[thirdparty/git.git] / archive-tar.c

/*
 * Copyright (c) 2005, 2006 Rene Scharfe
 */
#include "cache.h"
#include "config.h"
#include "tar.h"
#include "archive.h"
#include "object-store.h"
#include "streaming.h"
#include "run-command.h"

#define RECORDSIZE	(512)
#define BLOCKSIZE	(RECORDSIZE * 20)

static char block[BLOCKSIZE];
static unsigned long offset;

static int tar_umask = 002;

static int write_tar_filter_archive(const struct archiver *ar,
				    struct archiver_args *args);

/*
 * This is the max value that a ustar size header can specify, as it is fixed
 * at 11 octal digits. POSIX specifies that we switch to extended headers at
 * this size.
 *
 * Likewise for the mtime (which happens to use a buffer of the same size).
 */
#if ULONG_MAX == 0xFFFFFFFF
#define USTAR_MAX_SIZE ULONG_MAX
#else
#define USTAR_MAX_SIZE 077777777777UL
#endif
#if TIME_MAX == 0xFFFFFFFF
#define USTAR_MAX_MTIME TIME_MAX
#else
#define USTAR_MAX_MTIME 077777777777ULL
#endif

/* writes out the whole block, but only if it is full */
static void write_if_needed(void)
{
	if (offset == BLOCKSIZE) {
		write_or_die(1, block, BLOCKSIZE);
		offset = 0;
	}
}

/*
 * queues up writes, so that all our write(2) calls write exactly one
 * full block; pads writes to RECORDSIZE
 */
static void do_write_blocked(const void *data, unsigned long size)
{
	const char *buf = data;

	if (offset) {
		unsigned long chunk = BLOCKSIZE - offset;
		if (size < chunk)
			chunk = size;
		memcpy(block + offset, buf, chunk);
		size -= chunk;
		offset += chunk;
		buf += chunk;
		write_if_needed();
	}
	while (size >= BLOCKSIZE) {
		write_or_die(1, buf, BLOCKSIZE);
		size -= BLOCKSIZE;
		buf += BLOCKSIZE;
	}
	if (size) {
		memcpy(block + offset, buf, size);
		offset += size;
	}
}

static void finish_record(void)
{
	unsigned long tail;
	tail = offset % RECORDSIZE;
	if (tail)  {
		memset(block + offset, 0, RECORDSIZE - tail);
		offset += RECORDSIZE - tail;
	}
	write_if_needed();
}

static void write_blocked(const void *data, unsigned long size)
{
	do_write_blocked(data, size);
	finish_record();
}

/*
 * The end of tar archives is marked by 2*512 nul bytes and after that
 * follows the rest of the block (if any).
 */
static void write_trailer(void)
{
	int tail = BLOCKSIZE - offset;
	memset(block + offset, 0, tail);
	write_or_die(1, block, BLOCKSIZE);
	if (tail < 2 * RECORDSIZE) {
		memset(block, 0, offset);
		write_or_die(1, block, BLOCKSIZE);
	}
}

/*
 * queues up writes, so that all our write(2) calls write exactly one
 * full block; pads writes to RECORDSIZE
 */
static int stream_blocked(const struct object_id *oid)
{
	struct git_istream *st;
	enum object_type type;
	unsigned long sz;
	char buf[BLOCKSIZE];
	ssize_t readlen;

	st = open_istream(oid, &type, &sz, NULL);
	if (!st)
		return error(_("cannot stream blob %s"), oid_to_hex(oid));
	for (;;) {
		readlen = read_istream(st, buf, sizeof(buf));
		if (readlen <= 0)
			break;
		do_write_blocked(buf, readlen);
	}
	close_istream(st);
	if (!readlen)
		finish_record();
	return readlen;
}

/*
 * pax extended header records have the format "%u %s=%s\n".  %u contains
 * the size of the whole string (including the %u), the first %s is the
 * keyword, the second one is the value.  This function constructs such a
 * string and appends it to a struct strbuf.
 */
static void strbuf_append_ext_header(struct strbuf *sb, const char *keyword,
				     const char *value, size_t valuelen)
{
	size_t orig_len = sb->len;
	size_t len, tmp;

	/* "%u %s=%s\n" */
	len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
	for (tmp = 1; len / 10 >= tmp; tmp *= 10)
		len++;

	strbuf_grow(sb, len);
	strbuf_addf(sb, "%"PRIuMAX" %s=", (uintmax_t)len, keyword);
	strbuf_add(sb, value, valuelen);
	strbuf_addch(sb, '\n');

	if (len != sb->len - orig_len)
		warning("pax extended header length miscalculated as %"PRIuMAX
			", should be %"PRIuMAX,
			(uintmax_t)len, (uintmax_t)(sb->len - orig_len));
}

