+++ /dev/null
-/***********************************************************************
-*
-* discovery.c
-*
-* Perform PPPoE discovery
-*
-* Copyright (C) 1999 by Roaring Penguin Software Inc.
-*
-***********************************************************************/
-
-static char const RCSID[] =
-"$Id: discovery.c,v 1.6 2008/06/15 04:35:50 paulus Exp $";
-
-#define _GNU_SOURCE 1
-#include "pppoe.h"
-#include "pppd/pppd.h"
-#include "pppd/fsm.h"
-#include "pppd/lcp.h"
-
-#include <string.h>
-#include <stdlib.h>
-#include <errno.h>
-
-#ifdef HAVE_SYS_TIME_H
-#include <sys/time.h>
-#endif
-
-#ifdef HAVE_SYS_UIO_H
-#include <sys/uio.h>
-#endif
-
-#ifdef HAVE_UNISTD_H
-#include <unistd.h>
-#endif
-
-#ifdef USE_LINUX_PACKET
-#include <sys/ioctl.h>
-#include <fcntl.h>
-#endif
-
-#include <signal.h>
-
-/* Calculate time remaining until *exp, return 0 if now >= *exp */
-static int time_left(struct timeval *diff, struct timeval *exp)
-{
- struct timeval now;
-
- if (get_time(&now) < 0) {
- error("get_time: %m");
- return 0;
- }
-
- if (now.tv_sec > exp->tv_sec
- || (now.tv_sec == exp->tv_sec && now.tv_usec >= exp->tv_usec))
- return 0;
-
- diff->tv_sec = exp->tv_sec - now.tv_sec;
- diff->tv_usec = exp->tv_usec - now.tv_usec;
- if (diff->tv_usec < 0) {
- diff->tv_usec += 1000000;
- --diff->tv_sec;
- }
-
- return 1;
-}
-
-/**********************************************************************
-*%FUNCTION: parseForHostUniq
-*%ARGUMENTS:
-* type -- tag type
-* len -- tag length
-* data -- tag data.
-* extra -- user-supplied pointer. This is assumed to be a pointer to int.
-*%RETURNS:
-* Nothing
-*%DESCRIPTION:
-* If a HostUnique tag is found which matches our PID, sets *extra to 1.
-***********************************************************************/
-static void
-parseForHostUniq(UINT16_t type, UINT16_t len, unsigned char *data,
- void *extra)
-{
- PPPoETag *tag = extra;
-
- if (type == TAG_HOST_UNIQ && len == ntohs(tag->length))
- tag->length = memcmp(data, tag->payload, len);
-}
-
-/**********************************************************************
-*%FUNCTION: packetIsForMe
-*%ARGUMENTS:
-* conn -- PPPoE connection info
-* packet -- a received PPPoE packet
-*%RETURNS:
-* 1 if packet is for this PPPoE daemon; 0 otherwise.
-*%DESCRIPTION:
-* If we are using the Host-Unique tag, verifies that packet contains
-* our unique identifier.
-***********************************************************************/
-static int
-packetIsForMe(PPPoEConnection *conn, PPPoEPacket *packet)
-{
- PPPoETag hostUniq = conn->hostUniq;
-
- /* If packet is not directed to our MAC address, forget it */
- if (memcmp(packet->ethHdr.h_dest, conn->myEth, ETH_ALEN)) return 0;
-
- /* If we're not using the Host-Unique tag, then accept the packet */
- if (!conn->hostUniq.length) return 1;
-
- parsePacket(packet, parseForHostUniq, &hostUniq);
- return !hostUniq.length;
-}
-
-/**********************************************************************
-*%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
-***********************************************************************/
-static void
-parsePADOTags(UINT16_t type, UINT16_t len, unsigned char *data,
- void *extra)
-{
- struct PacketCriteria *pc = (struct PacketCriteria *) extra;
- PPPoEConnection *conn = pc->conn;
- UINT16_t mru;
- int i;
-
- switch(type) {
- case TAG_AC_NAME:
- pc->seenACName = 1;
- if (conn->printACNames) {
- info("Access-Concentrator: %.*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->serviceName && len == strlen(conn->serviceName) &&
