thread safer libc (note: safer, not safe)

Access to the global _res structure replaced by pointers to a
per thread instance.  If unthreaded the pointer is to the
global structure.

Also replaced a 64k stack array with malloc-ed memory so
threaded aps (with a default 64k stack) have a chance at working.
ok deraadt@

1 files changed, 101 insertions, 86 deletions

diff --git a/lib/libc/net/res_init.c b/lib/libc/net/res_init.c
index c55c7763a4e..a1d69f57b5e 100644
--- a/lib/libc/net/res_init.c
+++ b/lib/libc/net/res_init.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: res_init.c,v 1.27 2002/07/25 21:13:45 deraadt Exp $	*/
+/*	$OpenBSD: res_init.c,v 1.28 2003/01/28 04:58:00 marc Exp $	*/
 
 /*
  * ++Copyright++ 1985, 1989, 1993
@@ -64,7 +64,7 @@
 static char sccsid[] = "@(#)res_init.c	8.1 (Berkeley) 6/7/93";
 static char rcsid[] = "$From: res_init.c,v 8.7 1996/09/28 06:51:07 vixie Exp $";
 #else
-static char rcsid[] = "$OpenBSD: res_init.c,v 1.27 2002/07/25 21:13:45 deraadt Exp $";
+static char rcsid[] = "$OpenBSD: res_init.c,v 1.28 2003/01/28 04:58:00 marc Exp $";
 #endif
 #endif /* LIBC_SCCS and not lint */
 
@@ -86,6 +86,8 @@ static char rcsid[] = "$OpenBSD: res_init.c,v 1.27 2002/07/25 21:13:45 deraadt E
 #include <netdb.h>
 #endif /* INET6 */
 
+#include "thread_private.h"
+
 /*-------------------------------------- info about "sortlist" --------------
  * Marc Majka		1994/04/16
  * Allan Nathanson	1994/10/29 (BIND 4.9.3.x)
@@ -120,6 +122,9 @@ static u_int32_t net_mask(struct in_addr);
 /*
  * Resolver state default settings.
  */
+volatile struct _thread_private_key_struct __THREAD_KEY_NAME(_res) = {
+	PTHREAD_ONCE_INIT, 0
+};
 
 struct __res_state _res
 # if defined(__BIND_RES_TEXT)
@@ -127,6 +132,10 @@ struct __res_state _res
 # endif
 	;
 #ifdef INET6
+volatile struct _thread_private_key_struct __THREAD_KEY_NAME(_res_ext) = {
+	PTHREAD_ONCE_INIT, 0
+};
+
 struct __res_state_ext _res_ext;
 #endif /* INET6 */
 
@@ -154,6 +163,11 @@ struct __res_state_ext _res_ext;
 int
 res_init()
 {
+	struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
+#ifdef INET6
+	struct __res_state_ext *_res_extp = _THREAD_PRIVATE(_res_ext, _res_ext,
+							    &_res_ext);
+#endif
 	register FILE *fp;
 	register char *cp, **pp;
 	register int n;
@@ -189,33 +203,33 @@ res_init()
 	 * set in RES_DEFAULT).  Our solution is to declare such applications
 	 * "broken".  They could fool us by setting RES_INIT but none do (yet).
 	 */
-	if (!_res.retrans)
-		_res.retrans = RES_TIMEOUT;
-	if (!_res.retry)
-		_res.retry = 4;
-	if (!(_res.options & RES_INIT))
-		_res.options = RES_DEFAULT;
+	if (!_resp->retrans)
+		_resp->retrans = RES_TIMEOUT;
+	if (!_resp->retry)
+		_resp->retry = 4;
+	if (!(_resp->options & RES_INIT))
+		_resp->options = RES_DEFAULT;
 
 #ifdef USELOOPBACK
-	_res.nsaddr.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
+	_resp->nsaddr.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
 #else
-	_res.nsaddr.sin_addr.s_addr = INADDR_ANY;
+	_resp->nsaddr.sin_addr.s_addr = INADDR_ANY;
 #endif
-	_res.nsaddr.sin_family = AF_INET;
-	_res.nsaddr.sin_port = htons(NAMESERVER_PORT);
-	_res.nsaddr.sin_len = sizeof(struct sockaddr_in);
+	_resp->nsaddr.sin_family = AF_INET;
+	_resp->nsaddr.sin_port = htons(NAMESERVER_PORT);
+	_resp->nsaddr.sin_len = sizeof(struct sockaddr_in);
 #ifdef INET6
-	if (sizeof(_res_ext.nsaddr) >= _res.nsaddr.sin_len)
-		memcpy(&_res_ext.nsaddr, &_res.nsaddr, _res.nsaddr.sin_len);
+	if (sizeof(_res_extp->nsaddr) >= _resp->nsaddr.sin_len)
+		memcpy(&_res_extp->nsaddr, &_resp->nsaddr, _resp->nsaddr.sin_len);
 #endif
-	_res.nscount = 1;
-	_res.ndots = 1;
-	_res.pfcode = 0;
-	strlcpy(_res.lookups, "f", sizeof _res.lookups);
+	_resp->nscount = 1;
+	_resp->ndots = 1;
+	_resp->pfcode = 0;
+	strlcpy(_resp->lookups, "f", sizeof _resp->lookups);
 
