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   struct ip_addr 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, struct ip_addr *dst)
00096 {
00097   if (dst_idx < SNMP_TRAP_DESTINATIONS)
00098   {
00099     trap_dst[dst_idx].dip.addr = htonl(dst->addr);
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     if (m_stat->error_status == SNMP_ES_TOOBIG)
00149     {
00150       snmp_varbind_list_enc(&emptyvb, p, ofs);
00151     }
00152     else
00153     {
00154       snmp_varbind_list_enc(&m_stat->outvb, p, ofs);
00155     }
00156 
00157     switch (m_stat->error_status)
00158     {
00159       case SNMP_ES_TOOBIG:
00160         snmp_inc_snmpouttoobigs();
00161         break;
00162       case SNMP_ES_NOSUCHNAME:
00163         snmp_inc_snmpoutnosuchnames();
00164         break;
00165       case SNMP_ES_BADVALUE:
00166         snmp_inc_snmpoutbadvalues();
00167         break;
00168       case SNMP_ES_GENERROR:
00169         snmp_inc_snmpoutgenerrs();
00170         break;
00171     }
00172     snmp_inc_snmpoutgetresponses();
00173     snmp_inc_snmpoutpkts();
00174 
00175     /** @todo do we need separate rx and tx pcbs for threaded case? */
00176     /** connect to the originating source */
00177     udp_connect(m_stat->pcb, &m_stat->sip, m_stat->sp);
00178     err = udp_send(m_stat->pcb, p);
00179     if (err == ERR_MEM)
00180     {
00181       /** @todo release some memory, retry and return tooBig? tooMuchHassle? */
00182       err = ERR_MEM;
00183     }
00184     else
00185     {
00186       err = ERR_OK;
00187     }
00188     /** disassociate remote address and port with this pcb */
00189     udp_disconnect(m_stat->pcb);
00190 
00191     pbuf_free(p);
00192     LWIP_DEBUGF(SNMP_MSG_DEBUG, ("snmp_snd_response() done\n"));
00193     return err;
00194   }
00195   else
00196   {
00197     /* first pbuf alloc try or retry alloc failed
00198        very low on memory, couldn't return tooBig */
00199     return ERR_MEM;
00200   }
00201 }
00202 
00203 
00204 /**
00205  * Sends an generic or enterprise specific trap message.
00206  *
00207  * @param generic_trap is the trap code
00208  * @param eoid points to enterprise object identifier
00209  * @param specific_trap used for enterprise traps when generic_trap == 6
00210  * @return ERR_OK when success, ERR_MEM if we're out of memory
00211  *
00212  * @note the caller is responsible for filling in outvb in the trap_msg
00213  * @note the use of the enterpise identifier field
00214  * is per RFC1215.
00215  * Use .iso.org.dod.internet.mgmt.mib-2.snmp for generic traps
00216  * and .iso.org.dod.internet.private.enterprises.yourenterprise
00217  * (sysObjectID) for specific traps.
