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Copy pathebpfTable.py
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404 lines (332 loc) · 14.7 KB
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# Copyright (c) Barefoot Networks, Inc.
# Licensed under the Apache License, Version 2.0 (the "License")
from p4_hlir.hlir import p4_match_type, p4_field, p4_table, p4_header_instance
from programSerializer import ProgramSerializer
from compilationException import *
import ebpfProgram
import ebpfInstance
import ebpfCounter
import ebpfStructType
import ebpfAction
class EbpfTableKeyField(object):
def __init__(self, fieldname, instance, field, mask):
assert isinstance(instance, ebpfInstance.EbpfInstanceBase)
assert isinstance(field, ebpfStructType.EbpfField)
self.keyFieldName = fieldname
self.instance = instance
self.field = field
self.mask = mask
def serializeType(self, serializer):
assert isinstance(serializer, ProgramSerializer)
ftype = self.field.type
serializer.emitIndent()
ftype.declare(serializer, self.keyFieldName, False)
serializer.endOfStatement(True)
def serializeConstruction(self, keyName, serializer, program):
assert isinstance(serializer, ProgramSerializer)
assert isinstance(keyName, str)
assert isinstance(program, ebpfProgram.EbpfProgram)
if self.mask is not None:
maskExpression = " & {0}".format(self.mask)
else:
maskExpression = ""
if isinstance(self.instance, ebpfInstance.EbpfMetadata):
base = program.metadataStructName
else:
base = program.headerStructName
if isinstance(self.instance, ebpfInstance.SimpleInstance):
source = "{0}.{1}.{2}".format(
base, self.instance.name, self.field.name)
else:
assert isinstance(self.instance, ebpfInstance.EbpfHeaderStack)
source = "{0}.{1}[{2}].{3}".format(
base, self.instance.name,
self.instance.hlirInstance.index, self.field.name)
destination = "{0}.{1}".format(keyName, self.keyFieldName)
size = self.field.widthInBits()
serializer.emitIndent()
if size <= 32:
serializer.appendFormat("{0} = ({1}){2};",
destination, source, maskExpression)
else:
if maskExpression != "":
raise NotSupportedException(
"{0} Mask wider than 32 bits", self.field.hlirType)
serializer.appendFormat(
"memcpy(&{0}, &{1}, {2});", destination, source, size / 8)
serializer.newline()
class EbpfTableKey(object):
def __init__(self, match_fields, program):
assert isinstance(program, ebpfProgram.EbpfProgram)
self.expressions = []
self.fields = []
self.masks = []
self.fieldNamePrefix = "key_field_"
self.program = program
fieldNumber = 0
for f in match_fields:
field = f[0]
matchType = f[1]
mask = f[2]
if ((matchType is p4_match_type.P4_MATCH_TERNARY) or
(matchType is p4_match_type.P4_MATCH_LPM) or
(matchType is p4_match_type.P4_MATCH_RANGE)):
raise NotSupportedException(
False, "Match type {0}", matchType)
if matchType is p4_match_type.P4_MATCH_VALID:
# we should be really checking the valid field;
# p4_field is a header instance
assert isinstance(field, p4_header_instance)
instance = field
fieldname = "valid"
else:
assert isinstance(field, p4_field)
instance = field.instance
fieldname = field.name
if ebpfProgram.EbpfProgram.isArrayElementInstance(instance):
ebpfStack = program.getStackInstance(instance.base_name)
assert isinstance(ebpfStack, ebpfInstance.EbpfHeaderStack)
basetype = ebpfStack.basetype
eInstance = program.getStackInstance(instance.base_name)
else:
ebpfHeader = program.getInstance(instance.name)
assert isinstance(ebpfHeader, ebpfInstance.SimpleInstance)
basetype = ebpfHeader.type
eInstance = program.getInstance(instance.base_name)
ebpfField = basetype.getField(fieldname)
assert isinstance(ebpfField, ebpfStructType.EbpfField)
fieldName = self.fieldNamePrefix + str(fieldNumber)
fieldNumber += 1
keyField = EbpfTableKeyField(fieldName, eInstance, ebpfField, mask)
self.fields.append(keyField)
self.masks.append(mask)
@staticmethod
def fieldRank(field):
assert isinstance(field, EbpfTableKeyField)
return field.field.type.alignment()
def serializeType(self, serializer, keyTypeName):
assert isinstance(serializer, ProgramSerializer)
serializer.emitIndent()
serializer.appendFormat("struct {0} ", keyTypeName)
serializer.blockStart()
