Root/
1 | #include <linux/types.h> |
2 | #include <linux/netfilter.h> |
3 | #include <net/tcp.h> |
4 | |
5 | #include <net/netfilter/nf_conntrack.h> |
6 | #include <net/netfilter/nf_conntrack_extend.h> |
7 | #include <net/netfilter/nf_conntrack_seqadj.h> |
8 | |
9 | int nf_ct_seqadj_init(struct nf_conn *ct, enum ip_conntrack_info ctinfo, |
10 | s32 off) |
11 | { |
12 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
13 | struct nf_conn_seqadj *seqadj; |
14 | struct nf_ct_seqadj *this_way; |
15 | |
16 | if (off == 0) |
17 | return 0; |
18 | |
19 | set_bit(IPS_SEQ_ADJUST_BIT, &ct->status); |
20 | |
21 | seqadj = nfct_seqadj(ct); |
22 | this_way = &seqadj->seq[dir]; |
23 | this_way->offset_before = off; |
24 | this_way->offset_after = off; |
25 | return 0; |
26 | } |
27 | EXPORT_SYMBOL_GPL(nf_ct_seqadj_init); |
28 | |
29 | int nf_ct_seqadj_set(struct nf_conn *ct, enum ip_conntrack_info ctinfo, |
30 | __be32 seq, s32 off) |
31 | { |
32 | struct nf_conn_seqadj *seqadj = nfct_seqadj(ct); |
33 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
34 | struct nf_ct_seqadj *this_way; |
35 | |
36 | if (off == 0) |
37 | return 0; |
38 | |
39 | if (unlikely(!seqadj)) { |
40 | WARN_ONCE(1, "Missing nfct_seqadj_ext_add() setup call\n"); |
41 | return 0; |
42 | } |
43 | |
44 | set_bit(IPS_SEQ_ADJUST_BIT, &ct->status); |
45 | |
46 | spin_lock_bh(&ct->lock); |
47 | this_way = &seqadj->seq[dir]; |
48 | if (this_way->offset_before == this_way->offset_after || |
49 | before(this_way->correction_pos, ntohl(seq))) { |
50 | this_way->correction_pos = ntohl(seq); |
51 | this_way->offset_before = this_way->offset_after; |
52 | this_way->offset_after += off; |
53 | } |
54 | spin_unlock_bh(&ct->lock); |
55 | return 0; |
56 | } |
57 | EXPORT_SYMBOL_GPL(nf_ct_seqadj_set); |
58 | |
59 | void nf_ct_tcp_seqadj_set(struct sk_buff *skb, |
60 | struct nf_conn *ct, enum ip_conntrack_info ctinfo, |
61 | s32 off) |
62 | { |
63 | const struct tcphdr *th; |
64 | |
65 | if (nf_ct_protonum(ct) != IPPROTO_TCP) |
66 | return; |
67 | |
68 | th = (struct tcphdr *)(skb_network_header(skb) + ip_hdrlen(skb)); |
69 | nf_ct_seqadj_set(ct, ctinfo, th->seq, off); |
70 | } |
71 | EXPORT_SYMBOL_GPL(nf_ct_tcp_seqadj_set); |
72 | |
73 | /* Adjust one found SACK option including checksum correction */ |
74 | static void nf_ct_sack_block_adjust(struct sk_buff *skb, |
75 | struct tcphdr *tcph, |
76 | unsigned int sackoff, |
77 | unsigned int sackend, |
78 | struct nf_ct_seqadj *seq) |
79 | { |
80 | while (sackoff < sackend) { |
81 | struct tcp_sack_block_wire *sack; |
82 | __be32 new_start_seq, new_end_seq; |
83 | |
84 | sack = (void *)skb->data + sackoff; |
85 | if (after(ntohl(sack->start_seq) - seq->offset_before, |
86 | seq->correction_pos)) |
87 | new_start_seq = htonl(ntohl(sack->start_seq) - |
88 | seq->offset_after); |
89 | else |
90 | new_start_seq = htonl(ntohl(sack->start_seq) - |
91 | seq->offset_before); |
92 | |
93 | if (after(ntohl(sack->end_seq) - seq->offset_before, |
94 | seq->correction_pos)) |
95 | new_end_seq = htonl(ntohl(sack->end_seq) - |
96 | seq->offset_after); |
97 | else |
98 | new_end_seq = htonl(ntohl(sack->end_seq) - |
99 | seq->offset_before); |
100 | |
101 | pr_debug("sack_adjust: start_seq: %d->%d, end_seq: %d->%d\n", |
102 | ntohl(sack->start_seq), new_start_seq, |
103 | ntohl(sack->end_seq), new_end_seq); |
104 | |
105 | inet_proto_csum_replace4(&tcph->check, skb, |
106 | sack->start_seq, new_start_seq, 0); |
107 | inet_proto_csum_replace4(&tcph->check, skb, |
108 | sack->end_seq, new_end_seq, 0); |
109 | sack->start_seq = new_start_seq; |
110 | sack->end_seq = new_end_seq; |
111 | sackoff += sizeof(*sack); |
112 | } |
113 | } |
114 | |
115 | /* TCP SACK sequence number adjustment */ |
116 | static unsigned int nf_ct_sack_adjust(struct sk_buff *skb, |
117 | unsigned int protoff, |
118 | struct tcphdr *tcph, |
119 | struct nf_conn *ct, |
120 | enum ip_conntrack_info ctinfo) |
