From 78029b529ad98769685d607230b70f71832d5906 Mon Sep 17 00:00:00 2001
From: Richard Jones <rjones@trick.home.annexia.org>
Date: Sat, 18 Jul 2009 10:43:52 +0100
Subject: [PATCH] Make /sysroot path configurable.

Currently /sysroot is hard-coded throughout the daemon code.

This patch turns the path into a variable so that we can change
it in future, for example to allow standalone mode to be implemented.

This patch was tested by running all the C API tests successfully.
---
 daemon/augeas.c   |  5 +----
 daemon/checksum.c |  7 +++----
 daemon/cmp.c      | 10 ++--------
 daemon/command.c  | 27 +++++++++++++++++++--------
 daemon/cpmv.c     | 10 ++--------
 daemon/daemon.h   | 11 ++++++++---
 daemon/dir.c      |  7 ++-----
 daemon/du.c       |  5 +----
 daemon/file.c     | 12 ++++++------
 daemon/find.c     | 12 ++++++++++--
 daemon/grub.c     |  4 ++--
 daemon/guestfsd.c | 23 +++++++++++++++++++++++
 daemon/headtail.c |  6 ++----
 daemon/hexdump.c  |  6 +-----
 daemon/initrd.c   |  5 +++--
 daemon/ls.c       |  6 ++----
 daemon/mount.c    | 50 +++++++++++++++++++++++---------------------------
 daemon/scrub.c    | 10 ++--------
 daemon/strings.c  |  6 +-----
 daemon/tar.c      | 20 ++++++++++++--------
 daemon/wc.c       |  6 ++----
 21 files changed, 127 insertions(+), 121 deletions(-)

diff --git a/daemon/augeas.c b/daemon/augeas.c
index f75a1d6..79d41a4 100644
--- a/daemon/augeas.c
+++ b/daemon/augeas.c
@@ -53,7 +53,6 @@ do_aug_init (char *root, int flags)
 {
 #ifdef HAVE_AUGEAS
   char *buf;
-  int len;
 
   NEED_ROOT (-1);
   ABS_PATH (root, -1);
@@ -63,13 +62,11 @@ do_aug_init (char *root, int flags)
     aug = NULL;
   }
 
-  len = strlen (root) + 9;
-  buf = malloc (len);
+  buf = sysroot_path (root);
   if (!buf) {
     reply_with_perror ("malloc");
     return -1;
   }
-  snprintf (buf, len, "/sysroot%s", root);
 
   aug = aug_init (buf, NULL, flags);
   free (buf);
diff --git a/daemon/checksum.c b/daemon/checksum.c
index bb30b05..bd71182 100644
--- a/daemon/checksum.c
+++ b/daemon/checksum.c
@@ -33,7 +33,8 @@ do_checksum (char *csumtype, char *path)
   const char *program;
   char *buf;
   char *out, *err;
-  int r, len;
+  int r;
+  int len;
 
   NEED_ROOT (NULL);
   ABS_PATH (path, NULL);
@@ -58,13 +59,11 @@ do_checksum (char *csumtype, char *path)
   }
 
   /* Make the path relative to /sysroot. */
-  len = strlen (path) + 9;
-  buf = malloc (len);
+  buf = sysroot_path (path);
   if (!buf) {
     reply_with_perror ("malloc");
     return NULL;
   }
-  snprintf (buf, len, "/sysroot%s", path);
 
   r = command (&out, &err, program, buf, NULL);
   free (buf);
diff --git a/daemon/cmp.c b/daemon/cmp.c
index f650083..a2d92a3 100644
--- a/daemon/cmp.c
+++ b/daemon/cmp.c
@@ -31,7 +31,6 @@ int
 do_equal (char *file1, char *file2)
 {
   char *file1buf, *file2buf;
-  int file1len, file2len;
   char *err;
   int r;
 
@@ -39,24 +38,19 @@ do_equal (char *file1, char *file2)
   ABS_PATH (file1, -1);
   ABS_PATH (file2, -1);
 
