[thirdparty/git.git] / pkt-line.c

#include "cache.h"
#include "pkt-line.h"
#include "run-command.h"

char packet_buffer[LARGE_PACKET_MAX];
static const char *packet_trace_prefix = "git";
static struct trace_key trace_packet = TRACE_KEY_INIT(PACKET);
static struct trace_key trace_pack = TRACE_KEY_INIT(PACKFILE);

void packet_trace_identity(const char *prog)
{
	packet_trace_prefix = xstrdup(prog);
}

static const char *get_trace_prefix(void)
{
	return in_async() ? "sideband" : packet_trace_prefix;
}

static int packet_trace_pack(const char *buf, unsigned int len, int sideband)
{
	if (!sideband) {
		trace_verbatim(&trace_pack, buf, len);
		return 1;
	} else if (len && *buf == '\1') {
		trace_verbatim(&trace_pack, buf + 1, len - 1);
		return 1;
	} else {
		/* it's another non-pack sideband */
		return 0;
	}
}

static void packet_trace(const char *buf, unsigned int len, int write)
{
	int i;
	struct strbuf out;
	static int in_pack, sideband;

	if (!trace_want(&trace_packet) && !trace_want(&trace_pack))
		return;

	if (in_pack) {
		if (packet_trace_pack(buf, len, sideband))
			return;
	} else if (starts_with(buf, "PACK") || starts_with(buf, "\1PACK")) {
		in_pack = 1;
		sideband = *buf == '\1';
		packet_trace_pack(buf, len, sideband);

		/*
		 * Make a note in the human-readable trace that the pack data
		 * started.
		 */
		buf = "PACK ...";
		len = strlen(buf);
	}

	if (!trace_want(&trace_packet))
		return;

	/* +32 is just a guess for header + quoting */
	strbuf_init(&out, len+32);

	strbuf_addf(&out, "packet: %12s%c ",
		    get_trace_prefix(), write ? '>' : '<');

	/* XXX we should really handle printable utf8 */
	for (i = 0; i < len; i++) {
		/* suppress newlines */
		if (buf[i] == '\n')
			continue;
		if (buf[i] >= 0x20 && buf[i] <= 0x7e)
			strbuf_addch(&out, buf[i]);
		else
			strbuf_addf(&out, "\\%o", buf[i]);
	}

	strbuf_addch(&out, '\n');
	trace_strbuf(&trace_packet, &out);
	strbuf_release(&out);
}

/*
 * If we buffered things up above (we don't, but we should),
 * we'd flush it here
 */
void packet_flush(int fd)
{
	packet_trace("0000", 4, 1);
	write_or_die(fd, "0000", 4);
}

int packet_flush_gently(int fd)
{
	packet_trace("0000", 4, 1);
	if (write_in_full(fd, "0000", 4) < 0)
		return error("flush packet write failed");
	return 0;
}

void packet_buf_flush(struct strbuf *buf)
{
	packet_trace("0000", 4, 1);
	strbuf_add(buf, "0000", 4);
}

static void set_packet_header(char *buf, const int size)
{
	static char hexchar[] = "0123456789abcdef";

	#define hex(a) (hexchar[(a) & 15])
	buf[0] = hex(size >> 12);
	buf[1] = hex(size >> 8);
	buf[2] = hex(size >> 4);
	buf[3] = hex(size);
	#undef hex
}

static void format_packet(struct strbuf *out, const char *fmt, va_list args)
{
	size_t orig_len, n;

	orig_len = out->len;
	strbuf_addstr(out, "0000");
	strbuf_vaddf(out, fmt, args);
	n = out->len - orig_len;

	if (n > LARGE_PACKET_MAX)
		die("protocol error: impossibly long line");

	set_packet_header(&out->buf[orig_len], n);
	packet_trace(out->buf + orig_len + 4, n - 4, 1);
}

static int packet_write_fmt_1(int fd, int gently,
			      const char *fmt, va_list args)
{
	static struct strbuf buf = STRBUF_INIT;

	strbuf_reset(&buf);
	format_packet(&buf, fmt, args);
	if (write_in_full(fd, buf.buf, buf.len) < 0) {
		if (!gently) {
			check_pipe(errno);
			die_errno("packet write with format failed");
		}
		return error("packet write with format failed");
	}

	return 0;
}

void packet_write_fmt(int fd, const char *fmt, ...)
{
	va_list args;

