#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "sig.h"
#include "exit.h"
#include "open.h"
#include "seek.h"
#include "fmt.h"
#include "alloc.h"
#include "buffer.h"
#include "datetime.h"
#include "now.h"
#include "triggerpull.h"
#include "extra.h"
#include "auto_qmail.h"
#include "auto_uids.h"
#include "date822fmt.h"
#include "fmtqfn.h"
#include "env.h"
#include "wait.h"
#include "scan.h"

#define DEATH 86400 /* 24 hours; _must_ be below q-s's OSSIFIED (36 hours) */
#define ADDR 1003

char inbuf[2048];
struct buffer bi;
char outbuf[256];
struct buffer bo;

datetime_sec starttime;
struct datetime dt;
unsigned long mypid;
unsigned long uid;
char *pidfn;
struct stat pidst;
unsigned long messnum;
char *messfn;
char *todofn;
char *intdfn;
int messfd;
int intdfd;
int flagmademess = 0;
int flagmadeintd = 0;

void cleanup()
{
  if (flagmadeintd) {
   seek_trunc(intdfd,0);
   if (unlink(intdfn) == -1) return;
  }
  if (flagmademess) {
    seek_trunc(messfd,0);
    if (unlink(messfn) == -1) return;
  }
}

void die(int e) { _exit(e); }
void die_qhpsi() { cleanup(); die(71); }
void die_write() { cleanup(); die(53); }
void die_read() { cleanup(); die(54); }
void sigalrm() { /* thou shalt not clean up here */ die(52); }
void sigbug() { die(81); }

unsigned int receivedlen;
char *received;
/* "Received: (qmail-queue invoked by alias); 26 Sep 1995 04:46:54 -0000\n" */

static unsigned int receivedfmt(char *s)
{
  unsigned int i;
  unsigned int len;
  len = 0;

  i = fmt_str(s,"Received: (qmail "); len += i; if (s) s += i;
  i = fmt_ulong(s,mypid); len += i; if (s) s += i;
  i = fmt_str(s," invoked "); len += i; if (s) s += i;
  if (uid == auto_uida) { 
    i = fmt_str(s,"by alias"); len += i; if (s) s += i; 
  } else if (uid == auto_uidd) { 
    i = fmt_str(s,"from network"); len += i; if (s) s += i; 
  } else if (uid == auto_uids) { 
    i = fmt_str(s,"for bounce"); len += i; if (s) s += i; 
  } else {
    i = fmt_str(s,"by uid "); len += i; if (s) s += i;
    i = fmt_ulong(s,uid); len += i; if (s) s += i;
  }
  i = fmt_str(s,"); "); len += i; if (s) s += i;
  i = date822fmt(s,&dt); len += i; if (s) s += i;
  return len;
}

void received_setup()
{
  receivedlen = receivedfmt((char *) 0);
  received = alloc(receivedlen + 1);
  if (!received) die(51);
  receivedfmt(received);
}

unsigned int pidfmt(char *s,unsigned long seq)
{
  unsigned int i;
  unsigned int len;

  len = 0;
  i = fmt_str(s,"pid/"); len += i; if (s) s += i;
  i = fmt_ulong(s,mypid); len += i; if (s) s += i;
  i = fmt_str(s,"."); len += i; if (s) s += i;
  i = fmt_ulong(s,starttime); len += i; if (s) s += i;
  i = fmt_str(s,"."); len += i; if (s) s += i;
  i = fmt_ulong(s,seq); len += i; if (s) s += i;
  ++len; if (s) *s++ = 0;

  return len;
}

char *fnnum(char *dirslash,int flagsplit)
{
  char *s;

  s = alloc(fmtqfn((char *) 0,dirslash,messnum,flagsplit));
  if (!s) die(51);
  fmtqfn(s,dirslash,messnum,flagsplit);
  return s;
}

void pidopen(void)
{
  unsigned int len;
  unsigned long seq;

  seq = 1;
  len = pidfmt((char *) 0,seq);
  pidfn = alloc(len);
  if (!pidfn) die(51);

  for (seq = 1; seq < 10; ++seq) {
    if (pidfmt((char *) 0,seq) > len) die(81); /* paranoia */
    pidfmt(pidfn,seq);
    messfd = open_excl(pidfn);
    if (messfd != -1) return;
  }

 die(63);
}

char *qhpsi;

void qhpsiprog(char *arg)
{
  int wstat;
  int child;
  char *qhpsiargs[6] = { 0, 0, 0, 0, 0, 0 };
  char *x;
  unsigned long u; 
  int childrc; 
  int qhpsirc = 1;
  unsigned int size;
  unsigned int qhpsiminsize = 0;
  unsigned int qhpsimaxsize = 0;

  struct stat st;

  if (stat(messfn,&st) == -1) die(63);
  size = (unsigned int) st.st_size;

  x = env_get("QHPSIMINSIZE");
  if (x) { scan_ulong(x,&u); qhpsiminsize = (int) u; }
  if (qhpsiminsize) if (size < qhpsiminsize) return;
  x = env_get("QHPSIMAXSIZE");
  if (x) { scan_ulong(x,&u); qhpsimaxsize = (int) u; }
  if (qhpsimaxsize) if (size > qhpsimaxsize) return; 

