net/ipv6: Add gfp_flags to route add functions

Most FIB entries can be added using memory allocated with GFP_KERNEL.
Add gfp_flags to ip6_route_add and addrconf_dst_alloc. Code paths that
can be reached from the packet path (e.g., ndisc and autoconfig) or
atomic notifiers use GFP_ATOMIC; paths from user context (adding
addresses and routes) use GFP_KERNEL.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 38 insertions, 27 deletions

diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index cb6fb7e..ff70266 100644
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -100,7 +100,8 @@ void ip6_route_cleanup(void);
 
 int ipv6_route_ioctl(struct net *net, unsigned int cmd, void __user *arg);
 
-int ip6_route_add(struct fib6_config *cfg, struct netlink_ext_ack *extack);
+int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,
+		  struct netlink_ext_ack *extack);
 int ip6_ins_rt(struct net *net, struct rt6_info *rt);
 int ip6_del_rt(struct net *net, struct rt6_info *rt);
 
@@ -138,7 +139,8 @@ struct dst_entry *icmp6_dst_alloc(struct net_device *dev, struct flowi6 *fl6);
 void fib6_force_start_gc(struct net *net);
 
 struct rt6_info *addrconf_dst_alloc(struct net *net, struct inet6_dev *idev,
-				    const struct in6_addr *addr, bool anycast);
+				    const struct in6_addr *addr, bool anycast,
+				    gfp_t gfp_flags);
 
 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
 			       int flags);
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index c8df5c64..915cd07 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -1037,7 +1037,7 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr,
 		goto out;
 	}
 
-	rt = addrconf_dst_alloc(net, idev, addr, false);
+	rt = addrconf_dst_alloc(net, idev, addr, false, gfp_flags);
 	if (IS_ERR(rt)) {
 		err = PTR_ERR(rt);
 		rt = NULL;
@@ -2320,7 +2320,7 @@ static void  ipv6_try_regen_rndid(struct inet6_dev *idev, struct in6_addr *tmpad
 
 static void
 addrconf_prefix_route(struct in6_addr *pfx, int plen, struct net_device *dev,
-		      unsigned long expires, u32 flags)
+		      unsigned long expires, u32 flags, gfp_t gfp_flags)
 {
 	struct fib6_config cfg = {
 		.fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_PREFIX,
@@ -2345,7 +2345,7 @@ addrconf_prefix_route(struct in6_addr *pfx, int plen, struct net_device *dev,
 		cfg.fc_flags |= RTF_NONEXTHOP;
 #endif
 
-	ip6_route_add(&cfg, NULL);
+	ip6_route_add(&cfg, gfp_flags, NULL);
 }
 
 
@@ -2401,7 +2401,7 @@ static void addrconf_add_mroute(struct net_device *dev)
 
 	ipv6_addr_set(&cfg.fc_dst, htonl(0xFF000000), 0, 0, 0);
 
-	ip6_route_add(&cfg, NULL);
+	ip6_route_add(&cfg, GFP_ATOMIC, NULL);
 }
 
 static struct inet6_dev *addrconf_add_dev(struct net_device *dev)
@@ -2685,7 +2685,7 @@ void addrconf_prefix_rcv(struct net_device *dev, u8 *opt, int len, bool sllao)
 				expires = jiffies_to_clock_t(rt_expires);
 			}
 			addrconf_prefix_route(&pinfo->prefix, pinfo->prefix_len,
-					      dev, expires, flags);
+					      dev, expires, flags, GFP_ATOMIC);
 		}
 		ip6_rt_put(rt);
 	}
@@ -2900,7 +2900,7 @@ static int inet6_addr_add(struct net *net, int ifindex,
 	if (!IS_ERR(ifp)) {
 		if (!(ifa_flags & IFA_F_NOPREFIXROUTE)) {
 			addrconf_prefix_route(&ifp->addr, ifp->prefix_len, dev,
-					      expires, flags);
+					      expires, flags, GFP_KERNEL);
 		}
 
 		/* Send a netlink notification if DAD is enabled and
@@ -3053,7 +3053,8 @@ static void sit_add_v4_addrs(struct inet6_dev *idev)
 
 	if (addr.s6_addr32[3]) {
 		add_addr(idev, &addr, plen, scope);
-		addrconf_prefix_route(&addr, plen, idev->dev, 0, pflags);
+		addrconf_prefix_route(&addr, plen, idev->dev, 0, pflags,
+				      GFP_ATOMIC);
 		return;
 	}
 