-  file1len = strlen (file1) + 32;
-  file1buf = malloc (file1len);
+  file1buf = sysroot_path (file1);
   if (file1buf == NULL) {
     reply_with_perror ("malloc");
     return -1;
   }
 
-  file2len = strlen (file2) + 32;
-  file2buf = malloc (file2len);
+  file2buf = sysroot_path (file2);
   if (file2buf == NULL) {
     reply_with_perror ("malloc");
     free (file1buf);
     return -1;
   }
 
-  snprintf (file1buf, file1len, "/sysroot%s", file1);
-  snprintf (file2buf, file2len, "/sysroot%s", file2);
-
   r = commandr (NULL, &err, "cmp", "-s", file1buf, file2buf, NULL);
 
   free (file1buf);
diff --git a/daemon/command.c b/daemon/command.c
index 3f21807..0399255 100644
--- a/daemon/command.c
+++ b/daemon/command.c
@@ -31,6 +31,7 @@ do_command (char **argv)
 {
   char *out, *err;
   int r;
+  char *sysroot_proc, *sysroot_dev, *sysroot_dev_pts, *sysroot_sys;
   int proc_ok, dev_ok, dev_pts_ok, sys_ok;
 
   /* We need a root filesystem mounted to do this. */
@@ -53,23 +54,33 @@ do_command (char **argv)
    * We deliberately allow these commands to fail silently, BUT
    * if a mount fails, don't unmount the corresponding mount.
    */
-  r = command (NULL, NULL, "mount", "--bind", "/dev", "/sysroot/dev", NULL);
+  sysroot_dev = sysroot_path ("/dev");
+  sysroot_dev_pts = sysroot_path ("/dev/pts");
+  sysroot_proc = sysroot_path ("/proc");
+  sysroot_sys = sysroot_path ("/sys");
+
+  r = command (NULL, NULL, "mount", "--bind", "/dev", sysroot_dev, NULL);
   dev_ok = r != -1;
-  r = command (NULL, NULL, "mount", "--bind", "/dev/pts", "/sysroot/dev/pts", NULL);
+  r = command (NULL, NULL, "mount", "--bind", "/dev/pts", sysroot_dev_pts, NULL);
   dev_pts_ok = r != -1;
-  r = command (NULL, NULL, "mount", "--bind", "/proc", "/sysroot/proc", NULL);
+  r = command (NULL, NULL, "mount", "--bind", "/proc", sysroot_proc, NULL);
   proc_ok = r != -1;
-  r = command (NULL, NULL, "mount", "--bind", "/sys", "/sysroot/sys", NULL);
+  r = command (NULL, NULL, "mount", "--bind", "/sys", sysroot_sys, NULL);
   sys_ok = r != -1;
 
   CHROOT_IN;
   r = commandv (&out, &err, argv);
   CHROOT_OUT;
 
-  if (sys_ok) command (NULL, NULL, "umount", "/sysroot/sys", NULL);
-  if (proc_ok) command (NULL, NULL, "umount", "/sysroot/proc", NULL);
-  if (dev_pts_ok) command (NULL, NULL, "umount", "/sysroot/dev/pts", NULL);
-  if (dev_ok) command (NULL, NULL, "umount", "/sysroot/dev", NULL);
+  if (sys_ok) command (NULL, NULL, "umount", sysroot_sys, NULL);
+  if (proc_ok) command (NULL, NULL, "umount", sysroot_proc, NULL);
+  if (dev_pts_ok) command (NULL, NULL, "umount", sysroot_dev_pts, NULL);
+  if (dev_ok) command (NULL, NULL, "umount", sysroot_dev, NULL);
+
+  free (sysroot_dev);
+  free (sysroot_dev_pts);
+  free (sysroot_proc);
+  free (sysroot_sys);
 
   if (r == -1) {
     reply_with_error ("%s", err);
diff --git a/daemon/cpmv.c b/daemon/cpmv.c
index 5448a97..289a2da 100644
--- a/daemon/cpmv.c
+++ b/daemon/cpmv.c
@@ -49,7 +49,6 @@ static int
 cpmv_cmd (const char *cmd, const char *flags, const char *src, const char *dest)
 {
   char *srcbuf, *destbuf;
-  int srclen, destlen;
   char *err;
   int r;
 