- !strncmp((char *) data, conn->serviceName, len)) {
- pc->serviceNameOK = 1;
- }
- break;
- case TAG_AC_COOKIE:
- conn->cookie.type = htons(type);
- conn->cookie.length = htons(len);
- memcpy(conn->cookie.payload, data, len);
- break;
- case TAG_RELAY_SESSION_ID:
- conn->relayId.type = htons(type);
- conn->relayId.length = htons(len);
- memcpy(conn->relayId.payload, data, len);
- break;
- case TAG_PPP_MAX_PAYLOAD:
- if (len == sizeof(mru)) {
- memcpy(&mru, data, sizeof(mru));
- mru = ntohs(mru);
- if (mru >= ETH_PPPOE_MTU) {
- if (lcp_allowoptions[0].mru > mru)
- lcp_allowoptions[0].mru = mru;
- if (lcp_wantoptions[0].mru > mru)
- lcp_wantoptions[0].mru = mru;
- conn->seenMaxPayload = 1;
- }
- }
- break;
- case TAG_SERVICE_NAME_ERROR:
- error("PADO: Service-Name-Error: %.*s", (int) len, data);
- conn->error = 1;
- break;
- case TAG_AC_SYSTEM_ERROR:
- error("PADO: System-Error: %.*s", (int) len, data);
- conn->error = 1;
- break;
- case TAG_GENERIC_ERROR:
- error("PADO: Generic-Error: %.*s", (int) len, data);
- conn->error = 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
-***********************************************************************/
-static void
-parsePADSTags(UINT16_t type, UINT16_t len, unsigned char *data,
- void *extra)
-{
- PPPoEConnection *conn = (PPPoEConnection *) extra;
- UINT16_t mru;
- switch(type) {
- case TAG_SERVICE_NAME:
- dbglog("PADS: Service-Name: '%.*s'", (int) len, data);
- break;
- case TAG_PPP_MAX_PAYLOAD:
- if (len == sizeof(mru)) {
- memcpy(&mru, data, sizeof(mru));
- mru = ntohs(mru);
- if (mru >= ETH_PPPOE_MTU) {
- if (lcp_allowoptions[0].mru > mru)
- lcp_allowoptions[0].mru = mru;
- if (lcp_wantoptions[0].mru > mru)
- lcp_wantoptions[0].mru = mru;
- conn->seenMaxPayload = 1;
- }
- }
- break;
- case TAG_SERVICE_NAME_ERROR:
- error("PADS: Service-Name-Error: %.*s", (int) len, data);
- conn->error = 1;
- break;
- case TAG_AC_SYSTEM_ERROR:
- error("PADS: System-Error: %.*s", (int) len, data);
- conn->error = 1;
- break;
- case TAG_GENERIC_ERROR:
- error("PADS: Generic-Error: %.*s", (int) len, data);
- conn->error = 1;
- break;
- case TAG_RELAY_SESSION_ID:
- conn->relayId.type = htons(type);
- conn->relayId.length = htons(len);
- memcpy(conn->relayId.payload, data, len);
- break;
- }
-}
-
-/***********************************************************************
-*%FUNCTION: sendPADI
-*%ARGUMENTS:
-* conn -- PPPoEConnection structure
-*%RETURNS:
-* Nothing
-*%DESCRIPTION:
-* Sends a PADI packet
-***********************************************************************/
-static void
-sendPADI(PPPoEConnection *conn)
-{
- PPPoEPacket packet;
- unsigned char *cursor = packet.payload;
- PPPoETag *svc = (PPPoETag *) (&packet.payload);
- UINT16_t namelen = 0;
- UINT16_t plen;
- int omit_service_name = 0;
-
- if (conn->serviceName) {
- namelen = (UINT16_t) strlen(conn->serviceName);
- if (!strcmp(conn->serviceName, "NO-SERVICE-NAME-NON-RFC-COMPLIANT")) {
- omit_service_name = 1;
- }
- }
-
- /* Set destination to Ethernet broadcast address */
- memset(packet.ethHdr.h_dest, 0xFF, ETH_ALEN);
- memcpy(packet.ethHdr.h_source, conn->myEth, ETH_ALEN);
-
- packet.ethHdr.h_proto = htons(Eth_PPPOE_Discovery);
- packet.vertype = PPPOE_VER_TYPE(1, 1);
- packet.code = CODE_PADI;
- packet.session = 0;
-
- if (!omit_service_name) {
- plen = TAG_HDR_SIZE + namelen;
- CHECK_ROOM(cursor, packet.payload, plen);
-
- svc->type = TAG_SERVICE_NAME;
- svc->length = htons(namelen);
-
- if (conn->serviceName) {
