521 lines
14 KiB
C
521 lines
14 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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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/socket.h>
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#include <sys/time.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#include <arpa/nameser.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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/*
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* Separate a linked list of records into groups so that all records
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* in a group will belong to a single zone on the nameserver.
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* Create a dynamic update packet for each zone and send it to the
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* nameservers for that zone, and await answer.
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* Abort if error occurs in updating any zone.
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* Return the number of zones updated on success, < 0 on error.
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*
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* On error, caller must deal with the unsynchronized zones
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* eg. an A record might have been successfully added to the forward
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* zone but the corresponding PTR record would be missing if error
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* was encountered while updating the reverse zone.
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*/
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#define NSMAX 16
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struct ns1 {
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char nsname[MAXDNAME];
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struct in_addr nsaddr1;
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};
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struct zonegrp {
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char z_origin[MAXDNAME];
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int16_t z_class;
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char z_soardata[MAXDNAME + 5 * INT32SZ];
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struct ns1 z_ns[NSMAX];
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int z_nscount;
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ns_updrec * z_rr;
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struct zonegrp *z_next;
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};
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int
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res_update(ns_updrec *rrecp_in) {
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ns_updrec *rrecp, *tmprrecp;
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u_char buf[PACKETSZ], answer[PACKETSZ], packet[2*PACKETSZ];
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char name[MAXDNAME], zname[MAXDNAME], primary[MAXDNAME],
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mailaddr[MAXDNAME];
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u_char soardata[2*MAXCDNAME+5*INT32SZ];
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char *dname, *svdname, *cp1, *target;
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u_char *cp, *eom;
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HEADER *hp = (HEADER *) answer;
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struct zonegrp *zptr = NULL, *tmpzptr, *prevzptr, *zgrp_start = NULL;
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int i, j, k = 0, n, ancount, nscount, arcount, rcode, rdatasize,
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newgroup, done, myzone, seen_before, numzones = 0;
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u_int16_t dlen, class, qclass, type, qtype;
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u_int32_t ttl;
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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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for (rrecp = rrecp_in; rrecp; rrecp = rrecp->r_next) {
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dname = rrecp->r_dname;
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n = strlen(dname);
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if (dname[n-1] == '.')
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dname[n-1] = '\0';
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qtype = T_SOA;
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qclass = rrecp->r_class;
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done = 0;
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seen_before = 0;
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while (!done && dname) {
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if (qtype == T_SOA) {
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for (tmpzptr = zgrp_start;
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tmpzptr && !seen_before;
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tmpzptr = tmpzptr->z_next) {
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if (strcasecmp(dname,
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tmpzptr->z_origin) == 0 &&
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tmpzptr->z_class == qclass)
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seen_before++;
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for (tmprrecp = tmpzptr->z_rr;
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tmprrecp && !seen_before;
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tmprrecp = tmprrecp->r_grpnext)
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if (strcasecmp(dname, tmprrecp->r_dname) == 0
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&& tmprrecp->r_class == qclass) {
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seen_before++;
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break;
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}
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if (seen_before) {
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/*
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* Append to the end of
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* current group.
