Merge branch 'nd/checkout-noisy-unmerge'
[git] / pkt-line.c
1 #include "cache.h"
2 #include "pkt-line.h"
3 #include "run-command.h"
4
5 char packet_buffer[LARGE_PACKET_MAX];
6 static const char *packet_trace_prefix = "git";
7 static struct trace_key trace_packet = TRACE_KEY_INIT(PACKET);
8 static struct trace_key trace_pack = TRACE_KEY_INIT(PACKFILE);
9
10 void packet_trace_identity(const char *prog)
11 {
12         packet_trace_prefix = xstrdup(prog);
13 }
14
15 static const char *get_trace_prefix(void)
16 {
17         return in_async() ? "sideband" : packet_trace_prefix;
18 }
19
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
34 static void packet_trace(const char *buf, unsigned int len, int write)
35 {
36         int i;
37         struct strbuf out;
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         }
58
59         if (!trace_want(&trace_packet))
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 ",
66                     get_trace_prefix(), write ? '>' : '<');
67
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]);
77         }
78
79         strbuf_addch(&out, '\n');
80         trace_strbuf(&trace_packet, &out);
81         strbuf_release(&out);
82 }
83
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 {
90         packet_trace("0000", 4, 1);
91         write_or_die(fd, "0000", 4);
92 }
93
94 void packet_delim(int fd)
95 {
96         packet_trace("0001", 4, 1);
97         write_or_die(fd, "0001", 4);
98 }
99
100 int packet_flush_gently(int fd)
101 {
102         packet_trace("0000", 4, 1);
103         if (write_in_full(fd, "0000", 4) < 0)
104                 return error(_("flush packet write failed"));
105         return 0;
106 }
107
108 void packet_buf_flush(struct strbuf *buf)
109 {
110         packet_trace("0000", 4, 1);
111         strbuf_add(buf, "0000", 4);
112 }
113
114 void packet_buf_delim(struct strbuf *buf)
115 {
116         packet_trace("0001", 4, 1);
117         strbuf_add(buf, "0001", 4);
118 }
119
120 static void set_packet_header(char *buf, const int size)
121 {
122         static char hexchar[] = "0123456789abcdef";
123
124         #define hex(a) (hexchar[(a) & 15])
125         buf[0] = hex(size >> 12);
126         buf[1] = hex(size >> 8);
127         buf[2] = hex(size >> 4);
128         buf[3] = hex(size);
129         #undef hex
130 }
131
132 static void format_packet(struct strbuf *out, const char *prefix,
133                           const char *fmt, va_list args)
134 {
135         size_t orig_len, n;
136
137         orig_len = out->len;
138         strbuf_addstr(out, "0000");
139         strbuf_addstr(out, prefix);
140         strbuf_vaddf(out, fmt, args);
141         n = out->len - orig_len;
142
143         if (n > LARGE_PACKET_MAX)
144                 die(_("protocol error: impossibly long line"));
145
146         set_packet_header(&out->buf[orig_len], n);
147         packet_trace(out->buf + orig_len + 4, n - 4, 1);
148 }
149
150 static int packet_write_fmt_1(int fd, int gently, const char *prefix,
151                               const char *fmt, va_list args)
152 {
153         static struct strbuf buf = STRBUF_INIT;
154
155         strbuf_reset(&buf);
156         format_packet(&buf, prefix, fmt, args);
157         if (write_in_full(fd, buf.buf, buf.len) < 0) {
158                 if (!gently) {
159                         check_pipe(errno);
160                         die_errno(_("packet write with format failed"));
161                 }
162                 return error(_("packet write with format failed"));
163         }
164
165         return 0;
166 }
167
168 void packet_write_fmt(int fd, const char *fmt, ...)
169 {
170         va_list args;
171
172         va_start(args, fmt);
173         packet_write_fmt_1(fd, 0, "", fmt, args);
174         va_end(args);
175 }
176
177 int packet_write_fmt_gently(int fd, const char *fmt, ...)
