if_spppsubr.c

基于组件方式开发操作系统的OSKIT源代码

/*
 * Synchronous PPP/Cisco link level subroutines.
 * Keepalive protocol implemented in both Cisco and PPP modes.
 *
 * Copyright (C) 1994 Cronyx Ltd.
 * Author: Serge Vakulenko, <[e-mail]>
 *
 * This software is distributed with NO WARRANTIES, not even the implied
 * warranties for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Authors grant any other persons or organisations permission to use
 * or modify this software as long as this message is kept with the software,
 * all derivative works or modified versions.
 *
 * Version 1.9, Wed Oct  4 18:58:15 MSK 1995
 */
#undef DEBUG

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/mbuf.h>

#include <net/if.h>
#include <net/netisr.h>
#include <net/if_types.h>

#ifdef INET
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include <netinet/if_ether.h>
#endif

#ifdef NS
#include <netns/ns.h>
#include <netns/ns_if.h>
#endif

#ifdef ISO
#include <netiso/argo_debug.h>
#include <netiso/iso.h>
#include <netiso/iso_var.h>
#include <netiso/iso_snpac.h>
#endif

#include <net/if_sppp.h>

#ifdef DEBUG
#define print(s)        printf s
#else
#define print(s)        {/*void*/}
#endif

#define MAXALIVECNT     3               /* max. alive packets */

#define PPP_ALLSTATIONS 0xff            /* All-Stations broadcast address */
#define PPP_UI          0x03            /* Unnumbered Information */
#define PPP_IP          0x0021          /* Internet Protocol */
#define PPP_ISO         0x0023          /* ISO OSI Protocol */
#define PPP_XNS         0x0025          /* Xerox NS Protocol */
#define PPP_LCP         0xc021          /* Link Control Protocol */
#define PPP_IPCP        0x8021          /* Internet Protocol Control Protocol */

#define LCP_CONF_REQ    1               /* PPP LCP configure request */
#define LCP_CONF_ACK    2               /* PPP LCP configure acknowledge */
#define LCP_CONF_NAK    3               /* PPP LCP configure negative ack */
#define LCP_CONF_REJ    4               /* PPP LCP configure reject */
#define LCP_TERM_REQ    5               /* PPP LCP terminate request */
#define LCP_TERM_ACK    6               /* PPP LCP terminate acknowledge */
#define LCP_CODE_REJ    7               /* PPP LCP code reject */
#define LCP_PROTO_REJ   8               /* PPP LCP protocol reject */
#define LCP_ECHO_REQ    9               /* PPP LCP echo request */
#define LCP_ECHO_REPLY  10              /* PPP LCP echo reply */
#define LCP_DISC_REQ    11              /* PPP LCP discard request */

#define LCP_OPT_MRU             1       /* maximum receive unit */
#define LCP_OPT_ASYNC_MAP       2       /* async control character map */
#define LCP_OPT_AUTH_PROTO      3       /* authentication protocol */
#define LCP_OPT_QUAL_PROTO      4       /* quality protocol */
#define LCP_OPT_MAGIC           5       /* magic number */
#define LCP_OPT_RESERVED        6       /* reserved */
#define LCP_OPT_PROTO_COMP      7       /* protocol field compression */
#define LCP_OPT_ADDR_COMP       8       /* address/control field compression */

#define IPCP_CONF_REQ   LCP_CONF_REQ    /* PPP IPCP configure request */
#define IPCP_CONF_ACK   LCP_CONF_ACK    /* PPP IPCP configure acknowledge */
#define IPCP_CONF_NAK   LCP_CONF_NAK    /* PPP IPCP configure negative ack */
#define IPCP_CONF_REJ   LCP_CONF_REJ    /* PPP IPCP configure reject */
#define IPCP_TERM_REQ   LCP_TERM_REQ    /* PPP IPCP terminate request */
#define IPCP_TERM_ACK   LCP_TERM_ACK    /* PPP IPCP terminate acknowledge */
#define IPCP_CODE_REJ   LCP_CODE_REJ    /* PPP IPCP code reject */

