env_unix.c

来自「这是用C编写IMAP源代码」· C语言 代码 · 共 1,641 行 · 第 1/4 页

/* Write current time in internal format
 * Accepts: destination string
 */

void internal_date (char *date)
{
  do_date (date,NIL,"%02d-%s-%d %02d:%02d:%02d %+03d%02d",NIL);
}

/* Initialize server
 * Accepts: server name for syslog or NIL
 *	    /etc/services service name or NIL
 *	    alternate /etc/services service name or NIL
 *	    clock interrupt handler
 *	    kiss-of-death interrupt handler
 *	    hangup interrupt handler
 *	    termination interrupt handler
 */

void server_init (char *server,char *service,char *sslservice,
		  void *clkint,void *kodint,void *hupint,void *trmint)
{
				/* only do this if for init call */
  if (server && service && sslservice) {
    int mask;
    long port;
    struct servent *sv;
				/* set server name in syslog */
    openlog (server,LOG_PID,LOG_MAIL);
    fclose (stderr);		/* possibly save a process ID */
    dorc (NIL,NIL);		/* do systemwide configuration */
    /* Use SSL if SSL service, or if server starts with "s" and not service */
    if (((port = tcp_serverport ()) >= 0)) {
      if ((sv = getservbyname (service,"tcp")) && (port == ntohs (sv->s_port)))
	syslog (LOG_DEBUG,"%s service init from %s",service,tcp_clientaddr ());
      else if ((sv = getservbyname (sslservice,"tcp")) &&
	       (port == ntohs (sv->s_port))) {
	syslog (LOG_DEBUG,"%s SSL service init from %s",sslservice,
		tcp_clientaddr ());
	ssl_server_init (server);
      }
      else {			/* not service or SSL service port */
	syslog (LOG_DEBUG,"port %ld service init from %s",port,
		tcp_clientaddr ());
	if (*server == 's') ssl_server_init (server);
      }
    }
    switch (mask = umask (022)){/* check old umask */
    case 0:			/* definitely unreasonable */
    case 022:			/* don't need to change it */
      break;
    default:			/* already was a reasonable value */
      umask (mask);		/* so change it back */
    }
  }
  arm_signal (SIGALRM,clkint);	/* prepare for clock interrupt */
  arm_signal (SIGUSR2,kodint);	/* prepare for Kiss Of Death */
  arm_signal (SIGHUP,hupint);	/* prepare for hangup */
  arm_signal (SIGTERM,trmint);	/* prepare for termination */
}

/* Wait for stdin input
 * Accepts: timeout in seconds
 * Returns: T if have input on stdin, else NIL
 */

long server_input_wait (long seconds)
{
  fd_set rfd,efd;
  struct timeval tmo;
  FD_ZERO (&rfd);
  FD_ZERO (&efd);
  FD_SET (0,&rfd);
  FD_SET (0,&efd);
  tmo.tv_sec = seconds; tmo.tv_usec = 0;
  return select (1,&rfd,0,&efd,&tmo) ? LONGT : NIL;
}

/* Return UNIX password entry for user name
 * Accepts: user name string
 * Returns: password entry
 *
 * Tries all-lowercase form of user name if given user name fails
 */

static struct passwd *pwuser (unsigned char *user)
{
  unsigned char *s;
  struct passwd *pw = getpwnam (user);
  if (!pw) {			/* failed, see if any uppercase characters */
    for (s = user; *s && !isupper (*s); s++);
    if (*s) {			/* yes, try all lowercase form */
      pw = getpwnam (s = lcase (cpystr (user)));
      fs_give ((void **) &s);
    }
  }
  return pw;
}


/* Validate password for user name
 * Accepts: user name string
 *	    password string
 *	    argument count
 *	    argument vector
 * Returns: password entry if validated
 *
 * Tries password+1 if password fails and starts with space
 */

static struct passwd *valpwd (char *user,char *pwd,int argc,char *argv[])
{
  char *s;
  struct passwd *pw;
  struct passwd *ret = NIL;
  if (auth_md5.server) {	/* using CRAM-MD5 authentication? */
    if (s = auth_md5_pwd (user)) {
      if (!strcmp (s,pwd) || ((*pwd == ' ') && pwd[1] && !strcmp (s,pwd+1)))
	ret = pwuser (user);	/* validated, get passwd entry for user */
      memset (s,0,strlen (s));	/* erase sensitive information */
      fs_give ((void **) &s);
    }
  }
  else if (pw = pwuser (user)) {/* can get user? */
    s = cpystr (pw->pw_name);	/* copy returned name in case we need it */
    if (*pwd && !(ret = checkpw (pw,pwd,argc,argv)) &&
	(*pwd == ' ') && pwd[1] && (ret = pwuser (s)))
      ret = checkpw (pw,pwd+1,argc,argv);
    fs_give ((void **) &s);	/* don't need copy of name any more */
  }
  return ret;
}

/* Server log in
 * Accepts: user name string
 *	    password string
 *	    authenticating user name string
 *	    argument count
 *	    argument vector
 * Returns: T if password validated, NIL otherwise
 */

long server_login (char *user,char *pwd,char *authuser,int argc,char *argv[])
{
  struct passwd *pw = NIL;
  int level = LOG_NOTICE;
  char *err = "failed";
				/* cretins still haven't given up */
  if ((strlen (user) >= NETMAXUSER) ||
      (authuser && (strlen (authuser) >= NETMAXUSER))) {
    level = LOG_ALERT;		/* escalate this alert */
    err = "SYSTEM BREAK-IN ATTEMPT";
    logtry = 0;			/* render this session useless */
  }
  else if (logtry-- <= 0) err = "excessive login failures";
  else if (disablePlaintext) err = "disabled";
  else if (!(authuser && *authuser)) pw = valpwd (user,pwd,argc,argv);
  else if (valpwd (authuser,pwd,argc,argv)) pw = pwuser (user);
  if (pw && pw_login (pw,authuser,pw->pw_name,NIL,argc,argv)) return T;
  syslog (level|LOG_AUTH,"Login %s user=%.64s auth=%.64s host=%.80s",err,
	  user,(authuser && *authuser) ? authuser : user,tcp_clienthost ());
  sleep (3);			/* slow down possible cracker */
  return NIL;
}

/* Authenticated server log in
 * Accepts: user name string
 *	    authenticating user name string
 *	    argument count
 *	    argument vector
 * Returns: T if password validated, NIL otherwise
 */

long authserver_login (char *user,char *authuser,int argc,char *argv[])
{
  return pw_login (pwuser (user),authuser,user,NIL,argc,argv);
}


/* Log in as anonymous daemon
 * Accepts: argument count
 *	    argument vector
 * Returns: T if successful, NIL if error
 */

long anonymous_login (int argc,char *argv[])
{
				/* log in Mr. A. N. Onymous */
  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];
  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);
  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);
				/* force default prototype to be set */
  if (!createProto) createProto = &CREATEPROTO;
  if (!appendProto) appendProto = &EMPTYPROTO;
				/* 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)))
      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 ()
{
  char tmp[MAILTMPLEN];
  if (!myLocalHost) {
    gethostname(tmp,MAILTMPLEN);/* get local host name */
    myLocalHost = cpystr (tcp_canonical (tmp));
  }
  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 : "";
}