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*/
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for (tmprrecp = tmpzptr->z_rr;
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tmprrecp->r_grpnext;
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tmprrecp = tmprrecp->r_grpnext)
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(void)NULL;
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tmprrecp->r_grpnext = rrecp;
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rrecp->r_grpnext = NULL;
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done = 1;
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break;
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}
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}
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} else if (qtype == T_A) {
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for (tmpzptr = zgrp_start;
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tmpzptr && !done;
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tmpzptr = tmpzptr->z_next)
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for (i = 0; i < tmpzptr->z_nscount; i++)
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if (tmpzptr->z_class == qclass &&
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strcasecmp(tmpzptr->z_ns[i].nsname,
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dname) == 0 &&
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tmpzptr->z_ns[i].nsaddr1.s_addr != 0) {
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zptr->z_ns[k].nsaddr1.s_addr =
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tmpzptr->z_ns[i].nsaddr1.s_addr;
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done = 1;
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break;
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}
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}
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if (done)
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break;
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n = res_mkquery(QUERY, dname, qclass, qtype, NULL,
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0, NULL, buf, sizeof buf);
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if (n <= 0) {
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fprintf(stderr, "res_update: mkquery failed\n");
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return (n);
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}
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n = res_send(buf, n, answer, sizeof answer);
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if (n < 0) {
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fprintf(stderr, "res_update: send error for %s\n",
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rrecp->r_dname);
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return (n);
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} else if (n > sizeof(answer)) {
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fprintf(stderr, "res_update: buffer too small\n");
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return (-1);
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}
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if (n < HFIXEDSZ)
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return (-1);
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ancount = ntohs(hp->ancount);
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nscount = ntohs(hp->nscount);
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arcount = ntohs(hp->arcount);
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rcode = hp->rcode;
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cp = answer + HFIXEDSZ;
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eom = answer + n;
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/* skip the question section */
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n = dn_skipname(cp, eom);
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if (n < 0 || cp + n + 2 * INT16SZ > eom)
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return (-1);
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cp += n + 2 * INT16SZ;
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if (qtype == T_SOA) {
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if (ancount == 0 && nscount == 0 && arcount == 0) {
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/*
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* if (rcode == NOERROR) then the dname exists but
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* has no soa record associated with it.
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* if (rcode == NXDOMAIN) then the dname does not
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* exist and the server is replying out of NCACHE.
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* in either case, proceed with the next try
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*/
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dname = strchr(dname, '.');
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if (dname != NULL)
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dname++;
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continue;
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} else if ((rcode == NOERROR || rcode == NXDOMAIN) &&
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ancount == 0 &&
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nscount == 1 && arcount == 0) {
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/*
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* name/data does not exist, soa record supplied in the
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* authority section
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*/
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/* authority section must contain the soa record */
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if ((n = dn_expand(answer, eom, cp, zname,
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sizeof zname)) < 0)
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return (n);
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cp += n;
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if (cp + 2 * INT16SZ > eom)
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return (-1);
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GETSHORT(type, cp);
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GETSHORT(class, cp);
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if (type != T_SOA || class != qclass) {
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fprintf(stderr, "unknown answer\n");
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return (-1);
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}
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myzone = 0;
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svdname = dname;
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while (dname)
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if (strcasecmp(dname, zname) == 0) {
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myzone = 1;
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break;
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} else if ((dname = strchr(dname, '.')) != NULL)
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dname++;
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if (!myzone) {
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dname = strchr(svdname, '.');
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if (dname != NULL)
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dname++;
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continue;
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}
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nscount = 0;
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/* fallthrough */
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} else if (rcode == NOERROR && ancount == 1) {
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/*
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* found the zone name
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* new servers will supply NS records for the zone
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* in authority section and A records for those
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* nameservers in the additional section
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* older servers have to be explicitly queried for
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* NS records for the zone
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*/
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/* answer section must contain the soa record */
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if ((n = dn_expand(answer, eom, cp, zname,
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sizeof zname)) < 0)
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return (n);
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else
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cp += n;
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if (cp + 2 * INT16SZ > eom)
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return (-1);
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GETSHORT(type, cp);
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GETSHORT(class, cp);
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if (type == T_CNAME) {
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dname = strchr(dname, '.');
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if (dname != NULL)
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dname++;
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continue;
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}
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if (strcasecmp(dname, zname) != 0 ||
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type != T_SOA ||
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class != rrecp->r_class) {
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fprintf(stderr, "unknown answer\n");
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return (-1);
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}
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/* FALLTHROUGH */
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} else {
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fprintf(stderr,
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"unknown response: ans=%d, auth=%d, add=%d, rcode=%d\n",
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ancount, nscount, arcount, hp->rcode);
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return (-1);
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}
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if (cp + INT32SZ + INT16SZ > eom)
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return (-1);
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/* continue processing the soa record */
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GETLONG(ttl, cp);
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GETSHORT(dlen, cp);
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if (cp + dlen > eom)
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return (-1);
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newgroup = 1;
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zptr = zgrp_start;
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prevzptr = NULL;
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while (zptr) {
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if (strcasecmp(zname, zptr->z_origin) == 0 &&
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type == T_SOA && class == qclass) {
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newgroup = 0;
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break;
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}
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prevzptr = zptr;
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zptr = zptr->z_next;
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}
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if (!newgroup) {
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for (tmprrecp = zptr->z_rr;
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tmprrecp->r_grpnext;
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tmprrecp = tmprrecp->r_grpnext)
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;
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tmprrecp->r_grpnext = rrecp;
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rrecp->r_grpnext = NULL;
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done = 1;
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cp += dlen;
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break;
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} else {
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if ((n = dn_expand(answer, eom, cp, primary,
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sizeof primary)) < 0)
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return (n);
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cp += n;
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/*
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* We don't have to bounds check here because the
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* next use of 'cp' is in dn_expand().
