Commit 7029b960 authored by James Morris's avatar James Morris

[IPV6]: Link some packet walker helpers always statically.

Put the extension header helper funcs always statically into
the kernel even if ipv6 is built as a module, this is needed
for things like SELinux.
parent 37264b31
......@@ -16,7 +16,9 @@ obj-$(CONFIG_LLC) += llc/
obj-$(CONFIG_NET) += ethernet/ 802/ sched/ netlink/
obj-$(CONFIG_INET) += ipv4/ xfrm/
obj-$(CONFIG_UNIX) += unix/
obj-$(CONFIG_IPV6) += ipv6/
ifneq ($(CONFIG_IPV6),)
obj-y += ipv6/
endif
obj-$(CONFIG_PACKET) += packet/
obj-$(CONFIG_NET_KEY) += key/
obj-$(CONFIG_NET_SCHED) += sched/
......
......@@ -19,3 +19,5 @@ obj-$(CONFIG_INET6_IPCOMP) += ipcomp6.o
obj-$(CONFIG_NETFILTER) += netfilter/
obj-$(CONFIG_IPV6_TUNNEL) += ip6_tunnel.o
obj-y += exthdrs_core.o
......@@ -633,105 +633,3 @@ ipv6_dup_options(struct sock *sk, struct ipv6_txoptions *opt)
}
return opt2;
}
/*
* find out if nexthdr is a well-known extension header or a protocol
*/
int ipv6_ext_hdr(u8 nexthdr)
{
/*
* find out if nexthdr is an extension header or a protocol
*/
return ( (nexthdr == NEXTHDR_HOP) ||
(nexthdr == NEXTHDR_ROUTING) ||
(nexthdr == NEXTHDR_FRAGMENT) ||
(nexthdr == NEXTHDR_AUTH) ||
(nexthdr == NEXTHDR_NONE) ||
(nexthdr == NEXTHDR_DEST) );
}
/*
* Skip any extension headers. This is used by the ICMP module.
*
* Note that strictly speaking this conflicts with RFC 2460 4.0:
* ...The contents and semantics of each extension header determine whether
* or not to proceed to the next header. Therefore, extension headers must
* be processed strictly in the order they appear in the packet; a
* receiver must not, for example, scan through a packet looking for a
* particular kind of extension header and process that header prior to
* processing all preceding ones.
*
* We do exactly this. This is a protocol bug. We can't decide after a
* seeing an unknown discard-with-error flavour TLV option if it's a
* ICMP error message or not (errors should never be send in reply to
* ICMP error messages).
*
* But I see no other way to do this. This might need to be reexamined
* when Linux implements ESP (and maybe AUTH) headers.
* --AK
*
* This function parses (probably truncated) exthdr set "hdr"
* of length "len". "nexthdrp" initially points to some place,
* where type of the first header can be found.
*
* It skips all well-known exthdrs, and returns pointer to the start
* of unparsable area i.e. the first header with unknown type.
* If it is not NULL *nexthdr is updated by type/protocol of this header.
*
* NOTES: - if packet terminated with NEXTHDR_NONE it returns NULL.
* - it may return pointer pointing beyond end of packet,
* if the last recognized header is truncated in the middle.
* - if packet is truncated, so that all parsed headers are skipped,
* it returns NULL.
* - First fragment header is skipped, not-first ones
* are considered as unparsable.
* - ESP is unparsable for now and considered like
* normal payload protocol.
* - Note also special handling of AUTH header. Thanks to IPsec wizards.
*
* --ANK (980726)
*/
int ipv6_skip_exthdr(const struct sk_buff *skb, int start, u8 *nexthdrp, int len)
{
u8 nexthdr = *nexthdrp;
while (ipv6_ext_hdr(nexthdr)) {
struct ipv6_opt_hdr hdr;
int hdrlen;
if (len < (int)sizeof(struct ipv6_opt_hdr))
return -1;
if (nexthdr == NEXTHDR_NONE)
return -1;
if (skb_copy_bits(skb, start, &hdr, sizeof(hdr)))
BUG();
if (nexthdr == NEXTHDR_FRAGMENT) {
unsigned short frag_off;
if (skb_copy_bits(skb,
start+offsetof(struct frag_hdr,
frag_off),
&frag_off,
sizeof(frag_off))) {
return -1;
}
if (ntohs(frag_off) & ~0x7)
break;
hdrlen = 8;
} else if (nexthdr == NEXTHDR_AUTH)
hdrlen = (hdr.hdrlen+2)<<2;
else
hdrlen = ipv6_optlen(&hdr);
nexthdr = hdr.nexthdr;
len -= hdrlen;
start += hdrlen;
}
*nexthdrp = nexthdr;
return start;
}
/*
* IPv6 library code, needed by static components when full IPv6 support is
* not configured or static.
