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Merge pull request #4724 from mnin/master

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[Netfilter] Fix creating endless SNAT rules for ipv4
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Niklas Meyer 2022-10-06 12:18:23 +02:00 committed by GitHub
commit 9fb346751c
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1 changed files with 26 additions and 17 deletions
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29
data/Dockerfiles/netfilter/server.py
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@ -346,6 +346,8 @@ def snat4(snat_target):
rule.dst = '!' + rule.src
target = rule.create_target("SNAT")
target.to_source = snat_target
match = rule.create_match("comment")
match.comment = f'{int(round(time.time()))}'
return rule
while not quit_now:
@ -356,16 +358,23 @@ def snat4(snat_target):
table.refresh()
chain = iptc.Chain(table, 'POSTROUTING')
table.autocommit = False
if get_snat4_rule() not in chain.rules:
logCrit('Added POSTROUTING rule for source network %s to SNAT target %s' % (get_snat4_rule().src, snat_target))
chain.insert_rule(get_snat4_rule())
table.commit()
else:
for position, item in enumerate(chain.rules):
if item == get_snat4_rule():
if position != 0:
chain.delete_rule(get_snat4_rule())
table.commit()
new_rule = get_snat4_rule()
for position, rule in enumerate(chain.rules):
match = all((
new_rule.get_src() == rule.get_src(),
new_rule.get_dst() == rule.get_dst(),
new_rule.target.parameters == rule.target.parameters,
new_rule.target.name == rule.target.name
))
if position == 0:
if not match:
logInfo(f'Added POSTROUTING rule for source network {new_rule.src} to SNAT target {snat_target}')
chain.insert_rule(new_rule)
else:
if match:
logInfo(f'Remove rule for source network {new_rule.src} to SNAT target {snat_target} from POSTROUTING chain at position {position}')
chain.delete_rule(rule)
table.commit()
table.autocommit = True
except:
print('Error running SNAT4, retrying...')