feat(dhcp): support multiple dhcp ranges (#1734)

Author: m-dilorenzi

packages/ns-api/README.md

@@ -2732,35 +2732,38 @@ Response example:
 {
   "lan": {
     "device": "br-lan",
-    "start": "",
-    "end": "",
     "active": true,
     "force": true,
     "options": {
       "leasetime": "12h",
       "gateway": "192.168.100.1",
       "domain": "nethserver.org",
       "dns": "1.1.1.1 8.8.8.8",
-      "SIP ": "192.168.100.151"
+      "SIP": "192.168.100.151"
     },
     "zone": "lan",
-    "first": "192.168.100.2",
-    "last": "192.168.100.150",
+    "ranges": [
+      {
+        "first": "192.168.100.2",
+        "last": "192.168.100.150"
+      }
+    ],
     "ns_binding": 0
   },
   "blue": {
     "device": "eth2.1",
-    "start": "",
-    "end": "",
     "active": false,
     "force": false,
     "options": {},
     "zone": "",
+    "ranges": [],
     "ns_binding": 1
   }
 }
 ```
 
+The `ranges` field contains the list of active DHCP ranges configured for the interface. Multiple ranges are supported.
+
 ### list-dhcp-options
 
 List all supported DHCPv4 options:
@@ -2808,26 +2811,43 @@ Successfull response example:
       "120": "192.168.100.151"
     }
   ],
-  "first": "192.168.100.2",
-  "last": "192.168.100.150",
+  "ranges": [
+    {
+      "first": "192.168.100.2",
+      "last": "192.168.100.150"
+    },
+    {
+      "first": "192.168.100.200",
+      "last": "192.168.100.220"
+    }
+  ],
   "leasetime": "12h",
   "active": true,
   "force": true,
-  "ns_binding": 0
+  "ns_binding": 0,
+  "class_start_ip": "192.168.100.1",
+  "class_end_ip": "192.168.100.254"
 }
 ```
 
 Each element of the `options` array is a key-value object.
 The key is the DHCP option name or number, the value is the option value.
 Multiple values can be comma-separated.
 
+The `ranges` field contains the list of configured DHCP ranges. Multiple ranges are supported.
+The `class_start_ip` and `class_end_ip` fields represent the first and last usable IP addresses of the interface network (excluding network address and broadcast) and are used in the UI to check whether the entered IP is inside or outside the interface class range.
+
 ### edit-interface
 
-Change or add the DHCPv4 configuration for a given interface:
+Change or add the DHCPv4 configuration for a given interface. Multiple DHCP ranges are supported:
 ```
-api-cli ns.dhcp edit-interface --data '{"interface":"lan","first":"192.168.100.2","last":"192.168.100.150","active":true,"leasetime": "12h","force":true,"options":[{"gateway":"192.168.100.1"},{"domain":"nethserver.org"},{"dns":"1.1.1.1,8.8.8.8"},{"120":"192.168.100.151"}], "ns_binding": 0}'
+api-cli ns.dhcp edit-interface --data '{"interface":"lan","ranges":[{"first":"192.168.100.2","last":"192.168.100.150"},{"first":"192.168.100.200","last":"192.168.100.220"}],"active":true,"leasetime":"12h","force":true,"options":[{"gateway":"192.168.100.1"},{"domain":"nethserver.org"},{"dns":"1.1.1.1,8.8.8.8"},{"120":"192.168.100.151"}],"ns_binding":0}'
 ```
 
+The `ranges` field is an array of objects, each with `first` and `last` IP address fields defining a DHCP range.
+All ranges are saved with the same DHCP options, leasetime, and activation state.
+Existing ranges for the interface are fully replaced on each call.
+
 See [ns.dhcp get-interface][#get-interface] for the `options` array format.
 
