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     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   ip_addr_t 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) && !ip_addr_isany(&td->dip))
00231     {
00232       /* network order trap destination */
00233       ip_addr_copy(trap_msg.dip, td->dip);
00234       /* lookup current source address for this dst */
00235       dst_if = ip_route(&td->dip);
00236       ip_addr_copy(dst_ip, dst_if->ip_addr);
00237       /* @todo: what about IPv6? */
00238       trap_msg.sip_raw[0] = ip4_addr1(&dst_ip);
00239       trap_msg.sip_raw[1] = ip4_addr2(&dst_ip);
00240       trap_msg.sip_raw[2] = ip4_addr3(&dst_ip);
00241       trap_msg.sip_raw[3] = ip4_addr4(&dst_ip);
00242       trap_msg.gen_trap = generic_trap;
00243       trap_msg.spc_trap = specific_trap;
00244       if (generic_trap == SNMP_GENTRAP_ENTERPRISESPC)
00245       {
00246         /* enterprise-Specific trap */
00247         trap_msg.enterprise = eoid;
00248       }
00249       else
00250       {
00251         /* generic (MIB-II) trap */
00252         snmp_get_snmpgrpid_ptr(&trap_msg.enterprise);
00253       }
00254       snmp_get_sysuptime(&trap_msg.ts);
00255 
00256       /* pass 0, calculate length fields */
00257       tot_len = snmp_varbind_list_sum(&trap_msg.outvb);
00258       tot_len = snmp_trap_header_sum(&trap_msg, tot_len);
00259 
00260       /* allocate pbuf(s) */
00261       p = pbuf_alloc(PBUF_TRANSPORT, tot_len, PBUF_POOL);
00262       if (p != NULL)
00263       {
00264         u16_t ofs;
00265 
00266         /* pass 1, encode packet ino the pbuf(s) */
00267         ofs = snmp_trap_header_enc(&trap_msg, p);
00268         snmp_varbind_list_enc(&trap_msg.outvb, p, ofs);
00269 
00270         snmp_inc_snmpouttraps();
00271         snmp_inc_snmpoutpkts();
00272 
00273         /** send to the TRAP destination */
00274         udp_sendto(trap_msg.pcb, p, &trap_msg.dip, SNMP_TRAP_PORT);
00275 
00276         pbuf_free(p);
00277       }
00278       else
00279       {
00280         return ERR_MEM;
00281       }
00282     }
00283   }
00284   return ERR_OK;
00285 }
00286 
00287 void
00288 snmp_coldstart_trap(void)
00289 {
00290   trap_msg.outvb.head = NULL;
00291   trap_msg.outvb.tail = NULL;
00292   trap_msg.outvb.count = 0;
00293   snmp_send_trap(SNMP_GENTRAP_COLDSTART, NULL, 0);
00294 }
00295 
00296 void
00297 snmp_authfail_trap(void)
00298 {
00299   u8_t enable;
00300   snmp_get_snmpenableauthentraps(&enable);
00301   if (enable == 1)
00302   {
00303     trap_msg.outvb.head = NULL;
00304     trap_msg.outvb.tail = NULL;
00305     trap_msg.outvb.count = 0;
00306     snmp_send_trap(SNMP_GENTRAP_AUTHFAIL, NULL, 0);
00307   }
00308 }
00309 
00310 /**
00311  * Sums response header field lengths from tail to head and
00312  * returns resp_header_lengths for second encoding pass.
