+/* 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(int fd)
+{
+ if (kludge_around_eof && fd == sock_f_in)
+ exit_cleanup(0);
+
+ rprintf(FERROR, RSYNC_NAME ": connection unexpectedly closed "
+ "(%.0f bytes read so far)\n",
+ (double)stats.total_read);
+
+ 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_ZERO(&w_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_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, &w_fds, NULL, &tv);
+
+ if (count <= 0) {
+ if (errno == EBADF)
+ exit_cleanup(RERR_SOCKETIO);
+ check_timeout();
+ 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(fd); /* Doesn't return. */
+ if (errno == EINTR || errno == EWOULDBLOCK
+ || errno == EAGAIN)
+ continue;