178 {
179         int status;
180         va_list args;
181
182         va_start(args, fmt);
183         status = packet_write_fmt_1(fd, 1, "", fmt, args);
184         va_end(args);
185         return status;
186 }
187
188 static int packet_write_gently(const int fd_out, const char *buf, size_t size)
189 {
190         static char packet_write_buffer[LARGE_PACKET_MAX];
191         size_t packet_size;
192
193         if (size > sizeof(packet_write_buffer) - 4)
194                 return error(_("packet write failed - data exceeds max packet size"));
195
196         packet_trace(buf, size, 1);
197         packet_size = size + 4;
198         set_packet_header(packet_write_buffer, packet_size);
199         memcpy(packet_write_buffer + 4, buf, size);
200         if (write_in_full(fd_out, packet_write_buffer, packet_size) < 0)
201                 return error(_("packet write failed"));
202         return 0;
203 }
204
205 void packet_write(int fd_out, const char *buf, size_t size)
206 {
207         if (packet_write_gently(fd_out, buf, size))
208                 die_errno(_("packet write failed"));
209 }
210
211 void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
212 {
213         va_list args;
214
215         va_start(args, fmt);
216         format_packet(buf, "", fmt, args);
217         va_end(args);
218 }
219
220 void packet_buf_write_len(struct strbuf *buf, const char *data, size_t len)
221 {
222         size_t orig_len, n;
223
224         orig_len = buf->len;
225         strbuf_addstr(buf, "0000");
226         strbuf_add(buf, data, len);
227         n = buf->len - orig_len;
228
229         if (n > LARGE_PACKET_MAX)
230                 die(_("protocol error: impossibly long line"));
231
232         set_packet_header(&buf->buf[orig_len], n);
233         packet_trace(data, len, 1);
234 }
235
236 int write_packetized_from_fd(int fd_in, int fd_out)
237 {
238         static char buf[LARGE_PACKET_DATA_MAX];
239         int err = 0;
240         ssize_t bytes_to_write;
241
242         while (!err) {
243                 bytes_to_write = xread(fd_in, buf, sizeof(buf));
244                 if (bytes_to_write < 0)
245                         return COPY_READ_ERROR;
246                 if (bytes_to_write == 0)
247                         break;
248                 err = packet_write_gently(fd_out, buf, bytes_to_write);
249         }
250         if (!err)
251                 err = packet_flush_gently(fd_out);
252         return err;
253 }
254
255 int write_packetized_from_buf(const char *src_in, size_t len, int fd_out)
256 {
257         int err = 0;
258         size_t bytes_written = 0;
259         size_t bytes_to_write;
260
261         while (!err) {
262                 if ((len - bytes_written) > LARGE_PACKET_DATA_MAX)
263                         bytes_to_write = LARGE_PACKET_DATA_MAX;
264                 else
265                         bytes_to_write = len - bytes_written;
266                 if (bytes_to_write == 0)
267                         break;
268                 err = packet_write_gently(fd_out, src_in + bytes_written, bytes_to_write);
269                 bytes_written += bytes_to_write;
270         }
271         if (!err)
272                 err = packet_flush_gently(fd_out);
273         return err;
274 }
275
276 static int get_packet_data(int fd, char **src_buf, size_t *src_size,
277                            void *dst, unsigned size, int options)
278 {
279         ssize_t ret;
280
281         if (fd >= 0 && src_buf && *src_buf)
282                 BUG("multiple sources given to packet_read");
283
284         /* Read up to "size" bytes from our source, whatever it is. */
285         if (src_buf && *src_buf) {
286                 ret = size < *src_size ? size : *src_size;
287                 memcpy(dst, *src_buf, ret);
288                 *src_buf += ret;
289                 *src_size -= ret;
290         } else {
291                 ret = read_in_full(fd, dst, size);
292                 if (ret < 0)
293                         die_errno(_("read error"));
294         }
295
296         /* And complain if we didn't get enough bytes to satisfy the read. */
297         if (ret != size) {
298                 if (options & PACKET_READ_GENTLE_ON_EOF)
299                         return -1;
300
301                 die(_("the remote end hung up unexpectedly"));
302         }
303
304         return ret;
305 }
