pkt-line.c

   1 #include "cache.h"
   2 #include "pkt-line.h"
   3 #include "hex.h"
   4 #include "run-command.h"
   5
   6 char packet_buffer[LARGE_PACKET_MAX];
   7 static const char *packet_trace_prefix = "git";
   8 static struct trace_key trace_packet = TRACE_KEY_INIT(PACKET);
   9 static struct trace_key trace_pack = TRACE_KEY_INIT(PACKFILE);
  10
  11 void packet_trace_identity(const char *prog)
  12 {
  13         packet_trace_prefix = xstrdup(prog);
  14 }
  15
  16 static const char *get_trace_prefix(void)
  17 {
  18         return in_async() ? "sideband" : packet_trace_prefix;
  19 }
  20
  21 static int packet_trace_pack(const char *buf, unsigned int len, int sideband)
  22 {
  23         if (!sideband) {
  24                 trace_verbatim(&trace_pack, buf, len);
  25                 return 1;
  26         } else if (len && *buf == '\1') {
  27                 trace_verbatim(&trace_pack, buf + 1, len - 1);
  28                 return 1;
  29         } else {
  30                 /* it's another non-pack sideband */
  31                 return 0;
  32         }
  33 }
  34
  35 static void packet_trace(const char *buf, unsigned int len, int write)
  36 {
  37         int i;
  38         struct strbuf out;
  39         static int in_pack, sideband;
  40
  41         if (!trace_want(&trace_packet) && !trace_want(&trace_pack))
  42                 return;
  43
  44         if (in_pack) {
  45                 if (packet_trace_pack(buf, len, sideband))
  46                         return;
  47         } else if (starts_with(buf, "PACK") || starts_with(buf, "\1PACK")) {
  48                 in_pack = 1;
  49                 sideband = *buf == '\1';
  50                 packet_trace_pack(buf, len, sideband);
  51
  52                 /*
  53                  * Make a note in the human-readable trace that the pack data
  54                  * started.
  55                  */
  56                 buf = "PACK ...";
  57                 len = strlen(buf);
  58         }
  59
  60         if (!trace_want(&trace_packet))
  61                 return;
  62
  63         /* +32 is just a guess for header + quoting */
  64         strbuf_init(&out, len+32);
  65
  66         strbuf_addf(&out, "packet: %12s%c ",
  67                     get_trace_prefix(), write ? '>' : '<');
  68
  69         /* XXX we should really handle printable utf8 */
  70         for (i = 0; i < len; i++) {
  71                 /* suppress newlines */
  72                 if (buf[i] == '\n')
  73                         continue;
  74                 if (buf[i] >= 0x20 && buf[i] <= 0x7e)
  75                         strbuf_addch(&out, buf[i]);
  76                 else
  77                         strbuf_addf(&out, "\\%o", buf[i]);
  78         }
  79
  80         strbuf_addch(&out, '\n');
  81         trace_strbuf(&trace_packet, &out);
  82         strbuf_release(&out);
  83 }
  84
  85 /*
  86  * If we buffered things up above (we don't, but we should),
  87  * we'd flush it here
  88  */
  89 void packet_flush(int fd)
  90 {
  91         packet_trace("0000", 4, 1);
  92         if (write_in_full(fd, "0000", 4) < 0)
  93                 die_errno(_("unable to write flush packet"));
  94 }
  95
  96 void packet_delim(int fd)
  97 {
  98         packet_trace("0001", 4, 1);
  99         if (write_in_full(fd, "0001", 4) < 0)
 100                 die_errno(_("unable to write delim packet"));
 101 }
 102
 103 void packet_response_end(int fd)
 104 {
 105         packet_trace("0002", 4, 1);
 106         if (write_in_full(fd, "0002", 4) < 0)