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*/
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cp1 = (char *)soardata;
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strcpy(cp1, primary);
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cp1 += strlen(cp1) + 1;
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if ((n = dn_expand(answer, eom, cp, mailaddr,
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sizeof mailaddr)) < 0)
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return (n);
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cp += n;
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strcpy(cp1, mailaddr);
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cp1 += strlen(cp1) + 1;
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if (cp + 5*INT32SZ > eom)
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return (-1);
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memcpy(cp1, cp, 5*INT32SZ);
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cp += 5*INT32SZ;
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cp1 += 5*INT32SZ;
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rdatasize = (u_char *)cp1 - soardata;
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zptr = calloc(1, sizeof(struct zonegrp));
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if (zptr == NULL)
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return (-1);
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if (zgrp_start == NULL)
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zgrp_start = zptr;
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else
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prevzptr->z_next = zptr;
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zptr->z_rr = rrecp;
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rrecp->r_grpnext = NULL;
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strcpy(zptr->z_origin, zname);
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zptr->z_class = class;
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memcpy(zptr->z_soardata, soardata, rdatasize);
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/* fallthrough to process NS and A records */
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}
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} else if (qtype == T_NS) {
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if (rcode == NOERROR && ancount > 0) {
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strcpy(zname, dname);
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for (zptr = zgrp_start; zptr; zptr = zptr->z_next) {
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if (strcasecmp(zname, zptr->z_origin) == 0)
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break;
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}
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if (zptr == NULL)
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/* should not happen */
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return (-1);
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if (nscount > 0) {
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/*
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* answer and authority sections contain
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* the same information, skip answer section
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*/
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for (j = 0; j < ancount; j++) {
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n = dn_skipname(cp, eom);
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if (n < 0)
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return (-1);
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n += 2*INT16SZ + INT32SZ;
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if (cp + n + INT16SZ > eom)
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return (-1);
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cp += n;
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GETSHORT(dlen, cp);
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cp += dlen;
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}
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} else
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nscount = ancount;
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/* fallthrough to process NS and A records */
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} else {
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fprintf(stderr, "cannot determine nameservers for %s:\
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ans=%d, auth=%d, add=%d, rcode=%d\n",
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dname, ancount, nscount, arcount, hp->rcode);
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return (-1);
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}
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} else if (qtype == T_A) {
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if (rcode == NOERROR && ancount > 0) {
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arcount = ancount;
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ancount = nscount = 0;
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/* fallthrough to process A records */
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} else {
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fprintf(stderr, "cannot determine address for %s:\
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ans=%d, auth=%d, add=%d, rcode=%d\n",
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dname, ancount, nscount, arcount, hp->rcode);
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return (-1);
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}
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}
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/* process NS records for the zone */
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j = 0;
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for (i = 0; i < nscount; i++) {
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if ((n = dn_expand(answer, eom, cp, name,
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sizeof name)) < 0)
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return (n);
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cp += n;
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if (cp + 3 * INT16SZ + INT32SZ > eom)
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return (-1);
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GETSHORT(type, cp);
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GETSHORT(class, cp);
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GETLONG(ttl, cp);
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GETSHORT(dlen, cp);
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if (cp + dlen > eom)
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return (-1);
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if (strcasecmp(name, zname) == 0 &&
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type == T_NS && class == qclass) {
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if ((n = dn_expand(answer, eom, cp,
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name, sizeof name)) < 0)
