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.kapwihc2plp4f...@kafai-mbp.dhcp.thefacebook.com/ > Suggested-by: Martin KaFai Lau <ka...@fb.com> > Signed-off-by: Kuniyuki Iwashima <kun...@amazon.co.jp> > --- > 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-rev...@google.com/
