env_unix.c

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  return pw_login (getpwnam (ANONYMOUSUSER),NIL,NIL,
		   (char *) mail_parameters (NIL,GET_ANONYMOUSHOME,NIL),
		   argc,argv);
}

/* Finish log in and environment initialization
 * Accepts: passwd struct for loginpw()
 *	    optional authentication user name
 *	    user name (NIL for anonymous)
 *	    home directory (NIL to use directory from passwd struct)
 *	    argument count
 *	    argument vector
 * Returns: T if successful, NIL if error
 */

long pw_login (struct passwd *pw,char *auser,char *user,char *home,int argc,
	       char *argv[])
{
  struct group *gr;
  char **t;
  long ret = NIL;
  if (pw && pw->pw_uid) {	/* must have passwd struct for non-UID 0 */
				/* make safe copies of user and home */
    if (user) user = cpystr (pw->pw_name);
    home = cpystr (home ? home : pw->pw_dir);
				/* authorization ID .NE. authentication ID? */
    if (user && auser && *auser && compare_cstring (auser,user)) {
				/* scan list of mail administrators */
      if ((gr = getgrnam (ADMINGROUP)) && (t = gr->gr_mem)) while (*t && !ret)
	if (!compare_cstring (auser,*t++))
	  ret = pw_login (pw,NIL,user,home,argc,argv);
      syslog (LOG_NOTICE|LOG_AUTH,"%s %.80s override of user=%.80s host=%.80s",
	      ret ? "Admin" : "Failed",auser,user,tcp_clienthost ());
    }
    else if (closedBox) {	/* paranoid site, lock out other directories */
      if (chdir (home) || chroot (home))
	syslog (LOG_NOTICE|LOG_AUTH,
		"Login %s failed: unable to set chroot=%.80s host=%.80s",
		pw->pw_name,home,tcp_clienthost ());
      else if (loginpw (pw,argc,argv)) ret = env_init (user,NIL);
      else fatal ("Login failed after chroot");
    }
				/* normal login */
    else if (((pw->pw_uid == geteuid ()) || loginpw (pw,argc,argv)) &&
	     (ret = env_init (user,home))) chdir (myhomedir ());
    fs_give ((void **) &home);	/* clean up */
    if (user) fs_give ((void **) &user);
  }
  endpwent ();			/* in case shadow passwords in pw data */
  return ret;			/* return status */
}

/* Initialize environment
 * Accepts: user name (NIL for anonymous)
 *	    home directory name
 * Returns: T, always
 */