#define CISCO_MULTICAST         0x8f    /* Cisco multicast address */
#define CISCO_UNICAST           0x0f    /* Cisco unicast address */
#define CISCO_KEEPALIVE         0x8035  /* Cisco keepalive protocol */
#define CISCO_ADDR_REQ          0       /* Cisco address request */
#define CISCO_ADDR_REPLY        1       /* Cisco address reply */
#define CISCO_KEEPALIVE_REQ     2       /* Cisco keepalive request */

struct ppp_header {
	u_char address;
	u_char control;
	u_short protocol;
};
#define PPP_HEADER_LEN          sizeof (struct ppp_header)

struct lcp_header {
	u_char type;
	u_char ident;
	u_short len;
};
#define LCP_HEADER_LEN          sizeof (struct lcp_header)

struct cisco_packet {
	u_long type;
	u_long par1;
	u_long par2;
	u_short rel;
	u_short time0;
	u_short time1;
};
#define CISCO_PACKET_LEN 18

struct sppp *spppq;

/*
 * The following disgusting hack gets around the problem that IP TOS
 * can't be set yet.  We want to put "interactive" traffic on a high
 * priority queue.  To decide if traffic is interactive, we check that
 * a) it is TCP and b) one of its ports is telnet, rlogin or ftp control.
 */
static u_short interactive_ports[8] = {
	0,	513,	0,	0,
	0,	21,	0,	23,
};
#define INTERACTIVE(p) (interactive_ports[(p) & 7] == (p))

/*
 * Timeout routine activation macros.
 */
#define TIMO(p,s) if (! ((p)->pp_flags & PP_TIMO)) { \
			timeout (sppp_cp_timeout, (void*) (p), (s)*hz); \
			(p)->pp_flags |= PP_TIMO; }
#define UNTIMO(p) if ((p)->pp_flags & PP_TIMO) { \
			untimeout (sppp_cp_timeout, (void*) (p)); \
			(p)->pp_flags &= ~PP_TIMO; }

void sppp_keepalive (void *dummy);
void sppp_cp_send (struct sppp *sp, u_short proto, u_char type,
	u_char ident, u_short len, void *data);
void sppp_cisco_send (struct sppp *sp, int type, long par1, long par2);
void sppp_lcp_input (struct sppp *sp, struct mbuf *m);
void sppp_cisco_input (struct sppp *sp, struct mbuf *m);
void sppp_ipcp_input (struct sppp *sp, struct mbuf *m);
void sppp_lcp_open (struct sppp *sp);
void sppp_ipcp_open (struct sppp *sp);
int sppp_lcp_conf_parse_options (struct sppp *sp, struct lcp_header *h,
	int len, u_long *magic);
void sppp_cp_timeout (void *arg);
char *sppp_lcp_type_name (u_char type);
char *sppp_ipcp_type_name (u_char type);
void sppp_print_bytes (u_char *p, u_short len);

/*
 * Flush interface queue.
 */
static void qflush (struct ifqueue *ifq)
{
	struct mbuf *m, *n;

	n = ifq->ifq_head;
	while ((m = n)) {
		n = m->m_act;
		m_freem (m);
	}
	ifq->ifq_head = 0;
	ifq->ifq_tail = 0;
	ifq->ifq_len = 0;
}

/*
 * Process the received packet.
 */
void sppp_input (struct ifnet *ifp, struct mbuf *m)
{
	struct ppp_header *h;
	struct sppp *sp = (struct sppp*) ifp;
	struct ifqueue *inq = 0;
	int s;

	if (ifp->if_flags & IFF_UP)
		/* Count received bytes, add FCS and one flag */
		ifp->if_ibytes += m->m_pkthdr.len + 3;

	if (m->m_pkthdr.len <= PPP_HEADER_LEN) {
		/* Too small packet, drop it. */
		if (ifp->if_flags & IFF_DEBUG)
			printf ("%s%d: input packet is too small, %d bytes\n",
				ifp->if_name, ifp->if_unit, m->m_pkthdr.len);
drop:           ++ifp->if_iqdrops;
		m_freem (m);
		return;
	}

