/*
 * Generic uart / rs232/ serial port library
 *
 * Copyright (c) 2013, Roel Verdult
 * Copyright (c) 2018 Google
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 1. Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the copyright holders nor the
 * names of its contributors may be used to endorse or promote products
 * derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @file uart_posix.c
 *
 * This version of the library has functionality removed which was not used by
 * proxmark3 project.
 */

// Test if we are dealing with posix operating systems
#ifndef _WIN32	 
#define _DEFAULT_SOURCE

#include "uart.h"

#include <termios.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <limits.h>
#include <sys/time.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <netdb.h>

// Taken from https://github.com/unbit/uwsgi/commit/b608eb1772641d525bfde268fe9d6d8d0d5efde7
#ifndef SOL_TCP
# define SOL_TCP IPPROTO_TCP
#endif

typedef struct termios term_info;
typedef struct {
	int fd;           // Serial port file descriptor
	term_info tiOld;  // Terminal info before using the port
	term_info tiNew;  // Terminal info during the transaction
} serial_port_unix;

// Set time-out on 30 miliseconds
struct timeval timeout = {
	.tv_sec  =     0, // 0 second
	.tv_usec = 30000  // 30 000 micro seconds
};

serial_port uart_open(const char* pcPortName) {
	serial_port_unix* sp = calloc(sizeof(serial_port_unix), sizeof(uint8_t));
	if (sp == 0) return INVALID_SERIAL_PORT;

	if (memcmp(pcPortName, "tcp:", 4) == 0) {
		struct addrinfo *addr, *rp;
		char *addrstr = strdup(pcPortName + 4);

		if (addrstr == NULL) {
			printf("Error: strdup\n");
			return INVALID_SERIAL_PORT;
		}

		timeout.tv_usec = 300000  // 300 000 micro seconds
		
		char *colon = strrchr(addrstr, ':');
		char *portstr;
		if (colon) {
			portstr = colon + 1;
			*colon = '\0';
		} else {
			portstr = "7901";
		}

		int s = getaddrinfo(addrstr, portstr, NULL, &addr);
		if (s != 0) {
			printf("Error: getaddrinfo: %s\n", gai_strerror(s));
			freeaddrinfo(addr);
			free(addrstr);
			return INVALID_SERIAL_PORT;
		}

		int sfd;
		for (rp = addr; rp != NULL; rp = rp->ai_next) {
			sfd = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);

			if (sfd == -1)
				continue;

			if (connect(sfd, rp->ai_addr, rp->ai_addrlen) != -1)
				break;

			close(sfd);
		}

		if (rp == NULL) {               /* No address succeeded */
			printf("Error: Could not connect\n");
			freeaddrinfo(addr);
			free(addrstr);
			return INVALID_SERIAL_PORT;
		}

		freeaddrinfo(addr);
		free(addrstr);

		sp->fd = sfd;

		int one = 1;
		setsockopt(sp->fd, SOL_TCP, TCP_NODELAY, &one, sizeof(one));
		return sp;
	}

  
	sp->fd = open(pcPortName, O_RDWR | O_NOCTTY | O_NDELAY | O_NONBLOCK);
	if(sp->fd == -1) {
		uart_close(sp);
		return INVALID_SERIAL_PORT;
	}

	// Finally figured out a way to claim a serial port interface under unix
	// We just try to set a (advisory) lock on the file descriptor
	struct flock fl;
	fl.l_type   = F_WRLCK;
	fl.l_whence = SEEK_SET;
	fl.l_start  = 0;
	fl.l_len    = 0;
	fl.l_pid    = getpid();

	// Does the system allows us to place a lock on this file descriptor
	if (fcntl(sp->fd, F_SETLK, &fl) == -1) {
		// A conflicting lock is held by another process
		free(sp);
		return CLAIMED_SERIAL_PORT;
	}

	// Try to retrieve the old (current) terminal info struct
	if(tcgetattr(sp->fd,&sp->tiOld) == -1) {
		uart_close(sp);
		return INVALID_SERIAL_PORT;
	}

	// Duplicate the (old) terminal info struct
	sp->tiNew = sp->tiOld;