00218  */
00219 err_t
00220 snmp_send_trap(s8_t generic_trap, struct snmp_obj_id *eoid, s32_t specific_trap)
00221 {
00222   struct snmp_trap_dst *td;
00223   struct netif *dst_if;
00224   struct ip_addr dst_ip;
00225   struct pbuf *p;
00226   u16_t i,tot_len;
00227 
00228   for (i=0, td = &trap_dst[0]; i<SNMP_TRAP_DESTINATIONS; i++, td++)
00229   {
00230     if ((td->enable != 0) && (td->dip.addr != 0))
00231     {
00232       /* network order trap destination */
00233       trap_msg.dip.addr = td->dip.addr;
00234       /* lookup current source address for this dst */
00235       dst_if = ip_route(&td->dip);
00236       dst_ip.addr = ntohl(dst_if->ip_addr.addr);
00237       trap_msg.sip_raw[0] = dst_ip.addr >> 24;
00238       trap_msg.sip_raw[1] = dst_ip.addr >> 16;
00239       trap_msg.sip_raw[2] = dst_ip.addr >> 8;
00240       trap_msg.sip_raw[3] = dst_ip.addr;
00241       trap_msg.gen_trap = generic_trap;
00242       trap_msg.spc_trap = specific_trap;
00243       if (generic_trap == SNMP_GENTRAP_ENTERPRISESPC)
00244       {
00245         /* enterprise-Specific trap */
00246         trap_msg.enterprise = eoid;
00247       }
00248       else
00249       {
00250         /* generic (MIB-II) trap */
00251         snmp_get_snmpgrpid_ptr(&trap_msg.enterprise);
00252       }
00253       snmp_get_sysuptime(&trap_msg.ts);
00254 
00255       /* pass 0, calculate length fields */
00256       tot_len = snmp_varbind_list_sum(&trap_msg.outvb);
00257       tot_len = snmp_trap_header_sum(&trap_msg, tot_len);
00258 
00259       /* allocate pbuf(s) */
00260       p = pbuf_alloc(PBUF_TRANSPORT, tot_len, PBUF_POOL);
00261       if (p != NULL)
00262       {
00263         u16_t ofs;
00264 
00265         /* pass 1, encode packet ino the pbuf(s) */
00266         ofs = snmp_trap_header_enc(&trap_msg, p);
00267         snmp_varbind_list_enc(&trap_msg.outvb, p, ofs);
00268 
00269         snmp_inc_snmpouttraps();
00270         snmp_inc_snmpoutpkts();
00271 
00272         /** connect to the TRAP destination */
00273         udp_connect(trap_msg.pcb, &trap_msg.dip, SNMP_TRAP_PORT);
00274         udp_send(trap_msg.pcb, p);
00275         /** disassociate remote address and port with this pcb */
00276         udp_disconnect(trap_msg.pcb);
00277 
00278         pbuf_free(p);
00279       }
00280       else
00281       {
00282         return ERR_MEM;
00283       }
00284     }
00285   }
00286   return ERR_OK;
00287 }
00288 
00289 void
00290 snmp_coldstart_trap(void)
00291 {
00292   trap_msg.outvb.head = NULL;
00293   trap_msg.outvb.tail = NULL;
00294   trap_msg.outvb.count = 0;
00295   snmp_send_trap(SNMP_GENTRAP_COLDSTART, NULL, 0);
00296 }
00297 
00298 void
00299 snmp_authfail_trap(void)
00300 {
00301   u8_t enable;
00302   snmp_get_snmpenableauthentraps(&enable);
00303   if (enable == 1)
00304   {
00305     trap_msg.outvb.head = NULL;
00306     trap_msg.outvb.tail = NULL;
00307     trap_msg.outvb.count = 0;
00308     snmp_send_trap(SNMP_GENTRAP_AUTHFAIL, NULL, 0);
00309   }
00310 }
00311 
00312 /**
00313  * Sums response header field lengths from tail to head and
00314  * returns resp_header_lengths for second encoding pass.
