#include <sys/types.h>
#include <unistd.h>
#include <grp.h>
#include <pwd.h>
#include <ldap.h>
#include "auto_qmail.h"
#include "qmail.h"
#include "case.h"
#include "control.h"
#include "constmap.h"
#include "readwrite.h"
#include "buffer.h"
#include "fd.h"
#include "byte.h"
#include "case.h"
#include "str.h"
#include "stralloc.h"
#include "exit.h"
#include "logmsg.h"
#include "pathexec.h"
#include "getln.h"
#include "scan.h"

#define WHO "qmail-ldapam"

#define LDAP_SCOPE	LDAP_SCOPE_SUBTREE

#define MAIL_ACCOUNT_NAME "mail"
#define MAIL_ACCOUNT_UID 8
#define MAIL_ACCOUNT_GID 12

#define FDAUTH 3
#define FDPWD 5
#define FLAG_DIR "-d"
#define FLAG_MAIL "-m"

#define PORT_LDAP 389
#define PORT_LDAPS 636

char authbuf[BUFSIZE_AUTH];
buffer ba = BUFFER_INIT(write,FDAUTH,authbuf,sizeof(authbuf));
char bspace[512];
buffer bp;

struct constmap mapldapauth;
stralloc ldapcntl = {0};
stralloc disabled = {0};

/* LDAP binding params */

stralloc binddn = {0};
stralloc bindpw = {0};
stralloc bindpwds = {0};
stralloc bindbase = {0};
stralloc bindhost = {0};
stralloc bindmbox = {0};
stralloc filter = {0};

stralloc user = {0}; // user w/o domain appended
stralloc homeparam = {0};

unsigned long port = PORT_LDAP;

void temp_nomem()
{
  logmsg(WHO,110,FATAL,"out of memory");
}

void exit(int fail)
{
  int i;
  for (i = 0; i < sizeof(authbuf); ++i) authbuf[i] = 0;
  _exit(fail);
} 

int match = 0;

void read_passwd(void) 
{
  if (!bindpwds.len) {
    buffer_init(&bp,buffer_unixread,FDPWD,bspace,sizeof(bspace));
    if (getln(&bp,&bindpwds,&match,'\0') == -1)
      logmsg(WHO,111,ERROR,"unable to read password");
    close(5);
    if (match) --bindpwds.len;
  }
}

static int ldap_lookup(char *host,int port,char *user,char *pwd)
{
  char *attrs[] = { NULL }; 
  char *dn = 0;
  LDAP *ld;
  LDAPMessage *res, *entry;
  int r;

  if ((ld = ldap_init(host,port)) == 0) 
    logmsg(WHO,110,ERROR,"Unable to initialise LDAP connection");
  
//  if (starttls)
//    ldap_start_tls_s(LDAP *ld, LDAPControl **serverctrls, LDAPControl **clientctrls);


  r = ldap_simple_bind_s(ld,binddn.s,bindpw.s);
  if (r) logmsg(WHO,110,ERROR,"can't bind with LDAP server");

  r = ldap_search_s(ld,bindbase.s,LDAP_SCOPE,filter.s,attrs,0,&res);
  if (r) logmsg(WHO,1,ERROR,B("search failed:",ldap_err2string(r)));

  entry = ldap_first_entry(ld,res);
  if (!entry) return 1;

  dn = ldap_get_dn(ld,res);
  ldap_msgfree(res);
  r = ldap_simple_bind_s(ld,dn,pwd);
  if (r) return 1;

  ldap_memfree(dn);
  ldap_unbind(ld);

  return 0;
}

static int ldap_userhome(char *host,int port,char *user,char *pwd,char *mbox)
{
  char *attrs[] = { NULL };
  char **values;
  LDAP *ld;
  LDAPMessage *res, *entry;
  int r;
  
  if ((ld = ldap_init(host,port) == 0))
    logmsg(WHO,110,ERROR,"Unable to setup connection");

  r = ldap_simple_bind_s(ld,binddn.s,bindpw.s);
  if (r) logmsg(WHO,110,ERROR,"can't bind to LDAP server");

  r = ldap_search_s(ld,bindbase.s,LDAP_SCOPE,filter.s,attrs,0,&res);
  if (r) logmsg(WHO,1,ERROR,B("search failed: ",ldap_err2string(r)));

  entry = ldap_first_entry(ld,res);
  if (!entry) return 1;

  values = ldap_get_values(ld,entry,mbox);
  if (values && values[0]) {
    if (!stralloc_copys(&homeparam,values[0])) temp_nomem();
    if (!stralloc_cats(&homeparam,"../../")) temp_nomem();
    if (!stralloc_0(&homeparam)) temp_nomem();
  }

  ldap_msgfree(res);
  ldap_unbind(ld);

  return 0;
}

static stralloc cafile = {0};
static stralloc cadir = {0};
static stralloc certfile = {0};
static stralloc keyfile = {0};
static stralloc certpwd = {0};

