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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* LIC: GPL
13*
14* $Id$
15*
16***********************************************************************/
17
18#include "config.h"
19
20extern int IsSetID;
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 32-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
157extern void switchToRealID(void);
158extern void switchToEffectiveID(void);
159extern void dropPrivs(void);
160
161/* PPPoE codes */
162#define CODE_PADI 0x09
163#define CODE_PADO 0x07
164#define CODE_PADR 0x19
165#define CODE_PADS 0x65
166#define CODE_PADT 0xA7
167
168/* Extensions from draft-carrel-info-pppoe-ext-00 */
169/* I do NOT like PADM or PADN, but they are here for completeness */
170#define CODE_PADM 0xD3
171#define CODE_PADN 0xD4
172
173#define CODE_SESS 0x00
174
175/* PPPoE Tags */
176#define TAG_END_OF_LIST 0x0000
177#define TAG_SERVICE_NAME 0x0101
178#define TAG_AC_NAME 0x0102
179#define TAG_HOST_UNIQ 0x0103
180#define TAG_AC_COOKIE 0x0104
181#define TAG_VENDOR_SPECIFIC 0x0105
182#define TAG_RELAY_SESSION_ID 0x0110
183#define TAG_SERVICE_NAME_ERROR 0x0201
184#define TAG_AC_SYSTEM_ERROR 0x0202
185#define TAG_GENERIC_ERROR 0x0203
186
187/* Extensions from draft-carrel-info-pppoe-ext-00 */
188/* I do NOT like these tags one little bit */
189#define TAG_HURL 0x111
190#define TAG_MOTM 0x112
191#define TAG_IP_ROUTE_ADD 0x121
192
193/* Discovery phase states */
194#define STATE_SENT_PADI 0
195#define STATE_RECEIVED_PADO 1
196#define STATE_SENT_PADR 2
197#define STATE_SESSION 3
198#define STATE_TERMINATED 4
199
200/* How many PADI/PADS attempts? */
201#define MAX_PADI_ATTEMPTS 3
202
203/* Initial timeout for PADO/PADS */
204#define PADI_TIMEOUT 5
205
206/* States for scanning PPP frames */
207#define STATE_WAITFOR_FRAME_ADDR 0
208#define STATE_DROP_PROTO 1
209#define STATE_BUILDING_PACKET 2
210
211/* Special PPP frame characters */
212#define FRAME_ESC 0x7D
213#define FRAME_FLAG 0x7E
214#define FRAME_ADDR 0xFF
215#define FRAME_CTRL 0x03
216#define FRAME_ENC 0x20
217
218#define IPV4ALEN 4
219#define SMALLBUF 256
220
221/* A PPPoE Packet, including Ethernet headers */
222typedef struct PPPoEPacketStruct {
223 struct ethhdr ethHdr; /* Ethernet header */
224#ifdef PACK_BITFIELDS_REVERSED
225 unsigned int type:4; /* PPPoE Type (must be 1) */
226 unsigned int ver:4; /* PPPoE Version (must be 1) */
227#else
228 unsigned int ver:4; /* PPPoE Version (must be 1) */
229 unsigned int type:4; /* PPPoE Type (must be 1) */
230#endif
231 unsigned int code:8; /* PPPoE code */
232 unsigned int session:16; /* PPPoE session */
233 unsigned int length:16; /* Payload length */
234 unsigned char payload[ETH_DATA_LEN]; /* A bit of room to spare */
235} PPPoEPacket;
236
237/* Header size of a PPPoE packet */
238#define PPPOE_OVERHEAD 6 /* type, code, session, length */
239#define HDR_SIZE (sizeof(struct ethhdr) + PPPOE_OVERHEAD)
240#define MAX_PPPOE_PAYLOAD (ETH_DATA_LEN - PPPOE_OVERHEAD)
241#define MAX_PPPOE_MTU (MAX_PPPOE_PAYLOAD - 2)
242
243/* PPPoE Tag */
244
245typedef struct PPPoETagStruct {
246 unsigned int type:16; /* tag type */
247 unsigned int length:16; /* Length of payload */
248 unsigned char payload[ETH_DATA_LEN]; /* A LOT of room to spare */
249} PPPoETag;
250/* Header size of a PPPoE tag */
251#define TAG_HDR_SIZE 4
252
253/* Chunk to read from stdin */
254#define READ_CHUNK 4096
255
256/* Function passed to parsePacket */
257typedef void ParseFunc(UINT16_t type,
258 UINT16_t len,
259 unsigned char *data,
260 void *extra);
261
262#define PPPINITFCS16 0xffff /* Initial FCS value */
263
264/* Keep track of the state of a connection -- collect everything in
265 one spot */
266
267typedef struct PPPoEConnectionStruct {