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return (n);
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target = zptr->z_ns[j++].nsname;
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strcpy(target, name);
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}
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cp += dlen;
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}
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if (zptr->z_nscount == 0)
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zptr->z_nscount = j;
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/* get addresses for the nameservers */
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for (i = 0; i < arcount; i++) {
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if ((n = dn_expand(answer, eom, cp, name,
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sizeof name)) < 0)
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return (n);
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cp += n;
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if (cp + 3 * INT16SZ + INT32SZ > eom)
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return (-1);
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GETSHORT(type, cp);
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GETSHORT(class, cp);
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GETLONG(ttl, cp);
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GETSHORT(dlen, cp);
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if (cp + dlen > eom)
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return (-1);
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if (type == T_A && dlen == INT32SZ && class == qclass) {
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for (j = 0; j < zptr->z_nscount; j++)
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if (strcasecmp(name, zptr->z_ns[j].nsname) == 0) {
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memcpy(&zptr->z_ns[j].nsaddr1.s_addr, cp,
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INT32SZ);
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break;
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}
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}
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cp += dlen;
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}
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if (zptr->z_nscount == 0) {
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dname = zname;
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qtype = T_NS;
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continue;
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}
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done = 1;
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for (k = 0; k < zptr->z_nscount; k++)
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if (zptr->z_ns[k].nsaddr1.s_addr == 0) {
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done = 0;
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dname = zptr->z_ns[k].nsname;
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qtype = T_A;
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}
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} /* while */
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}
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_res.options |= RES_DEBUG;
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for (zptr = zgrp_start; zptr; zptr = zptr->z_next) {
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/* append zone section */
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rrecp = res_mkupdrec(ns_s_zn, zptr->z_origin,
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zptr->z_class, ns_t_soa, 0);
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if (rrecp == NULL) {
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fprintf(stderr, "saverrec error\n");
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fflush(stderr);
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return (-1);
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}
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rrecp->r_grpnext = zptr->z_rr;
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zptr->z_rr = rrecp;
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n = res_mkupdate(zptr->z_rr, packet, sizeof packet);
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if (n < 0) {
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fprintf(stderr, "res_mkupdate error\n");
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fflush(stderr);
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return (-1);
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} else
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fprintf(stdout, "res_mkupdate: packet size = %d\n", n);
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/*
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* Override the list of NS records from res_init() with
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* the authoritative nameservers for the zone being updated.
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* Sort primary to be the first in the list of nameservers.
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*/
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for (i = 0; i < zptr->z_nscount; i++) {
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if (strcasecmp(zptr->z_ns[i].nsname,
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zptr->z_soardata) == 0) {
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struct in_addr tmpaddr;
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if (i != 0) {
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strcpy(zptr->z_ns[i].nsname,
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zptr->z_ns[0].nsname);
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strcpy(zptr->z_ns[0].nsname,
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zptr->z_soardata);
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tmpaddr = zptr->z_ns[i].nsaddr1;
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zptr->z_ns[i].nsaddr1 =
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zptr->z_ns[0].nsaddr1;
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zptr->z_ns[0].nsaddr1 = tmpaddr;
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}
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break;
|
|
}
|
|
}
|
|
for (i = 0; i < MAXNS; i++) {
|
|
_res.nsaddr_list[i].sin_addr = zptr->z_ns[i].nsaddr1;
|
|
_res.nsaddr_list[i].sin_family = AF_INET;
|
|
_res.nsaddr_list[i].sin_port = htons(NAMESERVER_PORT);
|
|
}
|
|
_res.nscount = (zptr->z_nscount < MAXNS) ?
|
|
zptr->z_nscount : MAXNS;
|
|
n = res_send(packet, n, answer, sizeof(answer));
|
|
if (n < 0) {
|
|
fprintf(stderr, "res_send: send error, n=%d\n", n);
|
|
break;
|
|
} else if (n > sizeof(answer)) {
|
|
fprintf(stderr, "res_send: buffer too small\n");
|
|
break;
|
|
}
|
|
numzones++;
|
|
}
|
|
|
|
/* free malloc'ed memory */
|
|
while(zgrp_start) {
|
|
zptr = zgrp_start;
|
|
zgrp_start = zgrp_start->z_next;
|
|
res_freeupdrec(zptr->z_rr); /* Zone section we allocated. */
|
|
free((char *)zptr);
|
|
}
|
|
|
|
return (numzones);
|
|
}
|