+/* Initialize frame types to RFC 2516 values. Some broken peers apparently
+ use different frame types... sigh... */
+
+UINT16_t Eth_PPPOE_Discovery = ETH_PPPOE_DISCOVERY;
+UINT16_t Eth_PPPOE_Session = ETH_PPPOE_SESSION;
+
+/**********************************************************************
+*%FUNCTION: etherType
+*%ARGUMENTS:
+* packet -- a received PPPoE packet
+*%RETURNS:
+* ethernet packet type (see /usr/include/net/ethertypes.h)
+*%DESCRIPTION:
+* Checks the ethernet packet header to determine its type.
+* We should only be receveing DISCOVERY and SESSION types if the BPF
+* is set up correctly. Logs an error if an unexpected type is received.
+* Note that the ethernet type names come from "pppoe.h" and the packet
+* packet structure names use the LINUX dialect to maintain consistency
+* with the rest of this file. See the BSD section of "pppoe.h" for
+* translations of the data structure names.
+***********************************************************************/
+UINT16_t
+etherType(PPPoEPacket *packet)
+{
+ UINT16_t type = (UINT16_t) ntohs(packet->ethHdr.h_proto);
+ if (type != Eth_PPPOE_Discovery && type != Eth_PPPOE_Session) {
+ fprintf(stderr, "Invalid ether type 0x%x\n", type);
+ }
+ return type;
+}
+
+/**********************************************************************
+*%FUNCTION: openInterface
+*%ARGUMENTS:
+* ifname -- name of interface
+* type -- Ethernet frame type
+* hwaddr -- if non-NULL, set to the hardware address
+*%RETURNS:
+* A raw socket for talking to the Ethernet card. Exits on error.
+*%DESCRIPTION:
+* Opens a raw Ethernet socket
+***********************************************************************/
+int
+openInterface(char const *ifname, UINT16_t type, unsigned char *hwaddr)
+{
+ int optval=1;
+ int fd;
+ struct ifreq ifr;
+ int domain, stype;
+
+#ifdef HAVE_STRUCT_SOCKADDR_LL
+ struct sockaddr_ll sa;
+#else
+ struct sockaddr sa;
+#endif
+
+ memset(&sa, 0, sizeof(sa));
+
+#ifdef HAVE_STRUCT_SOCKADDR_LL
+ domain = PF_PACKET;
+ stype = SOCK_RAW;
+#else
+ domain = PF_INET;
+ stype = SOCK_PACKET;
+#endif
+
+ if ((fd = socket(domain, stype, htons(type))) < 0) {
+ /* Give a more helpful message for the common error case */
+ if (errno == EPERM) {
+ rp_fatal("Cannot create raw socket -- pppoe must be run as root.");
+ }
+ fatalSys("socket");
+ }
+
+ if (setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &optval, sizeof(optval)) < 0) {
+ fatalSys("setsockopt");
+ }
+
+ /* Fill in hardware address */
+ if (hwaddr) {
+ strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
+ if (ioctl(fd, SIOCGIFHWADDR, &ifr) < 0) {
+ fatalSys("ioctl(SIOCGIFHWADDR)");
+ }
+ memcpy(hwaddr, ifr.ifr_hwaddr.sa_data, ETH_ALEN);
+#ifdef ARPHRD_ETHER
+ if (ifr.ifr_hwaddr.sa_family != ARPHRD_ETHER) {
+ char buffer[256];
+ sprintf(buffer, "Interface %.16s is not Ethernet", ifname);
+ rp_fatal(buffer);
+ }
+#endif
+ if (NOT_UNICAST(hwaddr)) {
+ char buffer[256];
+ sprintf(buffer,
