pkt-line.c

   1 #include "cache.h"
   2 #include "pkt-line.h"
   3 #include "gettext.h"
   4 #include "hex.h"
   5 #include "run-command.h"
   6 #include "wrapper.h"
   7 #include "write-or-die.h"
   8
   9 char packet_buffer[LARGE_PACKET_MAX];
  10 static const char *packet_trace_prefix = "git";
  11 static struct trace_key trace_packet = TRACE_KEY_INIT(PACKET);
  12 static struct trace_key trace_pack = TRACE_KEY_INIT(PACKFILE);
  13
  14 void packet_trace_identity(const char *prog)
  15 {
  16         packet_trace_prefix = xstrdup(prog);
  17 }
  18
  19 static const char *get_trace_prefix(void)
  20 {
  21         return in_async() ? "sideband" : packet_trace_prefix;
  22 }
  23
  24 static int packet_trace_pack(const char *buf, unsigned int len, int sideband)
  25 {
  26         if (!sideband) {
  27                 trace_verbatim(&trace_pack, buf, len);
  28                 return 1;
  29         } else if (len && *buf == '\1') {
  30                 trace_verbatim(&trace_pack, buf + 1, len - 1);
  31                 return 1;
  32         } else {
  33                 /* it's another non-pack sideband */
  34                 return 0;
  35         }
  36 }
  37
  38 static void packet_trace(const char *buf, unsigned int len, int write)
  39 {
  40         int i;
  41         struct strbuf out;
  42         static int in_pack, sideband;
  43
  44         if (!trace_want(&trace_packet) && !trace_want(&trace_pack))
  45                 return;
  46
  47         if (in_pack) {
  48                 if (packet_trace_pack(buf, len, sideband))
  49                         return;
  50         } else if (starts_with(buf, "PACK") || starts_with(buf, "\1PACK")) {
  51                 in_pack = 1;
  52                 sideband = *buf == '\1';
  53                 packet_trace_pack(buf, len, sideband);
  54
  55                 /*
  56                  * Make a note in the human-readable trace that the pack data
  57                  * started.
  58                  */
  59                 buf = "PACK ...";
  60                 len = strlen(buf);
  61         }
  62
  63         if (!trace_want(&trace_packet))
  64                 return;
  65
  66         /* +32 is just a guess for header + quoting */
  67         strbuf_init(&out, len+32);
  68
  69         strbuf_addf(&out, "packet: %12s%c ",
  70                     get_trace_prefix(), write ? '>' : '<');
  71
  72         /* XXX we should really handle printable utf8 */
  73         for (i = 0; i < len; i++) {
  74                 /* suppress newlines */
  75                 if (buf[i] == '\n')
  76                         continue;
  77                 if (buf[i] >= 0x20 && buf[i] <= 0x7e)
  78                         strbuf_addch(&out, buf[i]);
  79                 else
  80                         strbuf_addf(&out, "\\%o", buf[i]);
  81         }
  82
  83         strbuf_addch(&out, '\n');
  84         trace_strbuf(&trace_packet, &out);
  85         strbuf_release(&out);
  86 }
  87
  88 /*
  89  * If we buffered things up above (we don't, but we should),
  90  * we'd flush it here
  91  */
  92 void packet_flush(int fd)
  93 {
  94         packet_trace("0000", 4, 1);
  95         if (write_in_full(fd, "0000", 4) < 0)
  96                 die_errno(_("unable to write flush packet"));
  97 }
  98
  99 void packet_delim(int fd)
 100 {
 101         packet_trace("0001", 4, 1);
 102         if (write_in_full(fd, "0001", 4) < 0)
 103                 die_errno(_("unable to write delim packet"));
 104 }
 105
 106 void packet_response_end(int fd)
 107 {
 108         packet_trace("0002", 4, 1);
 109         if (write_in_full(fd, "0002", 4) < 0)
