[PATCH v22 bpf-next 11/23] bpf: introduce bpf_xdp_get_buff_len helper
From: Lorenzo Bianconi <lorenzo@kernel.org>
Date: 2022-01-17 17:30:13
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [networking] (tcx & tc bpf, sock_addr), networking [general], the rest, xdp (express data path) · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, David S. Miller, Jesper Dangaard Brouer, John Fastabend
Introduce bpf_xdp_get_buff_len helper in order to return the xdp buffer total size (linear and paged area) Acked-by: Toke Hoiland-Jorgensen <redacted> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> --- include/net/xdp.h | 14 ++++++++++++++ include/uapi/linux/bpf.h | 7 +++++++ net/core/filter.c | 15 +++++++++++++++ tools/include/uapi/linux/bpf.h | 7 +++++++ 4 files changed, 43 insertions(+)
diff --git a/include/net/xdp.h b/include/net/xdp.h
index 2fc76cd6e09d..6caea9b633e4 100644
--- a/include/net/xdp.h
+++ b/include/net/xdp.h@@ -145,6 +145,20 @@ xdp_get_shared_info_from_buff(struct xdp_buff *xdp) return (struct skb_shared_info *)xdp_data_hard_end(xdp); } +static __always_inline unsigned int xdp_get_buff_len(struct xdp_buff *xdp) +{ + unsigned int len = xdp->data_end - xdp->data; + struct skb_shared_info *sinfo; + + if (likely(!xdp_buff_has_frags(xdp))) + goto out; + + sinfo = xdp_get_shared_info_from_buff(xdp); + len += sinfo->xdp_frags_size; +out: + return len; +} + struct xdp_frame { void *data; u16 len;
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 35e95d56f858..26c6c2bc6b43 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h@@ -5023,6 +5023,12 @@ union bpf_attr { * * Return * The number of arguments of the traced function. + * + * u64 bpf_xdp_get_buff_len(struct xdp_buff *xdp_md) + * Description + * Get the total size of a given xdp buff (linear and paged area) + * Return + * The total size of a given xdp buffer. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \
@@ -5211,6 +5217,7 @@ union bpf_attr { FN(get_func_arg), \ FN(get_func_ret), \ FN(get_func_arg_cnt), \ + FN(xdp_get_buff_len), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper
diff --git a/net/core/filter.c b/net/core/filter.c
index 4603b7cd3cd1..332f8e7802bc 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c@@ -3783,6 +3783,19 @@ static const struct bpf_func_proto sk_skb_change_head_proto = { .arg2_type = ARG_ANYTHING, .arg3_type = ARG_ANYTHING, }; + +BPF_CALL_1(bpf_xdp_get_buff_len, struct xdp_buff*, xdp) +{ + return xdp_get_buff_len(xdp); +} + +static const struct bpf_func_proto bpf_xdp_get_buff_len_proto = { + .func = bpf_xdp_get_buff_len, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, +}; + static unsigned long xdp_get_metalen(const struct xdp_buff *xdp) { return xdp_data_meta_unsupported(xdp) ? 0 :
@@ -7533,6 +7546,8 @@ xdp_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_xdp_redirect_map_proto; case BPF_FUNC_xdp_adjust_tail: return &bpf_xdp_adjust_tail_proto; + case BPF_FUNC_xdp_get_buff_len: + return &bpf_xdp_get_buff_len_proto; case BPF_FUNC_fib_lookup: return &bpf_xdp_fib_lookup_proto; case BPF_FUNC_check_mtu:
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 35e95d56f858..26c6c2bc6b43 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h@@ -5023,6 +5023,12 @@ union bpf_attr { * * Return * The number of arguments of the traced function. + * + * u64 bpf_xdp_get_buff_len(struct xdp_buff *xdp_md) + * Description + * Get the total size of a given xdp buff (linear and paged area) + * Return + * The total size of a given xdp buffer. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \
@@ -5211,6 +5217,7 @@ union bpf_attr { FN(get_func_arg), \ FN(get_func_ret), \ FN(get_func_arg_cnt), \ + FN(xdp_get_buff_len), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper
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2.34.1