/*
 * Like strbuf_append_ext_header, but for numeric values.
 */
static void strbuf_append_ext_header_uint(struct strbuf *sb,
					  const char *keyword,
					  uintmax_t value)
{
	char buf[40]; /* big enough for 2^128 in decimal, plus NUL */
	int len;

	len = xsnprintf(buf, sizeof(buf), "%"PRIuMAX, value);
	strbuf_append_ext_header(sb, keyword, buf, len);
}

static unsigned int ustar_header_chksum(const struct ustar_header *header)
{
	const unsigned char *p = (const unsigned char *)header;
	unsigned int chksum = 0;
	while (p < (const unsigned char *)header->chksum)
		chksum += *p++;
	chksum += sizeof(header->chksum) * ' ';
	p += sizeof(header->chksum);
	while (p < (const unsigned char *)header + sizeof(struct ustar_header))
		chksum += *p++;
	return chksum;
}

static size_t get_path_prefix(const char *path, size_t pathlen, size_t maxlen)
{
	size_t i = pathlen;
	if (i > 1 && path[i - 1] == '/')
		i--;
	if (i > maxlen)
		i = maxlen;
	do {
		i--;
	} while (i > 0 && path[i] != '/');
	return i;
}

static void prepare_header(struct archiver_args *args,
			   struct ustar_header *header,
			   unsigned int mode, unsigned long size)
{
	xsnprintf(header->mode, sizeof(header->mode), "%07o", mode & 07777);
	xsnprintf(header->size, sizeof(header->size), "%011"PRIoMAX , S_ISREG(mode) ? (uintmax_t)size : (uintmax_t)0);
	xsnprintf(header->mtime, sizeof(header->mtime), "%011lo", (unsigned long) args->time);

	xsnprintf(header->uid, sizeof(header->uid), "%07o", 0);
	xsnprintf(header->gid, sizeof(header->gid), "%07o", 0);
	strlcpy(header->uname, "root", sizeof(header->uname));
	strlcpy(header->gname, "root", sizeof(header->gname));
	xsnprintf(header->devmajor, sizeof(header->devmajor), "%07o", 0);
	xsnprintf(header->devminor, sizeof(header->devminor), "%07o", 0);

	memcpy(header->magic, "ustar", 6);
	memcpy(header->version, "00", 2);

	xsnprintf(header->chksum, sizeof(header->chksum), "%07o", ustar_header_chksum(header));
}

static void write_extended_header(struct archiver_args *args,
				  const struct object_id *oid,
				  const void *buffer, unsigned long size)
{
	struct ustar_header header;
	unsigned int mode;
	memset(&header, 0, sizeof(header));
	*header.typeflag = TYPEFLAG_EXT_HEADER;
	mode = 0100666;
	xsnprintf(header.name, sizeof(header.name), "%s.paxheader", oid_to_hex(oid));
	prepare_header(args, &header, mode, size);
	write_blocked(&header, sizeof(header));
	write_blocked(buffer, size);
}

static int write_tar_entry(struct archiver_args *args,
			   const struct object_id *oid,
			   const char *path, size_t pathlen,
			   unsigned int mode)
{
	struct ustar_header header;
	struct strbuf ext_header = STRBUF_INIT;
	unsigned int old_mode = mode;
	unsigned long size, size_in_header;
	void *buffer;
	int err = 0;

	memset(&header, 0, sizeof(header));

	if (S_ISDIR(mode) || S_ISGITLINK(mode)) {
		*header.typeflag = TYPEFLAG_DIR;
		mode = (mode | 0777) & ~tar_umask;
	} else if (S_ISLNK(mode)) {
		*header.typeflag = TYPEFLAG_LNK;
		mode |= 0777;
	} else if (S_ISREG(mode)) {
		*header.typeflag = TYPEFLAG_REG;
		mode = (mode | ((mode & 0100) ? 0777 : 0666)) & ~tar_umask;
	} else {
		return error(_("unsupported file mode: 0%o (SHA1: %s)"),
			     mode, oid_to_hex(oid));
	}
	if (pathlen > sizeof(header.name)) {
		size_t plen = get_path_prefix(path, pathlen,
					      sizeof(header.prefix));
		size_t rest = pathlen - plen - 1;
		if (plen > 0 && rest <= sizeof(header.name)) {
			memcpy(header.prefix, path, plen);
			memcpy(header.name, path + plen + 1, rest);
		} else {
			xsnprintf(header.name, sizeof(header.name), "%s.data",
				  oid_to_hex(oid));
			strbuf_append_ext_header(&ext_header, "path",
						 path, pathlen);
		}
	} else
		memcpy(header.name, path, pathlen);

