412 lines
10 KiB
C
412 lines
10 KiB
C
/*
|
|
* 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>
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include <sys/types.h>
|
|
#include <sys/param.h>
|
|
|
|
#include <netinet/in.h>
|
|
#include <arpa/nameser.h>
|
|
#include <arpa/inet.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);
|
|
}
|