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 1.4 2008/06/15 04:35:50 paulus Exp
13*
14***********************************************************************/
15
16#include "config.h"
17
18#include <stdio.h>		/* For FILE */
19#include <sys/types.h>		/* For pid_t */
20#include <ctype.h>
21#include <string.h>
22
23#include "pppd/pppd.h"		/* For error */
24
25/* How do we access raw Ethernet devices? */
26#undef USE_LINUX_PACKET
27#undef USE_BPF
28
29#if defined(HAVE_NETPACKET_PACKET_H) || defined(HAVE_LINUX_IF_PACKET_H)
30#define USE_LINUX_PACKET 1
31#elif defined(HAVE_SYS_DLPI_H)
32#define USE_DLPI
33#elif defined(HAVE_NET_BPF_H)
34#define USE_BPF 1
35#endif
36
37/* Sanity check */
38#if !defined(USE_BPF) && !defined(USE_LINUX_PACKET) && !defined(USE_DLPI)
39#error Unknown method for accessing raw Ethernet frames
40#endif
41
42#ifdef HAVE_SYS_SOCKET_H
43#include <sys/socket.h>
44#endif
45
46/* This has to be included before Linux 4.8's linux/in.h
47 * gets dragged in. */
48#include <netinet/in.h>
49
50/* Ugly header files on some Linux boxes... */
51#if defined(HAVE_LINUX_IF_H)
52#include <linux/if.h>
53#elif defined(HAVE_NET_IF_H)
54#include <net/if.h>
55#endif
56
57#ifdef HAVE_NET_IF_TYPES_H
58#include <net/if_types.h>
59#endif
60
61#define BPF_BUFFER_IS_EMPTY 1
62#define BPF_BUFFER_HAS_DATA 0
63
64/* Define various integer types -- assumes a char is 8 bits */
65#if SIZEOF_UNSIGNED_SHORT == 2
66typedef unsigned short UINT16_t;
67#elif SIZEOF_UNSIGNED_INT == 2
68typedef unsigned int UINT16_t;
69#else
70#error Could not find a 16-bit integer type
71#endif
72
73#if SIZEOF_UNSIGNED_SHORT == 4
74typedef unsigned short UINT32_t;
75#elif SIZEOF_UNSIGNED_INT == 4
76typedef unsigned int UINT32_t;
77#elif SIZEOF_UNSIGNED_LONG == 4
78typedef unsigned long UINT32_t;
79#else
80#error Could not find a 32-bit integer type
81#endif
82
83#ifdef HAVE_LINUX_IF_ETHER_H
84#include <linux/if_ether.h>
85#else
86
87#ifdef HAVE_NETINET_IF_ETHER_H
88#include <sys/types.h>
89
90#ifdef HAVE_SYS_SOCKET_H
91#include <sys/socket.h>
92#endif
93#ifndef HAVE_SYS_DLPI_H
94#include <netinet/if_ether.h>
95#endif
96#endif
97#endif
98
99/* Ethernet frame types according to RFC 2516 */
100#define ETH_PPPOE_DISCOVERY 0x8863
101#define ETH_PPPOE_SESSION   0x8864
102
103/* But some brain-dead peers disobey the RFC, so frame types are variables */
104extern UINT16_t Eth_PPPOE_Discovery;
105extern UINT16_t Eth_PPPOE_Session;
106
107/* PPPoE codes */
108#define CODE_PADI           0x09
109#define CODE_PADO           0x07
110#define CODE_PADR           0x19
111#define CODE_PADS           0x65
112#define CODE_PADT           0xA7
113
114/* Extensions from draft-carrel-info-pppoe-ext-00 */
115/* I do NOT like PADM or PADN, but they are here for completeness */
116#define CODE_PADM           0xD3
117#define CODE_PADN           0xD4
118
119#define CODE_SESS           0x00
120
121/* PPPoE Tags */
122#define TAG_END_OF_LIST        0x0000
123#define TAG_SERVICE_NAME       0x0101
124#define TAG_AC_NAME            0x0102
125#define TAG_HOST_UNIQ          0x0103
126#define TAG_AC_COOKIE          0x0104
127#define TAG_VENDOR_SPECIFIC    0x0105
128#define TAG_RELAY_SESSION_ID   0x0110
129#define TAG_PPP_MAX_PAYLOAD    0x0120
130#define TAG_SERVICE_NAME_ERROR 0x0201
131#define TAG_AC_SYSTEM_ERROR    0x0202
132#define TAG_GENERIC_ERROR      0x0203
133
134/* Extensions from draft-carrel-info-pppoe-ext-00 */
135/* I do NOT like these tags one little bit */
136#define TAG_HURL               0x111
137#define TAG_MOTM               0x112
138#define TAG_IP_ROUTE_ADD       0x121
139
140/* Discovery phase states */
141#define STATE_SENT_PADI     0
