tipc: convert legacy nl bearer enable/disable to nl compat

Introduce a framework for transcoding legacy nl action into actions
(.doit) calls from the new nl API. This is done by converting the
incoming TLV data into netlink data with nested netlink attributes.
Unfortunately due to the randomness of the legacy API we can't do this
generically so each legacy netlink command requires a specific
transcoding recipe. In this case for bearer enable and bearer disable.

Convert TIPC_CMD_ENABLE_BEARER and TIPC_CMD_DISABLE_BEARER into doit
compat calls.

Signed-off-by: Richard Alpe <richard.alpe@ericsson.com>
Reviewed-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 144 insertions, 0 deletions

diff --git a/net/tipc/netlink_compat.c b/net/tipc/netlink_compat.c
index bd75ea290e3a..12b0f4424797 100644
--- a/net/tipc/netlink_compat.c
+++ b/net/tipc/netlink_compat.c
@@ -49,6 +49,7 @@
 struct tipc_nl_compat_msg {
 	u16 cmd;
 	int rep_size;
+	int req_type;
 	struct sk_buff *rep;
 	struct tlv_desc *req;
 	struct sock *dst_sk;
@@ -59,6 +60,11 @@ struct tipc_nl_compat_cmd_dump {
 	int (*format)(struct tipc_nl_compat_msg *msg, struct nlattr **attrs);
 };
 
+struct tipc_nl_compat_cmd_doit {
+	int (*doit)(struct sk_buff *skb, struct genl_info *info);
+	int (*transcode)(struct sk_buff *skb, struct tipc_nl_compat_msg *msg);
+};
+
 static int tipc_skb_tailroom(struct sk_buff *skb)
 {
 	int tailroom;
@@ -213,6 +219,78 @@ static int tipc_nl_compat_dumpit(struct tipc_nl_compat_cmd_dump *cmd,
 	return err;
 }
 
+static int __tipc_nl_compat_doit(struct tipc_nl_compat_cmd_doit *cmd,
+				 struct tipc_nl_compat_msg *msg)
+{
+	int err;
+	struct sk_buff *doit_buf;
+	struct sk_buff *trans_buf;
+	struct nlattr **attrbuf;
+	struct genl_info info;
+
+	trans_buf = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!trans_buf)
+		return -ENOMEM;
+
+	err = (*cmd->transcode)(trans_buf, msg);
+	if (err)
+		goto trans_out;
+
+	attrbuf = kmalloc((tipc_genl_family.maxattr + 1) *
+			sizeof(struct nlattr *), GFP_KERNEL);
+	if (!attrbuf) {
+		err = -ENOMEM;
+		goto trans_out;
+	}
+
+	err = nla_parse(attrbuf, tipc_genl_family.maxattr,
+			(const struct nlattr *)trans_buf->data,
+			trans_buf->len, NULL);
+	if (err)
+		goto parse_out;
+
+	doit_buf = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!doit_buf) {
+		err = -ENOMEM;
+		goto parse_out;
+	}
+
+	doit_buf->sk = msg->dst_sk;
+
+	memset(&info, 0, sizeof(info));
+	info.attrs = attrbuf;
+
+	err = (*cmd->doit)(doit_buf, &info);
+
+	kfree_skb(doit_buf);
+parse_out:
+	kfree(attrbuf);
+trans_out:
+	kfree_skb(trans_buf);
+
+	return err;
+}
+
+static int tipc_nl_compat_doit(struct tipc_nl_compat_cmd_doit *cmd,
+			       struct tipc_nl_compat_msg *msg)
+{
+	int err;
+
+	if (msg->req_type && !TLV_CHECK_TYPE(msg->req, msg->req_type))
+		return -EINVAL;
+
+	err = __tipc_nl_compat_doit(cmd, msg);
+	if (err)
+		return err;
+
+	/* The legacy API considered an empty message a success message */
+	msg->rep = tipc_tlv_alloc(0);
+	if (!msg->rep)
+		return -ENOMEM;
+
+	return 0;
+}
+
 static int tipc_nl_compat_bearer_dump(struct tipc_nl_compat_msg *msg,
 				      struct nlattr **attrs)
 {
@@ -226,11 +304,65 @@ static int tipc_nl_compat_bearer_dump(struct tipc_nl_compat_msg *msg,
 			    nla_len(bearer[TIPC_NLA_BEARER_NAME]));
 }
 
