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 "trace.h"
   8 #include "wrapper.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])
 377 {
 378         int val = hex2chr(lenbuf_hex);
 379         return (val < 0) ? val : (val << 8) | hex2chr(lenbuf_hex + 2);
 380 }
 381
 382 static char *find_packfile_uri_path(const char *buffer)
 383 {
 384         const char *URI_MARK = "://";
 385         char *path;
 386         int len;
 387
 388         /* First char is sideband mark */
 389         buffer += 1;
 390
 391         len = strspn(buffer, "0123456789abcdefABCDEF");
 392         /* size of SHA1 and SHA256 hash */
 393         if (!(len == 40 || len == 64) || buffer[len] != ' ')
 394                 return NULL; /* required "<hash>SP" not seen */
 395
 396         path = strstr(buffer + len + 1, URI_MARK);
 397         if (!path)
 398                 return NULL;
 399
 400         path = strchr(path + strlen(URI_MARK), '/');
 401         if (!path || !*(path + 1))
 402                 return NULL;
 403
 404         /* position after '/' */
 405         return ++path;
 406 }
 407
 408 enum packet_read_status packet_read_with_status(int fd, char **src_buffer,
 409                                                 size_t *src_len, char *buffer,
 410                                                 unsigned size, int *pktlen,
 411                                                 int options)
 412 {
 413         int len;
 414         char linelen[4];
 415         char *uri_path_start;
 416
 417         if (get_packet_data(fd, src_buffer, src_len, linelen, 4, options) < 0) {
 418                 *pktlen = -1;
 419                 return PACKET_READ_EOF;
 420         }
 421
 422         len = packet_length(linelen);
 423
 424         if (len < 0) {
 425                 if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
 426                         return error(_("protocol error: bad line length "
 427                                        "character: %.4s"), linelen);
 428                 die(_("protocol error: bad line length character: %.4s"), linelen);
 429         } else if (!len) {
 430                 packet_trace("0000", 4, 0);
 431                 *pktlen = 0;
 432                 return PACKET_READ_FLUSH;
 433         } else if (len == 1) {
 434                 packet_trace("0001", 4, 0);
 435                 *pktlen = 0;
 436                 return PACKET_READ_DELIM;
 437         } else if (len == 2) {
 438                 packet_trace("0002", 4, 0);
 439                 *pktlen = 0;
 440                 return PACKET_READ_RESPONSE_END;
 441         } else if (len < 4) {
 442                 if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
 443                         return error(_("protocol error: bad line length %d"),
 444                                      len);
 445                 die(_("protocol error: bad line length %d"), len);
 446         }
 447
 448         len -= 4;
 449         if ((unsigned)len >= size) {
 450                 if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
 451                         return error(_("protocol error: bad line length %d"),
 452                                      len);
 453                 die(_("protocol error: bad line length %d"), len);
 454         }
 455
 456         if (get_packet_data(fd, src_buffer, src_len, buffer, len, options) < 0) {
 457                 *pktlen = -1;
 458                 return PACKET_READ_EOF;
 459         }
 460
 461         if ((options & PACKET_READ_CHOMP_NEWLINE) &&
 462             len && buffer[len-1] == '\n')
 463                 len--;
 464
 465         buffer[len] = 0;
 466         if (options & PACKET_READ_REDACT_URI_PATH &&
 467             (uri_path_start = find_packfile_uri_path(buffer))) {
 468                 const char *redacted = "<redacted>";
 469                 struct strbuf tracebuf = STRBUF_INIT;
 470                 strbuf_insert(&tracebuf, 0, buffer, len);
 471                 strbuf_splice(&tracebuf, uri_path_start - buffer,
 472                               strlen(uri_path_start), redacted, strlen(redacted));
 473                 packet_trace(tracebuf.buf, tracebuf.len, 0);
 474                 strbuf_release(&tracebuf);
 475         } else {
 476                 packet_trace(buffer, len, 0);
 477         }
 478
 479         if ((options & PACKET_READ_DIE_ON_ERR_PACKET) &&
 480             starts_with(buffer, "ERR "))
 481                 die(_("remote error: %s"), buffer + 4);
 482
 483         *pktlen = len;
 484         return PACKET_READ_NORMAL;
 485 }
 486
 487 int packet_read(int fd, char *buffer, unsigned size, int options)
 488 {
 489         int pktlen = -1;
 490
 491         packet_read_with_status(fd, NULL, NULL, buffer, size, &pktlen,
 492                                 options);
 493
 494         return pktlen;
 495 }
 496
 497 char *packet_read_line(int fd, int *dst_len)
 498 {
 499         int len = packet_read(fd, packet_buffer, sizeof(packet_buffer),
 500                               PACKET_READ_CHOMP_NEWLINE);
 501         if (dst_len)
 502                 *dst_len = len;
 503         return (len > 0) ? packet_buffer : NULL;
 504 }
 505
 506 int packet_read_line_gently(int fd, int *dst_len, char **dst_line)
 507 {
 508         int len = packet_read(fd, packet_buffer, sizeof(packet_buffer),
 509                               PACKET_READ_CHOMP_NEWLINE|PACKET_READ_GENTLE_ON_EOF);
 510         if (dst_len)
 511                 *dst_len = len;
 512         if (dst_line)
 513                 *dst_line = (len > 0) ? packet_buffer : NULL;
 514         return len;
 515 }
 516
 517 ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out, int options)
 518 {
 519         int packet_len;
 520
 521         size_t orig_len = sb_out->len;
 522         size_t orig_alloc = sb_out->alloc;
 523
 524         for (;;) {
 525                 strbuf_grow(sb_out, LARGE_PACKET_DATA_MAX);
 526                 packet_len = packet_read(fd_in,
 527                         /* strbuf_grow() above always allocates one extra byte to
 528                          * store a '\0' at the end of the string. packet_read()
 529                          * writes a '\0' extra byte at the end, too. Let it know
 530                          * that there is already room for the extra byte.