+ "Interface %.16s has broadcast/multicast MAC address??",
+ ifname);
+ rp_fatal(buffer);
+ }
+ }
+
+ /* Sanity check on MTU */
+ strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
+ if (ioctl(fd, SIOCGIFMTU, &ifr) < 0) {
+ fatalSys("ioctl(SIOCGIFMTU)");
+ }
+ if (ifr.ifr_mtu < ETH_DATA_LEN) {
+ fprintf(stderr, "Interface %.16s has MTU of %d -- should be %d.\n",
+ ifname, ifr.ifr_mtu, ETH_DATA_LEN);
+ fprintf(stderr, "You may have serious connection problems.\n");
+ }
+
+#ifdef HAVE_STRUCT_SOCKADDR_LL
+ /* Get interface index */
+ sa.sll_family = AF_PACKET;
+ sa.sll_protocol = htons(type);
+
+ strncpy(ifr.ifr_name, ifname, sizeof(ifr.ifr_name));
+ if (ioctl(fd, SIOCGIFINDEX, &ifr) < 0) {
+ fatalSys("ioctl(SIOCFIGINDEX): Could not get interface index");
+ }
+ sa.sll_ifindex = ifr.ifr_ifindex;
+
+#else
+ strcpy(sa.sa_data, ifname);
+#endif
+
+ /* We're only interested in packets on specified interface */
+ if (bind(fd, (struct sockaddr *) &sa, sizeof(sa)) < 0) {
+ fatalSys("bind");
+ }
+
+ return fd;
+}
+
+
+/***********************************************************************
+*%FUNCTION: sendPacket
+*%ARGUMENTS:
+* sock -- socket to send to
+* pkt -- the packet to transmit
+* size -- size of packet (in bytes)
+*%RETURNS:
+* 0 on success; -1 on failure
+*%DESCRIPTION:
+* Transmits a packet
+***********************************************************************/
+int
+sendPacket(PPPoEConnection *conn, int sock, PPPoEPacket *pkt, int size)
+{
+#if defined(HAVE_STRUCT_SOCKADDR_LL)
+ if (send(sock, pkt, size, 0) < 0) {
+ sysErr("send (sendPacket)");
+ return -1;
+ }
+#else
+ struct sockaddr sa;
+
+ if (!conn) {
+ rp_fatal("relay and server not supported on Linux 2.0 kernels");
+ }
+ strcpy(sa.sa_data, conn->ifName);
+ if (sendto(sock, pkt, size, 0, &sa, sizeof(sa)) < 0) {
+ sysErr("sendto (sendPacket)");
+ return -1;
+ }
+#endif
+ return 0;
+}
+
+/***********************************************************************
+*%FUNCTION: receivePacket
+*%ARGUMENTS:
+* sock -- socket to read from
+* pkt -- place to store the received packet
+* size -- set to size of packet in bytes
+*%RETURNS:
+* >= 0 if all OK; < 0 if error
+*%DESCRIPTION:
+* Receives a packet
+***********************************************************************/
+int
+receivePacket(int sock, PPPoEPacket *pkt, int *size)
+{
+ if ((*size = recv(sock, pkt, sizeof(PPPoEPacket), 0)) < 0) {
+ sysErr("recv (receivePacket)");
+ return -1;
+ }
+ return 0;
+}
+
+/**********************************************************************
+*%FUNCTION: parsePacket
+*%ARGUMENTS:
+* packet -- the PPPoE discovery packet to parse
+* func -- function called for each tag in the packet
+* extra -- an opaque data pointer supplied to parsing function
+*%RETURNS:
+* 0 if everything went well; -1 if there was an error
+*%DESCRIPTION:
+* Parses a PPPoE discovery packet, calling "func" for each tag in the packet.
+* "func" is passed the additional argument "extra".
