#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_ecache.h>
#include <net/netfilter/nf_conntrack_expect.h>
+#include <net/netfilter/nf_conntrack_seqadj.h>
#include <net/netfilter/nf_nat.h>
#include <net/netfilter/nf_nat_l3proto.h>
#include <net/netfilter/nf_nat_l4proto.h>
#include <net/netfilter/nf_nat_core.h>
#include <net/netfilter/nf_nat_helper.h>
-#define DUMP_OFFSET(x) \
- pr_debug("offset_before=%d, offset_after=%d, correction_pos=%u\n", \
- x->offset_before, x->offset_after, x->correction_pos);
-
-static DEFINE_SPINLOCK(nf_nat_seqofs_lock);
-
-/* Setup TCP sequence correction given this change at this sequence */
-static inline void
-adjust_tcp_sequence(u32 seq,
- int sizediff,
- struct nf_conn *ct,
- enum ip_conntrack_info ctinfo)
-{
- enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo);
- struct nf_conn_nat *nat = nfct_nat(ct);
- struct nf_nat_seq *this_way = &nat->seq[dir];
-
- pr_debug("adjust_tcp_sequence: seq = %u, sizediff = %d\n",
- seq, sizediff);
-
- pr_debug("adjust_tcp_sequence: Seq_offset before: ");
- DUMP_OFFSET(this_way);
-
- spin_lock_bh(&nf_nat_seqofs_lock);
-
- /* SYN adjust. If it's uninitialized, or this is after last
- * correction, record it: we don't handle more than one
- * adjustment in the window, but do deal with common case of a
- * retransmit */
- if (this_way->offset_before == this_way->offset_after ||
- before(this_way->correction_pos, seq)) {
- this_way->correction_pos = seq;
- this_way->offset_before = this_way->offset_after;
- this_way->offset_after += sizediff;
- }
- spin_unlock_bh(&nf_nat_seqofs_lock);
-
- pr_debug("adjust_tcp_sequence: Seq_offset after: ");
- DUMP_OFFSET(this_way);
-}
-
-/* Get the offset value, for conntrack */
-s16 nf_nat_get_offset(const struct nf_conn *ct,
- enum ip_conntrack_dir dir,
- u32 seq)
-{
- struct nf_conn_nat *nat = nfct_nat(ct);
- struct nf_nat_seq *this_way;
- s16 offset;
-
- if (!nat)
- return 0;
-
- this_way = &nat->seq[dir];
- spin_lock_bh(&nf_nat_seqofs_lock);
- offset = after(seq, this_way->correction_pos)
- ? this_way->offset_after : this_way->offset_before;
- spin_unlock_bh(&nf_nat_seqofs_lock);
-
- return offset;
-}
-
/* Frobs data inside this packet, which is linear. */
static void mangle_contents(struct sk_buff *skb,
unsigned int dataoff,
return 1;
}
-void nf_nat_set_seq_adjust(struct nf_conn *ct, enum ip_conntrack_info ctinfo,
- __be32 seq, s16 off)
-{
- if (!off)
- return;
- set_bit(IPS_SEQ_ADJUST_BIT, &ct->status);
- adjust_tcp_sequence(ntohl(seq), off, ct, ctinfo);
- nf_conntrack_event_cache(IPCT_NATSEQADJ, ct);
-}
-EXPORT_SYMBOL_GPL(nf_nat_set_seq_adjust);
-
-void nf_nat_tcp_seq_adjust(struct sk_buff *skb, struct nf_conn *ct,
- u32 ctinfo, int off)
-{
- const struct tcphdr *th;
-
- if (nf_ct_protonum(ct) != IPPROTO_TCP)
- return;
-
- th = (struct tcphdr *)(skb_network_header(skb)+ ip_hdrlen(skb));
- nf_nat_set_seq_adjust(ct, ctinfo, th->seq, off);
-}
-EXPORT_SYMBOL_GPL(nf_nat_tcp_seq_adjust);
-
/* Generic function for mangling variable-length address changes inside
* NATed TCP connections (like the PORT XXX,XXX,XXX,XXX,XXX,XXX
* command in FTP).
