On Wed, Jan 22, 2020 at 09:35 PM CET, Martin Lau wrote:
> On Wed, Jan 22, 2020 at 02:05:41PM +0100, Jakub Sitnicki wrote:
>> 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@xxxxxxxxxxxxxx>
>> ---
>> 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..ac205d31e4ad 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 *child);
> nit. "struct sock *child" vs ...
>
>> +#else
>> +static inline void tcp_bpf_clone(const struct sock *sk, struct sock *child)
>> +{
>> +}
>> +#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 sock *newsk" here.
>
> Could be a follow-up.
>
> Other than that,
> Acked-by: Martin KaFai Lau <kafai@xxxxxx>
Will fix in v4. Thanks!
