ipv6: Move ipv6_find_hdr() out of Netfilter code.

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>

2 files changed, 103 insertions, 103 deletions

diff --git a/net/ipv6/exthdrs_core.c b/net/ipv6/exthdrs_core.c
index f73d59a14131..8ea253ad35b1 100644
--- a/net/ipv6/exthdrs_core.c
+++ b/net/ipv6/exthdrs_core.c
@@ -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);
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index d7cb04506c3d..1ce4f157ce4f 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -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);