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

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

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

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

static int tar_umask = 002;

/* 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 write_blocked(const void *data, unsigned long size)
{
	const char *buf = data;
	unsigned long tail;

	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;
	}
	tail = offset % RECORDSIZE;
	if (tail)  {
		memset(block + offset, 0, RECORDSIZE - tail);
		offset += RECORDSIZE - tail;
	}
	write_if_needed();
}

/*
 * 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);
	}
}

/*
 * 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');
}

static unsigned int ustar_header_chksum(const struct ustar_header *header)
{
	char *p = (char *)header;
	unsigned int chksum = 0;
	while (p < header->chksum)
		chksum += *p++;
	chksum += sizeof(header->chksum) * ' ';
	p += sizeof(header->chksum);
	while (p < (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 > maxlen)
		i = maxlen;
	do {
		i--;
	} while (i > 0 && path[i] != '/');
	return i;
}

static int write_tar_entry(struct archiver_args *args,
		const unsigned char *sha1, const char *path, size_t pathlen,
		unsigned int mode, void *buffer, unsigned long size)
{
	struct ustar_header header;
	struct strbuf ext_header;
	int err = 0;

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

	if (!sha1) {
		*header.typeflag = TYPEFLAG_GLOBAL_HEADER;
		mode = 0100666;
		strcpy(header.name, "pax_global_header");
	} else if (!path) {
		*header.typeflag = TYPEFLAG_EXT_HEADER;
		mode = 0100666;
		sprintf(header.name, "%s.paxheader", sha1_to_hex(sha1));
	} else {
		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 {
				sprintf(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_ISLNK(mode) && buffer) {
		if (size > sizeof(header.linkname)) {
			sprintf(header.linkname, "see %s.paxheader",
			        sha1_to_hex(sha1));
			strbuf_append_ext_header(&ext_header, "linkpath",
			                         buffer, size);
		} else
			memcpy(header.linkname, buffer, size);
	}

	sprintf(header.mode, "%07o", mode & 07777);
	sprintf(header.size, "%011lo", S_ISREG(mode) ? size : 0);
	sprintf(header.mtime, "%011lo", args->time);

	sprintf(header.uid, "%07o", 0);
	sprintf(header.gid, "%07o", 0);
	strlcpy(header.uname, "root", sizeof(header.uname));
	strlcpy(header.gname, "root", sizeof(header.gname));
	sprintf(header.devmajor, "%07o", 0);
	sprintf(header.devminor, "%07o", 0);

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

	sprintf(header.chksum, "%07o", ustar_header_chksum(&header));

	if (ext_header.len > 0) {
		err = write_tar_entry(args, sha1, NULL, 0, 0, ext_header.buf,
				ext_header.len);
		if (err)
			return err;
	}
	strbuf_release(&ext_header);
	write_blocked(&header, sizeof(header));
	if (S_ISREG(mode) && buffer && size > 0)
		write_blocked(buffer, size);
	return err;
}

static int write_global_extended_header(struct archiver_args *args)
{
	const unsigned char *sha1 = args->commit_sha1;
	struct strbuf ext_header;
	int err;

	strbuf_init(&ext_header, 0);
	strbuf_append_ext_header(&ext_header, "comment", sha1_to_hex(sha1), 40);
	err = write_tar_entry(args, NULL, NULL, 0, 0, ext_header.buf,
			ext_header.len);
	strbuf_release(&ext_header);
	return err;
}

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 git_default_config(var, value, cb);
}

int write_tar_archive(struct archiver_args *args)
{
	int err = 0;

	git_config(git_tar_config, NULL);