 	/* Allow user to override the local domain definition */
 	if (issetugid() == 0 && (cp = getenv("LOCALDOMAIN")) != NULL) {
-		strlcpy(_res.defdname, cp, sizeof(_res.defdname));
+		strlcpy(_resp->defdname, cp, sizeof(_resp->defdname));
 		haveenv++;
 
 		/*
@@ -225,10 +239,10 @@ res_init()
 		 * 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;
+		cp = _resp->defdname;
+		pp = _resp->dnsrch;
 		*pp++ = cp;
-		for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) {
+		for (n = 0; *cp && pp < _resp->dnsrch + MAXDNSRCH; cp++) {
 			if (*cp == '\n')	/* silly backwards compat */
 				break;
 			else if (*cp == ' ' || *cp == '\t') {
@@ -253,7 +267,7 @@ res_init()
 	 line[sizeof(name) - 1] == '\t'))
 
 	if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) {
-	    strlcpy(_res.lookups, "bf", sizeof _res.lookups);
+	    strlcpy(_resp->lookups, "bf", sizeof _resp->lookups);
 
 	    /* read the config file */
 	    buf[0] = '\0';
@@ -277,8 +291,8 @@ res_init()
 			    cp++;
 		    if ((*cp == '\0') || (*cp == '\n'))
 			    continue;
-		    strlcpy(_res.defdname, cp, sizeof(_res.defdname));
-		    if ((cp = strpbrk(_res.defdname, " \t\n")) != NULL)
+		    strlcpy(_resp->defdname, cp, sizeof(_resp->defdname));
+		    if ((cp = strpbrk(_resp->defdname, " \t\n")) != NULL)
 			    *cp = '\0';
 		    havesearch = 0;
 		    continue;
@@ -287,7 +301,7 @@ res_init()
 		if (MATCH(buf, "lookup")) {
 		    char *sp = NULL;
 
