pk_input.c

早期freebsd实现

			m_freem (m);
			/*
			 * NB.  This is dangerous: sending a RR here can
			 * cause sequence number errors if a previous data
			 * packet has not yet been passed up to the application
			 * (RR's are normally generated via PRU_RCVD).
			 */
			pk_flowcontrol (lcp, 0, 1);
		} else {
			sbappendrecord (&so -> so_rcv, m);
			sorwakeup (so);
		}
		break;

	/* 
	 *  Interrupt packet received.
	 */
	case INTERRUPT + DATA_TRANSFER: 
		if (lcp -> lcd_reset_condition)
			break;
		lcp -> lcd_intrdata = xp -> packet_data;
		lcp -> lcd_template = pk_template (lcp -> lcd_lcn, X25_INTERRUPT_CONFIRM);
		pk_output (lcp);
		m -> m_data += PKHEADERLN;
		m -> m_len -= PKHEADERLN;
		m -> m_pkthdr.len -= PKHEADERLN;
		MCHTYPE(m, MT_OOBDATA);
		if (so) {
			if (so -> so_options & SO_OOBINLINE)
				sbinsertoob (&so -> so_rcv, m);
			else
				m_freem (m);
			sohasoutofband (so);
		}
		break;

	/* 
	 *  Interrupt confirmation packet received.
	 */
	case INTERRUPT_CONF + DATA_TRANSFER: 
		if (lcp -> lcd_reset_condition)
			break;
		if (lcp -> lcd_intrconf_pending == TRUE)
			lcp -> lcd_intrconf_pending = FALSE;
		else
			pk_procerror (RESET, lcp, "unexpected packet", 43);
		break;

	/* 
	 *  Receiver ready received. Rotate the output window and output
	 *  any data packets waiting transmission.
	 */
	case RR + DATA_TRANSFER: 
		if (lcp -> lcd_reset_condition ||
		    pk_ack (lcp, PR(xp)) != PACKET_OK) {
			ptype = DELETE_PACKET;
			break;
		}
		if (lcp -> lcd_rnr_condition == TRUE)
			lcp -> lcd_rnr_condition = FALSE;
		pk_output (lcp);
		break;

	/* 
	 *  Receiver Not Ready received. Packets up to the P(R) can be
	 *  be sent. Condition is cleared with a RR.
	 */
	case RNR + DATA_TRANSFER: 
		if (lcp -> lcd_reset_condition ||
		    pk_ack (lcp, PR(xp)) != PACKET_OK) {
			ptype = DELETE_PACKET;
			break;
		}
		lcp -> lcd_rnr_condition = TRUE;
		break;

	/* 
	 *  Reset packet received. Set state to FLOW_OPEN.  The Input and
	 *  Output window edges ar set to zero. Both the send and receive
	 *  numbers are reset. A confirmation is returned.
	 */
	case RESET + DATA_TRANSFER: 
		if (lcp -> lcd_reset_condition)
			/* Reset collision. Just ignore packet. */
			break;

		pk_resetcause (pkp, xp);
		lcp -> lcd_window_condition = lcp -> lcd_rnr_condition =
			lcp -> lcd_intrconf_pending = FALSE;
		lcp -> lcd_output_window = lcp -> lcd_input_window =
			lcp -> lcd_last_transmitted_pr = 0;
		lcp -> lcd_ssn = 0;
		lcp -> lcd_rsn = MODULUS - 1;

		lcp -> lcd_template = pk_template (lcp -> lcd_lcn, X25_RESET_CONFIRM);
		pk_output (lcp);

		pk_flush (lcp);
		if (so == 0)
			break;
		wakeup ((caddr_t) & so -> so_timeo);
		sorwakeup (so);
		sowwakeup (so);
		break;

	/* 
	 *  Reset confirmation received.
	 */
	case RESET_CONF + DATA_TRANSFER: 
		if (lcp -> lcd_reset_condition) {
			lcp -> lcd_reset_condition = FALSE;
			pk_output (lcp);
		}
		else
			pk_procerror (RESET, lcp, "unexpected packet", 32);
		break;

	case DATA + SENT_CLEAR: 
		ptype = DELETE_PACKET;
	case RR + SENT_CLEAR: 
	case RNR + SENT_CLEAR: 
	case INTERRUPT + SENT_CLEAR: 
	case INTERRUPT_CONF + SENT_CLEAR: 
	case RESET + SENT_CLEAR: 
	case RESET_CONF + SENT_CLEAR: 
		/* Just ignore p if we have sent a CLEAR already.
		   */
		break;

