diff options
Diffstat (limited to 'resolv/gethnamaddr.c')
| -rw-r--r-- | resolv/gethnamaddr.c | 736 |
1 files changed, 736 insertions, 0 deletions
diff --git a/resolv/gethnamaddr.c b/resolv/gethnamaddr.c new file mode 100644 index 0000000000..55a3fb09a4 --- /dev/null +++ b/resolv/gethnamaddr.c @@ -0,0 +1,736 @@ +/* + * ++Copyright++ 1985, 1988, 1993 + * - + * Copyright (c) 1985, 1988, 1993 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * - + * Portions Copyright (c) 1993 by Digital Equipment Corporation. + * + * 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, and that + * the name of Digital Equipment Corporation not be used in advertising or + * publicity pertaining to distribution of the document or software without + * specific, written prior permission. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL + * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES + * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT + * CORPORATION 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. + * - + * --Copyright-- + */ + +#if defined(LIBC_SCCS) && !defined(lint) +static char sccsid[] = "@(#)gethostnamadr.c 8.1 (Berkeley) 6/4/93"; +static char rcsid[] = "$Id$"; +#endif /* LIBC_SCCS and not lint */ + +#include <sys/param.h> +#include <sys/socket.h> +#include <netinet/in.h> +#include <arpa/inet.h> +#include <arpa/nameser.h> + +#include <stdio.h> +#include <netdb.h> +#include <resolv.h> +#include <ctype.h> +#include <errno.h> +#include <syslog.h> + +#ifndef LOG_AUTH +# define LOG_AUTH 0 +#endif + +#define MULTI_PTRS_ARE_ALIASES 1 /* XXX - experimental */ + +#if defined(BSD) && (BSD >= 199103) +# include <string.h> +#else +# include "../conf/portability.h" +#endif +#if defined(USE_OPTIONS_H) +# include <../conf/options.h> +#endif + +#define MAXALIASES 35 +#define MAXADDRS 35 + +static const char AskedForGot[] = + "gethostby*.getanswer: asked for \"%s\", got \"%s\""; + +static char *h_addr_ptrs[MAXADDRS + 1]; + +static struct hostent host; +static char *host_aliases[MAXALIASES]; +static char hostbuf[8*1024]; +static struct in_addr host_addr; +static FILE *hostf = NULL; +static int stayopen = 0; + +#ifdef RESOLVSORT +static void addrsort __P((char **, int)); +#endif + +#if PACKETSZ > 1024 +#define MAXPACKET PACKETSZ +#else +#define MAXPACKET 1024 +#endif + +typedef union { + HEADER hdr; + u_char buf[MAXPACKET]; +} querybuf; + +typedef union { + int32_t al; + char ac; +} align; + +extern int h_errno; + +#ifdef DEBUG +static void +dprintf(msg, num) + char *msg; + int num; +{ + if (_res.options & RES_DEBUG) { + int save = errno; + + printf(msg, num); + errno = save; + } +} +#else +# define dprintf(msg, num) /*nada*/ +#endif + +static struct hostent * +getanswer(answer, anslen, qname, qclass, qtype) + const querybuf *answer; + int anslen; + const char *qname; + int qclass, qtype; +{ + register const HEADER *hp; + register const u_char *cp; + register int n; + const u_char *eom; + char *bp, **ap, **hap; + int type, class, buflen, ancount, qdcount; + int haveanswer, had_error; + int toobig = 0; + char tbuf[MAXDNAME+1]; + + host.h_name = NULL; + eom = answer->buf + anslen; + /* + * find first satisfactory answer + */ + hp = &answer->hdr; + ancount = ntohs(hp->ancount); + qdcount = ntohs(hp->qdcount); + bp = hostbuf; + buflen = sizeof hostbuf; + cp = answer->buf + HFIXEDSZ; + if (qdcount != 1) { + h_errno = NO_RECOVERY; + return (NULL); + } + if ((n = dn_expand(answer->buf, eom, cp, bp, buflen)) < 0) { + h_errno = NO_RECOVERY; + return (NULL); + } + cp += n + QFIXEDSZ; + if (qtype == T_A) { + /* res_send() has already verified that the query name is the + * same as the one we sent; this just gets the expanded name + * (i.e., with the succeeding search-domain tacked on). + */ + n = strlen(bp) + 1; /* for the \0 */ + host.h_name = bp; + bp += n; + buflen -= n; + /* The qname can be abbreviated, but h_name is now absolute. */ + qname = host.h_name; + } + ap = host_aliases; + *ap = NULL; + host.h_aliases = host_aliases; + hap = h_addr_ptrs; + *hap = NULL; +#if BSD >= 43 || defined(h_addr) /* new-style hostent structure */ + host.h_addr_list = h_addr_ptrs; +#endif + haveanswer = 0; + had_error = 0; + while (ancount-- > 0 && cp < eom && !had_error) { + n = dn_expand(answer->buf, eom, cp, bp, buflen); + if (n < 0) { + had_error++; + continue; + } + cp += n; /* name */ + type = _getshort(cp); + cp += INT16SZ; /* type */ + class = _getshort(cp); + cp += INT16SZ + INT32SZ; /* class, TTL */ + n = _getshort(cp); + cp += INT16SZ; /* len */ + if (class != qclass) { + /* XXX - debug? syslog? */ + cp += n; + continue; /* XXX - had_error++ ? */ + } + if (qtype == T_A && type == T_CNAME) { + if (ap >= &host_aliases[MAXALIASES-1]) + continue; + n = dn_expand(answer->buf, eom, cp, tbuf, sizeof tbuf); + if (n < 0) { + had_error++; + continue; + } + cp += n; + if (host.h_name && strcasecmp(host.h_name, bp) != 0) { + syslog(LOG_NOTICE|LOG_AUTH, + "gethostby*.getanswer: asked for \"%s\", got CNAME for \"%s\"", + host.h_name, bp); + continue; /* XXX - had_error++ ? */ + } + /* Store alias. */ + *ap++ = bp; + n = strlen(bp) + 1; /* for the \0 */ + bp += n; + buflen -= n; + /* Get canonical name. */ + n = strlen(tbuf) + 1; /* for the \0 */ + if (n > buflen) { + had_error++; + continue; + } + strcpy(bp, tbuf); + host.h_name = bp; + bp += n; + buflen -= n; + continue; + } + if (type != qtype) { + syslog(LOG_NOTICE|LOG_AUTH, + "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"", + qname, p_class(qclass), p_type(qtype), + p_type(type)); + cp += n; + continue; /* XXX - had_error++ ? */ + } + switch (type) { + case T_PTR: + if (strcasecmp(qname, bp) != 0) { + syslog(LOG_NOTICE|LOG_AUTH, + AskedForGot, qname, bp); + cp += n; + continue; /* XXX - had_error++ ? */ + } + n = dn_expand(answer->buf, eom, cp, bp, buflen); + if (n < 0) { + had_error++; + break; + } +#if MULTI_PTRS_ARE_ALIASES + cp += n; + if (!haveanswer) + host.h_name = bp; + else if (ap < &host_aliases[MAXALIASES-1]) + *ap++ = bp; + else + n = -1; + if (n != -1) { + n = strlen(bp) + 1; /* for the \0 */ + bp += n; + buflen -= n; + } + break; +#else + host.h_name = bp; + h_errno = NETDB_SUCCESS; + return (&host); +#endif + case T_A: + if (strcasecmp(host.h_name, bp) != 0) { + syslog(LOG_NOTICE|LOG_AUTH, + AskedForGot, host.h_name, bp); + cp += n; + continue; /* XXX - had_error++ ? */ + } + if (haveanswer) { + if (n != host.h_length) { + cp += n; + continue; + } + } else { + register int nn; + + host.h_length = n; + host.h_addrtype = (class == C_IN) + ? AF_INET + : AF_UNSPEC; + host.h_name = bp; + nn = strlen(bp) + 1; /* for the \0 */ + bp += nn; + buflen -= nn; + } + + bp += sizeof(align) - ((u_long)bp % sizeof(align)); + + if (bp + n >= &hostbuf[sizeof hostbuf]) { + dprintf("size (%d) too big\n", n); + had_error++; + continue; + } + if (hap >= &h_addr_ptrs[MAXADDRS-1]) { + if (!toobig++) + dprintf("Too many addresses (%d)\n", + MAXADDRS); + cp += n; + continue; + } + bcopy(cp, *hap++ = bp, n); + bp += n; + cp += n; + break; + default: + dprintf("Impossible condition (type=%d)\n", type); + h_errno = NO_RECOVERY; + return (NULL); + } /*switch*/ + if (!had_error) + haveanswer++; + } /*while*/ + if (haveanswer) { + *ap = NULL; + *hap = NULL; +# if defined(RESOLVSORT) + /* + * Note: we sort even if host can take only one address + * in its return structures - should give it the "best" + * address in that case, not some random one + */ + if (_res.nsort && haveanswer > 1 && + qclass == C_IN && qtype == T_A) + addrsort(h_addr_ptrs, haveanswer); +# endif /*RESOLVSORT*/ +#if BSD >= 43 || defined(h_addr) /* new-style hostent structure */ + /* nothing */ +#else + host.h_addr = h_addr_ptrs[0]; +#endif /*BSD*/ + if (!host.h_name) { + n = strlen(qname) + 1; /* for the \0 */ + strcpy(bp, qname); + host.h_name = bp; + } + h_errno = NETDB_SUCCESS; + return (&host); + } else { + h_errno = TRY_AGAIN; + return (NULL); + } +} + +struct hostent * +gethostbyname(name) + const char *name; +{ + querybuf buf; + register const char *cp; + int n; + extern struct hostent *_gethtbyname(); + + /* + * if there aren't any dots, it could be a user-level alias. + * this is also done in res_query() since we are not the only + * function that looks up host names. + */ + if (!strchr(name, '.') && (cp = __hostalias(name))) + name = cp; + + /* + * disallow names consisting only of digits/dots, unless + * they end in a dot. + */ + if (isdigit(name[0])) + for (cp = name;; ++cp) { + if (!*cp) { + if (*--cp == '.') + break; + /* + * All-numeric, no dot at the end. + * Fake up a hostent as if we'd actually + * done a lookup. + */ + if (!inet_aton(name, &host_addr)) { + h_errno = HOST_NOT_FOUND; + return (NULL); + } + host.h_name = (char *)name; + host.h_aliases = host_aliases; + host_aliases[0] = NULL; + host.h_addrtype = AF_INET; + host.h_length = INT32SZ; + h_addr_ptrs[0] = (char *)&host_addr; + h_addr_ptrs[1] = NULL; +#if BSD >= 43 || defined(h_addr) /* new-style hostent structure */ + host.h_addr_list = h_addr_ptrs; +#else + host.h_addr = h_addr_ptrs[0]; +#endif + h_errno = NETDB_SUCCESS; + return (&host); + } + if (!isdigit(*cp) && *cp != '.') + break; + } + + if ((n = res_search(name, C_IN, T_A, buf.buf, sizeof(buf))) < 0) { + dprintf("res_search failed (%d)\n", n); + if (errno == ECONNREFUSED) + return (_gethtbyname(name)); + return (NULL); + } + return (getanswer(&buf, n, name, C_IN, T_A)); +} + +struct hostent * +gethostbyaddr(addr, len, type) + const char *addr; + int len, type; +{ + int n; + querybuf buf; + register struct hostent *hp; + char qbuf[MAXDNAME+1]; +#ifdef SUNSECURITY + register struct hostent *rhp; + char **haddr; + u_long old_options; + char hname2[MAXDNAME+1]; +#endif /*SUNSECURITY*/ + extern struct hostent *_gethtbyaddr(); + + if (type != AF_INET) { + errno = EAFNOSUPPORT; + h_errno = NETDB_INTERNAL; + return (NULL); + } + (void)sprintf(qbuf, "%u.%u.%u.%u.in-addr.arpa", + ((unsigned)addr[3] & 0xff), + ((unsigned)addr[2] & 0xff), + ((unsigned)addr[1] & 0xff), + ((unsigned)addr[0] & 0xff)); + n = res_query(qbuf, C_IN, T_PTR, (u_char *)buf.buf, sizeof buf.buf); + if (n < 0) { + dprintf("res_query failed (%d)\n", n); + if (errno == ECONNREFUSED) + return (_gethtbyaddr(addr, len, type)); + return (NULL); + } + if (!(hp = getanswer(&buf, n, qbuf, C_IN, T_PTR))) + return (NULL); /* h_errno was set by getanswer() */ +#ifdef SUNSECURITY + /* + * turn off search as the name should be absolute, + * 'localhost' should be matched by defnames + */ + strncpy(hname2, hp->h_name, MAXDNAME); + hname2[MAXDNAME] = '\0'; + old_options = _res.options; + _res.options &= ~RES_DNSRCH; + _res.options |= RES_DEFNAMES; + if (!(rhp = gethostbyname(hp->h_name))) { + syslog(LOG_NOTICE|LOG_AUTH, + "gethostbyaddr: No A record for %s (verifying [%s])", + hname2, inet_ntoa(*((struct in_addr *)addr))); + _res.options = old_options; + h_errno = HOST_NOT_FOUND; + return (NULL); + } + _res.options = old_options; + for (haddr = rhp->h_addr_list; *haddr; haddr++) + if (!memcmp(*haddr, addr, INADDRSZ)) + break; + if (!*haddr) { + syslog(LOG_NOTICE|LOG_AUTH, + "gethostbyaddr: A record of %s != PTR record [%s]", + hname2, inet_ntoa(*((struct in_addr *)addr))); + h_errno = HOST_NOT_FOUND; + return (NULL); + } +#endif /*SUNSECURITY*/ + hp->h_addrtype = type; + hp->h_length = len; + h_addr_ptrs[0] = (char *)&host_addr; + h_addr_ptrs[1] = NULL; + host_addr = *(struct in_addr *)addr; + h_errno = NETDB_SUCCESS; + return (hp); +} + +void +_sethtent(f) + int f; +{ + if (!hostf) + hostf = fopen(_PATH_HOSTS, "r" ); + else + rewind(hostf); + stayopen = f; +} + +void +_endhtent() +{ + if (hostf && !stayopen) { + (void) fclose(hostf); + hostf = NULL; + } +} + +struct hostent * +_gethtent() +{ + char *p; + register char *cp, **q; + + if (!hostf && !(hostf = fopen(_PATH_HOSTS, "r" ))) { + h_errno = NETDB_INTERNAL; + return (NULL); + } +again: + if (!(p = fgets(hostbuf, sizeof hostbuf, hostf))) { + h_errno = HOST_NOT_FOUND; + return (NULL); + } + if (*p == '#') + goto again; + if (!(cp = strpbrk(p, "#\n"))) + goto again; + *cp = '\0'; + if (!