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