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minix/commands/simple/host.c

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Initial revision
2005-04-21 16:53:53 +02:00
/*
* Copyright (c) 1986 Regents of the University of California
* All Rights Reserved
*
* Redistribution and use in source and binary forms are permitted
* provided that this notice is preserved and that due credit is given
* to the University of California at Berkeley. The name of the University
* may not be used to endorse or promote products derived from this
* software without specific prior written permission. This software
* is provided ``as is'' without express or implied warranty.
*/
/*
* Actually, this program is from Rutgers University, however it is
* based on nslookup and other pieces of named tools, so it needs
* that copyright notice.
*/
#if _MINIX
#include <sys/types.h>
#include <sys/ioctl.h>
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <net/hton.h>
#include <net/netlib.h>
#include <net/gen/in.h>
#include <net/gen/inet.h>
#include <net/gen/netdb.h>
#include <net/gen/nameser.h>
#include <net/gen/resolv.h>
#include <net/gen/socket.h>
#include <net/gen/tcp.h>
#include <net/gen/tcp_io.h>
typedef u8_t u_char;
typedef u16_t u_short;
typedef u32_t u_long;
#undef ERROR
#else
#include <stdio.h>
#include <sys/types.h>
#include <arpa/nameser.h>
#include <netdb.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <resolv.h>
#include <sys/param.h>
#include <strings.h>
#include <ctype.h>
#endif
extern int h_errno;
#define NUMMX 50
#define SUCCESS 0
#define TIME_OUT -1
#define NO_INFO -2
#define ERROR -3
#define NONAUTH -4
#define NAME_LEN 256
#ifndef T_TXT
#define T_TXT 16
#endif
#ifndef NO_DATA
#define NO_DATA NO_ADDRESS
#endif
#ifndef C_HS
#define C_HS 4
#endif
FILE *filePtr;
struct state orig;
extern struct state _res;
static u8_t *cname = NULL;
int getclass = C_IN;
int gettype, getdeftype = T_A;
int verbose = 0;
int list = 0;
int server_specified = 0;
union querybuf;
int main _ARGS(( int c, char *v[] ));
static int parsetype _ARGS(( char *s ));
static int parseclass _ARGS(( char *s ));
static void hperror _ARGS(( int errno ));
static void printanswer _ARGS(( struct hostent *hp ));
static int ListHosts _ARGS(( char *namePtr, int queryType ));
static int gethostinfo _ARGS(( char *name ));
static int getdomaininfo _ARGS(( char *name, char *domain ));
static int getinfo _ARGS(( char *name, char *domain, int type ));
static int printinfo _ARGS(( union querybuf *answer, u8_t *eom, int filter,
int isls ));
static char *DecodeError _ARGS(( int result ));
static u8_t *pr_rr _ARGS(( u8_t *cp, u8_t *msg, FILE *file, int filter ));
static u8_t * pr_cdname _ARGS(( u8_t *cp, u8_t *msg, u8_t *name, int namelen ));
static char *pr_class _ARGS(( int class ));
static char *pr_type _ARGS(( int type ));
static int tcpip_writeall _ARGS(( int fd, char *buf, unsigned siz ));
int
main(c, v)
char **v;
{
char *domain;
ipaddr_t addr;
register struct hostent *hp;
register char *s, *p;
register inverse = 0;
register waitmode = 0;
u8_t *oldcname;
int ncnames;
int isaddr;
res_init();
_res.retrans = 5;
if (c < 2) {
fprintf(stderr, "Usage: host [-w] [-v] [-r] [-d] [-V] [-t querytype] [-c class] [-a] host [server]\n -w to wait forever until reply\n -v for verbose output\n -r to disable recursive processing\n -d to turn on debugging output\n -t querytype to look for a specific type of information\n -c class to look for non-Internet data\n -a is equivalent to '-v -t *'\n -V to always use a virtual circuit\n");
exit(1);
}
while (c > 2 && v[1][0] == '-') {
if (strcmp (v[1], "-w") == 0) {
_res.retry = 1;
_res.retrans = 15;
waitmode = 1;
v++;
c--;
}
else if (strcmp (v[1], "-r") == 0) {
_res.options &= ~RES_RECURSE;
v++;
c--;
}
else if (strcmp (v[1], "-d") == 0) {
_res.options |= RES_DEBUG;
v++;
c--;
}
else if (strcmp (v[1], "-v") == 0) {
verbose = 1;
v++;
c--;
}
else if (strcmp (v[1], "-l") == 0) {
list = 1;
v++;
c--;
}
else if (strncmp (v[1], "-t", 2) == 0) {
v++;
c--;
gettype = parsetype(v[1]);
v++;
c--;
}
else if (strncmp (v[1], "-c", 2) == 0) {
v++;
c--;
getclass = parseclass(v[1]);
