diff options
Diffstat (limited to 'lib/libc/net/gethostnamadr.c')
| -rw-r--r-- | lib/libc/net/gethostnamadr.c | 637 |
1 files changed, 637 insertions, 0 deletions
diff --git a/lib/libc/net/gethostnamadr.c b/lib/libc/net/gethostnamadr.c new file mode 100644 index 0000000..cbb7d74 --- /dev/null +++ b/lib/libc/net/gethostnamadr.c @@ -0,0 +1,637 @@ +/*- + * 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[] = "From: @(#)gethostnamadr.c 8.1 (Berkeley) 6/4/93"; +/*static char rcsid[] = "From: Id: gethnamaddr.c,v 4.9.1.1 1993/05/02 22:43:03 vixie Rel ";*/ +static const char rcsid[] = + "$Id: gethostnamadr.c,v 1.3 1994/08/09 22:44:12 wollman Exp $"; +#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 <netdb.h> +#include <resolv.h> +#include <stdio.h> +#include <ctype.h> +#include <errno.h> +#include <string.h> + +#define MAXALIASES 35 +#define MAXADDRS 35 + +#define _PATH_HOSTCONF "/etc/host.conf" + +enum service_type { + SERVICE_NONE = 0, + SERVICE_BIND, + SERVICE_HOSTS, + SERVICE_NIS }; +#define SERVICE_MAX SERVICE_NIS + +static struct { + const char *name; + enum service_type type; +} service_names[] = { + { "hosts", SERVICE_HOSTS }, + { "/etc/hosts", SERVICE_HOSTS }, + { "hosttable", SERVICE_HOSTS }, + { "htable", SERVICE_HOSTS }, + { "bind", SERVICE_BIND }, + { "dns", SERVICE_BIND }, + { "domain", SERVICE_BIND }, + { "yp", SERVICE_NIS }, + { "yellowpages", SERVICE_NIS }, + { "nis", SERVICE_NIS }, + { 0, SERVICE_NONE } +}; + +static enum service_type service_order[SERVICE_MAX + 1]; +static int service_done = 0; + +static char *h_addr_ptrs[MAXADDRS + 1]; + +static struct hostent host; +static char *host_aliases[MAXALIASES]; +static char hostbuf[BUFSIZ+1]; +static struct in_addr host_addr; +static FILE *hostf = NULL; +static char hostaddr[MAXADDRS]; +static char *host_addrs[2]; +static int stayopen = 0; + +#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; + +static enum service_type +get_service_name(const char *name) { + int i; + for(i = 0; service_names[i].type != SERVICE_NONE; i++) { + if(!strcasecmp(name, service_names[i].name)) { + return service_names[i].type; + } + } + return SERVICE_NONE; +} + +static void +init_services() +{ + char *cp, buf[BUFSIZ]; + register int cc = 0; + FILE *fd; + + if ((fd = (FILE *)fopen(_PATH_HOSTCONF, "r")) == NULL) { + /* make some assumptions */ + service_order[0] = SERVICE_BIND; + service_order[1] = SERVICE_HOSTS; + service_order[2] = SERVICE_NONE; + } else { + while (fgets(buf, BUFSIZ, fd) != NULL && cc < SERVICE_MAX) { + if(buf[0] == '#') + continue; + + cp = strtok(buf, "\n \t,:;"); + do { + if(!isalpha(cp[0])) continue; + service_order[cc] = get_service_name(buf); + if(service_order[cc] != SERVICE_NONE) + cc++; + } while((cp = strtok((char *)0, "\n \t,:;")) + && (cc < SERVICE_MAX)); + } + service_order[cc] = SERVICE_NONE; + fclose(fd); + } + service_done = 1; +} + +static struct hostent * +getanswer(answer, anslen, iquery) + querybuf *answer; + int anslen; + int iquery; +{ + register HEADER *hp; + register u_char *cp; + register int n; + u_char *eom; + char *bp, **ap; + int type, class, buflen, ancount, qdcount; + int haveanswer, getclass = C_ANY; + char **hap; + + 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 + sizeof(HEADER); + if (qdcount) { + if (iquery) { + if ((n = dn_expand((u_char *)answer->buf, + (u_char *)eom, (u_char *)cp, (u_char *)bp, + buflen)) < 0) { + h_errno = NO_RECOVERY; + return ((struct hostent *) NULL); + } + cp += n + QFIXEDSZ; + host.h_name = bp; + n = strlen(bp) + 