+/* read from the file descriptor handling multiplexing -
+ return number of bytes read
+ never return <= 0 */
+static int read_unbuffered(int fd, char *buf, int len)
+{
+ static int remaining;
+ char ibuf[4];
+ int tag, ret=0;
+ char line[1024];
+
+ if (!io_multiplexing_in || fd != multiplex_in_fd)
+ return read_timeout(fd, buf, len);
+
+ while (ret == 0) {
+ if (remaining) {
+ len = MIN(len, remaining);
+ read_loop(fd, buf, len);
+ remaining -= len;
+ ret = len;
+ continue;
+ }
+
+ read_loop(fd, ibuf, 4);
+ tag = IVAL(ibuf, 0);
+
+ remaining = tag & 0xFFFFFF;
+ tag = tag >> 24;
+
+ if (tag == MPLEX_BASE) continue;
+
+ tag -= MPLEX_BASE;
+
+ if (tag != FERROR && tag != FINFO) {
+ rprintf(FERROR,"unexpected tag %d\n", tag);
+ exit_cleanup(RERR_STREAMIO);
+ }
+
+ if (remaining > sizeof(line)-1) {
+ rprintf(FERROR,"multiplexing overflow %d\n\n",
+ remaining);
+ exit_cleanup(RERR_STREAMIO);
+ }
+
+ read_loop(fd, line, remaining);
+ line[remaining] = 0;
+
+ rprintf(tag,"%s", line);
+ remaining = 0;
+ }
+
+ return ret;
+}