1/***********************************************************************
2*
3* pppoe.h
4*
5* Declaration of various PPPoE constants
6*
7* Copyright (C) 2000 Roaring Penguin Software Inc.
8*
9* This program may be distributed according to the terms of the GNU
10* General Public License, version 2 or (at your option) any later version.
11*
12* $Id: pppoe.h,v 1.2 2004/11/04 10:07:37 paulus Exp $
13*
14***********************************************************************/
15
16#ifdef __sun__
17#define __EXTENSIONS__
18#endif
19
20#include "config.h"
21
22#if defined(HAVE_NETPACKET_PACKET_H) || defined(HAVE_LINUX_IF_PACKET_H)
23#define _POSIX_SOURCE 1 /* For sigaction defines */
24#endif
25
26#include <stdio.h>		/* For FILE */
27#include <sys/types.h>		/* For pid_t */
28
29/* How do we access raw Ethernet devices? */
30#undef USE_LINUX_PACKET
31#undef USE_BPF
32
33#if defined(HAVE_NETPACKET_PACKET_H) || defined(HAVE_LINUX_IF_PACKET_H)
34#define USE_LINUX_PACKET 1
35#elif defined(HAVE_SYS_DLPI_H)
36#define USE_DLPI
37#elif defined(HAVE_NET_BPF_H)
38#define USE_BPF 1
39#endif
40
41/* Sanity check */
42#if !defined(USE_BPF) && !defined(USE_LINUX_PACKET) && !defined(USE_DLPI)
43#error Unknown method for accessing raw Ethernet frames
44#endif
45
46#ifdef HAVE_SYS_CDEFS_H
47#include <sys/cdefs.h>
48#endif
49
50#ifdef HAVE_SYS_SOCKET_H
51#include <sys/socket.h>
52#endif
53
54/* Ugly header files on some Linux boxes... */
55#if defined(HAVE_LINUX_IF_H)
56#include <linux/if.h>
57#elif defined(HAVE_NET_IF_H)
58#include <net/if.h>
59#endif
60
61#ifdef HAVE_NET_IF_TYPES_H
62#include <net/if_types.h>
63#endif
64
65#ifdef HAVE_NET_IF_DL_H
66#include <net/if_dl.h>
67#endif
68
69/* I'm not sure why this is needed... I do not have OpenBSD */
70#if defined(__OpenBSD__)
71#include <net/ppp_defs.h>
72#include <net/if_ppp.h>
73#endif
74
75#ifdef USE_BPF
76extern int bpfSize;
77struct PPPoEPacketStruct;
78void sessionDiscoveryPacket(struct PPPoEPacketStruct *packet);
79#define BPF_BUFFER_IS_EMPTY (bpfSize <= 0)
80#define BPF_BUFFER_HAS_DATA (bpfSize > 0)
81#define ethhdr ether_header
82#define h_dest ether_dhost
83#define h_source ether_shost
84#define h_proto ether_type
85#define	ETH_DATA_LEN ETHERMTU
86#define	ETH_ALEN ETHER_ADDR_LEN
87#else
88#undef USE_BPF
89#define BPF_BUFFER_IS_EMPTY 1
90#define BPF_BUFFER_HAS_DATA 0
91#endif
92
93#ifdef USE_DLPI
94#include <sys/ethernet.h>
95#define ethhdr ether_header
96#define	ETH_DATA_LEN ETHERMTU
97#define	ETH_ALEN ETHERADDRL
98#define h_dest ether_dhost.ether_addr_octet
99#define h_source ether_shost.ether_addr_octet
100#define h_proto ether_type
101
102/* cloned from dltest.h */
103#define         MAXDLBUF        8192
104#define         MAXDLADDR       1024
105#define         MAXWAIT         15
106#define         OFFADDR(s, n)   (u_char*)((char*)(s) + (int)(n))
107#define         CASERET(s)      case s:  return ("s")
108
109#endif
110
111/* Define various integer types -- assumes a char is 8 bits */
112#if SIZEOF_UNSIGNED_SHORT == 2
113typedef unsigned short UINT16_t;
114#elif SIZEOF_UNSIGNED_INT == 2
115typedef unsigned int UINT16_t;
116#else
117#error Could not find a 16-bit integer type
118#endif
119
120#if SIZEOF_UNSIGNED_SHORT == 4
121typedef unsigned short UINT32_t;
122#elif SIZEOF_UNSIGNED_INT == 4
123typedef unsigned int UINT32_t;
124#elif SIZEOF_UNSIGNED_LONG == 4
125typedef unsigned long UINT32_t;
126#else
127#error Could not find a 16-bit integer type
128#endif
129
130#ifdef HAVE_LINUX_IF_ETHER_H
131#include <linux/if_ether.h>
132#endif
