From d6be5fb9bc41ea77547204eeedd12132b26ad662 Mon Sep 17 00:00:00 2001 From: Vincent Bernat Date: Thu, 24 May 2012 09:44:43 +0200 Subject: agentx: add AgentX support to Quagga. --enable-snmp will enable AgentX support in Quagga. SMUX is still here and can be enabled with --enable-snmp=smux. AgentX support can be enabled with "agentx" in configuration file. As for SMUX, this command is not understood by vtysh. It can be disabled with "no agentx", though there is no real use of this since this command cannot be used with vtysh. If "agentx" and "no agentx" command were added to vtysh, it would not be possible to disable agentx support after enabling it because NetSNMP does not expose the appropriate methods for this. The internals of AgentX are hidden by NetSNMP. Therefore, we don't have a file descriptor to add to the threading system. We do not have the timers to set either. Therefore, the event loop is modified to make use of snmp_select_info() from NetSNMP. Traps are not supported yet. --- lib/agentx.c | 133 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 133 insertions(+) create mode 100644 lib/agentx.c (limited to 'lib/agentx.c') diff --git a/lib/agentx.c b/lib/agentx.c new file mode 100644 index 00000000..9cf6de5e --- /dev/null +++ b/lib/agentx.c @@ -0,0 +1,133 @@ +/* SNMP support + * Copyright (C) 2012 Vincent Bernat + * + * This file is part of GNU Zebra. + * + * GNU Zebra is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2, or (at your option) any + * later version. + * + * GNU Zebra is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with GNU Zebra; see the file COPYING. If not, write to the Free + * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA + * 02111-1307, USA. + */ + +#include + +#if defined HAVE_SNMP && defined SNMP_AGENTX +#include +#include + +#include "command.h" +#include "smux.h" + +int agentx_enabled = 0; + +/* AgentX node. */ +static struct cmd_node agentx_node = +{ + SMUX_NODE, + "" /* AgentX has no interface. */ +}; + +/* Logging NetSNMP messages */ +static int +agentx_log_callback(int major, int minor, + void *serverarg, void *clientarg) +{ + struct snmp_log_message *slm = (struct snmp_log_message *)serverarg; + char *msg = strdup (slm->msg); + if (msg) msg[strlen(msg)-1] = '\0'; + switch (slm->priority) + { + case LOG_EMERG: zlog_err ("snmp[emerg]: %s", msg?msg:slm->msg); break; + case LOG_ALERT: zlog_err ("snmp[alert]: %s", msg?msg:slm->msg); break; + case LOG_CRIT: zlog_err ("snmp[crit]: %s", msg?msg:slm->msg); break; + case LOG_ERR: zlog_err ("snmp[err]: %s", msg?msg:slm->msg); break; + case LOG_WARNING: zlog_warn ("snmp[warning]: %s", msg?msg:slm->msg); break; + case LOG_NOTICE: zlog_notice("snmp[notice]: %s", msg?msg:slm->msg); break; + case LOG_INFO: zlog_info ("snmp[info]: %s", msg?msg:slm->msg); break; + case LOG_DEBUG: zlog_debug ("snmp[debug]: %s", msg?msg:slm->msg); break; + } + free(msg); + return SNMP_ERR_NOERROR; +} + +static int +config_write_agentx (struct vty *vty) +{ + if (agentx_enabled) + vty_out (vty, "agentx%s", VTY_NEWLINE); + return 0; +} + +DEFUN (agentx_enable, + agentx_enable_cmd, + "agentx", + "SNMP AgentX protocol settings\n" + "SNMP AgentX settings\n") +{ + if (!agentx_enabled) + { + init_snmp("quagga"); + agentx_enabled = 1; + return CMD_SUCCESS; + } + vty_out (vty, "SNMP AgentX already enabled%s", VTY_NEWLINE); + return CMD_WARNING; +} + +DEFUN (no_agentx, + no_agentx_cmd, + "no agentx", + NO_STR + "SNMP AgentX protocol settings\n" + "SNMP AgentX settings\n") +{ + if (!agentx_enabled) return CMD_SUCCESS; + vty_out (vty, "SNMP AgentX support cannot be disabled once enabled%s", VTY_NEWLINE); + return CMD_WARNING; +} + +void +smux_init (struct thread_master *tm) +{ + netsnmp_enable_subagent (); + snmp_disable_log (); + snmp_enable_calllog (); + snmp_register_callback (SNMP_CALLBACK_LIBRARY, + SNMP_CALLBACK_LOGGING, + agentx_log_callback, + NULL); + init_agent ("quagga"); + + install_node (&agentx_node, config_write_agentx); + install_element (CONFIG_NODE, &agentx_enable_cmd); + install_element (CONFIG_NODE, &no_agentx_cmd); +} + +void +smux_register_mib (const char *descr, struct variable *var, + size_t width, int num, + oid name[], size_t namelen) +{ + register_mib (descr, var, width, num, name, namelen); +} + +int +smux_trap (const oid *name, size_t namelen, + const oid *iname, size_t inamelen, + const struct trap_object *trapobj, size_t trapobjlen, + unsigned int tick, u_char sptrap) +{ + return 1; +} + +#endif /* HAVE_SNMP */ -- cgit v1.2.3 From 4b89e45d928d41bb5d32a00ba7b402d6a3bbdf44 Mon Sep 17 00:00:00 2001 From: Vincent