+static int tipc_nl_compat_bearer_enable(struct sk_buff *skb,
+					struct tipc_nl_compat_msg *msg)
+{
+	struct nlattr *prop;
+	struct nlattr *bearer;
+	struct tipc_bearer_config *b;
+
+	b = (struct tipc_bearer_config *)TLV_DATA(msg->req);
+
+	bearer = nla_nest_start(skb, TIPC_NLA_BEARER);
+	if (!bearer)
+		return -EMSGSIZE;
+
+	if (nla_put_string(skb, TIPC_NLA_BEARER_NAME, b->name))
+		return -EMSGSIZE;
+
+	if (nla_put_u32(skb, TIPC_NLA_BEARER_DOMAIN, ntohl(b->disc_domain)))
+		return -EMSGSIZE;
+
+	if (ntohl(b->priority) <= TIPC_MAX_LINK_PRI) {
+		prop = nla_nest_start(skb, TIPC_NLA_BEARER_PROP);
+		if (!prop)
+			return -EMSGSIZE;
+		if (nla_put_u32(skb, TIPC_NLA_PROP_PRIO, ntohl(b->priority)))
+			return -EMSGSIZE;
+		nla_nest_end(skb, prop);
+	}
+	nla_nest_end(skb, bearer);
+
+	return 0;
+}
+
+static int tipc_nl_compat_bearer_disable(struct sk_buff *skb,
+					 struct tipc_nl_compat_msg *msg)
+{
+	char *name;
+	struct nlattr *bearer;
+
+	name = (char *)TLV_DATA(msg->req);
+
+	bearer = nla_nest_start(skb, TIPC_NLA_BEARER);
+	if (!bearer)
+		return -EMSGSIZE;
+
+	if (nla_put_string(skb, TIPC_NLA_BEARER_NAME, name))
+		return -EMSGSIZE;
+
+	nla_nest_end(skb, bearer);
+
+	return 0;
+}
+
 static int tipc_nl_compat_handle(struct tipc_nl_compat_msg *msg)
 {
 	struct tipc_nl_compat_cmd_dump dump;
+	struct tipc_nl_compat_cmd_doit doit;
 
 	memset(&dump, 0, sizeof(dump));
+	memset(&doit, 0, sizeof(doit));
 
 	switch (msg->cmd) {
 	case TIPC_CMD_GET_BEARER_NAMES:
@@ -238,6 +370,16 @@ static int tipc_nl_compat_handle(struct tipc_nl_compat_msg *msg)
 		dump.dumpit = tipc_nl_bearer_dump;
 		dump.format = tipc_nl_compat_bearer_dump;
 		return tipc_nl_compat_dumpit(&dump, msg);
+	case TIPC_CMD_ENABLE_BEARER:
+		msg->req_type = TIPC_TLV_BEARER_CONFIG;
+		doit.doit = tipc_nl_bearer_enable;
+		doit.transcode = tipc_nl_compat_bearer_enable;
+		return tipc_nl_compat_doit(&doit, msg);
+	case TIPC_CMD_DISABLE_BEARER:
+		msg->req_type = TIPC_TLV_BEARER_NAME;
+		doit.doit = tipc_nl_bearer_disable;
+		doit.transcode = tipc_nl_compat_bearer_disable;
+		return tipc_nl_compat_doit(&doit, msg);
 	}
 
 	return -EOPNOTSUPP;
@@ -335,6 +477,8 @@ static int tipc_nl_compat_tmp_wrap(struct sk_buff *skb, struct genl_info *info)
 
 	switch (req->cmd) {
 	case TIPC_CMD_GET_BEARER_NAMES:
+	case TIPC_CMD_ENABLE_BEARER:
+	case TIPC_CMD_DISABLE_BEARER:
 		return tipc_nl_compat_recv(skb, info);
 	}