	va_start(args, fmt);
	packet_write_fmt_1(fd, 0, fmt, args);
	va_end(args);
}

int packet_write_fmt_gently(int fd, const char *fmt, ...)
{
	int status;
	va_list args;

	va_start(args, fmt);
	status = packet_write_fmt_1(fd, 1, fmt, args);
	va_end(args);
	return status;
}

static int packet_write_gently(const int fd_out, const char *buf, size_t size)
{
	static char packet_write_buffer[LARGE_PACKET_MAX];
	size_t packet_size;

	if (size > sizeof(packet_write_buffer) - 4)
		return error("packet write failed - data exceeds max packet size");

	packet_trace(buf, size, 1);
	packet_size = size + 4;
	set_packet_header(packet_write_buffer, packet_size);
	memcpy(packet_write_buffer + 4, buf, size);
	if (write_in_full(fd_out, packet_write_buffer, packet_size) < 0)
		return error("packet write failed");
	return 0;
}

void packet_write(int fd_out, const char *buf, size_t size)
{
	if (packet_write_gently(fd_out, buf, size))
		die_errno("packet write failed");
}

void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
{
	va_list args;

	va_start(args, fmt);
	format_packet(buf, fmt, args);
	va_end(args);
}

int write_packetized_from_fd(int fd_in, int fd_out)
{
	static char buf[LARGE_PACKET_DATA_MAX];
	int err = 0;
	ssize_t bytes_to_write;

	while (!err) {
		bytes_to_write = xread(fd_in, buf, sizeof(buf));
		if (bytes_to_write < 0)
			return COPY_READ_ERROR;
		if (bytes_to_write == 0)
			break;
		err = packet_write_gently(fd_out, buf, bytes_to_write);
	}
	if (!err)
		err = packet_flush_gently(fd_out);
	return err;
}

int write_packetized_from_buf(const char *src_in, size_t len, int fd_out)
{
	int err = 0;
	size_t bytes_written = 0;
	size_t bytes_to_write;

	while (!err) {
		if ((len - bytes_written) > LARGE_PACKET_DATA_MAX)
			bytes_to_write = LARGE_PACKET_DATA_MAX;
		else
			bytes_to_write = len - bytes_written;
		if (bytes_to_write == 0)
			break;
		err = packet_write_gently(fd_out, src_in + bytes_written, bytes_to_write);
		bytes_written += bytes_to_write;
	}
	if (!err)
		err = packet_flush_gently(fd_out);
	return err;
}

static int get_packet_data(int fd, char **src_buf, size_t *src_size,
			   void *dst, unsigned size, int options)
{
	ssize_t ret;

	if (fd >= 0 && src_buf && *src_buf)
		die("BUG: multiple sources given to packet_read");

	/* Read up to "size" bytes from our source, whatever it is. */
	if (src_buf && *src_buf) {
		ret = size < *src_size ? size : *src_size;
		memcpy(dst, *src_buf, ret);
		*src_buf += ret;
		*src_size -= ret;
	} else {
		ret = read_in_full(fd, dst, size);
		if (ret < 0)
			die_errno("read error");
	}

	/* And complain if we didn't get enough bytes to satisfy the read. */
	if (ret != size) {
		if (options & PACKET_READ_GENTLE_ON_EOF)
			return -1;

		die("The remote end hung up unexpectedly");
	}

	return ret;
}

static int packet_length(const char *linelen)
{
	int val = hex2chr(linelen);
	return (val < 0) ? val : (val << 8) | hex2chr(linelen + 2);
}

int packet_read(int fd, char **src_buf, size_t *src_len,
		char *buffer, unsigned size, int options)
{
	int len, ret;
	char linelen[4];

	ret = get_packet_data(fd, src_buf, src_len, linelen, 4, options);
	if (ret < 0)
		return ret;
	len = packet_length(linelen);
	if (len < 0)
		die("protocol error: bad line length character: %.4s", linelen);
	if (!len) {
		packet_trace("0000", 4, 0);
		return 0;
	}
	len -= 4;
	if (len >= size)
		die("protocol error: bad line length %d", len);
	ret = get_packet_data(fd, src_buf, src_len, buffer, len, options);
	if (ret < 0)
		return ret;

	if ((options & PACKET_READ_CHOMP_NEWLINE) &&
	    len && buffer[len-1] == '\n')
		len--;

