diff mbox series

[net-next,v2,10/10] genetlink: allow dumping command-specific policy

Message ID 20201001225933.1373426-11-kuba@kernel.org
State New
Headers show
Series genetlink: support per-command policy dump | expand

Commit Message

Jakub Kicinski Oct. 1, 2020, 10:59 p.m. UTC 
Right now CTRL_CMD_GETPOLICY can only dump the family-wide
policy. Support dumping policy of a specific op.

v2:
 - make cmd U32, just in case.
v1:
 - don't echo op in the output in a naive way, this should
   make it cleaner to extend the output format for dumping
   policies for all the commands at once in the future.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 include/uapi/linux/genetlink.h |  1 +
 net/netlink/genetlink.c        | 24 +++++++++++++++++++-----
 2 files changed, 20 insertions(+), 5 deletions(-)

Comments

Johannes Berg Oct. 2, 2020, 6:34 a.m. UTC | #1 
On Thu, 2020-10-01 at 15:59 -0700, Jakub Kicinski wrote:
> Right now CTRL_CMD_GETPOLICY can only dump the family-wide
> policy. Support dumping policy of a specific op.
> 
> v2:
>  - make cmd U32, just in case.
> v1:
>  - don't echo op in the output in a naive way, this should
>    make it cleaner to extend the output format for dumping
>    policies for all the commands at once in the future.

Great, thanks :)

Reviewed-by: Johannes Berg <johannes@sipsolutions.net>

johannes
diff mbox series

Patch

diff --git a/include/uapi/linux/genetlink.h b/include/uapi/linux/genetlink.h
index 9c0636ec2286..7dbe2d5d7d46 100644
--- a/include/uapi/linux/genetlink.h
+++ b/include/uapi/linux/genetlink.h
@@ -64,6 +64,7 @@  enum {
 	CTRL_ATTR_OPS,
 	CTRL_ATTR_MCAST_GROUPS,
 	CTRL_ATTR_POLICY,
+	CTRL_ATTR_OP,
 	__CTRL_ATTR_MAX,
 };
 
diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index fc5d25bd5698..dd4b7a2979ac 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -123,7 +123,7 @@  static void genl_op_from_full(const struct genl_family *family,
 		op->policy = family->policy;
 }
 
-static int genl_get_cmd_full(u8 cmd, const struct genl_family *family,
+static int genl_get_cmd_full(u32 cmd, const struct genl_family *family,
 			     struct genl_ops *op)
 {
 	int i;
@@ -152,7 +152,7 @@  static void genl_op_from_small(const struct genl_family *family,
 	op->policy = family->policy;
 }
 
-static int genl_get_cmd_small(u8 cmd, const struct genl_family *family,
+static int genl_get_cmd_small(u32 cmd, const struct genl_family *family,
 			      struct genl_ops *op)
 {
 	int i;
@@ -166,7 +166,7 @@  static int genl_get_cmd_small(u8 cmd, const struct genl_family *family,
 	return -ENOENT;
 }
 
-static int genl_get_cmd(u8 cmd, const struct genl_family *family,
+static int genl_get_cmd(u32 cmd, const struct genl_family *family,
 			struct genl_ops *op)
 {
 	if (!genl_get_cmd_full(cmd, family, op))
@@ -1119,6 +1119,7 @@  static const struct nla_policy ctrl_policy_policy[] = {
 	[CTRL_ATTR_FAMILY_ID]	= { .type = NLA_U16 },
 	[CTRL_ATTR_FAMILY_NAME]	= { .type = NLA_NUL_STRING,
 				    .len = GENL_NAMSIZ - 1 },
+	[CTRL_ATTR_OP]		= { .type = NLA_U32 },
 };
 
 static int ctrl_dumppolicy_start(struct netlink_callback *cb)
@@ -1127,6 +1128,8 @@  static int ctrl_dumppolicy_start(struct netlink_callback *cb)
 	struct ctrl_dump_policy_ctx *ctx = (void *)cb->ctx;
 	struct nlattr **tb = info->attrs;
 	const struct genl_family *rt;
+	struct genl_ops op;
+	int err;
 
 	BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));
 
@@ -1147,10 +1150,21 @@  static int ctrl_dumppolicy_start(struct netlink_callback *cb)
 	if (!rt)
 		return -ENOENT;
 
-	if (!rt->policy)
+	if (tb[CTRL_ATTR_OP]) {
+		err = genl_get_cmd(nla_get_u32(tb[CTRL_ATTR_OP]), rt, &op);
+		if (err) {
+			NL_SET_BAD_ATTR(cb->extack, tb[CTRL_ATTR_OP]);
+			return err;
+		}
+	} else {
+		op.policy = rt->policy;
+		op.maxattr = rt->maxattr;
+	}
+
+	if (!op.policy)
 		return -ENODATA;
 
-	return netlink_policy_dump_start(rt->policy, rt->maxattr, &ctx->state);
+	return netlink_policy_dump_start(op.policy, op.maxattr, &ctx->state);
 }
 
 static int ctrl_dumppolicy(struct sk_buff *skb, struct netlink_callback *cb)