/*
 * Copyright (C) 2012 STRATO.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * 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., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <errno.h>
#include <time.h>
#include <getopt.h>

int print_binary = 0;
int print_multiline = 0;

/*
 * stream definitions taken from send.h, (C) Alexander Block
 */
#define BTRFS_SEND_STREAM_MAGIC "btrfs-stream"
#define BTRFS_SEND_STREAM_VERSION 1
#define BTRFS_SEND_BUF_SIZE (1024 * 64)

struct btrfs_stream_header {
	char magic[sizeof(BTRFS_SEND_STREAM_MAGIC)];
	uint32_t version;
} __attribute__ ((__packed__));

struct btrfs_cmd_header {
	/* len excluding the header */
	uint32_t len;
	uint16_t cmd;
	/* crc including the header with zero crc field */
	uint32_t crc;
} __attribute__ ((__packed__));

struct btrfs_tlv_header {
	uint16_t tlv_type;
	/* len excluding the header */
	uint16_t tlv_len;
} __attribute__ ((__packed__));

char *cmd_names[] = {
	"UNSPEC",
	"SUBVOL",
	"SNAPSHOT",
	"MKFILE",
	"MKDIR",
	"MKNOD",
	"MKFIFO",
	"MKSOCK",
	"SYMLINK",
	"RENAME",
	"LINK",
	"UNLINK",
	"RMDIR",
	"SET_XATTR",
	"REMOVE_XATTR",
	"WRITE",
	"CLONE",
	"TRUNCATE",
	"CHMOD",
	"CHOWN",
	"UTIMES",
	"END"
};
#define MAX_CMDS (sizeof(cmd_names) / sizeof(char *))

#define TYPE_UNDEF	0
#define TYPE_INT	1
#define TYPE_STRING	2
#define TYPE_BINARY	3
#define TYPE_TIME	4
#define TYPE_HEX	5
#define TYPE_OCTAL	6
#define TYPE_LEN_ONLY	7

struct attr_types {
	const char	*name;
	int		type;
} attrs[] = {
	{ "UNSPEC", TYPE_UNDEF },
	{ "UUID", TYPE_BINARY },
	{ "CTRANSID", TYPE_INT },
	{ "INO", TYPE_INT },
	{ "SIZE", TYPE_INT },
	{ "MODE", TYPE_OCTAL },
	{ "UID", TYPE_INT },
	{ "GID", TYPE_INT },
	{ "RDEV", TYPE_HEX },
	{ "CTIME", TYPE_TIME },
	{ "MTIME", TYPE_TIME },
	{ "ATIME", TYPE_TIME },
	{ "OTIME", TYPE_TIME },
	{ "XATTR_NAME", TYPE_STRING },
	{ "XATTR_DATA", TYPE_BINARY },
	{ "PATH", TYPE_STRING },
	{ "PATH_TO", TYPE_STRING },
	{ "PATH_LINK", TYPE_STRING },
	{ "FILE_OFFSET", TYPE_INT },
	{ "DATA", TYPE_LEN_ONLY },
	{ "CLONE_UUID", TYPE_BINARY },
	{ "CLONE_CTRANSID", TYPE_INT },
	{ "CLONE_PATH", TYPE_STRING },
	{ "CLONE_OFFSET", TYPE_INT },
	{ "CLONE_LEN", TYPE_INT }
};
#define MAX_ATTRS (sizeof(attrs) / sizeof(struct attr_types))

static int dump_file(FILE *in);

uint16_t
read16(const void *d)
{
	const uint8_t *data = d;

	return data[0] + (1 << 8) * (uint16_t)data[1];
}

uint32_t
read32(const void *d)
{
	const uint8_t *data = d;

	return read16(data) + (1 << 16) * (uint32_t)read16(data + 2);
}

uint64_t
read64(const void *d)
{
	const uint8_t *data = d;