142#define STATE_RECEIVED_PADO 1
143#define STATE_SENT_PADR     2
144#define STATE_SESSION       3
145#define STATE_TERMINATED    4
146
147/* How many PADI/PADS attempts? */
148#define MAX_PADI_ATTEMPTS 3
149
150/* Initial timeout for PADO/PADS */
151#define PADI_TIMEOUT 5
152
153/* States for scanning PPP frames */
154#define STATE_WAITFOR_FRAME_ADDR 0
155#define STATE_DROP_PROTO         1
156#define STATE_BUILDING_PACKET    2
157
158/* Special PPP frame characters */
159#define FRAME_ESC    0x7D
160#define FRAME_FLAG   0x7E
161#define FRAME_ADDR   0xFF
162#define FRAME_CTRL   0x03
163#define FRAME_ENC    0x20
164
165#define IPV4ALEN     4
166#define SMALLBUF   256
167
168/* There are other fixed-size buffers preventing
169   this from being increased to 16110. The buffer
170   sizes would need to be properly de-coupled from
171   the default MRU. For now, getting up to 1500 is
172   enough. */
173#define ETH_JUMBO_LEN 1508
174
175/* A PPPoE Packet, including Ethernet headers */
176typedef struct PPPoEPacketStruct {
177    struct ethhdr ethHdr;	/* Ethernet header */
178    unsigned int vertype:8;	/* PPPoE Version and Type (must both be 1) */
179    unsigned int code:8;	/* PPPoE code */
180    unsigned int session:16;	/* PPPoE session */
181    unsigned int length:16;	/* Payload length */
182    unsigned char payload[ETH_JUMBO_LEN]; /* A bit of room to spare */
183} PPPoEPacket;
184
185#define PPPOE_VER(vt)		((vt) >> 4)
186#define PPPOE_TYPE(vt)		((vt) & 0xf)
187#define PPPOE_VER_TYPE(v, t)	(((v) << 4) | (t))
188
189/* Header size of a PPPoE packet */
190#define PPPOE_OVERHEAD 6  /* type, code, session, length */
191#define HDR_SIZE (sizeof(struct ethhdr) + PPPOE_OVERHEAD)
192#define MAX_PPPOE_PAYLOAD (ETH_JUMBO_LEN - PPPOE_OVERHEAD)
193#define PPP_OVERHEAD 2  /* protocol */
194#define MAX_PPPOE_MTU (MAX_PPPOE_PAYLOAD - PPP_OVERHEAD)
195#define TOTAL_OVERHEAD (PPPOE_OVERHEAD + PPP_OVERHEAD)
196#define ETH_PPPOE_MTU (ETH_DATA_LEN - TOTAL_OVERHEAD)
197
198/* PPPoE Tag */
199
200typedef struct PPPoETagStruct {
201    unsigned int type:16;	/* tag type */
202    unsigned int length:16;	/* Length of payload */
203    unsigned char payload[ETH_JUMBO_LEN]; /* A LOT of room to spare */
204} PPPoETag;
205/* Header size of a PPPoE tag */
206#define TAG_HDR_SIZE 4
207
208/* Chunk to read from stdin */
209#define READ_CHUNK 4096
210
211/* Function passed to parsePacket */
212typedef void ParseFunc(UINT16_t type,
213		       UINT16_t len,
214		       unsigned char *data,
215		       void *extra);
216
217#define PPPINITFCS16    0xffff  /* Initial FCS value */
218
219/* Keep track of the state of a connection -- collect everything in
220   one spot */
221
222typedef struct PPPoEConnectionStruct {
223    int discoveryState;		/* Where we are in discovery */
224    int discoverySocket;	/* Raw socket for discovery frames */
225    int sessionSocket;		/* Raw socket for session frames */
226    unsigned char myEth[ETH_ALEN]; /* My MAC address */
227    unsigned char peerEth[ETH_ALEN]; /* Peer's MAC address */
228    unsigned char req_peer_mac[ETH_ALEN]; /* required peer MAC address */
229    unsigned char req_peer;	/* require mac addr to match req_peer_mac */
230    UINT16_t session;		/* Session ID */
231    char *ifName;		/* Interface name */
232    char *serviceName;		/* Desired service name, if any */
233    char *acName;		/* Desired AC name, if any */
234    int synchronous;		/* Use synchronous PPP */
235    PPPoETag hostUniq;		/* Use Host-Uniq tag */
236    int printACNames;		/* Just print AC names */
237    FILE *debugFile;		/* Debug file for dumping packets */
