[PATCH net-next v14 4/7] bonding: Processing extended arp_ip_target from user space.

[David Wilder <wilder@us.ibm.com>]

Changes to bond_netlink and bond_options to process extended
format arp_ip_target option sent from user space via the ip
command.

The extended format adds a list of vlan tags to the ip target address.

Signed-off-by: David Wilder <wilder@us.ibm.com>
---
 drivers/net/bonding/bond_netlink.c |   5 +-
 drivers/net/bonding/bond_options.c | 132 +++++++++++++++++++++++------
 2 files changed, 107 insertions(+), 30 deletions(-)

diff --git a/drivers/net/bonding/bond_netlink.c b/drivers/net/bonding/bond_netlink.c
index 566a11bb7f1e..15782745fa4d 100644
--- a/drivers/net/bonding/bond_netlink.c
+++ b/drivers/net/bonding/bond_netlink.c
@@ -307,9 +307,10 @@ static int bond_changelink(struct net_device *bond_dev, struct nlattr *tb[],
 			if (nla_len(attr) < sizeof(target))
 				return -EINVAL;
 
-			target = nla_get_be32(attr);
+			bond_opt_initextra(&newval,
+					   (__force void *)nla_data(attr),
+					   nla_len(attr));
 
-			bond_opt_initval(&newval, (__force u64)target);
 			err = __bond_opt_set(bond, BOND_OPT_ARP_TARGETS,
 					     &newval,
 					     data[IFLA_BOND_ARP_IP_TARGET],
diff --git a/drivers/net/bonding/bond_options.c b/drivers/net/bonding/bond_options.c
index 91d57ba968d6..9b930a6880b0 100644
--- a/drivers/net/bonding/bond_options.c
+++ b/drivers/net/bonding/bond_options.c
@@ -13,6 +13,7 @@
 #include <linux/ctype.h>
 #include <linux/inet.h>
 #include <linux/sched/signal.h>
+#include <linux/if_vlan.h>
 
 #include <net/bonding.h>
 #include <net/ndisc.h>
@@ -31,8 +32,10 @@ static int bond_option_use_carrier_set(struct bonding *bond,
 				       const struct bond_opt_value *newval);
 static int bond_option_arp_interval_set(struct bonding *bond,
 					const struct bond_opt_value *newval);
-static int bond_option_arp_ip_target_add(struct bonding *bond, __be32 target);
-static int bond_option_arp_ip_target_rem(struct bonding *bond, __be32 target);
+static int bond_option_arp_ip_target_add(struct bonding *bond,
+					 const struct bond_arp_target *target);
+static int bond_option_arp_ip_target_rem(struct bonding *bond,
+					 const struct bond_arp_target *target);
 static int bond_option_arp_ip_targets_set(struct bonding *bond,
 					  const struct bond_opt_value *newval);
 static int bond_option_ns_ip6_targets_set(struct bonding *bond,
@@ -1150,7 +1153,7 @@ static int bond_option_arp_interval_set(struct bonding *bond,
 }
 
 static void _bond_options_arp_ip_target_set(struct bonding *bond, int slot,
-					    __be32 target,
+					    const struct bond_arp_target *target,
 					    unsigned long last_rx)
 {
 	struct bond_arp_target *targets = bond->params.arp_targets;
@@ -1160,24 +1163,26 @@ static void _bond_options_arp_ip_target_set(struct bonding *bond, int slot,
 	if (slot >= 0 && slot < BOND_MAX_ARP_TARGETS) {
 		bond_for_each_slave(bond, slave, iter)
 			slave->target_last_arp_rx[slot] = last_rx;
-		targets[slot].target_ip = target;
+		memcpy(&targets[slot], target, sizeof(struct bond_arp_target));
 	}
 }
 
-static int _bond_option_arp_ip_target_add(struct bonding *bond, __be32 target)
+static int _bond_option_arp_ip_target_add(struct bonding *bond,
+					  const struct bond_arp_target *target)
 {
 	struct bond_arp_target *targets = bond->params.arp_targets;
+	char pbuf[BOND_OPTION_STRING_MAX_SIZE];
 	int ind;
 