	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;
}
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 RS	6	#include "archive.h"
	7
	8	#define RECORDSIZE (512)
	9	#define BLOCKSIZE (RECORDSIZE * 20)
	10
	11	static char block[BLOCKSIZE];
	12	static unsigned long offset;
	13
f08b3b0e	14	static int tar_umask = 002;
3d74982f RS	15
	16	/* writes out the whole block, but only if it is full */
	17	static void write_if_needed(void)
	18	{
	19	if (offset == BLOCKSIZE) {
	20	write_or_die(1, block, BLOCKSIZE);
	21	offset = 0;
	22	}
	23	}
	24
	25	/*
	26	* queues up writes, so that all our write(2) calls write exactly one
	27	* full block; pads writes to RECORDSIZE
	28	*/
	29	static void write_blocked(const void *data, unsigned long size)
	30	{
	31	const char *buf = data;
	32	unsigned long tail;
	33
	34	if (offset) {
	35	unsigned long chunk = BLOCKSIZE - offset;
	36	if (size < chunk)
	37	chunk = size;
	38	memcpy(block + offset, buf, chunk);
	39	size -= chunk;
	40	offset += chunk;
	41	buf += chunk;
	42	write_if_needed();
	43	}
	44	while (size >= BLOCKSIZE) {
	45	write_or_die(1, buf, BLOCKSIZE);
	46	size -= BLOCKSIZE;
	47	buf += BLOCKSIZE;
	48	}
	49	if (size) {
	50	memcpy(block + offset, buf, size);
	51	offset += size;
	52	}
	53	tail = offset % RECORDSIZE;
	54	if (tail) {
	55	memset(block + offset, 0, RECORDSIZE - tail);
	56	offset += RECORDSIZE - tail;
	57	}
	58	write_if_needed();
	59	}
	60
	61	/*
	62	* The end of tar archives is marked by 2*512 nul bytes and after that
	63	* follows the rest of the block (if any).
	64	*/
	65	static void write_trailer(void)
	66	{
	67	int tail = BLOCKSIZE - offset;
	68	memset(block + offset, 0, tail);
	69	write_or_die(1, block, BLOCKSIZE);
	70	if (tail < 2 * RECORDSIZE) {
	71	memset(block, 0, offset);
	72	write_or_die(1, block, BLOCKSIZE);
	73	}
	74	}
	75
3d74982f RS	76	/*
	77	* pax extended header records have the format "%u %s=%s\n". %u contains
	78	* the size of the whole string (including the %u), the first %s is the
	79	* keyword, the second one is the value. This function constructs such a
	80	* string and appends it to a struct strbuf.
	81	*/
	82	static void strbuf_append_ext_header(struct strbuf sb, const char keyword,
	83	const char *value, unsigned int valuelen)
	84	{
7a604f16	85	int len, tmp;
3d74982f RS	86
	87	/* "%u %s=%s\n" */
	88	len = 1 + 1 + strlen(keyword) + 1 + valuelen + 1;
	89	for (tmp = len; tmp > 9; tmp /= 10)
	90	len++;
	91
7a604f16 PH	92	strbuf_grow(sb, len);
	93	strbuf_addf(sb, "%u %s=", len, keyword);
	94	strbuf_add(sb, value, valuelen);
	95	strbuf_addch(sb, '\n');
3d74982f RS	96	}
	97
	98	static unsigned int ustar_header_chksum(const struct ustar_header *header)
	99	{
	100	char p = (char )header;
	101	unsigned int chksum = 0;
	102	while (p < header->chksum)
	103	chksum += *p++;
	104	chksum += sizeof(header->chksum) * ' ';
	105	p += sizeof(header->chksum);
	106	while (p < (char *)header + sizeof(struct ustar_header))
	107	chksum += *p++;
	108	return chksum;
	109	}
	110
562e25ab	111	static size_t get_path_prefix(const char *path, size_t pathlen, size_t maxlen)
3d74982f	112	{
562e25ab	113	size_t i = pathlen;
3d74982f RS	114	if (i > maxlen)
	115	i = maxlen;
	116	do {
	117	i--;
562e25ab	118	} while (i > 0 && path[i] != '/');
3d74982f RS	119	return i;
	120	}
	121
562e25ab RS	122	static int write_tar_entry(struct archiver_args *args,
	123	const unsigned char sha1, const char path, size_t pathlen,
	124	unsigned int mode, void *buffer, unsigned long size)
3d74982f RS	125	{
	126	struct ustar_header header;
	127	struct strbuf ext_header;
562e25ab	128	int err = 0;
3d74982f RS	129
3d74982f RS	130	memset(&header, 0, sizeof(header));
f1696ee3	131	strbuf_init(&ext_header, 0);
3d74982f RS	132
	133	if (!sha1) {
	134	*header.typeflag = TYPEFLAG_GLOBAL_HEADER;
	135	mode = 0100666;
	136	strcpy(header.name, "pax_global_header");
	137	} else if (!path) {
	138	*header.typeflag = TYPEFLAG_EXT_HEADER;
	139	mode = 0100666;
	140	sprintf(header.name, "%s.paxheader", sha1_to_hex(sha1));
