diff options
Diffstat (limited to 'net/ipv4/netfilter/ip_conntrack_proto_gre.c')
| -rw-r--r-- | net/ipv4/netfilter/ip_conntrack_proto_gre.c | 328 |
1 files changed, 0 insertions, 328 deletions
diff --git a/net/ipv4/netfilter/ip_conntrack_proto_gre.c b/net/ipv4/netfilter/ip_conntrack_proto_gre.c deleted file mode 100644 index ac1c49ef36a..00000000000 --- a/net/ipv4/netfilter/ip_conntrack_proto_gre.c +++ /dev/null @@ -1,328 +0,0 @@ -/* - * ip_conntrack_proto_gre.c - Version 3.0 - * - * Connection tracking protocol helper module for GRE. - * - * GRE is a generic encapsulation protocol, which is generally not very - * suited for NAT, as it has no protocol-specific part as port numbers. - * - * It has an optional key field, which may help us distinguishing two - * connections between the same two hosts. - * - * GRE is defined in RFC 1701 and RFC 1702, as well as RFC 2784 - * - * PPTP is built on top of a modified version of GRE, and has a mandatory - * field called "CallID", which serves us for the same purpose as the key - * field in plain GRE. - * - * Documentation about PPTP can be found in RFC 2637 - * - * (C) 2000-2005 by Harald Welte <laforge@gnumonks.org> - * - * Development of this code funded by Astaro AG (http://www.astaro.com/) - * - */ - -#include <linux/module.h> -#include <linux/types.h> -#include <linux/timer.h> -#include <linux/netfilter.h> -#include <linux/ip.h> -#include <linux/in.h> -#include <linux/list.h> -#include <linux/seq_file.h> -#include <linux/interrupt.h> - -static DEFINE_RWLOCK(ip_ct_gre_lock); - -#include <linux/netfilter_ipv4/ip_conntrack_protocol.h> -#include <linux/netfilter_ipv4/ip_conntrack_helper.h> -#include <linux/netfilter_ipv4/ip_conntrack_core.h> - -#include <linux/netfilter_ipv4/ip_conntrack_proto_gre.h> -#include <linux/netfilter_ipv4/ip_conntrack_pptp.h> - -MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>"); -MODULE_DESCRIPTION("netfilter connection tracking protocol helper for GRE"); - -/* shamelessly stolen from ip_conntrack_proto_udp.c */ -#define GRE_TIMEOUT (30*HZ) -#define GRE_STREAM_TIMEOUT (180*HZ) - -#if 0 -#define DEBUGP(format, args...) printk(KERN_DEBUG "%s:%s: " format, __FILE__, __FUNCTION__, ## args) -#define DUMP_TUPLE_GRE(x) printk("%u.%u.%u.%u:0x%x -> %u.%u.%u.%u:0x%x\n", \ - NIPQUAD((x)->src.ip), ntohs((x)->src.u.gre.key), \ - NIPQUAD((x)->dst.ip), ntohs((x)->dst.u.gre.key)) -#else -#define DEBUGP(x, args...) -#define DUMP_TUPLE_GRE(x) -#endif - -/* GRE KEYMAP HANDLING FUNCTIONS */ -static LIST_HEAD(gre_keymap_list); - -static inline int gre_key_cmpfn(const struct ip_ct_gre_keymap *km, - const struct ip_conntrack_tuple *t) -{ - return ((km->tuple.src.ip == t->src.ip) && - (km->tuple.dst.ip == t->dst.ip) && - (km->tuple.dst.protonum == t->dst.protonum) && - (km->tuple.dst.u.all == t->dst.u.all)); -} - -/* look up the source key for a given tuple */ -static __be16 gre_keymap_lookup(struct ip_conntrack_tuple *t) -{ - struct ip_ct_gre_keymap *km; - __be16 key = 0; - - read_lock_bh(&ip_ct_gre_lock); - list_for_each_entry(km, &gre_keymap_list, list) { - if (gre_key_cmpfn(km, t)) { - key = km->tuple.src.u.gre.key; - break; - } - } - read_unlock_bh(&ip_ct_gre_lock); - - DEBUGP("lookup src key 0x%x up key for ", key); - DUMP_TUPLE_GRE(t); - - return