diff options
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/dev.c | 14 | ||||
| -rw-r--r-- | net/core/filter.c | 15 | ||||
| -rw-r--r-- | net/core/xdp.c | 8 |
3 files changed, 29 insertions, 8 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 4c91de39890a..f937a3ff668d 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4617,6 +4617,11 @@ static u32 netif_receive_generic_xdp(struct sk_buff *skb, xdp->data_meta = xdp->data; xdp->data_end = xdp->data + hlen; xdp->data_hard_start = skb->data - skb_headroom(skb); + + /* SKB "head" area always have tailroom for skb_shared_info */ + xdp->frame_sz = (void *)skb_end_pointer(skb) - xdp->data_hard_start; + xdp->frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); + orig_data_end = xdp->data_end; orig_data = xdp->data; eth = (struct ethhdr *)xdp->data; @@ -4640,14 +4645,11 @@ static u32 netif_receive_generic_xdp(struct sk_buff *skb, skb_reset_network_header(skb); } - /* check if bpf_xdp_adjust_tail was used. it can only "shrink" - * pckt. - */ - off = orig_data_end - xdp->data_end; + /* check if bpf_xdp_adjust_tail was used */ + off = xdp->data_end - orig_data_end; if (off != 0) { skb_set_tail_pointer(skb, xdp->data_end - xdp->data); - skb->len -= off; - + skb->len += off; /* positive on grow, negative on shrink */ } /* check if XDP changed eth hdr such SKB needs update */ diff --git a/net/core/filter.c b/net/core/filter.c index 5815902bb617..a85eb538d4d6 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -3411,15 +3411,26 @@ static const struct bpf_func_proto bpf_xdp_adjust_head_proto = { 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 */ void *data_end = xdp->data_end + offset; - /* only shrinking is allowed for now. */ - if (unlikely(offset >= 0)) + /* Notice that xdp_data_hard_end have reserved some tailroom */ + if (unlikely(data_end > data_hard_end)) return -EINVAL; + /* ALL drivers MUST init xdp->frame_sz, chicken check below */ + if (unlikely(xdp->frame_sz > PAGE_SIZE)) { + WARN_ONCE(1, "Too BIG xdp->frame_sz = %d\n", xdp->frame_sz); + return -EINVAL; + } + if (unlikely(data_end < xdp->data + ETH_HLEN)) return -EINVAL; + /* Clear memory area on grow, can contain uninit kernel memory */ + if (offset > 0) + memset(xdp->data_end, 0, offset); + xdp->data_end = data_end; return 0; diff --git a/net/core/xdp.c b/net/core/xdp.c index 4c7ea85486af..490b8f5fa8ee 100644 --- a/net/core/xdp.c +++ b/net/core/xdp.c @@ -11,6 +11,7 @@ #include <linux/slab.h> #include <linux/idr.h> #include <linux/rhashtable.h> +#include <linux/bug.h> #include <net/page_pool.h> #include <net/xdp.h> @@ -496,3 +497,10 @@ struct xdp_frame *xdp_convert_zc_to_xdp_frame(struct xdp_buff *xdp) return xdpf; } EXPORT_SYMBOL_GPL(xdp_convert_zc_to_xdp_frame); + +/* Used by XDP_WARN macro, to avoid inlining WARN() in fast-path */ +void xdp_warn(const char *msg, const char *func, const int line) +{ + WARN(1, "XDP_WARN: %s(line:%d): %s\n", func, line, msg); +}; +EXPORT_SYMBOL_GPL(xdp_warn); |