git.oblomov.eu Git - git/blob - pkt-line.c

   1 #include "cache.h"
   2 #include "pkt-line.h"
   3 #include "run-command.h"
   4
   5 char packet_buffer[LARGE_PACKET_MAX];
   6 static const char *packet_trace_prefix = "git";
   7 static struct trace_key trace_packet = TRACE_KEY_INIT(PACKET);
   8 static struct trace_key trace_pack = TRACE_KEY_INIT(PACKFILE);
   9
  10 void packet_trace_identity(const char *prog)
  11 {
  12         packet_trace_prefix = xstrdup(prog);
  13 }
  14
  15 static const char *get_trace_prefix(void)
  16 {
  17         return in_async() ? "sideband" : packet_trace_prefix;
  18 }
  19
  20 static int packet_trace_pack(const char *buf, unsigned int len, int sideband)
  21 {
  22         if (!sideband) {
  23                 trace_verbatim(&trace_pack, buf, len);
  24                 return 1;
  25         } else if (len && *buf == '\1') {
  26                 trace_verbatim(&trace_pack, buf + 1, len - 1);
  27                 return 1;
  28         } else {
  29                 /* it's another non-pack sideband */
  30                 return 0;
  31         }
  32 }
  33
  34 static void packet_trace(const char *buf, unsigned int len, int write)
  35 {
  36         int i;
  37         struct strbuf out;
  38         static int in_pack, sideband;
  39
  40         if (!trace_want(&trace_packet) && !trace_want(&trace_pack))
  41                 return;
  42
  43         if (in_pack) {
  44                 if (packet_trace_pack(buf, len, sideband))
  45                         return;
  46         } else if (starts_with(buf, "PACK") || starts_with(buf, "\1PACK")) {
  47                 in_pack = 1;
  48                 sideband = *buf == '\1';
  49                 packet_trace_pack(buf, len, sideband);
  50
  51                 /*
  52                  * Make a note in the human-readable trace that the pack data
  53                  * started.
  54                  */
  55                 buf = "PACK ...";
  56                 len = strlen(buf);
  57         }
  58
  59         if (!trace_want(&trace_packet))
  60                 return;
  61
  62         /* +32 is just a guess for header + quoting */
  63         strbuf_init(&out, len+32);
  64
  65         strbuf_addf(&out, "packet: %12s%c ",
  66                     get_trace_prefix(), write ? '>' : '<');
  67
  68         /* XXX we should really handle printable utf8 */
  69         for (i = 0; i < len; i++) {
  70                 /* suppress newlines */
  71                 if (buf[i] == '\n')
  72                         continue;
  73                 if (buf[i] >= 0x20 && buf[i] <= 0x7e)
  74                         strbuf_addch(&out, buf[i]);
  75                 else
  76                         strbuf_addf(&out, "\\%o", buf[i]);
  77         }
  78
  79         strbuf_addch(&out, '\n');
  80         trace_strbuf(&trace_packet, &out);
  81         strbuf_release(&out);
  82 }
  83
  84 /*
  85  * If we buffered things up above (we don't, but we should),
  86  * we'd flush it here
  87  */
  88 void packet_flush(int fd)
  89 {
  90         packet_trace("0000", 4, 1);
  91         if (write_in_full(fd, "0000", 4) < 0)
  92                 die_errno(_("unable to write flush packet"));
  93 }
  94
  95 void packet_delim(int fd)
  96 {
  97         packet_trace("0001", 4, 1);
  98         if (write_in_full(fd, "0001", 4) < 0)
  99                 die_errno(_("unable to write delim packet"));
 100 }
 101
 102 int packet_flush_gently(int fd)
 103 {
 104         packet_trace("0000", 4, 1);
 105         if (write_in_full(fd, "0000", 4) < 0)
 106                 return error(_("flush packet write failed"));
 107         return 0;
 108 }
 109
 110 void packet_buf_flush(struct strbuf *buf)
 111 {
 112         packet_trace("0000", 4, 1);
 113         strbuf_add(buf, "0000", 4);
 114 }
 115
 116 void packet_buf_delim(struct strbuf *buf)
 117 {
 118         packet_trace("0001", 4, 1);
 119         strbuf_add(buf, "0001", 4);
 120 }
 121
 122 static void set_packet_header(char *buf, const int size)
 123 {
 124         static char hexchar[] = "0123456789abcdef";
 125
 126         #define hex(a) (hexchar[(a) & 15])
 127         buf[0] = hex(size >> 12);
 128         buf[1] = hex(size >> 8);
 129         buf[2] = hex(size >> 4);
 130         buf[3] = hex(size);
