pkt-line.c

   1 #include "git-compat-util.h"
   2 #include "copy.h"
   3 #include "pkt-line.h"
   4 #include "gettext.h"
   5 #include "hex.h"
   6 #include "run-command.h"
   7 #include "sideband.h"
   8 #include "trace.h"
   9 #include "write-or-die.h"
  10
  11 char packet_buffer[LARGE_PACKET_MAX];
  12 static const char *packet_trace_prefix = "git";
  13 static struct trace_key trace_packet = TRACE_KEY_INIT(PACKET);
  14 static struct trace_key trace_pack = TRACE_KEY_INIT(PACKFILE);
  15
  16 void packet_trace_identity(const char *prog)
  17 {
  18         packet_trace_prefix = xstrdup(prog);
  19 }
  20
  21 static const char *get_trace_prefix(void)
  22 {
  23         return in_async() ? "sideband" : packet_trace_prefix;
  24 }
  25
  26 static int packet_trace_pack(const char *buf, unsigned int len, int sideband)
  27 {
  28         if (!sideband) {
  29                 trace_verbatim(&trace_pack, buf, len);
  30                 return 1;
  31         } else if (len && *buf == '\1') {
  32                 trace_verbatim(&trace_pack, buf + 1, len - 1);
  33                 return 1;
  34         } else {
  35                 /* it's another non-pack sideband */
  36                 return 0;
  37         }
  38 }
  39
  40 static void packet_trace(const char *buf, unsigned int len, int write)
  41 {
  42         int i;
  43         struct strbuf out;
  44         static int in_pack, sideband;
  45
  46         if (!trace_want(&trace_packet) && !trace_want(&trace_pack))
  47                 return;
  48
  49         if (in_pack) {
  50                 if (packet_trace_pack(buf, len, sideband))
  51                         return;
  52         } else if (starts_with(buf, "PACK") || starts_with(buf, "\1PACK")) {
  53                 in_pack = 1;
  54                 sideband = *buf == '\1';
  55                 packet_trace_pack(buf, len, sideband);
  56
  57                 /*
  58                  * Make a note in the human-readable trace that the pack data
  59                  * started.
  60                  */
  61                 buf = "PACK ...";
  62                 len = strlen(buf);
  63         }
  64
  65         if (!trace_want(&trace_packet))
  66                 return;
  67
  68         /* +32 is just a guess for header + quoting */
  69         strbuf_init(&out, len+32);
  70
  71         strbuf_addf(&out, "packet: %12s%c ",
  72                     get_trace_prefix(), write ? '>' : '<');
  73
  74         /* XXX we should really handle printable utf8 */
  75         for (i = 0; i < len; i++) {
  76                 /* suppress newlines */
  77                 if (buf[i] == '\n')
  78                         continue;
  79                 if (buf[i] >= 0x20 && buf[i] <= 0x7e)
  80                         strbuf_addch(&out, buf[i]);
  81                 else
  82                         strbuf_addf(&out, "\\%o", buf[i]);
  83         }
  84
  85         strbuf_addch(&out, '\n');
  86         trace_strbuf(&trace_packet, &out);
  87         strbuf_release(&out);
  88 }
  89
  90 /*
  91  * If we buffered things up above (we don't, but we should),
  92  * we'd flush it here
  93  */
  94 void packet_flush(int fd)
  95 {
  96         packet_trace("0000", 4, 1);
  97         if (write_in_full(fd, "0000", 4) < 0)
  98                 die_errno(_("unable to write flush packet"));
  99 }
 100
 101 void packet_delim(int fd)
 102 {
 103         packet_trace("0001", 4, 1);
 104         if (write_in_full(fd, "0001", 4) < 0)
 105                 die_errno(_("unable to write delim packet"));
 106 }
 107
 108 void packet_response_end(int fd)
 109 {
 110         packet_trace("0002", 4, 1);
