[PATCH] IPv6: Fix tunnel encapsulation limit in ip6_tunnel.c

[Ville Nuorvala <vnuorval@xxxxxxxxxx>]

Hi,

I reread RFC 2473 and noticed the tunnel encapsulation limit handling was
off by one. This patch fixes the bug. Please apply!

Thanks,
Ville

--- linux-2.5.OLD/net/ipv6/ip6_tunnel.c 2003-08-18 10:04:23.000000000 +0300
+++ linux-2.5/net/ipv6/ip6_tunnel.c     2003-08-15 18:45:36.000000000 +0300
@@ -423,7 +423,7 @@

                if (teli && teli == info - 2) {
                        tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
-                       if (tel->encap_limit <= 1) {
+                       if (tel->encap_limit == 0) {
                                if (net_ratelimit())
                                        printk(KERN_WARNING
                                               "%s: Too small encapsulation "
@@ -669,7 +669,7 @@
        struct ipv6hdr *ipv6h = skb->nh.ipv6h;
        struct ipv6_txoptions *orig_opt = NULL;
        struct ipv6_txoptions *opt = NULL;
-       __u8 encap_limit = 0;
+       int encap_limit = -1;
        __u16 offset;
        struct flowi fl;
        struct ip6_flowlabel *fl_lbl = NULL;
@@ -692,7 +692,7 @@
        if ((offset = parse_tlv_tnl_enc_lim(skb, skb->nh.raw)) > 0) {
                struct ipv6_tlv_tnl_enc_lim *tel;
                tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->nh.raw[offset];
-               if (tel->encap_limit <= 1) {
+               if (tel->encap_limit == 0) {
                        icmpv6_send(skb, ICMPV6_PARAMPROB,
                                    ICMPV6_HDR_FIELD, offset + 2, skb->dev);
                        goto tx_err;
@@ -715,7 +715,7 @@
                if (fl_lbl)
                        orig_opt = fl_lbl->opt;
        }
-       if (encap_limit > 0) {
+       if (encap_limit >= 0) {
                if (!(opt = merge_options(sk, encap_limit, orig_opt))) {
                        goto tx_err_free_fl_lbl;
                }


--
Ville Nuorvala
Research Assistant, Institute of Digital Communications,
Helsinki University of Technology
email: vnuorval@xxxxxxxxxx, phone: +358 (0)9 451 5257