dundi-parser.c

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/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Digium, Inc.
 *
 * Mark Spencer <markster@digium.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief Distributed Universal Number Discovery (DUNDi)
 *
 */

/*** MODULEINFO
   <support_level>extended</support_level>
 ***/

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision: 369013 $")

#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#include "asterisk/frame.h"
#include "asterisk/utils.h"
#include "asterisk/dundi.h"
#include "dundi-parser.h"

static void internaloutput(const char *str)
{
   fputs(str, stdout);
}

static void internalerror(const char *str)
{
   fprintf(stderr, "WARNING: %s", str);
}

static void (*outputf)(const char *str) = internaloutput;
static void (*errorf)(const char *str) = internalerror;

char *dundi_eid_to_str_short(char *s, int maxlen, dundi_eid *eid)
{
   int x;
   char *os = s;
   if (maxlen < 13) {
      if (s && (maxlen > 0))
         *s = '\0';
   } else {
      for (x=0;x<6;x++) {
         sprintf(s, "%02X", eid->eid[x]);
         s += 2;
      }
   }
   return os;
}

int dundi_str_short_to_eid(dundi_eid *eid, const char *s)
{
   unsigned int eid_int[6];
   int x;
   if (sscanf(s, "%2x%2x%2x%2x%2x%2x", &eid_int[0], &eid_int[1], &eid_int[2],
       &eid_int[3], &eid_int[4], &eid_int[5]) != 6)
         return -1;
   for (x = 0; x < 6; x++)
      eid->eid[x] = eid_int[x];
   return 0;
}

int dundi_eid_zero(dundi_eid *eid)
{
   int x;
   for (x = 0; x < ARRAY_LEN(eid->eid); x++)
      if (eid->eid[x]) return 0;
   return 1;
}

static void dump_string(char *output, int maxlen, void *value, int len)
{
   if (maxlen > len + 1)
      maxlen = len + 1;

   snprintf(output, maxlen, "%s", (char *) value);
}

static void dump_cbypass(char *output, int maxlen, void *value, int len)
{
   snprintf(output, maxlen, "Bypass Caches");
}

static void dump_eid(char *output, int maxlen, void *value, int len)
{
   if (len == 6)
      ast_eid_to_str(output, maxlen, (dundi_eid *)value);
   else
      snprintf(output, maxlen, "Invalid EID len %d", len);
}

char *dundi_hint2str(char *buf, int bufsiz, int flags)
{
   strcpy(buf, "");
   buf[bufsiz-1] = '\0';
   if (flags & DUNDI_HINT_TTL_EXPIRED) {
      strncat(buf, "TTLEXPIRED|", bufsiz - strlen(buf) - 1);
   }
   if (flags & DUNDI_HINT_DONT_ASK) {
      strncat(buf, "DONTASK|", bufsiz - strlen(buf) - 1);
   }
   if (flags & DUNDI_HINT_UNAFFECTED) {
      strncat(buf, "UNAFFECTED|", bufsiz - strlen(buf) - 1);
   }
   /* Get rid of trailing | */
   if (ast_strlen_zero(buf))
      strcpy(buf, "NONE|");
   buf[strlen(buf)-1] = '\0';
   return buf;
}

static void dump_hint(char *output, int maxlen, void *value, int len)
{
   char tmp2[256];
   char tmp3[256];
   int datalen;
   struct dundi_hint *hint;
   if (len < sizeof(*hint)) {
      snprintf(output, maxlen, "<invalid contents>");
      return;
   }

   hint = (struct dundi_hint *) value;;

   datalen = len - offsetof(struct dundi_hint, data);
   if (datalen > sizeof(tmp3) - 1)
      datalen = sizeof(tmp3) - 1;

   memcpy(tmp3, hint->data, datalen);
   tmp3[datalen] = '\0';

   dundi_hint2str(tmp2, sizeof(tmp2), ntohs(hint->flags));

   if (ast_strlen_zero(tmp3))
      snprintf(output, maxlen, "[%s]", tmp2);
   else
      snprintf(output, maxlen, "[%s] %s", tmp2, tmp3);
}

static void dump_cause(char *output, int maxlen, void *value, int len)
{
   static const char * const causes[] = {
      "SUCCESS",
      "GENERAL",
      "DYNAMIC",
      "NOAUTH" ,
      };
   char tmp2[256];
   struct dundi_cause *cause;
   int datalen;
   int causecode;