	if (S_ISREG(mode) && !args->convert &&
	    oid_object_info(args->repo, oid, &size) == OBJ_BLOB &&
	    size > big_file_threshold)
		buffer = NULL;
	else if (S_ISLNK(mode) || S_ISREG(mode)) {
		enum object_type type;
		buffer = object_file_to_archive(args, path, oid, old_mode, &type, &size);
		if (!buffer)
			return error(_("cannot read %s"), oid_to_hex(oid));
	} else {
		buffer = NULL;
		size = 0;
	}

	if (S_ISLNK(mode)) {
		if (size > sizeof(header.linkname)) {
			xsnprintf(header.linkname, sizeof(header.linkname),
				  "see %s.paxheader", oid_to_hex(oid));
			strbuf_append_ext_header(&ext_header, "linkpath",
			                         buffer, size);
		} else
			memcpy(header.linkname, buffer, size);
	}

	size_in_header = size;
	if (S_ISREG(mode) && size > USTAR_MAX_SIZE) {
		size_in_header = 0;
		strbuf_append_ext_header_uint(&ext_header, "size", size);
	}

	prepare_header(args, &header, mode, size_in_header);

	if (ext_header.len > 0) {
		write_extended_header(args, oid, ext_header.buf,
				      ext_header.len);
	}
	strbuf_release(&ext_header);
	write_blocked(&header, sizeof(header));
	if (S_ISREG(mode) && size > 0) {
		if (buffer)
			write_blocked(buffer, size);
		else
			err = stream_blocked(oid);
	}
	free(buffer);
	return err;
}

static void write_global_extended_header(struct archiver_args *args)
{
	const unsigned char *sha1 = args->commit_sha1;
	struct strbuf ext_header = STRBUF_INIT;
	struct ustar_header header;
	unsigned int mode;

	if (sha1)
		strbuf_append_ext_header(&ext_header, "comment",
					 sha1_to_hex(sha1), 40);
	if (args->time > USTAR_MAX_MTIME) {
		strbuf_append_ext_header_uint(&ext_header, "mtime",
					      args->time);
		args->time = USTAR_MAX_MTIME;
	}

	if (!ext_header.len)
		return;

	memset(&header, 0, sizeof(header));
	*header.typeflag = TYPEFLAG_GLOBAL_HEADER;
	mode = 0100666;
	xsnprintf(header.name, sizeof(header.name), "pax_global_header");
	prepare_header(args, &header, mode, ext_header.len);
	write_blocked(&header, sizeof(header));
	write_blocked(ext_header.buf, ext_header.len);
	strbuf_release(&ext_header);
}

static struct archiver **tar_filters;
static int nr_tar_filters;
static int alloc_tar_filters;

static struct archiver *find_tar_filter(const char *name, int len)
{
	int i;
	for (i = 0; i < nr_tar_filters; i++) {
		struct archiver *ar = tar_filters[i];
		if (!strncmp(ar->name, name, len) && !ar->name[len])
			return ar;
	}
	return NULL;
}

static int tar_filter_config(const char *var, const char *value, void *data)
{
	struct archiver *ar;
	const char *name;
	const char *type;
	int namelen;

	if (parse_config_key(var, "tar", &name, &namelen, &type) < 0 || !name)
		return 0;

	ar = find_tar_filter(name, namelen);
	if (!ar) {
		ar = xcalloc(1, sizeof(*ar));
		ar->name = xmemdupz(name, namelen);
		ar->write_archive = write_tar_filter_archive;
		ar->flags = ARCHIVER_WANT_COMPRESSION_LEVELS;
		ALLOC_GROW(tar_filters, nr_tar_filters + 1, alloc_tar_filters);
		tar_filters[nr_tar_filters++] = ar;
	}

	if (!strcmp(type, "command")) {
		if (!value)
			return config_error_nonbool(var);
		free(ar->data);
		ar->data = xstrdup(value);
		return 0;
	}
	if (!strcmp(type, "remote")) {
		if (git_config_bool(var, value))
			ar->flags |= ARCHIVER_REMOTE;
		else
			ar->flags &= ~ARCHIVER_REMOTE;
		return 0;
	}

	return 0;
}

static int git_tar_config(const char *var, const char *value, void *cb)
{
	if (!strcmp(var, "tar.umask")) {
		if (value && !strcmp(value, "user")) {
			tar_umask = umask(0);
			umask(tar_umask);
		} else {
			tar_umask = git_config_int(var, value);
		}
		return 0;
	}

	return tar_filter_config(var, value, cb);
}

static int write_tar_archive(const struct archiver *ar,
			     struct archiver_args *args)
{
	int err = 0;

	write_global_extended_header(args);
	err = write_archive_entries(args, write_tar_entry);
	if (!err)
		write_trailer();
	return err;
}

static int write_tar_filter_archive(const struct archiver *ar,
				    struct archiver_args *args)
{
	struct strbuf cmd = STRBUF_INIT;
	struct child_process filter = CHILD_PROCESS_INIT;
	const char *argv[2];
	int r;

