1 files changed, 76 insertions, 0 deletions
diff --git a/filter_plugins/filters.py b/filter_plugins/filters.py
new file mode 100644
index 0000000..d0043b6
--- /dev/null
+++ b/filter_plugins/filters.py
@@ -0,0 +1,76 @@
+"""Custom Jinja2 filters for IPv4 address math."""
+import struct
+import socket
+
+
+def _ip_to_int(ip):
+    return struct.unpack("!I", socket.inet_aton(ip))[0]
+
+
+def _int_to_ip(n):
+    return socket.inet_ntoa(struct.pack("!I", n))
+
+
+def ipv4_network(cidr):
+    """Return the network address of a CIDR. '10.0.20.2/24' -> '10.0.20.0'"""
+    ip, prefix = cidr.split("/")
+    mask = (0xFFFFFFFF << (32 - int(prefix))) & 0xFFFFFFFF
+    return _int_to_ip(_ip_to_int(ip) & mask)
+
+
+def ipv4_nth(cidr, n):
+    """Return the nth host address relative to the given IP. '192.168.2.0/16' | ipv4_nth(101) -> '192.168.2.101'"""
+    ip, _ = cidr.split("/")
+    return _int_to_ip(_ip_to_int(ip) + int(n))
+
+
+def ipv4_nth_cidr(cidr, n):
+    """Return the nth host address with the original prefix. '10.0.20.0/24' | ipv4_nth_cidr(101) -> '10.0.20.101/24'"""
+    _, prefix = cidr.split("/")
+    return ipv4_nth(cidr, n) + "/" + prefix
+
+
+def ipv4_host(cidr):
+    """Return just the host part of a CIDR. '10.0.20.2/24' -> '10.0.20.2'"""
+    return cidr.split("/")[0]
+
+
+def ipv4_prefixlen(cidr):
+    """Return just the prefix length. '10.0.20.2/24' -> '24'"""
+    return cidr.split("/")[1]
+
+
+def normalize_zfs(entries):
+    """Expand short ZFS dataset names to full zroot/jails/volumes/ paths."""
+    result = []
+    for entry in entries:
+        e = dict(entry)
+        if '/' not in e.get('name', ''):
+            e['name'] = 'zroot/jails/volumes/' + e['name']
+        result.append(e)
+    return result
+
+
+def normalize_nullfs(entries):
+    """Expand short nullfs src names to full /usr/local/jails/volumes/ paths."""
+    result = []
+    for entry in entries:
+        e = dict(entry)
+        src = e.get('src', '')
+        if not src.startswith('/'):
+            e['src'] = '/usr/local/jails/volumes/' + src
+        result.append(e)
+    return result
+
+
+class FilterModule(object):
+    def filters(self):
+        return {
+            "ipv4_network": ipv4_network,
+            "ipv4_nth": ipv4_nth,
+            "ipv4_nth_cidr": ipv4_nth_cidr,
+            "ipv4_host": ipv4_host,
+            "ipv4_prefixlen": ipv4_prefixlen,
+            "normalize_zfs": normalize_zfs,
+            "normalize_nullfs": normalize_nullfs,
+        }