git

1
#include "git-compat-util.h"
2
#include "copy.h"
3
#include "pkt-line.h"
4
#include "gettext.h"
5
#include "hex.h"
6
#include "run-command.h"
7
#include "sideband.h"
8
#include "trace.h"
9
#include "write-or-die.h"
10

11
char packet_buffer[LARGE_PACKET_MAX];
12
static const char *packet_trace_prefix = "git";
13
static struct trace_key trace_packet = TRACE_KEY_INIT(PACKET);
14
static struct trace_key trace_pack = TRACE_KEY_INIT(PACKFILE);
15

16
void packet_trace_identity(const char *prog)
17
{
18
	packet_trace_prefix = xstrdup(prog);
19
}
20

21
static const char *get_trace_prefix(void)
22
{
23
	return in_async() ? "sideband" : packet_trace_prefix;
24
}
25

26
static int packet_trace_pack(const char *buf, unsigned int len, int sideband)
27
{
28
	if (!sideband) {
29
		trace_verbatim(&trace_pack, buf, len);
30
		return 1;
31
	} else if (len && *buf == '\1') {
32
		trace_verbatim(&trace_pack, buf + 1, len - 1);
33
		return 1;
34
	} else {
35
		/* it's another non-pack sideband */
36
		return 0;
37
	}
38
}
39

40
static void packet_trace(const char *buf, unsigned int len, int write)
41
{
42
	int i;
43
	struct strbuf out;
44
	static int in_pack, sideband;
45

46
	if (!trace_want(&trace_packet) && !trace_want(&trace_pack))
47
		return;
48

49
	if (in_pack) {
50
		if (packet_trace_pack(buf, len, sideband))
51
			return;
52
	} else if (starts_with(buf, "PACK") || starts_with(buf, "\1PACK")) {
53
		in_pack = 1;
54
		sideband = *buf == '\1';
55
		packet_trace_pack(buf, len, sideband);
56

57
		/*
58
		 * Make a note in the human-readable trace that the pack data
59
		 * started.
60
		 */
61
		buf = "PACK ...";
62
		len = strlen(buf);
63
	}
64

65
	if (!trace_want(&trace_packet))
66
		return;
67

68
	/* +32 is just a guess for header + quoting */
69
	strbuf_init(&out, len+32);
70

71
	strbuf_addf(&out, "packet: %12s%c ",
72
		    get_trace_prefix(), write ? '>' : '<');
73

74
	/* XXX we should really handle printable utf8 */
75
	for (i = 0; i < len; i++) {
76
		/* suppress newlines */
77
		if (buf[i] == '\n')
78
			continue;
79
		if (buf[i] >= 0x20 && buf[i] <= 0x7e)
80
			strbuf_addch(&out, buf[i]);
81
		else
82
			strbuf_addf(&out, "\\%o", buf[i]);
83
	}
84

85
	strbuf_addch(&out, '\n');
86
	trace_strbuf(&trace_packet, &out);
87
	strbuf_release(&out);
88
}
89

90
/*
91
 * If we buffered things up above (we don't, but we should),
92
 * we'd flush it here
93
 */
94
void packet_flush(int fd)
95
{
96
	packet_trace("0000", 4, 1);
97
	if (write_in_full(fd, "0000", 4) < 0)
98
		die_errno(_("unable to write flush packet"));
99
}
100

101
void packet_delim(int fd)
102
{
103
	packet_trace("0001", 4, 1);
104
	if (write_in_full(fd, "0001", 4) < 0)
105
		die_errno(_("unable to write delim packet"));
106
}
107

108
void packet_response_end(int fd)
109
{
110
	packet_trace("0002", 4, 1);
111
	if (write_in_full(fd, "0002", 4) < 0)
112
		die_errno(_("unable to write response end packet"));
113
}
114

115
int packet_flush_gently(int fd)
116
{
117
	packet_trace("0000", 4, 1);
118
	if (write_in_full(fd, "0000", 4) < 0)
119
		return error(_("flush packet write failed"));
120
	return 0;
121
}
122

