+ char buf[2048];
+ size_t n;
+ int fd = msg_fd_in;
+ int tag, len;
+
+ /* Temporarily disable msg_fd_in. This is needed to avoid looping back
+ * to this routine from read_timeout() and writefd_unbuffered(). */
+ msg_fd_in = -1;
+
+ read_loop(fd, buf, 4);
+ tag = IVAL(buf, 0);
+
+ len = tag & 0xFFFFFF;
+ tag = (tag >> 24) - MPLEX_BASE;
+
+ switch (tag) {
+ case MSG_DONE:
+ if (len != 0) {
+ rprintf(FERROR, "invalid message %d:%d\n", tag, len);
+ exit_cleanup(RERR_STREAMIO);
+ }
+ redo_list_add(-1);
+ break;
+ case MSG_REDO:
+ if (len != 4) {
+ rprintf(FERROR, "invalid message %d:%d\n", tag, len);
+ exit_cleanup(RERR_STREAMIO);
+ }
+ read_loop(fd, buf, 4);
+ redo_list_add(IVAL(buf,0));
+ break;
+ case MSG_INFO:
+ case MSG_ERROR:
+ case MSG_LOG:
+ while (len) {
+ n = len;
+ if (n >= sizeof buf)
+ n = sizeof buf - 1;
+ read_loop(fd, buf, n);
+ rwrite((enum logcode)tag, buf, n);
+ len -= n;
+ }
+ break;
+ default:
+ rprintf(FERROR, "unknown message %d:%d\n", tag, len);
+ exit_cleanup(RERR_STREAMIO);
+ }
+
+ msg_fd_in = fd;
+}
+
+/* Try to push messages off the list onto the wire. If we leave with more
+ * to do, return 0. On error, return -1. If everything flushed, return 1.
+ * This is only active in the receiver. */
+int msg_list_push(int flush_it_all)
+{
+ static int written = 0;
+ struct timeval tv;
+ fd_set fds;
+
+ if (msg_fd_out < 0)
+ return -1;
+
+ while (msg_list_head) {
+ struct msg_list *ml = msg_list_head;
+ int n = write(msg_fd_out, ml->buf + written, ml->len - written);
+ if (n < 0) {
+ if (errno == EINTR)
+ continue;
+ if (errno != EWOULDBLOCK && errno != EAGAIN)
+ return -1;
+ if (!flush_it_all)
+ return 0;
+ FD_ZERO(&fds);
+ FD_SET(msg_fd_out, &fds);
+ tv.tv_sec = select_timeout;
+ tv.tv_usec = 0;
+ if (!select(msg_fd_out+1, NULL, &fds, NULL, &tv))
+ check_timeout();
+ } else if ((written += n) == ml->len) {
+ free(ml->buf);
+ msg_list_head = ml->next;
+ if (!msg_list_head)
+ msg_list_tail = NULL;
+ free(ml);
+ written = 0;
+ }
+ }
+ return 1;
+}
+
+int get_redo_num(void)
+{
+ struct redo_list *next;
+ int num;
+
+ while (!redo_list_head)
+ read_msg_fd();
+
+ num = redo_list_head->num;
+ next = redo_list_head->next;
+ free(redo_list_head);
+ redo_list_head = next;
+ if (!next)
+ redo_list_tail = NULL;
+
+ return num;
+}
+
+/**
+ * When we're the receiver and we have a local --files-from list of names
+ * that needs to be sent over the socket to the sender, we have to do two
+ * things at the same time: send the sender a list of what files we're
+ * processing and read the incoming file+info list from the sender. We do
+ * this by augmenting the read_timeout() function to copy this data. It
+ * uses the io_filesfrom_buf to read a block of data from f_in (when it is
+ * ready, since it might be a pipe) and then blast it out f_out (when it
+ * is ready to receive more data).
+ */
+void io_set_filesfrom_fds(int f_in, int f_out)
+{
+ io_filesfrom_f_in = f_in;
+ io_filesfrom_f_out = f_out;
+ io_filesfrom_bp = io_filesfrom_buf;
+ io_filesfrom_lastchar = '\0';
+ io_filesfrom_buflen = 0;
+}
+
+/**
+ * It's almost always an error to get an EOF when we're trying to read
+ * from the network, because the protocol is self-terminating.
+ *
+ * However, there is one unfortunate cases where it is not, which is
+ * rsync <2.4.6 sending a list of modules on a server, since the list
+ * is terminated by closing the socket. So, for the section of the
+ * program where that is a problem (start_socket_client),
+ * kludge_around_eof is True and we just exit.
+ */
+static void whine_about_eof(void)
+{
+ if (kludge_around_eof)
+ exit_cleanup(0);
+
+ rprintf(FERROR, RSYNC_NAME ": connection unexpectedly closed "
+ "(%.0f bytes read so far)\n",
+ (double)stats.total_read);
+
+ exit_cleanup(RERR_STREAMIO);
+}
+
+
+static void die_from_readerr(int err)
+{
+ /* this prevents us trying to write errors on a dead socket */
+ io_multiplexing_close();
+
+ rsyserr(FERROR, err, "read error");
+ exit_cleanup(RERR_STREAMIO);
+}
+
+
+/**
+ * Read from a socket with I/O timeout. return the number of bytes
+ * read. If no bytes can be read then exit, never return a number <= 0.
