[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.
 *
 * 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 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 void 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);
}

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) {
		write_extended_header(args, sha1, 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(sha1);
	}
	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)
		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.
6e8e0991 JK	25	*
6e8e0991 JK	26	* Likewise for the mtime (which happens to use a buffer of the same size).
d1657b57	27	*/
29493589 JH	28	#if ULONG_MAX == 0xFFFFFFFF
29493589 JH	29	#define USTAR_MAX_SIZE ULONG_MAX
29493589	30	#else
3f789719	31	#define USTAR_MAX_SIZE 077777777777UL
dddbad72 JS	32	#endif
	33	#if TIME_MAX == 0xFFFFFFFF
	34	#define USTAR_MAX_MTIME TIME_MAX
	35	#else
3f789719	36	#define USTAR_MAX_MTIME 077777777777ULL
29493589	37	#endif
d1657b57	38
3d74982f RS	39	/* writes out the whole block, but only if it is full */
	40	static void write_if_needed(void)
	41	{
	42	if (offset == BLOCKSIZE) {
	43	write_or_die(1, block, BLOCKSIZE);
	44	offset = 0;
	45	}
	46	}
	47
	48	/*
	49	* queues up writes, so that all our write(2) calls write exactly one
	50	* full block; pads writes to RECORDSIZE
	51	*/
5544049d	52	static void do_write_blocked(const void *data, unsigned long size)
3d74982f RS	53	{
3d74982f RS	54	const char *buf = data;
3d74982f RS	55
	56	if (offset) {
	57	unsigned long chunk = BLOCKSIZE - offset;
	58	if (size < chunk)
	59	chunk = size;
	60	memcpy(block + offset, buf, chunk);
	61	size -= chunk;
	62	offset += chunk;
	63	buf += chunk;
	64	write_if_needed();
	65	}
	66	while (size >= BLOCKSIZE) {
	67	write_or_die(1, buf, BLOCKSIZE);
	68	size -= BLOCKSIZE;
	69	buf += BLOCKSIZE;
	70	}
	71	if (size) {
	72	memcpy(block + offset, buf, size);
	73	offset += size;
	74	}
5544049d NTND	75	}
	76
	77	static void finish_record(void)
	78	{
	79	unsigned long tail;
3d74982f RS	80	tail = offset % RECORDSIZE;
	81	if (tail) {
	82	memset(block + offset, 0, RECORDSIZE - tail);
	83	offset += RECORDSIZE - tail;
	84	}
	85	write_if_needed();
	86	}
	87
5544049d NTND	88	static void write_blocked(const void *data, unsigned long size)
	89	{
	90	do_write_blocked(data, size);
	91	finish_record();
	92	}
	93
3d74982f RS	94	/*
	95	* The end of tar archives is marked by 2*512 nul bytes and after that
	96	* follows the rest of the block (if any).
	97	*/
	98	static void write_trailer(void)
	99	{
	100	int tail = BLOCKSIZE - offset;
	101	memset(block + offset, 0, tail);
	102	write_or_die(1, block, BLOCKSIZE);
	103	if (tail < 2 * RECORDSIZE) {
	104	memset(block, 0, offset);
	105	write_or_die(1, block, BLOCKSIZE);
	106	}
	107	}
	108
5544049d NTND	109	/*
	110	* queues up writes, so that all our write(2) calls write exactly one
	111	* full block; pads writes to RECORDSIZE
	112	*/
	113	static int stream_blocked(const unsigned char *sha1)
	114	{
	115	struct git_istream *st;
	116	enum object_type type;
	117	unsigned long sz;
	118	char buf[BLOCKSIZE];
	119	ssize_t readlen;
	120
	121	st = open_istream(sha1, &type, &sz, NULL);
	122	if (!st)
	123	return error("cannot stream blob %s", sha1_to_hex(sha1));
	124	for (;;) {
	125	readlen = read_istream(st, buf, sizeof(buf));
	126	if (readlen <= 0)
	127	break;
	128	do_write_blocked(buf, readlen);
	129	}
	130	close_istream(st);
	131	if (!readlen)
	132	finish_record();
	133	return readlen;
	134	}
	135
3d74982f RS	136	/*
	137	* pax extended header records have the format "%u %s=%s\n". %u contains
	138	* the size of the whole string (including the %u), the first %s is the
	139	* keyword, the second one is the value. This function constructs such a
	140	* string and appends it to a struct strbuf.