   if (len < sizeof(*cause)) {
      snprintf(output, maxlen, "<invalid contents>");
      return;
   }

   cause = (struct dundi_cause*) value;
   causecode = cause->causecode;

   datalen = len - offsetof(struct dundi_cause, desc);
   if (datalen > sizeof(tmp2) - 1)
      datalen = sizeof(tmp2) - 1;

   memcpy(tmp2, cause->desc, datalen);
   tmp2[datalen] = '\0';

   if (causecode < ARRAY_LEN(causes)) {
      if (ast_strlen_zero(tmp2))
         snprintf(output, maxlen, "%s", causes[causecode]);
      else
         snprintf(output, maxlen, "%s: %s", causes[causecode], tmp2);
   } else {
      if (ast_strlen_zero(tmp2))
         snprintf(output, maxlen, "%d", causecode);
      else
         snprintf(output, maxlen, "%d: %s", causecode, tmp2);
   }
}

static void dump_int(char *output, int maxlen, void *value, int len)
{
   if (len == (int)sizeof(unsigned int))
      snprintf(output, maxlen, "%lu", (unsigned long)ntohl(*((unsigned int *)value)));
   else
      ast_copy_string(output, "Invalid INT", maxlen);
}

static void dump_short(char *output, int maxlen, void *value, int len)
{
   if (len == (int)sizeof(unsigned short))
      snprintf(output, maxlen, "%d", ntohs(*((unsigned short *)value)));
   else
      ast_copy_string(output, "Invalid SHORT", maxlen);
}

static void dump_byte(char *output, int maxlen, void *value, int len)
{
   if (len == (int)sizeof(unsigned char))
      snprintf(output, maxlen, "%d", *((unsigned char *)value));
   else
      ast_copy_string(output, "Invalid BYTE", maxlen);
}

static char *proto2str(int proto, char *buf, int bufsiz)
{  
   switch(proto) {
   case DUNDI_PROTO_NONE:
      strncpy(buf, "None", bufsiz - 1);
      break;
   case DUNDI_PROTO_IAX:
      strncpy(buf, "IAX", bufsiz - 1);
      break;
   case DUNDI_PROTO_SIP:
      strncpy(buf, "SIP", bufsiz - 1);
      break;
   case DUNDI_PROTO_H323:
      strncpy(buf, "H.323", bufsiz - 1);
      break;
   default:
      snprintf(buf, bufsiz, "Unknown Proto(%d)", proto);
   }
   buf[bufsiz-1] = '\0';
   return buf;
}

char *dundi_flags2str(char *buf, int bufsiz, int flags)
{
   strcpy(buf, "");
   buf[bufsiz-1] = '\0';
   if (flags & DUNDI_FLAG_EXISTS) {
      strncat(buf, "EXISTS|", bufsiz - strlen(buf) - 1);
   }
   if (flags & DUNDI_FLAG_MATCHMORE) {
      strncat(buf, "MATCHMORE|", bufsiz - strlen(buf) - 1);
   }
   if (flags & DUNDI_FLAG_CANMATCH) {
      strncat(buf, "CANMATCH|", bufsiz - strlen(buf) - 1);
   }
   if (flags & DUNDI_FLAG_IGNOREPAT) {
      strncat(buf, "IGNOREPAT|", bufsiz - strlen(buf) - 1);
   }
   if (flags & DUNDI_FLAG_RESIDENTIAL) {
      strncat(buf, "RESIDENCE|", bufsiz - strlen(buf) - 1);
   }
   if (flags & DUNDI_FLAG_COMMERCIAL) {
      strncat(buf, "COMMERCIAL|", bufsiz - strlen(buf) - 1);
   }
   if (flags & DUNDI_FLAG_MOBILE) {
      strncat(buf, "MOBILE", bufsiz - strlen(buf) - 1);
   }
   if (flags & DUNDI_FLAG_NOUNSOLICITED) {
      strncat(buf, "NOUNSLCTD|", bufsiz - strlen(buf) - 1);
   }
   if (flags & DUNDI_FLAG_NOCOMUNSOLICIT) {
      strncat(buf, "NOCOMUNSLTD|", bufsiz - strlen(buf) - 1);
   }
   /* Get rid of trailing | */
   if (ast_strlen_zero(buf))
      strcpy(buf, "NONE|");
   buf[strlen(buf)-1] = '\0';
   return buf;
}

