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         write_or_die(fd, "0000", 4);
  92 }
  93
  94 void packet_buf_flush(struct strbuf *buf)
  95 {
  96         packet_trace("0000", 4, 1);
  97         strbuf_add(buf, "0000", 4);
  98 }
  99
 100 #define hex(a) (hexchar[(a) & 15])
 101 static void format_packet(struct strbuf *out, const char *fmt, va_list args)
 102 {
 103         static char hexchar[] = "0123456789abcdef";
 104         size_t orig_len, n;
 105
 106         orig_len = out->len;
 107         strbuf_addstr(out, "0000");
 108         strbuf_vaddf(out, fmt, args);
 109         n = out->len - orig_len;
 110
 111         if (n > LARGE_PACKET_MAX)
 112                 die("protocol error: impossibly long line");
 113
 114         out->buf[orig_len + 0] = hex(n >> 12);
 115         out->buf[orig_len + 1] = hex(n >> 8);
 116         out->buf[orig_len + 2] = hex(n >> 4);
 117         out->buf[orig_len + 3] = hex(n);
 118         packet_trace(out->buf + orig_len + 4, n - 4, 1);
 119 }
 120
 121 void packet_write(int fd, const char *fmt, ...)
 122 {
 123         static struct strbuf buf = STRBUF_INIT;
 124         va_list args;
 125
 126         strbuf_reset(&buf);
 127         va_start(args, fmt);
 128         format_packet(&buf, fmt, args);
 129         va_end(args);
 130         write_or_die(fd, buf.buf, buf.len);
 131 }
 132
 133 void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
 134 {
 135         va_list args;
 136
 137         va_start(args, fmt);
 138         format_packet(buf, fmt, args);
 139         va_end(args);
 140 }
 141
 142 static int get_packet_data(int fd, char **src_buf, size_t *src_size,
 143                            void *dst, unsigned size, int options)
 144 {
 145         ssize_t ret;
 146
 147         if (fd >= 0 && src_buf && *src_buf)
 148                 die("BUG: multiple sources given to packet_read");
 149
 150         /* Read up to "size" bytes from our source, whatever it is. */
 151         if (src_buf && *src_buf) {
 152                 ret = size < *src_size ? size : *src_size;
 153                 memcpy(dst, *src_buf, ret);
 154                 *src_buf += ret;
 155                 *src_size -= ret;
 156         } else {
 157                 ret = read_in_full(fd, dst, size);
 158                 if (ret < 0)
 159                         die_errno("read error");
 160         }
 161
 162         /* And complain if we didn't get enough bytes to satisfy the read. */
 163         if (ret < size) {
 164                 if (options & PACKET_READ_GENTLE_ON_EOF)
 165                         return -1;
 166
 167                 die("The remote end hung up unexpectedly");
 168         }
 169
 170         return ret;
 171 }
 172
 173 static int packet_length(const char *linelen)
 174 {
 175         int val = hex2chr(linelen);
 176         return (val < 0) ? val : (val << 8) | hex2chr(linelen + 2);
 177 }
 178
 179 int packet_read(int fd, char **src_buf, size_t *src_len,
 180                 char *buffer, unsigned size, int options)
 181 {
 182         int len, ret;
 183         char linelen[4];
 184
 185         ret = get_packet_data(fd, src_buf, src_len, linelen, 4, options);
 186         if (ret < 0)
 187                 return ret;
 188         len = packet_length(linelen);
 189         if (len < 0)
 190                 die("protocol error: bad line length character: %.4s", linelen);
 191         if (!len) {
 192                 packet_trace("0000", 4, 0);
 193                 return 0;
 194         }
 195         len -= 4;
 196         if (len >= size)
 197                 die("protocol error: bad line length %d", len);
 198         ret = get_packet_data(fd, src_buf, src_len, buffer, len, options);
 199         if (ret < 0)
 200                 return ret;
 201
 202         if ((options & PACKET_READ_CHOMP_NEWLINE) &&
 203             len && buffer[len-1] == '\n')
 204                 len--;
 205
 206         buffer[len] = 0;
 207         packet_trace(buffer, len, 0);
 208         return len;
 209 }
 210
 211 static char *packet_read_line_generic(int fd,
 212                                       char **src, size_t *src_len,
 213                                       int *dst_len)
 214 {
 215         int len = packet_read(fd, src, src_len,
 216                               packet_buffer, sizeof(packet_buffer),
 217                               PACKET_READ_CHOMP_NEWLINE);
 218         if (dst_len)
 219                 *dst_len = len;
 220         return len ? packet_buffer : NULL;
 221 }
 222
 223 char *packet_read_line(int fd, int *len_p)
 224 {
 225         return packet_read_line_generic(fd, NULL, NULL, len_p);
 226 }
 227
 228 char *packet_read_line_buf(char **src, size_t *src_len, int *dst_len)
 229 {
 230         return packet_read_line_generic(-1, src, src_len, dst_len);
 231 }