From 76bebf3d2bf7bf005aba3f88033c20ba2fd77c57 Mon Sep 17 00:00:00 2001
From: Marc Fiuczynski <mef@cs.princeton.edu>
Date: Thu, 23 Dec 2004 21:30:10 +0000
Subject: [PATCH] Replaces pl-poddoit.c for icmp-based pod messages. Also
 supports udp-based pod messages.  Has the same argument format as
 pl-poddoit.c.

---
 pod.py | 141 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 141 insertions(+)
 create mode 100755 pod.py

diff --git a/pod.py b/pod.py
new file mode 100755
index 0000000..7e406df
--- /dev/null
+++ b/pod.py
@@ -0,0 +1,141 @@
+#! /usr/bin/env python
+#
+# Marc E. Fiuczynski <mef@cs.princeton.edu>
+# Copyright (C) 2004 The Trustees of Princeton University
+#
+# Client ping of death program for both udp & icmp
+
+import sys
+import struct
+import os
+import array
+import getopt
+from socket import *
+
+def usage():
+    sys.stdout = sys.stderr
+    print 'Usage: pod -i identityfile [--icmp,--udp] hostnamelist'
+    print ' -i identity  key where key may be - for stdin'
+    print ' --icmp icmp protocol only'
+    print ' --udp udp protocol only'
+    print ' by default both icmp and udp are used'
+
+
+UPOD_PORT = 664
+
+def _in_cksum(packet):
+    """THE RFC792 states: 'The 16 bit one's complement of
+    the one's complement sum of all 16 bit words in the header.'
+    Generates a checksum of a (ICMP) packet. Based on in_chksum found
+    in ping.c on FreeBSD.
+    """
+
+    # add byte if not dividable by 2
+    if len(packet) & 1:
+        packet = packet + '\0'
+
+    # split into 16-bit word and insert into a binary array
+    words = array.array('h', packet)
+    sum = 0
+
+    # perform ones complement arithmetic on 16-bit words
+    for word in words:
+        sum += (word & 0xffff)
+
+    hi = sum >> 16
+    lo = sum & 0xffff
+    sum = hi + lo
+    sum = sum + (sum >> 16)
+
+    return (~sum) & 0xffff # return ones complement
+
+def _construct(id, data):
+    """Constructs a ICMP IPOD packet
+    """
+    ICMP_TYPE = 6 # ping of death code used by PLK
+    ICMP_CODE = 0
+    ICMP_CHECKSUM = 0
+    ICMP_ID = 0
+    ICMP_SEQ_NR = 0
+
+    header = struct.pack('bbHHh', ICMP_TYPE, ICMP_CODE, ICMP_CHECKSUM, \
+                         ICMP_ID, ICMP_SEQ_NR+id)
+
+    packet = header + data          # ping packet without checksum
+    checksum = _in_cksum(packet)    # make checksum
+
+    # construct header with correct checksum
+    header = struct.pack('bbHHh', ICMP_TYPE, ICMP_CODE, checksum, ICMP_ID, \
+                         ICMP_SEQ_NR+id)
+
+    # ping packet *with* checksum
+    packet = header + data
+
+    # a perfectly formatted ICMP echo packet
+    return packet
+
+def icmp_pod(host,key):
+    uid = os.getuid()
+    if uid <> 0:
+        print "must be root to send icmp pod"
+        return
+    
+    s = socket(AF_INET, SOCK_RAW, getprotobyname("icmp"))
+    packet = _construct(0, key) # make a ping packet
+    addr = (host,1)
+    print 'pod sending icmp-based reboot request to %s' % host
+    for i in range(1,10):
+        s.sendto(packet, addr)
+
+def udp_pod(host,key):
+    addr = host, UPOD_PORT
+    s = socket(AF_INET, SOCK_DGRAM)
+    s.bind(('', 0))
+    packet = key
+    print 'pod sending udp-based reboot request to %s' % host
+    for i in range(1,10):
+        s.sendto(packet, addr)
+
+def noop_pod(host,key):
+    pass
+
+def main():
+    try:
+        opts, args = getopt.getopt(sys.argv[1:], "i:", ["icmp","udp"])
+    except getops.GetoptError:
+        usage()
+        sys.exit(2)
+        
+    hosts = args
+    protos = {'udp' : udp_pod, 'icmp' : icmp_pod}
+    key = None
+    for o, a in opts:
+        if o == "--icmp":
+            del protos['udp']
+        if o == "--udp":
+            del protos['icmp']
+        if o == "-i":
+            if len(a)==1 and a[0]=='-':
+                key = sys.stdin.readline()
+            else:
+                try:
+                    f = open(a)
+                    key = f.readline()
+                    key = k[:32]
+                    f.close()
+                except:
+                    print '%s not found' % a
+                    usage()
+                    sys.exit(2)
+
+    if key is None:
+        usage()
+        sys.exit(2)
+
+    protocols = ['udp','icmp']
+    for host in hosts:
+        for protocol in protocols:
+            pod = protos.get(protocol,noop_pod)
+            pod(host,key)
+
+main()
-- 
2.43.0