121 | { |
122 | unsigned int dir, optoff, optend; |
123 | struct nf_conn_seqadj *seqadj = nfct_seqadj(ct); |
124 | |
125 | optoff = protoff + sizeof(struct tcphdr); |
126 | optend = protoff + tcph->doff * 4; |
127 | |
128 | if (!skb_make_writable(skb, optend)) |
129 | return 0; |
130 | |
131 | dir = CTINFO2DIR(ctinfo); |
132 | |
133 | while (optoff < optend) { |
134 | /* Usually: option, length. */ |
135 | unsigned char *op = skb->data + optoff; |
136 | |
137 | switch (op[0]) { |
138 | case TCPOPT_EOL: |
139 | return 1; |
140 | case TCPOPT_NOP: |
141 | optoff++; |
142 | continue; |
143 | default: |
144 | /* no partial options */ |
145 | if (optoff + 1 == optend || |
146 | optoff + op[1] > optend || |
147 | op[1] < 2) |
148 | return 0; |
149 | if (op[0] == TCPOPT_SACK && |
150 | op[1] >= 2+TCPOLEN_SACK_PERBLOCK && |
151 | ((op[1] - 2) % TCPOLEN_SACK_PERBLOCK) == 0) |
152 | nf_ct_sack_block_adjust(skb, tcph, optoff + 2, |
153 | optoff+op[1], |
154 | &seqadj->seq[!dir]); |
155 | optoff += op[1]; |
156 | } |
157 | } |
158 | return 1; |
159 | } |
160 | |
161 | /* TCP sequence number adjustment. Returns 1 on success, 0 on failure */ |
162 | int nf_ct_seq_adjust(struct sk_buff *skb, |
163 | struct nf_conn *ct, enum ip_conntrack_info ctinfo, |
164 | unsigned int protoff) |
165 | { |
166 | enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); |
167 | struct tcphdr *tcph; |
168 | __be32 newseq, newack; |
169 | s32 seqoff, ackoff; |
170 | struct nf_conn_seqadj *seqadj = nfct_seqadj(ct); |
171 | struct nf_ct_seqadj *this_way, *other_way; |
172 | int res; |
173 | |
174 | this_way = &seqadj->seq[dir]; |
175 | other_way = &seqadj->seq[!dir]; |
176 | |
177 | if (!skb_make_writable(skb, protoff + sizeof(*tcph))) |
178 | return 0; |
179 | |
180 | tcph = (void *)skb->data + protoff; |
181 | spin_lock_bh(&ct->lock); |
182 | if (after(ntohl(tcph->seq), this_way->correction_pos)) |
183 | seqoff = this_way->offset_after; |
184 | else |
185 | seqoff = this_way->offset_before; |
186 | |
187 | if (after(ntohl(tcph->ack_seq) - other_way->offset_before, |
188 | other_way->correction_pos)) |
189 | ackoff = other_way->offset_after; |
190 | else |
191 | ackoff = other_way->offset_before; |
192 | |
193 | newseq = htonl(ntohl(tcph->seq) + seqoff); |
194 | newack = htonl(ntohl(tcph->ack_seq) - ackoff); |
195 | |
196 | inet_proto_csum_replace4(&tcph->check, skb, tcph->seq, newseq, 0); |
197 | inet_proto_csum_replace4(&tcph->check, skb, tcph->ack_seq, newack, 0); |
198 | |
199 | pr_debug("Adjusting sequence number from %u->%u, ack from %u->%u\n", |
200 | ntohl(tcph->seq), ntohl(newseq), ntohl(tcph->ack_seq), |
201 | ntohl(newack)); |
202 | |
203 | tcph->seq = newseq; |
204 | tcph->ack_seq = newack; |
205 | |
206 | res = nf_ct_sack_adjust(skb, protoff, tcph, ct, ctinfo); |
207 | spin_unlock_bh(&ct->lock); |
208 | |
209 | return res; |
210 | } |
211 | EXPORT_SYMBOL_GPL(nf_ct_seq_adjust); |
212 | |
213 | s32 nf_ct_seq_offset(const struct nf_conn *ct, |
214 | enum ip_conntrack_dir dir, |
215 | u32 seq) |
216 | { |
217 | struct nf_conn_seqadj *seqadj = nfct_seqadj(ct); |
218 | struct nf_ct_seqadj *this_way; |
219 | |
220 | if (!seqadj) |
221 | return 0; |
222 | |
223 | this_way = &seqadj->seq[dir]; |
224 | return after(seq, this_way->correction_pos) ? |
225 | this_way->offset_after : this_way->offset_before; |
226 | } |
227 | EXPORT_SYMBOL_GPL(nf_ct_seq_offset); |
228 | |
229 | static struct nf_ct_ext_type nf_ct_seqadj_extend __read_mostly = { |
230 | .len = sizeof(struct nf_conn_seqadj), |
231 | .align = __alignof__(struct nf_conn_seqadj), |
232 | .id = NF_CT_EXT_SEQADJ, |
233 | }; |
234 | |
235 | int nf_conntrack_seqadj_init(void) |
236 | { |
237 | return nf_ct_extend_register(&nf_ct_seqadj_extend); |
238 | } |
239 | |
240 | void nf_conntrack_seqadj_fini(void) |
241 | { |
242 | nf_ct_extend_unregister(&nf_ct_seqadj_extend); |
243 | } |
244 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9