datalen, oldlen);
if (adjust && rep_len != match_len)
- nf_nat_set_seq_adjust(ct, ctinfo, tcph->seq,
- (int)rep_len - (int)match_len);
+ nf_ct_seqadj_set(ct, ctinfo, tcph->seq,
+ (int)rep_len - (int)match_len);
return 1;
}
}
EXPORT_SYMBOL(nf_nat_mangle_udp_packet);
-/* Adjust one found SACK option including checksum correction */
-static void
-sack_adjust(struct sk_buff *skb,
- struct tcphdr *tcph,
- unsigned int sackoff,
- unsigned int sackend,
- struct nf_nat_seq *natseq)
-{
- while (sackoff < sackend) {
- struct tcp_sack_block_wire *sack;
- __be32 new_start_seq, new_end_seq;
-
- sack = (void *)skb->data + sackoff;
- if (after(ntohl(sack->start_seq) - natseq->offset_before,
- natseq->correction_pos))
- new_start_seq = htonl(ntohl(sack->start_seq)
- - natseq->offset_after);
- else
- new_start_seq = htonl(ntohl(sack->start_seq)
- - natseq->offset_before);
-
- if (after(ntohl(sack->end_seq) - natseq->offset_before,
- natseq->correction_pos))
- new_end_seq = htonl(ntohl(sack->end_seq)
- - natseq->offset_after);
- else
- new_end_seq = htonl(ntohl(sack->end_seq)
- - natseq->offset_before);
-
- pr_debug("sack_adjust: start_seq: %d->%d, end_seq: %d->%d\n",
- ntohl(sack->start_seq), new_start_seq,
- ntohl(sack->end_seq), new_end_seq);
-
- inet_proto_csum_replace4(&tcph->check, skb,
- sack->start_seq, new_start_seq, 0);
- inet_proto_csum_replace4(&tcph->check, skb,
- sack->end_seq, new_end_seq, 0);
- sack->start_seq = new_start_seq;
- sack->end_seq = new_end_seq;
- sackoff += sizeof(*sack);
- }
-}
-
-/* TCP SACK sequence number adjustment */
-static inline unsigned int
-nf_nat_sack_adjust(struct sk_buff *skb,
- unsigned int protoff,
- struct tcphdr *tcph,
- struct nf_conn *ct,
- enum ip_conntrack_info ctinfo)
-{
- unsigned int dir, optoff, optend;
- struct nf_conn_nat *nat = nfct_nat(ct);
-
- optoff = protoff + sizeof(struct tcphdr);
- optend = protoff + tcph->doff * 4;
-
- if (!skb_make_writable(skb, optend))
- return 0;
-
- dir = CTINFO2DIR(ctinfo);
-
- while (optoff < optend) {
- /* Usually: option, length. */
- unsigned char *op = skb->data + optoff;
-
- switch (op[0]) {
- case TCPOPT_EOL:
- return 1;
- case TCPOPT_NOP:
- optoff++;
- continue;
- default:
- /* no partial options */
- if (optoff + 1 == optend ||
- optoff + op[1] > optend ||
- op[1] < 2)
- return 0;
- if (op[0] == TCPOPT_SACK &&
- op[1] >= 2+TCPOLEN_SACK_PERBLOCK &&
- ((op[1] - 2) % TCPOLEN_SACK_PERBLOCK) == 0)
- sack_adjust(skb, tcph, optoff+2,
- optoff+op[1], &nat->seq[!dir]);
- optoff += op[1];
- }
- }
- return 1;
-}
-
-/* TCP sequence number adjustment. Returns 1 on success, 0 on failure */
-int
-nf_nat_seq_adjust(struct sk_buff *skb,
- struct nf_conn *ct,
- enum ip_conntrack_info ctinfo,
- unsigned int protoff)
-{
- struct tcphdr *tcph;
- int dir;
- __be32 newseq, newack;
- s16 seqoff, ackoff;
- struct nf_conn_nat *nat = nfct_nat(ct);
- struct nf_nat_seq *this_way, *other_way;
-
- dir = CTINFO2DIR(ctinfo);
-
- this_way = &nat->seq[dir];
- other_way = &nat->seq[!dir];
-
- if (!skb_make_writable(skb, protoff + sizeof(*tcph)))
- return 0;
-
- tcph = (void *)skb->data + protoff;
- if (after(ntohl(tcph->seq), this_way->correction_pos))
- seqoff = this_way->offset_after;
- else
- seqoff = this_way->offset_before;
-
- if (after(ntohl(tcph->ack_seq) - other_way->offset_before,
- other_way->correction_pos))
- ackoff = other_way->offset_after;
- else
- ackoff = other_way->offset_before;
-
- newseq = htonl(ntohl(tcph->seq) + seqoff);
- newack = htonl(ntohl(tcph->ack_seq) - ackoff);
-
- inet_proto_csum_replace4(&tcph->check, skb, tcph->seq, newseq, 0);
- inet_proto_csum_replace4(&tcph->check, skb, tcph->ack_seq, newack, 0);
-
- pr_debug("Adjusting sequence number from %u->%u, ack from %u->%u\n",
- ntohl(tcph->seq), ntohl(newseq), ntohl(tcph->ack_seq),
- ntohl(newack));
-
- tcph->seq = newseq;
- tcph->ack_seq = newack;
-
- return nf_nat_sack_adjust(skb, protoff, tcph, ct, ctinfo);
-}
-
/* Setup NAT on this expected conntrack so it follows master. */
/* If we fail to get a free NAT slot, we'll get dropped on confirm */
void nf_nat_follow_master(struct nf_conn *ct,
projects / ~andy / linux / blobdiff