[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 "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"
b2141fc1	5	#include "config.h"
3d74982f	6	#include "tar.h"
3d74982f	7	#include "archive.h"
5544049d	8	#include "streaming.h"
767cf457	9	#include "run-command.h"
3d74982f RS	10
	11	#define RECORDSIZE (512)
	12	#define BLOCKSIZE (RECORDSIZE * 20)
	13
	14	static char block[BLOCKSIZE];
	15	static unsigned long offset;
	16
f08b3b0e	17	static int tar_umask = 002;
3d74982f	18
767cf457 JK	19	static int write_tar_filter_archive(const struct archiver *ar,
	20	struct archiver_args *args);
	21
d1657b57 JK	22	/*
	23	* This is the max value that a ustar size header can specify, as it is fixed
	24	* at 11 octal digits. POSIX specifies that we switch to extended headers at
	25	* this size.
6e8e0991 JK	26	*
6e8e0991 JK	27	* Likewise for the mtime (which happens to use a buffer of the same size).
d1657b57	28	*/
29493589 JH	29	#if ULONG_MAX == 0xFFFFFFFF
29493589 JH	30	#define USTAR_MAX_SIZE ULONG_MAX
29493589	31	#else
3f789719	32	#define USTAR_MAX_SIZE 077777777777UL
dddbad72 JS	33	#endif
	34	#if TIME_MAX == 0xFFFFFFFF
	35	#define USTAR_MAX_MTIME TIME_MAX
	36	#else
3f789719	37	#define USTAR_MAX_MTIME 077777777777ULL
29493589	38	#endif
d1657b57	39
3d74982f RS	40	/* writes out the whole block, but only if it is full */
	41	static void write_if_needed(void)
	42	{
	43	if (offset == BLOCKSIZE) {
	44	write_or_die(1, block, BLOCKSIZE);
	45	offset = 0;
	46	}
	47	}
	48
	49	/*
	50	* queues up writes, so that all our write(2) calls write exactly one
	51	* full block; pads writes to RECORDSIZE
	52	*/
5544049d	53	static void do_write_blocked(const void *data, unsigned long size)
3d74982f RS	54	{
3d74982f RS	55	const char *buf = data;
3d74982f RS	56
	57	if (offset) {
	58	unsigned long chunk = BLOCKSIZE - offset;
	59	if (size < chunk)
	60	chunk = size;
	61	memcpy(block + offset, buf, chunk);
	62	size -= chunk;
	63	offset += chunk;
	64	buf += chunk;
	65	write_if_needed();
	66	}
	67	while (size >= BLOCKSIZE) {
	68	write_or_die(1, buf, BLOCKSIZE);
	69	size -= BLOCKSIZE;
	70	buf += BLOCKSIZE;
	71	}
	72	if (size) {
	73	memcpy(block + offset, buf, size);
	74	offset += size;
	75	}
5544049d NTND	76	}
	77
	78	static void finish_record(void)
	79	{
	80	unsigned long tail;
3d74982f RS	81	tail = offset % RECORDSIZE;
	82	if (tail) {
	83	memset(block + offset, 0, RECORDSIZE - tail);
	84	offset += RECORDSIZE - tail;
	85	}
	86	write_if_needed();
	87	}
	88
5544049d NTND	89	static void write_blocked(const void *data, unsigned long size)
	90	{
	91	do_write_blocked(data, size);
	92	finish_record();
	93	}
	94
3d74982f RS	95	/*
	96	* The end of tar archives is marked by 2*512 nul bytes and after that
	97	* follows the rest of the block (if any).
