[dpdk-dev] [PATCH v10 11/20] unci: add netlink exec

[Ferruh Yigit <ferruh.yigit@intel.com>]

Add netlink exec function, which sends a message to userspace and waits
and receives the response from userspace.

Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
---
 .../linuxapp/eal/include/exec-env/unci.h           |   6 +
 lib/librte_eal/linuxapp/unci/unci_dev.h            |   4 +
 lib/librte_eal/linuxapp/unci/unci_net.c            |   5 +
 lib/librte_eal/linuxapp/unci/unci_nl.c             | 180 +++++++++++++++++++++
 4 files changed, 195 insertions(+)

diff --git a/lib/librte_eal/linuxapp/eal/include/exec-env/unci.h b/lib/librte_eal/linuxapp/eal/include/exec-env/unci.h
index 6d3490aee..3d88b7ef3 100644
--- a/lib/librte_eal/linuxapp/eal/include/exec-env/unci.h
+++ b/lib/librte_eal/linuxapp/eal/include/exec-env/unci.h
@@ -74,6 +74,12 @@ struct unci_nl_msg {
 	int err;
 };
 
+enum unci_ethtool_msg_flag {
+	UNCI_MSG_FLAG_NONE,
+	UNCI_MSG_FLAG_REQUEST,
+	UNCI_MSG_FLAG_RESPONSE,
+};
+
 /* can go into include/uapi/linux/if_link.h */
 enum {
 	IFLA_UNCI_UNSPEC,
diff --git a/lib/librte_eal/linuxapp/unci/unci_dev.h b/lib/librte_eal/linuxapp/unci/unci_dev.h
index a748abf98..8d9ca6970 100644
--- a/lib/librte_eal/linuxapp/unci/unci_dev.h
+++ b/lib/librte_eal/linuxapp/unci/unci_dev.h
@@ -37,9 +37,13 @@
 struct unci_dev {
 	__u32 port_id;
 	__u32 pid;
+	struct completion msg_received;
+	u32 nb_timedout_msg;
 };
 
 int unci_nl_init(void);
 void unci_nl_release(void);
+int unci_nl_exec(u32 cmd, struct net_device *dev, void *in_data,
+		size_t in_len, void *out_data, size_t out_len);
 
 #endif /* _UNCI_DEV_H_ */
diff --git a/lib/librte_eal/linuxapp/unci/unci_net.c b/lib/librte_eal/linuxapp/unci/unci_net.c
index 1989b6d23..27b9f9f70 100644
--- a/lib/librte_eal/linuxapp/unci/unci_net.c
+++ b/lib/librte_eal/linuxapp/unci/unci_net.c
@@ -31,8 +31,13 @@ static const struct net_device_ops unci_net_netdev_ops = { 0 };
 
 static void unci_net_setup(struct net_device *dev)
 {
+	struct unci_dev *unci;
+
 	ether_setup(dev);
 	dev->netdev_ops = &unci_net_netdev_ops;
+
+	unci = netdev_priv(dev);
+	init_completion(&unci->msg_received);
 }
 
 static int unci_net_newlink(struct net *net, struct net_device *dev,
diff --git a/lib/librte_eal/linuxapp/unci/unci_nl.c b/lib/librte_eal/linuxapp/unci/unci_nl.c
index 1461a3309..fd79ec8f9 100644
--- a/lib/librte_eal/linuxapp/unci/unci_nl.c
+++ b/lib/librte_eal/linuxapp/unci/unci_nl.c
@@ -26,6 +26,180 @@
 
 #include "unci_dev.h"
 
