From: Jakub Sitnicki <jakub@cloudflare.com>
To: bpf@vger.kernel.org
Cc: netdev@vger.kernel.org, kernel-team@cloudflare.com,
John Fastabend <john.fastabend@gmail.com>,
Lorenz Bauer <lmb@cloudflare.com>, Martin Lau <kafai@fb.com>
Subject: [PATCH bpf-next v4 04/12] tcp_bpf: Don't let child socket inherit parent protocol ops on copy
Date: Thu, 23 Jan 2020 16:55:26 +0100 [thread overview]
Message-ID: <20200123155534.114313-5-jakub@cloudflare.com> (raw)
In-Reply-To: <20200123155534.114313-1-jakub@cloudflare.com>
Prepare for cloning listening sockets that have their protocol callbacks
overridden by sk_msg. Child sockets must not inherit parent callbacks that
access state stored in sk_user_data owned by the parent.
Restore the child socket protocol callbacks before it gets hashed and any
of the callbacks can get invoked.
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
---
include/net/tcp.h | 7 +++++++
net/ipv4/tcp_bpf.c | 13 +++++++++++++
net/ipv4/tcp_minisocks.c | 2 ++
3 files changed, 22 insertions(+)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 9dd975be7fdf..b969d5984f97 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2181,6 +2181,13 @@ int tcp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
int nonblock, int flags, int *addr_len);
int __tcp_bpf_recvmsg(struct sock *sk, struct sk_psock *psock,
struct msghdr *msg, int len, int flags);
+#ifdef CONFIG_NET_SOCK_MSG
+void tcp_bpf_clone(const struct sock *sk, struct sock *newsk);
+#else
+static inline void tcp_bpf_clone(const struct sock *sk, struct sock *newsk)
+{
+}
+#endif
/* Call BPF_SOCK_OPS program that returns an int. If the return value
* is < 0, then the BPF op failed (for example if the loaded BPF
diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c
index 4f25aba44ead..16060e0893a1 100644
--- a/net/ipv4/tcp_bpf.c
+++ b/net/ipv4/tcp_bpf.c
@@ -582,6 +582,19 @@ static void tcp_bpf_close(struct sock *sk, long timeout)
saved_close(sk, timeout);
}
+/* If a child got cloned from a listening socket that had tcp_bpf
+ * protocol callbacks installed, we need to restore the callbacks to
+ * the default ones because the child does not inherit the psock state
+ * that tcp_bpf callbacks expect.
+ */
+void tcp_bpf_clone(const struct sock *sk, struct sock *newsk)
+{
+ struct proto *prot = newsk->sk_prot;
+
+ if (prot->unhash == tcp_bpf_unhash)
+ newsk->sk_prot = sk->sk_prot_creator;
+}
+
enum {
TCP_BPF_IPV4,
TCP_BPF_IPV6,
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index ad3b56d9fa71..c8274371c3d0 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -548,6 +548,8 @@ struct sock *tcp_create_openreq_child(const struct sock *sk,
newtp->fastopen_req = NULL;
RCU_INIT_POINTER(newtp->fastopen_rsk, NULL);
+ tcp_bpf_clone(sk, newsk);
+
__TCP_INC_STATS(sock_net(sk), TCP_MIB_PASSIVEOPENS);
return newsk;
--
2.24.1
next prev parent reply other threads:[~2020-01-23 15:55 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-23 15:55 [PATCH bpf-next v4 00/12] Extend SOCKMAP to store listening sockets Jakub Sitnicki
2020-01-23 15:55 ` [PATCH bpf-next v4 01/12] bpf, sk_msg: Don't clear saved sock proto on restore Jakub Sitnicki
2020-01-23 15:55 ` [PATCH bpf-next v4 02/12] net, sk_msg: Annotate lockless access to sk_prot on clone Jakub Sitnicki
2020-01-23 17:18 ` Eric Dumazet
2020-01-23 18:56 ` Jakub Sitnicki
2020-01-23 19:15 ` John Fastabend
2020-01-27 9:36 ` Jakub Sitnicki
2020-01-23 15:55 ` [PATCH bpf-next v4 03/12] net, sk_msg: Clear sk_user_data pointer on clone if tagged Jakub Sitnicki
2020-01-23 15:55 ` Jakub Sitnicki [this message]
2020-01-23 15:55 ` [PATCH bpf-next v4 05/12] bpf, sockmap: Allow inserting listening TCP sockets into sockmap Jakub Sitnicki
2020-01-23 15:55 ` [PATCH bpf-next v4 06/12] bpf, sockmap: Don't set up sockmap progs for listening sockets Jakub Sitnicki
2020-01-23 15:55 ` [PATCH bpf-next v4 07/12] bpf, sockmap: Return socket cookie on lookup from syscall Jakub Sitnicki
2020-01-23 15:55 ` [PATCH bpf-next v4 08/12] bpf, sockmap: Let all kernel-land lookup values in SOCKMAP Jakub Sitnicki
2020-01-23 15:55 ` [PATCH bpf-next v4 09/12] bpf: Allow selecting reuseport socket from a SOCKMAP Jakub Sitnicki
2020-01-23 15:55 ` [PATCH bpf-next v4 10/12] net: Generate reuseport group ID on group creation Jakub Sitnicki
2020-01-23 17:02 ` Martin Lau
2020-01-23 15:55 ` [PATCH bpf-next v4 11/12] selftests/bpf: Extend SK_REUSEPORT tests to cover SOCKMAP Jakub Sitnicki
2020-01-23 15:55 ` [PATCH bpf-next v4 12/12] selftests/bpf: Tests for SOCKMAP holding listening sockets Jakub Sitnicki
2020-01-27 11:13 ` [PATCH bpf-next v4 00/12] Extend SOCKMAP to store " Daniel Borkmann
2020-01-27 13:03 ` Jakub Sitnicki
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