v++;
c--;
}
else if (strcmp (v[1], "-a") == 0) {
verbose = 1;
gettype = T_ANY;
v++;
c--;
}
else if (strcmp (v[1], "-V") == 0) {
_res.options |= RES_USEVC;
v++;
c--;
}
}
if (c > 2) {
s = v[2];
server_specified++;
if ((p = strchr(s, ':')) != NULL) *p++ = 0;
isaddr = inet_aton(s, &addr);
if (p != NULL) p[-1] = ':';
if (!isaddr) {
hp = gethostbyname(s);
if (hp == NULL) {
fprintf(stderr,"Error in looking up server name:\n");
hperror(h_errno);
exit(1);
}
_res.nsaddr= *(ipaddr_t *)hp->h_addr;
printf("Using domain server:\n");
printanswer(hp);
}
else {
_res.nsaddr_list[0]= addr;
_res.nsport_list[0]= htons(NAMESERVER_PORT);
printf("Using domain server %s",
inet_ntoa(_res.nsaddr));
if (p != NULL) {
printf(" on port %d", atoi(p));
_res.nsport_list[0]= htons(atoi(p));
}
printf(":\n");
}
}
domain = v[1];
if (strcmp (domain, ".") != 0 && inet_aton(domain, &addr)) {
static char ipname[sizeof("255.255.255.255.in-addr.arpa.")];
sprintf(ipname, "%d.%d.%d.%d.in-addr.arpa.",
((unsigned char *) &addr)[3],
((unsigned char *) &addr)[2],
((unsigned char *) &addr)[1],
((unsigned char *) &addr)[0]);
domain = ipname;
getdeftype = T_PTR;
}
hp = NULL;
h_errno = TRY_AGAIN;
/*
* we handle default domains ourselves, thank you
*/
_res.options &= ~RES_DEFNAMES;
if (list)
exit(ListHosts(domain, gettype ? gettype : getdeftype));
oldcname = NULL;
ncnames = 5;
while (hp == NULL && h_errno == TRY_AGAIN) {
cname = NULL;
if (oldcname == NULL)
hp = (struct hostent *)gethostinfo(domain);
else
hp = (struct hostent *)gethostinfo((char *)oldcname);
if (cname) {
if (ncnames-- == 0) {
printf("Too many cnames. Possible loop.\n");
exit(1);
}
oldcname = cname;
hp = NULL;
h_errno = TRY_AGAIN;
continue;
}
if (!waitmode)
break;
}
if (hp == NULL) {
hperror(h_errno);
exit(1);
}
exit(0);
}
static int
parsetype(s)
char *s;
{
if (strcmp(s,"a") == 0)
return(1);
if (strcmp(s,"ns") == 0)
return(2);
if (strcmp(s,"md") == 0)
return(3);
if (strcmp(s,"mf") == 0)
return(4);
if (strcmp(s,"cname") == 0)
return(5);
if (strcmp(s,"soa") == 0)
return(6);
if (strcmp(s,"mb") == 0)
return(7);
if (strcmp(s,"mg") == 0)
return(8);
if (strcmp(s,"mr") == 0)
return(9);
if (strcmp(s,"null") == 0)
return(10);
if (strcmp(s,"wks") == 0)
return(11);
if (strcmp(s,"ptr") == 0)
return(12);
if (strcmp(s,"hinfo") == 0)
return(13);
if (strcmp(s,"minfo") == 0)
return(14);
if (strcmp(s,"mx") == 0)
return(15);
if (strcmp(s,"txt") == 0) /* Roy */
return(T_TXT); /* Roy */
if (strcmp(s,"uinfo") == 0)
return(100);
if (strcmp(s,"uid") == 0)
return(101);
if (strcmp(s,"gid") == 0)
return(102);
if (strcmp(s,"unspec") == 0)
return(103);
if (strcmp(s,"any") == 0)
return(255);
if (strcmp(s,"*") == 0)
return(255);
if (atoi(s))
return(atoi(s));
fprintf(stderr, "Invalid query type: %s\n", s);
exit(2);
}
static int
parseclass(s)
char *s;
{
if (strcmp(s,"in") == 0)
return(C_IN);
if (strcmp(s,"chaos") == 0)
return(C_CHAOS);
if (strcmp(s,"hs") == 0)
return(C_HS);
if (strcmp(s,"any") == 0)
return(C_ANY);
if (atoi(s))
return(atoi(s));
fprintf(stderr, "Invalid query class: %s\n", s);
exit(2);
}
static void
printanswer(hp)
register struct hostent *hp;
{
register char **cp;
register ipaddr_t **hptr;
printf("Name: %s\n", hp->h_name);
printf("Address:");
for (hptr = (ipaddr_t **)hp->h_addr_list; *hptr; hptr++)
printf(" %s", inet_ntoa(*(ipaddr_t *)*hptr));
printf("\nAliases:");
for (cp = hp->h_aliases; cp && *cp && **cp; cp++)
printf(" %s", *cp);
printf("\n\n");
}
static void
hperror(errno)
int errno;
{
switch(errno) {
case HOST_NOT_FOUND:
fprintf(stderr,"Host not found.\n");
break;
case TRY_AGAIN:
fprintf(stderr,"Host not found, try again.\n");
break;
case NO_RECOVERY:
fprintf(stderr,"No recovery, Host not found.\n");
break;
case NO_ADDRESS:
fprintf(stderr,"There is an entry for this host, but it doesn't have what you requested.\n");
break;
}
}
typedef union querybuf {
dns_hdr_t qb1;
u8_t qb2[PACKETSZ];
} querybuf_t;
static u8_t hostbuf[BUFSIZ+1];
static int
gethostinfo(name)
char *name;
{
register char *cp, **domain;
int n;
int hp;
int nDomain;
if (strcmp(name, ".") == 0)
return(getdomaininfo(name, NULL));
for (cp = name, n = 0; *cp; cp++)
if (*cp == '.')
