@@ -19,6 +19,8 @@
/* For layer 4 checksum field offset. */
#include <linux/tcp.h>
#include <linux/udp.h>
+#include <net/gre.h>
+#include <net/pptp.h>
#include <linux/icmpv6.h>
#include <linux/ip.h>
#include <linux/ipv6.h>
@@ -100,6 +102,26 @@ static int __nft_payload_inner_offset(struct nft_pktinfo *pkt)
pkt->inneroff = thoff + __tcp_hdrlen(th);
}
break;
+ case IPPROTO_GRE: {
+ struct gre_base_hdr *gre, _gre;
+ u32 offset = 0;
+
+ gre = skb_header_pointer(pkt->skb, thoff, sizeof(_gre), &_gre);
+ if (!gre)
+ return -1;
+
+ if (gre->flags & GRE_CSUM) {
+ offset += sizeof_field(struct gre_full_hdr, csum) +
+ sizeof_field(struct gre_full_hdr, reserved1);
+ }
+ if (gre->flags & GRE_KEY)
+ offset += sizeof_field(struct gre_full_hdr, key);
+ if (gre->flags & GRE_SEQ)
+ offset += sizeof_field(struct pptp_gre_header, seq);
+
+ pkt->inneroff = thoff + sizeof(struct gre_base_hdr) + offset;
+ }
+ break;
default:
return -1;
}
Parse GRE packets to properly set up inner offset, this allow for matching on inner headers. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> --- v2: interpret GRE flags to handle variable GRE header size. net/netfilter/nft_payload.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)