123
void packet_buf_flush(struct strbuf *buf)
124
{
125
	packet_trace("0000", 4, 1);
126
	strbuf_add(buf, "0000", 4);
127
}
128

129
void packet_buf_delim(struct strbuf *buf)
130
{
131
	packet_trace("0001", 4, 1);
132
	strbuf_add(buf, "0001", 4);
133
}
134

135
void set_packet_header(char *buf, int size)
136
{
137
	static char hexchar[] = "0123456789abcdef";
138

139
	#define hex(a) (hexchar[(a) & 15])
140
	buf[0] = hex(size >> 12);
141
	buf[1] = hex(size >> 8);
142
	buf[2] = hex(size >> 4);
143
	buf[3] = hex(size);
144
	#undef hex
145
}
146

147
static void format_packet(struct strbuf *out, const char *prefix,
148
			  const char *fmt, va_list args)
149
{
150
	size_t orig_len, n;
151

152
	orig_len = out->len;
153
	strbuf_addstr(out, "0000");
154
	strbuf_addstr(out, prefix);
155
	strbuf_vaddf(out, fmt, args);
156
	n = out->len - orig_len;
157

158
	if (n > LARGE_PACKET_MAX)
159
		die(_("protocol error: impossibly long line"));
160

161
	set_packet_header(&out->buf[orig_len], n);
162
	packet_trace(out->buf + orig_len + 4, n - 4, 1);
163
}
164

165
static int packet_write_fmt_1(int fd, int gently, const char *prefix,
166
			      const char *fmt, va_list args)
167
{
168
	static struct strbuf buf = STRBUF_INIT;
169

170
	strbuf_reset(&buf);
171
	format_packet(&buf, prefix, fmt, args);
172
	if (write_in_full(fd, buf.buf, buf.len) < 0) {
173
		if (!gently) {
174
			check_pipe(errno);
175
			die_errno(_("packet write with format failed"));
176
		}
177
		return error(_("packet write with format failed"));
178
	}
179

180
	return 0;
181
}
182

183
void packet_write_fmt(int fd, const char *fmt, ...)
184
{
185
	va_list args;
186

187
	va_start(args, fmt);
188
	packet_write_fmt_1(fd, 0, "", fmt, args);
189
	va_end(args);
190
}
191

192
int packet_write_fmt_gently(int fd, const char *fmt, ...)
193
{
194
	int status;
195
	va_list args;
196

197
	va_start(args, fmt);
198
	status = packet_write_fmt_1(fd, 1, "", fmt, args);
199
	va_end(args);
200
	return status;
201
}
202

203
static int do_packet_write(const int fd_out, const char *buf, size_t size,
204
			   struct strbuf *err)
205
{
206
	char header[4];
207
	size_t packet_size;
208

209
	if (size > LARGE_PACKET_DATA_MAX) {
210
		strbuf_addstr(err, _("packet write failed - data exceeds max packet size"));
211
		return -1;
212
	}
213

214
	packet_trace(buf, size, 1);
215
	packet_size = size + 4;
216

217
	set_packet_header(header, packet_size);
218

219
	/*
220
	 * Write the header and the buffer in 2 parts so that we do
221
	 * not need to allocate a buffer or rely on a static buffer.
222
	 * This also avoids putting a large buffer on the stack which
223
	 * might have multi-threading issues.
224
	 */
225

226
	if (write_in_full(fd_out, header, 4) < 0 ||
227
	    write_in_full(fd_out, buf, size) < 0) {
228
		strbuf_addf(err, _("packet write failed: %s"), strerror(errno));
229
		return -1;
230
	}
231
	return 0;
232
}
233

234
static int packet_write_gently(const int fd_out, const char *buf, size_t size)
235
{
236
	struct strbuf err = STRBUF_INIT;
237
	if (do_packet_write(fd_out, buf, size, &err)) {
238
		error("%s", err.buf);
239
		strbuf_release(&err);
240
		return -1;
241
	}
242
	return 0;
243
}
244