@@ -3078,7 +3079,7 @@ static void sit_add_v4_addrs(struct inet6_dev *idev)
 
 				add_addr(idev, &addr, plen, flag);
 				addrconf_prefix_route(&addr, plen, idev->dev, 0,
-						      pflags);
+						      pflags, GFP_ATOMIC);
 			}
 		}
 	}
@@ -3118,7 +3119,8 @@ void addrconf_add_linklocal(struct inet6_dev *idev,
 	ifp = ipv6_add_addr(idev, addr, NULL, 64, IFA_LINK, addr_flags,
 			    INFINITY_LIFE_TIME, INFINITY_LIFE_TIME, true, NULL);
 	if (!IS_ERR(ifp)) {
-		addrconf_prefix_route(&ifp->addr, ifp->prefix_len, idev->dev, 0, 0);
+		addrconf_prefix_route(&ifp->addr, ifp->prefix_len, idev->dev,
+				      0, 0, GFP_ATOMIC);
 		addrconf_dad_start(ifp);
 		in6_ifa_put(ifp);
 	}
@@ -3233,7 +3235,8 @@ static void addrconf_addr_gen(struct inet6_dev *idev, bool prefix_route)
 			addrconf_add_linklocal(idev, &addr,
 					       IFA_F_STABLE_PRIVACY);
 		else if (prefix_route)
-			addrconf_prefix_route(&addr, 64, idev->dev, 0, 0);
+			addrconf_prefix_route(&addr, 64, idev->dev,
+					      0, 0, GFP_KERNEL);
 		break;
 	case IN6_ADDR_GEN_MODE_EUI64:
 		/* addrconf_add_linklocal also adds a prefix_route and we
@@ -3243,7 +3246,8 @@ static void addrconf_addr_gen(struct inet6_dev *idev, bool prefix_route)
 		if (ipv6_generate_eui64(addr.s6_addr + 8, idev->dev) == 0)
 			addrconf_add_linklocal(idev, &addr, 0);
 		else if (prefix_route)
-			addrconf_prefix_route(&addr, 64, idev->dev, 0, 0);
+			addrconf_prefix_route(&addr, 64, idev->dev,
+					      0, 0, GFP_ATOMIC);
 		break;
 	case IN6_ADDR_GEN_MODE_NONE:
 	default:
@@ -3346,7 +3350,8 @@ static int fixup_permanent_addr(struct net *net,
 	if (!ifp->rt || !ifp->rt->rt6i_node) {
 		struct rt6_info *rt, *prev;
 
-		rt = addrconf_dst_alloc(net, idev, &ifp->addr, false);
+		rt = addrconf_dst_alloc(net, idev, &ifp->addr, false,
+					GFP_ATOMIC);
 		if (IS_ERR(rt))
 			return PTR_ERR(rt);
 
@@ -3361,7 +3366,7 @@ static int fixup_permanent_addr(struct net *net,
 
 	if (!(ifp->flags & IFA_F_NOPREFIXROUTE)) {
 		addrconf_prefix_route(&ifp->addr, ifp->prefix_len,
-				      idev->dev, 0, 0);
+				      idev->dev, 0, 0, GFP_ATOMIC);
 	}
 
 	if (ifp->state == INET6_IFADDR_STATE_PREDAD)
@@ -4572,8 +4577,9 @@ static int inet6_addr_modify(struct inet6_ifaddr *ifp, u32 ifa_flags,
 		ipv6_ifa_notify(0, ifp);
 