*/
#include <net/ipv6.h>
/*
* find out if nexthdr is a well-known extension header or a protocol
*/
int ipv6_ext_hdr(u8 nexthdr)
{
/*
* find out if nexthdr is an extension header or a protocol
*/
return ( (nexthdr == NEXTHDR_HOP) ||
(nexthdr == NEXTHDR_ROUTING) ||
(nexthdr == NEXTHDR_FRAGMENT) ||
(nexthdr == NEXTHDR_AUTH) ||
(nexthdr == NEXTHDR_NONE) ||
(nexthdr == NEXTHDR_DEST) );
}
/*
* Skip any extension headers. This is used by the ICMP module.
*
* Note that strictly speaking this conflicts with RFC 2460 4.0:
* ...The contents and semantics of each extension header determine whether
* or not to proceed to the next header. Therefore, extension headers must
* be processed strictly in the order they appear in the packet; a
* receiver must not, for example, scan through a packet looking for a
* particular kind of extension header and process that header prior to
* processing all preceding ones.
*
* We do exactly this. This is a protocol bug. We can't decide after a
* seeing an unknown discard-with-error flavour TLV option if it's a
* ICMP error message or not (errors should never be send in reply to
* ICMP error messages).
*
* But I see no other way to do this. This might need to be reexamined
* when Linux implements ESP (and maybe AUTH) headers.
* --AK
*
* This function parses (probably truncated) exthdr set "hdr"
* of length "len". "nexthdrp" initially points to some place,
* where type of the first header can be found.
*
* It skips all well-known exthdrs, and returns pointer to the start
* of unparsable area i.e. the first header with unknown type.
* If it is not NULL *nexthdr is updated by type/protocol of this header.
*
* NOTES: - if packet terminated with NEXTHDR_NONE it returns NULL.
* - it may return pointer pointing beyond end of packet,
* if the last recognized header is truncated in the middle.
* - if packet is truncated, so that all parsed headers are skipped,
* it returns NULL.
* - First fragment header is skipped, not-first ones
* are considered as unparsable.
* - ESP is unparsable for now and considered like
* normal payload protocol.
* - Note also special handling of AUTH header. Thanks to IPsec wizards.
*
* --ANK (980726)
*/
int ipv6_skip_exthdr(const struct sk_buff *skb, int start, u8 *nexthdrp, int len)
{
u8 nexthdr = *nexthdrp;
while (ipv6_ext_hdr(nexthdr)) {
struct ipv6_opt_hdr hdr;
int hdrlen;
if (len < (int)sizeof(struct ipv6_opt_hdr))
return -1;
if (nexthdr == NEXTHDR_NONE)
return -1;
if (skb_copy_bits(skb, start, &hdr, sizeof(hdr)))
BUG();
if (nexthdr == NEXTHDR_FRAGMENT) {
unsigned short frag_off;
if (skb_copy_bits(skb,
start+offsetof(struct frag_hdr,
frag_off),
&frag_off,
sizeof(frag_off))) {
return -1;
}
if (ntohs(frag_off) & ~0x7)
break;
hdrlen = 8;
} else if (nexthdr == NEXTHDR_AUTH)
hdrlen = (hdr.hdrlen+2)<<2;
else
hdrlen = ipv6_optlen(&hdr);
nexthdr = hdr.nexthdr;
len -= hdrlen;
start += hdrlen;
}
*nexthdrp = nexthdr;
return start;
}
EXPORT_SYMBOL(ipv6_ext_hdr);
EXPORT_SYMBOL(ipv6_skip_exthdr);
......@@ -41,9 +41,7 @@ EXPORT_SYMBOL(xfrm6_rcv);
#endif
EXPORT_SYMBOL(rt6_lookup);
EXPORT_SYMBOL(fl6_sock_lookup);
EXPORT_SYMBOL(ipv6_ext_hdr);
EXPORT_SYMBOL(ip6_append_data);
EXPORT_SYMBOL(ip6_flush_pending_frames);
EXPORT_SYMBOL(ip6_push_pending_frames);
EXPORT_SYMBOL(ipv6_push_nfrag_opts);
EXPORT_SYMBOL(ipv6_skip_exthdr);
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