# Sort fields in decreasing size; this will ensure that
# there is no padding.
# Padding may cause the ebpf verification to fail,
# since padding fields are not initalized
fieldOrder = sorted(
self.fields, key=EbpfTableKey.fieldRank, reverse=True)
for f in fieldOrder:
assert isinstance(f, EbpfTableKeyField)
f.serializeType(serializer)
serializer.blockEnd(False)
serializer.endOfStatement(True)
def serializeConstruction(self, serializer, keyName, program):
serializer.emitIndent()
serializer.appendLine("/* construct key */")
for f in self.fields:
f.serializeConstruction(keyName, serializer, program)
class EbpfTable(object):
# noinspection PyUnresolvedReferences
def __init__(self, hlirtable, program, config):
assert isinstance(hlirtable, p4_table)
assert isinstance(program, ebpfProgram.EbpfProgram)
self.name = hlirtable.name
self.hlirtable = hlirtable
self.config = config
self.defaultActionMapName = (program.reservedPrefix +
self.name + "_miss")
self.key = EbpfTableKey(hlirtable.match_fields, program)
self.size = hlirtable.max_size
if self.size is None:
program.emitWarning(
"{0} does not specify a max_size; using 1024", hlirtable)
self.size = 1024
self.isHash = True # TODO: try to guess arrays when possible
self.dataMapName = self.name
self.actionEnumName = program.generateNewName(self.name + "_actions")
self.keyTypeName = program.generateNewName(self.name + "_key")
self.valueTypeName = program.generateNewName(self.name + "_value")
self.actions = []
if hlirtable.action_profile is not None:
raise NotSupportedException("{0}: action_profile tables",
hlirtable)
if hlirtable.support_timeout:
program.emitWarning("{0}: table timeout {1}; ignoring",
hlirtable, NotSupportedException.archError)
self.counters = []
if (hlirtable.attached_counters is not None):
for c in hlirtable.attached_counters:
ctr = program.getCounter(c.name)
assert isinstance(ctr, ebpfCounter.EbpfCounter)
self.counters.append(ctr)
if (len(hlirtable.attached_meters) > 0 or
len(hlirtable.attached_registers) > 0):
program.emitWarning("{0}: meters/registers {1}; ignored",
hlirtable, NotSupportedException.archError)
for a in hlirtable.actions:
action = program.getAction(a)
self.actions.append(action)
def serializeKeyType(self, serializer):
assert isinstance(serializer, ProgramSerializer)
self.key.serializeType(serializer, self.keyTypeName)
def serializeActionArguments(self, serializer, action):
assert isinstance(serializer, ProgramSerializer)
assert isinstance(action, ebpfAction.EbpfActionBase)
action.serializeArgumentsAsStruct(serializer)
def serializeValueType(self, serializer):
assert isinstance(serializer, ProgramSerializer)
# create an enum with tags for all actions
serializer.emitIndent()
serializer.appendFormat("enum {0} ", self.actionEnumName)
serializer.blockStart()
for a in self.actions:
name = a.name
serializer.emitIndent()
serializer.appendFormat("{0}_{1},", self.name, name)
serializer.newline()
serializer.blockEnd(False)
serializer.endOfStatement(True)
# a type-safe union: a struct with a tag and an union
serializer.emitIndent()
serializer.appendFormat("struct {0} ", self.valueTypeName)
serializer.blockStart()
serializer.emitIndent()
#serializer.appendFormat("enum {0} action;", self.actionEnumName)
# teporary workaround bcc bug
serializer.appendFormat("{0}32 action;",
self.config.uprefix)
serializer.newline()
serializer.emitIndent()
serializer.append("union ")
serializer.blockStart()
for a in self.actions:
self.serializeActionArguments(serializer, a)
serializer.blockEnd(False)
serializer.space()
serializer.appendLine("u;")
serializer.blockEnd(False)
serializer.endOfStatement(True)
def serialize(self, serializer, program):
assert isinstance(serializer, ProgramSerializer)
assert isinstance(program, ebpfProgram.EbpfProgram)
self.serializeKeyType(serializer)
self.serializeValueType(serializer)
