /* agreement with the test program on a 4-byte size header + * and 6-byte body. + */ + if (skb->len < 4) { + /* need more header to determine full length */ + return 0; + } + /* return full length decoded from header. + * the return value may be larger than skb->len which + * means framework must wait body coming. + */ + return 10; +} + +char _license[] SEC("license") = "GPL";
On Wed, Jan 22, 2025 at 06:09 PM +08, Jiayuan Chen wrote:
Add test cases for bpf + strparser and separated them from sockmap_basic, as strparser has more encapsulation and parsing capabilities compared to standard sockmap.
Signed-off-by: Jiayuan Chen mrpre@163.com
Acked-by: Jakub Sitnicki jakub@cloudflare.com
On Wed, Jan 22, 2025 at 06:09 PM +08, Jiayuan Chen wrote:
A previous commit described in this topic http://lore.kernel.org/bpf/20230523025618.113937-9-john.fastabend@gmail.com directly updated 'sk->copied_seq' in the tcp_eat_skb() function when the action of a BPF program was SK_REDIRECT. For other actions, like SK_PASS, the update logic for 'sk->copied_seq' was moved to tcp_bpf_recvmsg_parser() to ensure the accuracy of the 'fionread' feature.
That commit works for a single stream_verdict scenario, as it also modified 'sk_data_ready->sk_psock_verdict_data_ready->tcp_read_skb' to remove updating 'sk->copied_seq'.
However, for programs where both stream_parser and stream_verdict are active (strparser purpose), tcp_read_sock() was used instead of tcp_read_skb() (sk_data_ready->strp_data_ready->tcp_read_sock). tcp_read_sock() now still updates 'sk->copied_seq', leading to duplicated updates.
In summary, for strparser + SK_PASS, copied_seq is redundantly calculated in both tcp_read_sock() and tcp_bpf_recvmsg_parser().
The issue causes incorrect copied_seq calculations, which prevent correct data reads from the recv() interface in user-land.
Also we added test cases for bpf + strparser and separated them from sockmap_basic, as strparser has more encapsulation and parsing capabilities compared to sockmap.
V8 -> v9 https://lore.kernel.org/bpf/20250121050707.55523-1-mrpre@163.com/ Fixed some issues suggested by Jakub Sitnicki.
V7 -> V8 https://lore.kernel.org/bpf/20250116140531.108636-1-mrpre@163.com/ Avoid using add read_sock to psock. (Jakub Sitnicki) Avoid using warpper function to check whether strparser is supported.
V3 -> V7: https://lore.kernel.org/bpf/20250109094402.50838-1-mrpre@163.com/ https://lore.kernel.org/bpf/20241218053408.437295-1-mrpre@163.com/ Avoid introducing new proto_ops. (Jakub Sitnicki). Add more edge test cases for strparser + bpf. Fix patchwork fail of test cases code. Fix psock fetch without rcu lock. Move code of modifying to tcp_bpf.c.
V1 -> V3: https://lore.kernel.org/bpf/20241209152740.281125-1-mrpre@163.com/ Fix patchwork fail by adding Fixes tag. Save skb data offset for ENOMEM. (John Fastabend)
Thanks for addressing all feedback, Jiayuan. Series LGTM. Feel free to carry my tags if there is another iteration.
-jkbs
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