static void dump_answer(char *output, int maxlen, void *value, int len)
{
   struct dundi_answer *answer;
   char proto[40];
   char flags[40];
   char eid_str[40];
   char tmp[512]="";
   int datalen;

   if (len < sizeof(*answer)) {
      snprintf(output, maxlen, "Invalid Answer");
      return;
   }

   answer = (struct dundi_answer *)(value);

   datalen = len - offsetof(struct dundi_answer, data);
   if (datalen > sizeof(tmp) - 1)
      datalen = sizeof(tmp) - 1;

   memcpy(tmp, answer->data, datalen);
   tmp[datalen] = '\0';

   ast_eid_to_str(eid_str, sizeof(eid_str), &answer->eid);
   snprintf(output, maxlen, "[%s] %d <%s/%s> from [%s]", 
      dundi_flags2str(flags, sizeof(flags), ntohs(answer->flags)), 
      ntohs(answer->weight),
      proto2str(answer->protocol, proto, sizeof(proto)), 
         tmp, eid_str);
}

static void dump_encrypted(char *output, int maxlen, void *value, int len)
{
   char iv[33];
   int x;
   if ((len > 16) && !(len % 16)) {
      /* Build up IV */
      for (x=0;x<16;x++) {
         snprintf(iv + (x << 1), 3, "%02x", ((unsigned char *)value)[x]);
      }
      snprintf(output, maxlen, "[IV %s] %d encrypted blocks\n", iv, len / 16);
   } else
      snprintf(output, maxlen, "Invalid Encrypted Datalen %d", len);
}

static void dump_raw(char *output, int maxlen, void *value, int len)
{
   int x;
   unsigned char *u = value;
   output[maxlen - 1] = '\0';
   strcpy(output, "[ ");
   for (x=0;x<len;x++) {
      snprintf(output + strlen(output), maxlen - strlen(output) - 1, "%02x ", u[x]);
   }
   strncat(output + strlen(output), "]", maxlen - strlen(output) - 1);
}

static struct dundi_ie {
   int ie;
   char *name;
   void (*dump)(char *output, int maxlen, void *value, int len);
} infoelts[] = {
   { DUNDI_IE_EID, "ENTITY IDENT", dump_eid },
   { DUNDI_IE_CALLED_CONTEXT, "CALLED CONTEXT", dump_string },
   { DUNDI_IE_CALLED_NUMBER, "CALLED NUMBER", dump_string },
   { DUNDI_IE_EID_DIRECT, "DIRECT EID", dump_eid },
   { DUNDI_IE_ANSWER, "ANSWER", dump_answer },
   { DUNDI_IE_TTL, "TTL", dump_short },
   { DUNDI_IE_VERSION, "VERSION", dump_short },
   { DUNDI_IE_EXPIRATION, "EXPIRATION", dump_short },
   { DUNDI_IE_UNKNOWN, "UKWN DUNDI CMD", dump_byte },
   { DUNDI_IE_CAUSE, "CAUSE", dump_cause },
   { DUNDI_IE_REQEID, "REQUEST EID", dump_eid },
   { DUNDI_IE_ENCDATA, "ENCDATA", dump_encrypted },
   { DUNDI_IE_SHAREDKEY, "SHAREDKEY", dump_raw },
   { DUNDI_IE_SIGNATURE, "SIGNATURE", dump_raw },
   { DUNDI_IE_KEYCRC32, "KEYCRC32", dump_int },
   { DUNDI_IE_HINT, "HINT", dump_hint },
   { DUNDI_IE_DEPARTMENT, "DEPARTMENT", dump_string },
   { DUNDI_IE_ORGANIZATION, "ORGANIZTN", dump_string },
   { DUNDI_IE_LOCALITY, "LOCALITY", dump_string },
   { DUNDI_IE_STATE_PROV, "STATEPROV", dump_string },
   { DUNDI_IE_COUNTRY, "COUNTRY", dump_string },
   { DUNDI_IE_EMAIL, "EMAIL", dump_string },
   { DUNDI_IE_PHONE, "PHONE", dump_string },
   { DUNDI_IE_IPADDR, "ADDRESS", dump_string },
   { DUNDI_IE_CACHEBYPASS, "CBYPASS", dump_cbypass },
};

const char *dundi_ie2str(int ie)
{
   int x;
   for (x = 0; x < ARRAY_LEN(infoelts); x++) {
      if (infoelts[x].ie == ie)
         return infoelts[x].name;
   }
   return "Unknown IE";
}

