1 /***********************************************************************
5 * Implementation of user-space PPPoE redirector for Linux.
7 * Common functions used by PPPoE client and server
9 * Copyright (C) 2000 by Roaring Penguin Software Inc.
11 * This program may be distributed according to the terms of the GNU
12 * General Public License, version 2 or (at your option) any later version.
14 ***********************************************************************/
16 static char const RCSID[] =
17 "$Id: common.c,v 1.3 2008/06/09 08:34:23 paulus Exp $";
21 #include "pppd/pppd.h"
26 #include <syslog.h> /* for LOG_DEBUG */
32 /**********************************************************************
33 *%FUNCTION: parsePacket
35 * packet -- the PPPoE discovery packet to parse
36 * func -- function called for each tag in the packet
37 * extra -- an opaque data pointer supplied to parsing function
39 * 0 if everything went well; -1 if there was an error
41 * Parses a PPPoE discovery packet, calling "func" for each tag in the packet.
42 * "func" is passed the additional argument "extra".
43 ***********************************************************************/
45 parsePacket(PPPoEPacket *packet, ParseFunc *func, void *extra)
47 UINT16_t len = ntohs(packet->length);
48 unsigned char *curTag;
49 UINT16_t tagType, tagLen;
51 if (PPPOE_VER(packet->vertype) != 1) {
52 error("Invalid PPPoE version (%d)", PPPOE_VER(packet->vertype));
55 if (PPPOE_TYPE(packet->vertype) != 1) {
56 error("Invalid PPPoE type (%d)", PPPOE_TYPE(packet->vertype));
60 /* Do some sanity checks on packet */
61 if (len > ETH_JUMBO_LEN - PPPOE_OVERHEAD) { /* 6-byte overhead for PPPoE header */
62 error("Invalid PPPoE packet length (%u)", len);
66 /* Step through the tags */
67 curTag = packet->payload;
68 while (curTag - packet->payload + TAG_HDR_SIZE <= len) {
69 /* Alignment is not guaranteed, so do this by hand... */
70 tagType = (curTag[0] << 8) + curTag[1];
71 tagLen = (curTag[2] << 8) + curTag[3];
72 if (tagType == TAG_END_OF_LIST) {
75 if ((curTag - packet->payload) + tagLen + TAG_HDR_SIZE > len) {
76 error("Invalid PPPoE tag length (%u)", tagLen);
79 func(tagType, tagLen, curTag+TAG_HDR_SIZE, extra);
80 curTag = curTag + TAG_HDR_SIZE + tagLen;
85 /***********************************************************************
88 * conn -- PPPoE connection
89 * msg -- if non-NULL, extra error message to include in PADT packet.
94 ***********************************************************************/
96 sendPADT(PPPoEConnection *conn, char const *msg)
99 unsigned char *cursor = packet.payload;
103 /* Do nothing if no session established yet */
104 if (!conn->session) return;
106 /* Do nothing if no discovery socket */
107 if (conn->discoverySocket < 0) return;
109 memcpy(packet.ethHdr.h_dest, conn->peerEth, ETH_ALEN);
110 memcpy(packet.ethHdr.h_source, conn->myEth, ETH_ALEN);
112 packet.ethHdr.h_proto = htons(Eth_PPPOE_Discovery);
113 packet.vertype = PPPOE_VER_TYPE(1, 1);
114 packet.code = CODE_PADT;
115 packet.session = conn->session;
117 /* Reset Session to zero so there is no possibility of
118 recursive calls to this function by any signal handler */
121 /* If we're using Host-Uniq, copy it over */
122 if (conn->hostUniq.length) {
123 int len = ntohs(conn->hostUniq.length);
124 memcpy(cursor, &conn->hostUniq, len + TAG_HDR_SIZE);
125 cursor += len + TAG_HDR_SIZE;
126 plen += len + TAG_HDR_SIZE;
129 /* Copy error message */
132 size_t elen = strlen(msg);