	/* Get PPP header. */
	h = mtod (m, struct ppp_header*);
	m_adj (m, PPP_HEADER_LEN);

	switch (h->address) {
	default:        /* Invalid PPP packet. */
invalid:        if (ifp->if_flags & IFF_DEBUG)
			printf ("%s%d: invalid input packet <0x%x 0x%x 0x%x>\n",
				ifp->if_name, ifp->if_unit,
				h->address, h->control, ntohs (h->protocol));
		goto drop;
	case PPP_ALLSTATIONS:
		if (h->control != PPP_UI)
			goto invalid;
		if (sp->pp_flags & PP_CISCO) {
			if (ifp->if_flags & IFF_DEBUG)
				printf ("%s%d: PPP packet in Cisco mode <0x%x 0x%x 0x%x>\n",
					ifp->if_name, ifp->if_unit,
					h->address, h->control, ntohs (h->protocol));
			goto drop;
		}
		switch (ntohs (h->protocol)) {
		default:
			if (sp->lcp.state == LCP_STATE_OPENED)
				sppp_cp_send (sp, PPP_LCP, LCP_PROTO_REJ,
					++sp->pp_seq, m->m_pkthdr.len + 2,
					&h->protocol);
			if (ifp->if_flags & IFF_DEBUG)
				printf ("%s%d: invalid input protocol <0x%x 0x%x 0x%x>\n",
					ifp->if_name, ifp->if_unit,
					h->address, h->control, ntohs (h->protocol));
			++ifp->if_noproto;
			goto drop;
		case PPP_LCP:
			sppp_lcp_input ((struct sppp*) ifp, m);
			m_freem (m);
			return;
#ifdef INET
		case PPP_IPCP:
			if (sp->lcp.state == LCP_STATE_OPENED)
				sppp_ipcp_input ((struct sppp*) ifp, m);
			m_freem (m);
			return;
		case PPP_IP:
			if (sp->ipcp.state == IPCP_STATE_OPENED) {
				schednetisr (NETISR_IP);
				inq = &ipintrq;
			}
			break;
#endif
#ifdef NS
		case PPP_XNS:
			/* XNS IDPCP not implemented yet */
			if (sp->lcp.state == LCP_STATE_OPENED) {
				schednetisr (NETISR_NS);
				inq = &nsintrq;
			}
			break;
#endif
#ifdef ISO
		case PPP_ISO:
			/* OSI NLCP not implemented yet */
			if (sp->lcp.state == LCP_STATE_OPENED) {
				schednetisr (NETISR_ISO);
				inq = &clnlintrq;
			}
			break;
#endif
		}
		break;
	case CISCO_MULTICAST:
	case CISCO_UNICAST:
		/* Don't check the control field here (RFC 1547). */
		if (! (sp->pp_flags & PP_CISCO)) {
			if (ifp->if_flags & IFF_DEBUG)
				printf ("%s%d: Cisco packet in PPP mode <0x%x 0x%x 0x%x>\n",
					ifp->if_name, ifp->if_unit,
					h->address, h->control, ntohs (h->protocol));
			goto drop;
		}
		switch (ntohs (h->protocol)) {
		default:
			++ifp->if_noproto;
			goto invalid;
		case CISCO_KEEPALIVE:
			sppp_cisco_input ((struct sppp*) ifp, m);
			m_freem (m);
			return;
#ifdef INET
		case ETHERTYPE_IP:
			schednetisr (NETISR_IP);
			inq = &ipintrq;
			break;
#endif
#ifdef NS
		case ETHERTYPE_NS:
			schednetisr (NETISR_NS);
			inq = &nsintrq;
			break;
#endif
		}
		break;
	}

	if (! (ifp->if_flags & IFF_UP) || ! inq)
		goto drop;