	98	*/
	99	static void write_trailer(void)
	100	{
	101	int tail = BLOCKSIZE - offset;
	102	memset(block + offset, 0, tail);
	103	write_or_die(1, block, BLOCKSIZE);
	104	if (tail < 2 * RECORDSIZE) {
	105	memset(block, 0, offset);
	106	write_or_die(1, block, BLOCKSIZE);
	107	}
	108	}
	109
5544049d NTND	110	/*
	111	* queues up writes, so that all our write(2) calls write exactly one
	112	* full block; pads writes to RECORDSIZE
	113	*/
	114	static int stream_blocked(const unsigned char *sha1)
	115	{
	116	struct git_istream *st;
	117	enum object_type type;
	118	unsigned long sz;
	119	char buf[BLOCKSIZE];
	120	ssize_t readlen;
	121
	122	st = open_istream(sha1, &type, &sz, NULL);
	123	if (!st)
	124	return error("cannot stream blob %s", sha1_to_hex(sha1));
	125	for (;;) {
	126	readlen = read_istream(st, buf, sizeof(buf));
	127	if (readlen <= 0)
	128	break;
	129	do_write_blocked(buf, readlen);
	130	}
	131	close_istream(st);
	132	if (!readlen)
	133	finish_record();
	134	return readlen;
	135	}
	136
3d74982f RS	137	/*
	138	* pax extended header records have the format "%u %s=%s\n". %u contains
	139	* the size of the whole string (including the %u), the first %s is the
	140	* keyword, the second one is the value. This function constructs such a
	141	* string and appends it to a struct strbuf.
	142	*/
	143	static void strbuf_append_ext_header(struct strbuf sb, const char keyword,
	144	const char *value, unsigned int valuelen)
	145	{
7a604f16	146	int len, tmp;
3d74982f RS	147
	148	/* "%u %s=%s\n" */
	149	len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
	150	for (tmp = len; tmp > 9; tmp /= 10)
	151	len++;
	152
7a604f16 PH	153	strbuf_grow(sb, len);
	154	strbuf_addf(sb, "%u %s=", len, keyword);
	155	strbuf_add(sb, value, valuelen);
	156	strbuf_addch(sb, '\n');
3d74982f RS	157	}
3d74982f RS	158
d1657b57 JK	159	/*
	160	* Like strbuf_append_ext_header, but for numeric values.
	161	*/
	162	static void strbuf_append_ext_header_uint(struct strbuf *sb,
	163	const char *keyword,
	164	uintmax_t value)
	165	{
	166	char buf[40]; /* big enough for 2^128 in decimal, plus NUL */
	167	int len;
	168
	169	len = xsnprintf(buf, sizeof(buf), "%"PRIuMAX, value);
	170	strbuf_append_ext_header(sb, keyword, buf, len);
	171	}
	172
3d74982f RS	173	static unsigned int ustar_header_chksum(const struct ustar_header *header)
3d74982f RS	174	{
a5a46eb9	175	const unsigned char p = (const unsigned char )header;
3d74982f	176	unsigned int chksum = 0;
a5a46eb9	177	while (p < (const unsigned char *)header->chksum)
3d74982f RS	178	chksum += *p++;
	179	chksum += sizeof(header->chksum) * ' ';
	180	p += sizeof(header->chksum);
a5a46eb9	181	while (p < (const unsigned char *)header + sizeof(struct ustar_header))
3d74982f RS	182	chksum += *p++;
	183	return chksum;
	184	}
	185
562e25ab	186	static size_t get_path_prefix(const char *path, size_t pathlen, size_t maxlen)
3d74982f	187	{
562e25ab	188	size_t i = pathlen;
22f0dcd9 RS	189	if (i > 1 && path[i - 1] == '/')
22f0dcd9 RS	190	i--;
3d74982f RS	191	if (i > maxlen)
	192	i = maxlen;
	193	do {
	194	i--;
562e25ab	195	} while (i > 0 && path[i] != '/');
3d74982f RS	196	return i;
	197	}
	198
d240d410 NTND	199	static void prepare_header(struct archiver_args *args,
	200	struct ustar_header *header,
	201	unsigned int mode, unsigned long size)
	202	{
f2f02675 JK	203	xsnprintf(header->mode, sizeof(header->mode), "%07o", mode & 07777);