	if (!ar->data)
		BUG("tar-filter archiver called with no filter defined");

	strbuf_addstr(&cmd, ar->data);
	if (args->compression_level >= 0)
		strbuf_addf(&cmd, " -%d", args->compression_level);

	argv[0] = cmd.buf;
	argv[1] = NULL;
	filter.argv = argv;
	filter.use_shell = 1;
	filter.in = -1;

	if (start_command(&filter) < 0)
		die_errno(_("unable to start '%s' filter"), argv[0]);
	close(1);
	if (dup2(filter.in, 1) < 0)
		die_errno(_("unable to redirect descriptor"));
	close(filter.in);

	r = write_tar_archive(ar, args);

	close(1);
	if (finish_command(&filter) != 0)
		die(_("'%s' filter reported error"), argv[0]);

	strbuf_release(&cmd);
	return r;
}

static struct archiver tar_archiver = {
	"tar",
	write_tar_archive,
	ARCHIVER_REMOTE
};

void init_tar_archiver(void)
{
	int i;
	register_archiver(&tar_archiver);

	tar_filter_config("tar.tgz.command", "gzip -cn", NULL);
	tar_filter_config("tar.tgz.remote", "true", NULL);
	tar_filter_config("tar.tar.gz.command", "gzip -cn", NULL);
	tar_filter_config("tar.tar.gz.remote", "true", NULL);
	git_config(git_tar_config, NULL);
	for (i = 0; i < nr_tar_filters; i++) {
		/* omit any filters that never had a command configured */
		if (tar_filters[i]->data)
			register_archiver(tar_filters[i]);
	}
}
Commit	Line	Data
3d74982f RS	1	/*
	2	* Copyright (c) 2005, 2006 Rene Scharfe
	3	*/
3d74982f	4	#include "cache.h"
b2141fc1	5	#include "config.h"
3d74982f	6	#include "tar.h"
3d74982f	7	#include "archive.h"
cbd53a21	8	#include "object-store.h"
5544049d	9	#include "streaming.h"
767cf457	10	#include "run-command.h"
3d74982f RS	11
	12	#define RECORDSIZE (512)
	13	#define BLOCKSIZE (RECORDSIZE * 20)
	14
	15	static char block[BLOCKSIZE];
	16	static unsigned long offset;
	17
f08b3b0e	18	static int tar_umask = 002;
3d74982f	19
767cf457 JK	20	static int write_tar_filter_archive(const struct archiver *ar,
	21	struct archiver_args *args);
	22
d1657b57 JK	23	/*
	24	* This is the max value that a ustar size header can specify, as it is fixed
	25	* at 11 octal digits. POSIX specifies that we switch to extended headers at
	26	* this size.
6e8e0991 JK	27	*
6e8e0991 JK	28	* Likewise for the mtime (which happens to use a buffer of the same size).
d1657b57	29	*/
29493589 JH	30	#if ULONG_MAX == 0xFFFFFFFF
29493589 JH	31	#define USTAR_MAX_SIZE ULONG_MAX
29493589	32	#else
3f789719	33	#define USTAR_MAX_SIZE 077777777777UL
dddbad72 JS	34	#endif
	35	#if TIME_MAX == 0xFFFFFFFF
	36	#define USTAR_MAX_MTIME TIME_MAX
	37	#else
3f789719	38	#define USTAR_MAX_MTIME 077777777777ULL
29493589	39	#endif
d1657b57	40
3d74982f RS	41	/* writes out the whole block, but only if it is full */
	42	static void write_if_needed(void)
	43	{
	44	if (offset == BLOCKSIZE) {
	45	write_or_die(1, block, BLOCKSIZE);
	46	offset = 0;
	47	}
	48	}
	49
	50	/*
	51	* queues up writes, so that all our write(2) calls write exactly one
	52	* full block; pads writes to RECORDSIZE
	53	*/
5544049d	54	static void do_write_blocked(const void *data, unsigned long size)
3d74982f RS	55	{
3d74982f RS	56	const char *buf = data;
3d74982f RS	57
	58	if (offset) {
	59	unsigned long chunk = BLOCKSIZE - offset;
	60	if (size < chunk)
	61	chunk = size;
	62	memcpy(block + offset, buf, chunk);
	63	size -= chunk;
	64	offset += chunk;
	65	buf += chunk;
	66	write_if_needed();
	67	}
	68	while (size >= BLOCKSIZE) {
	69	write_or_die(1, buf, BLOCKSIZE);
	70	size -= BLOCKSIZE;
	71	buf += BLOCKSIZE;
	72	}
	73	if (size) {
	74	memcpy(block + offset, buf, size);
	75	offset += size;
	76	}
5544049d NTND	77	}
	78
	79	static void finish_record(void)
	80	{
	81	unsigned long tail;
3d74982f RS	82	tail = offset % RECORDSIZE;