	141	*/
	142	static void strbuf_append_ext_header(struct strbuf sb, const char keyword,
	143	const char *value, unsigned int valuelen)
	144	{
7a604f16	145	int len, tmp;
3d74982f RS	146
	147	/* "%u %s=%s\n" */
	148	len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
	149	for (tmp = len; tmp > 9; tmp /= 10)
	150	len++;
	151
7a604f16 PH	152	strbuf_grow(sb, len);
	153	strbuf_addf(sb, "%u %s=", len, keyword);
	154	strbuf_add(sb, value, valuelen);
	155	strbuf_addch(sb, '\n');
3d74982f RS	156	}
3d74982f RS	157
d1657b57 JK	158	/*
	159	* Like strbuf_append_ext_header, but for numeric values.
	160	*/
	161	static void strbuf_append_ext_header_uint(struct strbuf *sb,
	162	const char *keyword,
	163	uintmax_t value)
	164	{
	165	char buf[40]; /* big enough for 2^128 in decimal, plus NUL */
	166	int len;
	167
	168	len = xsnprintf(buf, sizeof(buf), "%"PRIuMAX, value);
	169	strbuf_append_ext_header(sb, keyword, buf, len);
	170	}
	171
3d74982f RS	172	static unsigned int ustar_header_chksum(const struct ustar_header *header)
3d74982f RS	173	{
a5a46eb9	174	const unsigned char p = (const unsigned char )header;
3d74982f	175	unsigned int chksum = 0;
a5a46eb9	176	while (p < (const unsigned char *)header->chksum)
3d74982f RS	177	chksum += *p++;
	178	chksum += sizeof(header->chksum) * ' ';
	179	p += sizeof(header->chksum);
a5a46eb9	180	while (p < (const unsigned char *)header + sizeof(struct ustar_header))
3d74982f RS	181	chksum += *p++;
	182	return chksum;
	183	}
	184
562e25ab	185	static size_t get_path_prefix(const char *path, size_t pathlen, size_t maxlen)
3d74982f	186	{
562e25ab	187	size_t i = pathlen;
22f0dcd9 RS	188	if (i > 1 && path[i - 1] == '/')
22f0dcd9 RS	189	i--;
3d74982f RS	190	if (i > maxlen)
	191	i = maxlen;
	192	do {
	193	i--;
562e25ab	194	} while (i > 0 && path[i] != '/');
3d74982f RS	195	return i;
	196	}
	197
d240d410 NTND	198	static void prepare_header(struct archiver_args *args,
	199	struct ustar_header *header,
	200	unsigned int mode, unsigned long size)
	201	{
f2f02675 JK	202	xsnprintf(header->mode, sizeof(header->mode), "%07o", mode & 07777);
	203	xsnprintf(header->size, sizeof(header->size), "%011lo", S_ISREG(mode) ? size : 0);
	204	xsnprintf(header->mtime, sizeof(header->mtime), "%011lo", (unsigned long) args->time);
d240d410	205
f2f02675 JK	206	xsnprintf(header->uid, sizeof(header->uid), "%07o", 0);
f2f02675 JK	207	xsnprintf(header->gid, sizeof(header->gid), "%07o", 0);
d240d410 NTND	208	strlcpy(header->uname, "root", sizeof(header->uname));
d240d410 NTND	209	strlcpy(header->gname, "root", sizeof(header->gname));
f2f02675 JK	210	xsnprintf(header->devmajor, sizeof(header->devmajor), "%07o", 0);
f2f02675 JK	211	xsnprintf(header->devminor, sizeof(header->devminor), "%07o", 0);
d240d410 NTND	212
	213	memcpy(header->magic, "ustar", 6);
	214	memcpy(header->version, "00", 2);
	215
9e6c1e91	216	xsnprintf(header->chksum, sizeof(header->chksum), "%07o", ustar_header_chksum(header));
d240d410 NTND	217	}
d240d410 NTND	218
560b0e8f RS	219	static void write_extended_header(struct archiver_args *args,