@@ -57,24 +56,19 @@ cpmv_cmd (const char *cmd, const char *flags, const char *src, const char *dest)
   ABS_PATH (src, -1);
   ABS_PATH (dest, -1);
 
-  srclen = strlen (src) + 32;
-  srcbuf = malloc (srclen);
+  srcbuf = sysroot_path (src);
   if (srcbuf == NULL) {
     reply_with_perror ("malloc");
     return -1;
   }
 
-  destlen = strlen (dest) + 32;
-  destbuf = malloc (destlen);
+  destbuf = sysroot_path (dest);
   if (destbuf == NULL) {
     reply_with_perror ("malloc");
     free (srcbuf);
     return -1;
   }
 
-  snprintf (srcbuf, srclen, "/sysroot%s", src);
-  snprintf (destbuf, destlen, "/sysroot%s", dest);
-
   if (flags)
     r = command (NULL, &err, cmd, flags, srcbuf, destbuf, NULL);
   else
diff --git a/daemon/daemon.h b/daemon/daemon.h
index 814d2b1..c2bbf3e 100644
--- a/daemon/daemon.h
+++ b/daemon/daemon.h
@@ -29,6 +29,13 @@
 #include "../src/guestfs_protocol.h"
 
 /*-- in guestfsd.c --*/
+extern int verbose;
+
+extern const char *sysroot;
+extern int sysroot_len;
+
+extern char *sysroot_path (const char *path);
+
 extern int xwrite (int sock, const void *buf, size_t len);
 extern int xread (int sock, void *buf, size_t len);
 
@@ -53,8 +60,6 @@ extern int device_name_translation (char *device, const char *func);
 
 extern void udev_settle (void);
 
-extern int verbose;
-
 /*-- in names.c (auto-generated) --*/
 extern const char *function_names[];
 
@@ -172,7 +177,7 @@ extern void reply (xdrproc_t xdrp, char *ret);
 #define CHROOT_IN				\
   do {						\
     int __old_errno = errno;			\
-    if (chroot ("/sysroot") == -1)		\
+    if (chroot (sysroot) == -1)			\
       perror ("CHROOT_IN: sysroot");		\
     errno = __old_errno;			\
   } while (0)
diff --git a/daemon/dir.c b/daemon/dir.c
index 6eb86bb..a8f066f 100644
--- a/daemon/dir.c
+++ b/daemon/dir.c
@@ -56,7 +56,7 @@ do_rmdir (char *path)
 int
 do_rm_rf (char *path)
 {
-  int r, len;
+  int r;
   char *buf, *err;
 
   NEED_ROOT (-1);
@@ -67,15 +67,12 @@ do_rm_rf (char *path)
     return -1;
   }
 
-  len = strlen (path) + 9;
-  buf = malloc (len);
+  buf = sysroot_path (path);
   if (buf == NULL) {
     reply_with_perror ("malloc");
     return -1;
   }
 
-  snprintf (buf, len, "/sysroot%s", path);
-
   r = command (NULL, &err, "rm", "-rf", buf, NULL);
   free (buf);
 
diff --git a/daemon/du.c b/daemon/du.c
index 6f1adba..735132a 100644
--- a/daemon/du.c
+++ b/daemon/du.c
@@ -35,19 +35,16 @@ do_du (char *path)
   int64_t rv;
   char *out, *err;
   char *buf;
-  int len;
 
   NEED_ROOT (-1);
   ABS_PATH (path, -1);
 
   /* Make the path relative to /sysroot. */
-  len = strlen (path) + 9;
-  buf = malloc (len);
+  buf = sysroot_path (path);
   if (!buf) {
     reply_with_perror ("malloc");
     return -1;
   }
-  snprintf (buf, len, "/sysroot%s", path);
 
   r = command (&out, &err, "du", "-s", buf, NULL);
   free (buf);
diff --git a/daemon/file.c b/daemon/file.c
index 98c356d..851d9e7 100644
--- a/daemon/file.c
+++ b/daemon/file.c
@@ -328,8 +328,9 @@ char *
 do_file (char *path)
 {
   char *out, *err;
-  int r, len, freeit = 0;
+  int r, freeit = 0;
   char *buf;
+  int len;
 
