1 /***********************************************************************
5 * Declaration of various PPPoE constants
7 * Copyright (C) 2000 Roaring Penguin Software Inc.
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.
12 * $Id: pppoe.h,v 1.4 2008/06/15 04:35:50 paulus Exp $
14 ***********************************************************************/
16 #include <stdio.h> /* For FILE */
17 #include <sys/types.h> /* For pid_t */
21 #include "pppd/pppd.h" /* For error */
23 /* How do we access raw Ethernet devices? */
24 #undef USE_LINUX_PACKET
27 #if defined(HAVE_NETPACKET_PACKET_H) || defined(HAVE_LINUX_IF_PACKET_H)
28 #define USE_LINUX_PACKET 1
29 #elif defined(HAVE_SYS_DLPI_H)
31 #elif defined(HAVE_NET_BPF_H)
36 #if !defined(USE_BPF) && !defined(USE_LINUX_PACKET) && !defined(USE_DLPI)
37 #error Unknown method for accessing raw Ethernet frames
40 #ifdef HAVE_SYS_SOCKET_H
41 #include <sys/socket.h>
44 /* This has to be included before Linux 4.8's linux/in.h
46 #include <netinet/in.h>
48 /* Ugly header files on some Linux boxes... */
49 #if defined(HAVE_LINUX_IF_H)
51 #elif defined(HAVE_NET_IF_H)
55 #ifdef HAVE_NET_IF_TYPES_H
56 #include <net/if_types.h>
59 #define BPF_BUFFER_IS_EMPTY 1
60 #define BPF_BUFFER_HAS_DATA 0
62 /* Define various integer types -- assumes a char is 8 bits */
63 #if SIZEOF_UNSIGNED_SHORT == 2
64 typedef unsigned short UINT16_t;
65 #elif SIZEOF_UNSIGNED_INT == 2
66 typedef unsigned int UINT16_t;
68 #error Could not find a 16-bit integer type
71 #if SIZEOF_UNSIGNED_SHORT == 4
72 typedef unsigned short UINT32_t;
73 #elif SIZEOF_UNSIGNED_INT == 4
74 typedef unsigned int UINT32_t;
75 #elif SIZEOF_UNSIGNED_LONG == 4
76 typedef unsigned long UINT32_t;
78 #error Could not find a 32-bit integer type
81 #ifdef HAVE_LINUX_IF_ETHER_H
82 #include <linux/if_ether.h>
85 #ifdef HAVE_NETINET_IF_ETHER_H
86 #include <sys/types.h>
88 #ifdef HAVE_SYS_SOCKET_H
89 #include <sys/socket.h>
91 #ifndef HAVE_SYS_DLPI_H
92 #include <netinet/if_ether.h>
97 /* Ethernet frame types according to RFC 2516 */
98 #define ETH_PPPOE_DISCOVERY 0x8863
99 #define ETH_PPPOE_SESSION 0x8864
101 /* But some brain-dead peers disobey the RFC, so frame types are variables */
102 extern UINT16_t Eth_PPPOE_Discovery;
103 extern UINT16_t Eth_PPPOE_Session;
106 #define CODE_PADI 0x09
107 #define CODE_PADO 0x07
108 #define CODE_PADR 0x19
109 #define CODE_PADS 0x65
110 #define CODE_PADT 0xA7
112 /* Extensions from draft-carrel-info-pppoe-ext-00 */
113 /* I do NOT like PADM or PADN, but they are here for completeness */
114 #define CODE_PADM 0xD3
115 #define CODE_PADN 0xD4
117 #define CODE_SESS 0x00
120 #define TAG_END_OF_LIST 0x0000
121 #define TAG_SERVICE_NAME 0x0101
122 #define TAG_AC_NAME 0x0102
123 #define TAG_HOST_UNIQ 0x0103
124 #define TAG_AC_COOKIE 0x0104
125 #define TAG_VENDOR_SPECIFIC 0x0105
126 #define TAG_RELAY_SESSION_ID 0x0110
127 #define TAG_PPP_MAX_PAYLOAD 0x0120
128 #define TAG_SERVICE_NAME_ERROR 0x0201
129 #define TAG_AC_SYSTEM_ERROR 0x0202
130 #define TAG_GENERIC_ERROR 0x0203
132 /* Extensions from draft-carrel-info-pppoe-ext-00 */
133 /* I do NOT like these tags one little bit */