	83	if (tail) {
	84	memset(block + offset, 0, RECORDSIZE - tail);
	85	offset += RECORDSIZE - tail;
	86	}
	87	write_if_needed();
	88	}
	89
5544049d NTND	90	static void write_blocked(const void *data, unsigned long size)
	91	{
	92	do_write_blocked(data, size);
	93	finish_record();
	94	}
	95
3d74982f RS	96	/*
	97	* The end of tar archives is marked by 2*512 nul bytes and after that
	98	* follows the rest of the block (if any).
	99	*/
	100	static void write_trailer(void)
	101	{
	102	int tail = BLOCKSIZE - offset;
	103	memset(block + offset, 0, tail);
	104	write_or_die(1, block, BLOCKSIZE);
	105	if (tail < 2 * RECORDSIZE) {
	106	memset(block, 0, offset);
	107	write_or_die(1, block, BLOCKSIZE);
	108	}
	109	}
	110
5544049d NTND	111	/*
	112	* queues up writes, so that all our write(2) calls write exactly one
	113	* full block; pads writes to RECORDSIZE
	114	*/
015ff4f8	115	static int stream_blocked(const struct object_id *oid)
5544049d NTND	116	{
	117	struct git_istream *st;
	118	enum object_type type;
	119	unsigned long sz;
	120	char buf[BLOCKSIZE];
	121	ssize_t readlen;
	122
ef7b5195	123	st = open_istream(oid, &type, &sz, NULL);
5544049d	124	if (!st)
d0482e69	125	return error(_("cannot stream blob %s"), oid_to_hex(oid));
5544049d NTND	126	for (;;) {
	127	readlen = read_istream(st, buf, sizeof(buf));
	128	if (readlen <= 0)
	129	break;
	130	do_write_blocked(buf, readlen);
	131	}
	132	close_istream(st);
	133	if (!readlen)
	134	finish_record();
	135	return readlen;
	136	}
	137
3d74982f RS	138	/*
	139	* pax extended header records have the format "%u %s=%s\n". %u contains
	140	* the size of the whole string (including the %u), the first %s is the
	141	* keyword, the second one is the value. This function constructs such a
	142	* string and appends it to a struct strbuf.
	143	*/
	144	static void strbuf_append_ext_header(struct strbuf sb, const char keyword,
17e9ef00	145	const char *value, size_t valuelen)
3d74982f	146	{
4060c199	147	size_t orig_len = sb->len;
17e9ef00	148	size_t len, tmp;
3d74982f RS	149
	150	/* "%u %s=%s\n" */
	151	len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
82a46af1	152	for (tmp = 1; len / 10 >= tmp; tmp *= 10)
3d74982f RS	153	len++;
3d74982f RS	154
7a604f16	155	strbuf_grow(sb, len);
17e9ef00	156	strbuf_addf(sb, "%"PRIuMAX" %s=", (uintmax_t)len, keyword);
7a604f16 PH	157	strbuf_add(sb, value, valuelen);
7a604f16 PH	158	strbuf_addch(sb, '\n');
4060c199 RS	159
4060c199 RS	160	if (len != sb->len - orig_len)
17e9ef00	161	warning("pax extended header length miscalculated as %"PRIuMAX
4060c199	162	", should be %"PRIuMAX,
17e9ef00	163	(uintmax_t)len, (uintmax_t)(sb->len - orig_len));
3d74982f RS	164	}
3d74982f RS	165
d1657b57 JK	166	/*
	167	* Like strbuf_append_ext_header, but for numeric values.
	168	*/
	169	static void strbuf_append_ext_header_uint(struct strbuf *sb,
	170	const char *keyword,
	171	uintmax_t value)
	172	{
	173	char buf[40]; /* big enough for 2^128 in decimal, plus NUL */
	174	int len;
	175
	176	len = xsnprintf(buf, sizeof(buf), "%"PRIuMAX, value);
	177	strbuf_append_ext_header(sb, keyword, buf, len);
	178	}
	179
3d74982f RS	180	static unsigned int ustar_header_chksum(const struct ustar_header *header)
3d74982f RS	181	{
a5a46eb9	182	const unsigned char p = (const unsigned char )header;
3d74982f	183	unsigned int chksum = 0;
a5a46eb9	184	while (p < (const unsigned char *)header->chksum)
3d74982f RS	185	chksum += *p++;
	186	chksum += sizeof(header->chksum) * ' ';
	187	p += sizeof(header->chksum);
a5a46eb9	188	while (p < (const unsigned char *)header + sizeof(struct ustar_header))
3d74982f RS	189	chksum += *p++;
	190	return chksum;
	191	}
