Monitor helper through UDP packages in xen

snf-image-helper/common.sh

@@ -44,6 +44,11 @@ MSG_TYPE_TASK_END="TASK_END"
 
 STDERR_LINE_SIZE=10
 
+IP="10.0.0.1"
+NETWORK="$IP/24"
+BROADCAST="${IP%.*}.255"
+PORT="48000"
+
 add_cleanup() {
     local cmd=""
     for arg; do cmd+=$(printf "%q " "$arg"); done
@@ -69,7 +74,8 @@ send_result_xen() {
 }
 
 send_monitor_message_xen() {
-    echo "$@" | socat STDIN INTERFACE:eth0
+    #Broadcast the message
+    echo "$@" | socat STDIO UDP-DATAGRAM:${BROADCAST}:${PORT},broadcast
 }
 
 prepare_helper() {
@@ -93,9 +99,9 @@ prepare_helper() {
         ;;
     xen-hvm|xen-pvm)
         $MOUNT -t xenfs xenfs /proc/xen
-        iptables -P OUTPUT DROP
-        ip link set eth0 arp off
+        ip addr add "$NETWORK" dev eth0
         ip link set eth0 up
+        ip route add default dev eth0
         export DOMID=$(xenstore-read domid)
         HYPERVISOR=xen
         ;;

snf-image-host/helper-monitor.py

@@ -22,6 +22,9 @@ import os
 import time
 import json
 import re
+import optparse
+import socket
+from scapy.all import sniff
 
 LINESIZE = 512
 BUFSIZE = 512
@@ -38,115 +41,155 @@ PROTOCOL = {
     'ERROR': ('error', 'messages')}
 
 
-def error(msg):
-    sys.stderr.write("HELPER-MONITOR ERROR: %s\n" % msg)
-    sys.exit(1)
+def parse_options(input_args):
+    usage = "Usage: %prog [options] <file-sescriptor>"
+    parser = optparse.OptionParser(usage=usage)
 
+    parser.add_option("-i", "--interface", type="string", dest="ifname",
+                      default=None, metavar="IFNAME",
+                      help="listen on interface IFNAME for monitoring data")
 
-def send(fd, msg_type, value):
-    subtype, value_name = PROTOCOL[msg_type]
+    parser.add_option("-f", "--filter", type="string", dest="filter",
+        help="add FILTER to incomint traffice when working on an interface",
+        default=None, metavar="FILTER")
 
-    msg = {}
-    msg['type'] = MSG_TYPE
-    msg['subtype'] = subtype
-    msg[value_name] = value
-    msg['timestamp'] = time.time()
-    os.write(fd, "%s\n" % json.dumps(msg))
+    options, args = parser.parse_args(input_args)
 
+    if len(args) != 1:
+        parser.error('Wrong number of argumets')
 
-if __name__ == "__main__":
-    usage = "Usage: %s <file-descriptor>\n" % PROGNAME
+    options.fd = args[0]
 
-    if len(sys.argv) != 2:
-        sys.stderr.write(usage)
-        sys.exit(1)
+    if options.filter is not None and options.ifname is None:
+        parser.error('You need to define an interface since filters are' \
+                     'defined')
 
-    try:
-        fd = int(sys.argv[1])
-    except ValueError:
-        error("File descriptor is not an integer")
+    return options
 
-    try:
-        os.fstat(fd)
-    except OSError:
-        error("File descriptor is not valid")
 
-    lines_left = 0
-    line_count = 0
-    stderr = ""
-    line = ""
-    while True:
-        # Can't use sys.stdin.readline since I want unbuffered I/O
-        new_data = os.read(sys.stdin.fileno(), BUFSIZE)
+def error(msg):
+    sys.stderr.write("HELPER-MONITOR ERROR: %s\n" % msg)
+    sys.exit(1)
 
-        if not new_data:
-            if not line:
-                break
+
+class HelperMonitor(object):
+    def __init__(self, fd):
+        self.fd = fd
+        self.lines_left = 0
+        self.line_count = 0
+        self.stderr = ""
+        self.line = ""
+
+    def process(self, data):
+        if not data:
+            if not self.line:
+                return
             else:
-                new_data = '\n'
+                data = '\n'
 
         while True:
-            split = new_data.split('\n', 1)
-            line += split[0]
+            split = data.split('\n', 1)
+            self.line += split[0]
             if len(split) == 1:
-                if len(line) > LINESIZE:
+                if len(self.line) > LINESIZE:
                     error("Line size exceeded the maximum allowed size")
                 break
 
-            new_data = split[1]
+            data = split[1]
 
-            line_count += 1
-            if line_count >= MAXLINES + 1:
+            self.line_count += 1
+            if self.line_count >= MAXLINES + 1:
                 error("Exceeded maximum allowed number of lines: %d." %
                       MAXLINES)
 
-            if lines_left > 0:
-                stderr += "%s\n" % line
-                lines_left -= 1
-                if lines_left == 0:
-                    send(fd, "STDERR", stderr)
-                    stderr = ""
-                line = ""
+            if self.lines_left > 0:
+                self.stderr += "%s\n" % line
+                self.lines_left -= 1
+                if self.lines_left == 0:
+                    self.send("STDERR", stderr)
+                    self.stderr = ""
+                self.line = ""
                 continue
 
-            line = line.strip()
-            if len(line) == 0:
+            self.line = self.line.strip()
+            if len(self.line) == 0:
                 continue
 
-            if line.startswith("STDERR:"):
+            if self.line.startswith("STDERR:"):
                 m = re.match("STDERR:(\d+):(.*)", line)
                 if not m:
                     error("Invalid syntax for STDERR line")
                 try:
-                    lines_left = int(m.group(1))
+                    self.lines_left = int(m.group(1))
                 except ValueError:
                     error("Second field in STDERR line must be an integer")
 
