/*
 * Copyright (c) 2014 Brian Swetland
 *
 * 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 <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/types.h>

#include "network.h"
#include "../app/lkboot/lkboot_protocol.h"

static int readx(int s, void *_data, int len) {
	char *data = _data;
	int r;
	while (len > 0) {
		r = read(s, data, len);
		if (r == 0) {
			fprintf(stderr, "error: eof during socket read\n");
			return -1;
		}
		if (r < 0) {
			if (errno == EINTR) continue;
			fprintf(stderr, "error: %s during socket read\n", strerror(errno));
			return -1;
		}
		data += r;
		len -= r;
	}
	return 0;
}

static int upload(int s, int txfd, size_t txlen, int do_endian_swap) {
	int err = 0;
	msg_hdr_t hdr;

	char *buf = malloc(txlen);
	if (!buf)
		return -1;

	if (readx(txfd, buf, txlen)) {
		fprintf(stderr, "error: reading from file\n");
		err = -1;
		goto done;
	}

	/* 4 byte swap data if requested */
	if (do_endian_swap) {
		size_t i;
		for (i = 0; i < txlen; i += 4) {
			char temp = buf[i];
			buf[i] = buf[i + 3];
			buf[i + 3] = temp;

			temp = buf[i + 1];
			buf[i + 1] = buf[i + 2];
			buf[i + 2] = temp;
		}
	}

	size_t pos = 0;
	while (pos < txlen) {
		size_t xfer = (txlen - pos > 65536) ? 65536 : txlen - pos;

		hdr.opcode = MSG_SEND_DATA;
		hdr.extra = 0;
		hdr.length = xfer - 1;
		if (write(s, &hdr, sizeof(hdr)) != sizeof(hdr)) {
			fprintf(stderr, "error: writing socket\n");
			err = -1;
			goto done;
		}
		if (write(s, buf + pos, xfer) != xfer) {
			fprintf(stderr, "error: writing socket\n");
			err = -1;
			goto done;
		}
		pos += xfer;
	}

	hdr.opcode = MSG_END_DATA;
	hdr.extra = 0;
	hdr.length = 0;
	if (write(s, &hdr, sizeof(hdr)) != sizeof(hdr)) {
		fprintf(stderr, "error: writing socket\n");
		err = -1;
		goto done;
	}

done:
	free(buf);

	return err;
}

static off_t trim_fpga_image(int fd, off_t len)
{
	/* fd should be at start of bitfile, seek until the
	 * ff ff ff ff aa 99 55 66 pattern is found and subtract
	 * the number of bytes read until pattern found.
	 */
	const unsigned char pat[] = { 0xff, 0xff, 0xff, 0xff, 0xaa, 0x99, 0x55, 0x66 };
	unsigned char buf[sizeof(pat)];

	memset(buf, 0, sizeof(buf));

	off_t i;
	for (i = 0; i < len; i++) {
		memmove(buf, buf + 1, sizeof(buf) - 1);
		if (read(fd, &buf[sizeof(buf) - 1], 1) < 1) {
			return -1;
		}

		/* look for pattern */
		if (memcmp(pat, buf, sizeof(pat)) == 0) {
			/* found it, rewind the fd and return the truncated length */
			lseek(fd, -sizeof(pat), SEEK_CUR);
			return len - (i + 1 - sizeof(pat));
		}
	}

	return -1;
}

#define DCC_SUBPROCESS "zynq-dcc"

static int start_dcc_subprocess(int *fd_in, int *fd_out)
{
	int outpipe[2];
	if (pipe(outpipe) != 0)
		return -1;

	int inpipe[2];
	if (pipe(inpipe) != 0)
		return -1;

	*fd_in = inpipe[0];
	*fd_out = outpipe[1];

	pid_t pid = fork();
	if (pid == 0) {
		/* we are the child */
		close(STDIN_FILENO);
		close(STDOUT_FILENO);

		dup2(outpipe[0], STDIN_FILENO);
		close(outpipe[1]);

		dup2(inpipe[1], STDOUT_FILENO);
		close(inpipe[0]);

		fprintf(stderr, "in the child\n");

		execlp(DCC_SUBPROCESS, DCC_SUBPROCESS, NULL);
		fprintf(stderr, "after exec, didn't work!\n");
	} else {
		fprintf(stderr, "in parent, pid %u\n", pid);

