The third batch
[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         if (write_in_full(fd, "0000", 4) < 0)
92                 die_errno(_("unable to write flush packet"));
93 }
94
95 void packet_delim(int fd)
96 {
97         packet_trace("0001", 4, 1);
98         if (write_in_full(fd, "0001", 4) < 0)
99                 die_errno(_("unable to write delim packet"));
100 }
101
102 int packet_flush_gently(int fd)
103 {
104         packet_trace("0000", 4, 1);
105         if (write_in_full(fd, "0000", 4) < 0)
106                 return error(_("flush packet write failed"));
107         return 0;
108 }
109
110 void packet_buf_flush(struct strbuf *buf)
111 {
112         packet_trace("0000", 4, 1);
113         strbuf_add(buf, "0000", 4);
114 }
115
116 void packet_buf_delim(struct strbuf *buf)
117 {
118         packet_trace("0001", 4, 1);
119         strbuf_add(buf, "0001", 4);
120 }
121
122 void set_packet_header(char *buf, int size)
123 {
124         static char hexchar[] = "0123456789abcdef";
125
126         #define hex(a) (hexchar[(a) & 15])
127         buf[0] = hex(size >> 12);
128         buf[1] = hex(size >> 8);
129         buf[2] = hex(size >> 4);
130         buf[3] = hex(size);
131         #undef hex
132 }
133
134 static void format_packet(struct strbuf *out, const char *prefix,
135                           const char *fmt, va_list args)
136 {
137         size_t orig_len, n;
138
139         orig_len = out->len;
140         strbuf_addstr(out, "0000");
141         strbuf_addstr(out, prefix);
142         strbuf_vaddf(out, fmt, args);
143         n = out->len - orig_len;
144
145         if (n > LARGE_PACKET_MAX)
146                 die(_("protocol error: impossibly long line"));
147
148         set_packet_header(&out->buf[orig_len], n);
149         packet_trace(out->buf + orig_len + 4, n - 4, 1);
150 }
151
152 static int packet_write_fmt_1(int fd, int gently, const char *prefix,
153                               const char *fmt, va_list args)
154 {
155         static struct strbuf buf = STRBUF_INIT;
156
157         strbuf_reset(&buf);
158         format_packet(&buf, prefix, fmt, args);
159         if (write_in_full(fd, buf.buf, buf.len) < 0) {
160                 if (!gently) {
161                         check_pipe(errno);
162                         die_errno(_("packet write with format failed"));
163                 }
164                 return error(_("packet write with format failed"));
165         }
166
167         return 0;
168 }
169
170 void packet_write_fmt(int fd, const char *fmt, ...)
171 {
172         va_list args;
173
174         va_start(args, fmt);
175         packet_write_fmt_1(fd, 0, "", fmt, args);
176         va_end(args);
177 }
178
179 int packet_write_fmt_gently(int fd, const char *fmt, ...)
