include/lwip/snmp_msg.h

0001 /**
0002  * @file
0003  * SNMP Agent message handling structures.
0004  */
0005
0006 /*
0007  * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands.
0008  * All rights reserved.
0009  *
0010  * Redistribution and use in source and binary forms, with or without modification,
0011  * are permitted provided that the following conditions are met:
0012  *
0013  * 1. Redistributions of source code must retain the above copyright notice,
0014  *    this list of conditions and the following disclaimer.
0015  * 2. Redistributions in binary form must reproduce the above copyright notice,
0016  *    this list of conditions and the following disclaimer in the documentation
0017  *    and/or other materials provided with the distribution.
0018  * 3. The name of the author may not be used to endorse or promote products
0019  *    derived from this software without specific prior written permission.
0020  *
0021  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
0022  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
0023  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
0024  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
0025  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
0026  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0027  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0028  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
0029  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
0030  * OF SUCH DAMAGE.
0031  *
0032  * Author: Christiaan Simons <christiaan.simons@axon.tv>
0033  */
0034
0035 #ifndef __LWIP_SNMP_MSG_H__
0036 #define __LWIP_SNMP_MSG_H__
0037
0038 #include "lwip/opt.h"
0039 #include "lwip/snmp.h"
0040 #include "lwip/snmp_structs.h"
0041
0042 #if LWIP_SNMP
0043
0044 #if SNMP_PRIVATE_MIB
0045 #include "private_mib.h"
0046 #endif
0047
0048 #ifdef __cplusplus
0049 extern "C" {
0050 #endif
0051
0052 /* The listen port of the SNMP agent. Clients have to make their requests to
0053    this port. Most standard clients won't work if you change this! */
0054 #ifndef SNMP_IN_PORT
0055 #define SNMP_IN_PORT 161
0056 #endif
0057 /* The remote port the SNMP agent sends traps to. Most standard trap sinks won't
0058    work if you change this! */
0059 #ifndef SNMP_TRAP_PORT
0060 #define SNMP_TRAP_PORT 162
0061 #endif
0062
0063 #define SNMP_ES_NOERROR 0
0064 #define SNMP_ES_TOOBIG 1
0065 #define SNMP_ES_NOSUCHNAME 2
0066 #define SNMP_ES_BADVALUE 3
0067 #define SNMP_ES_READONLY 4
0068 #define SNMP_ES_GENERROR 5
0069
0070 #define SNMP_GENTRAP_COLDSTART 0
0071 #define SNMP_GENTRAP_WARMSTART 1
0072 #define SNMP_GENTRAP_AUTHFAIL 4
0073 #define SNMP_GENTRAP_ENTERPRISESPC 6
0074
0075 struct snmp_varbind
0076 {
0077   /* next pointer, NULL for last in list */
0078   struct snmp_varbind *next;
0079   /* previous pointer, NULL for first in list */
0080   struct snmp_varbind *prev;
0081
0082   /* object identifier length (in s32_t) */
0083   u8_t ident_len;
0084   /* object identifier array */
0085   s32_t *ident;
0086
0087   /* object value ASN1 type */
0088   u8_t value_type;
0089   /* object value length (in u8_t) */
0090   u8_t value_len;
0091   /* object value */
0092   void *value;
0093
0094   /* encoding varbind seq length length */
0095   u8_t seqlenlen;
0096   /* encoding object identifier length length */
0097   u8_t olenlen;
0098   /* encoding object value length length */
0099   u8_t vlenlen;
