msg_out.c

00001 /**
00002  * @file
00003  * SNMP output message processing (RFC1157).
00004  *
00005  * Output responses and traps are build in two passes:
00006  *
00007  * Pass 0: iterate over the output message backwards to determine encoding lengths
00008  * Pass 1: the actual forward encoding of internal form into ASN1
00009  *
00010  * The single-pass encoding method described by Comer & Stevens
00011  * requires extra buffer space and copying for reversal of the packet.
00012  * The buffer requirement can be prohibitively large for big payloads
00013  * (>= 484) therefore we use the two encoding passes.
00014  */
00015 
00016 /*
00017  * Copyright (c) 2006 Axon Digital Design B.V., The Netherlands.
00018  * All rights reserved.
00019  *
00020  * Redistribution and use in source and binary forms, with or without modification,
00021  * are permitted provided that the following conditions are met:
00022  *
00023  * 1. Redistributions of source code must retain the above copyright notice,
00024  *    this list of conditions and the following disclaimer.
00025  * 2. Redistributions in binary form must reproduce the above copyright notice,
00026  *    this list of conditions and the following disclaimer in the documentation
00027  *    and/or other materials provided with the distribution.
00028  * 3. The name of the author may not be used to endorse or promote products
00029  *    derived from this software without specific prior written permission.
00030  *
00031  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
00032  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
00033  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
00034  * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
00035  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
00036  * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
00037  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
00038  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
00039  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
00040  * OF SUCH DAMAGE.
00041  *
00042  * Author: Christiaan Simons <christiaan.simons@axon.tv>
00043  */
00044 
00045 #include "lwip/opt.h"
00046 
00047 #if LWIP_SNMP /* don't build if not configured for use in lwipopts.h */
00048 
00049 #include "lwip/udp.h"
00050 #include "lwip/netif.h"
00051 #include "lwip/snmp.h"
00052 #include "lwip/snmp_asn1.h"
00053 #include "lwip/snmp_msg.h"
00054 
00055 struct snmp_trap_dst
00056 {
00057   /* destination IP address in network order */
00058   ip_addr_t dip;
00059   /* set to 0 when disabled, >0 when enabled */
00060   u8_t enable;
00061 };
00062 struct snmp_trap_dst trap_dst[SNMP_TRAP_DESTINATIONS];
00063 
00064 /** TRAP message structure */
00065 struct snmp_msg_trap trap_msg;
00066 
00067 static u16_t snmp_resp_header_sum(struct snmp_msg_pstat *m_stat, u16_t vb_len);
00068 static u16_t snmp_trap_header_sum(struct snmp_msg_trap *m_trap, u16_t vb_len);
00069 static u16_t snmp_varbind_list_sum(struct snmp_varbind_root *root);
00070 
00071 static u16_t snmp_resp_header_enc(struct snmp_msg_pstat *m_stat, struct pbuf *p);
00072 static u16_t snmp_trap_header_enc(struct snmp_msg_trap *m_trap, struct pbuf *p);
00073 static u16_t snmp_varbind_list_enc(struct snmp_varbind_root *root, struct pbuf *p, u16_t ofs);
00074 
00075 /**
00076  * Sets enable switch for this trap destination.
00077  * @param dst_idx index in 0 .. SNMP_TRAP_DESTINATIONS-1
00078  * @param enable switch if 0 destination is disabled >0 enabled.
00079  */
00080 void
00081 snmp_trap_dst_enable(u8_t dst_idx, u8_t enable)
00082 {
00083   if (dst_idx < SNMP_TRAP_DESTINATIONS)
00084   {
00085     trap_dst[dst_idx].enable = enable;
00086   }
00087 }
00088 
00089 /**
00090  * Sets IPv4 address for this trap destination.
00091  * @param dst_idx index in 0 .. SNMP_TRAP_DESTINATIONS-1
00092  * @param dst IPv4 address in host order.
00093  */
00094 void
00095 snmp_trap_dst_ip_set(u8_t dst_idx, ip_addr_t *dst)
00096 {
00097   if (dst_idx < SNMP_TRAP_DESTINATIONS)
00098   {
00099     ip_addr_set(&trap_dst[dst_idx].dip, dst);
00100   }
00101 }
00102 
00103 /**
00104  * Sends a 'getresponse' message to the request originator.