 107                 die_errno(_("unable to write response end packet"));
 108 }
 109
 110 int packet_flush_gently(int fd)
 111 {
 112         packet_trace("0000", 4, 1);
 113         if (write_in_full(fd, "0000", 4) < 0)
 114                 return error(_("flush packet write failed"));
 115         return 0;
 116 }
 117
 118 void packet_buf_flush(struct strbuf *buf)
 119 {
 120         packet_trace("0000", 4, 1);
 121         strbuf_add(buf, "0000", 4);
 122 }
 123
 124 void packet_buf_delim(struct strbuf *buf)
 125 {
 126         packet_trace("0001", 4, 1);
 127         strbuf_add(buf, "0001", 4);
 128 }
 129
 130 void set_packet_header(char *buf, int size)
 131 {
 132         static char hexchar[] = "0123456789abcdef";
 133
 134         #define hex(a) (hexchar[(a) & 15])
 135         buf[0] = hex(size >> 12);
 136         buf[1] = hex(size >> 8);
 137         buf[2] = hex(size >> 4);
 138         buf[3] = hex(size);
 139         #undef hex
 140 }
 141
 142 static void format_packet(struct strbuf *out, const char *prefix,
 143                           const char *fmt, va_list args)
 144 {
 145         size_t orig_len, n;
 146
 147         orig_len = out->len;
 148         strbuf_addstr(out, "0000");
 149         strbuf_addstr(out, prefix);
 150         strbuf_vaddf(out, fmt, args);
 151         n = out->len - orig_len;
 152
 153         if (n > LARGE_PACKET_MAX)
 154                 die(_("protocol error: impossibly long line"));
 155
 156         set_packet_header(&out->buf[orig_len], n);
 157         packet_trace(out->buf + orig_len + 4, n - 4, 1);
 158 }
 159
 160 static int packet_write_fmt_1(int fd, int gently, const char *prefix,
 161                               const char *fmt, va_list args)
 162 {
 163         static struct strbuf buf = STRBUF_INIT;
 164
 165         strbuf_reset(&buf);
 166         format_packet(&buf, prefix, fmt, args);
 167         if (write_in_full(fd, buf.buf, buf.len) < 0) {
 168                 if (!gently) {
 169                         check_pipe(errno);
 170                         die_errno(_("packet write with format failed"));
 171                 }
 172                 return error(_("packet write with format failed"));
 173         }
 174
 175         return 0;
 176 }
 177
 178 void packet_write_fmt(int fd, const char *fmt, ...)
 179 {
 180         va_list args;
 181
 182         va_start(args, fmt);
 183         packet_write_fmt_1(fd, 0, "", fmt, args);
 184         va_end(args);
 185 }
 186
 187 int packet_write_fmt_gently(int fd, const char *fmt, ...)
 188 {
 189         int status;
 190         va_list args;
 191
 192         va_start(args, fmt);
 193         status = packet_write_fmt_1(fd, 1, "", fmt, args);
 194         va_end(args);
 195         return status;
 196 }
 197
 198 static int do_packet_write(const int fd_out, const char *buf, size_t size,
 199                            struct strbuf *err)
 200 {
 201         char header[4];
 202         size_t packet_size;
 203
 204         if (size > LARGE_PACKET_DATA_MAX) {
 205                 strbuf_addstr(err, _("packet write failed - data exceeds max packet size"));
 206                 return -1;
 207         }
 208
 209         packet_trace(buf, size, 1);
 210         packet_size = size + 4;
 211
 212         set_packet_header(header, packet_size);
 213
 214         /*
 215          * Write the header and the buffer in 2 parts so that we do
 216          * not need to allocate a buffer or rely on a static buffer.
 217          * This also avoids putting a large buffer on the stack which
 218          * might have multi-threading issues.
