glib-compat: add g_unix_get_passwd_entry_qemu()

The glib function was introduced in 2.64. It's a safer version of
getpwnam, and also simpler to use than getpwnam_r.

Currently, it's only use by the next patch in qemu-ga, which doesn't
(well well...) need the thread safety guarantees. Since the fallback
version is still unsafe, I would rather keep the _qemu postfix, to make
sure it's not being misused by mistake. When/if necessary, we can
implement a safer fallback and drop the _qemu suffix.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michal Privoznik <mprivozn@redhat.com>
*fix checkpatch warnings about newlines before/after block comments
Signed-off-by: Michael Roth <michael.roth@amd.com>
This commit is contained in:
Marc-André Lureau 2020-10-20 12:12:51 +04:00 committed by Michael Roth
parent c67d2efd9d
commit 6d593ab451

View File

@ -30,6 +30,11 @@
#pragma GCC diagnostic ignored "-Wdeprecated-declarations" #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
#include <glib.h> #include <glib.h>
#if defined(G_OS_UNIX)
#include <glib-unix.h>
#include <sys/types.h>
#include <pwd.h>
#endif
/* /*
* Note that because of the GLIB_VERSION_MAX_ALLOWED constant above, allowing * Note that because of the GLIB_VERSION_MAX_ALLOWED constant above, allowing
@ -72,6 +77,29 @@
gint g_poll_fixed(GPollFD *fds, guint nfds, gint timeout); gint g_poll_fixed(GPollFD *fds, guint nfds, gint timeout);
#endif #endif
#if defined(G_OS_UNIX)
/*
* Note: The fallback implementation is not MT-safe, and it returns a copy of
* the libc passwd (must be g_free() after use) but not the content. Because of
* these important differences the caller must be aware of, it's not #define for
* GLib API substitution.
*/
static inline struct passwd *
g_unix_get_passwd_entry_qemu(const gchar *user_name, GError **error)
{
#if GLIB_CHECK_VERSION(2, 64, 0)
return g_unix_get_passwd_entry(user_name, error);
#else
struct passwd *p = getpwnam(user_name);
if (!p) {
g_set_error_literal(error, G_UNIX_ERROR, 0, g_strerror(errno));
return NULL;
}
return (struct passwd *)g_memdup(p, sizeof(*p));
#endif
}
#endif /* G_OS_UNIX */
#pragma GCC diagnostic pop #pragma GCC diagnostic pop
#endif #endif