00105  *
00106  * @param m_stat points to the current message request state source
00107  * @return ERR_OK when success, ERR_MEM if we're out of memory
00108  *
00109  * @note the caller is responsible for filling in outvb in the m_stat
00110  * and provide error-status and index (except for tooBig errors) ...
00111  */
00112 err_t
00113 snmp_send_response(struct snmp_msg_pstat *m_stat)
00114 {
00115   struct snmp_varbind_root emptyvb = {NULL, NULL, 0, 0, 0};
00116   struct pbuf *p;
00117   u16_t tot_len;
00118   err_t err;
00119 
00120   /* pass 0, calculate length fields */
00121   tot_len = snmp_varbind_list_sum(&m_stat->outvb);
00122   tot_len = snmp_resp_header_sum(m_stat, tot_len);
00123 
00124   /* try allocating pbuf(s) for complete response */
00125   p = pbuf_alloc(PBUF_TRANSPORT, tot_len, PBUF_POOL);
00126   if (p == NULL)
00127   {
00128     LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_snd_response() tooBig\n"));
00129 
00130     /* can't construct reply, return error-status tooBig */
00131     m_stat->error_status = SNMP_ES_TOOBIG;
00132     m_stat->error_index = 0;
00133     /* pass 0, recalculate lengths, for empty varbind-list */
00134     tot_len = snmp_varbind_list_sum(&emptyvb);
00135     tot_len = snmp_resp_header_sum(m_stat, tot_len);
00136     /* retry allocation once for header and empty varbind-list */
00137     p = pbuf_alloc(PBUF_TRANSPORT, tot_len, PBUF_POOL);
00138   }
00139   if (p != NULL)
00140   {
00141     /* first pbuf alloc try or retry alloc success */
00142     u16_t ofs;
00143 
00144     LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_snd_response() p != NULL\n"));
00145 
00146     /* pass 1, size error, encode packet ino the pbuf(s) */
00147     ofs = snmp_resp_header_enc(m_stat, p);
00148     snmp_varbind_list_enc(&m_stat->outvb, p, ofs);
00149 
00150     switch (m_stat->error_status)
00151     {
00152       case SNMP_ES_TOOBIG:
00153         snmp_inc_snmpouttoobigs();
00154         break;
00155       case SNMP_ES_NOSUCHNAME:
00156         snmp_inc_snmpoutnosuchnames();
00157         break;
00158       case SNMP_ES_BADVALUE:
00159         snmp_inc_snmpoutbadvalues();
00160         break;
00161       case SNMP_ES_GENERROR:
00162         snmp_inc_snmpoutgenerrs();
00163         break;
00164     }
00165     snmp_inc_snmpoutgetresponses();
00166     snmp_inc_snmpoutpkts();
00167 
00168     /** @todo do we need separate rx and tx pcbs for threaded case? */
00169     /** connect to the originating source */
00170     udp_connect(m_stat->pcb, &m_stat->sip, m_stat->sp);
00171     err = udp_send(m_stat->pcb, p);
00172     if (err == ERR_MEM)
00173     {
00174       /** @todo release some memory, retry and return tooBig? tooMuchHassle? */
00175       err = ERR_MEM;
00176     }
00177     else
00178     {
00179       err = ERR_OK;
00180     }
00181     /** disassociate remote address and port with this pcb */
00182     udp_disconnect(m_stat->pcb);
00183 
00184     pbuf_free(p);
00185     LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_snd_response() done\n"));
00186     return err;
00187   }
00188   else
00189   {
00190     /* first pbuf alloc try or retry alloc failed
00191        very low on memory, couldn't return tooBig */
00192     return ERR_MEM;
00193   }
00194 }
00195 
00196 
00197 /**
00198  * Sends an generic or enterprise specific trap message.
00199  *
00200  * @param generic_trap is the trap code
00201  * @param eoid points to enterprise object identifier
00202  * @param specific_trap used for enterprise traps when generic_trap == 6
00203  * @return ERR_OK when success, ERR_MEM if we're out of memory
00204  *
00205  * @note the caller is responsible for filling in outvb in the trap_msg
00206  * @note the use of the enterpise identifier field
00207  * is per RFC1215.
