I'm sending this mail just for logging because I failed to send mails only to LKML, netdev, and bpf yesterday. From: Martin KaFai Lau <kafai@xxxxxx> Date: Fri, 4 Dec 2020 11:58:07 -0800 > On Tue, Dec 01, 2020 at 11:44:16PM +0900, Kuniyuki Iwashima wrote: > > We will call sock_reuseport.prog for socket migration in the next commit, > > so the eBPF program has to know which listener is closing in order to > > select the new listener. > > > > Currently, we can get a unique ID for each listener in the userspace by > > calling bpf_map_lookup_elem() for BPF_MAP_TYPE_REUSEPORT_SOCKARRAY map. > > > > This patch makes the sk pointer available in sk_reuseport_md so that we can > > get the ID by BPF_FUNC_get_socket_cookie() in the eBPF program. > > > > Link: https://lore.kernel.org/netdev/20201119001154.kapwihc2plp4f7zc@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ > > Suggested-by: Martin KaFai Lau <kafai@xxxxxx> > > Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxxxx> > > --- > > include/uapi/linux/bpf.h | 8 ++++++++ > > net/core/filter.c | 12 +++++++++++- > > tools/include/uapi/linux/bpf.h | 8 ++++++++ > > 3 files changed, 27 insertions(+), 1 deletion(-) > > > > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > > index efe342bf3dbc..3e9b8bd42b4e 100644 > > --- a/include/uapi/linux/bpf.h > > +++ b/include/uapi/linux/bpf.h > > @@ -1650,6 +1650,13 @@ union bpf_attr { > > * A 8-byte long non-decreasing number on success, or 0 if the > > * socket field is missing inside *skb*. > > * > > + * u64 bpf_get_socket_cookie(struct bpf_sock *sk) > > + * Description > > + * Equivalent to bpf_get_socket_cookie() helper that accepts > > + * *skb*, but gets socket from **struct bpf_sock** context. > > + * Return > > + * A 8-byte long non-decreasing number. > > + * > > * u64 bpf_get_socket_cookie(struct bpf_sock_addr *ctx) > > * Description > > * Equivalent to bpf_get_socket_cookie() helper that accepts > > @@ -4420,6 +4427,7 @@ struct sk_reuseport_md { > > __u32 bind_inany; /* Is sock bound to an INANY address? */ > > __u32 hash; /* A hash of the packet 4 tuples */ > > __u8 migration; /* Migration type */ > > + __bpf_md_ptr(struct bpf_sock *, sk); /* current listening socket */ > > }; > > > > #define BPF_TAG_SIZE 8 > > diff --git a/net/core/filter.c b/net/core/filter.c > > index 0a0634787bb4..1059d31847ef 100644 > > --- a/net/core/filter.c > > +++ b/net/core/filter.c > > @@ -4628,7 +4628,7 @@ static const struct bpf_func_proto bpf_get_socket_cookie_sock_proto = { > > .func = bpf_get_socket_cookie_sock, > > .gpl_only = false, > > .ret_type = RET_INTEGER, > > - .arg1_type = ARG_PTR_TO_CTX, > > + .arg1_type = ARG_PTR_TO_SOCKET, > This will break existing bpf prog (BPF_PROG_TYPE_CGROUP_SOCK) > using this proto. A new proto is needed and there is > an on-going patch doing this [0]. > > [0]: https://lore.kernel.org/bpf/20201203213330.1657666-1-revest@xxxxxxxxxx/ Thank you for notifying me of this patch! I will define another proto, but may drop the part if the above patch is already merged then.
