popser.c

早期freebsd实现

/* popser.c - the POP service */
#ifndef	lint
static char ident[]="@(#)$Id: popser.c,v 1.31 1993/08/25 17:23:14 jromine Exp $";
#endif

#include "../h/mh.h"
#include "../h/dropsbr.h"
#ifdef	MPOP
#ifdef	BPOP
#include "../h/formatsbr.h"
#include "../h/scansbr.h"
#endif
#endif /* MPOP */
#include "../zotnet/bboards.h"
#include <stdio.h>
#include "../zotnet/mts.h"
#include <ctype.h>
#include <errno.h>
#include <pwd.h>
#include <signal.h>
#include "syslog.h"
#include <sys/types.h>
#include <sys/stat.h>
#ifdef KPOP
#include <krb.h>
#endif	/* KPOP */
#ifdef	SYS5
#include <fcntl.h>
#endif	/* SYS5 */
#ifdef	SHADOW
#include <shadow.h>
#endif	/* SHADOW */


#define	TRUE	1
#define	FALSE	0

#define	NVEC	5

#ifndef	POPSERVICE
#define	POPSERVICE	"pop"
#endif

/*  */

extern int  errno;

extern int  debug;
extern char myhost[];
extern char *myname;

#ifndef	POP2
static enum state {
    auth1, auth2, trans, update, halt, error
} mystate;
#else
static enum state {
    auth1, auth2, trans, mbox, item, ack, update, halt, error
} mystate;
#endif


static int     user (), pass ();
#ifdef	BPOP
static		isguest(), getbbmax();
#ifndef	MPOP
static	int	xtnd1(), xtnd2();
#else
static	int	xtnd1(), xtnd2(), xtnd3 ();
#endif /* MPOP */
#endif	/* BPOP */
#ifdef	RPOP
static int	rpop ();
#endif	/* RPOP */
#ifdef	APOP
static	int	apop ();
#endif
static int     status (), list (), retrieve (), delete (), reset ();
static int	top (), last ();
#ifdef	BPOP
static int	xtnd ();
#endif	/* BPOP */
static int     quit ();
#ifdef	POP2
static int	helo (), rdp2 (), acks (), ack2 (), fold (), nack ();
#endif	/* POP2 */

static struct vector {
    char   *v_cmd;
    int     v_min, v_max;
    int     (*v_vec) ();
    enum state v_valid;
    enum state v_win, v_lose;
}               vectors[] = {
    "user", 1, 1, user, auth1, auth2, auth1,
    "pass", 1, 1, pass, auth2, trans, auth1,
#ifdef	RPOP
    "rpop", 1, 1, rpop, auth2, trans, auth1,
#endif	/* RPOP */
#ifdef	APOP
    "apop", 2, 2, apop, auth1, trans, auth1,
#endif
    "quit", 0, 0, NULL, auth1, halt, halt,
    "quit", 0, 0, NULL, auth2, halt, halt,

    "stat", 0, 0, status, trans, trans, trans,
    "list", 0, 1, list, trans, trans, trans,
    "retr", 1, 1, retrieve, trans, trans, trans,
    "dele", 1, 1, delete, trans, trans, trans,
    "noop", 0, 0, NULL, trans, trans, trans,
    "rset", 0, 0, reset, trans, trans, trans,

    "top",  2, 2, top,  trans, trans, trans,
    "last", 0, 0, last, trans, trans, trans,
#ifdef	BPOP
#ifndef	MPOP
    "xtnd", 1, 2, xtnd, trans, trans, trans,
#else
    "xtnd", 1, 3, xtnd, trans, trans, trans,
#endif /* MPOP */
#endif	/* BPOP */
    "quit", 0, 0, quit, trans, halt, halt,

#ifdef	POP2
    "helo", 2, 2, helo, auth1, mbox, auth1,

    "fold", 1, 1, fold, mbox, mbox, mbox,
    "quit", 0, 0, quit, mbox, halt, halt,
    "read", 0, 1, rdp2, mbox, item, error,

    "fold", 1, 1, fold, item, mbox, mbox,
    "read", 0, 1, rdp2, item, item, error,
    "quit", 0, 0, quit, item, halt, halt,
    "retr", 0, 0, retrieve, item, ack, error,