 110                 die_errno(_("unable to write response end packet"));
 111 }
 112
 113 int packet_flush_gently(int fd)
 114 {
 115         packet_trace("0000", 4, 1);
 116         if (write_in_full(fd, "0000", 4) < 0)
 117                 return error(_("flush packet write failed"));
 118         return 0;
 119 }
 120
 121 void packet_buf_flush(struct strbuf *buf)
 122 {
 123         packet_trace("0000", 4, 1);
 124         strbuf_add(buf, "0000", 4);
 125 }
 126
 127 void packet_buf_delim(struct strbuf *buf)
 128 {
 129         packet_trace("0001", 4, 1);
 130         strbuf_add(buf, "0001", 4);
 131 }
 132
 133 void set_packet_header(char *buf, int size)
 134 {
 135         static char hexchar[] = "0123456789abcdef";
 136
 137         #define hex(a) (hexchar[(a) & 15])
 138         buf[0] = hex(size >> 12);
 139         buf[1] = hex(size >> 8);
 140         buf[2] = hex(size >> 4);
 141         buf[3] = hex(size);
 142         #undef hex
 143 }
 144
 145 static void format_packet(struct strbuf *out, const char *prefix,
 146                           const char *fmt, va_list args)
 147 {
 148         size_t orig_len, n;
 149
 150         orig_len = out->len;
 151         strbuf_addstr(out, "0000");
 152         strbuf_addstr(out, prefix);
 153         strbuf_vaddf(out, fmt, args);
 154         n = out->len - orig_len;
 155
 156         if (n > LARGE_PACKET_MAX)
 157                 die(_("protocol error: impossibly long line"));
 158
 159         set_packet_header(&out->buf[orig_len], n);
 160         packet_trace(out->buf + orig_len + 4, n - 4, 1);
 161 }
 162
 163 static int packet_write_fmt_1(int fd, int gently, const char *prefix,
 164                               const char *fmt, va_list args)
 165 {
 166         static struct strbuf buf = STRBUF_INIT;
 167
 168         strbuf_reset(&buf);
 169         format_packet(&buf, prefix, fmt, args);
 170         if (write_in_full(fd, buf.buf, buf.len) < 0) {
 171                 if (!gently) {
 172                         check_pipe(errno);
 173                         die_errno(_("packet write with format failed"));
 174                 }
 175                 return error(_("packet write with format failed"));
 176         }
 177
 178         return 0;
 179 }
 180
 181 void packet_write_fmt(int fd, const char *fmt, ...)
 182 {
 183         va_list args;
 184
 185         va_start(args, fmt);
 186         packet_write_fmt_1(fd, 0, "", fmt, args);
 187         va_end(args);
 188 }
 189
 190 int packet_write_fmt_gently(int fd, const char *fmt, ...)
 191 {
 192         int status;
 193         va_list args;
 194
 195         va_start(args, fmt);
 196         status = packet_write_fmt_1(fd, 1, "", fmt, args);
 197         va_end(args);
 198         return status;
 199 }
 200
 201 static int do_packet_write(const int fd_out, const char *buf, size_t size,
 202                            struct strbuf *err)
 203 {
 204         char header[4];
 205         size_t packet_size;
 206
 207         if (size > LARGE_PACKET_DATA_MAX) {
 208                 strbuf_addstr(err, _("packet write failed - data exceeds max packet size"));
 209                 return -1;
 210         }
 211
 212         packet_trace(buf, size, 1);
 213         packet_size = size + 4;
 214
 215         set_packet_header(header, packet_size);
 216
 217         /*
 218          * Write the header and the buffer in 2 parts so that we do
 219          * not need to allocate a buffer or rely on a static buffer.
 220          * This also avoids putting a large buffer on the stack which
 221          * might have multi-threading issues.