	buffer[len] = 0;
	packet_trace(buffer, len, 0);
	return len;
}

static char *packet_read_line_generic(int fd,
				      char **src, size_t *src_len,
				      int *dst_len)
{
	int len = packet_read(fd, src, src_len,
			      packet_buffer, sizeof(packet_buffer),
			      PACKET_READ_CHOMP_NEWLINE);
	if (dst_len)
		*dst_len = len;
	return (len > 0) ? packet_buffer : NULL;
}

char *packet_read_line(int fd, int *len_p)
{
	return packet_read_line_generic(fd, NULL, NULL, len_p);
}

int packet_read_line_gently(int fd, int *dst_len, char **dst_line)
{
	int len = packet_read(fd, NULL, NULL,
			      packet_buffer, sizeof(packet_buffer),
			      PACKET_READ_CHOMP_NEWLINE|PACKET_READ_GENTLE_ON_EOF);
	if (dst_len)
		*dst_len = len;
	if (dst_line)
		*dst_line = (len > 0) ? packet_buffer : NULL;
	return len;
}

char *packet_read_line_buf(char **src, size_t *src_len, int *dst_len)
{
	return packet_read_line_generic(-1, src, src_len, dst_len);
}

ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out)
{
	int packet_len;

	size_t orig_len = sb_out->len;
	size_t orig_alloc = sb_out->alloc;

	for (;;) {
		strbuf_grow(sb_out, LARGE_PACKET_DATA_MAX);
		packet_len = packet_read(fd_in, NULL, NULL,
			/* strbuf_grow() above always allocates one extra byte to
			 * store a '\0' at the end of the string. packet_read()
			 * writes a '\0' extra byte at the end, too. Let it know
			 * that there is already room for the extra byte.
			 */
			sb_out->buf + sb_out->len, LARGE_PACKET_DATA_MAX+1,
			PACKET_READ_GENTLE_ON_EOF);
		if (packet_len <= 0)
			break;
		sb_out->len += packet_len;
	}