		close(outpipe[0]);
		close(inpipe[1]);
	}

	return 0;
}

#define REPLYMAX (9 * 1024 * 1024)
static unsigned char replybuf[REPLYMAX];
static unsigned replylen = 0;

unsigned lkboot_get_reply(void **ptr) {
	*ptr = replybuf;
	return replylen;
}

int lkboot_txn(const char *host, const char *_cmd, int txfd, const char *args) {
	msg_hdr_t hdr;
	char cmd[128];
	char tmp[65536];
	off_t txlen = 0;
	int do_endian_swap = 0;
	int once = 1;
	int len;
	int fd_in, fd_out;
	int ret = 0;

	if (txfd != -1) {
		txlen = lseek(txfd, 0, SEEK_END);
		if (txlen > (512*1024*1024)) {
			fprintf(stderr, "error: file too large\n");
			return -1;
		}
		lseek(txfd, 0, SEEK_SET);
	}

	if (!strcmp(_cmd, "fpga")) {
		/* if we were asked to send an fpga image, try to find the sync words and
		 * trim all the data before it
		 */
		txlen = trim_fpga_image(txfd, txlen);
		if (txlen < 0) {
			fprintf(stderr, "error: fpga image doesn't contain sync pattern\n");
			return -1;
		}

		/* it'll need a 4 byte endian swap as well */
		do_endian_swap = 1;
	}

	len = snprintf(cmd, 128, "%s:%d:%s", _cmd, (int) txlen, args);
	if (len > 127) {
		fprintf(stderr, "error: command too large\n");
		return -1;
	}

	/* if host is -, use stdin/stdout */
	if (!strcmp(host, "-")) {
		fprintf(stderr, "using stdin/stdout for io\n");
		fd_in = STDIN_FILENO;
		fd_out = STDOUT_FILENO;
	} else if (!strcasecmp(host, "jtag")) {
		fprintf(stderr, "using zynq-dcc utility for io\n");
		if (start_dcc_subprocess(&fd_in, &fd_out) < 0) {
			fprintf(stderr, "error starting jtag subprocess, is it in your path?\n");
			return -1;
		}
	} else {
		in_addr_t addr = lookup_hostname(host);
		if (addr == 0) {
			fprintf(stderr, "error: cannot find host '%s'\n", host);
			return -1;
		}
		while ((fd_in = tcp_connect(addr, 1023)) < 0) {
			if (once) {
				fprintf(stderr, "error: cannot connect to host '%s'. retrying...\n", host);
				once = 0;
			}
			usleep(100000);
		}
		fd_out = fd_in;
	}

	hdr.opcode = MSG_CMD;
	hdr.extra = 0;
	hdr.length = len;
	if (write(fd_out, &hdr, sizeof(hdr)) != sizeof(hdr)) goto iofail;
	if (write(fd_out, cmd, len) != len) goto iofail;

	for (;;) {
		if (readx(fd_in, &hdr, sizeof(hdr))) goto iofail;
		switch (hdr.opcode) {
		case MSG_GO_AHEAD:
			if (upload(fd_out, txfd, txlen, do_endian_swap)) {
				ret = -1;
				goto out;
			}
			break;
		case MSG_OKAY:
			ret = 0;
			goto out;
		case MSG_FAIL:
			len = (hdr.length > 127) ? 127 : hdr.length;
			if (readx(fd_in, cmd, len)) {
				cmd[0] = 0;
			} else {
				cmd[len] = 0;
			}
			fprintf(stderr,"error: remote failure: %s\n", cmd);
			ret = -1;
			goto out;
		case MSG_SEND_DATA:
			len = hdr.length + 1;
			if (readx(fd_in, tmp, len)) goto iofail;
			if (len > (REPLYMAX - replylen)) {
				fprintf(stderr, "error: too much reply data\n");
				ret = -1;
				goto out;
			}
			memcpy(replybuf + replylen, tmp, len);
			replylen += len;
			break;
		default:
			fprintf(stderr, "error: unknown opcode %d\n", hdr.opcode);
			ret = -1;
			goto out;
		}
	}

iofail:
	fprintf(stderr, "error: socket io\n");
	ret = -1;

out:
	close(fd_in);
	if (fd_out != fd_in)
		close(fd_out);
	return ret;
}

// vim: noexpandtab