Generate faults in precondition testing stage

Also, queue applicable provisions to any existing fault in order to
be processed later.

lib/cwmp.coffee

@@ -83,6 +83,41 @@ writeResponse = (currentRequest, res) ->
     currentRequest.httpResponse.end(res.data)
 
 
+recordFault = (sessionData, fault, provisions, channels) ->
+  faults = sessionData.faults
+
+  for channel of channels
+    provs = sessionData.faults[channel]?.provisions or []
+    faults[channel] = Object.assign({provisions: provs}, fault)
+
+    if sessionData.retries[channel]?
+      ++ sessionData.retries[channel]
+    else
+      sessionData.retries[channel] = 0
+      if Object.keys(channels).length != 1
+        faults[channel].retryNow = true
+
+    if channels[channel] == 0
+      faults[channel].precondition = true
+
+    sessionData.faultsTouched ?= {}
+    sessionData.faultsTouched[channel] = true
+    util.log("#{sessionData.deviceId}: Fault occurred in channel #{channel} (retries: #{sessionData.retries[channel]})")
+
+  for provision, i in provisions
+    for channel of channels
+      if (channels[channel] >> i) & 1
+        faults[channel].provisions.push(provision)
+
+  for channel of channels
+    provs = faults[channel].provisions
+    faults[channel].provisions = []
+    appendProvisions(faults[channel].provisions, provs)
+
+  session.clearProvisions(sessionData)
+  return
+
+
 inform = (currentRequest, cwmpRequest) ->
   if config.get('LOG_INFORMS', currentRequest.sessionData.deviceId)
     util.log("#{currentRequest.sessionData.deviceId}: Inform (#{cwmpRequest.methodRequest.event}); retry count #{cwmpRequest.methodRequest.retryCount}")
@@ -105,15 +140,14 @@ inform = (currentRequest, cwmpRequest) ->
 
 
 transferComplete = (currentRequest, cwmpRequest) ->
-  session.transferComplete(currentRequest.sessionData, cwmpRequest.methodRequest, (err, rpcResponse, faults) ->
+  session.transferComplete(currentRequest.sessionData, cwmpRequest.methodRequest, (err, rpcResponse, fault, operation) ->
     throw err if err
 
-    for channel, fault of faults
-      if not fault.retries? and Object.keys(faults).length == 1
-        fault.retries = 0
+    if fault
+      for k, v of operation.retries
+        currentRequest.sessionData.retries[k] = v
 
-      currentRequest.sessionData.faults[channel] = fault
-      util.log("#{currentRequest.sessionData.deviceId}: Fault response for channel #{channel} (retries: #{fault.retries ? 0})")
+      recordFault(currentRequest.sessionData, fault, operation.provisions, operation.channels)
 
     res = soap.response({
       id : cwmpRequest.id,
@@ -146,12 +180,37 @@ testSchedule = (schedule, timestamp) ->
     return [false, first - timestamp]
 
 
+# Append providions and remove duplicates
+appendProvisions = (original, toAppend) ->
+  modified = false
+  stringified = new WeakMap()
+  for p, i in original
+    stringified.set(p, JSON.stringify(p))
+
+  for p, i in toAppend by -1
+    s = JSON.stringify(p)
+    for pp, j in original by -1
+      ss = stringified.get(pp)
+      if s == ss
+        if (not p) or j >= original.length - (toAppend.length - i)
+          p = null
+        else
+          original.splice(j, 1)
+          modified = true
+    if p
+      original.splice(original.length - (toAppend.length - i) + 1, 0, p)
+      stringified.set(p, s)
+      modified = true
+
+  return modified
+
+
 applyPresets = (currentRequest) ->
   cache.getPresets((err, presetsHash, presets) ->
     throw err if err
 
     # Filter presets based on existing faults
-    blackList = null
+    blackList = {}
     whiteList = null
     whiteListProvisions = null
 
@@ -159,18 +218,17 @@ applyPresets = (currentRequest) ->
 
     if currentRequest.sessionData.faults?
       for channel, fault of currentRequest.sessionData.faults
-        if fault.retries?
-          retryTimestamp = fault.timestamp + (RETRY_DELAY * Math.pow(2, fault.retries)) * 1000
-        else
+        if fault.retryNow
           retryTimestamp = 0
+        else
+          retryTimestamp = fault.timestamp + (RETRY_DELAY * Math.pow(2, currentRequest.sessionData.retries[channel])) * 1000
 
         if retryTimestamp <= currentRequest.sessionData.timestamp
           whiteList = channel
           whiteListProvisions = fault.provisions
           break
 