 222          */
 223
 224         if (write_in_full(fd_out, header, 4) < 0 ||
 225             write_in_full(fd_out, buf, size) < 0) {
 226                 strbuf_addf(err, _("packet write failed: %s"), strerror(errno));
 227                 return -1;
 228         }
 229         return 0;
 230 }
 231
 232 static int packet_write_gently(const int fd_out, const char *buf, size_t size)
 233 {
 234         struct strbuf err = STRBUF_INIT;
 235         if (do_packet_write(fd_out, buf, size, &err)) {
 236                 error("%s", err.buf);
 237                 strbuf_release(&err);
 238                 return -1;
 239         }
 240         return 0;
 241 }
 242
 243 void packet_write(int fd_out, const char *buf, size_t size)
 244 {
 245         struct strbuf err = STRBUF_INIT;
 246         if (do_packet_write(fd_out, buf, size, &err))
 247                 die("%s", err.buf);
 248 }
 249
 250 void packet_fwrite(FILE *f, const char *buf, size_t size)
 251 {
 252         size_t packet_size;
 253         char header[4];
 254
 255         if (size > LARGE_PACKET_DATA_MAX)
 256                 die(_("packet write failed - data exceeds max packet size"));
 257
 258         packet_trace(buf, size, 1);
 259         packet_size = size + 4;
 260
 261         set_packet_header(header, packet_size);
 262         fwrite_or_die(f, header, 4);
 263         fwrite_or_die(f, buf, size);
 264 }
 265
 266 void packet_fwrite_fmt(FILE *fh, const char *fmt, ...)
 267 {
 268        static struct strbuf buf = STRBUF_INIT;
 269        va_list args;
 270
 271        strbuf_reset(&buf);
 272
 273        va_start(args, fmt);
 274        format_packet(&buf, "", fmt, args);
 275        va_end(args);
 276
 277        fwrite_or_die(fh, buf.buf, buf.len);
 278 }
 279
 280 void packet_fflush(FILE *f)
 281 {
 282         packet_trace("0000", 4, 1);
 283         fwrite_or_die(f, "0000", 4);
 284         fflush_or_die(f);
 285 }
 286
 287 void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
 288 {
 289         va_list args;
 290
 291         va_start(args, fmt);
 292         format_packet(buf, "", fmt, args);
 293         va_end(args);
 294 }
 295
 296 int write_packetized_from_fd_no_flush(int fd_in, int fd_out)
 297 {
 298         char *buf = xmalloc(LARGE_PACKET_DATA_MAX);
 299         int err = 0;
 300         ssize_t bytes_to_write;
 301
 302         while (!err) {
 303                 bytes_to_write = xread(fd_in, buf, LARGE_PACKET_DATA_MAX);
 304                 if (bytes_to_write < 0) {
 305                         free(buf);
 306                         return COPY_READ_ERROR;
 307                 }
 308                 if (bytes_to_write == 0)
 309                         break;
 310                 err = packet_write_gently(fd_out, buf, bytes_to_write);
 311         }
 312         free(buf);
 313         return err;
 314 }
 315
 316 int write_packetized_from_buf_no_flush_count(const char *src_in, size_t len,
 317                                              int fd_out, int *packet_counter)
 318 {
 319         int err = 0;
 320         size_t bytes_written = 0;
 321         size_t bytes_to_write;
 322
 323         while (!err) {
 324                 if ((len - bytes_written) > LARGE_PACKET_DATA_MAX)
 325                         bytes_to_write = LARGE_PACKET_DATA_MAX;
 326                 else
 327                         bytes_to_write = len - bytes_written;
 328                 if (bytes_to_write == 0)
 329                         break;
 330                 err = packet_write_gently(fd_out, src_in + bytes_written, bytes_to_write);
 331                 bytes_written += bytes_to_write;
 332                 if (packet_counter)
 333                         (*packet_counter)++;
 334         }
 335         return err;
 336 }
 337
 338 static int get_packet_data(int fd, char **src_buf, size_t *src_size,
 339                            void *dst, unsigned size, int options)
 340 {
 341         ssize_t ret;
 342
 343         if (fd >= 0 && src_buf && *src_buf)
 344                 BUG("multiple sources given to packet_read");
 345
 346         /* Read up to "size" bytes from our source, whatever it is. */
 347         if (src_buf && *src_buf) {
 348                 ret = size < *src_size ? size : *src_size;
 349                 memcpy(dst, *src_buf, ret);
 350                 *src_buf += ret;
