net/ncsi: Add generic netlink family

Add a generic netlink family for NCSI. This supports three commands;
NCSI_CMD_PKG_INFO which returns information on packages and their
associated channels, NCSI_CMD_SET_INTERFACE which allows a specific
package or package/channel combination to be set as the preferred
choice, and NCSI_CMD_CLEAR_INTERFACE which clears any preferred setting.

Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 421 insertions, 0 deletions

diff --git a/net/ncsi/ncsi-netlink.c b/net/ncsi/ncsi-netlink.c
new file mode 100644
index 000000000000..d4201665a580
--- /dev/null
+++ b/net/ncsi/ncsi-netlink.c
@@ -0,0 +1,421 @@
+/*
+ * Copyright Samuel Mendoza-Jonas, IBM Corporation 2018.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/if_arp.h>
+#include <linux/rtnetlink.h>
+#include <linux/etherdevice.h>
+#include <linux/module.h>
+#include <net/genetlink.h>
+#include <net/ncsi.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <uapi/linux/ncsi.h>
+
+#include "internal.h"
+#include "ncsi-netlink.h"
+
+static struct genl_family ncsi_genl_family;
+
+static const struct nla_policy ncsi_genl_policy[NCSI_ATTR_MAX + 1] = {
+	[NCSI_ATTR_IFINDEX] =		{ .type = NLA_U32 },
+	[NCSI_ATTR_PACKAGE_LIST] =	{ .type = NLA_NESTED },
+	[NCSI_ATTR_PACKAGE_ID] =	{ .type = NLA_U32 },
+	[NCSI_ATTR_CHANNEL_ID] =	{ .type = NLA_U32 },
+};
+
+static struct ncsi_dev_priv *ndp_from_ifindex(struct net *net, u32 ifindex)
+{
+	struct ncsi_dev_priv *ndp;
+	struct net_device *dev;
+	struct ncsi_dev *nd;
+	struct ncsi_dev;
+
+	if (!net)
+		return NULL;
+
+	dev = dev_get_by_index(net, ifindex);
+	if (!dev) {
+		pr_err("NCSI netlink: No device for ifindex %u\n", ifindex);
+		return NULL;
+	}
+
+	nd = ncsi_find_dev(dev);
+	ndp = nd ? TO_NCSI_DEV_PRIV(nd) : NULL;
+
+	dev_put(dev);
+	return ndp;
+}
+
+static int ncsi_write_channel_info(struct sk_buff *skb,
+				   struct ncsi_dev_priv *ndp,
+				   struct ncsi_channel *nc)
+{
+	struct nlattr *vid_nest;
+	struct ncsi_channel_filter *ncf;
+	struct ncsi_channel_mode *m;
+	u32 *data;
+	int i;
+
+	nla_put_u32(skb, NCSI_CHANNEL_ATTR_ID, nc->id);
+	m = &nc->modes[NCSI_MODE_LINK];
+	nla_put_u32(skb, NCSI_CHANNEL_ATTR_LINK_STATE, m->data[2]);
+	if (nc->state == NCSI_CHANNEL_ACTIVE)
+		nla_put_flag(skb, NCSI_CHANNEL_ATTR_ACTIVE);
+	if (ndp->force_channel == nc)
+		nla_put_flag(skb, NCSI_CHANNEL_ATTR_FORCED);
+
+	nla_put_u32(skb, NCSI_CHANNEL_ATTR_VERSION_MAJOR, nc->version.version);
+	nla_put_u32(skb, NCSI_CHANNEL_ATTR_VERSION_MINOR, nc->version.alpha2);
+	nla_put_string(skb, NCSI_CHANNEL_ATTR_VERSION_STR, nc->version.fw_name);
+
+	vid_nest = nla_nest_start(skb, NCSI_CHANNEL_ATTR_VLAN_LIST);
