/*

 * Copyright (C) 2008  Kristian Høgsberg <krh@redhat.com>

 * Copyright (C) 2008  Red Hat, Inc

 * Copyright (C) 2009  J. Ali Harlow <ali@juiblex.co.uk>

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License along

 * with this program; if not, write to the Free Software Foundation, Inc.,

 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 */

#include "config.h"

#include <limits.h>

#include <string.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <stdlib.h>

#include <stdio.h>

#include <stdint.h>

#include <errno.h>

#include <unistd.h>

#include <fcntl.h>

#ifdef MSWIN_API

#include <windows.h>

#include <direct.h>

#endif

#if HAVE_SYS_MMAN_H

#include <sys/mman.h>

#endif

#include <assert.h>

#include "razor.h"

#include "razor-internal.h"

#ifndef O_BINARY

#define O_BINARY	0

#endif

#define RAZOR_ASCII_ISALPHA(c)	\

			((c) >= 'A' && (c) <= 'Z' || (c) >= 'a' && (c) <= 'z')

/* Required by gnulib on non-libc platforms */

char *program_name = "librazor";

static int allow_all_root_names = 0;

/*

 * Primarily intended for testing named roots under UNIX platforms.

 */

RAZOR_EXPORT void razor_disable_root_name_checks(int disable)

{

	allow_all_root_names = disable;

}

static int razor_valid_root_name(const char *name)

{

	if (allow_all_root_names)

		return !strchr(name,'/');

#ifdef MSWIN_API

	return RAZOR_ASCII_ISALPHA(name[0]) && name[1] == ':' &&

	       name[2] == '\0';

#else

	return name[0] == '\0';

#endif

}

int

razor_create_dir(const char *root, const char *path)

{

	char buffer[PATH_MAX], *p;

	const char *slash, *next;

	struct stat buf;

	/* Create all sub-directories in dir. We know root exists and

	 * is a dir, root does not end in a '/', and path either has a

	 * leading '/' or (on MS-Windows only) root is the empty string

	 * and path starts with drive (eg., "c:/windows"). */

	strcpy(buffer, root);

	p = buffer + strlen(buffer);

	slash = path;

	for (slash = path; *slash != '\0'; slash = next) {

		next = strchr(slash + 1, '/');

		if (next == NULL)

			break;

		memcpy(p, slash, next - slash);

		p += next - slash;

		*p = '\0';

		if (razor_valid_root_name(buffer))

			continue;

		if (stat(buffer, &buf) == 0) {

			if (!S_ISDIR(buf.st_mode)) {

				fprintf(stderr,

					"%s exists but is not a directory\n",

					buffer);

				return -1;

			}

		} else if (mkdir(buffer, 0777) < 0) {

			fprintf(stderr, "failed to make directory %s: %s\n",

				buffer, strerror(errno));

			return -1;

		}

		/* FIXME: What to do about permissions for dirs we

		 * have to create but are not in the cpio archive? */

	}

	return 0;

}

int

razor_remove(const char *path)

{

#ifdef MSWIN_API

	DWORD err;

	if (DeleteFile(path))

		return 0;

	err = GetLastError();

	if (err == ERROR_FILE_NOT_FOUND || err == ERROR_PATH_NOT_FOUND)

		return 0;

	if (SetFileAttributes(path, FILE_ATTRIBUTE_NORMAL) && DeleteFile(path))

		return 0;

	if (RemoveDirectory(path) || GetLastError() == ERROR_DIR_NOT_EMPTY)

		return 0;

	/*

	 * It would be tempting to use:

	 * 	MoveFileEx(path, NULL, MOVEFILE_DELAY_UNTIL_REBOOT)

	 * but unless we can guarantee that the system will be rebooted

	 * before we (or some other application) write another file with the

	 * same path, this is likely to cause more problems than it solves.

	 */

	/* Use remove() as a fallback so that errno is set appropriately */

#endif

	return remove(path);

}

int

razor_write(int fd, const void *data, size_t size)

{

	size_t rest;

	ssize_t written;

	const unsigned char *p;

	rest = size;

	p = data;

	while (rest > 0) {

		written = write(fd, p, rest);

		if (written < 0) {

			perror("write error");

			return -1;

		}

		rest -= written;

		p += written;

	}

	return 0;

}

void *

razor_file_get_contents(const char *filename, size_t *length)

{

	int fd;

	struct stat st;

	void *addr;

#if !HAVE_SYS_MMAN_H

	size_t nb;

	ssize_t res;

#endif

	fd = open(filename, O_RDONLY | O_BINARY);

	if (fd < 0)

		return NULL;

	if (fstat(fd, &st) < 0) {

		close(fd);

		return NULL;

