ipv6: Create init helper for fib6_nh

Similar to IPv4, consolidate the fib6_nh initialization into a helper.
As a new standalone function, add a cleanup path to put lwtstate on
error.

To avoid modifying fib6_config flags, move the reject check to a helper
that is invoked once by fib6_nh_init to reset the device and then
again in ip6_route_info_create to set the fib6_flags.

Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index 2acb78a..ce1f813 100644 (file)
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -444,6 +444,10 @@ static inline struct net_device *fib6_info_nh_dev(const struct fib6_info *f6i)
        return f6i->fib6_nh.nh_dev;
 }
 
+int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
+                struct fib6_config *cfg, gfp_t gfp_flags,
+                struct netlink_ext_ack *extack);
+
 static inline
 struct lwtunnel_state *fib6_info_nh_lwt(const struct fib6_info *f6i)
 {

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 61f231f..8c5a998 100644 (file)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2898,17 +2898,142 @@ out:
        return err;
 }
 
+static bool fib6_is_reject(u32 flags, struct net_device *dev, int addr_type)
+{
+       if ((flags & RTF_REJECT) ||
+           (dev && (dev->flags & IFF_LOOPBACK) &&
+            !(addr_type & IPV6_ADDR_LOOPBACK) &&
+            !(flags & RTF_LOCAL)))
+               return true;
+
+       return false;
+}
+
+int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
+                struct fib6_config *cfg, gfp_t gfp_flags,
+                struct netlink_ext_ack *extack)
+{
+       struct net_device *dev = NULL;
+       struct inet6_dev *idev = NULL;
+       int addr_type;
+       int err;
+
+       err = -ENODEV;
+       if (cfg->fc_ifindex) {
+               dev = dev_get_by_index(net, cfg->fc_ifindex);
+               if (!dev)
+                       goto out;
+               idev = in6_dev_get(dev);
+               if (!idev)
+                       goto out;
+       }
+
+       if (cfg->fc_flags & RTNH_F_ONLINK) {
+               if (!dev) {
+                       NL_SET_ERR_MSG(extack,
+                                      "Nexthop device required for onlink");
+                       goto out;
+               }
+
+               if (!(dev->flags & IFF_UP)) {
+                       NL_SET_ERR_MSG(extack, "Nexthop device is not up");
+                       err = -ENETDOWN;
+                       goto out;
+               }
+
+               fib6_nh->nh_flags |= RTNH_F_ONLINK;
+       }
+
+       if (cfg->fc_encap) {
+               struct lwtunnel_state *lwtstate;
+
+               err = lwtunnel_build_state(cfg->fc_encap_type,
+                                          cfg->fc_encap, AF_INET6, cfg,
+                                          &lwtstate, extack);
+               if (err)
+                       goto out;
+
+               fib6_nh->nh_lwtstate = lwtstate_get(lwtstate);
+       }
+
+       fib6_nh->nh_weight = 1;
+
+       /* We cannot add true routes via loopback here,
+        * they would result in kernel looping; promote them to reject routes
+        */
+       addr_type = ipv6_addr_type(&cfg->fc_dst);
+       if (fib6_is_reject(cfg->fc_flags, dev, addr_type)) {
+               /* hold loopback dev/idev if we haven't done so. */
+               if (dev != net->loopback_dev) {
+                       if (dev) {
+                               dev_put(dev);
+                               in6_dev_put(idev);
+                       }
+                       dev = net->loopback_dev;
+                       dev_hold(dev);
+                       idev = in6_dev_get(dev);
+                       if (!idev) {
+                               err = -ENODEV;
+                               goto out;
+                       }
+               }
+               goto set_dev;
+       }
+
+       if (cfg->fc_flags & RTF_GATEWAY) {
+               err = ip6_validate_gw(net, cfg, &dev, &idev, extack);
+               if (err)
+                       goto out;
+
+               fib6_nh->nh_gw = cfg->fc_gateway;
+       }
+
+       err = -ENODEV;
+       if (!dev)
+               goto out;
+
+       if (idev->cnf.disable_ipv6) {
+               NL_SET_ERR_MSG(extack, "IPv6 is disabled on nexthop device");
+               err = -EACCES;
+               goto out;
+       }
+
+       if (!(dev->flags & IFF_UP) && !cfg->fc_ignore_dev_down) {
+               NL_SET_ERR_MSG(extack, "Nexthop device is not up");
+               err = -ENETDOWN;
+               goto out;
+       }
+
+       if (!(cfg->fc_flags & (RTF_LOCAL | RTF_ANYCAST)) &&
+           !netif_carrier_ok(dev))
+               fib6_nh->nh_flags |= RTNH_F_LINKDOWN;
+
+set_dev:
+       fib6_nh->nh_dev = dev;
+       err = 0;
+out:
+       if (idev)
+               in6_dev_put(idev);
+
+       if (err) {
+               lwtstate_put(fib6_nh->nh_lwtstate);
+               fib6_nh->nh_lwtstate = NULL;
+               if (dev)
+                       dev_put(dev);
+       }
+
+       return err;
+}
+
 static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
                                              gfp_t gfp_flags,
                                              struct netlink_ext_ack *extack)
 {
        struct net *net = cfg->fc_nlinfo.nl_net;
        struct fib6_info *rt = NULL;
-       struct net_device *dev = NULL;
-       struct inet6_dev *idev = NULL;
        struct fib6_table *table;
-       int addr_type;
        int err = -EINVAL;
+       int addr_type;
 