 131         #undef hex
 132 }
 133
 134 static void format_packet(struct strbuf *out, const char *fmt, va_list args)
 135 {
 136         size_t orig_len, n;
 137
 138         orig_len = out->len;
 139         strbuf_addstr(out, "0000");
 140         strbuf_vaddf(out, fmt, args);
 141         n = out->len - orig_len;
 142
 143         if (n > LARGE_PACKET_MAX)
 144                 die(_("protocol error: impossibly long line"));
 145
 146         set_packet_header(&out->buf[orig_len], n);
 147         packet_trace(out->buf + orig_len + 4, n - 4, 1);
 148 }
 149
 150 static int packet_write_fmt_1(int fd, int gently,
 151                               const char *fmt, va_list args)
 152 {
 153         static struct strbuf buf = STRBUF_INIT;
 154
 155         strbuf_reset(&buf);
 156         format_packet(&buf, fmt, args);
 157         if (write_in_full(fd, buf.buf, buf.len) < 0) {
 158                 if (!gently) {
 159                         check_pipe(errno);
 160                         die_errno(_("packet write with format failed"));
 161                 }
 162                 return error(_("packet write with format failed"));
 163         }
 164
 165         return 0;
 166 }
 167
 168 void packet_write_fmt(int fd, const char *fmt, ...)
 169 {
 170         va_list args;
 171
 172         va_start(args, fmt);
 173         packet_write_fmt_1(fd, 0, fmt, args);
 174         va_end(args);
 175 }
 176
 177 int packet_write_fmt_gently(int fd, const char *fmt, ...)
 178 {
 179         int status;
 180         va_list args;
 181
 182         va_start(args, fmt);
 183         status = packet_write_fmt_1(fd, 1, fmt, args);
 184         va_end(args);
 185         return status;
 186 }
 187
 188 static int packet_write_gently(const int fd_out, const char *buf, size_t size)
 189 {
 190         static char packet_write_buffer[LARGE_PACKET_MAX];
 191         size_t packet_size;
 192
 193         if (size > sizeof(packet_write_buffer) - 4)
 194                 return error(_("packet write failed - data exceeds max packet size"));
 195
 196         packet_trace(buf, size, 1);
 197         packet_size = size + 4;
 198         set_packet_header(packet_write_buffer, packet_size);
 199         memcpy(packet_write_buffer + 4, buf, size);
 200         if (write_in_full(fd_out, packet_write_buffer, packet_size) < 0)
 201                 return error(_("packet write failed"));
 202         return 0;
 203 }
 204
 205 void packet_write(int fd_out, const char *buf, size_t size)
 206 {
 207         if (packet_write_gently(fd_out, buf, size))
 208                 die_errno(_("packet write failed"));
 209 }
 210
 211 void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
 212 {
 213         va_list args;
 214
 215         va_start(args, fmt);
 216         format_packet(buf, fmt, args);
 217         va_end(args);
 218 }
 219
 220 void packet_buf_write_len(struct strbuf *buf, const char *data, size_t len)
 221 {
 222         size_t orig_len, n;
 223
 224         orig_len = buf->len;
 225         strbuf_addstr(buf, "0000");
 226         strbuf_add(buf, data, len);
 227         n = buf->len - orig_len;
 228
 229         if (n > LARGE_PACKET_MAX)
 230                 die(_("protocol error: impossibly long line"));
 231
 232         set_packet_header(&buf->buf[orig_len], n);
 233         packet_trace(data, len, 1);
 234 }
 235
 236 int write_packetized_from_fd(int fd_in, int fd_out)
 237 {
 238         static char buf[LARGE_PACKET_DATA_MAX];
 239         int err = 0;
 240         ssize_t bytes_to_write;
 241
 242         while (!err) {
 243                 bytes_to_write = xread(fd_in, buf, sizeof(buf));
 244                 if (bytes_to_write < 0)
 245                         return COPY_READ_ERROR;
 246                 if (bytes_to_write == 0)
 247                         break;
 248                 err = packet_write_gently(fd_out, buf, bytes_to_write);
 249         }
 250         if (!err)
 251                 err = packet_flush_gently(fd_out);
 252         return err;
 253 }
 254
 255 int write_packetized_from_buf(const char *src_in, size_t len, int fd_out)
 256 {
 257         int err = 0;
 258         size_t bytes_written = 0;
 259         size_t bytes_to_write;
 260
 261         while (!err) {
