Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 1 | /* (C) 1999-2001 Paul `Rusty' Russell |
| 2 | * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License version 2 as |
| 6 | * published by the Free Software Foundation. |
| 7 | * |
| 8 | * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp> |
| 9 | * - enable working with Layer 3 protocol independent connection tracking. |
| 10 | * |
| 11 | * Derived from net/ipv4/netfilter/ip_conntrack_proto_udp.c |
| 12 | */ |
| 13 | |
| 14 | #include <linux/types.h> |
| 15 | #include <linux/sched.h> |
| 16 | #include <linux/timer.h> |
| 17 | #include <linux/module.h> |
| 18 | #include <linux/netfilter.h> |
| 19 | #include <linux/udp.h> |
| 20 | #include <linux/seq_file.h> |
| 21 | #include <linux/skbuff.h> |
| 22 | #include <linux/ipv6.h> |
| 23 | #include <net/ip6_checksum.h> |
| 24 | #include <net/checksum.h> |
| 25 | #include <linux/netfilter.h> |
| 26 | #include <linux/netfilter_ipv4.h> |
| 27 | #include <linux/netfilter_ipv6.h> |
| 28 | #include <net/netfilter/nf_conntrack_protocol.h> |
| 29 | |
Patrick McHardy | babbdb1 | 2006-01-09 17:48:09 -0800 | [diff] [blame] | 30 | unsigned int nf_ct_udp_timeout = 30*HZ; |
| 31 | unsigned int nf_ct_udp_timeout_stream = 180*HZ; |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 32 | |
| 33 | static int udp_pkt_to_tuple(const struct sk_buff *skb, |
| 34 | unsigned int dataoff, |
| 35 | struct nf_conntrack_tuple *tuple) |
| 36 | { |
| 37 | struct udphdr _hdr, *hp; |
| 38 | |
| 39 | /* Actually only need first 8 bytes. */ |
| 40 | hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr); |
| 41 | if (hp == NULL) |
| 42 | return 0; |
| 43 | |
| 44 | tuple->src.u.udp.port = hp->source; |
| 45 | tuple->dst.u.udp.port = hp->dest; |
| 46 | |
| 47 | return 1; |
| 48 | } |
| 49 | |
| 50 | static int udp_invert_tuple(struct nf_conntrack_tuple *tuple, |
| 51 | const struct nf_conntrack_tuple *orig) |
| 52 | { |
| 53 | tuple->src.u.udp.port = orig->dst.u.udp.port; |
| 54 | tuple->dst.u.udp.port = orig->src.u.udp.port; |
| 55 | return 1; |
| 56 | } |
| 57 | |
| 58 | /* Print out the per-protocol part of the tuple. */ |
| 59 | static int udp_print_tuple(struct seq_file *s, |
| 60 | const struct nf_conntrack_tuple *tuple) |
| 61 | { |
| 62 | return seq_printf(s, "sport=%hu dport=%hu ", |
| 63 | ntohs(tuple->src.u.udp.port), |
| 64 | ntohs(tuple->dst.u.udp.port)); |
| 65 | } |
| 66 | |
| 67 | /* Print out the private part of the conntrack. */ |
| 68 | static int udp_print_conntrack(struct seq_file *s, |
| 69 | const struct nf_conn *conntrack) |
| 70 | { |
| 71 | return 0; |
| 72 | } |
| 73 | |
| 74 | /* Returns verdict for packet, and may modify conntracktype */ |
| 75 | static int udp_packet(struct nf_conn *conntrack, |
| 76 | const struct sk_buff *skb, |
| 77 | unsigned int dataoff, |
| 78 | enum ip_conntrack_info ctinfo, |
| 79 | int pf, |
| 80 | unsigned int hooknum) |
| 81 | { |
| 82 | /* If we've seen traffic both ways, this is some kind of UDP |
| 83 | stream. Extend timeout. */ |
| 84 | if (test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)) { |
| 85 | nf_ct_refresh_acct(conntrack, ctinfo, skb, |
| 86 | nf_ct_udp_timeout_stream); |
| 87 | /* Also, more likely to be important, and not a probe */ |
| 88 | if (!test_and_set_bit(IPS_ASSURED_BIT, &conntrack->status)) |
| 89 | nf_conntrack_event_cache(IPCT_STATUS, skb); |
| 90 | } else |
| 91 | nf_ct_refresh_acct(conntrack, ctinfo, skb, nf_ct_udp_timeout); |
| 92 | |
| 93 | return NF_ACCEPT; |
| 94 | } |
| 95 | |
| 96 | /* Called when a new connection for this protocol found. */ |
| 97 | static int udp_new(struct nf_conn *conntrack, const struct sk_buff *skb, |
| 98 | unsigned int dataoff) |
| 99 | { |
| 100 | return 1; |
| 101 | } |
| 102 | |
| 103 | static int udp_error(struct sk_buff *skb, unsigned int dataoff, |
| 104 | enum ip_conntrack_info *ctinfo, |
| 105 | int pf, |