134 #define TAG_HURL 0x111
135 #define TAG_MOTM 0x112
136 #define TAG_IP_ROUTE_ADD 0x121
138 /* Discovery phase states */
139 #define STATE_SENT_PADI 0
140 #define STATE_RECEIVED_PADO 1
141 #define STATE_SENT_PADR 2
142 #define STATE_SESSION 3
143 #define STATE_TERMINATED 4
145 /* How many PADI/PADS attempts? */
146 #define MAX_PADI_ATTEMPTS 3
148 /* Initial timeout for PADO/PADS */
149 #define PADI_TIMEOUT 5
151 /* States for scanning PPP frames */
152 #define STATE_WAITFOR_FRAME_ADDR 0
153 #define STATE_DROP_PROTO 1
154 #define STATE_BUILDING_PACKET 2
156 /* Special PPP frame characters */
157 #define FRAME_ESC 0x7D
158 #define FRAME_FLAG 0x7E
159 #define FRAME_ADDR 0xFF
160 #define FRAME_CTRL 0x03
161 #define FRAME_ENC 0x20
166 /* There are other fixed-size buffers preventing
167 this from being increased to 16110. The buffer
168 sizes would need to be properly de-coupled from
169 the default MRU. For now, getting up to 1500 is
171 #define ETH_JUMBO_LEN 1508
173 /* A PPPoE Packet, including Ethernet headers */
174 typedef struct PPPoEPacketStruct {
175 struct ethhdr ethHdr; /* Ethernet header */
176 unsigned int vertype:8; /* PPPoE Version and Type (must both be 1) */
177 unsigned int code:8; /* PPPoE code */
178 unsigned int session:16; /* PPPoE session */
179 unsigned int length:16; /* Payload length */
180 unsigned char payload[ETH_JUMBO_LEN]; /* A bit of room to spare */
183 #define PPPOE_VER(vt) ((vt) >> 4)
184 #define PPPOE_TYPE(vt) ((vt) & 0xf)
185 #define PPPOE_VER_TYPE(v, t) (((v) << 4) | (t))
187 /* Header size of a PPPoE packet */
188 #define PPPOE_OVERHEAD 6 /* type, code, session, length */
189 #define HDR_SIZE (sizeof(struct ethhdr) + PPPOE_OVERHEAD)
190 #define MAX_PPPOE_PAYLOAD (ETH_JUMBO_LEN - PPPOE_OVERHEAD)
191 #define PPP_OVERHEAD 2 /* protocol */
192 #define MAX_PPPOE_MTU (MAX_PPPOE_PAYLOAD - PPP_OVERHEAD)
193 #define TOTAL_OVERHEAD (PPPOE_OVERHEAD + PPP_OVERHEAD)
194 #define ETH_PPPOE_MTU (ETH_DATA_LEN - TOTAL_OVERHEAD)
198 typedef struct PPPoETagStruct {
199 unsigned int type:16; /* tag type */
200 unsigned int length:16; /* Length of payload */
201 unsigned char payload[ETH_JUMBO_LEN]; /* A LOT of room to spare */
203 /* Header size of a PPPoE tag */
204 #define TAG_HDR_SIZE 4
206 /* Chunk to read from stdin */
207 #define READ_CHUNK 4096
209 /* Function passed to parsePacket */
210 typedef void ParseFunc(UINT16_t type,
215 #define PPPINITFCS16 0xffff /* Initial FCS value */
217 /* Keep track of the state of a connection -- collect everything in
220 typedef struct PPPoEConnectionStruct {
221 int discoveryState; /* Where we are in discovery */
222 int discoverySocket; /* Raw socket for discovery frames */
223 int sessionSocket; /* Raw socket for session frames */
224 unsigned char myEth[ETH_ALEN]; /* My MAC address */
225 unsigned char peerEth[ETH_ALEN]; /* Peer's MAC address */
226 unsigned char req_peer_mac[ETH_ALEN]; /* required peer MAC address */
227 unsigned char req_peer; /* require mac addr to match req_peer_mac */
228 UINT16_t session; /* Session ID */
229 char *ifName; /* Interface name */
230 char *serviceName; /* Desired service name, if any */
