release/src/router/snmp/agent/snmp_vars.c

   1 /*
   2  * snmp_vars.c - return a pointer to the named variable.
   3  *
   4  *
   5  */
   6 /***********************************************************
   7         Copyright 1988, 1989, 1990 by Carnegie Mellon University
   8         Copyright 1989  TGV, Incorporated
   9
  10                       All Rights Reserved
  11
  12 Permission to use, copy, modify, and distribute this software and its
  13 documentation for any purpose and without fee is hereby granted,
  14 provided that the above copyright notice appear in all copies and that
  15 both that copyright notice and this permission notice appear in
  16 supporting documentation, and that the name of CMU and TGV not be used
  17 in advertising or publicity pertaining to distribution of the software
  18 without specific, written prior permission.
  19
  20 CMU AND TGV DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  21 INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  22 EVENT SHALL CMU OR TGV BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  23 CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
  24 USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
  25 OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  26 PERFORMANCE OF THIS SOFTWARE.
  27 ******************************************************************/
  28 /*
  29  * additions, fixes and enhancements for Linux by Erik Schoenfelder
  30  * (schoenfr@ibr.cs.tu-bs.de) 1994/1995.
  31  * Linux additions taken from CMU to UCD stack by Jennifer Bray of Origin
  32  * (jbray@origin-at.co.uk) 1997
  33  */
  34
  35 /*
  36  * XXXWWW merge todo: incl/excl range changes in differences between
  37  * 1.194 and 1.199
  38  */
  39
  40 #include <net-snmp/net-snmp-config.h>
  41 #if HAVE_STRING_H
  42 #include <string.h>
  43 #endif
  44 #if HAVE_STDLIB_H
  45 #include <stdlib.h>
  46 #endif
  47 #include <sys/types.h>
  48 #include <stdio.h>
  49 #include <fcntl.h>
  50
  51 #if TIME_WITH_SYS_TIME
  52 # ifdef WIN32
  53 #  include <sys/timeb.h>
  54 # else
  55 #  include <sys/time.h>
  56 # endif
  57 # include <time.h>
  58 #else
  59 # if HAVE_SYS_TIME_H
  60 #  include <sys/time.h>
  61 # else
  62 #  include <time.h>
  63 # endif
  64 #endif
  65 #if HAVE_WINSOCK_H
  66 # include <winsock.h>
  67 #endif
  68 #if HAVE_SYS_SOCKET_H
  69 # include <sys/socket.h>
  70 #endif
  71 #if HAVE_SYS_STREAM_H
  72 #include <sys/stream.h>
  73 #endif
  74 #if HAVE_SYS_SOCKETVAR_H
  75 # include <sys/socketvar.h>
  76 #endif
  77 #if HAVE_NETINET_IN_H
  78 #include <netinet/in.h>
  79 #endif
  80 #if HAVE_NETINET_IN_SYSTM_H
  81 #include <netinet/in_systm.h>
  82 #endif
  83 #if HAVE_NETINET_IP_H
  84 #include <netinet/ip.h>
  85 #endif
  86 #ifdef INET6
  87 #if HAVE_NETINET_IP6_H
  88 #include <netinet/ip6.h>
  89 #endif
  90 #endif
  91 #if HAVE_SYS_QUEUE_H
  92 #include <sys/queue.h>
  93 #endif
  94 #if HAVE_NET_ROUTE_H
  95 #include <net/route.h>
  96 #endif
  97 #if HAVE_NETINET_IP_VAR_H
  98 #include <netinet/ip_var.h>
  99 #endif
 100 #ifdef INET6
 101 #if HAVE_NETINET6_IP6_VAR_H
 102 #include <netinet6/ip6_var.h>
 103 #endif
 104 #endif
 105 #if HAVE_NETINET_IN_PCB_H
 106 #include <netinet/in_pcb.h>
 107 #endif
 108 #if HAVE_INET_MIB2_H
 109 #include <inet/mib2.h>
 110 #endif
 111
 112 #if HAVE_DMALLOC_H
 113 #include <dmalloc.h>
 114 #endif
 115
 116 #include <net-snmp/net-snmp-includes.h>
 117 #include <net-snmp/agent/net-snmp-agent-includes.h>
 118 #include "kernel.h"
 119
 120 #include "mibgroup/struct.h"
 121 #include "snmpd.h"
 122 #include "net-snmp/agent/all_helpers.h"
 123 #include "mib_module_includes.h"
 124 #include "net-snmp/library/container.h"
 125
 126 #ifndef  MIN
 127 #define  MIN(a,b)                     (((a) < (b)) ? (a) : (b))
 128 #endif
 129
 130 /*
 131  * mib clients are passed a pointer to a oid buffer.  Some mib clients
 132  * * (namely, those first noticed in mibII/vacm.c) modify this oid buffer
 133  * * before they determine if they really need to send results back out
 134  * * using it.  If the master agent determined that the client was not the
 135  * * right one to talk with, it will use the same oid buffer to pass to the
 136  * * rest of the clients, which may not longer be valid.  This should be
 137  * * fixed in all clients rather than the master.  However, its not a
 138  * * particularily easy bug to track down so this saves debugging time at
 139  * * the expense of a few memcpy's.
 140  */
 141 #define MIB_CLIENTS_ARE_EVIL 1
 142
 143 extern netsnmp_subtree *subtrees;
 144
 145 /*
 146  *      Each variable name is placed in the variable table, without the
 147  * terminating substring that determines the instance of the variable.  When
 148  * a string is found that is lexicographicly preceded by the input string,
 149  * the function for that entry is called to find the method of access of the
 150  * instance of the named variable.  If that variable is not found, NULL is
 151  * returned, and the search through the table continues (it will probably
 152  * stop at the next entry).  If it is found, the function returns a character
 153  * pointer and a length or a function pointer.  The former is the address
 154  * of the operand, the latter is a write routine for the variable.