static void dump_ies(unsigned char *iedata, int spaces, int len)
{
   int ielen;
   int ie;
   int x;
   int found;
   char interp[1024];
   char tmp[1024];
   if (len < 2)
      return;
   while(len >= 2) {
      ie = iedata[0];
      ielen = iedata[1];
      /* Encrypted data is the remainder */
      if (ie == DUNDI_IE_ENCDATA)
         ielen = len - 2;
      if (ielen + 2> len) {
         snprintf(tmp, (int)sizeof(tmp), "Total IE length of %d bytes exceeds remaining frame length of %d bytes\n", ielen + 2, len);
         outputf(tmp);
         return;
      }
      found = 0;
      for (x = 0; x < ARRAY_LEN(infoelts); x++) {
         if (infoelts[x].ie == ie) {
            if (infoelts[x].dump) {
               infoelts[x].dump(interp, (int)sizeof(interp), iedata + 2, ielen);
               snprintf(tmp, (int)sizeof(tmp), "   %s%-15.15s : %s\n", (spaces ? "     " : "" ), infoelts[x].name, interp);
               outputf(tmp);
            } else {
               if (ielen)
                  snprintf(interp, (int)sizeof(interp), "%d bytes", ielen);
               else
                  strcpy(interp, "Present");
               snprintf(tmp, (int)sizeof(tmp), "   %s%-15.15s : %s\n", (spaces ? "     " : "" ), infoelts[x].name, interp);
               outputf(tmp);
            }
            found++;
         }
      }
      if (!found) {
         snprintf(tmp, (int)sizeof(tmp), "   %sUnknown IE %03d  : Present\n", (spaces ? "     " : "" ), ie);
         outputf(tmp);
      }
      iedata += (2 + ielen);
      len -= (2 + ielen);
   }
   outputf("\n");
}

void dundi_showframe(struct dundi_hdr *fhi, int rx, struct sockaddr_in *sin, int datalen)
{
   char *pref[] = {
      "Tx",
      "Rx",
      "    ETx",
      "    Erx" };
   char *commands[] = {
      "ACK         ",
      "DPDISCOVER  ",
      "DPRESPONSE  ",
      "EIDQUERY    ",
      "EIDRESPONSE ",
      "PRECACHERQ  ",
      "PRECACHERP  ",
      "INVALID     ",
      "UNKNOWN CMD ",
      "NULL        ",
      "REQREQ      ",
      "REGRESPONSE ",
      "CANCEL      ",
      "ENCRYPT     ",
      "ENCREJ      " };
   char class2[20];
   char *class;
   char subclass2[20];
   char *subclass;
   char tmp[256];
   if ((fhi->cmdresp & 0x3f) > (int)sizeof(commands)/(int)sizeof(char *)) {
      snprintf(class2, (int)sizeof(class2), "(%d?)", fhi->cmdresp);
      class = class2;
   } else {
      class = commands[(int)(fhi->cmdresp & 0x3f)];
   }
   snprintf(subclass2, (int)sizeof(subclass2), "%02x", fhi->cmdflags);
   subclass = subclass2;
   snprintf(tmp, (int)sizeof(tmp), 
      "%s-Frame -- OSeqno: %3.3d ISeqno: %3.3d Type: %s (%s)\n",
      pref[rx],
      fhi->oseqno, fhi->iseqno, class, fhi->cmdresp & 0x40 ? "Response" : "Command");
   outputf(tmp);
   snprintf(tmp, (int)sizeof(tmp), 
      "%s     Flags: %s STrans: %5.5d  DTrans: %5.5d [%s:%d]%s\n", (rx > 1) ? "     " : "",
      subclass, ntohs(fhi->strans) & ~DUNDI_FLAG_RESERVED, ntohs(fhi->dtrans) & ~DUNDI_FLAG_RETRANS,
      ast_inet_ntoa(sin->sin_addr), ntohs(sin->sin_port),
      fhi->cmdresp & 0x80 ? " (Final)" : "");
   outputf(tmp);
   dump_ies(fhi->ies, rx > 1, datalen);
}