 111         if (write_in_full(fd, "0002", 4) < 0)
 112                 die_errno(_("unable to write response end packet"));
 113 }
 114
 115 int packet_flush_gently(int fd)
 116 {
 117         packet_trace("0000", 4, 1);
 118         if (write_in_full(fd, "0000", 4) < 0)
 119                 return error(_("flush packet write failed"));
 120         return 0;
 121 }
 122
 123 void packet_buf_flush(struct strbuf *buf)
 124 {
 125         packet_trace("0000", 4, 1);
 126         strbuf_add(buf, "0000", 4);
 127 }
 128
 129 void packet_buf_delim(struct strbuf *buf)
 130 {
 131         packet_trace("0001", 4, 1);
 132         strbuf_add(buf, "0001", 4);
 133 }
 134
 135 void set_packet_header(char *buf, int size)
 136 {
 137         static char hexchar[] = "0123456789abcdef";
 138
 139         #define hex(a) (hexchar[(a) & 15])
 140         buf[0] = hex(size >> 12);
 141         buf[1] = hex(size >> 8);
 142         buf[2] = hex(size >> 4);
 143         buf[3] = hex(size);
 144         #undef hex
 145 }
 146
 147 static void format_packet(struct strbuf *out, const char *prefix,
 148                           const char *fmt, va_list args)
 149 {
 150         size_t orig_len, n;
 151
 152         orig_len = out->len;
 153         strbuf_addstr(out, "0000");
 154         strbuf_addstr(out, prefix);
 155         strbuf_vaddf(out, fmt, args);
 156         n = out->len - orig_len;
 157
 158         if (n > LARGE_PACKET_MAX)
 159                 die(_("protocol error: impossibly long line"));
 160
 161         set_packet_header(&out->buf[orig_len], n);
 162         packet_trace(out->buf + orig_len + 4, n - 4, 1);
 163 }
 164
 165 static int packet_write_fmt_1(int fd, int gently, const char *prefix,
 166                               const char *fmt, va_list args)
 167 {
 168         static struct strbuf buf = STRBUF_INIT;
 169
 170         strbuf_reset(&buf);
 171         format_packet(&buf, prefix, fmt, args);
 172         if (write_in_full(fd, buf.buf, buf.len) < 0) {
 173                 if (!gently) {
 174                         check_pipe(errno);
 175                         die_errno(_("packet write with format failed"));
 176                 }
 177                 return error(_("packet write with format failed"));
 178         }
 179
 180         return 0;
 181 }
 182
 183 void packet_write_fmt(int fd, const char *fmt, ...)
 184 {
 185         va_list args;
 186
 187         va_start(args, fmt);
 188         packet_write_fmt_1(fd, 0, "", fmt, args);
 189         va_end(args);
 190 }
 191
 192 int packet_write_fmt_gently(int fd, const char *fmt, ...)
 193 {
 194         int status;
 195         va_list args;
 196
 197         va_start(args, fmt);
 198         status = packet_write_fmt_1(fd, 1, "", fmt, args);
 199         va_end(args);
 200         return status;
 201 }
 202
 203 static int do_packet_write(const int fd_out, const char *buf, size_t size,
 204                            struct strbuf *err)
 205 {
 206         char header[4];
 207         size_t packet_size;
 208
 209         if (size > LARGE_PACKET_DATA_MAX) {
 210                 strbuf_addstr(err, _("packet write failed - data exceeds max packet size"));
 211                 return -1;
 212         }
 213
 214         packet_trace(buf, size, 1);
 215         packet_size = size + 4;
 216
 217         set_packet_header(header, packet_size);
 218
 219         /*
 220          * Write the header and the buffer in 2 parts so that we do
 221          * not need to allocate a buffer or rely on a static buffer.
 222          * This also avoids putting a large buffer on the stack which
 223          * might have multi-threading issues.
