lib/agentx.c - quagga - Gitiles

 /* SNMP support
  * Copyright (C) 2012 Vincent Bernat <bernat@luffy.cx>
  *
  * 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 <zebra.h>

 #if defined HAVE_SNMP && defined SNMP_AGENTX
 #include <net-snmp/net-snmp-config.h>
 #include <net-snmp/net-snmp-includes.h>
 #include <net-snmp/agent/net-snmp-agent-includes.h>
 #include <net-snmp/agent/snmp_vars.h>

 #include "command.h"
 #include "smux.h"

 static int agentx_enabled = 0;

 static struct thread_master *agentx_tm;
 static struct thread *timeout_thr = NULL;
 static struct list *events = NULL;

 static void agentx_events_update(void);

 static int
 agentx_timeout(struct thread *t)
 {
   timeout_thr = NULL;

   snmp_timeout ();
   run_alarms ();
   netsnmp_check_outstanding_agent_requests ();
   agentx_events_update ();
   return 0;
 }

 static int
 agentx_read(struct thread *t)
 {
   fd_set fds;
   struct listnode *ln = THREAD_ARG (t);
   list_delete_node (events, ln);

   FD_ZERO (&fds);
   FD_SET (THREAD_FD (t), &fds);
   snmp_read (&fds);

   netsnmp_check_outstanding_agent_requests ();
   agentx_events_update ();
   return 0;
 }

 static void
 agentx_events_update(void)
 {
   int maxfd = 0;
   int block = 1;
   struct timeval timeout = { .tv_sec = 0, .tv_usec = 0 };
   fd_set fds;
   struct listnode *ln;
   struct thread *thr;
   int fd, thr_fd;

   THREAD_OFF (timeout_thr);

   FD_ZERO (&fds);
   snmp_select_info (&maxfd, &fds, &timeout, &block);

   if (!block)
     timeout_thr = thread_add_timer_tv (agentx_tm, agentx_timeout, NULL, &timeout);

   ln = listhead (events);
   thr = ln ? listgetdata (ln) : NULL;
   thr_fd = thr ? THREAD_FD (thr) : -1;

   /* "two-pointer" / two-list simultaneous iteration
    * ln/thr/thr_fd point to the next existing event listener to hit while
    * fd counts to catch up */
   for (fd = 0; fd < maxfd; fd++)
     {
       /* caught up */
       if (thr_fd == fd)
         {
           struct listnode *nextln = listnextnode (ln);
           if (!FD_ISSET (fd, &fds))
             {
               thread_cancel (thr);
               list_delete_node (events, ln);
             }
           ln = nextln;
           thr = ln ? listgetdata (ln) : NULL;
           thr_fd = thr ? THREAD_FD (thr) : -1;
         }
       /* need listener, but haven't hit one where it would be */
       else if (FD_ISSET (fd, &fds))
         {
           struct listnode *newln;
           thr = thread_add_read (agentx_tm, agentx_read, NULL, fd);
           newln = listnode_add_before (events, ln, thr);
           thr->arg = newln;
         }
     }

   /* leftover event listeners at this point have fd > maxfd, delete them */
   while (ln)
     {
       struct listnode *nextln = listnextnode (ln);
       thread_cancel (listgetdata (ln));
       list_delete_node (events, ln);
       ln = nextln;
     }
 }

 /* 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");
       events = list_new();
       agentx_events_update ();
       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)
 {
   agentx_tm = 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 (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 (&notification_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 (&notification_vars,
 				     oid, oid_len,
 				     vp[j].type,
 				     val,
 				     val_len);
 	  break;
 	}
     }


   send_v2trap (notification_vars);
   snmp_free_varbind (notification_vars);
   agentx_events_update ();
   return 1;
 }

 #endif /* HAVE_SNMP */
	/* SNMP support
	* Copyright (C) 2012 Vincent Bernat <bernat@luffy.cx>
	*
	* 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 <zebra.h>

	#if defined HAVE_SNMP && defined SNMP_AGENTX
	#include <net-snmp/net-snmp-config.h>
	#include <net-snmp/net-snmp-includes.h>
	#include <net-snmp/agent/net-snmp-agent-includes.h>
	#include <net-snmp/agent/snmp_vars.h>

	#include "command.h"
	#include "smux.h"

	static int agentx_enabled = 0;

	static struct thread_master *agentx_tm;
	static struct thread *timeout_thr = NULL;
	static struct list *events = NULL;

	static void agentx_events_update(void);

	static int
	agentx_timeout(struct thread *t)
	{
	timeout_thr = NULL;

	snmp_timeout ();
	run_alarms ();
	netsnmp_check_outstanding_agent_requests ();
	agentx_events_update ();
	return 0;
	}

	static int
	agentx_read(struct thread *t)
	{
	fd_set fds;
	struct listnode *ln = THREAD_ARG (t);
	list_delete_node (events, ln);

	FD_ZERO (&fds);
	FD_SET (THREAD_FD (t), &fds);
	snmp_read (&fds);

	netsnmp_check_outstanding_agent_requests ();
	agentx_events_update ();
	return 0;
	}

	static void
	agentx_events_update(void)
	{
	int maxfd = 0;
	int block = 1;
	struct timeval timeout = { .tv_sec = 0, .tv_usec = 0 };
	fd_set fds;
	struct listnode *ln;
	struct thread *thr;
	int fd, thr_fd;

	THREAD_OFF (timeout_thr);

	FD_ZERO (&fds);
	snmp_select_info (&maxfd, &fds, &timeout, &block);

	if (!block)
	timeout_thr = thread_add_timer_tv (agentx_tm, agentx_timeout, NULL, &timeout);

	ln = listhead (events);
	thr = ln ? listgetdata (ln) : NULL;
	thr_fd = thr ? THREAD_FD (thr) : -1;

	/* "two-pointer" / two-list simultaneous iteration
	* ln/thr/thr_fd point to the next existing event listener to hit while
	* fd counts to catch up */
	for (fd = 0; fd < maxfd; fd++)
	{
	/* caught up */
	if (thr_fd == fd)
	{
	struct listnode *nextln = listnextnode (ln);
	if (!FD_ISSET (fd, &fds))
	{
	thread_cancel (thr);
	list_delete_node (events, ln);
	}
	ln = nextln;
	thr = ln ? listgetdata (ln) : NULL;
	thr_fd = thr ? THREAD_FD (thr) : -1;
	}
	/* need listener, but haven't hit one where it would be */
	else if (FD_ISSET (fd, &fds))
	{
	struct listnode *newln;
	thr = thread_add_read (agentx_tm, agentx_read, NULL, fd);
	newln = listnode_add_before (events, ln, thr);
	thr->arg = newln;
	}
	}

	/* leftover event listeners at this point have fd > maxfd, delete them */
	while (ln)
	{
	struct listnode *nextln = listnextnode (ln);
	thread_cancel (listgetdata (ln));
	list_delete_node (events, ln);
	ln = nextln;
	}
	}

	/* 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");
	events = list_new();
	agentx_events_update ();
	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)
	{
	agentx_tm = 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 (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 (&notification_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 (&notification_vars,
	oid, oid_len,
	vp[j].type,
	val,
	val_len);
	break;
	}
	}


	send_v2trap (notification_vars);
	snmp_free_varbind (notification_vars);
	agentx_events_update ();
	return 1;
	}

	#endif /* HAVE_SNMP */