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-rw-r--r--resolv/res_init.c289
1 files changed, 250 insertions, 39 deletions
diff --git a/resolv/res_init.c b/resolv/res_init.c
index f3bcebc099..b6b1368ea5 100644
--- a/resolv/res_init.c
+++ b/resolv/res_init.c
@@ -1,8 +1,8 @@
/*
- * ++Copyright++ 1985, 1989
+ * ++Copyright++ 1985, 1989, 1993
* -
- * Copyright (c) 1985, 1989 Regents of the University of California.
- * All rights reserved.
+ * Copyright (c) 1985, 1989, 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
@@ -54,7 +54,7 @@
*/
#if defined(LIBC_SCCS) && !defined(lint)
-static char sccsid[] = "@(#)res_init.c 6.15 (Berkeley) 2/24/91";
+static char sccsid[] = "@(#)res_init.c 8.1 (Berkeley) 6/7/93";
static char rcsid[] = "$Id$";
#endif /* LIBC_SCCS and not lint */
@@ -63,36 +63,56 @@ static char rcsid[] = "$Id$";
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
-#include <resolv.h>
+
#include <stdio.h>
-#include "../conf/portability.h"
+#include <ctype.h>
+#include <resolv.h>
+#if defined(BSD) && (BSD >= 199103)
+# include <unistd.h>
+# include <stdlib.h>
+# include <string.h>
+#else
+# include "../conf/portability.h"
+#endif
+
+#if defined(USE_OPTIONS_H)
+# include "../conf/options.h"
+#endif
+
+static void res_setoptions __P((char *, char *));
+
+#ifdef RESOLVSORT
+static u_int32_t net_mask __P((struct in_addr));
+#endif
+#if !defined(isascii) /* XXX - could be a function */
+# define isascii(c) (!(c & 0200))
+#endif
/*
- * Resolver state default settings
+ * Resolver state default settings.
*/
-struct __res_state _res = {
- RES_TIMEOUT, /* retransmition time interval */
- 4, /* number of times to retransmit */
- RES_DEFAULT, /* options flags */
- 1, /* number of name servers */
-};
+struct __res_state _res;
/*
* Set up default settings. If the configuration file exist, the values
* there will have precedence. Otherwise, the server address is set to
- * 127.0.0.1 and the default domain name comes from the gethostname().
+ * INADDR_ANY and the default domain name comes from the gethostname().
*
- * Previous resolver versions used INADDR_ANY rather than IN_LOOPBACKNET.
- * This has bad side-effects in the kernel since 0.0.0.0 means "any interface"
- * and the first one found may or may not be the loopback interface.
- * If it is a point-to-point interface, then the SLIP or PPP or DDCMP state
- * must be "up" in order for the packets to loop correctly. This is deemed
- * "bad".
+ * An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
+ * rather than INADDR_ANY ("0.0.0.0") as the default name server address
+ * since it was noted that INADDR_ANY actually meant ``the first interface
+ * you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
+ * it had to be "up" in order for you to reach your own name server. It
+ * was later decided that since the recommended practice is to always
+ * install local static routes through 127.0.0.1 for all your network
+ * interfaces, that we could solve this problem without a code change.
*
- * The configuration file should only be used if you want to redefine your
- * domain or run without a server on your machine.
+ * The configuration file should always be used, since it is the only way
+ * to specify a default domain. If you are running a server on your local
+ * machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
+ * in the configuration file.
*
* Return 0 if completes successfully, -1 on error
*/
@@ -100,24 +120,79 @@ res_init()
{
register FILE *fp;
register char *cp, **pp;
- register int n;
+ register int n, dots;
char buf[BUFSIZ];
int nserv = 0; /* number of nameserver records read from file */
int haveenv = 0;
int havesearch = 0;
+#ifdef RESOLVSORT
+ int nsort = 0;
+ char *net;
+#endif
+ /*
+ * These four fields used to be statically initialized. This made
+ * it hard to use this code in a shared library. It is necessary,
+ * now that we're doing dynamic initialization here, that we preserve
+ * the old semantics: if an application modifies one of these three
+ * fields of _res before res_init() is called, res_init() will not
+ * alter them. Of course, if an application is setting them to
+ * _zero_ before calling res_init(), hoping to override what used
+ * to be the static default, we can't detect it and unexpected results
+ * will follow. Zero for any of these fields would make no sense,
+ * so one can safely assume that the applications were already getting
+ * unexpected results.
