1 #include <linux/ipv6.h>
2 #include <linux/version.h>
5 #if LINUX_VERSION_CODE < KERNEL_VERSION(3,3,0)
6 int rpl_ipv6_skip_exthdr(const struct sk_buff *skb, int start,
7 u8 *nexthdrp, __be16 *frag_offp)
9 u8 nexthdr = *nexthdrp;
13 while (ipv6_ext_hdr(nexthdr)) {
14 struct ipv6_opt_hdr _hdr, *hp;
17 if (nexthdr == NEXTHDR_NONE)
19 hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr);
22 if (nexthdr == NEXTHDR_FRAGMENT) {
23 __be16 _frag_off, *fp;
24 fp = skb_header_pointer(skb,
25 start+offsetof(struct frag_hdr,
33 if (ntohs(*frag_offp) & ~0x7)
36 } else if (nexthdr == NEXTHDR_AUTH)
37 hdrlen = (hp->hdrlen+2)<<2;
39 hdrlen = ipv6_optlen(hp);
41 nexthdr = hp->nexthdr;
48 #endif /* Kernel version < 3.3 */
51 * find the offset to specified header or the protocol number of last header
52 * if target < 0. "last header" is transport protocol header, ESP, or
55 * Note that *offset is used as input/output parameter. an if it is not zero,
56 * then it must be a valid offset to an inner IPv6 header. This can be used
57 * to explore inner IPv6 header, eg. ICMPv6 error messages.
59 * If target header is found, its offset is set in *offset and return protocol
60 * number. Otherwise, return -1.
62 * If the first fragment doesn't contain the final protocol header or
63 * NEXTHDR_NONE it is considered invalid.
65 * Note that non-1st fragment is special case that "the protocol number
66 * of last header" is "next header" field in Fragment header. In this case,
67 * *offset is meaningless and fragment offset is stored in *fragoff if fragoff
70 * if flags is not NULL and it's a fragment, then the frag flag
71 * OVS_IP6T_FH_F_FRAG will be set. If it's an AH header, the
72 * OVS_IP6T_FH_F_AUTH flag is set and target < 0, then this function will
73 * stop at the AH header. If OVS_IP6T_FH_F_SKIP_RH flag was passed, then this
74 * function will skip all those routing headers, where segements_left was 0.
76 int rpl_ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset,
77 int target, unsigned short *fragoff, int *flags)
79 unsigned int start = skb_network_offset(skb) + sizeof(struct ipv6hdr);
80 u8 nexthdr = ipv6_hdr(skb)->nexthdr;
88 struct ipv6hdr _ip6, *ip6;
90 ip6 = skb_header_pointer(skb, *offset, sizeof(_ip6), &_ip6);
91 if (!ip6 || (ip6->version != 6)) {
92 printk(KERN_ERR "IPv6 header not found\n");
95 start = *offset + sizeof(struct ipv6hdr);
96 nexthdr = ip6->nexthdr;
98 len = skb->len - start;
101 struct ipv6_opt_hdr _hdr, *hp;
103 found = (nexthdr == target);
105 if ((!ipv6_ext_hdr(nexthdr)) || nexthdr == NEXTHDR_NONE) {
111 hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr);
115 if (nexthdr == NEXTHDR_ROUTING) {
116 struct ipv6_rt_hdr _rh, *rh;
118 rh = skb_header_pointer(skb, start, sizeof(_rh),
123 if (flags && (*flags & OVS_IP6T_FH_F_SKIP_RH) &&
124 rh->segments_left == 0)
128 if (nexthdr == NEXTHDR_FRAGMENT) {
129 unsigned short _frag_off;
132 if (flags) /* Indicate that this is a fragment */
133 *flags |= OVS_IP6T_FH_F_FRAG;
134 fp = skb_header_pointer(skb,
135 start+offsetof(struct frag_hdr,
142 _frag_off = ntohs(*fp) & ~0x7;
145 ((!ipv6_ext_hdr(hp->nexthdr)) ||
146 hp->nexthdr == NEXTHDR_NONE)) {
148 *fragoff = _frag_off;
154 } else if (nexthdr == NEXTHDR_AUTH) {
155 if (flags && (*flags & OVS_IP6T_FH_F_AUTH) &&
158 hdrlen = (hp->hdrlen + 2) << 2;
160 hdrlen = ipv6_optlen(hp);
163 nexthdr = hp->nexthdr;