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

/*
 * Copyright (c) 2005, 2006 Rene Scharfe
 */
#include "cache.h"
#include "tar.h"
#include "archive.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.
 */
#define USTAR_MAX_SIZE 077777777777UL

/* 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 unsigned char *sha1)
{
	struct git_istream *st;
	enum object_type type;
	unsigned long sz;
	char buf[BLOCKSIZE];
	ssize_t readlen;

	st = open_istream(sha1, &type, &sz, NULL);
	if (!st)
		return error("cannot stream blob %s", sha1_to_hex(sha1));
	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, unsigned int valuelen)
{
	int len, tmp;

	/* "%u %s=%s\n" */
	len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
	for (tmp = len; tmp > 9; tmp /= 10)
		len++;

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

/*
 * 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), "%011lo", S_ISREG(mode) ? size : 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 int write_extended_header(struct archiver_args *args,
				 const unsigned char *sha1,
				 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", sha1_to_hex(sha1));
	prepare_header(args, &header, mode, size);
	write_blocked(&header, sizeof(header));
	write_blocked(buffer, size);
	return 0;
}

static int write_tar_entry(struct archiver_args *args,
			   const unsigned char *sha1,
			   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, sha1_to_hex(sha1));
	}
	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",
				  sha1_to_hex(sha1));
			strbuf_append_ext_header(&ext_header, "path",
						 path, pathlen);
		}
	} else
		memcpy(header.name, path, pathlen);

	if (S_ISREG(mode) && !args->convert &&
	    sha1_object_info(sha1, &size) == OBJ_BLOB &&
	    size > big_file_threshold)
		buffer = NULL;
	else if (S_ISLNK(mode) || S_ISREG(mode)) {
		enum object_type type;
		buffer = sha1_file_to_archive(args, path, sha1, old_mode, &type, &size);
		if (!buffer)
			return error("cannot read %s", sha1_to_hex(sha1));
	} else {
		buffer = NULL;
		size = 0;
	}

	if (S_ISLNK(mode)) {
		if (size > sizeof(header.linkname)) {
			xsnprintf(header.linkname, sizeof(header.linkname),
				  "see %s.paxheader", sha1_to_hex(sha1));
			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) {
		err = write_extended_header(args, sha1, ext_header.buf,
					    ext_header.len);
		if (err) {
			free(buffer);
			return err;
		}
	}
	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(sha1);
	}
	free(buffer);
	return err;
}

static int 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;
	int err = 0;

	strbuf_append_ext_header(&ext_header, "comment", sha1_to_hex(sha1), 40);
	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);
	return err;
}

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;

