From fc9e50f5a5a4e1fa9ba2756f745a13e693cf6a06 Mon Sep 17 00:00:00 2001 From: Tom Herbert Date: Tue, 15 Dec 2015 15:41:37 -0800 Subject: netlink: add a start callback for starting a netlink dump The start callback allows the caller to set up a context for the dump callbacks. Presumably, the context can then be destroyed in the done callback. Signed-off-by: Tom Herbert Signed-off-by: David S. Miller --- net/netlink/af_netlink.c | 4 ++++ net/netlink/genetlink.c | 16 ++++++++++++++++ 2 files changed, 20 insertions(+) (limited to 'net/netlink') diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 59651af8cc27..81dc1bb6e016 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -2915,6 +2915,7 @@ int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, cb = &nlk->cb; memset(cb, 0, sizeof(*cb)); + cb->start = control->start; cb->dump = control->dump; cb->done = control->done; cb->nlh = nlh; @@ -2927,6 +2928,9 @@ int __netlink_dump_start(struct sock *ssk, struct sk_buff *skb, mutex_unlock(nlk->cb_mutex); + if (cb->start) + cb->start(cb); + ret = netlink_dump(sk); sock_put(sk); diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c index bc0e504f33a6..8e63662c6fb0 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -513,6 +513,20 @@ void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq, } EXPORT_SYMBOL(genlmsg_put); +static int genl_lock_start(struct netlink_callback *cb) +{ + /* our ops are always const - netlink API doesn't propagate that */ + const struct genl_ops *ops = cb->data; + int rc = 0; + + if (ops->start) { + genl_lock(); + rc = ops->start(cb); + genl_unlock(); + } + return rc; +} + static int genl_lock_dumpit(struct sk_buff *skb, struct netlink_callback *cb) { /* our ops are always const - netlink API doesn't propagate that */ @@ -577,6 +591,7 @@ static int genl_family_rcv_msg(struct genl_family *family, .module = family->module, /* we have const, but the netlink API doesn't */ .data = (void *)ops, + .start = genl_lock_start, .dump = genl_lock_dumpit, .done = genl_lock_done, }; @@ -588,6 +603,7 @@ static int genl_family_rcv_msg(struct genl_family *family, } else { struct netlink_dump_control c = { .module = family->module, + .start = ops->start, .dump = ops->dumpit, .done = ops->done, }; -- cgit v1.2.3