00313  *
00314  * @param vb_len varbind-list length
00315  * @param rhl points to returned header lengths
00316  * @return the required lenght for encoding the response header
00317  */
00318 static u16_t
00319 snmp_resp_header_sum(struct snmp_msg_pstat *m_stat, u16_t vb_len)
00320 {
00321   u16_t tot_len;
00322   struct snmp_resp_header_lengths *rhl;
00323 
00324   rhl = &m_stat->rhl;
00325   tot_len = vb_len;
00326   snmp_asn1_enc_s32t_cnt(m_stat->error_index, &rhl->erridxlen);
00327   snmp_asn1_enc_length_cnt(rhl->erridxlen, &rhl->erridxlenlen);
00328   tot_len += 1 + rhl->erridxlenlen + rhl->erridxlen;
00329 
00330   snmp_asn1_enc_s32t_cnt(m_stat->error_status, &rhl->errstatlen);
00331   snmp_asn1_enc_length_cnt(rhl->errstatlen, &rhl->errstatlenlen);
00332   tot_len += 1 + rhl->errstatlenlen + rhl->errstatlen;
00333 
00334   snmp_asn1_enc_s32t_cnt(m_stat->rid, &rhl->ridlen);
00335   snmp_asn1_enc_length_cnt(rhl->ridlen, &rhl->ridlenlen);
00336   tot_len += 1 + rhl->ridlenlen + rhl->ridlen;
00337 
00338   rhl->pdulen = tot_len;
00339   snmp_asn1_enc_length_cnt(rhl->pdulen, &rhl->pdulenlen);
00340   tot_len += 1 + rhl->pdulenlen;
00341 
00342   rhl->comlen = m_stat->com_strlen;
00343   snmp_asn1_enc_length_cnt(rhl->comlen, &rhl->comlenlen);
00344   tot_len += 1 + rhl->comlenlen + rhl->comlen;
00345 
00346   snmp_asn1_enc_s32t_cnt(snmp_version, &rhl->verlen);
00347   snmp_asn1_enc_length_cnt(rhl->verlen, &rhl->verlenlen);
00348   tot_len += 1 + rhl->verlen + rhl->verlenlen;
00349 
00350   rhl->seqlen = tot_len;
00351   snmp_asn1_enc_length_cnt(rhl->seqlen, &rhl->seqlenlen);
00352   tot_len += 1 + rhl->seqlenlen;
00353 
00354   return tot_len;
00355 }
00356 
00357 /**
00358  * Sums trap header field lengths from tail to head and
00359  * returns trap_header_lengths for second encoding pass.
00360  *
00361  * @param vb_len varbind-list length
00362  * @param thl points to returned header lengths
00363  * @return the required lenght for encoding the trap header
00364  */
00365 static u16_t
00366 snmp_trap_header_sum(struct snmp_msg_trap *m_trap, u16_t vb_len)
00367 {
00368   u16_t tot_len;
00369   struct snmp_trap_header_lengths *thl;
00370 
00371   thl = &m_trap->thl;
00372   tot_len = vb_len;
00373 
00374   snmp_asn1_enc_u32t_cnt(m_trap->ts, &thl->tslen);
00375   snmp_asn1_enc_length_cnt(thl->tslen, &thl->tslenlen);
00376   tot_len += 1 + thl->tslen + thl->tslenlen;
00377 
00378   snmp_asn1_enc_s32t_cnt(m_trap->spc_trap, &thl->strplen);
00379   snmp_asn1_enc_length_cnt(thl->strplen, &thl->strplenlen);
00380   tot_len += 1 + thl->strplen + thl->strplenlen;
00381 
00382   snmp_asn1_enc_s32t_cnt(m_trap->gen_trap, &thl->gtrplen);
00383   snmp_asn1_enc_length_cnt(thl->gtrplen, &thl->gtrplenlen);
00384   tot_len += 1 + thl->gtrplen + thl->gtrplenlen;
00385 
00386   thl->aaddrlen = 4;
00387   snmp_asn1_enc_length_cnt(thl->aaddrlen, &thl->aaddrlenlen);
00388   tot_len += 1 + thl->aaddrlen + thl->aaddrlenlen;
00389 
00390   snmp_asn1_enc_oid_cnt(m_trap->enterprise->len, &m_trap->enterprise->id[0], &thl->eidlen);
00391   snmp_asn1_enc_length_cnt(thl->eidlen, &thl->eidlenlen);
00392   tot_len += 1 + thl->eidlen + thl->eidlenlen;
00393 
00394   thl->pdulen = tot_len;
00395   snmp_asn1_enc_length_cnt(thl->pdulen, &thl->pdulenlen);
00396   tot_len += 1 + thl->pdulenlen;
00397 
00398   thl->comlen = sizeof(snmp_publiccommunity) - 1;
00399   snmp_asn1_enc_length_cnt(thl->comlen, &thl->comlenlen);
00400   tot_len += 1 + thl->comlenlen + thl->comlen;
00401 
00402   snmp_asn1_enc_s32t_cnt(snmp_version, &thl->verlen);
00403   snmp_asn1_enc_length_cnt(thl->verlen, &thl->verlenlen);
00404   tot_len += 1 + thl->verlen + thl->verlenlen;
00405 
00406   thl->seqlen = tot_len;
00407   snmp_asn1_enc_length_cnt(thl->seqlen, &thl->seqlenlen);
00408   tot_len += 1 + thl->seqlenlen;
00409 
00410   return tot_len;
00411 }
00412 
00413 /**
00414  * Sums varbind lengths from tail to head and
00415  * annotates lengths in varbind for second encoding pass.