	return read32(data) + (1ull << 32) * (uint64_t)read32(data + 4);
}

/* 
 * Extracted from the linux kernel source code, lib/libcrc32c.c.
 * 
 */
static const uint32_t crc32c_table[256] = {
	0x00000000L, 0xF26B8303L, 0xE13B70F7L, 0x1350F3F4L,
	0xC79A971FL, 0x35F1141CL, 0x26A1E7E8L, 0xD4CA64EBL,
	0x8AD958CFL, 0x78B2DBCCL, 0x6BE22838L, 0x9989AB3BL,
	0x4D43CFD0L, 0xBF284CD3L, 0xAC78BF27L, 0x5E133C24L,
	0x105EC76FL, 0xE235446CL, 0xF165B798L, 0x030E349BL,
	0xD7C45070L, 0x25AFD373L, 0x36FF2087L, 0xC494A384L,
	0x9A879FA0L, 0x68EC1CA3L, 0x7BBCEF57L, 0x89D76C54L,
	0x5D1D08BFL, 0xAF768BBCL, 0xBC267848L, 0x4E4DFB4BL,
	0x20BD8EDEL, 0xD2D60DDDL, 0xC186FE29L, 0x33ED7D2AL,
	0xE72719C1L, 0x154C9AC2L, 0x061C6936L, 0xF477EA35L,
	0xAA64D611L, 0x580F5512L, 0x4B5FA6E6L, 0xB93425E5L,
	0x6DFE410EL, 0x9F95C20DL, 0x8CC531F9L, 0x7EAEB2FAL,
	0x30E349B1L, 0xC288CAB2L, 0xD1D83946L, 0x23B3BA45L,
	0xF779DEAEL, 0x05125DADL, 0x1642AE59L, 0xE4292D5AL,
	0xBA3A117EL, 0x4851927DL, 0x5B016189L, 0xA96AE28AL,
	0x7DA08661L, 0x8FCB0562L, 0x9C9BF696L, 0x6EF07595L,
	0x417B1DBCL, 0xB3109EBFL, 0xA0406D4BL, 0x522BEE48L,
	0x86E18AA3L, 0x748A09A0L, 0x67DAFA54L, 0x95B17957L,
	0xCBA24573L, 0x39C9C670L, 0x2A993584L, 0xD8F2B687L,
	0x0C38D26CL, 0xFE53516FL, 0xED03A29BL, 0x1F682198L,
	0x5125DAD3L, 0xA34E59D0L, 0xB01EAA24L, 0x42752927L,
	0x96BF4DCCL, 0x64D4CECFL, 0x77843D3BL, 0x85EFBE38L,
	0xDBFC821CL, 0x2997011FL, 0x3AC7F2EBL, 0xC8AC71E8L,
	0x1C661503L, 0xEE0D9600L, 0xFD5D65F4L, 0x0F36E6F7L,
	0x61C69362L, 0x93AD1061L, 0x80FDE395L, 0x72966096L,
	0xA65C047DL, 0x5437877EL, 0x4767748AL, 0xB50CF789L,
	0xEB1FCBADL, 0x197448AEL, 0x0A24BB5AL, 0xF84F3859L,
	0x2C855CB2L, 0xDEEEDFB1L, 0xCDBE2C45L, 0x3FD5AF46L,
	0x7198540DL, 0x83F3D70EL, 0x90A324FAL, 0x62C8A7F9L,
	0xB602C312L, 0x44694011L, 0x5739B3E5L, 0xA55230E6L,
	0xFB410CC2L, 0x092A8FC1L, 0x1A7A7C35L, 0xE811FF36L,
	0x3CDB9BDDL, 0xCEB018DEL, 0xDDE0EB2AL, 0x2F8B6829L,
	0x82F63B78L, 0x709DB87BL, 0x63CD4B8FL, 0x91A6C88CL,
	0x456CAC67L, 0xB7072F64L, 0xA457DC90L, 0x563C5F93L,
	0x082F63B7L, 0xFA44E0B4L, 0xE9141340L, 0x1B7F9043L,
	0xCFB5F4A8L, 0x3DDE77ABL, 0x2E8E845FL, 0xDCE5075CL,
	0x92A8FC17L, 0x60C37F14L, 0x73938CE0L, 0x81F80FE3L,
	0x55326B08L, 0xA759E80BL, 0xB4091BFFL, 0x466298FCL,
	0x1871A4D8L, 0xEA1A27DBL, 0xF94AD42FL, 0x0B21572CL,
	0xDFEB33C7L, 0x2D80B0C4L, 0x3ED04330L, 0xCCBBC033L,
	0xA24BB5A6L, 0x502036A5L, 0x4370C551L, 0xB11B4652L,
	0x65D122B9L, 0x97BAA1BAL, 0x84EA524EL, 0x7681D14DL,
	0x2892ED69L, 0xDAF96E6AL, 0xC9A99D9EL, 0x3BC21E9DL,
	0xEF087A76L, 0x1D63F975L, 0x0E330A81L, 0xFC588982L,
	0xB21572C9L, 0x407EF1CAL, 0x532E023EL, 0xA145813DL,
	0x758FE5D6L, 0x87E466D5L, 0x94B49521L, 0x66DF1622L,
	0x38CC2A06L, 0xCAA7A905L, 0xD9F75AF1L, 0x2B9CD9F2L,
	0xFF56BD19L, 0x0D3D3E1AL, 0x1E6DCDEEL, 0xEC064EEDL,
	0xC38D26C4L, 0x31E6A5C7L, 0x22B65633L, 0xD0DDD530L,
	0x0417B1DBL, 0xF67C32D8L, 0xE52CC12CL, 0x1747422FL,
	0x49547E0BL, 0xBB3FFD08L, 0xA86F0EFCL, 0x5A048DFFL,
	0x8ECEE914L, 0x7CA56A17L, 0x6FF599E3L, 0x9D9E1AE0L,
	0xD3D3E1ABL, 0x21B862A8L, 0x32E8915CL, 0xC083125FL,
	0x144976B4L, 0xE622F5B7L, 0xF5720643L, 0x07198540L,
	0x590AB964L, 0xAB613A67L, 0xB831C993L, 0x4A5A4A90L,
	0x9E902E7BL, 0x6CFBAD78L, 0x7FAB5E8CL, 0x8DC0DD8FL,
	0xE330A81AL, 0x115B2B19L, 0x020BD8EDL, 0xF0605BEEL,
	0x24AA3F05L, 0xD6C1BC06L, 0xC5914FF2L, 0x37FACCF1L,
	0x69E9F0D5L, 0x9B8273D6L, 0x88D28022L, 0x7AB90321L,
	0xAE7367CAL, 0x5C18E4C9L, 0x4F48173DL, 0xBD23943EL,
	0xF36E6F75L, 0x0105EC76L, 0x12551F82L, 0xE03E9C81L,
	0x34F4F86AL, 0xC69F7B69L, 0xD5CF889DL, 0x27A40B9EL,
	0x79B737BAL, 0x8BDCB4B9L, 0x988C474DL, 0x6AE7C44EL,
	0xBE2DA0A5L, 0x4C4623A6L, 0x5F16D052L, 0xAD7D5351L
};