- memcpy(svc->payload, conn->serviceName, strlen(conn->serviceName));
- }
- cursor += namelen + TAG_HDR_SIZE;
- } else {
- plen = 0;
- }
-
- /* If we're using Host-Uniq, copy it over */
- if (conn->hostUniq.length) {
- int len = ntohs(conn->hostUniq.length);
- CHECK_ROOM(cursor, packet.payload, len + TAG_HDR_SIZE);
- memcpy(cursor, &conn->hostUniq, len + TAG_HDR_SIZE);
- cursor += len + TAG_HDR_SIZE;
- plen += len + TAG_HDR_SIZE;
- }
-
- /* Add our maximum MTU/MRU */
- if (MIN(lcp_allowoptions[0].mru, lcp_wantoptions[0].mru) > ETH_PPPOE_MTU) {
- PPPoETag maxPayload;
- UINT16_t mru = htons(MIN(lcp_allowoptions[0].mru, lcp_wantoptions[0].mru));
- maxPayload.type = htons(TAG_PPP_MAX_PAYLOAD);
- maxPayload.length = htons(sizeof(mru));
- memcpy(maxPayload.payload, &mru, sizeof(mru));
- CHECK_ROOM(cursor, packet.payload, sizeof(mru) + TAG_HDR_SIZE);
- memcpy(cursor, &maxPayload, sizeof(mru) + TAG_HDR_SIZE);
- cursor += sizeof(mru) + TAG_HDR_SIZE;
- plen += sizeof(mru) + TAG_HDR_SIZE;
- }
-
- packet.length = htons(plen);
-
- sendPacket(conn, conn->discoverySocket, &packet, (int) (plen + HDR_SIZE));
-}
-
-/**********************************************************************
-*%FUNCTION: waitForPADO
-*%ARGUMENTS:
-* conn -- PPPoEConnection structure
-* timeout -- how long to wait (in seconds)
-*%RETURNS:
-* Nothing
-*%DESCRIPTION:
-* Waits for a PADO packet and copies useful information
-***********************************************************************/
-void
-waitForPADO(PPPoEConnection *conn, int timeout)
-{
- fd_set readable;
- int r;
- struct timeval tv;
- struct timeval expire_at;
-
- PPPoEPacket packet;
- int len;
-
- struct PacketCriteria pc;
- pc.conn = conn;
- pc.acNameOK = (conn->acName) ? 0 : 1;
- pc.serviceNameOK = (conn->serviceName) ? 0 : 1;
- pc.seenACName = 0;
- pc.seenServiceName = 0;
- conn->seenMaxPayload = 0;
- conn->error = 0;
-
- if (get_time(&expire_at) < 0) {
- error("get_time (waitForPADO): %m");
- return;
- }
- expire_at.tv_sec += timeout;
-
- do {
- if (BPF_BUFFER_IS_EMPTY) {
- if (!time_left(&tv, &expire_at))
- return; /* Timed out */
-
- FD_ZERO(&readable);
- FD_SET(conn->discoverySocket, &readable);
-
- while(1) {
- r = select(conn->discoverySocket+1, &readable, NULL, NULL, &tv);
- if (r >= 0 || errno != EINTR || got_sigterm) break;
- }
- if (r < 0) {
- error("select (waitForPADO): %m");
- return;
- }
- if (r == 0)
- return; /* Timed out */
- }
-
- /* Get the packet */
- receivePacket(conn->discoverySocket, &packet, &len);
-
- /* Check length */
- if (ntohs(packet.length) + HDR_SIZE > len) {
- error("Bogus PPPoE length field (%u)",
- (unsigned int) ntohs(packet.length));
- continue;
- }
-
-#ifdef USE_BPF
- /* If it's not a Discovery packet, loop again */
- if (etherType(&packet) != Eth_PPPOE_Discovery) continue;
-#endif
-
- /* If it's not for us, loop again */
- if (!packetIsForMe(conn, &packet)) continue;
-
- if (packet.code == CODE_PADO) {
- if (NOT_UNICAST(packet.ethHdr.h_source)) {
- error("Ignoring PADO packet from non-unicast MAC address");
- continue;
- }
- if (conn->req_peer
- && memcmp(packet.ethHdr.h_source, conn->req_peer_mac, ETH_ALEN) != 0) {
- warn("Ignoring PADO packet from wrong MAC address");
- continue;
- }
- if (parsePacket(&packet, parsePADOTags, &pc) < 0)
- return;
- if (conn->error)
- return;
- if (!pc.seenACName) {
- error("Ignoring PADO packet with no AC-Name tag");
- continue;
- }
- if (!pc.seenServiceName) {
- error("Ignoring PADO packet with no Service-Name tag");
- continue;
- }
