def compose_standard_rules(rule1, rule2):
mid_ports = [val for val in rule2["in_ports"] if val in rule1["out_ports"]]
if len(mid_ports) == 0:
return None
# ## finding match
# rule 2 is a link rule
if rule2["match"] == None:
match = wildcard_copy(rule1["match"])
else:
# if rule 1 is a fwd or link rule
if rule1["mask"] == None:
# if rule 1 is a link rule
if rule1["match"] == None:
match = wildcard_copy(rule2["match"])
else:
match = wildcard_intersect(rule2["match"], rule1["match"])
# if rule 1 is a rewrite rule
else:
match_inv = wildcard_or(\
wildcard_and(rule2["match"], rule1['mask']), \
rule1['inverse_rewrite'])
match = wildcard_intersect(match_inv, rule1["match"])
if len(match) == 0:
return None
# ## finding mask and rewrite
mask = None
rewrite = None
if rule2["mask"] == None:
mask = rule1["mask"]
rewrite = rule1["rewrite"]
elif rule1["mask"] == None:
mask = rule2["mask"]
rewrite = rule2["rewrite"]
else:
# mask = mask1 & mask2
# rewrite = (rewrite1 & mask2) | (rewrite2 & !mask2)
mask = wildcard_and(rule1["mask"], rule2["mask"])
rewrite = wildcard_or(wildcard_and(rule1["rewrite"], rule2["mask"]), wildcard_and(rule2["rewrite"], wildcard_not(rule2["mask"])))
in_ports = rule1["in_ports"]
out_ports = rule2["out_ports"]
if rule1["file"] == rule2["file"]:
file_name = rule1["file"]
else:
file_name = "%s , %s" % (rule1["file"], rule2["file"])
lines = rule1["line"]
lines.extend(rule2["line"])
result_rule = TF.create_standard_rule(in_ports, match, out_ports, mask, rewrite, file_name, lines)
return result_rule
def set_rule(self, table, in_ports, out_ports, match, mask, rewrite):
'''
sets the essential infomation about a rule and automatically computes
inverse match and rewrite.
'''
self.input_ports = in_ports
self.output_ports = out_ports
self.match = match
self.mask = mask
self.rewrite = rewrite
self.table = table
if (mask.__class__ == wildcard and rewrite.__class__ == wildcard):
masked = wildcard_and(match, mask)
rewritten = wildcard_or(masked, rewrite)
self.inverse_match = rewritten
self.inverse_rewrite = wildcard_and(wildcard_not(mask), match)
else:
self.mask = None
self.rewrite = None
self.inverse_match = match
self.inverse_rewrite = None
return self
def set_rule(self,table,in_ports,out_ports,match,mask,rewrite):
'''
sets the essential infomation about a rule and automatically computes
inverse match and rewrite.
'''
self.input_ports = in_ports
self.output_ports = out_ports
self.match = match
self.mask = mask
self.rewrite = rewrite
self.table = table
if (mask.__class__ == wildcard and rewrite.__class__ == wildcard):
masked = wildcard_and(match, mask)
rewritten = wildcard_or(masked, rewrite)
self.inverse_match = rewritten
self.inverse_rewrite = wildcard_and(wildcard_not(mask), match)
else:
self.mask = None
self.rewrite = None
self.inverse_match = match
self.inverse_rewrite = None
return self
def find_new_field(self, field_match, field_mask, field_rewrite):
'''
finds out the new value for this field. If it is unknown
(i.e. there are wildcard bits in it), returns None.
'''
all_masked = True
for i in range(len(field_mask)):
if (field_mask[i] != 0xaaaa):
all_masked = False
if (all_masked):
return None
rw = wildcard_or(\
wildcard_and(field_match,field_mask),\
field_rewrite)
try:
value = int(rw.__str__(0).replace(",", ""), 2)
return value
except:
print "ERROR: Unexpected rewrite action. Ignored. %s - %s - %s - %s"%\
(field_match,field_mask,field_rewrite,rw)
return None
def find_new_field(self,field_match,field_mask,field_rewrite):
'''
finds out the new value for this field. If it is unknown
(i.e. there are wildcard bits in it), returns None.
'''
all_masked = True
for i in range (len(field_mask)):
if (field_mask[i] != 0xaaaa):
all_masked = False
if (all_masked):
return None
rw = wildcard_or(\
wildcard_and(field_match,field_mask),\
field_rewrite)
try:
value = int(rw.__str__(0).replace(",", ""),2)
return value
except:
print "ERROR: Unexpected rewrite action. Ignored. %s - %s - %s - %s"%\
(field_match,field_mask,field_rewrite,rw)
return None
