path: root/libwardrobe/src/main.c

/*
Copyright (c) 2008 Lars-Dominik Braun

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/

#include <time.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <curl/curl.h>

#include "wardrobe.h"
#include "md5.h"
#include "config.h"

#define WARDROBE_HTTP_BUFFER_SIZE 10000

void WardrobeSongInit (WardrobeSong_t *ws) {
	memset (ws, 0, sizeof (*ws));
}

/*	callback for curl, writes data to buffer
 *	@param received data
 *	@param block size
 *	@param blocks received
 *	@param write data into this buffer
 *	@return written bytes
 */
size_t WardrobeCurlRetToVar (void *ptr, size_t size, size_t nmemb,
		void *stream) {
	char *streamPtr = stream;

	if ((strlen (streamPtr) + nmemb) > (WARDROBE_HTTP_BUFFER_SIZE - 1)) {
		printf ("buffer overflow...\n");
		return 0;
	} else {
		memcpy (streamPtr+strlen(streamPtr), ptr, size*nmemb);
		return size*nmemb;
	}
}

/*	receive data from url using GET method
 *	@param initialized curl handle
 *	@param call this url
 *	@param put received data here, memory is allocated by this function
 *	@return nothing yet
 */
void WardrobeHttpGet (CURL *ch, const char *url, char **retData) {
	/* Let's hope nothing will be bigger than this... */
	char curlRet[WARDROBE_HTTP_BUFFER_SIZE];

	memset (curlRet, 0, sizeof (curlRet));

	curl_easy_setopt (ch, CURLOPT_URL, url);
	curl_easy_setopt (ch, CURLOPT_HTTPGET, 1L);
	curl_easy_setopt (ch, CURLOPT_WRITEFUNCTION, WardrobeCurlRetToVar);
	curl_easy_setopt (ch, CURLOPT_WRITEDATA, (void *) curlRet);

	curl_easy_perform (ch);

	*retData = strdup (curlRet);
}

/*	post data to url and receive answer as string
 *	@param initialized curl handle
 *	@param call this url
 *	@param post this data
 *	@param put received data here, memory is allocated by this function
 *	@return nothing yet
 */
void WardrobeHttpPost (CURL *ch, const char *url, const char *postData,
		char **retData) {
	/* Let's hope nothing will be bigger than this... */
	char curlRet[WARDROBE_HTTP_BUFFER_SIZE];

	memset (curlRet, 0, sizeof (curlRet));
	curl_easy_setopt (ch, CURLOPT_URL, url);
	curl_easy_setopt (ch, CURLOPT_POSTFIELDS, postData);
	curl_easy_setopt (ch, CURLOPT_WRITEFUNCTION, WardrobeCurlRetToVar);
	curl_easy_setopt (ch, CURLOPT_WRITEDATA, (void *) curlRet);

	curl_easy_perform (ch);

	*retData = strdup (curlRet);
}

/*	initialize wardrobe handle (setup curl, e.g.)
 *	@param wardrobe handle
 */
void WardrobeInit (WardrobeHandle_t *wh) {
	memset (wh, 0, sizeof (*wh));
	wh->ch = curl_easy_init ();
	curl_easy_setopt (wh->ch, CURLOPT_USERAGENT, PACKAGE_STRING);
	curl_easy_setopt (wh->ch, CURLOPT_CONNECTTIMEOUT, 60);
}

/*	free () replacement that does some checks and zeros memory
 *	@param pointer
 *	@param size or 0 to disable zeroing
 */
void WardrobeFree (void *ptr, size_t size) {
	if (ptr != NULL) {
		if (size > 0) {
			memset (ptr, 0, size);
		}
		free (ptr);
	}
}

/*	cleanup song
 *	@param song
 */
void WardrobeSongDestroy (WardrobeSong_t *ws) {
	WardrobeFree (ws->artist, 0);
	WardrobeFree (ws->title, 0);
	WardrobeFree (ws->album, 0);
	memset (ws, 0, sizeof (*ws));
}

/*	cleanup wardrobe handle
 *	@param initialized wardrobe handle
 */
void WardrobeDestroy (WardrobeHandle_t *wh) {
	WardrobeFree (wh->user, 0);
	WardrobeFree (wh->password, 0);
	curl_easy_cleanup (wh->ch);
	memset (wh, 0, sizeof (*wh));
}

/*	get session id from last.fm; you don't have to call this manually
 *	@param wardrobe handle
 *	@return _OK or error
 */
WardrobeReturn_t WardrobeHandshake (WardrobeHandle_t *wh) {
	char url[1024], tmp[100], *tmpDigest, *pwDigest, *ret;
	WardrobeReturn_t fRet = WARDROBE_RET_ERR;
	time_t currTStamp = time (NULL);

	tmpDigest = WardrobeMd5Calc (wh->password);
	snprintf (tmp, sizeof (tmp), "%s%li", tmpDigest, currTStamp);
	pwDigest = WardrobeMd5Calc (tmp);
	snprintf (url, sizeof (url), "http://post.audioscrobbler.com/"
			"?hs=true&p=1.2&c=tst&v=1.0&u=%s&t=%li&a=%s", wh->user,
			currTStamp, pwDigest);
	