- conn->numPADOs++;
- if (pc.acNameOK && pc.serviceNameOK) {
- memcpy(conn->peerEth, packet.ethHdr.h_source, ETH_ALEN);
- conn->discoveryState = STATE_RECEIVED_PADO;
- break;
- }
- }
- } while (conn->discoveryState != STATE_RECEIVED_PADO);
-}
-
-/***********************************************************************
-*%FUNCTION: sendPADR
-*%ARGUMENTS:
-* conn -- PPPoE connection structur
-*%RETURNS:
-* Nothing
-*%DESCRIPTION:
-* Sends a PADR packet
-***********************************************************************/
-static void
-sendPADR(PPPoEConnection *conn)
-{
- PPPoEPacket packet;
- PPPoETag *svc = (PPPoETag *) packet.payload;
- unsigned char *cursor = packet.payload;
-
- UINT16_t namelen = 0;
- UINT16_t plen;
-
- if (conn->serviceName) {
- namelen = (UINT16_t) strlen(conn->serviceName);
- }
- plen = TAG_HDR_SIZE + namelen;
- CHECK_ROOM(cursor, packet.payload, plen);
-
- memcpy(packet.ethHdr.h_dest, conn->peerEth, ETH_ALEN);
- memcpy(packet.ethHdr.h_source, conn->myEth, ETH_ALEN);
-
- packet.ethHdr.h_proto = htons(Eth_PPPOE_Discovery);
- packet.vertype = PPPOE_VER_TYPE(1, 1);
- packet.code = CODE_PADR;
- packet.session = 0;
-
- svc->type = TAG_SERVICE_NAME;
- svc->length = htons(namelen);
- if (conn->serviceName) {
- memcpy(svc->payload, conn->serviceName, namelen);
- }
- cursor += namelen + TAG_HDR_SIZE;
-
- /* If we're using Host-Uniq, copy it over */
- if (conn->hostUniq.length) {
- int len = ntohs(conn->hostUniq.length);
- CHECK_ROOM(cursor, packet.payload, len+TAG_HDR_SIZE);
- memcpy(cursor, &conn->hostUniq, len + TAG_HDR_SIZE);
- cursor += len + TAG_HDR_SIZE;
- plen += len + TAG_HDR_SIZE;
- }
-
- /* Add our maximum MTU/MRU */
- if (MIN(lcp_allowoptions[0].mru, lcp_wantoptions[0].mru) > ETH_PPPOE_MTU) {
- PPPoETag maxPayload;
- UINT16_t mru = htons(MIN(lcp_allowoptions[0].mru, lcp_wantoptions[0].mru));
- maxPayload.type = htons(TAG_PPP_MAX_PAYLOAD);
- maxPayload.length = htons(sizeof(mru));
- memcpy(maxPayload.payload, &mru, sizeof(mru));
- CHECK_ROOM(cursor, packet.payload, sizeof(mru) + TAG_HDR_SIZE);
- memcpy(cursor, &maxPayload, sizeof(mru) + TAG_HDR_SIZE);
- cursor += sizeof(mru) + TAG_HDR_SIZE;
- plen += sizeof(mru) + TAG_HDR_SIZE;
- }
-
- /* Copy cookie and relay-ID if needed */
- if (conn->cookie.type) {
- CHECK_ROOM(cursor, packet.payload,
- ntohs(conn->cookie.length) + TAG_HDR_SIZE);
- memcpy(cursor, &conn->cookie, ntohs(conn->cookie.length) + TAG_HDR_SIZE);
- cursor += ntohs(conn->cookie.length) + TAG_HDR_SIZE;
- plen += ntohs(conn->cookie.length) + TAG_HDR_SIZE;
- }
-
- if (conn->relayId.type) {
- CHECK_ROOM(cursor, packet.payload,
- ntohs(conn->relayId.length) + TAG_HDR_SIZE);
- memcpy(cursor, &conn->relayId, ntohs(conn->relayId.length) + TAG_HDR_SIZE);
- cursor += ntohs(conn->relayId.length) + TAG_HDR_SIZE;
- plen += ntohs(conn->relayId.length) + TAG_HDR_SIZE;
- }
-
- packet.length = htons(plen);
- sendPacket(conn, conn->discoverySocket, &packet, (int) (plen + HDR_SIZE));
-}
-
-/**********************************************************************
-*%FUNCTION: waitForPADS
-*%ARGUMENTS:
-* conn -- PPPoE connection info
-* timeout -- how long to wait (in seconds)
-*%RETURNS:
-* Nothing
-*%DESCRIPTION:
-* Waits for a PADS packet and copies useful information
-***********************************************************************/
-static void
-waitForPADS(PPPoEConnection *conn, int timeout)
-{
- fd_set readable;
- int r;
- struct timeval tv;
- struct timeval expire_at;
-
- PPPoEPacket packet;
- int len;
-
