[PATCH net-next v2 10/10] genetlink: allow dumping command-specific policy
From: Jakub Kicinski <kuba@kernel.org>
Date: 2020-10-01 23:00:02
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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(-)
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)
--
2.26.2