/* * Copyright (C) 2003-2009 The Music Player Daemon Project * http://www.musicpd.org * * 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., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #include "input/lastfm_input_plugin.h" #include "input_plugin.h" #include "tag.h" #include "conf.h" #include #include #undef G_LOG_DOMAIN #define G_LOG_DOMAIN "input_lastfm" static struct lastfm_data { char *user; char *md5; } lastfm_data; struct lastfm_input { /* our very own plugin wrapper */ struct input_plugin wrap_plugin; /* pointer to input stream's plugin */ const struct input_plugin *plugin; /* pointer to input stream's data */ void *data; /* current track's tag */ struct tag *tag; }; static bool lastfm_input_init(const struct config_param *param) { const char *passwd = config_get_block_string(param, "password", NULL); const char *user = config_get_block_string(param, "user", NULL); if (passwd == NULL || user == NULL) return false; lastfm_data.user = g_uri_escape_string(user, NULL, false); if (strlen(passwd) != 32) lastfm_data.md5 = g_compute_checksum_for_string(G_CHECKSUM_MD5, passwd, strlen(passwd)); else lastfm_data.md5 = g_strdup(passwd); return true; } static void lastfm_input_finish(void) { g_free(lastfm_data.user); g_free(lastfm_data.md5); } /** * Simple data fetcher. * @param url path or url of data to fetch. * @return data fetched, or NULL on error. Must be freed with g_free. */ static char * lastfm_get(const char *url) { struct input_stream input_stream; bool success; int ret; char buffer[4096]; size_t length = 0, nbytes; success = input_stream_open(&input_stream, url); if (!success) return NULL; while (!input_stream.ready) { ret = input_stream_buffer(&input_stream); if (ret < 0) { input_stream_close(&input_stream); return NULL; } } do { nbytes = input_stream_read(&input_stream, buffer + length, sizeof(buffer) - length); if (nbytes == 0) { if (input_stream_eof(&input_stream)) break; /* I/O error */ input_stream_close(&input_stream); return NULL; } length += nbytes; } while (length < sizeof(buffer)); input_stream_close(&input_stream); return g_strndup(buffer, length); } /** * Ini-style value fetcher. * @param response data through which to search. * @param name name of value to search for. * @return value for param name in param reponse or NULL on error. Free with g_free. */ static char * lastfm_find(const char *response, const char *name) { size_t name_length = strlen(name); while (true) { const char *eol = strchr(response, '\n'); if (eol == NULL) return NULL; if (strncmp(response, name, name_length) == 0 && response[name_length] == '=') { response += name_length + 1; return g_strndup(response, eol - response); } response = eol + 1; } } /** * Replace XML's five predefined entities with the equivalant characters. * glib doesn't seem to have code to do this, even in the xml parser. * We don't manage numerical character references such as &#nnnn; or &#xhhhh;. * @param value XML text to decode. * @return decoded string, which must be freed with g_free. * @todo make sure this is ok for utf-8. */ static char * lastfm_xmldecode(const char *value) { struct entity { const char *text; char repl; } entities[] = { {"&", '&'}, {""", '"'}, {"'", '\''}, {">", '>'}, {"<", '<'} }; char *txt = g_strdup(value); unsigned int i; for (i = 0; i < sizeof(entities)/sizeof(entities[0]); ++i) { char *p; int slen = strlen(entities[i].text); while ((p = strstr(txt, entities[i].text))) { *p = entities[i].repl; g_strlcpy(p + 1, p + slen, strlen(p) - slen); } } return txt; } /** * Extract the text between xml start and end tags specified by param tag. * Caveat: This function does not handle nested tags properly. * @param response XML to extract text from. * @param tag name of tag of which text should be extracted from. * @return text between tags specified by param tag, NULL on error; Must be freed with g_free. */ static char * lastfm_xmltag(const char *response, const char *tag) { char *tn = g_strconcat("<", tag, ">", NULL); char *p, *q; if (!(p = strstr(response, tn))) { g_free(tn); return NULL; } p += strlen(tn); g_free(tn); tn = g_strconcat("", NULL); if (!