/*********************************************************************** * * pppoe.h * * Declaration of various PPPoE constants * * Copyright (C) 2000 Roaring Penguin Software Inc. * * This program may be distributed according to the terms of the GNU * General Public License, version 2 or (at your option) any later version. * * Id: pppoe.h,v 1.4 2008/06/15 04:35:50 paulus Exp * ***********************************************************************/ #include "config.h" #include /* For FILE */ #include /* For pid_t */ #include #include #include "pppd/pppd.h" /* For error */ /* How do we access raw Ethernet devices? */ #undef USE_LINUX_PACKET #undef USE_BPF #if defined(HAVE_NETPACKET_PACKET_H) || defined(HAVE_LINUX_IF_PACKET_H) #define USE_LINUX_PACKET 1 #elif defined(HAVE_SYS_DLPI_H) #define USE_DLPI #elif defined(HAVE_NET_BPF_H) #define USE_BPF 1 #endif /* Sanity check */ #if !defined(USE_BPF) && !defined(USE_LINUX_PACKET) && !defined(USE_DLPI) #error Unknown method for accessing raw Ethernet frames #endif #ifdef HAVE_SYS_SOCKET_H #include #endif /* This has to be included before Linux 4.8's linux/in.h * gets dragged in. */ #include /* Ugly header files on some Linux boxes... */ #if defined(HAVE_LINUX_IF_H) #include #elif defined(HAVE_NET_IF_H) #include #endif #ifdef HAVE_NET_IF_TYPES_H #include #endif #define BPF_BUFFER_IS_EMPTY 1 #define BPF_BUFFER_HAS_DATA 0 /* Define various integer types -- assumes a char is 8 bits */ #if SIZEOF_UNSIGNED_SHORT == 2 typedef unsigned short UINT16_t; #elif SIZEOF_UNSIGNED_INT == 2 typedef unsigned int UINT16_t; #else #error Could not find a 16-bit integer type #endif #if SIZEOF_UNSIGNED_SHORT == 4 typedef unsigned short UINT32_t; #elif SIZEOF_UNSIGNED_INT == 4 typedef unsigned int UINT32_t; #elif SIZEOF_UNSIGNED_LONG == 4 typedef unsigned long UINT32_t; #else #error Could not find a 32-bit integer type #endif #ifdef HAVE_LINUX_IF_ETHER_H #include #else #ifdef HAVE_NETINET_IF_ETHER_H #include #ifdef HAVE_SYS_SOCKET_H #include #endif #ifndef HAVE_SYS_DLPI_H #include #endif #endif #endif /* Ethernet frame types according to RFC 2516 */ #define ETH_PPPOE_DISCOVERY 0x8863 #define ETH_PPPOE_SESSION 0x8864 /* But some brain-dead peers disobey the RFC, so frame types are variables */ extern UINT16_t Eth_PPPOE_Discovery; extern UINT16_t Eth_PPPOE_Session; /* PPPoE codes */ #define CODE_PADI 0x09 #define CODE_PADO 0x07 #define CODE_PADR 0x19 #define CODE_PADS 0x65 #define CODE_PADT 0xA7 /* Extensions from draft-carrel-info-pppoe-ext-00 */ /* I do NOT like PADM or PADN, but they are here for completeness */ #define CODE_PADM 0xD3 #define CODE_PADN 0xD4 #define CODE_SESS 0x00 /* PPPoE Tags */ #define TAG_END_OF_LIST 0x0000 #define TAG_SERVICE_NAME 0x0101 #define TAG_AC_NAME 0x0102 #define TAG_HOST_UNIQ 0x0103 #define TAG_AC_COOKIE 0x0104 #define TAG_VENDOR_SPECIFIC 0x0105 #define TAG_RELAY_SESSION_ID 0x0110 #define TAG_PPP_MAX_PAYLOAD 0x0120 #define TAG_SERVICE_NAME_ERROR 0x0201 #define TAG_AC_SYSTEM_ERROR 0x0202 #define TAG_GENERIC_ERROR 0x0203 /* Extensions from draft-carrel-info-pppoe-ext-00 */ /* I do NOT like these tags one little bit */ #define TAG_HURL 0x111 #define TAG_MOTM 0x112 #define TAG_IP_ROUTE_ADD 0x121 /* Discovery phase states */ #define STATE_SENT_PADI 0 #define STATE_RECEIVED_PADO 1 #define STATE_SENT_PADR 2 #define STATE_SESSION 3 #define STATE_TERMINATED 4 /* How many PADI/PADS attempts? */ #define MAX_PADI_ATTEMPTS 3 /* Initial timeout for PADO/PADS */ #define PADI_TIMEOUT 5 /* States for scanning PPP frames */ #define STATE_WAITFOR_FRAME_ADDR 0 #define STATE_DROP_PROTO 1 #define STATE_BUILDING_PACKET 2 /* Special PPP frame characters */ #define FRAME_ESC 0x7D #define FRAME_FLAG 0x7E #define FRAME_ADDR 0xFF #define FRAME_CTRL 0x03 #define FRAME_ENC 0x20 #define IPV4ALEN 4 #define SMALLBUF 256 /* There are other fixed-size buffers preventing this from being increased to 16110. The buffer sizes would need to be properly de-coupled from the default MRU. For now, getting up to 1500 is enough. */ #define ETH_JUMBO_LEN 1508 /* A PPPoE Packet, including Ethernet headers */ typedef struct PPPoEPacketStruct { struct ethhdr ethHdr; /* Ethernet header */ unsigned int vertype:8; /* PPPoE Version and Type (must both be 1) */ unsigned int code:8; /* PPPoE code */ unsigned int session:16; /* PPPoE session */ unsigned int length:16; /* Payload length */ unsigned char payload[ETH_JUMBO_LEN]; /* A bit of room to spare */ } PPPoEPacket; #define PPPOE_VER(vt) ((vt) >> 4) #define PPPOE_TYPE(vt) ((vt) & 0xf) #define PPPOE_VER_TYPE(v, t) (((v) << 4) | (t)) /* Header size of a PPPoE packet */ #define PPPOE_OVERHEAD 6 /* type, code, session, length */ #define HDR_SIZE (sizeof(struct ethhdr) + PPPOE_OVERHEAD) #define MAX_PPPOE_PAYLOAD (ETH_JUMBO_LEN - PPPOE_OVERHEAD) #define PPP_OVERHEAD 2 /* protocol */ #define MAX_PPPOE_MTU (MAX_PPPOE_PAYLOAD - PPP_OVERHEAD) #define TOTAL_OVERHEAD (PPPOE_OVERHEAD + PPP_OVERHEAD) #define ETH_PPPOE_MTU (ETH_DATA_LEN - TOTAL_OVERHEAD) /* PPPoE Tag */ typedef struct PPPoETagStruct { unsigned int type:16; /* tag type */ unsigned int length:16; /* Length of payload */ unsigned char payload[ETH_JUMBO_LEN]; /* A LOT of room to spare */ } PPPoETag; /* Header size of a PPPoE tag */ #define TAG_HDR_SIZE 4 /* Chunk to read from stdin */ #define READ_CHUNK 4096 /* Function passed to parsePacket */ typedef void ParseFunc(UINT16_t type, UINT16_t len, unsigned char *data, void *extra); #define PPPINITFCS16 0xffff /* Initial FCS value */ /* Keep track of the state of a connection -- collect everything in one spot */ typedef struct PPPoEConnectionStruct { int discoveryState; /* Where we are in discovery */ int discoverySocket; /* Raw socket for discovery frames */ int sessionSocket; /* Raw socket for session frames */ unsigned char myEth[ETH_ALEN]; /* My MAC address */ unsigned char peerEth[ETH_ALEN]; /* Peer's MAC address */ unsigned char req_peer_mac[ETH_ALEN]; /* required peer MAC address */ unsigned char req_peer; /* require mac addr to match req_peer_mac */ UINT16_t session; /* Session ID */ char *ifName; /* Interface name */ char *serviceName; /* Desired service name, if any */ char *acName; /* Desired AC name, if any */ int synchronous; /* Use synchronous PPP */ PPPoETag hostUniq; /* Use Host-Uniq tag */ int printACNames; /* Just print AC names */ FILE *debugFile; /* Debug file