 351                 *src_size -= ret;
 352         } else {
 353                 ret = read_in_full(fd, dst, size);
 354                 if (ret < 0) {
 355                         if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
 356                                 return error_errno(_("read error"));
 357                         die_errno(_("read error"));
 358                 }
 359         }
 360
 361         /* And complain if we didn't get enough bytes to satisfy the read. */
 362         if (ret != size) {
 363                 if (options & PACKET_READ_GENTLE_ON_EOF)
 364                         return -1;
 365
 366                 if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
 367                         return error(_("the remote end hung up unexpectedly"));
 368                 die(_("the remote end hung up unexpectedly"));
 369         }
 370
 371         return ret;
 372 }
 373
 374 int packet_length(const char lenbuf_hex[4])
 375 {
 376         int val = hex2chr(lenbuf_hex);
 377         return (val < 0) ? val : (val << 8) | hex2chr(lenbuf_hex + 2);
 378 }
 379
 380 static char *find_packfile_uri_path(const char *buffer)
 381 {
 382         const char *URI_MARK = "://";
 383         char *path;
 384         int len;
 385
 386         /* First char is sideband mark */
 387         buffer += 1;
 388
 389         len = strspn(buffer, "0123456789abcdefABCDEF");
 390         /* size of SHA1 and SHA256 hash */
 391         if (!(len == 40 || len == 64) || buffer[len] != ' ')
 392                 return NULL; /* required "<hash>SP" not seen */
 393
 394         path = strstr(buffer + len + 1, URI_MARK);
 395         if (!path)
 396                 return NULL;
 397
 398         path = strchr(path + strlen(URI_MARK), '/');
 399         if (!path || !*(path + 1))
 400                 return NULL;
 401
 402         /* position after '/' */
 403         return ++path;
 404 }
 405
 406 enum packet_read_status packet_read_with_status(int fd, char **src_buffer,
 407                                                 size_t *src_len, char *buffer,
 408                                                 unsigned size, int *pktlen,
 409                                                 int options)
 410 {
 411         int len;
 412         char linelen[4];
 413         char *uri_path_start;
 414
 415         if (get_packet_data(fd, src_buffer, src_len, linelen, 4, options) < 0) {
 416                 *pktlen = -1;
 417                 return PACKET_READ_EOF;
 418         }
 419
 420         len = packet_length(linelen);
 421
 422         if (len < 0) {
 423                 if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
 424                         return error(_("protocol error: bad line length "
 425                                        "character: %.4s"), linelen);
 426                 die(_("protocol error: bad line length character: %.4s"), linelen);
 427         } else if (!len) {
 428                 packet_trace("0000", 4, 0);
 429                 *pktlen = 0;
 430                 return PACKET_READ_FLUSH;
 431         } else if (len == 1) {
 432                 packet_trace("0001", 4, 0);
 433                 *pktlen = 0;
 434                 return PACKET_READ_DELIM;
 435         } else if (len == 2) {
 436                 packet_trace("0002", 4, 0);
 437                 *pktlen = 0;
 438                 return PACKET_READ_RESPONSE_END;
 439         } else if (len < 4) {
 440                 if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
 441                         return error(_("protocol error: bad line length %d"),
 442                                      len);
 443                 die(_("protocol error: bad line length %d"), len);
 444         }
 445
 446         len -= 4;
 447         if ((unsigned)len >= size) {
 448                 if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
 449                         return error(_("protocol error: bad line length %d"),
 450                                      len);
 451                 die(_("protocol error: bad line length %d"), len);
 452         }
 453
 454         if (get_packet_data(fd, src_buffer, src_len, buffer, len, options) < 0) {
 455                 *pktlen = -1;
 456                 return PACKET_READ_EOF;
 457         }
 458
