fedora core 6 1.2949 + vserver 2.2.0

[linux-2.6.git] / net / ipv4 / netfilter / ipt_ECN.c

diff --git a/net/ipv4/netfilter/ipt_ECN.c b/net/ipv4/netfilter/ipt_ECN.c
index 341e845..b55d670 100644 (file)
--- a/net/ipv4/netfilter/ipt_ECN.c
+++ b/net/ipv4/netfilter/ipt_ECN.c
@@ -27,23 +27,17 @@ MODULE_DESCRIPTION("iptables ECN modification module");
 static inline int
 set_ect_ip(struct sk_buff **pskb, const struct ipt_ECN_info *einfo)
 {
-       if (((*pskb)->nh.iph->tos & IPT_ECN_IP_MASK)
-           != (einfo->ip_ect & IPT_ECN_IP_MASK)) {
-               u_int16_t diffs[2];
+       struct iphdr *iph = (*pskb)->nh.iph;
 
-               if (!skb_ip_make_writable(pskb, sizeof(struct iphdr)))
+       if ((iph->tos & IPT_ECN_IP_MASK) != (einfo->ip_ect & IPT_ECN_IP_MASK)) {
+               __u8 oldtos;
+               if (!skb_make_writable(pskb, sizeof(struct iphdr)))
                        return 0;
-
-               diffs[0] = htons((*pskb)->nh.iph->tos) ^ 0xFFFF;
-               (*pskb)->nh.iph->tos &= ~IPT_ECN_IP_MASK;
-               (*pskb)->nh.iph->tos |= (einfo->ip_ect & IPT_ECN_IP_MASK);
-               diffs[1] = htons((*pskb)->nh.iph->tos);
-               (*pskb)->nh.iph->check
-                       = csum_fold(csum_partial((char *)diffs,
-                                                sizeof(diffs),
-                                                (*pskb)->nh.iph->check
-                                                ^0xFFFF));
-               (*pskb)->nfcache |= NFC_ALTERED;
+               iph = (*pskb)->nh.iph;
+               oldtos = iph->tos;
+               iph->tos &= ~IPT_ECN_IP_MASK;
+               iph->tos |= (einfo->ip_ect & IPT_ECN_IP_MASK);
+               nf_csum_replace2(&iph->check, htons(oldtos), htons(iph->tos));
        } 
        return 1;
 }
@@ -52,35 +46,33 @@ set_ect_ip(struct sk_buff **pskb, const struct ipt_ECN_info *einfo)
 static inline int
 set_ect_tcp(struct sk_buff **pskb, const struct ipt_ECN_info *einfo)
 {
-       struct tcphdr tcph;
-       u_int16_t diffs[2];
+       struct tcphdr _tcph, *tcph;
+       __be16 oldval;
 
        /* Not enought header? */
-       if (skb_copy_bits(*pskb, (*pskb)->nh.iph->ihl*4, &tcph, sizeof(tcph))
-           < 0)
+       tcph = skb_header_pointer(*pskb, (*pskb)->nh.iph->ihl*4,
+                                 sizeof(_tcph), &_tcph);
+       if (!tcph)
                return 0;
 
-       diffs[0] = ((u_int16_t *)&tcph)[6];
-       if (einfo->operation & IPT_ECN_OP_SET_ECE)
-               tcph.ece = einfo->proto.tcp.ece;
+       if ((!(einfo->operation & IPT_ECN_OP_SET_ECE) ||
+            tcph->ece == einfo->proto.tcp.ece) &&
+           ((!(einfo->operation & IPT_ECN_OP_SET_CWR) ||
+            tcph->cwr == einfo->proto.tcp.cwr)))
+               return 1;
+
+       if (!skb_make_writable(pskb, (*pskb)->nh.iph->ihl*4+sizeof(*tcph)))
+               return 0;
+       tcph = (void *)(*pskb)->nh.iph + (*pskb)->nh.iph->ihl*4;
 
