- /* Received rthdr:
-
- [ H1 -> H2 -> ... H_prev ] daddr=ME
-
- Inverted result:
- [ H_prev -> ... -> H1 ] daddr =sender
-
- Note, that IP output engine will rewrite this rthdr
- by rotating it left by one addr.
- */
-
- int n, i;
- struct rt0_hdr *rthdr = (struct rt0_hdr*)hdr;
- struct rt0_hdr *irthdr;
- struct ipv6_txoptions *opt;
- int hdrlen = ipv6_optlen(hdr);
-
- if (hdr->segments_left ||
- hdr->type != IPV6_SRCRT_TYPE_0 ||
- hdr->hdrlen & 0x01)
- return NULL;
-
- n = hdr->hdrlen >> 1;
- opt = sock_kmalloc(sk, sizeof(*opt) + hdrlen, GFP_ATOMIC);
- if (opt == NULL)
- return NULL;
- memset(opt, 0, sizeof(*opt));
- opt->tot_len = sizeof(*opt) + hdrlen;
- opt->srcrt = (void*)(opt+1);
- opt->opt_nflen = hdrlen;
-
- memcpy(opt->srcrt, hdr, sizeof(*hdr));
- irthdr = (struct rt0_hdr*)opt->srcrt;
- irthdr->reserved = 0;
- opt->srcrt->segments_left = n;
- for (i=0; i<n; i++)
- memcpy(irthdr->addr+i, rthdr->addr+(n-1-i), 16);
- return opt;