00208  * Use .iso.org.dod.internet.mgmt.mib-2.snmp for generic traps
00209  * and .iso.org.dod.internet.private.enterprises.yourenterprise
00210  * (sysObjectID) for specific traps.
00211  */
00212 err_t
00213 snmp_send_trap(s8_t generic_trap, struct snmp_obj_id *eoid, s32_t specific_trap)
00214 {
00215   struct snmp_trap_dst *td;
00216   struct netif *dst_if;
00217   ip_addr_t dst_ip;
00218   struct pbuf *p;
00219   u16_t i,tot_len;
00220 
00221   for (i=0, td = &trap_dst[0]; i<SNMP_TRAP_DESTINATIONS; i++, td++)
00222   {
00223     if ((td->enable != 0) && !ip_addr_isany(&td->dip))
00224     {
00225       /* network order trap destination */
00226       ip_addr_copy(trap_msg.dip, td->dip);
00227       /* lookup current source address for this dst */
00228       dst_if = ip_route(&td->dip);
00229       ip_addr_copy(dst_ip, dst_if->ip_addr);
00230       /* @todo: what about IPv6? */
00231       trap_msg.sip_raw[0] = ip4_addr1(&dst_ip);
00232       trap_msg.sip_raw[1] = ip4_addr2(&dst_ip);
00233       trap_msg.sip_raw[2] = ip4_addr3(&dst_ip);
00234       trap_msg.sip_raw[3] = ip4_addr4(&dst_ip);
00235       trap_msg.gen_trap = generic_trap;
00236       trap_msg.spc_trap = specific_trap;
00237       if (generic_trap == SNMP_GENTRAP_ENTERPRISESPC)
00238       {
00239         /* enterprise-Specific trap */
00240         trap_msg.enterprise = eoid;
00241       }
00242       else
00243       {
00244         /* generic (MIB-II) trap */
00245         snmp_get_snmpgrpid_ptr(&trap_msg.enterprise);
00246       }
00247       snmp_get_sysuptime(&trap_msg.ts);
00248 
00249       /* pass 0, calculate length fields */
00250       tot_len = snmp_varbind_list_sum(&trap_msg.outvb);
00251       tot_len = snmp_trap_header_sum(&trap_msg, tot_len);
00252 
00253       /* allocate pbuf(s) */
00254       p = pbuf_alloc(PBUF_TRANSPORT, tot_len, PBUF_POOL);
00255       if (p != NULL)
00256       {
00257         u16_t ofs;
00258 
00259         /* pass 1, encode packet ino the pbuf(s) */
00260         ofs = snmp_trap_header_enc(&trap_msg, p);
00261         snmp_varbind_list_enc(&trap_msg.outvb, p, ofs);
00262 
00263         snmp_inc_snmpouttraps();
00264         snmp_inc_snmpoutpkts();
00265 
00266         /** send to the TRAP destination */
00267         udp_sendto(trap_msg.pcb, p, &trap_msg.dip, SNMP_TRAP_PORT);
00268 
00269         pbuf_free(p);
00270       }
00271       else
00272       {
00273         return ERR_MEM;
00274       }
00275     }
00276   }
00277   return ERR_OK;
00278 }
00279 
00280 void
00281 snmp_coldstart_trap(void)
00282 {
00283   trap_msg.outvb.head = NULL;
00284   trap_msg.outvb.tail = NULL;
00285   trap_msg.outvb.count = 0;
00286   snmp_send_trap(SNMP_GENTRAP_COLDSTART, NULL, 0);
00287 }
00288 
00289 void
00290 snmp_authfail_trap(void)
00291 {
00292   u8_t enable;
00293   snmp_get_snmpenableauthentraps(&enable);
00294   if (enable == 1)
00295   {
00296     trap_msg.outvb.head = NULL;
00297     trap_msg.outvb.tail = NULL;
00298     trap_msg.outvb.count = 0;
00299     snmp_send_trap(SNMP_GENTRAP_AUTHFAIL, NULL, 0);
00300   }
00301 }
00302 
00303 /**
00304  * Sums response header field lengths from tail to head and
00305  * returns resp_header_lengths for second encoding pass.
