diff --git a/include/net/netfilter/ipv4/nf_defrag_ipv4.h b/include/net/netfilter/ipv4/nf_defrag_ipv4.h new file mode 100644 index 000000000000..6b00ea38546b --- /dev/null +++ b/include/net/netfilter/ipv4/nf_defrag_ipv4.h @@ -0,0 +1,6 @@ +#ifndef _NF_DEFRAG_IPV4_H +#define _NF_DEFRAG_IPV4_H + +extern void nf_defrag_ipv4_enable(void); + +#endif /* _NF_DEFRAG_IPV4_H */ diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig index 4e842d566428..07757ac8d5d8 100644 --- a/net/ipv4/netfilter/Kconfig +++ b/net/ipv4/netfilter/Kconfig @@ -5,10 +5,15 @@ menu "IP: Netfilter Configuration" depends on INET && NETFILTER +config NF_DEFRAG_IPV4 + tristate + default n + config NF_CONNTRACK_IPV4 tristate "IPv4 connection tracking support (required for NAT)" depends on NF_CONNTRACK default m if NETFILTER_ADVANCED=n + select NF_DEFRAG_IPV4 ---help--- Connection tracking keeps a record of what packets have passed through your machine, in order to figure out how they are related diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile index 1107edbe478f..5f9b650d90fc 100644 --- a/net/ipv4/netfilter/Makefile +++ b/net/ipv4/netfilter/Makefile @@ -18,6 +18,9 @@ obj-$(CONFIG_NF_CONNTRACK_IPV4) += nf_conntrack_ipv4.o obj-$(CONFIG_NF_NAT) += nf_nat.o +# defrag +obj-$(CONFIG_NF_DEFRAG_IPV4) += nf_defrag_ipv4.o + # NAT helpers (nf_conntrack) obj-$(CONFIG_NF_NAT_AMANDA) += nf_nat_amanda.o obj-$(CONFIG_NF_NAT_FTP) += nf_nat_ftp.o diff --git a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c index af69acc1d0f8..4a7c35275396 100644 --- a/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c +++ b/net/ipv4/netfilter/nf_conntrack_l3proto_ipv4.c @@ -1,3 +1,4 @@ + /* (C) 1999-2001 Paul `Rusty' Russell * (C) 2002-2004 Netfilter Core Team * @@ -24,6 +25,7 @@ #include #include #include +#include int (*nf_nat_seq_adjust_hook)(struct sk_buff *skb, struct nf_conn *ct, @@ -63,23 +65,6 @@ static int ipv4_print_tuple(struct seq_file *s, NIPQUAD(tuple->dst.u3.ip)); } -/* Returns new sk_buff, or NULL */ -static int nf_ct_ipv4_gather_frags(struct sk_buff *skb, u_int32_t user) -{ - int err; - - skb_orphan(skb); - - local_bh_disable(); - err = ip_defrag(skb, user); - local_bh_enable(); - - if (!err) - ip_send_check(ip_hdr(skb)); - - return err; -} - static int ipv4_get_l4proto(const struct sk_buff *skb, unsigned int nhoff, unsigned int *dataoff, u_int8_t *protonum) { @@ -144,28 +129,6 @@ out: return nf_conntrack_confirm(skb); } -static unsigned int ipv4_conntrack_defrag(unsigned int hooknum, - struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) -{ - /* Previously seen (loopback)? Ignore. Do this before - fragment check. */ - if (skb->nfct) - return NF_ACCEPT; - - /* Gather fragments. */ - if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) { - if (nf_ct_ipv4_gather_frags(skb, - hooknum == NF_INET_PRE_ROUTING ? - IP_DEFRAG_CONNTRACK_IN : - IP_DEFRAG_CONNTRACK_OUT)) - return NF_STOLEN; - } - return NF_ACCEPT; -} - static unsigned int ipv4_conntrack_in(unsigned int hooknum, struct sk_buff *skb, const struct net_device *in, @@ -194,13 +157,6 @@ static unsigned int ipv4_conntrack_local(unsigned int hooknum, /* Connection tracking may drop packets, but never alters them, so make it the first hook. */ static struct nf_hook_ops ipv4_conntrack_ops[] __read_mostly = { - { - .hook = ipv4_conntrack_defrag, - .owner = THIS_MODULE, - .pf = PF_INET, - .hooknum = NF_INET_PRE_ROUTING, - .priority = NF_IP_PRI_CONNTRACK_DEFRAG, - }, { .hook = ipv4_conntrack_in, .owner = THIS_MODULE, @@ -208,13 +164,6 @@ static struct nf_hook_ops ipv4_conntrack_ops[] __read_mostly = { .hooknum = NF_INET_PRE_ROUTING, .priority = NF_IP_PRI_CONNTRACK, }, - { - .hook = ipv4_conntrack_defrag, - .owner = THIS_MODULE, - .pf = PF_INET, - .hooknum = NF_INET_LOCAL_OUT, - .priority = NF_IP_PRI_CONNTRACK_DEFRAG, - }, { .hook = ipv4_conntrack_local, .owner = THIS_MODULE, @@ -422,6 +371,7 @@ static int __init nf_conntrack_l3proto_ipv4_init(void) int ret = 0; need_conntrack(); + nf_defrag_ipv4_enable(); ret = nf_register_sockopt(&so_getorigdst); if (ret < 0) { diff --git a/net/ipv4/netfilter/nf_defrag_ipv4.c b/net/ipv4/netfilter/nf_defrag_ipv4.c new file mode 100644 index 000000000000..aa2c50a180f7 --- /dev/null +++ b/net/ipv4/netfilter/nf_defrag_ipv4.c @@ -0,0 +1,96 @@ +/* (C) 1999-2001 Paul `Rusty' Russell + * (C) 2002-2004 Netfilter Core Team + * + * 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. + */ + +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +/* Returns new sk_buff, or NULL */ +static int nf_ct_ipv4_gather_frags(struct sk_buff *skb, u_int32_t user) +{ + int err; + + skb_orphan(skb); + + local_bh_disable(); + err = ip_defrag(skb, user); + local_bh_enable(); + + if (!err) + ip_send_check(ip_hdr(skb)); + + return err; +} + +static unsigned int ipv4_conntrack_defrag(unsigned int hooknum, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) +{ +#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE) + /* Previously seen (loopback)? Ignore. Do this before + fragment check. */ + if (skb->nfct) + return NF_ACCEPT; +#endif + + /* Gather fragments. */ + if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) { + if (nf_ct_ipv4_gather_frags(skb, + hooknum == NF_INET_PRE_ROUTING ? + IP_DEFRAG_CONNTRACK_IN : + IP_DEFRAG_CONNTRACK_OUT)) + return NF_STOLEN; + } + return NF_ACCEPT; +} + +static struct nf_hook_ops ipv4_defrag_ops[] = { + { + .hook = ipv4_conntrack_defrag, + .owner = THIS_MODULE, + .pf = PF_INET, + .hooknum = NF_INET_PRE_ROUTING, + .priority = NF_IP_PRI_CONNTRACK_DEFRAG, + }, + { + .hook = ipv4_conntrack_defrag, + .owner = THIS_MODULE, + .pf = PF_INET, + .hooknum = NF_INET_LOCAL_OUT, + .priority = NF_IP_PRI_CONNTRACK_DEFRAG, + }, +}; + +static int __init nf_defrag_init(void) +{ + return nf_register_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops)); +} + +static void __exit nf_defrag_fini(void) +{ + nf_unregister_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops)); +} + +void nf_defrag_ipv4_enable(void) +{ +} +EXPORT_SYMBOL_GPL(nf_defrag_ipv4_enable); + +module_init(nf_defrag_init); +module_exit(nf_defrag_fini); + +MODULE_LICENSE("GPL");