	192
562e25ab	193	static size_t get_path_prefix(const char *path, size_t pathlen, size_t maxlen)
3d74982f	194	{
562e25ab	195	size_t i = pathlen;
22f0dcd9 RS	196	if (i > 1 && path[i - 1] == '/')
22f0dcd9 RS	197	i--;
3d74982f RS	198	if (i > maxlen)
	199	i = maxlen;
	200	do {
	201	i--;
562e25ab	202	} while (i > 0 && path[i] != '/');
3d74982f RS	203	return i;
	204	}
	205
d240d410 NTND	206	static void prepare_header(struct archiver_args *args,
	207	struct ustar_header *header,
	208	unsigned int mode, unsigned long size)
	209	{
f2f02675	210	xsnprintf(header->mode, sizeof(header->mode), "%07o", mode & 07777);
ca473cef	211	xsnprintf(header->size, sizeof(header->size), "%011"PRIoMAX , S_ISREG(mode) ? (uintmax_t)size : (uintmax_t)0);
f2f02675	212	xsnprintf(header->mtime, sizeof(header->mtime), "%011lo", (unsigned long) args->time);
d240d410	213
f2f02675 JK	214	xsnprintf(header->uid, sizeof(header->uid), "%07o", 0);
f2f02675 JK	215	xsnprintf(header->gid, sizeof(header->gid), "%07o", 0);
d240d410 NTND	216	strlcpy(header->uname, "root", sizeof(header->uname));
d240d410 NTND	217	strlcpy(header->gname, "root", sizeof(header->gname));
f2f02675 JK	218	xsnprintf(header->devmajor, sizeof(header->devmajor), "%07o", 0);
f2f02675 JK	219	xsnprintf(header->devminor, sizeof(header->devminor), "%07o", 0);
d240d410 NTND	220
	221	memcpy(header->magic, "ustar", 6);
	222	memcpy(header->version, "00", 2);
	223
9e6c1e91	224	xsnprintf(header->chksum, sizeof(header->chksum), "%07o", ustar_header_chksum(header));
d240d410 NTND	225	}
d240d410 NTND	226
560b0e8f	227	static void write_extended_header(struct archiver_args *args,
015ff4f8	228	const struct object_id *oid,
560b0e8f	229	const void *buffer, unsigned long size)
d240d410 NTND	230	{
	231	struct ustar_header header;
	232	unsigned int mode;
	233	memset(&header, 0, sizeof(header));
	234	*header.typeflag = TYPEFLAG_EXT_HEADER;
15c6ef7b	235	mode = 0100666;
015ff4f8	236	xsnprintf(header.name, sizeof(header.name), "%s.paxheader", oid_to_hex(oid));
d240d410 NTND	237	prepare_header(args, &header, mode, size);
	238	write_blocked(&header, sizeof(header));
	239	write_blocked(buffer, size);
d240d410 NTND	240	}
d240d410 NTND	241
562e25ab	242	static int write_tar_entry(struct archiver_args *args,
015ff4f8	243	const struct object_id *oid,
9cb513b7 NTND	244	const char *path, size_t pathlen,
9cb513b7 NTND	245	unsigned int mode)
3d74982f RS	246	{
3d74982f RS	247	struct ustar_header header;
f285a2d7	248	struct strbuf ext_header = STRBUF_INIT;
9cb513b7	249	unsigned int old_mode = mode;
d1657b57	250	unsigned long size, size_in_header;
9cb513b7	251	void *buffer;
562e25ab	252	int err = 0;
3d74982f RS	253
3d74982f RS	254	memset(&header, 0, sizeof(header));
3d74982f	255
85390709 NTND	256	if (S_ISDIR(mode) \|\| S_ISGITLINK(mode)) {
	257	*header.typeflag = TYPEFLAG_DIR;
	258	mode = (mode \| 0777) & ~tar_umask;
	259	} else if (S_ISLNK(mode)) {
	260	*header.typeflag = TYPEFLAG_LNK;
	261	mode \|= 0777;
	262	} else if (S_ISREG(mode)) {
	263	*header.typeflag = TYPEFLAG_REG;
	264	mode = (mode \| ((mode & 0100) ? 0777 : 0666)) & ~tar_umask;
3d74982f	265	} else {
d0482e69	266	return error(_("unsupported file mode: 0%o (SHA1: %s)"),
015ff4f8	267	mode, oid_to_hex(oid));
85390709 NTND	268	}
	269	if (pathlen > sizeof(header.name)) {
	270	size_t plen = get_path_prefix(path, pathlen,
	271	sizeof(header.prefix));
	272	size_t rest = pathlen - plen - 1;
	273	if (plen > 0 && rest <= sizeof(header.name)) {
	274	memcpy(header.prefix, path, plen);
108332c7	275	memcpy(header.name, path + plen + 1, rest);
3d74982f	276	} else {
f2f02675	277	xsnprintf(header.name, sizeof(header.name), "%s.data",
