diff options
Diffstat (limited to 'net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c')
-rw-r--r-- | net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c | 556 |
1 files changed, 556 insertions, 0 deletions
diff --git a/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c new file mode 100644 index 0000000..e2c90b3 --- /dev/null +++ b/net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c @@ -0,0 +1,556 @@ +/* + * Copyright (C)2004 USAGI/WIDE Project + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * Author: + * Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp> + * + * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp> + * - support Layer 3 protocol independent connection tracking. + * Based on the original ip_conntrack code which had the following + * copyright information: + * (C) 1999-2001 Paul `Rusty' Russell + * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> + * + * 23 Mar 2004: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp> + * - add get_features() to support various size of conntrack + * structures. + */ + +#include <linux/config.h> +#include <linux/types.h> +#include <linux/ipv6.h> +#include <linux/in6.h> +#include <linux/netfilter.h> +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/icmp.h> +#include <linux/sysctl.h> +#include <net/ipv6.h> + +#include <linux/netfilter_ipv6.h> +#include <net/netfilter/nf_conntrack.h> +#include <net/netfilter/nf_conntrack_helper.h> +#include <net/netfilter/nf_conntrack_protocol.h> +#include <net/netfilter/nf_conntrack_l3proto.h> +#include <net/netfilter/nf_conntrack_core.h> + +#if 0 +#define DEBUGP printk +#else +#define DEBUGP(format, args...) +#endif + +DECLARE_PER_CPU(struct ip_conntrack_stat, nf_conntrack_stat); + +static int ipv6_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff, + struct nf_conntrack_tuple *tuple) +{ + u_int32_t _addrs[8], *ap; + + ap = skb_header_pointer(skb, nhoff + offsetof(struct ipv6hdr, saddr), + sizeof(_addrs), _addrs); + if (ap == NULL) + return 0; + + memcpy(tuple->src.u3.ip6, ap, sizeof(tuple->src.u3.ip6)); + memcpy(tuple->dst.u3.ip6, ap + 4, sizeof(tuple->dst.u3.ip6)); + + return 1; +} + +static int ipv6_invert_tuple(struct nf_conntrack_tuple *tuple, + const struct nf_conntrack_tuple *orig) +{ + memcpy(tuple->src.u3.ip6, orig->dst.u3.ip6, sizeof(tuple->src.u3.ip6)); + memcpy(tuple->dst.u3.ip6, orig->src.u3.ip6, sizeof(tuple->dst.u3.ip6)); + + return 1; +} + +static int ipv6_print_tuple(struct seq_file *s, + const struct nf_conntrack_tuple *tuple) +{ + return seq_printf(s, "src=%x:%x:%x:%x:%x:%x:%x:%x dst=%x:%x:%x:%x:%x:%x:%x:%x ", + NIP6(*((struct in6_addr *)tuple->src.u3.ip6)), + NIP6(*((struct in6_addr *)tuple->dst.u3.ip6))); +} + +static int ipv6_print_conntrack(struct seq_file *s, + const struct nf_conn *conntrack) +{ + return 0; +} + +/* + * 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. + */ + +int nf_ct_ipv6_skip_exthdr(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_prepare(struct sk_buff **pskb, unsigned int hooknum, unsigned int *dataoff, + u_int8_t *protonum) +{ + unsigned int extoff; + unsigned char pnum; + int protoff; + + extoff = (u8*)((*pskb)->nh.ipv6h + 1) - (*pskb)->data; + pnum = (*pskb)->nh.ipv6h->nexthdr; + + protoff = nf_ct_ipv6_skip_exthdr(*pskb, extoff, &pnum, + (*pskb)->len - extoff); + + /* + * (protoff == (*pskb)->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 > (*pskb)->len)) { + DEBUGP("ip6_conntrack_core: can't find proto in pkt\n"); + NF_CT_STAT_INC(error); + NF_CT_STAT_INC(invalid); + return -NF_ACCEPT; + } + + *dataoff = protoff; + *protonum = pnum; + return NF_ACCEPT; +} + +static u_int32_t ipv6_get_features(const struct nf_conntrack_tuple *tuple) +{ + return NF_CT_F_BASIC; +} + +static unsigned int ipv6_confirm(unsigned int hooknum, + struct sk_buff **pskb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) +{ + struct nf_conn *ct; + enum ip_conntrack_info ctinfo; + + /* This is where we call the helper: as the packet goes out. */ + ct = nf_ct_get(*pskb, &ctinfo); + if (ct && ct->helper) { + unsigned int ret, protoff; + unsigned int extoff = (u8*)((*pskb)->nh.ipv6h + 1) + - (*pskb)->data; + unsigned char pnum = (*pskb)->nh.ipv6h->nexthdr; + + protoff = nf_ct_ipv6_skip_exthdr(*pskb, extoff, &pnum, + (*pskb)->len - extoff); + if (protoff < 0 || protoff > (*pskb)->len || + pnum == NEXTHDR_FRAGMENT) { + DEBUGP("proto header not found\n"); + return NF_ACCEPT; + } + + ret = ct->helper->help(pskb, protoff, ct, ctinfo); + if (ret != NF_ACCEPT) + return ret; + } + + /* We've seen it coming out the other side: confirm it */ + + return nf_conntrack_confirm(pskb); +} + +extern struct sk_buff *nf_ct_frag6_gather(struct sk_buff *skb); +extern void nf_ct_frag6_output(unsigned int hooknum, struct sk_buff *skb, + struct net_device *in, + struct net_device *out, + int (*okfn)(struct sk_buff *)); +static unsigned int ipv6_defrag(unsigned int hooknum, + struct sk_buff **pskb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) +{ + struct sk_buff *reasm; + + /* Previously seen (loopback)? */ + if ((*pskb)->nfct) + return NF_ACCEPT; + + reasm = nf_ct_frag6_gather(*pskb); + + /* queued */ + if (reasm == NULL) + return NF_STOLEN; + + /* error occured or not fragmented */ + if (reasm == *pskb) + return NF_ACCEPT; + + nf_ct_frag6_output(hooknum, reasm, (struct net_device *)in, + (struct net_device *)out, okfn); + + return NF_STOLEN; +} + +static unsigned int ipv6_conntrack_in(unsigned int hooknum, + struct sk_buff **pskb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) +{ + struct sk_buff *reasm = (*pskb)->nfct_reasm; + + /* This packet is fragmented and has reassembled packet. */ + if (reasm) { + /* Reassembled packet isn't parsed yet ? */ + if (!reasm->nfct) { + unsigned int ret; + + ret = nf_conntrack_in(PF_INET6, hooknum, &reasm); + if (ret != NF_ACCEPT) + return ret; + } + nf_conntrack_get(reasm->nfct); + (*pskb)->nfct = reasm->nfct; + return NF_ACCEPT; + } + + return nf_conntrack_in(PF_INET6, hooknum, pskb); +} + +static unsigned int ipv6_conntrack_local(unsigned int hooknum, + struct sk_buff **pskb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) +{ + /* root is playing with raw sockets. */ + if ((*pskb)->len < sizeof(struct ipv6hdr)) { + if (net_ratelimit()) + printk("ipv6_conntrack_local: packet too short\n"); + return NF_ACCEPT; + } + return ipv6_conntrack_in(hooknum, pskb, in, out, okfn); +} + +/* Connection tracking may drop packets, but never alters them, so + make it the first hook. */ +static struct nf_hook_ops ipv6_conntrack_defrag_ops = { + .hook = ipv6_defrag, + .owner = THIS_MODULE, + .pf = PF_INET6, + .hooknum = NF_IP6_PRE_ROUTING, + .priority = NF_IP6_PRI_CONNTRACK_DEFRAG, +}; + +static struct nf_hook_ops ipv6_conntrack_in_ops = { + .hook = ipv6_conntrack_in, + .owner = THIS_MODULE, + .pf = PF_INET6, + .hooknum = NF_IP6_PRE_ROUTING, + .priority = NF_IP6_PRI_CONNTRACK, +}; + +static struct nf_hook_ops ipv6_conntrack_local_out_ops = { + .hook = ipv6_conntrack_local, + .owner = THIS_MODULE, + .pf = PF_INET6, + .hooknum = NF_IP6_LOCAL_OUT, + .priority = NF_IP6_PRI_CONNTRACK, +}; + +static struct nf_hook_ops ipv6_conntrack_defrag_local_out_ops = { + .hook = ipv6_defrag, + .owner = THIS_MODULE, + .pf = PF_INET6, + .hooknum = NF_IP6_LOCAL_OUT, + .priority = NF_IP6_PRI_CONNTRACK_DEFRAG, +}; + +/* Refragmenter; last chance. */ +static struct nf_hook_ops ipv6_conntrack_out_ops = { + .hook = ipv6_confirm, + .owner = THIS_MODULE, + .pf = PF_INET6, + .hooknum = NF_IP6_POST_ROUTING, + .priority = NF_IP6_PRI_LAST, +}; + +static struct nf_hook_ops ipv6_conntrack_local_in_ops = { + .hook = ipv6_confirm, + .owner = THIS_MODULE, + .pf = PF_INET6, + .hooknum = NF_IP6_LOCAL_IN, + .priority = NF_IP6_PRI_LAST-1, +}; + +#ifdef CONFIG_SYSCTL + +/* From nf_conntrack_proto_icmpv6.c */ +extern unsigned long nf_ct_icmpv6_timeout; + +/* From nf_conntrack_frag6.c */ +extern unsigned long nf_ct_frag6_timeout; +extern unsigned long nf_ct_frag6_low_thresh; +extern unsigned long nf_ct_frag6_high_thresh; + +static struct ctl_table_header *nf_ct_ipv6_sysctl_header; + +static ctl_table nf_ct_sysctl_table[] = { + { + .ctl_name = NET_NF_CONNTRACK_ICMPV6_TIMEOUT, + .procname = "nf_conntrack_icmpv6_timeout", + .data = &nf_ct_icmpv6_timeout, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = &proc_dointvec_jiffies, + }, + { + .ctl_name = NET_NF_CONNTRACK_FRAG6_TIMEOUT, + .procname = "nf_conntrack_frag6_timeout", + .data = &nf_ct_frag6_timeout, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = &proc_dointvec_jiffies, + }, + { + .ctl_name = NET_NF_CONNTRACK_FRAG6_LOW_THRESH, + .procname = "nf_conntrack_frag6_low_thresh", + .data = &nf_ct_frag6_low_thresh, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = &proc_dointvec_jiffies, + }, + { + .ctl_name = NET_NF_CONNTRACK_FRAG6_HIGH_THRESH, + .procname = "nf_conntrack_frag6_high_thresh", + .data = &nf_ct_frag6_high_thresh, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = &proc_dointvec_jiffies, + }, + { .ctl_name = 0 } +}; + +static ctl_table nf_ct_netfilter_table[] = { + { + .ctl_name = NET_NETFILTER, + .procname = "netfilter", + .mode = 0555, + .child = nf_ct_sysctl_table, + }, + { .ctl_name = 0 } +}; + +static ctl_table nf_ct_net_table[] = { + { + .ctl_name = CTL_NET, + .procname = "net", + .mode = 0555, + .child = nf_ct_netfilter_table, + }, + { .ctl_name = 0 } +}; +#endif + +struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv6 = { + .l3proto = PF_INET6, + .name = "ipv6", + .pkt_to_tuple = ipv6_pkt_to_tuple, + .invert_tuple = ipv6_invert_tuple, + .print_tuple = ipv6_print_tuple, + .print_conntrack = ipv6_print_conntrack, + .prepare = ipv6_prepare, + .get_features = ipv6_get_features, + .me = THIS_MODULE, +}; + +extern struct nf_conntrack_protocol nf_conntrack_protocol_tcp6; +extern struct nf_conntrack_protocol nf_conntrack_protocol_udp6; +extern struct nf_conntrack_protocol nf_conntrack_protocol_icmpv6; +extern int nf_ct_frag6_init(void); +extern void nf_ct_frag6_cleanup(void); +static int init_or_cleanup(int init) +{ + int ret = 0; + + if (!init) goto cleanup; + + ret = nf_ct_frag6_init(); + if (ret < 0) { + printk("nf_conntrack_ipv6: can't initialize frag6.