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[unix-history] / usr / src / usr.sbin / amd / amd / info_hes.c

/*
* Copyright (c) 1989 Jan-Simon Pendry
* Copyright (c) 1989 Imperial College of Science, Technology & Medicine
* Copyright (c) 1989 The Regents of the University of California.
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Jan-Simon Pendry at Imperial College, London.
*
* %sccs.include.redist.c%
*
*      @(#)info_hes.c  5.4 (Berkeley) %G%
*
* $Id: info_hes.c,v 5.2.2.1 1992/02/09 15:08:29 jsp beta $
*
*/

/*
* Get info from Hesiod
*
* Zone transfer code from Bruce Cole <cole@cs.wisc.edu>
*/

#include "am.h"

#ifdef HAS_HESIOD_MAPS
#include <hesiod.h>

#define HES_PREFIX      "hesiod."
#define HES_PREFLEN     7

#ifdef HAS_HESIOD_RELOAD
#include <arpa/nameser.h>
#include <resolv.h>
#include <sys/uio.h>
#include <netdb.h>

/*
* Patch up broken system include files
*/
#ifndef C_HS
#define C_HS    4
#endif
#ifndef T_TXT
#define T_TXT   16
#endif

static int soacnt;
static struct timeval hs_timeout;
static int servernum;
#endif /* HAS_HESIOD_RELOAD */

/*
* No easy way to probe the server - check the map name begins with "hesiod."
*/
int hesiod_init P((char *map, time_t *tp));
int hesiod_init(map, tp)
char *map;
time_t *tp;
{
#ifdef DEBUG
       dlog("hesiod_init(%s)", map);
#endif
       *tp = 0;
       return strncmp(map, HES_PREFIX, HES_PREFLEN) == 0 ? 0 : ENOENT;
}


/*
* Make Hesiod name.  Skip past the "hesiod."
* at the start of the map name and append
* ".automount".  The net effect is that a lookup
* of /defaults in hesiod.home will result in a
* call to hes_resolve("/defaults", "home.automount");
*/
#ifdef notdef
#define MAKE_HES_NAME(dest, src) sprintf(dest, "%s%s", src + HES_PREFLEN, ".automount")
#endif

/*
* Do a Hesiod nameserver call.
* Modify time is ignored by Hesiod - XXX
*/
int hesiod_search P((mnt_map *m, char *map, char **pval, time_t *tp));
int hesiod_search(m, map, key, pval, tp)
mnt_map *m;
char *map;
char *key;
char **pval;
time_t *tp;
{
       int error;
       char hes_key[MAXPATHLEN];
       char **rvec;
#ifdef DEBUG
       dlog("hesiod_search(m=%x, map=%s, key=%s, pval=%x tp=%x)", m, map, key, pval, tp);
#endif
       /*MAKE_HES_NAME(hes_map, map);*/
       sprintf(hes_key, "%s.%s", key, map+HES_PREFLEN);

       /*
        * Call the resolver
        */
#ifdef DEBUG
       dlog("hesiod_search: hes_resolve(%s, %s)", hes_key, "automount");
#ifdef HAS_HESIOD_RELOAD
       if (debug_flags & D_FULL)
               _res.options |= RES_DEBUG;
#endif
#endif
       rvec = hes_resolve(hes_key, "automount");
       /*
        * If a reply was forthcoming then return
        * it (and free subsequent replies)
        */
       if (rvec && *rvec) {
               *pval = *rvec;
               while (*++rvec)
                       free(*rvec);
               return 0;
       }

       /*
        * Otherwise reflect the hesiod error into a Un*x error
        */
#ifdef DEBUG
       dlog("hesiod_search: Error: %d", hes_error());
#endif
       switch (hes_error()) {
       case HES_ER_NOTFOUND:   error = ENOENT; break;
       case HES_ER_CONFIG:     error = EIO; break;
       case HES_ER_NET:        error = ETIMEDOUT; break;
       default:                error = EINVAL; break;
       }
#ifdef DEBUG
       dlog("hesiod_search: Returning: %d", error);
#endif
       return error;
}