+	if (!vid_nest)
+		return -ENOMEM;
+	ncf = nc->filters[NCSI_FILTER_VLAN];
+	i = -1;
+	if (ncf) {
+		while ((i = find_next_bit((void *)&ncf->bitmap, ncf->total,
+					  i + 1)) < ncf->total) {
+			data = ncsi_get_filter(nc, NCSI_FILTER_VLAN, i);
+			/* Uninitialised channels will have 'zero' vlan ids */
+			if (!data || !*data)
+				continue;
+			nla_put_u16(skb, NCSI_CHANNEL_ATTR_VLAN_ID,
+				    *(u16 *)data);
+		}
+	}
+	nla_nest_end(skb, vid_nest);
+
+	return 0;
+}
+
+static int ncsi_write_package_info(struct sk_buff *skb,
+				   struct ncsi_dev_priv *ndp, unsigned int id)
+{
+	struct nlattr *pnest, *cnest, *nest;
+	struct ncsi_package *np;
+	struct ncsi_channel *nc;
+	bool found;
+	int rc;
+
+	if (id > ndp->package_num) {
+		netdev_info(ndp->ndev.dev, "NCSI: No package with id %u\n", id);
+		return -ENODEV;
+	}
+
+	found = false;
+	NCSI_FOR_EACH_PACKAGE(ndp, np) {
+		if (np->id != id)
+			continue;
+		pnest = nla_nest_start(skb, NCSI_PKG_ATTR);
+		if (!pnest)
+			return -ENOMEM;
+		nla_put_u32(skb, NCSI_PKG_ATTR_ID, np->id);
+		if (ndp->force_package == np)
+			nla_put_flag(skb, NCSI_PKG_ATTR_FORCED);
+		cnest = nla_nest_start(skb, NCSI_PKG_ATTR_CHANNEL_LIST);
+		if (!cnest) {
+			nla_nest_cancel(skb, pnest);
+			return -ENOMEM;
+		}
+		NCSI_FOR_EACH_CHANNEL(np, nc) {
+			nest = nla_nest_start(skb, NCSI_CHANNEL_ATTR);
+			if (!nest) {
+				nla_nest_cancel(skb, cnest);
+				nla_nest_cancel(skb, pnest);
+				return -ENOMEM;
+			}
+			rc = ncsi_write_channel_info(skb, ndp, nc);
+			if (rc) {
+				nla_nest_cancel(skb, nest);
+				nla_nest_cancel(skb, cnest);
+				nla_nest_cancel(skb, pnest);
+				return rc;
+			}
+			nla_nest_end(skb, nest);
+		}
+		nla_nest_end(skb, cnest);
+		nla_nest_end(skb, pnest);
+		found = true;
+	}
+
+	if (!found)
+		return -ENODEV;
+
+	return 0;
+}
+
+static int ncsi_pkg_info_nl(struct sk_buff *msg, struct genl_info *info)
+{
+	struct ncsi_dev_priv *ndp;
+	unsigned int package_id;
+	struct sk_buff *skb;
+	struct nlattr *attr;
+	void *hdr;
+	int rc;
+
+	if (!info || !info->attrs)
+		return -EINVAL;
+
+	if (!info->attrs[NCSI_ATTR_IFINDEX])
+		return -EINVAL;
+
+	if (!info->attrs[NCSI_ATTR_PACKAGE_ID])
+		return -EINVAL;
+
+	ndp = ndp_from_ifindex(genl_info_net(info),
+			       nla_get_u32(info->attrs[NCSI_ATTR_IFINDEX]));
+	if (!ndp)
+		return -ENODEV;
+
+	skb = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+	if (!skb)
+		return -ENOMEM;
+
+	hdr = genlmsg_put(skb, info->snd_portid, info->snd_seq,
+			  &ncsi_genl_family, 0, NCSI_CMD_PKG_INFO);
+	if (!hdr) {
+		kfree(skb);
+		return -EMSGSIZE;
+	}
+
+	package_id = nla_get_u32(info->attrs[NCSI_ATTR_PACKAGE_ID]);
