Patrick McHardy | 59eecdf | 2007-07-14 20:48:44 -0700 | [diff] [blame] | 1 | /* (C) 1999-2001 Paul `Rusty' Russell |
| 2 | * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> |
| 3 | * (C) 2007 Patrick McHardy <kaber@trash.net> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License version 2 as |
| 7 | * published by the Free Software Foundation. |
| 8 | */ |
| 9 | |
| 10 | #include <linux/types.h> |
| 11 | #include <linux/timer.h> |
| 12 | #include <linux/module.h> |
Patrick McHardy | 59eecdf | 2007-07-14 20:48:44 -0700 | [diff] [blame] | 13 | #include <linux/udp.h> |
| 14 | #include <linux/seq_file.h> |
| 15 | #include <linux/skbuff.h> |
| 16 | #include <linux/ipv6.h> |
| 17 | #include <net/ip6_checksum.h> |
| 18 | #include <net/checksum.h> |
| 19 | |
| 20 | #include <linux/netfilter.h> |
| 21 | #include <linux/netfilter_ipv4.h> |
| 22 | #include <linux/netfilter_ipv6.h> |
| 23 | #include <net/netfilter/nf_conntrack_l4proto.h> |
| 24 | #include <net/netfilter/nf_conntrack_ecache.h> |
| 25 | |
| 26 | static unsigned int nf_ct_udplite_timeout __read_mostly = 30*HZ; |
| 27 | static unsigned int nf_ct_udplite_timeout_stream __read_mostly = 180*HZ; |
| 28 | |
| 29 | static int udplite_pkt_to_tuple(const struct sk_buff *skb, |
| 30 | unsigned int dataoff, |
| 31 | struct nf_conntrack_tuple *tuple) |
| 32 | { |
| 33 | struct udphdr _hdr, *hp; |
| 34 | |
| 35 | hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr); |
| 36 | if (hp == NULL) |
| 37 | return 0; |
| 38 | |
| 39 | tuple->src.u.udp.port = hp->source; |
| 40 | tuple->dst.u.udp.port = hp->dest; |
| 41 | return 1; |
| 42 | } |
| 43 | |
| 44 | static int udplite_invert_tuple(struct nf_conntrack_tuple *tuple, |
| 45 | const struct nf_conntrack_tuple *orig) |
| 46 | { |
| 47 | tuple->src.u.udp.port = orig->dst.u.udp.port; |
| 48 | tuple->dst.u.udp.port = orig->src.u.udp.port; |
| 49 | return 1; |
| 50 | } |
| 51 | |
| 52 | /* Print out the per-protocol part of the tuple. */ |
| 53 | static int udplite_print_tuple(struct seq_file *s, |
| 54 | const struct nf_conntrack_tuple *tuple) |
| 55 | { |
| 56 | return seq_printf(s, "sport=%hu dport=%hu ", |
| 57 | ntohs(tuple->src.u.udp.port), |
| 58 | ntohs(tuple->dst.u.udp.port)); |
| 59 | } |
| 60 | |
| 61 | /* Print out the private part of the conntrack. */ |
| 62 | static int udplite_print_conntrack(struct seq_file *s, |
| 63 | const struct nf_conn *conntrack) |
| 64 | { |
| 65 | return 0; |
| 66 | } |
| 67 | |
| 68 | /* Returns verdict for packet, and may modify conntracktype */ |
| 69 | static int udplite_packet(struct nf_conn *conntrack, |
| 70 | const struct sk_buff *skb, |
| 71 | unsigned int dataoff, |
| 72 | enum ip_conntrack_info ctinfo, |
| 73 | int pf, |
| 74 | unsigned int hooknum) |
| 75 | { |
| 76 | /* If we've seen traffic both ways, this is some kind of UDP |
| 77 | stream. Extend timeout. */ |
| 78 | if (test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)) { |
| 79 | nf_ct_refresh_acct(conntrack, ctinfo, skb, |
| 80 | nf_ct_udplite_timeout_stream); |
| 81 | /* Also, more likely to be important, and not a probe */ |
| 82 | if (!test_and_set_bit(IPS_ASSURED_BIT, &conntrack->status)) |
| 83 | nf_conntrack_event_cache(IPCT_STATUS, skb); |
| 84 | } else |
| 85 | nf_ct_refresh_acct(conntrack, ctinfo, skb, |
| 86 | nf_ct_udplite_timeout); |
| 87 | |
| 88 | return NF_ACCEPT; |
| 89 | } |
| 90 | |
| 91 | /* Called when a new connection for this protocol found. */ |