(q = strstr(p, tn))) { g_free(tn); return NULL; } g_free(tn); return g_strndup(p, q - p); } /** * Parses xspf track and generates mpd tag. * @return tag which must be freed with tag_free. */ static struct tag * lastfm_read_tag(const char *response) { struct tagalias { enum tag_type type; const char *xmltag; } aliases[] = { {TAG_ITEM_ARTIST, "creator"}, {TAG_ITEM_TITLE, "title"}, {TAG_ITEM_ALBUM, "album"} }; struct tag *tag = tag_new(); unsigned int i; char *track_time = lastfm_xmltag(response, "duration"); if (track_time != NULL) { int mtime = strtol(track_time, 0, 0); g_free(track_time); /* make sure to round up */ tag->time = ((mtime + 999) / 1000); } else tag->time = 0; for (i = 0; i < sizeof(aliases)/sizeof(aliases[0]); ++i) { char *p, *value = lastfm_xmltag(response, aliases[i].xmltag); if (value == NULL) continue; p = lastfm_xmldecode(value); g_free(value); value = p; tag_add_item(tag, aliases[i].type, value); g_free(value); } return tag; } static size_t lastfm_input_read_wrap(struct input_stream *is, void *ptr, size_t size) { size_t ret; struct lastfm_input *d = is->data; is->data = d->data; ret = (* d->plugin->read)(is, ptr, size); is->data = d; return ret; } static bool lastfm_input_eof_wrap(struct input_stream *is) { bool ret; struct lastfm_input *d = is->data; is->data = d->data; ret = (* d->plugin->eof)(is); is->data = d; return ret; } static bool lastfm_input_seek_wrap(struct input_stream *is, goffset offset, int whence) { bool ret; struct lastfm_input *d = is->data; is->data = d->data; ret = (* d->plugin->seek)(is, offset, whence); is->data = d; return ret; } static int lastfm_input_buffer_wrap(struct input_stream *is) { int ret; struct lastfm_input *d = is->data; is->data = d->data; ret = (* d->plugin->buffer)(is); is->data = d; return ret; } static struct tag * lastfm_input_tag(struct input_stream *is) { struct lastfm_input *d = is->data; struct tag *tag = d->tag; d->tag = NULL; return tag; } static void lastfm_input_close(struct input_stream *is) { struct lastfm_input *d = is->data; if (is->plugin->close) { is->data = d->data; is->plugin = d->plugin; (* is->plugin->close)(is); } if (d->tag) tag_free(d->tag); g_free(d); } static bool lastfm_input_open(struct input_stream *is, const char *url) { char *p, *q, *response, *track, *session, *stream_url; bool success; if (strncmp(url, "lastfm://", 9) != 0) return false; /* handshake */ p = g_strconcat("http://ws.audioscrobbler.com/radio/handshake.php?" "version=1.1.1&platform=linux&" "username=", lastfm_data.user, "&" "passwordmd5=", lastfm_data.md5, "&" "debug=0&partner=", NULL); response = lastfm_get(p); g_free(p); if (response == NULL) return false; /* extract session id from response */ session = lastfm_find(response, "session"); stream_url = lastfm_find(response, "stream_url"); g_free(response); if (session == NULL || stream_url == NULL) { g_free(session); g_free(stream_url); return false; } q = g_uri_escape_string(session, NULL, false); g_free(session); session = q; /* "adjust" last.fm radio */ if (strlen(url) > 9) { char *escaped_url; escaped_url = g_uri_escape_string(url, NULL, false); p = g_strconcat("http://ws.audioscrobbler.com/radio/adjust.php?" "session=", session, "&url=", escaped_url, "&debug=0", NULL); g_free(escaped_url); response = lastfm_get(p); g_free(response); g_free(p); if (response == NULL) { g_free(session); g_free(stream_url); return false; } } /* load the last.fm playlist */ p = g_strconcat("http://ws.audioscrobbler.com/radio/xspf.php?" "sk=", session, "&discovery=0&desktop=1.5.1.31879", NULL); g_free(session); response = lastfm_get(p); g_free(p); if (response == NULL) { g_free(stream_url); return false; } /* From here on, we only care about the first track, extract that * * Note: if you want to get information about the next track (needed * for continuous playback) extract the other track info here too. */ g_free(stream_url); track = lastfm_xmltag(response, "track"); g_free(response); /* If there are no tracks in the tracklist, it's possible that the * station doesn't have enough content. */ if (track == NULL) return false; stream_url = lastfm_xmltag(track, "location"); if (stream_url == NULL) { g_free(track); return false; } /* now really open the last.fm radio stream */ success = input_stream_open(is, stream_url); if (success) { /* instantiate our transparent wrapper plugin * this is needed so that the backend knows what functions are * properly available. */ struct lastfm_input *d = g_new0(struct lastfm_input, 1); d->wrap_plugin.name = "lastfm"; d->wrap_plugin.open = lastfm_input_open; d->wrap_plugin.close = lastfm_input_close; d->wrap_plugin.read = lastfm_input_read_wrap; d->wrap_plugin.eof = lastfm_input_eof_wrap; d->wrap_plugin.tag = lastfm_input_tag; if (is->seekable) d->wrap_plugin.seek = lastfm_input_seek_wrap; if (is->plugin->buffer) d->wrap_plugin.buffer = lastfm_input_buffer_wrap; d->tag = lastfm_read_tag(track); d->plugin = is->plugin; d->data = is->data; /* give the backend our wrapper plugin */ is->plugin = &d->wrap_plugin; is->data = d; } g_free(stream_url); g_free(track); return success; } const struct input_plugin lastfm_input_plugin = { .name = "lastfm", .init = lastfm_input_init, .finish = lastfm_input_finish, .open = lastfm_input_open, .close = lastfm_input_close, .tag = lastfm_input_tag, };