int dundi_ie_append_raw(struct dundi_ie_data *ied, unsigned char ie, void *data, int datalen)
{
   char tmp[256];
   if (datalen > ((int)sizeof(ied->buf) - ied->pos)) {
      snprintf(tmp, (int)sizeof(tmp), "Out of space for ie '%s' (%d), need %d have %d\n", dundi_ie2str(ie), ie, datalen, (int)sizeof(ied->buf) - ied->pos);
      errorf(tmp);
      return -1;
   }
   ied->buf[ied->pos++] = ie;
   ied->buf[ied->pos++] = datalen;
   memcpy(ied->buf + ied->pos, data, datalen);
   ied->pos += datalen;
   return 0;
}

int dundi_ie_append_cause(struct dundi_ie_data *ied, unsigned char ie, unsigned char cause, char *data)
{
   char tmp[256];
   int datalen = data ? strlen(data) + 1 : 1;
   if (datalen > ((int)sizeof(ied->buf) - ied->pos)) {
      snprintf(tmp, (int)sizeof(tmp), "Out of space for ie '%s' (%d), need %d have %d\n", dundi_ie2str(ie), ie, datalen, (int)sizeof(ied->buf) - ied->pos);
      errorf(tmp);
      return -1;
   }
   ied->buf[ied->pos++] = ie;
   ied->buf[ied->pos++] = datalen;
   ied->buf[ied->pos++] = cause;
   if (data) {
      memcpy(ied->buf + ied->pos, data, datalen-1);
      ied->pos += datalen-1;
   }
   return 0;
}

int dundi_ie_append_hint(struct dundi_ie_data *ied, unsigned char ie, unsigned short flags, char *data)
{
   char tmp[256];
   int datalen = data ? strlen(data) + 2 : 2;
   if (datalen > ((int)sizeof(ied->buf) - ied->pos)) {
      snprintf(tmp, (int)sizeof(tmp), "Out of space for ie '%s' (%d), need %d have %d\n", dundi_ie2str(ie), ie, datalen, (int)sizeof(ied->buf) - ied->pos);
      errorf(tmp);
      return -1;
   }
   ied->buf[ied->pos++] = ie;
   ied->buf[ied->pos++] = datalen;
   flags = htons(flags);
   memcpy(ied->buf + ied->pos, &flags, sizeof(flags));
   ied->pos += 2;
   if (data) {
      memcpy(ied->buf + ied->pos, data, datalen-2);
      ied->pos += datalen-2;
   }
   return 0;
}

int dundi_ie_append_encdata(struct dundi_ie_data *ied, unsigned char ie, unsigned char *iv, void *data, int datalen)
{
   char tmp[256];
   datalen += 16;
   if (datalen > ((int)sizeof(ied->buf) - ied->pos)) {
      snprintf(tmp, (int)sizeof(tmp), "Out of space for ie '%s' (%d), need %d have %d\n", dundi_ie2str(ie), ie, datalen, (int)sizeof(ied->buf) - ied->pos);
      errorf(tmp);
      return -1;
   }
   ied->buf[ied->pos++] = ie;
   ied->buf[ied->pos++] = datalen;
   memcpy(ied->buf + ied->pos, iv, 16);
   ied->pos += 16;
   if (data) {
      memcpy(ied->buf + ied->pos, data, datalen-16);
      ied->pos += datalen-16;
   }
   return 0;
}

int dundi_ie_append_answer(struct dundi_ie_data *ied, unsigned char ie, dundi_eid *eid, unsigned char protocol, unsigned short flags, unsigned short weight, char *data)
{
   char tmp[256];
   int datalen = data ? strlen(data) + 11 : 11;
   int x;
   unsigned short myw;
   if (datalen > ((int)sizeof(ied->buf) - ied->pos)) {
      snprintf(tmp, (int)sizeof(tmp), "Out of space for ie '%s' (%d), need %d have %d\n", dundi_ie2str(ie), ie, datalen, (int)sizeof(ied->buf) - ied->pos);
      errorf(tmp);
      return -1;
   }
   ied->buf[ied->pos++] = ie;
   ied->buf[ied->pos++] = datalen;
   for (x=0;x<6;x++)
      ied->buf[ied->pos++] = eid->eid[x];
   ied->buf[ied->pos++] = protocol;
   myw = htons(flags);
   memcpy(ied->buf + ied->pos, &myw, 2);
   ied->pos += 2;
   myw = htons(weight);
   memcpy(ied->buf + ied->pos, &myw, 2);
   ied->pos += 2;
   memcpy(ied->buf + ied->pos, data, datalen-11);
   ied->pos += datalen-11;
   return 0;
}

