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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 * $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
76 extern int bpfSize;
77 struct PPPoEPacketStruct;
78 void 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
113 typedef unsigned short UINT16_t;
114 #elif SIZEOF_UNSIGNED_INT == 2
115 typedef 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
121 typedef unsigned short UINT32_t;
122 #elif SIZEOF_UNSIGNED_INT == 4
123 typedef unsigned int UINT32_t;
124 #elif SIZEOF_UNSIGNED_LONG == 4
125 typedef 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 */
154 extern UINT16_t Eth_PPPOE_Discovery;
155 extern 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 */
206 typedef 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 
229 typedef 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 */
241 typedef 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 
251 typedef 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 */
273 struct PacketCriteria {
274     PPPoEConnection *conn;
275     int acNameOK;
276     int serviceNameOK;
277     int seenACName;
278     int seenServiceName;
279 };
280 
281 /* Function Prototypes */
282 UINT16_t etherType(PPPoEPacket *packet);
283 int openInterface(char const *ifname, UINT16_t type, unsigned char *hwaddr);
284 int sendPacket(PPPoEConnection *conn, int sock, PPPoEPacket *pkt, int size);
285 int receivePacket(int sock, PPPoEPacket *pkt, int *size);
286 void fatalSys(char const *str);
287 void rp_fatal(char const *str);
288 void printErr(char const *str);
289 void sysErr(char const *str);
290 void dumpPacket(FILE *fp, PPPoEPacket *packet, char const *dir);
291 void dumpHex(FILE *fp, unsigned char const *buf, int len);
292 int parsePacket(PPPoEPacket *packet, ParseFunc *func, void *extra);
293 void parseLogErrs(UINT16_t typ, UINT16_t len, unsigned char *data, void *xtra);
294 void syncReadFromPPP(PPPoEConnection *conn, PPPoEPacket *packet);
295 void asyncReadFromPPP(PPPoEConnection *conn, PPPoEPacket *packet);
296 void asyncReadFromEth(PPPoEConnection *conn, int sock, int clampMss);
297 void syncReadFromEth(PPPoEConnection *conn, int sock, int clampMss);
298 char *strDup(char const *str);
299 void sendPADT(PPPoEConnection *conn, char const *msg);
300 void sendSessionPacket(PPPoEConnection *conn,
301 		       PPPoEPacket *packet, int len);
302 void initPPP(void);
303 void clampMSS(PPPoEPacket *packet, char const *dir, int clampMss);
304 UINT16_t computeTCPChecksum(unsigned char *ipHdr, unsigned char *tcpHdr);
305 UINT16_t pppFCS16(UINT16_t fcs, unsigned char *cp, int len);
306 void discovery(PPPoEConnection *conn);
307 unsigned 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) \
313 do {\
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