Update.

2002-03-21  Ulrich Drepper  <drepper@redhat.com>

	* nscd/grpcache.c (addgrbyname): Improve buffer allocate with alloca.
	Use realloc if too large.
	(addgrbyid): Likewise.
	* nscd/hstcache.c (addhstbyname): Likewise.
	(addhstbyaddr): Likewise.
	(addhstbynamev6): Likewise.
	(addhstbyaddrv6): Likewise.
	* nscd/pwdcache.c (addpwbyname): Likewise.
	(addpwbyuid): Likewise.

3 files changed, 249 insertions, 47 deletions

diff --git a/nscd/grpcache.c b/nscd/grpcache.c
index a7895ad..ce84668 100644
--- a/nscd/grpcache.c
+++ b/nscd/grpcache.c
@@ -207,14 +207,14 @@ addgrbyname (struct database *db, int fd, request_header *req,
      simply insert it.  It does not matter if it is in there twice.  The
      pruning function only will look at the timestamp.  */
   int buflen = 1024;
-  char *buffer = alloca (buflen);
+  char *buffer = (char *) alloca (buflen);
   struct group resultbuf;
   struct group *grp;
   uid_t oldeuid = 0;
   bool use_malloc = false;
 
-  if (debug_level > 0)
-    dbg_log (_("Haven't found \"%s\" in group cache!"), (char *)key);
+  if (__builtin_expect (debug_level > 0, 0))
+    dbg_log (_("Haven't found \"%s\" in group cache!"), (char *) key);
 
   if (secure[grpdb])
     {
@@ -245,7 +245,7 @@ addgrbyname (struct database *db, int fd, request_header *req,
 	}
       else
 	{
-	  buffer = alloca (buflen);
+	  buffer = (char *) alloca (buflen);
 #if _STACK_GROWS_DOWN
 	  if (buffer + buflen == old_buffer)
 	    buflen = 2 * buflen - 1024;
@@ -278,7 +278,7 @@ addgrbygid (struct database *db, int fd, request_header *req,
      simply insert it.  It does not matter if it is in there twice.  The
      pruning function only will look at the timestamp.  */
   int buflen = 1024;
-  char *buffer = alloca (buflen);
+  char *buffer = (char *) alloca (buflen);
   struct group resultbuf;
   struct group *grp;
   uid_t oldeuid = 0;
@@ -286,16 +286,16 @@ addgrbygid (struct database *db, int fd, request_header *req,
   gid_t gid = strtoul ((char *)key, &ep, 10);
   bool use_malloc = false;
 
-  if (*(char*)key == '\0' || *ep != '\0')  /* invalid numeric gid */
+  if (*(char *) key == '\0' || *ep != '\0')  /* invalid numeric gid */
     {
       if (debug_level > 0)
-        dbg_log (_("Invalid numeric gid \"%s\"!"), (char *)key);
+        dbg_log (_("Invalid numeric gid \"%s\"!"), (char *) key);
 
       errno = EINVAL;
       return;
     }
 
-  if (debug_level > 0)
+  if (__builtin_expect (debug_level > 0, 0))
     dbg_log (_("Haven't found \"%d\" in group cache!"), gid);
 
   if (secure[grpdb])
@@ -327,7 +327,7 @@ addgrbygid (struct database *db, int fd, request_header *req,
 	}
       else
 	{
-	  buffer = alloca (buflen);
+	  buffer = (char *) alloca (buflen);
 #if _STACK_GROWS_DOWN
 	  if (buffer + buflen == old_buffer)
 	    buflen = 2 * buflen - 1024;
diff --git a/nscd/hstcache.c b/nscd/hstcache.c
index c7cdc4d..8866293 100644
--- a/nscd/hstcache.c
+++ b/nscd/hstcache.c
@@ -1,5 +1,5 @@
 /* Cache handling for host lookup.
-   Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
+   Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
 
@@ -22,6 +22,7 @@
 #include <errno.h>
 #include <error.h>
 #include <netdb.h>
+#include <stdbool.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -31,6 +32,7 @@
 #include <libintl.h>
 #include <arpa/inet.h>
 #include <arpa/nameser.h>
+#include <stackinfo.h>
 
 #include "nscd.h"
 #include "dbg_log.h"
@@ -289,14 +291,15 @@ addhstbyname (struct database *db, int fd, request_header *req,
      look again in the table whether the dataset is now available.  We
      simply insert it.  It does not matter if it is in there twice.  The
      pruning function only will look at the timestamp.  */
-  int buflen = 512;
-  char *buffer = alloca (buflen);
+  int buflen = 1024;
+  char *buffer = (char *) alloca (buflen);
   struct hostent resultbuf;
   struct hostent *hst;
   uid_t oldeuid = 0;
+  bool use_malloc = false;
 