133
134#include <netinet/in.h>
135
136#ifdef HAVE_NETINET_IF_ETHER_H
137#include <sys/types.h>
138
139#ifdef HAVE_SYS_SOCKET_H
140#include <sys/socket.h>
141#endif
142#ifndef HAVE_SYS_DLPI_H
143#include <netinet/if_ether.h>
144#endif
145#endif
146
147
148
149/* Ethernet frame types according to RFC 2516 */
150#define ETH_PPPOE_DISCOVERY 0x8863
151#define ETH_PPPOE_SESSION   0x8864
152
153/* But some brain-dead peers disobey the RFC, so frame types are variables */
154extern UINT16_t Eth_PPPOE_Discovery;
155extern UINT16_t Eth_PPPOE_Session;
156
157/* PPPoE codes */
158#define CODE_PADI           0x09
159#define CODE_PADO           0x07
160#define CODE_PADR           0x19
161#define CODE_PADS           0x65
162#define CODE_PADT           0xA7
163#define CODE_SESS           0x00
164
165/* PPPoE Tags */
166#define TAG_END_OF_LIST        0x0000
167#define TAG_SERVICE_NAME       0x0101
168#define TAG_AC_NAME            0x0102
169#define TAG_HOST_UNIQ          0x0103
170#define TAG_AC_COOKIE          0x0104
171#define TAG_VENDOR_SPECIFIC    0x0105
172#define TAG_RELAY_SESSION_ID   0x0110
173#define TAG_SERVICE_NAME_ERROR 0x0201
174#define TAG_AC_SYSTEM_ERROR    0x0202
175#define TAG_GENERIC_ERROR      0x0203
176
177/* Discovery phase states */
178#define STATE_SENT_PADI     0
179#define STATE_RECEIVED_PADO 1
180#define STATE_SENT_PADR     2
181#define STATE_SESSION       3
182#define STATE_TERMINATED    4
183
184/* How many PADI/PADS attempts? */
185#define MAX_PADI_ATTEMPTS 3
186
187/* Initial timeout for PADO/PADS */
188#define PADI_TIMEOUT 5
189
190/* States for scanning PPP frames */
191#define STATE_WAITFOR_FRAME_ADDR 0
192#define STATE_DROP_PROTO         1
193#define STATE_BUILDING_PACKET    2
194
195/* Special PPP frame characters */
196#define FRAME_ESC    0x7D
197#define FRAME_FLAG   0x7E
198#define FRAME_ADDR   0xFF
199#define FRAME_CTRL   0x03
200#define FRAME_ENC    0x20
201
202#define IPV4ALEN     4
203#define SMALLBUF   256
204
205/* A PPPoE Packet, including Ethernet headers */
206typedef struct PPPoEPacketStruct {
207    struct ethhdr ethHdr;	/* Ethernet header */
208#ifdef PACK_BITFIELDS_REVERSED
209    unsigned int type:4;	/* PPPoE Type (must be 1) */
210    unsigned int ver:4;		/* PPPoE Version (must be 1) */
211#else
212    unsigned int ver:4;		/* PPPoE Version (must be 1) */
213    unsigned int type:4;	/* PPPoE Type (must be 1) */
214#endif
215    unsigned int code:8;	/* PPPoE code */
216    unsigned int session:16;	/* PPPoE session */
217    unsigned int length:16;	/* Payload length */
218    unsigned char payload[ETH_DATA_LEN]; /* A bit of room to spare */
219} PPPoEPacket;
220
221/* Header size of a PPPoE packet */
222#define PPPOE_OVERHEAD 6  /* type, code, session, length */
223#define HDR_SIZE (sizeof(struct ethhdr) + PPPOE_OVERHEAD)
224#define MAX_PPPOE_PAYLOAD (ETH_DATA_LEN - PPPOE_OVERHEAD)
225#define MAX_PPPOE_MTU (MAX_PPPOE_PAYLOAD - 2)
226
227/* PPPoE Tag */
228
229typedef struct PPPoETagStruct {
230    unsigned int type:16;	/* tag type */
231    unsigned int length:16;	/* Length of payload */
232    unsigned char payload[ETH_DATA_LEN]; /* A LOT of room to spare */
233} PPPoETag;
234/* Header size of a PPPoE tag */
235#define TAG_HDR_SIZE 4
236
237/* Chunk to read from stdin */
238#define READ_CHUNK 4096
239
240/* Function passed to parsePacket */
241typedef void ParseFunc(UINT16_t type,
242		       UINT16_t len,
243		       unsigned char *data,
244		       void *extra);
245
246#define PPPINITFCS16    0xffff  /* Initial FCS value */
247
