snmp_msg.h

00001 /**
00002  * @file
00003  * SNMP Agent message handling structures.
00004  */
00005 
00006 /*
00007  * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands.
00008  * All rights reserved.
00009  *
00010  * Redistribution and use in source and binary forms, with or without modification,
00011  * are permitted provided that the following conditions are met:
00012  *
00013  * 1. Redistributions of source code must retain the above copyright notice,
00014  *    this list of conditions and the following disclaimer.
00015  * 2. Redistributions in binary form must reproduce the above copyright notice,
00016  *    this list of conditions and the following disclaimer in the documentation
00017  *    and/or other materials provided with the distribution.
00018  * 3. The name of the author may not be used to endorse or promote products
00019  *    derived from this software without specific prior written permission.
00020  *
00021  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
00022  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
00023  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
00024  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
00025  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
00026  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
00027  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
00028  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
00029  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
00030  * OF SUCH DAMAGE.
00031  *
00032  * Author: Christiaan Simons <christiaan.simons@axon.tv>
00033  */
00034 
00035 #ifndef __LWIP_SNMP_MSG_H__
00036 #define __LWIP_SNMP_MSG_H__
00037 
00038 #include "lwip/opt.h"
00039 #include "lwip/snmp.h"
00040 #include "lwip/snmp_structs.h"
00041 #include "lwip/ip_addr.h"
00042 #include "lwip/err.h"
00043 
00044 #if LWIP_SNMP
00045 
00046 #if SNMP_PRIVATE_MIB
00047 /* When using a private MIB, you have to create a file 'private_mib.h' that contains
00048  * a 'struct mib_array_node mib_private' which contains your MIB. */
00049 #include "private_mib.h"
00050 #endif
00051 
00052 #ifdef __cplusplus
00053 extern "C" {
00054 #endif
00055 
00056 /* The listen port of the SNMP agent. Clients have to make their requests to
00057    this port. Most standard clients won't work if you change this! */
00058 #ifndef SNMP_IN_PORT
00059 #define SNMP_IN_PORT 161
00060 #endif
00061 /* The remote port the SNMP agent sends traps to. Most standard trap sinks won't
00062    work if you change this! */
00063 #ifndef SNMP_TRAP_PORT
00064 #define SNMP_TRAP_PORT 162
00065 #endif
00066 
00067 #define SNMP_ES_NOERROR 0
00068 #define SNMP_ES_TOOBIG 1
00069 #define SNMP_ES_NOSUCHNAME 2
00070 #define SNMP_ES_BADVALUE 3
00071 #define SNMP_ES_READONLY 4
00072 #define SNMP_ES_GENERROR 5
00073 
00074 #define SNMP_GENTRAP_COLDSTART 0
00075 #define SNMP_GENTRAP_WARMSTART 1
00076 #define SNMP_GENTRAP_AUTHFAIL 4
00077 #define SNMP_GENTRAP_ENTERPRISESPC 6
00078 
00079 struct snmp_varbind
00080 {
00081   /* next pointer, NULL for last in list */
00082   struct snmp_varbind *next;
00083   /* previous pointer, NULL for first in list */
00084   struct snmp_varbind *prev;
00085 
00086   /* object identifier length (in s32_t) */
00087   u8_t ident_len;
00088   /* object identifier array */
00089   s32_t *ident;
00090 
00091   /* object value ASN1 type */
00092   u8_t value_type;
00093   /* object value length (in u8_t) */
00094   u8_t value_len;
00095   /* object value */
00096   void *value;
00097 
00098   /* encoding varbind seq length length */
00099   u8_t seqlenlen;
00100   /* encoding object identifier length length */
