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Diffstat (limited to 'net')
-rw-r--r--net/bpf/test_run.c3
-rw-r--r--net/core/dev.c10
-rw-r--r--net/core/filter.c41
3 files changed, 42 insertions, 12 deletions
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index 2ced48662c1f..68c3578343b4 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -170,7 +170,8 @@ int bpf_prog_test_run_xdp(struct bpf_prog *prog, const union bpf_attr *kattr,
xdp.rxq = &rxqueue->xdp_rxq;
retval = bpf_test_run(prog, &xdp, repeat, &duration);
- if (xdp.data != data + XDP_PACKET_HEADROOM + NET_IP_ALIGN)
+ if (xdp.data != data + XDP_PACKET_HEADROOM + NET_IP_ALIGN ||
+ xdp.data_end != xdp.data + size)
size = xdp.data_end - xdp.data;
ret = bpf_test_finish(kattr, uattr, xdp.data, size, retval, duration);
kfree(data);
diff --git a/net/core/dev.c b/net/core/dev.c
index a490ef643586..3e8ac127a7e1 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3997,9 +3997,9 @@ static u32 netif_receive_generic_xdp(struct sk_buff *skb,
struct bpf_prog *xdp_prog)
{
struct netdev_rx_queue *rxqueue;
+ void *orig_data, *orig_data_end;
u32 metalen, act = XDP_DROP;
struct xdp_buff xdp;
- void *orig_data;
int hlen, off;
u32 mac_len;
@@ -4038,6 +4038,7 @@ 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);
+ orig_data_end = xdp.data_end;
orig_data = xdp.data;
rxqueue = netif_get_rxqueue(skb);
@@ -4052,6 +4053,13 @@ static u32 netif_receive_generic_xdp(struct sk_buff *skb,
__skb_push(skb, -off);
skb->mac_header += off;
+ /* check if bpf_xdp_adjust_tail was used. it can only "shrink"
+ * pckt.
+ */
+ off = orig_data_end - xdp.data_end;
+ if (off != 0)
+ skb_set_tail_pointer(skb, xdp.data_end - xdp.data);
+
switch (act) {
case XDP_REDIRECT:
case XDP_TX:
diff --git a/net/core/filter.c b/net/core/filter.c
index a374b8560bc4..e25bc4a3aa1a 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2694,20 +2694,13 @@ BPF_CALL_2(bpf_xdp_adjust_head, struct xdp_buff *, xdp, int, offset)
{
void *xdp_frame_end = xdp->data_hard_start + sizeof(struct xdp_frame);
unsigned long metalen = xdp_get_metalen(xdp);
- void *data_start = xdp->data_hard_start + metalen;
+ void *data_start = xdp_frame_end + metalen;
void *data = xdp->data + offset;
if (unlikely(data < data_start ||
data > xdp->data_end - ETH_HLEN))
return -EINVAL;
- /* Avoid info leak, when reusing area prev used by xdp_frame */
- if (data < xdp_frame_end) {
- unsigned long clearlen = xdp_frame_end - data;
-
- memset(data, 0, clearlen);
- }
-
if (metalen)
memmove(xdp->data_meta + offset,
xdp->data_meta, metalen);
@@ -2725,14 +2718,39 @@ 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 *xdp_frame_end = xdp->data_hard_start + sizeof(struct xdp_frame);
void *meta = xdp->data_meta + offset;
unsigned long metalen = xdp->data - meta;
if (xdp_data_meta_unsupported(xdp))
return -ENOTSUPP;
- if (unlikely(meta < xdp->data_hard_start ||
+ if (unlikely(meta < xdp_frame_end ||
meta > xdp->data))
return -EINVAL;
if (unlikely((metalen & (sizeof(__u32) - 1)) ||
@@ -3074,7 +3092,8 @@ 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 +3907,8 @@ 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);
}