Message-ID: <20250508183014.2554525-3-wilder@us.ibm.com>
Date: Thu,  8 May 2025 11:29:29 -0700
From: David J Wilder <wilder@...ibm.com>
To: netdev@...r.kernel.org
Cc: jv@...sburgh.net, wilder@...ibm.com, pradeeps@...ux.vnet.ibm.com,
        pradeep@...ibm.com, i.maximets@....org, amorenoz@...hat.com,
        haliu@...hat.com
Subject: [PATCH net-next v1 2/2] bonding: Extend arp_ip_target format to allow for a list of vlan tags.

This change extends the "arp_ip_target" parameter format to allow for a
list of vlan tags to be included for each arp target. This new list of
tags is optional and may be omitted to preserve the current format and
process of gathering tags.  When provided the list of tags circumvents
the process of gathering tags by using the supplied list. An empty list
can be provided to simply skip the process of gathering tags.

Signed-off-by: David J Wilder <wilder@...ibm.com>
---
 drivers/net/bonding/bond_main.c | 140 ++++++++++++++++++++++++++++----
 1 file changed, 123 insertions(+), 17 deletions(-)

diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index ab388dab218a..12195e60c7de 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -2672,6 +2672,17 @@ static int __bond_release_one(struct net_device *bond_dev,
 	return 0;
 }
 
+/* helper to free arp_target.tags */
+static void free_tags(struct net_device *bond_dev)
+{
+	struct bonding *bond = netdev_priv(bond_dev);
+	struct arp_target *targets = bond->params.arp_targets;
+	int i;
+
+	for (i = 0; i < BOND_MAX_ARP_TARGETS && targets[i].tags; i++)
+		kfree(targets[i].tags);
+}
+
 /* A wrapper used because of ndo_del_link */
 int bond_release(struct net_device *bond_dev, struct net_device *slave_dev)
 {
@@ -3159,9 +3170,6 @@ static void bond_arp_send_all(struct bonding *bond, struct slave *slave)
 		target_ip = targets[i].target_ip;
 		tags = targets[i].tags;
 
-		slave_dbg(bond->dev, slave->dev, "%s: target %pI4\n",
-			  __func__, &target_ip);
-
 		/* Find out through which dev should the packet go */
 		rt = ip_route_output(dev_net(bond->dev), target_ip, 0, 0, 0,
 				     RT_SCOPE_LINK);
@@ -3182,9 +3190,13 @@ static void bond_arp_send_all(struct bonding *bond, struct slave *slave)
 		if (rt->dst.dev == bond->dev)
 			goto found;
 
-		rcu_read_lock();
-		tags = bond_verify_device_path(bond->dev, rt->dst.dev, 0);
-		rcu_read_unlock();
+		if (!tags) {
+			rcu_read_lock();
+			tags = bond_verify_device_path(bond->dev, rt->dst.dev, 0);
+			/* cache the tags */
+			targets[i].tags = tags;
+			rcu_read_unlock();
+		}
 
 		if (!IS_ERR_OR_NULL(tags))
 			goto found;
@@ -3200,7 +3212,6 @@ static void bond_arp_send_all(struct bonding *bond, struct slave *slave)
 		addr = bond_confirm_addr(rt->dst.dev, target_ip, 0);
 		ip_rt_put(rt);
 		bond_arp_send(slave, ARPOP_REQUEST, target_ip, addr, tags);
-		kfree(tags);
 	}
 }
 
@@ -6082,6 +6093,7 @@ static void bond_uninit(struct net_device *bond_dev)
 	/* Release the bonded slaves */
 	bond_for_each_slave(bond, slave, iter)
 		__bond_release_one(bond_dev, slave->dev, true, true);
+	free_tags(bond_dev);
 	netdev_info(bond_dev, "Released all slaves\n");
 
 #ifdef CONFIG_XFRM_OFFLOAD
@@ -6095,6 +6107,96 @@ static void bond_uninit(struct net_device *bond_dev)
 	bond_debug_unregister(bond);
 }
 
