genetlink: remove userhdr from struct genl_info

Only three families use info->userhdr today and going forward
we discourage using fixed headers in new families.
So having the pointer to user header in struct genl_info
is an overkill. Compute the header pointer at runtime.

Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Link: https://lore.kernel.org/r/20230814214723.2924989-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/block/drbd/drbd_nl.c b/drivers/block/drbd/drbd_nl.c
index cddae6f..d3538bd 100644 (file)
--- a/drivers/block/drbd/drbd_nl.c
+++ b/drivers/block/drbd/drbd_nl.c
@@ -159,7 +159,7 @@ static int drbd_msg_sprintf_info(struct sk_buff *skb, const char *fmt, ...)
 static int drbd_adm_prepare(struct drbd_config_context *adm_ctx,
        struct sk_buff *skb, struct genl_info *info, unsigned flags)
 {
-       struct drbd_genlmsghdr *d_in = info->userhdr;
+       struct drbd_genlmsghdr *d_in = genl_info_userhdr(info);
        const u8 cmd = info->genlhdr->cmd;
        int err;
 
@@ -1396,8 +1396,9 @@ static void drbd_suspend_al(struct drbd_device *device)
 
 static bool should_set_defaults(struct genl_info *info)
 {
-       unsigned flags = ((struct drbd_genlmsghdr*)info->userhdr)->flags;
-       return 0 != (flags & DRBD_GENL_F_SET_DEFAULTS);
+       struct drbd_genlmsghdr *dh = genl_info_userhdr(info);
+
+       return 0 != (dh->flags & DRBD_GENL_F_SET_DEFAULTS);
 }
 
 static unsigned int drbd_al_extents_max(struct drbd_backing_dev *bdev)
@@ -4276,7 +4277,7 @@ static void device_to_info(struct device_info *info,
 int drbd_adm_new_minor(struct sk_buff *skb, struct genl_info *info)
 {
        struct drbd_config_context adm_ctx;
-       struct drbd_genlmsghdr *dh = info->userhdr;
+       struct drbd_genlmsghdr *dh = genl_info_userhdr(info);
        enum drbd_ret_code retcode;
 
        retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_RESOURCE);

diff --git a/include/net/genetlink.h b/include/net/genetlink.h
index 0366d09..9dc21ec 100644 (file)
--- a/include/net/genetlink.h
+++ b/include/net/genetlink.h
@@ -95,7 +95,6 @@ struct genl_family {
  * @snd_portid: netlink portid of sender
  * @nlhdr: netlink message header
  * @genlhdr: generic netlink message header
- * @userhdr: user specific header
  * @attrs: netlink attributes
  * @_net: network namespace
  * @user_ptr: user pointers
@@ -106,7 +105,6 @@ struct genl_info {
        u32                     snd_portid;
        const struct nlmsghdr * nlhdr;
        struct genlmsghdr *     genlhdr;
-       void *                  userhdr;
        struct nlattr **        attrs;
        possible_net_t          _net;
        void *                  user_ptr[2];
@@ -123,6 +121,11 @@ static inline void genl_info_net_set(struct genl_info *info, struct net *net)
        write_pnet(&info->_net, net);
 }
 
+static inline void *genl_info_userhdr(const struct genl_info *info)
+{
+       return (u8 *)info->genlhdr + GENL_HDRLEN;
+}
+
 #define GENL_SET_ERR_MSG(info, msg) NL_SET_ERR_MSG((info)->extack, msg)
 
 #define GENL_SET_ERR_MSG_FMT(info, msg, args...) \

diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index 0d42856..f98f730 100644 (file)
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -943,7 +943,6 @@ static int genl_family_rcv_msg_doit(const struct genl_family *family,
        info.snd_portid = NETLINK_CB(skb).portid;
        info.nlhdr = nlh;
        info.genlhdr = nlmsg_data(nlh);
-       info.userhdr = nlmsg_data(nlh) + GENL_HDRLEN;
        info.attrs = attrbuf;
        info.extack = extack;
        genl_info_net_set(&info, net);

diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
index 0cfa1e9..0b9a785 100644 (file)
--- a/net/openvswitch/conntrack.c
+++ b/net/openvswitch/conntrack.c
@@ -1605,7 +1605,7 @@ static struct sk_buff *
 ovs_ct_limit_cmd_reply_start(struct genl_info *info, u8 cmd,
                             struct ovs_header **ovs_reply_header)
 {
-       struct ovs_header *ovs_header = info->userhdr;
+       struct ovs_header *ovs_header = genl_info_userhdr(info);
        struct sk_buff *skb;
 
        skb = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);

diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index d33cb73..0a974ee 100644 (file)
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -590,7 +590,7 @@ out:
 
 static int ovs_packet_cmd_execute(struct sk_buff *skb, struct genl_info *info)
 {
-       struct ovs_header *ovs_header = info->userhdr;
+       struct ovs_header *ovs_header = genl_info_userhdr(info);
        struct net *net = sock_net(skb->sk);
        struct nlattr **a = info->attrs;
        struct sw_flow_actions *acts;
@@ -967,7 +967,7 @@ static int ovs_flow_cmd_new(struct sk_buff *skb, struct genl_info *info)
 {
        struct net *net = sock_net(skb->sk);
        struct nlattr **a = info->attrs;
-       struct ovs_header *ovs_header = info->userhdr;
+       struct ovs_header *ovs_header = genl_info_userhdr(info);
        struct sw_flow *flow = NULL, *new_flow;
        struct sw_flow_mask mask;
        struct sk_buff *reply;
@@ -1214,7 +1214,7 @@ static int ovs_flow_cmd_set(struct sk_buff *skb, struct genl_info *info)
 {
        struct net *net = sock_net(skb->sk);
        struct nlattr **a = info->attrs;
-       struct ovs_header *ovs_header = info->userhdr;
+       struct ovs_header *ovs_header = genl_info_userhdr(info);
        struct sw_flow_key key;
        struct sw_flow *flow;
        struct sk_buff *reply = NULL;
@@ -1315,7 +1315,7 @@ error:
 static int ovs_flow_cmd_get(struct sk_buff *skb, struct genl_info *info)
 {
        struct nlattr **a = info->attrs;
-       struct ovs_header *ovs_header = info->userhdr;
+       struct ovs_header *ovs_header = genl_info_userhdr(info);
        struct net *net = sock_net(skb->sk);
        struct sw_flow_key key;
        struct sk_buff *reply;
@@ -1374,7 +1374,7 @@ unlock:
 static int ovs_flow_cmd_del(struct sk_buff *skb, struct genl_info *info)
 {
        struct nlattr **a = info->attrs;
-       struct ovs_header *ovs_header = info->userhdr;
+       struct ovs_header *ovs_header = genl_info_userhdr(info);
        struct net *net = sock_net(skb->sk);
        struct sw_flow_key key;
        struct sk_buff *reply;
@@ -1642,7 +1642,7 @@ static void ovs_dp_reset_user_features(struct sk_buff *skb,
 {
        struct datapath *dp;
 
-       dp = lookup_datapath(sock_net(skb->sk), info->userhdr,
+       dp = lookup_datapath(sock_net(skb->sk), genl_info_userhdr(info),
                             info->attrs);
        if (IS_ERR(dp))
                return;
@@ -1935,7 +1935,8 @@ static int ovs_dp_cmd_del(struct sk_buff *skb, struct genl_info *info)
                return -ENOMEM;
 
        ovs_lock();
-       dp = lookup_datapath(sock_net(skb->sk), info->userhdr, info->attrs);
+       dp = lookup_datapath(sock_net(skb->sk), genl_info_userhdr(info),
+                            info->attrs);
        err = PTR_ERR(dp);
        if (IS_ERR(dp))
                goto err_unlock_free;
@@ -1968,7 +1969,8 @@ static int ovs_dp_cmd_set(struct sk_buff *skb, struct genl_info *info)
                return -ENOMEM;
 
        ovs_lock();
-       dp = lookup_datapath(sock_net(skb->sk), info->userhdr, info->attrs);
+       dp = lookup_datapath(sock_net(skb->sk), genl_info_userhdr(info),
+                            info->attrs);
        err = PTR_ERR(dp);
        if (IS_ERR(dp))
                goto err_unlock_free;
@@ -2003,7 +2005,8 @@ static int ovs_dp_cmd_get(struct sk_buff *skb, struct genl_info *info)
                return -ENOMEM;
 
        ovs_lock();
-       dp = lookup_datapath(sock_net(skb->sk), info->userhdr, info->attrs);
+       dp = lookup_datapath(sock_net(skb->sk), genl_info_userhdr(info),
+                            info->attrs);
        if (IS_ERR(dp)) {
                err = PTR_ERR(dp);
                goto err_unlock_free;
@@ -2246,7 +2249,7 @@ static void ovs_update_headroom(struct datapath *dp, unsigned int new_headroom)
 static int ovs_vport_cmd_new(struct sk_buff *skb, struct genl_info *info)
 {
        struct nlattr **a = info->attrs;
-       struct ovs_header *ovs_header = info->userhdr;
+       struct ovs_header *ovs_header = genl_info_userhdr(info);
        struct vport_parms parms;
        struct sk_buff *reply;
        struct vport *vport;
@@ -2348,7 +2351,7 @@ static int ovs_vport_cmd_set(struct sk_buff *skb, struct genl_info *info)
                return -ENOMEM;
 
