Commit 704eae1f authored by Al Viro's avatar Al Viro Committed by Linus Torvalds
Browse files

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: default avatarAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent a34c4589

net/ipv6/ip6_tunnel.c

+8 −9
Original line number Diff line number Diff line
@@ -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,

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