	/* Check queue. */
	s = splimp ();
	if (IF_QFULL (inq)) {
		/* Queue overflow. */
		IF_DROP (inq);
		splx (s);
		if (ifp->if_flags & IFF_DEBUG)
			printf ("%s%d: protocol queue overflow\n",
				ifp->if_name, ifp->if_unit);
		goto drop;
	}
	IF_ENQUEUE (inq, m);
	splx (s);
}

/*
 * Enqueue transmit packet.
 */
int sppp_output (struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, struct rtentry *rt)
{
	struct sppp *sp = (struct sppp*) ifp;
	struct ppp_header *h;
	struct ifqueue *ifq;
	int s = splimp ();

	if (! (ifp->if_flags & IFF_UP) || ! (ifp->if_flags & IFF_RUNNING)) {
		m_freem (m);
		splx (s);
		return (ENETDOWN);
	}

	ifq = &ifp->if_snd;
#ifdef INET
	/*
	 * Put low delay, telnet, rlogin and ftp control packets
	 * in front of the queue.
	 */
	{
	struct ip *ip = mtod (m, struct ip*);
	struct tcphdr *tcp = (struct tcphdr*) ((long*)ip + ip->ip_hl);

	if (! IF_QFULL (&sp->pp_fastq) && ((ip->ip_tos & IPTOS_LOWDELAY) ||
	    ip->ip_p == IPPROTO_TCP &&
	    m->m_len >= sizeof (struct ip) + sizeof (struct tcphdr) &&
	    (INTERACTIVE (ntohs (tcp->th_sport)) ||
	    INTERACTIVE (ntohs (tcp->th_dport)))))
		ifq = &sp->pp_fastq;
	}
#endif

	/*
	 * Prepend general data packet PPP header. For now, IP only.
	 */
	M_PREPEND (m, PPP_HEADER_LEN, M_DONTWAIT);
	if (! m) {
		if (ifp->if_flags & IFF_DEBUG)
			printf ("%s%d: no memory for transmit header\n",
				ifp->if_name, ifp->if_unit);
		splx (s);
		return (ENOBUFS);
	}
	h = mtod (m, struct ppp_header*);
	if (sp->pp_flags & PP_CISCO) {
		h->address = CISCO_MULTICAST;        /* broadcast address */
		h->control = 0;
	} else {
		h->address = PPP_ALLSTATIONS;        /* broadcast address */
		h->control = PPP_UI;                 /* Unnumbered Info */
	}

	switch (dst->sa_family) {
#ifdef INET
	case AF_INET:   /* Internet Protocol */
		if (sp->pp_flags & PP_CISCO)
			h->protocol = htons (ETHERTYPE_IP);
		else if (sp->ipcp.state == IPCP_STATE_OPENED)
			h->protocol = htons (PPP_IP);
		else {
			m_freem (m);
			splx (s);
			return (ENETDOWN);
		}
		break;
#endif
#ifdef NS
	case AF_NS:     /* Xerox NS Protocol */
		h->protocol = htons ((sp->pp_flags & PP_CISCO) ?
			ETHERTYPE_NS : PPP_XNS);
		break;
#endif
#ifdef ISO
	case AF_ISO:    /* ISO OSI Protocol */
		if (sp->pp_flags & PP_CISCO)
			goto nosupport;
		h->protocol = htons (PPP_ISO);
		break;
#endif
nosupport:
	default:
		m_freem (m);
		splx (s);
		return (EAFNOSUPPORT);
	}

	/*
	 * Queue message on interface, and start output if interface
	 * not yet active.
	 */
	if (IF_QFULL (ifq)) {
		IF_DROP (&ifp->if_snd);
		m_freem (m);
		splx (s);
		return (ENOBUFS);
	}
	IF_ENQUEUE (ifq, m);
	if (! (ifp->if_flags & IFF_OACTIVE))
		(*ifp->if_start) (ifp);

	/*
	 * Count output packets and bytes.
	 * The packet length includes header, FCS and 1 flag,
	 * according to RFC 1333.
	 */
	ifp->if_obytes += m->m_pkthdr.len + 3;
	splx (s);
	return (0);
}