015ff4f8	278	oid_to_hex(oid));
85390709 NTND	279	strbuf_append_ext_header(&ext_header, "path",
85390709 NTND	280	path, pathlen);
3d74982f	281	}
85390709 NTND	282	} else
85390709 NTND	283	memcpy(header.name, path, pathlen);
3d74982f	284
5544049d	285	if (S_ISREG(mode) && !args->convert &&
b67b5512	286	oid_object_info(args->repo, oid, &size) == OBJ_BLOB &&
5544049d NTND	287	size > big_file_threshold)
	288	buffer = NULL;
	289	else if (S_ISLNK(mode) \|\| S_ISREG(mode)) {
9cb513b7	290	enum object_type type;
e5ec981a	291	buffer = object_file_to_archive(args, path, oid, old_mode, &type, &size);
9cb513b7	292	if (!buffer)
d0482e69	293	return error(_("cannot read %s"), oid_to_hex(oid));
9cb513b7 NTND	294	} else {
	295	buffer = NULL;
	296	size = 0;
	297	}
	298
	299	if (S_ISLNK(mode)) {
3d74982f	300	if (size > sizeof(header.linkname)) {
f2f02675	301	xsnprintf(header.linkname, sizeof(header.linkname),
015ff4f8	302	"see %s.paxheader", oid_to_hex(oid));
3d74982f RS	303	strbuf_append_ext_header(&ext_header, "linkpath",
	304	buffer, size);
	305	} else
	306	memcpy(header.linkname, buffer, size);
	307	}
	308
d1657b57 JK	309	size_in_header = size;
	310	if (S_ISREG(mode) && size > USTAR_MAX_SIZE) {
	311	size_in_header = 0;
	312	strbuf_append_ext_header_uint(&ext_header, "size", size);
	313	}
	314
	315	prepare_header(args, &header, mode, size_in_header);
3d74982f RS	316
3d74982f RS	317	if (ext_header.len > 0) {
015ff4f8	318	write_extended_header(args, oid, ext_header.buf,
560b0e8f	319	ext_header.len);
3d74982f	320	}
7a604f16	321	strbuf_release(&ext_header);
3d74982f	322	write_blocked(&header, sizeof(header));
5544049d NTND	323	if (S_ISREG(mode) && size > 0) {
	324	if (buffer)
	325	write_blocked(buffer, size);
	326	else
015ff4f8	327	err = stream_blocked(oid);
5544049d	328	}
9cb513b7	329	free(buffer);
562e25ab	330	return err;
3d74982f RS	331	}
3d74982f RS	332
5caeeb83	333	static void write_global_extended_header(struct archiver_args *args)
3d74982f	334	{
562e25ab	335	const unsigned char *sha1 = args->commit_sha1;
f285a2d7	336	struct strbuf ext_header = STRBUF_INIT;
d240d410 NTND	337	struct ustar_header header;
d240d410 NTND	338	unsigned int mode;
7a604f16	339
6e8e0991 JK	340	if (sha1)
	341	strbuf_append_ext_header(&ext_header, "comment",
	342	sha1_to_hex(sha1), 40);
	343	if (args->time > USTAR_MAX_MTIME) {
	344	strbuf_append_ext_header_uint(&ext_header, "mtime",
	345	args->time);
	346	args->time = USTAR_MAX_MTIME;
	347	}
	348
	349	if (!ext_header.len)
5caeeb83	350	return;
6e8e0991	351
d240d410 NTND	352	memset(&header, 0, sizeof(header));
d240d410 NTND	353	*header.typeflag = TYPEFLAG_GLOBAL_HEADER;
15c6ef7b	354	mode = 0100666;
5096d490	355	xsnprintf(header.name, sizeof(header.name), "pax_global_header");
d240d410 NTND	356	prepare_header(args, &header, mode, ext_header.len);
	357	write_blocked(&header, sizeof(header));
	358	write_blocked(ext_header.buf, ext_header.len);
7a604f16	359	strbuf_release(&ext_header);
3d74982f RS	360	}
3d74982f RS	361
767cf457 JK	362	static struct archiver **tar_filters;
	363	static int nr_tar_filters;
	364	static int alloc_tar_filters;
	365
	366	static struct archiver find_tar_filter(const char name, int len)
	367	{
	368	int i;
	369	for (i = 0; i < nr_tar_filters; i++) {
	370	struct archiver *ar = tar_filters[i];
	371	if (!strncmp(ar->name, name, len) && !ar->name[len])
	372	return ar;
	373	}
	374	return NULL;
	375	}
	376
	377	static int tar_filter_config(const char var, const char value, void *data)
	378	{
	379	struct archiver *ar;
767cf457 JK	380	const char *name;
	381	const char *type;
	382	int namelen;
	383
785a0429	384	if (parse_config_key(var, "tar", &name, &namelen, &type) < 0 \|\| !name)