	if (packet_len < 0) {
		if (orig_alloc == 0)
			strbuf_release(sb_out);
		else
			strbuf_setlen(sb_out, orig_len);
		return packet_len;
	}
	return sb_out->len - orig_len;
}
Commit	Line	Data
f3a3214e LT	1	#include "cache.h"
f3a3214e LT	2	#include "pkt-line.h"
fd89433d	3	#include "run-command.h"
f3a3214e	4
74543a04	5	char packet_buffer[LARGE_PACKET_MAX];
1e4cd68c	6	static const char *packet_trace_prefix = "git";
6aa30857	7	static struct trace_key trace_packet = TRACE_KEY_INIT(PACKET);
32359838	8	static struct trace_key trace_pack = TRACE_KEY_INIT(PACKFILE);
bbc30f99 JK	9
	10	void packet_trace_identity(const char *prog)
	11	{
	12	packet_trace_prefix = xstrdup(prog);
	13	}
	14
fd89433d JK	15	static const char *get_trace_prefix(void)
	16	{
	17	return in_async() ? "sideband" : packet_trace_prefix;
	18	}
	19
32359838 JK	20	static int packet_trace_pack(const char *buf, unsigned int len, int sideband)
	21	{
	22	if (!sideband) {
	23	trace_verbatim(&trace_pack, buf, len);
	24	return 1;
	25	} else if (len && *buf == '\1') {
	26	trace_verbatim(&trace_pack, buf + 1, len - 1);
	27	return 1;
	28	} else {
	29	/* it's another non-pack sideband */
	30	return 0;
	31	}
	32	}
	33
bbc30f99 JK	34	static void packet_trace(const char *buf, unsigned int len, int write)
	35	{
	36	int i;
	37	struct strbuf out;
32359838 JK	38	static int in_pack, sideband;
	39
	40	if (!trace_want(&trace_packet) && !trace_want(&trace_pack))
	41	return;
	42
	43	if (in_pack) {
	44	if (packet_trace_pack(buf, len, sideband))
	45	return;
	46	} else if (starts_with(buf, "PACK") \|\| starts_with(buf, "\1PACK")) {
	47	in_pack = 1;
	48	sideband = *buf == '\1';
	49	packet_trace_pack(buf, len, sideband);
	50
	51	/*
	52	* Make a note in the human-readable trace that the pack data
	53	* started.
	54	*/
	55	buf = "PACK ...";
	56	len = strlen(buf);
	57	}
bbc30f99	58
6aa30857	59	if (!trace_want(&trace_packet))
bbc30f99 JK	60	return;
	61
	62	/* +32 is just a guess for header + quoting */
	63	strbuf_init(&out, len+32);
	64
	65	strbuf_addf(&out, "packet: %12s%c ",
fd89433d	66	get_trace_prefix(), write ? '>' : '<');
bbc30f99	67
32359838 JK	68	/* XXX we should really handle printable utf8 */
	69	for (i = 0; i < len; i++) {
	70	/* suppress newlines */
	71	if (buf[i] == '\n')
	72	continue;
	73	if (buf[i] >= 0x20 && buf[i] <= 0x7e)
	74	strbuf_addch(&out, buf[i]);
	75	else
	76	strbuf_addf(&out, "\\%o", buf[i]);
bbc30f99 JK	77	}
	78
	79	strbuf_addch(&out, '\n');
6aa30857	80	trace_strbuf(&trace_packet, &out);
bbc30f99 JK	81	strbuf_release(&out);
	82	}
	83
f3a3214e LT	84	/*
	85	* If we buffered things up above (we don't, but we should),
	86	* we'd flush it here
	87	*/
	88	void packet_flush(int fd)
	89	{
bbc30f99	90	packet_trace("0000", 4, 1);
cdf4fb8e	91	write_or_die(fd, "0000", 4);
f3a3214e LT	92	}
f3a3214e LT	93
038ce90f LS	94	int packet_flush_gently(int fd)
	95	{
	96	packet_trace("0000", 4, 1);
4c95e3dd JK	97	if (write_in_full(fd, "0000", 4) < 0)
	98	return error("flush packet write failed");
	99	return 0;
038ce90f LS	100	}
038ce90f LS	101
f5615d24 SP	102	void packet_buf_flush(struct strbuf *buf)
f5615d24 SP	103	{
bbc30f99	104	packet_trace("0000", 4, 1);
f5615d24 SP	105	strbuf_add(buf, "0000", 4);
	106	}
	107
2f60bdd1	108	static void set_packet_header(char *buf, const int size)
f3a3214e	109	{
f3a3214e	110	static char hexchar[] = "0123456789abcdef";
2f60bdd1 LS	111
	112	#define hex(a) (hexchar[(a) & 15])
	113	buf[0] = hex(size >> 12);
	114	buf[1] = hex(size >> 8);
	115	buf[2] = hex(size >> 4);
	116	buf[3] = hex(size);
	117	#undef hex
	118	}
	119
	120	static void format_packet(struct strbuf out, const char fmt, va_list args)
	121	{
8e9faf27	122	size_t orig_len, n;
f3a3214e	123
8e9faf27 JK	124	orig_len = out->len;
	125	strbuf_addstr(out, "0000");
	126	strbuf_vaddf(out, fmt, args);
	127	n = out->len - orig_len;
	128
	129	if (n > LARGE_PACKET_MAX)
f3a3214e	130	die("protocol error: impossibly long line");
