/* * Copyright (c) 1985, 1988 Regents of the University of California. * All rights reserved. * * Redistribution and use in source and binary forms are permitted * provided that: (1) source distributions retain this entire copyright * notice and comment, and (2) distributions including binaries display * the following acknowledgement: ``This product includes software * developed by the University of California, Berkeley and its contributors'' * in the documentation or other materials provided with the distribution * and in all advertising materials mentioning features or use of this * software. 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. */ #if defined(LIBC_SCCS) && !defined(lint) static char sccsid[] = "@(#)gethostnamadr.c 6.41 (Berkeley) 6/1/90"; #endif /* LIBC_SCCS and not lint */ #ifdef _MINIX #include #include #include #include #include #include #include #include #include #include #include #include #else #include #include #include #include #include #include #include #include #include #include #endif /* AMOEABA */ #define MAXALIASES 35 #define MAXADDRS 35 static char *h_addr_ptrs[MAXADDRS + 1]; #ifdef _MINIX struct in_addr { ipaddr_t s_addr; }; typedef u32_t u_long; typedef u16_t u_short; typedef u8_t u_char; union querybuf; extern int dn_skipname _ARGS(( const u_char *comp_dn, const u_char *eom )); #define getshort _getshort static struct hostent *getanswer _ARGS(( union querybuf *answer, int anslen, int iquery )); #define bcmp memcmp #define bcopy(s, d, l) memcpy(d, s, l) #endif /* _MINIX */ static struct hostent host; static char *host_aliases[MAXALIASES]; static char hostbuf[BUFSIZ+1]; static struct in_addr host_addr; #ifndef _MINIX char *strpbrk(); #endif /* !_MINIX */ #if PACKETSZ > 1024 #define MAXPACKET PACKETSZ #else #define MAXPACKET 1024 #endif typedef union querybuf { dns_hdr_t hdr; u_char buf[MAXPACKET]; } querybuf_t; typedef union align { long al; char ac; } align_t; static struct hostent * getanswer(answer, anslen, iquery) querybuf_t *answer; int anslen; int iquery; { register dns_hdr_t *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->dh_ancount); qdcount = ntohs(hp->dh_qdcount); bp = hostbuf; buflen = sizeof(hostbuf); cp = answer->buf + sizeof(dns_hdr_t); if (qdcount) { if (iquery) { if ((n = dn_expand((u_char *)answer->buf, eom, 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->dh_flag1 & DHF_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, eom, cp, (u_char *)bp, buflen)) < 0) break; cp += n; type = getshort(cp); cp += sizeof(u_short); class = getshort(cp); cp += sizeof(u_short) + sizeof(u_long); n = getshort(cp); cp += sizeof(u_short); 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((u8_t *)answer->buf, eom, cp, (u8_t *)bp, buflen)) < 0) { cp += n; continue; } 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 += (size_t)(sizeof(align_t) - ((u_long)bp % sizeof(align_t))); 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 * gethostbyname(name) _CONST char *name; { querybuf_t buf; register _CONST char *cp; int n; /* * 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. What if someone types * 255.255.255.255? The test below will * succeed spuriously... ??? */ if ((host_addr.s_addr = inet_addr(name)) == -1) { 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_long); 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((char*)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 * gethostbyaddr(addr, len, type) const char *addr; int len, type; { int n; querybuf_t buf; register struct hostent *hp; char qbuf[MAXDNAME]; 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, (u8_t *)&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); }