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[IPV6] IPSEC: Support sending with Mobile IPv6 extension headers.
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Mobile IPv6 defines home address option as an option of destination
options header. It is placed before fragment header then
ip6_find_1stfragopt() is fixed to know about it.

Home address option also carries final source address of the flow,
then outbound AH calculation should take care of it like routing
header case.  Based on MIPL2 kernel patch.

Signed-off-by: Masahide NAKAMURA <nakam@linux-ipv6.org>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Masahide NAKAMURA authored and David S. Miller committed Sep 22, 2006
1 parent 7938323 commit 27637df
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Showing 2 changed files with 122 additions and 5 deletions.
109 changes: 109 additions & 0 deletions net/ipv6/ah6.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -74,6 +74,68 @@ static int zero_out_mutable_opts(struct ipv6_opt_hdr *opthdr)
return 0;
}

#ifdef CONFIG_IPV6_MIP6
/**
* ipv6_rearrange_destopt - rearrange IPv6 destination options header
* @iph: IPv6 header
* @destopt: destionation options header
*/
static void ipv6_rearrange_destopt(struct ipv6hdr *iph, struct ipv6_opt_hdr *destopt)
{
u8 *opt = (u8 *)destopt;
int len = ipv6_optlen(destopt);
int off = 0;
int optlen = 0;

off += 2;
len -= 2;

while (len > 0) {

switch (opt[off]) {

case IPV6_TLV_PAD0:
optlen = 1;
break;
default:
if (len < 2)
goto bad;
optlen = opt[off+1]+2;
if (len < optlen)
goto bad;

/* Rearrange the source address in @iph and the
* addresses in home address option for final source.
* See 11.3.2 of RFC 3775 for details.
*/
if (opt[off] == IPV6_TLV_HAO) {
struct in6_addr final_addr;
struct ipv6_destopt_hao *hao;

hao = (struct ipv6_destopt_hao *)&opt[off];
if (hao->length != sizeof(hao->addr)) {
if (net_ratelimit())
printk(KERN_WARNING "destopt hao: invalid header length: %u\n", hao->length);
goto bad;
}
ipv6_addr_copy(&final_addr, &hao->addr);
ipv6_addr_copy(&hao->addr, &iph->saddr);
ipv6_addr_copy(&iph->saddr, &final_addr);
}
break;
}

off += optlen;
len -= optlen;
}
if (len == 0)
return;

bad:
return;
}
#endif

/**
* ipv6_rearrange_rthdr - rearrange IPv6 routing header
* @iph: IPv6 header
Expand Down Expand Up @@ -113,7 +175,11 @@ static void ipv6_rearrange_rthdr(struct ipv6hdr *iph, struct ipv6_rt_hdr *rthdr)
ipv6_addr_copy(&iph->daddr, &final_addr);
}

#ifdef CONFIG_IPV6_MIP6
static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len, int dir)
#else
static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len)
#endif
{
union {
struct ipv6hdr *iph;
Expand All @@ -128,6 +194,28 @@ static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len)

while (exthdr.raw < end) {
switch (nexthdr) {
#ifdef CONFIG_IPV6_MIP6
case NEXTHDR_HOP:
if (!zero_out_mutable_opts(exthdr.opth)) {
LIMIT_NETDEBUG(
KERN_WARNING "overrun %sopts\n",
nexthdr == NEXTHDR_HOP ?
"hop" : "dest");
return -EINVAL;
}
break;
case NEXTHDR_DEST:
if (dir == XFRM_POLICY_OUT)
ipv6_rearrange_destopt(iph, exthdr.opth);
if (!zero_out_mutable_opts(exthdr.opth)) {
LIMIT_NETDEBUG(
KERN_WARNING "overrun %sopts\n",
nexthdr == NEXTHDR_HOP ?
"hop" : "dest");
return -EINVAL;
}
break;
#else
case NEXTHDR_HOP:
case NEXTHDR_DEST:
if (!zero_out_mutable_opts(exthdr.opth)) {
Expand All @@ -138,6 +226,7 @@ static int ipv6_clear_mutable_options(struct ipv6hdr *iph, int len)
return -EINVAL;
}
break;
#endif

case NEXTHDR_ROUTING:
ipv6_rearrange_rthdr(iph, exthdr.rth);
Expand All @@ -164,6 +253,9 @@ static int ah6_output(struct xfrm_state *x, struct sk_buff *skb)
u8 nexthdr;
char tmp_base[8];
struct {
#ifdef CONFIG_IPV6_MIP6
struct in6_addr saddr;
#endif
struct in6_addr daddr;
char hdrs[0];
} *tmp_ext;
Expand All @@ -188,10 +280,18 @@ static int ah6_output(struct xfrm_state *x, struct sk_buff *skb)
err = -ENOMEM;
goto error;
}
#ifdef CONFIG_IPV6_MIP6
memcpy(tmp_ext, &top_iph->saddr, extlen);
err = ipv6_clear_mutable_options(top_iph,
extlen - sizeof(*tmp_ext) +
sizeof(*top_iph),
XFRM_POLICY_OUT);
#else
memcpy(tmp_ext, &top_iph->daddr, extlen);
err = ipv6_clear_mutable_options(top_iph,
extlen - sizeof(*tmp_ext) +
sizeof(*top_iph));
#endif
if (err)
goto error_free_iph;
}
Expand Down Expand Up @@ -222,7 +322,11 @@ static int ah6_output(struct xfrm_state *x, struct sk_buff *skb)

memcpy(top_iph, tmp_base, sizeof(tmp_base));
if (tmp_ext) {
#ifdef CONFIG_IPV6_MIP6
memcpy(&top_iph->saddr, tmp_ext, extlen);
#else
memcpy(&top_iph->daddr, tmp_ext, extlen);
#endif
error_free_iph:
kfree(tmp_ext);
}
Expand Down Expand Up @@ -282,8 +386,13 @@ static int ah6_input(struct xfrm_state *x, struct sk_buff *skb)
if (!tmp_hdr)
goto out;
memcpy(tmp_hdr, skb->nh.raw, hdr_len);
#ifdef CONFIG_IPV6_MIP6
if (ipv6_clear_mutable_options(skb->nh.ipv6h, hdr_len, XFRM_POLICY_IN))
goto free_out;
#else
if (ipv6_clear_mutable_options(skb->nh.ipv6h, hdr_len))
goto free_out;
#endif
skb->nh.ipv6h->priority = 0;
skb->nh.ipv6h->flow_lbl[0] = 0;
skb->nh.ipv6h->flow_lbl[1] = 0;
Expand Down
18 changes: 13 additions & 5 deletions net/ipv6/ip6_output.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -475,17 +475,25 @@ int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
switch (**nexthdr) {

case NEXTHDR_HOP:
break;
case NEXTHDR_ROUTING:
found_rhdr = 1;
break;
case NEXTHDR_DEST:
if (**nexthdr == NEXTHDR_ROUTING) found_rhdr = 1;
if (**nexthdr == NEXTHDR_DEST && found_rhdr) return offset;
offset += ipv6_optlen(exthdr);
*nexthdr = &exthdr->nexthdr;
exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset);
#ifdef CONFIG_IPV6_MIP6
if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
break;
#endif
if (found_rhdr)
return offset;
break;
default :
return offset;
}

offset += ipv6_optlen(exthdr);
*nexthdr = &exthdr->nexthdr;
exthdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset);
}

return offset;
Expand Down

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