/************************************************************************* discovery.c** Perform PPPoE discovery** Copyright (C) 1999 by Roaring Penguin Software Inc.** LIC: GPL************************************************************************/#include <string.h>#include <stdlib.h>#include <errno.h>#include <pna.h>#include <tmlib/dprintf.h>#include <ppp.h>#include "syslog.h"#include "pppoe.h"#define BCOPY(p0, p1, n) memmove (p1, p0, n)extern u_char outpacket_buf[];extern char BroadcastAddr[6];int parsePacket(PPPoEPacket *packet, ParseFunc *func, void *extra);static void padi_timeout(caddr_t arg);static void padr_timeout(caddr_t arg);/***********************************************************************%FUNCTION: parsePADOTags*%ARGUMENTS:* type -- tag type* len -- tag length* data -- tag data* extra -- extra user data.  Should point to a PacketCriteria structure*          which gets filled in according to selected AC name and service*          name.*%RETURNS:* Nothing*%DESCRIPTION:* Picks interesting tags out of a PADO packet***********************************************************************/voidparsePADOTags(UINT16_t type, UINT16_t len, unsigned char *data,	      void *extra){    struct PacketCriteria *pc = (struct PacketCriteria *) extra;    PPPoEConnection *conn = pc->conn;    int i;    switch(type) {    case TAG_AC_NAME:	pc->seenACName = 1;	if (conn->printACNames) {	    printf("Access-Concentrator: %.*s\n", (int) len, data);	}	syslog(LOG_DEBUG, "PADO: AC-Name: '%.*s'", (int) len, data);	if (conn->acName && len == strlen(conn->acName) &&	    !strncmp((char *) data, conn->acName, len)) {	    pc->acNameOK = 1;	}	break;    case TAG_SERVICE_NAME:	pc->seenServiceName = 1;	if (conn->printACNames && len > 0) {	    printf("       Service-Name: %.*s\n", (int) len, data);	}	syslog(LOG_DEBUG, "PADO: Service-Name: '%.*s'", (int) len, data);	if (conn->serviceName && len == strlen(conn->serviceName) &&	    !strncmp((char *) data, conn->serviceName, len)) {	    pc->serviceNameOK = 1;	}	break;    case TAG_AC_COOKIE:	if (conn->printACNames) {	    printf("Got a cookie:");	    /* Print first 20 bytes of cookie */	    for (i=0; i<len && i < 20; i++) {		printf(" %02x", (unsigned) data[i]);	    }	    if (i < len) printf("...");	    printf("\n");	}	conn->cookie.type = htons(type);	conn->cookie.length = htons(len);	memcpy(conn->cookie.payload, data, len);	break;    case TAG_RELAY_SESSION_ID:	if (conn->printACNames) {	    printf("Got a Relay-ID:");	    /* Print first 20 bytes of relay ID */	    for (i=0; i<len && i < 20; i++) {		printf(" %02x", (unsigned) data[i]);	    }	    if (i < len) printf("...");	    printf("\n");	}	conn->relayId.type = htons(type);	conn->relayId.length = htons(len);	memcpy(conn->relayId.payload, data, len);	break;    case TAG_SERVICE_NAME_ERROR:	if (conn->printACNames) {	    printf("Got a Service-Name-Error tag: %.*s\n", (int) len, data);	} else {	    syslog(LOG_ERR, "PADO: Service-Name-Error: %.*s", (int) len, data);	    exit(1);	}	break;    case TAG_AC_SYSTEM_ERROR:	if (conn->printACNames) {	    printf("Got a System-Error tag: %.*s\n", (int) len, data);	} else {	    syslog(LOG_ERR, "PADO: System-Error: %.*s", (int) len, data);	    exit(1);	}	break;    case TAG_GENERIC_ERROR:	if (conn->printACNames) {	    printf("Got a Generic-Error tag: %.*s\n", (int) len, data);	} else {	    syslog(LOG_ERR, "PADO: Generic-Error: %.*s", (int) len, data);	    exit(1);	}	break;    }}/***********************************************************************%FUNCTION: parsePADSTags*%ARGUMENTS:* type -- tag type* len -- tag length* data -- tag data* extra -- extra user data (pointer to PPPoEConnection structure)*%RETURNS:* Nothing*%DESCRIPTION:* Picks interesting tags out of a PADS packet***********************************************************************/voidparsePADSTags(UINT16_t type, UINT16_t len, unsigned char *data,	      void *extra){    PPPoEConnection *conn = (PPPoEConnection *) extra;    switch(type) {    case TAG_SERVICE_NAME:	syslog(LOG_DEBUG, "PADS: Service-Name: '%.