diff options
Diffstat (limited to 'net')
-rw-r--r-- | net/netfilter/Kconfig | 10 | ||||
-rw-r--r-- | net/netfilter/Makefile | 1 | ||||
-rw-r--r-- | net/netfilter/nf_conntrack_proto_udplite.c | 266 |
3 files changed, 277 insertions, 0 deletions
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig index 9415b9a5dba6..3ac39f1ec775 100644 --- a/net/netfilter/Kconfig +++ b/net/netfilter/Kconfig @@ -102,6 +102,16 @@ config NF_CT_PROTO_SCTP If you want to compile it as a module, say M here and read <file:Documentation/kbuild/modules.txt>. If unsure, say `N'. +config NF_CT_PROTO_UDPLITE + tristate 'UDP-Lite protocol connection tracking support (EXPERIMENTAL)' + depends on EXPERIMENTAL && NF_CONNTRACK + help + With this option enabled, the layer 3 independent connection + tracking code will be able to do state tracking on UDP-Lite + connections. + + To compile it as a module, choose M here. If unsure, say N. + config NF_CONNTRACK_AMANDA tristate "Amanda backup protocol support" depends on NF_CONNTRACK diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile index 3e4a16aeb04e..0c054bf27973 100644 --- a/net/netfilter/Makefile +++ b/net/netfilter/Makefile @@ -16,6 +16,7 @@ obj-$(CONFIG_NF_CONNTRACK) += nf_conntrack.o # SCTP protocol connection tracking obj-$(CONFIG_NF_CT_PROTO_GRE) += nf_conntrack_proto_gre.o obj-$(CONFIG_NF_CT_PROTO_SCTP) += nf_conntrack_proto_sctp.o +obj-$(CONFIG_NF_CT_PROTO_UDPLITE) += nf_conntrack_proto_udplite.o # netlink interface for nf_conntrack obj-$(CONFIG_NF_CT_NETLINK) += nf_conntrack_netlink.o diff --git a/net/netfilter/nf_conntrack_proto_udplite.c b/net/netfilter/nf_conntrack_proto_udplite.c new file mode 100644 index 000000000000..93e747b5396e --- /dev/null +++ b/net/netfilter/nf_conntrack_proto_udplite.c @@ -0,0 +1,266 @@ +/* (C) 1999-2001 Paul `Rusty' Russell + * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> + * (C) 2007 Patrick McHardy <kaber@trash.net> + * + * 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 <linux/types.h> +#include <linux/timer.h> +#include <linux/module.h> +#include <linux/netfilter.h> +#include <linux/udp.h> +#include <linux/seq_file.h> +#include <linux/skbuff.h> +#include <linux/ipv6.h> +#include <net/ip6_checksum.h> +#include <net/checksum.h> + +#include <linux/netfilter.h> +#include <linux/netfilter_ipv4.h> +#include <linux/netfilter_ipv6.h> +#include <net/netfilter/nf_conntrack_l4proto.h> +#include <net/netfilter/nf_conntrack_ecache.h> + +static unsigned int nf_ct_udplite_timeout __read_mostly = 30*HZ; +static unsigned int nf_ct_udplite_timeout_stream __read_mostly = 180*HZ; + +static int udplite_pkt_to_tuple(const struct sk_buff *skb, + unsigned int dataoff, + struct nf_conntrack_tuple *tuple) +{ + struct udphdr _hdr, *hp; + + hp = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr); + if (hp == NULL) + return 0; + + tuple->src.u.udp.port = hp->source; + tuple->dst.u.udp.port = hp->dest; + return 1; +} + +static int udplite_invert_tuple(struct nf_conntrack_tuple *tuple, + const struct nf_conntrack_tuple *orig) +{ + tuple->src.u.udp.port = orig->dst.u.udp.port; + tuple->dst.u.udp.port = orig->src.u.udp.port; + return 1; +} + +/* Print out the per-protocol part of the tuple. */ +static int udplite_print_tuple(struct seq_file *s, + const struct nf_conntrack_tuple *tuple) +{ + return seq_printf(s, "sport=%hu dport=%hu ", + ntohs(tuple->src.u.udp.port), + ntohs(tuple->dst.u.udp.port)); +} + +/* Print out the private part of the conntrack. */ +static int udplite_print_conntrack(struct seq_file *s, + const struct nf_conn *conntrack) +{ + return 0; +} + +/* Returns verdict for packet, and may modify conntracktype */ +static int udplite_packet(struct nf_conn *conntrack, + const struct sk_buff *skb, + unsigned int dataoff, + enum ip_conntrack_info ctinfo, + int pf, + unsigned int hooknum) +{ + /* If we've seen traffic both ways, this is some kind of UDP + stream. Extend timeout. */ + if (test_bit(IPS_SEEN_REPLY_BIT, &conntrack->status)) { + nf_ct_refresh_acct(conntrack, ctinfo, skb, + nf_ct_udplite_timeout_stream); + /* Also, more likely to be important, and not a probe */ + if (!test_and_set_bit(IPS_ASSURED_BIT, &conntrack->status)) + nf_conntrack_event_cache(IPCT_STATUS, skb); + } else + nf_ct_refresh_acct(conntrack, ctinfo, skb, + nf_ct_udplite_timeout); + + return NF_ACCEPT; +} + +/* Called when a new connection for this protocol found. */ +static int udplite_new(struct nf_conn *conntrack, const struct sk_buff *skb, + unsigned int dataoff) +{ + return 1; +} + +static int udplite_error(struct sk_buff *skb, unsigned int dataoff, + enum ip_conntrack_info *ctinfo, + int pf, + unsigned int hooknum) +{ + unsigned int udplen = skb->len - dataoff; + struct udphdr _hdr, *hdr; + unsigned int cscov; + + /* Header is too small? */ + hdr = skb_header_pointer(skb, dataoff, sizeof(_hdr), &_hdr); + if (hdr == NULL) { + if (LOG_INVALID(IPPROTO_UDPLITE)) + nf_log_packet(pf, 0, skb, NULL, NULL, NULL, + "nf_ct_udplite: short packet "); + return -NF_ACCEPT; + } + + cscov = ntohs(hdr->len); + if (cscov == 0) + cscov = udplen; + else if (cscov < sizeof(*hdr) || cscov > udplen) { + if (LOG_INVALID(IPPROTO_UDPLITE)) + nf_log_packet(pf, 0, skb, NULL, NULL, NULL, + "nf_ct_udplite: invalid checksum coverage "); + return -NF_ACCEPT; + } + + /* UDPLITE mandates checksums */ + if (!hdr->check) { + if (LOG_INVALID(IPPROTO_UDPLITE)) + nf_log_packet(pf, 0, skb, NULL, NULL, NULL, + "nf_ct_udplite: checksum missing "); + return -NF_ACCEPT; + } + + /* Checksum invalid? Ignore. */ + if (nf_conntrack_checksum && !skb_csum_unnecessary(skb) && + ((pf == PF_INET && hooknum == NF_IP_PRE_ROUTING) || + (pf == PF_INET6 && hooknum == NF_IP6_PRE_ROUTING))) { + if (pf == PF_INET) { + struct iphdr *iph = ip_hdr(skb); + + skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, + udplen, IPPROTO_UDPLITE, 0); + } else { + struct ipv6hdr *ipv6h = ipv6_hdr(skb); + __wsum hsum = skb_checksum(skb, 0, dataoff, 0); + + skb->csum = ~csum_unfold( + csum_ipv6_magic(&ipv6h->saddr, &ipv6h->daddr, + udplen, IPPROTO_UDPLITE, + csum_sub(0, hsum))); + } + + skb->ip_summed = CHECKSUM_NONE; + if (__skb_checksum_complete_head(skb, dataoff + cscov)) { + if (LOG_INVALID(IPPROTO_UDPLITE)) + nf_log_packet(pf, 0, skb, NULL, NULL, NULL, + "nf_ct_udplite: bad UDPLite " + "checksum "); + return -NF_ACCEPT; + } + skb->ip_summed = CHECKSUM_UNNECESSARY; + } + + return NF_ACCEPT; +} + +#ifdef CONFIG_SYSCTL +static unsigned int udplite_sysctl_table_users; +static struct ctl_table_header *udplite_sysctl_header; +static struct ctl_table udplite_sysctl_table[] = { + { + .ctl_name = CTL_UNNUMBERED, + .procname = "nf_conntrack_udplite_timeout", + .data = &nf_ct_udplite_timeout, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = &proc_dointvec_jiffies, + }, + { + .ctl_name = CTL_UNNUMBERED, + .procname = "nf_conntrack_udplite_timeout_stream", + .data = &nf_ct_udplite_timeout_stream, + .maxlen = sizeof(unsigned int), + .mode = 0644, + .proc_handler = &proc_dointvec_jiffies, + }, + { + .ctl_name = 0 + } +}; +#endif /* CONFIG_SYSCTL */ + +static struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite4 __read_mostly = +{ + .l3proto = PF_INET, + .l4proto = IPPROTO_UDPLITE, + .name = "udplite", + .pkt_to_tuple = udplite_pkt_to_tuple, + .invert_tuple = udplite_invert_tuple, + .print_tuple = udplite_print_tuple, + .print_conntrack = udplite_print_conntrack, + .packet = udplite_packet, + .new = udplite_new, + .error = udplite_error, +#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) + .tuple_to_nfattr = nf_ct_port_tuple_to_nfattr, + .nfattr_to_tuple = nf_ct_port_nfattr_to_tuple, +#endif +#ifdef CONFIG_SYSCTL + .ctl_table_users = &udplite_sysctl_table_users, + .ctl_table_header = &udplite_sysctl_header, + .ctl_table = udplite_sysctl_table, +#endif +}; + +static struct nf_conntrack_l4proto nf_conntrack_l4proto_udplite6 __read_mostly = +{ + .l3proto = PF_INET6, + .l4proto = IPPROTO_UDPLITE, + .name = "udplite", + .pkt_to_tuple = udplite_pkt_to_tuple, + .invert_tuple = udplite_invert_tuple, + .print_tuple = udplite_print_tuple, + .print_conntrack = udplite_print_conntrack, + .packet = udplite_packet, + .new = udplite_new, + .error = udplite_error, +#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) + .tuple_to_nfattr = nf_ct_port_tuple_to_nfattr, + .nfattr_to_tuple = nf_ct_port_nfattr_to_tuple, +#endif +#ifdef CONFIG_SYSCTL + .ctl_table_users = &udplite_sysctl_table_users, + .ctl_table_header = &udplite_sysctl_header, + .ctl_table = udplite_sysctl_table, +#endif +}; + +static int __init nf_conntrack_proto_udplite_init(void) +{ + int err; + + err = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udplite4); + if (err < 0) + goto err1; + err = nf_conntrack_l4proto_register(&nf_conntrack_l4proto_udplite6); + if (err < 0) + goto err2; + return 0; +err2: + nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite4); +err1: + return err; +} + +static void __exit nf_conntrack_proto_udplite_exit(void) +{ + nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite6); + nf_conntrack_l4proto_unregister(&nf_conntrack_l4proto_udplite4); +} + +module_init(nf_conntrack_proto_udplite_init); +module_exit(nf_conntrack_proto_udplite_exit); + +MODULE_LICENSE("GPL"); |