-        blackList ?= []
-        blackList.push(channel)
+        blackList[channel] = if fault.precondition then 1 else 2
 
     currentRequest.sessionData.presetsHash = presetsHash
 
@@ -183,23 +241,24 @@ applyPresets = (currentRequest) ->
     parameters = {}
     filteredPresets = []
 
-    for p in presets
+    for preset in presets
       if whiteList?
-        continue if p.channel != whiteList
-      else if blackList and p.channel in blackList
+        continue if preset.channel != whiteList
+      else if blackList[channel] == 1
         continue
 
       eventsMatch = true
-      for k, v of p.events
+      for k, v of preset.events
         if (!v) != (!deviceEvents[k.replace(' ', '_')])
           eventsMatch = false
           break
 
-      continue if (not eventsMatch) or (p.schedule and not
-        (p.schedule.schedule and testSchedule(p.schedule, currentRequest.sessionData.timestamp)[0]))
+      continue if (not eventsMatch) or (preset.schedule and not
+        (preset.schedule.schedule and testSchedule(preset.schedule, currentRequest.sessionData.timestamp)[0]))
 
-      filteredPresets.push(p)
-      for k of p.precondition
+      filteredPresets.push(preset)
+      for k of preset.precondition
+        currentRequest.sessionData.channels[preset.channel] = 0
         p = k.split(/([^a-zA-Z0-9\-\_\.].*)/, 1)[0]
         parameters[p] = common.parsePath(p)
 
@@ -207,15 +266,19 @@ applyPresets = (currentRequest) ->
     for k, v of parameters
       declarations.push([v, 1, {value: 1}])
 
-    session.rpcRequest(currentRequest.sessionData, declarations, (err, faults, id, rpcRequest) ->
+    session.rpcRequest(currentRequest.sessionData, declarations, (err, fault, id, rpcRequest) ->
       throw err if err
 
-      if faults?
-        throw new Error('A fault occured while trying to discover parameters to test preset preconditions: ' + JSON.stringify(faults))
+      if fault
+        recordFault(currentRequest.sessionData, fault, currentRequest.sessionData.provisions, currentRequest.sessionData.channels)
+        session.clearProvisions(currentRequest.sessionData)
+        return applyPresets(currentRequest)
 
       if rpcRequest?
         return sendRpcRequest(currentRequest, id, rpcRequest)
 
+      session.clearProvisions(currentRequest.sessionData)
+
       for k, v of parameters
         unpacked = device.unpack(currentRequest.sessionData.deviceData, v)
         if unpacked[0] and (vv = currentRequest.sessionData.deviceData.attributes.get(unpacked[0]).value?[1])?
@@ -226,24 +289,37 @@ applyPresets = (currentRequest) ->
       if whiteList?
         session.addProvisions(currentRequest.sessionData, whiteList, whiteListProvisions)
 
+      appendProvisionsToFaults = {}
       for p in filteredPresets
         if query.testFilter(parameters, p.precondition)
-          session.addProvisions(currentRequest.sessionData, p.channel, p.provisions)
+          if blackList[p.channel] == 2
+            appendProvisionsToFaults[p.channel] =
+              (appendProvisionsToFaults[p.channel] or []).concat(p.provisions)
+          else
+            session.addProvisions(currentRequest.sessionData, p.channel, p.provisions)
 
-      session.rpcRequest(currentRequest.sessionData, null, (err, faults, id, rpcRequest, doneProvisions) ->
+      for channel, provisions of appendProvisionsToFaults
+        if appendProvisions(currentRequest.sessionData.faults[channel].provisions, provisions)
+          currentRequest.sessionData.faultsTouched ?= {}
+          currentRequest.sessionData.faultsTouched[channel] = true
+
+      session.rpcRequest(currentRequest.sessionData, null, (err, fault, id, rpcRequest) ->
         throw err if err
 