n++;
if (n && cp[-1] == '.') {
if (cp[-1] == '.')
cp[-1] = 0;
hp = getdomaininfo(name, (char *)NULL);
if (cp[-1] == 0)
cp[-1] = '.';
return (hp);
}
if (n == 0 && (cp = __hostalias(name))) {
if (verbose)
printf("Aliased to \"%s\"\n", cp);
_res.options |= RES_DEFNAMES;
return (getdomaininfo(cp, (char *)NULL));
}
#ifdef MAXDS
for (nDomain = 0;
_res.defdname_list[nDomain][0] != 0;
nDomain++) {
for (domain = _res.dnsrch_list[nDomain]; *domain; domain++) {
if (verbose)
printf("Trying domain \"%s\"\n", *domain);
hp = getdomaininfo(name, *domain);
if (hp)
return (hp);
}
}
#else
for (domain = _res.dnsrch; *domain; domain++) {
if (verbose)
printf("Trying domain \"%s\"\n", *domain);
hp = getdomaininfo(name, *domain);
if (hp)
return (hp);
}
#endif
if (h_errno != HOST_NOT_FOUND ||
(_res.options & RES_DNSRCH) == 0)
return (0);
if (verbose)
printf("Trying null domain\n");
return (getdomaininfo(name, (char *)NULL));
}
static int
getdomaininfo(name, domain)
char *name, *domain;
{
return getinfo(name, domain, gettype ? gettype : getdeftype);
}
static int
getinfo(name, domain, type)
char *name, *domain;
{
dns_hdr_t *hp;
u8_t *eom, *bp, *cp;
querybuf_t buf, answer;
int n, n1, i, j, nmx, ancount, nscount, arcount, qdcount, buflen;
u_short pref, class;
char host[2*MAXDNAME+2];
if (domain == NULL)
(void)sprintf(host, "%.*s", MAXDNAME, name);
else
(void)sprintf(host, "%.*s.%.*s", MAXDNAME, name, MAXDNAME, domain);
n = res_mkquery(QUERY, host, getclass, type, (char *)NULL, 0, NULL,
(char *)&buf, sizeof(buf));
if (n < 0) {
if (_res.options & RES_DEBUG)
printf("res_mkquery failed\n");
h_errno = NO_RECOVERY;
return(0);
}
n = res_send((char *)&buf, n, (char *)&answer, sizeof(answer));
if (n < 0) {
if (_res.options & RES_DEBUG)
printf("res_send failed\n");
h_errno = TRY_AGAIN;
return (0);
}
eom = (u8_t *)&answer + n;
return(printinfo(&answer, eom, T_ANY, 0));
}
static int
printinfo(answer, eom, filter, isls)
querybuf_t *answer;
u8_t *eom;
int filter;
int isls;
{
dns_hdr_t *hp;
u8_t *bp, *cp;
int n, n1, i, j, nmx, ancount, nscount, arcount, qdcount, buflen;
u_short pref, class;
/*
* find first satisfactory answer
*/
hp = (dns_hdr_t *) answer;
ancount = ntohs(hp->dh_ancount);
qdcount = ntohs(hp->dh_qdcount);
nscount = ntohs(hp->dh_nscount);
arcount = ntohs(hp->dh_arcount);
if (_res.options & RES_DEBUG || (verbose && isls == 0))
printf("rcode = %d (%s), ancount=%d\n",
hp->dh_flag2 & DHF_RCODE,
DecodeError(hp->dh_flag2 & DHF_RCODE), ancount);
if (hp->dh_flag2 & DHF_RCODE != NOERROR ||
(ancount+nscount+arcount) == 0) {
switch (hp->dh_flag2 & DHF_RCODE) {
case NXDOMAIN:
/* Check if it's an authoritive answer */
if (hp->dh_flag1 & DHF_AA) {
h_errno = HOST_NOT_FOUND;
return(0);
} else {
h_errno = TRY_AGAIN;
return(0);
}
case SERVFAIL:
h_errno = TRY_AGAIN;
return(0);
#ifdef OLDJEEVES
/*
* Jeeves (TOPS-20 server) still does not
* support MX records. For the time being,
* we must accept FORMERRs as the same as
* NOERROR.