133 err.type = htons(TAG_GENERIC_ERROR);
134 err.length = htons(elen);
135 strcpy(err.payload, msg);
136 memcpy(cursor, &err, elen + TAG_HDR_SIZE);
137 cursor += elen + TAG_HDR_SIZE;
138 plen += elen + TAG_HDR_SIZE;
141 /* Copy cookie and relay-ID if needed */
142 if (conn->cookie.type) {
143 CHECK_ROOM(cursor, packet.payload,
144 ntohs(conn->cookie.length) + TAG_HDR_SIZE);
145 memcpy(cursor, &conn->cookie, ntohs(conn->cookie.length) + TAG_HDR_SIZE);
146 cursor += ntohs(conn->cookie.length) + TAG_HDR_SIZE;
147 plen += ntohs(conn->cookie.length) + TAG_HDR_SIZE;
150 if (conn->relayId.type) {
151 CHECK_ROOM(cursor, packet.payload,
152 ntohs(conn->relayId.length) + TAG_HDR_SIZE);
153 memcpy(cursor, &conn->relayId, ntohs(conn->relayId.length) + TAG_HDR_SIZE);
154 cursor += ntohs(conn->relayId.length) + TAG_HDR_SIZE;
155 plen += ntohs(conn->relayId.length) + TAG_HDR_SIZE;
158 packet.length = htons(plen);
159 sendPacket(conn, conn->discoverySocket, &packet, (int) (plen + HDR_SIZE));
163 #define EH(x) (x)[0], (x)[1], (x)[2], (x)[3], (x)[4], (x)[5]
165 /* Print out a PPPOE packet for debugging */
166 void pppoe_printpkt(PPPoEPacket *packet,
167 void (*printer)(void *, char *, ...), void *arg)
169 int len = ntohs(packet->length);
170 int i, tag, tlen, text;
172 switch (ntohs(packet->ethHdr.h_proto)) {
173 case ETH_PPPOE_DISCOVERY:
174 printer(arg, "PPPOE Discovery V%dT%d ", PPPOE_VER(packet->vertype),
175 PPPOE_TYPE(packet->vertype));
176 switch (packet->code) {
178 printer(arg, "PADI");
181 printer(arg, "PADO");
184 printer(arg, "PADR");
187 printer(arg, "PADS");
190 printer(arg, "PADT");
193 printer(arg, "unknown code %x", packet->code);
195 printer(arg, " session 0x%x length %d\n", ntohs(packet->session), len);
197 case ETH_PPPOE_SESSION:
198 printer(arg, "PPPOE Session V%dT%d", PPPOE_VER(packet->vertype),
199 PPPOE_TYPE(packet->vertype));
200 printer(arg, " code 0x%x session 0x%x length %d\n", packet->code,
201 ntohs(packet->session), len);
204 printer(arg, "Unknown ethernet frame with proto = 0x%x\n",
205 ntohs(packet->ethHdr.h_proto));
208 printer(arg, " dst %02x:%02x:%02x:%02x:%02x:%02x ", EH(packet->ethHdr.h_dest));
209 printer(arg, " src %02x:%02x:%02x:%02x:%02x:%02x\n", EH(packet->ethHdr.h_source));
210 if (ntohs(packet->ethHdr.h_proto) != ETH_PPPOE_DISCOVERY)
213 for (i = 0; i + TAG_HDR_SIZE <= len; i += tlen) {
214 tag = (packet->payload[i] << 8) + packet->payload[i+1];
215 tlen = (packet->payload[i+2] << 8) + packet->payload[i+3];
216 if (i + tlen + TAG_HDR_SIZE > len)
222 case TAG_END_OF_LIST:
223 printer(arg, "end-of-list");
225 case TAG_SERVICE_NAME:
226 printer(arg, "service-name");
230 printer(arg, "AC-name");
234 printer(arg, "host-uniq");
237 printer(arg, "AC-cookie");
239 case TAG_VENDOR_SPECIFIC:
240 printer(arg, "vendor-specific");
242 case TAG_RELAY_SESSION_ID:
243 printer(arg, "relay-session-id");
245 case TAG_PPP_MAX_PAYLOAD:
246 printer(arg, "PPP-max-payload");
248 case TAG_SERVICE_NAME_ERROR:
249 printer(arg, "service-name-error");
252 case TAG_AC_SYSTEM_ERROR:
253 printer(arg, "AC-system-error");
256 case TAG_GENERIC_ERROR:
257 printer(arg, "generic-error");
261 printer(arg, "unknown tag 0x%x", tag);
265 printer(arg, " %.*v", tlen, &packet->payload[i]);
267 printer(arg, " %.*B", tlen, &packet->payload[i]);
269 printer(arg, " %.32B... (length %d)",
270 &packet->payload[i], tlen);
277 void pppoe_log_packet(const char *prefix, PPPoEPacket *packet)
279 init_pr_log(prefix, LOG_DEBUG);
280 pppoe_printpkt(packet, pr_log, NULL);