Andrew's git - gitweb.git/blob

   1#include "pkt-line.h"
   2#include "sideband.h"
   3
   4/*
   5 * Receive multiplexed output stream over git native protocol.
   6 * in_stream is the input stream from the remote, which carries data
   7 * in pkt_line format with band designator.  Demultiplex it into out
   8 * and err and return error appropriately.  Band #1 carries the
   9 * primary payload.  Things coming over band #2 is not necessarily
  10 * error; they are usually informative message on the standard error
  11 * stream, aka "verbose").  A message over band #3 is a signal that
  12 * the remote died unexpectedly.  A flush() concludes the stream.
  13 */
  14
  15#define PREFIX "remote:"
  16
  17#define ANSI_SUFFIX "\033[K"
  18#define DUMB_SUFFIX "        "
  19
  20#define FIX_SIZE 10  /* large enough for any of the above */
  21
  22int recv_sideband(const char *me, int in_stream, int out, int err)
  23{
  24        unsigned pf = strlen(PREFIX);
  25        unsigned sf;
  26        char buf[LARGE_PACKET_MAX + 2*FIX_SIZE];
  27        char *suffix, *term;
  28        int skip_pf = 0;
  29
  30        memcpy(buf, PREFIX, pf);
  31        term = getenv("TERM");
  32        if (term && strcmp(term, "dumb"))
  33                suffix = ANSI_SUFFIX;
  34        else
  35                suffix = DUMB_SUFFIX;
  36        sf = strlen(suffix);
  37
  38        while (1) {
  39                int band, len;
  40                len = packet_read_line(in_stream, buf + pf, LARGE_PACKET_MAX);
  41                if (len == 0)
  42                        break;
  43                if (len < 1) {
  44                        len = sprintf(buf, "%s: protocol error: no band designator\n", me);
  45                        safe_write(err, buf, len);
  46                        return SIDEBAND_PROTOCOL_ERROR;
  47                }
  48                band = buf[pf] & 0xff;
  49                len--;
  50                switch (band) {
  51                case 3:
  52                        buf[pf] = ' ';
  53                        buf[pf+1+len] = '\n';
  54                        safe_write(err, buf, pf+1+len+1);
  55                        return SIDEBAND_REMOTE_ERROR;
  56                case 2:
  57                        buf[pf] = ' ';
  58                        do {
  59                                char *b = buf;
  60                                int brk = 0;
  61
  62                                /*
  63                                 * If the last buffer didn't end with a line
  64                                 * break then we should not print a prefix
  65                                 * this time around.
  66                                 */
  67                                if (skip_pf) {
  68                                        b += pf+1;
  69                                } else {
  70                                        len += pf+1;
  71                                        brk += pf+1;
  72                                }
  73
  74                                /* Look for a line break. */
  75                                for (;;) {
  76                                        brk++;
  77                                        if (brk > len) {
  78                                                brk = 0;
  79                                                break;
  80                                        }
  81                                        if (b[brk-1] == '\n' ||
  82                                            b[brk-1] == '\r')
  83                                                break;
  84                                }
  85
  86                                /*
  87                                 * Let's insert a suffix to clear the end
  88                                 * of the screen line if a line break was
  89                                 * found.  Also, if we don't skip the
  90                                 * prefix, then a non-empty string must be
  91                                 * present too.
  92                                 */
  93                                if (brk > (skip_pf ? 0 : (pf+1 + 1))) {
  94                                        char save[FIX_SIZE];
  95                                        memcpy(save, b + brk, sf);
  96                                        b[brk + sf - 1] = b[brk - 1];
  97                                        memcpy(b + brk - 1, suffix, sf);
  98                                        safe_write(err, b, brk + sf);
  99                                        memcpy(b + brk, save, sf);
 100                                        len -= brk;
 101                                } else {
 102                                        int l = brk ? brk : len;
 103                                        safe_write(err, b, l);
 104                                        len -= l;
 105                                }
 106
 107                                skip_pf = !brk;
 108                                memmove(buf + pf+1, b + brk, len);
 109                        } while (len);
 110                        continue;
 111                case 1:
 112                        safe_write(out, buf + pf+1, len);
 113                        continue;
 114                default:
 115                        len = sprintf(buf,
 116                                      "%s: protocol error: bad band #%d\n",
 117                                      me, band);
 118                        safe_write(err, buf, len);
 119                        return SIDEBAND_PROTOCOL_ERROR;
 120                }
 121        }
 122        return 0;
 123}
 124
 125/*
 126 * fd is connected to the remote side; send the sideband data
 127 * over multiplexed packet stream.
 128 */
 129ssize_t send_sideband(int fd, int band, const char *data, ssize_t sz, int packet_max)
 130{
 131        ssize_t ssz = sz;
 132        const char *p = data;
 133
 134        while (sz) {
 135                unsigned n;
 136                char hdr[5];
 137
 138                n = sz;
 139                if (packet_max - 5 < n)
 140                        n = packet_max - 5;
 141                sprintf(hdr, "%04x", n + 5);
 142                hdr[4] = band;
 143                safe_write(fd, hdr, 5);
 144                safe_write(fd, p, n);
 145                p += n;
 146                sz -= n;
 147        }
 148        return ssz;
 149}