00315  *
00316  * @param vb_len varbind-list length
00317  * @param rhl points to returned header lengths
00318  * @return the required lenght for encoding the response header
00319  */
00320 static u16_t
00321 snmp_resp_header_sum(struct snmp_msg_pstat *m_stat, u16_t vb_len)
00322 {
00323   u16_t tot_len;
00324   struct snmp_resp_header_lengths *rhl;
00325 
00326   rhl = &m_stat->rhl;
00327   tot_len = vb_len;
00328   snmp_asn1_enc_s32t_cnt(m_stat->error_index, &rhl->erridxlen);
00329   snmp_asn1_enc_length_cnt(rhl->erridxlen, &rhl->erridxlenlen);
00330   tot_len += 1 + rhl->erridxlenlen + rhl->erridxlen;
00331 
00332   snmp_asn1_enc_s32t_cnt(m_stat->error_status, &rhl->errstatlen);
00333   snmp_asn1_enc_length_cnt(rhl->errstatlen, &rhl->errstatlenlen);
00334   tot_len += 1 + rhl->errstatlenlen + rhl->errstatlen;
00335 
00336   snmp_asn1_enc_s32t_cnt(m_stat->rid, &rhl->ridlen);
00337   snmp_asn1_enc_length_cnt(rhl->ridlen, &rhl->ridlenlen);
00338   tot_len += 1 + rhl->ridlenlen + rhl->ridlen;
00339 
00340   rhl->pdulen = tot_len;
00341   snmp_asn1_enc_length_cnt(rhl->pdulen, &rhl->pdulenlen);
00342   tot_len += 1 + rhl->pdulenlen;
00343 
00344   rhl->comlen = m_stat->com_strlen;
00345   snmp_asn1_enc_length_cnt(rhl->comlen, &rhl->comlenlen);
00346   tot_len += 1 + rhl->comlenlen + rhl->comlen;
00347 
00348   snmp_asn1_enc_s32t_cnt(snmp_version, &rhl->verlen);
00349   snmp_asn1_enc_length_cnt(rhl->verlen, &rhl->verlenlen);
00350   tot_len += 1 + rhl->verlen + rhl->verlenlen;
00351 
00352   rhl->seqlen = tot_len;
00353   snmp_asn1_enc_length_cnt(rhl->seqlen, &rhl->seqlenlen);
00354   tot_len += 1 + rhl->seqlenlen;
00355 
00356   return tot_len;
00357 }
00358 
00359 /**
00360  * Sums trap header field lengths from tail to head and
00361  * returns trap_header_lengths for second encoding pass.
00362  *
00363  * @param vb_len varbind-list length
00364  * @param thl points to returned header lengths
00365  * @return the required lenght for encoding the trap header
00366  */
00367 static u16_t
00368 snmp_trap_header_sum(struct snmp_msg_trap *m_trap, u16_t vb_len)
00369 {
00370   u16_t tot_len;
00371   struct snmp_trap_header_lengths *thl;
00372 
00373   thl = &m_trap->thl;
00374   tot_len = vb_len;
00375 
00376   snmp_asn1_enc_u32t_cnt(m_trap->ts, &thl->tslen);
00377   snmp_asn1_enc_length_cnt(thl->tslen, &thl->tslenlen);
00378   tot_len += 1 + thl->tslen + thl->tslenlen;
00379 
00380   snmp_asn1_enc_s32t_cnt(m_trap->spc_trap, &thl->strplen);
00381   snmp_asn1_enc_length_cnt(thl->strplen, &thl->strplenlen);
00382   tot_len += 1 + thl->strplen + thl->strplenlen;
00383 
00384   snmp_asn1_enc_s32t_cnt(m_trap->gen_trap, &thl->gtrplen);
00385   snmp_asn1_enc_length_cnt(thl->gtrplen, &thl->gtrplenlen);
00386   tot_len += 1 + thl->gtrplen + thl->gtrplenlen;
00387 
00388   thl->aaddrlen = 4;
00389   snmp_asn1_enc_length_cnt(thl->aaddrlen, &thl->aaddrlenlen);
00390   tot_len += 1 + thl->aaddrlen + thl->aaddrlenlen;
00391 
00392   snmp_asn1_enc_oid_cnt(m_trap->enterprise->len, &m_trap->enterprise->id[0], &thl->eidlen);
00393   snmp_asn1_enc_length_cnt(thl->eidlen, &thl->eidlenlen);
00394   tot_len += 1 + thl->eidlen + thl->eidlenlen;
00395 
00396   thl->pdulen = tot_len;
00397   snmp_asn1_enc_length_cnt(thl->pdulen, &thl->pdulenlen);
00398   tot_len += 1 + thl->pdulenlen;
00399 
00400   thl->comlen = sizeof(snmp_publiccommunity) - 1;
00401   snmp_asn1_enc_length_cnt(thl->comlen, &thl->comlenlen);
00402   tot_len += 1 + thl->comlenlen + thl->comlen;
00403 
00404   snmp_asn1_enc_s32t_cnt(snmp_version, &thl->verlen);
00405   snmp_asn1_enc_length_cnt(thl->verlen, &thl->verlenlen);
00406   tot_len += 1 + thl->verlen + thl->verlenlen;
00407 
00408   thl->seqlen = tot_len;
00409   snmp_asn1_enc_length_cnt(thl->seqlen, &thl->seqlenlen);
00410   tot_len += 1 + thl->seqlenlen;
00411 
00412   return tot_len;
00413 }
00414 
00415 /**
00416  * Sums varbind lengths from tail to head and
00417  * annotates lengths in varbind for second encoding pass.