	// Configure the serial port
	sp->tiNew.c_cflag = CS8 | CLOCAL | CREAD;
	sp->tiNew.c_iflag = IGNPAR;
	sp->tiNew.c_oflag = 0;
	sp->tiNew.c_lflag = 0;

	// Block until n bytes are received
	sp->tiNew.c_cc[VMIN] = 0;
	// Block until a timer expires (n * 100 mSec.)
	sp->tiNew.c_cc[VTIME] = 0;

	// Try to set the new terminal info struct
	if(tcsetattr(sp->fd, TCSANOW, &sp->tiNew) == -1) {
		uart_close(sp);
		return INVALID_SERIAL_PORT;
	}

  // Flush all lingering data that may exist
  tcflush(sp->fd, TCIOFLUSH);

#ifdef WITH_FPC
	if ( uart_set_speed(sp, 115200) ) {
		printf("[=] UART Setting serial baudrate 115200 [FPC enabled]\n");  
	} else {
		uart_set_speed(sp, 9600);
		printf("[=] UART Setting serial baudrate 9600 [FPC enabled]\n");		
	}
#else	
	// set speed, works for UBUNTU 14.04
	bool success = uart_set_speed(sp, 460800);
	if (success) {
		printf("[=] UART Setting serial baudrate 460800\n");
	} else {
		uart_set_speed(sp, 115200);
		printf("[=] UART Setting serial baudrate 115200\n");
	}
#endif  
	return sp;
}

void uart_close(const serial_port sp) {
	serial_port_unix* spu = (serial_port_unix*)sp;
	tcflush(spu->fd, TCIOFLUSH);
	tcsetattr(spu->fd, TCSANOW, &(spu->tiOld));
	struct flock fl;
	fl.l_type   = F_UNLCK;
	fl.l_whence = SEEK_SET;
	fl.l_start  = 0;
	fl.l_len    = 0;
	fl.l_pid    = getpid();

	// Does the system allows us to place a lock on this file descriptor
	int err = fcntl(spu->fd, F_SETLK, &fl);
	if ( err == -1) {
		//perror("fcntl");
	}  
	close(spu->fd);
	free(sp);
}

bool uart_receive(const serial_port sp, uint8_t* pbtRx, size_t pszMaxRxLen, size_t* pszRxLen) {
	int res;
	int byteCount;
	fd_set rfds;
	struct timeval tv;

	// Reset the output count
	*pszRxLen = 0;
  
	do {
		// Reset file descriptor
		FD_ZERO(&rfds);
		FD_SET(((serial_port_unix*)sp)->fd, &rfds);
		tv = timeout;
		res = select(((serial_port_unix*)sp)->fd + 1, &rfds, NULL, NULL, &tv);

		// Read error
		if (res < 0) {
			return false;
		}

		// Read time-out
		if (res == 0) {
			if (*pszRxLen == 0) {
				// Error, we received no data
				return false;
			} else {
				// We received some data, but nothing more is available
				return true;
			}
		}

		// Retrieve the count of the incoming bytes
		res = ioctl(((serial_port_unix*)sp)->fd, FIONREAD, &byteCount);
		if (res < 0) return false;

		// Cap the number of bytes, so we don't overrun the buffer
		if (pszMaxRxLen - (*pszRxLen) < byteCount) {
			byteCount = pszMaxRxLen - (*pszRxLen);
		}

		// There is something available, read the data
		res = read(((serial_port_unix*)sp)->fd, pbtRx + (*pszRxLen), byteCount);

		// Stop if the OS has some troubles reading the data
		if (res <= 0) return false;

		*pszRxLen += res;

		if (*pszRxLen == pszMaxRxLen) {
			// We have all the data we wanted.
			return true;
		}

	} while (byteCount);

	return true;
}

bool uart_send(const serial_port sp, const uint8_t* pbtTx, const size_t len) {
	int32_t res;
	size_t pos = 0;
	fd_set rfds;
	struct timeval tv;

	while (pos < len) {
		// Reset file descriptor
		FD_ZERO(&rfds);
		FD_SET(((serial_port_unix*)sp)->fd, &rfds);
		tv = timeout;
		res = select(((serial_port_unix*)sp)->fd+1, NULL, &rfds, NULL, &tv);

