I just saw the commit 13d70f5a5ecff367db2fb18ed4ebe433eab8a74c Sun May 24 09:51:15 2020 that already added "struct bpf_sock *, sk” for sk_msg_md.
So Just ignore my question. Thank you all anyway.
> 在 2020年6月8日，上午10:51，王黎 <wangli09@xxxxxxxxxxxx> 写道：
>
> Daniel, thanks for your comments.
>
> bpf_get_netns_cookie_sock really sounds better.
>
> But I still have another question that is how can I get the netns cookie when I invoke the function “msg_redirect_hash" because its parameter "struct sk_msg_md” does not have any netns information, and there is no "struct sock * ctx” to be used for the helper function “bpf_get_netns_cookie_sock" too. Add a field for sk_msg_md ? And just like I did for bpf_sock_ops ?
>
>
>
>> 在 2020年6月5日，下午11:22，Daniel Borkmann <daniel@xxxxxxxxxxxxx> 写道：
>>
>> On 6/5/20 4:53 PM, Jakub Sitnicki wrote:
>>> On Fri, Jun 05, 2020 at 02:40 PM CEST, Wang Li wrote:
>>>> Sometimes we need net namespace as part of the key for BPF_MAP_TYPE_SOCKHASH to
>>>> distinguish the connections with same five-tuples, for example when we do the
>>>> sock_map acceleration for the proxy that uses 127.0.0.1 to 127.0.0.1 connections
>>>> in different containers on same node.
>>>> And we export the netns inum instead of the real pointer of struct net to avoid
>>>> the potential security issue.
>>>>
>>>> Signed-off-by: Wang Li <wangli09@xxxxxxxxxxxx>
>>>> Signed-off-by: huangxuesen <huangxuesen@xxxxxxxxxxxx>
>>>> Signed-off-by: yangxingwu <yangxingwu@xxxxxxxxxxxx>
>>>> ---
>>>> include/uapi/linux/bpf.h | 2 ++
>>>> net/core/filter.c | 17 +++++++++++++++++
>>>> tools/include/uapi/linux/bpf.h | 2 ++
>>>> 3 files changed, 21 insertions(+)
>>>>
>>>> diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
>>>> index c65b374a5090..0fe7e459f023 100644
>>>> --- a/include/uapi/linux/bpf.h
>>>> +++ b/include/uapi/linux/bpf.h
>>>> @@ -3947,6 +3947,8 @@ struct bpf_sock_ops {
>>>> * there is a full socket. If not, the
>>>> * fields read as zero.
>>>> */
>>>> + __u32 netns_inum; /* The net namespace this sock belongs to */
>>>> +
>>> In uapi/linux/bpf.h we have a field `netns_ino` for storing net
>>> namespace inode number in a couple structs (bpf_prog_info,
>>> bpf_map_info). Would be nice to keep the naming constent.
>>
>> Adding in the middle will break programs. Also, currently we have the
>> merge window open and as such bpf-next is closed. Check status here [0].
>>
>> Regarding above, we recently added bpf_get_netns_cookie() helper, have
>> you tried to enable this one instead?
>>
>> [0] http://vger.kernel.org/~davem/net-next.html
>>
>>>> diff --git a/net/core/filter.c b/net/core/filter.c
>>>> index d01a244b5087..bfe448ace25f 100644
>>>> --- a/net/core/filter.c
>>>> +++ b/net/core/filter.c
>>>> @@ -8450,6 +8450,23 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type,
>>>> is_fullsock));
>>>> break;
>>>>
>>>> + case offsetof(struct bpf_sock_ops, netns_inum):
>>>> +#ifdef CONFIG_NET_NS
>>>> + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(
>>>> + struct bpf_sock_ops_kern, sk),
>>>> + si->dst_reg, si->src_reg,
>>>> + offsetof(struct bpf_sock_ops_kern, sk));
>>>> + *insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(
>>>> + struct sock_common, skc_net),
>>>> + si->dst_reg, si->dst_reg,
>>>> + offsetof(struct sock_common, skc_net));
>>>> + *insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->dst_reg,
>>>> + offsetof(struct net, ns.inum));
>>>> +#else
>>>> + *insn++ = BPF_MOV32_IMM(si->dst_reg, 0);
>>>> +#endif
>>>> + break;
>>>> +
>>>> case offsetof(struct bpf_sock_ops, state):
>>>> BUILD_BUG_ON(sizeof_field(struct sock_common, skc_state) != 1);
>>>>
>>>> diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
>>>> index c65b374a5090..0fe7e459f023 100644
>>>> --- a/tools/include/uapi/linux/bpf.h
>>>> +++ b/tools/include/uapi/linux/bpf.h
>>>> @@ -3947,6 +3947,8 @@ struct bpf_sock_ops {
>>>> * there is a full socket. If not, the
>>>> * fields read as zero.
>>>> */
>>>> + __u32 netns_inum; /* The net namespace this sock belongs to */
>>>> +
>>>> __u32 snd_cwnd;
>>>> __u32 srtt_us; /* Averaged RTT << 3 in usecs */
>>>> __u32 bpf_sock_ops_cb_flags; /* flags defined in uapi/linux/tcp.h */
>>
>