+
+	attr = nla_nest_start(skb, NCSI_ATTR_PACKAGE_LIST);
+	rc = ncsi_write_package_info(skb, ndp, package_id);
+
+	if (rc) {
+		nla_nest_cancel(skb, attr);
+		goto err;
+	}
+
+	nla_nest_end(skb, attr);
+
+	genlmsg_end(skb, hdr);
+	return genlmsg_reply(skb, info);
+
+err:
+	genlmsg_cancel(skb, hdr);
+	kfree(skb);
+	return rc;
+}
+
+static int ncsi_pkg_info_all_nl(struct sk_buff *skb,
+				struct netlink_callback *cb)
+{
+	struct nlattr *attrs[NCSI_ATTR_MAX];
+	struct ncsi_package *np, *package;
+	struct ncsi_dev_priv *ndp;
+	unsigned int package_id;
+	struct nlattr *attr;
+	void *hdr;
+	int rc;
+
+	rc = genlmsg_parse(cb->nlh, &ncsi_genl_family, attrs, NCSI_ATTR_MAX,
+			   ncsi_genl_policy, NULL);
+	if (rc)
+		return rc;
+
+	if (!attrs[NCSI_ATTR_IFINDEX])
+		return -EINVAL;
+
+	ndp = ndp_from_ifindex(get_net(sock_net(skb->sk)),
+			       nla_get_u32(attrs[NCSI_ATTR_IFINDEX]));
+
+	if (!ndp)
+		return -ENODEV;
+
+	package_id = cb->args[0];
+	package = NULL;
+	NCSI_FOR_EACH_PACKAGE(ndp, np)
+		if (np->id == package_id)
+			package = np;
+
+	if (!package)
+		return 0; /* done */
+
+	hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
+			  &ncsi_genl_family, 0,  NCSI_CMD_PKG_INFO);
+	if (!hdr) {
+		rc = -EMSGSIZE;
+		goto err;
+	}
+
+	attr = nla_nest_start(skb, NCSI_ATTR_PACKAGE_LIST);
+	rc = ncsi_write_package_info(skb, ndp, package->id);
+	if (rc) {
+		nla_nest_cancel(skb, attr);
+		goto err;
+	}
+
+	nla_nest_end(skb, attr);
+	genlmsg_end(skb, hdr);
+
+	cb->args[0] = package_id + 1;
+
+	return skb->len;
+err:
+	genlmsg_cancel(skb, hdr);
+	return rc;
+}
+
+static int ncsi_set_interface_nl(struct sk_buff *msg, struct genl_info *info)
+{
+	struct ncsi_package *np, *package;
+	struct ncsi_channel *nc, *channel;
+	u32 package_id, channel_id;
+	struct ncsi_dev_priv *ndp;
+	unsigned long flags;
+
+	if (!info || !info->attrs)
+		return -EINVAL;
+
+	if (!info->attrs[NCSI_ATTR_IFINDEX])
+		return -EINVAL;
+
+	if (!info->attrs[NCSI_ATTR_PACKAGE_ID])
+		return -EINVAL;
+
+	ndp = ndp_from_ifindex(get_net(sock_net(msg->sk)),
+			       nla_get_u32(info->attrs[NCSI_ATTR_IFINDEX]));
+	if (!ndp)
+		return -ENODEV;
+
+	package_id = nla_get_u32(info->attrs[NCSI_ATTR_PACKAGE_ID]);
+	package = NULL;
+
+	spin_lock_irqsave(&ndp->lock, flags);
+
+	NCSI_FOR_EACH_PACKAGE(ndp, np)
+		if (np->id == package_id)
+			package = np;
+	if (!package) {
+		/* The user has set a package that does not exist */
+		return -ERANGE;
+	}
+
+	channel = NULL;
+	if (!info->attrs[NCSI_ATTR_CHANNEL_ID]) {
+		/* Allow any channel */
+		channel_id = NCSI_RESERVED_CHANNEL;
+	} else {
+		channel_id = nla_get_u32(info->attrs[NCSI_ATTR_CHANNEL_ID]);
