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
  94int packet_flush_gently(int fd)
  95{
  96        packet_trace("0000", 4, 1);
  97        if (write_in_full(fd, "0000", 4) == 4)
  98                return 0;
  99        return error("flush packet write failed");
 100}
 101
 102void packet_buf_flush(struct strbuf *buf)
 103{
 104        packet_trace("0000", 4, 1);
 105        strbuf_add(buf, "0000", 4);
 106}
 107
 108static void set_packet_header(char *buf, const int size)
 109{
 110        static char hexchar[] = "0123456789abcdef";
 111
 112        #define hex(a) (hexchar[(a) & 15])
 113        buf[0] = hex(size >> 12);
 114        buf[1] = hex(size >> 8);
 115        buf[2] = hex(size >> 4);
 116        buf[3] = hex(size);
 117        #undef hex
 118}
 119
 120static void format_packet(struct strbuf *out, const char *fmt, va_list args)
 121{
 122        size_t orig_len, n;
 123
 124        orig_len = out->len;
 125        strbuf_addstr(out, "0000");
 126        strbuf_vaddf(out, fmt, args);
 127        n = out->len - orig_len;
 128
 129        if (n > LARGE_PACKET_MAX)
 130                die("protocol error: impossibly long line");
 131
 132        set_packet_header(&out->buf[orig_len], n);
 133        packet_trace(out->buf + orig_len + 4, n - 4, 1);
 134}
 135
 136static int packet_write_fmt_1(int fd, int gently,
 137                              const char *fmt, va_list args)
 138{
 139        struct strbuf buf = STRBUF_INIT;
 140        ssize_t count;
 141
 142        format_packet(&buf, fmt, args);
 143        count = write_in_full(fd, buf.buf, buf.len);
 144        if (count == buf.len)
 145                return 0;
 146
 147        if (!gently) {
 148                check_pipe(errno);
 149                die_errno("packet write with format failed");
 150        }
 151        return error("packet write with format failed");
 152}
 153
 154void packet_write_fmt(int fd, const char *fmt, ...)
 155{
 156        va_list args;
 157
 158        va_start(args, fmt);
 159        packet_write_fmt_1(fd, 0, fmt, args);
 160        va_end(args);
 161}
 162
 163int packet_write_fmt_gently(int fd, const char *fmt, ...)
 164{
 165        int status;
 166        va_list args;
 167
 168        va_start(args, fmt);
 169        status = packet_write_fmt_1(fd, 1, fmt, args);
 170        va_end(args);
 171        return status;
 172}
 173
 174static int packet_write_gently(const int fd_out, const char *buf, size_t size)
 175{
 176        static char packet_write_buffer[LARGE_PACKET_MAX];
 177        size_t packet_size;
 178
 179        if (size > sizeof(packet_write_buffer) - 4)
 180                return error("packet write failed - data exceeds max packet size");
 181
 182        packet_trace(buf, size, 1);
 183        packet_size = size + 4;
 184        set_packet_header(packet_write_buffer, packet_size);
 185        memcpy(packet_write_buffer + 4, buf, size);
 186        if (write_in_full(fd_out, packet_write_buffer, packet_size) == packet_size)
 187                return 0;
 188        return error("packet write failed");
 189}
 190
 191void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
 192{
 193        va_list args;
 194
 195        va_start(args, fmt);
 196        format_packet(buf, fmt, args);
 197        va_end(args);
 198}
 199
 200int write_packetized_from_fd(int fd_in, int fd_out)
 201{
 202        static char buf[LARGE_PACKET_DATA_MAX];
 203        int err = 0;
 204        ssize_t bytes_to_write;
 205
 206        while (!err) {
 207                bytes_to_write = xread(fd_in, buf, sizeof(buf));
 208                if (bytes_to_write < 0)
 209                        return COPY_READ_ERROR;
 210                if (bytes_to_write == 0)
 211                        break;
 212                err = packet_write_gently(fd_out, buf, bytes_to_write);
 213        }
 214        if (!err)
 215                err = packet_flush_gently(fd_out);
 216        return err;
 217}
 218
 219int write_packetized_from_buf(const char *src_in, size_t len, int fd_out)
 220{
 221        int err = 0;
 222        size_t bytes_written = 0;
 223        size_t bytes_to_write;
 224
 225        while (!err) {
 226                if ((len - bytes_written) > LARGE_PACKET_DATA_MAX)
 227                        bytes_to_write = LARGE_PACKET_DATA_MAX;
 228                else
 229                        bytes_to_write = len - bytes_written;
 230                if (bytes_to_write == 0)
 231                        break;
 232                err = packet_write_gently(fd_out, src_in + bytes_written, bytes_to_write);
 233                bytes_written += bytes_to_write;
