bpf, sockmap: Fix missing BPF_F_INGRESS flag when using apply_bytes

mainline inclusion
from mainline-v6.2-rc1
commit a351d608
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I65HYE
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a351d6087bf7d3d8440d58d3bf244ec64b89394a

---------------------------

When redirecting, we use sk_msg_to_ingress() to get the BPF_F_INGRESS
flag from the msg->flags. If apply_bytes is used and it is larger than
the current data being processed, sk_psock_msg_verdict() will not be
called when sendmsg() is called again. At this time, the msg->flags is 0,
and we lost the BPF_F_INGRESS flag.

So we need to save the BPF_F_INGRESS flag in sk_psock and use it when
redirection.

Fixes: 8934ce2f ("bpf: sockmap redirect ingress support")
Signed-off-by: NPengcheng Yang <yangpc@wangsu.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NJakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/1669718441-2654-3-git-send-email-yangpc@wangsu.comSigned-off-by: NLiu Jian <liujian56@huawei.com>

Conflicts:
	include/net/tcp.h

include/linux/skmsg.h

@@ -94,6 +94,7 @@ struct sk_psock {
 	u32				apply_bytes;
 	u32				cork_bytes;
 	u32				eval;
+	bool				redir_ingress; /* undefined if sk_redir is null */
 	struct sk_msg			*cork;
 	struct sk_psock_progs		progs;
 	struct sk_psock_parser		parser;

include/net/tcp.h

@@ -2238,8 +2238,8 @@ static inline void tcp_bpf_clone(const struct sock *sk, struct sock *newsk)
 #endif /* CONFIG_BPF_STREAM_PARSER */
 
 #ifdef CONFIG_NET_SOCK_MSG
-int tcp_bpf_sendmsg_redir(struct sock *sk, struct sk_msg *msg, u32 bytes,
-			  int flags);
+int tcp_bpf_sendmsg_redir(struct sock *sk, bool ingress,
+			struct sk_msg *msg, u32 bytes, int flags);
 int __tcp_bpf_recvmsg(struct sock *sk, struct sk_psock *psock,
 		      struct msghdr *msg, int len, int flags);
 #endif /* CONFIG_NET_SOCK_MSG */

net/core/skmsg.c

@@ -784,13 +784,16 @@ int sk_psock_msg_verdict(struct sock *sk, struct sk_psock *psock,
 	ret = sk_psock_map_verd(ret, msg->sk_redir);
 	psock->apply_bytes = msg->apply_bytes;
 	if (ret == __SK_REDIRECT) {
-		if (psock->sk_redir)
+		if (psock->sk_redir) {
 			sock_put(psock->sk_redir);
-		psock->sk_redir = msg->sk_redir;
-		if (!psock->sk_redir) {
+			psock->sk_redir = NULL;
+		}
+		if (!msg->sk_redir) {
 			ret = __SK_DROP;
 			goto out;
 		}
+		psock->redir_ingress = sk_msg_to_ingress(msg);
+		psock->sk_redir = msg->sk_redir;
 		sock_hold(psock->sk_redir);
 	}
 out:

net/ipv4/tcp_bpf.c

@@ -213,10 +213,9 @@ static int tcp_bpf_push_locked(struct sock *sk, struct sk_msg *msg,
 	return ret;
 }
 
-int tcp_bpf_sendmsg_redir(struct sock *sk, struct sk_msg *msg,
-			  u32 bytes, int flags)
+int tcp_bpf_sendmsg_redir(struct sock *sk, bool ingress,
+			  struct sk_msg *msg, u32 bytes, int flags)
 {
-	bool ingress = sk_msg_to_ingress(msg);
 	struct sk_psock *psock = sk_psock_get(sk);
 	int ret;
 
@@ -383,7 +382,7 @@ static int tcp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
 static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock,
 				struct sk_msg *msg, int *copied, int flags)
 {
-	bool cork = false, enospc = sk_msg_full(msg);
+	bool cork = false, enospc = sk_msg_full(msg), redir_ingress;
 	struct sock *sk_redir;
 	u32 tosend, origsize, sent, delta = 0;
 	u32 eval;
@@ -429,6 +428,7 @@ static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock,
 		sk_msg_apply_bytes(psock, tosend);
 		break;
 	case __SK_REDIRECT:
+		redir_ingress = psock->redir_ingress;
 		sk_redir = psock->sk_redir;
 		sk_msg_apply_bytes(psock, tosend);
 		if (!psock->apply_bytes) {
@@ -445,7 +445,8 @@ static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock,
 		release_sock(sk);
 
 		origsize = msg->sg.size;
-		ret = tcp_bpf_sendmsg_redir(sk_redir, msg, tosend, flags);
+		ret = tcp_bpf_sendmsg_redir(sk_redir, redir_ingress,
+					    msg, tosend, flags);
 		sent = origsize - msg->sg.size;
 
 		if (eval == __SK_REDIRECT)

net/tls/tls_sw.c

@@ -807,7 +807,7 @@ static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk,
 	struct sk_psock *psock;
 	struct sock *sk_redir;
 	struct tls_rec *rec;
-	bool enospc, policy;
+	bool enospc, policy, redir_ingress;
 	int err = 0, send;
 	u32 delta = 0;
 
@@ -852,6 +852,7 @@ static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk,
 		}
 		break;
 	case __SK_REDIRECT:
+		redir_ingress = psock->redir_ingress;
 		sk_redir = psock->sk_redir;
 		memcpy(&msg_redir, msg, sizeof(*msg));
 		if (msg->apply_bytes < send)
@@ -861,7 +862,8 @@ static int bpf_exec_tx_verdict(struct sk_msg *msg, struct sock *sk,
 		sk_msg_return_zero(sk, msg, send);
 		msg->sg.size -= send;
 		release_sock(sk);
-		err = tcp_bpf_sendmsg_redir(sk_redir, &msg_redir, send, flags);
+		err = tcp_bpf_sendmsg_redir(sk_redir, redir_ingress,
+					    &msg_redir, send, flags);
 		lock_sock(sk);
 		if (err < 0) {
 			*copied -= sk_msg_free_nocharge(sk, &msg_redir);