 262                 if ((len - bytes_written) > LARGE_PACKET_DATA_MAX)
 263                         bytes_to_write = LARGE_PACKET_DATA_MAX;
 264                 else
 265                         bytes_to_write = len - bytes_written;
 266                 if (bytes_to_write == 0)
 267                         break;
 268                 err = packet_write_gently(fd_out, src_in + bytes_written, bytes_to_write);
 269                 bytes_written += bytes_to_write;
 270         }
 271         if (!err)
 272                 err = packet_flush_gently(fd_out);
 273         return err;
 274 }
 275
 276 static int get_packet_data(int fd, char **src_buf, size_t *src_size,
 277                            void *dst, unsigned size, int options)
 278 {
 279         ssize_t ret;
 280
 281         if (fd >= 0 && src_buf && *src_buf)
 282                 BUG("multiple sources given to packet_read");
 283
 284         /* Read up to "size" bytes from our source, whatever it is. */
 285         if (src_buf && *src_buf) {
 286                 ret = size < *src_size ? size : *src_size;
 287                 memcpy(dst, *src_buf, ret);
 288                 *src_buf += ret;
 289                 *src_size -= ret;
 290         } else {
 291                 ret = read_in_full(fd, dst, size);
 292                 if (ret < 0)
 293                         die_errno(_("read error"));
 294         }
 295
 296         /* And complain if we didn't get enough bytes to satisfy the read. */
 297         if (ret != size) {
 298                 if (options & PACKET_READ_GENTLE_ON_EOF)
 299                         return -1;
 300
 301                 die(_("the remote end hung up unexpectedly"));
 302         }
 303
 304         return ret;
 305 }
 306
 307 static int packet_length(const char *linelen)
 308 {
 309         int val = hex2chr(linelen);
 310         return (val < 0) ? val : (val << 8) | hex2chr(linelen + 2);
 311 }
 312
 313 enum packet_read_status packet_read_with_status(int fd, char **src_buffer,
 314                                                 size_t *src_len, char *buffer,
 315                                                 unsigned size, int *pktlen,
 316                                                 int options)
 317 {
 318         int len;
 319         char linelen[4];
 320
 321         if (get_packet_data(fd, src_buffer, src_len, linelen, 4, options) < 0) {
 322                 *pktlen = -1;
 323                 return PACKET_READ_EOF;
 324         }
 325
 326         len = packet_length(linelen);
 327
 328         if (len < 0) {
 329                 die(_("protocol error: bad line length character: %.4s"), linelen);
 330         } else if (!len) {
 331                 packet_trace("0000", 4, 0);
 332                 *pktlen = 0;
 333                 return PACKET_READ_FLUSH;
 334         } else if (len == 1) {
 335                 packet_trace("0001", 4, 0);
 336                 *pktlen = 0;
 337                 return PACKET_READ_DELIM;
 338         } else if (len < 4) {
 339                 die(_("protocol error: bad line length %d"), len);
 340         }
 341
 342         len -= 4;
 343         if ((unsigned)len >= size)
 344                 die(_("protocol error: bad line length %d"), len);
 345
 346         if (get_packet_data(fd, src_buffer, src_len, buffer, len, options) < 0) {
 347                 *pktlen = -1;
 348                 return PACKET_READ_EOF;
 349         }
 350
 351         if ((options & PACKET_READ_CHOMP_NEWLINE) &&
 352             len && buffer[len-1] == '\n')
 353                 len--;
 354
 355         buffer[len] = 0;
 356         packet_trace(buffer, len, 0);
 357         *pktlen = len;
 358         return PACKET_READ_NORMAL;
 359 }
 360
 361 int packet_read(int fd, char **src_buffer, size_t *src_len,
 362                 char *buffer, unsigned size, int options)
 363 {
 364         int pktlen = -1;
 365
 366         packet_read_with_status(fd, src_buffer, src_len, buffer, size,
 367                                 &pktlen, options);
 368
 369         return pktlen;
 370 }
 371
 372 static char *packet_read_line_generic(int fd,
 373                                       char **src, size_t *src_len,
 374                                       int *dst_len)
 375 {
 376         int len = packet_read(fd, src, src_len,