long env_init (char *user,char *home)
{
  extern MAILSTREAM CREATEPROTO;
  extern MAILSTREAM EMPTYPROTO;
  struct passwd *pw;
  struct stat sbuf;
  char tmp[MAILTMPLEN];
				/* don't init if blocked */
  if (block_env_init) return LONGT;
  if (myUserName) fatal ("env_init called twice!");
				/* initially nothing in namespace list */
  nslist[0] = nslist[1] = nslist[2] = NIL;
				/* myUserName must be set before dorc() call */
  myUserName = cpystr (user ? user : ANONYMOUSUSER);
				/* force default prototypes to be set */
  if (!createProto) createProto = &CREATEPROTO;
  if (!appendProto) appendProto = &EMPTYPROTO;
  dorc (NIL,NIL);		/* do systemwide configuration */
  if (!home) {			/* closed box server */
				/* standard user can only reference home */
    if (user) nslist[0] = &nshome;
    else {			/* anonymous user */
      nslist[0] = &nsblackother; /* set root */
      anonymous = T;		/* flag as anonymous */
    }
    myHomeDir = cpystr ("");	/* home directory is root */
    sysInbox = cpystr ("INBOX");/* make system INBOX */
  }
  else {			/* open or black box */
    closedBox = NIL;		/* definitely not a closed box */
    if (user) {			/* remember user name and home directory */
      if (blackBoxDir) {	/* build black box directory name */
	sprintf (tmp,"%s/%s",blackBoxDir,myUserName);
				/* must exist */
	if (!((!stat (home = tmp,&sbuf) && (sbuf.st_mode & S_IFDIR)) ||
	      (blackBoxDefaultHome &&
	       !stat (home = blackBoxDefaultHome,&sbuf) &&
	       (sbuf.st_mode & S_IFDIR)))) fatal ("no home");
	sysInbox = (char *) fs_get (strlen (home) + 7);
				/* set system INBOX */
	sprintf (sysInbox,"%s/INBOX",home);
	blackBox = T;		/* mark that it's a black box */
				/* mbox meaningless if black box */
	mail_parameters (NIL,DISABLE_DRIVER,(void *) "mbox");
      }
      nslist[0] = &nshome;	/* home namespace */
				/* limited advertise namespaces */
      if (limitedadvertise) nslist[2] = &nslimited;
      else if (blackBox) {	/* black box namespaces */
	nslist[1] = &nsblackother;
	nslist[2] = &nsshared;
      }
      else {			/* open box namespaces */
	nslist[1] = &nsunixother;
	nslist[2] = advertisetheworld ? &nsworld : &nsshared;
      }
    }
    else {
      nslist[2] = &nsftp;	/* anonymous user */
      sprintf (tmp,"%s/INBOX",
	       home = (char *) mail_parameters (NIL,GET_ANONYMOUSHOME,NIL));
      sysInbox = cpystr (tmp);	/* make system INBOX */
      anonymous = T;		/* flag as anonymous */
    }
    myHomeDir = cpystr (home);	/* set home directory */
  }

  if (allowuserconfig) {	/* allow user config files */
    dorc (strcat (strcpy (tmp,myHomeDir),"/.mminit"),T);
    dorc (strcat (strcpy (tmp,myHomeDir),"/.imaprc"),NIL);
  }
  if (!closedBox && !noautomaticsharedns) {
				/* #ftp namespace */
    if (!ftpHome && (pw = getpwnam ("ftp"))) ftpHome = cpystr (pw->pw_dir);
				/* #public namespace */
    if (!publicHome && (pw = getpwnam ("imappublic")))
      publicHome = cpystr (pw->pw_dir);
				/* #shared namespace */
    if (!anonymous && !sharedHome && (pw = getpwnam ("imapshared")))
      sharedHome = cpystr (pw->pw_dir);
  }
  if (!myLocalHost) mylocalhost ();
  if (!myNewsrc) myNewsrc = cpystr(strcat (strcpy (tmp,myHomeDir),"/.newsrc"));
  if (!newsActive) newsActive = cpystr (ACTIVEFILE);
  if (!newsSpool) newsSpool = cpystr (NEWSSPOOL);
				/* re-do open action to get flags */
  (*createProto->dtb->open) (NIL);
  endpwent ();			/* close pw database */
  return T;
}
 
/* Return my user name
 * Accepts: pointer to optional flags
 * Returns: my user name
 */

char *myusername_full (unsigned long *flags)
{
  struct passwd *pw;
  struct stat sbuf;
  char *s;
  unsigned long euid;
  char *ret = UNLOGGEDUSER;
				/* no user name yet and not root? */
  if (!myUserName && (euid = geteuid ())) {
				/* yes, look up getlogin() user name or EUID */
    if (((s = (char *) getlogin ()) && *s && (strlen (s) < NETMAXUSER) &&
	 (pw = getpwnam (s)) && (pw->pw_uid == euid)) ||
	(pw = getpwuid (euid))) {
      if (block_env_init) {	/* don't env_init if blocked */
	if (flags) *flags = MU_LOGGEDIN;
	return pw->pw_name;
      }
      env_init (pw->pw_name,
		((s = getenv ("HOME")) && *s && (strlen (s) < NETMAXMBX) &&
		 !stat (s,&sbuf) && ((sbuf.st_mode & S_IFMT) == S_IFDIR)) ?
		s : pw->pw_dir);
    }
    else fatal ("Unable to look up user name");
  }
  if (myUserName) {		/* logged in? */
    if (flags) *flags = anonymous ? MU_ANONYMOUS : MU_LOGGEDIN;
    ret = myUserName;		/* return user name */
  }
  else if (flags) *flags = MU_NOTLOGGEDIN;
  return ret;
}


