libmpdclient: smaller error buffer

512 characters should be well enough for error messages which are
actually being displayed somewhere.  Use sizeof(errorStr) instead of
MPD_BUFFER_MAX_LENGTH everywhere.  Do proper length checking when
copying the output buffer to errorStr.

1 files changed, 22 insertions, 20 deletions

diff --git a/src/libmpdclient.c b/src/libmpdclient.c
index 8d1670f96..b29ffe746 100644
--- a/src/libmpdclient.c
+++ b/src/libmpdclient.c
@@ -87,7 +87,7 @@ static int winsock_dll_error(mpd_Connection *connection)
 	if ((WSAStartup(MAKEWORD(2, 2), &wsaData)) != 0 ||
 			LOBYTE(wsaData.wVersion) != 2 ||
 			HIBYTE(wsaData.wVersion) != 2 ) {
-		snprintf(connection->errorStr,MPD_BUFFER_MAX_LENGTH,
+		snprintf(connection->errorStr, sizeof(connection->errorStr),
 			 "Could not find usable WinSock DLL.");
 		connection->error = MPD_ERROR_SYSTEM;
 		return 1;
@@ -141,7 +141,7 @@ static int mpd_connect(mpd_Connection * connection, const char * host, int port,
 	error = getaddrinfo(host, service, &hints, &addrinfo);
 
 	if (error) {
-		snprintf(connection->errorStr,MPD_BUFFER_MAX_LENGTH,
+		snprintf(connection->errorStr, sizeof(connection->errorStr),
 			 "host \"%s\" not found: %s",host, gai_strerror(error));
 		connection->error = MPD_ERROR_UNKHOST;
 		return -1;
@@ -151,7 +151,7 @@ static int mpd_connect(mpd_Connection * connection, const char * host, int port,
 		/* create socket */
 		connection->sock = socket(res->ai_family, SOCK_STREAM, res->ai_protocol);
 		if (connection->sock < 0) {
-			snprintf(connection->errorStr, MPD_BUFFER_MAX_LENGTH,
+			snprintf(connection->errorStr, sizeof(connection->errorStr),
 			         "problems creating socket: %s",
 			         strerror(errno));
 			connection->error = MPD_ERROR_SYSTEM;
@@ -172,7 +172,7 @@ static int mpd_connect(mpd_Connection * connection, const char * host, int port,
 	freeaddrinfo(addrinfo);
 
 	if (connection->sock < 0) {
-		snprintf(connection->errorStr,MPD_BUFFER_MAX_LENGTH,
+		snprintf(connection->errorStr, sizeof(connection->errorStr),
 			 "problems connecting to \"%s\" on port"
 			 " %i: %s",host,port, strerror(errno));
 		connection->error = MPD_ERROR_CONNPORT;
@@ -192,7 +192,7 @@ static int mpd_connect(mpd_Connection * connection, const char * host, int port,
 	struct sockaddr_in sin;
 
 	if(!(he=gethostbyname(host))) {
-		snprintf(connection->errorStr,MPD_BUFFER_MAX_LENGTH,
+		snprintf(connection->errorStr, sizeof(connection->errorStr),
 			 "host \"%s\" not found",host);
 		connection->error = MPD_ERROR_UNKHOST;
 		return -1;
@@ -227,7 +227,7 @@ static int mpd_connect(mpd_Connection * connection, const char * host, int port,
 
 	/* connect stuff */
 	if (do_connect_fail(connection, dest, destlen)) {
-		snprintf(connection->errorStr,MPD_BUFFER_MAX_LENGTH,
+		snprintf(connection->errorStr, sizeof(connection->errorStr),
 			 "problems connecting to \"%s\" on port"
 			 " %i",host,port);
 		connection->error = MPD_ERROR_CONNPORT;
@@ -306,7 +306,7 @@ static int mpd_parseWelcome(mpd_Connection * connection, const char * host, int
 	int i;
 
 	if(strncmp(output,MPD_WELCOME_MESSAGE,strlen(MPD_WELCOME_MESSAGE))) {
-		snprintf(connection->errorStr,MPD_BUFFER_MAX_LENGTH,
+		snprintf(connection->errorStr, sizeof(connection->errorStr),
 			 "mpd not running on port %i on host \"%s\"",
 			 port,host);
 		connection->error = MPD_ERROR_NOTMPD;
@@ -319,8 +319,7 @@ static int mpd_parseWelcome(mpd_Connection * connection, const char * host, int
 		if(tmp) connection->version[i] = strtol(tmp,&test,10);
 
 		if (!tmp || (test[0] != '.' && test[0] != '\0')) {
-			snprintf(connection->errorStr,
-			         MPD_BUFFER_MAX_LENGTH,
+			snprintf(connection->errorStr, sizeof(connection->errorStr),
 			         "error parsing version number at "
 			         "\"%s\"",
 			         &output[strlen(MPD_WELCOME_MESSAGE)]);
@@ -369,7 +368,7 @@ static int mpd_connect_un(mpd_Connection * connection,
 		close(connection->sock);
 		connection->sock = 0;
 