-  if (debug_level > 0)
-    dbg_log (_("Haven't found \"%s\" in hosts cache!"), (char *)key);
+  if (__builtin_expect (debug_level > 0, 0))
+    dbg_log (_("Haven't found \"%s\" in hosts cache!"), (char *) key);
 
   if (secure[hstdb])
     {
@@ -309,15 +312,47 @@ addhstbyname (struct database *db, int fd, request_header *req,
 	 && h_errno == NETDB_INTERNAL
 	 && errno == ERANGE)
     {
+      char *old_buffer = buffer;
       errno = 0;
-      buflen += 256;
-      buffer = alloca (buflen);
+      buflen += 1024;
+
+      if (__builtin_expect (buflen > 32768, 0))
+	{
+	  buffer = (char *) realloc (use_malloc ? buffer : NULL, buflen);
+	  if (buffer == NULL)
+	    {
+	      /* We ran out of memory.  We cannot do anything but
+		 sending a negative response.  In reality this should
+		 never happen.  */
+	      hst = NULL;
+	      buffer = old_buffer;
+	      break;
+	    }
+	  use_malloc = true;
+	}
+      else
+	{
+	  buffer = (char *) alloca (buflen);
+#if _STACK_GROWS_DOWN
+	  if (buffer + buflen == old_buffer)
+	    buflen = 2 * buflen - 1024;
+#elif _STACK_GROWS_UP
+	  if (old_buffer + buflen - 1024 == buffer)
+	    {
+	      buffer = old_buffer;
+	      buflen = 2 * buflen - 1024;
+	    }
+#endif
+	}
     }
 
   if (secure[hstdb])
     seteuid (oldeuid);
 
   cache_addhst (db, fd, req, key, hst, uid);
+
+  if (use_malloc)
+    free (buffer);
 }
 
 
@@ -329,13 +364,14 @@ addhstbyaddr (struct database *db, int fd, request_header *req,
      look again in the table whether the dataset is now available.  We
      simply insert it.  It does not matter if it is in there twice.  The
      pruning function only will look at the timestamp.  */
-  int buflen = 512;
-  char *buffer = alloca (buflen);
+  int buflen = 1024;
+  char *buffer = (char *) alloca (buflen);
   struct hostent resultbuf;
   struct hostent *hst;
   uid_t oldeuid = 0;
+  bool use_malloc = false;
 
-  if (debug_level > 0)
+  if (__builtin_expect (debug_level > 0, 0))
     {
       char buf[INET_ADDRSTRLEN];
       dbg_log (_("Haven't found \"%s\" in hosts cache!"),
@@ -353,15 +389,47 @@ addhstbyaddr (struct database *db, int fd, request_header *req,
 	 && h_errno == NETDB_INTERNAL
 	 && errno == ERANGE)
     {
+      char *old_buffer = buffer;
       errno = 0;
-      buflen += 256;
-      buffer = alloca (buflen);
+      buflen += 1024;
+
+      if (__builtin_expect (buflen > 32768, 0))
+	{
+	  buffer = (char *) realloc (use_malloc ? buffer : NULL, buflen);
+	  if (buffer == NULL)
+	    {
+	      /* We ran out of memory.  We cannot do anything but
+		 sending a negative response.  In reality this should
+		 never happen.  */
+	      hst = NULL;
+	      buffer = old_buffer;
+	      break;
+	    }
+	  use_malloc = true;
+	}
+      else
+	{
+	  buffer = (char *) alloca (buflen);
+#if _STACK_GROWS_DOWN
+	  if (buffer + buflen == old_buffer)
+	    buflen = 2 * buflen - 1024;
+#elif _STACK_GROWS_UP
+	  if (old_buffer + buflen - 1024 == buffer)
+	    {
+	      buffer = old_buffer;
+	      buflen = 2 * buflen - 1024;
+	    }
+#endif
+	}
     }
 
   if (secure[hstdb])
     seteuid (oldeuid);
 
   cache_addhst (db, fd, req, key, hst, uid);
+
+  if (use_malloc)
+    free (buffer);
 }
 
 
@@ -373,13 +441,14 @@ addhstbynamev6 (struct database *db, int fd, request_header *req,
      look again in the table whether the dataset is now available.  We
      simply insert it.  It does not matter if it is in there twice.  The
      pruning function only will look at the timestamp.  */
-  int buflen = 512;
-  char *buffer = alloca (buflen);
+  int buflen = 1024;
+  char *buffer = (char *) alloca (buflen);
   struct hostent resultbuf;
   struct hostent *hst;
   uid_t oldeuid = 0;
+  bool use_malloc = false;
 
-  if (debug_level > 0)
+  if (__builtin_expect (debug_level > 0, 0))
     {
       char buf[INET6_ADDRSTRLEN];
 
