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ipv6: Move ipv6_find_hdr() out of Netfilter code.

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Open vSwitch will soon also use ipv6_find_hdr() so this moves it
out of Netfilter-specific code into a more common location.

Signed-off-by: Jesse Gross <jesse@nicira.com>
This commit is contained in:
Jesse Gross
2012-11-09 17:05:07 -08:00
parent c061853381
commit f8f626754e
5 changed files with 116 additions and 116 deletions
Download Patch File Download Diff File Expand all files Collapse all files

103
net/ipv6/exthdrs_core.c
View File

@@ -111,3 +111,106 @@ int ipv6_skip_exthdr(const struct sk_buff *skb, int start, u8 *nexthdrp,
return start;
}
EXPORT_SYMBOL(ipv6_skip_exthdr);
/*
* find the offset to specified header or the protocol number of last header
* if target < 0. "last header" is transport protocol header, ESP, or
* "No next header".
*
* Note that *offset is used as input/output parameter. an if it is not zero,
* then it must be a valid offset to an inner IPv6 header. This can be used
* to explore inner IPv6 header, eg. ICMPv6 error messages.
*
* If target header is found, its offset is set in *offset and return protocol
* number. Otherwise, return -1.
*
* If the first fragment doesn't contain the final protocol header or
* NEXTHDR_NONE it is considered invalid.
*
* Note that non-1st fragment is special case that "the protocol number
* of last header" is "next header" field in Fragment header. In this case,
* *offset is meaningless and fragment offset is stored in *fragoff if fragoff
* isn't NULL.
*
* if flags is not NULL and it's a fragment, then the frag flag IP6_FH_F_FRAG
* will be set. If it's an AH header, the IP6_FH_F_AUTH flag is set and
* target < 0, then this function will stop at the AH header.
*/
int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
int target, unsigned short *fragoff, int *flags)
{
unsigned int start = skb_network_offset(skb) + sizeof(struct ipv6hdr);
u8 nexthdr = ipv6_hdr(skb)->nexthdr;
unsigned int len;
if (fragoff)
*fragoff = 0;
if (*offset) {
struct ipv6hdr _ip6, *ip6;
ip6 = skb_header_pointer(skb, *offset, sizeof(_ip6), &_ip6);
if (!ip6 || (ip6->version != 6)) {
printk(KERN_ERR "IPv6 header not found\n");
return -EBADMSG;
}
start = *offset + sizeof(struct ipv6hdr);
nexthdr = ip6->nexthdr;
}
len = skb->len - start;
while (nexthdr != target) {
struct ipv6_opt_hdr _hdr, *hp;
unsigned int hdrlen;
if ((!ipv6_ext_hdr(nexthdr)) || nexthdr == NEXTHDR_NONE) {
if (target < 0)
break;
return -ENOENT;
}
hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr);
if (hp == NULL)
return -EBADMSG;
if (nexthdr == NEXTHDR_FRAGMENT) {
unsigned short _frag_off;
__be16 *fp;
if (flags) /* Indicate that this is a fragment */
*flags |= IP6_FH_F_FRAG;
fp = skb_header_pointer(skb,
start+offsetof(struct frag_hdr,
frag_off),
sizeof(_frag_off),
&_frag_off);
if (fp == NULL)
return -EBADMSG;
_frag_off = ntohs(*fp) & ~0x7;
if (_frag_off) {
if (target < 0 &&
((!ipv6_ext_hdr(hp->nexthdr)) ||
hp->nexthdr == NEXTHDR_NONE)) {
if (fragoff)
*fragoff = _frag_off;
return hp->nexthdr;
}
return -ENOENT;
}
hdrlen = 8;
} else if (nexthdr == NEXTHDR_AUTH) {
if (flags && (*flags & IP6_FH_F_AUTH) && (target < 0))
break;
hdrlen = (hp->hdrlen + 2) << 2;
} else
hdrlen = ipv6_optlen(hp);
nexthdr = hp->nexthdr;
len -= hdrlen;
start += hdrlen;
}
*offset = start;
return nexthdr;
}
EXPORT_SYMBOL(ipv6_find_hdr);