767cf457	385	return 0;
767cf457 JK	386
	387	ar = find_tar_filter(name, namelen);
	388	if (!ar) {
	389	ar = xcalloc(1, sizeof(*ar));
	390	ar->name = xmemdupz(name, namelen);
	391	ar->write_archive = write_tar_filter_archive;
	392	ar->flags = ARCHIVER_WANT_COMPRESSION_LEVELS;
	393	ALLOC_GROW(tar_filters, nr_tar_filters + 1, alloc_tar_filters);
	394	tar_filters[nr_tar_filters++] = ar;
	395	}
	396
	397	if (!strcmp(type, "command")) {
	398	if (!value)
	399	return config_error_nonbool(var);
	400	free(ar->data);
	401	ar->data = xstrdup(value);
	402	return 0;
	403	}
7b97730b JK	404	if (!strcmp(type, "remote")) {
	405	if (git_config_bool(var, value))
	406	ar->flags \|= ARCHIVER_REMOTE;
	407	else
	408	ar->flags &= ~ARCHIVER_REMOTE;
	409	return 0;
	410	}
767cf457 JK	411
	412	return 0;
	413	}
	414
ef90d6d4	415	static int git_tar_config(const char var, const char value, void *cb)
3d74982f RS	416	{
3d74982f RS	417	if (!strcmp(var, "tar.umask")) {
cc1816b0	418	if (value && !strcmp(value, "user")) {
3d74982f RS	419	tar_umask = umask(0);
	420	umask(tar_umask);
	421	} else {
	422	tar_umask = git_config_int(var, value);
	423	}
	424	return 0;
	425	}
767cf457 JK	426
767cf457 JK	427	return tar_filter_config(var, value, cb);
3d74982f RS	428	}
3d74982f RS	429
4d7c9898 JK	430	static int write_tar_archive(const struct archiver *ar,
4d7c9898 JK	431	struct archiver_args *args)
3d74982f	432	{
562e25ab	433	int err = 0;
3d74982f	434
5caeeb83 JK	435	write_global_extended_header(args);
5caeeb83 JK	436	err = write_archive_entries(args, write_tar_entry);
562e25ab RS	437	if (!err)
	438	write_trailer();
	439	return err;
3d74982f	440	}
13e0f88d	441
767cf457 JK	442	static int write_tar_filter_archive(const struct archiver *ar,
	443	struct archiver_args *args)
	444	{
	445	struct strbuf cmd = STRBUF_INIT;
d3180279	446	struct child_process filter = CHILD_PROCESS_INIT;
767cf457 JK	447	const char *argv[2];
	448	int r;
	449
	450	if (!ar->data)
033abf97	451	BUG("tar-filter archiver called with no filter defined");
767cf457 JK	452
	453	strbuf_addstr(&cmd, ar->data);
	454	if (args->compression_level >= 0)
	455	strbuf_addf(&cmd, " -%d", args->compression_level);
	456
767cf457 JK	457	argv[0] = cmd.buf;
	458	argv[1] = NULL;
	459	filter.argv = argv;
	460	filter.use_shell = 1;
	461	filter.in = -1;
	462
	463	if (start_command(&filter) < 0)
d0482e69	464	die_errno(_("unable to start '%s' filter"), argv[0]);
767cf457 JK	465	close(1);
767cf457 JK	466	if (dup2(filter.in, 1) < 0)
d0482e69	467	die_errno(_("unable to redirect descriptor"));
767cf457 JK	468	close(filter.in);
	469
	470	r = write_tar_archive(ar, args);
	471
	472	close(1);
	473	if (finish_command(&filter) != 0)
d0482e69	474	die(_("'%s' filter reported error"), argv[0]);
767cf457 JK	475
	476	strbuf_release(&cmd);
	477	return r;
	478	}
	479
13e0f88d JK	480	static struct archiver tar_archiver = {
	481	"tar",
	482	write_tar_archive,
7b97730b	483	ARCHIVER_REMOTE
13e0f88d JK	484	};
	485
	486	void init_tar_archiver(void)
	487	{
767cf457	488	int i;
13e0f88d	489	register_archiver(&tar_archiver);
767cf457	490
0e804e09	491	tar_filter_config("tar.tgz.command", "gzip -cn", NULL);
7b97730b	492	tar_filter_config("tar.tgz.remote", "true", NULL);
0e804e09	493	tar_filter_config("tar.tar.gz.command", "gzip -cn", NULL);
7b97730b	494	tar_filter_config("tar.tar.gz.remote", "true", NULL);
13e0f88d	495	git_config(git_tar_config, NULL);
767cf457 JK	496	for (i = 0; i < nr_tar_filters; i++) {
	497	/* omit any filters that never had a command configured */
	498	if (tar_filters[i]->data)
	499	register_archiver(tar_filters[i]);
	500	}
13e0f88d	501	}