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>

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 388e80b..b4db4b1 100644 (file)
--- 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 ad862ed..a8596eb 100644 (file)
--- 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 f865788..e427e65 100644 (file)
--- 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 f2b7d6c..618570f 100644 (file)
--- 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 f985252..ed05af6 100644 (file)
--- 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 91848ea..81e1c1e 100644 (file)
--- 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 f28e769..997cc4f 100644 (file)
--- 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)

diff --git a/include/net/netlink.h b/include/net/netlink.h
index c19ff92..1d2bbcc 100644 (file)
--- a/include/net/netlink.h
+++ b/include/net/netlink.h
@@ -157,7 +157,11 @@
  *   nla_parse()                       parse and validate stream of attrs
  *   nla_parse_nested()                        parse nested attributes
  *   nla_for_each_attr()               loop over all attributes
+ *   nla_for_each_attr_type()          loop over all attributes with the
+ *                                     given type
  *   nla_for_each_nested()             loop over the nested attributes
+ *   nla_for_each_nested_type()                loop over the nested attributes with
+ *                                     the given type
  *=========================================================================
  */
 
@@ -2070,6 +2074,18 @@ static inline int nla_total_size_64bit(int payload)
             nla_ok(pos, rem); \
             pos = nla_next(pos, &(rem)))
 
+/**
+ * nla_for_each_attr_type - iterate over a stream of attributes
+ * @pos: loop counter, set to current attribute
+ * @type: required attribute type for @pos
+ * @head: head of attribute stream
+ * @len: length of attribute stream
+ * @rem: initialized to len, holds bytes currently remaining in stream
+ */
+#define nla_for_each_attr_type(pos, type, head, len, rem) \
+       nla_for_each_attr(pos, head, len, rem) \
+               if (nla_type(pos) == type)
+
 /**
  * nla_for_each_nested - iterate over nested attributes
  * @pos: loop counter, set to current attribute
@@ -2079,6 +2095,17 @@ static inline int nla_total_size_64bit(int payload)
 #define nla_for_each_nested(pos, nla, rem) \
        nla_for_each_attr(pos, nla_data(nla), nla_len(nla), rem)
 
+/**
+ * nla_for_each_nested_type - iterate over nested attributes
+ * @pos: loop counter, set to current attribute
+ * @type: required attribute type for @pos
+ * @nla: attribute containing the nested attributes
+ * @rem: initialized to len, holds bytes currently remaining in stream
+ */
+#define nla_for_each_nested_type(pos, type, nla, rem) \
+       nla_for_each_nested(pos, nla, rem) \
+               if (nla_type(pos) == type)
+
 /**
  * nla_is_last - Test if attribute is last in stream
  * @nla: attribute to test

diff --git a/net/8021q/vlan_netlink.c b/net/8021q/vlan_netlink.c
index a3b6824..cf5219d 100644 (file)
--- a/net/8021q/vlan_netlink.c
+++ b/net/8021q/vlan_netlink.c
@@ -117,17 +117,15 @@ static int vlan_changelink(struct net_device *dev, struct nlattr *tb[],
                        return err;
        }
        if (data[IFLA_VLAN_INGRESS_QOS]) {
-               nla_for_each_nested(attr, data[IFLA_VLAN_INGRESS_QOS], rem) {
-                       if (nla_type(attr) != IFLA_VLAN_QOS_MAPPING)
-                               continue;
+               nla_for_each_nested_type(attr, IFLA_VLAN_QOS_MAPPING,
+                                        data[IFLA_VLAN_INGRESS_QOS], rem) {
                        m = nla_data(attr);
                        vlan_dev_set_ingress_priority(dev, m->to, m->from);
                }
        }
        if (data[IFLA_VLAN_EGRESS_QOS]) {
-               nla_for_each_nested(attr, data[IFLA_VLAN_EGRESS_QOS], rem) {
-                       if (nla_type(attr) != IFLA_VLAN_QOS_MAPPING)
-                               continue;
+               nla_for_each_nested_type(attr, IFLA_VLAN_QOS_MAPPING,
+                                        data[IFLA_VLAN_EGRESS_QOS], rem) {
                        m = nla_data(attr);
                        err = vlan_dev_set_egress_priority(dev, m->from, m->to);
                        if (err)

diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c
index 6c4d90b..bc01b3a 100644 (file)
--- a/net/core/bpf_sk_storage.c
+++ b/net/core/bpf_sk_storage.c
@@ -496,27 +496,22 @@ bpf_sk_storage_diag_alloc(const struct nlattr *nla_stgs)
        if (!bpf_capable())
                return ERR_PTR(-EPERM);
 
-       nla_for_each_nested(nla, nla_stgs, rem) {
-               if (nla_type(nla) == SK_DIAG_BPF_STORAGE_REQ_MAP_FD) {
-                       if (nla_len(nla) != sizeof(u32))
-                               return ERR_PTR(-EINVAL);
-                       nr_maps++;
-               }
+       nla_for_each_nested_type(nla, SK_DIAG_BPF_STORAGE_REQ_MAP_FD,
+                                nla_stgs, rem) {
+               if (nla_len(nla) != sizeof(u32))
+                       return ERR_PTR(-EINVAL);
+               nr_maps++;
        }
 
        diag = kzalloc(struct_size(diag, maps, nr_maps), GFP_KERNEL);
        if (!diag)
                return ERR_PTR(-ENOMEM);
 
