netlink: make range pointers in policies const

struct nla_policy is usually constant itself, but unless
we make the ranges inside constant we won't be able to
make range structs const. The ranges are not modified
by the core.

Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20231025162204.132528-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/bonding/bond_netlink.c

@@ -85,7 +85,7 @@ static int bond_fill_slave_info(struct sk_buff *skb,
 }
 
 /* Limit the max delay range to 300s */
-static struct netlink_range_validation delay_range = {
+static const struct netlink_range_validation delay_range = {
 	.max = 300000,
 };
 

drivers/net/vxlan/vxlan_mdb.c

@@ -311,7 +311,7 @@ vxlan_mdbe_src_list_pol[MDBE_SRC_LIST_MAX + 1] = {
 	[MDBE_SRC_LIST_ENTRY] = NLA_POLICY_NESTED(vxlan_mdbe_src_list_entry_pol),
 };
 
-static struct netlink_range_validation vni_range = {
+static const struct netlink_range_validation vni_range = {
 	.max = VXLAN_N_VID - 1,
 };
 

include/net/netlink.h

@@ -360,8 +360,8 @@ struct nla_policy {
 		const u32 mask;
 		const char *reject_message;
 		const struct nla_policy *nested_policy;
-		struct netlink_range_validation *range;
-		struct netlink_range_validation_signed *range_signed;
+		const struct netlink_range_validation *range;
+		const struct netlink_range_validation_signed *range_signed;
 		struct {
 			s16 min, max;
 		};

net/ipv6/ioam6_iptunnel.c

@@ -46,7 +46,7 @@ struct ioam6_lwt {
 	struct ioam6_lwt_encap	tuninfo;
 };
 
-static struct netlink_range_validation freq_range = {
+static const struct netlink_range_validation freq_range = {
 	.min = IOAM6_IPTUNNEL_FREQ_MIN,
 	.max = IOAM6_IPTUNNEL_FREQ_MAX,
 };

net/sched/sch_fq.c

@@ -897,7 +897,7 @@ static int fq_resize(struct Qdisc *sch, u32 log)
 	return 0;
 }
 
-static struct netlink_range_validation iq_range = {
+static const struct netlink_range_validation iq_range = {
 	.max = INT_MAX,
 };
 

net/sched/sch_fq_pie.c

@@ -202,7 +202,7 @@ static int fq_pie_qdisc_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 	return NET_XMIT_CN;
 }
 
-static struct netlink_range_validation fq_pie_q_range = {
+static const struct netlink_range_validation fq_pie_q_range = {
 	.min = 1,
 	.max = 1 << 20,
 };

net/sched/sch_qfq.c

@@ -213,7 +213,7 @@ static struct qfq_class *qfq_find_class(struct Qdisc *sch, u32 classid)
 	return container_of(clc, struct qfq_class, common);
 }
 
-static struct netlink_range_validation lmax_range = {
+static const struct netlink_range_validation lmax_range = {
 	.min = QFQ_MIN_LMAX,
 	.max = QFQ_MAX_LMAX,
 };

net/sched/sch_taprio.c

@@ -1015,7 +1015,7 @@ static const struct nla_policy taprio_tc_policy[TCA_TAPRIO_TC_ENTRY_MAX + 1] = {
 							      TC_FP_PREEMPTIBLE),
 };
 
-static struct netlink_range_validation_signed taprio_cycle_time_range = {
+static const struct netlink_range_validation_signed taprio_cycle_time_range = {
 	.min = 0,
 	.max = INT_MAX,
 };

net/wireless/nl80211.c

@@ -463,7 +463,7 @@ nl80211_sta_wme_policy[NL80211_STA_WME_MAX + 1] = {
 	[NL80211_STA_WME_MAX_SP] = { .type = NLA_U8 },
 };
 
-static struct netlink_range_validation nl80211_punct_bitmap_range = {
+static const struct netlink_range_validation nl80211_punct_bitmap_range = {
 	.min = 0,
 	.max = 0xffff,
 };

tools/net/ynl/ynl-gen-c.py

@@ -2038,7 +2038,7 @@ def print_kernel_policy_ranges(family, cw):
                 first = False
 
             sign = '' if attr.type[0] == 'u' else '_signed'
-            cw.block_start(line=f'struct netlink_range_validation{sign} {c_lower(attr.enum_name)}_range =')
+            cw.block_start(line=f'static const struct netlink_range_validation{sign} {c_lower(attr.enum_name)}_range =')
             members = []
             if 'min' in attr.checks:
                 members.append(('min', attr.get_limit('min')))