00306  *
00307  * @param vb_len varbind-list length
00308  * @param rhl points to returned header lengths
00309  * @return the required lenght for encoding the response header
00310  */
00311 static u16_t
00312 snmp_resp_header_sum(struct snmp_msg_pstat *m_stat, u16_t vb_len)
00313 {
00314   u16_t tot_len;
00315   struct snmp_resp_header_lengths *rhl;
00316 
00317   rhl = &m_stat->rhl;
00318   tot_len = vb_len;
00319   snmp_asn1_enc_s32t_cnt(m_stat->error_index, &rhl->erridxlen);
00320   snmp_asn1_enc_length_cnt(rhl->erridxlen, &rhl->erridxlenlen);
00321   tot_len += 1 + rhl->erridxlenlen + rhl->erridxlen;
00322 
00323   snmp_asn1_enc_s32t_cnt(m_stat->error_status, &rhl->errstatlen);
00324   snmp_asn1_enc_length_cnt(rhl->errstatlen, &rhl->errstatlenlen);
00325   tot_len += 1 + rhl->errstatlenlen + rhl->errstatlen;
00326 
00327   snmp_asn1_enc_s32t_cnt(m_stat->rid, &rhl->ridlen);
00328   snmp_asn1_enc_length_cnt(rhl->ridlen, &rhl->ridlenlen);
00329   tot_len += 1 + rhl->ridlenlen + rhl->ridlen;
00330 
00331   rhl->pdulen = tot_len;
00332   snmp_asn1_enc_length_cnt(rhl->pdulen, &rhl->pdulenlen);
00333   tot_len += 1 + rhl->pdulenlen;
00334 
00335   rhl->comlen = m_stat->com_strlen;
00336   snmp_asn1_enc_length_cnt(rhl->comlen, &rhl->comlenlen);
00337   tot_len += 1 + rhl->comlenlen + rhl->comlen;
00338 
00339   snmp_asn1_enc_s32t_cnt(snmp_version, &rhl->verlen);
00340   snmp_asn1_enc_length_cnt(rhl->verlen, &rhl->verlenlen);
00341   tot_len += 1 + rhl->verlen + rhl->verlenlen;
00342 
00343   rhl->seqlen = tot_len;
00344   snmp_asn1_enc_length_cnt(rhl->seqlen, &rhl->seqlenlen);
00345   tot_len += 1 + rhl->seqlenlen;
00346 
00347   return tot_len;
00348 }
00349 
00350 /**
00351  * Sums trap header field lengths from tail to head and
00352  * returns trap_header_lengths for second encoding pass.
00353  *
00354  * @param vb_len varbind-list length
00355  * @param thl points to returned header lengths
00356  * @return the required lenght for encoding the trap header
00357  */
00358 static u16_t
00359 snmp_trap_header_sum(struct snmp_msg_trap *m_trap, u16_t vb_len)
00360 {
00361   u16_t tot_len;
00362   struct snmp_trap_header_lengths *thl;
00363 
00364   thl = &m_trap->thl;
00365   tot_len = vb_len;
00366 
00367   snmp_asn1_enc_u32t_cnt(m_trap->ts, &thl->tslen);
00368   snmp_asn1_enc_length_cnt(thl->tslen, &thl->tslenlen);
00369   tot_len += 1 + thl->tslen + thl->tslenlen;
00370 
00371   snmp_asn1_enc_s32t_cnt(m_trap->spc_trap, &thl->strplen);
00372   snmp_asn1_enc_length_cnt(thl->strplen, &thl->strplenlen);
00373   tot_len += 1 + thl->strplen + thl->strplenlen;
00374 
00375   snmp_asn1_enc_s32t_cnt(m_trap->gen_trap, &thl->gtrplen);
00376   snmp_asn1_enc_length_cnt(thl->gtrplen, &thl->gtrplenlen);
00377   tot_len += 1 + thl->gtrplen + thl->gtrplenlen;
00378 
00379   thl->aaddrlen = 4;
00380   snmp_asn1_enc_length_cnt(thl->aaddrlen, &thl->aaddrlenlen);
00381   tot_len += 1 + thl->aaddrlen + thl->aaddrlenlen;
00382 
00383   snmp_asn1_enc_oid_cnt(m_trap->enterprise->len, &m_trap->enterprise->id[0], &thl->eidlen);
00384   snmp_asn1_enc_length_cnt(thl->eidlen, &thl->eidlenlen);
00385   tot_len += 1 + thl->eidlen + thl->eidlenlen;
00386 
00387   thl->pdulen = tot_len;
00388   snmp_asn1_enc_length_cnt(thl->pdulen, &thl->pdulenlen);
00389   tot_len += 1 + thl->pdulenlen;