    "acks", 0, 0, ack2, ack, item, error,
    "ackd", 0, 0, ack2, ack, item, error,
    "nack", 0, 0, rdp2, ack, item, error,
    "quit", 0, 0, NULL, ack, halt, halt,

#endif	/* POP2 */
    NULL
};

static struct vector  *getvector ();

/*  */

#ifdef	POP2
static int pop2 = NOTOK;	/* current pop2 msg, or NOTOK if pop3 */
#endif	/* POP2 */
#ifdef	DPOP
static int pop_uid;
static int pop_gid;
#endif	/* DPOP */

static int  rproto;
static char *hostname;
static char server[BUFSIZ];
static char timestamp[BUFSIZ];

static char username[BUFSIZ];

static char maildrop[BUFSIZ];
static int  mode;
static time_t mtime;
static FILE *dp;

static long lastseen;
static int  rmsgs;

#ifdef	BPOP
static int xtnded;

static int guest_uid;
static int guest_gid;

static struct bboard *BBhead = NULL;
static struct bboard *BBtail = NULL;

static long BBtime = 0L;

static struct bboard *getbbaux ();
#endif	/* BPOP */


struct Msg {			/* Msgs[0] contains info for entire maildrop */
    struct drop m_drop;
#define	m_id	m_drop.d_id
#define	m_size	m_drop.d_size
#define	m_last	m_drop.d_start	/* Msgs[i = 0] */
#define	m_start	m_drop.d_start	/* Msgs[i > 0] */
#define	m_stop	m_drop.d_stop

    unsigned    m_flags;
#define	MNULL	0x00
#define	MDELE	0x01
#define	MREAD	0x02
};

static int nMsgs = 0;
static struct Msg *Msgs = NULL;

static int  nmsgs;
static int  dmsgs;
#ifdef	MPOP
#ifdef	BPOP
static int   _sc_width = 0;
static char *nfs = NULL;
#endif
#endif /* MPOP */


#define	TRM	"."
#define	TRMLEN	(sizeof TRM - 1)
#define	IAC	255

static TYPESIG    pipeser ();

FILE   *input;
FILE   *output;

#ifndef	__STDC__
#ifdef	SYS5
struct passwd *getpwnam();
#endif
#endif

void	padvise (), padios ();
char   *crypt ();

#ifdef	POPUUMBOX
#define	MBX_READ	pmbx_read
static	int	pmbx_read ();
static	char   *p_copy(), *p_copyin(), *p_nextword();
static		p_cmatch(), p_isdate(), p_ishead(), p_parse(), any();
#else
#define	MBX_READ	mbx_read
#endif
extern	int	mbx_read ();

static int	setup(), setupaux(), read_map(), read_file(), pmbx_size();
static int	quitaux(), quitfile(), respond(), getline();
static	m_gMsgs(), multiline(), multiend(), putline();
/*  */

popinit () {
#ifdef	BPOP
    padvise (NULLCP, LOG_INFO, "initialize list of BBoards");

    BBhead = BBtail = NULL;
    while (getbbaux (NULLCP))
	continue;
#endif	/* BPOP */
}

popassert () {
#ifdef	BPOP
    register char **p;
    register struct bboard *bb,
                           *bp;

    if (BBtime == getbbtime ())
	return;

    padvise (NULLCP, LOG_INFO, "list of BBoards has changed");

    for (bb = BBhead; bb; bb = bp) {
	bp = bb -> bb_next;

	if (bb -> bb_name)
	    free (bb -> bb_name);
	if (bb -> bb_file)
	    free (bb -> bb_file);
	if (bb -> bb_archive)
	    free (bb -> bb_archive);
	if (bb -> bb_info)
	    free (bb -> bb_info);
	if (bb -> bb_map)
	    free (bb -> bb_map);
	if (bb -> bb_passwd)
	    free (bb -> bb_passwd);
	if (bb -> bb_date)
	    free (bb -> bb_date);
	if (bb -> bb_addr)
	    free (bb -> bb_addr);
	if (bb -> bb_request)
	    free (bb -> bb_request);
	if (bb -> bb_relay)
	    free (bb -> bb_relay);

	for (p = bb -> bb_aka; *p; p++)
	    free (*p);
	free ((char *) bb -> bb_aka);

	for (p = bb -> bb_leader; *p; p++)
	    free (*p);
	free ((char *) bb -> bb_leader);

	for (p = bb -> bb_dist; *p; p++)
	    free (*p);
	free ((char *) bb -> bb_dist);

	free ((char *) bb);
    }

    BBhead = BBtail = NULL;
    while (getbbaux (NULLCP))
	continue;
#endif	/* BPOP */
}