key; -} - -/* add a single keymap entry, associate with specified master ct */ -int -ip_ct_gre_keymap_add(struct ip_conntrack *ct, - struct ip_conntrack_tuple *t, int reply) -{ - struct ip_ct_gre_keymap **exist_km, *km; - - if (!ct->helper || strcmp(ct->helper->name, "pptp")) { - DEBUGP("refusing to add GRE keymap to non-pptp session\n"); - return -1; - } - - if (!reply) - exist_km = &ct->help.ct_pptp_info.keymap_orig; - else - exist_km = &ct->help.ct_pptp_info.keymap_reply; - - if (*exist_km) { - /* check whether it's a retransmission */ - list_for_each_entry(km, &gre_keymap_list, list) { - if (gre_key_cmpfn(km, t) && km == *exist_km) - return 0; - } - DEBUGP("trying to override keymap_%s for ct %p\n", - reply? "reply":"orig", ct); - return -EEXIST; - } - - km = kmalloc(sizeof(*km), GFP_ATOMIC); - if (!km) - return -ENOMEM; - - memcpy(&km->tuple, t, sizeof(*t)); - *exist_km = km; - - DEBUGP("adding new entry %p: ", km); - DUMP_TUPLE_GRE(&km->tuple); - - write_lock_bh(&ip_ct_gre_lock); - list_add_tail(&km->list, &gre_keymap_list); - write_unlock_bh(&ip_ct_gre_lock); - - return 0; -} - -/* destroy the keymap entries associated with specified master ct */ -void ip_ct_gre_keymap_destroy(struct ip_conntrack *ct) -{ - DEBUGP("entering for ct %p\n", ct); - - if (!ct->helper || strcmp(ct->helper->name, "pptp")) { - DEBUGP("refusing to destroy GRE keymap to non-pptp session\n"); - return; - } - - write_lock_bh(&ip_ct_gre_lock); - if (ct->help.ct_pptp_info.keymap_orig) { - DEBUGP("removing %p from list\n", - ct->help.ct_pptp_info.keymap_orig); - list_del(&ct->help.ct_pptp_info.keymap_orig->list); - kfree(ct->help.ct_pptp_info.keymap_orig); - ct->help.ct_pptp_info.keymap_orig = NULL; - } - if (ct->help.ct_pptp_info.keymap_reply) { - DEBUGP("removing %p from list\n", - ct->help.ct_pptp_info.keymap_reply); - list_del(&ct->help.ct_pptp_info.keymap_reply->list); - kfree(ct->help.ct_pptp_info.keymap_reply); - ct->help.ct_pptp_info.keymap_reply = NULL; - } - write_unlock_bh(&ip_ct_gre_lock); -} - - -/* PUBLIC CONNTRACK PROTO HELPER FUNCTIONS */ - -/* invert gre part of tuple */ -static int gre_invert_tuple(struct ip_conntrack_tuple *tuple, - const struct ip_conntrack_tuple *orig) -{ - tuple->dst.u.gre.key = orig->src.u.gre.key; - tuple->src.u.gre.key = orig->dst.u.gre.key; - - return 1; -} - -/* gre hdr info to tuple */ -static int gre_pkt_to_tuple(const struct sk_buff *skb, - unsigned int dataoff, - struct ip_conntrack_tuple *tuple) -{ - struct gre_hdr_pptp _pgrehdr, *pgrehdr; - __be16 srckey; - struct gre_hdr _grehdr, *grehdr; - - /* first only delinearize old RFC1701 GRE header */ - grehdr = skb_header_pointer(skb, dataoff, sizeof(_grehdr), &_grehdr); - if (!grehdr || grehdr->version != GRE_VERSION_PPTP) { - /* try to behave like "ip_conntrack_proto_generic" */ - tuple->src.u.all = 0; - tuple->dst.u.all = 0; - return 1; - } - - /* PPTP header is variable length, only need up to the call_id field */ - pgrehdr = skb_header_pointer(skb, dataoff, 8, &_pgrehdr); - if (!pgrehdr) - return 1; - - if (ntohs(grehdr->protocol) != GRE_PROTOCOL_PPTP) { - DEBUGP("GRE_VERSION_PPTP but unknown proto\n"); - return 0; - } - - tuple->dst.u.gre.key = pgrehdr->call_id; - srckey = gre_keymap_lookup(tuple); - tuple->src.u.gre.key = srckey; - - return 1; -} - -/* print gre part of tuple */ -static int gre_print_tuple(struct seq_file *s, - const struct ip_conntrack_tuple *tuple) -{ - return seq_printf(s, "srckey=0x%x dstkey=0x%x ", - ntohs(tuple->src.u.gre.key), - ntohs(tuple->dst.u.gre.key)); -} - -/* print private data for conntrack */ -static int gre_print_conntrack(struct seq_file *s, - const struct ip_conntrack *ct) -{ - return seq_printf(s, "timeout=%u, stream_timeout=%u ", - (ct->proto.gre.timeout / HZ), - (ct->proto.gre.stream_timeout / HZ)); -} - -/* Returns verdict for packet, and may modify conntrack */ -static int gre_packet(struct ip_conntrack *ct, - const struct sk_buff *skb, - enum ip_conntrack_info conntrackinfo) -{ - /* If we've seen traffic both ways, this is a GRE connection. - * Extend timeout. */ - if (ct->status & IPS_SEEN_REPLY) { - ip_ct_refresh_acct(ct, conntrackinfo, skb, - ct->proto.gre.stream_timeout); - /* Also, more likely to be important, and not a probe. */ - set_bit(IPS_ASSURED_BIT, &ct->status); - ip_conntrack_event_cache(IPCT_STATUS, skb); - } else - ip_ct_refresh_acct(ct, conntrackinfo, skb, - ct->proto.gre.timeout); - - return NF_ACCEPT; -} - -/* Called when a new connection for this protocol found. */ -static int gre_new(struct ip_conntrack *ct, - const struct sk_buff *skb) -{ - DEBUGP(": "); - DUMP_TUPLE_GRE(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple); - - /* initialize to sane value. Ideally a conntrack helper - * (e.g. in case of pptp) is increasing them */ - ct->proto.gre.stream_timeout = GRE_STREAM_TIMEOUT; - ct->proto.gre.timeout = GRE_TIMEOUT; - - return 1; -} - -/* Called when a conntrack entry has already been removed from the hashes - * and is about to be deleted from memory */ -static void gre_destroy(struct ip_conntrack *ct) -{ - struct ip_conntrack *master = ct->master; - DEBUGP(" entering\n"); - - if (!master) - DEBUGP("no master !?!\n"); - else - ip_ct_gre_keymap_destroy(master); -} - -/* protocol helper struct */ -static struct ip_conntrack_protocol gre = { - .proto = IPPROTO_GRE, - .name = "gre", - .pkt_to_tuple = gre_pkt_to_tuple, - .invert_tuple = gre_invert_tuple, - .print_tuple = gre_print_tuple, - .print_conntrack = gre_print_conntrack, - .packet = gre_packet, - .new = gre_new, - .destroy = gre_destroy, - .me = THIS_MODULE, -#if defined(CONFIG_IP_NF_CONNTRACK_NETLINK) || \ - defined(CONFIG_IP_NF_CONNTRACK_NETLINK_MODULE) - .tuple_to_nfattr = ip_ct_port_tuple_to_nfattr, - .nfattr_to_tuple = ip_ct_port_nfattr_to_tuple, -#endif -}; - -/* ip_conntrack_proto_gre initialization */ -int __init ip_ct_proto_gre_init(void) -{ - return ip_conntrack_protocol_register(&gre); -} - -/* This cannot be __exit, as it is invoked from ip_conntrack_helper_pptp.c's - * init() code on errors. - */ -void ip_ct_proto_gre_fini(void) -{ - struct list_head *pos, *n; - - /* delete all keymap entries */ - write_lock_bh(&ip_ct_gre_lock); - list_for_each_safe(pos, n, &gre_keymap_list) { - DEBUGP("deleting keymap %p at module unload time\n", pos); - list_del(pos); - kfree(pos); - } - write_unlock_bh(&ip_ct_gre_lock); - - ip_conntrack_protocol_unregister(&gre); -} - -EXPORT_SYMBOL(ip_ct_gre_keymap_add); -EXPORT_SYMBOL(ip_ct_gre_keymap_destroy); |