[httpd/json] Add json api to httpd

src/Makefile.am

@@ -108,6 +108,7 @@ forked_daapd_SOURCES = main.c \
 	httpd_rsp.c httpd_rsp.h \
 	httpd_daap.c httpd_daap.h \
 	httpd_dacp.c httpd_dacp.h \
+	httpd_jsonapi.c httpd_jsonapi.h \
 	httpd_streaming.c httpd_streaming.h \
 	http.c http.h \
 	dmap_common.c dmap_common.h \

src/httpd.c

@@ -59,6 +59,7 @@
 #include "httpd_rsp.h"
 #include "httpd_daap.h"
 #include "httpd_dacp.h"
+#include "httpd_jsonapi.h"
 #include "httpd_streaming.h"
 #include "transcode.h"
 #ifdef LASTFM
@@ -1221,6 +1222,12 @@ httpd_gen_cb(struct evhttp_request *req, void *arg)
     {
       dacp_request(req);
 
+      goto out;
+    }
+  else if (jsonapi_is_request(req, uri))
+    {
+      jsonapi_request(req);
+
       goto out;
     }
   else if (streaming_is_request(req, uri))
@@ -1495,6 +1502,14 @@ httpd_init(void)
       goto dacp_fail;
     }
 
+  ret = jsonapi_init();
+  if (ret < 0)
+    {
+      DPRINTF(E_FATAL, L_HTTPD, "JSON api init failed\n");
+
+      goto jsonapi_fail;
+    }
+
   streaming_init();
 
 #ifdef HAVE_EVENTFD
@@ -1601,6 +1616,8 @@ httpd_init(void)
 #endif
  pipe_fail:
   streaming_deinit();
+  jsonapi_deinit();
+ jsonapi_fail:
   dacp_deinit();
  dacp_fail:
   daap_deinit();
@@ -1647,6 +1664,7 @@ httpd_deinit(void)
     }
 
   streaming_deinit();
+  jsonapi_deinit();
   rsp_deinit();
   dacp_deinit();
   daap_deinit();