-       nla_for_each_nested(nla, nla_stgs, rem) {
-               struct bpf_map *map;
-               int map_fd;
-
-               if (nla_type(nla) != SK_DIAG_BPF_STORAGE_REQ_MAP_FD)
-                       continue;
+       nla_for_each_nested_type(nla, SK_DIAG_BPF_STORAGE_REQ_MAP_FD,
+                                nla_stgs, rem) {
+               int map_fd = nla_get_u32(nla);
+               struct bpf_map *map = bpf_map_get(map_fd);
 
-               map_fd = nla_get_u32(nla);
-               map = bpf_map_get(map_fd);
                if (IS_ERR(map)) {
                        err = PTR_ERR(map);
                        goto err_free;

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index a3d7847..283e42f 100644 (file)
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -5245,15 +5245,14 @@ static int rtnl_bridge_dellink(struct sk_buff *skb, struct nlmsghdr *nlh,
 
        br_spec = nlmsg_find_attr(nlh, sizeof(struct ifinfomsg), IFLA_AF_SPEC);
        if (br_spec) {
-               nla_for_each_nested(attr, br_spec, rem) {
-                       if (nla_type(attr) == IFLA_BRIDGE_FLAGS) {
-                               if (nla_len(attr) < sizeof(flags))
-                                       return -EINVAL;
+               nla_for_each_nested_type(attr, IFLA_BRIDGE_FLAGS, br_spec,
+                                        rem) {
+                       if (nla_len(attr) < sizeof(flags))
+                               return -EINVAL;
 
-                               have_flags = true;
-                               flags = nla_get_u16(attr);
-                               break;
-                       }
+                       have_flags = true;
+                       flags = nla_get_u16(attr);
+                       break;
                }
        }
 

diff --git a/net/devlink/dev.c b/net/devlink/dev.c
index 19dbf54..c609deb 100644 (file)
--- a/net/devlink/dev.c
+++ b/net/devlink/dev.c
@@ -1202,17 +1202,13 @@ static void __devlink_compat_running_version(struct devlink *devlink,
        if (err)
                goto free_msg;
 
-       nla_for_each_attr(nlattr, (void *)msg->data, msg->len, rem) {
+       nla_for_each_attr_type(nlattr, DEVLINK_ATTR_INFO_VERSION_RUNNING,
+                              (void *)msg->data, msg->len, rem) {
                const struct nlattr *kv;
                int rem_kv;
 
-               if (nla_type(nlattr) != DEVLINK_ATTR_INFO_VERSION_RUNNING)
-                       continue;
-
-               nla_for_each_nested(kv, nlattr, rem_kv) {
-                       if (nla_type(kv) != DEVLINK_ATTR_INFO_VERSION_VALUE)
-                               continue;
-
+               nla_for_each_nested_type(kv, DEVLINK_ATTR_INFO_VERSION_VALUE,
+                                        nlattr, rem_kv) {
                        strlcat(buf, nla_data(kv), len);
                        strlcat(buf, " ", len);
                }

diff --git a/net/sched/sch_mqprio.c b/net/sched/sch_mqprio.c
index 225353f..51d4013 100644 (file)
--- a/net/sched/sch_mqprio.c
+++ b/net/sched/sch_mqprio.c
@@ -215,10 +215,8 @@ static int mqprio_parse_tc_entries(struct Qdisc *sch, struct nlattr *nlattr_opt,
        for (tc = 0; tc < TC_QOPT_MAX_QUEUE; tc++)
                fp[tc] = priv->fp[tc];
 
-       nla_for_each_attr(n, nlattr_opt, nlattr_opt_len, rem) {
-               if (nla_type(n) != TCA_MQPRIO_TC_ENTRY)
-                       continue;
-
+       nla_for_each_attr_type(n, TCA_MQPRIO_TC_ENTRY, nlattr_opt,
+                              nlattr_opt_len, rem) {
                err = mqprio_parse_tc_entry(fp, n, &seen_tcs, extack);
                if (err)
                        goto out;

diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
index a0d54b4..1ab17e8 100644 (file)
--- a/net/sched/sch_taprio.c
+++ b/net/sched/sch_taprio.c
@@ -1752,10 +1752,7 @@ static int taprio_parse_tc_entries(struct Qdisc *sch,
                fp[tc] = q->fp[tc];
        }
 
-       nla_for_each_nested(n, opt, rem) {
-               if (nla_type(n) != TCA_TAPRIO_ATTR_TC_ENTRY)
-                       continue;
-
+       nla_for_each_nested_type(n, TCA_TAPRIO_ATTR_TC_ENTRY, opt, rem) {
                err = taprio_parse_tc_entry(sch, n, max_sdu, fp, &seen_tcs,
                                            extack);
                if (err)