/* Return my local host name
 * Returns: my local host name
 */

char *mylocalhost ()
{
  if (!myLocalHost) {
    char *s,tmp[MAILTMPLEN];
    char *t = "unknown";
    tmp[0] = tmp[MAILTMPLEN-1] = '\0';
    if (!gethostname (tmp,MAILTMPLEN-1) && tmp[0]) {
				/* sanity check of name */
      for (s = tmp; (*s > 0x20) && (*s < 0x7f); ++s);
      if (!*s) t = tcp_canonical (tmp);
    }
    myLocalHost = cpystr (t);
  }
  return myLocalHost;
}

/* Return my home directory name
 * Returns: my home directory name
 */

char *myhomedir ()
{
  if (!myHomeDir) myusername ();/* initialize if first time */
  return myHomeDir ? myHomeDir : "";
}


/* Return my home mailbox name
 * Returns: my home directory name
 */

static char *mymailboxdir ()
{
  char *home = myhomedir ();
				/* initialize if first time */
  if (!myMailboxDir && myHomeDir) {
    if (mailsubdir) {
      char tmp[MAILTMPLEN];
      sprintf (tmp,"%s/%s",home,mailsubdir);
      myMailboxDir = cpystr (tmp);/* use pre-defined subdirectory of home */
    }
    else myMailboxDir = cpystr (home);
  }
  return myMailboxDir ? myMailboxDir : "";
}


/* Return system standard INBOX
 * Accepts: buffer string
 */

char *sysinbox ()
{
  char tmp[MAILTMPLEN];
  if (!sysInbox) {		/* initialize if first time */
    sprintf (tmp,"%s/%s",MAILSPOOL,myusername ());
    sysInbox = cpystr (tmp);	/* system inbox is from mail spool */
  }
  return sysInbox;
}

/* Return mailbox directory name
 * Accepts: destination buffer
 *	    directory prefix
 *	    name in directory
 * Returns: file name or NIL if error
 */

char *mailboxdir (char *dst,char *dir,char *name)
{
  char tmp[MAILTMPLEN];
  if (dir || name) {		/* if either argument provided */
    if (dir) {
      if (strlen (dir) > NETMAXMBX) return NIL;
      strcpy (tmp,dir);		/* write directory prefix */
    }
    else tmp[0] = '\0';		/* otherwise null string */
    if (name) {
      if (strlen (name) > NETMAXMBX) return NIL;
      strcat (tmp,name);	/* write name in directory */
    }
				/* validate name, return its name */
    if (!mailboxfile (dst,tmp)) return NIL;
  }
				/* no arguments, wants mailbox directory */
  else strcpy (dst,mymailboxdir ());
  return dst;			/* return the name */
}

/* Return mailbox file name
 * Accepts: destination buffer
 *	    mailbox name
 * Returns: file name or empty string for driver-selected INBOX or NIL if error
 */