+		NCSI_FOR_EACH_CHANNEL(package, nc)
+			if (nc->id == channel_id)
+				channel = nc;
+	}
+
+	if (channel_id != NCSI_RESERVED_CHANNEL && !channel) {
+		/* The user has set a channel that does not exist on this
+		 * package
+		 */
+		netdev_info(ndp->ndev.dev, "NCSI: Channel %u does not exist!\n",
+			    channel_id);
+		return -ERANGE;
+	}
+
+	ndp->force_package = package;
+	ndp->force_channel = channel;
+	spin_unlock_irqrestore(&ndp->lock, flags);
+
+	netdev_info(ndp->ndev.dev, "Set package 0x%x, channel 0x%x%s as preferred\n",
+		    package_id, channel_id,
+		    channel_id == NCSI_RESERVED_CHANNEL ? " (any)" : "");
+
+	/* Bounce the NCSI channel to set changes */
+	ncsi_stop_dev(&ndp->ndev);
+	ncsi_start_dev(&ndp->ndev);
+
+	return 0;
+}
+
+static int ncsi_clear_interface_nl(struct sk_buff *msg, struct genl_info *info)
+{
+	struct ncsi_dev_priv *ndp;
+	unsigned long flags;
+
+	if (!info || !info->attrs)
+		return -EINVAL;
+
+	if (!info->attrs[NCSI_ATTR_IFINDEX])
+		return -EINVAL;
+
+	ndp = ndp_from_ifindex(get_net(sock_net(msg->sk)),
+			       nla_get_u32(info->attrs[NCSI_ATTR_IFINDEX]));
+	if (!ndp)
+		return -ENODEV;
+
+	/* Clear any override */
+	spin_lock_irqsave(&ndp->lock, flags);
+	ndp->force_package = NULL;
+	ndp->force_channel = NULL;
+	spin_unlock_irqrestore(&ndp->lock, flags);
+	netdev_info(ndp->ndev.dev, "NCSI: Cleared preferred package/channel\n");
+
+	/* Bounce the NCSI channel to set changes */
+	ncsi_stop_dev(&ndp->ndev);
+	ncsi_start_dev(&ndp->ndev);
+
+	return 0;
+}
+
+static const struct genl_ops ncsi_ops[] = {
+	{
+		.cmd = NCSI_CMD_PKG_INFO,
+		.policy = ncsi_genl_policy,
+		.doit = ncsi_pkg_info_nl,
+		.dumpit = ncsi_pkg_info_all_nl,
+		.flags = 0,
+	},
+	{
+		.cmd = NCSI_CMD_SET_INTERFACE,
+		.policy = ncsi_genl_policy,
+		.doit = ncsi_set_interface_nl,
+		.flags = GENL_ADMIN_PERM,
+	},
+	{
+		.cmd = NCSI_CMD_CLEAR_INTERFACE,
+		.policy = ncsi_genl_policy,
+		.doit = ncsi_clear_interface_nl,
+		.flags = GENL_ADMIN_PERM,
+	},
+};
+
+static struct genl_family ncsi_genl_family __ro_after_init = {
+	.name = "NCSI",
+	.version = 0,
+	.maxattr = NCSI_ATTR_MAX,
+	.module = THIS_MODULE,
+	.ops = ncsi_ops,
+	.n_ops = ARRAY_SIZE(ncsi_ops),
+};
+
+int ncsi_init_netlink(struct net_device *dev)
+{
+	int rc;
+
+	rc = genl_register_family(&ncsi_genl_family);
+	if (rc)
+		netdev_err(dev, "ncsi: failed to register netlink family\n");
+
+	return rc;
+}
+
+int ncsi_unregister_netlink(struct net_device *dev)
+{
+	int rc;
+
+	rc = genl_unregister_family(&ncsi_genl_family);
+	if (rc)
+		netdev_err(dev, "ncsi: failed to unregister netlink family\n");
+
+	return rc;
+}