+ *
+ * TODO: If the remote shell connection fails, then current versions
+ * actually report an "unexpected EOF" error here. Since it's a
+ * fairly common mistake to try to use rsh when ssh is required, we
+ * should trap that: if we fail to read any data at all, we should
+ * give a better explanation. We can tell whether the connection has
+ * started by looking e.g. at whether the remote version is known yet.
+ */
+static int read_timeout(int fd, char *buf, size_t len)
+{
+ int n, ret = 0;
+
+ io_flush(NORMAL_FLUSH);
+
+ while (ret == 0) {
+ /* until we manage to read *something* */
+ fd_set r_fds, w_fds;
+ struct timeval tv;
+ int maxfd = fd;
+ int count;
+
+ FD_ZERO(&r_fds);
+ FD_SET(fd, &r_fds);
+ if (msg_fd_in >= 0) {
+ FD_SET(msg_fd_in, &r_fds);
+ if (msg_fd_in > maxfd)
+ maxfd = msg_fd_in;
+ } else if (msg_list_head) {
+ FD_SET(msg_fd_out, &w_fds);
+ if (msg_fd_out > maxfd)
+ maxfd = msg_fd_out;
+ }
+ if (io_filesfrom_f_out >= 0) {
+ int new_fd;
+ if (io_filesfrom_buflen == 0) {
+ if (io_filesfrom_f_in >= 0) {
+ FD_SET(io_filesfrom_f_in, &r_fds);
+ new_fd = io_filesfrom_f_in;
+ } else {
+ io_filesfrom_f_out = -1;
+ new_fd = -1;
+ }
+ } else {
+ FD_ZERO(&w_fds);
+ FD_SET(io_filesfrom_f_out, &w_fds);
+ new_fd = io_filesfrom_f_out;
+ }
+ if (new_fd > maxfd)
+ maxfd = new_fd;
+ }
+
+ tv.tv_sec = select_timeout;
+ tv.tv_usec = 0;
+
+ errno = 0;
+
+ count = select(maxfd + 1, &r_fds,
+ io_filesfrom_buflen? &w_fds : NULL,
+ NULL, &tv);
+
+ if (count <= 0) {
+ check_timeout();
+ if (errno == EBADF)
+ exit_cleanup(RERR_SOCKETIO);
+ continue;
+ }
+
+ if (msg_fd_in >= 0 && FD_ISSET(msg_fd_in, &r_fds))
+ read_msg_fd();
+ else if (msg_list_head && FD_ISSET(msg_fd_out, &w_fds))
+ msg_list_push(NORMAL_FLUSH);
+
+ if (io_filesfrom_f_out >= 0) {
+ if (io_filesfrom_buflen) {
+ if (FD_ISSET(io_filesfrom_f_out, &w_fds)) {
+ int l = write(io_filesfrom_f_out,
+ io_filesfrom_bp,
+ io_filesfrom_buflen);
+ if (l > 0) {
+ if (!(io_filesfrom_buflen -= l))
+ io_filesfrom_bp = io_filesfrom_buf;
+ else
+ io_filesfrom_bp += l;
+ } else {
+ /* XXX should we complain? */
+ io_filesfrom_f_out = -1;
+ }
+ }
+ } else if (io_filesfrom_f_in >= 0) {
+ if (FD_ISSET(io_filesfrom_f_in, &r_fds)) {
+ int l = read(io_filesfrom_f_in,
+ io_filesfrom_buf,
+ sizeof io_filesfrom_buf);
+ if (l <= 0) {
+ /* Send end-of-file marker */
+ io_filesfrom_buf[0] = '\0';
+ io_filesfrom_buf[1] = '\0';
+ io_filesfrom_buflen = io_filesfrom_lastchar? 2 : 1;
+ io_filesfrom_f_in = -1;
+ } else {
+ if (!eol_nulls) {
+ char *s = io_filesfrom_buf + l;
+ /* Transform CR and/or LF into '\0' */
+ while (s-- > io_filesfrom_buf) {
+ if (*s == '\n' || *s == '\r')
+ *s = '\0';
+ }
+ }
+ if (!io_filesfrom_lastchar) {
+ /* Last buf ended with a '\0', so don't
+ * let this buf start with one. */
+ while (l && !*io_filesfrom_bp)
+ io_filesfrom_bp++, l--;
+ }
+ if (!l)
+ io_filesfrom_bp = io_filesfrom_buf;
+ else {
+ char *f = io_filesfrom_bp;
+ char *t = f;
+ char *eob = f + l;
+ /* Eliminate any multi-'\0' runs. */
+ while (f != eob) {
+ if (!(*t++ = *f++)) {
+ while (f != eob && !*f)
+ f++, l--;
+ }
+ }
+ io_filesfrom_lastchar = f[-1];
+ }
+ io_filesfrom_buflen = l;
+ }
+ }
+ }
+ }
+
+ if (!FD_ISSET(fd, &r_fds))
+ continue;
+
+ n = read(fd, buf, len);
+
+ if (n <= 0) {
+ if (n == 0)
+ whine_about_eof(); /* Doesn't return. */
+ if (errno == EINTR || errno == EWOULDBLOCK
+ || errno == EAGAIN)
+ continue;
+ die_from_readerr(errno); /* Doesn't return. */
+ }
+
+ buf += n;
+ len -= n;
+ ret += n;
+ if (io_timeout)
+ last_io = time(NULL);
+ }
+
+ return ret;
+}
+
+/**
+ * Read a line into the "fname" buffer (which must be at least MAXPATHLEN
+ * characters long).
