Allow $TMPDIR to override most temporary directory uses.

Be more consistent in allowing the user to override use of the
temporary directory by specifying $TMPDIR.  Also prefer P_tmpdir
macro (defined in <stdio.h>) if that is defined, rather than
hard-coding "/tmp" for the fallback location.

5 files changed, 41 insertions, 24 deletions

diff --git a/src/appliance.c b/src/appliance.c
index 2c1d7c94..163d7700 100644
--- a/src/appliance.c
+++ b/src/appliance.c
@@ -235,7 +235,7 @@ check_for_cached_appliance (guestfs_h *g,
                             const char *supermin_path, const char *checksum,
                             char **kernel, char **initrd, char **appliance)
 {
-  const char *tmpdir = guestfs___tmpdir ();
+  const char *tmpdir = guestfs_tmpdir ();
 
   size_t len = strlen (tmpdir) + strlen (checksum) + 2;
   char cachedir[len];
@@ -329,7 +329,7 @@ build_supermin_appliance (guestfs_h *g,
   if (g->verbose)
     guestfs___print_timestamped_message (g, "begin building supermin appliance");
 
-  const char *tmpdir = guestfs___tmpdir ();
+  const char *tmpdir = guestfs_tmpdir ();
   size_t cdlen = strlen (tmpdir) + strlen (checksum) + 2;
   char cachedir[cdlen];
   snprintf (cachedir, cdlen, "%s/%s", tmpdir, checksum);
diff --git a/src/guestfs-internal.h b/src/guestfs-internal.h
index ed82fded..212006d9 100644
--- a/src/guestfs-internal.h
+++ b/src/guestfs-internal.h
@@ -38,6 +38,11 @@
 #define N_(str) str
 #endif
 
+#define TMP_TEMPLATE_ON_STACK(var)                        \
+  const char *ttos_tmpdir = guestfs_tmpdir ();            \
+  char var[strlen (ttos_tmpdir) + 32];                    \
+  sprintf (var, "%s/libguestfsXXXXXX", ttos_tmpdir)       \
+
 #define UNIX_PATH_MAX 108
 
 #ifndef MAX
@@ -196,7 +201,6 @@ extern char *guestfs_safe_strdup (guestfs_h *g, const char *str);
 extern char *guestfs_safe_strndup (guestfs_h *g, const char *str, size_t n);
 extern void *guestfs_safe_memdup (guestfs_h *g, void *ptr, size_t size);
 extern void guestfs___print_timestamped_message (guestfs_h *g, const char *fs, ...);
-extern const char *guestfs___tmpdir (void);
 extern void guestfs___free_inspect_info (guestfs_h *g);
 extern int guestfs___set_busy (guestfs_h *g);
 extern int guestfs___end_busy (guestfs_h *g);
diff --git a/src/guestfs.h b/src/guestfs.h
index c23b9eb7..911e9565 100644
--- a/src/guestfs.h
+++ b/src/guestfs.h
@@ -89,6 +89,7 @@ extern void *guestfs_get_private (guestfs_h *g, const char *key);
  */
 extern void *guestfs_safe_malloc (guestfs_h *g, size_t nbytes);
 extern void *guestfs_safe_calloc (guestfs_h *g, size_t n, size_t s);
+extern const char *guestfs_tmpdir (void);
 /* End of private functions. */
 
 #ifdef __cplusplus
diff --git a/src/inspect.c b/src/inspect.c
index bce0fd6e..1f4096d1 100644
--- a/src/inspect.c
+++ b/src/inspect.c
@@ -227,6 +227,15 @@ is_regular_file (const char *filename)
 static char *
 cpio_arch (guestfs_h *g, const char *file, const char *path)
 {
+  TMP_TEMPLATE_ON_STACK (dir);
+#define dir_len (strlen (dir))
+#define initrd_len (dir_len + 16)
+  char initrd[initrd_len];
+#define cmd_len (dir_len + 256)
+  char cmd[cmd_len];
+#define bin_len (dir_len + 32)
+  char bin[bin_len];
+
   char *ret = NULL;
 
   const char *method;
@@ -237,20 +246,16 @@ cpio_arch (guestfs_h *g, const char *file, const char *path)
   else
     method = "cat";
 
-  char dir[] = "/tmp/initrd.XXXXXX";
-#define dir_len (sizeof dir)
   if (mkdtemp (dir) == NULL) {
     perrorf (g, "mkdtemp");
     goto out;
   }
 