uint32_t crc32c(uint32_t crc, unsigned char const *data, int size)
{
	while (size--)
		crc = crc32c_table[(crc ^ *data++) & 0xffl] ^ (crc >> 8);
	return crc;
}

int
print_attr(int type, char *buf, int len)
{
	switch (type) {
	case TYPE_UNDEF:
		break;
	case TYPE_INT:
	case TYPE_HEX:
	case TYPE_OCTAL:;
		uint64_t v;
		char *format = NULL;

		if (len != 8) {
			printf("invalid length for integer type attribute\n");
			return -1;
		}
		if (type == TYPE_INT)
			format = "%lld";
		else if (type == TYPE_HEX)
			format = "%llx";
		else if (type == TYPE_OCTAL)
			format = "%llo";
		v = read64(buf);
		printf(format, v);
		break;
	case TYPE_STRING:
		printf("%.*s", len, buf);
		break;
	case TYPE_BINARY:;
		int i;
		if (print_binary)
			for (i = 0; i < len; ++i)
				printf("%02x", (unsigned char)buf[i]);
		else
			printf("<blob len %d>", len);
		break;
	case TYPE_TIME:;
		uint64_t sec;
		uint32_t nsec;
		struct tm *t;
		time_t	tim;

		if (len != 12) {
			printf("invalid length for timespec attribute\n");
			return -1;
		}
		sec = read64(buf);
		nsec = read32(buf + 8);
		tim = sec; /* XXX lossy */
		t = localtime(&tim);
		printf("%04d-%02d-%02d %02d:%02d:%02d.%09d",
			t->tm_year + 1900, t->tm_mon + 1, t->tm_mday,
			t->tm_hour, t->tm_min, t->tm_sec, nsec);
		break;
	case TYPE_LEN_ONLY:
		printf("length %d", len);
		break;
	}

	return 0;
}

int
do_read(FILE *in, void *buf, int len, off_t *offset)
{
	int ret;

	if (len == 0)
		return 0;

	ret = fread(buf, 1, len, in);
	if (ret == 0)
		return 1;

	if (ret != len) {
		printf("read error (@offset %lu): %d=%s\n",
		       (unsigned long)*offset, errno, strerror(errno));
		return -1;
	}
	*offset += len;
	return 0;
}

void
usage(void)
{
	fprintf(stderr, "usage: fardump [-v] [-m] files...\n");
	fprintf(stderr, "          -v        : print uuids\n");
	fprintf(stderr, "          -m        : print multiline\n");
	exit(1);
}

int
main(int argc, char **argv)
{
	int	c;
	int	ret = 0;