*/
case FORMERR:
#endif /* OLDJEEVES */
case NOERROR:
/* TpB - set a return error for this case. NO_DATA */
h_errno = NO_DATA;
return(0); /* was 1,but now indicates exception */
#ifndef OLDJEEVES
case FORMERR:
#endif /* OLDJEEVES */
case NOTIMP:
case REFUSED:
h_errno = NO_RECOVERY;
return(0);
}
return (0);
}
bp = hostbuf;
nmx = 0;
buflen = sizeof(hostbuf);
cp = (u8_t *)answer + sizeof(dns_hdr_t);
if (qdcount) {
cp += dn_skipname((u8_t *)cp,(u8_t *)eom) + QFIXEDSZ;
while (--qdcount > 0)
cp += dn_skipname((u8_t *)cp,(u8_t *)eom) + QFIXEDSZ;
}
if (ancount) {
if (!(hp->dh_flag1 & DHF_AA))
if (verbose && isls == 0)
printf("The following answer is not authoritative:\n");
while (--ancount >= 0 && cp && cp < eom) {
cp = pr_rr(cp, (u8_t *)answer, stdout, filter);
/*
* When we ask for address and there is a CNAME, it seems to return
* both the CNAME and the address. Since we trace down the CNAME
* chain ourselves, we don't really want to print the address at
* this point.
*/
if (cname && ! verbose)
return (1);
}
}
if (! verbose)
return (1);
if (nscount) {
printf("For authoritative answers, see:\n");
while (--nscount >= 0 && cp && cp < eom) {
cp = pr_rr(cp, (u8_t *)answer, stdout, filter);
}
}
if (arcount) {
printf("Additional information:\n");
while (--arcount >= 0 && cp && cp < eom) {
cp = pr_rr(cp, (u8_t *)answer, stdout, filter);
}
}
return(1);
}
static u8_t cnamebuf[MAXDNAME];
/*
* Print resource record fields in human readable form.
*/
static u8_t *
pr_rr(cp, msg, file, filter)
u8_t *cp, *msg;
FILE *file;
int filter;
{
int type, class, dlen, n, c, proto, ttl;
ipaddr_t inaddr;
u8_t *cp1;
struct protoent *protop;
struct servent *servp;
char punc;
int doprint;
u8_t name[MAXDNAME];
if ((cp = pr_cdname(cp, msg, name, sizeof(name))) == NULL)
return (NULL); /* compression error */
type = _getshort(cp);
cp += sizeof(u_short);
class = _getshort(cp);
cp += sizeof(u_short);
ttl = _getlong(cp);
cp += sizeof(u_long);
if (filter == type || filter == T_ANY ||
(filter == T_A && (type == T_PTR || type == T_NS)))
doprint = 1;
else
doprint = 0;
if (doprint)
if (verbose)
fprintf(file,"%s\t%d%s\t%s",
name, ttl, pr_class(class), pr_type(type));
else
fprintf(file,"%s%s %s",name, pr_class(class), pr_type(type));
if (verbose)
punc = '\t';
else
punc = ' ';
dlen = _getshort(cp);
cp += sizeof(u_short);
cp1 = cp;
/*
* Print type specific data, if appropriate
*/
switch (type) {
case T_A:
switch (class) {
case C_IN:
bcopy((char *)cp, (char *)&inaddr, sizeof(inaddr));
if (dlen == 4) {
if (doprint)
fprintf(file,"%c%s", punc,
inet_ntoa(inaddr));
cp += dlen;
} else if (dlen == 7) {
if (doprint) {
fprintf(file,"%c%s", punc,
inet_ntoa(inaddr));
fprintf(file,", protocol = %d", cp[4]);
fprintf(file,", port = %d",
(cp[5] << 8) + cp[6]);
}
cp += dlen;
}
break;
}
break;
case T_CNAME:
if (dn_expand(msg, msg + 512, cp, cnamebuf,
sizeof(cnamebuf)-1) >= 0) {
strcat((char *) cnamebuf, ".");
if (gettype != T_CNAME && gettype != T_ANY)
cname = cnamebuf;
}
case T_MB:
#ifdef OLDRR
case T_MD:
case T_MF:
#endif /* OLDRR */
case T_MG:
case T_MR:
case T_NS:
case T_PTR:
cp = pr_cdname(cp, msg, name, sizeof(name));
if (doprint)
fprintf(file,"%c%s",punc, name);
break;
case T_HINFO:
if (n = *cp++) {
if (doprint)
fprintf(file,"%c%.*s", punc, n, cp);
cp += n;
}
if (n = *cp++) {
if (doprint)
fprintf(file,"%c%.*s", punc, n, cp);
cp += n;
}
break;
case T_SOA:
cp = pr_cdname(cp, msg, name, sizeof(name));
if (doprint)
fprintf(file,"\t%s", name);
cp = pr_cdname(cp, msg, name, sizeof(name));
if (doprint)
fprintf(file," %s", name);
if (doprint)
fprintf(file,"(\n\t\t\t%ld\t;serial (version)", _getlong(cp));
cp += sizeof(u_long);
if (doprint)
fprintf(file,"\n\t\t\t%ld\t;refresh period", _getlong(cp));