245
void packet_write(int fd_out, const char *buf, size_t size)
246
{
247
	struct strbuf err = STRBUF_INIT;
248
	if (do_packet_write(fd_out, buf, size, &err))
249
		die("%s", err.buf);
250
}
251

252
void packet_fwrite(FILE *f, const char *buf, size_t size)
253
{
254
	size_t packet_size;
255
	char header[4];
256

257
	if (size > LARGE_PACKET_DATA_MAX)
258
		die(_("packet write failed - data exceeds max packet size"));
259

260
	packet_trace(buf, size, 1);
261
	packet_size = size + 4;
262

263
	set_packet_header(header, packet_size);
264
	fwrite_or_die(f, header, 4);
265
	fwrite_or_die(f, buf, size);
266
}
267

268
void packet_fwrite_fmt(FILE *fh, const char *fmt, ...)
269
{
270
       static struct strbuf buf = STRBUF_INIT;
271
       va_list args;
272

273
       strbuf_reset(&buf);
274

275
       va_start(args, fmt);
276
       format_packet(&buf, "", fmt, args);
277
       va_end(args);
278

279
       fwrite_or_die(fh, buf.buf, buf.len);
280
}
281

282
void packet_fflush(FILE *f)
283
{
284
	packet_trace("0000", 4, 1);
285
	fwrite_or_die(f, "0000", 4);
286
	fflush_or_die(f);
287
}
288

289
void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
290
{
291
	va_list args;
292

293
	va_start(args, fmt);
294
	format_packet(buf, "", fmt, args);
295
	va_end(args);
296
}
297

298
int write_packetized_from_fd_no_flush(int fd_in, int fd_out)
299
{
300
	char *buf = xmalloc(LARGE_PACKET_DATA_MAX);
301
	int err = 0;
302
	ssize_t bytes_to_write;
303

304
	while (!err) {
305
		bytes_to_write = xread(fd_in, buf, LARGE_PACKET_DATA_MAX);
306
		if (bytes_to_write < 0) {
307
			free(buf);
308
			return COPY_READ_ERROR;
309
		}
310
		if (bytes_to_write == 0)
311
			break;
312
		err = packet_write_gently(fd_out, buf, bytes_to_write);
313
	}
314
	free(buf);
315
	return err;
316
}
317

318
int write_packetized_from_buf_no_flush_count(const char *src_in, size_t len,
319
					     int fd_out, int *packet_counter)
320
{
321
	int err = 0;
322
	size_t bytes_written = 0;
323
	size_t bytes_to_write;
324

325
	while (!err) {
326
		if ((len - bytes_written) > LARGE_PACKET_DATA_MAX)
327
			bytes_to_write = LARGE_PACKET_DATA_MAX;
328
		else
329
			bytes_to_write = len - bytes_written;
330
		if (bytes_to_write == 0)
331
			break;
332
		err = packet_write_gently(fd_out, src_in + bytes_written, bytes_to_write);
333
		bytes_written += bytes_to_write;
334
		if (packet_counter)
335
			(*packet_counter)++;
336
	}
337
	return err;
338
}
339

340
static int get_packet_data(int fd, char **src_buf, size_t *src_size,
341
			   void *dst, unsigned size, int options)
342
{
343
	ssize_t ret;
344

345
	if (fd >= 0 && src_buf && *src_buf)
346
		BUG("multiple sources given to packet_read");
347

348
	/* Read up to "size" bytes from our source, whatever it is. */
349
	if (src_buf && *src_buf) {
350
		ret = size < *src_size ? size : *src_size;
351
		memcpy(dst, *src_buf, ret);
352
		*src_buf += ret;
353
		*src_size -= ret;
354
	} else {
355
		ret = read_in_full(fd, dst, size);
356
		if (ret < 0) {
357
			if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
358
				return error_errno(_("read error"));
359
			die_errno(_("read error"));
360
		}
361
	}
362