self.config.serializeTableDeclaration(
serializer, self.dataMapName, self.isHash,
"struct " + self.keyTypeName,
"struct " + self.valueTypeName, self.size)
self.config.serializeTableDeclaration(
serializer, self.defaultActionMapName, False,
program.arrayIndexType, "struct " + self.valueTypeName, 1)
def serializeCode(self, serializer, program, nextNode):
assert isinstance(serializer, ProgramSerializer)
assert isinstance(program, ebpfProgram.EbpfProgram)
hitVarName = program.reservedPrefix + "hit"
keyname = "key"
valueName = "value"
serializer.newline()
serializer.emitIndent()
serializer.appendFormat("{0}:", program.getLabel(self))
serializer.newline()
serializer.emitIndent()
serializer.blockStart()
serializer.emitIndent()
serializer.appendFormat("{0}8 {1};", program.config.uprefix, hitVarName)
serializer.newline()
serializer.emitIndent()
serializer.appendFormat("struct {0} {1} = {{}};", self.keyTypeName, keyname)
serializer.newline()
serializer.emitIndent()
serializer.appendFormat(
"struct {0} *{1};", self.valueTypeName, valueName)
serializer.newline()
self.key.serializeConstruction(serializer, keyname, program)
serializer.emitIndent()
serializer.appendFormat("{0} = 1;", hitVarName)
serializer.newline()
serializer.emitIndent()
serializer.appendLine("/* perform lookup */")
serializer.emitIndent()
program.config.serializeLookup(
serializer, self.dataMapName, keyname, valueName)
serializer.newline()
serializer.emitIndent()
serializer.appendFormat("if ({0} == NULL) ", valueName)
serializer.blockStart()
serializer.emitIndent()
serializer.appendFormat("{0} = 0;", hitVarName)
serializer.newline()
serializer.emitIndent()
serializer.appendLine("/* miss; find default action */")
serializer.emitIndent()
program.config.serializeLookup(
serializer, self.defaultActionMapName,
program.zeroKeyName, valueName)
serializer.newline()
serializer.blockEnd(True)
if len(self.counters) > 0:
serializer.emitIndent()
serializer.append("else ")
serializer.blockStart()
for c in self.counters:
assert isinstance(c, ebpfCounter.EbpfCounter)
if c.autoIncrement:
serializer.emitIndent()
serializer.blockStart()
c.serializeCode(keyname, serializer, program)
serializer.blockEnd(True)
serializer.blockEnd(True)
serializer.emitIndent()
serializer.appendFormat("if ({0} != NULL) ", valueName)
serializer.blockStart()
serializer.emitIndent()
serializer.appendLine("/* run action */")
self.runAction(serializer, self.name, valueName, program, nextNode)
nextNode = self.hlirtable.next_
if "hit" in nextNode:
node = nextNode["hit"]
if node is None:
node = nextNode
label = program.getLabel(node)
serializer.emitIndent()
serializer.appendFormat("if (hit) goto {0};", label)
serializer.newline()
node = nextNode["miss"]
if node is None:
node = nextNode
label = program.getLabel(node)
serializer.emitIndent()
serializer.appendFormat("else goto {0};", label)
serializer.newline()
serializer.blockEnd(True)
if not "hit" in nextNode:
# Catch-all
serializer.emitIndent()
serializer.appendFormat("goto end;")
serializer.newline()
serializer.blockEnd(True)
def runAction(self, serializer, tableName, valueName, program, nextNode):
serializer.emitIndent()
serializer.appendFormat("switch ({0}->action) ", valueName)
serializer.blockStart()
for a in self.actions:
assert isinstance(a, ebpfAction.EbpfActionBase)
serializer.emitIndent()
serializer.appendFormat("case {0}_{1}: ", tableName, a.name)
serializer.newline()
serializer.emitIndent()
serializer.blockStart()
a.serializeBody(serializer, valueName, program)
serializer.blockEnd(True)
serializer.emitIndent()
nextNodes = self.hlirtable.next_
if a.hliraction in nextNodes:
node = nextNodes[a.hliraction]
if node is None:
node = nextNode
label = program.getLabel(node)
serializer.appendFormat("goto {0};", label)
else:
serializer.appendFormat("break;")
serializer.newline()
serializer.blockEnd(True)