 459         if ((options & PACKET_READ_CHOMP_NEWLINE) &&
 460             len && buffer[len-1] == '\n')
 461                 len--;
 462
 463         buffer[len] = 0;
 464         if (options & PACKET_READ_REDACT_URI_PATH &&
 465             (uri_path_start = find_packfile_uri_path(buffer))) {
 466                 const char *redacted = "<redacted>";
 467                 struct strbuf tracebuf = STRBUF_INIT;
 468                 strbuf_insert(&tracebuf, 0, buffer, len);
 469                 strbuf_splice(&tracebuf, uri_path_start - buffer,
 470                               strlen(uri_path_start), redacted, strlen(redacted));
 471                 packet_trace(tracebuf.buf, tracebuf.len, 0);
 472                 strbuf_release(&tracebuf);
 473         } else {
 474                 packet_trace(buffer, len, 0);
 475         }
 476
 477         if ((options & PACKET_READ_DIE_ON_ERR_PACKET) &&
 478             starts_with(buffer, "ERR "))
 479                 die(_("remote error: %s"), buffer + 4);
 480
 481         *pktlen = len;
 482         return PACKET_READ_NORMAL;
 483 }
 484
 485 int packet_read(int fd, char *buffer, unsigned size, int options)
 486 {
 487         int pktlen = -1;
 488
 489         packet_read_with_status(fd, NULL, NULL, buffer, size, &pktlen,
 490                                 options);
 491
 492         return pktlen;
 493 }
 494
 495 char *packet_read_line(int fd, int *dst_len)
 496 {
 497         int len = packet_read(fd, packet_buffer, sizeof(packet_buffer),
 498                               PACKET_READ_CHOMP_NEWLINE);
 499         if (dst_len)
 500                 *dst_len = len;
 501         return (len > 0) ? packet_buffer : NULL;
 502 }
 503
 504 int packet_read_line_gently(int fd, int *dst_len, char **dst_line)
 505 {
 506         int len = packet_read(fd, packet_buffer, sizeof(packet_buffer),
 507                               PACKET_READ_CHOMP_NEWLINE|PACKET_READ_GENTLE_ON_EOF);
 508         if (dst_len)
 509                 *dst_len = len;
 510         if (dst_line)
 511                 *dst_line = (len > 0) ? packet_buffer : NULL;
 512         return len;
 513 }
 514
 515 ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out, int options)
 516 {
 517         int packet_len;
 518
 519         size_t orig_len = sb_out->len;
 520         size_t orig_alloc = sb_out->alloc;
 521
 522         for (;;) {
 523                 strbuf_grow(sb_out, LARGE_PACKET_DATA_MAX);
 524                 packet_len = packet_read(fd_in,
 525                         /* strbuf_grow() above always allocates one extra byte to
 526                          * store a '\0' at the end of the string. packet_read()
 527                          * writes a '\0' extra byte at the end, too. Let it know
 528                          * that there is already room for the extra byte.
 529                          */
 530                         sb_out->buf + sb_out->len, LARGE_PACKET_DATA_MAX+1,
 531                         options);
 532                 if (packet_len <= 0)
 533                         break;
 534                 sb_out->len += packet_len;
 535         }
 536
 537         if (packet_len < 0) {
 538                 if (orig_alloc == 0)
 539                         strbuf_release(sb_out);
 540                 else
 541                         strbuf_setlen(sb_out, orig_len);
 542                 return packet_len;
 543         }
 544         return sb_out->len - orig_len;
 545 }
 546
 547 int recv_sideband(const char *me, int in_stream, int out)
 548 {
 549         char buf[LARGE_PACKET_MAX + 1];
 550         int len;
 551         struct strbuf scratch = STRBUF_INIT;
 552         enum sideband_type sideband_type;
 553
 554         while (1) {
 555                 int status = packet_read_with_status(in_stream, NULL, NULL,
 556                                                      buf, LARGE_PACKET_MAX,
 557                                                      &len,
 558                                                      PACKET_READ_GENTLE_ON_EOF);
 559                 if (!demultiplex_sideband(me, status, buf, len, 0, &scratch,
 560                                           &sideband_type))
 561                         continue;
 562                 switch (sideband_type) {
 563                 case SIDEBAND_PRIMARY:
 564                         write_or_die(out, buf + 1, len - 1);