8e9faf27	131
2f60bdd1	132	set_packet_header(&out->buf[orig_len], n);
8e9faf27	133	packet_trace(out->buf + orig_len + 4, n - 4, 1);
f5615d24 SP	134	}
f5615d24 SP	135
70428d1a LS	136	static int packet_write_fmt_1(int fd, int gently,
	137	const char *fmt, va_list args)
	138	{
150efef1	139	static struct strbuf buf = STRBUF_INIT;
70428d1a	140
150efef1	141	strbuf_reset(&buf);
70428d1a	142	format_packet(&buf, fmt, args);
4c95e3dd JK	143	if (write_in_full(fd, buf.buf, buf.len) < 0) {
	144	if (!gently) {
	145	check_pipe(errno);
	146	die_errno("packet write with format failed");
	147	}
	148	return error("packet write with format failed");
70428d1a	149	}
4c95e3dd JK	150
4c95e3dd JK	151	return 0;
70428d1a LS	152	}
70428d1a LS	153
81c634e9	154	void packet_write_fmt(int fd, const char *fmt, ...)
f5615d24 SP	155	{
f5615d24 SP	156	va_list args;
f5615d24 SP	157
f5615d24 SP	158	va_start(args, fmt);
70428d1a LS	159	packet_write_fmt_1(fd, 0, fmt, args);
	160	va_end(args);
	161	}
	162
	163	int packet_write_fmt_gently(int fd, const char *fmt, ...)
	164	{
	165	int status;
	166	va_list args;
	167
	168	va_start(args, fmt);
	169	status = packet_write_fmt_1(fd, 1, fmt, args);
f5615d24	170	va_end(args);
70428d1a	171	return status;
f3a3214e LT	172	}
f3a3214e LT	173
edfb780c LS	174	static int packet_write_gently(const int fd_out, const char *buf, size_t size)
	175	{
	176	static char packet_write_buffer[LARGE_PACKET_MAX];
	177	size_t packet_size;
	178
	179	if (size > sizeof(packet_write_buffer) - 4)
	180	return error("packet write failed - data exceeds max packet size");
	181
	182	packet_trace(buf, size, 1);
	183	packet_size = size + 4;
	184	set_packet_header(packet_write_buffer, packet_size);
	185	memcpy(packet_write_buffer + 4, buf, size);
4c95e3dd JK	186	if (write_in_full(fd_out, packet_write_buffer, packet_size) < 0)
	187	return error("packet write failed");
	188	return 0;
edfb780c LS	189	}
edfb780c LS	190
5d2124b3 BW	191	void packet_write(int fd_out, const char *buf, size_t size)
	192	{
	193	if (packet_write_gently(fd_out, buf, size))
	194	die_errno("packet write failed");
	195	}
	196
f5615d24 SP	197	void packet_buf_write(struct strbuf buf, const char fmt, ...)
	198	{
	199	va_list args;
f5615d24 SP	200
f5615d24 SP	201	va_start(args, fmt);
8e9faf27	202	format_packet(buf, fmt, args);
f5615d24	203	va_end(args);
f5615d24 SP	204	}
f5615d24 SP	205
bb643d8b LS	206	int write_packetized_from_fd(int fd_in, int fd_out)
	207	{
	208	static char buf[LARGE_PACKET_DATA_MAX];
	209	int err = 0;
	210	ssize_t bytes_to_write;
	211
	212	while (!err) {
	213	bytes_to_write = xread(fd_in, buf, sizeof(buf));
	214	if (bytes_to_write < 0)
	215	return COPY_READ_ERROR;
	216	if (bytes_to_write == 0)
	217	break;
	218	err = packet_write_gently(fd_out, buf, bytes_to_write);
	219	}
	220	if (!err)
	221	err = packet_flush_gently(fd_out);
	222	return err;
	223	}
	224
	225	int write_packetized_from_buf(const char *src_in, size_t len, int fd_out)
	226	{
	227	int err = 0;
	228	size_t bytes_written = 0;
	229	size_t bytes_to_write;
	230
	231	while (!err) {
	232	if ((len - bytes_written) > LARGE_PACKET_DATA_MAX)
	233	bytes_to_write = LARGE_PACKET_DATA_MAX;
	234	else
	235	bytes_to_write = len - bytes_written;
	236	if (bytes_to_write == 0)
	237	break;
	238	err = packet_write_gently(fd_out, src_in + bytes_written, bytes_to_write);
	239	bytes_written += bytes_to_write;
	240	}
	241	if (!err)
	242	err = packet_flush_gently(fd_out);
	243	return err;
	244	}
	245
4981fe75 JK	246	static int get_packet_data(int fd, char *src_buf, size_t src_size,
4981fe75 JK	247	void *dst, unsigned size, int options)
f3a3214e	248	{
4981fe75 JK	249	ssize_t ret;
	250
	251	if (fd >= 0 && src_buf && *src_buf)
	252	die("BUG: multiple sources given to packet_read");
	253
	254	/* Read up to "size" bytes from our source, whatever it is. */
	255	if (src_buf && *src_buf) {
	256	ret = size < src_size ? size : src_size;
	257	memcpy(dst, *src_buf, ret);