cp += sizeof(u_long);
if (doprint)
fprintf(file,"\n\t\t\t%ld\t;retry refresh this often", _getlong(cp));
cp += sizeof(u_long);
if (doprint)
fprintf(file,"\n\t\t\t%ld\t;expiration period", _getlong(cp));
cp += sizeof(u_long);
if (doprint)
fprintf(file,"\n\t\t\t%ld\t;minimum TTL\n\t\t\t)", _getlong(cp));
cp += sizeof(u_long);
break;
case T_MX:
if (doprint)
if (verbose)
fprintf(file,"\t%d ",_getshort(cp));
else
fprintf(file," (pri=%d) by ",_getshort(cp));
cp += sizeof(u_short);
cp = pr_cdname(cp, msg, name, sizeof(name));
if (doprint)
fprintf(file, "%s", name);
break;
case T_MINFO:
cp = pr_cdname(cp, msg, name, sizeof(name));
if (doprint)
fprintf(file,"%c%s",punc, name);
cp = pr_cdname(cp, msg, name, sizeof(name));
if (doprint)
fprintf(file," %s", name);
break;
/* Roy start */
case T_TXT:
if (n = *cp++) {
if (doprint)
fprintf(file,"%c%.*s", punc, n, cp);
cp += n;
}
break;
/* Roy end */
case T_UINFO:
if (doprint)
fprintf(file,"%c%s", punc, cp);
cp += dlen;
break;
case T_UID:
case T_GID:
if (dlen == 4) {
if (doprint)
fprintf(file,"%c%ld", punc, _getlong(cp));
cp += sizeof(int);
}
break;
case T_WKS:
if (dlen < sizeof(u_long) + 1)
break;
bcopy((char *)cp, (char *)&inaddr, sizeof(inaddr));
cp += sizeof(u_long);
proto = *cp++;
protop = getprotobynumber(proto);
if (doprint)
if (protop)
fprintf(file,"%c%s %s", punc,
inet_ntoa(inaddr), protop->p_name);
else
fprintf(file,"%c%s %d", punc,
inet_ntoa(inaddr), proto);
n = 0;
while (cp < cp1 + dlen) {
c = *cp++;
do {
if (c & 0200) {
servp = NULL;
if (protop)
servp = getservbyport (htons(n),
protop->p_name);
if (doprint)
if (servp)
fprintf(file, " %s", servp->s_name);
else
fprintf(file, " %d", n);
}
c <<= 1;
} while (++n & 07);
}
break;
default:
if (doprint)
fprintf(file,"%c???", punc);
cp += dlen;
}
if (cp != cp1 + dlen)
fprintf(file,"packet size error (%#x != %#x)\n", cp, cp1+dlen);
if (doprint)
fprintf(file,"\n");
return (cp);
}
static char nbuf[20];
/*
* Return a string for the type
*/
static char *
pr_type(type)
int type;
{
switch (type) {
case T_A:
return(verbose? "A" : "has address");
case T_NS: /* authoritative server */
return("NS");
#ifdef OLDRR
case T_MD: /* mail destination */
return("MD");
case T_MF: /* mail forwarder */
return("MF");
#endif /* OLDRR */
case T_CNAME: /* connonical name */
return(verbose? "CNAME" : "is a nickname for");
case T_SOA: /* start of authority zone */
return("SOA");
case T_MB: /* mailbox domain name */
return("MB");
case T_MG: /* mail group member */
return("MG");
case T_MX: /* mail routing info */
return(verbose? "MX" : "mail is handled");
/* Roy start */
case T_TXT: /* TXT - descriptive info */
return(verbose? "TXT" : "descriptive text");
/* Roy end */
case T_MR: /* mail rename name */
return("MR");
case T_NULL: /* null resource record */
return("NULL");
case T_WKS: /* well known service */
return("WKS");
case T_PTR: /* domain name pointer */
return("PTR");
case T_HINFO: /* host information */
return("HINFO");
case T_MINFO: /* mailbox information */
return("MINFO");
case T_AXFR: /* zone transfer */
return("AXFR");
case T_MAILB: /* mail box */
return("MAILB");
case T_MAILA: /* mail address */
return("MAILA");
case T_ANY: /* matches any type */
return("ANY");
case T_UINFO:
return("UINFO");
case T_UID:
return("UID");
case T_GID:
return("GID");
default:
return (sprintf(nbuf, "%d", type) == EOF ? NULL : nbuf);
}
}
/*
* Return a mnemonic for class
*/
static char *
pr_class(class)
int class;
{
switch (class) {
case C_IN: /* internet class */
return(verbose? " IN" : "");
case C_CHAOS: /* chaos class */
return(verbose? " CHAOS" : "");
case C_HS: /* Hesiod class */
return(verbose? " HS" : "");
case C_ANY: /* matches any class */
return(" ANY");
default:
return (sprintf(nbuf," %d", class) == EOF ? NULL : nbuf);
}
}
static u8_t *
pr_cdname(cp, msg, name, namelen)
u8_t *cp, *msg;
u8_t *name;
int namelen;
{
int n;
if ((n = dn_expand(msg, msg + 512, cp, name, namelen - 2)) < 0)
return (NULL);
if (name[0] == '\0') {
name[0] = '.';
name[1] = '\0';
}
return (cp + n);
}
char *resultcodes[] = {
"NOERROR",
"FORMERR",
"SERVFAIL",
"NXDOMAIN",
"NOTIMP",
"REFUSED",
"6",
"7",
"8",
"9",
"10",
"11",
"12",
"13",
"14",
"NOCHANGE",
};
/*
******************************************************************************
*
* ListHosts --
*
* Requests the name server to do a zone transfer so we
* find out what hosts it knows about.
*
* Results:
* SUCCESS the listing was successful.
* ERROR the server could not be contacted because
* a socket could not be obtained or an error
* occured while receiving, or the output file
* could not be opened.
*
******************************************************************************
*/
static int
ListHosts(namePtr, queryType)
char *namePtr;
int queryType; /* e.g. T_A */
{
querybuf_t buf, answer;
dns_hdr_t *headerPtr;
int msglen;
int amtToRead;
int numRead;
int i;
int numAnswers = 0;
int result;
int soacnt = 0;
u_short len;
int dlen;
int type;
int nscount;
u8_t *cp, *nmp;
u8_t name[NAME_LEN];
char dname[2][NAME_LEN];
u8_t domain[NAME_LEN];
/* names and addresses of name servers to try */
#define NUMNS 8
char nsname[NUMNS][NAME_LEN];
int nshaveaddr[NUMNS];
#define IPADDRSIZE 4
#define NUMNSADDR 16
char nsipaddr[NUMNSADDR][IPADDRSIZE];
int numns;
int numnsaddr;
int thisns;
struct hostent *hp;
enum {
NO_ERRORS,
ERR_READING_LEN,
ERR_READING_MSG,
ERR_PRINTING
} error = NO_ERRORS;
char *tcp_serv_name;
int tcp_fd;
nwio_tcpconf_t tcpconf;
nwio_tcpcl_t clopt;
int terrno;
/*
* normalize to not have trailing dot. We do string compares below
* of info from name server, and it won't have trailing dots.
*/
i = strlen(namePtr);
if (namePtr[i-1] == '.')
namePtr[i-1] = 0;
if (server_specified) {
bcopy((char *)&_res.nsaddr, nsipaddr[0], IPADDRSIZE);
numnsaddr = 1;
}
else {
/*
* First we have to find out where to look. This needs a NS query,
* possibly followed by looking up addresses for some of the names.
*/
msglen = res_mkquery(QUERY, namePtr, C_IN, T_NS,
(char *)0, 0, (struct rrec *)0,
(char *)&buf, sizeof(buf));
if (msglen < 0) {
printf("res_mkquery failed\n");
return (ERROR);
}
msglen = res_send((char *)&buf,msglen,(char *)&answer, sizeof(answer));
if (msglen < 0) {
printf("Unable to get to nameserver -- try again later\n");
return (ERROR);
}
if (_res.options & RES_DEBUG || verbose)
printf("rcode = %d (%s), ancount=%d\n",
answer.qb1.dh_flag2 & DHF_RCODE,
DecodeError(answer.qb1.dh_flag2 & DHF_RCODE),
ntohs(answer.qb1.dh_ancount));
/*
* Analyze response to our NS lookup
*/
nscount = ntohs(answer.qb1.dh_ancount) + ntohs(answer.qb1.dh_nscount) +
ntohs(answer.qb1.dh_arcount);
if (answer.qb1.dh_flag2 & DHF_RCODE != NOERROR || nscount == 0) {
switch (answer.qb1.dh_flag2 & DHF_RCODE) {
case NXDOMAIN:
/* Check if it's an authoritive answer */
if (answer.qb1.dh_flag1 & DHF_AA) {
printf("No such domain\n");
} else {
printf("Unable to get information about domain -- try again later.\n");
}
break;
case SERVFAIL:
printf("Unable to get information about that domain -- try again later.\n");
break;
case NOERROR:
printf("That domain exists, but seems to be a leaf node.\n");
break;
case FORMERR:
case NOTIMP:
case REFUSED:
printf("Unrecoverable error looking up domain name.\n");
break;
}
return (0);
}
cp = answer.qb2 + sizeof(dns_hdr_t);
if (ntohs(answer.qb1.dh_qdcount) > 0)
cp += dn_skipname(cp, answer.qb2 + msglen) + QFIXEDSZ;
numns = 0;
numnsaddr = 0;
/*
* Look at response from NS lookup for NS and A records.