-        if faults?
-          for channel, fault of faults
-            if not fault.retries? and Object.keys(faults).length == 1
-              fault.retries = 0
-            currentRequest.sessionData.faults[channel] = fault
-            util.log("#{currentRequest.sessionData.deviceId}: Fault response for channel #{channel} (retries: #{fault.retries ? 0})")
+        if fault
+          recordFault(currentRequest.sessionData, fault, currentRequest.sessionData.provisions, currentRequest.sessionData.channels)
+          session.clearProvisions(currentRequest.sessionData)
+          return applyPresets(currentRequest)
 
-          return nextRpc(currentRequest)
+        if not rpcRequest?
+          for channel, flags of currentRequest.sessionData.channels
+            if flags and channel of currentRequest.sessionData.faults
+              delete currentRequest.sessionData.faults[channel]
+              currentRequest.sessionData.faultsTouched ?= {}
+              currentRequest.sessionData.faultsTouched[channel] = true
 
-        for p, i in doneProvisions or []
-          delete currentRequest.sessionData.faults[currentRequest.sessionData.channels[i]]
+          if whiteList?
+            return applyPresets(currentRequest)
 
         sendRpcRequest(currentRequest, id, rpcRequest)
       )
@@ -252,11 +328,11 @@ applyPresets = (currentRequest) ->
 
 
 nextRpc = (currentRequest) ->
-  session.rpcRequest(currentRequest.sessionData, null, (err, faults, id, rpcRequest, doneProvisions) ->
+  session.rpcRequest(currentRequest.sessionData, null, (err, fault, id, rpcRequest) ->
     throw err if err
 
-    if faults?
-      for channel, fault of faults
+    if fault
+      for channel of currentRequest.sessionData.channels
         if channel.startsWith('_task_')
           taskId = channel.slice(6)
           for t, j in currentRequest.sessionData.tasks
@@ -265,19 +341,20 @@ nextRpc = (currentRequest) ->
               fault.expiry = t.expiry if t.expiry?
               break
 
-        if not fault.retries? and Object.keys(faults).length == 1
-          fault.retries = 0
-        currentRequest.sessionData.faults[channel] = fault
-        util.log("#{currentRequest.sessionData.deviceId}: Fault response for channel #{channel} (retries: #{fault.retries ? 0})")
-
+      recordFault(currentRequest.sessionData, fault, currentRequest.sessionData.provisions, currentRequest.sessionData.channels)
+      session.clearProvisions(currentRequest.sessionData)
       return nextRpc(currentRequest)
 
     if rpcRequest?
       return sendRpcRequest(currentRequest, id, rpcRequest)
 
-    for p, i in doneProvisions or []
-      delete currentRequest.sessionData.faults[currentRequest.sessionData.channels[i]]
+    for channel, flags of currentRequest.sessionData.channels
+      if flags and channel of currentRequest.sessionData.faults
+        delete currentRequest.sessionData.faults[channel]
+        currentRequest.sessionData.faultsTouched ?= {}
+        currentRequest.sessionData.faultsTouched[channel] = true
 
+    for p in currentRequest.sessionData.provisions
       if p[0] == '_task'
         currentRequest.sessionData.doneTasks ?= []
         currentRequest.sessionData.doneTasks.push(p[1])
@@ -286,6 +363,8 @@ nextRpc = (currentRequest) ->
             currentRequest.sessionData.tasks.splice(j, 1)
             break
 
+    session.clearProvisions(currentRequest.sessionData)
+
     for task in currentRequest.sessionData.tasks
       # Delete if expired
       if task.expiry <= currentRequest.sessionData.timestamp
@@ -333,13 +412,32 @@ sendRpcRequest = (currentRequest, id, rpcRequest) ->
       db.clearTasks(currentRequest.sessionData.doneTasks, (err) ->
         throw err if err
 
-        if not currentRequest.sessionData.faults?
-          return writeResponse(currentRequest, soap.response(null))
+        counter = 1
 
