[IPV6]: Allow to replace skbuff by TLV parser.

[deliverable/linux.git] / net / ipv6 / exthdrs.c

diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index 8d3a0e17314de11a17b7618b05a7841fcefd487c..1cdd0f0b5d34d28ed68bf32a4e2c3012c3852605 100644 (file)
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -49,6 +49,49 @@
 
 #include <asm/uaccess.h>
 
+int ipv6_find_tlv(struct sk_buff *skb, int offset, int type)
+{
+       int packet_len = skb->tail - skb->nh.raw;
+       struct ipv6_opt_hdr *hdr;
+       int len;
+
+       if (offset + 2 > packet_len)
+               goto bad;
+       hdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset);
+       len = ((hdr->hdrlen + 1) << 3);
+
+       if (offset + len > packet_len)
+               goto bad;
+
+       offset += 2;
+       len -= 2;
+
+       while (len > 0) {
+               int opttype = skb->nh.raw[offset];
+               int optlen;
+
+               if (opttype == type)
+                       return offset;
+
+               switch (opttype) {
+               case IPV6_TLV_PAD0:
+                       optlen = 1;
+                       break;
+               default:
+                       optlen = skb->nh.raw[offset + 1] + 2;
+                       if (optlen > len)
+                               goto bad;
+                       break;
+               }
+               offset += optlen;
+               len -= optlen;
+       }
+       /* not_found */
+       return -1;
+ bad:
+       return -1;
+}
+
 /*
  *     Parsing tlv encoded headers.
  *
@@ -59,7 +102,7 @@
 
 struct tlvtype_proc {
        int     type;
-       int     (*func)(struct sk_buff *skb, int offset);
+       int     (*func)(struct sk_buff **skbp, int offset);
 };
 
 /*********************
@@ -68,8 +111,10 @@ struct tlvtype_proc {
 
 /* An unknown option is detected, decide what to do */
 
-static int ip6_tlvopt_unknown(struct sk_buff *skb, int optoff)
+static int ip6_tlvopt_unknown(struct sk_buff **skbp, int optoff)
 {
+       struct sk_buff *skb = *skbp;
+
        switch ((skb->nh.raw[optoff] & 0xC0) >> 6) {
        case 0: /* ignore */
                return 1;
@@ -94,8 +139,9 @@ static int ip6_tlvopt_unknown(struct sk_buff *skb, int optoff)
 
 /* Parse tlv encoded option header (hop-by-hop or destination) */
 
-static int ip6_parse_tlv(struct tlvtype_proc *procs, struct sk_buff *skb)
+static int ip6_parse_tlv(struct tlvtype_proc *procs, struct sk_buff **skbp)
 {
+       struct sk_buff *skb = *skbp;
        struct tlvtype_proc *curr;
        int off = skb->h.raw - skb->nh.raw;
        int len = ((skb->h.raw[1]+1)<<3);
@@ -125,13 +171,13 @@ static int ip6_parse_tlv(struct tlvtype_proc *procs, struct sk_buff *skb)
                                        /* type specific length/alignment 
                                           checks will be performed in the 
                                           func(). */
-                                       if (curr->func(skb, off) == 0)
+                                       if (curr->func(skbp, off) == 0)
                                                return 0;
                                        break;
                                }
                        }
                        if (curr->type < 0) {
-                               if (ip6_tlvopt_unknown(skb, off) == 0)
+                               if (ip6_tlvopt_unknown(skbp, off) == 0)
                                        return 0;
                        }
                        break;
@@ -170,7 +216,8 @@ static int ipv6_destopt_rcv(struct sk_buff **skbp)
        opt->lastopt = skb->h.raw - skb->nh.raw;
        opt->dst1 = skb->h.raw - skb->nh.raw;
 
-       if (ip6_parse_tlv(tlvprocdestopt_lst, skb)) {
+       if (ip6_parse_tlv(tlvprocdestopt_lst, skbp)) {
+               skb = *skbp;
                skb->h.raw += ((skb->h.raw[1]+1)<<3);
                opt->nhoff = opt->dst1;
                return 1;
@@ -474,8 +521,10 @@ EXPORT_SYMBOL_GPL(ipv6_invert_rthdr);
 
 /* Router Alert as of RFC 2711 */
 
-static int ipv6_hop_ra(struct sk_buff *skb, int optoff)
+static int ipv6_hop_ra(struct sk_buff **skbp, int optoff)
 {
+       struct sk_buff *skb = *skbp;
+
        if (skb->nh.raw[optoff+1] == 2) {
                IP6CB(skb)->ra = optoff;
                return 1;
@@ -488,8 +537,9 @@ static int ipv6_hop_ra(struct sk_buff *skb, int optoff)
 
 /* Jumbo payload */
 
-static int ipv6_hop_jumbo(struct sk_buff *skb, int optoff)
+static int ipv6_hop_jumbo(struct sk_buff **skbp, int optoff)
 {
+       struct sk_buff *skb = *skbp;
        u32 pkt_len;
 
        if (skb->nh.raw[optoff+1] != 4 || (optoff&3) != 2) {
@@ -538,8 +588,9 @@ static struct tlvtype_proc tlvprochopopt_lst[] = {
        { -1, }
 };
 
-int ipv6_parse_hopopts(struct sk_buff *skb)
+int ipv6_parse_hopopts(struct sk_buff **skbp)
 {
+       struct sk_buff *skb = *skbp;
        struct inet6_skb_parm *opt = IP6CB(skb);
 
        /*
@@ -555,7 +606,8 @@ int ipv6_parse_hopopts(struct sk_buff *skb)
        }
 
        opt->hop = sizeof(struct ipv6hdr);
-       if (ip6_parse_tlv(tlvprochopopt_lst, skb)) {
+       if (ip6_parse_tlv(tlvprochopopt_lst, skbp)) {
+               skb = *skbp;
                skb->h.raw += (skb->h.raw[1]+1)<<3;
                opt->nhoff = sizeof(struct ipv6hdr);
                return 1;