#ifdef HAS_HESIOD_RELOAD
/*
* Zone transfer...
*/

#define MAXHSNS 8
#define MAX_NSADDR 16

static char *hs_domain;
static mnt_map *hs_map;
static int hs_nscount;
static char nsaddr_list[MAX_NSADDR][sizeof(struct in_addr)];

int hesiod_reload P((mnt_map *m, char *map, void (*fn)()));
int hesiod_reload(m, map, fn)
mnt_map *m;
char *map;
void (*fn)();
{
       char *zone_name, *cp;
       short domainlen;
       int status;

#ifdef DEBUG
       dlog("hesiod_reload (%x %s %x)", m, map, fn);
#endif DEBUG
       if (status = res_init()) {
#ifdef DEBUG
               dlog("hesiod_reload: res_init failed with %d", status);
#endif
               return(status);
       }
       _res.retrans = 90;
       hs_map = m;
       domainlen = strlen(hostdomain);
       zone_name = hes_to_bind(map+HES_PREFLEN, "automount");
       if (*zone_name == '.')
               zone_name++;
       hs_domain = zone_name;
       /* Traverse the DNS tree until we find an SOA we can transfer from.
        (Our initial zone_name is likely to just be a subtree of a
        real zone). */
       do {
               /* If we can't find any NS records, go up a level in the
                  DNS tree */
               if (hs_get_ns_list(zone_name) == 0 &&
                   hs_zone_transfer(zone_name) == 0)
                       return(0);
               /* Move up DNS tree by one component */
               if (cp = strchr(zone_name, '.'))
                       zone_name = ++cp;
               else
                       break;
       } while (strlen(zone_name) >= domainlen);
#ifdef DEBUG
       dlog("hesiod_reload: Giving up on %s", hs_domain);
#endif
       return(-1);
}

hs_zone_transfer(domain)
char *domain;
{
       int status, len;
       char buf[PACKETSZ];
       /* Want to make sure ansbuf is well alligned */
       long ansbuf[PACKETSZ/sizeof(long)];

#ifdef DEBUG
       dlog("hs_zone_transfer (%s)", domain);
#endif
       if ((len = res_mkquery(QUERY, domain, C_HS, T_AXFR,
                              (char *)NULL, 0, NULL, buf, PACKETSZ)) == -1) {
#ifdef DEBUG
               dlog("hs_zone_transfer: res_mkquery failed");
#endif
               errno = 0;
               return(-1);
       }
       if ((status = hs_res_send(buf, len, (char *)ansbuf, PACKETSZ)) == -1) {
#ifdef DEBUG
           dlog("hs_zone_transfer: hs_res_send failed.  status %d errno %d",
                status, errno);
#endif
               errno = 0;
               return(-1);
       }
       return(0);
}

#define hs_server_addr(ns) ((struct in_addr *) nsaddr_list[ns])

hs_res_send(buf, buflen, answer, anslen)
char *buf;
int buflen;
char *answer;
int anslen;
{
       int retry, ns;
       u_short id, len;
       HEADER *hp = (HEADER *) buf;
       struct iovec iov[2];
       static int s = -1;
       int status;
       struct sockaddr_in server;

       soacnt = 0;
       id = hp->id;
       /*
        * Send request, RETRY times, or until successful
        */
       for (retry = _res.retry; retry > 0; retry--) {
               for (ns = 0; ns < hs_nscount; ns++) {
                       hs_timeout.tv_sec =
                               (_res.retrans << (_res.retry - retry))
                               / hs_nscount;
                       if (hs_timeout.tv_sec <= 0)
                               hs_timeout.tv_sec = 1;
                       hs_timeout.tv_usec = 0;
                       if (s < 0) {
                               s = socket(AF_INET, SOCK_STREAM, 0);
                               if (s < 0) {
                                       continue;
                               }
                               servernum = ns;
                               bcopy(hs_server_addr(ns), &server.sin_addr,
                                     sizeof(struct in_addr));
                               server.sin_family = AF_INET;
                               server.sin_port = htons(NAMESERVER_PORT);
                                       