	/* 
	 *  Restart sets all the permanent virtual circuits to the "Data
	 *  Transfer" stae and  all the switched virtual circuits to the
	 *  "Ready" state.
	 */
	case RESTART + READY: 
		switch (pkp -> pk_state) {
		case DTE_SENT_RESTART: 
			/* 
			 * Restart collision.
			 * If case the restart cause is "DTE originated" we
			 * have a DTE-DTE situation and are trying to resolve
			 * who is going to play DTE/DCE [ISO 8208:4.2-4.5]
			 */
			if (RESTART_DTE_ORIGINATED(xp)) {
				pk_restart (pkp, X25_RESTART_DTE_ORIGINATED);
				pk_message (0, pkp -> pk_xcp,
					    "RESTART collision");
				if ((pkp -> pk_restartcolls++) > MAXRESTARTCOLLISIONS) {
					pk_message (0, pkp -> pk_xcp,
						    "excessive RESTART collisions");
					pkp -> pk_restartcolls = 0;
				}
				break;
			}
			pkp -> pk_state = DTE_READY;
			pkp -> pk_dxerole |= DTE_PLAYDTE;
			pkp -> pk_dxerole &= ~DTE_PLAYDCE;
			pk_message (0, pkp -> pk_xcp,
				"Packet level operational");
			pk_message (0, pkp -> pk_xcp, 
				    "Assuming DTE role");
			if (pkp -> pk_dxerole & DTE_CONNECTPENDING)
				pk_callcomplete (pkp);
			break;

		default: 
			pk_restart (pkp, -1);
			pk_restartcause (pkp, xp);
			pkp -> pk_chan[0] -> lcd_template = pk_template (0,
				X25_RESTART_CONFIRM);
			pk_output (pkp -> pk_chan[0]);
			pkp -> pk_state = DTE_READY;
			pkp -> pk_dxerole |= RESTART_DTE_ORIGINATED(xp) ? DTE_PLAYDCE :
				DTE_PLAYDTE;
			if (pkp -> pk_dxerole & DTE_PLAYDTE) {
				pkp -> pk_dxerole &= ~DTE_PLAYDCE;
				pk_message (0, pkp -> pk_xcp, 
					    "Assuming DTE role");
			} else {
				pkp -> pk_dxerole &= ~DTE_PLAYDTE;
				pk_message (0, pkp -> pk_xcp, 
					 "Assuming DCE role");
			}
			if (pkp -> pk_dxerole & DTE_CONNECTPENDING)
				pk_callcomplete (pkp);
		}
		break;

	/* 
	 *  Restart confirmation received. All logical channels are set
	 *  to READY. 
	 */
	case RESTART_CONF + READY: 
		switch (pkp -> pk_state) {
		case DTE_SENT_RESTART: 
			pkp -> pk_state = DTE_READY;
			pkp -> pk_dxerole |= DTE_PLAYDTE;
			pkp -> pk_dxerole &= ~DTE_PLAYDCE;
			pk_message (0, pkp -> pk_xcp,
				    "Packet level operational");
			pk_message (0, pkp -> pk_xcp,
				    "Assuming DTE role");
			if (pkp -> pk_dxerole & DTE_CONNECTPENDING)
				pk_callcomplete (pkp);
			break;

		default: 
			/* Restart local procedure error. */
			pk_restart (pkp, X25_RESTART_LOCAL_PROCEDURE_ERROR);
			pkp -> pk_state = DTE_SENT_RESTART;
			pkp -> pk_dxerole &= ~(DTE_PLAYDTE | DTE_PLAYDCE);
		}
		break;

	default: 
		if (lcp) {
			pk_procerror (CLEAR, lcp, "unknown packet error", 33);
			pk_message (lcn, pkp -> pk_xcp,
				"\"%s\" unexpected in \"%s\" state",
				pk_name[ptype/MAXSTATES], pk_state[lcdstate]);
		} else
			pk_message (lcn, pkp -> pk_xcp,
				"packet arrived on unassigned lcn");
		break;
	}
	if (so == 0 && lcp && lcp -> lcd_upper && lcdstate == DATA_TRANSFER) {
		if (ptype != DATA && ptype != INTERRUPT)
			MCHTYPE(m, MT_CONTROL);
		lcp -> lcd_upper (lcp, m);
	} else if (ptype != DATA && ptype != INTERRUPT)
		m_freem (m);
}