   NEED_ROOT_OR_IS_DEVICE (path, NULL);
   ABS_PATH (path, NULL);
@@ -337,13 +338,11 @@ do_file (char *path)
   if (strncmp (path, "/dev/", 5) == 0)
     buf = (char *) path;
   else {
-    len = strlen (path) + 9;
-    buf = malloc (len);
+    buf = sysroot_path (path);
     if (!buf) {
       reply_with_perror ("malloc");
       return NULL;
     }
-    snprintf (buf, len, "/sysroot%s", path);
     freeit = 1;
   }
 
@@ -389,7 +388,7 @@ do_zfile (char *method, char *path)
   NEED_ROOT (NULL);
   ABS_PATH (path, NULL);
 
-  len = 2 * strlen (path) + 64;
+  len = 2 * strlen (path) + sysroot_len + 64;
   cmd = malloc (len);
   if (!cmd) {
     reply_with_perror ("malloc");
@@ -406,7 +405,8 @@ do_zfile (char *method, char *path)
     return NULL;
   }
 
-  strcat (cmd, " /sysroot");
+  strcat (cmd, " ");
+  strcat (cmd, sysroot);
   shell_quote (cmd + strlen (cmd), len - strlen (cmd), path);
   strcat (cmd, " | file -bsL -");
 
diff --git a/daemon/find.c b/daemon/find.c
index 85994b6..d882953 100644
--- a/daemon/find.c
+++ b/daemon/find.c
@@ -56,21 +56,27 @@ do_find (char *dir)
   FILE *fp;
   char **res = NULL;
   int size = 0, alloc = 0;
-  char sysrootdir[PATH_MAX];
+  char *sysrootdir;
   char str[PATH_MAX];
 
   NEED_ROOT (NULL);
   ABS_PATH (dir, NULL);
 
-  snprintf (sysrootdir, sizeof sysrootdir, "/sysroot%s", dir);
+  sysrootdir = sysroot_path (dir);
+  if (!sysrootdir) {
+    reply_with_perror ("malloc");
+    return NULL;
+  }
 
   r = stat (sysrootdir, &statbuf);
   if (r == -1) {
     reply_with_perror ("%s", dir);
+    free (sysrootdir);
     return NULL;
   }
   if (!S_ISDIR (statbuf.st_mode)) {
     reply_with_error ("%s: not a directory", dir);
+    free (sysrootdir);
     return NULL;
   }
 
@@ -81,11 +87,13 @@ do_find (char *dir)
   cmd = malloc (len);
   if (!cmd) {
     reply_with_perror ("malloc");
+    free (sysrootdir);
     return NULL;
   }
 
   strcpy (cmd, "find ");
   shell_quote (cmd+5, len-5, sysrootdir);
+  free (sysrootdir);
   strcat (cmd, " -print0");
 
   if (verbose)
diff --git a/daemon/grub.c b/daemon/grub.c
index 29fe294..3b1768f 100644
--- a/daemon/grub.c
+++ b/daemon/grub.c
@@ -36,13 +36,13 @@ do_grub_install (char *root, char *device)
   ABS_PATH (root, -1);
   IS_DEVICE (device, -1);
 
-  len = strlen (root) + 64;
+  len = strlen (root) + sysroot_len + 64;
   buf = malloc (len);
   if (!buf) {
     reply_with_perror ("malloc");
     return -1;
   }
-  snprintf (buf, len, "--root-directory=/sysroot%s", root);
+  snprintf (buf, len, "--root-directory=%s%s", sysroot, root);
 
   r = command (NULL, &err, "/sbin/grub-install", buf, device, NULL);
   free (buf);
diff --git a/daemon/guestfsd.c b/daemon/guestfsd.c
index 87065b9..5c250f0 100644
--- a/daemon/guestfsd.c
+++ b/daemon/guestfsd.c
@@ -47,6 +47,10 @@ static void usage (void);
 
 int verbose = 0;
 