	if (args->commit_sha1)
		err = write_global_extended_header(args);
	if (!err)
		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)
		die("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"
3d74982f	5	#include "tar.h"
3d74982f	6	#include "archive.h"
5544049d	7	#include "streaming.h"
767cf457	8	#include "run-command.h"
3d74982f RS	9
	10	#define RECORDSIZE (512)
	11	#define BLOCKSIZE (RECORDSIZE * 20)
	12
	13	static char block[BLOCKSIZE];
	14	static unsigned long offset;
	15
f08b3b0e	16	static int tar_umask = 002;
3d74982f	17
767cf457 JK	18	static int write_tar_filter_archive(const struct archiver *ar,
	19	struct archiver_args *args);
	20
d1657b57 JK	21	/*
	22	* This is the max value that a ustar size header can specify, as it is fixed
	23	* at 11 octal digits. POSIX specifies that we switch to extended headers at
	24	* this size.
	25	*/
	26	#define USTAR_MAX_SIZE 077777777777UL
	27
3d74982f RS	28	/* writes out the whole block, but only if it is full */
	29	static void write_if_needed(void)
	30	{
	31	if (offset == BLOCKSIZE) {
	32	write_or_die(1, block, BLOCKSIZE);
	33	offset = 0;
	34	}
	35	}
	36
	37	/*
	38	* queues up writes, so that all our write(2) calls write exactly one
	39	* full block; pads writes to RECORDSIZE
	40	*/
5544049d	41	static void do_write_blocked(const void *data, unsigned long size)
3d74982f RS	42	{
3d74982f RS	43	const char *buf = data;
3d74982f RS	44
	45	if (offset) {
	46	unsigned long chunk = BLOCKSIZE - offset;
	47	if (size < chunk)
	48	chunk = size;
	49	memcpy(block + offset, buf, chunk);
	50	size -= chunk;
	51	offset += chunk;
	52	buf += chunk;
	53	write_if_needed();
	54	}
	55	while (size >= BLOCKSIZE) {
	56	write_or_die(1, buf, BLOCKSIZE);
	57	size -= BLOCKSIZE;
	58	buf += BLOCKSIZE;
	59	}
	60	if (size) {
	61	memcpy(block + offset, buf, size);
	62	offset += size;
	63	}
5544049d NTND	64	}
	65
	66	static void finish_record(void)
	67	{
	68	unsigned long tail;
3d74982f RS	69	tail = offset % RECORDSIZE;
	70	if (tail) {
	71	memset(block + offset, 0, RECORDSIZE - tail);
	72	offset += RECORDSIZE - tail;
	73	}
	74	write_if_needed();
	75	}
	76
5544049d NTND	77	static void write_blocked(const void *data, unsigned long size)
	78	{
	79	do_write_blocked(data, size);
	80	finish_record();
	81	}
	82
3d74982f RS	83	/*
	84	* The end of tar archives is marked by 2*512 nul bytes and after that
	85	* follows the rest of the block (if any).
	86	*/
	87	static void write_trailer(void)
	88	{
	89	int tail = BLOCKSIZE - offset;
	90	memset(block + offset, 0, tail);
	91	write_or_die(1, block, BLOCKSIZE);
	92	if (tail < 2 * RECORDSIZE) {
	93	memset(block, 0, offset);
	94	write_or_die(1, block, BLOCKSIZE);
	95	}
	96	}
	97
5544049d NTND	98	/*
	99	* queues up writes, so that all our write(2) calls write exactly one
	100	* full block; pads writes to RECORDSIZE
	101	*/
	102	static int stream_blocked(const unsigned char *sha1)
	103	{
	104	struct git_istream *st;
	105	enum object_type type;
	106	unsigned long sz;
	107	char buf[BLOCKSIZE];
	108	ssize_t readlen;
	109
	110	st = open_istream(sha1, &type, &sz, NULL);
	111	if (!st)
	112	return error("cannot stream blob %s", sha1_to_hex(sha1));
	113	for (;;) {
	114	readlen = read_istream(st, buf, sizeof(buf));
	115	if (readlen <= 0)
	116	break;
	117	do_write_blocked(buf, readlen);
	118	}
	119	close_istream(st);
	120	if (!readlen)
	121	finish_record();
	122	return readlen;
	123	}
	124
3d74982f RS	125	/*
	126	* pax extended header records have the format "%u %s=%s\n". %u contains
	127	* the size of the whole string (including the %u), the first %s is the
	128	* keyword, the second one is the value. This function constructs such a
	129	* string and appends it to a struct strbuf.
	130	*/
	131	static void strbuf_append_ext_header(struct strbuf sb, const char keyword,
	132	const char *value, unsigned int valuelen)
	133	{
7a604f16	134	int len, tmp;
3d74982f RS	135
	136	/* "%u %s=%s\n" */
