Libguestfs - Feb 2018 - [PATCH] tmpdirs: Make the ‘su broken’ error message actionable.

Revert "tmpdirs: Blame systemd because su is broken."

This reverts commit 9464304d7a6b9b01e9eee32620ef3831e2b10875.

Replace with an actionable error message.
---
 lib/tmpdirs.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/lib/tmpdirs.c b/lib/tmpdirs.c
index bda3ee694..804c58be0 100644
--- a/lib/tmpdirs.c
+++ b/lib/tmpdirs.c
@@ -180,18 +180,22 @@ guestfs_impl_get_sockdir (guestfs_h *g)
 }
 
 static int
-lazy_make_tmpdir (guestfs_h *g, char *(*getdir) (guestfs_h *g), char **dest)
+lazy_make_tmpdir (guestfs_h *g,
+                  char *(*getdir) (guestfs_h *g), int is_runtime_dir,
+                  char **dest)
 {
   if (!*dest) {
     CLEANUP_FREE char *tmpdir = getdir (g);
     char *tmppath = safe_asprintf (g, "%s/libguestfsXXXXXX", tmpdir);
     if (mkdtemp (tmppath) == NULL) {
-      int bad_systemd = errno == EACCES && STRPREFIX (tmpdir,
"/run/user/");
+      int bad_systemd = is_runtime_dir && errno == EACCES &&
+        STRPREFIX (tmpdir, "/run/user/");
 
       if (!bad_systemd)
         perrorf (g, _("%s: cannot create temporary directory"),
tmppath);
       else
-        error (g, _("%s: cannot create temporary directory.  You may be
hitting systemd bug https://bugzilla.redhat.com/967509"), tmppath);
+        error (g, _("%s: cannot create temporary directory.  It may be
that $XDG_RUNTIME_DIR is pointing to a directory which we cannot write to, for
example if you used ‘su [user]’ to change to this user account (see
https://bugzilla.redhat.com/967509).  You can correct this by adjusting
XDG_RUNTIME_DIR and possibly creating /run/user/%d with the right
ownership."),
+               tmppath, (int) geteuid ());
       free (tmppath);
       return -1;
     }
@@ -219,13 +223,13 @@ lazy_make_tmpdir (guestfs_h *g, char *(*getdir) (guestfs_h
*g), char **dest)
 int
 guestfs_int_lazy_make_tmpdir (guestfs_h *g)
 {
-  return lazy_make_tmpdir (g, guestfs_get_tmpdir, &g->tmpdir);
+  return lazy_make_tmpdir (g, guestfs_get_tmpdir, 0, &g->tmpdir);
 }
 
 int
 guestfs_int_lazy_make_sockdir (guestfs_h *g)
 {
-  return lazy_make_tmpdir (g, guestfs_get_sockdir, &g->sockdir);
+  return lazy_make_tmpdir (g, guestfs_get_sockdir, 1, &g->sockdir);
 }
 
 /**
-- 
2.13.2

On Wednesday, 7 February 2018 17:29:12 CET Richard W.M. Jones
wrote:
> Revert "tmpdirs: Blame systemd because su is broken."
> 
> This reverts commit 9464304d7a6b9b01e9eee32620ef3831e2b10875.
> 
> Replace with an actionable error message.
> ---
>  lib/tmpdirs.c | 14 +++++++++-----
>  1 file changed, 9 insertions(+), 5 deletions(-)
> 
> diff --git a/lib/tmpdirs.c b/lib/tmpdirs.c
> index bda3ee694..804c58be0 100644
> --- a/lib/tmpdirs.c
> +++ b/lib/tmpdirs.c
> @@ -180,18 +180,22 @@ guestfs_impl_get_sockdir (guestfs_h *g)
>  }
>  
>  static int
> -lazy_make_tmpdir (guestfs_h *g, char *(*getdir) (guestfs_h *g), char
**dest)
> +lazy_make_tmpdir (guestfs_h *g,
> +                  char *(*getdir) (guestfs_h *g), int is_runtime_dir,
> +                  char **dest)
>  {
>    if (!*dest) {
>      CLEANUP_FREE char *tmpdir = getdir (g);
>      char *tmppath = safe_asprintf (g, "%s/libguestfsXXXXXX",
tmpdir);
>      if (mkdtemp (tmppath) == NULL) {
> -      int bad_systemd = errno == EACCES && STRPREFIX (tmpdir,
"/run/user/");
> +      int bad_systemd = is_runtime_dir && errno == EACCES
&&
> +        STRPREFIX (tmpdir, "/run/user/");
s/bad_systemd/bad_runtime_dir/

ACK with the above change.

-- 
Pino Toscano