0100   /* encoding varbind seq length */
0101   u16_t seqlen;
0102   /* encoding object identifier length */
0103   u16_t olen;
0104   /* encoding object value length */
0105   u16_t vlen;
0106 };
0107
0108 struct snmp_varbind_root
0109 {
0110   struct snmp_varbind *head;
0111   struct snmp_varbind *tail;
0112   /* number of variable bindings in list */
0113   u8_t count;
0114   /* encoding varbind-list seq length length */
0115   u8_t seqlenlen;
0116   /* encoding varbind-list seq length */
0117   u16_t seqlen;
0118 };
0119
0120 /** output response message header length fields */
0121 struct snmp_resp_header_lengths
0122 {
0123   /* encoding error-index length length */
0124   u8_t erridxlenlen;
0125   /* encoding error-status length length */
0126   u8_t errstatlenlen;
0127   /* encoding request id length length */
0128   u8_t ridlenlen;
0129   /* encoding pdu length length */
0130   u8_t pdulenlen;
0131   /* encoding community length length */
0132   u8_t comlenlen;
0133   /* encoding version length length */
0134   u8_t verlenlen;
0135   /* encoding sequence length length */
0136   u8_t seqlenlen;
0137
0138   /* encoding error-index length */
0139   u16_t erridxlen;
0140   /* encoding error-status length */
0141   u16_t errstatlen;
0142   /* encoding request id length */
0143   u16_t ridlen;
0144   /* encoding pdu length */
0145   u16_t pdulen;
0146   /* encoding community length */
0147   u16_t comlen;
0148   /* encoding version length */
0149   u16_t verlen;
0150   /* encoding sequence length */
0151   u16_t seqlen;
0152 };
0153
0154 /** output response message header length fields */
0155 struct snmp_trap_header_lengths
0156 {
0157   /* encoding timestamp length length */
0158   u8_t tslenlen;
0159   /* encoding specific-trap length length */
0160   u8_t strplenlen;
0161   /* encoding generic-trap length length */
0162   u8_t gtrplenlen;
0163   /* encoding agent-addr length length */
0164   u8_t aaddrlenlen;
0165   /* encoding enterprise-id length length */
0166   u8_t eidlenlen;
0167   /* encoding pdu length length */
0168   u8_t pdulenlen;
0169   /* encoding community length length */
0170   u8_t comlenlen;
0171   /* encoding version length length */
0172   u8_t verlenlen;
0173   /* encoding sequence length length */
0174   u8_t seqlenlen;
0175
0176   /* encoding timestamp length */
0177   u16_t tslen;
0178   /* encoding specific-trap length */
0179   u16_t strplen;
0180   /* encoding generic-trap length */
0181   u16_t gtrplen;
0182   /* encoding agent-addr length */
0183   u16_t aaddrlen;
0184   /* encoding enterprise-id length */
0185   u16_t eidlen;
0186   /* encoding pdu length */
0187   u16_t pdulen;
0188   /* encoding community length */
0189   u16_t comlen;
0190   /* encoding version length */
0191   u16_t verlen;
0192   /* encoding sequence length */
0193   u16_t seqlen;
0194 };
0195
0196 /* Accepting new SNMP messages. */
0197 #define SNMP_MSG_EMPTY                 0
0198 /* Search for matching object for variable binding. */
0199 #define SNMP_MSG_SEARCH_OBJ            1
0200 /* Perform SNMP operation on in-memory object.
0201    Pass-through states, for symmetry only. */
0202 #define SNMP_MSG_INTERNAL_GET_OBJDEF   2
0203 #define SNMP_MSG_INTERNAL_GET_VALUE    3
0204 #define SNMP_MSG_INTERNAL_SET_TEST     4
0205 #define SNMP_MSG_INTERNAL_GET_OBJDEF_S 5
0206 #define SNMP_MSG_INTERNAL_SET_VALUE    6
0207 /* Perform SNMP operation on object located externally.
