+static void ndisc_ra_useropt(struct sk_buff *ra, struct nd_opt_hdr *opt)
+{
+ struct icmp6hdr *icmp6h = (struct icmp6hdr *)skb_transport_header(ra);
+ struct sk_buff *skb;
+ struct nlmsghdr *nlh;
+ struct nduseroptmsg *ndmsg;
+ struct net *net = dev_net(ra->dev);
+ int err;
+ int base_size = NLMSG_ALIGN(sizeof(struct nduseroptmsg)
+ + (opt->nd_opt_len << 3));
+ size_t msg_size = base_size + nla_total_size(sizeof(struct in6_addr));
+
+ skb = nlmsg_new(msg_size, GFP_ATOMIC);
+ if (skb == NULL) {
+ err = -ENOBUFS;
+ goto errout;
+ }
+
+ nlh = nlmsg_put(skb, 0, 0, RTM_NEWNDUSEROPT, base_size, 0);
+ if (nlh == NULL) {
+ goto nla_put_failure;
+ }
+
+ ndmsg = nlmsg_data(nlh);
+ ndmsg->nduseropt_family = AF_INET6;
+ ndmsg->nduseropt_ifindex = ra->dev->ifindex;
+ ndmsg->nduseropt_icmp_type = icmp6h->icmp6_type;
+ ndmsg->nduseropt_icmp_code = icmp6h->icmp6_code;
+ ndmsg->nduseropt_opts_len = opt->nd_opt_len << 3;
+
+ memcpy(ndmsg + 1, opt, opt->nd_opt_len << 3);
+
+ NLA_PUT(skb, NDUSEROPT_SRCADDR, sizeof(struct in6_addr),
+ &ipv6_hdr(ra)->saddr);
+ nlmsg_end(skb, nlh);
+
+ err = rtnl_notify(skb, net, 0, RTNLGRP_ND_USEROPT, NULL,
+ GFP_ATOMIC);
+ if (err < 0)
+ goto errout;
+
+ return;
+
+nla_put_failure:
+ nlmsg_free(skb);
+ err = -EMSGSIZE;
+errout:
+ rtnl_set_sk_err(net, RTNLGRP_ND_USEROPT, err);
+}
+