src/httpd_jsonapi.c

@@ -0,0 +1,577 @@
+/*
+ * Copyright (C) 2017 Christian Meffert <christian.meffert@googlemail.com>
+ *
+ * Adapted from httpd_adm.c:
+ * Copyright (C) 2015 Stuart NAIFEH <stu@naifeh.org>
+ *
+ * Adapted from httpd_daap.c and httpd.c:
+ * Copyright (C) 2009-2011 Julien BLACHE <jb@jblache.org>
+ * Copyright (C) 2010 Kai Elwert <elwertk@googlemail.com>
+ *
+ * Adapted from mt-daapd:
+ * Copyright (C) 2003-2007 Ron Pedde <ron@pedde.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include "httpd_jsonapi.h"
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+#include <event2/event.h>
+#include <event2/buffer.h>
+#include <event2/keyvalq_struct.h>
+#include <json.h>
+#include <regex.h>
+#include <string.h>
+
+#include "conffile.h"
+#include "db.h"
+#include "httpd.h"
+#include "library.h"
+#include "logger.h"
+#include "misc_json.h"
+#include "remote_pairing.h"
+#ifdef HAVE_SPOTIFY_H
+# include "spotify_webapi.h"
+# include "spotify.h"
+#endif
+
+struct uri_map
+{
+  regex_t preg;
+  char *regexp;
+  int (*handler)(struct evhttp_request *req, struct evbuffer *evbuf, char *uri, struct evkeyvalq *query);
+};
+
+
+
+/*
+ * Endpoint to retrieve configuration values
+ *
+ * Example response:
+ *
+ * {
+ *  "websocket_port": 6603,
+ *  "version": "25.0"
+ * }
+ */
+static int
+jsonapi_reply_config(struct evhttp_request *req, struct evbuffer *evbuf, char *uri, struct evkeyvalq *query)
+{
+  json_object *reply;
+  json_object *buildopts;
+  int websocket_port;
+  char **buildoptions;
+  int i;
+  int ret;
+
+  reply = json_object_new_object();
+
+  // Websocket port
+#ifdef WEBSOCKET
+  websocket_port = cfg_getint(cfg_getsec(cfg, "general"), "websocket_port");
+#else
+  websocket_port = 0;
+#endif
+  json_object_object_add(reply, "websocket_port", json_object_new_int(websocket_port));
+
+  // forked-daapd version
+  json_object_object_add(reply, "version", json_object_new_string(VERSION));
+
+  // enabled build options
+  buildopts = json_object_new_array();
+  buildoptions = buildopts_get();
+  for (i = 0; buildoptions[i]; i++)
+    {
+      json_object_array_add(buildopts, json_object_new_string(buildoptions[i]));
+    }
+  json_object_object_add(reply, "buildoptions", buildopts);
+
+  ret = evbuffer_add_printf(evbuf, "%s", json_object_to_json_string(reply));
+  jparse_free(reply);
+  if (ret < 0)
+    {
+      DPRINTF(E_LOG, L_WEB, "config: Couldn't add config data to response buffer.\n");
+      return -1;
+    }
+
+  return 0;
+}
+
+/*
+ * Endpoint to retrieve informations about the library
+ *
+ * Example response:
+ *
+ * {
+ *  "artists": 84,
+ *  "albums": 151,
+ *  "songs": 3085,
+ *  "db_playtime": 687824,
+ *  "updating": false
+ *}
+ */
+static int
+jsonapi_reply_library(struct evhttp_request *req, struct evbuffer *evbuf, char *uri, struct evkeyvalq *query)
+{
+  struct query_params qp;
+  struct filecount_info fci;
+  int artists;
+  int albums;
+  bool is_scanning;
+  json_object *reply;
+  int ret;
+
+  // Fetch values for response
+
+  memset(&qp, 0, sizeof(struct query_params));
+  qp.type = Q_COUNT_ITEMS;
+  ret = db_filecount_get(&fci, &qp);
+  if (ret < 0)
+    {
+      DPRINTF(E_LOG, L_WEB, "library: failed to get file count info\n");
+      return -1;
+    }
+
+  artists = db_files_get_artist_count();
+  albums = db_files_get_album_count();
+
+  is_scanning = library_is_scanning();
+
+
+  // Build json response
+
+  reply = json_object_new_object();
+
+  json_object_object_add(reply, "artists", json_object_new_int(artists));
+  json_object_object_add(reply, "albums", json_object_new_int(albums));
+  json_object_object_add(reply, "songs", json_object_new_int(fci.count));
+  json_object_object_add(reply, "db_playtime", json_object_new_int64((fci.length / 1000)));