	141	} else {
302b9282	142	if (S_ISDIR(mode) \|\| S_ISGITLINK(mode)) {
3d74982f RS	143	*header.typeflag = TYPEFLAG_DIR;
	144	mode = (mode \| 0777) & ~tar_umask;
	145	} else if (S_ISLNK(mode)) {
	146	*header.typeflag = TYPEFLAG_LNK;
	147	mode \|= 0777;
	148	} else if (S_ISREG(mode)) {
	149	*header.typeflag = TYPEFLAG_REG;
	150	mode = (mode \| ((mode & 0100) ? 0777 : 0666)) & ~tar_umask;
	151	} else {
562e25ab RS	152	return error("unsupported file mode: 0%o (SHA1: %s)",
562e25ab RS	153	mode, sha1_to_hex(sha1));
3d74982f	154	}
562e25ab RS	155	if (pathlen > sizeof(header.name)) {
	156	size_t plen = get_path_prefix(path, pathlen,
	157	sizeof(header.prefix));
	158	size_t rest = pathlen - plen - 1;
3d74982f	159	if (plen > 0 && rest <= sizeof(header.name)) {
562e25ab RS	160	memcpy(header.prefix, path, plen);
562e25ab RS	161	memcpy(header.name, path + plen + 1, rest);
3d74982f RS	162	} else {
	163	sprintf(header.name, "%s.data",
	164	sha1_to_hex(sha1));
	165	strbuf_append_ext_header(&ext_header, "path",
562e25ab	166	path, pathlen);
3d74982f RS	167	}
3d74982f RS	168	} else
562e25ab	169	memcpy(header.name, path, pathlen);
3d74982f RS	170	}
	171
	172	if (S_ISLNK(mode) && buffer) {
	173	if (size > sizeof(header.linkname)) {
	174	sprintf(header.linkname, "see %s.paxheader",
	175	sha1_to_hex(sha1));
	176	strbuf_append_ext_header(&ext_header, "linkpath",
	177	buffer, size);
	178	} else
	179	memcpy(header.linkname, buffer, size);
	180	}
	181
	182	sprintf(header.mode, "%07o", mode & 07777);
	183	sprintf(header.size, "%011lo", S_ISREG(mode) ? size : 0);
562e25ab	184	sprintf(header.mtime, "%011lo", args->time);
3d74982f	185
3d74982f RS	186	sprintf(header.uid, "%07o", 0);
3d74982f RS	187	sprintf(header.gid, "%07o", 0);
f08b3b0e RS	188	strlcpy(header.uname, "root", sizeof(header.uname));
f08b3b0e RS	189	strlcpy(header.gname, "root", sizeof(header.gname));
3d74982f RS	190	sprintf(header.devmajor, "%07o", 0);
	191	sprintf(header.devminor, "%07o", 0);
	192
	193	memcpy(header.magic, "ustar", 6);
	194	memcpy(header.version, "00", 2);
	195
	196	sprintf(header.chksum, "%07o", ustar_header_chksum(&header));
	197
	198	if (ext_header.len > 0) {
562e25ab RS	199	err = write_tar_entry(args, sha1, NULL, 0, 0, ext_header.buf,
	200	ext_header.len);
	201	if (err)
	202	return err;
3d74982f	203	}
7a604f16	204	strbuf_release(&ext_header);
3d74982f RS	205	write_blocked(&header, sizeof(header));
	206	if (S_ISREG(mode) && buffer && size > 0)
	207	write_blocked(buffer, size);
562e25ab	208	return err;
3d74982f RS	209	}
3d74982f RS	210
562e25ab	211	static int write_global_extended_header(struct archiver_args *args)
3d74982f	212	{
562e25ab	213	const unsigned char *sha1 = args->commit_sha1;
3d74982f	214	struct strbuf ext_header;
562e25ab	215	int err;
7a604f16	216
f1696ee3	217	strbuf_init(&ext_header, 0);
3d74982f	218	strbuf_append_ext_header(&ext_header, "comment", sha1_to_hex(sha1), 40);
562e25ab RS	219	err = write_tar_entry(args, NULL, NULL, 0, 0, ext_header.buf,
562e25ab RS	220	ext_header.len);
7a604f16	221	strbuf_release(&ext_header);
562e25ab	222	return err;
3d74982f RS	223	}
3d74982f RS	224
ef90d6d4	225	static int git_tar_config(const char var, const char value, void *cb)
3d74982f RS	226	{
3d74982f RS	227	if (!strcmp(var, "tar.umask")) {
cc1816b0	228	if (value && !strcmp(value, "user")) {
3d74982f RS	229	tar_umask = umask(0);
	230	umask(tar_umask);
	231	} else {
	232	tar_umask = git_config_int(var, value);
	233	}
	234	return 0;
	235	}
ef90d6d4	236	return git_default_config(var, value, cb);
3d74982f RS	237	}
3d74982f RS	238
3d74982f RS	239	int write_tar_archive(struct archiver_args *args)
3d74982f RS	240	{
562e25ab	241	int err = 0;
3d74982f	242
562e25ab	243	git_config(git_tar_config, NULL);
3d74982f RS	244
3d74982f RS	245	if (args->commit_sha1)
562e25ab RS	246	err = write_global_extended_header(args);
	247	if (!err)
	248	err = write_archive_entries(args, write_tar_entry);
	249	if (!err)
	250	write_trailer();
	251	return err;
3d74982f	252	}