net: The world is not perfect patch.

  Unless there will be any objection here, I suggest consider the
following patch which simply removes the code for the
-DI_WISH_WORLD_WERE_PERFECT in the three methods which use it.

The compilation errors we get when using -DI_WISH_WORLD_WERE_PERFECT
show that this code was not built and not used for really a long time.

Signed-off-by: Rami Rosen <ramirose@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 145 deletions

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 2ada033406de..4342cba4ff82 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -313,9 +313,8 @@ static void ipgre_tunnel_uninit(struct net_device *dev)
 
 static void ipgre_err(struct sk_buff *skb, u32 info)
 {
-#ifndef I_WISH_WORLD_WERE_PERFECT
 
-/* It is not :-( All the routers (except for Linux) return only
+/* All the routers (except for Linux) return only
    8 bytes of packet payload. It means, that precise relaying of
    ICMP in the real Internet is absolutely infeasible.
 
@@ -398,149 +397,6 @@ static void ipgre_err(struct sk_buff *skb, u32 info)
 out:
         read_unlock(&ipgre_lock);
         return;
-#else
-        struct iphdr *iph = (struct iphdr*)dp;
-        struct iphdr *eiph;
-        __be16       *p = (__be16*)(dp+(iph->ihl<<2));
-        const int type = icmp_hdr(skb)->type;
-        const int code = icmp_hdr(skb)->code;
-        int rel_type = 0;
-        int rel_code = 0;
-        __be32 rel_info = 0;
-        __u32 n = 0;
-        __be16 flags;
-        int grehlen = (iph->ihl<<2) + 4;
-        struct sk_buff *skb2;
-        struct flowi fl;
-        struct rtable *rt;
-
-        if (p[1] != htons(ETH_P_IP))
-                return;
-
-        flags = p[0];
-        if (flags&(GRE_CSUM|GRE_KEY|GRE_SEQ|GRE_ROUTING|GRE_VERSION)) {
-                if (flags&(GRE_VERSION|GRE_ROUTING))
-                        return;
-                if (flags&GRE_CSUM)
-                        grehlen += 4;
-                if (flags&GRE_KEY)
-                        grehlen += 4;
-                if (flags&GRE_SEQ)
-                        grehlen += 4;
-        }
-        if (len < grehlen + sizeof(struct iphdr))
-                return;
-        eiph = (struct iphdr*)(dp + grehlen);
-
-        switch (type) {
-        default:
-                return;
-        case ICMP_PARAMETERPROB:
-                n = ntohl(icmp_hdr(skb)->un.gateway) >> 24;
-                if (n < (iph->ihl<<2))
-                        return;
-
-                /* So... This guy found something strange INSIDE encapsulated
-                   packet. Well, he is fool, but what can we do ?
-                 */
-                rel_type = ICMP_PARAMETERPROB;
-                n -= grehlen;
-                rel_info = htonl(n << 24);
-                break;
-
-        case ICMP_DEST_UNREACH:
-                switch (code) {
-                case ICMP_SR_FAILED:
-                case ICMP_PORT_UNREACH:
-                        /* Impossible event. */
-                        return;
-                case ICMP_FRAG_NEEDED:
-                        /* And it is the only really necessary thing :-) */
-                        n = ntohs(icmp_hdr(skb)->un.frag.mtu);
-                        if (n < grehlen+68)
-                                return;
-                        n -= grehlen;
-                        /* BSD 4.2 MORE DOES NOT EXIST IN NATURE. */
-                        if (n > ntohs(eiph->tot_len))
-                                return;
-                        rel_info = htonl(n);
-                        break;
-                default:
-                        /* All others are translated to HOST_UNREACH.
-                           rfc2003 contains "deep thoughts" about NET_UNREACH,
-                           I believe, it is just ether pollution. --ANK
-                         */
-                        rel_type = ICMP_DEST_UNREACH;
-                        rel_code = ICMP_HOST_UNREACH;
-                        break;
-                }
-                break;
-        case ICMP_TIME_EXCEEDED:
-                if (code != ICMP_EXC_TTL)
-                        return;
-                break;
-        }
-
-        /* Prepare fake skb to feed it to icmp_send */
-        skb2 = skb_clone(skb, GFP_ATOMIC);
-        if (skb2 == NULL)
-                return;
-        dst_release(skb2->dst);
-        skb2->dst = NULL;
-        skb_pull(skb2, skb->data - (u8*)eiph);
-        skb_reset_network_header(skb2);
-
-        /* Try to guess incoming interface */
-        memset(&fl, 0, sizeof(fl));
-        fl.fl4_dst = eiph->saddr;
-        fl.fl4_tos = RT_TOS(eiph->tos);
-        fl.proto = IPPROTO_GRE;
-        if (ip_route_output_key(dev_net(skb->dev), &rt, &fl)) {
-                kfree_skb(skb2);
-                return;
-        }
-        skb2->dev = rt->u.dst.dev;
-
-        /* route "incoming" packet */
-        if (rt->rt_flags&RTCF_LOCAL) {
-                ip_rt_put(rt);
-                rt = NULL;
-                fl.fl4_dst = eiph->daddr;
-                fl.fl4_src = eiph->saddr;
-                fl.fl4_tos = eiph->tos;
-                if (ip_route_output_key(dev_net(skb->dev), &rt, &fl) ||
-                    rt->u.dst.dev->type != ARPHRD_IPGRE) {
-                        ip_rt_put(rt);
-                        kfree_skb(skb2);
-                        return;
-                }
-        } else {
-                ip_rt_put(rt);
-                if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos, skb2->dev) ||
-                    skb2->dst->dev->type != ARPHRD_IPGRE) {
-                        kfree_skb(skb2);
-                        return;
-                }
-        }
-
-        /* change mtu on this route */
-        if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
-                if (n > dst_mtu(skb2->dst)) {
-                        kfree_skb(skb2);
-                        return;
-                }
-                skb2->dst->ops->update_pmtu(skb2->dst, n);
-        } else if (type == ICMP_TIME_EXCEEDED) {
-                struct ip_tunnel *t = netdev_priv(skb2->dev);
-                if (t->parms.iph.ttl) {
-                        rel_type = ICMP_DEST_UNREACH;
-                        rel_code = ICMP_HOST_UNREACH;
-                }
-        }
-
-        icmp_send(skb2, rel_type, rel_code, rel_info);
-        kfree_skb(skb2);
-#endif
 }
 
 static inline void ipgre_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb)