| #include "cache.h" |
| #include "pkt-line.h" |
| |
| static const char *packet_trace_prefix = "git"; |
| static const char trace_key[] = "GIT_TRACE_PACKET"; |
| |
| void packet_trace_identity(const char *prog) |
| { |
| packet_trace_prefix = xstrdup(prog); |
| } |
| |
| static void packet_trace(const char *buf, unsigned int len, int write) |
| { |
| int i; |
| struct strbuf out; |
| |
| if (!trace_want(trace_key)) |
| return; |
| |
| /* +32 is just a guess for header + quoting */ |
| strbuf_init(&out, len+32); |
| |
| strbuf_addf(&out, "packet: %12s%c ", |
| packet_trace_prefix, write ? '>' : '<'); |
| |
| if ((len >= 4 && !prefixcmp(buf, "PACK")) || |
| (len >= 5 && !prefixcmp(buf+1, "PACK"))) { |
| strbuf_addstr(&out, "PACK ..."); |
| unsetenv(trace_key); |
| } |
| else { |
| /* XXX we should really handle printable utf8 */ |
| for (i = 0; i < len; i++) { |
| /* suppress newlines */ |
| if (buf[i] == '\n') |
| continue; |
| if (buf[i] >= 0x20 && buf[i] <= 0x7e) |
| strbuf_addch(&out, buf[i]); |
| else |
| strbuf_addf(&out, "\\%o", buf[i]); |
| } |
| } |
| |
| strbuf_addch(&out, '\n'); |
| trace_strbuf(trace_key, &out); |
| strbuf_release(&out); |
| } |
| |
| /* |
| * Write a packetized stream, where each line is preceded by |
| * its length (including the header) as a 4-byte hex number. |
| * A length of 'zero' means end of stream (and a length of 1-3 |
| * would be an error). |
| * |
| * This is all pretty stupid, but we use this packetized line |
| * format to make a streaming format possible without ever |
| * over-running the read buffers. That way we'll never read |
| * into what might be the pack data (which should go to another |
| * process entirely). |
| * |
| * The writing side could use stdio, but since the reading |
| * side can't, we stay with pure read/write interfaces. |
| */ |
| ssize_t safe_write(int fd, const void *buf, ssize_t n) |
| { |
| ssize_t nn = n; |
| while (n) { |
| int ret = xwrite(fd, buf, n); |
| if (ret > 0) { |
| buf = (char *) buf + ret; |
| n -= ret; |
| continue; |
| } |
| if (!ret) |
| die("write error (disk full?)"); |
| die_errno("write error"); |
| } |
| return nn; |
| } |
| |
| /* |
| * If we buffered things up above (we don't, but we should), |
| * we'd flush it here |
| */ |
| void packet_flush(int fd) |
| { |
| packet_trace("0000", 4, 1); |
| safe_write(fd, "0000", 4); |
| } |
| |
| void packet_buf_flush(struct strbuf *buf) |
| { |
| packet_trace("0000", 4, 1); |
| strbuf_add(buf, "0000", 4); |
| } |
| |
| #define hex(a) (hexchar[(a) & 15]) |
| static char buffer[1000]; |
| static unsigned format_packet(const char *fmt, va_list args) |
| { |
| static char hexchar[] = "0123456789abcdef"; |
| unsigned n; |
| |
| n = vsnprintf(buffer + 4, sizeof(buffer) - 4, fmt, args); |
| if (n >= sizeof(buffer)-4) |
| die("protocol error: impossibly long line"); |
| n += 4; |
| buffer[0] = hex(n >> 12); |
| buffer[1] = hex(n >> 8); |
| buffer[2] = hex(n >> 4); |
| buffer[3] = hex(n); |
| packet_trace(buffer+4, n-4, 1); |
| return n; |
| } |
| |
| void packet_write(int fd, const char *fmt, ...) |
| { |
| va_list args; |
| unsigned n; |
| |
| va_start(args, fmt); |
| n = format_packet(fmt, args); |
| va_end(args); |
| safe_write(fd, buffer, n); |
| } |
| |
| void packet_buf_write(struct strbuf *buf, const char *fmt, ...) |
| { |
| va_list args; |
| unsigned n; |
| |
| va_start(args, fmt); |
| n = format_packet(fmt, args); |
| va_end(args); |
| strbuf_add(buf, buffer, n); |
| } |
| |
| static int safe_read(int fd, void *buffer, unsigned size, int return_line_fail) |
| { |
| ssize_t ret = read_in_full(fd, buffer, size); |
| if (ret < 0) |
| die_errno("read error"); |
| else if (ret < size) { |
| if (return_line_fail) |
| return -1; |
| |
| die("The remote end hung up unexpectedly"); |
| } |
| |
| return ret; |
| } |
| |
| static int packet_length(const char *linelen) |
| { |
| int n; |
| int len = 0; |
| |
| for (n = 0; n < 4; n++) { |
| unsigned char c = linelen[n]; |
| len <<= 4; |
| if (c >= '0' && c <= '9') { |
| len += c - '0'; |
| continue; |
| } |
| if (c >= 'a' && c <= 'f') { |
| len += c - 'a' + 10; |
| continue; |
| } |
| if (c >= 'A' && c <= 'F') { |
| len += c - 'A' + 10; |
| continue; |
| } |
| return -1; |
| } |
| return len; |
| } |
| |
| static int packet_read_internal(int fd, char *buffer, unsigned size, int return_line_fail) |
| { |
| int len, ret; |
| char linelen[4]; |
| |
| ret = safe_read(fd, linelen, 4, return_line_fail); |
| if (return_line_fail && ret < 0) |
| return ret; |
| len = packet_length(linelen); |
| if (len < 0) |
| die("protocol error: bad line length character: %.4s", linelen); |
| if (!len) { |
| packet_trace("0000", 4, 0); |
| return 0; |
| } |
| len -= 4; |
| if (len >= size) |
| die("protocol error: bad line length %d", len); |
| ret = safe_read(fd, buffer, len, return_line_fail); |
| if (return_line_fail && ret < 0) |
| return ret; |
| buffer[len] = 0; |
| packet_trace(buffer, len, 0); |
| return len; |
| } |
| |
| int packet_read(int fd, char *buffer, unsigned size) |
| { |
| return packet_read_internal(fd, buffer, size, 1); |
| } |
| |
| int packet_read_line(int fd, char *buffer, unsigned size) |
| { |
| return packet_read_internal(fd, buffer, size, 0); |
| } |
| |
| int packet_get_line(struct strbuf *out, |
| char **src_buf, size_t *src_len) |
| { |
| int len; |
| |
| if (*src_len < 4) |
| return -1; |
| len = packet_length(*src_buf); |
| if (len < 0) |
| return -1; |
| if (!len) { |
| *src_buf += 4; |
| *src_len -= 4; |
| packet_trace("0000", 4, 0); |
| return 0; |
| } |
| if (*src_len < len) |
| return -2; |
| |
| *src_buf += 4; |
| *src_len -= 4; |
| len -= 4; |
| |
| strbuf_add(out, *src_buf, len); |
| *src_buf += len; |
| *src_len -= len; |
| packet_trace(out->buf, out->len, 0); |
| return len; |
| } |