 Successfull response:
@@ -2840,6 +2860,13 @@ Error response example:
 {"error": "interface_not_found"}
 ```
 
+Validation errors:
+- `first_is_empty`: the `first` IP address of a range is empty
+- `last_is_empty`: the `last` IP address of a range is empty
+- `ip_out_of_interface_network`: the `first` or `last` IP address is not within the interface network
+- `last_must_be_greater_than_first`: the `last` IP address must be greater than `first`
+- `invalid` (ns_binding): `ns_binding` value is not 0, 1, or 2
+
 ### list-active-leases
 
 List active DHCPv4 leases:

packages/ns-api/files/ns.dhcp

@@ -1,7 +1,7 @@
 #!/usr/bin/python3
 
 #
-# Copyright (C) 2023 Nethesis S.r.l.
+# Copyright (C) 2026 Nethesis S.r.l.
 # SPDX-License-Identifier: GPL-2.0-only
 #
 
@@ -52,7 +52,6 @@ def list_custom_dhcp_options():
             continue
     return ret
 
-
 def list_dhcp_options():
     ret = {}
     pd = subprocess.run(["dnsmasq", "--help", "dhcp"], capture_output=True, text=True)
@@ -82,7 +81,7 @@ def list_interfaces():
     if not dhcps:
         dhcps = []
     for i in interfaces:
-        record = {"device": "", "start": "", "end": "", "active": False, "options": {}, "force": False, "ns_binding": 0 }
+        record = {"device": "", "active": False, "options": {}, "force": False, "ns_binding": 0, "ranges": [] }
         # skip loopback, bond devices, wans, aliases and interfaces with no IP address (e.g. DHCP interfaces)
         if i == "loopback" or i in wans or not ('ipaddr' in interfaces[i]) or interfaces[i].get('proto') == 'bonding' or interfaces[i].get('device', '').startswith('@'):
             continue
@@ -94,7 +93,7 @@ def list_interfaces():
             if 'interface' in ds and ds['interface'] == i:
                 if 'ignore' in ds and ds['ignore'] == "1":
                     continue
-                (record['first'], record['last']) = conf_to_range(interfaces[i]['ipaddr'], interfaces[i]['netmask'], ds.get('start', 100), ds.get('limit', 150))
+                (first, last) = conf_to_range(interfaces[i]['ipaddr'], interfaces[i]['netmask'], ds.get('start', 100), ds.get('limit', 150))
                 record['active'] = ds.get('dhcpv4', 'server') == 'server'
                 # handle existing active configurations:
                 # - old default was force off, as OpenWrt
@@ -111,7 +110,7 @@ def list_interfaces():
                         tmp = opt.split(",")
                         tmp[0] = tmp[0].removeprefix('option:')
                         record['options'][tmp[0]] = " ".join(tmp[1:])
-                break
+                record['ranges'].append({"first": first, "last": last})
         ret[i] = record
 
     return ret
@@ -125,66 +124,89 @@ def edit_interface(args):
     # ns-binding validation, this check is more controller-safe
     if 'ns_binding' in args and args['ns_binding'] not in [0, 1, 2]:
         return utils.validation_error("ns_binding", "invalid", args["ns_binding"])
-    # handle migrated dhcp config: issue #855
-    dhcp_id = args['interface']
+
+    ipaddr = u.get('network', args['interface'], 'ipaddr')
+    netmask = u.get('network', args['interface'], 'netmask')
+    network = ipaddress.ip_network(f"{ipaddr}/{netmask}", strict=False)
+    
+    # ranges validation
+    for r in args['ranges']:
+        r['first'] = r['first'].strip()
+        r['last'] = r['last'].strip()
+        if not r['first']:
+            return utils.validation_error("first", "first_is_empty", r["first"])
+        if not r['last']:
+            return utils.validation_error("last", "last_is_empty", r["last"])
+        first_ip = ipaddress.ip_address(r['first'])
+        last_ip = ipaddress.ip_address(r['last'])
+        if not (network.network_address < first_ip < network.broadcast_address):
+            return utils.validation_error("first", "ip_out_of_interface_network", r["first"])
+        if not (network.network_address < last_ip < network.broadcast_address):
+            return utils.validation_error("last", "ip_out_of_interface_network", r["last"])
+        if ip2int(r['last']) <= ip2int(r['first']):
+            return utils.validation_error("last", "last_must_be_greater_than_first", r["last"])
+
     dhcp_servers = utils.get_all_by_type(u, 'dhcp', 'dhcp')
     for server in dhcp_servers:
         if dhcp_servers[server]['interface'] == args['interface']:
-            dhcp_id = server
+            u.delete('dhcp', server)
+
+    for r in args['ranges']:
+        dhcp_id = f"{args['interface']}_{utils.get_random_id()}"
+        (start, limit) = range_to_conf(ipaddr, netmask, r["first"], r["last"])
+        u.set("dhcp", dhcp_id, 'dhcp')
+        if args['active']:
+            u.set("dhcp", dhcp_id, 'dhcpv4', 'server')
+        else:
+            u.set("dhcp", dhcp_id, 'dhcpv4', 'disabled')
+        u.set("dhcp", dhcp_id, "limit", limit)
+        u.set("dhcp", dhcp_id, "start", start)
+        u.set("dhcp", dhcp_id, "leasetime", args["leasetime"])
+        u.set("dhcp", dhcp_id, "interface", args['interface'])
+        u.set("dhcp", dhcp_id, "force", '1' if args.get('force', False) else '0')
+        u.set("dhcp", dhcp_id, "instance", "ns_dnsmasq")
+        if 'ns_binding' in args:
+            u.set("dhcp", dhcp_id, "ns_binding", args.get('ns_binding'))