Patrick McHardy | 96f6bf8 | 2006-04-06 14:19:24 -0700 | [diff] [blame] | 106 | unsigned int hooknum) |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 107 | { |
| 108 | unsigned int udplen = skb->len - dataoff; |
| 109 | struct udphdr _hdr, *hdr; |
| 110 | |
| 111 | /* Header is too small? */ |
| 112 | hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr); |
| 113 | if (hdr == NULL) { |
| 114 | if (LOG_INVALID(IPPROTO_UDP)) |
| 115 | nf_log_packet(pf, 0, skb, NULL, NULL, NULL, |
| 116 | "nf_ct_udp: short packet "); |
| 117 | return -NF_ACCEPT; |
| 118 | } |
| 119 | |
| 120 | /* Truncated/malformed packets */ |
| 121 | if (ntohs(hdr->len) > udplen || ntohs(hdr->len) < sizeof(*hdr)) { |
| 122 | if (LOG_INVALID(IPPROTO_UDP)) |
| 123 | nf_log_packet(pf, 0, skb, NULL, NULL, NULL, |
| 124 | "nf_ct_udp: truncated/malformed packet "); |
| 125 | return -NF_ACCEPT; |
| 126 | } |
| 127 | |
| 128 | /* Packet with no checksum */ |
| 129 | if (!hdr->check) |
| 130 | return NF_ACCEPT; |
| 131 | |
| 132 | /* Checksum invalid? Ignore. |
| 133 | * We skip checking packets on the outgoing path |
| 134 | * because the semantic of CHECKSUM_HW is different there |
| 135 | * and moreover root might send raw packets. |
| 136 | * FIXME: Source route IP option packets --RR */ |
Patrick McHardy | 39a27a3 | 2006-05-29 18:23:54 -0700 | [diff] [blame^] | 137 | if (nf_conntrack_checksum && |
| 138 | ((pf == PF_INET && hooknum == NF_IP_PRE_ROUTING) || |
Patrick McHardy | 96f6bf8 | 2006-04-06 14:19:24 -0700 | [diff] [blame] | 139 | (pf == PF_INET6 && hooknum == NF_IP6_PRE_ROUTING)) && |
| 140 | nf_checksum(skb, hooknum, dataoff, IPPROTO_UDP, pf)) { |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 141 | if (LOG_INVALID(IPPROTO_UDP)) |
| 142 | nf_log_packet(pf, 0, skb, NULL, NULL, NULL, |
| 143 | "nf_ct_udp: bad UDP checksum "); |
| 144 | return -NF_ACCEPT; |
| 145 | } |
| 146 | |
| 147 | return NF_ACCEPT; |
| 148 | } |
| 149 | |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 150 | struct nf_conntrack_protocol nf_conntrack_protocol_udp4 = |
| 151 | { |
| 152 | .l3proto = PF_INET, |
| 153 | .proto = IPPROTO_UDP, |
| 154 | .name = "udp", |
| 155 | .pkt_to_tuple = udp_pkt_to_tuple, |
| 156 | .invert_tuple = udp_invert_tuple, |
| 157 | .print_tuple = udp_print_tuple, |
| 158 | .print_conntrack = udp_print_conntrack, |
| 159 | .packet = udp_packet, |
| 160 | .new = udp_new, |
Patrick McHardy | 96f6bf8 | 2006-04-06 14:19:24 -0700 | [diff] [blame] | 161 | .error = udp_error, |
Pablo Neira Ayuso | c1d10ad | 2006-01-05 12:19:05 -0800 | [diff] [blame] | 162 | #if defined(CONFIG_NF_CT_NETLINK) || \ |
| 163 | defined(CONFIG_NF_CT_NETLINK_MODULE) |
| 164 | .tuple_to_nfattr = nf_ct_port_tuple_to_nfattr, |
| 165 | .nfattr_to_tuple = nf_ct_port_nfattr_to_tuple, |
| 166 | #endif |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 167 | }; |
| 168 | |
| 169 | struct nf_conntrack_protocol nf_conntrack_protocol_udp6 = |
| 170 | { |
| 171 | .l3proto = PF_INET6, |
| 172 | .proto = IPPROTO_UDP, |
| 173 | .name = "udp", |
| 174 | .pkt_to_tuple = udp_pkt_to_tuple, |
| 175 | .invert_tuple = udp_invert_tuple, |
| 176 | .print_tuple = udp_print_tuple, |
| 177 | .print_conntrack = udp_print_conntrack, |
| 178 | .packet = udp_packet, |
| 179 | .new = udp_new, |
Patrick McHardy | 96f6bf8 | 2006-04-06 14:19:24 -0700 | [diff] [blame] | 180 | .error = udp_error, |
Pablo Neira Ayuso | c1d10ad | 2006-01-05 12:19:05 -0800 | [diff] [blame] | 181 | #if defined(CONFIG_NF_CT_NETLINK) || \ |
| 182 | defined(CONFIG_NF_CT_NETLINK_MODULE) |
| 183 | .tuple_to_nfattr = nf_ct_port_tuple_to_nfattr, |
| 184 | .nfattr_to_tuple = nf_ct_port_nfattr_to_tuple, |
| 185 | #endif |
Yasuyuki Kozakai | 9fb9cbb | 2005-11-09 16:38:16 -0800 | [diff] [blame] | 186 | }; |
| 187 | |
| 188 | EXPORT_SYMBOL(nf_conntrack_protocol_udp4); |
| 189 | EXPORT_SYMBOL(nf_conntrack_protocol_udp6); |