	}

	*length = st.st_size;

#if HAVE_SYS_MMAN_H

	addr = mmap(NULL, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);

#else

	addr = malloc(st.st_size);

	if (addr) {

		nb = 0;

		while(nb < st.st_size) {

			res = read(fd, addr + nb, st.st_size - nb);

			if (res <= 0) {

				free(addr);

				addr = NULL;

				break;

			}

			nb += res;

		}

	}

#endif

	close(fd);

#if HAVE_SYS_MMAN_H

	if (addr == MAP_FAILED)

		addr = NULL;

#endif

	return addr;

}

int

razor_file_free_contents(void *addr, size_t length)

{

#if HAVE_SYS_MMAN_H

	return munmap(addr, length);

#else

	free(addr);

	return 0;

#endif

}

struct qsort_context {

	size_t size;

	razor_compare_with_data_func_t compare;

	void *data;

};

static void

qsort_swap(void *p1, void *p2, size_t size)

{

	char buffer[size];

	memcpy(buffer, p1, size);

	memcpy(p1, p2, size);

	memcpy(p2, buffer, size);

}

static void

__qsort_with_data(void *base, size_t nelem, uint32_t *map,

		  struct qsort_context *ctx)

{

	void *p, *start, *end, *pivot;

	uint32_t *mp, *mstart, *mend, tmp;

	int left, right, result;

	size_t size = ctx->size;

	p = base;

	start = base;

	end = base + nelem * size;

	mp = map;

	mstart = map;

	mend = map + nelem;

	pivot = base + (rand() % nelem) * size;

	while (p < end) {

		result = ctx->compare(p, pivot, ctx->data);

		if (result < 0) {

			qsort_swap(p, start, size);

			tmp = *mp;

			*mp = *mstart;

			*mstart = tmp;

			if (start == pivot)

				pivot = p;

			start += size;

			mstart++;

			p += size;

			mp++;

		} else if (result == 0) {

			p += size;

			mp++;

		} else {

 			end -= size;

			mend--;

			qsort_swap(p, end, size);

			tmp = *mp;

			*mp = *mend;

			*mend = tmp;

			if (end == pivot)

				pivot = p;

		}

	}

	left = (start - base) / size;

	right = (base + nelem * size - end) / size;

	if (left > 1)

		__qsort_with_data(base, left, map, ctx);

	if (right > 1)

		__qsort_with_data(end, right, mend, ctx);

}

uint32_t *

razor_qsort_with_data(void *base, size_t nelem, size_t size,

		      razor_compare_with_data_func_t compare, void *data)

{

	struct qsort_context ctx;

	uint32_t *map;

	int i;

	if (nelem == 0)

		return NULL;

	ctx.size = size;

	ctx.compare = compare;

	ctx.data = data;

	map = malloc(nelem * sizeof (uint32_t));

	for (i = 0; i < nelem; i++)

		map[i] = i;

	__qsort_with_data(base, nelem, map, &ctx);

	return map;

}

void environment_init(struct environment *env)

{

	env->is_set = 0;

	array_init(&env->string_pool);

	array_init(&env->vars);

}

void environment_add_variable(struct environment *env,

			      const char *variable, const char *value)

{

	char *s;

	uint32_t *r;

	assert(!env->is_set);

	s = array_add(&env->string_pool,

		      strlen(variable) + strlen(value) + 2);

	sprintf(s, "%s=%s", variable, value);

	r = array_add(&env->vars, sizeof *r);

	*r = s - (char *)env->string_pool.data;

}

void environment_set(struct environment *env)

{

	int i, count;

	char *s;

        uint32_t *r;

	if (!env->is_set) {

		count = env->vars.size / sizeof(uint32_t);

		r = (uint32_t *)env->vars.data;

		for (i = 0; i < count; i++) {

			s = env->string_pool.data + *r++;

			putenv(s);

		}

		env->is_set = 1;

	}

}

void environment_unset(struct environment *env)

{

	int i, count;

	char c, *s, *t;

        uint32_t *r;

	if (env->is_set) {

		count = env->vars.size / sizeof(uint32_t);

		r = (uint32_t *)env->vars.data;

		for (i = 0; i < count; i++) {

			s = env->string_pool.data + *r++;

			t = strchr(s, '=') + 1;

			c = *t;

			*t = '\0';

			putenv(s);

			*t = c;

		}

		env->is_set = 0;

	}

}

void environment_release(struct environment *env)

{

	environment_unset(env);

	array_release(&env->string_pool);

	array_release(&env->vars);

}