  if (*arg) {
    switch (child = fork()) {
      case -1:
        die_qhpsi();
      case 0:
        qhpsiargs[0] = arg; 
        qhpsiargs[1] = messfn;
        qhpsiargs[2] = env_get("QHPSIARG1");
        if (!qhpsiargs[2]) qhpsiargs[2] = 0; 
        qhpsiargs[3] = env_get("QHPSIARG2");
        if (!qhpsiargs[3]) qhpsiargs[3] = 0; 
        qhpsiargs[4] = env_get("QHPSIARG3");
        if (!qhpsiargs[4]) qhpsiargs[4] = 0; 
        x = env_get("QHPSIRC");
        if (x) { scan_ulong(x,&u); qhpsirc = (int) u; }
        execvp(*qhpsiargs,qhpsiargs);
        die_qhpsi();
    }
    if (wait_pid(&wstat,child) == -1) die_qhpsi();
    if (wait_crashed(wstat)) die_qhpsi();
    childrc = wait_exitcode(wstat); 
    if (childrc == qhpsirc) { cleanup(); die(32); }
    else if (childrc != 0) die_qhpsi(); 
  }
}

char tmp[FMT_ULONG];

int main()
{
  unsigned int len;
  char ch;
  int fd;

  sig_blocknone();
  umask(033);
  if (chdir(auto_qmail) == -1) die(61);
  if (chdir("queue") == -1) die(62);

  mypid = getpid();
  uid = getuid();
  starttime = now();
  datetime_tai(&dt,starttime);
  qhpsi = env_get("QHPSI");

  received_setup();

  sig_pipeignore();
  sig_miscignore();
  sig_alarmcatch(sigalrm);
  sig_bugcatch(sigbug);

  alarm(DEATH);

  pidopen();
  if (fstat(messfd,&pidst) == -1) die(63);

  messnum = pidst.st_ino;
  messfn = fnnum("mess/",1);
  todofn = fnnum("todo/",1);
  intdfn = fnnum("intd/",1);

  if (link(pidfn,messfn) == -1) die(64);
  if (unlink(pidfn) == -1) die(63);
  flagmademess = 1;

  buffer_init(&bo,write,messfd,outbuf,sizeof(outbuf));
  buffer_init(&bi,read,0,inbuf,sizeof(inbuf));

  if (buffer_put(&bo,received,receivedlen) == -1) die_write();

  switch (buffer_copy(&bo,&bi)) {
    case -2: die_read();
    case -3: die_write();
  }
  if (buffer_flush(&bo) == -1) die_write();
  if (fsync(messfd) == -1) die_write();

  intdfd = open_excl(intdfn);
  if (intdfd == -1) die(65);
  flagmadeintd = 1;

  buffer_init(&bo,write,intdfd,outbuf,sizeof(outbuf));
  buffer_init(&bi,read,1,inbuf,sizeof(inbuf));

  if (buffer_put(&bo,"u",1) == -1) die_write();
  if (buffer_put(&bo,tmp,fmt_ulong(tmp,uid)) == -1) die_write();
  if (buffer_put(&bo,"",1) == -1) die_write();

  if (buffer_put(&bo,"p",1) == -1) die_write();
  if (buffer_put(&bo,tmp,fmt_ulong(tmp,mypid)) == -1) die_write();
  if (buffer_put(&bo,"",1) == -1) die_write();

  if (buffer_get(&bi,&ch,1) < 1) die_read();
  if (ch != 'F') die(91);
  if (buffer_put(&bo,&ch,1) == -1) die_write();
  for (len = 0; len < ADDR; ++len) {
    if (buffer_get(&bi,&ch,1) < 1) die_read();
    if (buffer_put(&bo,&ch,1) == -1) die_write();
    if (!ch) break;
  }
  if (len >= ADDR) die(11);

  if (buffer_put(&bo,QUEUE_EXTRA,QUEUE_EXTRALEN) == -1) die_write();

  for (;;) {
    if (buffer_get(&bi,&ch,1) < 1) die_read();
    if (!ch) break;
    if (ch == 'Q') { qhpsi = 0; break; }
    if (ch != 'T') die(91);
    if (buffer_put(&bo,&ch,1) == -1) die_write();
    for (len = 0; len < ADDR; ++len) {
      if (buffer_get(&bi,&ch,1) < 1) die_read();
      if (buffer_put(&bo,&ch,1) == -1) die_write();
      if (!ch) break;
    }
    if (len >= ADDR) die(11);
  }

  if (qhpsi) qhpsiprog(qhpsi);

  if (buffer_flush(&bo) == -1) die_write();
  if (fsync(intdfd) == -1) die_write();

  if (link(intdfn,todofn) == -1) die(66);
  if ((fd = open(todofn,O_RDONLY)) < 0 || fsync(fd) < 0 || close(fd)) die(66);

  triggerpull();
  die(0);
}