+ */
+int read_filesfrom_line(int fd, char *fname)
+{
+ char ch, *s, *eob = fname + MAXPATHLEN - 1;
+ int cnt;
+ int reading_remotely = remote_filesfrom_file != NULL;
+ int nulls = eol_nulls || reading_remotely;
+
+ start:
+ s = fname;
+ while (1) {
+ cnt = read(fd, &ch, 1);
+ if (cnt < 0 && (errno == EWOULDBLOCK
+ || errno == EINTR || errno == EAGAIN)) {
+ struct timeval tv;
+ fd_set fds;
+ FD_ZERO(&fds);
+ FD_SET(fd, &fds);
+ tv.tv_sec = select_timeout;
+ tv.tv_usec = 0;
+ if (!select(fd+1, &fds, NULL, NULL, &tv))
+ check_timeout();
+ continue;
+ }
+ if (cnt != 1)
+ break;
+ if (nulls? !ch : (ch == '\r' || ch == '\n')) {
+ /* Skip empty lines if reading locally. */
+ if (!reading_remotely && s == fname)
+ continue;
+ break;
+ }
+ if (s < eob)
+ *s++ = ch;
+ }
+ *s = '\0';
+
+ /* Dump comments. */
+ if (*fname == '#' || *fname == ';')
+ goto start;
+
+ return s - fname;
+}
+
+
+/**
+ * Continue trying to read len bytes - don't return until len has been
+ * read.
+ **/
+static void read_loop(int fd, char *buf, size_t len)
+{
+ while (len) {
+ int n = read_timeout(fd, buf, len);
+
+ buf += n;
+ len -= n;
+ }
+}
+
+
+/**
+ * Read from the file descriptor handling multiplexing - return number
+ * of bytes read.
+ *
+ * Never returns <= 0.
+ */
+static int readfd_unbuffered(int fd, char *buf, size_t len)
+{
+ static size_t remaining;
+ int tag, ret = 0;
+ char line[1024];
+ static char *buffer;
+ static size_t bufferIdx = 0;
+ static size_t bufferSz;
+
+ if (fd != multiplex_in_fd)
+ return read_timeout(fd, buf, len);
+
+ if (!io_multiplexing_in && remaining == 0) {
+ if (!buffer) {
+ bufferSz = 2 * IO_BUFFER_SIZE;
+ buffer = new_array(char, bufferSz);
+ if (!buffer)
+ out_of_memory("readfd_unbuffered");
+ }
+ remaining = read_timeout(fd, buffer, bufferSz);
+ bufferIdx = 0;
+ }
+
+ while (ret == 0) {
+ if (remaining) {
+ len = MIN(len, remaining);
+ memcpy(buf, buffer + bufferIdx, len);
+ bufferIdx += len;
+ remaining -= len;
+ ret = len;
+ break;
+ }
+
+ read_loop(fd, line, 4);
+ tag = IVAL(line, 0);
+
+ remaining = tag & 0xFFFFFF;
+ tag = (tag >> 24) - MPLEX_BASE;
+
+ switch (tag) {
+ case MSG_DATA:
+ if (!buffer || remaining > bufferSz) {
+ buffer = realloc_array(buffer, char, remaining);
+ if (!buffer)
+ out_of_memory("readfd_unbuffered");
+ bufferSz = remaining;
+ }
+ read_loop(fd, buffer, remaining);
+ bufferIdx = 0;
+ break;
+ case MSG_INFO:
+ case MSG_ERROR:
+ if (remaining >= sizeof line) {
+ rprintf(FERROR, "multiplexing overflow %d:%ld\n\n",
+ tag, (long)remaining);
+ exit_cleanup(RERR_STREAMIO);
+ }
+ read_loop(fd, line, remaining);
+ rwrite((enum logcode)tag, line, remaining);
+ remaining = 0;
+ break;
+ default:
+ rprintf(FERROR, "unexpected tag %d\n", tag);
+ exit_cleanup(RERR_STREAMIO);
+ }
+ }
+
+ if (remaining == 0)
+ io_flush(NORMAL_FLUSH);
+
+ return ret;
+}