00101   u8_t olenlen;
00102   /* encoding object value length length */
00103   u8_t vlenlen;
00104   /* encoding varbind seq length */
00105   u16_t seqlen;
00106   /* encoding object identifier length */
00107   u16_t olen;
00108   /* encoding object value length */
00109   u16_t vlen;
00110 };
00111 
00112 struct snmp_varbind_root
00113 {
00114   struct snmp_varbind *head;
00115   struct snmp_varbind *tail;
00116   /* number of variable bindings in list */
00117   u8_t count;
00118   /* encoding varbind-list seq length length */
00119   u8_t seqlenlen;
00120   /* encoding varbind-list seq length */
00121   u16_t seqlen;
00122 };
00123 
00124 /** output response message header length fields */
00125 struct snmp_resp_header_lengths
00126 {
00127   /* encoding error-index length length */
00128   u8_t erridxlenlen;
00129   /* encoding error-status length length */
00130   u8_t errstatlenlen;
00131   /* encoding request id length length */
00132   u8_t ridlenlen;
00133   /* encoding pdu length length */
00134   u8_t pdulenlen;
00135   /* encoding community length length */
00136   u8_t comlenlen;
00137   /* encoding version length length */
00138   u8_t verlenlen;
00139   /* encoding sequence length length */
00140   u8_t seqlenlen;
00141 
00142   /* encoding error-index length */
00143   u16_t erridxlen;
00144   /* encoding error-status length */
00145   u16_t errstatlen;
00146   /* encoding request id length */
00147   u16_t ridlen;
00148   /* encoding pdu length */
00149   u16_t pdulen;
00150   /* encoding community length */
00151   u16_t comlen;
00152   /* encoding version length */
00153   u16_t verlen;
00154   /* encoding sequence length */
00155   u16_t seqlen;
00156 };
00157 
00158 /** output response message header length fields */
00159 struct snmp_trap_header_lengths
00160 {
00161   /* encoding timestamp length length */
00162   u8_t tslenlen;
00163   /* encoding specific-trap length length */
00164   u8_t strplenlen;
00165   /* encoding generic-trap length length */
00166   u8_t gtrplenlen;
00167   /* encoding agent-addr length length */
00168   u8_t aaddrlenlen;
00169   /* encoding enterprise-id length length */
00170   u8_t eidlenlen;
00171   /* encoding pdu length length */
00172   u8_t pdulenlen;
00173   /* encoding community length length */
00174   u8_t comlenlen;
00175   /* encoding version length length */
00176   u8_t verlenlen;
00177   /* encoding sequence length length */
00178   u8_t seqlenlen;
00179 
00180   /* encoding timestamp length */
00181   u16_t tslen;
00182   /* encoding specific-trap length */
00183   u16_t strplen;
00184   /* encoding generic-trap length */
00185   u16_t gtrplen;
00186   /* encoding agent-addr length */
00187   u16_t aaddrlen;
00188   /* encoding enterprise-id length */
00189   u16_t eidlen;
00190   /* encoding pdu length */
00191   u16_t pdulen;
00192   /* encoding community length */
00193   u16_t comlen;
00194   /* encoding version length */
00195   u16_t verlen;
00196   /* encoding sequence length */
00197   u16_t seqlen;
00198 };
00199 
00200 /* Accepting new SNMP messages. */
00201 #define SNMP_MSG_EMPTY                 0
00202 /* Search for matching object for variable binding. */
00203 #define SNMP_MSG_SEARCH_OBJ            1
00204 /* Perform SNMP operation on in-memory object.
00205    Pass-through states, for symmetry only. */
00206 #define SNMP_MSG_INTERNAL_GET_OBJDEF   2
00207 #define SNMP_MSG_INTERNAL_GET_VALUE    3
00208 #define SNMP_MSG_INTERNAL_SET_TEST     4
00209 #define SNMP_MSG_INTERNAL_GET_OBJDEF_S 5
00210 #define SNMP_MSG_INTERNAL_SET_VALUE    6
00211 /* Perform SNMP operation on object located externally.
