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, 29 insertions, 31 deletions

diff --git a/src/lib/libc/net/gethostnamadr.c b/src/lib/libc/net/gethostnamadr.c
index 909ce573b7..5211f423c6 100644
--- a/src/lib/libc/net/gethostnamadr.c
+++ b/src/lib/libc/net/gethostnamadr.c
@@ -52,7 +52,7 @@
  */
 
 #if defined(LIBC_SCCS) && !defined(lint)
-static char rcsid[] = "$OpenBSD: gethostnamadr.c,v 1.53 2002/08/27 08:53:13 itojun Exp $";
+static char rcsid[] = "$OpenBSD: gethostnamadr.c,v 1.54 2003/01/28 04:58:00 marc Exp $";
 #endif /* LIBC_SCCS and not lint */
 
 #include <sys/param.h>
@@ -160,6 +160,7 @@ getanswer(answer, anslen, qname, qtype)
         const char *qname;
         int qtype;
 {
+        struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
         register const HEADER *hp;
         register const u_char *cp;
         register int n;
@@ -339,7 +340,7 @@ getanswer(answer, anslen, qname, qtype)
                         break;
 #else
                         host.h_name = bp;
-                        if (_res.options & RES_USE_INET6) {
+                        if (_resp->options & RES_USE_INET6) {
                                 n = strlen(bp) + 1;     /* for the \0 */
                                 bp += n;
                                 map_v4v6_hostent(&host, &bp, ep);
@@ -379,7 +380,7 @@ getanswer(answer, anslen, qname, qtype)
 
                         if (bp + n >= &hostbuf[sizeof hostbuf]) {
 #ifdef DEBUG
-                                if (_res.options & RES_DEBUG)
+                                if (_resp->options & RES_DEBUG)
                                         printf("size (%d) too big\n", n);
 #endif
                                 had_error++;
@@ -388,7 +389,7 @@ getanswer(answer, anslen, qname, qtype)
                         if (hap >= &h_addr_ptrs[MAXADDRS-1]) {
                                 if (!toobig++)
 #ifdef DEBUG
-                                        if (_res.options & RES_DEBUG)
+                                        if (_resp->options & RES_DEBUG)
                                                 printf("Too many addresses (%d)\n", MAXADDRS);
 #endif
                                 cp += n;
@@ -411,7 +412,7 @@ getanswer(answer, anslen, qname, qtype)
                  * in its return structures - should give it the "best"
                  * address in that case, not some random one
                  */
-                if (_res.nsort && haveanswer > 1 && qtype == T_A)
+                if (_resp->nsort && haveanswer > 1 && qtype == T_A)
                         addrsort(h_addr_ptrs, haveanswer);
 # endif /*RESOLVSORT*/
                 if (!host.h_name) {
@@ -422,7 +423,7 @@ getanswer(answer, anslen, qname, qtype)
                         host.h_name = bp;
                         bp += n;
                 }
-                if (_res.options & RES_USE_INET6)
+                if (_resp->options & RES_USE_INET6)
                         map_v4v6_hostent(&host, &bp, ep);
                 h_errno = NETDB_SUCCESS;
                 return (&host);
@@ -484,27 +485,24 @@ gethostbyaddr_r(addr, len, af, he, buf, buflen, errorp)
 /* XXX RFC2133 expects a gethostbyname2_r() -- unimplemented */
 #endif
 
-_THREAD_PRIVATE_MUTEX(gethostnamadr);
-
 struct hostent *
 gethostbyname(name)
         const char *name;
 {
+        struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
         struct hostent *hp;
         extern struct hostent *_gethtbyname2();
 
-        _THREAD_PRIVATE_MUTEX_LOCK(gethostnamadr);
-        if ((_res.options & RES_INIT) == 0 && res_init() == -1)
+        if ((_resp->options & RES_INIT) == 0 && res_init() == -1)
                 hp = _gethtbyname2(name, AF_INET);
 
-        else if (_res.options & RES_USE_INET6) {
+        else if (_resp->options & RES_USE_INET6) {
                 hp = gethostbyname2(name, AF_INET6);
                 if (hp == NULL)
                         hp = gethostbyname2(name, AF_INET);
         }
         else
                 hp = gethostbyname2(name, AF_INET);
-        _THREAD_PRIVATE_MUTEX_UNLOCK(gethostnamadr);
         return hp;
 }
 
@@ -513,6 +511,7 @@ gethostbyname2(name, af)
         const char *name;
         int af;
 {
+        struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
         querybuf *buf;
         register const char *cp;
         char *bp, *ep;
@@ -521,7 +520,7 @@ gethostbyname2(name, af)
         register struct hostent *hp;
         char lookups[MAXDNSLUS];
 
-        if ((_res.options & RES_INIT) == 0 && res_init() == -1)
+        if ((_resp->options & RES_INIT) == 0 && res_init() == -1)
                 return (_gethtbyname2(name, af));
 
         switch (af) {
@@ -577,7 +576,7 @@ gethostbyname2(name, af)
                                 h_addr_ptrs[0] = (char *)host_addr;
                                 h_addr_ptrs[1] = NULL;
                                 host.h_addr_list = h_addr_ptrs;
-                                if (_res.options & RES_USE_INET6)
+                                if (_resp->options & RES_USE_INET6)
                                         map_v4v6_hostent(&host, &bp, ep);
                                 h_errno = NETDB_SUCCESS;
                                 return (&host);
@@ -616,7 +615,7 @@ gethostbyname2(name, af)
                                 break;
                 }
 