int dundi_ie_append_addr(struct dundi_ie_data *ied, unsigned char ie, struct sockaddr_in *sin)
{
   return dundi_ie_append_raw(ied, ie, sin, (int)sizeof(struct sockaddr_in));
}

int dundi_ie_append_int(struct dundi_ie_data *ied, unsigned char ie, unsigned int value) 
{
   unsigned int newval;
   newval = htonl(value);
   return dundi_ie_append_raw(ied, ie, &newval, (int)sizeof(newval));
}

int dundi_ie_append_short(struct dundi_ie_data *ied, unsigned char ie, unsigned short value) 
{
   unsigned short newval;
   newval = htons(value);
   return dundi_ie_append_raw(ied, ie, &newval, (int)sizeof(newval));
}

int dundi_ie_append_str(struct dundi_ie_data *ied, unsigned char ie, char *str)
{
   return dundi_ie_append_raw(ied, ie, str, strlen(str));
}

int dundi_ie_append_eid(struct dundi_ie_data *ied, unsigned char ie, dundi_eid *eid)
{
   return dundi_ie_append_raw(ied, ie, (unsigned char *)eid, sizeof(dundi_eid));
}

int dundi_ie_append_byte(struct dundi_ie_data *ied, unsigned char ie, unsigned char dat)
{
   return dundi_ie_append_raw(ied, ie, &dat, 1);
}

int dundi_ie_append(struct dundi_ie_data *ied, unsigned char ie) 
{
   return dundi_ie_append_raw(ied, ie, NULL, 0);
}

