* * **BPF_F_ADJ_ROOM_ENCAP_L4_UDP **:
* Use with ENCAP_L3 flags to further specify the tunnel type.
*
+ * * **BPF_F_ADJ_ROOM_ENCAP_L2(len) **:
+ * Use with ENCAP_L3/L4 flags to further specify the tunnel
+ * type; **len** is the length of the inner MAC header.
+ *
* A call to this helper is susceptible to change the underlaying
* packet buffer. Therefore, at load time, all checks on pointers
* previously done by the verifier are invalidated and must be
/* BPF_FUNC_skb_adjust_room flags. */
#define BPF_F_ADJ_ROOM_FIXED_GSO (1ULL << 0)
+#define BPF_ADJ_ROOM_ENCAP_L2_MASK 0xff
+#define BPF_ADJ_ROOM_ENCAP_L2_SHIFT 56
+
#define BPF_F_ADJ_ROOM_ENCAP_L3_IPV4 (1ULL << 1)
#define BPF_F_ADJ_ROOM_ENCAP_L3_IPV6 (1ULL << 2)
#define BPF_F_ADJ_ROOM_ENCAP_L4_GRE (1ULL << 3)
#define BPF_F_ADJ_ROOM_ENCAP_L4_UDP (1ULL << 4)
+#define BPF_F_ADJ_ROOM_ENCAP_L2(len) (((__u64)len & \
+ BPF_ADJ_ROOM_ENCAP_L2_MASK) \
+ << BPF_ADJ_ROOM_ENCAP_L2_SHIFT)
/* Mode for BPF_FUNC_skb_adjust_room helper. */
enum bpf_adj_room_mode {
#define BPF_F_ADJ_ROOM_MASK (BPF_F_ADJ_ROOM_FIXED_GSO | \
BPF_F_ADJ_ROOM_ENCAP_L3_MASK | \
BPF_F_ADJ_ROOM_ENCAP_L4_GRE | \
- BPF_F_ADJ_ROOM_ENCAP_L4_UDP)
+ BPF_F_ADJ_ROOM_ENCAP_L4_UDP | \
+ BPF_F_ADJ_ROOM_ENCAP_L2( \
+ BPF_ADJ_ROOM_ENCAP_L2_MASK))
static int bpf_skb_net_grow(struct sk_buff *skb, u32 off, u32 len_diff,
u64 flags)
{
+ u8 inner_mac_len = flags >> BPF_ADJ_ROOM_ENCAP_L2_SHIFT;
bool encap = flags & BPF_F_ADJ_ROOM_ENCAP_L3_MASK;
u16 mac_len = 0, inner_net = 0, inner_trans = 0;
unsigned int gso_type = SKB_GSO_DODGY;
mac_len = skb->network_header - skb->mac_header;
inner_net = skb->network_header;
+ if (inner_mac_len > len_diff)
+ return -EINVAL;
inner_trans = skb->transport_header;
}
return ret;
if (encap) {
- /* inner mac == inner_net on l3 encap */
- skb->inner_mac_header = inner_net;
+ skb->inner_mac_header = inner_net - inner_mac_len;
skb->inner_network_header = inner_net;
skb->inner_transport_header = inner_trans;
skb_set_inner_protocol(skb, skb->protocol);
gso_type |= SKB_GSO_GRE;
else if (flags & BPF_F_ADJ_ROOM_ENCAP_L3_IPV6)
gso_type |= SKB_GSO_IPXIP6;
- else
+ else if (flags & BPF_F_ADJ_ROOM_ENCAP_L3_IPV4)
gso_type |= SKB_GSO_IPXIP4;
if (flags & BPF_F_ADJ_ROOM_ENCAP_L4_GRE ||