-  char dir_initrd[dir_len + 16];
-  snprintf (dir_initrd, dir_len + 16, "%s/initrd", dir);
-  if (guestfs_download (g, path, dir_initrd) == -1)
+  snprintf (initrd, initrd_len, "%s/initrd", dir);
+  if (guestfs_download (g, path, initrd) == -1)
     goto out;
 
-  char cmd[dir_len + 256];
-  snprintf (cmd, dir_len + 256,
+  snprintf (cmd, cmd_len,
             "cd %s && %s initrd | cpio --quiet -id " INITRD_BINARIES1,
             dir, method);
   int r = system (cmd);
@@ -259,11 +264,10 @@ cpio_arch (guestfs_h *g, const char *file, const char *path)
     goto out;
   }
 
-  char bin[dir_len + 32];
   const char *bins[] = INITRD_BINARIES2;
   size_t i;
   for (i = 0; i < sizeof bins / sizeof bins[0]; ++i) {
-    snprintf (bin, dir_len + 32, "%s/%s", dir, bins[i]);
+    snprintf (bin, bin_len, "%s/%s", dir, bins[i]);
 
     if (is_regular_file (bin)) {
       int flags = g->verbose ? MAGIC_DEBUG : 0;
@@ -305,11 +309,14 @@ cpio_arch (guestfs_h *g, const char *file, const char *path)
    * contain shell meta-characters because of the way it was
    * constructed above.
    */
-  snprintf (cmd, dir_len + 256, "rm -rf %s", dir);
+  snprintf (cmd, cmd_len, "rm -rf %s", dir);
   ignore_value (system (cmd));
 
   return ret;
 #undef dir_len
+#undef initrd_len
+#undef cmd_len
+#undef bin_len
 }
 
 char *
@@ -983,6 +990,13 @@ static int
 check_windows_registry (guestfs_h *g, struct inspect_fs *fs,
                         const char *systemroot)
 {
+  TMP_TEMPLATE_ON_STACK (dir);
+#define dir_len (strlen (dir))
+#define software_hive_len (dir_len + 16)
+  char software_hive[software_hive_len];
+#define cmd_len (dir_len + 16)
+  char cmd[cmd_len];
+
   size_t len = strlen (systemroot) + 64;
   char software[len];
   snprintf (software, len, "%s/system32/config/software", systemroot);
@@ -998,15 +1012,12 @@ check_windows_registry (guestfs_h *g, struct inspect_fs *fs,
   hive_h *h = NULL;
   hive_value_h *values = NULL;
 
-  char dir[] = "/tmp/winreg.XXXXXX";
-#define dir_len 18
   if (mkdtemp (dir) == NULL) {
     perrorf (g, "mkdtemp");
     goto out;
   }
 
-  char software_hive[dir_len + 16];
-  snprintf (software_hive, dir_len + 16, "%s/software", dir);
+  snprintf (software_hive, software_hive_len, "%s/software", dir);
 
   if (guestfs_download (g, software_path, software_hive) == -1)
     goto out;
@@ -1092,10 +1103,11 @@ check_windows_registry (guestfs_h *g, struct inspect_fs *fs,
    * contain shell meta-characters because of the way it was
    * constructed above.
    */
-  char cmd[dir_len + 16];
-  snprintf (cmd, dir_len + 16, "rm -rf %s", dir);
+  snprintf (cmd, cmd_len, "rm -rf %s", dir);
   ignore_value (system (cmd));
 #undef dir_len
+#undef software_hive_len
+#undef cmd_len
 
   return ret;
 }
diff --git a/src/launch.c b/src/launch.c
index e0ad165f..f9d8329f 100644
--- a/src/launch.c
+++ b/src/launch.c
@@ -249,10 +249,7 @@ guestfs__launch (guestfs_h *g)
 
   /* Make the temporary directory. */
   if (!g->tmpdir) {
-    const char *tmpdir = guestfs___tmpdir ();
-    char dir_template[strlen (tmpdir) + 32];
-    sprintf (dir_template, "%s/libguestfsXXXXXX", tmpdir);
-
+    TMP_TEMPLATE_ON_STACK (dir_template);
     g->tmpdir = safe_strdup (g, dir_template);
     if (mkdtemp (g->tmpdir) == NULL) {
       perrorf (g, _("%s: cannot create temporary directory"), dir_template);
@@ -649,8 +646,11 @@ guestfs__launch (guestfs_h *g)
   return -1;
 }
 
+/* Return the location of the tmpdir (eg. "/tmp") and allow users
+ * to override it at runtime using $TMPDIR.
+ */
 const char *
-guestfs___tmpdir (void)
+guestfs_tmpdir (void)
 {
   const char *tmpdir;