	137	len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
	138	for (tmp = len; tmp > 9; tmp /= 10)
	139	len++;
	140
7a604f16 PH	141	strbuf_grow(sb, len);
	142	strbuf_addf(sb, "%u %s=", len, keyword);
	143	strbuf_add(sb, value, valuelen);
	144	strbuf_addch(sb, '\n');
3d74982f RS	145	}
3d74982f RS	146
d1657b57 JK	147	/*
	148	* Like strbuf_append_ext_header, but for numeric values.
	149	*/
	150	static void strbuf_append_ext_header_uint(struct strbuf *sb,
	151	const char *keyword,
	152	uintmax_t value)
	153	{
	154	char buf[40]; /* big enough for 2^128 in decimal, plus NUL */
	155	int len;
	156
	157	len = xsnprintf(buf, sizeof(buf), "%"PRIuMAX, value);
	158	strbuf_append_ext_header(sb, keyword, buf, len);
	159	}
	160
3d74982f RS	161	static unsigned int ustar_header_chksum(const struct ustar_header *header)
3d74982f RS	162	{
a5a46eb9	163	const unsigned char p = (const unsigned char )header;
3d74982f	164	unsigned int chksum = 0;
a5a46eb9	165	while (p < (const unsigned char *)header->chksum)
3d74982f RS	166	chksum += *p++;
	167	chksum += sizeof(header->chksum) * ' ';
	168	p += sizeof(header->chksum);
a5a46eb9	169	while (p < (const unsigned char *)header + sizeof(struct ustar_header))
3d74982f RS	170	chksum += *p++;
	171	return chksum;
	172	}
	173
562e25ab	174	static size_t get_path_prefix(const char *path, size_t pathlen, size_t maxlen)
3d74982f	175	{
562e25ab	176	size_t i = pathlen;
22f0dcd9 RS	177	if (i > 1 && path[i - 1] == '/')
22f0dcd9 RS	178	i--;
3d74982f RS	179	if (i > maxlen)
	180	i = maxlen;
	181	do {
	182	i--;
562e25ab	183	} while (i > 0 && path[i] != '/');
3d74982f RS	184	return i;
	185	}
	186
d240d410 NTND	187	static void prepare_header(struct archiver_args *args,
	188	struct ustar_header *header,
	189	unsigned int mode, unsigned long size)
	190	{
f2f02675 JK	191	xsnprintf(header->mode, sizeof(header->mode), "%07o", mode & 07777);
	192	xsnprintf(header->size, sizeof(header->size), "%011lo", S_ISREG(mode) ? size : 0);
	193	xsnprintf(header->mtime, sizeof(header->mtime), "%011lo", (unsigned long) args->time);
d240d410	194
f2f02675 JK	195	xsnprintf(header->uid, sizeof(header->uid), "%07o", 0);
f2f02675 JK	196	xsnprintf(header->gid, sizeof(header->gid), "%07o", 0);
d240d410 NTND	197	strlcpy(header->uname, "root", sizeof(header->uname));
d240d410 NTND	198	strlcpy(header->gname, "root", sizeof(header->gname));
f2f02675 JK	199	xsnprintf(header->devmajor, sizeof(header->devmajor), "%07o", 0);
f2f02675 JK	200	xsnprintf(header->devminor, sizeof(header->devminor), "%07o", 0);
d240d410 NTND	201
	202	memcpy(header->magic, "ustar", 6);
	203	memcpy(header->version, "00", 2);
	204
9e6c1e91	205	xsnprintf(header->chksum, sizeof(header->chksum), "%07o", ustar_header_chksum(header));
d240d410 NTND	206	}
	207
	208	static int write_extended_header(struct archiver_args *args,
	209	const unsigned char *sha1,
	210	const void *buffer, unsigned long size)
	211	{
	212	struct ustar_header header;
	213	unsigned int mode;
	214	memset(&header, 0, sizeof(header));
	215	*header.typeflag = TYPEFLAG_EXT_HEADER;
15c6ef7b	216	mode = 0100666;
f2f02675	217	xsnprintf(header.name, sizeof(header.name), "%s.paxheader", sha1_to_hex(sha1));
d240d410 NTND	218	prepare_header(args, &header, mode, size);
	219	write_blocked(&header, sizeof(header));
	220	write_blocked(buffer, size);
	221	return 0;
	222	}
	223
562e25ab	224	static int write_tar_entry(struct archiver_args *args,
9cb513b7 NTND	225	const unsigned char *sha1,
	226	const char *path, size_t pathlen,
	227	unsigned int mode)
3d74982f RS	228	{
3d74982f RS	229	struct ustar_header header;
f285a2d7	230	struct strbuf ext_header = STRBUF_INIT;
9cb513b7	231	unsigned int old_mode = mode;
d1657b57	232	unsigned long size, size_in_header;
9cb513b7	233	void *buffer;
562e25ab	234	int err = 0;
3d74982f RS	235
3d74982f RS	236	memset(&header, 0, sizeof(header));
3d74982f	237
85390709 NTND	238	if (S_ISDIR(mode) \|\| S_ISGITLINK(mode)) {
	239	*header.typeflag = TYPEFLAG_DIR;