 219          */
 220
 221         if (write_in_full(fd_out, header, 4) < 0 ||
 222             write_in_full(fd_out, buf, size) < 0) {
 223                 strbuf_addf(err, _("packet write failed: %s"), strerror(errno));
 224                 return -1;
 225         }
 226         return 0;
 227 }
 228
 229 static int packet_write_gently(const int fd_out, const char *buf, size_t size)
 230 {
 231         struct strbuf err = STRBUF_INIT;
 232         if (do_packet_write(fd_out, buf, size, &err)) {
 233                 error("%s", err.buf);
 234                 strbuf_release(&err);
 235                 return -1;
 236         }
 237         return 0;
 238 }
 239
 240 void packet_write(int fd_out, const char *buf, size_t size)
 241 {
 242         struct strbuf err = STRBUF_INIT;
 243         if (do_packet_write(fd_out, buf, size, &err))
 244                 die("%s", err.buf);
 245 }
 246
 247 void packet_fwrite(FILE *f, const char *buf, size_t size)
 248 {
 249         size_t packet_size;
 250         char header[4];
 251
 252         if (size > LARGE_PACKET_DATA_MAX)
 253                 die(_("packet write failed - data exceeds max packet size"));
 254
 255         packet_trace(buf, size, 1);
 256         packet_size = size + 4;
 257
 258         set_packet_header(header, packet_size);
 259         fwrite_or_die(f, header, 4);
 260         fwrite_or_die(f, buf, size);
 261 }
 262
 263 void packet_fwrite_fmt(FILE *fh, const char *fmt, ...)
 264 {
 265        static struct strbuf buf = STRBUF_INIT;
 266        va_list args;
 267
 268        strbuf_reset(&buf);
 269
 270        va_start(args, fmt);
 271        format_packet(&buf, "", fmt, args);
 272        va_end(args);
 273
 274        fwrite_or_die(fh, buf.buf, buf.len);
 275 }
 276
 277 void packet_fflush(FILE *f)
 278 {
 279         packet_trace("0000", 4, 1);
 280         fwrite_or_die(f, "0000", 4);
 281         fflush_or_die(f);
 282 }
 283
 284 void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
 285 {
 286         va_list args;
 287
 288         va_start(args, fmt);
 289         format_packet(buf, "", fmt, args);
 290         va_end(args);
 291 }
 292
 293 int write_packetized_from_fd_no_flush(int fd_in, int fd_out)
 294 {
 295         char *buf = xmalloc(LARGE_PACKET_DATA_MAX);
 296         int err = 0;
 297         ssize_t bytes_to_write;
 298
 299         while (!err) {
 300                 bytes_to_write = xread(fd_in, buf, LARGE_PACKET_DATA_MAX);
 301                 if (bytes_to_write < 0) {
 302                         free(buf);
 303                         return COPY_READ_ERROR;
 304                 }
 305                 if (bytes_to_write == 0)
 306                         break;
 307                 err = packet_write_gently(fd_out, buf, bytes_to_write);
 308         }
 309         free(buf);
 310         return err;
 311 }
 312
 313 int write_packetized_from_buf_no_flush_count(const char *src_in, size_t len,
 314                                              int fd_out, int *packet_counter)
 315 {
 316         int err = 0;
 317         size_t bytes_written = 0;
 318         size_t bytes_to_write;
 319
 320         while (!err) {
 321                 if ((len - bytes_written) > LARGE_PACKET_DATA_MAX)
 322                         bytes_to_write = LARGE_PACKET_DATA_MAX;
 323                 else
 324                         bytes_to_write = len - bytes_written;
 325                 if (bytes_to_write == 0)
 326                         break;
 327                 err = packet_write_gently(fd_out, src_in + bytes_written, bytes_to_write);
 328                 bytes_written += bytes_to_write;
 329                 if (packet_counter)
 330                         (*packet_counter)++;
 331         }
 332         return err;
 333 }
 334
 335 static int get_packet_data(int fd, char **src_buf, size_t *src_size,
 336                            void *dst, unsigned size, int options)
 337 {
 338         ssize_t ret;
 339
 340         if (fd >= 0 && src_buf && *src_buf)
 341                 BUG("multiple sources given to packet_read");
 342
 343         /* Read up to "size" bytes from our source, whatever it is. */
 344         if (src_buf && *src_buf) {
 345                 ret = size < *src_size ? size : *src_size;
 346                 memcpy(dst, *src_buf, ret);
 347                 *src_buf += ret;