                               if (connect(s, &server,
                                           sizeof(struct sockaddr)) < 0) {
                                       (void) close(s);
                                       s = -1;
                                       continue;
                               }
                       }
                       /*
                        * Send length & message
                        */
                       len = htons((u_short)buflen);
                       iov[0].iov_base = (caddr_t)&len;
                       iov[0].iov_len = sizeof(len);
                       iov[1].iov_base = buf;
                       iov[1].iov_len = buflen;
                       if (writev(s, iov, 2) != sizeof(len) + buflen) {
                               (void) close(s);
                               s = -1;
                               continue;
                       }
                       status = 0;
                       while (s != -1 && soacnt < 2 && status != -2) {
                               if ((status =
                                    hs_readresp(s, answer, anslen)) == -1) {
                                       (void) close(s);
                                       s = -1;
                                       continue;
                               }
                       }
                       if (status == -2) {
                               /* There was a permanent error transfering this
                                  zone.  Give up. */
                               if (s != -1) {
                                       (void) close(s);
                                       s = -1;
                               }
                               return(-1);
                       }
                       if (s == -1)
                               continue;
                       return (0);
               }
       }
       if (errno == 0)
               errno = ETIMEDOUT;
       return (-1);
}

/* Returns:
  0: Success
  -1: Error
  -2: Permanent failure
*/
hs_readresp(s, answer, anslen)
int s;
char *answer;
int anslen;
{
       register int len, n;
       char *cp;

       cp = answer;
       len = sizeof(short);
       while (len != 0 &&
              (n = hs_res_vcread(s, (char *)cp, (int)len, &hs_timeout)) > 0) {
               cp += n;
               len -= n;
       }
       if (n <= 0)
               return(-1);
       cp = answer;
       if ((len = _getshort(cp)) > anslen) {
#ifdef DEBUG
               dlog("hs_readresp: response too long: %d", len);
#endif
               return(-1);
       }
       while (len != 0 &&
              (n = hs_res_vcread(s, (char *)cp, (int)len, &hs_timeout)) > 0) {
               cp += n;
               len -= n;
       }
       if (n <= 0)
               return(-1);
       return(hs_parse(answer, answer+PACKETSZ));
}

hs_res_vcread(sock, buf, buflen, timeout)
int sock, buflen;
char *buf;
struct timeval *timeout;
{
       register int n;

       if ((n = hs_res_selwait(sock, timeout)) > 0)
               return(read(sock, buf, buflen));
       else
               return(n);
}

hs_res_selwait(sock, timeout)
int sock;
struct timeval *timeout;
{
       fd_set dsmask;
       register int n;

       /*
        * Wait for reply
        */
       FD_ZERO(&dsmask);
       FD_SET(sock, &dsmask);
       n = select(sock+1, &dsmask, (fd_set *)NULL,
                  (fd_set *)NULL, timeout);
       return(n);
}

/* Returns:
  0: Success
  -1: Error
  -2: Permanent failure
*/
hs_parse(msg, eom)
char *msg, *eom;
{
       register char *cp;
       register HEADER *hp;
       register int n, len;
       int qdcount, ancount;
       char key[PACKETSZ];
       char *key_cpy, *value, *hs_make_value();
       short type;