00212    In theory this could be used for building a proxy agent.
00213    Practical use is for an enterprise spc. app. gateway. */
00214 #define SNMP_MSG_EXTERNAL_GET_OBJDEF   7
00215 #define SNMP_MSG_EXTERNAL_GET_VALUE    8
00216 #define SNMP_MSG_EXTERNAL_SET_TEST     9
00217 #define SNMP_MSG_EXTERNAL_GET_OBJDEF_S 10
00218 #define SNMP_MSG_EXTERNAL_SET_VALUE    11
00219 
00220 #define SNMP_COMMUNITY_STR_LEN 64
00221 struct snmp_msg_pstat
00222 {
00223   /* lwIP local port (161) binding */
00224   struct udp_pcb *pcb;
00225   /* source IP address */
00226   ip_addr_t sip;
00227   /* source UDP port */
00228   u16_t sp;
00229   /* request type */
00230   u8_t rt;
00231   /* request ID */
00232   s32_t rid;
00233   /* error status */
00234   s32_t error_status;
00235   /* error index */
00236   s32_t error_index;
00237   /* community name (zero terminated) */
00238   u8_t community[SNMP_COMMUNITY_STR_LEN + 1];
00239   /* community string length (exclusive zero term) */
00240   u8_t com_strlen;
00241   /* one out of MSG_EMPTY, MSG_DEMUX, MSG_INTERNAL, MSG_EXTERNAL_x */
00242   u8_t state;
00243   /* saved arguments for MSG_EXTERNAL_x */
00244   struct mib_external_node *ext_mib_node;
00245   struct snmp_name_ptr ext_name_ptr;
00246   struct obj_def ext_object_def;
00247   struct snmp_obj_id ext_oid;
00248   /* index into input variable binding list */
00249   u8_t vb_idx;
00250   /* ptr into input variable binding list */
00251   struct snmp_varbind *vb_ptr;
00252   /* list of variable bindings from input */
00253   struct snmp_varbind_root invb;
00254   /* list of variable bindings to output */
00255   struct snmp_varbind_root outvb;
00256   /* output response lengths used in ASN encoding */
00257   struct snmp_resp_header_lengths rhl;
00258 };
00259 
00260 struct snmp_msg_trap
00261 {
00262   /* lwIP local port (161) binding */
00263   struct udp_pcb *pcb;
00264   /* destination IP address in network order */
00265   ip_addr_t dip;
00266 
00267   /* source enterprise ID (sysObjectID) */
00268   struct snmp_obj_id *enterprise;
00269   /* source IP address, raw network order format */
00270   u8_t sip_raw[4];
00271   /* generic trap code */
00272   u32_t gen_trap;
00273   /* specific trap code */
00274   u32_t spc_trap;
00275   /* timestamp */
00276   u32_t ts;
00277   /* list of variable bindings to output */
00278   struct snmp_varbind_root outvb;
00279   /* output trap lengths used in ASN encoding */
00280   struct snmp_trap_header_lengths thl;
00281 };
00282 
00283 /** Agent Version constant, 0 = v1 oddity */
00284 extern const s32_t snmp_version;
00285 /** Agent default "public" community string */
00286 extern const char snmp_publiccommunity[7];
00287 
00288 extern struct snmp_msg_trap trap_msg;
00289 
00290 /** Agent setup, start listening to port 161. */
00291 void snmp_init(void);
00292 void snmp_trap_dst_enable(u8_t dst_idx, u8_t enable);
00293 void snmp_trap_dst_ip_set(u8_t dst_idx, ip_addr_t *dst);
00294 
00295 /** Varbind-list functions. */
00296 struct snmp_varbind* snmp_varbind_alloc(struct snmp_obj_id *oid, u8_t type, u8_t len);
00297 void snmp_varbind_free(struct snmp_varbind *vb);
00298 void snmp_varbind_list_free(struct snmp_varbind_root *root);
00299 void snmp_varbind_tail_add(struct snmp_varbind_root *root, struct snmp_varbind *vb);
00300 struct snmp_varbind* snmp_varbind_tail_remove(struct snmp_varbind_root *root);
00301 
00302 /** Handle an internal (recv) or external (private response) event. */
00303 void snmp_msg_event(u8_t request_id);
00304 err_t snmp_send_response(struct snmp_msg_pstat *m_stat);
00305 err_t snmp_send_trap(s8_t generic_trap, struct snmp_obj_id *eoid, s32_t specific_trap);
00306 void snmp_coldstart_trap(void);
00307 void snmp_authfail_trap(void);
00308 
00309 #ifdef __cplusplus
00310 }
00311 #endif
00312 
00313 #endif /* LWIP_SNMP */
00314 
00315 #endif /* __LWIP_SNMP_MSG_H__ */