00390 
00391   thl->comlen = sizeof(snmp_publiccommunity) - 1;
00392   snmp_asn1_enc_length_cnt(thl->comlen, &thl->comlenlen);
00393   tot_len += 1 + thl->comlenlen + thl->comlen;
00394 
00395   snmp_asn1_enc_s32t_cnt(snmp_version, &thl->verlen);
00396   snmp_asn1_enc_length_cnt(thl->verlen, &thl->verlenlen);
00397   tot_len += 1 + thl->verlen + thl->verlenlen;
00398 
00399   thl->seqlen = tot_len;
00400   snmp_asn1_enc_length_cnt(thl->seqlen, &thl->seqlenlen);
00401   tot_len += 1 + thl->seqlenlen;
00402 
00403   return tot_len;
00404 }
00405 
00406 /**
00407  * Sums varbind lengths from tail to head and
00408  * annotates lengths in varbind for second encoding pass.
00409  *
00410  * @param root points to the root of the variable binding list
00411  * @return the required lenght for encoding the variable bindings
00412  */
00413 static u16_t
00414 snmp_varbind_list_sum(struct snmp_varbind_root *root)
00415 {
00416   struct snmp_varbind *vb;
00417   u32_t *uint_ptr;
00418   s32_t *sint_ptr;
00419   u16_t tot_len;
00420 
00421   tot_len = 0;
00422   vb = root->tail;
00423   while ( vb != NULL )
00424   {
00425     /* encoded value lenght depends on type */
00426     switch (vb->value_type)
00427     {
00428       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG):
00429         sint_ptr = (s32_t*)vb->value;
00430         snmp_asn1_enc_s32t_cnt(*sint_ptr, &vb->vlen);
00431         break;
00432       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_COUNTER):
00433       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_GAUGE):
00434       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_TIMETICKS):
00435         uint_ptr = (u32_t*)vb->value;
00436         snmp_asn1_enc_u32t_cnt(*uint_ptr, &vb->vlen);
00437         break;
00438       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR):
00439       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_NUL):
00440       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR):
00441       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_OPAQUE):
00442         vb->vlen = vb->value_len;
00443         break;
00444       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID):
00445         sint_ptr = (s32_t*)vb->value;
00446         snmp_asn1_enc_oid_cnt(vb->value_len / sizeof(s32_t), sint_ptr, &vb->vlen);
00447         break;
00448       default:
00449         /* unsupported type */
00450         vb->vlen = 0;
00451         break;
00452     };
00453     /* encoding length of value length field */
00454     snmp_asn1_enc_length_cnt(vb->vlen, &vb->vlenlen);
00455     snmp_asn1_enc_oid_cnt(vb->ident_len, vb->ident, &vb->olen);
00456     snmp_asn1_enc_length_cnt(vb->olen, &vb->olenlen);
00457 
00458     vb->seqlen = 1 + vb->vlenlen + vb->vlen;
00459     vb->seqlen += 1 + vb->olenlen + vb->olen;
00460     snmp_asn1_enc_length_cnt(vb->seqlen, &vb->seqlenlen);
00461 
00462     /* varbind seq */
00463     tot_len += 1 + vb->seqlenlen + vb->seqlen;
00464 
00465     vb = vb->prev;
00466   }
00467 
00468   /* varbind-list seq */
00469   root->seqlen = tot_len;
00470   snmp_asn1_enc_length_cnt(root->seqlen, &root->seqlenlen);
00471   tot_len += 1 + root->seqlenlen;
00472 
00473   return tot_len;
00474 }
00475 
00476 /**
00477  * Encodes response header from head to tail.