| 92 | static int udplite_new(struct nf_conn *conntrack, const struct sk_buff *skb, |
| 93 | unsigned int dataoff) |
| 94 | { |
| 95 | return 1; |
| 96 | } |
| 97 | |
| 98 | static int udplite_error(struct sk_buff *skb, unsigned int dataoff, |
| 99 | enum ip_conntrack_info *ctinfo, |
| 100 | int pf, |
| 101 | unsigned int hooknum) |
| 102 | { |
| 103 | unsigned int udplen = skb->len - dataoff; |
| 104 | struct udphdr _hdr, *hdr; |
| 105 | unsigned int cscov; |
| 106 | |
| 107 | /* Header is too small? */ |
| 108 | hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr); |
| 109 | if (hdr == NULL) { |
| 110 | if (LOG_INVALID(IPPROTO_UDPLITE)) |
| 111 | nf_log_packet(pf, 0, skb, NULL, NULL, NULL, |
| 112 | "nf_ct_udplite: short packet "); |
| 113 | return -NF_ACCEPT; |
| 114 | } |
| 115 | |
| 116 | cscov = ntohs(hdr->len); |
| 117 | if (cscov == 0) |
| 118 | cscov = udplen; |
| 119 | else if (cscov < sizeof(*hdr) || cscov > udplen) { |
| 120 | if (LOG_INVALID(IPPROTO_UDPLITE)) |
| 121 | nf_log_packet(pf, 0, skb, NULL, NULL, NULL, |
| 122 | "nf_ct_udplite: invalid checksum coverage "); |
| 123 | return -NF_ACCEPT; |
| 124 | } |
| 125 | |
| 126 | /* UDPLITE mandates checksums */ |
| 127 | if (!hdr->check) { |
| 128 | if (LOG_INVALID(IPPROTO_UDPLITE)) |
| 129 | nf_log_packet(pf, 0, skb, NULL, NULL, NULL, |
| 130 | "nf_ct_udplite: checksum missing "); |
| 131 | return -NF_ACCEPT; |
| 132 | } |
| 133 | |
| 134 | /* Checksum invalid? Ignore. */ |
| 135 | if (nf_conntrack_checksum && !skb_csum_unnecessary(skb) && |
| 136 | ((pf == PF_INET && hooknum == NF_IP_PRE_ROUTING) || |
| 137 | (pf == PF_INET6 && hooknum == NF_IP6_PRE_ROUTING))) { |
| 138 | if (pf == PF_INET) { |
| 139 | struct iphdr *iph = ip_hdr(skb); |
| 140 | |
| 141 | skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, |
| 142 | udplen, IPPROTO_UDPLITE, 0); |
| 143 | } else { |
| 144 | struct ipv6hdr *ipv6h = ipv6_hdr(skb); |
| 145 | __wsum hsum = skb_checksum(skb, 0, dataoff, 0); |
| 146 | |
| 147 | skb->csum = ~csum_unfold( |
| 148 | csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, |
| 149 | udplen, IPPROTO_UDPLITE, |
| 150 | csum_sub(0, hsum))); |
| 151 | } |
| 152 | |
| 153 | skb->ip_summed = CHECKSUM_NONE; |
| 154 | if (__skb_checksum_complete_head(skb, dataoff + cscov)) { |
| 155 | if (LOG_INVALID(IPPROTO_UDPLITE)) |
| 156 | nf_log_packet(pf, 0, skb, NULL, NULL, NULL, |
| 157 | "nf_ct_udplite: bad UDPLite " |
| 158 | "checksum "); |
| 159 | return -NF_ACCEPT; |
| 160 | } |
| 161 | skb->ip_summed = CHECKSUM_UNNECESSARY; |
| 162 | } |
| 163 | |
| 164 | return NF_ACCEPT; |
| 165 | } |
| 166 | |
| 167 | #ifdef CONFIG_SYSCTL |
| 168 | static unsigned int udplite_sysctl_table_users; |
| 169 | static struct ctl_table_header *udplite_sysctl_header; |
| 170 | static struct ctl_table udplite_sysctl_table[] = { |
| 171 | { |
| 172 | .ctl_name = CTL_UNNUMBERED, |
| 173 | .procname = "nf_conntrack_udplite_timeout", |
| 174 | .data = &nf_ct_udplite_timeout, |
| 175 | .maxlen = sizeof(unsigned int), |
| 176 | .mode = 0644, |
| 177 | .proc_handler = &proc_dointvec_jiffies, |
| 178 | }, |
| 179 | { |
| 180 | .ctl_name = CTL_UNNUMBERED, |
| 181 | .procname = "nf_conntrack_udplite_timeout_stream", |
| 182 | .data = &nf_ct_udplite_timeout_stream, |
| 183 | .maxlen = sizeof(unsigned int), |
| 184 | .mode = 0644, |
| 185 | .proc_handler = &proc_dointvec_jiffies, |
| 186 | }, |
