netlink: introduce type-checking attribute iteration

There are, especially with multi-attr arrays, many cases
of needing to iterate all attributes of a specific type
in a netlink message or a nested attribute. Add specific
macros to support that case.

Also convert many instances using this spatch:

    @@
    iterator nla_for_each_attr;
    iterator name nla_for_each_attr_type;
    identifier nla;
    expression head, len, rem;
    expression ATTR;
    type T;
    identifier x;
    @@
    -nla_for_each_attr(nla, head, len, rem)
    +nla_for_each_attr_type(nla, ATTR, head, len, rem)
     {
    <... T x; ...>
    -if (nla_type(nla) == ATTR) {
     ...
    -}
     }

    @@
    identifier nla;
    iterator nla_for_each_nested;
    iterator name nla_for_each_nested_type;
    expression attr, rem;
    expression ATTR;
    type T;
    identifier x;
    @@
    -nla_for_each_nested(nla, attr, rem)
    +nla_for_each_nested_type(nla, ATTR, attr, rem)
     {
    <... T x; ...>
    -if (nla_type(nla) == ATTR) {
     ...
    -}
     }

    @@
    iterator nla_for_each_attr;
    iterator name nla_for_each_attr_type;
    identifier nla;
    expression head, len, rem;
    expression ATTR;
    type T;
    identifier x;
    @@
    -nla_for_each_attr(nla, head, len, rem)
    +nla_for_each_attr_type(nla, ATTR, head, len, rem)
     {
    <... T x; ...>
    -if (nla_type(nla) != ATTR) continue;
     ...
     }

    @@
    identifier nla;
    iterator nla_for_each_nested;
    iterator name nla_for_each_nested_type;
    expression attr, rem;
    expression ATTR;
    type T;
    identifier x;
    @@
    -nla_for_each_nested(nla, attr, rem)
    +nla_for_each_nested_type(nla, ATTR, attr, rem)
     {
    <... T x; ...>
    -if (nla_type(nla) != ATTR) continue;
     ...
     }

Although I had to undo one bad change this made, and
I also adjusted some other code for whitespace and to
use direct variable initialization now.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20240328203144.b5a6c895fb80.I1869b44767379f204998ff44dd239803f39c23e0@changeid
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

7 files changed, 11 insertions, 35 deletions

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 388e80bf91f5..b4db4b1aaffb 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -14581,12 +14581,9 @@ static int bnxt_bridge_setlink(struct net_device *dev, struct nlmsghdr *nlh,
 	if (!br_spec)
 		return -EINVAL;
 
-	nla_for_each_nested(attr, br_spec, rem) {
+	nla_for_each_nested_type(attr, IFLA_BRIDGE_MODE, br_spec, rem) {
 		u16 mode;
 
-		if (nla_type(attr) != IFLA_BRIDGE_MODE)
-			continue;
-
 		mode = nla_get_u16(attr);
 		if (mode == bp->br_mode)
 			break;
diff --git a/drivers/net/ethernet/emulex/benet/be_main.c b/drivers/net/ethernet/emulex/benet/be_main.c
index ad862ed7888a..a8596ebcdfd6 100644
--- a/drivers/net/ethernet/emulex/benet/be_main.c
+++ b/drivers/net/ethernet/emulex/benet/be_main.c
@@ -4982,10 +4982,7 @@ static int be_ndo_bridge_setlink(struct net_device *dev, struct nlmsghdr *nlh,
 	if (!br_spec)
 		return -EINVAL;
 
-	nla_for_each_nested(attr, br_spec, rem) {
-		if (nla_type(attr) != IFLA_BRIDGE_MODE)
-			continue;
-
+	nla_for_each_nested_type(attr, IFLA_BRIDGE_MODE, br_spec, rem) {
 		mode = nla_get_u16(attr);
 		if (BE3_chip(adapter) && mode == BRIDGE_MODE_VEPA)
 			return -EOPNOTSUPP;
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index f86578857e8a..e427e65af205 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -13108,13 +13108,9 @@ static int i40e_ndo_bridge_setlink(struct net_device *dev,
 	if (!br_spec)
 		return -EINVAL;
 
-	nla_for_each_nested(attr, br_spec, rem) {
-		__u16 mode;
+	nla_for_each_nested_type(attr, IFLA_BRIDGE_MODE, br_spec, rem) {
+		__u16 mode = nla_get_u16(attr);
 
-		if (nla_type(attr) != IFLA_BRIDGE_MODE)
-			continue;
-
-		mode = nla_get_u16(attr);
 		if ((mode != BRIDGE_MODE_VEPA) &&
 		    (mode != BRIDGE_MODE_VEB))
 			return -EINVAL;
diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index f2b7d6ca8805..618570f23580 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -7993,12 +7993,9 @@ ice_bridge_setlink(struct net_device *dev, struct nlmsghdr *nlh,
 	if (!br_spec)
 		return -EINVAL;
 
-	nla_for_each_nested(attr, br_spec, rem) {
-		__u16 mode;
+	nla_for_each_nested_type(attr, IFLA_BRIDGE_MODE, br_spec, rem) {
+		__u16 mode = nla_get_u16(attr);
 
-		if (nla_type(attr) != IFLA_BRIDGE_MODE)
-			continue;
-		mode = nla_get_u16(attr);
 		if (mode != BRIDGE_MODE_VEPA && mode != BRIDGE_MODE_VEB)
 			return -EINVAL;
 		/* Continue  if bridge mode is not being flipped */
diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index f985252c8c8d..ed05af665466 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -10061,15 +10061,10 @@ static int ixgbe_ndo_bridge_setlink(struct net_device *dev,
 	if (!br_spec)
 		return -EINVAL;
 
-	nla_for_each_nested(attr, br_spec, rem) {
-		int status;
-		__u16 mode;
+	nla_for_each_nested_type(attr, IFLA_BRIDGE_MODE, br_spec, rem) {
+		__u16 mode = nla_get_u16(attr);
+		int status = ixgbe_configure_bridge_mode(adapter, mode);
 
-		if (nla_type(attr) != IFLA_BRIDGE_MODE)
-			continue;
-
-		mode = nla_get_u16(attr);
-		status = ixgbe_configure_bridge_mode(adapter, mode);
 		if (status)
 			return status;
 
diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
index 91848eae4565..81e1c1e401f9 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en_main.c
@@ -4950,10 +4950,7 @@ static int mlx5e_bridge_setlink(struct net_device *dev, struct nlmsghdr *nlh,
 	if (!br_spec)
 		return -EINVAL;
 
-	nla_for_each_nested(attr, br_spec, rem) {
-		if (nla_type(attr) != IFLA_BRIDGE_MODE)
-			continue;
-
+	nla_for_each_nested_type(attr, IFLA_BRIDGE_MODE, br_spec, rem) {
 		mode = nla_get_u16(attr);
 		if (mode > BRIDGE_MODE_VEPA)
 			return -EINVAL;
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
index f28e769e6fda..997cc4fcffdb 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_common.c
@@ -2289,10 +2289,7 @@ static int nfp_net_bridge_setlink(struct net_device *dev, struct nlmsghdr *nlh,
 	if (!br_spec)
 		return -EINVAL;
 
-	nla_for_each_nested(attr, br_spec, rem) {
-		if (nla_type(attr) != IFLA_BRIDGE_MODE)
-			continue;
-
+	nla_for_each_nested_type(attr, IFLA_BRIDGE_MODE, br_spec, rem) {
 		new_ctrl = nn->dp.ctrl;
 		mode = nla_get_u16(attr);
 		if (mode == BRIDGE_MODE_VEPA)