* Re: [PATCH net-2.6] [NET] The world is not perfect patch.
2008-05-20 21:33 ` David Miller
@ 2008-05-21 7:33 ` Rami Rosen
2008-05-22 0:48 ` David Miller
0 siblings, 1 reply; 4+ messages in thread
From: Rami Rosen @ 2008-05-21 7:33 UTC (permalink / raw)
To: David Miller; +Cc: netdev, linux-kernel
[-- Attachment #1: Type: text/plain, Size: 868 bytes --]
Hi,
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.
Regards,
Rami Rosen
Signed-off-by: Rami Rosen <ramirose@gmail.com>
On Wed, May 21, 2008 at 12:33 AM, David Miller <davem@davemloft.net> wrote:
> From: "Rami Rosen" <ramirose@gmail.com>
> Date: Tue, 20 May 2008 12:29:26 +0300
>
>> There are three methods in the network stack which start with
>> #ifndef I_WISH_WORLD_WERE_PERFECT.
>
> I think it is better to delete this code. It is impossible
> for anyone to build test it without making source modifications,
> therefore it will continute to break over and over again over
> time.
>
[-- Attachment #2: patch.txt --]
[-- Type: text/plain, Size: 11150 bytes --]
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 2ada033..4342cba 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)
diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c
index 149111f..af5cb53 100644
--- a/net/ipv4/ipip.c
+++ b/net/ipv4/ipip.c
@@ -278,9 +278,8 @@ static void ipip_tunnel_uninit(struct net_device *dev)
static int ipip_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.
*/
@@ -337,133 +336,6 @@ static int ipip_err(struct sk_buff *skb, u32 info)
out:
read_unlock(&ipip_lock);
return err;
-#else
- struct iphdr *iph = (struct iphdr*)dp;
- int hlen = iph->ihl<<2;
- struct iphdr *eiph;
- 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;
- struct sk_buff *skb2;
- struct flowi fl;
- struct rtable *rt;
-
- if (len < hlen + sizeof(struct iphdr))
- return 0;
- eiph = (struct iphdr*)(dp + hlen);
-
- switch (type) {
- default:
- return 0;
- case ICMP_PARAMETERPROB:
- n = ntohl(icmp_hdr(skb)->un.gateway) >> 24;
- if (n < hlen)
- return 0;
-
- /* So... This guy found something strange INSIDE encapsulated
- packet. Well, he is fool, but what can we do ?
- */
- rel_type = ICMP_PARAMETERPROB;
- rel_info = htonl((n - hlen) << 24);
- break;
-
- case ICMP_DEST_UNREACH:
- switch (code) {
- case ICMP_SR_FAILED:
- case ICMP_PORT_UNREACH:
- /* Impossible event. */
- return 0;
- case ICMP_FRAG_NEEDED:
- /* And it is the only really necessary thing :-) */
- n = ntohs(icmp_hdr(skb)->un.frag.mtu);
- if (n < hlen+68)
- return 0;
- n -= hlen;
- /* BSD 4.2 MORE DOES NOT EXIST IN NATURE. */
- if (n > ntohs(eiph->tot_len))
- return 0;
- 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 0;
- break;
- }
-
- /* Prepare fake skb to feed it to icmp_send */
- skb2 = skb_clone(skb, GFP_ATOMIC);
- if (skb2 == NULL)
- return 0;
- 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_daddr = eiph->saddr;
- fl.fl4_tos = RT_TOS(eiph->tos);
- fl.proto = IPPROTO_IPIP;
- if (ip_route_output_key(dev_net(skb->dev), &rt, &key)) {
- kfree_skb(skb2);
- return 0;
- }
- skb2->dev = rt->u.dst.dev;
-
- /* route "incoming" packet */
- if (rt->rt_flags&RTCF_LOCAL) {
- ip_rt_put(rt);
- rt = NULL;
- fl.fl4_daddr = 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_TUNNEL) {
- ip_rt_put(rt);
- kfree_skb(skb2);
- return 0;
- }
- } else {
- ip_rt_put(rt);
- if (ip_route_input(skb2, eiph->daddr, eiph->saddr, eiph->tos, skb2->dev) ||
- skb2->dst->dev->type != ARPHRD_TUNNEL) {
- kfree_skb(skb2);
- return 0;
- }
- }
-
- /* change mtu on this route */
- if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
- if (n > dst_mtu(skb2->dst)) {
- kfree_skb(skb2);
- return 0;
- }
- 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);
- return 0;
-#endif
}
static inline void ipip_ecn_decapsulate(const struct iphdr *outer_iph,
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 5a6fab9..3de6ffd 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -403,9 +403,8 @@ static void ipip6_tunnel_uninit(struct net_device *dev)
static int ipip6_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.
