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-rw-r--r--shadow/sgetspent.c58
1 files changed, 44 insertions, 14 deletions
diff --git a/shadow/sgetspent.c b/shadow/sgetspent.c
index 05d997c..ecfe01e 100644
--- a/shadow/sgetspent.c
+++ b/shadow/sgetspent.c
@@ -16,33 +16,63 @@
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
+#include <errno.h>
+#include <libc-lock.h>
#include <shadow.h>
-#include <stdio.h>
#include <stdlib.h>
-#include <string.h>
-#define MAX(a, b) ((a) > (b) ? (a) : (b))
+/* A reasonable size for a buffer to start with. */
+#define BUFLEN_SPWD 1024
+
+/* We need to protect the dynamic buffer handling. */
+__libc_lock_define_initialized (static, lock);
/* Read one shadow entry from the given stream. */
struct spwd *
sgetspent (const char *string)
{
+ static char *buffer;
+ static size_t buffer_size;
static struct spwd resbuf;
- static int max_size = 0;
- static char *buffer = NULL;
struct spwd *result;
- int len;
+ int save;
+
+ /* Get lock. */
+ __libc_lock_lock (lock);
- len = strlen (string) + 1;
- if (len > max_size)
+ /* Allocate buffer if not yet available. */
+ if (buffer == NULL)
{
- max_size = MAX (128, len + 32);
- buffer = realloc (buffer, max_size);
- if (buffer == NULL)
- return NULL;
+ buffer_size = BUFLEN_SPWD;
+ buffer = malloc (buffer_size);
}
- return __sgetspent_r (string, &resbuf, buffer, max_size, &result)
- ? NULL : result;
+ while (buffer != NULL
+ && __sgetspent_r (string, &resbuf, buffer, buffer_size, &result) != 0
+ && errno == ERANGE)
+ {
+ char *new_buf;
+ buffer_size += BUFLEN_SPWD;
+ new_buf = realloc (buffer, buffer_size);
+ if (new_buf == NULL)
+ {
+ /* We are out of memory. Free the current buffer so that the
+ process gets a chance for a normal termination. */
+ save = errno;
+ free (buffer);
+ __set_errno (save);
+ }
+ buffer = new_buf;
+ }
+
+ if (buffer == NULL)
+ result = NULL;
+
+ /* Release lock. Preserve error value. */
+ save = errno;
+ __libc_lock_unlock (lock);
+ __set_errno (save);
+
+ return result;
}