+/* Location to mount root device. */
+const char *sysroot = "/sysroot"; /* No trailing slash. */
+int sysroot_len = 8;
+
 int
 main (int argc, char *argv[])
 {
@@ -221,6 +225,25 @@ main (int argc, char *argv[])
   exit (0);
 }
 
+/* Turn "/path" into "/sysroot/path".
+ *
+ * Caller must check for NULL and call reply_with_perror ("malloc")
+ * if it is.  Caller must also free the string.
+ */
+char *
+sysroot_path (const char *path)
+{
+  char *r;
+  int len = strlen (path) + sysroot_len + 1;
+
+  r = malloc (len);
+  if (r == NULL)
+    return NULL;
+
+  snprintf (r, len, "%s%s", sysroot, path);
+  return r;
+}
+
 int
 xwrite (int sock, const void *buf, size_t len)
 {
diff --git a/daemon/headtail.c b/daemon/headtail.c
index 6d24851..af2648c 100644
--- a/daemon/headtail.c
+++ b/daemon/headtail.c
@@ -32,20 +32,18 @@ headtail (const char *prog, const char *flag, const char *n, char *path)
 {
   char *buf;
   char *out, *err;
-  int r, len;
+  int r;
   char **lines;
 
   NEED_ROOT (NULL);
   ABS_PATH (path, NULL);
 
   /* Make the path relative to /sysroot. */
-  len = strlen (path) + 9;
-  buf = malloc (len);
+  buf = sysroot_path (path);
   if (!buf) {
     reply_with_perror ("malloc");
     return NULL;
   }
-  snprintf (buf, len, "/sysroot%s", path);
 
   r = command (&out, &err, prog, flag, n, buf, NULL);
   free (buf);
diff --git a/daemon/hexdump.c b/daemon/hexdump.c
index a582c57..e2d8300 100644
--- a/daemon/hexdump.c
+++ b/daemon/hexdump.c
@@ -28,7 +28,6 @@
 char *
 do_hexdump (char *path)
 {
-  int len;
   char *buf;
   int r;
   char *out, *err;
@@ -36,15 +35,12 @@ do_hexdump (char *path)
   NEED_ROOT (NULL);
   ABS_PATH (path, NULL);
 
-  len = strlen (path) + 9;
-  buf = malloc (len);
+  buf = sysroot_path (path);
   if (!buf) {
     reply_with_perror ("malloc");
     return NULL;
   }
 
-  snprintf (buf, len, "/sysroot%s", path);
-
   r = command (&out, &err, "hexdump", "-C", buf, NULL);
   free (buf);
   if (r == -1) {
diff --git a/daemon/initrd.c b/daemon/initrd.c
index 7b32a08..392b811 100644
--- a/daemon/initrd.c
+++ b/daemon/initrd.c
@@ -41,14 +41,15 @@ do_initrd_list (char *path)
   ABS_PATH (path, NULL);
 
   /* "zcat /sysroot/<path> | cpio --quiet -it", but path must be quoted. */
-  len = 64 + 2 * strlen (path);
+  len = 64 + sysroot_len + 2 * strlen (path);
   cmd = malloc (len);
   if (!cmd) {
     reply_with_perror ("malloc");
     return NULL;
   }
 
-  strcpy (cmd, "zcat /sysroot");
+  strcpy (cmd, "zcat ");
+  strcat (cmd, sysroot);
   shell_quote (cmd+13, len-13, path);
   strcat (cmd, " | cpio --quiet -it");
 
diff --git a/daemon/ls.c b/daemon/ls.c
index a440080..4d4714e 100644
--- a/daemon/ls.c
+++ b/daemon/ls.c
@@ -77,7 +77,7 @@ do_ls (char *path)
 char *
 do_ll (char *path)
 {
-  int r, len;
+  int r;
   char *out, *err;
   char *spath;
 
