lib/liblwip/include/lwip/snmp_msg.h

   1 /**
   2  * @file
   3  * SNMP Agent message handling structures.
   4  */
   5
   6 /*
   7  * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands.
   8  * All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without modification,
  11  * are permitted provided that the following conditions are met:
  12  *
  13  * 1. Redistributions of source code must retain the above copyright notice,
  14  *    this list of conditions and the following disclaimer.
  15  * 2. Redistributions in binary form must reproduce the above copyright notice,
  16  *    this list of conditions and the following disclaimer in the documentation
  17  *    and/or other materials provided with the distribution.
  18  * 3. The name of the author may not be used to endorse or promote products
  19  *    derived from this software without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
  22  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  23  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
  24  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  25  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
  26  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
  29  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
  30  * OF SUCH DAMAGE.
  31  *
  32  * Author: Christiaan Simons <christiaan.simons@axon.tv>
  33  */
  34
  35 #ifndef __LWIP_SNMP_MSG_H__
  36 #define __LWIP_SNMP_MSG_H__
  37
  38 #include "lwip/opt.h"
  39 #include "lwip/snmp.h"
  40 #include "lwip/snmp_structs.h"
  41 #include "lwip/ip_addr.h"
  42 #include "lwip/err.h"
  43
  44 #if LWIP_SNMP
  45
  46 #if SNMP_PRIVATE_MIB
  47 /* When using a private MIB, you have to create a file 'private_mib.h' that contains
  48  * a 'struct mib_array_node mib_private' which contains your MIB. */
  49 #include "private_mib.h"
  50 #endif
  51
  52 #ifdef __cplusplus
  53 extern "C" {
  54 #endif
  55
  56 /* The listen port of the SNMP agent. Clients have to make their requests to
  57    this port. Most standard clients won't work if you change this! */
  58 #ifndef SNMP_IN_PORT
  59 #define SNMP_IN_PORT 161
  60 #endif
  61 /* The remote port the SNMP agent sends traps to. Most standard trap sinks won't
  62    work if you change this! */
  63 #ifndef SNMP_TRAP_PORT
  64 #define SNMP_TRAP_PORT 162
  65 #endif
  66
  67 #define SNMP_ES_NOERROR 0
  68 #define SNMP_ES_TOOBIG 1
  69 #define SNMP_ES_NOSUCHNAME 2
  70 #define SNMP_ES_BADVALUE 3
  71 #define SNMP_ES_READONLY 4
  72 #define SNMP_ES_GENERROR 5
  73
  74 #define SNMP_GENTRAP_COLDSTART 0
  75 #define SNMP_GENTRAP_WARMSTART 1
  76 #define SNMP_GENTRAP_AUTHFAIL 4
  77 #define SNMP_GENTRAP_ENTERPRISESPC 6
  78
  79 struct snmp_varbind
  80 {
  81   /* next pointer, NULL for last in list */
  82   struct snmp_varbind *next;
  83   /* previous pointer, NULL for first in list */
  84   struct snmp_varbind *prev;
  85
  86   /* object identifier length (in s32_t) */
  87   u8_t ident_len;
  88   /* object identifier array */
  89   s32_t *ident;
  90
  91   /* object value ASN1 type */
  92   u8_t value_type;
  93   /* object value length (in u8_t) */
  94   u8_t value_len;
  95   /* object value */
  96   void *value;
  97
  98   /* encoding varbind seq length length */
  99   u8_t seqlenlen;
 100   /* encoding object identifier length length */
 101   u8_t olenlen;
 102   /* encoding object value length length */
 103   u8_t vlenlen;
