Add daemon using varlink for communication

include/wtmpdb.h

@@ -32,6 +32,10 @@
 
 #define _PATH_WTMPDB "/var/lib/wtmpdb/wtmp.db"
 
+#define _VARLINK_WTMPDB_SOCKET_DIR "/run/wtmpdb"
+#define _VARLINK_WTMPDB_SOCKET_WRITER _VARLINK_WTMPDB_SOCKET_DIR"/writer.socket"
+#define _VARLINK_WTMPDB_SOCKET_READER _VARLINK_WTMPDB_SOCKET_DIR"/reader.socket"
+
 #define EMPTY           0  /* No valid user accounting information.  */
 #define BOOT_TIME       1  /* Time of system boot.  */
 #define RUNLEVEL        2  /* The system's runlevel. Unused with systemd. */
@@ -54,7 +58,11 @@ extern int wtmpdb_read_all (const char *db_path,
 		            int (*cb_func) (void *unused, int argc,
 				            char **argv, char **azColName),
 			    char **error);
-extern int wtmpdb_rotate (const char *db_path, const int days, char **error, 
+extern int wtmpdb_read_all_v2 (const char *db_path,
+			       int (*cb_func) (void *unused, int argc,
+					       char **argv, char **azColName),
+			       void *userdata, char **error);
+extern int wtmpdb_rotate (const char *db_path, const int days, char **error,
 			  char **wtmpdb_name, uint64_t *entries);
 
 /* Returns last "BOOT_TIME" entry as usec */

lib/basics.h

@@ -0,0 +1,17 @@
+// SPDX-License-Identifier: BSD-2-Clause
+
+#pragma once
+
+#define _cleanup_(x) __attribute__((__cleanup__(x)))
+#define _unused_(x) x __attribute__((unused))
+
+#define mfree(memory)                           \
+        ({                                      \
+                free(memory);                   \
+                (typeof(memory)) NULL;          \
+        })
+
+static inline void freep(void *p) {
+        *(void**)p = mfree(*(void**) p);
+}
+

lib/libwtmpdb.c

@@ -25,10 +25,16 @@
   POSSIBILITY OF SUCH DAMAGE.
 */
 
+#include <errno.h>
 #include <stddef.h>
+#include <stdlib.h>
 
+#include "basics.h"
 #include "wtmpdb.h"
 #include "sqlite.h"
+#include "varlink.h"
+
+static int varlink_is_active = 1;
 
 /*
   Add new wtmp entry to db.
@@ -40,8 +46,27 @@ wtmpdb_login (const char *db_path, int type, const char *user,
 	      uint64_t usec_login, const char *tty, const char *rhost,
 	      const char *service, char **error)
 {
-  return sqlite_login (db_path?db_path:_PATH_WTMPDB, type, user, usec_login, tty, rhost,
-		       service, error);
+  /* we can use varlink only if no specific database is requested */
+  if (varlink_is_active && db_path == NULL)
+    {
+      int64_t id;
+
+      id = varlink_login (type, user, usec_login, tty, rhost,
+			  service, error);
+      if (id >= 0)
+	return id;
+
+      if (id == -ECONNREFUSED)
+	{
+	  varlink_is_active = 0;
+	  *error = mfree (*error);
+	}
+      else
+	return id; /* return the error if wtmpdbd is active */
+    }
+
+  return sqlite_login (db_path?db_path:_PATH_WTMPDB, type, user,
+		       usec_login, tty, rhost, service, error);
 }
 
 /*
@@ -54,40 +79,123 @@ int
 wtmpdb_logout (const char *db_path, int64_t id, uint64_t usec_logout,
 	       char **error)
 {
+  /* we can use varlink only if no specific database is requested */
+  if (varlink_is_active && db_path == NULL)
+    {
+      int r;
+
+      r = varlink_logout (id, usec_logout, error);
+      if (r >= 0)
+	return r;
+
+      if (id == -ECONNREFUSED)
+	{
+	  varlink_is_active = 0;
+	  *error = mfree (*error);
+	}
+      else
+	return r; /* return the error if wtmpdbd is active */
+    }
+
   return sqlite_logout (db_path?db_path:_PATH_WTMPDB, id, usec_logout, error);
 }
 
 int64_t
 wtmpdb_get_id (const char *db_path, const char *tty, char **error)
 {
+  /* we can use varlink only if no specific database is requested */
+  if (varlink_is_active && db_path == NULL)
+    {
+      int64_t id;
+
+      id = varlink_get_id (tty, error);
+      if (id >= 0)
+	return id;
+
+      if (id == -ECONNREFUSED)
+	{
+	  varlink_is_active = 0;
+	  *error = mfree (*error);
+	}
+      else
+	return id; /* return the error if wtmpdbd is active */
+    }
+
   return sqlite_get_id (db_path?db_path:_PATH_WTMPDB, tty, error);
 }
 
 /* Reads all entries from database and calls the callback function for
    each entry.
    Returns 0 on success, -1 on failure. */
 int
-wtmpdb_read_all  (const char *db_path,
-		  int (*cb_func)(void *unused, int argc, char **argv,
-				 char **azColName),
-		  char **error)
+wtmpdb_read_all (const char *db_path,
+		 int (*cb_func)(void *unused, int argc, char **argv,
+				char **azColName),
+		 char **error)
 {
-  return sqlite_read_all (db_path?db_path:_PATH_WTMPDB, cb_func, error);
+  return sqlite_read_all (db_path?db_path:_PATH_WTMPDB, cb_func, NULL, error);
+}
+
+int
+wtmpdb_read_all_v2 (const char *db_path,
+		    int (*cb_func)(void *unused, int argc, char **argv,
+				   char **azColName),
+		    void *userdata, char **error)
+{
+  return sqlite_read_all (db_path?db_path:_PATH_WTMPDB, cb_func, userdata, error);
 }
 
