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// 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];
}
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