[PATCH 2/2] libmbim,utils: new internal __mbim_user_allowed() method

[Roshan Pius]

Allows to check whether the user is allowed to use the MBIM device.

Also fixes mbim_proxy_open() to make sure we always set the GError when FALSE is
returned.

---
 src/libmbim-glib/mbim-proxy.c | 39 ++++++---------------------------------
 src/libmbim-glib/mbim-utils.c | 33 +++++++++++++++++++++++++++++++++
 src/libmbim-glib/mbim-utils.h |  2 ++
 3 files changed, 41 insertions(+), 33 deletions(-)

diff --git a/src/libmbim-glib/mbim-proxy.c b/src/libmbim-glib/mbim-proxy.c
index fc69cd7..e87b57a 100644
--- a/src/libmbim-glib/mbim-proxy.c
+++ b/src/libmbim-glib/mbim-proxy.c
@@ -27,7 +27,6 @@
 #include <sys/file.h>
 #include <sys/types.h>
 #include <errno.h>
-#include <pwd.h>
 
 #include <glib.h>
 #include <glib/gstdio.h>
@@ -1044,7 +1043,6 @@ incoming_cb (GSocketService *service,
     Client *client;
     GCredentials *credentials;
     GError *error = NULL;
-    struct passwd *expected_usr = NULL;
     uid_t uid;
 
     g_debug ("Client (%d) connection open...", g_socket_get_fd (g_socket_connection_get_socket (connection)));
@@ -1064,20 +1062,13 @@ incoming_cb (GSocketService *service,
         return;
     }
 
-    expected_usr = getpwnam (MBIM_USERNAME);
-    if (!expected_usr) {
-        g_warning ("Unknown user configured: %s", MBIM_USERNAME);
-        /* Falling back to check for root user if the configured user is unknown */
-        if (uid != 0) {
-            g_warning ("Client not allowed: Not enough privileges");
-            return;
-        }
-    }
-    else if (uid != expected_usr->pw_uid) {
-        g_warning ("Client not allowed: Not the expected user: %s", MBIM_USERNAME);
+    if (!__mbim_user_allowed (uid, &error)) {
+        g_warning ("Client not allowed: %s", error->message);
+        g_error_free (error);
         return;
     }
 
+
     /* Create client */
     client = g_slice_new0 (Client);
     client->self = self;
@@ -1226,26 +1217,8 @@ MbimProxy *
 mbim_proxy_new (GError **error)
 {
     MbimProxy *self;
-    struct passwd *expected_usr = NULL;
-
-    /* Only the specified user can run the mbim-proxy */
-    expected_usr = getpwnam (MBIM_USERNAME);
-    if (!expected_usr) {
-        g_warning ("Unknown user configured: %s", MBIM_USERNAME);
-        /* Falling back to check for root user if the configured user is unknown */
-        if (getuid () != 0) {
-            g_set_error (error,
-                         MBIM_CORE_ERROR,
-                         MBIM_CORE_ERROR_FAILED,
-                          "Not enough privileges");
-            return NULL;
-        }
-    }
-    else if (getuid () != expected_usr->pw_uid) {
-        g_set_error (error,
-                     MBIM_CORE_ERROR,
-                     MBIM_CORE_ERROR_FAILED,
-                     "Not started with the expected user: %s", MBIM_USERNAME);
+
+    if (!__mbim_user_allowed (getuid(), error)) {
         return NULL;
     }
 
diff --git a/src/libmbim-glib/mbim-utils.c b/src/libmbim-glib/mbim-utils.c
index 12fab7a..f5a766b 100644
--- a/src/libmbim-glib/mbim-utils.c
+++ b/src/libmbim-glib/mbim-utils.c
@@ -25,8 +25,10 @@
 #include <string.h>
 #include <stdint.h>
 #include <stdio.h>
+#include <pwd.h>
 
 #include "mbim-utils.h"
+#include "mbim-error-types.h"
 
 /**
  * SECTION:mbim-utils
@@ -73,6 +75,37 @@ __mbim_utils_str_hex (gconstpointer mem,
 }
 
 /*****************************************************************************/
+gboolean
+__mbim_user_allowed (uid_t uid,
+                     GError **error)
+{
+    struct passwd *expected_usr = NULL;
+
+    expected_usr = getpwnam (MBIM_USERNAME);
+    if (!expected_usr) {
+        g_warning ("Unknown user configured: %s", MBIM_USERNAME);
+        /* Falling back to check for root user if the configured user is unknown */
+        if (uid == 0)
+            return TRUE;
+
+        g_set_error (error,
+                     MBIM_CORE_ERROR,
+                     MBIM_CORE_ERROR_FAILED,
+                     "Not enough privileges (unknown username %s)", MBIM_USERNAME);
+        return FALSE;
+    }
+
+    if (uid == expected_usr->pw_uid)
+        return TRUE;
+
+    g_set_error (error,
+                 MBIM_CORE_ERROR,
+                 MBIM_CORE_ERROR_FAILED,
+                 "Not enough privileges");
+    return FALSE;
+}
+
+/*****************************************************************************/
 
 static volatile gint __traces_enabled = FALSE;
 
diff --git a/src/libmbim-glib/mbim-utils.h b/src/libmbim-glib/mbim-utils.h
index 62bbc92..ee5632f 100644
--- a/src/libmbim-glib/mbim-utils.h
+++ b/src/libmbim-glib/mbim-utils.h
@@ -42,6 +42,8 @@ void     mbim_utils_set_traces_enabled (gboolean enabled);
 gchar *__mbim_utils_str_hex (gconstpointer mem,
                              gsize         size,
                              gchar         delimiter);
+gboolean __mbim_user_allowed (uid_t uid,
+                              GError **error);
 #endif
 
 G_END_DECLS
-- 
2.1.0.rc2.206.gedb03e5