*/
for (;nscount; nscount--) {
cp += dn_expand(answer.qb2, answer.qb2 + msglen, cp,
domain, sizeof(domain));
type = _getshort(cp);
cp += sizeof(u_short) + sizeof(u_short) + sizeof(u_long);
dlen = _getshort(cp);
cp += sizeof(u_short);
if (type == T_NS) {
if (dn_expand(answer.qb2, answer.qb2 + msglen, cp,
name, sizeof(name)) >= 0) {
if (numns < NUMNS && strcasecmp((char *)domain, namePtr) == 0) {
for (i = 0; i < numns; i++)
if (strcasecmp(nsname[i], (char *)name) == 0)
break; /* duplicate */
if (i >= numns) {
strncpy(nsname[numns], (char *)name, sizeof(name));
nshaveaddr[numns] = 0;
numns++;
}
}
}
}
else if (type == T_A) {
if (numnsaddr < NUMNSADDR)
for (i = 0; i < numns; i++) {
if (strcasecmp(nsname[i], (char *)domain) == 0) {
nshaveaddr[i]++;
bcopy((char *)cp, nsipaddr[numnsaddr],IPADDRSIZE);
numnsaddr++;
break;
}
}
}
cp += dlen;
}
/*
* Usually we'll get addresses for all the servers in the additional
* info section. But in case we don't, look up their addresses.
*/
for (i = 0; i < numns; i++) {
if (! nshaveaddr[i]) {
register long **hptr;
int numaddrs = 0;
hp = gethostbyname(nsname[i]);
if (hp) {
for (hptr = (long **)hp->h_addr_list; *hptr; hptr++)
if (numnsaddr < NUMNSADDR) {
bcopy((char *)*hptr, nsipaddr[numnsaddr],IPADDRSIZE);
numnsaddr++;
numaddrs++;
}
}
if (_res.options & RES_DEBUG || verbose)
printf("Found %d addresses for %s by extra query\n",
numaddrs, nsname[i]);
}
else
if (_res.options & RES_DEBUG || verbose)
printf("Found %d addresses for %s\n",
nshaveaddr[i], nsname[i]);
}
}
/*
* Now nsipaddr has numnsaddr addresses for name servers that
* serve the requested domain. Now try to find one that will
* accept a zone transfer.
*/
thisns = 0;
again:
numAnswers = 0;
soacnt = 0;
/*
* Create a query packet for the requested domain name.
*
*/
msglen = res_mkquery(QUERY, namePtr, getclass, T_AXFR,
(char *)0, 0, (struct rrec *)0,
(char *) &buf, sizeof(buf));
if (msglen < 0) {
if (_res.options & RES_DEBUG) {
fprintf(stderr, "ListHosts: Res_mkquery failed\n");
}
return (ERROR);
}
/*
* Set up a virtual circuit to the server.
*/
tcp_serv_name= getenv("TCP_DEVICE");
if (!tcp_serv_name)
tcp_serv_name= TCP_DEVICE;
for (;thisns < numnsaddr; thisns++)
{
tcp_fd= open(tcp_serv_name, O_RDWR);
if (tcp_fd == -1)
{
fprintf(stderr, "unable to open '%s': %s\n", tcp_serv_name,
strerror(errno));
return ERROR;
}
tcpconf.nwtc_flags= NWTC_EXCL | NWTC_LP_SEL | NWTC_SET_RA |
NWTC_SET_RP;
tcpconf.nwtc_remaddr= *(ipaddr_t *)nsipaddr[thisns];
tcpconf.nwtc_remport= _res.nsport_list[0];
result= ioctl(tcp_fd, NWIOSTCPCONF, &tcpconf);
if (result == -1)
{
fprintf(stderr, "tcp_ioc_setconf failed: %s\n",
strerror(errno));
close(tcp_fd);
return ERROR;
}
if (_res.options & RES_DEBUG || verbose)
printf("Trying %s\n", inet_ntoa(tcpconf.nwtc_remaddr));
clopt.nwtcl_flags= 0;
result= ioctl(tcp_fd, NWIOTCPCONN, &clopt);
if (result == 0)
break;
terrno= errno;
if (verbose)
fprintf(stderr,
"Connection failed, trying next server: %s\n",
strerror(errno));
close(tcp_fd);
}
if (thisns >= numnsaddr) {
printf("No server for that domain responded\n");
if (!verbose)
fprintf(stderr, "Error from the last server was: %s\n",
strerror(terrno));
return(ERROR);
}
/*
* Send length & message for zone transfer
*/
len = htons(msglen);
result= tcpip_writeall(tcp_fd, (char *)&len, sizeof(len));
if (result != sizeof(len))
{
fprintf(stderr, "write failed: %s\n", strerror(errno));
close(tcp_fd);
return ERROR;
}
result= tcpip_writeall(tcp_fd, (char *)&buf, msglen);
if (result != msglen)
{
fprintf(stderr, "write failed: %s\n",
strerror(errno));
close(tcp_fd);
return ERROR;
}
filePtr = stdout;
while (1) {
/*
* Read the length of the response.