 348                 *src_size -= ret;
 349         } else {
 350                 ret = read_in_full(fd, dst, size);
 351                 if (ret < 0) {
 352                         if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
 353                                 return error_errno(_("read error"));
 354                         die_errno(_("read error"));
 355                 }
 356         }
 357
 358         /* And complain if we didn't get enough bytes to satisfy the read. */
 359         if (ret != size) {
 360                 if (options & PACKET_READ_GENTLE_ON_EOF)
 361                         return -1;
 362
 363                 if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
 364                         return error(_("the remote end hung up unexpectedly"));
 365                 die(_("the remote end hung up unexpectedly"));
 366         }
 367
 368         return ret;
 369 }
 370
 371 int packet_length(const char lenbuf_hex[4])
 372 {
 373         int val = hex2chr(lenbuf_hex);
 374         return (val < 0) ? val : (val << 8) | hex2chr(lenbuf_hex + 2);
 375 }
 376
 377 static char *find_packfile_uri_path(const char *buffer)
 378 {
 379         const char *URI_MARK = "://";
 380         char *path;
 381         int len;
 382
 383         /* First char is sideband mark */
 384         buffer += 1;
 385
 386         len = strspn(buffer, "0123456789abcdefABCDEF");
 387         /* size of SHA1 and SHA256 hash */
 388         if (!(len == 40 || len == 64) || buffer[len] != ' ')
 389                 return NULL; /* required "<hash>SP" not seen */
 390
 391         path = strstr(buffer + len + 1, URI_MARK);
 392         if (!path)
 393                 return NULL;
 394
 395         path = strchr(path + strlen(URI_MARK), '/');
 396         if (!path || !*(path + 1))
 397                 return NULL;
 398
 399         /* position after '/' */
 400         return ++path;
 401 }
 402
 403 enum packet_read_status packet_read_with_status(int fd, char **src_buffer,
 404                                                 size_t *src_len, char *buffer,
 405                                                 unsigned size, int *pktlen,
 406                                                 int options)
 407 {
 408         int len;
 409         char linelen[4];
 410         char *uri_path_start;
 411
 412         if (get_packet_data(fd, src_buffer, src_len, linelen, 4, options) < 0) {
 413                 *pktlen = -1;
 414                 return PACKET_READ_EOF;
 415         }
 416
 417         len = packet_length(linelen);
 418
 419         if (len < 0) {
 420                 if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
 421                         return error(_("protocol error: bad line length "
 422                                        "character: %.4s"), linelen);
 423                 die(_("protocol error: bad line length character: %.4s"), linelen);
 424         } else if (!len) {
 425                 packet_trace("0000", 4, 0);
 426                 *pktlen = 0;
 427                 return PACKET_READ_FLUSH;
 428         } else if (len == 1) {
 429                 packet_trace("0001", 4, 0);
 430                 *pktlen = 0;
 431                 return PACKET_READ_DELIM;
 432         } else if (len == 2) {
 433                 packet_trace("0002", 4, 0);
 434                 *pktlen = 0;
 435                 return PACKET_READ_RESPONSE_END;
 436         } else if (len < 4) {
 437                 if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
 438                         return error(_("protocol error: bad line length %d"),
 439                                      len);
 440                 die(_("protocol error: bad line length %d"), len);
 441         }
 442
 443         len -= 4;
 444         if ((unsigned)len >= size) {
 445                 if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
 446                         return error(_("protocol error: bad line length %d"),
 447                                      len);
 448                 die(_("protocol error: bad line length %d"), len);
 449         }
 450
 451         if (get_packet_data(fd, src_buffer, src_len, buffer, len, options) < 0) {
 452                 *pktlen = -1;
 453                 return PACKET_READ_EOF;
 454         }
 455