180 {
181         int status;
182         va_list args;
183
184         va_start(args, fmt);
185         status = packet_write_fmt_1(fd, 1, "", fmt, args);
186         va_end(args);
187         return status;
188 }
189
190 static int packet_write_gently(const int fd_out, const char *buf, size_t size)
191 {
192         static char packet_write_buffer[LARGE_PACKET_MAX];
193         size_t packet_size;
194
195         if (size > sizeof(packet_write_buffer) - 4)
196                 return error(_("packet write failed - data exceeds max packet size"));
197
198         packet_trace(buf, size, 1);
199         packet_size = size + 4;
200         set_packet_header(packet_write_buffer, packet_size);
201         memcpy(packet_write_buffer + 4, buf, size);
202         if (write_in_full(fd_out, packet_write_buffer, packet_size) < 0)
203                 return error(_("packet write failed"));
204         return 0;
205 }
206
207 void packet_write(int fd_out, const char *buf, size_t size)
208 {
209         if (packet_write_gently(fd_out, buf, size))
210                 die_errno(_("packet write failed"));
211 }
212
213 void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
214 {
215         va_list args;
216
217         va_start(args, fmt);
218         format_packet(buf, "", fmt, args);
219         va_end(args);
220 }
221
222 void packet_buf_write_len(struct strbuf *buf, const char *data, size_t len)
223 {
224         size_t orig_len, n;
225
226         orig_len = buf->len;
227         strbuf_addstr(buf, "0000");
228         strbuf_add(buf, data, len);
229         n = buf->len - orig_len;
230
231         if (n > LARGE_PACKET_MAX)
232                 die(_("protocol error: impossibly long line"));
233
234         set_packet_header(&buf->buf[orig_len], n);
235         packet_trace(data, len, 1);
236 }
237
238 int write_packetized_from_fd(int fd_in, int fd_out)
239 {
240         static char buf[LARGE_PACKET_DATA_MAX];
241         int err = 0;
242         ssize_t bytes_to_write;
243
244         while (!err) {
245                 bytes_to_write = xread(fd_in, buf, sizeof(buf));
246                 if (bytes_to_write < 0)
247                         return COPY_READ_ERROR;
248                 if (bytes_to_write == 0)
249                         break;
250                 err = packet_write_gently(fd_out, buf, bytes_to_write);
251         }
252         if (!err)
253                 err = packet_flush_gently(fd_out);
254         return err;
255 }
256
257 int write_packetized_from_buf(const char *src_in, size_t len, int fd_out)
258 {
259         int err = 0;
260         size_t bytes_written = 0;
261         size_t bytes_to_write;
262
263         while (!err) {
264                 if ((len - bytes_written) > LARGE_PACKET_DATA_MAX)
265                         bytes_to_write = LARGE_PACKET_DATA_MAX;
266                 else
267                         bytes_to_write = len - bytes_written;
268                 if (bytes_to_write == 0)
269                         break;
270                 err = packet_write_gently(fd_out, src_in + bytes_written, bytes_to_write);
271                 bytes_written += bytes_to_write;
272         }
273         if (!err)
274                 err = packet_flush_gently(fd_out);
275         return err;
276 }
277
278 static int get_packet_data(int fd, char **src_buf, size_t *src_size,
279                            void *dst, unsigned size, int options)
280 {
281         ssize_t ret;
282
283         if (fd >= 0 && src_buf && *src_buf)
284                 BUG("multiple sources given to packet_read");
285
286         /* Read up to "size" bytes from our source, whatever it is. */
287         if (src_buf && *src_buf) {
288                 ret = size < *src_size ? size : *src_size;
289                 memcpy(dst, *src_buf, ret);
290                 *src_buf += ret;
291                 *src_size -= ret;
292         } else {
293                 ret = read_in_full(fd, dst, size);
294                 if (ret < 0)
295                         die_errno(_("read error"));
296         }
297
298         /* And complain if we didn't get enough bytes to satisfy the read. */
299         if (ret != size) {
300                 if (options & PACKET_READ_GENTLE_ON_EOF)
301                         return -1;
302
303                 die(_("the remote end hung up unexpectedly"));
304         }
305
306         return ret;
307 }