363
	/* And complain if we didn't get enough bytes to satisfy the read. */
364
	if (ret != size) {
365
		if (options & PACKET_READ_GENTLE_ON_EOF)
366
			return -1;
367

368
		if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
369
			return error(_("the remote end hung up unexpectedly"));
370
		die(_("the remote end hung up unexpectedly"));
371
	}
372

373
	return ret;
374
}
375

376
int packet_length(const char lenbuf_hex[4], size_t size)
377
{
378
	if (size < 4)
379
		BUG("buffer too small");
380
	return	hexval(lenbuf_hex[0]) << 12 |
381
		hexval(lenbuf_hex[1]) <<  8 |
382
		hexval(lenbuf_hex[2]) <<  4 |
383
		hexval(lenbuf_hex[3]);
384
}
385

386
static char *find_packfile_uri_path(const char *buffer)
387
{
388
	const char *URI_MARK = "://";
389
	char *path;
390
	int len;
391

392
	/* First char is sideband mark */
393
	buffer += 1;
394

395
	len = strspn(buffer, "0123456789abcdefABCDEF");
396
	/* size of SHA1 and SHA256 hash */
397
	if (!(len == 40 || len == 64) || buffer[len] != ' ')
398
		return NULL; /* required "<hash>SP" not seen */
399

400
	path = strstr(buffer + len + 1, URI_MARK);
401
	if (!path)
402
		return NULL;
403

404
	path = strchr(path + strlen(URI_MARK), '/');
405
	if (!path || !*(path + 1))
406
		return NULL;
407

408
	/* position after '/' */
409
	return ++path;
410
}
411

412
enum packet_read_status packet_read_with_status(int fd, char **src_buffer,
413
						size_t *src_len, char *buffer,
414
						unsigned size, int *pktlen,
415
						int options)
416
{
417
	int len;
418
	char linelen[4];
419
	char *uri_path_start;
420

421
	if (get_packet_data(fd, src_buffer, src_len, linelen, 4, options) < 0) {
422
		*pktlen = -1;
423
		return PACKET_READ_EOF;
424
	}
425

426
	len = packet_length(linelen, sizeof(linelen));
427

428
	if (len < 0) {
429
		if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
430
			return error(_("protocol error: bad line length "
431
				       "character: %.4s"), linelen);
432
		die(_("protocol error: bad line length character: %.4s"), linelen);
433
	} else if (!len) {
434
		packet_trace("0000", 4, 0);
435
		*pktlen = 0;
436
		return PACKET_READ_FLUSH;
437
	} else if (len == 1) {
438
		packet_trace("0001", 4, 0);
439
		*pktlen = 0;
440
		return PACKET_READ_DELIM;
441
	} else if (len == 2) {
442
		packet_trace("0002", 4, 0);
443
		*pktlen = 0;
444
		return PACKET_READ_RESPONSE_END;
445
	} else if (len < 4) {
446
		if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
447
			return error(_("protocol error: bad line length %d"),
448
				     len);
449
		die(_("protocol error: bad line length %d"), len);
450
	}
451

452
	len -= 4;
453
	if ((unsigned)len >= size) {
454
		if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
455
			return error(_("protocol error: bad line length %d"),
456
				     len);
457
		die(_("protocol error: bad line length %d"), len);
458
	}
459

460
	if (get_packet_data(fd, src_buffer, src_len, buffer, len, options) < 0) {
461
		*pktlen = -1;
462
		return PACKET_READ_EOF;
463
	}
464

465
	if ((options & PACKET_READ_CHOMP_NEWLINE) &&
466
	    len && buffer[len-1] == '\n') {
467
		if (options & PACKET_READ_USE_SIDEBAND) {
468
			int band = *buffer & 0xff;
469
			switch (band) {
470
			case 1:
471
				/* Chomp newline for payload */
472
				len--;
473
				break;
474
			case 2:
475
			case 3:
476
				/*
477
				 * Do not chomp newline for progress and error
478
				 * message.
479
				 */
480
				break;
481
			default:
482
				/*
483
				 * Bad sideband, let's leave it to
484
				 * demultiplex_sideband() to catch this error.
485
				 */
486
				break;
487
			}
488
		} else {
489
			len--;
490
		}
491
	}
492