	258	*src_buf += ret;
	259	*src_size -= ret;
	260	} else {
	261	ret = read_in_full(fd, dst, size);
	262	if (ret < 0)
	263	die_errno("read error");
	264	}
	265
	266	/* And complain if we didn't get enough bytes to satisfy the read. */
61d36330	267	if (ret != size) {
03809429	268	if (options & PACKET_READ_GENTLE_ON_EOF)
46284dd1 HV	269	return -1;
46284dd1 HV	270
c697ad14	271	die("The remote end hung up unexpectedly");
46284dd1 HV	272	}
	273
	274	return ret;
f3a3214e LT	275	}
f3a3214e LT	276
f5615d24	277	static int packet_length(const char *linelen)
f3a3214e	278	{
d2330973 RS	279	int val = hex2chr(linelen);
d2330973 RS	280	return (val < 0) ? val : (val << 8) \| hex2chr(linelen + 2);
f5615d24 SP	281	}
f5615d24 SP	282
4981fe75 JK	283	int packet_read(int fd, char *src_buf, size_t src_len,
4981fe75 JK	284	char *buffer, unsigned size, int options)
f5615d24	285	{
46284dd1	286	int len, ret;
f5615d24 SP	287	char linelen[4];
f5615d24 SP	288
4981fe75	289	ret = get_packet_data(fd, src_buf, src_len, linelen, 4, options);
03809429	290	if (ret < 0)
46284dd1	291	return ret;
f5615d24 SP	292	len = packet_length(linelen);
f5615d24 SP	293	if (len < 0)
743c4b7b	294	die("protocol error: bad line length character: %.4s", linelen);
bbc30f99 JK	295	if (!len) {
bbc30f99 JK	296	packet_trace("0000", 4, 0);
f3a3214e	297	return 0;
bbc30f99	298	}
f3a3214e LT	299	len -= 4;
	300	if (len >= size)
	301	die("protocol error: bad line length %d", len);
4981fe75	302	ret = get_packet_data(fd, src_buf, src_len, buffer, len, options);
03809429	303	if (ret < 0)
46284dd1	304	return ret;
819b929d JK	305
	306	if ((options & PACKET_READ_CHOMP_NEWLINE) &&
	307	len && buffer[len-1] == '\n')
	308	len--;
	309
f3a3214e	310	buffer[len] = 0;
bbc30f99	311	packet_trace(buffer, len, 0);
f3a3214e LT	312	return len;
f3a3214e LT	313	}
f5615d24	314
4981fe75 JK	315	static char *packet_read_line_generic(int fd,
	316	char *src, size_t src_len,
	317	int *dst_len)
46284dd1	318	{
4981fe75 JK	319	int len = packet_read(fd, src, src_len,
4981fe75 JK	320	packet_buffer, sizeof(packet_buffer),
74543a04	321	PACKET_READ_CHOMP_NEWLINE);
4981fe75 JK	322	if (dst_len)
4981fe75 JK	323	*dst_len = len;
974b50c5	324	return (len > 0) ? packet_buffer : NULL;
46284dd1 HV	325	}
46284dd1 HV	326
4981fe75	327	char packet_read_line(int fd, int len_p)
f5615d24	328	{
4981fe75 JK	329	return packet_read_line_generic(fd, NULL, NULL, len_p);
4981fe75 JK	330	}
f5615d24	331
825b9226 BP	332	int packet_read_line_gently(int fd, int dst_len, char *dst_line)
	333	{
	334	int len = packet_read(fd, NULL, NULL,
	335	packet_buffer, sizeof(packet_buffer),
	336	PACKET_READ_CHOMP_NEWLINE\|PACKET_READ_GENTLE_ON_EOF);
	337	if (dst_len)
	338	*dst_len = len;
	339	if (dst_line)
	340	*dst_line = (len > 0) ? packet_buffer : NULL;
	341	return len;
	342	}
	343
4981fe75 JK	344	char packet_read_line_buf(char src, size_t src_len, int *dst_len)
	345	{
	346	return packet_read_line_generic(-1, src, src_len, dst_len);
f5615d24	347	}
bb643d8b LS	348
	349	ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out)
	350	{
	351	int packet_len;
	352
	353	size_t orig_len = sb_out->len;
	354	size_t orig_alloc = sb_out->alloc;
	355
	356	for (;;) {
	357	strbuf_grow(sb_out, LARGE_PACKET_DATA_MAX);
	358	packet_len = packet_read(fd_in, NULL, NULL,
	359	/* strbuf_grow() above always allocates one extra byte to
	360	* store a '\0' at the end of the string. packet_read()
	361	* writes a '\0' extra byte at the end, too. Let it know
	362	* that there is already room for the extra byte.
	363	*/
	364	sb_out->buf + sb_out->len, LARGE_PACKET_DATA_MAX+1,
	365	PACKET_READ_GENTLE_ON_EOF);
	366	if (packet_len <= 0)
	367	break;
	368	sb_out->len += packet_len;
	369	}
	370
	371	if (packet_len < 0) {
	372	if (orig_alloc == 0)
	373	strbuf_release(sb_out);
	374	else
	375	strbuf_setlen(sb_out, orig_len);
	376	return packet_len;
	377	}
	378	return sb_out->len - orig_len;
	379	}