-        db.syncFaults(currentRequest.sessionData.deviceId, currentRequest.sessionData.faults, (err) ->
-          throw err if err
-          writeResponse(currentRequest, soap.response(null))
-        )
+        for k of currentRequest.sessionData.faultsTouched
+          ++ counter
+          if currentRequest.sessionData.faults[k]
+            currentRequest.sessionData.faults[k].retries = currentRequest.sessionData.retries[k]
+            db.saveFault(currentRequest.sessionData.deviceId, k, currentRequest.sessionData.faults[k], (err) ->
+              -- counter
+              if err and counter >= 0
+                throw err
+
+              if counter == 0
+                return writeResponse(currentRequest, soap.response(null))
+            )
+          else
+            db.deleteFault(currentRequest.sessionData.deviceId, k, (err) ->
+              -- counter
+              if err and counter >= 0
+                throw err
+
+              if counter == 0
+                return writeResponse(currentRequest, soap.response(null))
+            )
+
+        if -- counter == 0
+          return writeResponse(currentRequest, soap.response(null))
       )
     )
     return
@@ -490,7 +588,10 @@ listener = (httpRequest, httpResponse) ->
 
             # Delete expired faults
             for k, v of sessionData.faults
-              delete sessionData.faults[k] if v.expiry >= sessionData.timestamp
+              if v.expiry >= sessionData.timestamp
+                delete sessionData.faults[k]
+                sessionData.faultsTouched ?= {}
+                sessionData.faultsTouched[k] = true
 
             f(null, sessionData)
           )
@@ -529,36 +630,32 @@ listener = (httpRequest, httpResponse) ->
           nextRpc(currentRequest)
         )
       else if cwmpRequest.fault?
-        session.rpcFault(currentRequest.sessionData, cwmpRequest.id, cwmpRequest.fault, (err, faults) ->
+        session.rpcFault(currentRequest.sessionData, cwmpRequest.id, cwmpRequest.fault, (err, fault) ->
           throw err if err
 
-          for channel, fault of faults
-            if channel.startsWith('_task_')
-              taskId = channel.slice(6)
-              for t, j in currentRequest.sessionData.tasks
-                if t._id == taskId
-                  currentRequest.sessionData.tasks.splice(j, 1)
-                  fault.expiry = t.expiry if t.expiry?
-                  break
-
-            if not fault.retries? and Object.keys(faults).length == 1
-              fault.retries = 0
-
-            currentRequest.sessionData.faults[channel] = fault
-            util.log("#{currentRequest.sessionData.deviceId}: Fault response for channel #{channel} (retries: #{fault.retries ? 0})")
+          if fault
+            for channel of currentRequest.sessionData.channels
+              if channel.startsWith('_task_')
+                taskId = channel.slice(6)
+                for t, j in currentRequest.sessionData.tasks
+                  if t._id == taskId
+                    currentRequest.sessionData.tasks.splice(j, 1)
+                    fault.expiry = t.expiry if t.expiry?
+                    break
 
+            recordFault(currentRequest.sessionData, fault, currentRequest.sessionData.provisions, currentRequest.sessionData.channels)
+            session.clearProvisions(currentRequest.sessionData)
           nextRpc(currentRequest)
         )
       else # CPE sent empty response
-        session.timeoutOperations(currentRequest.sessionData, (err, faults) ->
+        session.timeoutOperations(currentRequest.sessionData, (err, faults, operations) ->
           throw err if err
 
-          for channel, fault of faults
-            if not fault.retries? and Object.keys(faults).length == 1
-              fault.retries = 0
+          for fault, i in faults
+            for k, v of operations[i].retries
+              sessionData.retries[k] = v
 
-            currentRequest.sessionData.faults[channel] = fault
-            util.log("#{currentRequest.sessionData.deviceId}: Fault response for channel #{channel} (retries: #{fault.retries ? 0})")
+            recordFault(currentRequest.sessionData, fault, operations[i].provisions, operations[i].channels)
 
           nextRpc(currentRequest)
         )

lib/db.coffee

@@ -527,6 +527,7 @@ getFaults = (deviceId, callback) ->
       delete r.device
       r.timestamp = +r.timestamp
       r.expiry = +r.expiry if r.expiry?
+      r.provisions = JSON.parse(r.provisions)
       faults[channel] = r
 
     CACHE_DURATION = config.get('PRESETS_CACHE_DURATION', deviceId)
@@ -537,6 +538,25 @@ getFaults = (deviceId, callback) ->
   )
 
