Skip to contentSkip to conversation

ip6_tunnel - endianness annotations

PATCH New Al Viro 1 participant 1 message Jul 26, 2007

Subsystems (2)
Networking IPv4/IPv6
lore
Share & tools
lore

Al Viro

author
#0 lore raw

PATCH 1/1 ip6_tunnel - endianness annotations

Convert rel_info to host-endian before calling ip6_tnl_err(). The things become much more straightforward that way. The key observation (and the reason why that code actually worked) is that after ip6_tnl_err() we either immediately bailed out or had rel_info set to 0 or had it set to host-endian and guaranteed to hit
(rel_type == ICMP_DEST_UNREACH && rel_code == ICMP_FRAG_NEEDED) case. So inconsistent endianness didn't really lead to bugs, but it had been subtle and prone to breakage. New variant is saner and obviously safe.

Signed-off-by Al Viro <[email protected]>
---
 net/ipv6/ip6_tunnel.c |   17 ++++++++---------
 1 files changed, 8 insertions(+), 9 deletions(-)
net/ipv6/ip6_tunnel.c +8 -9
index df30976..ca774d8 100644
@@ -385,7 +385,7 @@ parse_tlv_tnl_enc_lim(struct sk_buff *skb, __u8 * raw)
 
 static int
 ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
-	    int *type, int *code, int *msg, __be32 *info, int offset)
+	    int *type, int *code, int *msg, __u32 *info, int offset)
 {
 	struct ipv6hdr *ipv6h = (struct ipv6hdr *) skb->data;
 	struct ip6_tnl *t;

@@ -435,7 +435,7 @@ ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
 		if ((*code) == ICMPV6_HDR_FIELD)
 			teli = parse_tlv_tnl_enc_lim(skb, skb->data);
 
-		if (teli && teli == ntohl(*info) - 2) {
+		if (teli && teli == *info - 2) {
 			tel = (struct ipv6_tlv_tnl_enc_lim *) &skb->data[teli];
 			if (tel->encap_limit == 0) {
 				if (net_ratelimit())

@@ -452,7 +452,7 @@ ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
 		}
 		break;
 	case ICMPV6_PKT_TOOBIG:
-		mtu = ntohl(*info) - offset;
+		mtu = *info - offset;
 		if (mtu < IPV6_MIN_MTU)
 			mtu = IPV6_MIN_MTU;
 		t->dev->mtu = mtu;

@@ -478,12 +478,12 @@ out:
 
 static int
 ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
-	   int type, int code, int offset, __u32 info)
+	   int type, int code, int offset, __be32 info)
 {
 	int rel_msg = 0;
 	int rel_type = type;
 	int rel_code = code;
-	__u32 rel_info = info;
+	__u32 rel_info = ntohl(info);
 	int err;
 	struct sk_buff *skb2;
 	struct iphdr *eiph;

@@ -564,10 +564,9 @@ ip4ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
 			goto out;
 
 		skb2->dst->ops->update_pmtu(skb2->dst, rel_info);
-		rel_info = htonl(rel_info);
 	}
 
-	icmp_send(skb2, rel_type, rel_code, rel_info);
+	icmp_send(skb2, rel_type, rel_code, htonl(rel_info));
 
 out:
 	kfree_skb(skb2);

@@ -576,12 +575,12 @@ out:
 
 static int
 ip6ip6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
-	   int type, int code, int offset, __u32 info)
+	   int type, int code, int offset, __be32 info)
 {
 	int rel_msg = 0;
 	int rel_type = type;
 	int rel_code = code;
-	__u32 rel_info = info;
+	__u32 rel_info = ntohl(info);
 	int err;
 
 	err = ip6_tnl_err(skb, IPPROTO_IPV6, opt, &rel_type, &rel_code,
Signature · 1 line
1.5.3.GIT