306
307 static int packet_length(const char *linelen)
308 {
309         int val = hex2chr(linelen);
310         return (val < 0) ? val : (val << 8) | hex2chr(linelen + 2);
311 }
312
313 enum packet_read_status packet_read_with_status(int fd, char **src_buffer,
314                                                 size_t *src_len, char *buffer,
315                                                 unsigned size, int *pktlen,
316                                                 int options)
317 {
318         int len;
319         char linelen[4];
320
321         if (get_packet_data(fd, src_buffer, src_len, linelen, 4, options) < 0) {
322                 *pktlen = -1;
323                 return PACKET_READ_EOF;
324         }
325
326         len = packet_length(linelen);
327
328         if (len < 0) {
329                 die(_("protocol error: bad line length character: %.4s"), linelen);
330         } else if (!len) {
331                 packet_trace("0000", 4, 0);
332                 *pktlen = 0;
333                 return PACKET_READ_FLUSH;
334         } else if (len == 1) {
335                 packet_trace("0001", 4, 0);
336                 *pktlen = 0;
337                 return PACKET_READ_DELIM;
338         } else if (len < 4) {
339                 die(_("protocol error: bad line length %d"), len);
340         }
341
342         len -= 4;
343         if ((unsigned)len >= size)
344                 die(_("protocol error: bad line length %d"), len);
345
346         if (get_packet_data(fd, src_buffer, src_len, buffer, len, options) < 0) {
347                 *pktlen = -1;
348                 return PACKET_READ_EOF;
349         }
350
351         if ((options & PACKET_READ_DIE_ON_ERR_PACKET) &&
352             starts_with(buffer, "ERR "))
353                 die(_("remote error: %s"), buffer + 4);
354
355         if ((options & PACKET_READ_CHOMP_NEWLINE) &&
356             len && buffer[len-1] == '\n')
357                 len--;
358
359         buffer[len] = 0;
360         packet_trace(buffer, len, 0);
361         *pktlen = len;
362         return PACKET_READ_NORMAL;
363 }
364
365 int packet_read(int fd, char **src_buffer, size_t *src_len,
366                 char *buffer, unsigned size, int options)
367 {
368         int pktlen = -1;
369
370         packet_read_with_status(fd, src_buffer, src_len, buffer, size,
371                                 &pktlen, options);
372
373         return pktlen;
374 }
375
376 static char *packet_read_line_generic(int fd,
377                                       char **src, size_t *src_len,
378                                       int *dst_len)
379 {
380         int len = packet_read(fd, src, src_len,
381                               packet_buffer, sizeof(packet_buffer),
382                               PACKET_READ_CHOMP_NEWLINE);
383         if (dst_len)
384                 *dst_len = len;
385         return (len > 0) ? packet_buffer : NULL;
386 }
387
388 char *packet_read_line(int fd, int *len_p)
389 {
390         return packet_read_line_generic(fd, NULL, NULL, len_p);
391 }
392
393 int packet_read_line_gently(int fd, int *dst_len, char **dst_line)
394 {
395         int len = packet_read(fd, NULL, NULL,
396                               packet_buffer, sizeof(packet_buffer),
397                               PACKET_READ_CHOMP_NEWLINE|PACKET_READ_GENTLE_ON_EOF);
398         if (dst_len)
399                 *dst_len = len;
400         if (dst_line)
401                 *dst_line = (len > 0) ? packet_buffer : NULL;
402         return len;
403 }
404
405 char *packet_read_line_buf(char **src, size_t *src_len, int *dst_len)
406 {
407         return packet_read_line_generic(-1, src, src_len, dst_len);
408 }
409
410 ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out)
411 {
412         int packet_len;
413
414         size_t orig_len = sb_out->len;
415         size_t orig_alloc = sb_out->alloc;
416
417         for (;;) {
418                 strbuf_grow(sb_out, LARGE_PACKET_DATA_MAX);
419                 packet_len = packet_read(fd_in, NULL, NULL,
420                         /* strbuf_grow() above always allocates one extra byte to
421                          * store a '\0' at the end of the string. packet_read()
422                          * writes a '\0' extra byte at the end, too. Let it know
423                          * that there is already room for the extra byte.
