From: Sameeh Jubran <same...@amazon.com>
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 <same...@amazon.com>
Co-developed-by: Lorenzo Bianconi <lore...@kernel.org>
Signed-off-by: Lorenzo Bianconi <lore...@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
--
2.26.2