@@ -90,13 +90,11 @@ do_ll (char *path)
    * interactive sessions.  For the same reason, you can also "escape"
    * the sysroot (eg. 'll /..').
    */
-  len = strlen (path) + 9;
-  spath = malloc (len);
+  spath = sysroot_path (path);
   if (!spath) {
     reply_with_perror ("malloc");
     return NULL;
   }
-  snprintf (spath, len, "/sysroot%s", path);
 
   r = command (&out, &err, "ls", "-la", spath, NULL);
   free (spath);
diff --git a/daemon/mount.c b/daemon/mount.c
index 20811f1..e7265fe 100644
--- a/daemon/mount.c
+++ b/daemon/mount.c
@@ -44,7 +44,7 @@ int
 do_mount_vfs (char *options, char *vfstype,
 	      char *device, char *mountpoint)
 {
-  int len, r, is_root;
+  int r, is_root;
   char *mp;
   char *error;
 
@@ -57,16 +57,12 @@ do_mount_vfs (char *options, char *vfstype,
     return -1;
   }
 
-  len = strlen (mountpoint) + 9;
-
-  mp = malloc (len);
+  mp = sysroot_path (mountpoint);
   if (!mp) {
     reply_with_perror ("malloc");
     return -1;
   }
 
-  snprintf (mp, len, "/sysroot%s", mountpoint);
-
   if (vfstype)
     r = command (NULL, &error,
 		 "mount", "-o", options, "-t", vfstype, device, mp, NULL);
@@ -111,7 +107,7 @@ do_mount_options (char *options, char *device,
 int
 do_umount (char *pathordevice)
 {
-  int len, freeit = 0, r;
+  int freeit = 0, r;
   char *buf;
   char *err;
 
@@ -119,14 +115,12 @@ do_umount (char *pathordevice)
     buf = pathordevice;
     IS_DEVICE (buf, -1);
   } else {
-    len = strlen (pathordevice) + 9;
-    freeit = 1;
-    buf = malloc (len);
+    buf = sysroot_path (pathordevice);
     if (buf == NULL) {
       reply_with_perror ("malloc");
       return -1;
     }
-    snprintf (buf, len, "/sysroot%s", pathordevice);
+    freeit = 1;
   }
 
   r = command (NULL, &err, "umount", buf, NULL);
@@ -153,6 +147,7 @@ mounts_or_mountpoints (int mp)
   int size = 0, alloc = 0;
   char *p, *pend, *p2;
   int len;
+  char matching[5 + sysroot_len];
 
   r = command (&out, &err, "mount", NULL);
   if (r == -1) {
@@ -164,6 +159,11 @@ mounts_or_mountpoints (int mp)
 
   free (err);
 
+  /* Lines have the format:
+   *   /dev/foo on /mountpoint type ...
+   */
+  snprintf (matching, 5 + sysroot_len, " on %s", sysroot);
+
   p = out;
   while (p) {
     pend = strchr (p, '\n');
@@ -172,10 +172,7 @@ mounts_or_mountpoints (int mp)
       pend++;
     }
 
-    /* Lines have the format:
-     *   /dev/foo on /mountpoint type ...
-     */
-    p2 = strstr (p, " on /sysroot");
+    p2 = strstr (p, matching);
     if (p2 != NULL) {
       *p2 = '\0';
       if (add_string (&ret, &size, &alloc, p) == -1) {
@@ -183,7 +180,7 @@ mounts_or_mountpoints (int mp)
 	return NULL;
       }
       if (mp) {
-	p2 += 12;		/* skip " on /sysroot" */
+	p2 += 4 + sysroot_len;	/* skip " on /sysroot" */
 	len = strcspn (p2, " ");
 
 	if (len == 0)		/* .. just /sysroot, so we turn it into "/" */
@@ -249,6 +246,7 @@ do_umount_all (void)
   char **mounts = NULL;
   int size = 0, alloc = 0;
   char *p, *p2, *p3, *pend;
+  char matching[5 + sysroot_len];
 
   r = command (&out, &err, "mount", NULL);
   if (r == -1) {
@@ -260,6 +258,11 @@ do_umount_all (void)
 
   free (err);
 
