415 lines
10 KiB
C
415 lines
10 KiB
C
/*
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* Copyright (c) 1996 by Internet Software Consortium.
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
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* ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
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* CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
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* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
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* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
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* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
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* SOFTWARE.
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*/
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/*
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* Based on the Dynamic DNS reference implementation by Viraj Bais
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* <viraj_bais@ccm.fm.intel.com>
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*/
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#if !defined(lint) && !defined(SABER)
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static char rcsid[] = "$Id: res_mkupdate.c,v 1.11 1998/01/26 23:08:45 halley Exp $";
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#endif /* not lint */
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#include <sys/types.h>
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#include <sys/param.h>
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#include <netinet/in.h>
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#include <arpa/nameser.h>
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#include <arpa/inet.h>
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#include <errno.h>
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#include <limits.h>
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#include <netdb.h>
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#include <resolv.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <ctype.h>
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#include "res_config.h"
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static int getnum_str(u_char **, u_char *);
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static int getword_str(char *, int, u_char **, u_char *);
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#define ShrinkBuffer(x) if ((buflen -= x) < 0) return (-2);
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/*
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* Form update packets.
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* Returns the size of the resulting packet if no error
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* On error,
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* returns -1 if error in reading a word/number in rdata
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* portion for update packets
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* -2 if length of buffer passed is insufficient
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* -3 if zone section is not the first section in
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* the linked list, or section order has a problem
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* -4 on a number overflow
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* -5 unknown operation or no records
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*/
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int
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res_mkupdate(ns_updrec *rrecp_in, u_char *buf, int buflen) {
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ns_updrec *rrecp_start = rrecp_in;
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HEADER *hp;
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u_char c, *cp, *cp1, *sp1, *sp2, *startp, *endp;
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int n, i, j, found, soanum, multiline;
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ns_updrec *rrecp, *tmprrecp, *recptr = NULL;
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struct in_addr ina;
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char buf2[MAXDNAME];
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int section, numrrs = 0, counts[ns_s_max];
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u_int16_t rtype, rclass;
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u_int32_t n1, rttl;
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u_char *dnptrs[20], **dpp, **lastdnptr;
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if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
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h_errno = NETDB_INTERNAL;
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return (-1);
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}
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/*
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* Initialize header fields.
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*/
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if ((buf == NULL) || (buflen < HFIXEDSZ))
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return (-1);
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memset(buf, 0, HFIXEDSZ);
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hp = (HEADER *) buf;
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hp->id = htons(++_res.id);
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hp->opcode = ns_o_update;
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hp->rcode = NOERROR;
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sp1 = buf + 2*INT16SZ; /* save pointer to zocount */
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cp = buf + HFIXEDSZ;
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buflen -= HFIXEDSZ;
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dpp = dnptrs;
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*dpp++ = buf;
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*dpp++ = NULL;
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lastdnptr = dnptrs + sizeof dnptrs / sizeof dnptrs[0];
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if (rrecp_start == NULL)
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return (-5);
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else if (rrecp_start->r_section != S_ZONE)
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return (-3);
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memset(counts, 0, sizeof counts);
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for (rrecp = rrecp_start; rrecp; rrecp = rrecp->r_grpnext) {
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numrrs++;
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section = rrecp->r_section;
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if (section < 0 || section >= ns_s_max)
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return (-1);
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counts[section]++;
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for (i = section + 1; i < ns_s_max; i++)
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if (counts[i])
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return (-3);
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rtype = rrecp->r_type;
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rclass = rrecp->r_class;
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rttl = rrecp->r_ttl;
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/* overload class and type */
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if (section == S_PREREQ) {
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rttl = 0;
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switch (rrecp->r_opcode) {
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case YXDOMAIN:
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rclass = C_ANY;
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rtype = T_ANY;
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rrecp->r_size = 0;
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break;
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case NXDOMAIN:
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rclass = C_NONE;
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rtype = T_ANY;
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rrecp->r_size = 0;
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break;
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case NXRRSET:
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rclass = C_NONE;
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rrecp->r_size = 0;
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break;
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case YXRRSET:
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if (rrecp->r_size == 0)
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rclass = C_ANY;
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break;
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default:
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fprintf(stderr,
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"res_mkupdate: incorrect opcode: %d\n",
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rrecp->r_opcode);