 104   /* encoding varbind seq length */
 105   u16_t seqlen;
 106   /* encoding object identifier length */
 107   u16_t olen;
 108   /* encoding object value length */
 109   u16_t vlen;
 110 };
 111
 112 struct snmp_varbind_root
 113 {
 114   struct snmp_varbind *head;
 115   struct snmp_varbind *tail;
 116   /* number of variable bindings in list */
 117   u8_t count;
 118   /* encoding varbind-list seq length length */
 119   u8_t seqlenlen;
 120   /* encoding varbind-list seq length */
 121   u16_t seqlen;
 122 };
 123
 124 /** output response message header length fields */
 125 struct snmp_resp_header_lengths
 126 {
 127   /* encoding error-index length length */
 128   u8_t erridxlenlen;
 129   /* encoding error-status length length */
 130   u8_t errstatlenlen;
 131   /* encoding request id length length */
 132   u8_t ridlenlen;
 133   /* encoding pdu length length */
 134   u8_t pdulenlen;
 135   /* encoding community length length */
 136   u8_t comlenlen;
 137   /* encoding version length length */
 138   u8_t verlenlen;
 139   /* encoding sequence length length */
 140   u8_t seqlenlen;
 141
 142   /* encoding error-index length */
 143   u16_t erridxlen;
 144   /* encoding error-status length */
 145   u16_t errstatlen;
 146   /* encoding request id length */
 147   u16_t ridlen;
 148   /* encoding pdu length */
 149   u16_t pdulen;
 150   /* encoding community length */
 151   u16_t comlen;
 152   /* encoding version length */
 153   u16_t verlen;
 154   /* encoding sequence length */
 155   u16_t seqlen;
 156 };
 157
 158 /** output response message header length fields */
 159 struct snmp_trap_header_lengths
 160 {
 161   /* encoding timestamp length length */
 162   u8_t tslenlen;
 163   /* encoding specific-trap length length */
 164   u8_t strplenlen;
 165   /* encoding generic-trap length length */
 166   u8_t gtrplenlen;
 167   /* encoding agent-addr length length */
 168   u8_t aaddrlenlen;
 169   /* encoding enterprise-id length length */
 170   u8_t eidlenlen;
 171   /* encoding pdu length length */
 172   u8_t pdulenlen;
 173   /* encoding community length length */
 174   u8_t comlenlen;
 175   /* encoding version length length */
 176   u8_t verlenlen;
 177   /* encoding sequence length length */
 178   u8_t seqlenlen;
 179
 180   /* encoding timestamp length */
 181   u16_t tslen;
 182   /* encoding specific-trap length */
 183   u16_t strplen;
 184   /* encoding generic-trap length */
 185   u16_t gtrplen;
 186   /* encoding agent-addr length */
 187   u16_t aaddrlen;
 188   /* encoding enterprise-id length */
 189   u16_t eidlen;
 190   /* encoding pdu length */
 191   u16_t pdulen;
 192   /* encoding community length */
 193   u16_t comlen;
 194   /* encoding version length */
 195   u16_t verlen;
 196   /* encoding sequence length */
 197   u16_t seqlen;
 198 };
 199
 200 /* Accepting new SNMP messages. */
 201 #define SNMP_MSG_EMPTY                 0
 202 /* Search for matching object for variable binding. */
 203 #define SNMP_MSG_SEARCH_OBJ            1
 204 /* Perform SNMP operation on in-memory object.
 205    Pass-through states, for symmetry only. */
 206 #define SNMP_MSG_INTERNAL_GET_OBJDEF   2
 207 #define SNMP_MSG_INTERNAL_GET_VALUE    3
 208 #define SNMP_MSG_INTERNAL_SET_TEST     4
 209 #define SNMP_MSG_INTERNAL_GET_OBJDEF_S 5
 210 #define SNMP_MSG_INTERNAL_SET_VALUE    6
 211 /* Perform SNMP operation on object located externally.