268 int discoveryState; /* Where we are in discovery */
269 int discoverySocket; /* Raw socket for discovery frames */
270 int sessionSocket; /* Raw socket for session frames */
271 unsigned char myEth[ETH_ALEN]; /* My MAC address */
272 unsigned char peerEth[ETH_ALEN]; /* Peer's MAC address */
273 UINT16_t session; /* Session ID */
274 char *ifName; /* Interface name */
275 char *serviceName; /* Desired service name, if any */
276 char *acName; /* Desired AC name, if any */
277 int synchronous; /* Use synchronous PPP */
278 int useHostUniq; /* Use Host-Uniq tag */
279 int printACNames; /* Just print AC names */
280 int skipDiscovery; /* Skip discovery */
281 int noDiscoverySocket; /* Don't even open discovery socket */
282 int killSession; /* Kill session and exit */
283 FILE *debugFile; /* Debug file for dumping packets */
284 int numPADOs; /* Number of PADO packets received */
285 PPPoETag cookie; /* We have to send this if we get it */
286 PPPoETag relayId; /* Ditto */
287 int PADSHadError; /* If PADS had an error tag */
288 int discoveryTimeout; /* Timeout for discovery packets */
289} PPPoEConnection;
290
291/* Structure used to determine acceptable PADO or PADS packet */
292struct PacketCriteria {
293 PPPoEConnection *conn;
294 int acNameOK;
295 int serviceNameOK;
296 int seenACName;
297 int seenServiceName;
298};
299
300/* Function Prototypes */
301UINT16_t etherType(PPPoEPacket *packet);
302int openInterface(char const *ifname, UINT16_t type, unsigned char *hwaddr);
303int sendPacket(PPPoEConnection *conn, int sock, PPPoEPacket *pkt, int size);
304int receivePacket(int sock, PPPoEPacket *pkt, int *size);
305void fatalSys(char const *str);
306void rp_fatal(char const *str);
307void printErr(char const *str);
308void sysErr(char const *str);
309#ifdef DEBUGGING_ENABLED
310void dumpPacket(FILE *fp, PPPoEPacket *packet, char const *dir);
311void dumpHex(FILE *fp, unsigned char const *buf, int len);
312#endif
313int parsePacket(PPPoEPacket *packet, ParseFunc *func, void *extra);
314void parseLogErrs(UINT16_t typ, UINT16_t len, unsigned char *data, void *xtra);
315void pktLogErrs(char const *pkt, UINT16_t typ, UINT16_t len, unsigned char *data, void *xtra);
316void syncReadFromPPP(PPPoEConnection *conn, PPPoEPacket *packet);
317void asyncReadFromPPP(PPPoEConnection *conn, PPPoEPacket *packet);
318void asyncReadFromEth(PPPoEConnection *conn, int sock, int clampMss);
319void syncReadFromEth(PPPoEConnection *conn, int sock, int clampMss);
320char *strDup(char const *str);
321void sendPADT(PPPoEConnection *conn, char const *msg);
322void sendPADTf(PPPoEConnection *conn, char const *fmt, ...);
323
324void sendSessionPacket(PPPoEConnection *conn,
325 PPPoEPacket *packet, int len);
326void initPPP(void);
327void clampMSS(PPPoEPacket *packet, char const *dir, int clampMss);
328UINT16_t computeTCPChecksum(unsigned char *ipHdr, unsigned char *tcpHdr);
329UINT16_t pppFCS16(UINT16_t fcs, unsigned char *cp, int len);
330void discovery(PPPoEConnection *conn);
331unsigned char *findTag(PPPoEPacket *packet, UINT16_t tagType,
332 PPPoETag *tag);
333
334#define SET_STRING(var, val) do { if (var) free(var); var = strDup(val); } while(0);
335
336#define CHECK_ROOM(cursor, start, len) \
337do {\
338 if (((cursor)-(start))+(len) > MAX_PPPOE_PAYLOAD) { \
339 syslog(LOG_ERR, "Would create too-long packet"); \
340 return; \
341 } \
342} while(0)
343
344/* True if Ethernet address is broadcast or multicast */
345#define NOT_UNICAST(e) ((e[0] & 0x01) != 0)
346#define BROADCAST(e) ((e[0] & e[1] & e[2] & e[3] & e[4] & e[5]) == 0xFF)
347#define NOT_BROADCAST(e) ((e[0] & e[1] & e[2] & e[3] & e[4] & e[5]) != 0xFF)
348
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