/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright 2015 Gary Mills * Copyright 2008 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ /* All Rights Reserved */ /* * University Copyright- Copyright (c) 1982, 1986, 1988 * The Regents of the University of California * All Rights Reserved * * University Acknowledgment- Portions of this document are derived from * software developed by the University of California, Berkeley, and its * contributors. */ #include <sys/types.h> #include <sys/sockio.h> #include <sys/socket.h> #include <netinet/in.h> #include <stdio.h> #include <string.h> #include <stdlib.h> #include <unistd.h> #include <stropts.h> #include <arpa/nameser.h> #include <resolv.h> #include <netinet/in.h> #include <net/if.h> #include <netinet/if_ether.h> #include <arpa/inet.h> /* * Undocumented external function in libnsl */ extern int getdomainname(char *, int); #define MAXIFS 256 /* * Resolver state default settings */ struct state _res = { RES_TIMEOUT, /* retransmition time interval */ 4, /* number of times to retransmit */ RES_DEFAULT, /* options flags */ 1, /* number of name servers */ }; /* * Set up default settings. If the configuration file exist, the values * there will have precedence. Otherwise, the server address is set to * INADDR_LOOPBACK and the default domain name comes from the gethostname(). * BUT if the NIS/RPC domain name is set, that is used if all else fails. * * The configuration file should only be used if you want to redefine your * domain or run without a server on your machine. * * Note the user can always override then domain name with the environment * variable LOCALDOMAIN which has absolute priority. * * * Return 0 if completes successfully, -1 on error */ int res_init(void) { register FILE *fp; register char *cp, **pp; register int n; char buf[BUFSIZ]; int nserv = 0; /* number of nameserver records read from file */ int haveenv = 0; int havesearch = 0; _res.nsaddr.sin_addr.s_addr = htonl(INADDR_LOOPBACK); /* INADDR_ANY */ _res.nsaddr.sin_family = AF_INET; _res.nsaddr.sin_port = htons(NAMESERVER_PORT); _res.nscount = 1; #ifdef SIOCGIFNUM { int numifs, s, n, int_up; struct ifconf ifc; register struct ifreq *ifrp; struct ifreq ifr; unsigned bufsize; unsigned int flags; char *buf; if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { perror("socket"); return (-1); } if (ioctl(s, SIOCGIFNUM, (char *)&numifs) < 0) { numifs = MAXIFS; } bufsize = numifs * sizeof (struct ifreq); buf = (char *)malloc(bufsize); if (buf == NULL) { perror("out of memory"); (void) close(s); return (-1); } ifc.ifc_len = bufsize; ifc.ifc_buf = buf; if (ioctl(s, SIOCGIFCONF, (char *)&ifc) < 0) { perror("ifconfig: SIOCGIFCONF"); (void) close(s); free(buf); return (-1); } int_up = 0; ifrp = ifc.ifc_req; for (n = ifc.ifc_len / sizeof (struct ifreq); n > 0; n--, ifrp++) { (void) memset((void *) &ifr, 0, sizeof (ifr)); strncpy(ifr.ifr_name, ifrp->ifr_name, sizeof (ifr.ifr_name)); if (ioctl(s, SIOCGIFFLAGS, (char *)&ifr) < 0) { perror("SIOCGIFFLAGS"); (void) close(s); free(buf); return (-1); } flags = ifr.ifr_flags; /* we are looking for a non-loopback interface */ if ((flags & IFF_UP) && ((flags & IFF_LOOPBACK) == 0)) int_up = 1; } (void) close(s); free(buf); if (int_up == 0) /* all the non-LOOPBACK interfaces