 
+saveFault = (deviceId, channel, fault, callback) ->
+  fault._id = "#{deviceId}:#{channel}"
+  fault.device = deviceId
+  fault.channel = channel
+  fault.timestamp = new Date(fault.timestamp)
+  fault.provisions = JSON.stringify(fault.provisions)
+  faultsCollection.save(fault, (err) ->
+    return callback(err) if err
+    redisClient.del("#{deviceId}_faults", callback)
+  )
+
+
+deleteFault = (deviceId, channel, callback) ->
+  faultsCollection.remove({_id: "#{deviceId}:#{channel}"}, (err) ->
+    return callback(err) if err
+    redisClient.del("#{deviceId}_faults", callback)
+  )
+
+
 
 getDueTasks = (deviceId, timestamp, callback) ->
   cur = tasksCollection.find({
@@ -586,61 +606,6 @@ clearTasks = (taskIds, callback) ->
   tasksCollection.remove({'_id' : {'$in' : (new mongodb.ObjectID(id) for id in taskIds)}}, callback)
 
 
-syncFaults = (deviceId, faults, callback) ->
-  getFaults(deviceId, (err, existingFaults) ->
-    return callback(err) if err
-
-    counter = 1
-    toDelete = []
-    for k of existingFaults
-      if k not of faults
-        toDelete.push("#{deviceId}:#{k}")
-
-    if toDelete.length
-      ++ counter
-      faultsCollection.remove({'_id' : {'$in' : toDelete}}, (err) ->
-        if err
-          callback(err) if counter
-          return counter = 0
-
-        if -- counter == 0
-          return redisClient.del("#{deviceId}_faults", callback)
-      )
-
-    for channel, fault of faults
-      continue if existingFaults[channel]? and fault.retries == existingFaults[channel].retries
-      do (channel, fault) ->
-        ++ counter
-        fault._id = "#{deviceId}:#{channel}"
-        fault.device = deviceId
-        fault.channel = channel
-        fault.timestamp = new Date(fault.timestamp)
-        fault.expiry = new Date(fault.expiry) if fault.expiry?
-
-        faultsCollection.save(fault, (err) ->
-          if err
-            callback(err) if counter
-            return counter = 0
-
-          if channel.startsWith('_task_')
-            return tasksCollection.update({_id: new mongodb.ObjectID(channel.slice(6))}, {$set: {fault: fault.fault, retries: fault.retries}}, (err) ->
-              if err
-                callback(err) if counter
-                return counter = 0
-
-              if -- counter == 0
-                return redisClient.del("#{deviceId}_faults", callback)
-            )
-          else
-            if -- counter == 0
-              return redisClient.del("#{deviceId}_faults", callback)
-        )
-
-    if -- counter == 0
-      return callback()
-  )
-
-
 getOperations = (deviceId, callback) ->
   operationsCollection.find({'_id' : {'$regex' : "^#{common.escapeRegExp(deviceId)}\\:"}}).toArray((err, res) ->
     return callback(err) if err
@@ -687,7 +652,9 @@ exports.disconnect = disconnect
 exports.fetchDevice = fetchDevice
 exports.saveDevice = saveDevice
 exports.getDueTasksAndFaultsAndOperations = getDueTasksAndFaultsAndOperations
+exports.getFaults = getFaults
+exports.saveFault = saveFault
+exports.deleteFault = deleteFault
 exports.clearTasks = clearTasks
-exports.syncFaults = syncFaults
 exports.saveOperation = saveOperation
 exports.deleteOperation = deleteOperation

lib/session.coffee

@@ -47,8 +47,9 @@ init = (deviceId, cwmpVersion, timeout, callback) ->
     cwmpVersion : cwmpVersion
     timeout : timeout
     provisions: []
-    channels: []
-    revisions: []
+    channels: {}
+    virtualParameters: []
+    revisions: [0]
     rpcCount: 0
     iteration: 0
     extensionsCache: {}
@@ -159,7 +160,6 @@ transferComplete = (sessionData, rpcReq, callback) ->
     # TODO Show a warning instead
     throw new Error('Invalid command key')
   instance = operation.args.instance
-  faults = {}
 
   delete sessionData.operations[commandKey]
   sessionData.operationsTouched ?= {}
@@ -167,19 +167,14 @@ transferComplete = (sessionData, rpcReq, callback) ->
 
   if rpcReq.faultStruct? and rpcReq.faultStruct.faultCode != '0'
     return revertDownloadParameters(sessionData, operation.args.instance, (err) ->
-      for channel, provisions of operation.provisions
-        faults[channel] = {
-          provisions: provisions
-          timestamp: sessionData.timestamp
-          code: "cwmp.#{rpcReq.faultStruct.faultCode}"
-          message: rpcReq.faultStruct.faultString
-          detail: rpcReq.faultStruct
-        }
+      fault = {
+        code: "cwmp.#{rpcReq.faultStruct.faultCode}"
+        message: rpcReq.faultStruct.faultString
+        detail: rpcReq.faultStruct
+        timestamp: operation.timestamp
+      }
 