	240	mode = (mode \| 0777) & ~tar_umask;
	241	} else if (S_ISLNK(mode)) {
	242	*header.typeflag = TYPEFLAG_LNK;
	243	mode \|= 0777;
	244	} else if (S_ISREG(mode)) {
	245	*header.typeflag = TYPEFLAG_REG;
	246	mode = (mode \| ((mode & 0100) ? 0777 : 0666)) & ~tar_umask;
3d74982f	247	} else {
85390709 NTND	248	return error("unsupported file mode: 0%o (SHA1: %s)",
	249	mode, sha1_to_hex(sha1));
	250	}
	251	if (pathlen > sizeof(header.name)) {
	252	size_t plen = get_path_prefix(path, pathlen,
	253	sizeof(header.prefix));
	254	size_t rest = pathlen - plen - 1;
	255	if (plen > 0 && rest <= sizeof(header.name)) {
	256	memcpy(header.prefix, path, plen);
108332c7	257	memcpy(header.name, path + plen + 1, rest);
3d74982f	258	} else {
f2f02675 JK	259	xsnprintf(header.name, sizeof(header.name), "%s.data",
f2f02675 JK	260	sha1_to_hex(sha1));
85390709 NTND	261	strbuf_append_ext_header(&ext_header, "path",
85390709 NTND	262	path, pathlen);
3d74982f	263	}
85390709 NTND	264	} else
85390709 NTND	265	memcpy(header.name, path, pathlen);
3d74982f	266
5544049d NTND	267	if (S_ISREG(mode) && !args->convert &&
	268	sha1_object_info(sha1, &size) == OBJ_BLOB &&
	269	size > big_file_threshold)
	270	buffer = NULL;
	271	else if (S_ISLNK(mode) \|\| S_ISREG(mode)) {
9cb513b7 NTND	272	enum object_type type;
	273	buffer = sha1_file_to_archive(args, path, sha1, old_mode, &type, &size);
	274	if (!buffer)
	275	return error("cannot read %s", sha1_to_hex(sha1));
	276	} else {
	277	buffer = NULL;
	278	size = 0;
	279	}
	280
	281	if (S_ISLNK(mode)) {
3d74982f	282	if (size > sizeof(header.linkname)) {
f2f02675 JK	283	xsnprintf(header.linkname, sizeof(header.linkname),
f2f02675 JK	284	"see %s.paxheader", sha1_to_hex(sha1));
3d74982f RS	285	strbuf_append_ext_header(&ext_header, "linkpath",
	286	buffer, size);
	287	} else
	288	memcpy(header.linkname, buffer, size);
	289	}
	290
d1657b57 JK	291	size_in_header = size;
	292	if (S_ISREG(mode) && size > USTAR_MAX_SIZE) {
	293	size_in_header = 0;
	294	strbuf_append_ext_header_uint(&ext_header, "size", size);
	295	}
	296
	297	prepare_header(args, &header, mode, size_in_header);
3d74982f RS	298
3d74982f RS	299	if (ext_header.len > 0) {
d240d410 NTND	300	err = write_extended_header(args, sha1, ext_header.buf,
d240d410 NTND	301	ext_header.len);
9cb513b7 NTND	302	if (err) {
9cb513b7 NTND	303	free(buffer);
562e25ab	304	return err;
9cb513b7	305	}
3d74982f	306	}
7a604f16	307	strbuf_release(&ext_header);
3d74982f	308	write_blocked(&header, sizeof(header));
5544049d NTND	309	if (S_ISREG(mode) && size > 0) {
	310	if (buffer)
	311	write_blocked(buffer, size);
	312	else
	313	err = stream_blocked(sha1);
	314	}
9cb513b7	315	free(buffer);
562e25ab	316	return err;
3d74982f RS	317	}
3d74982f RS	318
562e25ab	319	static int write_global_extended_header(struct archiver_args *args)
3d74982f	320	{
562e25ab	321	const unsigned char *sha1 = args->commit_sha1;
f285a2d7	322	struct strbuf ext_header = STRBUF_INIT;
d240d410 NTND	323	struct ustar_header header;
	324	unsigned int mode;
	325	int err = 0;
7a604f16	326
3d74982f	327	strbuf_append_ext_header(&ext_header, "comment", sha1_to_hex(sha1), 40);
d240d410 NTND	328	memset(&header, 0, sizeof(header));
d240d410 NTND	329	*header.typeflag = TYPEFLAG_GLOBAL_HEADER;
15c6ef7b	330	mode = 0100666;
5096d490	331	xsnprintf(header.name, sizeof(header.name), "pax_global_header");
d240d410 NTND	332	prepare_header(args, &header, mode, ext_header.len);
	333	write_blocked(&header, sizeof(header));
	334	write_blocked(ext_header.buf, ext_header.len);
7a604f16	335	strbuf_release(&ext_header);
562e25ab	336	return err;
3d74982f RS	337	}
3d74982f RS	338
767cf457 JK	339	static struct archiver **tar_filters;
	340	static int nr_tar_filters;
	341	static int alloc_tar_filters;
	342
	343	static struct archiver find_tar_filter(const char name, int len)
	344	{
	345	int i;
	346	for (i = 0; i < nr_tar_filters; i++) {
	347	struct archiver *ar = tar_filters[i];