+ */
+ if (!_res.retrans)
+ _res.retrans = RES_TIMEOUT;
+ if (!_res.retry)
+ _res.retry = 4;
+ if (!_res.options)
+ _res.options = RES_DEFAULT;
+
+#ifdef USELOOPBACK
_res.nsaddr.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
+#else
+ _res.nsaddr.sin_addr.s_addr = INADDR_ANY;
+#endif
_res.nsaddr.sin_family = AF_INET;
_res.nsaddr.sin_port = htons(NAMESERVER_PORT);
_res.nscount = 1;
+ _res.ndots = 1;
_res.pfcode = 0;
/* Allow user to override the local domain definition */
if ((cp = getenv("LOCALDOMAIN")) != NULL) {
- (void)strncpy(_res.defdname, cp, sizeof(_res.defdname));
- if ((cp = strpbrk(_res.defdname, " \t\n")) != NULL)
- *cp = '\0';
+ (void)strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
haveenv++;
+
+ /*
+ * Set search list to be blank-separated strings
+ * from rest of env value. Permits users of LOCALDOMAIN
+ * to still have a search list, and anyone to set the
+ * one that they want to use as an individual (even more
+ * important now that the rfc1535 stuff restricts searches)
+ */
+ cp = _res.defdname;
+ pp = _res.dnsrch;
+ *pp++ = cp;
+ for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) {
+ if (*cp == '\n') /* silly backwards compat */
+ break;
+ else if (*cp == ' ' || *cp == '\t') {
+ *cp = 0;
+ n = 1;
+ } else if (n) {
+ *pp++ = cp;
+ n = 0;
+ havesearch = 1;
+ }
+ }
+ /* null terminate last domain if there are excess */
+ while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
+ cp++;
+ *cp = '\0';
+ *pp++ = 0;
}
if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) {
@@ -162,7 +237,9 @@ res_init()
cp = _res.defdname;
pp = _res.dnsrch;
*pp++ = cp;
- for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) {
+ for (n = 0;
+ *cp && pp < _res.dnsrch + MAXDNSRCH;
+ cp++) {
if (*cp == ' ' || *cp == '\t') {
*cp = 0;
n = 1;
@@ -196,33 +273,167 @@ res_init()
}
continue;
}
+#ifdef RESOLVSORT
+ if (!strncmp(buf, "sortlist", sizeof("sortlist") -1)) {
+ struct in_addr a;
+
+ cp = buf + sizeof("sortlist") - 1;
+ while (nsort < MAXRESOLVSORT) {
+ while (*cp == ' ' || *cp == '\t')
+ cp++;
+ if (*cp == '\0' || *cp == '\n' || *cp == ';')
+ break;
+ net = cp;
+ while (*cp && *cp != '/' &&
+ isascii(*cp) && !isspace(*cp))
+ cp++;
+ n = *cp;
+ *cp = 0;
+ if (inet_aton(net, &a)) {
+ _res.sort_list[nsort].addr = a;
+ if (n == '/') {
+ *cp++ = n;
+ net = cp;
+ while (*cp && isascii(*cp) && !isspace(*cp))
+ cp++;
+ n = *cp;
+ *cp = 0;
+ if (inet_aton(net, &a)) {
+ _res.sort_list[nsort].mask = a.s_addr;
+ } else {
+ _res.sort_list[nsort].mask =
+ net_mask(_res.sort_list[nsort].addr);
+ }
+ } else {
+ _res.sort_list[nsort].mask =
+ net_mask(_res.sort_list[nsort].addr);
+ }
+ nsort++;
+ }
+ *cp++ = n;
+ }
+ continue;
+ }
+#endif
+ if (!strncmp(buf, "options", sizeof("options") -1)) {
+ res_setoptions(buf + sizeof("options") - 1, "conf");
+ continue;
+ }
}
if (nserv > 1)
_res.nscount = nserv;
+#ifdef RESOLVSORT
+ _res.nsort = nsort;
+#endif
(void) fclose(fp);
- }
+ } /*if(fopen)*/
if (_res.defdname[0] == 0) {
- if (gethostname(buf, sizeof(_res.defdname)) == 0 &&
- (cp = strchr(buf, '.')))