        /* RTF_PCPU is an internal flag; can not be set by userspace */
        if (cfg->fc_flags & RTF_PCPU) {
@@ -2942,30 +3067,6 @@ static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
                goto out;
        }
 #endif
-       if (cfg->fc_ifindex) {
-               err = -ENODEV;
-               dev = dev_get_by_index(net, cfg->fc_ifindex);
-               if (!dev)
-                       goto out;
-               idev = in6_dev_get(dev);
-               if (!idev)
-                       goto out;
-       }
-
-       if (cfg->fc_flags & RTNH_F_ONLINK) {
-               if (!dev) {
-                       NL_SET_ERR_MSG(extack,
-                                      "Nexthop device required for onlink");
-                       err = -ENODEV;
-                       goto out;
-               }
-
-               if (!(dev->flags & IFF_UP)) {
-                       NL_SET_ERR_MSG(extack, "Nexthop device is not up");
-                       err = -ENETDOWN;
-                       goto out;
-               }
-       }
 
        err = -ENOBUFS;
        if (cfg->fc_nlinfo.nlh &&
@@ -3009,18 +3110,10 @@ static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
                cfg->fc_protocol = RTPROT_BOOT;
        rt->fib6_protocol = cfg->fc_protocol;
 
-       addr_type = ipv6_addr_type(&cfg->fc_dst);
-
-       if (cfg->fc_encap) {
-               struct lwtunnel_state *lwtstate;
-
-               err = lwtunnel_build_state(cfg->fc_encap_type,
-                                          cfg->fc_encap, AF_INET6, cfg,
-                                          &lwtstate, extack);
-               if (err)
-                       goto out;
-               rt->fib6_nh.nh_lwtstate = lwtstate_get(lwtstate);
-       }
+       rt->fib6_table = table;
+       rt->fib6_metric = cfg->fc_metric;
+       rt->fib6_type = cfg->fc_type;
+       rt->fib6_flags = cfg->fc_flags;
 
        ipv6_addr_prefix(&rt->fib6_dst.addr, &cfg->fc_dst, cfg->fc_dst_len);
        rt->fib6_dst.plen = cfg->fc_dst_len;
@@ -3031,62 +3124,20 @@ static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
        ipv6_addr_prefix(&rt->fib6_src.addr, &cfg->fc_src, cfg->fc_src_len);
        rt->fib6_src.plen = cfg->fc_src_len;
 #endif
-
-       rt->fib6_metric = cfg->fc_metric;
-       rt->fib6_nh.nh_weight = 1;
-
-       rt->fib6_type = cfg->fc_type;
+       err = fib6_nh_init(net, &rt->fib6_nh, cfg, gfp_flags, extack);
+       if (err)
+               goto out;
 
        /* We cannot add true routes via loopback here,
-          they would result in kernel looping; promote them to reject routes
+        * they would result in kernel looping; promote them to reject routes
         */
-       if ((cfg->fc_flags & RTF_REJECT) ||
-           (dev && (dev->flags & IFF_LOOPBACK) &&
-            !(addr_type & IPV6_ADDR_LOOPBACK) &&
-            !(cfg->fc_flags & RTF_LOCAL))) {
-               /* hold loopback dev/idev if we haven't done so. */
-               if (dev != net->loopback_dev) {
-                       if (dev) {
-                               dev_put(dev);
-                               in6_dev_put(idev);
-                       }
-                       dev = net->loopback_dev;
-                       dev_hold(dev);
-                       idev = in6_dev_get(dev);
-                       if (!idev) {
-                               err = -ENODEV;
-                               goto out;
-                       }
-               }
-               rt->fib6_flags = RTF_REJECT|RTF_NONEXTHOP;
-               goto install_route;
-       }
-
-       if (cfg->fc_flags & RTF_GATEWAY) {
-               err = ip6_validate_gw(net, cfg, &dev, &idev, extack);
-               if (err)
-                       goto out;
-
-               rt->fib6_nh.nh_gw = cfg->fc_gateway;
-       }
-
-       err = -ENODEV;
-       if (!dev)
-               goto out;
-
-       if (idev->cnf.disable_ipv6) {
-               NL_SET_ERR_MSG(extack, "IPv6 is disabled on nexthop device");
-               err = -EACCES;
-               goto out;
-       }
-
-       if (!(dev->flags & IFF_UP) && !cfg->fc_ignore_dev_down) {
-               NL_SET_ERR_MSG(extack, "Nexthop device is not up");
-               err = -ENETDOWN;
-               goto out;
-       }
+       addr_type = ipv6_addr_type(&cfg->fc_dst);
+       if (fib6_is_reject(cfg->fc_flags, rt->fib6_nh.nh_dev, addr_type))
+               rt->fib6_flags = RTF_REJECT | RTF_NONEXTHOP;
 
        if (!ipv6_addr_any(&cfg->fc_prefsrc)) {
+               struct net_device *dev = fib6_info_nh_dev(rt);
+
                if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) {
                        NL_SET_ERR_MSG(extack, "Invalid source address");
                        err = -EINVAL;
@@ -3097,26 +3148,8 @@ static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
        } else
                rt->fib6_prefsrc.plen = 0;
 
-       rt->fib6_flags = cfg->fc_flags;
-
-install_route:
-       if (!(rt->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) &&
-           !netif_carrier_ok(dev))
-               rt->fib6_nh.nh_flags |= RTNH_F_LINKDOWN;
-       rt->fib6_nh.nh_flags |= (cfg->fc_flags & RTNH_F_ONLINK);
-       rt->fib6_nh.nh_dev = dev;
-       rt->fib6_table = table;
-
-       if (idev)
-               in6_dev_put(idev);
-
        return rt;
 out:
-       if (dev)
-               dev_put(dev);
-       if (idev)
-               in6_dev_put(idev);
-
        fib6_info_release(rt);
        return ERR_PTR(err);
 }