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* [PATCH] squid-asnbl: Fix for bug#13023 - squid-asnbl-helper segfaulting and shutdown squid
@ 2023-03-22 18:28 Adolf Belka
  2023-05-17 12:37 ` Adolf Belka
  0 siblings, 1 reply; 4+ messages in thread
From: Adolf Belka @ 2023-03-22 18:28 UTC (permalink / raw)
  To: development

[-- Attachment #1: Type: text/plain, Size: 6790 bytes --]

- Patch provided by bug reporter. Here is the description of the problem from the bug.
   First I discovered that the helper only sometimes throwing the error and quits even
   for the same values and queries. Also the timespan until the error happens was quite
   different for every restart of squid  (minutes to hours). And it does not depend on
   the traffic on the proxy, even one connection could cause a crash while ten or
   hundrets won't. After a few days of testing different solutions and done a lot of
   debugging, redesigning the function did not fully solve the problem. Such standard
   things like checking the result variable for NULL (or it's equivalent "is None" in
   python) before evaluating it's subfunction produces the exact same error message. But
   with that knowledge it more and more turns out that python3 sometimes 'detects' the
   local return variable if it was a misused global. So for a full fix, the return
   variable also has to be initialized that python3 won't detect it's usage as an
   'UnboundLocalError' to succesfully fix this bug.
- LFS file updated to run patch before copying helper into place.
- Update of rootfile not needed.
- Bug reporter has been requested to raise this issue at the git repo for squid-asnbl.

Fixes: Bug#13023
Tested-by: Nicolas Pӧhlmann <business(a)hardcoretec.com>
Signed-off-by: Adolf Belka <adolf.belka(a)ipfire.org>
---
 lfs/squid-asnbl                               |   1 +
 ...les_to_make_compatible_with_python_3.patch | 100 ++++++++++++++++++
 2 files changed, 101 insertions(+)
 create mode 100644 src/patches/squid/squid-asnbl-0.2.4_initialise_global_variables_to_make_compatible_with_python_3.patch

diff --git a/lfs/squid-asnbl b/lfs/squid-asnbl
index 130b28460..b003d605b 100644
--- a/lfs/squid-asnbl
+++ b/lfs/squid-asnbl
@@ -75,6 +75,7 @@ $(subst %,%_BLAKE2,$(objects)) :
 $(TARGET) : $(patsubst %,$(DIR_DL)/%,$(objects))
 	@$(PREBUILD)
 	@rm -rf $(DIR_APP) && cd $(DIR_SRC) && tar zvxf $(DIR_DL)/$(DL_FILE)
+	cd $(DIR_APP) && patch -Np1 -i $(DIR_SRC)/src/patches/squid/squid-asnbl-0.2.4_initialise_global_variables_to_make_compatible_with_python_3.patch
 
