From d567bd004a55660df5f18da8d79a6fc88be76ed1 Mon Sep 17 00:00:00 2001
From: whatdoineed2do/Ray <whatdoineed2do@nospam.gmail.com>
Date: Sat, 11 Jul 2020 14:10:11 +0100
Subject: [PATCH] [db,conf,json] new backup endpoint

---
 src/conffile.c      |  1 +
 src/db.c            | 61 +++++++++++++++++++++++++++++++++++++++++++++
 src/db.h            |  2 ++
 src/httpd_jsonapi.c | 22 ++++++++++++++++
 4 files changed, 86 insertions(+)

diff --git a/src/conffile.c b/src/conffile.c
index 6cc6173e..7f535ed9 100644
--- a/src/conffile.c
+++ b/src/conffile.c
@@ -46,6 +46,7 @@ static cfg_opt_t sec_general[] =
   {
     CFG_STR("uid", "nobody", CFGF_NONE),
     CFG_STR("db_path", STATEDIR "/cache/" PACKAGE "/songs3.db", CFGF_NONE),
+    CFG_STR("db_backup_path", NULL, CFGF_NONE),
     CFG_STR("logfile", STATEDIR "/log/" PACKAGE ".log", CFGF_NONE),
     CFG_INT_CB("loglevel", E_LOG, CFGF_NONE, &cb_loglevel),
     CFG_STR("admin_password", NULL, CFGF_NONE),
diff --git a/src/db.c b/src/db.c
index 25ec6673..8635d010 100644
--- a/src/db.c
+++ b/src/db.c
@@ -6946,6 +6946,67 @@ db_statements_prepare(void)
   return 0;
 }
 
+int
+db_backup()
+{
+  int ret;
+  sqlite3 *backup_hdl;
+  sqlite3_backup *backup;
+  const char *backup_path;
+
+  char resolved_bp[PATH_MAX];
+  char resolved_dbp[PATH_MAX];
+
+  backup_path = cfg_getstr(cfg_getsec(cfg, "general"), "db_backup_path");
+  if (!backup_path)
+    {
+      DPRINTF(E_LOG, L_DB, "Backup not enabled, 'db_backup_path' is unset\n");
+      return -2;
+    }
+
+  if (realpath(db_path, resolved_dbp) == NULL || realpath(backup_path, resolved_bp) == NULL)
+    {
+      DPRINTF(E_LOG, L_DB, "Failed to resolve real path of db/backup path: %s\n", strerror(errno));
+      goto error;
+    }
+
+  if (strcmp(resolved_bp, resolved_dbp) == 0)
+    {
+      DPRINTF(E_LOG, L_DB, "Backup path same as main db path, ignoring\n");
+      return -2;
+    }
+
+  DPRINTF(E_INFO, L_DB, "Backup starting...\n");
+
+  ret = sqlite3_open(backup_path, &backup_hdl);
+  if (ret != SQLITE_OK)
+    {
+      DPRINTF(E_WARN, L_DB, "Failed to create backup '%s': %s\n", backup_path, sqlite3_errmsg(backup_hdl));
+      goto error;
+    }
+
+  backup = sqlite3_backup_init(backup_hdl, "main", hdl, "main");
+  if (!backup)
+    {
+      DPRINTF(E_WARN, L_DB, "Failed to initiate backup '%s': %s\n", backup_path, sqlite3_errmsg(backup_hdl));
+      goto error;
+    }
+
+  ret = sqlite3_backup_step(backup, -1);
+  sqlite3_backup_finish(backup);
+  sqlite3_close(backup_hdl);
+
+  if (ret == SQLITE_DONE || ret == SQLITE_OK)
+    DPRINTF(E_INFO, L_DB, "Backup complete to '%s'\n", backup_path);
+  else
+    DPRINTF(E_WARN, L_DB, "Failed to complete backup '%s': %s (%d)\n", backup_path, sqlite3_errstr(ret), ret);
+
+  return ret;
+
+error:
+  return -1;
+}
+
 int
 db_perthread_init(void)
 {
diff --git a/src/db.h b/src/db.h
index 22084fce..cfb8efff 100644
--- a/src/db.h
+++ b/src/db.h
@@ -938,6 +938,8 @@ db_watch_enum_end(struct watch_enum *we);
 int
 db_watch_enum_fetchwd(struct watch_enum *we, uint32_t *wd);
 
+int
+db_backup();
 
 int
 db_perthread_init(void);
diff --git a/src/httpd_jsonapi.c b/src/httpd_jsonapi.c
index 89a9d2e0..6b17fdf8 100644
--- a/src/httpd_jsonapi.c
+++ b/src/httpd_jsonapi.c
@@ -4213,6 +4213,24 @@ jsonapi_reply_search(struct httpd_request *hreq)
   return HTTP_OK;
 }
 
+static int
+jsonapi_reply_library_backup(struct httpd_request *hreq)
+{
+  int ret;
+  ret = db_backup();
+
+  if (ret < 0)
+  {
+    if (ret == -2)
+      return HTTP_SERVUNAVAIL;  // not enabled by config
+
+    return HTTP_INTERNAL;
+  }
+
+  return HTTP_OK;
+}
+
+
 static struct httpd_uri_map adm_handlers[] =
   {
     { EVHTTP_REQ_GET,    "^/api/config$",                                jsonapi_reply_config },
@@ -4284,6 +4302,7 @@ static struct httpd_uri_map adm_handlers[] =
     { EVHTTP_REQ_GET,    "^/api/library/count$",                         jsonapi_reply_library_count },
     { EVHTTP_REQ_GET,    "^/api/library/files$",                         jsonapi_reply_library_files },
     { EVHTTP_REQ_POST,   "^/api/library/add$",                           jsonapi_reply_library_add },
+    { EVHTTP_REQ_PUT,    "^/api/library/backup$",                        jsonapi_reply_library_backup },
 
     { EVHTTP_REQ_GET,    "^/api/search$",                                jsonapi_reply_search },
 
@@ -4344,6 +4363,9 @@ jsonapi_request(struct evhttp_request *req, struct httpd_uri_parsed *uri_parsed)
       case HTTP_NOTFOUND:            /* 404 Not Found */
 	httpd_send_error(req, status_code, "Not Found");
 	break;
+      case HTTP_SERVUNAVAIL:            /* 503 */
+        httpd_send_error(req, status_code, "Service Unavailable");
+        break;
       case HTTP_INTERNAL:            /* 500 Internal Server Error */
       default:
 	httpd_send_error(req, HTTP_INTERNAL, "Internal Server Error");