231 char *acName; /* Desired AC name, if any */
232 int synchronous; /* Use synchronous PPP */
233 PPPoETag hostUniq; /* Use Host-Uniq tag */
234 int numPADOs; /* Number of PADO packets received */
235 PPPoETag cookie; /* We have to send this if we get it */
236 PPPoETag relayId; /* Ditto */
237 int error; /* Error packet received */
238 int discoveryTimeout; /* Timeout for discovery packets */
239 int discoveryAttempts; /* Number of discovery attempts */
241 int storedmtu; /* Stored MTU */
242 int storedmru; /* Stored MRU */
247 /* Structure used to determine acceptable PADO or PADS packet */
248 struct PacketCriteria {
249 PPPoEConnection *conn;
256 /* Function Prototypes */
257 UINT16_t etherType(PPPoEPacket *packet);
258 int openInterface(char const *ifname, UINT16_t type, unsigned char *hwaddr);
259 int sendPacket(PPPoEConnection *conn, int sock, PPPoEPacket *pkt, int size);
260 int receivePacket(int sock, PPPoEPacket *pkt, int *size);
261 int parsePacket(PPPoEPacket *packet, ParseFunc *func, void *extra);
262 void parseLogErrs(UINT16_t typ, UINT16_t len, unsigned char *data, void *xtra);
263 void syncReadFromPPP(PPPoEConnection *conn, PPPoEPacket *packet);
264 void asyncReadFromPPP(PPPoEConnection *conn, PPPoEPacket *packet);
265 void asyncReadFromEth(PPPoEConnection *conn, int sock, int clampMss);
266 void syncReadFromEth(PPPoEConnection *conn, int sock, int clampMss);
267 char *strDup(char const *str);
268 void sendPADT(PPPoEConnection *conn, char const *msg);
269 void sendSessionPacket(PPPoEConnection *conn,
270 PPPoEPacket *packet, int len);
272 void clampMSS(PPPoEPacket *packet, char const *dir, int clampMss);
273 UINT16_t computeTCPChecksum(unsigned char *ipHdr, unsigned char *tcpHdr);
274 UINT16_t pppFCS16(UINT16_t fcs, unsigned char *cp, int len);
275 void discovery1(PPPoEConnection *conn);
276 void discovery2(PPPoEConnection *conn);
277 unsigned char *findTag(PPPoEPacket *packet, UINT16_t tagType,
280 extern int pppoe_verbose;
281 void pppoe_printpkt(PPPoEPacket *packet,
282 void (*printer)(void *, char *, ...), void *arg);
283 void pppoe_log_packet(const char *prefix, PPPoEPacket *packet);
285 static inline int parseHostUniq(const char *uniq, PPPoETag *tag)
287 unsigned i, len = strlen(uniq);
290 (((x) <= '9') ? ((x) - '0') : \
291 (((x) <= 'F') ? ((x) - 'A' + 10) : \
294 if (!len || len % 2 || len / 2 > sizeof(tag->payload))
297 for (i = 0; i < len; i += 2) {
298 if (!isxdigit(uniq[i]) || !isxdigit(uniq[i+1]))
301 tag->payload[i / 2] = (char)(hex(uniq[i]) << 4 | hex(uniq[i+1]));
306 tag->type = htons(TAG_HOST_UNIQ);
307 tag->length = htons(len / 2);
311 #define SET_STRING(var, val) do { if (var) free(var); var = strDup(val); } while(0);
313 #define CHECK_ROOM(cursor, start, len) \
315 if (((cursor)-(start))+(len) > MAX_PPPOE_PAYLOAD) { \
316 error("Would create too-long packet"); \
321 /* True if Ethernet address is broadcast or multicast */
322 #define NOT_UNICAST(e) ((e[0] & 0x01) != 0)
323 #define BROADCAST(e) ((e[0] & e[1] & e[2] & e[3] & e[4] & e[5]) == 0xFF)
324 #define NOT_BROADCAST(e) ((e[0] & e[1] & e[2] & e[3] & e[4] & e[5]) != 0xFF)