	204	xsnprintf(header->size, sizeof(header->size), "%011lo", S_ISREG(mode) ? size : 0);
	205	xsnprintf(header->mtime, sizeof(header->mtime), "%011lo", (unsigned long) args->time);
d240d410	206
f2f02675 JK	207	xsnprintf(header->uid, sizeof(header->uid), "%07o", 0);
f2f02675 JK	208	xsnprintf(header->gid, sizeof(header->gid), "%07o", 0);
d240d410 NTND	209	strlcpy(header->uname, "root", sizeof(header->uname));
d240d410 NTND	210	strlcpy(header->gname, "root", sizeof(header->gname));
f2f02675 JK	211	xsnprintf(header->devmajor, sizeof(header->devmajor), "%07o", 0);
f2f02675 JK	212	xsnprintf(header->devminor, sizeof(header->devminor), "%07o", 0);
d240d410 NTND	213
	214	memcpy(header->magic, "ustar", 6);
	215	memcpy(header->version, "00", 2);
	216
9e6c1e91	217	xsnprintf(header->chksum, sizeof(header->chksum), "%07o", ustar_header_chksum(header));
d240d410 NTND	218	}
d240d410 NTND	219
560b0e8f RS	220	static void write_extended_header(struct archiver_args *args,
	221	const unsigned char *sha1,
	222	const void *buffer, unsigned long size)
d240d410 NTND	223	{
	224	struct ustar_header header;
	225	unsigned int mode;
	226	memset(&header, 0, sizeof(header));
	227	*header.typeflag = TYPEFLAG_EXT_HEADER;
15c6ef7b	228	mode = 0100666;
f2f02675	229	xsnprintf(header.name, sizeof(header.name), "%s.paxheader", sha1_to_hex(sha1));
d240d410 NTND	230	prepare_header(args, &header, mode, size);
	231	write_blocked(&header, sizeof(header));
	232	write_blocked(buffer, size);
d240d410 NTND	233	}
d240d410 NTND	234
562e25ab	235	static int write_tar_entry(struct archiver_args *args,
9cb513b7 NTND	236	const unsigned char *sha1,
	237	const char *path, size_t pathlen,
	238	unsigned int mode)
3d74982f RS	239	{
3d74982f RS	240	struct ustar_header header;
f285a2d7	241	struct strbuf ext_header = STRBUF_INIT;
9cb513b7	242	unsigned int old_mode = mode;
d1657b57	243	unsigned long size, size_in_header;
9cb513b7	244	void *buffer;
562e25ab	245	int err = 0;
3d74982f RS	246
3d74982f RS	247	memset(&header, 0, sizeof(header));
3d74982f	248
85390709 NTND	249	if (S_ISDIR(mode) \|\| S_ISGITLINK(mode)) {
	250	*header.typeflag = TYPEFLAG_DIR;
	251	mode = (mode \| 0777) & ~tar_umask;
	252	} else if (S_ISLNK(mode)) {
	253	*header.typeflag = TYPEFLAG_LNK;
	254	mode \|= 0777;
	255	} else if (S_ISREG(mode)) {
	256	*header.typeflag = TYPEFLAG_REG;
	257	mode = (mode \| ((mode & 0100) ? 0777 : 0666)) & ~tar_umask;
3d74982f	258	} else {
85390709 NTND	259	return error("unsupported file mode: 0%o (SHA1: %s)",
	260	mode, sha1_to_hex(sha1));
	261	}
	262	if (pathlen > sizeof(header.name)) {
	263	size_t plen = get_path_prefix(path, pathlen,
	264	sizeof(header.prefix));
	265	size_t rest = pathlen - plen - 1;
	266	if (plen > 0 && rest <= sizeof(header.name)) {
	267	memcpy(header.prefix, path, plen);
108332c7	268	memcpy(header.name, path + plen + 1, rest);
3d74982f	269	} else {
f2f02675 JK	270	xsnprintf(header.name, sizeof(header.name), "%s.data",
f2f02675 JK	271	sha1_to_hex(sha1));
85390709 NTND	272	strbuf_append_ext_header(&ext_header, "path",
85390709 NTND	273	path, pathlen);
3d74982f	274	}
85390709 NTND	275	} else
85390709 NTND	276	memcpy(header.name, path, pathlen);
3d74982f	277
5544049d NTND	278	if (S_ISREG(mode) && !args->convert &&
	279	sha1_object_info(sha1, &size) == OBJ_BLOB &&
	280	size > big_file_threshold)
	281	buffer = NULL;
	282	else if (S_ISLNK(mode) \|\| S_ISREG(mode)) {
9cb513b7 NTND	283	enum object_type type;
	284	buffer = sha1_file_to_archive(args, path, sha1, old_mode, &type, &size);
	285	if (!buffer)
	286	return error("cannot read %s", sha1_to_hex(sha1));
	287	} else {
	288	buffer = NULL;
	289	size = 0;
	290	}
	291
	292	if (S_ISLNK(mode)) {
3d74982f	293	if (size > sizeof(header.linkname)) {
f2f02675 JK	294	xsnprintf(header.linkname, sizeof(header.linkname),
f2f02675 JK	295	"see %s.paxheader", sha1_to_hex(sha1));
3d74982f RS	296	strbuf_append_ext_header(&ext_header, "linkpath",
	297	buffer, size);
	298	} else
	299	memcpy(header.linkname, buffer, size);
	300	}
	301
d1657b57 JK	302	size_in_header = size;
	303	if (S_ISREG(mode) && size > USTAR_MAX_SIZE) {
	304	size_in_header = 0;
	305	strbuf_append_ext_header_uint(&ext_header, "size", size);
	306	}
	307
	308	prepare_header(args, &header, mode, size_in_header);
3d74982f RS	309
3d74982f RS	310	if (ext_header.len > 0) {
560b0e8f RS	311	write_extended_header(args, sha1, ext_header.buf,
560b0e8f RS	312	ext_header.len);
3d74982f	313	}
7a604f16	314	strbuf_release(&ext_header);
3d74982f	315	write_blocked(&header, sizeof(header));
5544049d NTND	316	if (S_ISREG(mode) && size > 0) {
	317	if (buffer)
	318	write_blocked(buffer, size);
	319	else
	320	err = stream_blocked(sha1);
	321	}
9cb513b7	322	free(buffer);
562e25ab	323	return err;
3d74982f RS	324	}
3d74982f RS	325
5caeeb83	326	static void write_global_extended_header(struct archiver_args *args)
3d74982f	327	{
562e25ab	328	const unsigned char *sha1 = args->commit_sha1;
f285a2d7	329	struct strbuf ext_header = STRBUF_INIT;
d240d410 NTND	330	struct ustar_header header;
d240d410 NTND	331	unsigned int mode;
7a604f16	332
6e8e0991 JK	333	if (sha1)
	334	strbuf_append_ext_header(&ext_header, "comment",
	335	sha1_to_hex(sha1), 40);
	336	if (args->time > USTAR_MAX_MTIME) {
	337	strbuf_append_ext_header_uint(&ext_header, "mtime",
	338	args->time);
	339	args->time = USTAR_MAX_MTIME;
	340	}
	341
	342	if (!ext_header.len)
5caeeb83	343	return;
6e8e0991	344
d240d410 NTND	345	memset(&header, 0, sizeof(header));
d240d410 NTND	346	*header.typeflag = TYPEFLAG_GLOBAL_HEADER;
15c6ef7b	347	mode = 0100666;
5096d490	348	xsnprintf(header.name, sizeof(header.name), "pax_global_header");
d240d410 NTND	349	prepare_header(args, &header, mode, ext_header.len);
	350	write_blocked(&header, sizeof(header));
	351	write_blocked(ext_header.buf, ext_header.len);
7a604f16	352	strbuf_release(&ext_header);
3d74982f RS	353	}
3d74982f RS	354
767cf457 JK	355	static struct archiver **tar_filters;
	356	static int nr_tar_filters;
	357	static int alloc_tar_filters;
	358
	359	static struct archiver find_tar_filter(const char name, int len)
	360	{
	361	int i;
	362	for (i = 0; i < nr_tar_filters; i++) {
	363	struct archiver *ar = tar_filters[i];
	364	if (!strncmp(ar->name, name, len) && !ar->name[len])
	365	return ar;
	366	}
	367	return NULL;
	368	}
	369
	370	static int tar_filter_config(const char var, const char value, void *data)
	371	{
	372	struct archiver *ar;
767cf457 JK	373	const char *name;
	374	const char *type;
	375	int namelen;
	376
785a0429	377	if (parse_config_key(var, "tar", &name, &namelen, &type) < 0 \|\| !name)
767cf457	378	return 0;
767cf457 JK	379
	380	ar = find_tar_filter(name, namelen);
	381	if (!ar) {
	382	ar = xcalloc(1, sizeof(*ar));
