[GENL]: Add genlmsg_put_reply() to simplify building reply headers

By modyfing genlmsg_put() to take a genl_family and by adding
genlmsg_put_reply() the process of constructing the netlink
and generic netlink headers is simplified.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

7 files changed, 51 insertions, 95 deletions

diff --git a/include/net/genetlink.h b/include/net/genetlink.h
index 797c18b5041f..7fd131c9a8cc 100644
--- a/include/net/genetlink.h
+++ b/include/net/genetlink.h
@@ -79,34 +79,51 @@ extern struct sock *genl_sock;
  * @skb: socket buffer holding the message
  * @pid: netlink pid the message is addressed to
  * @seq: sequence number (usually the one of the sender)
- * @type: netlink message type
- * @hdrlen: length of the user specific header
+ * @family: generic netlink family
  * @flags netlink message flags
  * @cmd: generic netlink command
- * @version: version
  *
  * Returns pointer to user specific header
  */
 static inline void *genlmsg_put(struct sk_buff *skb, u32 pid, u32 seq,
-                                int type, int hdrlen, int flags,
-                                u8 cmd, u8 version)
+                                struct genl_family *family, int flags, u8 cmd)
 {
         struct nlmsghdr *nlh;
         struct genlmsghdr *hdr;
 
-        nlh = nlmsg_put(skb, pid, seq, type, GENL_HDRLEN + hdrlen, flags);
+        nlh = nlmsg_put(skb, pid, seq, family->id, GENL_HDRLEN +
+                        family->hdrsize, flags);
         if (nlh == NULL)
                 return NULL;
 
         hdr = nlmsg_data(nlh);
         hdr->cmd = cmd;
-        hdr->version = version;
+        hdr->version = family->version;
         hdr->reserved = 0;
 
         return (char *) hdr + GENL_HDRLEN;
 }
 
 /**
+ * genlmsg_put_reply - Add generic netlink header to a reply message
+ * @skb: socket buffer holding the message
+ * @info: receiver info
+ * @family: generic netlink family
+ * @flags: netlink message flags
+ * @cmd: generic netlink command
+ *
+ * Returns pointer to user specific header
+ */
+static inline void *genlmsg_put_reply(struct sk_buff *skb,
+                                      struct genl_info *info,
+                                      struct genl_family *family,
+                                      int flags, u8 cmd)
+{
+        return genlmsg_put(skb, info->snd_pid, info->snd_seq, family,
+                           flags, cmd);
+}
+
+/**
  * genlmsg_end - Finalize a generic netlink message
  * @skb: socket buffer the message is stored in
  * @hdr: user specific header
diff --git a/kernel/taskstats.c b/kernel/taskstats.c
index faa5239813ce..d3d28919d4b4 100644
--- a/kernel/taskstats.c
+++ b/kernel/taskstats.c
@@ -85,13 +85,9 @@ static int prepare_reply(struct genl_info *info, u8 cmd, struct sk_buff **skbp,
                 int seq = get_cpu_var(taskstats_seqnum)++;
                 put_cpu_var(taskstats_seqnum);
 
-                reply = genlmsg_put(skb, 0, seq,
-                                family.id, 0, 0,
-                                cmd, family.version);
+                reply = genlmsg_put(skb, 0, seq, &family, 0, cmd);
         } else
-                reply = genlmsg_put(skb, info->snd_pid, info->snd_seq,
-                                family.id, 0, 0,
-                                cmd, family.version);
+                reply = genlmsg_put_reply(skb, info, &family, 0, cmd);
         if (reply == NULL) {
                 nlmsg_free(skb);
                 return -EINVAL;
diff --git a/net/netlabel/netlabel_cipso_v4.c b/net/netlabel/netlabel_cipso_v4.c
index 52628878524c..fe9851fac85d 100644
--- a/net/netlabel/netlabel_cipso_v4.c
+++ b/net/netlabel/netlabel_cipso_v4.c
@@ -457,12 +457,8 @@ list_start:
                 ret_val = -ENOMEM;
                 goto list_failure;
         }
-        data = netlbl_netlink_hdr_put(ans_skb,
-                                      info->snd_pid,
-                                      info->snd_seq,
-                                      netlbl_cipsov4_gnl_family.id,
-                                      0,
-                                      NLBL_CIPSOV4_C_LIST);
+        data = genlmsg_put_reply(ans_skb, info, &netlbl_cipsov4_gnl_family,
+                                 0, NLBL_CIPSOV4_C_LIST);
         if (data == NULL) {
                 ret_val = -ENOMEM;
                 goto list_failure;
@@ -607,12 +603,9 @@ static int netlbl_cipsov4_listall_cb(struct cipso_v4_doi *doi_def, void *arg)
         struct netlbl_cipsov4_doiwalk_arg *cb_arg = arg;
         void *data;
 