248/* Keep track of the state of a connection -- collect everything in
249   one spot */
250
251typedef struct PPPoEConnectionStruct {
252    int discoveryState;		/* Where we are in discovery */
253    int discoverySocket;	/* Raw socket for discovery frames */
254    int sessionSocket;		/* Raw socket for session frames */
255    unsigned char myEth[ETH_ALEN]; /* My MAC address */
256    unsigned char peerEth[ETH_ALEN]; /* Peer's MAC address */
257    UINT16_t session;		/* Session ID */
258    char *ifName;		/* Interface name */
259    char *serviceName;		/* Desired service name, if any */
260    char *acName;		/* Desired AC name, if any */
261    int synchronous;		/* Use synchronous PPP */
262    int useHostUniq;		/* Use Host-Uniq tag */
263    int printACNames;		/* Just print AC names */
264    int skipDiscovery;		/* Skip discovery */
265    int noDiscoverySocket;	/* Don't even open discovery socket */
266    FILE *debugFile;		/* Debug file for dumping packets */
267    int numPADOs;		/* Number of PADO packets received */
268    PPPoETag cookie;		/* We have to send this if we get it */
269    PPPoETag relayId;		/* Ditto */
270} PPPoEConnection;
271
272/* Structure used to determine acceptable PADO or PADS packet */
273struct PacketCriteria {
274    PPPoEConnection *conn;
275    int acNameOK;
276    int serviceNameOK;
277    int seenACName;
278    int seenServiceName;
279};
280
281/* Function Prototypes */
282UINT16_t etherType(PPPoEPacket *packet);
283int openInterface(char const *ifname, UINT16_t type, unsigned char *hwaddr);
284int sendPacket(PPPoEConnection *conn, int sock, PPPoEPacket *pkt, int size);
285int receivePacket(int sock, PPPoEPacket *pkt, int *size);
286void fatalSys(char const *str);
287void rp_fatal(char const *str);
288void printErr(char const *str);
289void sysErr(char const *str);
290void dumpPacket(FILE *fp, PPPoEPacket *packet, char const *dir);
291void dumpHex(FILE *fp, unsigned char const *buf, int len);
292int parsePacket(PPPoEPacket *packet, ParseFunc *func, void *extra);
293void parseLogErrs(UINT16_t typ, UINT16_t len, unsigned char *data, void *xtra);
294void syncReadFromPPP(PPPoEConnection *conn, PPPoEPacket *packet);
295void asyncReadFromPPP(PPPoEConnection *conn, PPPoEPacket *packet);
296void asyncReadFromEth(PPPoEConnection *conn, int sock, int clampMss);
297void syncReadFromEth(PPPoEConnection *conn, int sock, int clampMss);
298char *strDup(char const *str);
299void sendPADT(PPPoEConnection *conn, char const *msg);
300void sendSessionPacket(PPPoEConnection *conn,
301		       PPPoEPacket *packet, int len);
302void initPPP(void);
303void clampMSS(PPPoEPacket *packet, char const *dir, int clampMss);
304UINT16_t computeTCPChecksum(unsigned char *ipHdr, unsigned char *tcpHdr);
305UINT16_t pppFCS16(UINT16_t fcs, unsigned char *cp, int len);
306void discovery(PPPoEConnection *conn);
307unsigned char *findTag(PPPoEPacket *packet, UINT16_t tagType,
308		       PPPoETag *tag);
309
310#define SET_STRING(var, val) do { if (var) free(var); var = strDup(val); } while(0);
311
312#define CHECK_ROOM(cursor, start, len) \
313do {\
314    if (((cursor)-(start))+(len) > MAX_PPPOE_PAYLOAD) { \
315        syslog(LOG_ERR, "Would create too-long packet"); \
316        return; \
317    } \
318} while(0)
319
320/* True if Ethernet address is broadcast or multicast */
321#define NOT_UNICAST(e) ((e[0] & 0x01) != 0)
322#define BROADCAST(e) ((e[0] & e[1] & e[2] & e[3] & e[4] & e[5]) == 0xFF)
323#define NOT_BROADCAST(e) ((e[0] & e[1] & e[2] & e[3] & e[4] & e[5]) != 0xFF)
324