		// Write error
		if (res < 0) {
			printf("UART:: write error (%d)\n", res);
			return false;
		}

		// Write time-out
		if (res == 0) {
			printf("UART:: write time-out\n");
			return false;
		}

		// Send away the bytes
		res = write(((serial_port_unix*)sp)->fd, pbtTx + pos, len - pos);

		// Stop if the OS has some troubles sending the data
		if (res <= 0) return false;

		pos += res;
	}
	return true;
}

bool uart_set_speed(serial_port sp, const uint32_t uiPortSpeed) {
	const serial_port_unix* spu = (serial_port_unix*)sp;
	speed_t stPortSpeed;
	switch (uiPortSpeed) {
		case 0: stPortSpeed = B0; break;
		case 50: stPortSpeed = B50; break;
		case 75: stPortSpeed = B75; break;
		case 110: stPortSpeed = B110; break;
		case 134: stPortSpeed = B134; break;
		case 150: stPortSpeed = B150; break;
		case 300: stPortSpeed = B300; break;
		case 600: stPortSpeed = B600; break;
		case 1200: stPortSpeed = B1200; break;
		case 1800: stPortSpeed = B1800; break;
		case 2400: stPortSpeed = B2400; break;
		case 4800: stPortSpeed = B4800; break;
		case 9600: stPortSpeed = B9600; break;
		case 19200: stPortSpeed = B19200; break;
		case 38400: stPortSpeed = B38400; break;
#  ifdef B57600
		case 57600: stPortSpeed = B57600; break;
#  endif
#  ifdef B115200
		case 115200: stPortSpeed = B115200; break;
#  endif
#  ifdef B230400
		case 230400: stPortSpeed = B230400; break;
#  endif
#  ifdef B460800
		case 460800: stPortSpeed = B460800; break;
#  endif
#  ifdef B921600
		case 921600: stPortSpeed = B921600; break;
#  endif
		default: return false;
	};
	struct termios ti;
	if (tcgetattr(spu->fd,&ti) == -1) return false;
	// Set port speed (Input and Output)
	cfsetispeed(&ti, stPortSpeed);
	cfsetospeed(&ti, stPortSpeed);
	return (tcsetattr(spu->fd, TCSANOW, &ti) != -1);
}

uint32_t uart_get_speed(const serial_port sp) {
	struct termios ti;
	uint32_t uiPortSpeed;
	const serial_port_unix* spu = (serial_port_unix*)sp;
	
	if (tcgetattr(spu->fd, &ti) == -1) 
		return 0;
	
	// Set port speed (Input)
	speed_t stPortSpeed = cfgetispeed(&ti);
	switch (stPortSpeed) {
		case B0: uiPortSpeed = 0; break;
		case B50: uiPortSpeed = 50; break;
		case B75: uiPortSpeed = 75; break;
		case B110: uiPortSpeed = 110; break;
		case B134: uiPortSpeed = 134; break;
		case B150: uiPortSpeed = 150; break;
		case B300: uiPortSpeed = 300; break;
		case B600: uiPortSpeed = 600; break;
		case B1200: uiPortSpeed = 1200; break;
		case B1800: uiPortSpeed = 1800; break;
		case B2400: uiPortSpeed = 2400; break;
		case B4800: uiPortSpeed = 4800; break;
		case B9600: uiPortSpeed = 9600; break;
		case B19200: uiPortSpeed = 19200; break;
		case B38400: uiPortSpeed = 38400; break;
#  ifdef B57600
		case B57600: uiPortSpeed = 57600; break;
#  endif
#  ifdef B115200
		case B115200: uiPortSpeed = 115200; break;
#  endif
#  ifdef B230400
		case B230400: uiPortSpeed = 230400; break;
#  endif
#  ifdef B460800
		case B460800: uiPortSpeed = 460800; break;
#  endif
#  ifdef B921600
		case B921600: uiPortSpeed = 921600; break;
#  endif
		default: return 0;
	};
	return uiPortSpeed;
}
#endif