        ovs_lock();
-       vport = lookup_vport(sock_net(skb->sk), info->userhdr, a);
+       vport = lookup_vport(sock_net(skb->sk), genl_info_userhdr(info), a);
        err = PTR_ERR(vport);
        if (IS_ERR(vport))
                goto exit_unlock_free;
@@ -2404,7 +2407,7 @@ static int ovs_vport_cmd_del(struct sk_buff *skb, struct genl_info *info)
                return -ENOMEM;
 
        ovs_lock();
-       vport = lookup_vport(sock_net(skb->sk), info->userhdr, a);
+       vport = lookup_vport(sock_net(skb->sk), genl_info_userhdr(info), a);
        err = PTR_ERR(vport);
        if (IS_ERR(vport))
                goto exit_unlock_free;
@@ -2447,7 +2450,7 @@ exit_unlock_free:
 static int ovs_vport_cmd_get(struct sk_buff *skb, struct genl_info *info)
 {
        struct nlattr **a = info->attrs;
-       struct ovs_header *ovs_header = info->userhdr;
+       struct ovs_header *ovs_header = genl_info_userhdr(info);
        struct sk_buff *reply;
        struct vport *vport;
        int err;

diff --git a/net/openvswitch/meter.c b/net/openvswitch/meter.c
index c4ebf81..cc08e04 100644 (file)
--- a/net/openvswitch/meter.c
+++ b/net/openvswitch/meter.c
@@ -211,7 +211,7 @@ ovs_meter_cmd_reply_start(struct genl_info *info, u8 cmd,
                          struct ovs_header **ovs_reply_header)
 {
        struct sk_buff *skb;
-       struct ovs_header *ovs_header = info->userhdr;
+       struct ovs_header *ovs_header = genl_info_userhdr(info);
 
        skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
        if (!skb)
@@ -272,7 +272,7 @@ error:
 
 static int ovs_meter_cmd_features(struct sk_buff *skb, struct genl_info *info)
 {
-       struct ovs_header *ovs_header = info->userhdr;
+       struct ovs_header *ovs_header = genl_info_userhdr(info);
        struct ovs_header *ovs_reply_header;
        struct nlattr *nla, *band_nla;
        struct sk_buff *reply;
@@ -409,7 +409,7 @@ static int ovs_meter_cmd_set(struct sk_buff *skb, struct genl_info *info)
        struct dp_meter *meter, *old_meter;
        struct sk_buff *reply;
        struct ovs_header *ovs_reply_header;
-       struct ovs_header *ovs_header = info->userhdr;
+       struct ovs_header *ovs_header = genl_info_userhdr(info);
        struct dp_meter_table *meter_tbl;
        struct datapath *dp;
        int err;
@@ -482,7 +482,7 @@ exit_free_meter:
 
 static int ovs_meter_cmd_get(struct sk_buff *skb, struct genl_info *info)
 {
-       struct ovs_header *ovs_header = info->userhdr;
+       struct ovs_header *ovs_header = genl_info_userhdr(info);
        struct ovs_header *ovs_reply_header;
        struct nlattr **a = info->attrs;
        struct dp_meter *meter;
@@ -535,7 +535,7 @@ exit_unlock:
 
 static int ovs_meter_cmd_del(struct sk_buff *skb, struct genl_info *info)
 {
-       struct ovs_header *ovs_header = info->userhdr;
+       struct ovs_header *ovs_header = genl_info_userhdr(info);
        struct ovs_header *ovs_reply_header;
        struct nlattr **a = info->attrs;
        struct dp_meter *old_meter;

diff --git a/net/tipc/netlink_compat.c b/net/tipc/netlink_compat.c
index 9b47c84..299cd67 100644 (file)
--- a/net/tipc/netlink_compat.c
+++ b/net/tipc/netlink_compat.c
@@ -1294,7 +1294,7 @@ static int tipc_nl_compat_recv(struct sk_buff *skb, struct genl_info *info)
        struct tipc_nl_compat_msg msg;
        struct nlmsghdr *req_nlh;
        struct nlmsghdr *rep_nlh;
-       struct tipc_genlmsghdr *req_userhdr = info->userhdr;
+       struct tipc_genlmsghdr *req_userhdr = genl_info_userhdr(info);
 
        memset(&msg, 0, sizeof(msg));