-		snprintf(connection->errorStr,MPD_BUFFER_MAX_LENGTH,
+		snprintf(connection->errorStr, sizeof(connection->errorStr),
 			 "problems connecting to \"%s\": %s",
 			 host, strerror(errno));
 		connection->error = MPD_ERROR_CONNPORT;
@@ -389,8 +388,7 @@ mpd_Connection * mpd_newConnection(const char * host, int port, float timeout) {
 
 	connection->buflen = 0;
 	connection->bufstart = 0;
-	strcpy(connection->errorStr,"");
-	connection->error = 0;
+	mpd_clearError(connection);
 	connection->doneProcessing = 0;
 	connection->commandList = 0;
 	connection->listOks = 0;
@@ -421,7 +419,7 @@ mpd_Connection * mpd_newConnection(const char * host, int port, float timeout) {
 				      &(connection->buffer[connection->buflen]),
 				      MPD_BUFFER_MAX_LENGTH-connection->buflen,0);
 			if(readed<=0) {
-				snprintf(connection->errorStr,MPD_BUFFER_MAX_LENGTH,
+				snprintf(connection->errorStr, sizeof(connection->errorStr),
 					 "problems getting a response from"
 					 " \"%s\" on port %i : %s",host,
 					 port, strerror(errno));
@@ -434,14 +432,14 @@ mpd_Connection * mpd_newConnection(const char * host, int port, float timeout) {
 			if (SELECT_ERRNO_IGNORE)
 				continue;
 			snprintf(connection->errorStr,
-				 MPD_BUFFER_MAX_LENGTH,
+				 sizeof(connection->errorStr),
 				 "problems connecting to \"%s\" on port"
 				 " %i",host,port);
 			connection->error = MPD_ERROR_CONNPORT;
 			return connection;
 		}
 		else {
-			snprintf(connection->errorStr,MPD_BUFFER_MAX_LENGTH,
+			snprintf(connection->errorStr, sizeof(connection->errorStr),
 				 "timeout in attempting to get a response from"
 				 " \"%s\" on port %i",host,port);
 			connection->error = MPD_ERROR_NORESPONSE;
@@ -500,7 +498,7 @@ static void mpd_executeCommand(mpd_Connection *connection,
 		if(ret<=0)
 		{
 			if (SENDRECV_ERRNO_IGNORE) continue;
-			snprintf(connection->errorStr,MPD_BUFFER_MAX_LENGTH,
+			snprintf(connection->errorStr, sizeof(connection->errorStr),
 			         "problems giving command \"%s\"",command);
 			connection->error = MPD_ERROR_SENDING;
 			return;
@@ -515,7 +513,7 @@ static void mpd_executeCommand(mpd_Connection *connection,
 
 	if(commandLen>0) {
 		perror("");
-		snprintf(connection->errorStr,MPD_BUFFER_MAX_LENGTH,
+		snprintf(connection->errorStr, sizeof(connection->errorStr),
 		         "timeout sending command \"%s\"",command);
 		connection->error = MPD_ERROR_TIMEOUT;
 		return;
@@ -631,11 +629,16 @@ static void mpd_getNextReturnElement(mpd_Connection * connection) {
 	}
 
 	if(strncmp(output,"ACK",strlen("ACK"))==0) {
+		size_t length = strlen(output);
 		char * test;
 		char * needle;
 		int val;
 
-		strcpy(connection->errorStr, output);
+		if (length >= sizeof(connection->errorStr))
+			length = sizeof(connection->errorStr) - 1;
+
+		memcpy(connection->errorStr, output, length);
+		connection->errorStr[length] = 0;
 		connection->error = MPD_ERROR_ACK;
 		connection->errorCode = MPD_ACK_ERROR_UNK;
 		connection->errorAt = MPD_ERROR_AT_UNK;
@@ -664,9 +667,8 @@ static void mpd_getNextReturnElement(mpd_Connection * connection) {
 		connection->returnElement = mpd_newReturnElement(name,&(value[1]));
 	}
 	else {
-		snprintf(connection->errorStr,MPD_BUFFER_MAX_LENGTH,
+		snprintf(connection->errorStr, sizeof(connection->errorStr),
 			 "error parsing: %s:%s",name,value);
-		connection->errorStr[MPD_BUFFER_MAX_LENGTH] = '\0';
 		connection->error = 1;
 	}
 }