[checkmk-commits] Check_MK Git: check_mk: #2477 FIX SNMP: Fixed exception when processing specific SNMP data with missing columns

Module: check_mk Branch: master Commit: bfa9cce34cde2c7aaa97c37d13e2cfeff24d8903 URL: http://git.mathias-kettner.de/git/?p=check_mk.git;a=commit;h=bfa9cce34cde2c… Author: Lars Michelsen &lt;lm(a)mathias-kettner.de&gt; Date: Fri Jul 24 15:08:20 2015 +0200 #2477 FIX SNMP: Fixed exception when processing specific SNMP data with missing columns When processing SNMP tables which have a) end OIDs which are not increasing and b) some columns are missing some indexes, this could lead into mixed up rows and even exceptions during processing of this data. This occured e.g. on Bintec RLX125000 devices where the interfaces OIDs were not reported in numerical order by their end OIDs as one would expect in SNMP. --- .werks/2477 | 14 +++++++ ChangeLog | 1 + modules/snmp.py | 116 ++++++++++++++++++++++++++++++++----------------------- 3 files changed, 82 insertions(+), 49 deletions(-) diff --git a/.werks/2477 b/.werks/2477 new file mode 100644 index 0000000..42ca28c --- /dev/null +++ b/.werks/2477 @@ -0,0 +1,14 @@ +Title: SNMP: Fixed exception when processing specific SNMP data with missing columns +Level: 1 +Component: checks +Compatible: compat +Version: 1.2.7i3 +Date: 1437743112 +Class: fix + +When processing SNMP tables which have a) end OIDs which are not increasing and +b) some columns are missing some indexes, this could lead into mixed up rows and +even exceptions during processing of this data. + +This occured e.g. on Bintec RLX125000 devices where the interfaces OIDs were +not reported in numerical order by their end OIDs as one would expect in SNMP. diff --git a/ChangeLog b/ChangeLog index e52d97e..d0d64b6 100644 --- a/ChangeLog +++ b/ChangeLog @@ -75,6 +75,7 @@ * 2377 FIX: cpu.loads: Fix output of reference for predition (was scaled wrongly by number of cores) * 2473 FIX: cisco_asa_failover: Reworked check to reflect expected primary/secondary states of devices... * 2476 FIX: check_bi_aggr: Fixed exception when authentication is enabled + * 2477 FIX: SNMP: Fixed exception when processing specific SNMP data with missing columns... Multisite: * 2385 SEC: Fixed possible reflected XSS on all GUI pages where users can produce unhandled exceptions... diff --git a/modules/snmp.py b/modules/snmp.py index 4e1231c..ad097a6 100644 --- a/modules/snmp.py +++ b/modules/snmp.py @@ -90,6 +90,10 @@ def oid_to_intlist(oid): def cmp_oids(o1, o2): return cmp(oid_to_intlist(o1), oid_to_intlist(o2)) +def cmp_oid_pairs(pair1, pair2): + return cmp(oid_to_intlist(pair1[0].lstrip('.')), + oid_to_intlist(pair2[0].lstrip('.'))) + def snmpv3_contexts_of_host(hostname): return host_extra_conf(hostname, snmpv3_contexts) @@ -209,70 +213,84 @@ def get_snmp_table(hostname, ip, check_type, oid_info): # prepend suboid to first column - if suboid and len(columns) > 0: + if suboid and columns: fetchoid, first_column = columns[0] new_first_column = [] for o, val in first_column: new_first_column.append((o, str(suboid) + "." + str(val))) columns[0] = fetchoid, new_first_column - # Swap X and Y axis of table (we want one list of columns per item) # Here we have to deal with a nasty problem: Some brain-dead devices # omit entries in some sub OIDs. This happens e.g. for CISCO 3650 # in the interfaces MIB with 64 bit counters. So we need to look at # the OIDs and watch out for gaps we need to fill with dummy values. + new_columns = sanitize_snmp_table_columns(columns) - # First compute the complete list of end-oids appearing in the output - # by looping all results and putting the endoids to a flat list - endoids = [] - for fetchoid, column in columns: - for o, value in column: - endoid = extract_end_oid(fetchoid, o) - if endoid not in endoids: - endoids.append(endoid) - - # The list needs to be sorted to prevent problems when the first - # column has missing values in the middle of the tree. Since we - # work with strings of numerical components, a simple string sort - # is not correct. 1.14 must come after 1.2! - endoids.sort(cmp = cmp_oids) - - # Now fill gaps in columns where some endois are missing - new_columns = [] - for fetchoid, column in columns: - i = 0 - new_column = [] - # Loop all lines to fill holes in the middle of the list. All - # columns check the following lines for the correct endoid. If - # an endoid differs empty values are added until the hole is filled - for o, value in column: - eo = extract_end_oid(fetchoid, o) - if len(column) != len(endoids): - while i < len(endoids) and endoids[i] != eo: - new_column.append("") # (beginoid + '.' +endoids[i], "" ) ) - i += 1 - new_column.append(value) - i += 1 - - # At the end check if trailing OIDs are missing - while i < len(endoids): - new_column.append("") # (beginoid + '.' +endoids[i], "") ) - i += 1 - new_columns.append(new_column) - columns = new_columns - - # Now construct table by swapping X and Y - new_info = [] - index = 0 - if len(columns) > 0: - for item in columns[0]: - new_info.append([ c[index] for c in columns ]) - index += 1 - info += new_info + info += construct_snmp_table_of_rows(new_columns) return info +def sanitize_snmp_table_columns(columns): + # First compute the complete list of end-oids appearing in the output + # by looping all results and putting the endoids to a flat list + endoids = [] + for fetchoid, column in columns: + for o, value in column: + endoid = extract_end_oid(fetchoid, o) + if endoid not in endoids: + endoids.append(endoid) + + # The list needs to be sorted to prevent problems when the first + # column has missing values in the middle of the tree. Since we + # work with strings of numerical components, a simple string sort + # is not correct. 1.14 must come after 1.2! + endoids.sort(cmp = cmp_oids) + + # Now fill gaps in columns where some endois are missing + new_columns = [] + for fetchoid, column in columns: + # It might happen that end OIDs are not ordered. Fix the OID sorting to make + # it comparable to the already sorted endoids list. Otherwise we would get + # some mixups when filling gaps + # FIXME: Performance? Maybe check whether or not endoids has changed anything and only sort in this case + column.sort(cmp = cmp_oid_pairs) + + i = 0 + new_column = [] + # Loop all lines to fill holes in the middle of the list. All + # columns check the following lines for the correct endoid. If + # an endoid differs empty values are added until the hole is filled + for o, value in column: + eo = extract_end_oid(fetchoid, o) + if len(column) != len(endoids): + while i < len(endoids) and endoids[i] != eo: + new_column.append("") # (beginoid + '.' +endoids[i], "" ) ) + i += 1 + new_column.append(value) + i += 1 + + # At the end check if trailing OIDs are missing + while i < len(endoids): + new_column.append("") # (beginoid + '.' +endoids[i], "") ) + i += 1 + new_columns.append(new_column) + + return new_columns + + +def construct_snmp_table_of_rows(columns): + if not columns: + return [] + + # Now construct table by swapping X and Y. + new_info = [] + for index in range(len(columns[0])): + row = [ c[index] for c in columns ] + new_info.append(row) + return new_info + + # SNMP-Helper functions used in various checks def check_snmp_misc(item, params, info):