*s'", (int) len, data);	break;    case TAG_SERVICE_NAME_ERROR:	syslog(LOG_ERR, "PADS: Service-Name-Error: %.*s", (int) len, data);	exit(1);    case TAG_AC_SYSTEM_ERROR:	syslog(LOG_ERR, "PADS: System-Error: %.*s", (int) len, data);	exit(1);    case TAG_GENERIC_ERROR:	syslog(LOG_ERR, "PADS: Generic-Error: %.*s", (int) len, data);	exit(1);    case TAG_RELAY_SESSION_ID:	conn->relayId.type = htons(type);	conn->relayId.length = htons(len);	memcpy(conn->relayId.payload, data, len);	break;    }}/*Parse PADT packet*/voidparseLogErrs(UINT16_t type, UINT16_t len, unsigned char *data, void *extra){    switch(type) {    case TAG_SERVICE_NAME_ERROR:	syslog(LOG_ERR, "PADT: Service-Name-Error: %.*s", (int) len, data);	break;    case TAG_AC_SYSTEM_ERROR:	syslog(LOG_ERR, "PADT: System-Error: %.*s", (int) len, data);	break;    case TAG_GENERIC_ERROR:	syslog(LOG_ERR, "PADT: Generic-Error: %.*s", (int) len, data);	break;    }}/************************************************************************%FUNCTION: sendPADI*%ARGUMENTS:* conn -- PPPoEConnection structure*%RETURNS:* Nothing*%DESCRIPTION:* Sends a PADI packet***********************************************************************/voidsendPADI(PPPoEConnection *conn){        UINT16_t namelen = 0;    UINT16_t plen;    u_char *outp = outpacket_buf;    int tm,i;        if (conn->serviceName) {	namelen = (UINT16_t) strlen(conn->serviceName);    }    plen = TAG_HDR_SIZE + namelen;        tm = PADI_TIMEOUT;    for(i=0;i<conn->padi_trans;i++) tm = tm*2;          PUTSHORT(ETH_PPPOE_DISCOVERY, outp);    PUTCHAR(0x11,outp);     PUTCHAR(CODE_PADI, outp);    PUTSHORT(0, outp);    PUTSHORT(plen, outp);    PUTSHORT(TAG_SERVICE_NAME, outp);    PUTSHORT(namelen, outp);    if (conn->serviceName) {	BCOPY(conn->serviceName, outp, namelen);    }    output( BroadcastAddr, 0, outpacket_buf, plen+8 );    TIMEOUT(padi_timeout, (caddr_t)(conn), tm);    ++conn->padi_trans;    conn->discoveryState = STATE_SENT_PADI;    syslog(LOG_INFO, "send PADI: Sent code %d .", CODE_PADI);    }/************************************************************************%FUNCTION: recvPADO*%ARGUMENTS:   *conn -- PPPoEConnection structure*%RETURNS:      Nothing*%DESCRIPTION:  Receive a PADO packet***********************************************************************/voidrecvPADO(PPPoEConnection *conn, unsigned char *ptr, unsigned int num){    PPPoEPacket *packet;    struct PacketCriteria pc;        pc.conn          = conn;    pc.acNameOK      = (conn->acName)      ? 0 : 1;    pc.serviceNameOK = (conn->serviceName) ? 0 : 1;    pc.seenACName    = 0;    pc.seenServiceName = 0;        packet = (PPPoEPacket *)ptr;        if (ntohs(packet->length) + HDR_SIZE > num) {	    syslog(LOG_ERR, "Bogus PPPoE length field (%u)", (unsigned int) ntohs(packet->length));	    goto error;    }        if (memcmp(packet->h_dest, conn->myEth, ETH_ALEN)) {    	    syslog(LOG_ERR, "This packet is not for me !");    	    goto error;    }         if (NOT_UNICAST(packet->h_source)) {    	    syslog(LOG_ERR, "This packet is not unicast !");    	    goto error;	      }        parsePacket(packet, parsePADOTags, &pc);        if (!pc.seenACName) {	    syslog(LOG_ERR, "Ignoring PADO packet with no AC-Name tag !");    	    goto error;	  	    }    if (!pc.seenServiceName) {	    syslog(LOG_ERR, "Ignoring PADO packet with no Service-Name tag !");    	    goto error;	  		    }        conn->numPADOs++;    if (pc.acNameOK && pc.serviceNameOK) {	    memcpy(conn->peerEth, packet->h_source, ETH_ALEN);	    if (conn->printACNames) {		    printf("AC-Ethernet-Address: %02x:%02x:%02x:%02x:%02x:%02x\n",			   (unsigned) conn->peerEth[0],			   (unsigned) conn->peerEth[1],