       hp = (HEADER *)msg;
       if (hp->rcode != NOERROR || hp->opcode != QUERY) {
               char dq[20];
#ifdef DEBUG
               dlog("Bad response (%d) from nameserver %s", hp->rcode, inet_dquad(dq, hs_server_addr(servernum)->s_addr));
#endif DEBUG
               return(-1);
       }
       cp = msg + sizeof(HEADER);
       ancount = ntohs(hp->ancount);
       qdcount = ntohs(hp->qdcount);
       while (qdcount-- > 0)
               cp += dn_skipname(cp, eom) + QFIXEDSZ;
       if (soacnt == 0 && ancount == 0) {
               /* XXX We should look for NS records to find SOA */
#ifdef DEBUG
               dlog("No SOA found");
#endif
               return(-2);
       }
       while (ancount-- > 0 && cp < eom) {
               if ((n = dn_expand(msg, eom, cp, key, PACKETSZ)) < 0)
                       break;
               cp += n;
               if ((type = _getshort(cp)) == T_SOA) {
                       soacnt++;
               }
               cp += 2*sizeof(u_short) + sizeof(u_long);
               len = _getshort(cp);
               cp += sizeof(u_short);
               /* Check to see if key is in our domain */
               if (type == T_TXT && hs_strip_our_domain(key)) {
                       value = hs_make_value(cp, len);
                       if (value == NULL)
                               return(-1);
                       key_cpy = strdup(key);
#ifdef DEBUG
                       dlog("hs_parse: Parsed key: %s, value: %s", key,
                            value);
#endif
                       mapc_add_kv(hs_map, key_cpy, value);
               }
               cp += len;
               errno = 0;
       }
       return(0);
}

/* Check to see if the domain name in the supplied argument matches
  hs_domain.  Strip hs_domain from supplied argument if so. */
hs_strip_our_domain(name)
char *name;
{
       char *end_pos;
       short targ_len, cur_len;
       
       targ_len = strlen(hs_domain);
       cur_len = strlen(name);
       if (cur_len <= targ_len)
               return(0);
       end_pos = &name[cur_len - targ_len];
       if (strcmp(end_pos, hs_domain) != 0)
               return(0);
       if (*--end_pos != '.')
               return(0);
       *end_pos = '\0';
       return(1);
}

#define MAXDATA 8*1024

char *
hs_make_value(cp, len)
char *cp;
int len;
{
       char *value, *cpcpy, *valuep;
       int cnt, nextcnt, totalcnt, lencpy;
#ifdef DEBUG
       char *dbgname;

       dbgname = &cp[1];
#endif DEBUG

       lencpy = len;
       cpcpy = cp;
       totalcnt = 0;
       cnt = *cpcpy++;
       while (cnt) {
               totalcnt += cnt;
               lencpy -= cnt+1;
               if (lencpy == 0)
                       break;
               nextcnt = cpcpy[cnt];
               cpcpy = &cpcpy[cnt+1];
               cnt = nextcnt;
       }
       if (totalcnt < 1 || totalcnt > MAXDATA || totalcnt > len) {
#ifdef DEBUG
               dlog("TXT RR not of expected length (%d %d): %s", totalcnt,
                    len, dbgname);
#endif DEBUG
               return(NULL);
       }
       /* Allocate null terminated string */
       value = (char *) xmalloc(totalcnt+1);
       value[totalcnt] = '\0';
       cnt = *cp++;
       valuep = value;
       while (cnt) {
               bcopy(cp, valuep, cnt);
               len -= cnt+1;
               if (len == 0)
                       break;
               valuep = &valuep[cnt];
               nextcnt = cp[cnt];
               cp = &cp[cnt+1];
               cnt = nextcnt;
       }
       return(value);
}

hs_make_ns_query(domain, ansbuf)
char *domain;
char *ansbuf;
{
       int status, len;
       char buf[PACKETSZ];

       if ((len = res_mkquery(QUERY, domain, C_HS, T_NS,
                              (char *)NULL, 0, NULL, buf, PACKETSZ)) == -1) {
#ifdef DEBUG
               dlog("hs_get_ns_list: res_mkquery failed");
#endif
               errno = 0;
               return(-1);
       }
       if ((status = res_send(buf, len, (char *)ansbuf, PACKETSZ)) == -1) {
#ifdef DEBUG
           dlog("hs_get_ns_list: res_send failed.  status %d errno %d",
                status, errno);
#endif
               errno = 0;
               return(-1);
       }
       return(0);
}

