fedora core 6 1.2949 + vserver 2.2.0
[linux-2.6.git] / net / ipv4 / netfilter / ip_nat_helper_pptp.c
index ac00489..ec957bb 100644 (file)
  *     2005-06-10 - Version 3.0
  *       - kernel >= 2.6.11 version,
  *        funded by Oxcoda NetBox Blue (http://www.netboxblue.com/)
- * 
+ *
  */
 
-#include <linux/config.h>
 #include <linux/module.h>
 #include <linux/ip.h>
 #include <linux/tcp.h>
@@ -52,6 +51,8 @@
 
 #define IP_NAT_PPTP_VERSION "3.0"
 
+#define REQ_CID(req, off)              (*(__be16 *)((char *)(req) + (off)))
+
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");
 MODULE_DESCRIPTION("Netfilter NAT helper module for PPTP");
@@ -84,25 +85,23 @@ static void pptp_nat_expected(struct ip_conntrack *ct,
                DEBUGP("we are PNS->PAC\n");
                /* therefore, build tuple for PAC->PNS */
                t.src.ip = master->tuplehash[IP_CT_DIR_REPLY].tuple.src.ip;
-               t.src.u.gre.key = htons(master->help.ct_pptp_info.pac_call_id);
+               t.src.u.gre.key = master->help.ct_pptp_info.pac_call_id;
                t.dst.ip = master->tuplehash[IP_CT_DIR_REPLY].tuple.dst.ip;
-               t.dst.u.gre.key = htons(master->help.ct_pptp_info.pns_call_id);
+               t.dst.u.gre.key = master->help.ct_pptp_info.pns_call_id;
                t.dst.protonum = IPPROTO_GRE;
        } else {
                DEBUGP("we are PAC->PNS\n");
                /* build tuple for PNS->PAC */
                t.src.ip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.ip;
-               t.src.u.gre.key = 
-                       htons(master->nat.help.nat_pptp_info.pns_call_id);
+               t.src.u.gre.key = master->nat.help.nat_pptp_info.pns_call_id;
                t.dst.ip = master->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.ip;
-               t.dst.u.gre.key = 
-                       htons(master->nat.help.nat_pptp_info.pac_call_id);
+               t.dst.u.gre.key = master->nat.help.nat_pptp_info.pac_call_id;
                t.dst.protonum = IPPROTO_GRE;
        }
 
        DEBUGP("trying to unexpect other dir: ");
        DUMP_TUPLE(&t);
-       other_exp = ip_conntrack_expect_find(&t);
+       other_exp = ip_conntrack_expect_find_get(&t);
        if (other_exp) {
                ip_conntrack_unexpect_related(other_exp);
                ip_conntrack_expect_put(other_exp);
@@ -148,57 +147,58 @@ pptp_outbound_pkt(struct sk_buff **pskb,
 {
        struct ip_ct_pptp_master *ct_pptp_info = &ct->help.ct_pptp_info;
        struct ip_nat_pptp *nat_pptp_info = &ct->nat.help.nat_pptp_info;
-       u_int16_t msg, new_callid;
+       u_int16_t msg;
+       __be16 new_callid;
        unsigned int cid_off;
 
