[dpdk-dev] [PATCH 2/5] net/mlx5: retrieve device index from Netlink

[Nelio Laranjeiro <nelio.laranjeiro@6wind.com>]

This patch new file is not compiled yet, it starts a series necessary to
fix some issues with VF devices.

Signed-off-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>
---
 drivers/net/mlx5/mlx5_vf.c | 134 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 134 insertions(+)
 create mode 100644 drivers/net/mlx5/mlx5_vf.c

diff --git a/drivers/net/mlx5/mlx5_vf.c b/drivers/net/mlx5/mlx5_vf.c
new file mode 100644
index 000000000..357407f56
--- /dev/null
+++ b/drivers/net/mlx5/mlx5_vf.c
@@ -0,0 +1,134 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright 2018 6WIND S.A.
+ * Copyright 2018 Mellanox Technologies, Ltd.
+ */
+
+#include <linux/rtnetlink.h>
+#include <linux/netlink.h>
+
+#include <rte_netlink.h>
+
+#include "mlx5.h"
+#include "mlx5_utils.h"
+
+/* Data exchanged between Netlink library and PMD. */
+struct mlx5_vf_iface {
+	struct rte_eth_dev *dev; /**< Pointer to Ethernet device. */
+	int iface_idx; /**< Network Interface index. */
+};
+
+/**
+ * Parse Netlink message to retrieve the interface index.
+ *
+ * @param nh
+ *   Pointer to Netlink Message Header.
+ * @param arg
+ *   PMD data register with this callback.
+ *
+ * @return
+ *   0 on success, -1 otherwise.
+ */
+static int
+mlx5_vf_iface_idx_cb(struct nlmsghdr *nh, void *arg)
+{
+	struct mlx5_vf_iface *data = arg;
+	struct rte_eth_dev *dev = data->dev;
+	const struct ether_addr *mac = &dev->data->mac_addrs[0];
+	struct ifinfomsg *iface;
+	struct rtattr *attribute;
+	int len;
+
+	/**
+	 * Leave right away if the index does not match its initialised value.
+	 * Interface index has already been found.
+	 */
+	if (data->iface_idx != -1)
+		return 0;
+	iface = NLMSG_DATA(nh);
+	len = nh->nlmsg_len - NLMSG_LENGTH(sizeof(*iface));
+	for (attribute = IFLA_RTA(iface);
+	     RTA_OK(attribute, len);
+	     attribute = RTA_NEXT(attribute, len)) {
+		if (attribute->rta_type == IFLA_ADDRESS &&
+		    !memcmp(RTA_DATA(attribute), mac, ETHER_ADDR_LEN)) {
+#ifndef NDEBUG
+			struct ether_addr m;
+
+			memcpy(&m, RTA_DATA(attribute), ETHER_ADDR_LEN);
+			DRV_LOG(DEBUG,
+				"port %u interace %d MAC address"
+				" %02X:%02X:%02X:%02X:%02X:%02X",
+				dev->data->port_id,
+				iface->ifi_index,
+				m.addr_bytes[0], m.addr_bytes[1],
+				m.addr_bytes[2], m.addr_bytes[3],
+				m.addr_bytes[4], m.addr_bytes[5]);
+#endif
+			data->iface_idx = iface->ifi_index;
+			return 0;
+		}
+	}
+	data->iface_idx = -1;
+	return 0;
+}
+
+/**
+ * Retrieve interface Netlink interface index.
+ *
+ * @param dev
+ *   Pointer to Ethernet device.
+ *
+ * @return
+ *   Interface index, a negative errno value otherwise and rte_errno is set.
+ */
+static int
+mlx5_vf_iface_idx(struct rte_eth_dev *dev)
+{
+	struct nl_req {
+		struct nlmsghdr hdr;
+		struct rtgenmsg gen;
+	} req = {
+		.hdr = {
+			.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtgenmsg)),
+			.nlmsg_type = RTM_GETLINK,
+			.nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP | NLM_F_ROOT,
+		},
+		.gen = {
+			.rtgen_family =  AF_UNSPEC,
+		},
+	};
+	struct mlx5_vf_iface data = {
+		.dev = dev,
+		.iface_idx = -1,
+	};
+	int fd;
+	int ret;
+
+	fd = rte_nl_init(RTMGRP_LINK);
+	if (fd < 0) {
+		rte_errno = errno;
+		goto error;
+	}
+	ret = rte_nl_send(fd, &req.hdr);
+	if (ret == -1) {
+		rte_errno = errno;
+		goto error;
+	}
+	ret = rte_nl_recv(fd, mlx5_vf_iface_idx_cb, &data);
+	if (ret == -1) {
+		rte_errno = errno;
+		goto error;
+	}
+	rte_nl_final(fd);
+	if (data.iface_idx == -1) {
+		rte_errno = EAGAIN;
+		goto error;
+	}
+	return data.iface_idx;
+error:
+	if (fd >= 0)
+		rte_nl_final(fd);
+	DRV_LOG(DEBUG, "port %u cannot retrieve Netlink Interface index %s",
+		dev->data->port_id, strerror(rte_errno));
+	return -rte_errno;
+}
-- 
2.11.0