(cp = strpbrk(p, " \t"))) + goto again; + *cp++ = '\0'; + /* THIS STUFF IS INTERNET SPECIFIC */ + if (!inet_aton(p, &host_addr)) + goto again; + h_addr_ptrs[0] = (char *)&host_addr; + h_addr_ptrs[1] = NULL; +#if BSD >= 43 || defined(h_addr) /* new-style hostent structure */ + host.h_addr_list = h_addr_ptrs; +#else + host.h_addr = h_addr_ptrs[0]; +#endif + host.h_length = INT32SZ; + host.h_addrtype = AF_INET; + while (*cp == ' ' || *cp == '\t') + cp++; + host.h_name = cp; + q = host.h_aliases = host_aliases; + if (cp = strpbrk(cp, " \t")) + *cp++ = '\0'; + while (cp && *cp) { + if (*cp == ' ' || *cp == '\t') { + cp++; + continue; + } + if (q < &host_aliases[MAXALIASES - 1]) + *q++ = cp; + if (cp = strpbrk(cp, " \t")) + *cp++ = '\0'; + } + *q = NULL; + h_errno = NETDB_SUCCESS; + return (&host); +} + +struct hostent * +_gethtbyname(name) + char *name; +{ + register struct hostent *p; + register char **cp; + + _sethtent(0); + while (p = _gethtent()) { + if (strcasecmp(p->h_name, name) == 0) + break; + for (cp = p->h_aliases; *cp != 0; cp++) + if (strcasecmp(*cp, name) == 0) + goto found; + } +found: + _endhtent(); + return (p); +} + +struct hostent * +_gethtbyaddr(addr, len, type) + const char *addr; + int len, type; +{ + register struct hostent *p; + + _sethtent(0); + while (p = _gethtent()) + if (p->h_addrtype == type && !bcmp(p->h_addr, addr, len)) + break; + _endhtent(); + return (p); +} + +#ifdef RESOLVSORT +static void +addrsort(ap, num) + char **ap; + int num; +{ + int i, j; + char **p; + short aval[MAXADDRS]; + int needsort = 0; + + p = ap; + for (i = 0; i < num; i++, p++) { + for (j = 0 ; (unsigned)j < _res.nsort; j++) + if (_res.sort_list[j].addr.s_addr == + (((struct in_addr *)(*p))->s_addr & _res.sort_list[j].mask)) + break; + aval[i] = j; + if (needsort == 0 && i > 0 && j < aval[i-1]) + needsort = i; + } + if (!needsort) + return; + + while (needsort < num) { + for (j = needsort - 1; j >= 0; j--) { + if (aval[j] > aval[j+1]) { + char *hp; + + i = aval[j]; + aval[j] = aval[j+1]; + aval[j+1] = i; + + hp = ap[j]; + ap[j] = ap[j+1]; + ap[j+1] = hp; + + } else + break; + } + needsort++; + } +} +#endif + +#if defined(BSD43_BSD43_NFS) || defined(sun) +/* some libc's out there are bound internally to these names (UMIPS) */ +void +ht_sethostent(stayopen) + int stayopen; +{ + _sethtent(stayopen); +} + +void +ht_endhostent() +{ + _endhtent(); +} + +struct hostent * +ht_gethostbyname(name) + char *name; +{ + return (_gethtbyname(name)); +} + +struct hostent * +ht_gethostbyaddr(addr, len, type) + const char *addr; + int len, type; +{ + return (_gethtbyaddr(addr, len, type)); +} + +struct hostent * +gethostent() +{ + return (_gethtent()); +} + +void +dns_service() +{ + return; +} + +#undef dn_skipname +dn_skipname(comp_dn, eom) + const u_char *comp_dn, *eom; +{ + return (__dn_skipname(comp_dn, eom)); +} +#endif /*old-style libc with yp junk in it*/ + +#ifdef ultrix +/* more icky libc packaging in ultrix */ +int +local_hostname_length(hostname) + const char *hostname; +{ + int len_host, len_domain; + + if (!*_res.defdname) + res_init(); + len_host = strlen(hostname); + len_domain = strlen(_res.defdname); + if (len_host > len_domain && + !strcasecmp(hostname + len_host - len_domain, _res.defdname) && + hostname[len_host - len_domain - 1] == '.') + return (len_host - len_domain - 1); + return (0); +} +#endif |