 224          */
 225
 226         if (write_in_full(fd_out, header, 4) < 0 ||
 227             write_in_full(fd_out, buf, size) < 0) {
 228                 strbuf_addf(err, _("packet write failed: %s"), strerror(errno));
 229                 return -1;
 230         }
 231         return 0;
 232 }
 233
 234 static int packet_write_gently(const int fd_out, const char *buf, size_t size)
 235 {
 236         struct strbuf err = STRBUF_INIT;
 237         if (do_packet_write(fd_out, buf, size, &err)) {
 238                 error("%s", err.buf);
 239                 strbuf_release(&err);
 240                 return -1;
 241         }
 242         return 0;
 243 }
 244
 245 void packet_write(int fd_out, const char *buf, size_t size)
 246 {
 247         struct strbuf err = STRBUF_INIT;
 248         if (do_packet_write(fd_out, buf, size, &err))
 249                 die("%s", err.buf);
 250 }
 251
 252 void packet_fwrite(FILE *f, const char *buf, size_t size)
 253 {
 254         size_t packet_size;
 255         char header[4];
 256
 257         if (size > LARGE_PACKET_DATA_MAX)
 258                 die(_("packet write failed - data exceeds max packet size"));
 259
 260         packet_trace(buf, size, 1);
 261         packet_size = size + 4;
 262
 263         set_packet_header(header, packet_size);
 264         fwrite_or_die(f, header, 4);
 265         fwrite_or_die(f, buf, size);
 266 }
 267
 268 void packet_fwrite_fmt(FILE *fh, const char *fmt, ...)
 269 {
 270        static struct strbuf buf = STRBUF_INIT;
 271        va_list args;
 272
 273        strbuf_reset(&buf);
 274
 275        va_start(args, fmt);
 276        format_packet(&buf, "", fmt, args);
 277        va_end(args);
 278
 279        fwrite_or_die(fh, buf.buf, buf.len);
 280 }
 281
 282 void packet_fflush(FILE *f)
 283 {
 284         packet_trace("0000", 4, 1);
 285         fwrite_or_die(f, "0000", 4);
 286         fflush_or_die(f);
 287 }
 288
 289 void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
 290 {
 291         va_list args;
 292
 293         va_start(args, fmt);
 294         format_packet(buf, "", fmt, args);
 295         va_end(args);
 296 }
 297
 298 int write_packetized_from_fd_no_flush(int fd_in, int fd_out)
 299 {
 300         char *buf = xmalloc(LARGE_PACKET_DATA_MAX);
 301         int err = 0;
 302         ssize_t bytes_to_write;
 303
 304         while (!err) {
 305                 bytes_to_write = xread(fd_in, buf, LARGE_PACKET_DATA_MAX);
 306                 if (bytes_to_write < 0) {
 307                         free(buf);
 308                         return COPY_READ_ERROR;
 309                 }
 310                 if (bytes_to_write == 0)
 311                         break;
 312                 err = packet_write_gently(fd_out, buf, bytes_to_write);
 313         }
 314         free(buf);
 315         return err;
 316 }
 317
 318 int write_packetized_from_buf_no_flush_count(const char *src_in, size_t len,
 319                                              int fd_out, int *packet_counter)
 320 {
 321         int err = 0;
 322         size_t bytes_written = 0;
 323         size_t bytes_to_write;
 324
 325         while (!err) {
 326                 if ((len - bytes_written) > LARGE_PACKET_DATA_MAX)
 327                         bytes_to_write = LARGE_PACKET_DATA_MAX;
 328                 else
 329                         bytes_to_write = len - bytes_written;
 330                 if (bytes_to_write == 0)
 331                         break;
 332                 err = packet_write_gently(fd_out, src_in + bytes_written, bytes_to_write);
 333                 bytes_written += bytes_to_write;
 334                 if (packet_counter)
 335                         (*packet_counter)++;
 336         }
 337         return err;
 338 }
 339
 340 static int get_packet_data(int fd, char **src_buf, size_t *src_size,
 341                            void *dst, unsigned size, int options)
 342 {
 343         ssize_t ret;
 344
 345         if (fd >= 0 && src_buf && *src_buf)
 346                 BUG("multiple sources given to packet_read");
 347
 348         /* Read up to "size" bytes from our source, whatever it is. */
 349         if (src_buf && *src_buf) {
 350                 ret = size < *src_size ? size : *src_size;
 351                 memcpy(dst, *src_buf, ret);
 352                 *src_buf += ret;
 353                 *src_size -= ret;
 354         } else {
 355                 ret = read_in_full(fd, dst, size);
 356                 if (ret < 0) {
 357                         if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
 358                                 return error_errno(_("read error"));
 359                         die_errno(_("read error"));
 360                 }
 361         }
 362
