wardrobe: libwardrobe is a last.fm scrobbling library

1 files changed, 310 insertions, 0 deletions

diff --git a/libwardrobe/src/main.c b/libwardrobe/src/main.c
new file mode 100644
index 0000000..f188d46
--- /dev/null
+++ b/libwardrobe/src/main.c
@@ -0,0 +1,310 @@
+/*
+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 "md5.h"
+
+typedef struct {
+	char *user;
+	char *password;
+	char authToken[100];
+	char postUrl[1024];
+	CURL *ch;
+} WardrobeHandle_t;
+
+typedef struct {
+	char *artist;
+	char *title;
+	time_t started;
+	time_t length;
+} WardrobeSong_t;
+
+typedef enum {WARDROBE_RET_ERR, WARDROBE_RET_OK,
+		WARDROBE_RET_CLIENT_BANNED, WARDROBE_RET_BADAUTH,
+		WARDROBE_RET_BADTIME, WARDROBE_RET_BADSESSION} WardrobeReturn_t;
+
+#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 *charPtr = ptr;
+	char *streamPtr = stream;
+
+	if (strlen (streamPtr) + nmemb > WARDROBE_HTTP_BUFFER_SIZE) {
+		printf ("buffer overflow...\n");
+		return 0;
+	} else {
+		memcpy (streamPtr+strlen(streamPtr), charPtr, 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, 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_WRITEFUNCTION, WardrobeCurlRetToVar);
+	curl_easy_setopt (ch, CURLOPT_WRITEDATA, 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, char *url, 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, 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 ();
+}
+
+/*	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);
+	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) {
+	/* we'll use gmt */
+	time_t currTime = time (NULL);
+	time_t currGmTime = mktime (gmtime (&currTime));
+	char url[1024], tmp[100], *tmpDigest, *pwDigest, *ret;
+	WardrobeReturn_t fRet = WARDROBE_RET_ERR;
+
+	tmpDigest = WardrobeMd5Calc (wh->password);
+	snprintf (tmp, sizeof (tmp), "%s%li", tmpDigest, currGmTime);
+	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,
+			currGmTime, 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,
+		WardrobeSong_t *ws) {
+	char postContent[10000];
+	char *urlencArtist, *urlencTitle, *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);
+
+	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]=&n[0]=&m[0]=",
+			wh->authToken, urlencArtist, urlencTitle, ws->started,
+			ws->length);
+
+	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);
+	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,
+		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;
+}
+
+/*	return dynamic allocated error string, don't forget to free it
+ *	@param error int
+ *	@return human readable error string or NULL on error
+ */
+char *WardrobeErrorToString (WardrobeReturn_t ret) {
+	switch (ret) {
+		case WARDROBE_RET_ERR:
+			return strdup ("Unknown error.\n");
+			break;
+
+		case WARDROBE_RET_OK:
+			return strdup ("Everything's fine :)\n");
+			break;
+
+		case WARDROBE_RET_CLIENT_BANNED:
+			return strdup ("Client banned. Try to update your software.\n");
+			break;
+			
+		case WARDROBE_RET_BADAUTH:
+			return strdup ("Wrong username or password.\n");
+			break;
+		
+		case WARDROBE_RET_BADTIME:
+			return strdup ("System time wrong. Check your system time and "
+					"correct it.\n");
+			break;
+		
+		case WARDROBE_RET_BADSESSION:
+			return strdup ("Bad session. Try to login again.\n");
+			break;
+	}
+	return NULL;
+}