00418  *
00419  * @param root points to the root of the variable binding list
00420  * @return the required lenght for encoding the variable bindings
00421  */
00422 static u16_t
00423 snmp_varbind_list_sum(struct snmp_varbind_root *root)
00424 {
00425   struct snmp_varbind *vb;
00426   u32_t *uint_ptr;
00427   s32_t *sint_ptr;
00428   u16_t tot_len;
00429 
00430   tot_len = 0;
00431   vb = root->tail;
00432   while ( vb != NULL )
00433   {
00434     /* encoded value lenght depends on type */
00435     switch (vb->value_type)
00436     {
00437       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG):
00438         sint_ptr = vb->value;
00439         snmp_asn1_enc_s32t_cnt(*sint_ptr, &vb->vlen);
00440         break;
00441       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_COUNTER):
00442       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_GAUGE):
00443       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_TIMETICKS):
00444         uint_ptr = vb->value;
00445         snmp_asn1_enc_u32t_cnt(*uint_ptr, &vb->vlen);
00446         break;
00447       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR):
00448       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_NUL):
00449       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR):
00450       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_OPAQUE):
00451         vb->vlen = vb->value_len;
00452         break;
00453       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID):
00454         sint_ptr = vb->value;
00455         snmp_asn1_enc_oid_cnt(vb->value_len / sizeof(s32_t), sint_ptr, &vb->vlen);
00456         break;
00457       default:
00458         /* unsupported type */
00459         vb->vlen = 0;
00460         break;
00461     };
00462     /* encoding length of value length field */
00463     snmp_asn1_enc_length_cnt(vb->vlen, &vb->vlenlen);
00464     snmp_asn1_enc_oid_cnt(vb->ident_len, vb->ident, &vb->olen);
00465     snmp_asn1_enc_length_cnt(vb->olen, &vb->olenlen);
00466 
00467     vb->seqlen = 1 + vb->vlenlen + vb->vlen;
00468     vb->seqlen += 1 + vb->olenlen + vb->olen;
00469     snmp_asn1_enc_length_cnt(vb->seqlen, &vb->seqlenlen);
00470 
00471     /* varbind seq */
00472     tot_len += 1 + vb->seqlenlen + vb->seqlen;
00473 
00474     vb = vb->prev;
00475   }
00476 
00477   /* varbind-list seq */
00478   root->seqlen = tot_len;
00479   snmp_asn1_enc_length_cnt(root->seqlen, &root->seqlenlen);
00480   tot_len += 1 + root->seqlenlen;
00481 
00482   return tot_len;
00483 }
00484 
00485 /**
00486  * Encodes response header from head to tail.
