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 v7 03/11] tcp_bpf: Don't let child socket inherit parent protocol ops on copy
Date: Tue, 18 Feb 2020 17:10:15 +0000 [thread overview]
Message-ID: <20200218171023.844439-4-jakub@cloudflare.com> (raw)
In-Reply-To: <20200218171023.844439-1-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.
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
---
include/net/tcp.h | 7 +++++++
net/ipv4/tcp_bpf.c | 14 ++++++++++++++
net/ipv4/tcp_minisocks.c | 2 ++
3 files changed, 23 insertions(+)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index a5ea27df3c2b..07f947cc80e6 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2203,6 +2203,13 @@ 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 dd183b050642..7d6e1b75d4d4 100644
--- a/net/ipv4/tcp_bpf.c
+++ b/net/ipv4/tcp_bpf.c
@@ -693,3 +693,17 @@ int tcp_bpf_init(struct sock *sk)
rcu_read_unlock();
return 0;
}
+
+/* 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)
+{
+ int family = sk->sk_family == AF_INET6 ? TCP_BPF_IPV6 : TCP_BPF_IPV4;
+ struct proto *prot = newsk->sk_prot;
+
+ if (prot == &tcp_bpf_prots[family][TCP_BPF_BASE])
+ newsk->sk_prot = sk->sk_prot_creator;
+}
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:[~2020-02-18 17:10 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-18 17:10 [PATCH bpf-next v7 00/11] Extend SOCKMAP/SOCKHASH to store listening sockets Jakub Sitnicki
2020-02-18 17:10 ` [PATCH bpf-next v7 01/11] net, sk_msg: Annotate lockless access to sk_prot on clone Jakub Sitnicki
2020-02-18 17:10 ` [PATCH bpf-next v7 02/11] net, sk_msg: Clear sk_user_data pointer on clone if tagged Jakub Sitnicki
2020-02-18 17:10 ` Jakub Sitnicki [this message]
2020-02-21 3:28 ` [PATCH bpf-next v7 03/11] tcp_bpf: Don't let child socket inherit parent protocol ops on copy John Fastabend
2020-02-18 17:10 ` [PATCH bpf-next v7 04/11] bpf, sockmap: Allow inserting listening TCP sockets into sockmap Jakub Sitnicki
2020-02-21 3:33 ` John Fastabend
2020-02-18 17:10 ` [PATCH bpf-next v7 05/11] bpf, sockmap: Don't set up upcalls and progs for listening sockets Jakub Sitnicki
2020-02-21 3:42 ` John Fastabend
2020-02-18 17:10 ` [PATCH bpf-next v7 06/11] bpf, sockmap: Return socket cookie on lookup from syscall Jakub Sitnicki
2020-02-21 3:45 ` John Fastabend
2020-02-18 17:10 ` [PATCH bpf-next v7 07/11] bpf, sockmap: Let all kernel-land lookup values in SOCKMAP/SOCKHASH Jakub Sitnicki
2020-02-21 3:46 ` John Fastabend
2020-02-18 17:10 ` [PATCH bpf-next v7 08/11] bpf: Allow selecting reuseport socket from a SOCKMAP/SOCKHASH Jakub Sitnicki
2020-02-18 17:10 ` [PATCH bpf-next v7 09/11] net: Generate reuseport group ID on group creation Jakub Sitnicki
2020-02-18 17:10 ` [PATCH bpf-next v7 10/11] selftests/bpf: Extend SK_REUSEPORT tests to cover SOCKMAP/SOCKHASH Jakub Sitnicki
2020-02-21 3:52 ` John Fastabend
2020-02-18 17:10 ` [PATCH bpf-next v7 11/11] selftests/bpf: Tests for sockmap/sockhash holding listening sockets Jakub Sitnicki
2020-02-21 3:56 ` John Fastabend
2020-02-21 21:41 ` [PATCH bpf-next v7 00/11] Extend SOCKMAP/SOCKHASH to store " Daniel Borkmann
2020-02-22 0:47 ` Alexei Starovoitov
2020-02-22 13:49 ` Jakub Sitnicki
2020-02-23 21:43 ` Alexei Starovoitov
2020-02-24 13:59 ` Jakub Sitnicki
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