diff options
Diffstat (limited to 'net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c')
-rw-r--r-- | net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c | 137 |
1 files changed, 71 insertions, 66 deletions
diff --git a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c index 4794f96cf2e0..8860d23e61cf 100644 --- a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c +++ b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c @@ -28,6 +28,7 @@ #include <net/netfilter/nf_conntrack_core.h> #include <net/netfilter/nf_conntrack_zones.h> #include <net/netfilter/ipv6/nf_conntrack_ipv6.h> +#include <net/netfilter/nf_nat_helper.h> #include <net/netfilter/ipv6/nf_defrag_ipv6.h> #include <net/netfilter/nf_log.h> @@ -64,82 +65,31 @@ static int ipv6_print_tuple(struct seq_file *s, tuple->src.u3.ip6, tuple->dst.u3.ip6); } -/* - * Based on ipv6_skip_exthdr() in net/ipv6/exthdr.c - * - * This function parses (probably truncated) exthdr set "hdr" - * of length "len". "nexthdrp" initially points to some place, - * where type of the first header can be found. - * - * It skips all well-known exthdrs, and returns pointer to the start - * of unparsable area i.e. the first header with unknown type. - * if success, *nexthdr is updated by type/protocol of this header. - * - * NOTES: - it may return pointer pointing beyond end of packet, - * if the last recognized header is truncated in the middle. - * - if packet is truncated, so that all parsed headers are skipped, - * it returns -1. - * - if packet is fragmented, return pointer of the fragment header. - * - ESP is unparsable for now and considered like - * normal payload protocol. - * - Note also special handling of AUTH header. Thanks to IPsec wizards. - */ - -static int nf_ct_ipv6_skip_exthdr(const struct sk_buff *skb, int start, - u8 *nexthdrp, int len) -{ - u8 nexthdr = *nexthdrp; - - while (ipv6_ext_hdr(nexthdr)) { - struct ipv6_opt_hdr hdr; - int hdrlen; - - if (len < (int)sizeof(struct ipv6_opt_hdr)) - return -1; - if (nexthdr == NEXTHDR_NONE) - break; - if (nexthdr == NEXTHDR_FRAGMENT) - break; - if (skb_copy_bits(skb, start, &hdr, sizeof(hdr))) - BUG(); - if (nexthdr == NEXTHDR_AUTH) - hdrlen = (hdr.hdrlen+2)<<2; - else - hdrlen = ipv6_optlen(&hdr); - - nexthdr = hdr.nexthdr; - len -= hdrlen; - start += hdrlen; - } - - *nexthdrp = nexthdr; - return start; -} - static int ipv6_get_l4proto(const struct sk_buff *skb, unsigned int nhoff, unsigned int *dataoff, u_int8_t *protonum) { unsigned int extoff = nhoff + sizeof(struct ipv6hdr); - unsigned char pnum; + __be16 frag_off; int protoff; + u8 nexthdr; if (skb_copy_bits(skb, nhoff + offsetof(struct ipv6hdr, nexthdr), - &pnum, sizeof(pnum)) != 0) { + &nexthdr, sizeof(nexthdr)) != 0) { pr_debug("ip6_conntrack_core: can't get nexthdr\n"); return -NF_ACCEPT; } - protoff = nf_ct_ipv6_skip_exthdr(skb, extoff, &pnum, skb->len - extoff); + protoff = ipv6_skip_exthdr(skb, extoff, &nexthdr, &frag_off); /* * (protoff == skb->len) mean that the packet doesn't have no data * except of IPv6 & ext headers. but it's tracked anyway. - YK */ - if ((protoff < 0) || (protoff > skb->len)) { + if (protoff < 0 || (frag_off & htons(~0x7)) != 0) { pr_debug("ip6_conntrack_core: can't find proto in pkt\n"); return -NF_ACCEPT; } *dataoff = protoff; - *protonum = pnum; + *protonum = nexthdr; return NF_ACCEPT; } @@ -153,10 +103,10 @@ static unsigned int ipv6_helper(unsigned int hooknum, const struct nf_conn_help *help; const struct nf_conntrack_helper *helper; enum ip_conntrack_info ctinfo; - unsigned int ret, protoff; - unsigned int extoff = (u8 *)(ipv6_hdr(skb) + 1) - skb->data; - unsigned char pnum = ipv6_hdr(skb)->nexthdr; - + unsigned int ret; + __be16 frag_off; + int protoff; + u8 nexthdr; /* This is where we call the helper: as the packet goes out. */ ct = nf_ct_get(skb, &ctinfo); @@ -171,9 +121,10 @@ static unsigned int ipv6_helper(unsigned int hooknum, if (!helper) return NF_ACCEPT; - protoff = nf_ct_ipv6_skip_exthdr(skb, extoff, &pnum, - skb->len - extoff); - if (protoff > skb->len || pnum == NEXTHDR_FRAGMENT) { + nexthdr = ipv6_hdr(skb)->nexthdr; + protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr, + &frag_off); + if (protoff < 0 || (frag_off & htons(~0x7)) != 0) { pr_debug("proto header not found\n"); return NF_ACCEPT; } @@ -192,6 +143,36 @@ static unsigned int ipv6_confirm(unsigned int hooknum, const struct net_device *out, int (*okfn)(struct sk_buff *)) { + struct nf_conn *ct; + enum ip_conntrack_info ctinfo; + unsigned char pnum = ipv6_hdr(skb)->nexthdr; + int protoff; + __be16 frag_off; + + ct = nf_ct_get(skb, &ctinfo); + if (!ct || ctinfo == IP_CT_RELATED_REPLY) + goto out; + + protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &pnum, + &frag_off); + if (protoff < 0 || (frag_off & htons(~0x7)) != 0) { + pr_debug("proto header not found\n"); + goto out; + } + + /* adjust seqs for loopback traffic only in outgoing direction */ + if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) && + !nf_is_loopback_packet(skb)) { + typeof(nf_nat_seq_adjust_hook) seq_adjust; + + seq_adjust = rcu_dereference(nf_nat_seq_adjust_hook); + if (!seq_adjust || + !seq_adjust(skb, ct, ctinfo, protoff)) { + NF_CT_STAT_INC_ATOMIC(nf_ct_net(ct), drop); + return NF_DROP; + } + } +out: /* We've seen it coming out the other side: confirm it */ return nf_conntrack_confirm(skb); } @@ -199,9 +180,14 @@ static unsigned int ipv6_confirm(unsigned int hooknum, static unsigned int __ipv6_conntrack_in(struct net *net, unsigned int hooknum, struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, int (*okfn)(struct sk_buff *)) { struct sk_buff *reasm = skb->nfct_reasm; + const struct nf_conn_help *help; + struct nf_conn *ct; + enum ip_conntrack_info ctinfo; /* This packet is fragmented and has reassembled packet. */ if (reasm) { @@ -213,6 +199,25 @@ static unsigned int __ipv6_conntrack_in(struct net *net, if (ret != NF_ACCEPT) return ret; } + + /* Conntrack helpers need the entire reassembled packet in the + * POST_ROUTING hook. In case of unconfirmed connections NAT + * might reassign a helper, so the entire packet is also + * required. + */ + ct = nf_ct_get(reasm, &ctinfo); + if (ct != NULL && !nf_ct_is_untracked(ct)) { + help = nfct_help(ct); + if ((help && help->helper) || !nf_ct_is_confirmed(ct)) { + nf_conntrack_get_reasm(skb); + NF_HOOK_THRESH(NFPROTO_IPV6, hooknum, reasm, + (struct net_device *)in, + (struct net_device *)out, + okfn, NF_IP6_PRI_CONNTRACK + 1); + return NF_DROP_ERR(-ECANCELED); + } + } + nf_conntrack_get(reasm->nfct); skb->nfct = reasm->nfct; skb->nfctinfo = reasm->nfctinfo; @@ -228,7 +233,7 @@ static unsigned int ipv6_conntrack_in(unsigned int hooknum, const struct net_device *out, int (*okfn)(struct sk_buff *)) { - return __ipv6_conntrack_in(dev_net(in), hooknum, skb, okfn); + return __ipv6_conntrack_in(dev_net(in), hooknum, skb, in, out, okfn); } static unsigned int ipv6_conntrack_local(unsigned int hooknum, @@ -242,7 +247,7 @@ static unsigned int ipv6_conntrack_local(unsigned int hooknum, net_notice_ratelimited("ipv6_conntrack_local: packet too short\n"); return NF_ACCEPT; } - return __ipv6_conntrack_in(dev_net(out), hooknum, skb, okfn); + return __ipv6_conntrack_in(dev_net(out), hooknum, skb, in, out, okfn); } static struct nf_hook_ops ipv6_conntrack_ops[] __read_mostly = { |