--- /dev/null
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * 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.
+ *
+ * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
+ * - move L3 protocol dependent part to this file.
+ * 23 Mar 2004: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp>
+ * - add get_features() to support various size of conntrack
+ * structures.
+ *
+ * Derived from net/ipv4/netfilter/ip_conntrack_standalone.c
+ */
+
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/ip.h>
+#include <linux/netfilter.h>
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/icmp.h>
+#include <linux/sysctl.h>
+#include <net/route.h>
+#include <net/ip.h>
+
+#include <linux/netfilter_ipv4.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>
+#include <net/netfilter/ipv4/nf_conntrack_ipv4.h>
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(format, args...)
+#endif
+
+DECLARE_PER_CPU(struct nf_conntrack_stat, nf_conntrack_stat);
+
+static int ipv4_pkt_to_tuple(const struct sk_buff *skb, unsigned int nhoff,
+ struct nf_conntrack_tuple *tuple)
+{
+ u_int32_t _addrs[2], *ap;
+ ap = skb_header_pointer(skb, nhoff + offsetof(struct iphdr, saddr),
+ sizeof(u_int32_t) * 2, _addrs);
+ if (ap == NULL)
+ return 0;
+
+ tuple->src.u3.ip = ap[0];
+ tuple->dst.u3.ip = ap[1];
+
+ return 1;
+}
+
+static int ipv4_invert_tuple(struct nf_conntrack_tuple *tuple,
+ const struct nf_conntrack_tuple *orig)
+{
+ tuple->src.u3.ip = orig->dst.u3.ip;
+ tuple->dst.u3.ip = orig->src.u3.ip;
+
+ return 1;
+}
+
+static int ipv4_print_tuple(struct seq_file *s,
+ const struct nf_conntrack_tuple *tuple)
+{
+ return seq_printf(s, "src=%u.%u.%u.%u dst=%u.%u.%u.%u ",
+ NIPQUAD(tuple->src.u3.ip),
+ NIPQUAD(tuple->dst.u3.ip));
+}
+
+static int ipv4_print_conntrack(struct seq_file *s,
+ const struct nf_conn *conntrack)
+{
+ return 0;
+}
+
+/* Returns new sk_buff, or NULL */
+static struct sk_buff *
+nf_ct_ipv4_gather_frags(struct sk_buff *skb, u_int32_t user)
+{
+ skb_orphan(skb);
+
+ local_bh_disable();
+ skb = ip_defrag(skb, user);
+ local_bh_enable();
+
+ if (skb)
+ ip_send_check(skb->nh.iph);
+
+ return skb;
+}
+
+static int
+ipv4_prepare(struct sk_buff **pskb, unsigned int hooknum, unsigned int *dataoff,
+ u_int8_t *protonum)
+{
+ /* Never happen */
+ if ((*pskb)->nh.iph->frag_off & htons(IP_OFFSET)) {
+ if (net_ratelimit()) {
+ printk(KERN_ERR "ipv4_prepare: Frag of proto %u (hook=%u)\n",
+ (*pskb)->nh.iph->protocol, hooknum);
+ }
+ return -NF_DROP;
+ }
+
+ *dataoff = (*pskb)->nh.raw - (*pskb)->data + (*pskb)->nh.iph->ihl*4;
+ *protonum = (*pskb)->nh.iph->protocol;
+
+ return NF_ACCEPT;
+}
+
+int nat_module_is_loaded = 0;
+static u_int32_t ipv4_get_features(const struct nf_conntrack_tuple *tuple)
+{
+ if (nat_module_is_loaded)
+ return NF_CT_F_NAT;
+
+ return NF_CT_F_BASIC;
+}
+
+static unsigned int ipv4_confirm(unsigned int hooknum,
+ struct sk_buff **pskb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
+ /* We've seen it coming out the other side: confirm it */
+ return nf_conntrack_confirm(pskb);
+}
+
+static unsigned int ipv4_conntrack_help(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;
+ struct nf_conn_help *help;
+
+ /* This is where we call the helper: as the packet goes out. */
+ ct = nf_ct_get(*pskb, &ctinfo);
+ if (!ct)
+ return NF_ACCEPT;
+
+ help = nfct_help(ct);
+ if (!help || !help->helper)
+ return NF_ACCEPT;
+
+ return help->helper->help(pskb,
+ (*pskb)->nh.raw - (*pskb)->data
+ + (*pskb)->nh.iph->ihl*4,
+ ct, ctinfo);
+}
+
+static unsigned int ipv4_conntrack_defrag(unsigned int hooknum,
+ struct sk_buff **pskb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
+#if !defined(CONFIG_IP_NF_NAT) && !defined(CONFIG_IP_NF_NAT_MODULE)
+ /* Previously seen (loopback)? Ignore. Do this before
+ fragment check. */
+ if ((*pskb)->nfct)
+ return NF_ACCEPT;
+#endif
+
+ /* Gather fragments. */
+ if ((*pskb)->nh.iph->frag_off & htons(IP_MF|IP_OFFSET)) {
+ *pskb = nf_ct_ipv4_gather_frags(*pskb,
+ hooknum == NF_IP_PRE_ROUTING ?