/*  */

#ifdef KPOP
static char *kusername;

kpop (in, out, principal, rhost, auth)
int   in,
      out;
char  *principal, *rhost;
int auth;
#else	/* KPOP */
pop (in, out, priv, rhost)
int	in,
	out,
	priv;
char   *rhost;
#endif	/* KPOP */
{
    char    buffer[BUFSIZ],
           *vec[NVEC + 1];
#if	defined (DPOP) || defined (BPOP)
    register struct passwd *pw;
#endif	/* defined (DPOP) || defined (BPOP) */
    register struct vector *v;

    m_foil (NULLCP);
    mts_init (myname);

    hostname = rhost;
#ifdef KPOP
    rproto = 1;
    (void) sprintf (server, "%s KPOP server", myhost);
#else
    rproto = priv;
    (void) sprintf (server, "%s server", priv ? "RPOP" : "POP");
#endif	/* KPOP */

    if ((input = fdopen (in, "r")) == NULL
	    || (output = fdopen (out, "w")) == NULL) {/* you lose big */
	(void) respond (NOTOK, "%s loses on initialization", server);
	return;
    }
    (void) signal (SIGPIPE, pipeser);
#ifdef KPOP
    if (principal == NULLCP) {
	char buf[512];
	strcpy(buf,  "Authentication failed: ");
	strcat(buf, krb_err_txt[auth]);
	(void) respond (NOTOK, buf);
	return;
    }
    kusername = principal;
#endif	/* KPOP */

#ifdef	DPOP
    if ((pw = getpwnam (POPUID)) == NULL || !setpwinfo (pw, POPDB, 1)) {
	(void) respond (NOTOK, "%s loses on DB initialization -- %s",
		    server, pw ? getbberr () : "POP user-id unknown");
	return;
    }
    pop_uid = pw -> pw_uid;
    pop_gid = pw -> pw_gid;
#endif	/* DPOP */
#ifdef	BPOP
    if ((pw = getpwnam (popbbuser)) && pw -> pw_uid) {
	guest_uid = pw -> pw_uid;
	guest_gid = pw -> pw_gid;
    }
    else
	guest_uid = guest_gid = 0;
#endif	/* BPOP */

    {
	long	clock;

	(void) time (&clock);
	(void) sprintf (timestamp, "<%d.%ld@%s>", getpid (), clock, myhost);
    }
    (void) respond (OK, "%s ready %s", server, timestamp);

    for (mystate = auth1; mystate != halt && mystate != error;)
	switch (getline (buffer, sizeof buffer, input)) {
	    case OK: 
		if ((v = getvector (buffer, vec)) == NULL)
		    continue;
		mystate = (v -> v_vec ? (v -> v_vec) (vec)
			: respond (OK, NULLCP)) == OK
		    ? v -> v_win
		    : v -> v_lose;
		break;

	    case NOTOK: 
	    case DONE: 
		mystate = error;
		(void) respond (NOTOK, "%s signing off", server);
		break;
	}
}

/*  */
#ifdef	POP2
static int  helo (vec)		/* sort of "user" and "pass" */
register char  **vec;
{
    pop2 = 0;				/* now we're talkin' pop2! */
    make_lower (username, vec[1]);	/* helo user pass */
    return pass (++vec);		/* user pass */
}
#endif

static int  user (vec)
register char  **vec;
{
    make_lower (username, vec[1]);
#ifdef KPOP
    if (!strcmp(username, kusername))
      return respond (OK, "Kerberos authentication succeeded. Send username as password (%s)", username);
    else {
	respond (NOTOK, "Wrong username supplied (%s vs. %s)",
		 kusername, username);
	return (NOTOK);
    }
#else
    return respond (OK, "password required for %s", username);
#endif
}