 456         if ((options & PACKET_READ_CHOMP_NEWLINE) &&
 457             len && buffer[len-1] == '\n')
 458                 len--;
 459
 460         buffer[len] = 0;
 461         if (options & PACKET_READ_REDACT_URI_PATH &&
 462             (uri_path_start = find_packfile_uri_path(buffer))) {
 463                 const char *redacted = "<redacted>";
 464                 struct strbuf tracebuf = STRBUF_INIT;
 465                 strbuf_insert(&tracebuf, 0, buffer, len);
 466                 strbuf_splice(&tracebuf, uri_path_start - buffer,
 467                               strlen(uri_path_start), redacted, strlen(redacted));
 468                 packet_trace(tracebuf.buf, tracebuf.len, 0);
 469                 strbuf_release(&tracebuf);
 470         } else {
 471                 packet_trace(buffer, len, 0);
 472         }
 473
 474         if ((options & PACKET_READ_DIE_ON_ERR_PACKET) &&
 475             starts_with(buffer, "ERR "))
 476                 die(_("remote error: %s"), buffer + 4);
 477
 478         *pktlen = len;
 479         return PACKET_READ_NORMAL;
 480 }
 481
 482 int packet_read(int fd, char *buffer, unsigned size, int options)
 483 {
 484         int pktlen = -1;
 485
 486         packet_read_with_status(fd, NULL, NULL, buffer, size, &pktlen,
 487                                 options);
 488
 489         return pktlen;
 490 }
 491
 492 char *packet_read_line(int fd, int *dst_len)
 493 {
 494         int len = packet_read(fd, packet_buffer, sizeof(packet_buffer),
 495                               PACKET_READ_CHOMP_NEWLINE);
 496         if (dst_len)
 497                 *dst_len = len;
 498         return (len > 0) ? packet_buffer : NULL;
 499 }
 500
 501 int packet_read_line_gently(int fd, int *dst_len, char **dst_line)
 502 {
 503         int len = packet_read(fd, packet_buffer, sizeof(packet_buffer),
 504                               PACKET_READ_CHOMP_NEWLINE|PACKET_READ_GENTLE_ON_EOF);
 505         if (dst_len)
 506                 *dst_len = len;
 507         if (dst_line)
 508                 *dst_line = (len > 0) ? packet_buffer : NULL;
 509         return len;
 510 }
 511
 512 ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out, int options)
 513 {
 514         int packet_len;
 515
 516         size_t orig_len = sb_out->len;
 517         size_t orig_alloc = sb_out->alloc;
 518
 519         for (;;) {
 520                 strbuf_grow(sb_out, LARGE_PACKET_DATA_MAX);
 521                 packet_len = packet_read(fd_in,
 522                         /* strbuf_grow() above always allocates one extra byte to
 523                          * store a '\0' at the end of the string. packet_read()
 524                          * writes a '\0' extra byte at the end, too. Let it know
 525                          * that there is already room for the extra byte.
 526                          */
 527                         sb_out->buf + sb_out->len, LARGE_PACKET_DATA_MAX+1,
 528                         options);
 529                 if (packet_len <= 0)
 530                         break;
 531                 sb_out->len += packet_len;
 532         }
 533
 534         if (packet_len < 0) {
 535                 if (orig_alloc == 0)
 536                         strbuf_release(sb_out);
 537                 else
 538                         strbuf_setlen(sb_out, orig_len);
 539                 return packet_len;
 540         }
 541         return sb_out->len - orig_len;
 542 }
 543
 544 int recv_sideband(const char *me, int in_stream, int out)
 545 {
 546         char buf[LARGE_PACKET_MAX + 1];
 547         int len;
 548         struct strbuf scratch = STRBUF_INIT;
 549         enum sideband_type sideband_type;
 550
 551         while (1) {
 552                 int status = packet_read_with_status(in_stream, NULL, NULL,
 553                                                      buf, LARGE_PACKET_MAX,
 554                                                      &len,
 555                                                      PACKET_READ_GENTLE_ON_EOF);
 556                 if (!demultiplex_sideband(me, status, buf, len, 0, &scratch,
 557                                           &sideband_type))
 558                         continue;
 559                 switch (sideband_type) {
 560                 case SIDEBAND_PRIMARY:
 561                         write_or_die(out, buf + 1, len - 1);