+       oldval = ((__be16 *)tcph)[6];
+       if (einfo->operation & IPT_ECN_OP_SET_ECE)
+               tcph->ece = einfo->proto.tcp.ece;
        if (einfo->operation & IPT_ECN_OP_SET_CWR)
-               tcph.cwr = einfo->proto.tcp.cwr;
-       diffs[1] = ((u_int16_t *)&tcph)[6];
-
-       /* Only mangle if it's changed. */
-       if (diffs[0] != diffs[1]) {
-               diffs[0] = diffs[0] ^ 0xFFFF;
-               if (!skb_ip_make_writable(pskb,
-                                         (*pskb)->nh.iph->ihl*4+sizeof(tcph)))
-                       return 0;
-               tcph.check = csum_fold(csum_partial((char *)diffs,
-                                                   sizeof(diffs),
-                                                   tcph.check^0xFFFF));
-               memcpy((*pskb)->data + (*pskb)->nh.iph->ihl*4,
-                      &tcph, sizeof(tcph));
-               (*pskb)->nfcache |= NFC_ALTERED;
-       }
+               tcph->cwr = einfo->proto.tcp.cwr;
+
+       nf_proto_csum_replace2(&tcph->check, *pskb,
+                               oldval, ((__be16 *)tcph)[6], 0);
        return 1;
 }
 
@@ -89,8 +81,8 @@ target(struct sk_buff **pskb,
        const struct net_device *in,
        const struct net_device *out,
        unsigned int hooknum,
-       const void *targinfo,
-       void *userinfo)
+       const struct xt_target *target,
+       const void *targinfo)
 {
        const struct ipt_ECN_info *einfo = targinfo;
 
@@ -108,24 +100,13 @@ target(struct sk_buff **pskb,
 
 static int
 checkentry(const char *tablename,
-          const struct ipt_entry *e,
+          const void *e_void,
+          const struct xt_target *target,
            void *targinfo,
-           unsigned int targinfosize,
            unsigned int hook_mask)
 {
        const struct ipt_ECN_info *einfo = (struct ipt_ECN_info *)targinfo;
-
-       if (targinfosize != IPT_ALIGN(sizeof(struct ipt_ECN_info))) {
-               printk(KERN_WARNING "ECN: targinfosize %u != %Zu\n",
-                      targinfosize,
-                      IPT_ALIGN(sizeof(struct ipt_ECN_info)));
-               return 0;
-       }
-
-       if (strcmp(tablename, "mangle") != 0) {
-               printk(KERN_WARNING "ECN: can only be called from \"mangle\" table, not \"%s\"\n", tablename);
-               return 0;
-       }
+       const struct ipt_entry *e = e_void;
 
        if (einfo->operation & IPT_ECN_OP_MASK) {
                printk(KERN_WARNING "ECN: unsupported ECN operation %x\n",
@@ -137,33 +118,33 @@ checkentry(const char *tablename,
                        einfo->ip_ect);
                return 0;
        }
-
        if ((einfo->operation & (IPT_ECN_OP_SET_ECE|IPT_ECN_OP_SET_CWR))
-           && e->ip.proto != IPPROTO_TCP) {
+           && (e->ip.proto != IPPROTO_TCP || (e->ip.invflags & IPT_INV_PROTO))) {
                printk(KERN_WARNING "ECN: cannot use TCP operations on a "
                       "non-tcp rule\n");
                return 0;
        }
-
        return 1;
 }
 
 static struct ipt_target ipt_ecn_reg = {
        .name           = "ECN",
        .target         = target,
+       .targetsize     = sizeof(struct ipt_ECN_info),
+       .table          = "mangle",
        .checkentry     = checkentry,
        .me             = THIS_MODULE,
 };
 
-static int __init init(void)
+static int __init ipt_ecn_init(void)
 {
        return ipt_register_target(&ipt_ecn_reg);
 }
 
-static void __exit fini(void)
+static void __exit ipt_ecn_fini(void)
 {
        ipt_unregister_target(&ipt_ecn_reg);
 }
 
-module_init(init);
-module_exit(fini);
+module_init(ipt_ecn_init);
+module_exit(ipt_ecn_fini);