\n"); + goto cleanup_nothing; + } + ret = nf_conntrack_protocol_register(&nf_conntrack_protocol_tcp6); + if (ret < 0) { + printk("nf_conntrack_ipv6: can't register tcp.\n"); + goto cleanup_frag6; + } + + ret = nf_conntrack_protocol_register(&nf_conntrack_protocol_udp6); + if (ret < 0) { + printk("nf_conntrack_ipv6: can't register udp.\n"); + goto cleanup_tcp; + } + + ret = nf_conntrack_protocol_register(&nf_conntrack_protocol_icmpv6); + if (ret < 0) { + printk("nf_conntrack_ipv6: can't register icmpv6.\n"); + goto cleanup_udp; + } + + ret = nf_conntrack_l3proto_register(&nf_conntrack_l3proto_ipv6); + if (ret < 0) { + printk("nf_conntrack_ipv6: can't register ipv6\n"); + goto cleanup_icmpv6; + } + + ret = nf_register_hook(&ipv6_conntrack_defrag_ops); + if (ret < 0) { + printk("nf_conntrack_ipv6: can't register pre-routing defrag " + "hook.\n"); + goto cleanup_ipv6; + } + + ret = nf_register_hook(&ipv6_conntrack_defrag_local_out_ops); + if (ret < 0) { + printk("nf_conntrack_ipv6: can't register local_out defrag " + "hook.\n"); + goto cleanup_defragops; + } + + ret = nf_register_hook(&ipv6_conntrack_in_ops); + if (ret < 0) { + printk("nf_conntrack_ipv6: can't register pre-routing hook.\n"); + goto cleanup_defraglocalops; + } + + ret = nf_register_hook(&ipv6_conntrack_local_out_ops); + if (ret < 0) { + printk("nf_conntrack_ipv6: can't register local out hook.\n"); + goto cleanup_inops; + } + + ret = nf_register_hook(&ipv6_conntrack_out_ops); + if (ret < 0) { + printk("nf_conntrack_ipv6: can't register post-routing hook.\n"); + goto cleanup_inandlocalops; + } + + ret = nf_register_hook(&ipv6_conntrack_local_in_ops); + if (ret < 0) { + printk("nf_conntrack_ipv6: can't register local in hook.\n"); + goto cleanup_inoutandlocalops; + } + +#ifdef CONFIG_SYSCTL + nf_ct_ipv6_sysctl_header = register_sysctl_table(nf_ct_net_table, 0); + if (nf_ct_ipv6_sysctl_header == NULL) { + printk("nf_conntrack: can't register to sysctl.\n"); + ret = -ENOMEM; + goto cleanup_localinops; + } +#endif + return ret; + + cleanup: + synchronize_net(); +#ifdef CONFIG_SYSCTL + unregister_sysctl_table(nf_ct_ipv6_sysctl_header); + cleanup_localinops: +#endif + nf_unregister_hook(&ipv6_conntrack_local_in_ops); + cleanup_inoutandlocalops: + nf_unregister_hook(&ipv6_conntrack_out_ops); + cleanup_inandlocalops: + nf_unregister_hook(&ipv6_conntrack_local_out_ops); + cleanup_inops: + nf_unregister_hook(&ipv6_conntrack_in_ops); + cleanup_defraglocalops: + nf_unregister_hook(&ipv6_conntrack_defrag_local_out_ops); + cleanup_defragops: + nf_unregister_hook(&ipv6_conntrack_defrag_ops); + cleanup_ipv6: + nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv6); + cleanup_icmpv6: + nf_conntrack_protocol_unregister(&nf_conntrack_protocol_icmpv6); + cleanup_udp: + nf_conntrack_protocol_unregister(&nf_conntrack_protocol_udp6); + cleanup_tcp: + nf_conntrack_protocol_unregister(&nf_conntrack_protocol_tcp6); + cleanup_frag6: + nf_ct_frag6_cleanup(); + cleanup_nothing: + return ret; +} + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Yasuyuki KOZAKAI @USAGI <yasuyuki.kozakai@toshiba.co.jp>"); + +static int __init init(void) +{ + need_nf_conntrack(); + return init_or_cleanup(1); +} + +static void __exit fini(void) +{ + init_or_cleanup(0); +} + +module_init(init); +module_exit(fini); + +void need_ip6_conntrack(void) +{ +} + +EXPORT_SYMBOL(need_ip6_conntrack); |