00416  *
00417  * @param root points to the root of the variable binding list
00418  * @return the required lenght for encoding the variable bindings
00419  */
00420 static u16_t
00421 snmp_varbind_list_sum(struct snmp_varbind_root *root)
00422 {
00423   struct snmp_varbind *vb;
00424   u32_t *uint_ptr;
00425   s32_t *sint_ptr;
00426   u16_t tot_len;
00427 
00428   tot_len = 0;
00429   vb = root->tail;
00430   while ( vb != NULL )
00431   {
00432     /* encoded value lenght depends on type */
00433     switch (vb->value_type)
00434     {
00435       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG):
00436         sint_ptr = (s32_t*)vb->value;
00437         snmp_asn1_enc_s32t_cnt(*sint_ptr, &vb->vlen);
00438         break;
00439       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_COUNTER):
00440       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_GAUGE):
00441       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_TIMETICKS):
00442         uint_ptr = (u32_t*)vb->value;
00443         snmp_asn1_enc_u32t_cnt(*uint_ptr, &vb->vlen);
00444         break;
00445       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR):
00446       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_NUL):
00447       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR):
00448       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_OPAQUE):
00449         vb->vlen = vb->value_len;
00450         break;
00451       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID):
00452         sint_ptr = (s32_t*)vb->value;
00453         snmp_asn1_enc_oid_cnt(vb->value_len / sizeof(s32_t), sint_ptr, &vb->vlen);
00454         break;
00455       default:
00456         /* unsupported type */
00457         vb->vlen = 0;
00458         break;
00459     };
00460     /* encoding length of value length field */
00461     snmp_asn1_enc_length_cnt(vb->vlen, &vb->vlenlen);
00462     snmp_asn1_enc_oid_cnt(vb->ident_len, vb->ident, &vb->olen);
00463     snmp_asn1_enc_length_cnt(vb->olen, &vb->olenlen);
00464 
00465     vb->seqlen = 1 + vb->vlenlen + vb->vlen;
00466     vb->seqlen += 1 + vb->olenlen + vb->olen;
00467     snmp_asn1_enc_length_cnt(vb->seqlen, &vb->seqlenlen);
00468 
00469     /* varbind seq */
00470     tot_len += 1 + vb->seqlenlen + vb->seqlen;
00471 
00472     vb = vb->prev;
00473   }
00474 
00475   /* varbind-list seq */
00476   root->seqlen = tot_len;
00477   snmp_asn1_enc_length_cnt(root->seqlen, &root->seqlenlen);
00478   tot_len += 1 + root->seqlenlen;
00479 
00480   return tot_len;
00481 }
00482 
00483 /**
00484  * Encodes response header from head to tail.
