[PATCH v4 bpf-next 06/13] bpf: introduce bpf_xdp_get_frags_{count, total_size} helpers
From: Lorenzo Bianconi <lorenzo@kernel.org>
Date: 2020-10-02 14:42:52
Also in:
bpf
Subsystem:
bpf [general] (safe dynamic programs and tools), bpf [networking] (tcx & tc bpf, sock_addr), networking [general], the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Sameeh Jubran <redacted> Introduce the two following bpf helpers in order to provide some metadata about a xdp multi-buff fame to bpf layer: - bpf_xdp_get_frags_count() get the number of fragments for a given xdp multi-buffer. * bpf_xdp_get_frags_total_size() get the total size of fragments for a given xdp multi-buffer. Signed-off-by: Sameeh Jubran <redacted> Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> --- include/uapi/linux/bpf.h | 14 ++++++++++++ net/core/filter.c | 42 ++++++++++++++++++++++++++++++++++ tools/include/uapi/linux/bpf.h | 14 ++++++++++++ 3 files changed, 70 insertions(+)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 4f556cfcbfbe..0715995eb18c 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h@@ -3668,6 +3668,18 @@ union bpf_attr { * Return * The helper returns **TC_ACT_REDIRECT** on success or * **TC_ACT_SHOT** on error. + * + * int bpf_xdp_get_frags_count(struct xdp_buff *xdp_md) + * Description + * Get the number of fragments for a given xdp multi-buffer. + * Return + * The number of fragments + * + * int bpf_xdp_get_frags_total_size(struct xdp_buff *xdp_md) + * Description + * Get the total size of fragments for a given xdp multi-buffer. + * Return + * The total size of fragments for a given xdp multi-buffer. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \
@@ -3823,6 +3835,8 @@ union bpf_attr { FN(seq_printf_btf), \ FN(skb_cgroup_classid), \ FN(redirect_neigh), \ + FN(xdp_get_frags_count), \ + FN(xdp_get_frags_total_size), \ /* */ /* 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 3fb6adad1957..4c55b788c4c5 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c@@ -3739,6 +3739,44 @@ static const struct bpf_func_proto bpf_xdp_adjust_head_proto = { .arg2_type = ARG_ANYTHING, }; +BPF_CALL_1(bpf_xdp_get_frags_count, struct xdp_buff*, xdp) +{ + struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp); + + return xdp->mb ? sinfo->nr_frags : 0; +} + +const struct bpf_func_proto bpf_xdp_get_frags_count_proto = { + .func = bpf_xdp_get_frags_count, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, +}; + +BPF_CALL_1(bpf_xdp_get_frags_total_size, struct xdp_buff*, xdp) +{ + struct skb_shared_info *sinfo; + int nfrags, i, size = 0; + + if (likely(!xdp->mb)) + return 0; + + sinfo = xdp_get_shared_info_from_buff(xdp); + nfrags = min_t(u8, sinfo->nr_frags, MAX_SKB_FRAGS); + + for (i = 0; i < nfrags; i++) + size += skb_frag_size(&sinfo->frags[i]); + + return size; +} + +const struct bpf_func_proto bpf_xdp_get_frags_total_size_proto = { + .func = bpf_xdp_get_frags_total_size, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, +}; + BPF_CALL_2(bpf_xdp_adjust_tail, struct xdp_buff *, xdp, int, offset) { void *data_hard_end = xdp_data_hard_end(xdp); /* use xdp->frame_sz */
@@ -7092,6 +7130,10 @@ 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_frags_count: + return &bpf_xdp_get_frags_count_proto; + case BPF_FUNC_xdp_get_frags_total_size: + return &bpf_xdp_get_frags_total_size_proto; case BPF_FUNC_fib_lookup: return &bpf_xdp_fib_lookup_proto; #ifdef CONFIG_INET
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 4f556cfcbfbe..0715995eb18c 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h@@ -3668,6 +3668,18 @@ union bpf_attr { * Return * The helper returns **TC_ACT_REDIRECT** on success or * **TC_ACT_SHOT** on error. + * + * int bpf_xdp_get_frags_count(struct xdp_buff *xdp_md) + * Description + * Get the number of fragments for a given xdp multi-buffer. + * Return + * The number of fragments + * + * int bpf_xdp_get_frags_total_size(struct xdp_buff *xdp_md) + * Description + * Get the total size of fragments for a given xdp multi-buffer. + * Return + * The total size of fragments for a given xdp multi-buffer. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \
@@ -3823,6 +3835,8 @@ union bpf_attr { FN(seq_printf_btf), \ FN(skb_cgroup_classid), \ FN(redirect_neigh), \ + FN(xdp_get_frags_count), \ + FN(xdp_get_frags_total_size), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper
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2.26.2