	WardrobeHttpGet (wh->ch, url, &ret);

	/* parse answer */
	if (memcmp (ret, "OK", 2) == 0) {
		char *newlines[5];
		size_t i;
		newlines[0] = ret;
		/* split string */
		for (i = 1; i < sizeof (newlines) / sizeof (*newlines); i++) {
			newlines[i] = strchr (newlines[i-1]+1, '\n');
		}
		/* copy needed values */
		if (newlines[2] - newlines[1]-1 < sizeof (wh->authToken)) {
			memcpy (wh->authToken, newlines[1]+1, newlines[2] -
					newlines[1]-1);
		} else {
			printf ("buffer overflow!\n");
		}
		if (newlines[4] - newlines[3]-1 < sizeof (wh->postUrl)) {
			memcpy (wh->postUrl, newlines[3]+1, newlines[4] -
					newlines[3]-1);
		} else {
			printf ("buffer overflow!\n");
		}
		fRet = WARDROBE_RET_OK;
	} else if (memcmp (ret, "BADAUTH", 7) == 0) {
		fRet = WARDROBE_RET_BADAUTH;
	} else if (memcmp (ret, "BADTIME", 7) == 0) {
		fRet = WARDROBE_RET_BADTIME;
	} else if (memcmp (ret, "BANNED", 6) == 0) {
		fRet = WARDROBE_RET_CLIENT_BANNED;
	}

	WardrobeFree (tmpDigest, WARDROBE_MD5_DIGEST_LEN);
	WardrobeFree (pwDigest, WARDROBE_MD5_DIGEST_LEN);
	WardrobeFree (ret, 0);

	return fRet;
}

/*	_really_ submit song to last.fm
 *	@param wardrobe handle
 *	@param song
 *	@return _OK or error
 */
WardrobeReturn_t WardrobeSendSong (WardrobeHandle_t *wh,
		const WardrobeSong_t *ws) {
	char postContent[10000];
	char *urlencArtist, *urlencTitle, *urlencAlbum, *ret;
	WardrobeReturn_t fRet = WARDROBE_RET_ERR;

	urlencArtist = curl_easy_escape (wh->ch, ws->artist, 0);
	urlencTitle = curl_easy_escape (wh->ch, ws->title, 0);
	urlencAlbum = curl_easy_escape (wh->ch, ws->album, 0);

	snprintf (postContent, sizeof (postContent), "s=%s&a[0]=%s&t[0]=%s&"
			"i[0]=%li&o[0]=P&r[0]=&l[0]=%li&b[0]=%s&n[0]=&m[0]=",
			wh->authToken, urlencArtist, urlencTitle, ws->started,
			ws->length, urlencAlbum);

	WardrobeHttpPost (wh->ch, wh->postUrl, postContent, &ret);
	if (memcmp (ret, "OK", 2) == 0) {
		fRet = WARDROBE_RET_OK;
	} else if (memcmp (ret, "BADSESSION", 10) == 0) {
		fRet = WARDROBE_RET_BADSESSION;
	}

	curl_free (urlencArtist);
	curl_free (urlencTitle);
	curl_free (urlencAlbum);
	WardrobeFree (ret, 0);

	return fRet;
}

/*	submit played track to last.fm
 *	@public yes
 *	@param wardrobe handle
 *	@param song data
 *	@return _OK or error
 */
WardrobeReturn_t WardrobeSubmit (WardrobeHandle_t *wh,
		const WardrobeSong_t *ws) {
	size_t i;
	WardrobeReturn_t fRet = WARDROBE_RET_ERR;

	if (strlen (wh->authToken) <= 0 && (fRet = WardrobeHandshake (wh)) !=
			WARDROBE_RET_OK) {
		return fRet;
	}
	for (i = 0; i < 2; i++) {
		fRet = WardrobeSendSong (wh, ws);
		if (fRet == WARDROBE_RET_OK) {
			return WARDROBE_RET_OK;
		} else if (fRet == WARDROBE_RET_BADSESSION &&
				(fRet = WardrobeHandshake (wh)) != WARDROBE_RET_OK) {
			return fRet;
		}
	}
	return fRet;
}

/*	error string
 *	@param error int
 *	@return human readable error string or NULL on error
 */
const char *WardrobeErrorToString (WardrobeReturn_t ret) {
	switch (ret) {
		case WARDROBE_RET_ERR:
			return "Unknown error.";
			break;

		case WARDROBE_RET_OK:
			return "Everything's fine :)";
			break;

		case WARDROBE_RET_CLIENT_BANNED:
			return "Client banned. Try to update your software.";
			break;
			
		case WARDROBE_RET_BADAUTH:
			return "Wrong username or password.";
			break;
		
		case WARDROBE_RET_BADTIME:
			return "System time wrong. Check your system time and "
					"correct it.";
			break;
		
		case WARDROBE_RET_BADSESSION:
			return "Bad session. Try to login again.";
			break;

		default:
			return "Unknown Error.";
			break;
	}
}