 363         /* And complain if we didn't get enough bytes to satisfy the read. */
 364         if (ret != size) {
 365                 if (options & PACKET_READ_GENTLE_ON_EOF)
 366                         return -1;
 367
 368                 if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
 369                         return error(_("the remote end hung up unexpectedly"));
 370                 die(_("the remote end hung up unexpectedly"));
 371         }
 372
 373         return ret;
 374 }
 375
 376 int packet_length(const char lenbuf_hex[4], size_t size)
 377 {
 378         if (size < 4)
 379                 BUG("buffer too small");
 380         return  hexval(lenbuf_hex[0]) << 12 |
 381                 hexval(lenbuf_hex[1]) <<  8 |
 382                 hexval(lenbuf_hex[2]) <<  4 |
 383                 hexval(lenbuf_hex[3]);
 384 }
 385
 386 static char *find_packfile_uri_path(const char *buffer)
 387 {
 388         const char *URI_MARK = "://";
 389         char *path;
 390         int len;
 391
 392         /* First char is sideband mark */
 393         buffer += 1;
 394
 395         len = strspn(buffer, "0123456789abcdefABCDEF");
 396         /* size of SHA1 and SHA256 hash */
 397         if (!(len == 40 || len == 64) || buffer[len] != ' ')
 398                 return NULL; /* required "<hash>SP" not seen */
 399
 400         path = strstr(buffer + len + 1, URI_MARK);
 401         if (!path)
 402                 return NULL;
 403
 404         path = strchr(path + strlen(URI_MARK), '/');
 405         if (!path || !*(path + 1))
 406                 return NULL;
 407
 408         /* position after '/' */
 409         return ++path;
 410 }
 411
 412 enum packet_read_status packet_read_with_status(int fd, char **src_buffer,
 413                                                 size_t *src_len, char *buffer,
 414                                                 unsigned size, int *pktlen,
 415                                                 int options)
 416 {
 417         int len;
 418         char linelen[4];
 419         char *uri_path_start;
 420
 421         if (get_packet_data(fd, src_buffer, src_len, linelen, 4, options) < 0) {
 422                 *pktlen = -1;
 423                 return PACKET_READ_EOF;
 424         }
 425
 426         len = packet_length(linelen, sizeof(linelen));
 427
 428         if (len < 0) {
 429                 if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
 430                         return error(_("protocol error: bad line length "
 431                                        "character: %.4s"), linelen);
 432                 die(_("protocol error: bad line length character: %.4s"), linelen);
 433         } else if (!len) {
 434                 packet_trace("0000", 4, 0);
 435                 *pktlen = 0;
 436                 return PACKET_READ_FLUSH;
 437         } else if (len == 1) {
 438                 packet_trace("0001", 4, 0);
 439                 *pktlen = 0;
 440                 return PACKET_READ_DELIM;
 441         } else if (len == 2) {
 442                 packet_trace("0002", 4, 0);
 443                 *pktlen = 0;
 444                 return PACKET_READ_RESPONSE_END;
 445         } else if (len < 4) {
 446                 if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
 447                         return error(_("protocol error: bad line length %d"),
 448                                      len);
 449                 die(_("protocol error: bad line length %d"), len);
 450         }
 451
 452         len -= 4;
 453         if ((unsigned)len >= size) {
 454                 if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
 455                         return error(_("protocol error: bad line length %d"),
 456                                      len);
 457                 die(_("protocol error: bad line length %d"), len);
 458         }
 459
 460         if (get_packet_data(fd, src_buffer, src_len, buffer, len, options) < 0) {
 461                 *pktlen = -1;
 462                 return PACKET_READ_EOF;
 463         }
 464
 465         if ((options & PACKET_READ_CHOMP_NEWLINE) &&
 466             len && buffer[len-1] == '\n') {
 467                 if (options & PACKET_READ_USE_SIDEBAND) {
 468                         int band = *buffer & 0xff;
 469                         switch (band) {
 470                         case 1:
 471                                 /* Chomp newline for payload */
 472                                 len--;
 473                                 break;
 474                         case 2:
 475                         case 3:
 476                                 /*
 477                                  * Do not chomp newline for progress and error
 478                                  * message.
