// Copyright (C) 1999,2000 Bruce Guenter <bruceg@em.ca>

//

// 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

#include <config.h>

#include <errno.h>

#include <stdlib.h>

#include <unistd.h>

#include <sys/stat.h>

#include "ac/time.h"

#include "ac/wait.h"

#include <signal.h>

#include "fdbuf/fdbuf.h"

#include "cli/cli.h"

#include "vcommand.h"

#include "misc/itoa.h"

#include "misc/stat_fns.h"

#include "misc/exec.h"

const char* cli_program = "vdeliver";

const char* cli_help_prefix = "VMailMgr delivery agent\n";

const char* cli_help_suffix = "";

const char* cli_args_usage = "";

const int cli_args_min = 0;

const int cli_args_max = 0;

static int addufline = false;

static int addrpline = true;

static int adddtline = true;

static int o_quiet = false;

// vdeliver is the unified e-mail message delivery agent for virtual

// domains managed by vmailmgr.

// It is run from the F<.qmail-default> file, and automatically handles

// delivery to any user within a virtual domain.

cli_option cli_options[] = {

  { 'D', 0, cli_option::flag, true, &adddtline,

    "Add a \"Delivered-To:\" line (default)", 0 },

  // Add the C<Return-Path:> line to the top of the message. (default)

  { 'F', 0, cli_option::flag, true, &addufline,

    "Add a \"From \" mailbox line", 0 },

  { 'R', 0, cli_option::flag, true, &addrpline,

    "Add a \"Return-Path:\" line (default)", 0 },

  { 'd', 0, cli_option::flag, false, &adddtline,

    "Do not add the \"Delivered-To:\" line", 0 },

  //Do not add the C<Delivered-To:> line to the top of the message.

  { 'f', 0, cli_option::flag, false, &addufline,

    "Do not add the \"From \" mailbox line (default)", 0 },

  // Do not add the C<From> mailbox line to the top of the message.

  // Note that this line is never added when the message is being

  // re-injected into the mail stream. (default)

  { 0, "quiet", cli_option::flag, true, &o_quiet,

    "Suppress all status messages", 0 },

  { 'r', 0, cli_option::flag, false, &addrpline,

    "Do not add the \"Return-Path:\" line", 0 },

  // Do not add the C<Return-Path:> line to the top of the message.

  {0}

};

// RETURN VALUE

//

// Returns 0 if delivery was successful,

// 100 if a fatal error occurred,

// or 111 if a temporary error occurred.

// ENVIRONMENT

//

// F<vdeliver> expects to be run by F<qmail-local> as it requires several

// of the environment variables that it sets.

// See the I<qmail-command>(8) manual page for full details on these

// variables.

// In particular, it requires C<DTLINE>, C<EXT>, C<HOST>, C<RPLINE>,

// C<SENDER>, C<UFLINE>, and C<USER>.

// SEE ALSO

//

// checkvpw(1), I<qmail-command>(8)

#ifndef HAVE_GETHOSTNAME

int gethostname(char *name, size_t len);

#endif

const char* make_hostname()

{

  static char buf[512];

  gethostname(buf, 511);

  return buf;

}

void exit_msg(const char* msg, int code)

{

  if(!o_quiet)

    fout << "vdeliver: " << msg << endl;

  exit(code);

}

void exit_msg(const char* msg1, const mystring& msg2, int code)

{

  if(!o_quiet)

    fout << "vdeliver: " << msg1 << msg2 << endl;

  exit(code);

}

void die_fail(const char* msg) { exit_msg(msg, 100); }

void die_temp(const char* msg) { exit_msg(msg, 111); }

void fail_quota()

{

  die_fail("Delivery failed due to system quota violation");

}

mystring read_me()

{

  static mystring me;

  static mystring mefilename = config->qmail_root() + "control/me";

  if(!me) {

    fdibuf in(mefilename.c_str());

    if(in)

      in.getline(me);

  }

  if(!me)

    die_temp("control/me is empty!");

  return me;

}

char* ufline;

char* rpline;

char* dtline;

bool dump(fdobuf& out, bool dosync)

{

  if((ufline && !out.write(ufline, strlen(ufline))) ||

     (rpline && !out.write(rpline, strlen(rpline))) ||

     (dtline && !out.write(dtline, strlen(dtline))) ||

     !fin.rewind() ||

     !fdbuf_copy(fin, out)) {

    out.close();

    return false;

  }

  if(dosync && !out.sync())

    return false;

  if(!out.close())

    return false;

  return true;

}

static mystring partname;

static mystring maildir;

void deliver_partial()

{

  const mystring newdir = maildir + "/new";

  const mystring tmpdir = maildir + "/tmp";

  if(!is_dir(tmpdir.c_str()) || !is_dir(newdir.c_str()))

    die_temp("Destination directory does not appear to be a maildir.");

  const mystring hostname = make_hostname();

  pid_t pid = getpid();

  for(;; sleep(2)) {

    partname = "/" + mystring(itoa(time(0))) + "." + itoa(pid)

      + "." + hostname;

    mystring newfile = newdir + partname;

    mystring tmpfile = tmpdir + partname;

    if(is_exist(tmpfile.c_str()))

      continue;

    else {

      fdobuf out(tmpfile.c_str(), fdobuf::create | fdobuf::excl, 0600);

      if(!out) {

#ifdef EDQUOT

	if(out.error_number() == EDQUOT)

	  fail_quota();