+  /* Lines have the format:
+   *   /dev/foo on /mountpoint type ...
+   */
+  snprintf (matching, 5 + sysroot_len, " on %s", sysroot);
+
   p = out;
   while (p) {
     pend = strchr (p, '\n');
@@ -268,10 +271,7 @@ do_umount_all (void)
       pend++;
     }
 
-    /* Lines have the format:
-     *   /dev/foo on /mountpoint type ...
-     */
-    p2 = strstr (p, " on /sysroot");
+    p2 = strstr (p, matching);
     if (p2 != NULL) {
       p2 += 4;
       p3 = p2 + strcspn (p2, " ");
@@ -315,7 +315,7 @@ do_umount_all (void)
 int
 do_mount_loop (char *file, char *mountpoint)
 {
-  int len, r;
+  int r;
   char *buf, *mp;
   char *error;
 
@@ -323,22 +323,18 @@ do_mount_loop (char *file, char *mountpoint)
   ABS_PATH (file, -1);
 
   /* We have to prefix /sysroot on both the filename and the mountpoint. */
-  len = strlen (mountpoint) + 9;
-  mp = malloc (len);
+  mp = sysroot_path (mountpoint);
   if (!mp) {
     reply_with_perror ("malloc");
     return -1;
   }
-  snprintf (mp, len, "/sysroot%s", mountpoint);
 
-  len = strlen (file) + 9;
-  buf = malloc (len);
+  buf = sysroot_path (file);
   if (!file) {
     reply_with_perror ("malloc");
     free (mp);
     return -1;
   }
-  snprintf (buf, len, "/sysroot%s", file);
 
   r = command (NULL, &error, "mount", "-o", "loop", buf, mp, NULL);
   free (mp);
diff --git a/daemon/scrub.c b/daemon/scrub.c
index 2f14bcb..6e205a0 100644
--- a/daemon/scrub.c
+++ b/daemon/scrub.c
@@ -51,7 +51,6 @@ int
 do_scrub_file (char *file)
 {
   char *buf;
-  int len;
   char *err;
   int r;
 
@@ -59,13 +58,11 @@ do_scrub_file (char *file)
   ABS_PATH (file, -1);
 
   /* Make the path relative to /sysroot. */
-  len = strlen (file) + 9;
-  buf = malloc (len);
+  buf = sysroot_path (file);
   if (!buf) {
     reply_with_perror ("malloc");
     return -1;
   }
-  snprintf (buf, len, "/sysroot%s", file);
 
   r = command (NULL, &err, "scrub", "-r", buf, NULL);
   free (buf);
@@ -84,7 +81,6 @@ int
 do_scrub_freespace (char *dir)
 {
   char *buf;
-  int len;
   char *err;
   int r;
 
@@ -92,13 +88,11 @@ do_scrub_freespace (char *dir)
   ABS_PATH (dir, -1);
 
   /* Make the path relative to /sysroot. */
-  len = strlen (dir) + 9;
-  buf = malloc (len);
+  buf = sysroot_path (dir);
   if (!buf) {
     reply_with_perror ("malloc");
     return -1;
   }
-  snprintf (buf, len, "/sysroot%s", dir);
 
   r = command (NULL, &err, "scrub", "-X", buf, NULL);
   free (buf);
diff --git a/daemon/strings.c b/daemon/strings.c
index 2c52532..c0e073f 100644
--- a/daemon/strings.c
+++ b/daemon/strings.c
@@ -28,7 +28,6 @@
 char **
 do_strings_e (char *encoding, char *path)
 {
-  int len;
   char *buf;
   int r;
   char *out, *err;
@@ -37,15 +36,12 @@ do_strings_e (char *encoding, char *path)
   NEED_ROOT (NULL);
   ABS_PATH (path, NULL);
 
-  len = strlen (path) + 9;
-  buf = malloc (len);
+  buf = sysroot_path (path);
   if (!buf) {
     reply_with_perror ("malloc");
     return NULL;
   }
 