+***********************************************************************/
+int
+parsePacket(PPPoEPacket *packet, ParseFunc *func, void *extra)
+{
+ UINT16_t len = ntohs(packet->length);
+ unsigned char *curTag;
+ UINT16_t tagType, tagLen;
+
+ if (PPPOE_VER(packet->vertype) != 1) {
+ fprintf(stderr, "Invalid PPPoE version (%d)\n",
+ PPPOE_VER(packet->vertype));
+ return -1;
+ }
+ if (PPPOE_TYPE(packet->vertype) != 1) {
+ fprintf(stderr, "Invalid PPPoE type (%d)\n",
+ PPPOE_TYPE(packet->vertype));
+ return -1;
+ }
+
+ /* Do some sanity checks on packet */
+ if (len > ETH_DATA_LEN - 6) { /* 6-byte overhead for PPPoE header */
+ fprintf(stderr, "Invalid PPPoE packet length (%u)\n", len);
+ return -1;
+ }
+
+ /* Step through the tags */
+ curTag = packet->payload;
+ while(curTag - packet->payload < len) {
+ /* Alignment is not guaranteed, so do this by hand... */
+ tagType = (curTag[0] << 8) + curTag[1];
+ tagLen = (curTag[2] << 8) + curTag[3];
+ if (tagType == TAG_END_OF_LIST) {
+ return 0;
+ }
+ if ((curTag - packet->payload) + tagLen + TAG_HDR_SIZE > len) {
+ fprintf(stderr, "Invalid PPPoE tag length (%u)\n", tagLen);
+ return -1;
+ }
+ func(tagType, tagLen, curTag+TAG_HDR_SIZE, extra);
+ curTag = curTag + TAG_HDR_SIZE + tagLen;
+ }
+ return 0;
+}
+
+/**********************************************************************
+*%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.
+***********************************************************************/
+void
+parseForHostUniq(UINT16_t type, UINT16_t len, unsigned char *data,
+ void *extra)
+{
+ int *val = (int *) extra;
+ if (type == TAG_HOST_UNIQ && len == sizeof(pid_t)) {
+ pid_t tmp;
+ memcpy(&tmp, data, len);
+ if (tmp == getpid()) {
+ *val = 1;
+ }
+ }
+}
+
+/**********************************************************************
+*%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.
+***********************************************************************/
+int
+packetIsForMe(PPPoEConnection *conn, PPPoEPacket *packet)
+{
+ int forMe = 0;
+
+ /* 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->useHostUniq) return 1;
+
+ parsePacket(packet, parseForHostUniq, &forMe);
+ return forMe;
+}
+
+/**********************************************************************
+*%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
+***********************************************************************/
+void
+parsePADOTags(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;
+ printf("Access-Concentrator: %.*s\n", (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 (len > 0) {
+ printf(" Service-Name: %.*s\n", (int) len, data);
+ }
+ if (conn->serviceName && len == strlen(conn->serviceName) &&
+ !strncmp((char *) data, conn->serviceName, len)) {
+ pc->serviceNameOK = 1;
+ }
+ break;
+ case TAG_AC_COOKIE:
+ 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:
+ 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:
+ printf("Got a Service-Name-Error tag: %.*s\n", (int) len, data);
+ break;
+ case TAG_AC_SYSTEM_ERROR:
+ printf("Got a System-Error tag: %.*s\n", (int) len, data);
+ break;
+ case TAG_GENERIC_ERROR:
+ printf("Got a Generic-Error tag: %.*s\n", (int) len, data);
+ break;
+ }
+}
+
+/***********************************************************************
+*%FUNCTION: sendPADI
+*%ARGUMENTS:
+* conn -- PPPoEConnection structure
+*%RETURNS:
+* Nothing
+*%DESCRIPTION:
+* Sends a PADI packet
+***********************************************************************/
+void
+sendPADI(PPPoEConnection *conn)
+{
+ PPPoEPacket packet;
+ unsigned char *cursor = packet.payload;
+ PPPoETag *svc = (PPPoETag *) (&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);
+
+ /* 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;
+
+ svc->type = TAG_SERVICE_NAME;