308
309 static int packet_length(const char *linelen)
310 {
311         int val = hex2chr(linelen);
312         return (val < 0) ? val : (val << 8) | hex2chr(linelen + 2);
313 }
314
315 enum packet_read_status packet_read_with_status(int fd, char **src_buffer,
316                                                 size_t *src_len, char *buffer,
317                                                 unsigned size, int *pktlen,
318                                                 int options)
319 {
320         int len;
321         char linelen[4];
322
323         if (get_packet_data(fd, src_buffer, src_len, linelen, 4, options) < 0) {
324                 *pktlen = -1;
325                 return PACKET_READ_EOF;
326         }
327
328         len = packet_length(linelen);
329
330         if (len < 0) {
331                 die(_("protocol error: bad line length character: %.4s"), linelen);
332         } else if (!len) {
333                 packet_trace("0000", 4, 0);
334                 *pktlen = 0;
335                 return PACKET_READ_FLUSH;
336         } else if (len == 1) {
337                 packet_trace("0001", 4, 0);
338                 *pktlen = 0;
339                 return PACKET_READ_DELIM;
340         } else if (len < 4) {
341                 die(_("protocol error: bad line length %d"), len);
342         }
343
344         len -= 4;
345         if ((unsigned)len >= size)
346                 die(_("protocol error: bad line length %d"), len);
347
348         if (get_packet_data(fd, src_buffer, src_len, buffer, len, options) < 0) {
349                 *pktlen = -1;
350                 return PACKET_READ_EOF;
351         }
352
353         if ((options & PACKET_READ_CHOMP_NEWLINE) &&
354             len && buffer[len-1] == '\n')
355                 len--;
356
357         buffer[len] = 0;
358         packet_trace(buffer, len, 0);
359
360         if ((options & PACKET_READ_DIE_ON_ERR_PACKET) &&
361             starts_with(buffer, "ERR "))
362                 die(_("remote error: %s"), buffer + 4);
363
364         *pktlen = len;
365         return PACKET_READ_NORMAL;
366 }
367
368 int packet_read(int fd, char **src_buffer, size_t *src_len,
369                 char *buffer, unsigned size, int options)
370 {
371         int pktlen = -1;
372
373         packet_read_with_status(fd, src_buffer, src_len, buffer, size,
374                                 &pktlen, options);
375
376         return pktlen;
377 }
378
379 static char *packet_read_line_generic(int fd,
380                                       char **src, size_t *src_len,
381                                       int *dst_len)
382 {
383         int len = packet_read(fd, src, src_len,
384                               packet_buffer, sizeof(packet_buffer),
385                               PACKET_READ_CHOMP_NEWLINE);
386         if (dst_len)
387                 *dst_len = len;
388         return (len > 0) ? packet_buffer : NULL;
389 }
390
391 char *packet_read_line(int fd, int *len_p)
392 {
393         return packet_read_line_generic(fd, NULL, NULL, len_p);
394 }
395
396 int packet_read_line_gently(int fd, int *dst_len, char **dst_line)
397 {
398         int len = packet_read(fd, NULL, NULL,
399                               packet_buffer, sizeof(packet_buffer),
400                               PACKET_READ_CHOMP_NEWLINE|PACKET_READ_GENTLE_ON_EOF);
401         if (dst_len)
402                 *dst_len = len;
403         if (dst_line)
404                 *dst_line = (len > 0) ? packet_buffer : NULL;
405         return len;
406 }
407
408 char *packet_read_line_buf(char **src, size_t *src_len, int *dst_len)
409 {
410         return packet_read_line_generic(-1, src, src_len, dst_len);
411 }
412
413 ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out)
414 {
415         int packet_len;
416
417         size_t orig_len = sb_out->len;
418         size_t orig_alloc = sb_out->alloc;
419
420         for (;;) {
421                 strbuf_grow(sb_out, LARGE_PACKET_DATA_MAX);
422                 packet_len = packet_read(fd_in, NULL, NULL,
423                         /* strbuf_grow() above always allocates one extra byte to
424                          * store a '\0' at the end of the string. packet_read()
425                          * writes a '\0' extra byte at the end, too. Let it know
426                          * that there is already room for the extra byte.