	348	if (!strncmp(ar->name, name, len) && !ar->name[len])
	349	return ar;
	350	}
	351	return NULL;
	352	}
	353
	354	static int tar_filter_config(const char var, const char value, void *data)
	355	{
	356	struct archiver *ar;
767cf457 JK	357	const char *name;
	358	const char *type;
	359	int namelen;
	360
785a0429	361	if (parse_config_key(var, "tar", &name, &namelen, &type) < 0 \|\| !name)
767cf457	362	return 0;
767cf457 JK	363
	364	ar = find_tar_filter(name, namelen);
	365	if (!ar) {
	366	ar = xcalloc(1, sizeof(*ar));
	367	ar->name = xmemdupz(name, namelen);
	368	ar->write_archive = write_tar_filter_archive;
	369	ar->flags = ARCHIVER_WANT_COMPRESSION_LEVELS;
	370	ALLOC_GROW(tar_filters, nr_tar_filters + 1, alloc_tar_filters);
	371	tar_filters[nr_tar_filters++] = ar;
	372	}
	373
	374	if (!strcmp(type, "command")) {
	375	if (!value)
	376	return config_error_nonbool(var);
	377	free(ar->data);
	378	ar->data = xstrdup(value);
	379	return 0;
	380	}
7b97730b JK	381	if (!strcmp(type, "remote")) {
	382	if (git_config_bool(var, value))
	383	ar->flags \|= ARCHIVER_REMOTE;
	384	else
	385	ar->flags &= ~ARCHIVER_REMOTE;
	386	return 0;
	387	}
767cf457 JK	388
	389	return 0;
	390	}
	391
ef90d6d4	392	static int git_tar_config(const char var, const char value, void *cb)
3d74982f RS	393	{
3d74982f RS	394	if (!strcmp(var, "tar.umask")) {
cc1816b0	395	if (value && !strcmp(value, "user")) {
3d74982f RS	396	tar_umask = umask(0);
	397	umask(tar_umask);
	398	} else {
	399	tar_umask = git_config_int(var, value);
	400	}
	401	return 0;
	402	}
767cf457 JK	403
767cf457 JK	404	return tar_filter_config(var, value, cb);
3d74982f RS	405	}
3d74982f RS	406
4d7c9898 JK	407	static int write_tar_archive(const struct archiver *ar,
4d7c9898 JK	408	struct archiver_args *args)
3d74982f	409	{
562e25ab	410	int err = 0;
3d74982f	411
3d74982f	412	if (args->commit_sha1)
562e25ab RS	413	err = write_global_extended_header(args);
	414	if (!err)
	415	err = write_archive_entries(args, write_tar_entry);
	416	if (!err)
	417	write_trailer();
	418	return err;
3d74982f	419	}
13e0f88d	420
767cf457 JK	421	static int write_tar_filter_archive(const struct archiver *ar,
	422	struct archiver_args *args)
	423	{
	424	struct strbuf cmd = STRBUF_INIT;
d3180279	425	struct child_process filter = CHILD_PROCESS_INIT;
767cf457 JK	426	const char *argv[2];
	427	int r;
	428
	429	if (!ar->data)
	430	die("BUG: tar-filter archiver called with no filter defined");
	431
	432	strbuf_addstr(&cmd, ar->data);
	433	if (args->compression_level >= 0)
	434	strbuf_addf(&cmd, " -%d", args->compression_level);
	435
767cf457 JK	436	argv[0] = cmd.buf;
	437	argv[1] = NULL;
	438	filter.argv = argv;
	439	filter.use_shell = 1;
	440	filter.in = -1;
	441
	442	if (start_command(&filter) < 0)
	443	die_errno("unable to start '%s' filter", argv[0]);
	444	close(1);
	445	if (dup2(filter.in, 1) < 0)
	446	die_errno("unable to redirect descriptor");
	447	close(filter.in);
	448
	449	r = write_tar_archive(ar, args);
	450
	451	close(1);
	452	if (finish_command(&filter) != 0)
	453	die("'%s' filter reported error", argv[0]);
	454
	455	strbuf_release(&cmd);
	456	return r;
	457	}
	458
13e0f88d JK	459	static struct archiver tar_archiver = {
	460	"tar",
	461	write_tar_archive,
7b97730b	462	ARCHIVER_REMOTE
13e0f88d JK	463	};
	464
	465	void init_tar_archiver(void)
	466	{
767cf457	467	int i;
13e0f88d	468	register_archiver(&tar_archiver);
767cf457	469
0e804e09	470	tar_filter_config("tar.tgz.command", "gzip -cn", NULL);
7b97730b	471	tar_filter_config("tar.tgz.remote", "true", NULL);
0e804e09	472	tar_filter_config("tar.tar.gz.command", "gzip -cn", NULL);
7b97730b	473	tar_filter_config("tar.tar.gz.remote", "true", NULL);
13e0f88d	474	git_config(git_tar_config, NULL);
767cf457 JK	475	for (i = 0; i < nr_tar_filters; i++) {
	476	/* omit any filters that never had a command configured */
	477	if (tar_filters[i]->data)
	478	register_archiver(tar_filters[i]);
	479	}
13e0f88d	480	}