493
	buffer[len] = 0;
494
	if (options & PACKET_READ_REDACT_URI_PATH &&
495
	    (uri_path_start = find_packfile_uri_path(buffer))) {
496
		const char *redacted = "<redacted>";
497
		struct strbuf tracebuf = STRBUF_INIT;
498
		strbuf_insert(&tracebuf, 0, buffer, len);
499
		strbuf_splice(&tracebuf, uri_path_start - buffer,
500
			      strlen(uri_path_start), redacted, strlen(redacted));
501
		packet_trace(tracebuf.buf, tracebuf.len, 0);
502
		strbuf_release(&tracebuf);
503
	} else {
504
		packet_trace(buffer, len, 0);
505
	}
506

507
	if ((options & PACKET_READ_DIE_ON_ERR_PACKET) &&
508
	    starts_with(buffer, "ERR "))
509
		die(_("remote error: %s"), buffer + 4);
510

511
	*pktlen = len;
512
	return PACKET_READ_NORMAL;
513
}
514

515
int packet_read(int fd, char *buffer, unsigned size, int options)
516
{
517
	int pktlen = -1;
518

519
	packet_read_with_status(fd, NULL, NULL, buffer, size, &pktlen,
520
				options);
521

522
	return pktlen;
523
}
524

525
char *packet_read_line(int fd, int *dst_len)
526
{
527
	int len = packet_read(fd, packet_buffer, sizeof(packet_buffer),
528
			      PACKET_READ_CHOMP_NEWLINE);
529
	if (dst_len)
530
		*dst_len = len;
531
	return (len > 0) ? packet_buffer : NULL;
532
}
533

534
int packet_read_line_gently(int fd, int *dst_len, char **dst_line)
535
{
536
	int len = packet_read(fd, packet_buffer, sizeof(packet_buffer),
537
			      PACKET_READ_CHOMP_NEWLINE|PACKET_READ_GENTLE_ON_EOF);
538
	if (dst_len)
539
		*dst_len = len;
540
	if (dst_line)
541
		*dst_line = (len > 0) ? packet_buffer : NULL;
542
	return len;
543
}
544

545
ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out, int options)
546
{
547
	int packet_len;
548

549
	size_t orig_len = sb_out->len;
550
	size_t orig_alloc = sb_out->alloc;
551

552
	for (;;) {
553
		strbuf_grow(sb_out, LARGE_PACKET_DATA_MAX);
554
		packet_len = packet_read(fd_in,
555
			/* strbuf_grow() above always allocates one extra byte to
556
			 * store a '\0' at the end of the string. packet_read()
557
			 * writes a '\0' extra byte at the end, too. Let it know
558
			 * that there is already room for the extra byte.
559
			 */
560
			sb_out->buf + sb_out->len, LARGE_PACKET_DATA_MAX+1,
561
			options);
562
		if (packet_len <= 0)
563
			break;
564
		sb_out->len += packet_len;
565
	}
566

567
	if (packet_len < 0) {
568
		if (orig_alloc == 0)
569
			strbuf_release(sb_out);
570
		else
571
			strbuf_setlen(sb_out, orig_len);
572
		return packet_len;
573
	}
574
	return sb_out->len - orig_len;
575
}
576

577
int recv_sideband(const char *me, int in_stream, int out)
578
{
579
	char buf[LARGE_PACKET_MAX + 1];
580
	int len;
581
	struct strbuf scratch = STRBUF_INIT;
582
	enum sideband_type sideband_type;
583