 	if (!(ifa_flags & IFA_F_NOPREFIXROUTE)) {
-		addrconf_prefix_route(&ifp->addr, ifp->prefix_len, ifp->idev->dev,
-				      expires, flags);
+		addrconf_prefix_route(&ifp->addr, ifp->prefix_len,
+				      ifp->idev->dev, expires, flags,
+				      GFP_KERNEL);
 	} else if (had_prefixroute) {
 		enum cleanup_prefix_rt_t action;
 		unsigned long rt_expires;
@@ -5614,7 +5620,8 @@ static void __ipv6_ifa_notify(int event, struct inet6_ifaddr *ifp)
 			addrconf_join_anycast(ifp);
 		if (!ipv6_addr_any(&ifp->peer_addr))
 			addrconf_prefix_route(&ifp->peer_addr, 128,
-					      ifp->idev->dev, 0, 0);
+					      ifp->idev->dev, 0, 0,
+					      GFP_KERNEL);
 		break;
 	case RTM_DELADDR:
 		if (ifp->idev->cnf.forwarding)
diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c
index 1122fb2..e456386 100644
--- a/net/ipv6/anycast.c
+++ b/net/ipv6/anycast.c
@@ -267,7 +267,7 @@ int __ipv6_dev_ac_inc(struct inet6_dev *idev, const struct in6_addr *addr)
 	}
 
 	net = dev_net(idev->dev);
-	rt = addrconf_dst_alloc(net, idev, addr, true);
+	rt = addrconf_dst_alloc(net, idev, addr, true, GFP_ATOMIC);
 	if (IS_ERR(rt)) {
 		err = PTR_ERR(rt);
 		goto out;
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index d635d71..56a854b 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2866,6 +2866,7 @@ out:
 }
 
 static struct rt6_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;
@@ -3086,12 +3087,13 @@ out:
 	return ERR_PTR(err);
 }
 
-int ip6_route_add(struct fib6_config *cfg, struct netlink_ext_ack *extack)
+int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,
+		  struct netlink_ext_ack *extack)
 {
 	struct rt6_info *rt;
 	int err;
 
-	rt = ip6_route_info_create(cfg, extack);
+	rt = ip6_route_info_create(cfg, gfp_flags, extack);
 	if (IS_ERR(rt))
 		return PTR_ERR(rt);
 
@@ -3418,7 +3420,7 @@ static struct rt6_info *rt6_add_route_info(struct net *net,
 	if (!prefixlen)
 		cfg.fc_flags |= RTF_DEFAULT;
 
-	ip6_route_add(&cfg, NULL);
+	ip6_route_add(&cfg, GFP_ATOMIC, NULL);
 
 	return rt6_get_route_info(net, prefix, prefixlen, gwaddr, dev);
 }
@@ -3469,7 +3471,7 @@ struct rt6_info *rt6_add_dflt_router(struct net *net,
 
 	cfg.fc_gateway = *gwaddr;
 
-	if (!ip6_route_add(&cfg, NULL)) {
+	if (!ip6_route_add(&cfg, GFP_ATOMIC, NULL)) {
 		struct fib6_table *table;
 
 		table = fib6_get_table(dev_net(dev), cfg.fc_table);
@@ -3567,7 +3569,7 @@ int ipv6_route_ioctl(struct net *net, unsigned int cmd, void __user *arg)
 		rtnl_lock();
 		switch (cmd) {
 		case SIOCADDRT:
-			err = ip6_route_add(&cfg, NULL);
+			err = ip6_route_add(&cfg, GFP_KERNEL, NULL);
 			break;
 		case SIOCDELRT:
 			err = ip6_route_del(&cfg, NULL);
@@ -3640,7 +3642,7 @@ static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff
 struct rt6_info *addrconf_dst_alloc(struct net *net,
 				    struct inet6_dev *idev,
 				    const struct in6_addr *addr,
-				    bool anycast)
+				    bool anycast, gfp_t gfp_flags)
 {
 	u32 tb_id;
 	struct net_device *dev = idev->dev;
@@ -4293,7 +4295,7 @@ static int ip6_route_multipath_add(struct fib6_config *cfg,
 		}
 
 		r_cfg.fc_flags |= (rtnh->rtnh_flags & RTNH_F_ONLINK);
-		rt = ip6_route_info_create(&r_cfg, extack);
+		rt = ip6_route_info_create(&r_cfg, GFP_KERNEL, extack);
 		if (IS_ERR(rt)) {
 			err = PTR_ERR(rt);
 			rt = NULL;
@@ -4446,7 +4448,7 @@ static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
 	if (cfg.fc_mp)
 		return ip6_route_multipath_add(&cfg, extack);
 	else
-		return ip6_route_add(&cfg, extack);
+		return ip6_route_add(&cfg, GFP_KERNEL, extack);
 }
 
 static size_t rt6_nlmsg_size(struct rt6_info *rt)