Merge branch 'bounce'

6 files changed, 298 insertions, 3 deletions

diff --git a/lib/Makefile.am b/lib/Makefile.am
index 2094f04..dba622d 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -17,6 +17,7 @@ libmisc_a_SOURCES = \
 	itoa.h itoa.cc \
 	makefield.cc makefield.h \
 	netstring.h netstring.cc \
+	forkexec.cc forkexec.h \
 	selfpipe.cc selfpipe.h \
 	setenv.cc setenv.h
 
diff --git a/lib/autoclose.h b/lib/autoclose.h
new file mode 100644
index 0000000..8bd38fd
--- /dev/null
+++ b/lib/autoclose.h
@@ -0,0 +1,68 @@
+#ifndef NULLMAILER_AUTOCLOSE__H__
+#define NULLMAILER_AUTOCLOSE__H__
+
+#include <unistd.h>
+
+// Simple inline wrapper to automatically close an open file descriptor
+class autoclose
+{
+  private:
+  int fd;
+
+  public:
+  inline autoclose(int f = -1) : fd(f) { }
+  inline ~autoclose() { close(); }
+  inline operator int() const { return fd; }
+  inline int operator =(int f)
+  {
+    close();
+    return fd = f;
+  }
+  inline void close()
+  {
+    if (fd >= 0) {
+      ::close(fd);
+      fd = -1;
+    }
+  }
+};
+
+// Simple inline wrapper to handle opening and closing a pipe pair
+class autoclose_pipe
+{
+  private:
+  int fds[2];
+
+  public:
+  inline autoclose_pipe()
+  {
+    fds[0] = fds[1] = -1;
+  }
+  inline ~autoclose_pipe()
+  {
+    close();
+  }
+  inline int operator[](int i) const { return fds[i]; }
+  inline bool open()
+  {
+    return pipe(fds) == 0;
+  }
+  inline void close()
+  {
+    if (fds[0] >= 0) {
+      ::close(fds[0]);
+      ::close(fds[1]);
+      fds[0] = fds[1] = -1;
+    }
+  }
+  // Close one half of the pair, return the other, and mark both as if they were closed.
+  inline int extract(int which)
+  {
+    int result = fds[which];
+    ::close(fds[1-which]);
+    fds[0] = fds[1] = -1;
+    return result;
+  }
+};
+
+#endif // NULLMAILER_AUTOCLOSE__H__
diff --git a/lib/forkexec.cc b/lib/forkexec.cc
new file mode 100644
index 0000000..67a3842
--- /dev/null
+++ b/lib/forkexec.cc
@@ -0,0 +1,171 @@
+// nullmailer -- a simple relay-only MTA
+// Copyright (C) 2016  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 "config.h"
+#include <errno.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include "cli++/cli++.h"
+#include "fdbuf/fdbuf.h"
+#include "mystring/mystring.h"
+#include "defines.h"
+#include "errcodes.h"
+#include "forkexec.h"
+
+#define ERR(MSG) do{ ferr << cli_program << ": " << MSG << ": " << strerror(errno) << endl; } while(0)
+#define FAIL(MSG) do{ ERR(MSG); return false; }while(0)
+
+static int fdnull = -1;
+
+fork_exec::fork_exec(const char* p)
+  : pid(-1), name(p)
+{
+}
+
+fork_exec::~fork_exec()
+{
+  wait();
+}
+
+bool fork_exec::operator!() const
+{
+  return pid < 0;
+}
+
+bool fork_exec::start(const char* args[], int redirn, int redirs[])
+{
+  autoclose_pipe pipes[redirn];
+  for (int i = 0; i < redirn; i++) {
+    if (redirs[i] == REDIRECT_PIPE_TO || redirs[i] == REDIRECT_PIPE_FROM)
+      if (!pipes[i].open())
+        FAIL("Could not create pipe");
+    if (redirs[i] == REDIRECT_NULL)
+      if (fdnull < 0)
+        if ((fdnull = open("/dev/null", O_RDWR)) < 0)
+          FAIL("Could not open \"/dev/null\"");
+  }
+  if ((pid = fork()) < 0)
+    FAIL("Could not fork");
+  if (pid == 0) {
+    // Child process, exec program
+    for (int i = 0; i < redirn; i++) {
+      int r = redirs[i];
+      if (r == REDIRECT_NULL)
+        dup2(fdnull, i);
+      else if (r == REDIRECT_PIPE_FROM) {
+        dup2(pipes[i][1], i);
+        pipes[i].close();
+      }
+      else if (r == REDIRECT_PIPE_TO) {
+        dup2(pipes[i][0], i);
+        pipes[i].close();
+      }
+      else if (r > 0) {
+        dup2(r, i);
+        if (r >= redirn)
+          close(r);
+      }
+    }
+    execv(args[0], (char**)args);
+    ERR("Could not exec " << name);
+    _exit(ERR_EXEC_FAILED);
+  }
+  for (int i = 0; i < redirn; i++) {
+    if (redirs[i] == REDIRECT_PIPE_TO)
+      redirs[i] = pipes[i].extract(1);
+    else if (redirs[i] == REDIRECT_PIPE_FROM)
+      redirs[i] = pipes[i].extract(0);
+  }
+  return true;
+}
+
+bool fork_exec::start(const char* program, int redirn, int redirs[])
+{
+  const char* args[2] = { program, NULL };
+  return start(args, redirn, redirs);
+}
+
+int fork_exec::wait_status()
+{
+  if (pid > 0) {
+    int status;
+    if (waitpid(pid, &status, 0) == pid) {
+      pid = -1;
+      return status;
+    }
+  }
+  return -1;
+}
+
+bool fork_exec::wait()
+{
+  if (pid > 0) {
+    int status = wait_status();
+    if (status < 0)
+      FAIL("Error catching the return value from " << name);
+    if (WIFEXITED(status)) {
+      status = WEXITSTATUS(status);
+      if (status) {
+        ferr << cli_program << ": " << name << " failed: " << status << endl;
+        return false;
+      }
+    }
+    else
+      FAIL(name << " crashed or was killed");
+  }
+  return true;
+}
+
+mystring program_path(const char* basedir, const char* program, const char* envvar)
+{
+  if (envvar) {
+    const char* env;
+    if ((env = getenv(envvar)) != NULL)
+      return env;
+  }
+  mystring path = basedir;
+  path += '/';
+  path += program;
+  return path;
+}
+    
+static const char* nqpath()
+{
+  static mystring cache;
+  if (!cache)
+    cache = program_path(SBIN_DIR, "nullmailer-queue", "NULLMAILER_QUEUE");
+  return cache.c_str();
+}
+
+queue_pipe::queue_pipe()
+  : fork_exec("nullmailer-queue")
+{
+}
+
+int queue_pipe::start()
+{
+  int redirs[] = { REDIRECT_PIPE_TO, REDIRECT_NULL, REDIRECT_NULL };
+  if (!fork_exec::start(nqpath(), 3, redirs))
+    return -1;
+  return redirs[0];
+}
diff --git a/lib/forkexec.h b/lib/forkexec.h
new file mode 100644
index 0000000..8857d93
--- /dev/null
+++ b/lib/forkexec.h
@@ -0,0 +1,41 @@
+#ifndef NULLMAILER__FORK_EXEC__H
+#define NULLMAILER__FORK_EXEC__H
+
+#include <sys/types.h>
+#include <sys/wait.h>
+#include "mystring/mystring.h"
+#include "autoclose.h"
+
+mystring program_path(const char* basedir, const char* name, const char* envvar);
+
+#define REDIRECT_NONE -1
+#define REDIRECT_NULL -2
+#define REDIRECT_PIPE_FROM -3
+#define REDIRECT_PIPE_TO -4
+
+class fork_exec
+{
+ private:
+  pid_t pid;
+  const char* name;
+
+ public:
+  fork_exec(const char*);
+  ~fork_exec();
+  bool operator!() const;
+
+  bool start(const char* args[], int redirn, int redirs[]);
+  bool start(const char* program, int redirn, int redirs[]);
+  bool wait();
+  int wait_status();
+  inline void kill(int sig) { ::kill(pid, sig); }
+};
+
+class queue_pipe : public fork_exec
+{
+  public:
+  queue_pipe();
+  int start();
+};
+
+#endif
diff --git a/lib/makefield.cc b/lib/makefield.cc
index 69b7843..464842e 100644
--- a/lib/makefield.cc
+++ b/lib/makefield.cc
@@ -26,10 +26,11 @@
 #include "itoa.h"
 #include "mystring/mystring.h"
 