 479                                  */
 480                                 break;
 481                         default:
 482                                 /*
 483                                  * Bad sideband, let's leave it to
 484                                  * demultiplex_sideband() to catch this error.
 485                                  */
 486                                 break;
 487                         }
 488                 } else {
 489                         len--;
 490                 }
 491         }
 492
 493         buffer[len] = 0;
 494         if (options & PACKET_READ_REDACT_URI_PATH &&
 495             (uri_path_start = find_packfile_uri_path(buffer))) {
 496                 const char *redacted = "<redacted>";
 497                 struct strbuf tracebuf = STRBUF_INIT;
 498                 strbuf_insert(&tracebuf, 0, buffer, len);
 499                 strbuf_splice(&tracebuf, uri_path_start - buffer,
 500                               strlen(uri_path_start), redacted, strlen(redacted));
 501                 packet_trace(tracebuf.buf, tracebuf.len, 0);
 502                 strbuf_release(&tracebuf);
 503         } else {
 504                 packet_trace(buffer, len, 0);
 505         }
 506
 507         if ((options & PACKET_READ_DIE_ON_ERR_PACKET) &&
 508             starts_with(buffer, "ERR "))
 509                 die(_("remote error: %s"), buffer + 4);
 510
 511         *pktlen = len;
 512         return PACKET_READ_NORMAL;
 513 }
 514
 515 int packet_read(int fd, char *buffer, unsigned size, int options)
 516 {
 517         int pktlen = -1;
 518
 519         packet_read_with_status(fd, NULL, NULL, buffer, size, &pktlen,
 520                                 options);
 521
 522         return pktlen;
 523 }
 524
 525 char *packet_read_line(int fd, int *dst_len)
 526 {
 527         int len = packet_read(fd, packet_buffer, sizeof(packet_buffer),
 528                               PACKET_READ_CHOMP_NEWLINE);
 529         if (dst_len)
 530                 *dst_len = len;
 531         return (len > 0) ? packet_buffer : NULL;
 532 }
 533
 534 int packet_read_line_gently(int fd, int *dst_len, char **dst_line)
 535 {
 536         int len = packet_read(fd, packet_buffer, sizeof(packet_buffer),
 537                               PACKET_READ_CHOMP_NEWLINE|PACKET_READ_GENTLE_ON_EOF);
 538         if (dst_len)
 539                 *dst_len = len;
 540         if (dst_line)
 541                 *dst_line = (len > 0) ? packet_buffer : NULL;
 542         return len;
 543 }
 544
 545 ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out, int options)
 546 {
 547         int packet_len;
 548
 549         size_t orig_len = sb_out->len;
 550         size_t orig_alloc = sb_out->alloc;
 551
 552         for (;;) {
 553                 strbuf_grow(sb_out, LARGE_PACKET_DATA_MAX);
 554                 packet_len = packet_read(fd_in,
 555                         /* strbuf_grow() above always allocates one extra byte to
 556                          * store a '\0' at the end of the string. packet_read()
 557                          * writes a '\0' extra byte at the end, too. Let it know
 558                          * that there is already room for the extra byte.
