[Libguestfs] [PATCH 05/67] daemon: cap-get-file: Return empty string if no capability on file (RHBZ#989356).

From: "Richard W.M. Jones" <rjones(a)redhat.com&gt; Return an empty string (instead of an error) if no capabilities are set on a file, and document that in the API. (cherry picked from commit c663ab3bb9ab02fb3ca6209333c2d5402081c4de) --- daemon/cap.c | 12 ++++++++++++ generator/actions.ml | 4 +++- 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/daemon/cap.c b/daemon/cap.c index d1f0398..1d732c5 100644 --- a/daemon/cap.c +++ b/daemon/cap.c @@ -48,6 +48,18 @@ do_cap_get_file (const char *path) CHROOT_OUT; if (cap == NULL) { + /* The getcap utility (part of libcap) ignores ENODATA. It just + * means there is no capability attached to the file (RHBZ#989356). + */ + if (errno == ENODATA) { + ret = strdup (""); + if (ret == NULL) { + reply_with_perror ("strdup"); + return NULL; + } + return ret; + } + reply_with_perror ("%s", path); return NULL; } diff --git a/generator/actions.ml b/generator/actions.ml index 238553d..d30aec8 100644 --- a/generator/actions.ml +++ b/generator/actions.ml @@ -10928,7 +10928,9 @@ attached to directory C<dir>." }; shortdesc = "get the Linux capabilities attached to a file"; longdesc = "\ This function returns the Linux capabilities attached to C<path>. -The capabilities set is returned in text form (see L<cap_to_text(3)>)." }; +The capabilities set is returned in text form (see L<cap_to_text(3)>). + +If no capabilities are attached to a file, an empty string is returned." }; { defaults with name = "cap_set_file"; -- 1.8.3.1