#include <unistd.h>

#include "buffer.h"
#include "byte.h"
#include "case.h"
#include "cdbread.h"
#include "error.h"
#include "exit.h"
#include "fd.h"
#include "open.h"
#include "prot.h"
#include "readclose.h"
#include "scan.h"
#include "stralloc.h"
#include "wait.h"

#include "qlx.h"
#include "spawn.h"

#ifdef USE_CONFIG
  #include "fehsqm-config.h"
#else
  #include "auto_qmail.h"
  #include "auto_uids.h"
#endif

char *aliasempty;

void initialize(int argc, char **argv)
{
  aliasempty = argv[1];
  if (!aliasempty) _exit(100);
}

int truncreport = 3000;

void report(buffer *log, int wstat, char *s, int len)
{
  int i;
  if (wait_crashed(wstat)) {
    buffer_putsflush(log, "Zqmail-lspawn: qmail-local crashed.\n");
    return;
  }

  switch (wait_exitcode(wstat)) {
    case QLX_CDB:     buffer_putsflush(log, "Zqmail-lspawn: Trouble reading users/assign.cdb.\n"); return;
    case QLX_NOMEM:   buffer_putsflush(log, "Zqmail-lspawn: Out of memory.\n"); return;
    case QLX_SYS:     buffer_putsflush(log, "Zqmail-lspawn: Temporary failure.\n"); return;
    case QLX_NOALIAS: buffer_putsflush(log, "Zqmail-lspawn: Unable to find alias user!\n"); return;
    case QLX_ROOT:
      buffer_putsflush(log, "Zqmail-spawn: Not allowed to perform deliveries as root.\n");
      return;
    case QLX_USAGE:    buffer_putsflush(log, "Zqmail-spawn: Internal bug.\n"); return;
    case QLX_NFS:      buffer_putsflush(log, "Zqmail-spawn: NFS failure in qmail-local.\n"); return;
    case QLX_EXECHARD: buffer_putsflush(log, "Dqmail-spawn: Unable to run qmail-local.\n"); return;
    case QLX_EXECSOFT: buffer_putsflush(log, "Zqmail-spawn: Unable to run qmail-local.\n"); return;
    case QLX_EXECPW:   buffer_putsflush(log, "Zqmail-spawn: Unable to run qmail-getpw.\n"); return;
    case 111:
    case 71:
    case 74:
    case 75:           buffer_put(log, "Z", 1); break;
    case 0:            buffer_put(log, "K", 1); break;
    case 100:
    default:           buffer_put(log, "D", 1); break;
  }

  for (i = 0; i < len; ++i)
    if (!s[i]) break;

  buffer_put(log, s, i);
}

stralloc lower = {0};
stralloc nughde = {0};
stralloc wildchars = {0};

static struct cdb c;

static void nughde_get(char *local)
{
  char *(args[3]);
  int pi[2];
  int gpwpid;
  int gpwstat;
  int r;
  int fd;
  int flagwild;

  if (!stralloc_copys(&lower, "!")) _exit(QLX_NOMEM);
  if (!stralloc_cats(&lower, local)) _exit(QLX_NOMEM);
  if (!stralloc_0(&lower)) _exit(QLX_NOMEM);
  case_lowerb(lower.s, lower.len);

  if (!stralloc_copys(&nughde, "")) _exit(QLX_NOMEM);

  fd = open_read("users/assign.cdb");
  if (fd == -1)
    if (errno != ENOENT) _exit(QLX_CDB);

  if (fd != -1) {
    unsigned int i;

    cdb_init(&c, fd);
    r = cdb_find(&c, "", 0);
    if (r != 1) _exit(QLX_CDB);
    if (!stralloc_ready(&wildchars, cdb_datalen(&c))) _exit(QLX_NOMEM);
    wildchars.len = cdb_datalen(&c);
    if (cdb_read(&c, wildchars.s, wildchars.len, cdb_datapos(&c)) == -1) _exit(QLX_CDB);

    i = lower.len;
    flagwild = 0;