 559                          */
 560                         sb_out->buf + sb_out->len, LARGE_PACKET_DATA_MAX+1,
 561                         options);
 562                 if (packet_len <= 0)
 563                         break;
 564                 sb_out->len += packet_len;
 565         }
 566
 567         if (packet_len < 0) {
 568                 if (orig_alloc == 0)
 569                         strbuf_release(sb_out);
 570                 else
 571                         strbuf_setlen(sb_out, orig_len);
 572                 return packet_len;
 573         }
 574         return sb_out->len - orig_len;
 575 }
 576
 577 int recv_sideband(const char *me, int in_stream, int out)
 578 {
 579         char buf[LARGE_PACKET_MAX + 1];
 580         int len;
 581         struct strbuf scratch = STRBUF_INIT;
 582         enum sideband_type sideband_type;
 583
 584         while (1) {
 585                 int status = packet_read_with_status(in_stream, NULL, NULL,
 586                                                      buf, LARGE_PACKET_MAX,
 587                                                      &len,
 588                                                      PACKET_READ_GENTLE_ON_EOF);
 589                 if (!demultiplex_sideband(me, status, buf, len, 0, &scratch,
 590                                           &sideband_type))
 591                         continue;
 592                 switch (sideband_type) {
 593                 case SIDEBAND_PRIMARY:
 594                         write_or_die(out, buf + 1, len - 1);
 595                         break;
 596                 default: /* errors: message already written */
 597                         if (scratch.len > 0)
 598                                 BUG("unhandled incomplete sideband: '%s'",
 599                                     scratch.buf);
 600                         return sideband_type;
 601                 }
 602         }
 603 }
 604
 605 /* Packet Reader Functions */
 606 void packet_reader_init(struct packet_reader *reader, int fd,
 607                         char *src_buffer, size_t src_len,
 608                         int options)
 609 {
 610         memset(reader, 0, sizeof(*reader));
 611
 612         reader->fd = fd;
 613         reader->src_buffer = src_buffer;
 614         reader->src_len = src_len;
 615         reader->buffer = packet_buffer;
 616         reader->buffer_size = sizeof(packet_buffer);
 617         reader->options = options;
 618         reader->me = "git";
 619         reader->hash_algo = &hash_algos[GIT_HASH_SHA1];
 620         strbuf_init(&reader->scratch, 0);
 621 }
 622
 623 enum packet_read_status packet_reader_read(struct packet_reader *reader)
 624 {
 625         if (reader->line_peeked) {
 626                 reader->line_peeked = 0;
 627                 return reader->status;
 628         }
 629
 630         if (reader->use_sideband)
 631                 reader->options |= PACKET_READ_USE_SIDEBAND;
 632
 633         /*
 634          * Consume all progress packets until a primary payload packet is
 635          * received
 636          */
 637         while (1) {
 638                 enum sideband_type sideband_type;
 639                 reader->status = packet_read_with_status(reader->fd,
 640                                                          &reader->src_buffer,
 641                                                          &reader->src_len,
 642                                                          reader->buffer,
 643                                                          reader->buffer_size,
 644                                                          &reader->pktlen,
 645                                                          reader->options);
 646                 if (!reader->use_sideband)
 647                         break;
 648                 if (demultiplex_sideband(reader->me, reader->status,
 649                                          reader->buffer, reader->pktlen, 1,
 650                                          &reader->scratch, &sideband_type))
 651                         break;
 652         }
 653
 654         if (reader->status == PACKET_READ_NORMAL)
 655                 /* Skip the sideband designator if sideband is used */
 656                 reader->line = reader->use_sideband ?
 657                         reader->buffer + 1 : reader->buffer;
 658         else
 659                 reader->line = NULL;
 660
 661         return reader->status;
 662 }
 663
 664 enum packet_read_status packet_reader_peek(struct packet_reader *reader)
 665 {
 666         /* Only allow peeking a single line */
 667         if (reader->line_peeked)
 668                 return reader->status;
 669
 670         /* Peek a line by reading it and setting peeked flag */
 671         packet_reader_read(reader);
 672         reader->line_peeked = 1;
 673         return reader->status;
 674 }
 675
 676 void packet_writer_init(struct packet_writer *writer, int dest_fd)
 677 {
 678         writer->dest_fd = dest_fd;
 679         writer->use_sideband = 0;
 680 }
 681
 682 void packet_writer_write(struct packet_writer *writer, const char *fmt, ...)
 683 {
 684         va_list args;
 685
 686         va_start(args, fmt);
 687         packet_write_fmt_1(writer->dest_fd, 0,
 688                            writer->use_sideband ? "\001" : "", fmt, args);
 689         va_end(args);
 690 }
 691
 692 void packet_writer_error(struct packet_writer *writer, const char *fmt, ...)
 693 {
 694         va_list args;
 695
 696         va_start(args, fmt);
 697         packet_write_fmt_1(writer->dest_fd, 0,
 698                            writer->use_sideband ? "\003" : "ERR ", fmt, args);
 699         va_end(args);
 700 }
 701
 702 void packet_writer_delim(struct packet_writer *writer)
 703 {
 704         packet_delim(writer->dest_fd);
 705 }
 706
 707 void packet_writer_flush(struct packet_writer *writer)
 708 {
 709         packet_flush(writer->dest_fd);
 710 }