00485  */
00486 static u16_t
00487 snmp_resp_header_enc(struct snmp_msg_pstat *m_stat, struct pbuf *p)
00488 {
00489   u16_t ofs;
00490 
00491   ofs = 0;
00492   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ));
00493   ofs += 1;
00494   snmp_asn1_enc_length(p, ofs, m_stat->rhl.seqlen);
00495   ofs += m_stat->rhl.seqlenlen;
00496 
00497   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
00498   ofs += 1;
00499   snmp_asn1_enc_length(p, ofs, m_stat->rhl.verlen);
00500   ofs += m_stat->rhl.verlenlen;
00501   snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.verlen, snmp_version);
00502   ofs += m_stat->rhl.verlen;
00503 
00504   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR));
00505   ofs += 1;
00506   snmp_asn1_enc_length(p, ofs, m_stat->rhl.comlen);
00507   ofs += m_stat->rhl.comlenlen;
00508   snmp_asn1_enc_raw(p, ofs, m_stat->rhl.comlen, m_stat->community);
00509   ofs += m_stat->rhl.comlen;
00510 
00511   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_GET_RESP));
00512   ofs += 1;
00513   snmp_asn1_enc_length(p, ofs, m_stat->rhl.pdulen);
00514   ofs += m_stat->rhl.pdulenlen;
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.ridlen);
00519   ofs += m_stat->rhl.ridlenlen;
00520   snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.ridlen, m_stat->rid);
00521   ofs += m_stat->rhl.ridlen;
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.errstatlen);
00526   ofs += m_stat->rhl.errstatlenlen;
00527   snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.errstatlen, m_stat->error_status);
00528   ofs += m_stat->rhl.errstatlen;
00529 
00530   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
00531   ofs += 1;
00532   snmp_asn1_enc_length(p, ofs, m_stat->rhl.erridxlen);
00533   ofs += m_stat->rhl.erridxlenlen;
00534   snmp_asn1_enc_s32t(p, ofs, m_stat->rhl.erridxlen, m_stat->error_index);
00535   ofs += m_stat->rhl.erridxlen;
00536 
00537   return ofs;
00538 }
00539 
00540 /**
00541  * Encodes trap header from head to tail.
00542  */
00543 static u16_t
00544 snmp_trap_header_enc(struct snmp_msg_trap *m_trap, struct pbuf *p)
00545 {
00546   u16_t ofs;
00547 
00548   ofs = 0;
00549   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ));
00550   ofs += 1;
00551   snmp_asn1_enc_length(p, ofs, m_trap->thl.seqlen);
00552   ofs += m_trap->thl.seqlenlen;
00553 
00554   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
00555   ofs += 1;
00556   snmp_asn1_enc_length(p, ofs, m_trap->thl.verlen);
00557   ofs += m_trap->thl.verlenlen;
00558   snmp_asn1_enc_s32t(p, ofs, m_trap->thl.verlen, snmp_version);
00559   ofs += m_trap->thl.verlen;
00560 
00561   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR));
00562   ofs += 1;
00563   snmp_asn1_enc_length(p, ofs, m_trap->thl.comlen);
00564   ofs += m_trap->thl.comlenlen;
00565   snmp_asn1_enc_raw(p, ofs, m_trap->thl.comlen, (u8_t *)&snmp_publiccommunity[0]);
00566   ofs += m_trap->thl.comlen;
00567 
00568   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_CONTXT | SNMP_ASN1_CONSTR | SNMP_ASN1_PDU_TRAP));
00569   ofs += 1;
00570   snmp_asn1_enc_length(p, ofs, m_trap->thl.pdulen);
00571   ofs += m_trap->thl.pdulenlen;
00572 
00573   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID));
00574   ofs += 1;
00575   snmp_asn1_enc_length(p, ofs, m_trap->thl.eidlen);
00576   ofs += m_trap->thl.eidlenlen;
00577   snmp_asn1_enc_oid(p, ofs, m_trap->enterprise->len, &m_trap->enterprise->id[0]);
00578   ofs += m_trap->thl.eidlen;
00579 
00580   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR));
00581   ofs += 1;
00582   snmp_asn1_enc_length(p, ofs, m_trap->thl.aaddrlen);
00583   ofs += m_trap->thl.aaddrlenlen;
00584   snmp_asn1_enc_raw(p, ofs, m_trap->thl.aaddrlen, &m_trap->sip_raw[0]);
00585   ofs += m_trap->thl.aaddrlen;
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.gtrplen);
00590   ofs += m_trap->thl.gtrplenlen;
00591   snmp_asn1_enc_u32t(p, ofs, m_trap->thl.gtrplen, m_trap->gen_trap);
00592   ofs += m_trap->thl.gtrplen;
00593 
00594   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG));
00595   ofs += 1;
00596   snmp_asn1_enc_length(p, ofs, m_trap->thl.strplen);
00597   ofs += m_trap->thl.strplenlen;
00598   snmp_asn1_enc_u32t(p, ofs, m_trap->thl.strplen, m_trap->spc_trap);
00599   ofs += m_trap->thl.strplen;
00600 
00601   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_TIMETICKS));
00602   ofs += 1;
00603   snmp_asn1_enc_length(p, ofs, m_trap->thl.tslen);
00604   ofs += m_trap->thl.tslenlen;
00605   snmp_asn1_enc_u32t(p, ofs, m_trap->thl.tslen, m_trap->ts);
00606   ofs += m_trap->thl.tslen;
00607 
00608   return ofs;
00609 }
00610 
00611 /**
00612  * Encodes varbind list from head to tail.