    do {
      /* i > 0 */
      if (!flagwild || (i == 1)
          || (byte_chr(wildchars.s, wildchars.len, lower.s[i - 1]) < wildchars.len))
      {
        r = cdb_find(&c, lower.s, i);
        if (r == -1) _exit(QLX_CDB);
        if (r == 1) {
          if (!stralloc_ready(&nughde, cdb_datalen(&c))) _exit(QLX_NOMEM);
          nughde.len = cdb_datalen(&c);
          if (cdb_read(&c, nughde.s, nughde.len, cdb_datapos(&c)) == -1) _exit(QLX_CDB);
          if (flagwild)
            if (!stralloc_cats(&nughde, local + i - 1)) _exit(QLX_NOMEM);
          if (!stralloc_0(&nughde)) _exit(QLX_NOMEM);
          close(fd);
          return;
        }
      }
      --i;
      flagwild = 1;
    } while (i);

    close(fd);
  }

  if (pipe(pi) == -1) _exit(QLX_SYS);

  args[0] = "bin/qmail-getpw";
  args[1] = local;
  args[2] = 0;
  switch (gpwpid = fork()) {
    case -1: _exit(QLX_SYS);
    case 0:
      if (prot_gid(auto_gidn) == -1) _exit(QLX_USAGE);
      if (prot_uid(auto_uidp) == -1) _exit(QLX_USAGE);
      close(pi[0]);
      if (fd_move(1, pi[1]) == -1) _exit(QLX_SYS);
      execv(*args, args);
      _exit(QLX_EXECPW);
  }
  close(pi[1]);

  if (readclose_append(pi[0], &nughde, 128) == -1) _exit(QLX_SYS);

  if (wait_pid(&gpwstat, gpwpid) != -1) {
    if (wait_crashed(gpwstat)) _exit(QLX_SYS);
    if (wait_exitcode(gpwstat) != 0) _exit(wait_exitcode(gpwstat));
  }
}

int spawn(int fdmess, int fdout, const char *s, char *r, const int at)
{
  int f;

  if (!(f = fork())) {
    char *(args[11]);
    unsigned long u;
    int n;
    int uid;
    int gid;
    char *x;
    unsigned int xlen;

    r[at] = 0;
    if (!r[0]) _exit(0); /* <> */

    if (chdir(auto_qmail) == -1) _exit(QLX_USAGE);

    nughde_get(r);

    x = nughde.s;
    xlen = nughde.len;

    args[0] = "bin/qmail-local";
    args[1] = "--";
    args[2] = x;
    n = byte_chr(x, xlen, 0);
    if (n++ == xlen) _exit(QLX_USAGE);
    x += n;
    xlen -= n;

    scan_ulong(x, &u);
    uid = u;
    n = byte_chr(x, xlen, 0);
    if (n++ == xlen) _exit(QLX_USAGE);
    x += n;
    xlen -= n;

    scan_ulong(x, &u);
    gid = u;
    n = byte_chr(x, xlen, 0);
    if (n++ == xlen) _exit(QLX_USAGE);
    x += n;
    xlen -= n;

    args[3] = x;
    n = byte_chr(x, xlen, 0);
    if (n++ == xlen) _exit(QLX_USAGE);
    x += n;
    xlen -= n;

    args[4] = r;
    args[5] = x;
    n = byte_chr(x, xlen, 0);
    if (n++ == xlen) _exit(QLX_USAGE);
    x += n;
    xlen -= n;

    args[6] = x;
    n = byte_chr(x, xlen, 0);
    if (n++ == xlen) _exit(QLX_USAGE);
    x += n;
    xlen -= n;

    args[7] = r + at + 1;
    args[8] = s;
    args[9] = aliasempty;
    args[10] = 0;

    if (fd_move(0, fdmess) == -1) _exit(QLX_SYS);
    if (fd_move(1, fdout) == -1) _exit(QLX_SYS);
    if (fd_copy(2, 1) == -1) _exit(QLX_SYS);
    if (prot_gid(gid) == -1) _exit(QLX_USAGE);
    if (prot_uid(uid) == -1) _exit(QLX_USAGE);
    if (!getuid()) _exit(QLX_ROOT);

    execv(*args, args);
    if (errno) _exit(QLX_EXECSOFT);
    _exit(QLX_EXECHARD);
  }
  return f;
}