	220	const unsigned char *sha1,
	221	const void *buffer, unsigned long size)
d240d410 NTND	222	{
	223	struct ustar_header header;
	224	unsigned int mode;
	225	memset(&header, 0, sizeof(header));
	226	*header.typeflag = TYPEFLAG_EXT_HEADER;
15c6ef7b	227	mode = 0100666;
f2f02675	228	xsnprintf(header.name, sizeof(header.name), "%s.paxheader", sha1_to_hex(sha1));
d240d410 NTND	229	prepare_header(args, &header, mode, size);
	230	write_blocked(&header, sizeof(header));
	231	write_blocked(buffer, size);
d240d410 NTND	232	}
d240d410 NTND	233
562e25ab	234	static int write_tar_entry(struct archiver_args *args,
9cb513b7 NTND	235	const unsigned char *sha1,
	236	const char *path, size_t pathlen,
	237	unsigned int mode)
3d74982f RS	238	{
3d74982f RS	239	struct ustar_header header;
f285a2d7	240	struct strbuf ext_header = STRBUF_INIT;
9cb513b7	241	unsigned int old_mode = mode;
d1657b57	242	unsigned long size, size_in_header;
9cb513b7	243	void *buffer;
562e25ab	244	int err = 0;
3d74982f RS	245
3d74982f RS	246	memset(&header, 0, sizeof(header));
3d74982f	247
85390709 NTND	248	if (S_ISDIR(mode) \|\| S_ISGITLINK(mode)) {
	249	*header.typeflag = TYPEFLAG_DIR;
	250	mode = (mode \| 0777) & ~tar_umask;
	251	} else if (S_ISLNK(mode)) {
	252	*header.typeflag = TYPEFLAG_LNK;
	253	mode \|= 0777;
	254	} else if (S_ISREG(mode)) {
	255	*header.typeflag = TYPEFLAG_REG;
	256	mode = (mode \| ((mode & 0100) ? 0777 : 0666)) & ~tar_umask;
3d74982f	257	} else {
85390709 NTND	258	return error("unsupported file mode: 0%o (SHA1: %s)",
	259	mode, sha1_to_hex(sha1));
	260	}
	261	if (pathlen > sizeof(header.name)) {
	262	size_t plen = get_path_prefix(path, pathlen,
	263	sizeof(header.prefix));
	264	size_t rest = pathlen - plen - 1;
	265	if (plen > 0 && rest <= sizeof(header.name)) {
	266	memcpy(header.prefix, path, plen);
108332c7	267	memcpy(header.name, path + plen + 1, rest);
3d74982f	268	} else {
f2f02675 JK	269	xsnprintf(header.name, sizeof(header.name), "%s.data",
f2f02675 JK	270	sha1_to_hex(sha1));
85390709 NTND	271	strbuf_append_ext_header(&ext_header, "path",
85390709 NTND	272	path, pathlen);
3d74982f	273	}
85390709 NTND	274	} else
85390709 NTND	275	memcpy(header.name, path, pathlen);
3d74982f	276
5544049d NTND	277	if (S_ISREG(mode) && !args->convert &&
	278	sha1_object_info(sha1, &size) == OBJ_BLOB &&
	279	size > big_file_threshold)
	280	buffer = NULL;
	281	else if (S_ISLNK(mode) \|\| S_ISREG(mode)) {
9cb513b7 NTND	282	enum object_type type;
	283	buffer = sha1_file_to_archive(args, path, sha1, old_mode, &type, &size);
	284	if (!buffer)
	285	return error("cannot read %s", sha1_to_hex(sha1));
	286	} else {
	287	buffer = NULL;
	288	size = 0;
	289	}
	290
	291	if (S_ISLNK(mode)) {
3d74982f	292	if (size > sizeof(header.linkname)) {
f2f02675 JK	293	xsnprintf(header.linkname, sizeof(header.linkname),
f2f02675 JK	294	"see %s.paxheader", sha1_to_hex(sha1));
3d74982f RS	295	strbuf_append_ext_header(&ext_header, "linkpath",
	296	buffer, size);
	297	} else
	298	memcpy(header.linkname, buffer, size);
