On Thu, Feb 20, 2025 at 3:13 PM Rahul Sandhu <nvraxn@xxxxxxxxx> wrote:
>
> Passing a const char *path to basename(3) is a glibc specific
> extension.
>
> Signed-off-by: Rahul Sandhu <nvraxn@xxxxxxxxx>
> ---
> libsemanage/src/conf-parse.y | 3 +++
> libsemanage/src/direct_api.c | 3 +++
> 2 files changed, 6 insertions(+)
>
> diff --git a/libsemanage/src/conf-parse.y b/libsemanage/src/conf-parse.y
> index 6cb8a598..97cc5438 100644
> --- a/libsemanage/src/conf-parse.y
> +++ b/libsemanage/src/conf-parse.y
> @@ -50,6 +50,9 @@ static external_prog_t *new_external;
> static int parse_errors;
>
> #define PASSIGN(p1,p2) { free(p1); p1 = p2; }
> +#if !defined(__GLIBC__)
> +#define basename(src) (strrchr(src, '/') ? strrchr(src, '/') + 1 : src)
> +#endif
>
> %}
>
> diff --git a/libsemanage/src/direct_api.c b/libsemanage/src/direct_api.c
> index 99cba7f7..4459a7d7 100644
> --- a/libsemanage/src/direct_api.c
> +++ b/libsemanage/src/direct_api.c
> @@ -63,6 +63,9 @@
> #define PIPE_READ 0
> #define PIPE_WRITE 1
> #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
> +#if !defined(__GLIBC__)
> +#define basename(src) (strrchr(src, '/') ? strrchr(src, '/') + 1 : src)
> +#endif
>
> static void semanage_direct_destroy(semanage_handle_t * sh);
> static int semanage_direct_disconnect(semanage_handle_t * sh);
> --
> 2.48.1
>
What system are you on where you run libsemange without glibc, just curious?
I am not opposed to adding an implementation for basename where the
input can be read only for non-glibc, but this patch doesn't work:
Per the man page, https://man7.org/linux/man-pages/man3/basename.3.html,
basename("/") should return "/", this one return "\0"
basename("/usr/"); should return "usr", this returns "\0".
There are two ways you could approach this:
1. If you wanted to do an implementation, I would add it to
utilities.c/h and call it something other than basename so we don't
get any odd issues with it choosing the one from the headers over the
macro. Perhaps libsemange_basename(). On glibc systems this would just
call basename directly and on non-glibc systems do the implementation
with your own logic.
2. Just copy the path into a modifiable buffer on non-glibc systems
I would do both approaches. Create a utility routine that calls
basename for glibc and for non-glibc just copies it to a modifiable
buffer and then calls basename over rolling our own and the bugs
associated with it, also add a unit test for this. This would keep the
logic in one place and be dirt simple.
Bill