@@ -398,15 +467,47 @@ addhstbynamev6 (struct database *db, int fd, request_header *req,
 	 && h_errno == NETDB_INTERNAL
 	 && errno == ERANGE)
     {
+      char *old_buffer = buffer;
       errno = 0;
-      buflen += 256;
-      buffer = alloca (buflen);
+      buflen += 1024;
+
+      if (__builtin_expect (buflen > 32768, 0))
+	{
+	  buffer = (char *) realloc (use_malloc ? buffer : NULL, buflen);
+	  if (buffer == NULL)
+	    {
+	      /* We ran out of memory.  We cannot do anything but
+		 sending a negative response.  In reality this should
+		 never happen.  */
+	      hst = NULL;
+	      buffer = old_buffer;
+	      break;
+	    }
+	  use_malloc = true;
+	}
+      else
+	{
+	  buffer = (char *) alloca (buflen);
+#if _STACK_GROWS_DOWN
+	  if (buffer + buflen == old_buffer)
+	    buflen = 2 * buflen - 1024;
+#elif _STACK_GROWS_UP
+	  if (old_buffer + buflen - 1024 == buffer)
+	    {
+	      buffer = old_buffer;
+	      buflen = 2 * buflen - 1024;
+	    }
+#endif
+	}
     }
 
   if (secure[hstdb])
     seteuid (oldeuid);
 
   cache_addhst (db, fd, req, key, hst, uid);
+
+  if (use_malloc)
+    free (buffer);
 }
 
 
@@ -418,13 +519,14 @@ addhstbyaddrv6 (struct database *db, int fd, request_header *req,
      look again in the table whether the dataset is now available.  We
      simply insert it.  It does not matter if it is in there twice.  The
      pruning function only will look at the timestamp.  */
-  int buflen = 512;
-  char *buffer = alloca (buflen);
+  int buflen = 1024;
+  char *buffer = (char *) alloca (buflen);
   struct hostent resultbuf;
   struct hostent *hst;
   uid_t oldeuid = 0;
+  bool use_malloc = false;
 
-  if (debug_level > 0)
+  if (__builtin_expect (debug_level > 0, 0))
     {
       char buf[INET6_ADDRSTRLEN];
       dbg_log (_("Haven't found \"%s\" in hosts cache!"),
@@ -442,13 +544,45 @@ addhstbyaddrv6 (struct database *db, int fd, request_header *req,
 	 && h_errno == NETDB_INTERNAL
 	 && errno == ERANGE)
     {
+      char *old_buffer = buffer;
       errno = 0;
-      buflen += 256;
-      buffer = alloca (buflen);
+      buflen += 1024;
+
+      if (__builtin_expect (buflen > 32768, 0))
+	{
+	  buffer = (char *) realloc (use_malloc ? buffer : NULL, buflen);
+	  if (buffer == NULL)
+	    {
+	      /* We ran out of memory.  We cannot do anything but
+		 sending a negative response.  In reality this should
+		 never happen.  */
+	      hst = NULL;
+	      buffer = old_buffer;
+	      break;
+	    }
+	  use_malloc = true;
+	}
+      else
+	{
+	  buffer = (char *) alloca (buflen);
+#if _STACK_GROWS_DOWN
+	  if (buffer + buflen == old_buffer)
+	    buflen = 2 * buflen - 1024;
+#elif _STACK_GROWS_UP
+	  if (old_buffer + buflen - 1024 == buffer)
+	    {
+	      buffer = old_buffer;
+	      buflen = 2 * buflen - 1024;
+	    }
+#endif
+	}
     }
 
   if (secure[hstdb])
     seteuid (oldeuid);
 
   cache_addhst (db, fd, req, key, hst, uid);
+
+  if (use_malloc)
+    free (buffer);
 }
diff --git a/nscd/pwdcache.c b/nscd/pwdcache.c
index cae3303..9d88c88 100644
--- a/nscd/pwdcache.c
+++ b/nscd/pwdcache.c
@@ -1,5 +1,5 @@
 /* Cache handling for passwd lookup.
-   Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
+   Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998.
 
@@ -21,6 +21,7 @@
 #include <errno.h>
 #include <error.h>
 #include <pwd.h>
+#include <stdbool.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -28,6 +29,7 @@
 #include <time.h>
 #include <unistd.h>
 #include <libintl.h>
+#include <stackinfo.h>
 
 #include "nscd.h"
 #include "dbg_log.h"
@@ -200,14 +202,15 @@ addpwbyname (struct database *db, int fd, request_header *req,
      look again in the table whether the dataset is now available.  We
      simply insert it.  It does not matter if it is in there twice.  The
      pruning function only will look at the timestamp.  */
-  int buflen = 256;
-  char *buffer = alloca (buflen);
+  int buflen = 1024;
+  char *buffer = (char *) alloca (buflen);
   struct passwd resultbuf;
   struct passwd *pwd;
   uid_t oldeuid = 0;
+  bool use_malloc = false;
 