+ if (gethostname(buf, sizeof(_res.defdname) - 1) == 0 &&
+ (cp = strchr(buf, '.'))) {
(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++;
+ *pp = NULL;
+
+#ifndef RFC1535
+ dots = 0;
+ for (cp = _res.defdname; *cp; cp++)
+ dots += (*cp == '.');
+
cp = _res.defdname;
- for (;
- n >= LOCALDOMAINPARTS && pp < _res.dnsrch + MAXDFLSRCH;
- n--) {
- cp = strchr(cp, '.');
- *pp++ = ++cp;
+ while (pp < _res.dnsrch + MAXDFLSRCH) {
+ if (dots < LOCALDOMAINPARTS) {
+ break;
+ }
+ cp = strchr(cp, '.') + 1; /* we know there is one */
+ *pp++ = cp;
+ dots--;
}
- *pp++ = 0;
+ *pp = NULL;
+#ifdef DEBUG
+ if (_res.options & RES_DEBUG) {
+ printf(";; res_init()... default dnsrch list:\n");
+ for (pp = _res.dnsrch; *pp; pp++) {
+ printf(";;\t%s\n", *pp);
+ }
+ printf(";;\t..END..\n");
+ }
+#endif /*DEBUG*/
+#endif /*!RFC1535*/
+ }
+
+ if ((cp = getenv("RES_OPTIONS")) != NULL) {
+ res_setoptions(cp, "env");
}
_res.options |= RES_INIT;
return (0);
}
+
+
+static void
+res_setoptions(options, source)
+ char *options, *source;
+{
+ char *cp = options;
+ int i;
+
+#ifdef DEBUG
+ if (_res.options & RES_DEBUG) {
+ printf(";; res_setoptions(\"%s\", \"%s\")...\n",
+ options, source);
+ }
+#endif
+ while (*cp) {
+ /* skip leading and inner runs of spaces */
+ while (*cp == ' ' || *cp == '\t')
+ cp++;
+ /* search for and process individual options */
+ if (!strncmp(cp, "ndots:", sizeof("ndots:")-1)) {
+ i = atoi(cp + sizeof("ndots:") - 1);
+ if (i <= RES_MAXNDOTS)
+ _res.ndots = i;
+ else
+ _res.ndots = RES_MAXNDOTS;
+#ifdef DEBUG
+ if (_res.options & RES_DEBUG) {
+ printf(";;\tndots=%d\n", _res.ndots);
+ }
+#endif
+ } else if (!strncmp(cp, "debug", sizeof("debug")-1)) {
+#ifdef DEBUG
+ if (!(_res.options & RES_DEBUG)) {
+ printf(";; res_setoptions(\"%s\", \"%s\")..\n",
+ options, source);
+ _res.options |= RES_DEBUG;
+ }
+ printf(";;\tdebug\n");
+#endif
+ } else {
+ /* XXX - print a warning here? */
+ }
+ /* skip to next run of spaces */
+ while (*cp && *cp != ' ' && *cp != '\t')
+ cp++;
+ }
+}
+
+#ifdef RESOLVSORT
+static u_int32_t
+net_mask(in) /* XXX - should really use system's version of this */
+ struct in_addr in;
+{
+ register u_int32_t i = ntohl(in.s_addr);
+
+ if (IN_CLASSA(i))
+ return (htonl(IN_CLASSA_NET));
+ else if (IN_CLASSB(i))
+ return (htonl(IN_CLASSB_NET));
+ else
+ return (htonl(IN_CLASSC_NET));
+}
+#endif
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