char *mailboxfile (char *dst,char *name)
{
  struct passwd *pw;
  char *s;
  if (!name || !*name || (*name == '{') || (strlen (name) > NETMAXMBX) ||
      ((anonymous || blackBox || restrictBox || (*name == '#')) &&
       (strstr (name,"..") || strstr (name,"//") || strstr (name,"/~"))))
    dst = NIL;			/* invalid name */
  else switch (*name) {		/* determine mailbox type based upon name */
  case '#':			/* namespace name */
				/* #ftp/ namespace */
    if (((name[1] == 'f') || (name[1] == 'F')) &&
	((name[2] == 't') || (name[2] == 'T')) &&
	((name[3] == 'p') || (name[3] == 'P')) &&
	(name[4] == '/') && ftpHome) sprintf (dst,"%s/%s",ftpHome,name+5);
				/* #public/ and #shared/ namespaces */
    else if ((((name[1] == 'p') || (name[1] == 'P')) &&
	      ((name[2] == 'u') || (name[2] == 'U')) &&
	      ((name[3] == 'b') || (name[3] == 'B')) &&
	      ((name[4] == 'l') || (name[4] == 'L')) &&
	      ((name[5] == 'i') || (name[5] == 'I')) &&
	      ((name[6] == 'c') || (name[6] == 'C')) &&
	      (name[7] == '/') && (s = publicHome)) ||
	     (!anonymous && ((name[1] == 's') || (name[1] == 'S')) &&
	      ((name[2] == 'h') || (name[2] == 'H')) &&
	      ((name[3] == 'a') || (name[3] == 'A')) &&
	      ((name[4] == 'r') || (name[4] == 'R')) &&
	      ((name[5] == 'e') || (name[5] == 'E')) &&
	      ((name[6] == 'd') || (name[6] == 'D')) &&
	      (name[7] == '/') && (s = sharedHome)))
      sprintf (dst,"%s/%s",s,compare_cstring (name+8,"INBOX") ?
	       name+8 : "INBOX");
    else dst = NIL;		/* unknown namespace */
    break;

  case '/':			/* root access */
    if (anonymous) dst = NIL;	/* anonymous forbidden to do this */
    else if (blackBox) {	/* other user access if blackbox */
      if (restrictBox & RESTRICTOTHERUSER) dst = NIL;
				/* see if other user INBOX */
      else if ((s = strchr (name+1,'/')) && !compare_cstring (s+1,"INBOX")) {
	*s = '\0';		/* temporarily tie off string */
	sprintf (dst,"%s/%s/INBOX",blackBoxDir,name+1);
	*s = '/';		/* in case caller cares */
      }
      else sprintf (dst,"%s/%s",blackBoxDir,name+1);
    }
    else if ((restrictBox & RESTRICTROOT) && strcmp (name,sysinbox ()))
      dst = NIL;		/* restricted and not access to sysinbox */
    else strcpy (dst,name);	/* unrestricted, copy root name */
    break;
  case '~':			/* other user access */
				/* bad syntax or anonymous can't win */
    if (!*++name || anonymous) dst = NIL;
				/* ~/ equivalent to ordinary name */
    else if (*name == '/') sprintf (dst,"%s/%s",mymailboxdir (),name+1);
				/* other user forbidden if closed/restricted */
    else if (closedBox || (restrictBox & RESTRICTOTHERUSER)) dst = NIL;
    else if (blackBox) {	/* black box form of other user */
				/* see if other user INBOX */
      if ((s = strchr (name,'/')) && compare_cstring (s+1,"INBOX")) {
	*s = '\0';		/* temporarily tie off string */
	sprintf (dst,"%s/%s/INBOX",blackBoxDir,name);
	*s = '/';		/* in case caller cares */
      }
      else sprintf (dst,"%s/%s",blackBoxDir,name);
    }
    else {			/* clear box other user */
				/* copy user name */
      for (s = dst; *name && (*name != '/'); *s++ = *name++);
      *s++ = '\0';		/* tie off user name, look up in passwd file */
      if ((pw = getpwnam (dst)) && pw->pw_dir) {
	if (*name) name++;	/* skip past the slash */
				/* canonicalize case of INBOX */
	if (!compare_cstring (name,"INBOX")) name = "INBOX";
				/* remove trailing / from directory */
	if ((s = strrchr (pw->pw_dir,'/')) && !s[1]) *s = '\0';
				/* don't allow ~root/ if restricted root */
	if ((restrictBox & RESTRICTROOT) && !*pw->pw_dir) dst = NIL;
				/* build final name w/ subdir if needed */
	else if (mailsubdir) sprintf (dst,"%s/%s/%s",pw->pw_dir,mailsubdir,name);
	else sprintf (dst,"%s/%s",pw->pw_dir,name);
      }
      else dst = NIL;		/* no such user */