#endif

	continue;

      }

      if(!dump(out, true)) {

#ifdef EDQUOT

	if(out.error_number() == EDQUOT)

	  fail_quota();

#endif

	die_temp("Error writing the output file.");

      }

      return;

    }

  }

}

void deliver_fail(const char* msg)

{

  mystring tmpfile = maildir + "/tmp/" + partname;

  unlink(tmpfile.c_str());

  die_temp(msg);

}

void deliver_final()

{

  mystring tmpfile = maildir + "/tmp/" + partname;

  mystring newfile = maildir + "/new/" + partname;

  if(link(tmpfile.c_str(), newfile.c_str()))

    deliver_fail("Error linking the temp file to the new file.");

  if(unlink(tmpfile.c_str()))

    deliver_fail("Error unlinking the temp file.");

}

void write_envelope(fdobuf& out,

		    mystring sender, mystring recipient, mystring host)

{

  out << 'F' << sender << '\0';

  for(mystring_iter iter = recipient; iter; ++iter) {

    mystring r = *iter;

    int at = r.find_first('@');

    out << 'T' << r;

    // If the address has no '@', add the virtual domain

    if(at < 0)

      out << '@' << host;

    // If it has an '@', but no domain, add the local domain

    else if((unsigned)at == r.length()-1)

      out << read_me();

    // Else, nothing to add, address already copied

    out << '\0';

  }

  out << '\0';

}

void inject(mystring sender, mystring recip, mystring host)

{

  int pipe1[2];

  int pipe2[2];

  if(pipe(pipe1) || pipe(pipe2))

    deliver_fail("System call to 'pipe' failed.");

  mystring qq = config->qmail_root() + "bin/qmail-queue";

  pid_t pid;

  switch(pid = fork()) {

  case -1:

    deliver_fail("System call to 'fork' failed.");

  case 0:

    close(pipe1[1]);

    close(pipe2[1]);

    if((dup2(pipe1[0], 0) != 0) || (dup2(pipe2[0], 1) != 1))

      exit(111);

    execl(qq.c_str(), qq.c_str(), 0);

    die_temp("Exec of qmail-queue failed.");

  default:

    close(pipe1[0]);

    close(pipe2[0]);

    signal(SIGPIPE, SIG_IGN);

    ufline = 0;

    rpline = 0;

    fdobuf out(pipe1[1], true);

    if(!dump(out, false))

      deliver_fail("Error writing to pipe");

    fdobuf env(pipe2[1], true);

    write_envelope(env, sender, recip, host);

    if(!env.flush() || !env.close())

      deliver_fail("Error sending envelope to pipe");

    int status;

    if(waitpid(pid, &status, WUNTRACED) != pid)

      deliver_fail("System call to 'waitpid' failed.");

    if(!WIFEXITED(status))

      deliver_fail("qmail-queue crashed!");

    if(WEXITSTATUS(status))

      deliver_fail("qmail-queue exited with an error!");

  }

}

void enqueue(mystring recipient, mystring host, mystring sender)

{

  int f = sender.find_first('@');

  if(f > 0) {

    presetenv("QMAILUSER=", sender.left(f));

    presetenv("QMAILHOST=", sender.right(f+1));

  }

  inject(sender, recipient, host);

}

int cli_main(int, char*[])

{

  if(!go_home())

    return 1;

#define ENV_VAR(VAR,ENV) const char* tmp__##VAR = getenv(#ENV); if(!tmp__##VAR) die_fail(#ENV " is not set"); mystring VAR = tmp__##VAR;

  ENV_VAR(user, USER);

  ENV_VAR(ext, EXT);

  ENV_VAR(host, HOST);

  ENV_VAR(sender, SENDER);

#undef ENV_VAR

#define ENV_VAR(VAR,ENV) VAR = getenv(#ENV); if(!VAR) die_fail(#ENV " is not set");

  ENV_VAR(ufline, UFLINE);

  ENV_VAR(rpline, RPLINE);

  ENV_VAR(dtline, DTLINE);

#undef ENV_VAR

  if(!addufline)

    ufline = 0;

  if(!addrpline)

    rpline = 0;

  if(!adddtline)

    dtline = 0;

  vpwentry* vpw = domain.lookup(ext, false);

  if(!vpw)

    die_fail(mystring("Invalid or unknown virtual user '" + ext + "'").c_str());

  if(vpw->expiry < (unsigned)time(0))

    die_fail(mystring("Virtual user '" + ext + "' has expired").c_str());

  vpw->export_env();

  bool enabled = vpw->is_mailbox_enabled && !!vpw->mailbox;

  int r = execute("vdeliver-predeliver");

  if(r)

    exit_msg("Execution of vdeliver-predeliver failed", r);

  if(enabled) {

    maildir = vpw->mailbox;

    deliver_partial();

  }

  if(!!vpw->forwards)

    enqueue(vpw->forwards, host, sender);

  if(enabled)

    deliver_final();

  if(!fin.rewind()) {

    if(!o_quiet)

      fout << "Could not re-rewind standard input" << endl;

  }

  else if(execute("vdeliver-postdeliver"))

    if(!o_quiet)

      fout << "Execution of vdeliver-postdeliver failed" << endl;

  return 0;

}