00487  */
00488 static u16_t
00489 snmp_resp_header_enc(struct snmp_msg_pstat *m_stat, struct pbuf *p)
00490 {
00491   u16_t ofs;
00492 
00493   ofs = 0;
00494   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ));
00495   ofs += 1;
00496   snmp_asn1_enc_length(p, ofs, m_stat->rhl.seqlen);
00497   ofs += m_stat->rhl.seqlenlen;
00498 
00499   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
00500   ofs += 1;
00501   snmp_asn1_enc_length(p, ofs, m_stat->rhl.verlen);
00502   ofs += m_stat->rhl.verlenlen;
00503   snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.verlen, snmp_version);
00504   ofs += m_stat->rhl.verlen;
00505 
00506   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR));
00507   ofs += 1;
00508   snmp_asn1_enc_length(p, ofs, m_stat->rhl.comlen);
00509   ofs += m_stat->rhl.comlenlen;
00510   snmp_asn1_enc_raw(p, ofs, m_stat->rhl.comlen, m_stat->community);
00511   ofs += m_stat->rhl.comlen;
00512 
00513   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_RESP));
00514   ofs += 1;
00515   snmp_asn1_enc_length(p, ofs, m_stat->rhl.pdulen);
00516   ofs += m_stat->rhl.pdulenlen;
00517 
00518   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
00519   ofs += 1;
00520   snmp_asn1_enc_length(p, ofs, m_stat->rhl.ridlen);
00521   ofs += m_stat->rhl.ridlenlen;
00522   snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.ridlen, m_stat->rid);
00523   ofs += m_stat->rhl.ridlen;
00524 
00525   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
00526   ofs += 1;
00527   snmp_asn1_enc_length(p, ofs, m_stat->rhl.errstatlen);
00528   ofs += m_stat->rhl.errstatlenlen;
00529   snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.errstatlen, m_stat->error_status);
00530   ofs += m_stat->rhl.errstatlen;
00531 
00532   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
00533   ofs += 1;
00534   snmp_asn1_enc_length(p, ofs, m_stat->rhl.erridxlen);
00535   ofs += m_stat->rhl.erridxlenlen;
00536   snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.erridxlen, m_stat->error_index);
00537   ofs += m_stat->rhl.erridxlen;
00538 
00539   return ofs;
00540 }
00541 
00542 /**
00543  * Encodes trap header from head to tail.
00544  */
00545 static u16_t
00546 snmp_trap_header_enc(struct snmp_msg_trap *m_trap, struct pbuf *p)
00547 {
00548   u16_t ofs;
00549 
00550   ofs = 0;
00551   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ));
00552   ofs += 1;
00553   snmp_asn1_enc_length(p, ofs, m_trap->thl.seqlen);
00554   ofs += m_trap->thl.seqlenlen;
00555 
00556   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
00557   ofs += 1;
00558   snmp_asn1_enc_length(p, ofs, m_trap->thl.verlen);
00559   ofs += m_trap->thl.verlenlen;
00560   snmp_asn1_enc_s32t(p, ofs, m_trap->thl.verlen, snmp_version);
00561   ofs += m_trap->thl.verlen;
00562 
00563   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR));
00564   ofs += 1;
00565   snmp_asn1_enc_length(p, ofs, m_trap->thl.comlen);
00566   ofs += m_trap->thl.comlenlen;
00567   snmp_asn1_enc_raw(p, ofs, m_trap->thl.comlen, (u8_t *)&snmp_publiccommunity[0]);
00568   ofs += m_trap->thl.comlen;
00569 
00570   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_TRAP));
00571   ofs += 1;
00572   snmp_asn1_enc_length(p, ofs, m_trap->thl.pdulen);
00573   ofs += m_trap->thl.pdulenlen;
00574 
00575   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID));
00576   ofs += 1;
00577   snmp_asn1_enc_length(p, ofs, m_trap->thl.eidlen);
00578   ofs += m_trap->thl.eidlenlen;
00579   snmp_asn1_enc_oid(p, ofs, m_trap->enterprise->len, &m_trap->enterprise->id[0]);
00580   ofs += m_trap->thl.eidlen;
00581 
00582   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR));
00583   ofs += 1;