are DOWN */ return (-1); } #endif /* SIOCGIFNUM */ /* * for the benefit of hidden NIS domains, we use the same procedure * as sendmail: convert leading + to dot, then drop to first dot */ (void) getdomainname(buf, BUFSIZ); if (buf[0] == '+') buf[0] = '.'; #ifdef SYSV cp = strchr(buf, (int)'.'); #else cp = index(buf, '.'); #endif if (cp == NULL) strcpy(_res.defdname, buf); else strcpy(_res.defdname, cp+1); /* Allow user to override the local domain definition */ if ((cp = getenv("LOCALDOMAIN")) != NULL) { (void) strncpy(_res.defdname, cp, sizeof (_res.defdname)); haveenv++; } if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) { /* read the config file */ while (fgets(buf, sizeof (buf), fp) != NULL) { /* read default domain name */ if (!strncmp(buf, "domain", sizeof ("domain") - 1)) { if (haveenv) /* skip if have from environ */ continue; cp = buf + sizeof ("domain") - 1; while (*cp == ' ' || *cp == '\t') cp++; if ((*cp == '\0') || (*cp == '\n')) continue; (void) strncpy(_res.defdname, cp, sizeof (_res.defdname) - 1); #ifdef SYSV if ((cp = strchr(_res.defdname, (int)'\n')) != NULL) #else if ((cp = index(_res.defdname, '\n')) != NULL) #endif *cp = '\0'; havesearch = 0; continue; } /* set search list */ if (!strncmp(buf, "search", sizeof ("search") - 1)) { if (haveenv) /* skip if have from environ */ continue; cp = buf + sizeof ("search") - 1; while (*cp == ' ' || *cp == '\t') cp++; if ((*cp == '\0') || (*cp == '\n')) continue; (void) strncpy(_res.defdname, cp, sizeof (_res.defdname) - 1); #ifdef SYSV if ((cp = strchr(_res.defdname, (int)'\n')) != NULL) #else if ((cp = index(_res.defdname, '\n')) != NULL) #endif *cp = '\0'; /* * Set search list to be blank-separated strings * on rest of line. */ cp = _res.defdname; pp = _res.dnsrch; *pp++ = cp; for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) { if (*cp == ' ' || *cp == '\t') { *cp = 0; n = 1; } else if (n) { *pp++ = cp; n = 0; } } /* null terminate last domain if there are excess */ while (*cp != '\0' && *cp != ' ' && *cp != '\t') cp++; *cp = '\0'; *pp++ = 0; havesearch = 1; continue; } /* read nameservers to query */ if (!strncmp(buf, "nameserver", sizeof ("nameserver") - 1) && (nserv < MAXNS)) { cp = buf + sizeof ("nameserver") - 1; while (*cp == ' ' || *cp == '\t') cp++; if ((*cp == '\0') || (*cp == '\n')) continue; if ((_res.nsaddr_list[nserv].sin_addr.s_addr = inet_addr(cp)) == (unsigned) -1) { _res.nsaddr_list[n].sin_addr.s_addr = INADDR_ANY; continue; } _res.nsaddr_list[nserv].sin_family = AF_INET; _res.nsaddr_list[nserv].sin_port = htons(NAMESERVER_PORT); nserv++; continue; } } if (nserv > 1) _res.nscount = nserv; (void) fclose(fp); } if (_res.defdname[0] == 0) { if (gethostname(buf, sizeof (_res.defdname)) == 0 && #ifdef SYSV (cp = strchr(buf, (int)'.'))) #else (cp = index(buf, '.'))) #endif (void) strcpy(_res.defdname, cp + 1); } /* find components of local domain that might be searched */ if (havesearch == 0) { pp = _res.dnsrch; *pp++ = _res.defdname; for (cp = _res.defdname, n = 0; *cp; cp++) if (*cp == '.') n++; cp = _res.defdname; for (; n >= LOCALDOMAINPARTS && pp < _res.dnsrch + MAXDFLSRCH; n--) { #ifdef SYSV cp = strchr(cp, (int)'.'); #else cp = index(cp, '.'); #endif *pp++ = ++cp; } *pp++ = 0; } _res.options |= RES_INIT; return (0); }