From: Sameeh Jubran <sameehj@xxxxxxxxxx> The implementation is based on this [0] draft by Jesper D. Brouer. Provided two new helpers: * bpf_xdp_get_frag_count() * bpf_xdp_get_frags_total_size() [0] xdp mb design - https://github.com/xdp-project/xdp-project/blob/master/areas/core/xdp-multi-buffer01-design.org Signed-off-by: Sameeh Jubran <sameehj@xxxxxxxxxx> Co-developed-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx> Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx> --- 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 a22812561064..6f97dce8cccf 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -3586,6 +3586,18 @@ union bpf_attr { * the data in *dst*. This is a wrapper of **copy_from_user**\ (). * Return * 0 on success, or a negative error in case of failure. + * + * int bpf_xdp_get_frag_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), \ @@ -3737,6 +3749,8 @@ union bpf_attr { FN(inode_storage_delete), \ FN(d_path), \ FN(copy_from_user), \ + FN(xdp_get_frag_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 706f8db0ccf8..7f33cfae219c 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3475,6 +3475,44 @@ static const struct bpf_func_proto bpf_xdp_adjust_head_proto = { .arg2_type = ARG_ANYTHING, }; +BPF_CALL_1(bpf_xdp_get_frag_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_frag_count_proto = { + .func = bpf_xdp_get_frag_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 */ @@ -6824,6 +6862,10 @@ 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_frag_count: + return &bpf_xdp_get_frag_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 a22812561064..6f97dce8cccf 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3586,6 +3586,18 @@ union bpf_attr { * the data in *dst*. This is a wrapper of **copy_from_user**\ (). * Return * 0 on success, or a negative error in case of failure. + * + * int bpf_xdp_get_frag_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), \ @@ -3737,6 +3749,8 @@ union bpf_attr { FN(inode_storage_delete), \ FN(d_path), \ FN(copy_from_user), \ + FN(xdp_get_frag_count), \ + FN(xdp_get_frags_total_size), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper -- 2.26.2