static
prune_dnic (from, to, dnicname, xcp)
char *from, *to, *dnicname;
register struct x25config *xcp;
{
	register char *cp1 = from, *cp2 = from;
	if (xcp -> xc_prepnd0 && *cp1 == '0') {
		from = ++cp1;
		goto copyrest;
	}
	if (xcp -> xc_nodnic) {
		for (cp1 = dnicname; *cp2 = *cp1++;)
			cp2++;
		cp1 = from;
	}
copyrest:
	for (cp1 = dnicname; *cp2 = *cp1++;)
		cp2++;
}
/* static */
pk_simple_bsd (from, to, lower, len)
register octet *from, *to;
register len, lower;
{
	register int c;
	while (--len >= 0) {
		c = *from;
		if (lower & 0x01)
			*from++;
		else
			c >>= 4;
		c &= 0x0f; c |= 0x30; *to++ = c; lower++;
	}
	*to = 0;
}

/*static octet * */
pk_from_bcd (a, iscalling, sa, xcp)
register struct x25_calladdr *a;
register struct sockaddr_x25 *sa;
register struct x25config *xcp;
{
	octet buf[MAXADDRLN+1];
	octet *cp;
	unsigned count;

	bzero ((caddr_t) sa, sizeof (*sa));
	sa -> x25_len = sizeof (*sa);
	sa -> x25_family = AF_CCITT;
	if (iscalling) {
		cp = a -> address_field + (X25GBITS(a -> addrlens, called_addrlen) / 2);
		count = X25GBITS(a -> addrlens, calling_addrlen);
		pk_simple_bsd (cp, buf, X25GBITS(a -> addrlens, called_addrlen), count);
	} else {
		count = X25GBITS(a -> addrlens, called_addrlen);
		pk_simple_bsd (a -> address_field, buf, 0, count);
	}
	if (xcp -> xc_addr.x25_net && (xcp -> xc_nodnic || xcp -> xc_prepnd0)) {
		octet dnicname[sizeof (long) * NBBY/3 + 2];

		sprintf ((char *) dnicname, "%d", xcp -> xc_addr.x25_net);
		prune_dnic ((char *) buf, sa -> x25_addr, dnicname, xcp);
	} else
		bcopy ((caddr_t) buf, (caddr_t) sa -> x25_addr, count + 1);
}

static
save_extra (m0, fp, so)
struct mbuf *m0;
octet *fp;
struct socket *so;
{
	register struct mbuf *m;
	struct cmsghdr cmsghdr;
	if (m = m_copy (m, 0, (int)M_COPYALL)) {
		int off = fp - mtod (m0, octet *);
		int len = m -> m_pkthdr.len - off + sizeof (cmsghdr);
		cmsghdr.cmsg_len = len;
		cmsghdr.cmsg_level = AF_CCITT;
		cmsghdr.cmsg_type = PK_FACILITIES;
		m_adj (m, off);
		M_PREPEND (m, sizeof (cmsghdr), M_DONTWAIT);
		if (m == 0)
			return;
		bcopy ((caddr_t)&cmsghdr, mtod (m, caddr_t), sizeof (cmsghdr));
		MCHTYPE(m, MT_CONTROL);
		sbappendrecord (&so -> so_rcv, m);
	}
}

/* 
 * This routine handles incoming call packets. It matches the protocol
 * field on the Call User Data field (usually the first four bytes) with 
 * sockets awaiting connections.
 */

pk_incoming_call (pkp, m0)
struct mbuf *m0;
struct pkcb *pkp;
{
	register struct pklcd *lcp = 0, *l;
	register struct sockaddr_x25 *sa;
	register struct x25_calladdr *a;
	register struct socket *so = 0;
	struct	x25_packet *xp = mtod (m0, struct x25_packet *);
	struct	mbuf *m;
	struct	x25config *xcp = pkp -> pk_xcp;
	int len = m0 -> m_pkthdr.len;
	unsigned udlen;
	char *errstr = "server unavailable";
	octet *u, *facp;
	int lcn = LCN(xp);