00613  */
00614 static u16_t
00615 snmp_varbind_list_enc(struct snmp_varbind_root *root, struct pbuf *p, u16_t ofs)
00616 {
00617   struct snmp_varbind *vb;
00618   s32_t *sint_ptr;
00619   u32_t *uint_ptr;
00620   u8_t *raw_ptr;
00621 
00622   snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ));
00623   ofs += 1;
00624   snmp_asn1_enc_length(p, ofs, root->seqlen);
00625   ofs += root->seqlenlen;
00626 
00627   vb = root->head;
00628   while ( vb != NULL )
00629   {
00630     snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_CONSTR | SNMP_ASN1_SEQ));
00631     ofs += 1;
00632     snmp_asn1_enc_length(p, ofs, vb->seqlen);
00633     ofs += vb->seqlenlen;
00634 
00635     snmp_asn1_enc_type(p, ofs, (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID));
00636     ofs += 1;
00637     snmp_asn1_enc_length(p, ofs, vb->olen);
00638     ofs += vb->olenlen;
00639     snmp_asn1_enc_oid(p, ofs, vb->ident_len, &vb->ident[0]);
00640     ofs += vb->olen;
00641 
00642     snmp_asn1_enc_type(p, ofs, vb->value_type);
00643     ofs += 1;
00644     snmp_asn1_enc_length(p, ofs, vb->vlen);
00645     ofs += vb->vlenlen;
00646 
00647     switch (vb->value_type)
00648     {
00649       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_INTEG):
00650         sint_ptr = (s32_t*)vb->value;
00651         snmp_asn1_enc_s32t(p, ofs, vb->vlen, *sint_ptr);
00652         break;
00653       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_COUNTER):
00654       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_GAUGE):
00655       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_TIMETICKS):
00656         uint_ptr = (u32_t*)vb->value;
00657         snmp_asn1_enc_u32t(p, ofs, vb->vlen, *uint_ptr);
00658         break;
00659       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OC_STR):
00660       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_IPADDR):
00661       case (SNMP_ASN1_APPLIC | SNMP_ASN1_PRIMIT | SNMP_ASN1_OPAQUE):
00662         raw_ptr = (u8_t*)vb->value;
00663         snmp_asn1_enc_raw(p, ofs, vb->vlen, raw_ptr);
00664         break;
00665       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_NUL):
00666         break;
00667       case (SNMP_ASN1_UNIV | SNMP_ASN1_PRIMIT | SNMP_ASN1_OBJ_ID):
00668         sint_ptr = (s32_t*)vb->value;
00669         snmp_asn1_enc_oid(p, ofs, vb->value_len / sizeof(s32_t), sint_ptr);
00670         break;
00671       default:
00672         /* unsupported type */
00673         break;
00674     };
00675     ofs += vb->vlen;
00676     vb = vb->next;
00677   }
00678   return ofs;
00679 }
00680 
00681 #endif /* LWIP_SNMP */