-        if operation.retries[channel]?
-          faults[channel].retries = operation.retries[channel] + 1
-
-      return callback(err, {type : 'TransferCompleteResponse'}, faults)
+      return callback(err, {type : 'TransferCompleteResponse'}, fault, operation)
     )
 
   loadPath(sessionData, ['Downloads', instance, '*'])
@@ -215,7 +210,7 @@ transferComplete = (sessionData, rpcReq, callback) ->
       {value: [timestamp, [+rpcReq.completeTime, 'xsd:dateTime']]}, toClear)
 
     clear(sessionData, toClear, (err) ->
-      return callback(err, {type : 'TransferCompleteResponse'}, faults)
+      return callback(err, {type : 'TransferCompleteResponse'})
     )
   )
 
@@ -240,7 +235,8 @@ revertDownloadParameters = (sessionData, instance, callback) ->
 
 
 timeoutOperations = (sessionData, callback) ->
-  faults = {}
+  faults = []
+  operations = []
   counter = 1
 
   for commandKey, operation of sessionData.operations
@@ -254,16 +250,13 @@ timeoutOperations = (sessionData, callback) ->
       sessionData.operationsTouched ?= {}
       sessionData.operationsTouched[commandKey] = 1
 
-      for channel, provisions of operation.provisions
-        faults[channel] = {
-          provisions: provisions
-          timestamp: sessionData.timestamp
-          code: 'timeout'
-          message: 'Download operation timeed out'
-        }
+      faults.push({
+        code: 'timeout'
+        message: 'Download operation timed out'
+        timestamp: operation.timestamp
+      })
 
-        if operation.retries[channel]?
-          faults[channel].retries = operation.retries[channel] + 1
+      operations.push(operation)
 
       ++ counter
       revertDownloadParameters(sessionData, operation.args.instance, (err) ->
@@ -271,36 +264,41 @@ timeoutOperations = (sessionData, callback) ->
         if err and counter > 0
           counter = 0
 
-        return callback(err, faults) if counter == 0
+        return callback(err, faults, operations) if counter == 0
       )
 
   -- counter
-  return callback(null, faults) if counter == 0
+  return callback(null, faults, operations) if counter == 0
 
 
 addProvisions = (sessionData, channel, provisions) ->
-  if sessionData.revisions[0] > 0
-    sessionData.deviceData.timestamps.collapse(1)
-    sessionData.deviceData.attributes.collapse(1)
-
   delete sessionData.syncState
   delete sessionData.rpcRequest
   sessionData.declarations = []
   sessionData.doneProvisions = 0
-  sessionData.provisions[0] ?= []
-  sessionData.provisions.length = 1
-  sessionData.revisions = [0]
-  sessionData.extensionsCache = {}
+  if sessionData.revisions[sessionData.revisions.length - 1] > 0
+    sessionData.deviceData.timestamps.collapse(1)
+    sessionData.deviceData.attributes.collapse(1)
+    sessionData.revisions = [0]
+    sessionData.extensionsCache = {}
+
+  channels = [channel]
 
   for provision, i in provisions
     # Remove duplicate provisions
-    for p, j in sessionData.provisions[0]
-      if channel == sessionData.channels[j] and JSON.stringify(p) == JSON.stringify(provision)
-        sessionData.provisions[0].splice(j, 1)
-        sessionData.channels.splice(j, 1)
+    provisionStr = JSON.stringify(provision)
+    for p, j in sessionData.provisions
+      if JSON.stringify(p) == provisionStr
+        sessionData.provisions.splice(j, 1)
+        for c of sessionData.channels
+          channels.push(c) if sessionData.channels[c] & (1 << j)
+          a = sessionData.channels[c] >> (j + 1)
+          sessionData.channels[c] &= ((1 << j) - 1)
+          sessionData.channels[c] |= (a << j)
 