int main (int argc, char **argv) 
{
  char *authuser = 0;
  char *ldaparam = 0;
  char *domain = 0;
  char *password = 0;
  char *host = 0;
  int authlen = 0;
  int buflen = 0;
  int domlen = 0;
  int flaghome = 0;
  int flagmail = 0;
  int i = 0; 
  int f, h, j, k, p, c, r, t, w;
  int rc;

  if (!argv[1]) logmsg(WHO,100,USAGE,"qmail-ldapam [-d|-m] prog");
  if (!case_diffs(argv[1],FLAG_DIR)) {
    if (!argv[2]) logmsg(WHO,100,USAGE,"qmail-ldapam [-d|-m] prog");
    flaghome = 1;
  } else {
    if (!case_diffs(argv[1],FLAG_MAIL)) {
      if (!argv[2]) logmsg(WHO,100,USAGE,"qmail-ldapam [-d|-m] prog");
      flagmail = 1;
    }
  }

  for (;;) {
    do
      rc = read(FDAUTH,authbuf + buflen,sizeof(authbuf) - buflen);
    while ((rc == -1) && (errno == EINTR));
    if (r == -1) exit(111);
    if (rc == 0) break;
    buflen += rc;
    if (buflen >= sizeof(authbuf)) exit(2);
  }
  close(FDAUTH);

  authuser = authbuf + i;       /* username */
  if (i == buflen) exit(2);
  while (authbuf[i++])          /* password */
    if (i == buflen) exit(2);
  password= authbuf + i;
  if (i == buflen) exit(2);

  authlen = str_len(authuser);
  if (!stralloc_copyb(&user,authuser,authlen)) temp_nomem();

  if ((i = byte_rchr(authuser,authlen,'@')))    /* @domain */
    if (i < authlen && authuser[i] == '@') {
      domain = authuser + i;
      domlen = str_len(domain);
      case_lowerb(domain,domlen);
      user.len = 0;
      if (!stralloc_copyb(&user,authuser,i)) temp_nomem();
    }
  if (!stralloc_0(&user)) exit(111);

  /* Read control file users/ldapauth and go for checks */

  if (chdir(auto_qmail) == -1) exit(110);

  switch (control_readfile(&ldapcntl,"control/ldapauth",0)) {
    case -1: exit(110);
    case  0: if (!constmap_init(&mapldapauth,"",0,1)) temp_nomem();
    case  1: if (!constmap_init(&mapldapauth,ldapcntl.s,ldapcntl.len,1)) temp_nomem();
  }

  /* Check for disabled authuser/domains */

  if (!stralloc_copys(&disabled,"!")) temp_nomem();
  if (!stralloc_catb(&disabled,authuser,authlen)) temp_nomem();
  if (constmap(&mapldapauth,disabled.s,disabled.len)) temp_nomem();

  if (domlen) {
    disabled.len = 0;
    if (!stralloc_copys(&disabled,"!")) temp_nomem();
    if (!stralloc_catb(&disabled,domain,domlen)) temp_nomem();
    if (constmap(&mapldapauth,disabled.s,disabled.len)) temp_nomem();
  }

  if (!ldaparam && domlen)
    ldaparam = constmap(&mapldapauth,domain,domlen);  // 1. ldap server by domain
  if (!ldaparam)
    ldaparam = constmap(&mapldapauth,"*",1);          // 2. one ldap for all

  if (!ldaparam) exit(1);

  /* Evaluate LDAP lookup params:     i       j    h    p    t  c    w   f      h       
                          Host:Bind_DN|Bind_PW|Base|Host;Port|CA|Cert:Pwd|Filter:Homedir */

  if (!stralloc_copys(&bindhost,"localhost")) temp_nomem();      /* Default LDAP host */
  if (!stralloc_copys(&bindmbox,"homeDirectory")) temp_nomem();  /* Default POSIX name*/

  i = str_chr(ldaparam,'|');                                         /* Bind DN */
  if (ldaparam[i] == '|') {
    ldaparam[i] = 0;

    j = str_chr(ldaparam + i,'|');                                   /* Bind PWD */
    if (ldaparam[i + j + 1] == '|') {
      ldaparam[i + j + 1] = 0;

      k = str_chr(ldaparam + i + j + 2,'|');                         /* Base */
      if (ldaparam[i + j + k + 2] == '|') {
        ldaparam[i + j + k + 2] = 0;
        if (!stralloc_copys(&bindbase,ldaparam + i + j + 2)) temp_nomem();

        p = str_chr(ldaparam + i + j + k + 3,';');                  /* Host;Port */
        if (ldaparam[i + j + k + p + 3] == ';') {
          ldaparam[i + j + k + p + 2] = 0;
          if (p > 0) scan_ulong(ldaparam + i + j + k + p + 4,&port);
          if (!stralloc_copys(&bindhost,ldaparam + i + j + k + 3)) temp_nomem();