-  if (debug_level > 0)
-    dbg_log (_("Haven't found \"%s\" in password cache!"), (char *)key);
+  if (__builtin_expect (debug_level > 0, 0))
+    dbg_log (_("Haven't found \"%s\" in password cache!"), (char *) key);
 
   if (secure[pwddb])
     {
@@ -218,15 +221,47 @@ addpwbyname (struct database *db, int fd, request_header *req,
   while (__getpwnam_r (key, &resultbuf, buffer, buflen, &pwd) != 0
 	 && errno == ERANGE)
     {
+      char *old_buffer = buffer;
       errno = 0;
-      buflen += 256;
-      buffer = alloca (buflen);
+      buflen += 1024;
+
+      if (__builtin_expect (buflen > 32768, 0))
+	{
+	  buffer = (char *) realloc (use_malloc ? buffer : NULL, buflen);
+	  if (buffer == NULL)
+	    {
+	      /* We ran out of memory.  We cannot do anything but
+		 sending a negative response.  In reality this should
+		 never happen.  */
+	      pwd = NULL;
+	      buffer = old_buffer;
+	      break;
+	    }
+	  use_malloc = true;
+	}
+      else
+	{
+	  buffer = (char *) alloca (buflen);
+#if _STACK_GROWS_DOWN
+	  if (buffer + buflen == old_buffer)
+	    buflen = 2 * buflen - 1024;
+#elif _STACK_GROWS_UP
+	  if (old_buffer + buflen - 1024 == buffer)
+	    {
+	      buffer = old_buffer;
+	      buflen = 2 * buflen - 1024;
+	    }
+#endif
+	}
     }
 
   if (secure[pwddb])
     seteuid (oldeuid);
 
   cache_addpw (db, fd, req, key, pwd, c_uid);
+
+  if (use_malloc)
+    free (buffer);
 }
 
 
@@ -239,23 +274,24 @@ addpwbyuid (struct database *db, int fd, request_header *req,
      simply insert it.  It does not matter if it is in there twice.  The
      pruning function only will look at the timestamp.  */
   int buflen = 256;
-  char *buffer = alloca (buflen);
+  char *buffer = (char *) alloca (buflen);
   struct passwd resultbuf;
   struct passwd *pwd;
   uid_t oldeuid = 0;
   char *ep;
-  uid_t uid = strtoul ((char*) key, &ep, 10); 
-  
-  if (*(char*)key == '\0' || *ep != '\0')  /* invalid numeric uid */
+  uid_t uid = strtoul ((char *) key, &ep, 10);
+  bool use_malloc = false;
+
+  if (*(char *) key == '\0' || *ep != '\0')  /* invalid numeric uid */
     {
-      if (debug_level > 0) 
-        dbg_log (_("Invalid numeric uid \"%s\"!"), (char *)key);
+      if (debug_level > 0)
+        dbg_log (_("Invalid numeric uid \"%s\"!"), (char *) key);
 
       errno = EINVAL;
       return;
     }
 
-  if (debug_level > 0)
+  if (__builtin_expect (debug_level > 0, 0))
     dbg_log (_("Haven't found \"%d\" in password cache!"), uid);
 
   if (secure[pwddb])
@@ -267,13 +303,45 @@ addpwbyuid (struct database *db, int fd, request_header *req,
   while (__getpwuid_r (uid, &resultbuf, buffer, buflen, &pwd) != 0
 	 && errno == ERANGE)
     {
+      char *old_buffer = buffer;
       errno = 0;
-      buflen += 256;
-      buffer = alloca (buflen);
+      buflen += 1024;
+
+      if (__builtin_expect (buflen > 32768, 0))
+	{
+	  buffer = (char *) realloc (use_malloc ? buffer : NULL, buflen);
+	  if (buffer == NULL)
+	    {
+	      /* We ran out of memory.  We cannot do anything but
+		 sending a negative response.  In reality this should
+		 never happen.  */
+	      pwd = NULL;
+	      buffer = old_buffer;
+	      break;
+	    }
+	  use_malloc = true;
+	}
+      else
+	{
+	  buffer = (char *) alloca (buflen);
+#if _STACK_GROWS_DOWN
+	  if (buffer + buflen == old_buffer)
+	    buflen = 2 * buflen - 1024;
+#elif _STACK_GROWS_UP
+	  if (old_buffer + buflen - 1024 == buffer)
+	    {
+	      buffer = old_buffer;
+	      buflen = 2 * buflen - 1024;
+	    }
+#endif
+	}
     }
 
   if (secure[pwddb])
     seteuid (oldeuid);
 
   cache_addpw (db, fd, req, key, pwd, c_uid);
+
+  if (use_malloc)
+    free (buffer);
 }