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fflush(stderr);
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return (-1);
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}
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} else if (section == S_UPDATE) {
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switch (rrecp->r_opcode) {
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case DELETE:
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rclass = rrecp->r_size == 0 ? C_ANY : C_NONE;
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break;
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case ADD:
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break;
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default:
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fprintf(stderr,
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"res_mkupdate: incorrect opcode: %d\n",
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rrecp->r_opcode);
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fflush(stderr);
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return (-1);
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}
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}
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/*
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* XXX appending default domain to owner name is omitted,
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* fqdn must be provided
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*/
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if ((n = dn_comp(rrecp->r_dname, cp, buflen, dnptrs,
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lastdnptr)) < 0)
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return (-1);
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cp += n;
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ShrinkBuffer(n + 2*INT16SZ);
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PUTSHORT(rtype, cp);
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PUTSHORT(rclass, cp);
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if (section == S_ZONE) {
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if (numrrs != 1 || rrecp->r_type != T_SOA)
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return (-3);
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continue;
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}
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ShrinkBuffer(INT32SZ + INT16SZ);
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PUTLONG(rttl, cp);
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sp2 = cp; /* save pointer to length byte */
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cp += INT16SZ;
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if (rrecp->r_size == 0) {
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if (section == S_UPDATE && rclass != C_ANY)
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return (-1);
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else {
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PUTSHORT(0, sp2);
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continue;
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}
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}
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startp = rrecp->r_data;
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endp = startp + rrecp->r_size - 1;
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/* XXX this should be done centrally. */
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switch (rrecp->r_type) {
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case T_A:
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if (!getword_str(buf2, sizeof buf2, &startp, endp))
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return (-1);
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if (!inet_aton(buf2, &ina))
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return (-1);
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n1 = ntohl(ina.s_addr);
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ShrinkBuffer(INT32SZ);
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PUTLONG(n1, cp);
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break;
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case T_CNAME:
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case T_MB:
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case T_MG:
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case T_MR:
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case T_NS:
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case T_PTR:
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if (!getword_str(buf2, sizeof buf2, &startp, endp))
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return (-1);
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n = dn_comp(buf2, cp, buflen, dnptrs, lastdnptr);
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if (n < 0)
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return (-1);
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cp += n;
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ShrinkBuffer(n);
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break;
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case T_MINFO:
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case T_SOA:
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case T_RP:
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for (i = 0; i < 2; i++) {
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if (!getword_str(buf2, sizeof buf2, &startp,
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endp))
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return (-1);
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n = dn_comp(buf2, cp, buflen,
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dnptrs, lastdnptr);
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if (n < 0)
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return (-1);
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cp += n;
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ShrinkBuffer(n);
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}
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if (rrecp->r_type == T_SOA) {
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ShrinkBuffer(5 * INT32SZ);
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while (isspace(*startp) || !*startp)
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startp++;
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if (*startp == '(') {
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multiline = 1;
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startp++;
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} else
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multiline = 0;
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/* serial, refresh, retry, expire, minimum */
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for (i = 0; i < 5; i++) {
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soanum = getnum_str(&startp, endp);
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if (soanum < 0)
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return (-1);
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PUTLONG(soanum, cp);
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}
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if (multiline) {
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while (isspace(*startp) || !*startp)
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startp++;
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if (*startp != ')')
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return (-1);
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}
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}
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break;
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case T_MX:
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case T_AFSDB:
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case T_RT:
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n = getnum_str(&startp, endp);
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if (n < 0)
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return (-1);
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PUTSHORT(n, cp);
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ShrinkBuffer(INT16SZ);
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if (!getword_str(buf2, sizeof buf2, &startp, endp))
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return (-1);
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n = dn_comp(buf2, cp, buflen, dnptrs, lastdnptr);
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if (n < 0)
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return (-1);
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cp += n;
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ShrinkBuffer(n);
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break;
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case T_PX:
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n = getnum_str(&startp, endp);
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if (n < 0)
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return (-1);
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PUTSHORT(n, cp);