 234        }
 235        if (!err)
 236                err = packet_flush_gently(fd_out);
 237        return err;
 238}
 239
 240static int get_packet_data(int fd, char **src_buf, size_t *src_size,
 241                           void *dst, unsigned size, int options)
 242{
 243        ssize_t ret;
 244
 245        if (fd >= 0 && src_buf && *src_buf)
 246                die("BUG: multiple sources given to packet_read");
 247
 248        /* Read up to "size" bytes from our source, whatever it is. */
 249        if (src_buf && *src_buf) {
 250                ret = size < *src_size ? size : *src_size;
 251                memcpy(dst, *src_buf, ret);
 252                *src_buf += ret;
 253                *src_size -= ret;
 254        } else {
 255                ret = read_in_full(fd, dst, size);
 256                if (ret < 0)
 257                        die_errno("read error");
 258        }
 259
 260        /* And complain if we didn't get enough bytes to satisfy the read. */
 261        if (ret < size) {
 262                if (options & PACKET_READ_GENTLE_ON_EOF)
 263                        return -1;
 264
 265                die("The remote end hung up unexpectedly");
 266        }
 267
 268        return ret;
 269}
 270
 271static int packet_length(const char *linelen)
 272{
 273        int val = hex2chr(linelen);
 274        return (val < 0) ? val : (val << 8) | hex2chr(linelen + 2);
 275}
 276
 277int packet_read(int fd, char **src_buf, size_t *src_len,
 278                char *buffer, unsigned size, int options)
 279{
 280        int len, ret;
 281        char linelen[4];
 282
 283        ret = get_packet_data(fd, src_buf, src_len, linelen, 4, options);
 284        if (ret < 0)
 285                return ret;
 286        len = packet_length(linelen);
 287        if (len < 0)
 288                die("protocol error: bad line length character: %.4s", linelen);
 289        if (!len) {
 290                packet_trace("0000", 4, 0);
 291                return 0;
 292        }
 293        len -= 4;
 294        if (len >= size)
 295                die("protocol error: bad line length %d", len);
 296        ret = get_packet_data(fd, src_buf, src_len, buffer, len, options);
 297        if (ret < 0)
 298                return ret;
 299
 300        if ((options & PACKET_READ_CHOMP_NEWLINE) &&
 301            len && buffer[len-1] == '\n')
 302                len--;
 303
 304        buffer[len] = 0;
 305        packet_trace(buffer, len, 0);
 306        return len;
 307}
 308
 309static char *packet_read_line_generic(int fd,
 310                                      char **src, size_t *src_len,
 311                                      int *dst_len)
 312{
 313        int len = packet_read(fd, src, src_len,
 314                              packet_buffer, sizeof(packet_buffer),
 315                              PACKET_READ_CHOMP_NEWLINE);
 316        if (dst_len)
 317                *dst_len = len;
 318        return len ? packet_buffer : NULL;
 319}
 320
 321char *packet_read_line(int fd, int *len_p)
 322{
 323        return packet_read_line_generic(fd, NULL, NULL, len_p);
 324}
 325
 326char *packet_read_line_buf(char **src, size_t *src_len, int *dst_len)
 327{
 328        return packet_read_line_generic(-1, src, src_len, dst_len);
 329}
 330
 331ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out)
 332{
 333        int packet_len;
 334
 335        size_t orig_len = sb_out->len;
 336        size_t orig_alloc = sb_out->alloc;
 337
 338        for (;;) {
 339                strbuf_grow(sb_out, LARGE_PACKET_DATA_MAX);
 340                packet_len = packet_read(fd_in, NULL, NULL,
 341                        /* strbuf_grow() above always allocates one extra byte to
 342                         * store a '\0' at the end of the string. packet_read()
 343                         * writes a '\0' extra byte at the end, too. Let it know
 344                         * that there is already room for the extra byte.
 345                         */
 346                        sb_out->buf + sb_out->len, LARGE_PACKET_DATA_MAX+1,
 347                        PACKET_READ_GENTLE_ON_EOF);
 348                if (packet_len <= 0)
 349                        break;
 350                sb_out->len += packet_len;
 351        }
 352
 353        if (packet_len < 0) {
 354                if (orig_alloc == 0)
 355                        strbuf_release(sb_out);
 356                else
 357                        strbuf_setlen(sb_out, orig_len);
 358                return packet_len;
 359        }
 360        return sb_out->len - orig_len;
 361}