for dumping packets */ int numPADOs; /* Number of PADO packets received */ PPPoETag cookie; /* We have to send this if we get it */ PPPoETag relayId; /* Ditto */ int error; /* Error packet received */ int debug; /* Set to log packets sent and received */ int discoveryTimeout; /* Timeout for discovery packets */ int discoveryAttempts; /* Number of discovery attempts */ int seenMaxPayload; int mtu; /* Stored MTU */ int mru; /* Stored MRU */ } PPPoEConnection; /* Structure used to determine acceptable PADO or PADS packet */ struct PacketCriteria { PPPoEConnection *conn; int acNameOK; int serviceNameOK; int seenACName; int seenServiceName; }; /* Function Prototypes */ UINT16_t etherType(PPPoEPacket *packet); int openInterface(char const *ifname, UINT16_t type, unsigned char *hwaddr); int sendPacket(PPPoEConnection *conn, int sock, PPPoEPacket *pkt, int size); int receivePacket(int sock, PPPoEPacket *pkt, int *size); void fatalSys(char const *str); void dumpPacket(FILE *fp, PPPoEPacket *packet, char const *dir); void dumpHex(FILE *fp, unsigned char const *buf, int len); int parsePacket(PPPoEPacket *packet, ParseFunc *func, void *extra); void parseLogErrs(UINT16_t typ, UINT16_t len, unsigned char *data, void *xtra); void syncReadFromPPP(PPPoEConnection *conn, PPPoEPacket *packet); void asyncReadFromPPP(PPPoEConnection *conn, PPPoEPacket *packet); void asyncReadFromEth(PPPoEConnection *conn, int sock, int clampMss); void syncReadFromEth(PPPoEConnection *conn, int sock, int clampMss); char *strDup(char const *str); void sendPADT(PPPoEConnection *conn, char const *msg); void sendSessionPacket(PPPoEConnection *conn, PPPoEPacket *packet, int len); void initPPP(void); void clampMSS(PPPoEPacket *packet, char const *dir, int clampMss); UINT16_t computeTCPChecksum(unsigned char *ipHdr, unsigned char *tcpHdr); UINT16_t pppFCS16(UINT16_t fcs, unsigned char *cp, int len); void discovery(PPPoEConnection *conn); unsigned char *findTag(PPPoEPacket *packet, UINT16_t tagType, PPPoETag *tag); void pppoe_printpkt(PPPoEPacket *packet, void (*printer)(void *, char *, ...), void *arg); void pppoe_log_packet(const char *prefix, PPPoEPacket *packet); static inline int parseHostUniq(const char *uniq, PPPoETag *tag) { unsigned i, len = strlen(uniq); #define hex(x) \ (((x) <= '9') ? ((x) - '0') : \ (((x) <= 'F') ? ((x) - 'A' + 10) : \ ((x) - 'a' + 10))) if (!len || len % 2 || len / 2 > sizeof(tag->payload)) return 0; for (i = 0; i < len; i += 2) { if (!isxdigit(uniq[i]) || !isxdigit(uniq[i+1])) return 0; tag->payload[i / 2] = (char)(hex(uniq[i]) << 4 | hex(uniq[i+1])); } #undef hex tag->type = htons(TAG_HOST_UNIQ); tag->length = htons(len / 2); return 1; } #define SET_STRING(var, val) do { if (var) free(var); var = strDup(val); } while(0); #define CHECK_ROOM(cursor, start, len) \ do {\ if (((cursor)-(start))+(len) > MAX_PPPOE_PAYLOAD) { \ error("Would create too-long packet"); \ return; \ } \ } while(0) /* True if Ethernet address is broadcast or multicast */ #define NOT_UNICAST(e) ((e[0] & 0x01) != 0) #define BROADCAST(e) ((e[0] & e[1] & e[2] & e[3] & e[4] & e[5]) == 0xFF) #define NOT_BROADCAST(e) ((e[0] & e[1] & e[2] & e[3] & e[4] & e[5]) != 0xFF)