 155  *
 156  * u_char *
 157  * findVar(name, length, exact, var_len, write_method)
 158  * oid      *name;          IN/OUT - input name requested, output name found
 159  * int      length;         IN/OUT - number of sub-ids in the in and out oid's
 160  * int      exact;          IN - TRUE if an exact match was requested.
 161  * int      len;            OUT - length of variable or 0 if function returned.
 162  * int      write_method;   OUT - pointer to function to set variable,
 163  *                                otherwise 0
 164  *
 165  *     The writeVar function is returned to handle row addition or complex
 166  * writes that require boundary checking or executing an action.
 167  * This routine will be called three times for each varbind in the packet.
 168  * The first time for each varbind, action is set to RESERVE1.  The type
 169  * and value should be checked during this pass.  If any other variables
 170  * in the MIB depend on this variable, this variable will be stored away
 171  * (but *not* committed!) in a place where it can be found by a call to
 172  * writeVar for a dependent variable, even in the same PDU.  During
 173  * the second pass, action is set to RESERVE2.  If this variable is dependent
 174  * on any other variables, it will check them now.  It must check to see
 175  * if any non-committed values have been stored for variables in the same
 176  * PDU that it depends on.  Sometimes resources will need to be reserved
 177  * in the first two passes to guarantee that the operation can proceed
 178  * during the third pass.  During the third pass, if there were no errors
 179  * in the first two passes, writeVar is called for every varbind with action
 180  * set to COMMIT.  It is now that the values should be written.  If there
 181  * were errors during the first two passes, writeVar is called in the third
 182  * pass once for each varbind, with the action set to FREE.  An opportunity
 183  * is thus provided to free those resources reserved in the first two passes.
 184  *
 185  * writeVar(action, var_val, var_val_type, var_val_len, statP, name, name_len)
 186  * int      action;         IN - RESERVE1, RESERVE2, COMMIT, or FREE
 187  * u_char   *var_val;       IN - input or output buffer space
 188  * u_char   var_val_type;   IN - type of input buffer
 189  * int      var_val_len;    IN - input and output buffer len
 190  * u_char   *statP;         IN - pointer to local statistic
 191  * oid      *name           IN - pointer to name requested
 192  * int      name_len        IN - number of sub-ids in the name
 193  */
 194
 195 long            long_return;
 196 #ifndef ibm032
 197 u_char          return_buf[258];
 198 #else
 199 u_char          return_buf[256];        /* nee 64 */
 200 #endif
 201
 202 struct timeval  starttime;
 203 netsnmp_session *callback_master_sess;
 204 int             callback_master_num;
 205
 206 /*
 207  * init_agent() returns non-zero on error
 208  */
 209 int
 210 init_agent(const char *app)
 211 {
 212     int             r = 0;
 213
 214     /*
 215      * get current time (ie, the time the agent started)
 216      */
 217     gettimeofday(&starttime, NULL);
 218     starttime.tv_sec--;
 219     starttime.tv_usec += 1000000L;
 220
 221     /*
 222      * we handle alarm signals ourselves in the select loop
 223      */
 224     netsnmp_ds_set_boolean(NETSNMP_DS_LIBRARY_ID,
 225                            NETSNMP_DS_LIB_ALARM_DONT_USE_SIG, 1);
 226
 227 #ifdef CAN_USE_NLIST
 228     init_kmem("/dev/kmem");
 229 #endif
 230
 231     setup_tree();
 232
 233     init_agent_read_config(app);
 234
 235 #ifdef TESTING
 236     auto_nlist_print_tree(-2, 0);
 237 #endif
 238
 239 #ifndef WIN32
 240         /*
 241          * the pipe call creates fds that select chokes on, so
 242          * disable callbacks on WIN32 until a fix can be found
 243          */
 244     /*
 245      * always register a callback transport for internal use
 246      */
 247     callback_master_sess = netsnmp_callback_open(0, handle_snmp_packet,
 248                                                  netsnmp_agent_check_packet,
 249                                                  netsnmp_agent_check_parse);
 250     if (callback_master_sess)
 251         callback_master_num = callback_master_sess->local_port;
 252     else
 253 #endif
 254         callback_master_num = -1;
 255
 256     netsnmp_init_helpers();
 257     init_traps();
 258     netsnmp_container_init_list();
 259
 260     /*
 261      * initialize agentx subagent if necessary.
 262      */
 263 #ifdef USING_AGENTX_SUBAGENT_MODULE
 264     if (netsnmp_ds_get_boolean(NETSNMP_DS_APPLICATION_ID,
 265                                NETSNMP_DS_AGENT_ROLE) == SUB_AGENT) {
 266         r = subagent_pre_init();
 267         init_subagent();
 268     }
 269 #endif
 270
 271     /*
 272      * Register configuration tokens from transport modules.
 273      */
 274 #ifdef SNMP_TRANSPORT_UDP_DOMAIN
 275     netsnmp_udp_agent_config_tokens_register();
 276 #endif
 277 #ifdef SNMP_TRANSPORT_UDPIPV6_DOMAIN
 278     netsnmp_udp6_agent_config_tokens_register();
 279 #endif
 280
 281 #ifdef NETSNMP_EMBEDDED_PERL
 282     init_perl();
 283 #endif
 284
 285     return r;
 286 }                               /* end init_agent() */
 287
 288 oid             nullOid[] = { 0, 0 };
 289 int             nullOidLen = sizeof(nullOid);