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 | 13 +++++++++++++ tools/include/uapi/linux/bpf.h | 2 ++ 3 files changed, 17 insertions(+) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 7a48e0055500..c7f6848c0226 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 0cd3cc2af9c1..0737673c727c 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1920,6 +1920,11 @@ static void bpf_prog_load_fixup_attach_type(union bpf_attr *attr) attr->expected_attach_type = BPF_CGROUP_INET_SOCK_CREATE; break; + case BPF_PROG_TYPE_SK_REUSEPORT: + if (!attr->expected_attach_type) + attr->expected_attach_type = + BPF_SK_REUSEPORT_SELECT; + break; } } @@ -2003,6 +2008,14 @@ 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; + } 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 7a48e0055500..c7f6848c0226 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)