	299	}
	300
d1657b57 JK	301	size_in_header = size;
	302	if (S_ISREG(mode) && size > USTAR_MAX_SIZE) {
	303	size_in_header = 0;
	304	strbuf_append_ext_header_uint(&ext_header, "size", size);
	305	}
	306
	307	prepare_header(args, &header, mode, size_in_header);
3d74982f RS	308
3d74982f RS	309	if (ext_header.len > 0) {
560b0e8f RS	310	write_extended_header(args, sha1, ext_header.buf,
560b0e8f RS	311	ext_header.len);
3d74982f	312	}
7a604f16	313	strbuf_release(&ext_header);
3d74982f	314	write_blocked(&header, sizeof(header));
5544049d NTND	315	if (S_ISREG(mode) && size > 0) {
	316	if (buffer)
	317	write_blocked(buffer, size);
	318	else
	319	err = stream_blocked(sha1);
	320	}
9cb513b7	321	free(buffer);
562e25ab	322	return err;
3d74982f RS	323	}
3d74982f RS	324
5caeeb83	325	static void write_global_extended_header(struct archiver_args *args)
3d74982f	326	{
562e25ab	327	const unsigned char *sha1 = args->commit_sha1;
f285a2d7	328	struct strbuf ext_header = STRBUF_INIT;
d240d410 NTND	329	struct ustar_header header;
d240d410 NTND	330	unsigned int mode;
7a604f16	331
6e8e0991 JK	332	if (sha1)
	333	strbuf_append_ext_header(&ext_header, "comment",
	334	sha1_to_hex(sha1), 40);
	335	if (args->time > USTAR_MAX_MTIME) {
	336	strbuf_append_ext_header_uint(&ext_header, "mtime",
	337	args->time);
	338	args->time = USTAR_MAX_MTIME;
	339	}
	340
	341	if (!ext_header.len)
5caeeb83	342	return;
6e8e0991	343
d240d410 NTND	344	memset(&header, 0, sizeof(header));
d240d410 NTND	345	*header.typeflag = TYPEFLAG_GLOBAL_HEADER;
15c6ef7b	346	mode = 0100666;
5096d490	347	xsnprintf(header.name, sizeof(header.name), "pax_global_header");
d240d410 NTND	348	prepare_header(args, &header, mode, ext_header.len);
	349	write_blocked(&header, sizeof(header));
	350	write_blocked(ext_header.buf, ext_header.len);
7a604f16	351	strbuf_release(&ext_header);
3d74982f RS	352	}
3d74982f RS	353
767cf457 JK	354	static struct archiver **tar_filters;
	355	static int nr_tar_filters;
	356	static int alloc_tar_filters;
	357
	358	static struct archiver find_tar_filter(const char name, int len)
	359	{
	360	int i;
	361	for (i = 0; i < nr_tar_filters; i++) {
	362	struct archiver *ar = tar_filters[i];
	363	if (!strncmp(ar->name, name, len) && !ar->name[len])
	364	return ar;
	365	}
	366	return NULL;
	367	}
	368
	369	static int tar_filter_config(const char var, const char value, void *data)
	370	{
	371	struct archiver *ar;
767cf457 JK	372	const char *name;
	373	const char *type;
	374	int namelen;
	375
785a0429	376	if (parse_config_key(var, "tar", &name, &namelen, &type) < 0 \|\| !name)
767cf457	377	return 0;
767cf457 JK	378
	379	ar = find_tar_filter(name, namelen);
	380	if (!ar) {
	381	ar = xcalloc(1, sizeof(*ar));
	382	ar->name = xmemdupz(name, namelen);
	383	ar->write_archive = write_tar_filter_archive;
	384	ar->flags = ARCHIVER_WANT_COMPRESSION_LEVELS;
	385	ALLOC_GROW(tar_filters, nr_tar_filters + 1, alloc_tar_filters);
	386	tar_filters[nr_tar_filters++] = ar;
	387	}
	388
	389	if (!strcmp(type, "command")) {
	390	if (!value)
