[v3 RFC PATCH 4/8] netlink: Add NLM_F_NOREPLY flags.
From: David Miller <davem@davemloft.net>
Date: 2011-03-03 01:01:25
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
It is used to bypass the response generation for "GET" type operations. This mechanism can then be used to allow a query operation to be used in a "benchmarking" role, since the actual overhead of the netlink communications will be muted. The first query to support this is inet_rtm_getroute(). Signed-off-by: David S. Miller <davem@davemloft.net> --- include/linux/netlink.h | 2 ++ net/ipv4/route.c | 3 +++ 2 files changed, 5 insertions(+), 0 deletions(-)
diff --git a/include/linux/netlink.h b/include/linux/netlink.h
index e2b9e63..a4bc8d2 100644
--- a/include/linux/netlink.h
+++ b/include/linux/netlink.h@@ -61,6 +61,8 @@ struct nlmsghdr { #define NLM_F_CREATE 0x400 /* Create, if it does not exist */ #define NLM_F_APPEND 0x800 /* Add to end of list */ +#define NLM_F_NOREPLY 0x1000 /* Do not generate reply */ + /* 4.4BSD ADD NLM_F_CREATE|NLM_F_EXCL 4.4BSD CHANGE NLM_F_REPLACE
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index efefefa..e59241f 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c@@ -2110,6 +2110,9 @@ static int inet_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void goto errout_free; skb_dst_set(skb, &rt->dst); + if (nlh->nlmsg_flags & NLM_F_NOREPLY) + goto errout_free; + if (rtm->rtm_flags & RTM_F_NOTIFY) rt->rt_flags |= RTCF_NOTIFY;
--
1.7.4.1