584
	while (1) {
585
		int status = packet_read_with_status(in_stream, NULL, NULL,
586
						     buf, LARGE_PACKET_MAX,
587
						     &len,
588
						     PACKET_READ_GENTLE_ON_EOF);
589
		if (!demultiplex_sideband(me, status, buf, len, 0, &scratch,
590
					  &sideband_type))
591
			continue;
592
		switch (sideband_type) {
593
		case SIDEBAND_PRIMARY:
594
			write_or_die(out, buf + 1, len - 1);
595
			break;
596
		default: /* errors: message already written */
597
			if (scratch.len > 0)
598
				BUG("unhandled incomplete sideband: '%s'",
599
				    scratch.buf);
600
			return sideband_type;
601
		}
602
	}
603
}
604

605
/* Packet Reader Functions */
606
void packet_reader_init(struct packet_reader *reader, int fd,
607
			char *src_buffer, size_t src_len,
608
			int options)
609
{
610
	memset(reader, 0, sizeof(*reader));
611

612
	reader->fd = fd;
613
	reader->src_buffer = src_buffer;
614
	reader->src_len = src_len;
615
	reader->buffer = packet_buffer;
616
	reader->buffer_size = sizeof(packet_buffer);
617
	reader->options = options;
618
	reader->me = "git";
619
	reader->hash_algo = &hash_algos[GIT_HASH_SHA1];
620
	strbuf_init(&reader->scratch, 0);
621
}
622

623
enum packet_read_status packet_reader_read(struct packet_reader *reader)
624
{
625
	if (reader->line_peeked) {
626
		reader->line_peeked = 0;
627
		return reader->status;
628
	}
629

630
	if (reader->use_sideband)
631
		reader->options |= PACKET_READ_USE_SIDEBAND;
632

633
	/*
634
	 * Consume all progress packets until a primary payload packet is
635
	 * received
636
	 */
637
	while (1) {
638
		enum sideband_type sideband_type;
639
		reader->status = packet_read_with_status(reader->fd,
640
							 &reader->src_buffer,
641
							 &reader->src_len,
642
							 reader->buffer,
643
							 reader->buffer_size,
644
							 &reader->pktlen,
645
							 reader->options);
646
		if (!reader->use_sideband)
647
			break;
648
		if (demultiplex_sideband(reader->me, reader->status,
649
					 reader->buffer, reader->pktlen, 1,
650
					 &reader->scratch, &sideband_type))
651
			break;
652
	}
653

654
	if (reader->status == PACKET_READ_NORMAL)
655
		/* Skip the sideband designator if sideband is used */
656
		reader->line = reader->use_sideband ?
657
			reader->buffer + 1 : reader->buffer;
658
	else
659
		reader->line = NULL;
660

661
	return reader->status;
662
}
663

664
enum packet_read_status packet_reader_peek(struct packet_reader *reader)
665
{
666
	/* Only allow peeking a single line */
667
	if (reader->line_peeked)
668
		return reader->status;
669

670
	/* Peek a line by reading it and setting peeked flag */
671
	packet_reader_read(reader);
672
	reader->line_peeked = 1;
673
	return reader->status;
674
}
675

676
void packet_writer_init(struct packet_writer *writer, int dest_fd)
677
{
678
	writer->dest_fd = dest_fd;
679
	writer->use_sideband = 0;
680
}
681

682
void packet_writer_write(struct packet_writer *writer, const char *fmt, ...)
683
{
684
	va_list args;
685

686
	va_start(args, fmt);
687
	packet_write_fmt_1(writer->dest_fd, 0,
688
			   writer->use_sideband ? "\001" : "", fmt, args);
689
	va_end(args);
690
}
691

692
void packet_writer_error(struct packet_writer *writer, const char *fmt, ...)
693
{
694
	va_list args;
695

696
	va_start(args, fmt);
697
	packet_write_fmt_1(writer->dest_fd, 0,
698
			   writer->use_sideband ? "\003" : "ERR ", fmt, args);
699
	va_end(args);
700
}
701

702
void packet_writer_delim(struct packet_writer *writer)
703
{
704
	packet_delim(writer->dest_fd);
705
}
706

707
void packet_writer_flush(struct packet_writer *writer)
708
{
709
	packet_flush(writer->dest_fd);
710
}
711