*/
cp = (u8_t *) &buf;
amtToRead = sizeof(u_short);
while(amtToRead > 0)
{
result = read(tcp_fd, (char *)cp, amtToRead);
if (result <= 0)
break;
cp += result;
amtToRead -= result;
}
if (amtToRead) {
error = ERR_READING_LEN;
break;
}
if ((len = htons(*(u_short *)&buf)) == 0) {
break; /* nothing left to read */
}
/*
* Read the response.
*/
amtToRead = len;
cp = (u8_t *) &buf;
while(amtToRead > 0)
{
result = read(tcp_fd, (char *)cp, amtToRead);
if (result<= 0)
break;
cp += result;
amtToRead -= result;
}
if (amtToRead) {
error = ERR_READING_MSG;
break;
}
i = buf.qb1.dh_flag2 & DHF_RCODE;
if (i != NOERROR || ntohs(buf.qb1.dh_ancount) == 0) {
if ((thisns+1) < numnsaddr &&
(i == SERVFAIL || i == NOTIMP || i == REFUSED)) {
if (_res.options & RES_DEBUG || verbose)
printf("Server failed, trying next server: %s\n",
i != NOERROR ?
DecodeError(i) : "Premature end of data");
close(tcp_fd);
thisns++;
goto again;
}
printf("Server failed: %s\n",
i != NOERROR ? DecodeError(i) : "Premature end of data");
break;
}
result = printinfo(&buf, cp, queryType, 1);
if (! result) {
error = ERR_PRINTING;
break;
}
numAnswers++;
cp = buf.qb2 + sizeof(dns_hdr_t);
if (ntohs(buf.qb1.dh_qdcount) > 0)
cp += dn_skipname(cp, buf.qb2 + len) + QFIXEDSZ;
nmp = cp;
cp += dn_skipname(cp, (u_char *)&buf + len);
if ((_getshort(cp) == T_SOA)) {
dn_expand(buf.qb2, buf.qb2 + len, nmp, (u8_t *)dname[soacnt],
sizeof(dname[0]));
if (soacnt) {
if (strcmp(dname[0], dname[1]) == 0)
break;
} else
soacnt++;
}
}
close(tcp_fd);
switch (error) {
case NO_ERRORS:
return (SUCCESS);
case ERR_READING_LEN:
return(ERROR);
case ERR_PRINTING:
fprintf(stderr,"*** Error during listing of %s: %s\n",
namePtr, DecodeError(result));
return(result);
case ERR_READING_MSG:
headerPtr = (dns_hdr_t *) &buf;
fprintf(stderr,"ListHosts: error receiving zone transfer:\n");
fprintf(stderr,
" result: %s, answers = %d, authority = %d, additional = %d\n",
resultcodes[headerPtr->dh_flag2 & DHF_RCODE],
ntohs(headerPtr->dh_ancount),
ntohs(headerPtr->dh_nscount),
ntohs(headerPtr->dh_arcount));
return(ERROR);
default:
return(ERROR);
}
}
static char *
DecodeError(result)
int result;
{
switch(result) {
case NOERROR: return("Success"); break;
case FORMERR: return("Format error"); break;
case SERVFAIL: return("Server failed"); break;
case NXDOMAIN: return("Non-existent domain"); break;
case NOTIMP: return("Not implemented"); break;
case REFUSED: return("Query refused"); break;
case NOCHANGE: return("No change"); break;
case NO_INFO: return("No information"); break;
case ERROR: return("Unspecified error"); break;
case TIME_OUT: return("Timed out"); break;
case NONAUTH: return("Non-authoritative answer"); break;
default: break;
}
return("BAD ERROR VALUE");
}
static int tcpip_writeall(fd, buf, siz)
int fd;
char *buf;
unsigned siz;
{
unsigned siz_org;
int nbytes;
siz_org= siz;
while (siz)
{
nbytes= write(fd, buf, siz);
if (nbytes == -1)
return nbytes;
assert(siz >= nbytes);
buf += nbytes;
siz -= nbytes;
}
return siz_org;
}
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