	/* First, copy the data from the incoming call packet to a X25 address
	   descriptor. It is to be regretted that you have
	   to parse the facilities into a sockaddr to determine
	   if reverse charging is being requested */
	if ((m = m_get (M_DONTWAIT, MT_SONAME)) == 0)
		return;
	sa = mtod (m, struct sockaddr_x25 *);
	a = (struct x25_calladdr *) &xp -> packet_data;
	facp = u = (octet *) (a -> address_field +
		((X25GBITS(a -> addrlens, called_addrlen) + X25GBITS(a -> addrlens, calling_addrlen) + 1) / 2));
	u += *u + 1;
	udlen = min (16, ((octet *) xp) + len - u);
	if (udlen < 0)
		udlen = 0;
	pk_from_bcd (a, 1, sa, pkp -> pk_xcp); /* get calling address */
	pk_parse_facilities (facp, sa);
	bcopy ((caddr_t) u, sa -> x25_udata, udlen);
	sa -> x25_udlen = udlen;

	/*
	 * Now, loop through the listen sockets looking for a match on the
	 * PID. That is the first few octets of the user data field.
	 * This is the closest thing to a port number for X.25 packets.
	 * It does provide a way of multiplexing services at the user level. 
	 */

	for (l = pk_listenhead; l; l = l -> lcd_listen) {
		struct sockaddr_x25 *sxp = l -> lcd_ceaddr;

		if (bcmp (sxp -> x25_udata, u, sxp -> x25_udlen))
			continue;
		if (sxp -> x25_net &&
		    sxp -> x25_net != xcp -> xc_addr.x25_net)
			continue;
		/*
		 * don't accept incoming calls with the D-Bit on
		 * unless the server agrees
		 */
		if (X25GBITS(xp -> bits, d_bit) && !(sxp -> x25_opts.op_flags & X25_DBIT)) {
			errstr = "incoming D-Bit mismatch";
			break;
		}
		/*
		 * don't accept incoming collect calls unless
		 * the server sets the reverse charging option.
		 */
		if ((sxp -> x25_opts.op_flags & (X25_OLDSOCKADDR|X25_REVERSE_CHARGE)) == 0 &&
			sa -> x25_opts.op_flags & X25_REVERSE_CHARGE) {
			errstr = "incoming collect call refused";
			break;
		}
		if (l -> lcd_so) {
			if (so = sonewconn (l -> lcd_so, SS_ISCONNECTED))
				    lcp = (struct pklcd *) so -> so_pcb;
		} else 
			lcp = pk_attach ((struct socket *) 0);
		if (lcp == 0) {
			/*
			 * Insufficient space or too many unaccepted
			 * connections.  Just throw the call away.
			 */
			errstr = "server malfunction";
			break;
		}
		lcp -> lcd_upper = l -> lcd_upper;
		lcp -> lcd_upnext = l -> lcd_upnext;
		lcp -> lcd_lcn = lcn;
		lcp -> lcd_state = RECEIVED_CALL;
		sa -> x25_opts.op_flags |= (sxp -> x25_opts.op_flags &
			~X25_REVERSE_CHARGE) | l -> lcd_flags;
		pk_assoc (pkp, lcp, sa);
		lcp -> lcd_faddr = *sa;
		lcp -> lcd_laddr.x25_udlen = sxp -> x25_udlen;
		lcp -> lcd_craddr = &lcp -> lcd_faddr;
		lcp -> lcd_template = pk_template (lcp -> lcd_lcn, X25_CALL_ACCEPTED);
		if (lcp -> lcd_flags & X25_DBIT) {
			if (X25GBITS(xp -> bits, d_bit))
				X25SBITS(mtod (lcp -> lcd_template,
					struct x25_packet *) -> bits, d_bit, 1);
			else
				lcp -> lcd_flags &= ~X25_DBIT;
		}
		if (so) {
			pk_output (lcp);
			soisconnected (so);
			if (so -> so_options & SO_OOBINLINE)
				save_extra (m0, facp, so);
		} else if (lcp -> lcd_upper) {
			(*lcp -> lcd_upper) (lcp, m0);
		}
		(void) m_free (m);
		return;
	}

