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 }