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authorThomas Graf <tgraf@suug.ch>2013-11-30 13:21:30 +0100
committerJesse Gross <jesse@nicira.com>2014-01-06 15:51:53 -0800
commitbb9b18fb55b03477fe5bdd3e97245d6d4d3dee4f (patch)
tree02d730abd6f31752a842f8c1d9f30d62d185e0b2
parent663efa3696232300a8ad3a46bb10482fc0b861cf (diff)
downloadlinux-bb9b18fb55b03477fe5bdd3e97245d6d4d3dee4f.tar.bz2
genl: Add genlmsg_new_unicast() for unicast message allocation
Allocates a new sk_buff large enough to cover the specified payload plus required Netlink headers. Will check receiving socket for memory mapped i/o capability and use it if enabled. Will fall back to non-mapped skb if message size exceeds the frame size of the ring. Signed-of-by: Thomas Graf <tgraf@suug.ch> Reviewed-by: Daniel Borkmann <dborkman@redhat.com> Signed-off-by: Jesse Gross <jesse@nicira.com>
-rw-r--r--include/net/genetlink.h4
-rw-r--r--net/netlink/genetlink.c21
2 files changed, 25 insertions, 0 deletions
diff --git a/include/net/genetlink.h b/include/net/genetlink.h
index 1b177ed803b7..93695f0e22a5 100644
--- a/include/net/genetlink.h
+++ b/include/net/genetlink.h
@@ -73,6 +73,7 @@ struct genl_family {
* @attrs: netlink attributes
* @_net: network namespace
* @user_ptr: user pointers
+ * @dst_sk: destination socket
*/
struct genl_info {
u32 snd_seq;
@@ -85,6 +86,7 @@ struct genl_info {
struct net * _net;
#endif
void * user_ptr[2];
+ struct sock * dst_sk;
};
static inline struct net *genl_info_net(struct genl_info *info)
@@ -177,6 +179,8 @@ void genl_notify(struct genl_family *family,
struct sk_buff *skb, struct net *net, u32 portid,
u32 group, struct nlmsghdr *nlh, gfp_t flags);
+struct sk_buff *genlmsg_new_unicast(size_t payload, struct genl_info *info,
+ gfp_t flags);
void *genlmsg_put(struct sk_buff *skb, u32 portid, u32 seq,
struct genl_family *family, int flags, u8 cmd);
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 4518a57aa5fe..85bf42e2a943 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -454,6 +454,26 @@ int genl_unregister_family(struct genl_family *family)
EXPORT_SYMBOL(genl_unregister_family);
/**
+ * genlmsg_new_unicast - Allocate generic netlink message for unicast
+ * @payload: size of the message payload
+ * @info: information on destination
+ * @flags: the type of memory to allocate
+ *
+ * Allocates a new sk_buff large enough to cover the specified payload
+ * plus required Netlink headers. Will check receiving socket for
+ * memory mapped i/o capability and use it if enabled. Will fall back
+ * to non-mapped skb if message size exceeds the frame size of the ring.
+ */
+struct sk_buff *genlmsg_new_unicast(size_t payload, struct genl_info *info,
+ gfp_t flags)
+{
+ size_t len = nlmsg_total_size(genlmsg_total_size(payload));
+
+ return netlink_alloc_skb(info->dst_sk, len, info->snd_portid, flags);
+}
+EXPORT_SYMBOL_GPL(genlmsg_new_unicast);
+
+/**
* genlmsg_put - Add generic netlink header to netlink message
* @skb: socket buffer holding the message
* @portid: netlink portid the message is addressed to
@@ -593,6 +613,7 @@ static int genl_family_rcv_msg(struct genl_family *family,
info.genlhdr = nlmsg_data(nlh);
info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN;
info.attrs = attrbuf;
+ info.dst_sk = skb->sk;
genl_info_net_set(&info, net);
memset(&info.user_ptr, 0, sizeof(info.user_ptr));