+ IP_DEFRAG_CONNTRACK_IN :
+ IP_DEFRAG_CONNTRACK_OUT);
+ if (!*pskb)
+ return NF_STOLEN;
+ }
+ return NF_ACCEPT;
+}
+
+static unsigned int ipv4_conntrack_in(unsigned int hooknum,
+ struct sk_buff **pskb,
+ const struct net_device *in,
+ const struct net_device *out,
+ int (*okfn)(struct sk_buff *))
+{
+ return nf_conntrack_in(PF_INET, hooknum, pskb);
+}
+
+static unsigned int ipv4_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 iphdr)
+ || (*pskb)->nh.iph->ihl * 4 < sizeof(struct iphdr)) {
+ if (net_ratelimit())
+ printk("ipt_hook: happy cracking.\n");
+ return NF_ACCEPT;
+ }
+ return nf_conntrack_in(PF_INET, hooknum, pskb);
+}
+
+/* Connection tracking may drop packets, but never alters them, so
+ make it the first hook. */
+static struct nf_hook_ops ipv4_conntrack_ops[] = {
+ {
+ .hook = ipv4_conntrack_defrag,
+ .owner = THIS_MODULE,
+ .pf = PF_INET,
+ .hooknum = NF_IP_PRE_ROUTING,
+ .priority = NF_IP_PRI_CONNTRACK_DEFRAG,
+ },
+ {
+ .hook = ipv4_conntrack_in,
+ .owner = THIS_MODULE,
+ .pf = PF_INET,
+ .hooknum = NF_IP_PRE_ROUTING,
+ .priority = NF_IP_PRI_CONNTRACK,
+ },
+ {
+ .hook = ipv4_conntrack_defrag,
+ .owner = THIS_MODULE,
+ .pf = PF_INET,
+ .hooknum = NF_IP_LOCAL_OUT,
+ .priority = NF_IP_PRI_CONNTRACK_DEFRAG,
+ },
+ {
+ .hook = ipv4_conntrack_local,
+ .owner = THIS_MODULE,
+ .pf = PF_INET,
+ .hooknum = NF_IP_LOCAL_OUT,
+ .priority = NF_IP_PRI_CONNTRACK,
+ },
+ {
+ .hook = ipv4_conntrack_help,
+ .owner = THIS_MODULE,
+ .pf = PF_INET,
+ .hooknum = NF_IP_POST_ROUTING,
+ .priority = NF_IP_PRI_CONNTRACK_HELPER,
+ },
+ {
+ .hook = ipv4_conntrack_help,
+ .owner = THIS_MODULE,
+ .pf = PF_INET,
+ .hooknum = NF_IP_LOCAL_IN,
+ .priority = NF_IP_PRI_CONNTRACK_HELPER,
+ },
+ {
+ .hook = ipv4_confirm,
+ .owner = THIS_MODULE,
+ .pf = PF_INET,
+ .hooknum = NF_IP_POST_ROUTING,
+ .priority = NF_IP_PRI_CONNTRACK_CONFIRM,
+ },
+ {
+ .hook = ipv4_confirm,
+ .owner = THIS_MODULE,
+ .pf = PF_INET,
+ .hooknum = NF_IP_LOCAL_IN,
+ .priority = NF_IP_PRI_CONNTRACK_CONFIRM,
+ },
+};
+
+#ifdef CONFIG_SYSCTL
+/* From nf_conntrack_proto_icmp.c */
+extern unsigned int nf_ct_icmp_timeout;
+static struct ctl_table_header *nf_ct_ipv4_sysctl_header;
+
+static ctl_table nf_ct_sysctl_table[] = {
+ {
+ .ctl_name = NET_NF_CONNTRACK_ICMP_TIMEOUT,
+ .procname = "nf_conntrack_icmp_timeout",
+ .data = &nf_ct_icmp_timeout,
+ .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
+
+/* Fast function for those who don't want to parse /proc (and I don't
+ blame them). */
+/* Reversing the socket's dst/src point of view gives us the reply
+ mapping. */
+static int
+getorigdst(struct sock *sk, int optval, void __user *user, int *len)
+{
+ struct inet_sock *inet = inet_sk(sk);
+ struct nf_conntrack_tuple_hash *h;
+ struct nf_conntrack_tuple tuple;
+
+ NF_CT_TUPLE_U_BLANK(&tuple);
+ tuple.src.u3.ip = inet->rcv_saddr;
+ tuple.src.u.tcp.port = inet->sport;
+ tuple.dst.u3.ip = inet->daddr;