 
 /* Reads all entries from database and calls the callback function for
    each entry.
-   Returns 0 on success, -1 on failure. */
+   Returns 0 on success, < 0 on failure. */
 int
 wtmpdb_rotate (const char *db_path, const int days, char **error,
 	       char **wtmpdb_name, uint64_t *entries)
 {
-  return sqlite_rotate (db_path, days, wtmpdb_name, entries, error);
+  /* we can use varlink only if no specific database is requested */
+  if (varlink_is_active && db_path == NULL)
+    {
+      int r;
+
+      r = varlink_rotate (days, wtmpdb_name, entries, error);
+      if (r >= 0)
+	return r;
+
+      if (r == -ECONNREFUSED)
+	{
+	  varlink_is_active = 0;
+	  *error = mfree (*error);
+	}
+      else
+	return r; /* return the error if wtmpdbd is active */
+    }
+
+  return sqlite_rotate (db_path?db_path:_PATH_WTMPDB, days, wtmpdb_name, entries, error);
 }
 
+/* returns boottime entry on success or 0 in error case */
 uint64_t
 wtmpdb_get_boottime (const char *db_path, char **error)
 {
+  /* we can use varlink only if no specific database is requested */
+  if (varlink_is_active && db_path == NULL)
+    {
+      int r;
+      uint64_t boottime;
+
+      r = varlink_get_boottime (&boottime, error);
+      if (r >= 0)
+	return boottime;
+
+      if (r == -ECONNREFUSED)
+	{
+	  varlink_is_active = 0;
+	  *error = mfree (*error);
+	}
+      else
+	return 0; /* return the error if wtmpdbd is active */
+    }
+
   return sqlite_get_boottime (db_path?db_path:_PATH_WTMPDB, error);
 }

lib/libwtmpdb.map

@@ -16,4 +16,7 @@ LIBWTMPDB_0.8 {
   global:
         wtmpdb_get_boottime;
 } LIBWTMPDB_0.7;
-
+LIBWTMPDB_0.50 {
+  global:
+	wtmpdb_read_all_v2;
+} LIBWTMPDB_0.8;

lib/logwtmpdb.c

@@ -64,13 +64,13 @@ logwtmpdb (const char *db_path, const char *tty, const char *name,
 
   if (name != NULL && strlen (name) > 0)
     { /* login */
-      retval = wtmpdb_login (db_path ? db_path : _PATH_WTMPDB, USER_PROCESS,
-			     name, time, tty, host, service, error);
+      retval = wtmpdb_login (db_path, USER_PROCESS, name, time, tty,
+		      	     host, service, error);
     }
   else
     { /* logout */
-      int64_t id = wtmpdb_get_id (db_path ? db_path : _PATH_WTMPDB, tty, error);
-      retval = wtmpdb_logout (db_path ? db_path : _PATH_WTMPDB, id, time, error);
+      int64_t id = wtmpdb_get_id (db_path, tty, error);
+      retval = wtmpdb_logout (db_path, id, time, error);
     }
 
   return retval;

lib/mkdir_p.c

@@ -0,0 +1,77 @@
+/* SPDX-License-Identifier: BSD-2-Clause
+
+  Copyright (c) 2024, Thorsten Kukuk <[email protected]>
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+
+  1. Redistributions of source code must retain the above copyright notice,
+     this list of conditions and the following disclaimer.
+
+  2. Redistributions in binary form must reproduce the above copyright
+     notice, this list of conditions and the following disclaimer in the
+     documentation and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+  POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#include <errno.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <libgen.h>
+
+#include "mkdir_p.h"
+
+int
+mkdir_p(const char *path, mode_t mode)
+{
+  if (path == NULL)
+    return -EINVAL;
+
+  if (mkdir(path, mode) == 0)
+    return 0;
+
+  if (errno == EEXIST)
+    {
+      struct stat st;
+
+      /* Check if the existing path is a directory */
+      if (stat(path, &st) != 0)
+        return -errno;
+
+      /* If not, fail with ENOTDIR */
+      if (!S_ISDIR(st.st_mode))
+        return -ENOTDIR;
+
+      /* if it is a directory, return */
+      return 0;
+    }
+
+  /* If it fails for any reason but ENOENT, fail */
+  if (errno != ENOENT)
+    return -errno;
+
+  char *buf = strdup(path);
+  if (buf == NULL)
+    return -ENOMEM;
+
+  int r = mkdir_p(dirname(buf), mode);
+  free(buf);
+  /* if we couldn't create the parent, fail, too */
+  if (r < 0)
+    return r;
+
+  return mkdir(path, mode);
+}
+

lib/mkdir_p.h

@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: BSD-2-Clause
+
+  Copyright (c) 2024, Thorsten Kukuk <[email protected]>
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+
+  1. Redistributions of source code must retain the above copyright notice,
+     this list of conditions and the following disclaimer.
+
+  2. Redistributions in binary form must reproduce the above copyright
+     notice, this list of conditions and the following disclaimer in the
+     documentation and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+  POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#pragma once
+
+#include <sys/stat.h>
+
+extern int mkdir_p(const char *path, mode_t mode);
+