+  json_object_object_add(reply, "updating", json_object_new_boolean(is_scanning));
+
+  ret = evbuffer_add_printf(evbuf, "%s", json_object_to_json_string(reply));
+  jparse_free(reply);
+  if (ret < 0)
+    {
+      DPRINTF(E_LOG, L_WEB, "library: Couldn't add library information data to response buffer.\n");
+      return -1;
+    }
+
+  return 0;
+}
+
+/*
+ * Endpoint to trigger a library rescan
+ */
+static int
+jsonapi_reply_update(struct evhttp_request *req, struct evbuffer *evbuf, char *uri, struct evkeyvalq *query)
+{
+  library_rescan();
+  return 0;
+}
+
+/*
+ * Endpoint to retrieve information about the spotify integration
+ *
+ * Exampe response:
+ *
+ * {
+ *  "enabled": true,
+ *  "oauth_uri": "https://accounts.spotify.com/authorize/?client_id=...
+ * }
+ */
+static int
+jsonapi_reply_spotify(struct evhttp_request *req, struct evbuffer *evbuf, char *uri, struct evkeyvalq *query)
+{
+  int httpd_port;
+  char __attribute__((unused)) redirect_uri[256];
+  char *oauth_uri;
+  json_object *reply;
+  int ret;
+
+  reply = json_object_new_object();
+
+#ifdef HAVE_SPOTIFY_H
+  struct spotify_status_info info;
+
+  json_object_object_add(reply, "enabled", json_object_new_boolean(true));
+
+  httpd_port = cfg_getint(cfg_getsec(cfg, "library"), "port");
+  snprintf(redirect_uri, sizeof(redirect_uri), "http://forked-daapd.local:%d/oauth/spotify", httpd_port);
+
+  oauth_uri = spotifywebapi_oauth_uri_get(redirect_uri);
+  if (!uri)
+    {
+      DPRINTF(E_LOG, L_WEB, "Cannot display Spotify oauth interface (http_form_uriencode() failed)\n");
+    }
+  else
+    {
+      json_object_object_add(reply, "oauth_uri", json_object_new_string(oauth_uri));
+      free(oauth_uri);
+    }
+
+  spotify_status_info_get(&info);
+  json_object_object_add(reply, "libspotify_installed", json_object_new_boolean(info.libspotify_installed));
+  json_object_object_add(reply, "libspotify_logged_in", json_object_new_boolean(info.libspotify_logged_in));
+  json_object_object_add(reply, "libspotify_user", json_object_new_string(info.libspotify_user));
+  json_object_object_add(reply, "webapi_token_valid", json_object_new_boolean(info.webapi_token_valid));
+  json_object_object_add(reply, "webapi_user", json_object_new_string(info.webapi_user));
+
+#else
+  json_object_object_add(reply, "enabled", json_object_new_boolean(false));
+#endif
+
+  ret = evbuffer_add_printf(evbuf, "%s", json_object_to_json_string(reply));
+  jparse_free(reply);
+  if (ret < 0)
+    {
+      DPRINTF(E_LOG, L_WEB, "spotify: Couldn't add spotify information data to response buffer.\n");
+      return -1;
+    }
+
+  return 0;
+}
+
+static int
+jsonapi_reply_spotify_login(struct evhttp_request *req, struct evbuffer *evbuf, char *uri, struct evkeyvalq *query)
+{
+  struct evbuffer *in_evbuf;
+  json_object* request;
+  const char *user;
+  const char *password;
+  char *errmsg = NULL;
+  json_object* reply;
+  json_object* errors;
+  int ret;
+
+  DPRINTF(E_DBG, L_WEB, "Received spotify login request\n");
+
+#ifdef HAVE_SPOTIFY_H
+  in_evbuf = evhttp_request_get_input_buffer(req);
+  request = jparse_obj_from_evbuffer(in_evbuf);
+  if (!request)
+    {
+      DPRINTF(E_LOG, L_WEB, "Failed to parse incoming request\n");
+      return -1;
+    }
+
+  reply = json_object_new_object();
+
+  user = jparse_str_from_obj(request, "user");
+  password = jparse_str_from_obj(request, "password");
+  if (user && strlen(user) > 0 && password && strlen(password) > 0)
+    {
+      ret = spotify_login_user(user, password, &errmsg);
+      if (ret < 0)
+	{
+	  json_object_object_add(reply, "success", json_object_new_boolean(false));
+	  errors = json_object_new_object();
