Adding upstream version 0.7.1.upstream/0.7.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 72 insertions, 0 deletions

diff --git a/port_for/ephemeral.py b/port_for/ephemeral.py
new file mode 100644
index 0000000..a3c03ec
--- /dev/null
+++ b/port_for/ephemeral.py
@@ -0,0 +1,72 @@
+# -*- coding: utf-8 -*-
+"""
+This module provide utilities to find ephemeral port ranges for the current OS.
+See http://www.ncftp.com/ncftpd/doc/misc/ephemeral_ports.html for more info
+about ephemeral port ranges.
+
+Currently only Linux and BSD (including OS X) are supported.
+"""
+import subprocess
+from typing import List, Tuple, Dict
+
+DEFAULT_EPHEMERAL_PORT_RANGE = (32768, 65535)
+
+
+def port_ranges() -> List[Tuple[int, int]]:
+    """
+    Returns a list of ephemeral port ranges for current machine.
+    """
+    try:
+        return _linux_ranges()
+    except (OSError, IOError):  # not linux, try BSD
+        try:
+            ranges = _bsd_ranges()
+            if ranges:
+                return ranges
+        except (OSError, IOError):
+            pass
+
+    # fallback
+    return [DEFAULT_EPHEMERAL_PORT_RANGE]
+
+
+def _linux_ranges() -> List[Tuple[int, int]]:
+    with open("/proc/sys/net/ipv4/ip_local_port_range") as f:
+        # use readline() instead of read() for linux + musl
+        low, high = f.readline().split()
+        return [(int(low), int(high))]
+
+
+def _bsd_ranges() -> List[Tuple[int, int]]:
+    pp = subprocess.Popen(
+        ["sysctl", "net.inet.ip.portrange"], stdout=subprocess.PIPE
+    )
+    stdout, stderr = pp.communicate()
+    lines = stdout.decode("ascii").split("\n")
+    out: Dict[str, str] = dict(
+        [
+            [x.strip().rsplit(".")[-1] for x in line.split(":")]
+            for line in lines
+            if line
+        ]
+    )
+
+    ranges = [
+        # FreeBSD & Mac
+        ("first", "last"),
+        ("lowfirst", "lowlast"),
+        ("hifirst", "hilast"),
+        # OpenBSD
+        ("portfirst", "portlast"),
+        ("porthifirst", "porthilast"),
+    ]
+
+    res = []
+    for rng in ranges:
+        try:
+            low, high = int(out[rng[0]]), int(out[rng[1]])
+            if low <= high:
+                res.append((low, high))
+        except KeyError:
+            pass
+    return res