-	if (!bond_is_ip_target_ok(target)) {
+	if (!bond_is_ip_target_ok(target->target_ip)) {
 		netdev_err(bond->dev, "invalid ARP target %pI4 specified for addition\n",
-			   &target);
+			   &target->target_ip);
 		return -EINVAL;
 	}
 
-	if (bond_get_targets_ip(targets, target) != -1) { /* dup */
+	if (bond_get_targets_ip(targets, target->target_ip) != -1) { /* dup */
 		netdev_err(bond->dev, "ARP target %pI4 is already present\n",
-			   &target);
+			   &target->target_ip);
 		return -EINVAL;
 	}
 
@@ -1187,43 +1192,46 @@ static int _bond_option_arp_ip_target_add(struct bonding *bond, __be32 target)
 		return -EINVAL;
 	}
 
-	netdev_dbg(bond->dev, "Adding ARP target %pI4\n", &target);
+	netdev_dbg(bond->dev, "Adding ARP target %s\n",
+		   bond_arp_target_to_string(target, pbuf, sizeof(pbuf)));
 
 	_bond_options_arp_ip_target_set(bond, ind, target, jiffies);
 
 	return 0;
 }
 
-static int bond_option_arp_ip_target_add(struct bonding *bond, __be32 target)
+static int bond_option_arp_ip_target_add(struct bonding *bond,
+					 const struct bond_arp_target *target)
 {
 	return _bond_option_arp_ip_target_add(bond, target);
 }
 
-static int bond_option_arp_ip_target_rem(struct bonding *bond, __be32 target)
+static int bond_option_arp_ip_target_rem(struct bonding *bond,
+					 const struct bond_arp_target *target)
 {
 	struct bond_arp_target *targets = bond->params.arp_targets;
+	unsigned long *targets_rx;
 	struct list_head *iter;
 	struct slave *slave;
-	unsigned long *targets_rx;
 	int ind, i;
 
-	if (!bond_is_ip_target_ok(target)) {
+	if (!bond_is_ip_target_ok(target->target_ip)) {
 		netdev_err(bond->dev, "invalid ARP target %pI4 specified for removal\n",
-			   &target);
+			   &target->target_ip);
 		return -EINVAL;
 	}
 
-	ind = bond_get_targets_ip(targets, target);
+	ind = bond_get_targets_ip(targets, target->target_ip);
 	if (ind == -1) {
 		netdev_err(bond->dev, "unable to remove nonexistent ARP target %pI4\n",
-			   &target);
+			   &target->target_ip);
 		return -EINVAL;
 	}
 
 	if (ind == 0 && !targets[1].target_ip && bond->params.arp_interval)
 		netdev_warn(bond->dev, "Removing last arp target with arp_interval on\n");
 
-	netdev_dbg(bond->dev, "Removing ARP target %pI4\n", &target);
+	netdev_dbg(bond->dev, "Removing ARP target %pI4\n", &target->target_ip);
 
 	bond_for_each_slave(bond, slave, iter) {
 		targets_rx = slave->target_last_arp_rx;
@@ -1231,42 +1239,110 @@ static int bond_option_arp_ip_target_rem(struct bonding *bond, __be32 target)
 			targets_rx[i] = targets_rx[i+1];
 		targets_rx[i] = 0;
 	}
-	for (i = ind; (i < BOND_MAX_ARP_TARGETS - 1) && targets[i + 1].target_ip; i++)
-		targets[i] = targets[i+1];
+
+	bond_free_vlan_tag(&targets[ind]);
+
+	for (i = ind; (i < BOND_MAX_ARP_TARGETS - 1) && targets[i + 1].target_ip; i++) {
+		targets[i].target_ip = targets[i + 1].target_ip;
+		targets[i].tags = targets[i + 1].tags;
+		targets[i].flags = targets[i + 1].flags;
+	}
 	targets[i].target_ip = 0;
+	targets[i].flags = 0;
+	targets[i].tags = NULL;
 
