From f908d26b2c41d9a924371099c4979e4b5d385165 Mon Sep 17 00:00:00 2001 From: John Fastabend Date: Fri, 19 Oct 2018 19:56:50 -0700 Subject: [PATCH] bpf: libbpf support for msg_push_data Add support for new bpf_msg_push_data in libbpf. Signed-off-by: John Fastabend Signed-off-by: Daniel Borkmann --- tools/include/uapi/linux/bpf.h | 20 +++++++++++++++++++- tools/testing/selftests/bpf/bpf_helpers.h | 2 ++ 2 files changed, 21 insertions(+), 1 deletion(-) diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index a2fb333290dc..852dc17ab47a 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -2240,6 +2240,23 @@ union bpf_attr { * pointer that was returned from bpf_sk_lookup_xxx\ (). * Return * 0 on success, or a negative error in case of failure. + * + * int bpf_msg_push_data(struct sk_buff *skb, u32 start, u32 len, u64 flags) + * Description + * For socket policies, insert *len* bytes into msg at offset + * *start*. + * + * If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a + * *msg* it may want to insert metadata or options into the msg. + * This can later be read and used by any of the lower layer BPF + * hooks. + * + * This helper may fail if under memory pressure (a malloc + * fails) in these cases BPF programs will get an appropriate + * error and BPF programs will need to handle them. + * + * Return + * 0 on success, or a negative error in case of failure. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -2331,7 +2348,8 @@ union bpf_attr { FN(sk_release), \ FN(map_push_elem), \ FN(map_pop_elem), \ - FN(map_peek_elem), + FN(map_peek_elem), \ + FN(msg_push_data), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h index 6407a3df0f3b..686e57ce40f4 100644 --- a/tools/testing/selftests/bpf/bpf_helpers.h +++ b/tools/testing/selftests/bpf/bpf_helpers.h @@ -111,6 +111,8 @@ static int (*bpf_msg_cork_bytes)(void *ctx, int len) = (void *) BPF_FUNC_msg_cork_bytes; static int (*bpf_msg_pull_data)(void *ctx, int start, int end, int flags) = (void *) BPF_FUNC_msg_pull_data; +static int (*bpf_msg_push_data)(void *ctx, int start, int end, int flags) = + (void *) BPF_FUNC_msg_push_data; static int (*bpf_bind)(void *ctx, void *addr, int addr_len) = (void *) BPF_FUNC_bind; static int (*bpf_xdp_adjust_tail)(void *ctx, int offset) = -- 2.30.2