+ svc->length = htons(namelen);
+ CHECK_ROOM(cursor, packet.payload, namelen+TAG_HDR_SIZE);
+
+ if (conn->serviceName) {
+ memcpy(svc->payload, conn->serviceName, strlen(conn->serviceName));
+ }
+ cursor += namelen + TAG_HDR_SIZE;
+
+ /* If we're using Host-Uniq, copy it over */
+ if (conn->useHostUniq) {
+ PPPoETag hostUniq;
+ pid_t pid = getpid();
+ hostUniq.type = htons(TAG_HOST_UNIQ);
+ hostUniq.length = htons(sizeof(pid));
+ memcpy(hostUniq.payload, &pid, sizeof(pid));
+ CHECK_ROOM(cursor, packet.payload, sizeof(pid) + TAG_HDR_SIZE);
+ memcpy(cursor, &hostUniq, sizeof(pid) + TAG_HDR_SIZE);
+ cursor += sizeof(pid) + TAG_HDR_SIZE;
+ plen += sizeof(pid) + TAG_HDR_SIZE;
+ }
+
+ packet.length = htons(plen);
+
+ sendPacket(conn, conn->discoverySocket, &packet, (int) (plen + HDR_SIZE));
+ if (conn->debugFile) {
+ dumpPacket(conn->debugFile, &packet, "SENT");
+ fprintf(conn->debugFile, "\n");
+ fflush(conn->debugFile);
+ }
+}
+
+/**********************************************************************
+*%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;
+ 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->error = 0;
+
+ do {
+ if (BPF_BUFFER_IS_EMPTY) {
+ tv.tv_sec = timeout;
+ tv.tv_usec = 0;
+
+ FD_ZERO(&readable);
+ FD_SET(conn->discoverySocket, &readable);
+
+ while(1) {
+ r = select(conn->discoverySocket+1, &readable, NULL, NULL, &tv);
+ if (r >= 0 || errno != EINTR) break;
+ }
+ if (r < 0) {
+ perror("select (waitForPADO)");
+ return;
+ }
+ if (r == 0) return; /* Timed out */
+ }
+
+ /* Get the packet */
+ receivePacket(conn->discoverySocket, &packet, &len);
+
+ /* Check length */
+ if (ntohs(packet.length) + HDR_SIZE > len) {
+ fprintf(stderr, "Bogus PPPoE length field (%u)\n",
+ (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 (conn->debugFile) {
+ dumpPacket(conn->debugFile, &packet, "RCVD");
+ fprintf(conn->debugFile, "\n");
+ fflush(conn->debugFile);
+ }
+ /* If it's not for us, loop again */
+ if (!packetIsForMe(conn, &packet)) continue;
+
+ if (packet.code == CODE_PADO) {
+ if (BROADCAST(packet.ethHdr.h_source)) {
+ fprintf(stderr, "Ignoring PADO packet from broadcast MAC address\n");
+ continue;
+ }
+ parsePacket(&packet, parsePADOTags, &pc);
+ if (conn->error)
+ return;
+ if (!pc.seenACName) {
+ fprintf(stderr, "Ignoring PADO packet with no AC-Name tag\n");
+ continue;
+ }
+ if (!pc.seenServiceName) {
+ fprintf(stderr, "Ignoring PADO packet with no Service-Name tag\n");
+ continue;
+ }
+ conn->numPADOs++;
+ printf("--------------------------------------------------\n");
+ if (pc.acNameOK && pc.serviceNameOK) {
+ memcpy(conn->peerEth, packet.ethHdr.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],
+ (unsigned) conn->peerEth[2],
+ (unsigned) conn->peerEth[3],
+ (unsigned) conn->peerEth[4],
+ (unsigned) conn->peerEth[5]);
+ continue;
+ }
+ conn->discoveryState = STATE_RECEIVED_PADO;
+ break;
+ }
+ }
+ } while (conn->discoveryState != STATE_RECEIVED_PADO);
+}
+
+/**********************************************************************
+*%FUNCTION: discovery
+*%ARGUMENTS:
+* conn -- PPPoE connection info structure
+*%RETURNS:
+* Nothing
+*%DESCRIPTION:
+* Performs the PPPoE discovery phase
+***********************************************************************/
+void
+discovery(PPPoEConnection *conn)
+{
+ int padiAttempts = 0;
+ int timeout = PADI_TIMEOUT;
+
+ conn->discoverySocket =
+ openInterface(conn->ifName, Eth_PPPOE_Discovery, conn->myEth);
+
+ do {
+ padiAttempts++;
+ if (padiAttempts > MAX_PADI_ATTEMPTS) {
+ fprintf(stderr, "Timeout waiting for PADO packets\n");
+ close(conn->discoverySocket);
+ conn->discoverySocket = -1;
+ return;
+ }
+ sendPADI(conn);
+ conn->discoveryState = STATE_SENT_PADI;
+ waitForPADO(conn, timeout);
+ } while (!conn->numPADOs);
+}
+
projects / ppp.git / commitdiff