-stable review patch. If anyone has any objections, please let us know. --------------------- From: Jorge Boncompte While porting some changes of the 2.6.21-rc7 pptp/proto_gre conntrack and nat modules to a 2.4.32 kernel I noticed that the gre_key function returns a wrong pointer to the GRE key of a version 0 packet thus corrupting the packet payload. The intended behaviour for GREv0 packets is to act like nf_conntrack_proto_generic/nf_nat_proto_unknown so I have ripped the offending functions (not used anymore) and modified the nf_nat_proto_gre modules to not touch version 0 (non PPTP) packets. Signed-off-by: Jorge Boncompte Signed-off-by: Patrick McHardy Signed-off-by: Chris Wright --- commit 244c67aee5750eb3a79c727d09c01a500e68bbbe tree 29bbce944bba681886a6d58c0c6b7bca3858c0e1 parent 8d8b10482fffcb72b15515231bb942e2ad6395c9 author Jorge Boncompte Thu, 03 May 2007 02:50:51 +0200 committer Patrick McHardy Thu, 03 May 2007 02:50:51 +0200 include/linux/netfilter/nf_conntrack_proto_gre.h | 18 ---------------- include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h | 19 ----------------- net/ipv4/netfilter/ip_nat_proto_gre.c | 20 +++++++----------- net/ipv4/netfilter/nf_nat_proto_gre.c | 20 +++++++----------- 4 files changed, 16 insertions(+), 61 deletions(-) --- linux-2.6.21.1.orig/include/linux/netfilter/nf_conntrack_proto_gre.h +++ linux-2.6.21.1/include/linux/netfilter/nf_conntrack_proto_gre.h @@ -87,24 +87,6 @@ int nf_ct_gre_keymap_add(struct nf_conn /* delete keymap entries */ void nf_ct_gre_keymap_destroy(struct nf_conn *ct); -/* get pointer to gre key, if present */ -static inline __be32 *gre_key(struct gre_hdr *greh) -{ - if (!greh->key) - return NULL; - if (greh->csum || greh->routing) - return (__be32 *)(greh+sizeof(*greh)+4); - return (__be32 *)(greh+sizeof(*greh)); -} - -/* get pointer ot gre csum, if present */ -static inline __sum16 *gre_csum(struct gre_hdr *greh) -{ - if (!greh->csum) - return NULL; - return (__sum16 *)(greh+sizeof(*greh)); -} - extern void nf_ct_gre_keymap_flush(void); extern void nf_nat_need_gre(void); --- linux-2.6.21.1.orig/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h +++ linux-2.6.21.1/include/linux/netfilter_ipv4/ip_conntrack_proto_gre.h @@ -90,25 +90,6 @@ int ip_ct_gre_keymap_add(struct ip_connt /* delete keymap entries */ void ip_ct_gre_keymap_destroy(struct ip_conntrack *ct); - -/* get pointer to gre key, if present */ -static inline __be32 *gre_key(struct gre_hdr *greh) -{ - if (!greh->key) - return NULL; - if (greh->csum || greh->routing) - return (__be32 *) (greh+sizeof(*greh)+4); - return (__be32 *) (greh+sizeof(*greh)); -} - -/* get pointer ot gre csum, if present */ -static inline __sum16 *gre_csum(struct gre_hdr *greh) -{ - if (!greh->csum) - return NULL; - return (__sum16 *) (greh+sizeof(*greh)); -} - #endif /* __KERNEL__ */ #endif /* _CONNTRACK_PROTO_GRE_H */ --- linux-2.6.21.1.orig/net/ipv4/netfilter/ip_nat_proto_gre.c +++ linux-2.6.21.1/net/ipv4/netfilter/ip_nat_proto_gre.c @@ -70,6 +70,11 @@ gre_unique_tuple(struct ip_conntrack_tup __be16 *keyptr; unsigned int min, i, range_size; + /* If there is no master conntrack we are not PPTP, + do not change tuples */ + if (!conntrack->master) + return 0; + if (maniptype == IP_NAT_MANIP_SRC) keyptr = &tuple->src.u.gre.key; else @@ -122,18 +127,9 @@ gre_manip_pkt(struct sk_buff **pskb, if (maniptype == IP_NAT_MANIP_DST) { /* key manipulation is always dest */ switch (greh->version) { - case 0: - if (!greh->key) { - DEBUGP("can't nat GRE w/o key\n"); - break; - } - if (greh->csum) { - /* FIXME: Never tested this code... */ - nf_proto_csum_replace4(gre_csum(greh), *pskb, - *(gre_key(greh)), - tuple->dst.u.gre.key, 0); - } - *(gre_key(greh)) = tuple->dst.u.gre.key; + case GRE_VERSION_1701: + /* We do not currently NAT any GREv0 packets. + * Try to behave like "ip_nat_proto_unknown" */ break; case GRE_VERSION_PPTP: DEBUGP("call_id -> 0x%04x\n", --- linux-2.6.21.1.orig/net/ipv4/netfilter/nf_nat_proto_gre.c +++ linux-2.6.21.1/net/ipv4/netfilter/nf_nat_proto_gre.c @@ -72,6 +72,11 @@ gre_unique_tuple(struct nf_conntrack_tup __be16 *keyptr; unsigned int min, i, range_size; + /* If there is no master conntrack we are not PPTP, + do not change tuples */ + if (!conntrack->master) + return 0; + if (maniptype == IP_NAT_MANIP_SRC) keyptr = &tuple->src.u.gre.key; else @@ -122,18 +127,9 @@ gre_manip_pkt(struct sk_buff **pskb, uns if (maniptype != IP_NAT_MANIP_DST) return 1; switch (greh->version) { - case 0: - if (!greh->key) { - DEBUGP("can't nat GRE w/o key\n"); - break; - } - if (greh->csum) { - /* FIXME: Never tested this code... */ - nf_proto_csum_replace4(gre_csum(greh), *pskb, - *(gre_key(greh)), - tuple->dst.u.gre.key, 0); - } - *(gre_key(greh)) = tuple->dst.u.gre.key; + case GRE_VERSION_1701: + /* We do not currently NAT any GREv0 packets. + * Try to behave like "nf_nat_proto_unknown" */ break; case GRE_VERSION_PPTP: DEBUGP("call_id -> 0x%04x\n", ntohs(tuple->dst.u.gre.key)); -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/