103
net/ipv6/netfilter/ip6_tables.c
View File

@@ -2273,112 +2273,9 @@ static void __exit ip6_tables_fini(void)
unregister_pernet_subsys(&ip6_tables_net_ops);
}
/*
* find the offset to specified header or the protocol number of last header
* if target < 0. "last header" is transport protocol header, ESP, or
* "No next header".
*
* Note that *offset is used as input/output parameter. an if it is not zero,
* then it must be a valid offset to an inner IPv6 header. This can be used
* to explore inner IPv6 header, eg. ICMPv6 error messages.
*
* If target header is found, its offset is set in *offset and return protocol
* number. Otherwise, return -1.
*
* If the first fragment doesn't contain the final protocol header or
* NEXTHDR_NONE it is considered invalid.
*
* Note that non-1st fragment is special case that "the protocol number
* of last header" is "next header" field in Fragment header. In this case,
* *offset is meaningless and fragment offset is stored in *fragoff if fragoff
* isn't NULL.
*
* if flags is not NULL and it's a fragment, then the frag flag IP6T_FH_F_FRAG
* will be set. If it's an AH header, the IP6T_FH_F_AUTH flag is set and
* target < 0, then this function will stop at the AH header.
*/
int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
int target, unsigned short *fragoff, int *flags)
{
unsigned int start = skb_network_offset(skb) + sizeof(struct ipv6hdr);
u8 nexthdr = ipv6_hdr(skb)->nexthdr;
unsigned int len;
if (fragoff)
*fragoff = 0;
if (*offset) {
struct ipv6hdr _ip6, *ip6;
ip6 = skb_header_pointer(skb, *offset, sizeof(_ip6), &_ip6);
if (!ip6 || (ip6->version != 6)) {
printk(KERN_ERR "IPv6 header not found\n");
return -EBADMSG;
}
start = *offset + sizeof(struct ipv6hdr);
nexthdr = ip6->nexthdr;
}
len = skb->len - start;
while (nexthdr != target) {
struct ipv6_opt_hdr _hdr, *hp;
unsigned int hdrlen;
if ((!ipv6_ext_hdr(nexthdr)) || nexthdr == NEXTHDR_NONE) {
if (target < 0)
break;
return -ENOENT;
}
hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr);
if (hp == NULL)
return -EBADMSG;
if (nexthdr == NEXTHDR_FRAGMENT) {
unsigned short _frag_off;
__be16 *fp;
if (flags) /* Indicate that this is a fragment */
*flags |= IP6T_FH_F_FRAG;
fp = skb_header_pointer(skb,
start+offsetof(struct frag_hdr,
frag_off),
sizeof(_frag_off),
&_frag_off);
if (fp == NULL)
return -EBADMSG;
_frag_off = ntohs(*fp) & ~0x7;
if (_frag_off) {
if (target < 0 &&
((!ipv6_ext_hdr(hp->nexthdr)) ||
hp->nexthdr == NEXTHDR_NONE)) {
if (fragoff)
*fragoff = _frag_off;
return hp->nexthdr;
}
return -ENOENT;
}
hdrlen = 8;
} else if (nexthdr == NEXTHDR_AUTH) {
if (flags && (*flags & IP6T_FH_F_AUTH) && (target < 0))
break;
hdrlen = (hp->hdrlen + 2) << 2;
} else
hdrlen = ipv6_optlen(hp);
nexthdr = hp->nexthdr;
len -= hdrlen;
start += hdrlen;
}
*offset = start;
return nexthdr;
}
EXPORT_SYMBOL(ip6t_register_table);
EXPORT_SYMBOL(ip6t_unregister_table);
EXPORT_SYMBOL(ip6t_do_table);
EXPORT_SYMBOL(ipv6_find_hdr);
module_init(ip6_tables_init);
module_exit(ip6_tables_fini);