Bernat Date: Thu, 24 May 2012 21:22:01 +0200 Subject: smux: remove `tick` argument from smux_trap() smux_trap() contains an argument whose use appears to be to set sysUpTime.0/timestamp field in SNMP trap. However, this value is not used in smux_trap(). Moreover, it is expected that this field is the value of sysUpTime.0 when the trap was sent and not any other time related to the trap. To avoid any confusion, we remove this field from the signature of the function. --- lib/agentx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib/agentx.c') diff --git a/lib/agentx.c b/lib/agentx.c index 9cf6de5e..2358581f 100644 --- a/lib/agentx.c +++ b/lib/agentx.c @@ -125,7 +125,7 @@ int smux_trap (const oid *name, size_t namelen, const oid *iname, size_t inamelen, const struct trap_object *trapobj, size_t trapobjlen, - unsigned int tick, u_char sptrap) + u_char sptrap) { return 1; } -- cgit v1.2.3 From b7c0d0651cd64f644d02ef5e4d1b82febe7e57d8 Mon Sep 17 00:00:00 2001 From: Vincent Bernat Date: Fri, 25 May 2012 11:17:01 +0200 Subject: agentx: handle SNMP traps smux_trap() signature has been changed to provide appropriate level information to send SNMPv2 notifications. This includes the addition of the enterprise OID to use (from which is derived the SNMP trap OID) and the MIB registry to locate the appropriate function for variable bindings provided by the trap. The SMUX implementation has been updated but ignore the provided enterprise OID. Instead, it still uses the SMUX peer OID to keep compatibility with previous versions of Quagga. The SMUX implementation also ignores the provided MIB registry since it uses smux_get() function to grab the appropriate values. This is not possible with the AgentX implementation since there is no such function provided by NetSNMP. --- lib/agentx.c | 82 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 81 insertions(+), 1 deletion(-) (limited to 'lib/agentx.c') diff --git a/lib/agentx.c b/lib/agentx.c index 2358581f..be6b4320 100644 --- a/lib/agentx.c +++ b/lib/agentx.c @@ -122,11 +122,91 @@ smux_register_mib (const char *descr, struct variable *var, } int -smux_trap (const oid *name, size_t namelen, +smux_trap (struct variable *vp, size_t vp_len, + const oid *ename, size_t enamelen, + const oid *name, size_t namelen, const oid *iname, size_t inamelen, const struct trap_object *trapobj, size_t trapobjlen, u_char sptrap) { + oid objid_snmptrap[] = { 1, 3, 6, 1, 6, 3, 1, 1, 4, 1, 0 }; + size_t objid_snmptrap_len = sizeof objid_snmptrap / sizeof (oid); + oid notification_oid[MAX_OID_LEN]; + size_t notification_oid_len; + unsigned int i; + + netsnmp_variable_list *notification_vars = NULL; + if (!agentx_enabled) return 0; + + /* snmpTrapOID */ + oid_copy (notification_oid, ename, enamelen); + notification_oid[enamelen] = sptrap; + notification_oid_len = enamelen + 1; + snmp_varlist_add_variable (¬ification_vars, + objid_snmptrap, objid_snmptrap_len, + ASN_OBJECT_ID, + (u_char *) notification_oid, + notification_oid_len * sizeof(oid)); + + /* Provided bindings */ + for (i = 0; i < trapobjlen; i++) + { + unsigned int j; + oid oid[MAX_OID_LEN]; + size_t oid_len, onamelen; + u_char *val; + size_t val_len; + WriteMethod *wm = NULL; + struct variable cvp; + + /* Make OID. */ + if (trapobj[i].namelen > 0) + { + /* Columnar object */ + onamelen = trapobj[i].namelen; + oid_copy (oid, name, namelen); + oid_copy (oid + namelen, trapobj[i].name, onamelen); + oid_copy (oid + namelen + onamelen, iname, inamelen); + oid_len = namelen + onamelen + inamelen; + } + else + { + /* Scalar object */ + onamelen = trapobj[i].namelen * (-1); + oid_copy (oid, name, namelen); + oid_copy (oid + namelen, trapobj[i].name, onamelen); + oid[onamelen + namelen] = 0; + oid_len = namelen + onamelen + 1; + } + + /* Locate the appropriate function and type in the MIB registry. */ + for (j = 0; j < vp_len; j++) + { + if (oid_compare (trapobj[i].name, onamelen, vp[j].name, vp[j].namelen) != 0) + continue; + /* We found the appropriate variable in the MIB registry. */ + oid_copy(cvp.name, name, namelen); + oid_copy(cvp.name + namelen, vp[j].name, vp[j].namelen); + cvp.namelen = namelen + vp[j].namelen; + cvp.type = vp[j].type; + cvp.magic = vp[j].magic; + cvp.acl = vp[j].acl; + cvp.findVar = vp[j].findVar; + /* Grab the result. */ + val = cvp.findVar (&cvp, oid, &oid_len, 1, &val_len, &wm); + if (!val) break; + snmp_varlist_add_variable (¬ification_vars, + oid, oid_len, + vp[j].type, + val, + val_len); + break; + } + } + + + send_v2trap (notification_vars); + snmp_free_varbind (notification_vars); return 1; } -- cgit v1.2.3