-		    bzero(_res.lookups, sizeof _res.lookups);
+		    bzero(_resp->lookups, sizeof _resp->lookups);
 		    cp = buf + sizeof("lookup") - 1;
 		    for (n = 0;; cp++) {
 		    	    if (n == MAXDNSLUS)
@@ -295,14 +309,14 @@ res_init()
 			    if ((*cp == '\0') || (*cp == '\n')) {
 				    if (sp) {
 					    if (*sp=='y' || *sp=='b' || *sp=='f')
-						    _res.lookups[n++] = *sp;
+						    _resp->lookups[n++] = *sp;
 					    sp = NULL;
 				    }
 				    break;
 			    } else if ((*cp == ' ') || (*cp == '\t') || (*cp == ',')) {
 				    if (sp) {
 					    if (*sp=='y' || *sp=='b' || *sp=='f')
-						    _res.lookups[n++] = *sp;
+						    _resp->lookups[n++] = *sp;
 					    sp = NULL;
 				    }
 			    } else if (sp == NULL)
@@ -319,17 +333,17 @@ res_init()
 			    cp++;
 		    if ((*cp == '\0') || (*cp == '\n'))
 			    continue;
-		    strlcpy(_res.defdname, cp, sizeof(_res.defdname));
-		    if ((cp = strchr(_res.defdname, '\n')) != NULL)
+		    strlcpy(_resp->defdname, cp, sizeof(_resp->defdname));
+		    if ((cp = strchr(_resp->defdname, '\n')) != NULL)
 			    *cp = '\0';
 		    /*
 		     * Set search list to be blank-separated strings
 		     * on rest of line.
 		     */
-		    cp = _res.defdname;
-		    pp = _res.dnsrch;
+		    cp = _resp->defdname;
+		    pp = _resp->dnsrch;
 		    *pp++ = cp;
-		    for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) {
+		    for (n = 0; *cp && pp < _resp->dnsrch + MAXDNSRCH; cp++) {
 			    if (*cp == ' ' || *cp == '\t') {
 				    *cp = 0;
 				    n = 1;
@@ -375,19 +389,19 @@ res_init()
 		    res = NULL;
 		    if (getaddrinfo(cp, pbuf, &hints, &res) == 0 &&
 			    res->ai_next == NULL) {
-			if (res->ai_addrlen <= sizeof(_res_ext.nsaddr_list[nserv])) {
-			    memcpy(&_res_ext.nsaddr_list[nserv], res->ai_addr,
+			if (res->ai_addrlen <= sizeof(_res_extp->nsaddr_list[nserv])) {
+			    memcpy(&_res_extp->nsaddr_list[nserv], res->ai_addr,
 				res->ai_addrlen);
 			} else {
-			    memset(&_res_ext.nsaddr_list[nserv], 0,
-				sizeof(_res_ext.nsaddr_list[nserv]));
+			    memset(&_res_extp->nsaddr_list[nserv], 0,
+				sizeof(_res_extp->nsaddr_list[nserv]));
 			}
-			if (res->ai_addrlen <= sizeof(_res.nsaddr_list[nserv])) {
-			    memcpy(&_res.nsaddr_list[nserv], res->ai_addr,
+			if (res->ai_addrlen <= sizeof(_resp->nsaddr_list[nserv])) {
+			    memcpy(&_resp->nsaddr_list[nserv], res->ai_addr,
 				res->ai_addrlen);
 			} else {
-			    memset(&_res.nsaddr_list[nserv], 0,
-				sizeof(_res.nsaddr_list[nserv]));
+			    memset(&_resp->nsaddr_list[nserv], 0,
+				sizeof(_resp->nsaddr_list[nserv]));
 			}
 			nserv++;
 		    }
@@ -395,11 +409,11 @@ res_init()
 			freeaddrinfo(res);
 #else /* INET6 */
 		    if ((*cp != '\0') && (*cp != '\n') && inet_aton(cp, &a)) {
-			_res.nsaddr_list[nserv].sin_addr = a;
-			_res.nsaddr_list[nserv].sin_family = AF_INET;
-			_res.nsaddr_list[nserv].sin_port =
+			_resp->nsaddr_list[nserv].sin_addr = a;
+			_resp->nsaddr_list[nserv].sin_family = AF_INET;
+			_resp->nsaddr_list[nserv].sin_port =
 				htons(NAMESERVER_PORT);
-			_res.nsaddr_list[nserv].sin_len =
+			_resp->nsaddr_list[nserv].sin_len =
 				sizeof(struct sockaddr_in);
 			nserv++;
 		    }
@@ -428,7 +442,7 @@ res_init()
 			n = *cp;
 			*cp = 0;
 			if (inet_aton(net, &a)) {
-			    _res.sort_list[nsort].addr = a;
+			    _resp->sort_list[nsort].addr = a;
 			    if (ISSORTMASK(n)) {
 				*cp++ = n;
 				net = cp;
@@ -438,29 +452,29 @@ res_init()
 				n = *cp;
 				*cp = 0;
 				if (inet_aton(net, &a)) {
-				    _res.sort_list[nsort].mask = a.s_addr;
+				    _resp->sort_list[nsort].mask = a.s_addr;
 				} else {
-				    _res.sort_list[nsort].mask = 
-					net_mask(_res.sort_list[nsort].addr);
+				    _resp->sort_list[nsort].mask = 
+					net_mask(_resp->sort_list[nsort].addr);
 				}
 			    } else {
-				_res.sort_list[nsort].mask = 
-				    net_mask(_res.sort_list[nsort].addr);
+				_resp->sort_list[nsort].mask = 
+				    net_mask(_resp->sort_list[nsort].addr);
 			    }
 #ifdef INET6
-			    _res_ext.sort_list[nsort].af = AF_INET;
-			    _res_ext.sort_list[nsort].addr.ina =
-				_res.sort_list[nsort].addr;
-			    _res_ext.sort_list[nsort].mask.ina.s_addr =
-				_res.sort_list[nsort].mask;
+			    _res_extp->sort_list[nsort].af = AF_INET;
+			    _res_extp->sort_list[nsort].addr.ina =
+				_resp->sort_list[nsort].addr;
+			    _res_extp->sort_list[nsort].mask.ina.s_addr =
+				_resp->sort_list[nsort].mask;
 #endif /* INET6 */
 			    nsort++;
 			}
 #ifdef INET6
 			else if (inet_pton(AF_INET6, net, &a6) == 1) {
-			    _res_ext.sort_list[nsort].af = AF_INET6;
-			    _res_ext.sort_list[nsort].addr.in6a = a6;
-			    u = (u_char *)&_res_ext.sort_list[nsort].mask.in6a;
+			    _res_extp->sort_list[nsort].af = AF_INET6;
+			    _res_extp->sort_list[nsort].addr.in6a = a6;
+			    u = (u_char *)&_res_extp->sort_list[nsort].mask.in6a;
 			    *cp++ = n;
 			    net = cp;
 			    while (*cp && *cp != ';' &&
@@ -510,33 +524,33 @@ res_init()
 		}
 	    }
 	    if (nserv > 1) 
-		_res.nscount = nserv;
+		_resp->nscount = nserv;
 #ifdef RESOLVSORT
-	    _res.nsort = nsort;
+	    _resp->nsort = nsort;
 #endif
 	    (void) fclose(fp);
 	}
-	if (_res.defdname[0] == 0 &&
-	    gethostname(buf, sizeof(_res.defdname) - 1) == 0 &&
+	if (_resp->defdname[0] == 0 &&
+	    gethostname(buf, sizeof(_resp->defdname) - 1) == 0 &&
 	    (cp = strchr(buf, '.')) != NULL)
 	{
-		strlcpy(_res.defdname, cp + 1,
-		        sizeof(_res.defdname));
+		strlcpy(_resp->defdname, cp + 1,
+		        sizeof(_resp->defdname));
 	}
 