+	  json_object_object_add(errors, "error", json_object_new_string(errmsg));
+	  json_object_object_add(reply, "errors", errors);
+	}
+      else
+	{
+	  json_object_object_add(reply, "success", json_object_new_boolean(true));
+	}
+      free(errmsg);
+    }
+  else
+    {
+      DPRINTF(E_LOG, L_WEB, "No user or password in spotify login post request\n");
+
+      json_object_object_add(reply, "success", json_object_new_boolean(false));
+      errors = json_object_new_object();
+      if (!user || strlen(user) == 0)
+	json_object_object_add(errors, "user", json_object_new_string("Username is required"));
+      if (!password || strlen(password) == 0)
+	json_object_object_add(errors, "password", json_object_new_string("Password is required"));
+      json_object_object_add(reply, "errors", errors);
+    }
+
+  ret = evbuffer_add_printf(evbuf, "%s", json_object_to_json_string(reply));
+  jparse_free(reply);
+  if (ret < 0)
+    {
+      DPRINTF(E_LOG, L_WEB, "spotify: Couldn't add spotify login data to response buffer.\n");
+      return -1;
+    }
+
+#else
+  DPRINTF(E_LOG, L_WEB, "Received spotify login request but was not compiled with enable-spotify\n");
+#endif
+
+  return 0;
+}
+
+/*
+ * Endpoint to kickoff pairing of a daap/dacp client
+ *
+ * Expects the paring pin to be present in the post request body, e. g.:
+ *
+ * {
+ *   "pin": "1234"
+ * }
+ */
+static int
+pairing_kickoff(struct evhttp_request* req)
+{
+  struct evbuffer *evbuf;
+  json_object* request;
+  const char* message;
+
+  evbuf = evhttp_request_get_input_buffer(req);
+  request = jparse_obj_from_evbuffer(evbuf);
+  if (!request)
+    {
+      DPRINTF(E_LOG, L_WEB, "Failed to parse incoming request\n");
+      return -1;
+    }
+
+  DPRINTF(E_DBG, L_WEB, "Received pairing post request: %s\n", json_object_to_json_string(request));
+
+  message = jparse_str_from_obj(request, "pin");
+  if (message)
+    remote_pairing_kickoff((char **)&message);
+  else
+    DPRINTF(E_LOG, L_WEB, "Missing pin in request body: %s\n", json_object_to_json_string(request));
+
+  jparse_free(request);
+
+  return 0;
+}
+
+/*
+ * Endpoint to retrieve pairing information
+ *
+ * Example response:
+ *
+ * {
+ *  "active": true,
+ *  "remote": "remote name"
+ * }
+ */
+static int
+pairing_get(struct evbuffer *evbuf)
+{
+  char *remote_name;
+  json_object *reply;
+  int ret;
+
+  remote_name = remote_pairing_get_name();
+
+  reply = json_object_new_object();
+
+  if (remote_name)
+    {
+      json_object_object_add(reply, "active", json_object_new_boolean(true));
+      json_object_object_add(reply, "remote", json_object_new_string(remote_name));
+    }
+  else
+    {
+      json_object_object_add(reply, "active", json_object_new_boolean(false));
+    }
+
+  ret = evbuffer_add_printf(evbuf, "%s", json_object_to_json_string(reply));
+  jparse_free(reply);
+  free(remote_name);
+
+  if (ret < 0)
+    {
+      DPRINTF(E_LOG, L_WEB, "pairing: Couldn't add pairing information data to response buffer.\n");
+      return -1;
+    }
+
+  return 0;
+}
+
+/*
+ * Endpoint to pair daap/dacp client
+ *
+ * If request is a GET request, returns information about active pairing remote.
+ * If request is a POST request, tries to pair the active remote with the given pin.
+ */
+static int
+jsonapi_reply_pairing(struct evhttp_request *req, struct evbuffer *evbuf, char *uri, struct evkeyvalq *query)
+{
+  if (evhttp_request_get_command(req) == EVHTTP_REQ_POST)
+    {
+      return pairing_kickoff(req);
+    }
+
+  return pairing_get(evbuf);
+}
+
+static struct uri_map adm_handlers[] =
+  {
+    { .regexp = "^/api/config", .handler = jsonapi_reply_config },
+    { .regexp = "^/api/library", .handler = jsonapi_reply_library },