00478  */
00479 static u16_t
00480 snmp_resp_header_enc(struct snmp_msg_pstat *m_stat, struct pbuf *p)
00481 {
00482   u16_t ofs;
00483 
00484   ofs = 0;
00485   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ));
00486   ofs += 1;
00487   snmp_asn1_enc_length(p, ofs, m_stat->rhl.seqlen);
00488   ofs += m_stat->rhl.seqlenlen;
00489 
00490   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
00491   ofs += 1;
00492   snmp_asn1_enc_length(p, ofs, m_stat->rhl.verlen);
00493   ofs += m_stat->rhl.verlenlen;
00494   snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.verlen, snmp_version);
00495   ofs += m_stat->rhl.verlen;
00496 
00497   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR));
00498   ofs += 1;
00499   snmp_asn1_enc_length(p, ofs, m_stat->rhl.comlen);
00500   ofs += m_stat->rhl.comlenlen;
00501   snmp_asn1_enc_raw(p, ofs, m_stat->rhl.comlen, m_stat->community);
00502   ofs += m_stat->rhl.comlen;
00503 
00504   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_RESP));
00505   ofs += 1;
00506   snmp_asn1_enc_length(p, ofs, m_stat->rhl.pdulen);
00507   ofs += m_stat->rhl.pdulenlen;
00508 
00509   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
00510   ofs += 1;
00511   snmp_asn1_enc_length(p, ofs, m_stat->rhl.ridlen);
00512   ofs += m_stat->rhl.ridlenlen;
00513   snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.ridlen, m_stat->rid);
00514   ofs += m_stat->rhl.ridlen;
00515 
00516   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
00517   ofs += 1;
00518   snmp_asn1_enc_length(p, ofs, m_stat->rhl.errstatlen);
00519   ofs += m_stat->rhl.errstatlenlen;
00520   snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.errstatlen, m_stat->error_status);
00521   ofs += m_stat->rhl.errstatlen;
00522 
00523   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
00524   ofs += 1;
00525   snmp_asn1_enc_length(p, ofs, m_stat->rhl.erridxlen);
00526   ofs += m_stat->rhl.erridxlenlen;
00527   snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.erridxlen, m_stat->error_index);
00528   ofs += m_stat->rhl.erridxlen;
00529 
00530   return ofs;
00531 }
00532 
00533 /**
00534  * Encodes trap header from head to tail.
00535  */
00536 static u16_t
00537 snmp_trap_header_enc(struct snmp_msg_trap *m_trap, struct pbuf *p)
00538 {
00539   u16_t ofs;
00540 
00541   ofs = 0;
00542   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ));
00543   ofs += 1;
00544   snmp_asn1_enc_length(p, ofs, m_trap->thl.seqlen);
00545   ofs += m_trap->thl.seqlenlen;
00546 
00547   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
00548   ofs += 1;
00549   snmp_asn1_enc_length(p, ofs, m_trap->thl.verlen);
00550   ofs += m_trap->thl.verlenlen;
00551   snmp_asn1_enc_s32t(p, ofs, m_trap->thl.verlen, snmp_version);
00552   ofs += m_trap->thl.verlen;
00553 
00554   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR));
00555   ofs += 1;
00556   snmp_asn1_enc_length(p, ofs, m_trap->thl.comlen);
00557   ofs += m_trap->thl.comlenlen;
00558   snmp_asn1_enc_raw(p, ofs, m_trap->thl.comlen, (u8_t *)&snmp_publiccommunity[0]);
00559   ofs += m_trap->thl.comlen;
00560 
00561   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_TRAP));
00562   ofs += 1;
00563   snmp_asn1_enc_length(p, ofs, m_trap->thl.pdulen);
00564   ofs += m_trap->thl.pdulenlen;
00565 
00566   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID));
00567   ofs += 1;
00568   snmp_asn1_enc_length(p, ofs, m_trap->thl.eidlen);
00569   ofs += m_trap->thl.eidlenlen;
00570   snmp_asn1_enc_oid(p, ofs, m_trap->enterprise->len, &m_trap->enterprise->id[0]);
00571   ofs += m_trap->thl.eidlen;
00572 
00573   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR));
00574   ofs += 1;