+ tuple.dst.u.tcp.port = inet->dport;
+ tuple.src.l3num = PF_INET;
+ tuple.dst.protonum = IPPROTO_TCP;
+
+ /* We only do TCP at the moment: is there a better way? */
+ if (strcmp(sk->sk_prot->name, "TCP")) {
+ DEBUGP("SO_ORIGINAL_DST: Not a TCP socket\n");
+ return -ENOPROTOOPT;
+ }
+
+ if ((unsigned int) *len < sizeof(struct sockaddr_in)) {
+ DEBUGP("SO_ORIGINAL_DST: len %u not %u\n",
+ *len, sizeof(struct sockaddr_in));
+ return -EINVAL;
+ }
+
+ h = nf_conntrack_find_get(&tuple, NULL);
+ if (h) {
+ struct sockaddr_in sin;
+ struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
+
+ sin.sin_family = AF_INET;
+ sin.sin_port = ct->tuplehash[IP_CT_DIR_ORIGINAL]
+ .tuple.dst.u.tcp.port;
+ sin.sin_addr.s_addr = ct->tuplehash[IP_CT_DIR_ORIGINAL]
+ .tuple.dst.u3.ip;
+ memset(sin.sin_zero, 0, sizeof(sin.sin_zero));
+
+ DEBUGP("SO_ORIGINAL_DST: %u.%u.%u.%u %u\n",
+ NIPQUAD(sin.sin_addr.s_addr), ntohs(sin.sin_port));
+ nf_ct_put(ct);
+ if (copy_to_user(user, &sin, sizeof(sin)) != 0)
+ return -EFAULT;
+ else
+ return 0;
+ }
+ DEBUGP("SO_ORIGINAL_DST: Can't find %u.%u.%u.%u/%u-%u.%u.%u.%u/%u.\n",
+ NIPQUAD(tuple.src.u3.ip), ntohs(tuple.src.u.tcp.port),
+ NIPQUAD(tuple.dst.u3.ip), ntohs(tuple.dst.u.tcp.port));
+ return -ENOENT;
+}
+
+#if defined(CONFIG_NF_CT_NETLINK) || \
+ defined(CONFIG_NF_CT_NETLINK_MODULE)
+
+#include <linux/netfilter/nfnetlink.h>
+#include <linux/netfilter/nfnetlink_conntrack.h>
+
+static int ipv4_tuple_to_nfattr(struct sk_buff *skb,
+ const struct nf_conntrack_tuple *tuple)
+{
+ NFA_PUT(skb, CTA_IP_V4_SRC, sizeof(u_int32_t),
+ &tuple->src.u3.ip);
+ NFA_PUT(skb, CTA_IP_V4_DST, sizeof(u_int32_t),
+ &tuple->dst.u3.ip);
+ return 0;
+
+nfattr_failure:
+ return -1;
+}
+
+static const size_t cta_min_ip[CTA_IP_MAX] = {
+ [CTA_IP_V4_SRC-1] = sizeof(u_int32_t),
+ [CTA_IP_V4_DST-1] = sizeof(u_int32_t),
+};
+
+static int ipv4_nfattr_to_tuple(struct nfattr *tb[],
+ struct nf_conntrack_tuple *t)
+{
+ if (!tb[CTA_IP_V4_SRC-1] || !tb[CTA_IP_V4_DST-1])
+ return -EINVAL;
+
+ if (nfattr_bad_size(tb, CTA_IP_MAX, cta_min_ip))
+ return -EINVAL;
+
+ t->src.u3.ip =
+ *(u_int32_t *)NFA_DATA(tb[CTA_IP_V4_SRC-1]);
+ t->dst.u3.ip =
+ *(u_int32_t *)NFA_DATA(tb[CTA_IP_V4_DST-1]);
+
+ return 0;
+}
+#endif
+
+static struct nf_sockopt_ops so_getorigdst = {
+ .pf = PF_INET,
+ .get_optmin = SO_ORIGINAL_DST,
+ .get_optmax = SO_ORIGINAL_DST+1,
+ .get = &getorigdst,
+};
+
+struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv4 = {
+ .l3proto = PF_INET,
+ .name = "ipv4",
+ .pkt_to_tuple = ipv4_pkt_to_tuple,
+ .invert_tuple = ipv4_invert_tuple,
+ .print_tuple = ipv4_print_tuple,
+ .print_conntrack = ipv4_print_conntrack,
+ .prepare = ipv4_prepare,
+ .get_features = ipv4_get_features,
+#if defined(CONFIG_NF_CT_NETLINK) || \
+ defined(CONFIG_NF_CT_NETLINK_MODULE)
+ .tuple_to_nfattr = ipv4_tuple_to_nfattr,
+ .nfattr_to_tuple = ipv4_nfattr_to_tuple,
+#endif
