Merge branch 'bpf-fix-wrong-copied_seq-calculation-and-add-tests'

Jiayuan Chen says:

====================
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.
====================

Link: https://patch.msgid.link/20250122100917.49845-1-mrpre@163.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

3 files changed, 12 insertions, 0 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/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/include/net/tcp.h b/include/net/tcp.h
index 5b2b04835688..9c044fb9ab26 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