[PATCH bpf v9 1/5] strparser: add read_sock callback

[Jiayuan Chen <mrpre@163.com>]

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;
 
-- 
2.43.5