238    int numPADOs;		/* Number of PADO packets received */
239    PPPoETag cookie;		/* We have to send this if we get it */
240    PPPoETag relayId;		/* Ditto */
241    int error;			/* Error packet received */
242    int debug;			/* Set to log packets sent and received */
243    int discoveryTimeout;       /* Timeout for discovery packets */
244    int discoveryAttempts;      /* Number of discovery attempts */
245    int seenMaxPayload;
246    int mtu;			/* Stored MTU */
247    int mru;			/* Stored MRU */
248} PPPoEConnection;
249
250/* Structure used to determine acceptable PADO or PADS packet */
251struct PacketCriteria {
252    PPPoEConnection *conn;
253    int acNameOK;
254    int serviceNameOK;
255    int seenACName;
256    int seenServiceName;
257};
258
259/* Function Prototypes */
260UINT16_t etherType(PPPoEPacket *packet);
261int openInterface(char const *ifname, UINT16_t type, unsigned char *hwaddr);
262int sendPacket(PPPoEConnection *conn, int sock, PPPoEPacket *pkt, int size);
263int receivePacket(int sock, PPPoEPacket *pkt, int *size);
264void fatalSys(char const *str);
265void dumpPacket(FILE *fp, PPPoEPacket *packet, char const *dir);
266void dumpHex(FILE *fp, unsigned char const *buf, int len);
267int parsePacket(PPPoEPacket *packet, ParseFunc *func, void *extra);
268void parseLogErrs(UINT16_t typ, UINT16_t len, unsigned char *data, void *xtra);
269void syncReadFromPPP(PPPoEConnection *conn, PPPoEPacket *packet);
270void asyncReadFromPPP(PPPoEConnection *conn, PPPoEPacket *packet);
271void asyncReadFromEth(PPPoEConnection *conn, int sock, int clampMss);
272void syncReadFromEth(PPPoEConnection *conn, int sock, int clampMss);
273char *strDup(char const *str);
274void sendPADT(PPPoEConnection *conn, char const *msg);
275void sendSessionPacket(PPPoEConnection *conn,
276		       PPPoEPacket *packet, int len);
277void initPPP(void);
278void clampMSS(PPPoEPacket *packet, char const *dir, int clampMss);
279UINT16_t computeTCPChecksum(unsigned char *ipHdr, unsigned char *tcpHdr);
280UINT16_t pppFCS16(UINT16_t fcs, unsigned char *cp, int len);
281void discovery(PPPoEConnection *conn);
282unsigned char *findTag(PPPoEPacket *packet, UINT16_t tagType,
283		       PPPoETag *tag);
284
285void pppoe_printpkt(PPPoEPacket *packet,
286		    void (*printer)(void *, char *, ...), void *arg);
287void pppoe_log_packet(const char *prefix, PPPoEPacket *packet);
288
289static inline int parseHostUniq(const char *uniq, PPPoETag *tag)
290{
291    unsigned i, len = strlen(uniq);
292
293#define hex(x) \
294    (((x) <= '9') ? ((x) - '0') : \
295        (((x) <= 'F') ? ((x) - 'A' + 10) : \
296            ((x) - 'a' + 10)))
297
298    if (!len || len % 2 || len / 2 > sizeof(tag->payload))
299        return 0;
300
301    for (i = 0; i < len; i += 2) {
302        if (!isxdigit(uniq[i]) || !isxdigit(uniq[i+1]))
303            return 0;
304
305        tag->payload[i / 2] = (char)(hex(uniq[i]) << 4 | hex(uniq[i+1]));
306    }
307
308#undef hex
309
310    tag->type = htons(TAG_HOST_UNIQ);
311    tag->length = htons(len / 2);
312    return 1;
313}
314
315#define SET_STRING(var, val) do { if (var) free(var); var = strDup(val); } while(0);
316
317#define CHECK_ROOM(cursor, start, len) \
318do {\
319    if (((cursor)-(start))+(len) > MAX_PPPOE_PAYLOAD) { \
320	error("Would create too-long packet");	\
321        return; \
322    } \
323} while(0)
324
325/* True if Ethernet address is broadcast or multicast */
326#define NOT_UNICAST(e) ((e[0] & 0x01) != 0)
327#define BROADCAST(e) ((e[0] & e[1] & e[2] & e[3] & e[4] & e[5]) == 0xFF)
328#define NOT_BROADCAST(e) ((e[0] & e[1] & e[2] & e[3] & e[4] & e[5]) != 0xFF)
329