From d387f6ad10764fc2174373b4a1cca443adee36e3 Mon Sep 17 00:00:00 2001 From: Thomas Graf Date: Tue, 15 Aug 2006 00:31:06 -0700 Subject: [NETLINK]: Add notification message sending interface Adds nlmsg_notify() implementing proper notification logic. The message is multicasted to all listeners in the group. The applications the requests orignates from can request a unicast back report in which case said socket will be excluded from the multicast to avoid duplicated notifications. nlmsg_multicast() is extended to take allocation flags to allow notification in atomic contexts. Signed-off-by: Thomas Graf Signed-off-by: David S. Miller --- net/netlink/af_netlink.c | 34 +++++++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-) (limited to 'net/netlink/af_netlink.c') diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 0f36ddc0b72..a80e4456e20 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -1549,6 +1549,38 @@ void netlink_queue_skip(struct nlmsghdr *nlh, struct sk_buff *skb) skb_pull(skb, msglen); } +/** + * nlmsg_notify - send a notification netlink message + * @sk: netlink socket to use + * @skb: notification message + * @pid: destination netlink pid for reports or 0 + * @group: destination multicast group or 0 + * @report: 1 to report back, 0 to disable + * @flags: allocation flags + */ +int nlmsg_notify(struct sock *sk, struct sk_buff *skb, u32 pid, + unsigned int group, int report, gfp_t flags) +{ + int err = 0; + + if (group) { + int exclude_pid = 0; + + if (report) { + atomic_inc(&skb->users); + exclude_pid = pid; + } + + /* errors reported via destination sk->sk_err */ + nlmsg_multicast(sk, skb, exclude_pid, group, flags); + } + + if (report) + err = nlmsg_unicast(sk, skb, pid); + + return err; +} + #ifdef CONFIG_PROC_FS struct nl_seq_iter { int link; @@ -1802,4 +1834,4 @@ EXPORT_SYMBOL(netlink_set_err); EXPORT_SYMBOL(netlink_set_nonroot); EXPORT_SYMBOL(netlink_unicast); EXPORT_SYMBOL(netlink_unregister_notifier); - +EXPORT_SYMBOL(nlmsg_notify); -- cgit v1.2.3