 377                               packet_buffer, sizeof(packet_buffer),
 378                               PACKET_READ_CHOMP_NEWLINE);
 379         if (dst_len)
 380                 *dst_len = len;
 381         return (len > 0) ? packet_buffer : NULL;
 382 }
 383
 384 char *packet_read_line(int fd, int *len_p)
 385 {
 386         return packet_read_line_generic(fd, NULL, NULL, len_p);
 387 }
 388
 389 int packet_read_line_gently(int fd, int *dst_len, char **dst_line)
 390 {
 391         int len = packet_read(fd, NULL, NULL,
 392                               packet_buffer, sizeof(packet_buffer),
 393                               PACKET_READ_CHOMP_NEWLINE|PACKET_READ_GENTLE_ON_EOF);
 394         if (dst_len)
 395                 *dst_len = len;
 396         if (dst_line)
 397                 *dst_line = (len > 0) ? packet_buffer : NULL;
 398         return len;
 399 }
 400
 401 char *packet_read_line_buf(char **src, size_t *src_len, int *dst_len)
 402 {
 403         return packet_read_line_generic(-1, src, src_len, dst_len);
 404 }
 405
 406 ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out)
 407 {
 408         int packet_len;
 409
 410         size_t orig_len = sb_out->len;
 411         size_t orig_alloc = sb_out->alloc;
 412
 413         for (;;) {
 414                 strbuf_grow(sb_out, LARGE_PACKET_DATA_MAX);
 415                 packet_len = packet_read(fd_in, NULL, NULL,
 416                         /* strbuf_grow() above always allocates one extra byte to
 417                          * store a '\0' at the end of the string. packet_read()
 418                          * writes a '\0' extra byte at the end, too. Let it know
 419                          * that there is already room for the extra byte.
 420                          */
 421                         sb_out->buf + sb_out->len, LARGE_PACKET_DATA_MAX+1,
 422                         PACKET_READ_GENTLE_ON_EOF);
 423                 if (packet_len <= 0)
 424                         break;
 425                 sb_out->len += packet_len;
 426         }
 427
 428         if (packet_len < 0) {
 429                 if (orig_alloc == 0)
 430                         strbuf_release(sb_out);
 431                 else
 432                         strbuf_setlen(sb_out, orig_len);
 433                 return packet_len;
 434         }
 435         return sb_out->len - orig_len;
 436 }
 437
 438 /* Packet Reader Functions */
 439 void packet_reader_init(struct packet_reader *reader, int fd,
 440                         char *src_buffer, size_t src_len,
 441                         int options)
 442 {
 443         memset(reader, 0, sizeof(*reader));
 444
 445         reader->fd = fd;
 446         reader->src_buffer = src_buffer;
 447         reader->src_len = src_len;
 448         reader->buffer = packet_buffer;
 449         reader->buffer_size = sizeof(packet_buffer);
 450         reader->options = options;
 451 }
 452
 453 enum packet_read_status packet_reader_read(struct packet_reader *reader)
 454 {
 455         if (reader->line_peeked) {
 456                 reader->line_peeked = 0;
 457                 return reader->status;
 458         }
 459
 460         reader->status = packet_read_with_status(reader->fd,
 461                                                  &reader->src_buffer,
 462                                                  &reader->src_len,
 463                                                  reader->buffer,
 464                                                  reader->buffer_size,
 465                                                  &reader->pktlen,
 466                                                  reader->options);
 467
 468         if (reader->status == PACKET_READ_NORMAL)
 469                 reader->line = reader->buffer;
 470         else
 471                 reader->line = NULL;
 472
 473         return reader->status;
 474 }
 475
 476 enum packet_read_status packet_reader_peek(struct packet_reader *reader)
 477 {
 478         /* Only allow peeking a single line */
 479         if (reader->line_peeked)
 480                 return reader->status;
 481
 482         /* Peek a line by reading it and setting peeked flag */
 483         packet_reader_read(reader);
 484         reader->line_peeked = 1;
 485         return reader->status;
 486 }