 565                         break;
 566                 default: /* errors: message already written */
 567                         if (scratch.len > 0)
 568                                 BUG("unhandled incomplete sideband: '%s'",
 569                                     scratch.buf);
 570                         return sideband_type;
 571                 }
 572         }
 573 }
 574
 575 /* Packet Reader Functions */
 576 void packet_reader_init(struct packet_reader *reader, int fd,
 577                         char *src_buffer, size_t src_len,
 578                         int options)
 579 {
 580         memset(reader, 0, sizeof(*reader));
 581
 582         reader->fd = fd;
 583         reader->src_buffer = src_buffer;
 584         reader->src_len = src_len;
 585         reader->buffer = packet_buffer;
 586         reader->buffer_size = sizeof(packet_buffer);
 587         reader->options = options;
 588         reader->me = "git";
 589         reader->hash_algo = &hash_algos[GIT_HASH_SHA1];
 590 }
 591
 592 enum packet_read_status packet_reader_read(struct packet_reader *reader)
 593 {
 594         struct strbuf scratch = STRBUF_INIT;
 595
 596         if (reader->line_peeked) {
 597                 reader->line_peeked = 0;
 598                 return reader->status;
 599         }
 600
 601         /*
 602          * Consume all progress packets until a primary payload packet is
 603          * received
 604          */
 605         while (1) {
 606                 enum sideband_type sideband_type;
 607                 reader->status = packet_read_with_status(reader->fd,
 608                                                          &reader->src_buffer,
 609                                                          &reader->src_len,
 610                                                          reader->buffer,
 611                                                          reader->buffer_size,
 612                                                          &reader->pktlen,
 613                                                          reader->options);
 614                 if (!reader->use_sideband)
 615                         break;
 616                 if (demultiplex_sideband(reader->me, reader->status,
 617                                          reader->buffer, reader->pktlen, 1,
 618                                          &scratch, &sideband_type))
 619                         break;
 620         }
 621
 622         if (reader->status == PACKET_READ_NORMAL)
 623                 /* Skip the sideband designator if sideband is used */
 624                 reader->line = reader->use_sideband ?
 625                         reader->buffer + 1 : reader->buffer;
 626         else
 627                 reader->line = NULL;
 628
 629         return reader->status;
 630 }
 631
 632 enum packet_read_status packet_reader_peek(struct packet_reader *reader)
 633 {
 634         /* Only allow peeking a single line */
 635         if (reader->line_peeked)
 636                 return reader->status;
 637
 638         /* Peek a line by reading it and setting peeked flag */
 639         packet_reader_read(reader);
 640         reader->line_peeked = 1;
 641         return reader->status;
 642 }
 643
 644 void packet_writer_init(struct packet_writer *writer, int dest_fd)
 645 {
 646         writer->dest_fd = dest_fd;
 647         writer->use_sideband = 0;
 648 }
 649
 650 void packet_writer_write(struct packet_writer *writer, const char *fmt, ...)
 651 {
 652         va_list args;
 653
 654         va_start(args, fmt);
 655         packet_write_fmt_1(writer->dest_fd, 0,
 656                            writer->use_sideband ? "\001" : "", fmt, args);
 657         va_end(args);
 658 }
 659
 660 void packet_writer_error(struct packet_writer *writer, const char *fmt, ...)
 661 {
 662         va_list args;
 663
 664         va_start(args, fmt);
 665         packet_write_fmt_1(writer->dest_fd, 0,
 666                            writer->use_sideband ? "\003" : "ERR ", fmt, args);
 667         va_end(args);
 668 }
 669
 670 void packet_writer_delim(struct packet_writer *writer)
 671 {
 672         packet_delim(writer->dest_fd);
 673 }
 674
 675 void packet_writer_flush(struct packet_writer *writer)
 676 {
 677         packet_flush(writer->dest_fd);
 678 }