diff options
| -rw-r--r-- | include/uapi/linux/bpf.h | 10 | ||||
| -rw-r--r-- | net/core/filter.c | 29 |
2 files changed, 37 insertions, 2 deletions
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index c5ec89732a8d..9a2d1a04eb24 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -755,6 +755,13 @@ union bpf_attr { * @addr: pointer to struct sockaddr to bind socket to * @addr_len: length of sockaddr structure * Return: 0 on success or negative error code + * + * int bpf_xdp_adjust_tail(xdp_md, delta) + * Adjust the xdp_md.data_end by delta. Only shrinking of packet's + * size is supported. + * @xdp_md: pointer to xdp_md + * @delta: A negative integer to be added to xdp_md.data_end + * Return: 0 on success or negative on error */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -821,7 +828,8 @@ union bpf_attr { FN(msg_apply_bytes), \ FN(msg_cork_bytes), \ FN(msg_pull_data), \ - FN(bind), + FN(bind), \ + FN(xdp_adjust_tail), /* integer value in 'imm' field of BPF_CALL instruction selects which helper * function eBPF program intends to call diff --git a/net/core/filter.c b/net/core/filter.c index a374b8560bc4..29318598fd60 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -2725,6 +2725,30 @@ static const struct bpf_func_proto bpf_xdp_adjust_head_proto = { .arg2_type = ARG_ANYTHING, }; +BPF_CALL_2(bpf_xdp_adjust_tail, struct xdp_buff *, xdp, int, offset) +{ + void *data_end = xdp->data_end + offset; + + /* only shrinking is allowed for now. */ + if (unlikely(offset >= 0)) + return -EINVAL; + + if (unlikely(data_end < xdp->data + ETH_HLEN)) + return -EINVAL; + + xdp->data_end = data_end; + + return 0; +} + +static const struct bpf_func_proto bpf_xdp_adjust_tail_proto = { + .func = bpf_xdp_adjust_tail, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, + .arg2_type = ARG_ANYTHING, +}; + BPF_CALL_2(bpf_xdp_adjust_meta, struct xdp_buff *, xdp, int, offset) { void *meta = xdp->data_meta + offset; @@ -3074,7 +3098,8 @@ bool bpf_helper_changes_pkt_data(void *func) func == bpf_l4_csum_replace || func == bpf_xdp_adjust_head || func == bpf_xdp_adjust_meta || - func == bpf_msg_pull_data) + func == bpf_msg_pull_data || + func == bpf_xdp_adjust_tail) return true; return false; @@ -3888,6 +3913,8 @@ xdp_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_xdp_redirect_proto; case BPF_FUNC_redirect_map: return &bpf_xdp_redirect_map_proto; + case BPF_FUNC_xdp_adjust_tail: + return &bpf_xdp_adjust_tail_proto; default: return bpf_base_func_proto(func_id); } |