/*-
 * Copyright (c) 2010-2011 Varnish Software AS
 * All rights reserved.
 *
 * Author: Poul-Henning Kamp <phk@phk.freebsd.dk>
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 AUTHOR OR CONTRIBUTORS 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.
 */

#include "config.h"

#include <sys/types.h>
#include <sys/uio.h>

#include <errno.h>
#include <poll.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "vdef.h"

#include "vas.h"	// XXX Flexelint "not used" - but req'ed for assert()
#include "vcli.h"
#include "vsha256.h"

void
VCLI_AuthResponse(int S_fd, const char *challenge,
    char response[CLI_AUTH_RESPONSE_LEN + 1])
{
	VSHA256_CTX ctx;
	uint8_t buf[VSHA256_LEN];
	int i;

	assert(CLI_AUTH_RESPONSE_LEN == (VSHA256_LEN * 2));

	VSHA256_Init(&ctx);
	VSHA256_Update(&ctx, challenge, 32);
	VSHA256_Update(&ctx, "\n", 1);
	do {
		i = read(S_fd, buf, 1);
		if (i == 1)
			VSHA256_Update(&ctx, buf, i);
	} while (i > 0);
	VSHA256_Update(&ctx, challenge, 32);
	VSHA256_Update(&ctx, "\n", 1);
	VSHA256_Final(buf, &ctx);
	for (i = 0; i < VSHA256_LEN; i++)
		assert(snprintf(response + 2 * i, 3, "%02x", buf[i]) == 2);
}

int
VCLI_WriteResult(int fd, unsigned status, const char *result)
{
	int i, l;
	struct iovec iov[3];
	char nl[2] = "\n";
	size_t len;
	char res[CLI_LINE0_LEN + 2];	/*
					 * NUL + one more so we can catch
					 * any misformats by snprintf
					 */

	assert(status >= 100);
	assert(status <= 999);		/*lint !e650 const out of range */

	len = strlen(result);

	i = snprintf(res, sizeof res,
	    "%-3d %-8zd\n", status, len);
	assert(i == CLI_LINE0_LEN);
	assert(strtoul(res + 3, NULL, 10) == len);

	iov[0].iov_base = res;
	iov[0].iov_len = CLI_LINE0_LEN;

	iov[1].iov_base = (void*)(uintptr_t)result;	/* TRUST ME */
	iov[1].iov_len = len;

	iov[2].iov_base = nl;
	iov[2].iov_len = 1;

	for (l = i = 0; i < 3; i++)
		l += iov[i].iov_len;
	i = writev(fd, iov, 3);
	return (i != l);
}

static int
read_tmo(int fd, char *ptr, unsigned len, double tmo)
{
	int i, j, to;
	struct pollfd pfd;

	if (tmo > 0)
		to = (int)(tmo * 1e3);
	else
		to = -1;
	pfd.fd = fd;
	pfd.events = POLLIN;
	for (j = 0; len > 0; ) {
		i = poll(&pfd, 1, to);
		if (i < 0) {
			errno = EINTR;
			return (-1);
		}
		if (i == 0) {
			errno = ETIMEDOUT;
			return (-1);
		}
		i = read(fd, ptr, len);
		if (i < 0)
			return (i);
		if (i == 0)
			break;
		len -= i;
		ptr += i;
		j += i;
	}
	return (j);
}

int
VCLI_ReadResult(int fd, unsigned *status, char **ptr, double tmo)
{
	char res[CLI_LINE0_LEN];	/* For NUL */
	int i, j;
	unsigned u, v, s;
	char *p = NULL;
	const char *err = "CLI communication error (hdr)";

	if (status == NULL)
		status = &s;
	if (ptr != NULL)
		*ptr = NULL;
	do {
		i = read_tmo(fd, res, CLI_LINE0_LEN, tmo);
		if (i != CLI_LINE0_LEN)
			break;

		if (res[3] != ' ')
			break;

		if (res[CLI_LINE0_LEN - 1] != '\n')
			break;

		res[CLI_LINE0_LEN - 1] = '\0';
		j = sscanf(res, "%u %u\n", &u, &v);
		if (j != 2)
			break;

		err = "CLI communication error (body)";

		*status = u;
		p = malloc(v + 1L);
		if (p == NULL)
			break;

		i = read_tmo(fd, p, v + 1, tmo);
		if (i < 0)
			break;
		if (i != v + 1)
			break;
		if (p[v] != '\n')
			break;

		p[v] = '\0';
		if (ptr == NULL)
			free(p);
		else
			*ptr = p;
		return (0);
	} while (0);

	free(p);
	*status = CLIS_COMMS;
	if (ptr != NULL)
		*ptr = strdup(err);
	return (*status);
}