-        data = netlbl_netlink_hdr_put(cb_arg->skb,
-                                      NETLINK_CB(cb_arg->nl_cb->skb).pid,
-                                      cb_arg->seq,
-                                      netlbl_cipsov4_gnl_family.id,
-                                      NLM_F_MULTI,
-                                      NLBL_CIPSOV4_C_LISTALL);
+        data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).pid,
+                           cb_arg->seq, &netlbl_cipsov4_gnl_family,
+                           NLM_F_MULTI, NLBL_CIPSOV4_C_LISTALL);
         if (data == NULL)
                 goto listall_cb_failure;
 
diff --git a/net/netlabel/netlabel_mgmt.c b/net/netlabel/netlabel_mgmt.c
index 784693735e0d..e8c80f33f3d7 100644
--- a/net/netlabel/netlabel_mgmt.c
+++ b/net/netlabel/netlabel_mgmt.c
@@ -188,12 +188,9 @@ static int netlbl_mgmt_listall_cb(struct netlbl_dom_map *entry, void *arg)
         struct netlbl_domhsh_walk_arg *cb_arg = arg;
         void *data;
 
-        data = netlbl_netlink_hdr_put(cb_arg->skb,
-                                      NETLINK_CB(cb_arg->nl_cb->skb).pid,
-                                      cb_arg->seq,
-                                      netlbl_mgmt_gnl_family.id,
-                                      NLM_F_MULTI,
-                                      NLBL_MGMT_C_LISTALL);
+        data = genlmsg_put(cb_arg->skb, NETLINK_CB(cb_arg->nl_cb->skb).pid,
+                           cb_arg->seq, &netlbl_mgmt_gnl_family,
+                           NLM_F_MULTI, NLBL_MGMT_C_LISTALL);
         if (data == NULL)
                 goto listall_cb_failure;
 
@@ -359,12 +356,8 @@ static int netlbl_mgmt_listdef(struct sk_buff *skb, struct genl_info *info)
         ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
         if (ans_skb == NULL)
                 return -ENOMEM;
-        data = netlbl_netlink_hdr_put(ans_skb,
-                                      info->snd_pid,
-                                      info->snd_seq,
-                                      netlbl_mgmt_gnl_family.id,
-                                      0,
-                                      NLBL_MGMT_C_LISTDEF);
+        data = genlmsg_put_reply(ans_skb, info, &netlbl_mgmt_gnl_family,
+                                 0, NLBL_MGMT_C_LISTDEF);
         if (data == NULL)
                 goto listdef_failure;
 
@@ -422,12 +415,9 @@ static int netlbl_mgmt_protocols_cb(struct sk_buff *skb,
         int ret_val = -ENOMEM;
         void *data;
 
-        data = netlbl_netlink_hdr_put(skb,
-                                      NETLINK_CB(cb->skb).pid,
-                                      cb->nlh->nlmsg_seq,
-                                      netlbl_mgmt_gnl_family.id,
-                                      NLM_F_MULTI,
-                                      NLBL_MGMT_C_PROTOCOLS);
+        data = genlmsg_put(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
+                           &netlbl_mgmt_gnl_family, NLM_F_MULTI,
+                           NLBL_MGMT_C_PROTOCOLS);
         if (data == NULL)
                 goto protocols_cb_failure;
 