 	/* find components of local domain that might be searched */
 	if (havesearch == 0) {
-		pp = _res.dnsrch;
-		*pp++ = _res.defdname;
+		pp = _resp->dnsrch;
+		*pp++ = _resp->defdname;
 		*pp = NULL;
 
 #ifndef RFC1535
 		dots = 0;
-		for (cp = _res.defdname; *cp; cp++)
+		for (cp = _resp->defdname; *cp; cp++)
 			dots += (*cp == '.');
 
-		cp = _res.defdname;
-		while (pp < _res.dnsrch + MAXDFLSRCH) {
+		cp = _resp->defdname;
+		while (pp < _resp->dnsrch + MAXDFLSRCH) {
 			if (dots < LOCALDOMAINPARTS)
 				break;
 			cp = strchr(cp, '.') + 1;    /* we know there is one */
@@ -545,9 +559,9 @@ res_init()
 		}
 		*pp = NULL;
 #ifdef DEBUG
-		if (_res.options & RES_DEBUG) {
+		if (_resp->options & RES_DEBUG) {
 			printf(";; res_init()... default dnsrch list:\n");
-			for (pp = _res.dnsrch; *pp; pp++)
+			for (pp = _resp->dnsrch; *pp; pp++)
 				printf(";;\t%s\n", *pp);
 			printf(";;\t..END..\n");
 		}
@@ -556,10 +570,10 @@ res_init()
 	}
 
 	if (issetugid())
-		_res.options |= RES_NOALIASES;
+		_resp->options |= RES_NOALIASES;
 	else if ((cp = getenv("RES_OPTIONS")) != NULL)
 		res_setoptions(cp, "env");
-	_res.options |= RES_INIT;
+	_resp->options |= RES_INIT;
 	return (0);
 }
 
@@ -568,12 +582,13 @@ static void
 res_setoptions(options, source)
 	char *options, *source;
 {
+	struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
 	char *cp = options;
 	char *endp;
 	long l;
 
 #ifdef DEBUG
-	if (_res.options & RES_DEBUG)
+	if (_resp->options & RES_DEBUG)
 		printf(";; res_setoptions(\"%s\", \"%s\")...\n",
 		       options, source);
 #endif
@@ -588,31 +603,31 @@ res_setoptions(options, source)
 			if (l >= 0 && endp != p &&
 			    (*endp = '\0' || isspace(*endp))) {
 				if (l <= RES_MAXNDOTS)
-					_res.ndots = l;
+					_resp->ndots = l;
 				else
-					_res.ndots = RES_MAXNDOTS;
+					_resp->ndots = RES_MAXNDOTS;
 #ifdef DEBUG
-				if (_res.options & RES_DEBUG)
-					printf(";;\tndots=%u\n", _res.ndots);
+				if (_resp->options & RES_DEBUG)
+					printf(";;\tndots=%u\n", _resp->ndots);
 #endif
 			}
 		} else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
 #ifdef DEBUG
-			if (!(_res.options & RES_DEBUG)) {
+			if (!(_resp->options & RES_DEBUG)) {
 				printf(";; res_setoptions(\"%s\", \"%s\")..\n",
 				       options, source);
-				_res.options |= RES_DEBUG;
+				_resp->options |= RES_DEBUG;
 			}
 			printf(";;\tdebug\n");
 #endif
 		} else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
-			_res.options |= RES_USE_INET6;
+			_resp->options |= RES_USE_INET6;
 		} else if (!strncmp(cp, "insecure1", sizeof("insecure1") - 1)) {
-			_res.options |= RES_INSECURE1;
+			_resp->options |= RES_INSECURE1;
 		} else if (!strncmp(cp, "insecure2", sizeof("insecure2") - 1)) {
-			_res.options |= RES_INSECURE2;
+			_resp->options |= RES_INSECURE2;
 		} else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
-			_res.options |= RES_USE_EDNS0;
+			_resp->options |= RES_USE_EDNS0;
 		} else {
 			/* XXX - print a warning here? */
 		}