00584   snmp_asn1_enc_length(p, ofs, m_trap->thl.aaddrlen);
00585   ofs += m_trap->thl.aaddrlenlen;
00586   snmp_asn1_enc_raw(p, ofs, m_trap->thl.aaddrlen, &m_trap->sip_raw[0]);
00587   ofs += m_trap->thl.aaddrlen;
00588 
00589   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
00590   ofs += 1;
00591   snmp_asn1_enc_length(p, ofs, m_trap->thl.gtrplen);
00592   ofs += m_trap->thl.gtrplenlen;
00593   snmp_asn1_enc_u32t(p, ofs, m_trap->thl.gtrplen, m_trap->gen_trap);
00594   ofs += m_trap->thl.gtrplen;
00595 
00596   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
00597   ofs += 1;
00598   snmp_asn1_enc_length(p, ofs, m_trap->thl.strplen);
00599   ofs += m_trap->thl.strplenlen;
00600   snmp_asn1_enc_u32t(p, ofs, m_trap->thl.strplen, m_trap->spc_trap);
00601   ofs += m_trap->thl.strplen;
00602 
00603   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_TIMETICKS));
00604   ofs += 1;
00605   snmp_asn1_enc_length(p, ofs, m_trap->thl.tslen);
00606   ofs += m_trap->thl.tslenlen;
00607   snmp_asn1_enc_u32t(p, ofs, m_trap->thl.tslen, m_trap->ts);
00608   ofs += m_trap->thl.tslen;
00609 
00610   return ofs;
00611 }
00612 
00613 /**
00614  * Encodes varbind list from head to tail.
00615  */
00616 static u16_t
00617 snmp_varbind_list_enc(struct snmp_varbind_root *root, struct pbuf *p, u16_t ofs)
00618 {
00619   struct snmp_varbind *vb;
00620   s32_t *sint_ptr;
00621   u32_t *uint_ptr;
00622   u8_t *raw_ptr;
00623 
00624   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ));
00625   ofs += 1;
00626   snmp_asn1_enc_length(p, ofs, root->seqlen);
00627   ofs += root->seqlenlen;
00628 
00629   vb = root->head;
00630   while ( vb != NULL )
00631   {
00632     snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ));
00633     ofs += 1;
00634     snmp_asn1_enc_length(p, ofs, vb->seqlen);
00635     ofs += vb->seqlenlen;
00636 
00637     snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID));
00638     ofs += 1;
00639     snmp_asn1_enc_length(p, ofs, vb->olen);
00640     ofs += vb->olenlen;
00641     snmp_asn1_enc_oid(p, ofs, vb->ident_len, &vb->ident[0]);
00642     ofs += vb->olen;
00643 
00644     snmp_asn1_enc_type(p, ofs, vb->value_type);
00645     ofs += 1;
00646     snmp_asn1_enc_length(p, ofs, vb->vlen);
00647     ofs += vb->vlenlen;
00648 
00649     switch (vb->value_type)
00650     {
00651       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG):
00652         sint_ptr = vb->value;
00653         snmp_asn1_enc_s32t(p, ofs, vb->vlen, *sint_ptr);
00654         break;
00655       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_COUNTER):
00656       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_GAUGE):
00657       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_TIMETICKS):
00658         uint_ptr = vb->value;
00659         snmp_asn1_enc_u32t(p, ofs, vb->vlen, *uint_ptr);
00660         break;
00661       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR):
00662       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR):
00663       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_OPAQUE):
00664         raw_ptr = vb->value;
00665         snmp_asn1_enc_raw(p, ofs, vb->vlen, raw_ptr);
00666         break;
00667       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_NUL):
00668         break;
00669       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID):
00670         sint_ptr = vb->value;
00671         snmp_asn1_enc_oid(p, ofs, vb->value_len / sizeof(s32_t), sint_ptr);
00672         break;
00673       default:
00674         /* unsupported type */
00675         break;
00676     };
00677     ofs += vb->vlen;
00678     vb = vb->next;
00679   }
00680   return ofs;
00681 }
00682 
00683 #endif /* LWIP_SNMP */