-    sessionData.provisions[0].push(provision)
-    sessionData.channels.push(channel)
+    for c in channels
+      sessionData.channels[channel] |= (1 << sessionData.provisions.length)
+    sessionData.provisions.push(provision)
 
 
 clearProvisions = (sessionData) ->
@@ -311,10 +309,10 @@ clearProvisions = (sessionData) ->
   delete sessionData.syncState
   delete sessionData.rpcRequest
   sessionData.provisions = []
-  sessionData.channels = []
+  sessionData.channels = {}
   sessionData.declarations = []
   sessionData.doneProvisions = 0
-  sessionData.revisions = []
+  sessionData.revisions = [0]
   sessionData.extensionsCache = {}
 
 
@@ -584,39 +582,32 @@ rpcRequest = (sessionData, _declarations, callback) ->
   if sessionData.rpcRequest?
     return callback(null, null, generateRpcId(sessionData), sessionData.rpcRequest)
 
-  if sessionData.declarations.length < sessionData.provisions.length
+  if sessionData.virtualParameters.length == 0 and
+      sessionData.declarations.length == 0 and
+      sessionData.doneProvisions
+    return callback()
+
+  if sessionData.declarations.length <= sessionData.virtualParameters.length
     inception = sessionData.declarations.length
     revision = sessionData.revisions[inception] + 1
     sessionData.deviceData.timestamps.revision = revision
     sessionData.deviceData.attributes.revision = revision
-    run = if inception == 0 then runProvisions else runVirtualParameters
 
-    return run(sessionData, sessionData.provisions[inception], sessionData.revisions[inception - 1] ? 0, sessionData.revisions[inception], (err, fault, done, decs, toClear) ->
+    if inception == 0
+      run = runProvisions
+      provisions = sessionData.provisions
+    else
+      run = runVirtualParameters
+      provisions = sessionData.virtualParameters[inception - 1]
+
+    return run(sessionData, provisions, sessionData.revisions[inception - 1] or 0, sessionData.revisions[inception], (err, fault, done, decs, toClear) ->
       return callback(err) if err
 
       if fault
-        faults = {}
-        for p, i in sessionData.provisions[0]
-          channel = sessionData.channels[i]
-          f = faults[channel]
-          if not f?
-            f = {
-              provisions: []
-              timestamp: sessionData.timestamp
-              code: fault.code
-              message: fault.message
-              detail: fault.detail
-            }
-
-            if sessionData.retries[channel]?
-              f.retries = sessionData.retries[channel] + 1
-
-            faults[channel] = f
-
-          f.provisions.push(p)
-
-        clearProvisions(sessionData)
-        return callback(null, faults)
+        fault.timestamp = sessionData.timestamp
+        fault.provisions = sessionData.provisions
+        fault.channels = sessionData.channels
+        return callback(null, fault)
 
       sessionData.declarations.push(decs)
       sessionData.doneProvisions |= 1 << inception if done or not decs.length
@@ -638,8 +629,6 @@ rpcRequest = (sessionData, _declarations, callback) ->
     delete sessionData.syncState
     sessionData.declarations[0] ?= []
     sessionData.declarations[0] = sessionData.declarations[0].concat(_declarations)
-    sessionData.provisions[0] ?= []
-    sessionData.revisions[0] ?= 0
 
     for d in _declarations
       for ad in device.getAliasDeclarations(d[0], 1)
@@ -687,27 +676,12 @@ rpcRequest = (sessionData, _declarations, callback) ->
       sessionData.revisions.length >= 8 or
       sessionData.iteration >= 64
 