-                if lines_left > STDERR_MAXLINES:
+                if self.lines_left > STDERR_MAXLINES:
                     error("Too many lines in the STDERR output")
-                elif lines_left < 0:
+                elif self.lines_left < 0:
                     error("Second field of STDERR: %d is invalid" % lines_left)
 
-                if lines_left > 0:
-                    stderr = m.group(2) + "\n"
-                    lines_left -= 1
-
-                if lines_left == 0:
-                    send(fd, "STDERR", stderr)
-                    stderr = ""
-            elif line.startswith("TASK_START:") \
-                or line.startswith("TASK_END:") \
-                or line.startswith("WARNING:") \
-                or line.startswith("ERROR:"):
-                (msg_type, _, value) = line.partition(':')
-
-                if line.startswith("WARNING:") or line.startswith("ERROR:"):
+                if self.lines_left > 0:
+                    self.stderr = m.group(2) + "\n"
+                    self.lines_left -= 1
+
+                if self.lines_left == 0:
+                    self.send("STDERR", stderr)
+                    self.stderr = ""
+            elif self.line.startswith("TASK_START:") \
+                or self.line.startswith("TASK_END:") \
+                or self.line.startswith("WARNING:") \
+                or self.line.startswith("ERROR:"):
+                (msg_type, _, value) = self.line.partition(':')
+
+                if self.line.startswith("WARNING:") or \
+                    self.line.startswith("ERROR:"):
                     value = [value]
-                send(fd, msg_type, value)
+                self.send(msg_type, value)
             else:
                 error("Unknown command!")
 
             # Remove the processed line
-            line = ""
+            self.line = ""
+
+    def send(self, msg_type, value):
+        subtype, value_name = PROTOCOL[msg_type]
+
+        msg = {}
+        msg['type'] = MSG_TYPE
+        msg['subtype'] = subtype
+        msg[value_name] = value
+        msg['timestamp'] = time.time()
+        os.write(self.fd, "%s\n" % json.dumps(msg))
+
+
+if __name__ == "__main__":
+    options = parse_options(sys.argv[1:])
+
+    try:
+        fd = int(options.fd)
+    except ValueError:
+        error("File descriptor is not an integer")
+
+    try:
+        os.fstat(fd)
+    except OSError:
+        error("File descriptor is not valid")
+
+    monitor = HelperMonitor(fd)
+
+    if options.ifname is not None:
+        try:
+            sniff(filter=options.filter, iface=options.ifname,
+                prn=lambda x: monitor.process(x.payload.getfieldval("load")))
+        except socket.error as e:
+            # Network is down
+            if e.errno == 100:
+                monitor.process(None)
+            else:
+                raise
+    else:
+        for data in os.read(sys.stdin.fileno(), BUFSIZE):
+            monitor.process(data)
 
 # vim: set sta sts=4 shiftwidth=4 sw=4 et ai :

snf-image-host/vif-snf-image

@@ -3,13 +3,10 @@
 dir=$(dirname "$0")
 . "$dir"/vif-common.sh
 
-ip link set "$vif" arp off
-ip link set "$vif" allmulticast off
-ip link set "$vif" dynamic off
-ip link set "$vif" multicast off
-
 echo 0 > /proc/sys/net/ipv6/conf/$vif/autoconf
 echo 1 > /proc/sys/net/ipv6/conf/$vif/disable_ipv6
+echo 0 > /proc/sys/net/ipv4/conf/$vif/forwarding
+echo 0 > /proc/sys/net/ipv4/conf/$vif/proxy_arp
 
 ip link set $vif up
 

snf-image-host/xen-common.sh

@@ -29,7 +29,7 @@ launch_helper() {
 
     if ! xenstore-exists snf-image-helper; then
         xenstore-write snf-image-helper ""
-		#add_cleanup xenstore-rm snf-image-helper
+	#add_cleanup xenstore-rm snf-image-helper
     fi
 
     helperid=$(xm domid "$name")
@@ -37,14 +37,14 @@ launch_helper() {
     add_cleanup xenstore-rm snf-image-helper/${helperid}
     xenstore-chmod snf-image-helper/${helperid} r0 w${helperid}
 
-    socat INTERFACE:vif${helperid}.0 EXEC:"./helper-monitor.py ${MONITOR_FD}" &
+    filter='udp and dst port 48000 and dst host 10.0.0.255 and src host 10.0.0.1'
+    $TIMEOUT -k $HELPER_HARD_TIMEOUT $HELPER_SOFT_TIMEOUT \
+      ./helper-monitor.py -i "vif${helperid}.0" -f "$filter" ${MONITOR_FD} &
     monitor_pid=$!
 
     set +e
-
     $TIMEOUT -k $HELPER_HARD_TIMEOUT $HELPER_SOFT_TIMEOUT \
       socat EXEC:"xm console $name",pty STDOUT | sed -u 's|^|HELPER: |g'
-
     rc=$?
     set -e
 
@@ -52,6 +52,17 @@ launch_helper() {
 
     check_helper_rc "$rc"
 
+    set +e
+    wait "$monitor_pid"
+    monitor_rc=$?
+    set -e
+
+    if [ $rc -ne 0 ];
+       log_error "Helper VM monitoring failed"
+       report_error "Helper VM monitoring failed"
+       exit 1
+    fi
+
     report_info "Checking customization status..."
     result=$(xenstore-read snf-image-helper/$helperid)
     report_info "Customization status is: $result"