          t = str_chr(ldaparam + i + j + k + 3,'|');                 /* Trust Cert */
          if (ldaparam[i + j + k + t + 3] == '|') {
            ldaparam[i + j + k + t + 3] = 0;
            if (ldaparam[i + j + k + t + 2] == '/') {
              if (!stralloc_copys(&cadir,ldaparam + i + j + k + t + 3)) temp_nomem();
              if (!stralloc_0(&cadir)) temp_nomem();
            } else {
              if (!stralloc_copys(&cafile,ldaparam + i + j + k + t + 3)) temp_nomem();
              if (!stralloc_0(&cafile)) temp_nomem();
            }

            w = str_chr(ldaparam + i + j + k + t + 4,':');           /* Cert:Pwd */
            if (ldaparam[i + j + k + t + w + 4] == ':') {
              ldaparam[i + j + k + t + w + 4] = 0;
              if (!stralloc_copys(&certfile,ldaparam + i + j + k + t + 4)) temp_nomem();

             f = str_chr(ldaparam + i + j + k + t + w + 5,':');       /* Filter */
             if (ldaparam[i + j + k + t + w + 4] == '|') {
               ldaparam[i + j + k + t + w + 4] = 0;
               if (!stralloc_copys(&certpwd,ldaparam + i + j + k + f + 4)) temp_nomem();

               h = str_chr(ldaparam + i + j + k + 3,'|');          /* Homedir */
               if (ldaparam[i + j + k + h + 3] == '|') {
                 ldaparam[i + j + k + t + 3] = 0;
                 if (!stralloc_copys(&bindmbox,ldaparam + i + j + k + 3)) temp_nomem();
                 if (!stralloc_0(&bindmbox)) temp_nomem();
               }  
                
             } // f
           } // c
         } // t
       } // k
      } // j

      if (!stralloc_copys(&bindpw,ldaparam + i + 1)) temp_nomem();
      if (!stralloc_0(&bindpw)) temp_nomem();
    }  // i
    if (!stralloc_copys(&binddn,ldaparam)) temp_nomem();
    if (!stralloc_0(&binddn)) temp_nomem();
  }	

  if (flagmail) {                                          /* LDAP filter */      
    if (!stralloc_copys(&filter,"(&(mail=")) temp_nomem();
    if (!stralloc_cats(&filter,authuser)) temp_nomem();
    if (!stralloc_cats(&filter,"))")) temp_nomem();
    if (!stralloc_0(&filter)) temp_nomem();
  } else {
    if (!stralloc_copys(&filter,"(&uid=")) temp_nomem();
    if (!stralloc_cat(&filter,&user)) temp_nomem();
    if (!stralloc_cats(&filter,")(dc=")) temp_nomem();
    if (!stralloc_cats(&filter,host)) temp_nomem();
    if (!stralloc_cats(&filter,"))")) temp_nomem();
    if (!stralloc_0(&filter)) temp_nomem();
  }

  if (!str_diff(bindpw.s,"*")) {
    read_passwd();

    for (i = 0; i < bindpwds.len; i++) {
      if (bindpwds.s[i] == ' ') {
        if (!stralloc_copyb(&bindpw,bindpwds.s,i - 1)) temp_nomem();
        if (!stralloc_0(&bindpw)) temp_nomem();
        host = bindhost.s;
	      if (!ldap_lookup(host,port,authuser,password)) break;
        bindpwds.s = bindpwds.s + i;
        ++i;
      }
    }
    logmsg(WHO,110,ERROR,B("can't bind to LDAP host: ",host));
  } else 
   	if (ldap_lookup(host,port,authuser,password))
      logmsg(WHO,110,ERROR,B("can't bind to LDAP host: ",host));

  /* Now we check the user's mailbox for POP3 and IMAP4 capabilities */

  if (flaghome) {
  	if (ldap_userhome(host,port,authuser,password,bindmbox.s)) exit(1);

    if (initgroups(MAIL_ACCOUNT_NAME, MAIL_ACCOUNT_GID)) 
      logmsg(WHO,107,ERROR,B("Unable to set supplementary groups: ",strerror(errno)));
    if (setgid(MAIL_ACCOUNT_GID))
      logmsg(WHO,106,ERROR,B("Unable to set gid: ",strerror(errno)));
    if (setuid(MAIL_ACCOUNT_UID))
      logmsg(WHO,105,ERROR,B("Unable to set uid: ",strerror(errno)));
    if (chdir(homeparam.s)) 
      logmsg(WHO,108,ERROR,B("Unable to change to home dir: ",homeparam.s,strerror(errno)));
  }

  for (i = 0; i < sizeof(authbuf); ++i) authbuf[i] = 0;

  if (flaghome || flagmail) pathexec(argv + 2);
  else pathexec(argv + 1);
  exit(111);
}