-    faults = {}
-    for p, i in sessionData.provisions[0]
-      channel = sessionData.channels[i]
-      fault = faults[channel]
-      if not fault?
-        fault = {
-          provisions: []
-          timestamp: sessionData.timestamp
-          code: 'endless_cycle'
-          message: 'The provision seems to be repeating indefinitely'
-        }
-
-        if sessionData.retries[channel]?
-          fault.retries = sessionData.retries[channel] + 1
-
-        faults[channel] = fault
-
-      fault.provisions.push(p)
-
-    clearProvisions(sessionData)
-    return callback(null, faults)
+    fault = {
+      code: 'endless_cycle'
+      message: 'The provision seems to be repeating indefinitely'
+      timestmap: sessionData.timestamp
+    }
+    return callback(null, fault)
 
   inception = sessionData.declarations.length - 1
 
@@ -818,7 +792,7 @@ rpcRequest = (sessionData, _declarations, callback) ->
         sessionData.rpcRequest = generateSetRpcRequest(sessionData)
 
   if provisions
-    sessionData.provisions.push(provisions)
+    sessionData.virtualParameters.push(provisions)
     sessionData.revisions.push(sessionData.revisions[inception])
     return rpcRequest(sessionData, null, callback)
 
@@ -827,18 +801,12 @@ rpcRequest = (sessionData, _declarations, callback) ->
 
   ++ sessionData.revisions[inception]
   sessionData.declarations.pop()
-  while sessionData.doneProvisions & (1 << (sessionData.provisions.length - 1))
-    doneProvisions = sessionData.provisions.pop()
+
+  while sessionData.doneProvisions & (2 << (sessionData.virtualParameters.length - 1))
+    doneProvisions = sessionData.virtualParameters.pop()
     sessionData.revisions.pop()
     sessionData.declarations.pop()
-    sessionData.doneProvisions &= (1 << sessionData.provisions.length) - 1
-    if not sessionData.provisions.length
-      delete sessionData.syncState
-      sessionData.deviceData.timestamps.collapse(1)
-      sessionData.deviceData.attributes.collapse(1)
-      sessionData.extensionsCache = {}
-      return callback(null, null, null, null, doneProvisions)
-
+    sessionData.doneProvisions &= (2 << sessionData.virtualParameters.length) - 1
     rev = sessionData.revisions[sessionData.revisions.length - 1]
     sessionData.deviceData.timestamps.collapse(rev + 1)
     sessionData.deviceData.attributes.collapse(rev + 1)
@@ -1527,7 +1495,8 @@ rpcResponse = (sessionData, id, rpcRes, callback) ->
         operation = {
           type: 'Download'
           timestamp: sessionData.timestamp
-          provisions: {}
+          provisions: sessionData.provisions
+          channels: sessionData.channels
           retries: {}
           args: {
             instance: rpcReq.instance
@@ -1537,12 +1506,9 @@ rpcResponse = (sessionData, id, rpcRes, callback) ->
           }
         }
 
-        for provision, i in sessionData.provisions[0]
-          channel = sessionData.channels[i]
-          operation.provisions[channel] ?= []
-          operation.provisions[channel].push(provision)
-          if sessionData.faults[channel]?
-            operation.retries[channel] = sessionData.faults[channel].retries or 0
+        for channel of sessionData.channels
+          if sessionData.retries[channel]?
+            operation.retries[channel] = sessionData.retries[channel]
 
         sessionData.operations[rpcReq.commandKey] = operation
         sessionData.operationsTouched ?= {}
@@ -1558,31 +1524,15 @@ rpcFault = (sessionData, id, faultResponse, callback) ->
   # TODO Consider handling invalid parameter faults by automatically refreshing
   # relevant data model portions
 
-  if not sessionData.provisions[0]?.length
-    throw new Error('A fault occured while trying to discover parameters to test preset preconditions: ' + JSON.stringify(flt))
+  fault = {
+    code: "cwmp.#{faultResponse.detail.faultCode}"
+    message: faultResponse.detail.faultString
+    detail: faultResponse.detail
+    timestamp: sessionData.timestamp
+  }
 
-  faults = {}
-  for p, i in sessionData.provisions[0]
-    channel = sessionData.channels[i]
-    fault = faults[channel]
-    if not fault?
-      fault = {
-        provisions: []
-        timestamp: sessionData.timestamp
-        code: "cwmp.#{faultResponse.detail.faultCode}"
-        message: faultResponse.detail.faultString
-        detail: faultResponse.detail
-      }
-
-      if sessionData.retries[channel]?
-        fault.retries = sessionData.retries[channel] + 1
-
-      faults[channel] = fault
-
-    fault.provisions.push(p)
-
-  clearProvisions(sessionData)
-  return callback(null, faults)
+  delete sessionData.syncState
+  return callback(null, fault)
 
 
 deserialize = (sessionDataString, callback) ->