/*  */

static int  pass (vec)
register char  **vec;
{
    int	guest = 0;
#ifndef	DPOP
    register struct passwd *pw;
#ifdef	SHADOW
    register struct spwd *shpw;
#endif	/* SHADOW */
#else	/* DPOP */
    register struct bboard *pw;
#endif	/* DPOP */

#ifdef KPOP
#ifndef DPOP
    if ((pw = getpwnam (username)) != NULL)
      return setup(pw, FALSE);
    else
      return respond (NOTOK, "no local password entry");
#else
    {
      static struct bboard entry;
      static char entry_file[BUFSIZ] = "/usr/spool/pop";
      
      pw = &entry;
      pw->bb_name = username;
      strcat(entry_file, username);
      pw->bb_file = entry_file;
      return setup(pw, FALSE);
    }
#endif
#else	/* KPOP */

#ifndef	DPOP
#ifdef	BPOP
    if (isguest ()) {
#ifdef	TRUSTED
	static passwd gw;

	gw.pw_name = popbbuser;
	gw.pw_uid = guest_uid;
	pw = &gw;
#endif	/* TRUSTED */
	guest = 1;
	goto anonymous;
    }
#endif	/* BPOP */
    if ((pw = getpwnam (username)) == NULL
#ifndef	SHADOW
	    || *pw -> pw_passwd == NULL
	    || strcmp (crypt (vec[1], pw -> pw_passwd), pw -> pw_passwd)) {
#else	/* SHADOW */
	    || (shpw = getspnam (username)) == NULL
	    || *shpw -> sp_pwdp == NULL
	    || strcmp (crypt (vec[1], shpw -> sp_pwdp), shpw -> sp_pwdp)) {
#endif	/* SHADOW */
#ifdef	TRUSTED
	trusted (0, hostname, NULLCP, 0, pw ? pw -> pw_name : username,
	    pw && pw -> pw_uid == 0, POPSERVICE, "tcp", NULL);
#endif	/* TRUSTED */
	return respond (NOTOK, "login incorrect");
    }
#else	/* DPOP */
#ifdef	BPOP
    if (isguest ()) {
	static struct bboard gw;

	gw.bb_name = popbbuser;
	pw = &gw;
	guest = 1;
	goto anonymous;
    }
#endif	/* BPOP */
    if (((pw = getbbnam (username)) == NULL
		&& (pw = getbbaka (username)) == NULL)
	    || *pw -> bb_passwd == NULL
	    || strcmp (crypt (vec[1], pw -> bb_passwd), pw -> bb_passwd)) {
#ifdef	TRUSTED
	trusted (0, hostname, NULLCP, 0, pw ? pw -> bb_name : username,
	    0, POPSERVICE, "tcp", NULL);
#endif	/* TRUSTED */
	return respond (NOTOK, "login incorrect");
    }
#endif	/* DPOP */

#ifdef	BPOP
anonymous: ;
#endif	/* BPOP */
#ifdef	TRUSTED
    if (trusted (1, hostname, NULLCP, 0, myhost,
#ifndef	DPOP
		pw -> pw_name, pw -> pw_uid == 0,
#else	/* DPOP */
		pw -> bb_name, 0,
#endif	/* DPOP */
		POPSERVICE, "tcp", NULL)
	    == 0)
	return respond (NOTOK, "permission denied");
#endif	/* TRUSTED */
    return setup (pw, guest);
#endif /* KPOP */
}

/*  */

#ifdef	BPOP
static  isguest () {
    int	    i;
    register char  *cp;
    char    buffer[BUFSIZ];
    register FILE  *fp;

    if (strcmp (username, popbbuser) || !guest_uid)
	return FALSE;
    if (popbblist == NULL || (fp = fopen (popbblist, "r")) == NULL)
	return TRUE;

    i = FALSE;
    if (hostname)
	while (fgets (buffer, sizeof buffer, fp)) {
	    if (cp = index (buffer, '\n'))
		*cp = NULL;
	    if (strcmp (buffer, hostname) == 0) {
		i = TRUE;
		break;
	    }
	}

    (void) fclose (fp);

    return i;
}
#endif	/* BPOP */

/*  */

#ifdef	RPOP
static int rpop (vec)
register char  **vec;
{
#ifndef	DPOP
    register struct passwd *pw;
#else	/* DPOP */
    register int hostok = 0;
    register char  *bp,
		   *cp;