-mystring make_date()
+mystring make_date(time_t t)
 {
   char buf[256];
-  time_t t = time(0);
+  if (t == 0)
+    t = time(0);
   struct tm* l = localtime(&t);
   strftime(buf, 256, "%a, %d %b %Y %H:%M:%S ", l);
 #ifdef TM_HAS_GMTOFF
@@ -74,3 +75,15 @@ mystring make_messageid(const mystring& idhost)
   tmp += '>';
   return tmp;
 }
+
+mystring make_boundary()
+{
+  struct timeval tv;
+  gettimeofday(&tv, 0);
+  mystring tmp = itoa(tv.tv_sec);
+  tmp += '.';
+  tmp += itoa(tv.tv_usec, 6);
+  tmp += '.';
+  tmp += itoa(getpid());
+  return tmp;
+}
diff --git a/lib/makefield.h b/lib/makefield.h
index 1ac1169..9686ef2 100644
--- a/lib/makefield.h
+++ b/lib/makefield.h
@@ -1,7 +1,8 @@
 #ifndef NULLMAILER__MAKEFIELD__H__
 #define NULLMAILER__MAKEFIELD__H__
 
-extern mystring make_date();
+extern mystring make_date(time_t t = 0);
 extern mystring make_messageid(const mystring& idhost);
+extern mystring make_boundary();
 
 #endif // NULLMAILER__MAKEFIELD__H__