@@ -495,12 +485,8 @@ static int netlbl_mgmt_version(struct sk_buff *skb, struct genl_info *info)
         ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
         if (ans_skb == NULL)
                 return -ENOMEM;
-        data = netlbl_netlink_hdr_put(ans_skb,
-                                      info->snd_pid,
-                                      info->snd_seq,
-                                      netlbl_mgmt_gnl_family.id,
-                                      0,
-                                      NLBL_MGMT_C_VERSION);
+        data = genlmsg_put_reply(ans_skb, info, &netlbl_mgmt_gnl_family,
+                                 0, NLBL_MGMT_C_VERSION);
         if (data == NULL)
                 goto version_failure;
 
diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c
index 57dd07b51be6..a1d4ae51db04 100644
--- a/net/netlabel/netlabel_unlabeled.c
+++ b/net/netlabel/netlabel_unlabeled.c
@@ -141,12 +141,8 @@ static int netlbl_unlabel_list(struct sk_buff *skb, struct genl_info *info)
         ans_skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
         if (ans_skb == NULL)
                 goto list_failure;
-        data = netlbl_netlink_hdr_put(ans_skb,
-                                      info->snd_pid,
-                                      info->snd_seq,
-                                      netlbl_unlabel_gnl_family.id,
-                                      0,
-                                      NLBL_UNLABEL_C_LIST);
+        data = genlmsg_put_reply(ans_skb, info, &netlbl_unlabel_gnl_family,
+                                 0, NLBL_UNLABEL_C_LIST);
         if (data == NULL) {
                 ret_val = -ENOMEM;
                 goto list_failure;
diff --git a/net/netlabel/netlabel_user.h b/net/netlabel/netlabel_user.h
index 47967ef32964..6d7f4ab46c2b 100644
--- a/net/netlabel/netlabel_user.h
+++ b/net/netlabel/netlabel_user.h
@@ -42,37 +42,6 @@
 /* NetLabel NETLINK helper functions */
 
 /**
- * netlbl_netlink_hdr_put - Write the NETLINK buffers into a sk_buff
- * @skb: the packet
- * @pid: the PID of the receipient
- * @seq: the sequence number
- * @type: the generic NETLINK message family type
- * @cmd: command
- *
- * Description:
- * Write both a NETLINK nlmsghdr structure and a Generic NETLINK genlmsghdr
- * struct to the packet.  Returns a pointer to the start of the payload buffer
- * on success or NULL on failure.
- *
- */
-static inline void *netlbl_netlink_hdr_put(struct sk_buff *skb,
-                                           u32 pid,
-                                           u32 seq,
-                                           int type,
-                                           int flags,
-                                           u8 cmd)
-{
-        return genlmsg_put(skb,
-                           pid,
-                           seq,
-                           type,
-                           0,
-                           flags,
-                           cmd,
-                           NETLBL_PROTO_VERSION);
-}
-
-/**
  * netlbl_netlink_auditinfo - Fetch the audit information from a NETLINK msg
  * @skb: the packet
  * @audit_info: NetLabel audit information
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 0249a56a9aad..8903ef93db5b 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -384,6 +384,13 @@ static void genl_rcv(struct sock *sk, int len)
  * Controller
  **************************************************************************/
 
+static struct genl_family genl_ctrl = {
+        .id = GENL_ID_CTRL,
+        .name = "nlctrl",
+        .version = 0x1,
+        .maxattr = CTRL_ATTR_MAX,
+};
+
 static int ctrl_fill_info(struct genl_family *family, u32 pid, u32 seq,
                           u32 flags, struct sk_buff *skb, u8 cmd)
 {
@@ -392,8 +399,7 @@ static int ctrl_fill_info(struct genl_family *family, u32 pid, u32 seq,
         void *hdr;
         int idx = 1;
 
-        hdr = genlmsg_put(skb, pid, seq, GENL_ID_CTRL, 0, flags, cmd,
-                          family->version);
+        hdr = genlmsg_put(skb, pid, seq, &genl_ctrl, flags, cmd);
         if (hdr == NULL)
                 return -1;
 
@@ -562,13 +568,6 @@ static struct genl_ops genl_ctrl_ops = {
         .policy         = ctrl_policy,
 };
 
-static struct genl_family genl_ctrl = {
-        .id = GENL_ID_CTRL,
-        .name = "nlctrl",
-        .version = 0x1,
-        .maxattr = CTRL_ATTR_MAX,
-};
-
 static int __init genl_init(void)
 {
         int i, err;