From 39977a83d4d8cd5e8b22ca9111a4b05851c4c418 Mon Sep 17 00:00:00 2001 From: Tom Herbert Date: Tue, 15 Dec 2015 15:41:37 -0800 Subject: BACKPORT: netlink: add a start callback for starting a netlink dump commit fc9e50f5a5a4e1fa9ba2756f745a13e693cf6a06 upstream. 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 Cc: Guenter Roeck Signed-off-by: Greg Kroah-Hartman (cherry picked from commit 142afbc6b2f33832f332ce5b561aa817edfff0b4) Change-Id: Ibaaffde651e76be2defeaa081ae56ca9e8f93602 --- 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 20fda4ee1..2c1c841f0 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -2567,6 +2567,7 @@ 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; @@ -2579,6 +2580,9 @@ 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 c7408dd8f..44feb83e0 100644 --- a/net/netlink/genetlink.c +++ b/net/netlink/genetlink.c @@ -544,6 +544,20 @@ 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) { struct genl_ops *ops = cb->data; @@ -605,6 +619,7 @@ static int genl_family_rcv_msg(struct genl_family *family, struct netlink_dump_control c = { .module = family->module, .data = ops, + .start = genl_lock_start, .dump = genl_lock_dumpit, .done = genl_lock_done, }; @@ -616,6 +631,7 @@ static int genl_family_rcv_msg(struct genl_family *family, } else { struct netlink_dump_control c = { .module = family->module, + .start = genl_lock_start, .dump = ops->dumpit, .done = ops->done, }; -- cgit v1.2.3