[PATCH iproute2-next v5 1/1] iproute: Extend bonding's "arp_ip_target" parameter to add vlan tags.

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

This change extends the "arp_ip_target" parameter format to allow for
a list of vlan tags to be included for each arp target.

The new format for arp_ip_target is:
arp_ip_target=ipv4-address[vlan-tag\...],...

Examples:
arp_ip_target=10.0.0.1[10]
arp_ip_target=10.0.0.1[100/200]

The inclusion of the list of vlan tags is optional. The new logic
preserves both forward and backward compatibility with the kernel
and iproute2 versions. Comparability is also persevered for:
ip -d link list.

Signed-off-by: David Wilder <wilder@us.ibm.com>
---
 ip/iplink_bond.c | 125 +++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 115 insertions(+), 10 deletions(-)

diff --git a/ip/iplink_bond.c b/ip/iplink_bond.c
index d6960f6d..7dbe9d58 100644
--- a/ip/iplink_bond.c
+++ b/ip/iplink_bond.c
@@ -173,6 +173,53 @@ static void explain(void)
 	print_explain(stderr);
 }
 
+#define BOND_VLAN_PROTO_NONE htons(0xffff)
+#define BOND_MAX_VLAN_TAGS 5
+
+struct bond_vlan_tag {
+	__be16	vlan_proto;
+	__be16	vlan_id;
+};
+
+static struct bond_vlan_tag *bond_vlan_tags_parse(char *vlan_list, int level, int *size)
+{
+	struct bond_vlan_tag *tags = NULL;
+	char *vlan;
+	int n;
+
+	if (level > BOND_MAX_VLAN_TAGS) {
+		fprintf(stderr,
+			"Error: Too many vlan tags specified, maximum is %d.\n",
+			BOND_MAX_VLAN_TAGS);
+		exit(1);
+	}
+
+	if (!vlan_list || strlen(vlan_list) == 0) {
+		tags = calloc(level + 1, sizeof(*tags));
+		*size = (level + 1) * (sizeof(*tags));
+		if (tags)
+			tags[level].vlan_proto = BOND_VLAN_PROTO_NONE;
+		return tags;
+	}
+
+	for (vlan = strsep(&vlan_list, "/"); (vlan != 0); level++) {
+		tags = bond_vlan_tags_parse(vlan_list, level + 1, size);
+		if (!tags)
+			continue;
+
+		tags[level].vlan_proto = htons(ETH_P_8021Q);
+		n = sscanf(vlan, "%hu", &(tags[level].vlan_id));
+
+		if (n != 1 || tags[level].vlan_id < 1 ||
+		    tags[level].vlan_id > 4094)
+			return NULL;
+
+		return tags;
+	}
+
+	return NULL;
+}
+
 static int bond_parse_opt(struct link_util *lu, int argc, char **argv,
 			  struct nlmsghdr *n)
 {
@@ -239,12 +286,29 @@ static int bond_parse_opt(struct link_util *lu, int argc, char **argv,
 				NEXT_ARG();
 				char *targets = strdupa(*argv);
 				char *target = strtok(targets, ",");
-				int i;
+				struct bond_vlan_tag *tags;
+				int size, i;
 
 				for (i = 0; target && i < BOND_MAX_ARP_TARGETS; i++) {
-					__u32 addr = get_addr32(target);
+					struct __attribute__((packed)) Data {
+						__u32 addr;
+						struct bond_vlan_tag vlans[];
+					} data;
+					char *vlan_list, *dup;
+
+					dup = strdupa(target);
+					data.addr = get_addr32(strsep(&dup, "["));
+					vlan_list = strsep(&dup, "]");
+
+					if (vlan_list) {
+						tags = bond_vlan_tags_parse(vlan_list, 0, &size);
+						memcpy(&data.vlans, tags, size);
+						addattr_l(n, 1024, i, &data,
+							  sizeof(data.addr)+size);
+					} else {
+						addattr32(n, 1024, i, data.addr);
+					}
 
-					addattr32(n, 1024, i, addr);
 					target = strtok(NULL, ",");
 				}
 				addattr_nest_end(n, nest);
@@ -498,21 +562,62 @@ static void bond_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
 
 	if (tb[IFLA_BOND_ARP_IP_TARGET]) {
 		struct rtattr *iptb[BOND_MAX_ARP_TARGETS + 1];
+		SPRINT_BUF(pbuf);
+		int i;
 
 		parse_rtattr_nested(iptb, BOND_MAX_ARP_TARGETS,
 				    tb[IFLA_BOND_ARP_IP_TARGET]);
 
 		if (iptb[0]) {
 			open_json_array(PRINT_JSON, "arp_ip_target");
-			print_string(PRINT_FP, NULL, "arp_ip_target ", NULL);
+			print_color_string(PRINT_FP, COLOR_INET, NULL,
+					   "arp_ip_target ", NULL);
 		}
 
-		for (i = 0; i < BOND_MAX_ARP_TARGETS; i++) {
-			if (iptb[i])
-				print_string(PRINT_ANY,
-					     NULL,
-					     "%s",
-					     rt_addr_n2a_rta(AF_INET, iptb[i]));
+		for (i = 0; i < BOND_MAX_ARP_TARGETS && iptb[i]; i++) {
+			struct __attribute__((packed)) Data {
+				__u32 addr;
+				struct bond_vlan_tag vlans[BOND_MAX_VLAN_TAGS + 1];
+			} data;
+			int size = sizeof(pbuf);
+			int num, level;
+
+			if (RTA_PAYLOAD(iptb[i]) < sizeof(data.addr) ||
+			    RTA_PAYLOAD(iptb[i]) > sizeof(data)) {
+				fprintf(stderr, "Internal Error: Bad payload for arp_ip_target.\n");
+				exit(1);
+			}
+			memcpy(&data, RTA_DATA(iptb[i]), RTA_PAYLOAD(iptb[i]));
+
+			num = snprintf(&pbuf[0], size, "%s",
+				       rt_addr_n2a(AF_INET, sizeof(data.addr), &data.addr));
+
+			if (RTA_PAYLOAD(iptb[i]) > sizeof(data.addr)) {
+				num = num + snprintf(&pbuf[num], size - num, "[");
+
+				for (level = 0;
+				     data.vlans[level].vlan_proto != BOND_VLAN_PROTO_NONE;
+				     level++) {
+
+					if (level > BOND_MAX_VLAN_TAGS) {
+						fprintf(stderr,
+							"Internal Error: too many vlan tags.\n");
+						exit(1);
+					}
+
+					if (level != 0)
+						num = num + snprintf(&pbuf[num], size - num, "/");
+
+					num = num + snprintf(&pbuf[num], size - num,
+							     "%u", data.vlans[level].vlan_id);
+				}
+
+				num = num - snprintf(&pbuf[num], size - num, "]");
+
+			}
+
+			print_color_string(PRINT_ANY, COLOR_INET, NULL, "%s", pbuf);
+
 			if (!is_json_context()
 			    && i < BOND_MAX_ARP_TARGETS-1
 			    && iptb[i+1])
-- 
2.50.1