424                          */
425                         sb_out->buf + sb_out->len, LARGE_PACKET_DATA_MAX+1,
426                         PACKET_READ_GENTLE_ON_EOF);
427                 if (packet_len <= 0)
428                         break;
429                 sb_out->len += packet_len;
430         }
431
432         if (packet_len < 0) {
433                 if (orig_alloc == 0)
434                         strbuf_release(sb_out);
435                 else
436                         strbuf_setlen(sb_out, orig_len);
437                 return packet_len;
438         }
439         return sb_out->len - orig_len;
440 }
441
442 int recv_sideband(const char *me, int in_stream, int out)
443 {
444         char buf[LARGE_PACKET_MAX + 1];
445         int len;
446         struct strbuf scratch = STRBUF_INIT;
447         enum sideband_type sideband_type;
448
449         while (1) {
450                 len = packet_read(in_stream, NULL, NULL, buf, LARGE_PACKET_MAX,
451                                   0);
452                 if (!demultiplex_sideband(me, buf, len, 0, &scratch,
453                                           &sideband_type))
454                         continue;
455                 switch (sideband_type) {
456                 case SIDEBAND_PRIMARY:
457                         write_or_die(out, buf + 1, len - 1);
458                         break;
459                 default: /* errors: message already written */
460                         return sideband_type;
461                 }
462         }
463 }
464
465 /* Packet Reader Functions */
466 void packet_reader_init(struct packet_reader *reader, int fd,
467                         char *src_buffer, size_t src_len,
468                         int options)
469 {
470         memset(reader, 0, sizeof(*reader));
471
472         reader->fd = fd;
473         reader->src_buffer = src_buffer;
474         reader->src_len = src_len;
475         reader->buffer = packet_buffer;
476         reader->buffer_size = sizeof(packet_buffer);
477         reader->options = options;
478         reader->me = "git";
479 }
480
481 enum packet_read_status packet_reader_read(struct packet_reader *reader)
482 {
483         struct strbuf scratch = STRBUF_INIT;
484
485         if (reader->line_peeked) {
486                 reader->line_peeked = 0;
487                 return reader->status;
488         }
489
490         /*
491          * Consume all progress packets until a primary payload packet is
492          * received
493          */
494         while (1) {
495                 enum sideband_type sideband_type;
496                 reader->status = packet_read_with_status(reader->fd,
497                                                          &reader->src_buffer,
498                                                          &reader->src_len,
499                                                          reader->buffer,
500                                                          reader->buffer_size,
501                                                          &reader->pktlen,
502                                                          reader->options);
503                 if (!reader->use_sideband)
504                         break;
505                 if (demultiplex_sideband(reader->me, reader->buffer,
506                                          reader->pktlen, 1, &scratch,
507                                          &sideband_type))
508                         break;
509         }
510
511         if (reader->status == PACKET_READ_NORMAL)
512                 /* Skip the sideband designator if sideband is used */
513                 reader->line = reader->use_sideband ?
514                         reader->buffer + 1 : reader->buffer;
515         else
516                 reader->line = NULL;
517
518         return reader->status;
519 }
520
521 enum packet_read_status packet_reader_peek(struct packet_reader *reader)
522 {
523         /* Only allow peeking a single line */
524         if (reader->line_peeked)
525                 return reader->status;
526
527         /* Peek a line by reading it and setting peeked flag */
528         packet_reader_read(reader);
529         reader->line_peeked = 1;
530         return reader->status;
531 }
532
533 void packet_writer_init(struct packet_writer *writer, int dest_fd)
534 {
535         writer->dest_fd = dest_fd;
536         writer->use_sideband = 0;
537 }
538
539 void packet_writer_write(struct packet_writer *writer, const char *fmt, ...)
540 {
541         va_list args;
542
543         va_start(args, fmt);
544         packet_write_fmt_1(writer->dest_fd, 0,
545                            writer->use_sideband ? "\001" : "", fmt, args);
546         va_end(args);
547 }
548
549 void packet_writer_error(struct packet_writer *writer, const char *fmt, ...)
550 {
551         va_list args;
552
553         va_start(args, fmt);
554         packet_write_fmt_1(writer->dest_fd, 0,
555                            writer->use_sideband ? "\003" : "ERR ", fmt, args);
556         va_end(args);
557 }
558
559 void packet_writer_delim(struct packet_writer *writer)
560 {
561         packet_delim(writer->dest_fd);
562 }
563
564 void packet_writer_flush(struct packet_writer *writer)
565 {
566         packet_flush(writer->dest_fd);
567 }