Disable SNMP supply levels when the community name is cleared (Issue #…

…5354)

backend/snmp-supplies.c:
- Look for empty community name.

cups/snmp.c:
- Allow empty community name.

man/cups-snmp.conf.man:
- Document behavior of empty community name.

CHANGES.md

@@ -1,4 +1,4 @@
-CHANGES - 2.3b6 - 2018-11-07
+CHANGES - 2.3b6 - 2018-11-08
 ============================
 
 Changes in CUPS v2.3b6
@@ -21,6 +21,9 @@ Changes in CUPS v2.3b6
 - The IPP Everywhere "driver" now properly supports face-up printers
  (Issue #5345)
 - Fixed some typos in the label printer drivers (Issue #5350)
+- Setting the `Community` name to the empty string in `snmp.conf` now disables
+ SNMP supply level monitoring by all the standard network backends
+ (Issue #5354)
 - Multi-file jobs could get stuck if the backend failed (Issue #5359,
  Issue #5413)
 - The IPP Everywhere "driver" no longer does local filtering when printing to

backend/snmp-supplies.c

@@ -440,6 +440,7 @@ backend_init_supplies(
 {
  int i, /* Looping var */
  type; /* Current marker type */
+ const char *community; /* SNMP community name */
  cups_file_t *cachefile; /* Cache file */
  const char *cachedir; /* CUPS_CACHEDIR value */
  char addrstr[1024], /* Address string */
@@ -507,6 +508,10 @@ backend_init_supplies(
  * See if we should be getting supply levels via SNMP...
  */
 
+ community = _cupsSNMPDefaultCommunity();
+ if (!*community)
+ return;
+
  if ((ppd = ppdOpenFile(getenv("PPD"))) == NULL ||
  ((ppdattr = ppdFindAttr(ppd, "cupsSNMPSupplies", NULL)) != NULL &&
  ppdattr->value && _cups_strcasecmp(ppdattr->value, "true")))
@@ -528,7 +533,7 @@ backend_init_supplies(
  */
 
  if (!_cupsSNMPWrite(snmp_fd, addr, CUPS_SNMP_VERSION_1,
- _cupsSNMPDefaultCommunity(), CUPS_ASN1_GET_REQUEST, 1,
+ community, CUPS_ASN1_GET_REQUEST, 1,
  hrDeviceDescr))
  return;
 
@@ -605,7 +610,7 @@ backend_init_supplies(
 
 
  if (!_cupsSNMPWrite(snmp_fd, &current_addr, CUPS_SNMP_VERSION_1,
- _cupsSNMPDefaultCommunity(), CUPS_ASN1_GET_REQUEST, 1,
+ community, CUPS_ASN1_GET_REQUEST, 1,
  prtGeneralCurrentLocalization))
  return;
 
@@ -626,7 +631,7 @@ backend_init_supplies(
 
 
  if (!_cupsSNMPWrite(snmp_fd, &current_addr, CUPS_SNMP_VERSION_1,
- _cupsSNMPDefaultCommunity(), CUPS_ASN1_GET_REQUEST, 1,
+ community, CUPS_ASN1_GET_REQUEST, 1,
  oid))
  return;
 
@@ -651,7 +656,7 @@ backend_init_supplies(
  */
 
  _cupsSNMPWalk(snmp_fd, &current_addr, CUPS_SNMP_VERSION_1,
- _cupsSNMPDefaultCommunity(), prtMarkerSuppliesEntry,
+ community, prtMarkerSuppliesEntry,
  CUPS_SUPPLY_TIMEOUT, backend_walk_cb, NULL);
  }
 
@@ -685,7 +690,7 @@ backend_init_supplies(
  strlcpy(supplies[i].color, "none", sizeof(supplies[i].color));
 
  _cupsSNMPWalk(snmp_fd, &current_addr, CUPS_SNMP_VERSION_1,
- _cupsSNMPDefaultCommunity(), prtMarkerColorantValue,
+ community, prtMarkerColorantValue,
  CUPS_SUPPLY_TIMEOUT, backend_walk_cb, NULL);
 
  /*

cups/snmp.c

@@ -129,9 +129,13 @@ _cupsSNMPDefaultCommunity(void)
  {
  linenum = 0;
  while (cupsFileGetConf(fp, line, sizeof(line), &value, &linenum))
- if (!_cups_strcasecmp(line, "Community") && value)
+ if (!_cups_strcasecmp(line, "Community"))
  {
- strlcpy(cg->snmp_community, value, sizeof(cg->snmp_community));
+ if (value)
+ strlcpy(cg->snmp_community, value, sizeof(cg->snmp_community));
+ else
+ cg->snmp_community[0] = '\0';
+
  break;
  }
 

man/cups-snmp.conf.man

@@ -6,7 +6,7 @@
 .\"
 .\" Licensed under Apache License v2.0. See the file "LICENSE" for more information.
 .\"
-.TH snmp.conf 5 "CUPS" "10 June 2014" "Apple Inc."
+.TH snmp.conf 5 "CUPS" "8 November 2018" "Apple Inc."
 .SH NAME
 snmp.conf \- snmp configuration file for cups
 .SH DESCRIPTION
@@ -32,6 +32,7 @@ There is no default for the broadcast address.
 Specifies the community name to use.
 Only a single community name may be specified.
 The default community name is "public".
+If no name is specified, all SNMP functions are disabled.
 .TP 5
 \fBDebugLevel \fInumber\fR
 Specifies the logging level from 0 (none) to 3 (everything).