Unify the short-circuit translator logic

* libdiskfs/dir-lookup.c (short_circuited_callback1): Move function to
libfshelp.
(diskfs_S_dir_lookup): Use the function from libfshelp instead.
* libdiskfs/fsys-getroot.c (diskfs_S_fsys_getroot): Adapt accordingly.
* libdiskfs/trans-callback.c (_diskfs_translator_callback2_fn): Likewise.
* libfshelp/fetch-root.c (fshelp_short_circuited_callback1): New function.
* libfshelp/fshelp.h (struct fshelp_stat_cookie): New definition.
(fshelp_short_circuited_callback1): New prototype.
* libnetfs/dir-lookup.c (short_circuited_callback1): Drop function.
(netfs_S_dir_lookup): Use the function from libfshelp instead.
* libnetfs/fsys-getroot.c (netfs_S_fsys_getroot): Adapt accordingly.
* libnetfs/trans-callback.c (_netfs_translator_callback2_fn): Likewise.

2 files changed, 56 insertions, 0 deletions

diff --git a/libfshelp/fetch-root.c b/libfshelp/fetch-root.c
index eb0f3152..75aa2d37 100644
--- a/libfshelp/fetch-root.c
+++ b/libfshelp/fetch-root.c
@@ -20,7 +20,9 @@
 
 #include <assert.h>
 #include <hurd/fsys.h>
+#include <hurd/paths.h>
 #include <hurd/ports.h>
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
@@ -197,3 +199,41 @@ fshelp_fetch_root (struct transbox *box, void *cookie,
 
   return err;
 }
+
+/* A callback function for short-circuited translators.  S_ISLNK and
+   S_IFSOCK must be handled elsewhere.  */
+error_t
+fshelp_short_circuited_callback1 (void *cookie1, void *cookie2,
+				  uid_t *uid, gid_t *gid,
+				  char **argz, size_t *argz_len)
+{
+  struct fshelp_stat_cookie2 *statc = cookie2;
+
+  switch (*statc->modep & S_IFMT)
+    {
+    case S_IFCHR:
+    case S_IFBLK:
+      if (asprintf (argz, "%s%c%d%c%d",
+		    (S_ISCHR (*statc->modep)
+		     ? _HURD_CHRDEV : _HURD_BLKDEV),
+		    0, major (statc->statp->st_rdev),
+		    0, minor (statc->statp->st_rdev)) < 0)
+	return ENOMEM;
+      *argz_len = strlen (*argz) + 1;
+      *argz_len += strlen (*argz + *argz_len) + 1;
+      *argz_len += strlen (*argz + *argz_len) + 1;
+      break;
+    case S_IFIFO:
+      if (asprintf (argz, "%s", _HURD_FIFO) < 0)
+	return ENOMEM;
+      *argz_len = strlen (*argz) + 1;
+      break;
+    default:
+      return ENOENT;
+    }
+
+  *uid = statc->statp->st_uid;
+  *gid = statc->statp->st_gid;
+
+  return 0;
+}
diff --git a/libfshelp/fshelp.h b/libfshelp/fshelp.h
index d04c0561..ecd9335d 100644
--- a/libfshelp/fshelp.h
+++ b/libfshelp/fshelp.h
@@ -148,6 +148,22 @@ typedef error_t (*fshelp_fetch_root_callback1_t) (void *cookie1, void *cookie2,
 						  uid_t *uid, gid_t *gid,
 						  char **argz, size_t *argz_len);
 
+/* A cookie for fshelp_short_circuited_callback1.  Such a structure
+   must be passed to the call to fshelp_fetch_root.  */
+struct fshelp_stat_cookie2
+{
+  io_statbuf_t *statp;
+  mode_t *modep;
+  void *next;
+};
+
+/* A callback function for short-circuited translators.  S_ISLNK and
+   S_IFSOCK must be handled elsewhere.  */
+error_t fshelp_short_circuited_callback1 (void *cookie1, void *cookie2,
+					  uid_t *uid, gid_t *gid,
+					  char **argz, size_t *argz_len);
+
+
 /* This routine is called by fshelp_fetch_root to fetch more information.
    Return an unauthenticated node for the file itself in *UNDERLYING and
    *UNDERLYING_TYPE (opened with FLAGS).  COOKIE1 is the cookie passed in