+#define UNCI_GENL_MSG_LEN 1536
+
+#define UNCI_CMD_TIMEOUT 500 /* ms */
+
+static struct response_buffer {
+	int magic; /* for sanity check */
+	void *buffer;
+	size_t length;
+	struct completion *msg_received;
+	int *err;
+	u32 in_use;
+} response_buffer;
+
+static DEFINE_MUTEX(sync_lock);
+
+static int unci_response_buffer_register(int magic, void *buffer, size_t length,
+		struct completion *msg_received, int *err)
+{
+	if (!response_buffer.in_use) {
+		response_buffer.magic = magic;
+		response_buffer.buffer = buffer;
+		response_buffer.length = length;
+		response_buffer.msg_received = msg_received;
+		response_buffer.err = err;
+		response_buffer.in_use = 1;
+		return 0;
+	}
+
+	return 1;
+}
+
+static void unci_response_buffer_unregister(int magic)
+{
+	if (response_buffer.in_use) {
+		if (magic == response_buffer.magic) {
+			response_buffer.magic = -1;
+			response_buffer.buffer = NULL;
+			response_buffer.length = 0;
+			response_buffer.msg_received = NULL;
+			response_buffer.err = NULL;
+			response_buffer.in_use = 0;
+		} else {
+			pr_err("Unregister magic mismatch\n");
+		}
+	}
+}
+
+static void nl_recv_user_request(struct unci_nl_msg *nl_msg)
+{
+	/* Userspace requests not supported yet */
+	pr_debug("Request from userspace received\n");
+}
+
+static void nl_recv_user_response(struct unci_nl_msg *nl_msg)
+{
+	struct completion *msg_received;
+	size_t recv_len;
+	size_t expected_len;
+
+	if (response_buffer.in_use) {
+		if (response_buffer.buffer != NULL) {
+			recv_len = nl_msg->output_buffer_len;
+			expected_len = response_buffer.length;
+
+			memcpy(response_buffer.buffer,
+					nl_msg->output_buffer,
+					response_buffer.length);
+
+			if (nl_msg->err == 0 && recv_len != expected_len)
+				pr_info("Expected and received len not match "
+					"%zu - %zu\n", recv_len, expected_len);
+		}
+
+		*response_buffer.err = nl_msg->err;
+		msg_received = response_buffer.msg_received;
+		unci_response_buffer_unregister(response_buffer.magic);
+		complete(msg_received);
+	}
+}
+
+static struct genl_family unci_genl_family;
+
+static int unci_nl_send(u32 cmd_id, u32 port_id, u32 pid, void *in_data,
+		size_t in_data_len)
+{
+	struct unci_nl_msg nl_msg;
+	struct sk_buff *skb;
+	void *payload;
+	u32 size = 0;
+
+	if (pid == 0)
+		return -1;
+
+	memset(&nl_msg, 0, sizeof(struct unci_nl_msg));
+	nl_msg.cmd_id = cmd_id;
+	nl_msg.port_id = port_id;
+
+	if (in_data) {
+		if (in_data_len == 0 || in_data_len > UNCI_NL_MSG_LEN)
+			return -EINVAL;
+		nl_msg.input_buffer_len = in_data_len;
+		memcpy(nl_msg.input_buffer, in_data, in_data_len);
+	}
+
+	skb = genlmsg_new(UNCI_GENL_MSG_LEN, GFP_ATOMIC);
+	if (!skb)
+		return -ENOMEM;
+
+	size = sizeof(struct unci_nl_msg) + GENL_HDRLEN +
+		unci_genl_family.hdrsize;
+
+	payload = genlmsg_put(skb, 0, 0, &unci_genl_family, 0, UNCI_CMD_MSG);
+	if (payload == NULL) {
+		nlmsg_free(skb);
+		return -EMSGSIZE;
+	}
+
+	nla_put(skb, UNCI_ATTR_MSG, sizeof(struct unci_nl_msg), &nl_msg);
+
+	genlmsg_end(skb, payload);
+
+	genlmsg_unicast(&init_net, skb, pid);
+	pr_debug("Sent cmd:%u port:%u pid:%u\n", cmd_id, port_id, pid);
+
+	return 0;
+}
+
+int unci_nl_exec(u32 cmd, struct net_device *dev, void *in_data,
+		size_t in_data_len, void *out_data, size_t out_data_len)
+{
+	struct unci_dev *unci = netdev_priv(dev);
+	int err = -EINVAL;
+	int ret;
+
+	if (out_data_len > UNCI_NL_MSG_LEN) {
+		pr_err("Message is too big to receive:%zu\n", out_data_len);
+		return err;
+	}
+
+	mutex_lock(&sync_lock);
+	ret = unci_response_buffer_register(cmd, out_data, out_data_len,
+			&unci->msg_received, &err);
+	if (ret) {
+		mutex_unlock(&sync_lock);
+		return -EINVAL;
+	}
+
+	ret = unci_nl_send(cmd, unci->port_id, unci->pid, in_data, in_data_len);
+	if (ret) {
+		unci_response_buffer_unregister(response_buffer.magic);
+		mutex_unlock(&sync_lock);
+		return ret;
+	}
+
+	ret = wait_for_completion_interruptible_timeout(&unci->msg_received,
+			 msecs_to_jiffies(UNCI_CMD_TIMEOUT));
+	if (ret == 0 || err < 0) {
+		unci_response_buffer_unregister(response_buffer.magic);
+		mutex_unlock(&sync_lock);
+		if (ret == 0) { /* timeout */
+			unci->nb_timedout_msg++;
+			pr_info("Command timed-out for port:%u cmd:%u (%u)\n",
+				unci->port_id, cmd, unci->nb_timedout_msg);
+			return -EINVAL;
+		}
+		pr_debug("Command return error for port:%d cmd:%d err:%d\n",
+				unci->port_id, cmd, err);
+		return err;
+	}
+	mutex_unlock(&sync_lock);
+
+	return 0;
+}
+
 static int unci_genl_process(struct sk_buff *skb, struct genl_info *info)
 {
 	struct nlattr **attrs = info->attrs;
@@ -37,6 +211,12 @@ static int unci_genl_process(struct sk_buff *skb, struct genl_info *info)
 	nla_memcpy(&nl_msg, attrs[UNCI_ATTR_MSG], sizeof(struct unci_nl_msg));
 	pr_debug("cmd: %u\n", nl_msg.cmd_id);
 
+	if (nl_msg.flag & UNCI_MSG_FLAG_REQUEST) {
+		nl_recv_user_request(&nl_msg);
+		return 0;
+	}
+
+	nl_recv_user_response(&nl_msg);
 	return 0;
 }
 
-- 
2.13.0