+    { .regexp = "^/api/update", .handler = jsonapi_reply_update },
+    { .regexp = "^/api/spotify-login", .handler = jsonapi_reply_spotify_login },
+    { .regexp = "^/api/spotify", .handler = jsonapi_reply_spotify },
+    { .regexp = "^/api/pairing", .handler = jsonapi_reply_pairing },
+    { .regexp = NULL, .handler = NULL }
+  };
+
+void
+jsonapi_request(struct evhttp_request *req)
+{
+  char *full_uri;
+  char *uri;
+  char *ptr;
+  struct evbuffer *evbuf;
+  struct evkeyvalq query;
+  struct evkeyvalq *headers;
+  int handler;
+  int ret;
+  int i;
+
+  /* Check authentication */
+  if (!httpd_admin_check_auth(req))
+    {
+      DPRINTF(E_DBG, L_WEB, "JSON api request denied;\n");
+      return;
+    }
+
+  memset(&query, 0, sizeof(struct evkeyvalq));
+
+  full_uri = httpd_fixup_uri(req);
+  if (!full_uri)
+    {
+      evhttp_send_error(req, HTTP_BADREQUEST, "Bad Request");
+      return;
+    }
+
+  ptr = strchr(full_uri, '?');
+  if (ptr)
+    *ptr = '\0';
+
+  uri = strdup(full_uri);
+  if (!uri)
+    {
+      free(full_uri);
+      evhttp_send_error(req, HTTP_BADREQUEST, "Bad Request");
+      return;
+    }
+
+  if (ptr)
+    *ptr = '?';
+
+  ptr = uri;
+  uri = evhttp_decode_uri(uri);
+  free(ptr);
+
+  DPRINTF(E_DBG, L_WEB, "Web admin request: %s\n", full_uri);
+
+  handler = -1;
+  for (i = 0; adm_handlers[i].handler; i++)
+    {
+      ret = regexec(&adm_handlers[i].preg, uri, 0, NULL, 0);
+      if (ret == 0)
+	{
+	  handler = i;
+	  break;
+	}
+    }
+
+  if (handler < 0)
+    {
+      DPRINTF(E_LOG, L_WEB, "Unrecognized web admin request\n");
+
+      evhttp_send_error(req, HTTP_BADREQUEST, "Bad Request");
+
+      free(uri);
+      free(full_uri);
+      return;
+    }
+
+  evbuf = evbuffer_new();
+  if (!evbuf)
+    {
+      DPRINTF(E_LOG, L_WEB, "Could not allocate evbuffer for Web Admin reply\n");
+
+      evhttp_send_error(req, HTTP_SERVUNAVAIL, "Internal Server Error");
+
+      free(uri);
+      free(full_uri);
+      return;
+    }
+
+  evhttp_parse_query(full_uri, &query);
+
+  headers = evhttp_request_get_output_headers(req);
+  evhttp_add_header(headers, "DAAP-Server", "forked-daapd/" VERSION);
+
+  ret = adm_handlers[handler].handler(req, evbuf, uri, &query);
+  if (ret < 0)
+    {
+      evhttp_send_error(req, 500, "Internal Server Error");
+    }
+  else
+    {
+      headers = evhttp_request_get_output_headers(req);
+      evhttp_add_header(headers, "Content-Type", "application/json");
+      httpd_send_reply(req, HTTP_OK, "OK", evbuf, 0);
+    }
+
+  evbuffer_free(evbuf);
+  evhttp_clear_headers(&query);
+  free(uri);
+  free(full_uri);
+}
+
+int
+jsonapi_is_request(struct evhttp_request *req, char *uri)
+{
+  if (strncmp(uri, "/api/", strlen("/api/")) == 0)
+    return 1;
+  if (strcmp(uri, "/api") == 0)
+    return 1;
+
+  return 0;
+}
+
+int
+jsonapi_init(void)
+{
+  char buf[64];
+  int i;
+  int ret;
+
+  for (i = 0; adm_handlers[i].handler; i++)
+    {
+      ret = regcomp(&adm_handlers[i].preg, adm_handlers[i].regexp, REG_EXTENDED | REG_NOSUB);
+      if (ret != 0)
+	{
+	  regerror(ret, &adm_handlers[i].preg, buf, sizeof(buf));
+
+	  DPRINTF(E_FATAL, L_WEB, "Admin web interface init failed; regexp error: %s\n", buf);
+	  return -1;
+	}
+    }
+
+  return 0;
+}
+
+void
+jsonapi_deinit(void)
+{
+  int i;
+
+  for (i = 0; adm_handlers[i].handler; i++)
+    regfree(&adm_handlers[i].preg);
+}
+

src/httpd_jsonapi.h

@@ -0,0 +1,19 @@
+
+#ifndef __HTTPD_JSONAPI_H__
+#define __HTTPD_JSONAPI_H__
+
+#include <event2/http.h>
+
+int
+jsonapi_init(void);
+
+void
+jsonapi_deinit(void);
+
+void
+jsonapi_request(struct evhttp_request *req);
+
+int
+jsonapi_is_request(struct evhttp_request *req, char *uri);
+
+#endif /* !__HTTPD_JSONAPI_H__ */