- djm@cvs.openbsd.org 2007/06/14 22:48:05

     [ssh.c]
     when waiting for the multiplex exit status, read until the master end
     writes an entire int of data *and* closes the client_fd; fixes mux
     regression spotted by dtucker, ok dtucker@

diff --git a/ChangeLog b/ChangeLog
index 22a60b8529dd47cf660183f6bbb81ee25798c0eb..0c08d6548f627f82cb7c1ce50d38737d1d20deae 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -6,6 +6,11 @@
    - djm@cvs.openbsd.org 2007/06/14 21:43:25
      [ssh.c]
      handle EINTR when waiting for mux exit status properly
+   - djm@cvs.openbsd.org 2007/06/14 22:48:05
+     [ssh.c]
+     when waiting for the multiplex exit status, read until the master end
+     writes an entire int of data *and* closes the client_fd; fixes mux
+     regression spotted by dtucker, ok dtucker@
 
 20070612
  - (dtucker) OpenBSD CVS Sync

diff --git a/ssh.c b/ssh.c
index 446184ca18c452edf6402f31f172cc33e886101c..4393289554fe6550e6669019e84fe7b068f9943e 100644 (file)
--- a/ssh.c
+++ b/ssh.c
@@ -1307,7 +1307,7 @@ static void
 control_client(const char *path)
 {
        struct sockaddr_un addr;
-       int i, r, fd, sock, exitval, num_env, addr_len;
+       int i, r, fd, sock, exitval[2], num_env, addr_len;
        Buffer m;
        char *term;
        extern char **environ;
@@ -1456,10 +1456,16 @@ control_client(const char *path)
        if (tty_flag)
                enter_raw_mode();
 
-       /* Stick around until the controlee closes the client_fd */
-       exitval = 0;
+       /*
+        * Stick around until the controlee closes the client_fd.
+        * Before it does, it is expected to write this process' exit
+        * value (one int). This process must read the value and wait for
+        * the closure of the client_fd; if this one closes early, the 
+        * multiplex master will terminate early too (possibly losing data).
+        */
+       exitval[0] = 0;
        for (i = 0; !control_client_terminate && i < (int)sizeof(exitval);) {
-               r = read(sock, (char *)&exitval + i, sizeof(exitval) - i);
+               r = read(sock, (char *)exitval + i, sizeof(exitval) - i);
                if (r == 0) {
                        debug2("Received EOF from master");
                        break;
@@ -1471,20 +1477,23 @@ control_client(const char *path)
                }
                i += r;
        }
+
        close(sock);
        leave_raw_mode();
-
+       if (i > (int)sizeof(int))
+               fatal("%s: master returned too much data (%d > %lu)",
+                   __func__, i, sizeof(int));
        if (control_client_terminate) {
                debug2("Exiting on signal %d", control_client_terminate);
-               exitval = 255;
-       } else if (i < (int)sizeof(exitval)) {
+               exitval[0] = 255;
+       } else if (i < (int)sizeof(int)) {
                debug2("Control master terminated unexpectedly");
-               exitval = 255;
+               exitval[0] = 255;
        } else
-               debug2("Received exit status from master %d", exitval);
+               debug2("Received exit status from master %d", exitval[0]);
 
        if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
-               fprintf(stderr, "Connection to master closed.\r\n");
+               fprintf(stderr, "Shared connection to %s closed.\r\n", host);
 
-       exit(exitval);
+       exit(exitval[0]);
 }