	/*
	 * If the call fails for whatever reason, we still need to build a
	 * skeleton LCD in order to be able to properly  receive the CLEAR
	 * CONFIRMATION.
	 */
#ifdef WATERLOO		/* be explicit */
	if (l == 0 && bcmp (sa -> x25_udata, "ean", 3) == 0)
		pk_message (lcn, pkp -> pk_xcp, "host=%s ean%c: %s",
			sa -> x25_addr, sa -> x25_udata[3] & 0xff, errstr);
	else if (l == 0 && bcmp (sa -> x25_udata, "\1\0\0\0", 4) == 0)
		pk_message (lcn, pkp -> pk_xcp, "host=%s x29d: %s",
			sa -> x25_addr, errstr);
	else
#endif
	pk_message (lcn, pkp -> pk_xcp, "host=%s pid=%x %x %x %x: %s",
		sa -> x25_addr, sa -> x25_udata[0] & 0xff,
		sa -> x25_udata[1] & 0xff, sa -> x25_udata[2] & 0xff,
		sa -> x25_udata[3] & 0xff, errstr);
	if ((lcp = pk_attach ((struct socket *)0)) == 0) {
		(void) m_free (m);
		return;
	}
	lcp -> lcd_lcn = lcn;
	lcp -> lcd_state = RECEIVED_CALL;
	pk_assoc (pkp, lcp, sa);
	(void) m_free (m);
	pk_clear (lcp, 0, 1);
}

pk_call_accepted (lcp, m)
struct pklcd *lcp;
struct mbuf *m;
{
	register struct x25_calladdr *ap;
	register octet *fcp;
	struct x25_packet *xp = mtod (m, struct x25_packet *);
	int len = m -> m_len;

	lcp -> lcd_state = DATA_TRANSFER;
	if (lcp -> lcd_so)
		soisconnected (lcp -> lcd_so);
	if ((lcp -> lcd_flags & X25_DBIT) && (X25GBITS(xp -> bits, d_bit) == 0))
		lcp -> lcd_flags &= ~X25_DBIT;
	if (len > 3) {
		ap = (struct x25_calladdr *) &xp -> packet_data;
		fcp = (octet *) ap -> address_field + (X25GBITS(ap -> addrlens, calling_addrlen) +
			X25GBITS(ap -> addrlens, called_addrlen) + 1) / 2;
		if (fcp + *fcp <= ((octet *) xp) + len)
			pk_parse_facilities (fcp, lcp -> lcd_ceaddr);
	}
	pk_assoc (lcp -> lcd_pkp, lcp, lcp -> lcd_ceaddr);
	if (lcp -> lcd_so == 0 && lcp -> lcd_upper)
		lcp -> lcd_upper (lcp, m);
}

pk_parse_facilities (fcp, sa)
register octet *fcp;
register struct sockaddr_x25 *sa;
{
	register octet *maxfcp;

	maxfcp = fcp + *fcp;
	fcp++;
	while (fcp < maxfcp) {
		/*
		 * Ignore national DCE or DTE facilities
		 */
		if (*fcp == 0 || *fcp == 0xff)
			break;
		switch (*fcp) {
		case FACILITIES_WINDOWSIZE:
			sa -> x25_opts.op_wsize = fcp[1];
			fcp += 3;
			break;

		case FACILITIES_PACKETSIZE:
			sa -> x25_opts.op_psize = fcp[1];
			fcp += 3;
			break;

		case FACILITIES_THROUGHPUT:
			sa -> x25_opts.op_speed = fcp[1];
			fcp += 2;
			break;

		case FACILITIES_REVERSE_CHARGE:
			if (fcp[1] & 01)
				sa -> x25_opts.op_flags |= X25_REVERSE_CHARGE;
			/*
			 * Datapac specific: for a X.25(1976) DTE, bit 2
			 * indicates a "hi priority" (eg. international) call.
			 */
			if (fcp[1] & 02 && sa -> x25_opts.op_psize == 0)
				sa -> x25_opts.op_psize = X25_PS128;
			fcp += 2;
			break;

		default:
/*printf("unknown facility %x, class=%d\n", *fcp, (*fcp & 0xc0) >> 6);*/
			switch ((*fcp & 0xc0) >> 6) {
			case 0:			/* class A */
				fcp += 2;
				break;

			case 1:
				fcp += 3;
				break;

			case 2:
				fcp += 4;
				break;

			case 3:
				fcp++;
				fcp += *fcp;
			}
		}
	}
}