netdev - [PATCH net-next 9/9] genetlink: allow dumping command-specific policy

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu,  1 Oct 2020 11:30:16 -0700
From:   Jakub Kicinski <kuba@...nel.org>
To:     davem@...emloft.net
Cc:     netdev@...r.kernel.org, andrew@...n.ch, johannes@...solutions.net,
        jiri@...nulli.us, mkubecek@...e.cz, dsahern@...nel.org,
        pablo@...filter.org, Jakub Kicinski <kuba@...nel.org>
Subject: [PATCH net-next 9/9] genetlink: allow dumping command-specific policy

Right now CTRL_CMD_GETPOLICY can only dump the family-wide
policy. Support dumping policy of a specific op.

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@...nel.org>
---
 include/uapi/linux/genetlink.h |  1 +
 net/netlink/genetlink.c        | 18 ++++++++++++++++--
 2 files changed, 17 insertions(+), 2 deletions(-)

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 81f0b960e9f8..bc5a6fd60abc 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -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_U8 },
 };
 
 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_u8(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)
-- 
2.26.2