On Tue, Dec 1, 2020 at 6:49 AM Kuniyuki Iwashima <kuniyu@xxxxxxxxxxxx> wrote: > > This commit adds new bpf_attach_type for BPF_PROG_TYPE_SK_REUSEPORT to > check if the attached eBPF program is capable of migrating sockets. > > When the eBPF program is attached, the kernel runs it for socket migration > only if the expected_attach_type is BPF_SK_REUSEPORT_SELECT_OR_MIGRATE. > The kernel will change the behaviour depending on the returned value: > > - SK_PASS with selected_sk, select it as a new listener > - SK_PASS with selected_sk NULL, fall back to the random selection > - SK_DROP, cancel the migration > > Link: https://lore.kernel.org/netdev/20201123003828.xjpjdtk4ygl6tg6h@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/ > Suggested-by: Martin KaFai Lau <kafai@xxxxxx> > Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxxxx> > --- > include/uapi/linux/bpf.h | 2 ++ > kernel/bpf/syscall.c | 8 ++++++++ > tools/include/uapi/linux/bpf.h | 2 ++ > 3 files changed, 12 insertions(+) > > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > index 85278deff439..cfc207ae7782 100644 > --- a/include/uapi/linux/bpf.h > +++ b/include/uapi/linux/bpf.h > @@ -241,6 +241,8 @@ enum bpf_attach_type { > BPF_XDP_CPUMAP, > BPF_SK_LOOKUP, > BPF_XDP, > + BPF_SK_REUSEPORT_SELECT, > + BPF_SK_REUSEPORT_SELECT_OR_MIGRATE, > __MAX_BPF_ATTACH_TYPE > }; > > diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c > index f3fe9f53f93c..a0796a8de5ea 100644 > --- a/kernel/bpf/syscall.c > +++ b/kernel/bpf/syscall.c > @@ -2036,6 +2036,14 @@ bpf_prog_load_check_attach(enum bpf_prog_type prog_type, > if (expected_attach_type == BPF_SK_LOOKUP) > return 0; > return -EINVAL; > + case BPF_PROG_TYPE_SK_REUSEPORT: > + switch (expected_attach_type) { > + case BPF_SK_REUSEPORT_SELECT: > + case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE: > + return 0; > + default: > + return -EINVAL; > + } this is a kernel regression, previously expected_attach_type wasn't enforced, so user-space could have provided any number without an error. > case BPF_PROG_TYPE_EXT: > if (expected_attach_type) > return -EINVAL; > diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h > index 85278deff439..cfc207ae7782 100644 > --- a/tools/include/uapi/linux/bpf.h > +++ b/tools/include/uapi/linux/bpf.h > @@ -241,6 +241,8 @@ enum bpf_attach_type { > BPF_XDP_CPUMAP, > BPF_SK_LOOKUP, > BPF_XDP, > + BPF_SK_REUSEPORT_SELECT, > + BPF_SK_REUSEPORT_SELECT_OR_MIGRATE, > __MAX_BPF_ATTACH_TYPE > }; > > -- > 2.17.2 (Apple Git-113) >