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ShrinkBuffer(INT16SZ);
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for (i = 0; i < 2; i++) {
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if (!getword_str(buf2, sizeof buf2, &startp,
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endp))
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return (-1);
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n = dn_comp(buf2, cp, buflen, dnptrs,
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lastdnptr);
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if (n < 0)
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return (-1);
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cp += n;
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ShrinkBuffer(n);
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}
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break;
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case T_WKS:
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case T_HINFO:
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case T_TXT:
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case T_X25:
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case T_ISDN:
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case T_NSAP:
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case T_LOC:
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/* XXX - more fine tuning needed here */
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ShrinkBuffer(rrecp->r_size);
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memcpy(cp, rrecp->r_data, rrecp->r_size);
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cp += rrecp->r_size;
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break;
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default:
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return (-1);
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} /*switch*/
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n = (u_int16_t)((cp - sp2) - INT16SZ);
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PUTSHORT(n, sp2);
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} /*for*/
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hp->qdcount = htons(counts[0]);
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hp->ancount = htons(counts[1]);
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hp->nscount = htons(counts[2]);
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hp->arcount = htons(counts[3]);
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return (cp - buf);
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}
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/*
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* Get a whitespace delimited word from a string (not file)
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* into buf. modify the start pointer to point after the
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* word in the string.
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*/
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static int
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getword_str(char *buf, int size, u_char **startpp, u_char *endp) {
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char *cp;
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int c;
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for (cp = buf; *startpp <= endp; ) {
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c = **startpp;
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if (isspace(c) || c == '\0') {
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if (cp != buf) /* trailing whitespace */
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break;
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else { /* leading whitespace */
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(*startpp)++;
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continue;
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}
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}
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(*startpp)++;
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if (cp >= buf+size-1)
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break;
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*cp++ = (u_char)c;
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}
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*cp = '\0';
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return (cp != buf);
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}
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/*
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* Get a whitespace delimited number from a string (not file) into buf
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* update the start pointer to point after the number in the string.
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*/
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static int
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getnum_str(u_char **startpp, u_char *endp) {
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int c, n;
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int seendigit = 0;
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int seendecimal = 0;
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int m = 0;
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for (n = 0; *startpp <= endp; ) {
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c = **startpp;
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if (isspace(c) || c == '\0') {
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if (seendigit) /* trailing whitespace */
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break;
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else { /* leading whitespace */
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(*startpp)++;
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continue;
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}
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}
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if (c == ';') {
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while ((*startpp <= endp) &&
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((c = **startpp) != '\n'))
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(*startpp)++;
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if (seendigit)
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break;
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continue;
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}
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if (!isdigit(c)) {
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if (c == ')' && seendigit) {
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(*startpp)--;
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break;
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}
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return (-1);
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}
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(*startpp)++;
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n = n * 10 + (c - '0');
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seendigit = 1;
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}
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return (n + m);
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}
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/*
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* Allocate a resource record buffer & save rr info.
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*/
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ns_updrec *
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res_mkupdrec(int section, const char *dname,
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u_int class, u_int type, u_long ttl) {
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ns_updrec *rrecp = (ns_updrec *)calloc(1, sizeof(ns_updrec));
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if (!rrecp || !(rrecp->r_dname = strdup(dname)))
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return (NULL);
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rrecp->r_class = class;
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rrecp->r_type = type;
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rrecp->r_ttl = ttl;
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rrecp->r_section = section;
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return (rrecp);
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}
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/*
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* Free a resource record buffer created by res_mkupdrec.
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*/
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void
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res_freeupdrec(ns_updrec *rrecp) {
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/* Note: freeing r_dp is the caller's responsibility. */
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if (rrecp->r_dname != NULL)
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free(rrecp->r_dname);
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free(rrecp);
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}
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