*/
@@ -462,92 +461,6 @@ static int ipip6_err(struct sk_buff *skb, u32 info)
out:
read_unlock(&ipip6_lock);
return err;
-#else
- struct iphdr *iph = (struct iphdr*)dp;
- int hlen = iph->ihl<<2;
- struct ipv6hdr *iph6;
- const int type = icmp_hdr(skb)->type;
- const int code = icmp_hdr(skb)->code;
- int rel_type = 0;
- int rel_code = 0;
- int rel_info = 0;
- struct sk_buff *skb2;
- struct rt6_info *rt6i;
-
- if (len < hlen + sizeof(struct ipv6hdr))
- return;
- iph6 = (struct ipv6hdr*)(dp + hlen);
-
- switch (type) {
- default:
- return;
- case ICMP_PARAMETERPROB:
- if (icmp_hdr(skb)->un.gateway < hlen)
- return;
-
- /* So... This guy found something strange INSIDE encapsulated
- packet. Well, he is fool, but what can we do ?
- */
- rel_type = ICMPV6_PARAMPROB;
- rel_info = icmp_hdr(skb)->un.gateway - hlen;
- break;
-
- case ICMP_DEST_UNREACH:
- switch (code) {
- case ICMP_SR_FAILED:
- case ICMP_PORT_UNREACH:
- /* Impossible event. */
- return;
- case ICMP_FRAG_NEEDED:
- /* Too complicated case ... */
- return;
- 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 = ICMPV6_DEST_UNREACH;
- rel_code = ICMPV6_ADDR_UNREACH;
- break;
- }
- break;
- case ICMP_TIME_EXCEEDED:
- if (code != ICMP_EXC_TTL)
- return;
- rel_type = ICMPV6_TIME_EXCEED;
- rel_code = ICMPV6_EXC_HOPLIMIT;
- break;
- }
-
- /* Prepare fake skb to feed it to icmpv6_send */
- skb2 = skb_clone(skb, GFP_ATOMIC);
- if (skb2 == NULL)
- return 0;
- dst_release(skb2->dst);
- skb2->dst = NULL;
- skb_pull(skb2, skb->data - (u8*)iph6);
- skb_reset_network_header(skb2);
-
- /* Try to guess incoming interface */
- rt6i = rt6_lookup(dev_net(skb->dev), &iph6->saddr, NULL, NULL, 0);
- if (rt6i && rt6i->rt6i_dev) {
- skb2->dev = rt6i->rt6i_dev;
-
- rt6i = rt6_lookup(dev_net(skb->dev),
- &iph6->daddr, &iph6->saddr, NULL, 0);
-
- if (rt6i && rt6i->rt6i_dev && rt6i->rt6i_dev->type == ARPHRD_SIT) {
- struct ip_tunnel *t = netdev_priv(rt6i->rt6i_dev);
- if (rel_type == ICMPV6_TIME_EXCEED && t->parms.iph.ttl) {
- rel_type = ICMPV6_DEST_UNREACH;
- rel_code = ICMPV6_ADDR_UNREACH;
- }
- icmpv6_send(skb2, rel_type, rel_code, rel_info, skb2->dev);
- }
- }
- kfree_skb(skb2);
- return 0;
-#endif
}
static inline void ipip6_ecn_decapsulate(struct iphdr *iph, struct sk_buff *skb)
^ permalink raw reply related [flat|nested] 4+ messages in thread