database: refactor path compute of database

Change-Id: I6d0f90e72d9896c1b9a2827d318e4b1296a6f47d
Signed-off-by: José Bollo <jose.bollo@iot.bzh>

diff --git a/ll-database-binding/src/ll-database-binding.c b/ll-database-binding/src/ll-database-binding.c
index 2206bb0..ae0003b 100644 (file)
--- a/ll-database-binding/src/ll-database-binding.c
+++ b/ll-database-binding/src/ll-database-binding.c
@@ -35,7 +35,7 @@
 #define MAX_PATH 1024
 #endif
 
-#define DBFILE         "/ll-database-binding.db"
+#define DBFILE         "ll-database-binding.db"
 
 #if !defined(TO_STRING_FLAGS)
 # if !defined(JSON_C_TO_STRING_NOSLASHESCAPE)
@@ -45,8 +45,7 @@
 #endif
 
 // ----- Globals -----
-static DB*             database;
-static char    database_file[MAX_PATH];
+static DB *database;
 
 // ----- Binding's declarations -----
 static int ll_database_binding_init();
@@ -57,34 +56,53 @@ static void verb_read(struct afb_req req);
 
 // ----- Binding's implementations -----
 
+/**
+ * @brief Get the path to the database
+ */
+static int get_database_path(char *buffer, size_t size)
+{
+       static const char dbfile[] = DBFILE;
+
+       char *home, *config;
+       int rc;
+
+       config = secure_getenv("XDG_CONFIG_HOME");
+       if (config)
+               rc = snprintf(buffer, size, "%s/.config/%s", home, dbfile);
+       else
+       {
+               home = secure_getenv("HOME");
+               if (home)
+                       rc = snprintf(buffer, size, "%s/.config/%s", home, dbfile);
+               else
+               {
+                       struct passwd *pwd = getpwuid(getuid());
+                       if (pwd)
+                               rc = snprintf(buffer, size, "%s/.config/%s", result->pw_dir, dbfile);
+                       else
+                               rc = snprintf(buffer, size, "/home/%d/.config/%s", (int)getuid(), dbfile);
+               }
+       }
+       return rc;
+}
+
 /**
  * @brief Initialize the binding.
  * @return Exit code, zero if success.
  */
 static int ll_database_binding_init()
 {
-       struct passwd pwd;
-       struct passwd* result;
-       char buf[MAX_PATH];
-       size_t bufsize;
+       char path[MAX_PATH];
        int ret;
 
-       bufsize = sysconf(_SC_GETPW_R_SIZE_MAX);
-       if (bufsize == -1 || bufsize > MAX_PATH) bufsize = MAX_PATH;
-
-       ret = getpwuid_r(getuid(), &pwd, buf, bufsize, &result);
-       if (result == NULL)
+       ret = get_database_path(path, sizeof path);
+       if (ret < 0 || (int)ret >=  (int)(sizeof path))
        {
-               if (ret == 0) AFB_ERROR("User not found");
-               else AFB_ERROR("getpwuid_r failed with %d code", ret);
+               AFB_ERROR("Can't compute the database filename");
                return -1;
        }
 
-       memset(database_file, 0, MAX_PATH);
-       strcat(database_file, result->pw_dir);
-       strcat(database_file, DBFILE);
-
-       AFB_INFO("The database file is '%s'", database_file);
+       AFB_INFO("opening database %s", path);
 
        if ((ret = db_create(&database, NULL, 0)) != 0)
        {
@@ -92,9 +110,9 @@ static int ll_database_binding_init()
                return -1;
        }
 
-       if ((ret = database->open(database, NULL, database_file, NULL, DB_BTREE, DB_CREATE, 0664)) != 0)
+       if ((ret = database->open(database, NULL, path, NULL, DB_BTREE, DB_CREATE, 0664)) != 0)
        {
-               AFB_ERROR("Failed to open the '%s' database: %s.", database_file, db_strerror(ret));
+               AFB_ERROR("Failed to open the '%s' database: %s.", path, db_strerror(ret));
                database->close(database, 0);
                return -1;
        }