 	return 0;
 }
 
 void bond_option_arp_ip_targets_clear(struct bonding *bond)
 {
+	struct bond_arp_target empty_target = {};
 	int i;
 
 	for (i = 0; i < BOND_MAX_ARP_TARGETS; i++)
-		_bond_options_arp_ip_target_set(bond, i, 0, 0);
+		_bond_options_arp_ip_target_set(bond, i, &empty_target, 0);
+}
+
+/**
+ * bond_validate_tags - validate an array of bond_vlan_tag.
+ * @tags: the array to validate
+ * @len: the length in bytes of @tags
+ *
+ * Validate that @tags points to a valid array of struct bond_vlan_tag.
+ * Returns: the length of the validated bytes in the array or -1 if no
+ * valid list is found.
+ */
+static int bond_validate_tags(struct bond_vlan_tag *tags, size_t len)
+{
+	size_t i, ntags = 0;
+
+	if (len == 0 || !tags)
+		return 0;
+
+	if (len % sizeof(struct bond_vlan_tag) != 0)
+		return -1;
+
+	for (i = 0; i <= len; i = i + sizeof(struct bond_vlan_tag)) {
+		if (ntags > BOND_MAX_VLAN_TAGS)
+			break;
+
+		if (tags->vlan_proto == BOND_VLAN_PROTO_NONE)
+			return i + sizeof(struct bond_vlan_tag);
+
+		if (!tags->vlan_id || tags->vlan_id >= VLAN_VID_MASK)
+			break;
+		tags++;
+		ntags++;
+	}
+	return -1;
 }
 
 static int bond_option_arp_ip_targets_set(struct bonding *bond,
 					  const struct bond_opt_value *newval)
 {
-	int ret = -EPERM;
-	__be32 target;
+	size_t len = (size_t)newval->extra_len;
+	char *extra = (char *)newval->extra;
+	struct bond_arp_target target = {};
+	int size, ret = -EPERM;
 
 	if (newval->string) {
+		/* Adding or removing arp_ip_target from sysfs */
 		if (strlen(newval->string) < 1 ||
-		    !in4_pton(newval->string + 1, -1, (u8 *)&target, -1, NULL)) {
+		    !in4_pton(newval->string + 1, -1, (u8 *)&target.target_ip,
+			      -1, NULL)) {
 			netdev_err(bond->dev, "invalid ARP target specified\n");
 			return ret;
 		}
 		if (newval->string[0] == '+')
-			ret = bond_option_arp_ip_target_add(bond, target);
+			ret = bond_option_arp_ip_target_add(bond, &target);
 		else if (newval->string[0] == '-')
-			ret = bond_option_arp_ip_target_rem(bond, target);
+			ret = bond_option_arp_ip_target_rem(bond, &target);
 		else
 			netdev_err(bond->dev, "no command found in arp_ip_targets file - use +<addr> or -<addr>\n");
 	} else {
-		target = newval->value;
-		ret = bond_option_arp_ip_target_add(bond, target);
+		/* Adding arp_ip_target from netlink. aka: ip command */
+		memcpy(&target.target_ip, newval->extra, sizeof(__be32));
+		len = len - sizeof(target.target_ip);
+		extra = extra + sizeof(target.target_ip);
+
+		size = bond_validate_tags((struct bond_vlan_tag *)extra, len);
+
+		if (size > 0) {
+			target.tags = kmalloc((size_t)size, GFP_ATOMIC);
+			if (!target.tags)
+				return -ENOMEM;
+			memcpy(target.tags, extra, size);
+			target.flags |= BOND_TARGET_USERTAGS;
+		} else if (size == -1) {
+			netdev_err(bond->dev, "Invalid list of vlans provided with %pI4\n",
+				   &target.target_ip);
+			return -EINVAL;
+		}
+
+		ret = bond_option_arp_ip_target_add(bond, &target);
+
+		if (ret)
+			kfree(target.tags);
 	}
 
 	return ret;
-- 
2.50.1