Added a send timeout in nullmailer-send, to kill sending messages that

stall.

3 files changed, 118 insertions, 0 deletions

diff --git a/lib/Makefile.am b/lib/Makefile.am
index d39807a..102d9e5 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -16,6 +16,7 @@ libmisc_a_SOURCES = \
 	itoa.h itoa.cc \
 	makefield.cc \
 	netstring.h netstring.cc \
+	selfpipe.cc selfpipe.h \
 	setenv.cc setenv.h
 
 libnullmailer_a_SOURCES =
diff --git a/lib/selfpipe.cc b/lib/selfpipe.cc
new file mode 100644
index 0000000..e8e9cc1
--- /dev/null
+++ b/lib/selfpipe.cc
@@ -0,0 +1,101 @@
+// nullmailer -- a simple relay-only MTA
+// Copyright (C) 2007  Bruce Guenter <bruce@untroubled.org>
+//
+// 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+// You can contact me at <bruce@untroubled.org>.  There is also a mailing list
+// available to discuss this package.  To subscribe, send an email to
+// <nullmailer-subscribe@lists.untroubled.org>.
+
+#include <sys/types.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <unistd.h>
+#include "selfpipe.h"
+
+static int fds[2] = { -1, -1 };
+
+static int fcntl_fl_on(int fd, int flag)
+{
+  int flags;
+  int newflags;
+  if ((flags = fcntl(fd, F_GETFL, 0)) == -1)
+    return 0;
+  if ((newflags = flags | flag) != flags)
+    if (fcntl(fd, F_SETFL, newflags))
+      return 0;
+  return 1;
+}
+
+selfpipe::selfpipe()
+{
+  if (fds[0] < 0) {
+    if (pipe(fds) != -1) {
+      if (fcntl_fl_on(fds[0], O_NONBLOCK)
+	  && fcntl_fl_on(fds[1], O_NONBLOCK)
+	  && fcntl_fl_on(fds[1], FD_CLOEXEC)
+	  && fcntl_fl_on(fds[1], FD_CLOEXEC))
+	return;
+
+      close(fds[0]);
+      close(fds[1]);
+    }
+    fds[0] = fds[1] = -1;
+  }
+}
+
+selfpipe::operator bool() const
+{
+  return fds[0] >= 0;
+}
+
+static void catcher(int sig)
+{
+  signal(sig, catcher);
+  write(fds[1], &sig, sizeof sig);
+}
+
+void selfpipe::catchsig(int sig)
+{
+  signal(sig, catcher);
+}
+
+int selfpipe::caught()
+{
+  int buf;
+  if (read(fds[0], &buf, sizeof buf) == sizeof buf)
+    return buf;
+  return 0;
+}
+
+int selfpipe::waitsig(int timeout)
+{
+  fd_set fdset;
+  FD_ZERO(&fdset);
+  FD_SET(fds[0], &fdset);
+  struct timeval tv;
+  tv.tv_sec = timeout;
+  tv.tv_usec = 0;
+  int s;
+  while ((s = select(fds[0] + 1, &fdset, 0, 0,
+		     (timeout <= 0) ? 0 : &tv)) == -1) {
+    if (errno != EINTR)
+      return -1;
+  }
+  if (s == 1)
+    return caught();
+  return 0;
+}
diff --git a/lib/selfpipe.h b/lib/selfpipe.h
new file mode 100644
index 0000000..1ad2136
--- /dev/null
+++ b/lib/selfpipe.h
@@ -0,0 +1,16 @@
+#ifndef NULLMAILER_SELFPIPE__H__
+#define NULLMAILER_SELFPIPE__H__
+
+class selfpipe
+{
+ public:
+  selfpipe();
+
+  operator bool() const;
+
+  void catchsig(int sig);
+  int caught();
+  int waitsig(int timeout = 0);
+};
+
+#endif // NULLMAILER_SELFPIPE__H__