0208    In theory this could be used for building a proxy agent.
0209    Practical use is for an enterprise spc. app. gateway. */
0210 #define SNMP_MSG_EXTERNAL_GET_OBJDEF   7
0211 #define SNMP_MSG_EXTERNAL_GET_VALUE    8
0212 #define SNMP_MSG_EXTERNAL_SET_TEST     9
0213 #define SNMP_MSG_EXTERNAL_GET_OBJDEF_S 10
0214 #define SNMP_MSG_EXTERNAL_SET_VALUE    11
0215
0216 #define SNMP_COMMUNITY_STR_LEN 64
0217 struct snmp_msg_pstat
0218 {
0219   /* lwIP local port (161) binding */
0220   struct udp_pcb *pcb;
0221   /* source IP address */
0222   struct ip_addr sip;
0223   /* source UDP port */
0224   u16_t sp;
0225   /* request type */
0226   u8_t rt;
0227   /* request ID */
0228   s32_t rid;
0229   /* error status */
0230   s32_t error_status;
0231   /* error index */
0232   s32_t error_index;
0233   /* community name (zero terminated) */
0234   u8_t community[SNMP_COMMUNITY_STR_LEN + 1];
0235   /* community string length (exclusive zero term) */
0236   u8_t com_strlen;
0237   /* one out of MSG_EMPTY, MSG_DEMUX, MSG_INTERNAL, MSG_EXTERNAL_x */
0238   u8_t state;
0239   /* saved arguments for MSG_EXTERNAL_x */
0240   struct mib_external_node *ext_mib_node;
0241   struct snmp_name_ptr ext_name_ptr;
0242   struct obj_def ext_object_def;
0243   struct snmp_obj_id ext_oid;
0244   /* index into input variable binding list */
0245   u8_t vb_idx;
0246   /* ptr into input variable binding list */
0247   struct snmp_varbind *vb_ptr;
0248   /* list of variable bindings from input */
0249   struct snmp_varbind_root invb;
0250   /* list of variable bindings to output */
0251   struct snmp_varbind_root outvb;
0252   /* output response lengths used in ASN encoding */
0253   struct snmp_resp_header_lengths rhl;
0254 };
0255
0256 struct snmp_msg_trap
0257 {
0258   /* lwIP local port (161) binding */
0259   struct udp_pcb *pcb;
0260   /* destination IP address in network order */
0261   struct ip_addr dip;
0262
0263   /* source enterprise ID (sysObjectID) */
0264   struct snmp_obj_id *enterprise;
0265   /* source IP address, raw network order format */
0266   u8_t sip_raw[4];
0267   /* generic trap code */
0268   u32_t gen_trap;
0269   /* specific trap code */
0270   u32_t spc_trap;
0271   /* timestamp */
0272   u32_t ts;
0273   /* list of variable bindings to output */
0274   struct snmp_varbind_root outvb;
0275   /* output trap lengths used in ASN encoding */
0276   struct snmp_trap_header_lengths thl;
0277 };
0278
0279 /** Agent Version constant, 0 = v1 oddity */
0280 extern const s32_t snmp_version;
0281 /** Agent default "public" community string */
0282 extern const char snmp_publiccommunity[7];
0283
0284 extern struct snmp_msg_trap trap_msg;
0285
0286 /** Agent setup, start listening to port 161. */
0287 void snmp_init(void);
0288 void snmp_trap_dst_enable(u8_t dst_idx, u8_t enable);
0289 void snmp_trap_dst_ip_set(u8_t dst_idx, struct ip_addr *dst);
0290
0291 /** Varbind-list functions. */
0292 struct snmp_varbind* snmp_varbind_alloc(struct snmp_obj_id *oid, u8_t type, u8_t len);
0293 void snmp_varbind_free(struct snmp_varbind *vb);
0294 void snmp_varbind_list_free(struct snmp_varbind_root *root);
0295 void snmp_varbind_tail_add(struct snmp_varbind_root *root, struct snmp_varbind *vb);
0296 struct snmp_varbind* snmp_varbind_tail_remove(struct snmp_varbind_root *root);
0297
0298 /** Handle an internal (recv) or external (private response) event. */
0299 void snmp_msg_event(u8_t request_id);
0300 err_t snmp_send_response(struct snmp_msg_pstat *m_stat);
0301 err_t snmp_send_trap(s8_t generic_trap, struct snmp_obj_id *eoid, s32_t specific_trap);
0302 void snmp_coldstart_trap(void);
0303 void snmp_authfail_trap(void);
0304
0305 #ifdef __cplusplus
0306 }
0307 #endif
0308
0309 #endif /* LWIP_SNMP */
0310
0311 #endif /* __LWIP_SNMP_MSG_H__ */