+        u.set("dhcp", dhcp_id, "ignore", '0')
+        opts = []
+        for opt in args['options']:
+            k = list(opt.keys())[0]
+            v = opt[k].strip().rstrip(',')
+            if v:
+                if k.isdigit(): # custom option, no "option" prefix
+                    opts.append(f"{k},{v}")
+                else:
+                    opts.append(f"option:{k},{v}")
+        u.set("dhcp", dhcp_id, "dhcp_option", opts)
 
-    u.set("dhcp", dhcp_id, 'dhcp')
-    ipaddr = u.get('network', args['interface'], 'ipaddr')
-    netmask = u.get('network', args['interface'], 'netmask')
-    args['first'] = args['first'].strip()
-    args['last'] = args['last'].strip()
-    if ip2int(args['first']) > ip2int(args['last']):
-        return utils.validation_error("last", "last_must_be_greater_than_first", args["last"])
-    (start, limit) = range_to_conf(ipaddr, netmask, args["first"].strip(), args["last"].strip())
-    if args['active']:
-        u.set("dhcp", dhcp_id, 'dhcpv4', 'server')
-    else:
-        u.set("dhcp", dhcp_id, 'dhcpv4', 'disabled')
-    u.set("dhcp", dhcp_id, "limit", limit)
-    u.set("dhcp", dhcp_id, "start", start)
-    u.set("dhcp", dhcp_id, "leasetime", args["leasetime"])
-    u.set("dhcp", dhcp_id, "interface", args['interface'])
-    u.set("dhcp", dhcp_id, "force", '1' if args.get('force', False) else '0')
-    u.set("dhcp", dhcp_id, "instance", "ns_dnsmasq")
-    if 'ns_binding' in args:
-        u.set("dhcp", dhcp_id, "ns_binding", args.get('ns_binding'))
-    opts = []
-    for opt in args['options']:
-        k = list(opt.keys())[0]
-        v = opt[k].strip().rstrip(',')
-        if v:
-            if k.isdigit(): # custom option, no "option" preffix
-                opts.append(f"{k},{v}")
-            else:
-                opts.append(f"option:{k},{v}")
-    u.set("dhcp", dhcp_id, "dhcp_option", opts)
-    u.set("dhcp", dhcp_id, "ignore", '0')
     u.save("dhcp")
     return {"interface": args["interface"]}
 
 def get_interface(args):
     u = EUci()
-    ret = {"interface": args["interface"], "options": [], "first": "", "last": "", "active": False}
-    try:
-        items = utils.get_all_by_type(u, "dhcp", "dhcp")
-        for i in items:
-            if items[i].get('interface') == args['interface']:
-                dhcp = u.get_all('dhcp', i)
-        if not dhcp:
-            raise Exception # fallback to default
-    except:
-        dhcp = {"start": 100, "limit": 150, "leasetime": "12h", "dhcpv4": "disabled", "dhcp_option": []}
+    ret = {"interface": args["interface"], "options": [], "active": False, "ranges": []}
     try:
         interface = u.get_all("network", args["interface"])
     except:
         interface = {}
 
+    items = utils.get_all_by_type(u, "dhcp", "dhcp")
+    dhcp_sections = []
+    for i in items:
+        if items[i].get('interface') == args['interface'] and items[i].get('ignore', '0') != '1':
+            dhcp_sections.append(u.get_all('dhcp', i))
+
+    if not dhcp_sections:
+        dhcp_sections = [{"start": 100, "limit": 150, "leasetime": "12h", "dhcpv4": "disabled", "dhcp_option": []}]
+
+    # get options from the first dhcp section since they are the same for all sections
+    dhcp = dhcp_sections[0]
+
     if 'ipaddr' in interface:
-        (ret['first'], ret['last']) = conf_to_range(interface['ipaddr'], interface['netmask'], dhcp.get('start', 100), dhcp.get('limit', 150))
+        for ds in dhcp_sections:
+            (first, last) = conf_to_range(interface['ipaddr'], interface['netmask'], ds.get('start', 100), ds.get('limit', 150))
+            ret['ranges'].append({"first": first, "last": last})
+
     ret["leasetime"] = dhcp.get("leasetime")
     ret["active"] = dhcp.get("dhcpv4", "server") == "server"
     # handle existing active configurations:
@@ -201,6 +223,10 @@ def get_interface(args):
             tmp[0] = tmp[0].removeprefix('option:')
             ret["options"].append({tmp[0]: ",".join(tmp[1:])})
     ret['ns_binding'] = int(dhcp.get('ns_binding', 0))
+    if 'ipaddr' in interface and 'netmask' in interface:
+        network = ipaddress.ip_network(f"{interface['ipaddr']}/{interface['netmask']}", strict=False)
+        ret['class_start_ip'] = str(network.network_address + 1)
+        ret['class_end_ip'] = str(network.broadcast_address - 1)
 
     return ret
 
@@ -261,7 +287,6 @@ def is_reserved(u, mac, exclude_lease_id=''):
 
     return False
 
-
 def count_ip_occurrences(e_uci, ip):
     occurrences = 0
     for item in utils.get_all_by_type(e_uci, 'dhcp', 'host'):
@@ -272,7 +297,6 @@ def count_ip_occurrences(e_uci, ip):
 
     return occurrences
 
-
 def add_static_lease(args):
     u = EUci()
     if is_reserved(u, args["macaddr"]):
@@ -346,8 +370,10 @@ if cmd == 'list':
         "get-interface": {"interface": "lan"},
         "edit-interface": {
             "interface": "lan",
-            "first": "192.168.100.2",
-            "last": "192.168.100.150",
+            "ranges": [
+                {"first": "192.168.100.2", "last": "192.168.100.150"},
+                {"first": "192.168.100.200", "last": "192.168.100.220"}
+            ],
             "leasetime": "12h",
             "active": True,
             "force": True,