-       new_callid = htons(ct_pptp_info->pns_call_id);
-       
+       new_callid = ct_pptp_info->pns_call_id;
+
        switch (msg = ntohs(ctlh->messageType)) {
-               case PPTP_OUT_CALL_REQUEST:
-                       cid_off = offsetof(union pptp_ctrl_union, ocreq.callID);
-                       /* FIXME: ideally we would want to reserve a call ID
-                        * here.  current netfilter NAT core is not able to do
-                        * this :( For now we use TCP source port. This breaks
-                        * multiple calls within one control session */
-
-                       /* save original call ID in nat_info */
-                       nat_pptp_info->pns_call_id = ct_pptp_info->pns_call_id;
-
-                       /* don't use tcph->source since we are at a DSTmanip
-                        * hook (e.g. PREROUTING) and pkt is not mangled yet */
-                       new_callid = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.tcp.port;
-
-                       /* save new call ID in ct info */
-                       ct_pptp_info->pns_call_id = ntohs(new_callid);
-                       break;
-               case PPTP_IN_CALL_REPLY:
-                       cid_off = offsetof(union pptp_ctrl_union, icreq.callID);
-                       break;
-               case PPTP_CALL_CLEAR_REQUEST:
-                       cid_off = offsetof(union pptp_ctrl_union, clrreq.callID);
-                       break;
-               default:
-                       DEBUGP("unknown outbound packet 0x%04x:%s\n", msg,
-                             (msg <= PPTP_MSG_MAX)? 
-                             pptp_msg_name[msg]:pptp_msg_name[0]);
-                       /* fall through */
-
-               case PPTP_SET_LINK_INFO:
-                       /* only need to NAT in case PAC is behind NAT box */
-               case PPTP_START_SESSION_REQUEST:
-               case PPTP_START_SESSION_REPLY:
-               case PPTP_STOP_SESSION_REQUEST:
-               case PPTP_STOP_SESSION_REPLY:
-               case PPTP_ECHO_REQUEST:
-               case PPTP_ECHO_REPLY:
-                       /* no need to alter packet */
-                       return NF_ACCEPT;
+       case PPTP_OUT_CALL_REQUEST:
+               cid_off = offsetof(union pptp_ctrl_union, ocreq.callID);
+               /* FIXME: ideally we would want to reserve a call ID
+                * here.  current netfilter NAT core is not able to do
+                * this :( For now we use TCP source port. This breaks
+                * multiple calls within one control session */
+
+               /* save original call ID in nat_info */
+               nat_pptp_info->pns_call_id = ct_pptp_info->pns_call_id;
+
+               /* don't use tcph->source since we are at a DSTmanip
+                * hook (e.g. PREROUTING) and pkt is not mangled yet */
+               new_callid = ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u.tcp.port;
+
+               /* save new call ID in ct info */
+               ct_pptp_info->pns_call_id = new_callid;
+               break;
+       case PPTP_IN_CALL_REPLY:
+               cid_off = offsetof(union pptp_ctrl_union, icack.callID);
+               break;
+       case PPTP_CALL_CLEAR_REQUEST:
+               cid_off = offsetof(union pptp_ctrl_union, clrreq.callID);
+               break;
+       default:
+               DEBUGP("unknown outbound packet 0x%04x:%s\n", msg,
+                     (msg <= PPTP_MSG_MAX)?
+                     pptp_msg_name[msg]:pptp_msg_name[0]);
+               /* fall through */
+
+       case PPTP_SET_LINK_INFO:
+               /* only need to NAT in case PAC is behind NAT box */
+       case PPTP_START_SESSION_REQUEST:
+       case PPTP_START_SESSION_REPLY:
+       case PPTP_STOP_SESSION_REQUEST:
+       case PPTP_STOP_SESSION_REPLY:
+       case PPTP_ECHO_REQUEST:
+       case PPTP_ECHO_REPLY:
+               /* no need to alter packet */
+               return NF_ACCEPT;
        }
 
        /* only OUT_CALL_REQUEST, IN_CALL_REPLY, CALL_CLEAR_REQUEST pass
         * down to here */
        DEBUGP("altering call id from 0x%04x to 0x%04x\n",
-               ntohs(*(u_int16_t *)pptpReq + cid_off), ntohs(new_callid));
+               ntohs(REQ_CID(pptpReq, cid_off)), ntohs(new_callid));
 
        /* mangle packet */
        if (ip_nat_mangle_tcp_packet(pskb, ct, ctinfo,
@@ -211,80 +211,28 @@ pptp_outbound_pkt(struct sk_buff **pskb,
        return NF_ACCEPT;
 }
 
-static int
+static void
 pptp_exp_gre(struct ip_conntrack_expect *expect_orig,
             struct ip_conntrack_expect *expect_reply)
 {
-       struct ip_ct_pptp_master *ct_pptp_info = 
-                               &expect_orig->master->help.ct_pptp_info;
-       struct ip_nat_pptp *nat_pptp_info = 
-                               &expect_orig->master->nat.help.nat_pptp_info;
-
        struct ip_conntrack *ct = expect_orig->master;
-
-       struct ip_conntrack_tuple inv_t;
-       struct ip_conntrack_tuple *orig_t, *reply_t;
+       struct ip_ct_pptp_master *ct_pptp_info = &ct->help.ct_pptp_info;
+       struct ip_nat_pptp *nat_pptp_info = &ct->nat.help.nat_pptp_info;
 
        /* save original PAC call ID in nat_info */
        nat_pptp_info->pac_call_id = ct_pptp_info->pac_call_id;
 