void dundi_set_output(void (*func)(const char *))
{
   outputf = func;
}

void dundi_set_error(void (*func)(const char *))
{
   errorf = func;
}

int dundi_parse_ies(struct dundi_ies *ies, unsigned char *data, int datalen)
{
   /* Parse data into information elements */
   int len;
   int ie;
   char tmp[256];
   memset(ies, 0, (int)sizeof(struct dundi_ies));
   ies->ttl = -1;
   ies->expiration = -1;
   ies->unknowncmd = -1;
   ies->cause = -1;
   while(datalen >= 2) {
      ie = data[0];
      len = data[1];
      if (len > datalen - 2) {
         errorf("Information element length exceeds message size\n");
         return -1;
      }
      switch(ie) {
      case DUNDI_IE_EID:
      case DUNDI_IE_EID_DIRECT:
         if (len != (int)sizeof(dundi_eid)) {
            errorf("Improper entity identifer, expecting 6 bytes!\n");
         } else if (ies->eidcount < DUNDI_MAX_STACK) {
            ies->eids[ies->eidcount] = (dundi_eid *)(data + 2);
            ies->eid_direct[ies->eidcount] = (ie == DUNDI_IE_EID_DIRECT);
            ies->eidcount++;
         } else
            errorf("Too many entities in stack!\n");
         break;
      case DUNDI_IE_REQEID:
         if (len != (int)sizeof(dundi_eid)) {
            errorf("Improper requested entity identifer, expecting 6 bytes!\n");
         } else
            ies->reqeid = (dundi_eid *)(data + 2);
         break;
      case DUNDI_IE_CALLED_CONTEXT:
         ies->called_context = (char *)data + 2;
         break;
      case DUNDI_IE_CALLED_NUMBER:
         ies->called_number = (char *)data + 2;
         break;
      case DUNDI_IE_ANSWER:
         if (len < sizeof(struct dundi_answer)) {
            snprintf(tmp, (int)sizeof(tmp), "Answer expected to be >=%d bytes long but was %d\n", (int)sizeof(struct dundi_answer), len);
            errorf(tmp);
         } else {
            if (ies->anscount < DUNDI_MAX_ANSWERS)
               ies->answers[ies->anscount++]= (struct dundi_answer *)(data + 2);
            else 
               errorf("Ignoring extra answers!\n");
         }
         break;
      case DUNDI_IE_TTL:
         if (len != (int)sizeof(unsigned short)) {
            snprintf(tmp, (int)sizeof(tmp), "Expecting ttl to be %d bytes long but was %d\n", (int)sizeof(unsigned short), len);
            errorf(tmp);
         } else
            ies->ttl = ntohs(*((unsigned short *)(data + 2)));
         break;
      case DUNDI_IE_VERSION:
         if (len != (int)sizeof(unsigned short)) {
            snprintf(tmp, (int)sizeof(tmp),  "Expecting version to be %d bytes long but was %d\n", (int)sizeof(unsigned short), len);
            errorf(tmp);
         } else
            ies->version = ntohs(*((unsigned short *)(data + 2)));
         break;
      case DUNDI_IE_EXPIRATION:
         if (len != (int)sizeof(unsigned short)) {
            snprintf(tmp, (int)sizeof(tmp),  "Expecting expiration to be %d bytes long but was %d\n", (int)sizeof(unsigned short), len);
            errorf(tmp);
         } else
            ies->expiration = ntohs(*((unsigned short *)(data + 2)));
         break;
      case DUNDI_IE_KEYCRC32:
         if (len != (int)sizeof(unsigned int)) {
            snprintf(tmp, (int)sizeof(tmp),  "Expecting expiration to be %d bytes long but was %d\n", (int)sizeof(unsigned int), len);
            errorf(tmp);
         } else
            ies->keycrc32 = ntohl(*((unsigned int *)(data + 2)));
         break;
      case DUNDI_IE_UNKNOWN:
         if (len == 1)
            ies->unknowncmd = data[2];
         else {
            snprintf(tmp, (int)sizeof(tmp), "Expected single byte Unknown command, but was %d long\n", len);
            errorf(tmp);
         }
         break;
      case DUNDI_IE_CAUSE:
         if (len >= 1) {
            ies->cause = data[2];
            ies->causestr = (char *)data + 3;
         } else {
            snprintf(tmp, (int)sizeof(tmp), "Expected at least one byte cause, but was %d long\n", len);
            errorf(tmp);
         }
         break;
      case DUNDI_IE_HINT:
         if (len >= 2) {
            ies->hint = (struct dundi_hint *)(data + 2);
         } else {
            snprintf(tmp, (int)sizeof(tmp), "Expected at least two byte hint, but was %d long\n", len);
            errorf(tmp);
         }
         break;
      case DUNDI_IE_DEPARTMENT:
         ies->q_dept = (char *)data + 2;
         break;
      case DUNDI_IE_ORGANIZATION:
         ies->q_org = (char *)data + 2;
         break;
      case DUNDI_IE_LOCALITY:
         ies->q_locality = (char *)data + 2;
         break;
      case DUNDI_IE_STATE_PROV:
         ies->q_stateprov = (char *)data + 2;
         break;
      case DUNDI_IE_COUNTRY:
         ies->q_country = (char *)data + 2;
         break;
      case DUNDI_IE_EMAIL:
         ies->q_email = (char *)data + 2;
         break;
      case DUNDI_IE_PHONE:
         ies->q_phone = (char *)data + 2;
         break;
      case DUNDI_IE_IPADDR:
         ies->q_ipaddr = (char *)data + 2;
         break;
      case DUNDI_IE_ENCDATA:
         /* Recalculate len as the remainder of the message, regardless of
            theoretical length */
         len = datalen - 2;
         if ((len > 16) && !(len % 16)) {
            ies->encblock = (struct dundi_encblock *)(data + 2);
            ies->enclen = len - 16;
         } else {
            snprintf(tmp, (int)sizeof(tmp), "Invalid encrypted data length %d\n", len);
            errorf(tmp);
         }
         break;
      case DUNDI_IE_SHAREDKEY:
         if (len == 128) {
            ies->encsharedkey = (unsigned char *)(data + 2);
         } else {
            snprintf(tmp, (int)sizeof(tmp), "Invalid encrypted shared key length %d\n", len);
            errorf(tmp);
         }
         break;
      case DUNDI_IE_SIGNATURE:
         if (len == 128) {
            ies->encsig = (unsigned char *)(data + 2);
         } else {
            snprintf(tmp, (int)sizeof(tmp), "Invalid encrypted signature length %d\n", len);
            errorf(tmp);
         }
         break;
      case DUNDI_IE_CACHEBYPASS:
         ies->cbypass = 1;
         break;
      default:
         snprintf(tmp, (int)sizeof(tmp), "Ignoring unknown information element '%s' (%d) of length %d\n", dundi_ie2str(ie), ie, len);
         outputf(tmp);
      }
      /* Overwrite information element with 0, to null terminate previous portion */
      data[0] = 0;
      datalen -= (len + 2);
      data += (len + 2);
   }
   /* Null-terminate last field */
   *data = '\0';
   if (datalen) {
      errorf("Invalid information element contents, strange boundary\n");
      return -1;
   }
   return 0;
}