427                          */
428                         sb_out->buf + sb_out->len, LARGE_PACKET_DATA_MAX+1,
429                         PACKET_READ_GENTLE_ON_EOF);
430                 if (packet_len <= 0)
431                         break;
432                 sb_out->len += packet_len;
433         }
434
435         if (packet_len < 0) {
436                 if (orig_alloc == 0)
437                         strbuf_release(sb_out);
438                 else
439                         strbuf_setlen(sb_out, orig_len);
440                 return packet_len;
441         }
442         return sb_out->len - orig_len;
443 }
444
445 int recv_sideband(const char *me, int in_stream, int out)
446 {
447         char buf[LARGE_PACKET_MAX + 1];
448         int len;
449         struct strbuf scratch = STRBUF_INIT;
450         enum sideband_type sideband_type;
451
452         while (1) {
453                 len = packet_read(in_stream, NULL, NULL, buf, LARGE_PACKET_MAX,
454                                   0);
455                 if (!demultiplex_sideband(me, buf, len, 0, &scratch,
456                                           &sideband_type))
457                         continue;
458                 switch (sideband_type) {
459                 case SIDEBAND_PRIMARY:
460                         write_or_die(out, buf + 1, len - 1);
461                         break;
462                 default: /* errors: message already written */
463                         return sideband_type;
464                 }
465         }
466 }
467
468 /* Packet Reader Functions */
469 void packet_reader_init(struct packet_reader *reader, int fd,
470                         char *src_buffer, size_t src_len,
471                         int options)
472 {
473         memset(reader, 0, sizeof(*reader));
474
475         reader->fd = fd;
476         reader->src_buffer = src_buffer;
477         reader->src_len = src_len;
478         reader->buffer = packet_buffer;
479         reader->buffer_size = sizeof(packet_buffer);
480         reader->options = options;
481         reader->me = "git";
482 }
483
484 enum packet_read_status packet_reader_read(struct packet_reader *reader)
485 {
486         struct strbuf scratch = STRBUF_INIT;
487
488         if (reader->line_peeked) {
489                 reader->line_peeked = 0;
490                 return reader->status;
491         }
492
493         /*
494          * Consume all progress packets until a primary payload packet is
495          * received
496          */
497         while (1) {
498                 enum sideband_type sideband_type;
499                 reader->status = packet_read_with_status(reader->fd,
500                                                          &reader->src_buffer,
501                                                          &reader->src_len,
502                                                          reader->buffer,
503                                                          reader->buffer_size,
504                                                          &reader->pktlen,
505                                                          reader->options);
506                 if (!reader->use_sideband)
507                         break;
508                 if (demultiplex_sideband(reader->me, reader->buffer,
509                                          reader->pktlen, 1, &scratch,
510                                          &sideband_type))
511                         break;
512         }
513
514         if (reader->status == PACKET_READ_NORMAL)
515                 /* Skip the sideband designator if sideband is used */
516                 reader->line = reader->use_sideband ?
517                         reader->buffer + 1 : reader->buffer;
518         else
519                 reader->line = NULL;
520
521         return reader->status;
522 }
523
524 enum packet_read_status packet_reader_peek(struct packet_reader *reader)
525 {
526         /* Only allow peeking a single line */
527         if (reader->line_peeked)
528                 return reader->status;
529
530         /* Peek a line by reading it and setting peeked flag */
531         packet_reader_read(reader);
532         reader->line_peeked = 1;
533         return reader->status;
534 }
535
536 void packet_writer_init(struct packet_writer *writer, int dest_fd)
537 {
538         writer->dest_fd = dest_fd;
539         writer->use_sideband = 0;
540 }
541
542 void packet_writer_write(struct packet_writer *writer, const char *fmt, ...)
543 {
544         va_list args;
545
546         va_start(args, fmt);
547         packet_write_fmt_1(writer->dest_fd, 0,
548                            writer->use_sideband ? "\001" : "", fmt, args);
549         va_end(args);
550 }
551
552 void packet_writer_error(struct packet_writer *writer, const char *fmt, ...)
553 {
554         va_list args;
555
556         va_start(args, fmt);
557         packet_write_fmt_1(writer->dest_fd, 0,
558                            writer->use_sideband ? "\003" : "ERR ", fmt, args);
559         va_end(args);
560 }
561
562 void packet_writer_delim(struct packet_writer *writer)
563 {
564         packet_delim(writer->dest_fd);
565 }
566
567 void packet_writer_flush(struct packet_writer *writer)
568 {
569         packet_flush(writer->dest_fd);
570 }