Andrew's git - gitweb.git/blob

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