--- /dev/null
+/*
+ Copyright (C) Andrew Tridgell 1998
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+/* support the max connections option */
+#include "rsync.h"
+
+int yield_connection(char *fname, int max_connections)
+{
+ int fd, i;
+ pid_t mypid=getpid(), pid=0;
+
+ if (max_connections <= 0)
+ return 1;
+
+ fd = open(fname,O_RDWR);
+ if (fd == -1) {
+ rprintf(FERROR,"Couldn't open lock file %s (%s)\n",fname,strerror(errno));
+ return 0;
+ }
+
+ if (!lock_file(fd)) {
+ rprintf(FERROR,"failed to lock %s\n", fname);
+ close(fd);
+ return 0;
+ }
+
+ /* find the right spot */
+ for (i=0;i<max_connections;i++) {
+ if (read(fd, &pid, sizeof(pid)) != sizeof(pid)) {
+ unlock_file(fd);
+ close(fd);
+ return 0;
+ }
+ if (pid == mypid) break;
+ }
+
+ if (i == max_connections) {
+ rprintf(FERROR,"Entry not found in lock file %s\n",fname);
+ unlock_file(fd);
+ close(fd);
+ return 0;
+ }
+
+ pid = 0;
+
+ /* remove our mark */
+ if (lseek(fd,i*sizeof(pid),SEEK_SET) != i*sizeof(pid) ||
+ write(fd, &pid,sizeof(pid)) != sizeof(pid)) {
+ rprintf(FERROR,"Couldn't update lock file %s (%s)\n",fname,strerror(errno));
+ unlock_file(fd);
+ close(fd);
+ return 0;
+ }
+
+ unlock_file(fd);
+ close(fd);
+ return 1;
+}
+
+
+/****************************************************************************
+simple routine to do connection counting
+****************************************************************************/
+int claim_connection(char *fname,int max_connections)
+{
+ int fd, i;
+ pid_t pid;
+
+ if (max_connections <= 0)
+ return 1;
+
+ fd = open(fname,O_RDWR|O_CREAT, 0600);
+
+ if (fd == -1) {
+ return 0;
+ }
+
+ if (!lock_file(fd)) {
+ rprintf(FERROR,"failed to lock %s\n", fname);
+ close(fd);
+ return 0;
+ }
+
+ /* find a free spot */
+ for (i=0;i<max_connections;i++) {
+ if (read(fd,&pid,sizeof(pid)) != sizeof(pid)) break;
+ if (pid == 0 || !process_exists(pid)) break;
+ }
+
+ if (i == max_connections) {
+ unlock_file(fd);
+ close(fd);
+ return 0;
+ }
+
+ pid = getpid();
+
+ if (lseek(fd,i*sizeof(pid),SEEK_SET) != i*sizeof(pid) ||
+ write(fd, &pid,sizeof(pid)) != sizeof(pid)) {
+ unlock_file(fd);
+ close(fd);
+ return 0;
+ }
+
+ unlock_file(fd);
+ close(fd);
+ return 1;
+}