+ .me = THIS_MODULE,
+};
+
+extern struct nf_conntrack_protocol nf_conntrack_protocol_tcp4;
+extern struct nf_conntrack_protocol nf_conntrack_protocol_udp4;
+extern struct nf_conntrack_protocol nf_conntrack_protocol_icmp;
+
+MODULE_ALIAS("nf_conntrack-" __stringify(AF_INET));
+MODULE_LICENSE("GPL");
+
+static int __init nf_conntrack_l3proto_ipv4_init(void)
+{
+ int ret = 0;
+
+ need_conntrack();
+
+ ret = nf_register_sockopt(&so_getorigdst);
+ if (ret < 0) {
+ printk(KERN_ERR "Unable to register netfilter socket option\n");
+ return ret;
+ }
+
+ ret = nf_conntrack_protocol_register(&nf_conntrack_protocol_tcp4);
+ if (ret < 0) {
+ printk("nf_conntrack_ipv4: can't register tcp.\n");
+ goto cleanup_sockopt;
+ }
+
+ ret = nf_conntrack_protocol_register(&nf_conntrack_protocol_udp4);
+ if (ret < 0) {
+ printk("nf_conntrack_ipv4: can't register udp.\n");
+ goto cleanup_tcp;
+ }
+
+ ret = nf_conntrack_protocol_register(&nf_conntrack_protocol_icmp);
+ if (ret < 0) {
+ printk("nf_conntrack_ipv4: can't register icmp.\n");
+ goto cleanup_udp;
+ }
+
+ ret = nf_conntrack_l3proto_register(&nf_conntrack_l3proto_ipv4);
+ if (ret < 0) {
+ printk("nf_conntrack_ipv4: can't register ipv4\n");
+ goto cleanup_icmp;
+ }
+
+ ret = nf_register_hooks(ipv4_conntrack_ops,
+ ARRAY_SIZE(ipv4_conntrack_ops));
+ if (ret < 0) {
+ printk("nf_conntrack_ipv4: can't register hooks.\n");
+ goto cleanup_ipv4;
+ }
+#ifdef CONFIG_SYSCTL
+ nf_ct_ipv4_sysctl_header = register_sysctl_table(nf_ct_net_table, 0);
+ if (nf_ct_ipv4_sysctl_header == NULL) {
+ printk("nf_conntrack: can't register to sysctl.\n");
+ ret = -ENOMEM;
+ goto cleanup_hooks;
+ }
+#endif
+ return ret;
+
+#ifdef CONFIG_SYSCTL
+ cleanup_hooks:
+ nf_unregister_hooks(ipv4_conntrack_ops, ARRAY_SIZE(ipv4_conntrack_ops));
+#endif
+ cleanup_ipv4:
+ nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv4);
+ cleanup_icmp:
+ nf_conntrack_protocol_unregister(&nf_conntrack_protocol_icmp);
+ cleanup_udp:
+ nf_conntrack_protocol_unregister(&nf_conntrack_protocol_udp4);
+ cleanup_tcp:
+ nf_conntrack_protocol_unregister(&nf_conntrack_protocol_tcp4);
+ cleanup_sockopt:
+ nf_unregister_sockopt(&so_getorigdst);
+ return ret;
+}
+
+static void __exit nf_conntrack_l3proto_ipv4_fini(void)
+{
+ synchronize_net();
+#ifdef CONFIG_SYSCTL
+ unregister_sysctl_table(nf_ct_ipv4_sysctl_header);
+#endif
+ nf_unregister_hooks(ipv4_conntrack_ops, ARRAY_SIZE(ipv4_conntrack_ops));
+ nf_conntrack_l3proto_unregister(&nf_conntrack_l3proto_ipv4);
+ nf_conntrack_protocol_unregister(&nf_conntrack_protocol_icmp);
+ nf_conntrack_protocol_unregister(&nf_conntrack_protocol_udp4);
+ nf_conntrack_protocol_unregister(&nf_conntrack_protocol_tcp4);
+ nf_unregister_sockopt(&so_getorigdst);
+}
+
+module_init(nf_conntrack_l3proto_ipv4_init);
+module_exit(nf_conntrack_l3proto_ipv4_fini);
+
+EXPORT_SYMBOL(nf_ct_ipv4_gather_frags);
git://git.onelab.eu / linux-2.6.git / blobdiff