-       /* alter expectation */
-       orig_t = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
-       reply_t = &ct->tuplehash[IP_CT_DIR_REPLY].tuple;
-
        /* alter expectation for PNS->PAC direction */
-       invert_tuplepr(&inv_t, &expect_orig->tuple);
-       expect_orig->saved_proto.gre.key = htons(ct_pptp_info->pns_call_id);
-       expect_orig->tuple.src.u.gre.key = htons(nat_pptp_info->pns_call_id);
-       expect_orig->tuple.dst.u.gre.key = htons(ct_pptp_info->pac_call_id);
+       expect_orig->saved_proto.gre.key = ct_pptp_info->pns_call_id;
+       expect_orig->tuple.src.u.gre.key = nat_pptp_info->pns_call_id;
+       expect_orig->tuple.dst.u.gre.key = ct_pptp_info->pac_call_id;
        expect_orig->dir = IP_CT_DIR_ORIGINAL;
-       inv_t.src.ip = reply_t->src.ip;
-       inv_t.dst.ip = reply_t->dst.ip;
-       inv_t.src.u.gre.key = htons(nat_pptp_info->pac_call_id);
-       inv_t.dst.u.gre.key = htons(ct_pptp_info->pns_call_id);
-
-       if (!ip_conntrack_expect_related(expect_orig)) {
-               DEBUGP("successfully registered expect\n");
-       } else {
-               DEBUGP("can't expect_related(expect_orig)\n");
-               return 1;
-       }
 
        /* alter expectation for PAC->PNS direction */
-       invert_tuplepr(&inv_t, &expect_reply->tuple);
-       expect_reply->saved_proto.gre.key = htons(nat_pptp_info->pns_call_id);
-       expect_reply->tuple.src.u.gre.key = htons(nat_pptp_info->pac_call_id);
-       expect_reply->tuple.dst.u.gre.key = htons(ct_pptp_info->pns_call_id);
+       expect_reply->saved_proto.gre.key = nat_pptp_info->pns_call_id;
+       expect_reply->tuple.src.u.gre.key = nat_pptp_info->pac_call_id;
+       expect_reply->tuple.dst.u.gre.key = ct_pptp_info->pns_call_id;
        expect_reply->dir = IP_CT_DIR_REPLY;
-       inv_t.src.ip = orig_t->src.ip;
-       inv_t.dst.ip = orig_t->dst.ip;
-       inv_t.src.u.gre.key = htons(nat_pptp_info->pns_call_id);
-       inv_t.dst.u.gre.key = htons(ct_pptp_info->pac_call_id);
-
-       if (!ip_conntrack_expect_related(expect_reply)) {
-               DEBUGP("successfully registered expect\n");
-       } else {
-               DEBUGP("can't expect_related(expect_reply)\n");
-               ip_conntrack_unexpect_related(expect_orig);
-               return 1;
-       }
-
-       if (ip_ct_gre_keymap_add(ct, &expect_reply->tuple, 0) < 0) {
-               DEBUGP("can't register original keymap\n");
-               ip_conntrack_unexpect_related(expect_orig);
-               ip_conntrack_unexpect_related(expect_reply);
-               return 1;
-       }
-
-       if (ip_ct_gre_keymap_add(ct, &inv_t, 1) < 0) {
-               DEBUGP("can't register reply keymap\n");
-               ip_conntrack_unexpect_related(expect_orig);
-               ip_conntrack_unexpect_related(expect_reply);
-               ip_ct_gre_keymap_destroy(ct);
-               return 1;
-       }
-
-       return 0;
 }
 
 /* inbound packets == from PAC to PNS */
@@ -296,15 +244,15 @@ pptp_inbound_pkt(struct sk_buff **pskb,
                 union pptp_ctrl_union *pptpReq)
 {
        struct ip_nat_pptp *nat_pptp_info = &ct->nat.help.nat_pptp_info;
-       u_int16_t msg, new_cid = 0, new_pcid;
-       unsigned int pcid_off, cid_off = 0;
+       u_int16_t msg;
+       __be16 new_pcid;
+       unsigned int pcid_off;
 
-       new_pcid = htons(nat_pptp_info->pns_call_id);
+       new_pcid = nat_pptp_info->pns_call_id;
 
        switch (msg = ntohs(ctlh->messageType)) {
        case PPTP_OUT_CALL_REPLY:
                pcid_off = offsetof(union pptp_ctrl_union, ocack.peersCallID);
-               cid_off = offsetof(union pptp_ctrl_union, ocack.callID);
                break;
        case PPTP_IN_CALL_CONNECT:
                pcid_off = offsetof(union pptp_ctrl_union, iccon.peersCallID);
@@ -323,7 +271,7 @@ pptp_inbound_pkt(struct sk_buff **pskb,
                break;
 
        default:
-               DEBUGP("unknown inbound packet %s\n", (msg <= PPTP_MSG_MAX)? 
+               DEBUGP("unknown inbound packet %s\n", (msg <= PPTP_MSG_MAX)?
                        pptp_msg_name[msg]:pptp_msg_name[0]);
                /* fall through */
 
