From 3765d35ed8b9363cbf72ffe2282002d717a40843 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Thu, 25 May 2017 10:42:36 -0700 Subject: net: ipv4: Convert inet_rtm_getroute to rcu versions of route lookup Convert inet_rtm_getroute to use ip_route_input_rcu and ip_route_output_key_hash_rcu passing the fib_result arg to both. The rcu lock is held through the creation of the response, so the rtable/dst does not need to be attached to the skb and is passed to rt_fill_info directly. In converting from ip_route_output_key to ip_route_output_key_hash_rcu the xfrm_lookup_route in ip_route_output_flow is dropped since flowi4_proto is not set for a route get request. Signed-off-by: David Ahern Signed-off-by: Roopa Prabhu Signed-off-by: David S. Miller --- net/ipv4/route.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) (limited to 'net/ipv4/route.c') diff --git a/net/ipv4/route.c b/net/ipv4/route.c index d8fcecce3839..1fa9127ec4db 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -2534,11 +2534,11 @@ struct rtable *ip_route_output_flow(struct net *net, struct flowi4 *flp4, } EXPORT_SYMBOL_GPL(ip_route_output_flow); +/* called with rcu_read_lock held */ static int rt_fill_info(struct net *net, __be32 dst, __be32 src, u32 table_id, struct flowi4 *fl4, struct sk_buff *skb, u32 portid, - u32 seq) + u32 seq, struct rtable *rt) { - struct rtable *rt = skb_rtable(skb); struct rtmsg *r; struct nlmsghdr *nlh; unsigned long expires = 0; @@ -2653,6 +2653,7 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, struct net *net = sock_net(in_skb->sk); struct rtmsg *rtm; struct nlattr *tb[RTA_MAX+1]; + struct fib_result res = {}; struct rtable *rt = NULL; struct flowi4 fl4; __be32 dst = 0; @@ -2709,10 +2710,12 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, fl4.flowi4_mark = mark; fl4.flowi4_uid = uid; + rcu_read_lock(); + if (iif) { struct net_device *dev; - dev = __dev_get_by_index(net, iif); + dev = dev_get_by_index_rcu(net, iif); if (!dev) { err = -ENODEV; goto errout_free; @@ -2721,14 +2724,14 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, skb->protocol = htons(ETH_P_IP); skb->dev = dev; skb->mark = mark; - err = ip_route_input(skb, dst, src, rtm->rtm_tos, dev); + err = ip_route_input_rcu(skb, dst, src, rtm->rtm_tos, + dev, &res); rt = skb_rtable(skb); if (err == 0 && rt->dst.error) err = -rt->dst.error; } else { - rt = ip_route_output_key(net, &fl4); - + rt = ip_route_output_key_hash_rcu(net, &fl4, &res, skb); err = 0; if (IS_ERR(rt)) err = PTR_ERR(rt); @@ -2737,7 +2740,6 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, if (err) goto errout_free; - skb_dst_set(skb, &rt->dst); if (rtm->rtm_flags & RTM_F_NOTIFY) rt->rt_flags |= RTCF_NOTIFY; @@ -2745,15 +2747,18 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, table_id = rt->rt_table_id; err = rt_fill_info(net, dst, src, table_id, &fl4, skb, - NETLINK_CB(in_skb).portid, nlh->nlmsg_seq); + NETLINK_CB(in_skb).portid, nlh->nlmsg_seq, rt); if (err < 0) goto errout_free; + rcu_read_unlock(); + err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); errout: return err; errout_free: + rcu_read_unlock(); kfree_skb(skb); goto errout; } -- cgit v1.2.3-59-g8ed1b