-  snprintf (buf, len, "/sysroot%s", path);
-
   r = command (&out, &err, "strings", "-e", encoding, buf, NULL);
   free (buf);
   if (r == -1) {
diff --git a/daemon/tar.c b/daemon/tar.c
index 9540827..3008574 100644
--- a/daemon/tar.c
+++ b/daemon/tar.c
@@ -49,7 +49,7 @@ do_tar_in (char *dir)
   }
 
   /* "tar -C /sysroot%s -xf -" but we have to quote the dir. */
-  len = 2 * strlen (dir) + 32;
+  len = 2 * strlen (dir) + sysroot_len + 32;
   cmd = malloc (len);
   if (!cmd) {
     err = errno;
@@ -58,7 +58,8 @@ do_tar_in (char *dir)
     reply_with_perror ("malloc");
     return -1;
   }
-  strcpy (cmd, "tar -C /sysroot");
+  strcpy (cmd, "tar -C ");
+  strcat (cmd, sysroot);
   shell_quote (cmd+15, len-15, dir);
   strcat (cmd, " -xf -");
 
@@ -112,13 +113,14 @@ do_tar_out (char *dir)
   ABS_PATH (dir, -1);
 
   /* "tar -C /sysroot%s -cf - ." but we have to quote the dir. */
-  len = 2 * strlen (dir) + 32;
+  len = 2 * strlen (dir) + sysroot_len + 32;
   cmd = malloc (len);
   if (!cmd) {
     reply_with_perror ("malloc");
     return -1;
   }
-  strcpy (cmd, "tar -C /sysroot");
+  strcpy (cmd, "tar -C ");
+  strcat (cmd, sysroot);
   shell_quote (cmd+15, len-15, dir);
   strcat (cmd, " -cf - .");
 
@@ -175,7 +177,7 @@ do_tgz_in (char *dir)
   }
 
   /* "tar -C /sysroot%s -zxf -" but we have to quote the dir. */
-  len = 2 * strlen (dir) + 32;
+  len = 2 * strlen (dir) + sysroot_len + 32;
   cmd = malloc (len);
   if (!cmd) {
     err = errno;
@@ -184,7 +186,8 @@ do_tgz_in (char *dir)
     reply_with_perror ("malloc");
     return -1;
   }
-  strcpy (cmd, "tar -C /sysroot");
+  strcpy (cmd, "tar -C ");
+  strcat (cmd, sysroot);
   shell_quote (cmd+15, len-15, dir);
   strcat (cmd, " -zxf -");
 
@@ -238,13 +241,14 @@ do_tgz_out (char *dir)
   ABS_PATH (dir, -1);
 
   /* "tar -C /sysroot%s -zcf - ." but we have to quote the dir. */
-  len = 2 * strlen (dir) + 32;
+  len = 2 * strlen (dir) + sysroot_len + 32;
   cmd = malloc (len);
   if (!cmd) {
     reply_with_perror ("malloc");
     return -1;
   }
-  strcpy (cmd, "tar -C /sysroot");
+  strcpy (cmd, "tar -C ");
+  strcat (cmd, sysroot);
   shell_quote (cmd+15, len-15, dir);
   strcat (cmd, " -zcf - .");
 
diff --git a/daemon/wc.c b/daemon/wc.c
index 370ffdd..4878b57 100644
--- a/daemon/wc.c
+++ b/daemon/wc.c
@@ -32,19 +32,17 @@ wc (char *flag, char *path)
 {
   char *buf;
   char *out, *err;
-  int r, len;
+  int r;
 
   NEED_ROOT (-1);
   ABS_PATH (path, -1);
 
   /* Make the path relative to /sysroot. */
-  len = strlen (path) + 9;
-  buf = malloc (len);
+  buf = sysroot_path (path);
   if (!buf) {
     reply_with_perror ("malloc");
     return -1;
   }
-  snprintf (buf, len, "/sysroot%s", path);
 
   r = command (&out, &err, "wc", flag, buf, NULL);
   free (buf);
-- 
1.8.3.1