	383	ar->name = xmemdupz(name, namelen);
	384	ar->write_archive = write_tar_filter_archive;
	385	ar->flags = ARCHIVER_WANT_COMPRESSION_LEVELS;
	386	ALLOC_GROW(tar_filters, nr_tar_filters + 1, alloc_tar_filters);
	387	tar_filters[nr_tar_filters++] = ar;
	388	}
	389
	390	if (!strcmp(type, "command")) {
	391	if (!value)
	392	return config_error_nonbool(var);
	393	free(ar->data);
	394	ar->data = xstrdup(value);
	395	return 0;
	396	}
7b97730b JK	397	if (!strcmp(type, "remote")) {
	398	if (git_config_bool(var, value))
	399	ar->flags \|= ARCHIVER_REMOTE;
	400	else
	401	ar->flags &= ~ARCHIVER_REMOTE;
	402	return 0;
	403	}
767cf457 JK	404
	405	return 0;
	406	}
	407
ef90d6d4	408	static int git_tar_config(const char var, const char value, void *cb)
3d74982f RS	409	{
3d74982f RS	410	if (!strcmp(var, "tar.umask")) {
cc1816b0	411	if (value && !strcmp(value, "user")) {
3d74982f RS	412	tar_umask = umask(0);
	413	umask(tar_umask);
	414	} else {
	415	tar_umask = git_config_int(var, value);
	416	}
	417	return 0;
	418	}
767cf457 JK	419
767cf457 JK	420	return tar_filter_config(var, value, cb);
3d74982f RS	421	}
3d74982f RS	422
4d7c9898 JK	423	static int write_tar_archive(const struct archiver *ar,
4d7c9898 JK	424	struct archiver_args *args)
3d74982f	425	{
562e25ab	426	int err = 0;
3d74982f	427
5caeeb83 JK	428	write_global_extended_header(args);
5caeeb83 JK	429	err = write_archive_entries(args, write_tar_entry);
562e25ab RS	430	if (!err)
	431	write_trailer();
	432	return err;
3d74982f	433	}
13e0f88d	434
767cf457 JK	435	static int write_tar_filter_archive(const struct archiver *ar,
	436	struct archiver_args *args)
	437	{
	438	struct strbuf cmd = STRBUF_INIT;
d3180279	439	struct child_process filter = CHILD_PROCESS_INIT;
767cf457 JK	440	const char *argv[2];
	441	int r;
	442
	443	if (!ar->data)
	444	die("BUG: tar-filter archiver called with no filter defined");
	445
	446	strbuf_addstr(&cmd, ar->data);
	447	if (args->compression_level >= 0)
	448	strbuf_addf(&cmd, " -%d", args->compression_level);
	449
767cf457 JK	450	argv[0] = cmd.buf;
	451	argv[1] = NULL;
	452	filter.argv = argv;
	453	filter.use_shell = 1;
	454	filter.in = -1;
	455
	456	if (start_command(&filter) < 0)
	457	die_errno("unable to start '%s' filter", argv[0]);
	458	close(1);
	459	if (dup2(filter.in, 1) < 0)
	460	die_errno("unable to redirect descriptor");
	461	close(filter.in);
	462
	463	r = write_tar_archive(ar, args);
	464
	465	close(1);
	466	if (finish_command(&filter) != 0)
	467	die("'%s' filter reported error", argv[0]);
	468
	469	strbuf_release(&cmd);
	470	return r;
	471	}
	472
13e0f88d JK	473	static struct archiver tar_archiver = {
	474	"tar",
	475	write_tar_archive,
7b97730b	476	ARCHIVER_REMOTE
13e0f88d JK	477	};
	478
	479	void init_tar_archiver(void)
	480	{
767cf457	481	int i;
13e0f88d	482	register_archiver(&tar_archiver);
767cf457	483
0e804e09	484	tar_filter_config("tar.tgz.command", "gzip -cn", NULL);
7b97730b	485	tar_filter_config("tar.tgz.remote", "true", NULL);
0e804e09	486	tar_filter_config("tar.tar.gz.command", "gzip -cn", NULL);
7b97730b	487	tar_filter_config("tar.tar.gz.remote", "true", NULL);
13e0f88d	488	git_config(git_tar_config, NULL);
767cf457 JK	489	for (i = 0; i < nr_tar_filters; i++) {
	490	/* omit any filters that never had a command configured */
	491	if (tar_filters[i]->data)
	492	register_archiver(tar_filters[i]);
	493	}
13e0f88d	494	}