Libc-1353.100.2.tar.gz

[apple/libc.git] / stdlib / grantpt.c

diff --git a/stdlib/grantpt.c b/stdlib/grantpt.c
index c8653ec961c0f327cc009286a679aaf33d28ce1f..bbc52cb04502a3570d77c402ba65ea4c7407ce9a 100644 (file)
--- a/stdlib/grantpt.c
+++ b/stdlib/grantpt.c
@@ -21,7 +21,11 @@
  * @APPLE_LICENSE_HEADER_END@
  */
 
+#include <os/assumes.h>
+#include <os/once_private.h>
+#include <pthread.h>
 #include <stdlib.h>
+#include <string.h>
 #include <sys/ioctl.h>
 #include <sys/stat.h>
 #include <fcntl.h>
@@ -53,6 +57,19 @@ grantpt(int fd)
        return ioctl(fd, TIOCPTYGRANT);
 }
 
+// defined by TIOCPTYGNAME
+#define PTSNAME_MAX_SIZE 128
+
+static pthread_key_t ptsname_buffer_specific_key;
+static os_once_t ptsname_once;
+
+static void
+ptsname_once_init(void *ctx __unused)
+{
+       int ret = pthread_key_create(&ptsname_buffer_specific_key, free);
+       os_assert_zero(ret);
+}
+
 /*
  * ptsname call for cloning pty implementation.
  *
@@ -62,29 +79,59 @@ grantpt(int fd)
 char *
 ptsname(int fd)
 {
-       static char *ptsnamebuf = NULL;
+       os_once(&ptsname_once, NULL, ptsname_once_init);
+       char *ptsnamebuf = pthread_getspecific(ptsname_buffer_specific_key);
+
+       if (ptsnamebuf == NULL) {
+               ptsnamebuf = malloc(PTSNAME_MAX_SIZE);
+               os_assert(ptsnamebuf);
+
+               int error = pthread_setspecific(ptsname_buffer_specific_key, ptsnamebuf);
+               os_assert_zero(error);
+       }
+
+       int error = ptsname_r(fd, ptsnamebuf, PTSNAME_MAX_SIZE);
+
+       return error ? NULL : ptsnamebuf;
+}
+
+int
+ptsname_r(int fd, char *buffer, size_t buflen)
+{
        int error;
-       char *retval = NULL;
        struct stat sbuf;
+       char ptsnamebuf[PTSNAME_MAX_SIZE];
 
-       if (ptsnamebuf == NULL) {
-               ptsnamebuf = malloc(128); // defined by TIOCPTYGNAME
+       if (!buffer) {
+               errno = EINVAL;
+               return -1;
        }
-       
+
        error = ioctl(fd, TIOCPTYGNAME, ptsnamebuf);
-       if (!error) {
-               /*
-                * XXX TSD
-                *
-                * POSIX: Handle device rename test case, which is expected
-                * to fail if the pty has been renamed.
-                */
-               if (stat(ptsnamebuf, &sbuf) == 0) {
-                       retval = ptsnamebuf;
-               }
+       if (error) {
+               return -1;
        }
 
-       return (retval);
+       /*
+        * XXX TSD
+        *
+        * POSIX: Handle device rename test case, which is expected
+        * to fail if the pty has been renamed.
+        */
+       error = stat(ptsnamebuf, &sbuf);
+       if (error) {
+               return -1;
+       }
+
+       size_t len = strlen(ptsnamebuf) + 1;
+       if (buflen < len) {
+               errno = ERANGE;
+               return -1;
+       }
+
+       memcpy(buffer, ptsnamebuf, len);
+
+       return 0;
 }
 
 /*