 212    In theory this could be used for building a proxy agent.
 213    Practical use is for an enterprise spc. app. gateway. */
 214 #define SNMP_MSG_EXTERNAL_GET_OBJDEF   7
 215 #define SNMP_MSG_EXTERNAL_GET_VALUE    8
 216 #define SNMP_MSG_EXTERNAL_SET_TEST     9
 217 #define SNMP_MSG_EXTERNAL_GET_OBJDEF_S 10
 218 #define SNMP_MSG_EXTERNAL_SET_VALUE    11
 219
 220 #define SNMP_COMMUNITY_STR_LEN 64
 221 struct snmp_msg_pstat
 222 {
 223   /* lwIP local port (161) binding */
 224   struct udp_pcb *pcb;
 225   /* source IP address */
 226   ip_addr_t sip;
 227   /* source UDP port */
 228   u16_t sp;
 229   /* request type */
 230   u8_t rt;
 231   /* request ID */
 232   s32_t rid;
 233   /* error status */
 234   s32_t error_status;
 235   /* error index */
 236   s32_t error_index;
 237   /* community name (zero terminated) */
 238   u8_t community[SNMP_COMMUNITY_STR_LEN + 1];
 239   /* community string length (exclusive zero term) */
 240   u8_t com_strlen;
 241   /* one out of MSG_EMPTY, MSG_DEMUX, MSG_INTERNAL, MSG_EXTERNAL_x */
 242   u8_t state;
 243   /* saved arguments for MSG_EXTERNAL_x */
 244   struct mib_external_node *ext_mib_node;
 245   struct snmp_name_ptr ext_name_ptr;
 246   struct obj_def ext_object_def;
 247   struct snmp_obj_id ext_oid;
 248   /* index into input variable binding list */
 249   u8_t vb_idx;
 250   /* ptr into input variable binding list */
 251   struct snmp_varbind *vb_ptr;
 252   /* list of variable bindings from input */
 253   struct snmp_varbind_root invb;
 254   /* list of variable bindings to output */
 255   struct snmp_varbind_root outvb;
 256   /* output response lengths used in ASN encoding */
 257   struct snmp_resp_header_lengths rhl;
 258 };
 259
 260 struct snmp_msg_trap
 261 {
 262   /* lwIP local port (161) binding */
 263   struct udp_pcb *pcb;
 264   /* destination IP address in network order */
 265   ip_addr_t dip;
 266
 267   /* source enterprise ID (sysObjectID) */
 268   struct snmp_obj_id *enterprise;
 269   /* source IP address, raw network order format */
 270   u8_t sip_raw[4];
 271   /* generic trap code */
 272   u32_t gen_trap;
 273   /* specific trap code */
 274   u32_t spc_trap;
 275   /* timestamp */
 276   u32_t ts;
 277   /* list of variable bindings to output */
 278   struct snmp_varbind_root outvb;
 279   /* output trap lengths used in ASN encoding */
 280   struct snmp_trap_header_lengths thl;
 281 };
 282
 283 /** Agent Version constant, 0 = v1 oddity */
 284 extern const s32_t snmp_version;
 285 /** Agent default "public" community string */
 286 extern const char snmp_publiccommunity[7];
 287
 288 extern struct snmp_msg_trap trap_msg;
 289
 290 /** Agent setup, start listening to port 161. */
 291 void snmp_init(void);
 292 void snmp_trap_dst_enable(u8_t dst_idx, u8_t enable);
 293 void snmp_trap_dst_ip_set(u8_t dst_idx, ip_addr_t *dst);
 294
 295 /** Varbind-list functions. */
 296 struct snmp_varbind* snmp_varbind_alloc(struct snmp_obj_id *oid, u8_t type, u8_t len);
 297 void snmp_varbind_free(struct snmp_varbind *vb);
 298 void snmp_varbind_list_free(struct snmp_varbind_root *root);
 299 void snmp_varbind_tail_add(struct snmp_varbind_root *root, struct snmp_varbind *vb);
 300 struct snmp_varbind* snmp_varbind_tail_remove(struct snmp_varbind_root *root);
 301
 302 /** Handle an internal (recv) or external (private response) event. */
 303 void snmp_msg_event(u8_t request_id);
 304 err_t snmp_send_response(struct snmp_msg_pstat *m_stat);
 305 err_t snmp_send_trap(s8_t generic_trap, struct snmp_obj_id *eoid, s32_t specific_trap);
 306 void snmp_coldstart_trap(void);
 307 void snmp_authfail_trap(void);
 308
 309 #ifdef __cplusplus
 310 }
 311 #endif
 312
 313 #endif /* LWIP_SNMP */
 314
 315 #endif /* __LWIP_SNMP_MSG_H__ */