	while ((c = getopt(argc, argv, "mv")) != EOF) {
		switch(c) {
		case 'v':
			print_binary = 1;
			break;
		case 'm':
			print_multiline = 1;
			break;
		case 'h':
		case '?':
			usage();
		}
	}

	if (argc < optind)
		usage();

	if (optind == argc)
		ret = dump_file(stdin);
	else while (optind < argc) {
		FILE *in;

		if (!strcmp(argv[optind], "-")) {
			ret = dump_file(stdin);
		} else {
			in = fopen(argv[optind], "rb");
			if (!in) {
				ret = -errno;
				fprintf(stderr,
					"open file %s for reading failed: %s\n",
					argv[optind], strerror(errno));
				break;
			}
			ret = dump_file(in);
			fclose(in);
		}
		if (ret)
			break;
		optind++;
	}

	exit(-ret);
}

static int
dump_file(FILE *in)
{
	int ret;
	unsigned char buf[BTRFS_SEND_BUF_SIZE];
	struct btrfs_stream_header h;
	struct btrfs_cmd_header cmd;
	unsigned char *p;
	extern char *optarg;
	extern int optind;
	off_t	cmd_offset;
	off_t	stream_offset = 0;

	cmd_offset = stream_offset;
	ret = do_read(in, &h, sizeof(h), &stream_offset);
	if (ret) {
		printf("failed to read header\n");
		goto out;
	}
	if (strncmp(h.magic, BTRFS_SEND_STREAM_MAGIC, sizeof(h.magic))) {
		printf("bad magic\n");
		goto out_ret_1;
	}
	if (read32(&h.version) != BTRFS_SEND_STREAM_VERSION) {
		printf("invalid version %d\n", read32(&h.version));
		goto out_ret_1;
	}
	printf("stream header, version %d\n", read32(&h.version));

	while (1) {
		uint32_t clen;
		uint32_t crc_is;
		uint32_t crc_should;
		uint32_t c;

		cmd_offset = stream_offset;
		ret = do_read(in, &cmd, sizeof(cmd), &stream_offset);
		if (ret == 1) {
			ret = 0;
			break;
		}
		if (ret) {
			printf("failed to read command header (cmd @offset %lu)\n",
			       (unsigned long)cmd_offset);	
			goto out;
		}
		clen = read32(&cmd.len);
		if (clen > sizeof(buf)) {
			printf("cmd too long for buf, clen=%d (cmd @offset %lu)\n",
			       clen, (unsigned long)cmd_offset);
			goto out_ret_1;
		}
		ret = do_read(in, buf, clen, &stream_offset);
		if (ret) {
			printf("failed to read command contents (cmd @offset %lu)\n",
			       (unsigned long)cmd_offset);
			goto out;
		}
		crc_is = read32(&cmd.crc);
		cmd.crc = 0;
		crc_should = crc32c(0, (unsigned char *)&cmd, sizeof(cmd));
		crc_should = crc32c(crc_should, buf, clen);
		if (crc_is != crc_should) {
			printf("crcs don't match, 0x%x != 0x%x (cmd @offset %lu)\n",
				crc_is, crc_should, (unsigned long)cmd_offset);
			goto out_ret_1;
		}
		c = read16(&cmd.cmd);
		if (c < 1 || c >= MAX_CMDS) {
			printf("cmd %d out of range (cmd @offset %lu)\n", c,
			       (unsigned long)cmd_offset);
			goto out_ret_1;
		}
		if (print_multiline)
			printf("%s\n", cmd_names[c]);
		else
			printf("%s: ", cmd_names[c]);
		p = buf;
		int first = 1;
		while (clen) {
			struct btrfs_tlv_header *tlv;
			uint16_t type;
			uint16_t len;

			tlv = (struct btrfs_tlv_header *)p;
			type = read16(&tlv->tlv_type);
			len = read16(&tlv->tlv_len);

			if (type < 1 || type >= MAX_ATTRS) {
				printf("attr %d out of range (cmd @offset %lu)\n",
				       type, (unsigned long)cmd_offset);
				goto out_ret_1;
			}
			if (!first && !print_multiline)
				printf(", ");
			first = 0;
		
			if (print_multiline)
				printf("    ");
			printf("%s ", attrs[type].name);
			ret = print_attr(attrs[type].type,
					 (void *)(tlv + 1), len);
			if (ret)
				goto out;
			if (print_multiline)
				printf("\n");

			p += sizeof(*tlv) + len;
			clen -= sizeof(*tlv) + len;
		}
		printf("\n");
	}

out:
	return ret;

out_ret_1:
	return -1;
}