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| author | Pablo Neira Ayuso <pablo@netfilter.org> | 2009-02-18 01:40:43 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2009-02-20 01:01:08 -0800 |
| commit | be0c22a46cfb79ab2342bb28fde99afa94ef868e (patch) | |
| tree | da112ef3066d75a7e5adcfe3355ad2b60ef1929b /net/netlink/af_netlink.c | |
| parent | 2d96cf8cdfd625da51e5d237d564cd75d3147547 (diff) | |
| download | linux-be0c22a46cfb79ab2342bb28fde99afa94ef868e.tar.gz linux-be0c22a46cfb79ab2342bb28fde99afa94ef868e.tar.bz2 linux-be0c22a46cfb79ab2342bb28fde99afa94ef868e.zip | |
netlink: add NETLINK_BROADCAST_ERROR socket option
This patch adds NETLINK_BROADCAST_ERROR which is a netlink
socket option that the listener can set to make netlink_broadcast()
return errors in the delivery to the caller. This option is useful
if the caller of netlink_broadcast() do something with the result
of the message delivery, like in ctnetlink where it drops a network
packet if the event delivery failed, this is used to enable reliable
logging and state-synchronization. If this socket option is not set,
netlink_broadcast() only reports ESRCH errors and silently ignore
ENOBUFS errors, which is what most netlink_broadcast() callers
should do.
This socket option is based on a suggestion from Patrick McHardy.
Patrick McHardy can exchange this patch for a beer from me ;).
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/netlink/af_netlink.c')
| -rw-r--r-- | net/netlink/af_netlink.c | 25 |
1 files changed, 23 insertions, 2 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 6ee69c27f806..ed587be1e1c2 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -85,6 +85,7 @@ struct netlink_sock { #define NETLINK_KERNEL_SOCKET 0x1 #define NETLINK_RECV_PKTINFO 0x2 +#define NETLINK_BROADCAST_SEND_ERROR 0x4 static inline struct netlink_sock *nlk_sk(struct sock *sk) { @@ -995,12 +996,15 @@ static inline int do_one_broadcast(struct sock *sk, netlink_overrun(sk); /* Clone failed. Notify ALL listeners. */ p->failure = 1; + if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR) + p->delivery_failure = 1; } else if (sk_filter(sk, p->skb2)) { kfree_skb(p->skb2); p->skb2 = NULL; } else if ((val = netlink_broadcast_deliver(sk, p->skb2)) < 0) { netlink_overrun(sk); - p->delivery_failure = 1; + if (nlk->flags & NETLINK_BROADCAST_SEND_ERROR) + p->delivery_failure = 1; } else { p->congested |= val; p->delivered = 1; @@ -1048,7 +1052,7 @@ int netlink_broadcast(struct sock *ssk, struct sk_buff *skb, u32 pid, if (info.skb2) kfree_skb(info.skb2); - if (info.delivery_failure || info.failure) + if (info.delivery_failure) return -ENOBUFS; if (info.delivered) { @@ -1163,6 +1167,13 @@ static int netlink_setsockopt(struct socket *sock, int level, int optname, err = 0; break; } + case NETLINK_BROADCAST_ERROR: + if (val) + nlk->flags |= NETLINK_BROADCAST_SEND_ERROR; + else + nlk->flags &= ~NETLINK_BROADCAST_SEND_ERROR; + err = 0; + break; default: err = -ENOPROTOOPT; } @@ -1195,6 +1206,16 @@ static int netlink_getsockopt(struct socket *sock, int level, int optname, return -EFAULT; err = 0; break; + case NETLINK_BROADCAST_ERROR: + if (len < sizeof(int)) + return -EINVAL; + len = sizeof(int); + val = nlk->flags & NETLINK_BROADCAST_SEND_ERROR ? 1 : 0; + if (put_user(len, optlen) || + put_user(val, optval)) + return -EFAULT; + err = 0; + break; default: err = -ENOPROTOOPT; } |