static void
add_address(addr)
struct in_addr *addr;
{
       char dq[20];
       bcopy((char *)addr, nsaddr_list[hs_nscount++], sizeof(struct in_addr));
#ifdef DEBUG
       dlog("Adding NS address %s", inet_dquad(dq, addr->s_addr));
#endif DEBUG
}

hs_get_ns_list(domain)
char *domain;
{
       register HEADER *hp;
       int qdcount, nscount;
       register char *cp;
       register int n, len;
       char key[PACKETSZ], name[PACKETSZ], msg[PACKETSZ], *eom;
       register long **hptr;
       struct hostent *ghp;
       int numns;
       char nsname[MAXHSNS][MAXDATA];
       int nshaveaddr[MAXHSNS], i;
       short type;

       if (hs_make_ns_query(domain, msg) == -1)
               return(-1);
       numns = hs_nscount = 0;
       eom = &msg[PACKETSZ];
       bzero(nsname, sizeof(nsname));
       hp = (HEADER *)msg;
       if (hp->rcode != NOERROR || hp->opcode != QUERY) {
#ifdef DEBUG
               dlog("Bad response (%d) from nameserver %#x", hp->rcode,
                     hs_server_addr(servernum)->s_addr);
#endif DEBUG
               return(-1);
       }
       cp = msg + sizeof(HEADER);
       qdcount = ntohs(hp->qdcount);
       while (qdcount-- > 0)
               cp += dn_skipname(cp, eom) + QFIXEDSZ;
       nscount = ntohs(hp->ancount) + ntohs(hp->nscount) + ntohs(hp->arcount);
#ifdef DEBUG
       dlog("hs_get_ns_list: Processing %d response records", nscount);
#endif
       for (;nscount; nscount--) {
               if ((n = dn_expand(msg, eom, cp, key, PACKETSZ)) < 0)
                       break;
               cp += n;
               type = _getshort(cp);
               cp += 2*sizeof(u_short) + sizeof(u_long);
               len = _getshort(cp);
               cp += sizeof(u_short);
#ifdef DEBUG
               dlog("hs_get_ns_list: Record type: %d", type);
#endif
               switch (type) {
               case T_NS:
                       if (numns >= MAXHSNS || strcasecmp(domain, key) != 0)
                               break;
                       if ((n = dn_expand(msg, eom, cp, name, PACKETSZ)) < 0)
                               break;
#ifdef DEBUG
                       dlog("hs_get_ns_list: NS name: %s", name);
#endif
                       for (i = 0; i < numns; i++)
                               if (strcasecmp(nsname[i], name) == 0)
                                       break;
                       if (i == numns) {
#ifdef DEBUG
                               dlog("hs_get_ns_list: Saving name %s", name);
#endif
                               strncpy(nsname[numns], name, MAXDATA);
                               nshaveaddr[numns] = 0;
                               numns++;
                       }
                       break;
               case T_A:
                       if (hs_nscount == MAX_NSADDR)
                               break;
                       for (i = 0; i < numns; i++) {
                               if (strcasecmp(nsname[i], domain) == 0) {
                                       nshaveaddr[i]++;
                                       add_address((struct in_addr *) cp);
                                       break;
                               }
                       }
                       break;
               default:
                       break;
               }
               if (hs_nscount == MAX_NSADDR)
                       break;
               cp += len;
               errno = 0;
       }
#ifdef  DEBUG
       dlog("hs_get_ns_list: Found %d NS records", numns);
#endif
       for (i = 0; i < numns; i++) {
               if (nshaveaddr[i])
                       continue;
               if ((ghp = gethostbyname(nsname[i])) == 0)
                       continue;
               for (hptr = (long **)ghp->h_addr_list;
                    *hptr && hs_nscount < MAX_NSADDR; hptr++) {
                       add_address((struct in_addr *) *hptr);
               }
       }
       if (hs_nscount)
               return(0);
#ifdef DEBUG
       dlog("No NS records found for %s", domain);
       return(-1);
#endif DEBUG
}
#endif /* HAS_HESIOD_RELOAD */
#endif /* HAS_HESIOD_MAPS */