 562                         break;
 563                 default: /* errors: message already written */
 564                         if (scratch.len > 0)
 565                                 BUG("unhandled incomplete sideband: '%s'",
 566                                     scratch.buf);
 567                         return sideband_type;
 568                 }
 569         }
 570 }
 571
 572 /* Packet Reader Functions */
 573 void packet_reader_init(struct packet_reader *reader, int fd,
 574                         char *src_buffer, size_t src_len,
 575                         int options)
 576 {
 577         memset(reader, 0, sizeof(*reader));
 578
 579         reader->fd = fd;
 580         reader->src_buffer = src_buffer;
 581         reader->src_len = src_len;
 582         reader->buffer = packet_buffer;
 583         reader->buffer_size = sizeof(packet_buffer);
 584         reader->options = options;
 585         reader->me = "git";
 586         reader->hash_algo = &hash_algos[GIT_HASH_SHA1];
 587 }
 588
 589 enum packet_read_status packet_reader_read(struct packet_reader *reader)
 590 {
 591         struct strbuf scratch = STRBUF_INIT;
 592
 593         if (reader->line_peeked) {
 594                 reader->line_peeked = 0;
 595                 return reader->status;
 596         }
 597
 598         /*
 599          * Consume all progress packets until a primary payload packet is
 600          * received
 601          */
 602         while (1) {
 603                 enum sideband_type sideband_type;
 604                 reader->status = packet_read_with_status(reader->fd,
 605                                                          &reader->src_buffer,
 606                                                          &reader->src_len,
 607                                                          reader->buffer,
 608                                                          reader->buffer_size,
 609                                                          &reader->pktlen,
 610                                                          reader->options);
 611                 if (!reader->use_sideband)
 612                         break;
 613                 if (demultiplex_sideband(reader->me, reader->status,
 614                                          reader->buffer, reader->pktlen, 1,
 615                                          &scratch, &sideband_type))
 616                         break;
 617         }
 618
 619         if (reader->status == PACKET_READ_NORMAL)
 620                 /* Skip the sideband designator if sideband is used */
 621                 reader->line = reader->use_sideband ?
 622                         reader->buffer + 1 : reader->buffer;
 623         else
 624                 reader->line = NULL;
 625
 626         return reader->status;
 627 }
 628
 629 enum packet_read_status packet_reader_peek(struct packet_reader *reader)
 630 {
 631         /* Only allow peeking a single line */
 632         if (reader->line_peeked)
 633                 return reader->status;
 634
 635         /* Peek a line by reading it and setting peeked flag */
 636         packet_reader_read(reader);
 637         reader->line_peeked = 1;
 638         return reader->status;
 639 }
 640
 641 void packet_writer_init(struct packet_writer *writer, int dest_fd)
 642 {
 643         writer->dest_fd = dest_fd;
 644         writer->use_sideband = 0;
 645 }
 646
 647 void packet_writer_write(struct packet_writer *writer, const char *fmt, ...)
 648 {
 649         va_list args;
 650
 651         va_start(args, fmt);
 652         packet_write_fmt_1(writer->dest_fd, 0,
 653                            writer->use_sideband ? "\001" : "", fmt, args);
 654         va_end(args);
 655 }
 656
 657 void packet_writer_error(struct packet_writer *writer, const char *fmt, ...)
 658 {
 659         va_list args;
 660
 661         va_start(args, fmt);
 662         packet_write_fmt_1(writer->dest_fd, 0,
 663                            writer->use_sideband ? "\003" : "ERR ", fmt, args);
 664         va_end(args);
 665 }
 666
 667 void packet_writer_delim(struct packet_writer *writer)
 668 {
 669         packet_delim(writer->dest_fd);
 670 }
 671
 672 void packet_writer_flush(struct packet_writer *writer)
 673 {
 674         packet_flush(writer->dest_fd);
 675 }