 	# Install ASNBL helper script
 	cd $(DIR_APP) && install -o root -g root -m 0755 asnbl-helper.py /usr/bin/asnbl-helper.py
diff --git a/src/patches/squid/squid-asnbl-0.2.4_initialise_global_variables_to_make_compatible_with_python_3.patch b/src/patches/squid/squid-asnbl-0.2.4_initialise_global_variables_to_make_compatible_with_python_3.patch
new file mode 100644
index 000000000..e540d4e76
--- /dev/null
+++ b/src/patches/squid/squid-asnbl-0.2.4_initialise_global_variables_to_make_compatible_with_python_3.patch
@@ -0,0 +1,100 @@
+--- squid-asnbl-0.2.4/asnbl-helper_orig.py
++++ squid-asnbl-0.2.4/asnbl-helper.py
+@@ -172,17 +172,19 @@
+     return parsedasns
+ 
+ 
+-def resolve_asn(ipaddr: str, asndb):
+-    """ Function call: resolve_asn(IP address to be resolved,
+-                                   ASN database instance object)
+-    This function looks up the Autonomous System for the given IP address. It expects
+-    an IPFire location database object to be passed as a second parameter, hence relying
+-    on another function to set that up. """
++def resolve_asn(ipaddr: str):
++    """ Function call: resolve_asn(IP address to be resolved)
++    This function looks up the Autonomous System for the given IP address. """
++
++    # Fix for #13023
++    # Initialize the result variable before it's first use, otherwise python3
++    # will sometimes detect a 'mismatch' using global and local variables
++    lookup_result = None
+ 
+     # libloc cannot handle ipaddress objects here, so casting into a string is necessary
+     # for good measure, to avoid exceptions here...
+     try:
+-        result = asndb.lookup(str(ipaddr))
++        lookup_result = ASNDB.lookup(str(ipaddr))
+     except BlockingIOError:
+         # XXX: Prevent likely libloc bug from causing this helper to crash
+         # (see upstream bug https://bugzilla.ipfire.org/show_bug.cgi?id=13023)
+@@ -190,21 +192,25 @@
+ 
+     # In case nothing was returned above, satisfy result expectation to this function...
+     try:
+-        if not result.asn:
++        if not lookup_result.asn:
+             return 0
+     except AttributeError:
+         return 0
+ 
+-    return result.asn
+-
+-
+-def asndb_response_tests(testdata: str, asndb):
+-    """ Function call: asndb_response_tests(response rest data,
+-                                            ASN database instance object)
++    return lookup_result.asn
++
++
++def asndb_response_tests(testdata: str):
++    """ Function call: asndb_response_tests(response rest data)
+ 
+     This function asserts the given ASN database to return expected ASNs for
+     given IP addresses in order to be considered operational. It returns
+     True if this test succeeds, and False otherwise. """
++
++    # Fix for #13023
++    # Initialize the result variable before it's first use, otherwise python3
++    # will sometimes detect a 'mismatch' using global and local variables
++    lookup_result_test = None
+ 
+     tresult = True
+ 
+@@ -216,13 +222,13 @@
+ 
+     for stestdata in ptdata:
+         LOGIT.debug("Running response test for '%s' against ASNDB '%s' ...",
+-                    stestdata, asndb)
+-
+-        returndata = resolve_asn(stestdata[0], asndb)
+-
+-        if returndata != int(stestdata[1]):
++                    stestdata, ASNDB)
++
++        lookup_result_test = resolve_asn(stestdata[0])
++
++        if lookup_result_test != int(stestdata[1]):
+             LOGIT.error("Response test failed for ASNDB '%s' (tuple: %s), aborting",
+-                        asndb, stestdata)
++                        ASNDB, stestdata)
+             tresult = False
+             break
+ 
+@@ -428,7 +434,7 @@
+ ASNDB = set_up_location_database(config["GENERAL"]["ASNDB_PATH"])
+ 
+ LOGIT.debug("Running ASN database response tests...")
+-if asndb_response_tests(config["GENERAL"]["TESTDATA"], ASNDB):
++if asndb_response_tests(config["GENERAL"]["TESTDATA"]):
+     LOGIT.debug("ASN database operational - excellent. Waiting for input...")
+ else:
+     LOGIT.error("ASN database response tests failed, aborting")
+@@ -490,7 +496,7 @@
+     ASNS = []
+     for singleip in IPS:
+         # Enumerate ASN for this IP address...
+-        resolvedasn = resolve_asn(singleip, ASNDB)
++        resolvedasn = resolve_asn(singleip)
+ 
+         # In case protection against destinations without public AS announcements for their
+         # IP addresses is desired, the query will be denied in case ASN = 0 appears in an
-- 
2.39.2


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2023-03-22 18:28 [PATCH] squid-asnbl: Fix for bug#13023 - squid-asnbl-helper segfaulting and shutdown squid Adolf Belka
2023-05-17 12:37 ` Adolf Belka
2023-07-01 16:04   ` Adolf Belka
2023-07-01 19:29     ` Peter Müller

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