	391	return config_error_nonbool(var);
	392	free(ar->data);
	393	ar->data = xstrdup(value);
	394	return 0;
	395	}
7b97730b JK	396	if (!strcmp(type, "remote")) {
	397	if (git_config_bool(var, value))
	398	ar->flags \|= ARCHIVER_REMOTE;
	399	else
	400	ar->flags &= ~ARCHIVER_REMOTE;
	401	return 0;
	402	}
767cf457 JK	403
	404	return 0;
	405	}
	406
ef90d6d4	407	static int git_tar_config(const char var, const char value, void *cb)
3d74982f RS	408	{
3d74982f RS	409	if (!strcmp(var, "tar.umask")) {
cc1816b0	410	if (value && !strcmp(value, "user")) {
3d74982f RS	411	tar_umask = umask(0);
	412	umask(tar_umask);
	413	} else {
	414	tar_umask = git_config_int(var, value);
	415	}
	416	return 0;
	417	}
767cf457 JK	418
767cf457 JK	419	return tar_filter_config(var, value, cb);
3d74982f RS	420	}
3d74982f RS	421
4d7c9898 JK	422	static int write_tar_archive(const struct archiver *ar,
4d7c9898 JK	423	struct archiver_args *args)
3d74982f	424	{
562e25ab	425	int err = 0;
3d74982f	426
5caeeb83 JK	427	write_global_extended_header(args);
5caeeb83 JK	428	err = write_archive_entries(args, write_tar_entry);
562e25ab RS	429	if (!err)
	430	write_trailer();
	431	return err;
3d74982f	432	}
13e0f88d	433
767cf457 JK	434	static int write_tar_filter_archive(const struct archiver *ar,
	435	struct archiver_args *args)
	436	{
	437	struct strbuf cmd = STRBUF_INIT;
d3180279	438	struct child_process filter = CHILD_PROCESS_INIT;
767cf457 JK	439	const char *argv[2];
	440	int r;
	441
	442	if (!ar->data)
	443	die("BUG: tar-filter archiver called with no filter defined");
	444
	445	strbuf_addstr(&cmd, ar->data);
	446	if (args->compression_level >= 0)
	447	strbuf_addf(&cmd, " -%d", args->compression_level);
	448
767cf457 JK	449	argv[0] = cmd.buf;
	450	argv[1] = NULL;
	451	filter.argv = argv;
	452	filter.use_shell = 1;
	453	filter.in = -1;
	454
	455	if (start_command(&filter) < 0)
	456	die_errno("unable to start '%s' filter", argv[0]);
	457	close(1);
	458	if (dup2(filter.in, 1) < 0)
	459	die_errno("unable to redirect descriptor");
	460	close(filter.in);
	461
	462	r = write_tar_archive(ar, args);
	463
	464	close(1);
	465	if (finish_command(&filter) != 0)
	466	die("'%s' filter reported error", argv[0]);
	467
	468	strbuf_release(&cmd);
	469	return r;
	470	}
	471
13e0f88d JK	472	static struct archiver tar_archiver = {
	473	"tar",
	474	write_tar_archive,
7b97730b	475	ARCHIVER_REMOTE
13e0f88d JK	476	};
	477
	478	void init_tar_archiver(void)
	479	{
767cf457	480	int i;
13e0f88d	481	register_archiver(&tar_archiver);
767cf457	482
0e804e09	483	tar_filter_config("tar.tgz.command", "gzip -cn", NULL);
7b97730b	484	tar_filter_config("tar.tgz.remote", "true", NULL);
0e804e09	485	tar_filter_config("tar.tar.gz.command", "gzip -cn", NULL);
7b97730b	486	tar_filter_config("tar.tar.gz.remote", "true", NULL);
13e0f88d	487	git_config(git_tar_config, NULL);
767cf457 JK	488	for (i = 0; i < nr_tar_filters; i++) {
	489	/* omit any filters that never had a command configured */
	490	if (tar_filters[i]->data)
	491	register_archiver(tar_filters[i]);
	492	}
13e0f88d	493	}