| 187 | { |
| 188 | .ctl_name = 0 |
| 189 | } |
| 190 | }; |
| 191 | #endif /* CONFIG_SYSCTL */ |
| 192 | |
| 193 | static struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite4 __read_mostly = |
| 194 | { |
| 195 | .l3proto = PF_INET, |
| 196 | .l4proto = IPPROTO_UDPLITE, |
| 197 | .name = "udplite", |
| 198 | .pkt_to_tuple = udplite_pkt_to_tuple, |
| 199 | .invert_tuple = udplite_invert_tuple, |
| 200 | .print_tuple = udplite_print_tuple, |
| 201 | .print_conntrack = udplite_print_conntrack, |
| 202 | .packet = udplite_packet, |
| 203 | .new = udplite_new, |
| 204 | .error = udplite_error, |
| 205 | #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) |
Patrick McHardy | fdf7083 | 2007-09-28 14:37:41 -0700 | [diff] [blame] | 206 | .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr, |
| 207 | .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple, |
Patrick McHardy | f73e924 | 2007-09-28 14:39:55 -0700 | [diff] [blame] | 208 | .nla_policy = nf_ct_port_nla_policy, |
Patrick McHardy | 59eecdf | 2007-07-14 20:48:44 -0700 | [diff] [blame] | 209 | #endif |
| 210 | #ifdef CONFIG_SYSCTL |
| 211 | .ctl_table_users = &udplite_sysctl_table_users, |
| 212 | .ctl_table_header = &udplite_sysctl_header, |
| 213 | .ctl_table = udplite_sysctl_table, |
| 214 | #endif |
| 215 | }; |
| 216 | |
| 217 | static struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite6 __read_mostly = |
| 218 | { |
| 219 | .l3proto = PF_INET6, |
| 220 | .l4proto = IPPROTO_UDPLITE, |
| 221 | .name = "udplite", |
| 222 | .pkt_to_tuple = udplite_pkt_to_tuple, |
| 223 | .invert_tuple = udplite_invert_tuple, |
| 224 | .print_tuple = udplite_print_tuple, |
| 225 | .print_conntrack = udplite_print_conntrack, |
| 226 | .packet = udplite_packet, |
| 227 | .new = udplite_new, |
| 228 | .error = udplite_error, |
| 229 | #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) |
Patrick McHardy | fdf7083 | 2007-09-28 14:37:41 -0700 | [diff] [blame] | 230 | .tuple_to_nlattr = nf_ct_port_tuple_to_nlattr, |
| 231 | .nlattr_to_tuple = nf_ct_port_nlattr_to_tuple, |
Patrick McHardy | f73e924 | 2007-09-28 14:39:55 -0700 | [diff] [blame] | 232 | .nla_policy = nf_ct_port_nla_policy, |
Patrick McHardy | 59eecdf | 2007-07-14 20:48:44 -0700 | [diff] [blame] | 233 | #endif |
| 234 | #ifdef CONFIG_SYSCTL |
| 235 | .ctl_table_users = &udplite_sysctl_table_users, |
| 236 | .ctl_table_header = &udplite_sysctl_header, |
| 237 | .ctl_table = udplite_sysctl_table, |
| 238 | #endif |
| 239 | }; |
| 240 | |
| 241 | static int __init nf_conntrack_proto_udplite_init(void) |
| 242 | { |
| 243 | int err; |
| 244 | |
| 245 | err = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udplite4); |
| 246 | if (err < 0) |
| 247 | goto err1; |
| 248 | err = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udplite6); |
| 249 | if (err < 0) |
| 250 | goto err2; |
| 251 | return 0; |
| 252 | err2: |
| 253 | nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite4); |
| 254 | err1: |
| 255 | return err; |
| 256 | } |
| 257 | |
| 258 | static void __exit nf_conntrack_proto_udplite_exit(void) |
| 259 | { |
| 260 | nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite6); |
| 261 | nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite4); |
| 262 | } |
| 263 | |
| 264 | module_init(nf_conntrack_proto_udplite_init); |
| 265 | module_exit(nf_conntrack_proto_udplite_exit); |
| 266 | |
| 267 | MODULE_LICENSE("GPL"); |