@@ -342,7 +290,7 @@ pptp_inbound_pkt(struct sk_buff **pskb,
 
        /* mangle packet */
        DEBUGP("altering peer call id from 0x%04x to 0x%04x\n",
-               ntohs(*(u_int16_t *)pptpReq + pcid_off), ntohs(new_pcid));
+               ntohs(REQ_CID(pptpReq, pcid_off)), ntohs(new_pcid));
 
        if (ip_nat_mangle_tcp_packet(pskb, ct, ctinfo,
                                     pcid_off + sizeof(struct pptp_pkt_hdr) +
@@ -350,17 +298,6 @@ pptp_inbound_pkt(struct sk_buff **pskb,
                                     sizeof(new_pcid), (char *)&new_pcid,
                                     sizeof(new_pcid)) == 0)
                return NF_DROP;
-
-       if (new_cid) {
-               DEBUGP("altering call id from 0x%04x to 0x%04x\n",
-                       ntohs(*(u_int16_t *)pptpReq + cid_off), ntohs(new_cid));
-               if (ip_nat_mangle_tcp_packet(pskb, ct, ctinfo,
-                                            cid_off + sizeof(struct pptp_pkt_hdr) +
-                                            sizeof(struct PptpControlHeader),
-                                            sizeof(new_cid), (char *)&new_cid,
-                                            sizeof(new_cid)) == 0)
-                       return NF_DROP;
-       }
        return NF_ACCEPT;
 }
 
@@ -368,7 +305,7 @@ pptp_inbound_pkt(struct sk_buff **pskb,
 extern int __init ip_nat_proto_gre_init(void);
 extern void __exit ip_nat_proto_gre_fini(void);
 
-static int __init init(void)
+static int __init ip_nat_helper_pptp_init(void)
 {
        int ret;
 
@@ -378,37 +315,36 @@ static int __init init(void)
        if (ret < 0)
                return ret;
 
-       BUG_ON(ip_nat_pptp_hook_outbound);
-       ip_nat_pptp_hook_outbound = &pptp_outbound_pkt;
+       BUG_ON(rcu_dereference(ip_nat_pptp_hook_outbound));
+       rcu_assign_pointer(ip_nat_pptp_hook_outbound, pptp_outbound_pkt);
 
-       BUG_ON(ip_nat_pptp_hook_inbound);
-       ip_nat_pptp_hook_inbound = &pptp_inbound_pkt;
+       BUG_ON(rcu_dereference(ip_nat_pptp_hook_inbound));
+       rcu_assign_pointer(ip_nat_pptp_hook_inbound, pptp_inbound_pkt);
 
-       BUG_ON(ip_nat_pptp_hook_exp_gre);
-       ip_nat_pptp_hook_exp_gre = &pptp_exp_gre;
+       BUG_ON(rcu_dereference(ip_nat_pptp_hook_exp_gre));
+       rcu_assign_pointer(ip_nat_pptp_hook_exp_gre, pptp_exp_gre);
 
-       BUG_ON(ip_nat_pptp_hook_expectfn);
-       ip_nat_pptp_hook_expectfn = &pptp_nat_expected;
+       BUG_ON(rcu_dereference(ip_nat_pptp_hook_expectfn));
+       rcu_assign_pointer(ip_nat_pptp_hook_expectfn, pptp_nat_expected);
 
        printk("ip_nat_pptp version %s loaded\n", IP_NAT_PPTP_VERSION);
        return 0;
 }
 
-static void __exit fini(void)
+static void __exit ip_nat_helper_pptp_fini(void)
 {
        DEBUGP("cleanup_module\n" );
 
-       ip_nat_pptp_hook_expectfn = NULL;
-       ip_nat_pptp_hook_exp_gre = NULL;
-       ip_nat_pptp_hook_inbound = NULL;
-       ip_nat_pptp_hook_outbound = NULL;
+       rcu_assign_pointer(ip_nat_pptp_hook_expectfn, NULL);
+       rcu_assign_pointer(ip_nat_pptp_hook_exp_gre, NULL);
+       rcu_assign_pointer(ip_nat_pptp_hook_inbound, NULL);
+       rcu_assign_pointer(ip_nat_pptp_hook_outbound, NULL);
+       synchronize_rcu();
 
        ip_nat_proto_gre_fini();
-       /* Make sure noone calls it, meanwhile */
-       synchronize_net();
 
        printk("ip_nat_pptp version %s unloaded\n", IP_NAT_PPTP_VERSION);
 }
 
-module_init(init);
-module_exit(fini);
+module_init(ip_nat_helper_pptp_init);
+module_exit(ip_nat_helper_pptp_fini);