00575   snmp_asn1_enc_length(p, ofs, m_trap->thl.aaddrlen);
00576   ofs += m_trap->thl.aaddrlenlen;
00577   snmp_asn1_enc_raw(p, ofs, m_trap->thl.aaddrlen, &m_trap->sip_raw[0]);
00578   ofs += m_trap->thl.aaddrlen;
00579 
00580   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
00581   ofs += 1;
00582   snmp_asn1_enc_length(p, ofs, m_trap->thl.gtrplen);
00583   ofs += m_trap->thl.gtrplenlen;
00584   snmp_asn1_enc_u32t(p, ofs, m_trap->thl.gtrplen, m_trap->gen_trap);
00585   ofs += m_trap->thl.gtrplen;
00586 
00587   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
00588   ofs += 1;
00589   snmp_asn1_enc_length(p, ofs, m_trap->thl.strplen);
00590   ofs += m_trap->thl.strplenlen;
00591   snmp_asn1_enc_u32t(p, ofs, m_trap->thl.strplen, m_trap->spc_trap);
00592   ofs += m_trap->thl.strplen;
00593 
00594   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_TIMETICKS));
00595   ofs += 1;
00596   snmp_asn1_enc_length(p, ofs, m_trap->thl.tslen);
00597   ofs += m_trap->thl.tslenlen;
00598   snmp_asn1_enc_u32t(p, ofs, m_trap->thl.tslen, m_trap->ts);
00599   ofs += m_trap->thl.tslen;
00600 
00601   return ofs;
00602 }
00603 
00604 /**
00605  * Encodes varbind list from head to tail.
00606  */
00607 static u16_t
00608 snmp_varbind_list_enc(struct snmp_varbind_root *root, struct pbuf *p, u16_t ofs)
00609 {
00610   struct snmp_varbind *vb;
00611   s32_t *sint_ptr;
00612   u32_t *uint_ptr;
00613   u8_t *raw_ptr;
00614 
00615   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ));
00616   ofs += 1;
00617   snmp_asn1_enc_length(p, ofs, root->seqlen);
00618   ofs += root->seqlenlen;
00619 
00620   vb = root->head;
00621   while ( vb != NULL )
00622   {
00623     snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ));
00624     ofs += 1;
00625     snmp_asn1_enc_length(p, ofs, vb->seqlen);
00626     ofs += vb->seqlenlen;
00627 
00628     snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID));
00629     ofs += 1;
00630     snmp_asn1_enc_length(p, ofs, vb->olen);
00631     ofs += vb->olenlen;
00632     snmp_asn1_enc_oid(p, ofs, vb->ident_len, &vb->ident[0]);
00633     ofs += vb->olen;
00634 
00635     snmp_asn1_enc_type(p, ofs, vb->value_type);
00636     ofs += 1;
00637     snmp_asn1_enc_length(p, ofs, vb->vlen);
00638     ofs += vb->vlenlen;
00639 
00640     switch (vb->value_type)
00641     {
00642       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG):
00643         sint_ptr = (s32_t*)vb->value;
00644         snmp_asn1_enc_s32t(p, ofs, vb->vlen, *sint_ptr);
00645         break;
00646       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_COUNTER):
00647       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_GAUGE):
00648       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_TIMETICKS):
00649         uint_ptr = (u32_t*)vb->value;
00650         snmp_asn1_enc_u32t(p, ofs, vb->vlen, *uint_ptr);
00651         break;
00652       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR):
00653       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR):
00654       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_OPAQUE):
00655         raw_ptr = (u8_t*)vb->value;
00656         snmp_asn1_enc_raw(p, ofs, vb->vlen, raw_ptr);
00657         break;
00658       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_NUL):
00659         break;
00660       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID):
00661         sint_ptr = (s32_t*)vb->value;
00662         snmp_asn1_enc_oid(p, ofs, vb->value_len / sizeof(s32_t), sint_ptr);
00663         break;
00664       default:
00665         /* unsupported type */
00666         break;
00667     };
00668     ofs += vb->vlen;
00669     vb = vb->next;
00670   }
00671   return ofs;
00672 }
00673 
00674 #endif /* LWIP_SNMP */