-        bcopy(_res.lookups, lookups, sizeof lookups);
+        bcopy(_resp->lookups, lookups, sizeof lookups);
         if (lookups[0] == '\0')
                 strlcpy(lookups, "bf", sizeof lookups);
 
@@ -638,7 +637,7 @@ gethostbyname2(name, af)
                             sizeof(buf->buf))) < 0) {
                                 free(buf);
 #ifdef DEBUG
-                                if (_res.options & RES_DEBUG)
+                                if (_resp->options & RES_DEBUG)
                                         printf("res_search failed\n");
 #endif
                                 break;
@@ -660,6 +659,7 @@ gethostbyaddr(addr, len, af)
         const char *addr;       /* XXX should have been def'd as u_char! */
         int len, af;
 {
+        struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
         const u_char *uaddr = (const u_char *)addr;
         int n, size, i;
         querybuf *buf;
@@ -669,10 +669,8 @@ gethostbyaddr(addr, len, af)
         char lookups[MAXDNSLUS];
         struct hostent *res;
         
-        _THREAD_PRIVATE_MUTEX_LOCK(gethostnamadr);
-        if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
+        if ((_resp->options & RES_INIT) == 0 && res_init() == -1) {
                 res = _gethtbyaddr(addr, len, af);
-                _THREAD_PRIVATE_MUTEX_UNLOCK(gethostnamadr);
                 return (res);
         }
 
@@ -701,13 +699,11 @@ gethostbyaddr(addr, len, af)
         default:
                 errno = EAFNOSUPPORT;
                 h_errno = NETDB_INTERNAL;
-                _THREAD_PRIVATE_MUTEX_UNLOCK(gethostnamadr);
                 return (NULL);
         }
         if (size != len) {
                 errno = EINVAL;
                 h_errno = NETDB_INTERNAL;
-                _THREAD_PRIVATE_MUTEX_UNLOCK(gethostnamadr);
                 return (NULL);
         }
         switch (af) {
@@ -725,7 +721,7 @@ gethostbyaddr(addr, len, af)
                 break;
         }
 
-        bcopy(_res.lookups, lookups, sizeof lookups);
+        bcopy(_resp->lookups, lookups, sizeof lookups);
         if (lookups[0] == '\0')
                 strlcpy(lookups, "bf", sizeof lookups);
 
@@ -755,7 +751,7 @@ gethostbyaddr(addr, len, af)
                         if (n < 0) {
                                 free(buf);
 #ifdef DEBUG
-                                if (_res.options & RES_DEBUG)
+                                if (_resp->options & RES_DEBUG)
                                         printf("res_query failed\n");
 #endif
                                 break;
@@ -770,7 +766,7 @@ gethostbyaddr(addr, len, af)
                         bcopy(addr, host_addr, len);
                         h_addr_ptrs[0] = (char *)host_addr;
                         h_addr_ptrs[1] = NULL;
-                        if (af == AF_INET && (_res.options & RES_USE_INET6)) {
+                        if (af == AF_INET && (_resp->options & RES_USE_INET6)) {
                                 map_v4v6_address((char*)host_addr,
                                     (char*)host_addr);
                                 hp->h_addrtype = AF_INET6;
@@ -783,7 +779,6 @@ gethostbyaddr(addr, len, af)
                         break;
                 }
         }
-        _THREAD_PRIVATE_MUTEX_UNLOCK(gethostnamadr);
         /* XXX h_errno not correct in all cases... */
         return (hp);
 }
@@ -811,6 +806,7 @@ _endhtent()
 struct hostent *
 _gethtent()
 {
+        struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
         char *p;
         register char *cp, **q;
         int af;
@@ -842,7 +838,7 @@ _gethtent()
                 af = AF_INET6;
                 len = IN6ADDRSZ;
         } else if (inet_pton(AF_INET, p, host_addr) > 0) {
-                if (_res.options & RES_USE_INET6) {
+                if (_resp->options & RES_USE_INET6) {
                         map_v4v6_address((char*)host_addr, (char*)host_addr);
                         af = AF_INET6;
                         len = IN6ADDRSZ;
@@ -880,7 +876,7 @@ _gethtent()
                         *cp++ = '\0';
         }
         *q = NULL;
-        if (_res.options & RES_USE_INET6) {
+        if (_resp->options & RES_USE_INET6) {
                 char *bp = hostbuf;
                 char *ep = hostbuf + sizeof hostbuf;
 
@@ -894,10 +890,11 @@ struct hostent *
 _gethtbyname(name)
         const char *name;
 {
+        struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
         extern struct hostent *_gethtbyname2();
         struct hostent *hp;
 
-        if (_res.options & RES_USE_INET6) {
+        if (_resp->options & RES_USE_INET6) {
                 hp = _gethtbyname2(name, AF_INET6);
                 if (hp)
                         return (hp);
@@ -1136,6 +1133,7 @@ addrsort(ap, num)
         char **ap;
         int num;
 {
+        struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res);
         int i, j;
         char **p;
         short aval[MAXADDRS];
@@ -1143,9 +1141,9 @@ addrsort(ap, num)
 
         p = ap;
         for (i = 0; i < num; i++, p++) {
-                for (j = 0 ; (unsigned)j < _res.nsort; j++)
-                        if (_res.sort_list[j].addr.s_addr == 
-                            (((struct in_addr *)(*p))->s_addr & _res.sort_list[j].mask))
+                for (j = 0 ; (unsigned)j < _resp->nsort; j++)
+                        if (_resp->sort_list[j].addr.s_addr == 
+                            (((struct in_addr *)(*p))->s_addr & _resp->sort_list[j].mask))
                                 break;
                 aval[i] = j;
                 if (needsort == 0 && i > 0 && j < aval[i-1])