+static inline __be32 sk_extract_addr(struct sockaddr *addr)
+{
+ return ((struct sockaddr_in *) addr)->sin_addr.s_addr;
+}
+
+static int put_rtax(struct nlattr *mx, int len, int type, u32 value)
+{
+ struct nlattr *nla;
+
+ nla = (struct nlattr *) ((char *) mx + len);
+ nla->nla_type = type;
+ nla->nla_len = nla_attr_size(4);
+ *(u32 *) nla_data(nla) = value;
+
+ return len + nla_total_size(4);
+}
+
+static int rtentry_to_fib_config(int cmd, struct rtentry *rt,
+ struct fib_config *cfg)
+{
+ __be32 addr;
+ int plen;
+
+ memset(cfg, 0, sizeof(*cfg));
+
+ if (rt->rt_dst.sa_family != AF_INET)
+ return -EAFNOSUPPORT;
+
+ /*
+ * Check mask for validity:
+ * a) it must be contiguous.
+ * b) destination must have all host bits clear.
+ * c) if application forgot to set correct family (AF_INET),
+ * reject request unless it is absolutely clear i.e.
+ * both family and mask are zero.
+ */
+ plen = 32;
+ addr = sk_extract_addr(&rt->rt_dst);
+ if (!(rt->rt_flags & RTF_HOST)) {
+ __be32 mask = sk_extract_addr(&rt->rt_genmask);
+
+ if (rt->rt_genmask.sa_family != AF_INET) {
+ if (mask || rt->rt_genmask.sa_family)
+ return -EAFNOSUPPORT;
+ }
+
+ if (bad_mask(mask, addr))
+ return -EINVAL;
+
+ plen = inet_mask_len(mask);
+ }
+
+ cfg->fc_dst_len = plen;
+ cfg->fc_dst = addr;
+
+ if (cmd != SIOCDELRT) {
+ cfg->fc_nlflags = NLM_F_CREATE;
+ cfg->fc_protocol = RTPROT_BOOT;
+ }
+
+ if (rt->rt_metric)
+ cfg->fc_priority = rt->rt_metric - 1;
+
+ if (rt->rt_flags & RTF_REJECT) {
+ cfg->fc_scope = RT_SCOPE_HOST;
+ cfg->fc_type = RTN_UNREACHABLE;
+ return 0;
+ }
+
+ cfg->fc_scope = RT_SCOPE_NOWHERE;
+ cfg->fc_type = RTN_UNICAST;
+
+ if (rt->rt_dev) {
+ char *colon;
+ struct net_device *dev;
+ char devname[IFNAMSIZ];
+
+ if (copy_from_user(devname, rt->rt_dev, IFNAMSIZ-1))
+ return -EFAULT;
+
+ devname[IFNAMSIZ-1] = 0;
+ colon = strchr(devname, ':');
+ if (colon)
+ *colon = 0;
+ dev = __dev_get_by_name(devname);
+ if (!dev)
+ return -ENODEV;
+ cfg->fc_oif = dev->ifindex;
+ if (colon) {
+ struct in_ifaddr *ifa;
+ struct in_device *in_dev = __in_dev_get_rtnl(dev);
+ if (!in_dev)
+ return -ENODEV;
+ *colon = ':';
+ for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next)
+ if (strcmp(ifa->ifa_label, devname) == 0)
+ break;
+ if (ifa == NULL)
+ return -ENODEV;
+ cfg->fc_prefsrc = ifa->ifa_local;
+ }
+ }
+
+ addr = sk_extract_addr(&rt->rt_gateway);
+ if (rt->rt_gateway.sa_family == AF_INET && addr) {
+ cfg->fc_gw = addr;
+ if (rt->rt_flags & RTF_GATEWAY &&
+ inet_addr_type(addr) == RTN_UNICAST)
+ cfg->fc_scope = RT_SCOPE_UNIVERSE;
+ }
+
+ if (cmd == SIOCDELRT)
+ return 0;
+
+ if (rt->rt_flags & RTF_GATEWAY && !cfg->fc_gw)
+ return -EINVAL;
+
+ if (cfg->fc_scope == RT_SCOPE_NOWHERE)
+ cfg->fc_scope = RT_SCOPE_LINK;
+
+ if (rt->rt_flags & (RTF_MTU | RTF_WINDOW | RTF_IRTT)) {
+ struct nlattr *mx;
+ int len = 0;
+
+ mx = kzalloc(3 * nla_total_size(4), GFP_KERNEL);
+ if (mx == NULL)
+ return -ENOMEM;
+
+ if (rt->rt_flags & RTF_MTU)
+ len = put_rtax(mx, len, RTAX_ADVMSS, rt->rt_mtu - 40);
+
+ if (rt->rt_flags & RTF_WINDOW)
+ len = put_rtax(mx, len, RTAX_WINDOW, rt->rt_window);
+
+ if (rt->rt_flags & RTF_IRTT)
+ len = put_rtax(mx, len, RTAX_RTT, rt->rt_irtt << 3);
+
+ cfg->fc_mx = mx;
+ cfg->fc_mx_len = len;
+ }
+
+ return 0;
+}
+