 531                          */
 532                         sb_out->buf + sb_out->len, LARGE_PACKET_DATA_MAX+1,
 533                         options);
 534                 if (packet_len <= 0)
 535                         break;
 536                 sb_out->len += packet_len;
 537         }
 538
 539         if (packet_len < 0) {
 540                 if (orig_alloc == 0)
 541                         strbuf_release(sb_out);
 542                 else
 543                         strbuf_setlen(sb_out, orig_len);
 544                 return packet_len;
 545         }
 546         return sb_out->len - orig_len;
 547 }
 548
 549 int recv_sideband(const char *me, int in_stream, int out)
 550 {
 551         char buf[LARGE_PACKET_MAX + 1];
 552         int len;
 553         struct strbuf scratch = STRBUF_INIT;
 554         enum sideband_type sideband_type;
 555
 556         while (1) {
 557                 int status = packet_read_with_status(in_stream, NULL, NULL,
 558                                                      buf, LARGE_PACKET_MAX,
 559                                                      &len,
 560                                                      PACKET_READ_GENTLE_ON_EOF);
 561                 if (!demultiplex_sideband(me, status, buf, len, 0, &scratch,
 562                                           &sideband_type))
 563                         continue;
 564                 switch (sideband_type) {
 565                 case SIDEBAND_PRIMARY:
 566                         write_or_die(out, buf + 1, len - 1);
 567                         break;
 568                 default: /* errors: message already written */
 569                         if (scratch.len > 0)
 570                                 BUG("unhandled incomplete sideband: '%s'",
 571                                     scratch.buf);
 572                         return sideband_type;
 573                 }
 574         }
 575 }
 576
 577 /* Packet Reader Functions */
 578 void packet_reader_init(struct packet_reader *reader, int fd,
 579                         char *src_buffer, size_t src_len,
 580                         int options)
 581 {
 582         memset(reader, 0, sizeof(*reader));
 583
 584         reader->fd = fd;
 585         reader->src_buffer = src_buffer;
 586         reader->src_len = src_len;
 587         reader->buffer = packet_buffer;
 588         reader->buffer_size = sizeof(packet_buffer);
 589         reader->options = options;
 590         reader->me = "git";
 591         reader->hash_algo = &hash_algos[GIT_HASH_SHA1];
 592 }
 593
 594 enum packet_read_status packet_reader_read(struct packet_reader *reader)
 595 {
 596         struct strbuf scratch = STRBUF_INIT;
 597
 598         if (reader->line_peeked) {
 599                 reader->line_peeked = 0;
 600                 return reader->status;
 601         }
 602
 603         /*
 604          * Consume all progress packets until a primary payload packet is
 605          * received
 606          */
 607         while (1) {
 608                 enum sideband_type sideband_type;
 609                 reader->status = packet_read_with_status(reader->fd,
 610                                                          &reader->src_buffer,
 611                                                          &reader->src_len,
 612                                                          reader->buffer,
 613                                                          reader->buffer_size,
 614                                                          &reader->pktlen,
 615                                                          reader->options);
 616                 if (!reader->use_sideband)
 617                         break;
 618                 if (demultiplex_sideband(reader->me, reader->status,
 619                                          reader->buffer, reader->pktlen, 1,
 620                                          &scratch, &sideband_type))
 621                         break;
 622         }
 623
 624         if (reader->status == PACKET_READ_NORMAL)
 625                 /* Skip the sideband designator if sideband is used */
 626                 reader->line = reader->use_sideband ?
 627                         reader->buffer + 1 : reader->buffer;
 628         else
 629                 reader->line = NULL;
 630
 631         return reader->status;
 632 }
 633
 634 enum packet_read_status packet_reader_peek(struct packet_reader *reader)
 635 {
 636         /* Only allow peeking a single line */
 637         if (reader->line_peeked)
 638                 return reader->status;
 639
 640         /* Peek a line by reading it and setting peeked flag */
 641         packet_reader_read(reader);
 642         reader->line_peeked = 1;
 643         return reader->status;
 644 }
 645
 646 void packet_writer_init(struct packet_writer *writer, int dest_fd)
 647 {
 648         writer->dest_fd = dest_fd;
 649         writer->use_sideband = 0;
 650 }
 651
 652 void packet_writer_write(struct packet_writer *writer, const char *fmt, ...)
 653 {
 654         va_list args;
 655
 656         va_start(args, fmt);
 657         packet_write_fmt_1(writer->dest_fd, 0,
 658                            writer->use_sideband ? "\001" : "", fmt, args);
 659         va_end(args);
 660 }
 661
 662 void packet_writer_error(struct packet_writer *writer, const char *fmt, ...)
 663 {
 664         va_list args;
 665
 666         va_start(args, fmt);
 667         packet_write_fmt_1(writer->dest_fd, 0,
 668                            writer->use_sideband ? "\003" : "ERR ", fmt, args);
 669         va_end(args);
 670 }
 671
 672 void packet_writer_delim(struct packet_writer *writer)
 673 {
 674         packet_delim(writer->dest_fd);
 675 }
 676
 677 void packet_writer_flush(struct packet_writer *writer)
 678 {
 679         packet_flush(writer->dest_fd);
 680 }