- if (get_time(&expire_at) < 0) {
- error("get_time (waitForPADS): %m");
- return;
- }
- expire_at.tv_sec += timeout;
-
- conn->error = 0;
- do {
- if (BPF_BUFFER_IS_EMPTY) {
- if (!time_left(&tv, &expire_at))
- return; /* Timed out */
-
- FD_ZERO(&readable);
- FD_SET(conn->discoverySocket, &readable);
-
- while(1) {
- r = select(conn->discoverySocket+1, &readable, NULL, NULL, &tv);
- if (r >= 0 || errno != EINTR || got_sigterm) break;
- }
- if (r < 0) {
- error("select (waitForPADS): %m");
- return;
- }
- if (r == 0)
- return; /* Timed out */
- }
-
- /* Get the packet */
- receivePacket(conn->discoverySocket, &packet, &len);
-
- /* Check length */
- if (ntohs(packet.length) + HDR_SIZE > len) {
- error("Bogus PPPoE length field (%u)",
- (unsigned int) ntohs(packet.length));
- continue;
- }
-
-#ifdef USE_BPF
- /* If it's not a Discovery packet, loop again */
- if (etherType(&packet) != Eth_PPPOE_Discovery) continue;
-#endif
-
- /* If it's not from the AC, it's not for me */
- if (memcmp(packet.ethHdr.h_source, conn->peerEth, ETH_ALEN)) continue;
-
- /* If it's not for us, loop again */
- if (!packetIsForMe(conn, &packet)) continue;
-
- /* Is it PADS? */
- if (packet.code == CODE_PADS) {
- /* Parse for goodies */
- if (parsePacket(&packet, parsePADSTags, conn) < 0)
- return;
- if (conn->error)
- return;
- conn->discoveryState = STATE_SESSION;
- break;
- }
- } while (conn->discoveryState != STATE_SESSION);
-
- /* Don't bother with ntohs; we'll just end up converting it back... */
- conn->session = packet.session;
-
- info("PPP session is %d", (int) ntohs(conn->session));
-
- /* RFC 2516 says session id MUST NOT be zero or 0xFFFF */
- if (ntohs(conn->session) == 0 || ntohs(conn->session) == 0xFFFF) {
- error("Access concentrator used a session value of %x -- the AC is violating RFC 2516", (unsigned int) ntohs(conn->session));
- }
-}
-
-/**********************************************************************
-*%FUNCTION: discovery
-*%ARGUMENTS:
-* conn -- PPPoE connection info structure
-*%RETURNS:
-* Nothing
-*%DESCRIPTION:
-* Performs the PPPoE discovery phase
-***********************************************************************/
-void
-discovery(PPPoEConnection *conn)
-{
- int padiAttempts = 0;
- int padrAttempts = 0;
- int timeout = conn->discoveryTimeout;
-
- do {
- padiAttempts++;
- if (got_sigterm || padiAttempts > conn->discoveryAttempts) {
- warn("Timeout waiting for PADO packets");
- close(conn->discoverySocket);
- conn->discoverySocket = -1;
- return;
- }
- sendPADI(conn);
- conn->discoveryState = STATE_SENT_PADI;
- waitForPADO(conn, timeout);
-
- timeout *= 2;
- } while (conn->discoveryState == STATE_SENT_PADI);
-
- timeout = conn->discoveryTimeout;
- do {
- padrAttempts++;
- if (got_sigterm || padrAttempts > conn->discoveryAttempts) {
- warn("Timeout waiting for PADS packets");
- close(conn->discoverySocket);
- conn->discoverySocket = -1;
- return;
- }
- sendPADR(conn);
- conn->discoveryState = STATE_SENT_PADR;
- waitForPADS(conn, timeout);
- timeout *= 2;
- } while (conn->discoveryState == STATE_SENT_PADR);
-
- if (!conn->seenMaxPayload) {
- /* RFC 4638: MUST limit MTU/MRU to 1492 */
- if (lcp_allowoptions[0].mru > ETH_PPPOE_MTU)
- lcp_allowoptions[0].mru = ETH_PPPOE_MTU;
- if (lcp_wantoptions[0].mru > ETH_PPPOE_MTU)
- lcp_wantoptions[0].mru = ETH_PPPOE_MTU;
- }
-
- /* We're done. */
- close(conn->discoverySocket);
- conn->discoverySocket = -1;
- conn->discoveryState = STATE_SESSION;
- return;
-}
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