1; + bp += n; + buflen -= n; + } else + cp += __dn_skipname(cp, eom) + QFIXEDSZ; + while (--qdcount > 0) + cp += __dn_skipname(cp, eom) + QFIXEDSZ; + } else if (iquery) { + if (hp->aa) + h_errno = HOST_NOT_FOUND; + else + h_errno = TRY_AGAIN; + return ((struct hostent *) NULL); + } + 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; + while (--ancount >= 0 && cp < eom) { + if ((n = dn_expand((u_char *)answer->buf, (u_char *)eom, + (u_char *)cp, (u_char *)bp, buflen)) < 0) + break; + cp += n; + type = _getshort(cp); + cp += sizeof(u_int16_t); + class = _getshort(cp); + cp += sizeof(u_int16_t) + sizeof(u_int32_t); + n = _getshort(cp); + cp += sizeof(u_int16_t); + if (type == T_CNAME) { + cp += n; + if (ap >= &host_aliases[MAXALIASES-1]) + continue; + *ap++ = bp; + n = strlen(bp) + 1; + bp += n; + buflen -= n; + continue; + } + if (iquery && type == T_PTR) { + if ((n = dn_expand((u_char *)answer->buf, + (u_char *)eom, (u_char *)cp, (u_char *)bp, + buflen)) < 0) + break; + cp += n; + host.h_name = bp; + return(&host); + } + if (iquery || type != T_A) { +#ifdef DEBUG + if (_res.options & RES_DEBUG) + printf("unexpected answer type %d, size %d\n", + type, n); +#endif + cp += n; + continue; + } + if (haveanswer) { + if (n != host.h_length) { + cp += n; + continue; + } + if (class != getclass) { + cp += n; + continue; + } + } else { + host.h_length = n; + getclass = class; + host.h_addrtype = (class == C_IN) ? AF_INET : AF_UNSPEC; + if (!iquery) { + host.h_name = bp; + bp += strlen(bp) + 1; + } + } + + bp += sizeof(align) - ((u_int32_t)bp % sizeof(align)); + + if (bp + n >= &hostbuf[sizeof(hostbuf)]) { +#ifdef DEBUG + if (_res.options & RES_DEBUG) + printf("size (%d) too big\n", n); +#endif + break; + } + bcopy(cp, *hap++ = bp, n); + bp +=n; + cp += n; + haveanswer++; + } + if (haveanswer) { + *ap = NULL; +#if BSD >= 43 || defined(h_addr) /* new-style hostent structure */ + *hap = NULL; +#else + host.h_addr = h_addr_ptrs[0]; +#endif + return (&host); + } else { + h_errno = TRY_AGAIN; + return ((struct hostent *) NULL); + } +} + +struct hostent * +_getdnsbyname(name) + const char *name; +{ + querybuf buf; + register const char *cp; + int n; + extern struct hostent *_gethtbyname(); + + /* + * 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((struct hostent *) NULL); + } + host.h_name = (char *)name; + host.h_aliases = host_aliases; + host_aliases[0] = NULL; + host.h_addrtype = AF_INET; + host.h_length = sizeof(u_int32_t); + h_addr_ptrs[0] = (char *)&host_addr; + h_addr_ptrs[1] = (char *)0; +#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 + return (&host); + } + if (!isdigit(*cp) && *cp != '.') + break; + } + + if ((n = res_search(name, C_IN, T_A, buf.buf, sizeof(buf))) < 0) { +#ifdef DEBUG + if (_res.options & RES_DEBUG) + printf("res_search failed\n"); +#endif + return ((struct hostent *) NULL); + } + return (getanswer(&buf, n, 0)); +} + +struct hostent * +_getdnsbyaddr(addr, len, type) + const char *addr; + int len, type; +{ + int n; + querybuf buf; + register struct hostent *hp; + char qbuf[MAXDNAME]; + extern struct hostent *_gethtbyaddr(); + + if (type != AF_INET) + return ((struct hostent *) 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, (char *)&buf, sizeof(buf)); + if (n < 0) { +#ifdef DEBUG + if (_res.options & RES_DEBUG) + printf("res_query failed\n"); +#endif + return ((struct hostent *) NULL); + } + hp = getanswer(&buf, n, 1); + if (hp == NULL) + return ((struct hostent *) NULL); + hp->h_addrtype = type; + hp->h_length = len; + h_addr_ptrs[0] = (char *)&host_addr; + h_addr_ptrs[1] = (char *)0; + host_addr = *(struct in_addr *)addr; +#if BSD < 43 && !defined(h_addr) /* new-style hostent structure */ + hp->h_addr = h_addr_ptrs[0]; +#endif + return(hp); +} + +void +_sethtent(f) + int f; +{ + if (hostf == NULL) + 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 == NULL && (hostf = fopen(_PATH_HOSTS, "r" )) == NULL) + return (NULL); +again: + if ((p = fgets(hostbuf, BUFSIZ, hostf)) == NULL) + return (NULL); + if (*p == '#') + goto again; + cp = strpbrk(p, "#\n"); + if (cp == NULL) + goto again; + *cp = '\0'; + cp = strpbrk(p, " \t"); + if (cp == NULL) + goto again; + *cp++ = '\0'; + /* THIS STUFF IS INTERNET SPECIFIC */ +#if BSD >= 43 || defined(h_addr) /* new-style hostent structure */ + host.h_addr_list = host_addrs; +#endif + host.h_addr = hostaddr; + *((u_int32_t *)host.h_addr) = inet_addr(p); + host.h_length = sizeof (u_int32_t); + host.h_addrtype = AF_INET; + while (*cp == ' ' || *cp == '\t') + cp++; + host.h_name = cp; + q = host.h_aliases = host_aliases; + cp = strpbrk(cp, " \t"); + if (cp != NULL) + *cp++ = '\0'; + while (cp && *cp) { + if (*cp == ' ' || *cp == '\t') { + cp++; + continue; + } + if (q < &host_aliases[MAXALIASES - 1]) + *q++ = cp; + cp = strpbrk(cp, " \t"); + if (cp != NULL) + *cp++ = '\0'; + } + *q = NULL; + 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 YP +struct hostent * +_getnishost(name, map) + char *name, *map; +{ + register char *cp, *dp, **q; + char *result; + int resultlen; + static struct hostent h; + static char *domain = (char *)NULL; + + if (domain == (char *)NULL) + if (yp_get_default_domain (&domain)) + return ((struct hostent *)NULL); + + if (yp_match(domain, map, name, strlen(name), &result, &resultlen)) + return ((struct hostent *)NULL); + + if (cp = index(result, '\n')) + *cp = '\0'; + + cp = strpbrk(result, " \t"); + *cp++ = '\0'; +#if BSD >= 43 || defined(h_addr) /* new-style hostent structure */ + h.h_addr_list = host_addrs; +#endif + h.h_addr = hostaddr; + *((u_long *)h.h_addr) = inet_addr(result); + h.h_length = sizeof(u_long); + h.h_addrtype = AF_INET; + while (*cp == ' ' || *cp == '\t') + cp++; + h.h_name = cp; + q = h.h_aliases = host_aliases; + cp = strpbrk(cp, " \t"); + if (cp != NULL) + *cp++ = '\0'; + while (cp && *cp) { + if (*cp == ' ' || *cp == '\t') { + cp++; + continue; + } + if (q < &host_aliases[MAXALIASES - 1]) + *q++ = cp; + cp = strpbrk(cp, " \t"); + if (cp != NULL) + *cp++ = '\0'; + } + *q = NULL; + return (&h); +} +#endif /* YP */ + +struct hostent * +gethostbyname(const char *name) +{ + struct hostent *hp = 0; + int nserv = 0; + + if(!service_done) { + init_services(); + } + + while(!hp) { + switch(service_order[nserv]) { + case SERVICE_NONE: + return 0; + case SERVICE_HOSTS: + hp = _gethtbyname(name); + break; + case SERVICE_BIND: + hp = _getdnsbyname(name); + break; + case SERVICE_NIS: +#ifdef YP + hp = _getnishost(name, "hosts.byname"); +#endif + break; + } + nserv++; + } + return hp; +} + +struct hostent * +gethostbyaddr(const char *addr, int len, int type) +{ + struct hostent *hp = 0; + int nserv = 0; + + if(!service_done) { + init_services(); + } + + while(!hp) { + switch(service_order[nserv]) { + case SERVICE_NONE: + return 0; + case SERVICE_HOSTS: + hp = _gethtbyaddr(addr, len, type); + break; + case SERVICE_BIND: + hp = _getdnsbyaddr(addr, len, type); + break; + case SERVICE_NIS: +#ifdef YP + hp = _getnishost(addr, "hosts.byaddr"); +#endif + break; + } + nserv++; + } + return hp; +} + |
