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/src/lib/libc/net/res_init.c b/src/lib/libc/net/res_init.c
index c55c7763a4..a1d69f57b5 100644
--- a/src/lib/libc/net/res_init.c
+++ b/src/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? */
                 }