+/* Convert vlan_list into struct bond_vlan_tag.
+ * Inspired by bond_verify_device_path();
+ */
+static struct bond_vlan_tag *vlan_tags_parse(char *vlan_list, int level)
+{
+	struct bond_vlan_tag *tags;
+	char *vlan;
+
+	if (!vlan_list || strlen(vlan_list) == 0) {
+		tags = kcalloc(level + 1, sizeof(*tags), GFP_ATOMIC);
+		if (!tags)
+			return ERR_PTR(-ENOMEM);
+		tags[level].vlan_proto = BOND_VLAN_PROTO_NONE;
+		return tags;
+	}
+
+	for (vlan = strsep(&vlan_list, "/"); (vlan != 0); level++) {
+		tags = vlan_tags_parse(vlan_list, level + 1);
+		if (IS_ERR_OR_NULL(tags)) {
+			if (IS_ERR(tags))
+				return tags;
+			continue;
+		}
+
+		tags[level].vlan_proto = __cpu_to_be16(ETH_P_8021Q);
+		if (kstrtou16(vlan, 0, &tags[level].vlan_id))
+			return ERR_PTR(-EINVAL);
+
+		if (tags[level].vlan_id < 1 || tags[level].vlan_id > 4094) {
+			kfree(tags);
+			return ERR_PTR(-EINVAL);
+		}
+
+		return tags;
+	}
+
+	return NULL;
+}
+
+/**
+ * arp_ip_target_opt_parse - parse a single arp_ip_target option value string
+ * @src: the option value to be parsed
+ * @dest: struct arp_target to place the results.
+ *
+ * This function parses a single arp_ip_target string in the form:
+ * x.x.x.x[tag/....] into a struct arp_target.
+ * Returns 0 on success.
+ */
+static int arp_ip_target_opt_parse(char *src, struct arp_target *dest)
+{
+	char *ipv4, *vlan_list;
+	char target[128], *args;
+	struct bond_vlan_tag *tags = NULL;
+	__be32 ip;
+
+	/* Prevent buffer overflow */
+	if (strlen(src) > 128)
+		return -E2BIG;
+
+	pr_debug("Parsing arp_ip_target (%s)\n", src);
+
+	/* copy arp_ip_target[i] to local array, strsep works
+	 * destructively...
+	 */
+	args = strcpy(target, src);
+	ipv4 = strsep(&args, "[");
+
+	/* not a complete check, but good enough to catch mistakes */
+	if (!in4_pton(ipv4, -1, (u8 *)&ip, -1, NULL) ||
+	    !bond_is_ip_target_ok(ip)) {
+		return -EINVAL;
+	}
+
+	/* extract vlan tags */
+	vlan_list = strsep(&args, "]");
+
+	/* If a vlan list was not supplied skip the processing of the list.
+	 * A value of "[]" is a valid list and should be handled a such.
+	 */
+	if (vlan_list) {
+		tags = vlan_tags_parse(vlan_list, 0);
+		if (IS_ERR(tags))
+			return PTR_ERR(tags);
+	}
+
+	dest->target_ip = ip;
+	dest->tags = tags;
+	return 0;
+}
+
 /*------------------------- Module initialization ---------------------------*/
 
 static int __init bond_check_params(struct bond_params *params)
@@ -6289,21 +6391,25 @@ static int __init bond_check_params(struct bond_params *params)
 
 	for (arp_ip_count = 0, i = 0;
 	     (arp_ip_count < BOND_MAX_ARP_TARGETS) && arp_ip_target[i]; i++) {
-		__be32 ip;
+		struct arp_target tmp_arp_target;
 
-		/* not a complete check, but good enough to catch mistakes */
-		if (!in4_pton(arp_ip_target[i], -1, (u8 *)&ip, -1, NULL) ||
-		    !bond_is_ip_target_ok(ip)) {
+		if (arp_ip_target_opt_parse(arp_ip_target[i], &tmp_arp_target)) {
 			pr_warn("Warning: bad arp_ip_target module parameter (%s), ARP monitoring will not be performed\n",
 				arp_ip_target[i]);
 			arp_interval = 0;
-		} else {
-			if (bond_get_targets_ip(arp_target, ip) == -1)
-				arp_target[arp_ip_count++].target_ip = ip;
-			else
-				pr_warn("Warning: duplicate address %pI4 in arp_ip_target, skipping\n",
-					&ip);
+			break;
 		}
+
+		if (bond_get_targets_ip(arp_target, tmp_arp_target.target_ip) != -1) {
+			pr_warn("Warning: duplicate address %pI4 in arp_ip_target, skipping\n",
+				&tmp_arp_target.target_ip);
+			kfree(tmp_arp_target.tags);
+			continue;
+		}
+
+		arp_target[i].target_ip = tmp_arp_target.target_ip;
+		arp_target[i].tags = tmp_arp_target.tags;
+		++arp_ip_count;
 	}
 
 	if (arp_interval && !arp_ip_count) {
-- 
2.43.5

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