--- /dev/null
+/***********************************************************************
+*
+* common.c
+*
+* Implementation of user-space PPPoE redirector for Linux.
+*
+* Common functions used by PPPoE client and server
+*
+* Copyright (C) 2000 by Roaring Penguin Software Inc.
+*
+* This program may be distributed according to the terms of the GNU
+* General Public License, version 2 or (at your option) any later version.
+*
+***********************************************************************/
+
+static char const RCSID[] =
+"$Id: common.c,v 1.3 2008/06/09 08:34:23 paulus Exp $";
+
+#define _GNU_SOURCE 1
+#include "pppoe.h"
+#include "pppd/pppd.h"
+
+#include <string.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <syslog.h> /* for LOG_DEBUG */
+
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif
+
+/**********************************************************************
+*%FUNCTION: parsePacket
+*%ARGUMENTS:
+* packet -- the PPPoE discovery packet to parse
+* func -- function called for each tag in the packet
+* extra -- an opaque data pointer supplied to parsing function
+*%RETURNS:
+* 0 if everything went well; -1 if there was an error
+*%DESCRIPTION:
+* Parses a PPPoE discovery packet, calling "func" for each tag in the packet.
+* "func" is passed the additional argument "extra".
+***********************************************************************/
+int
+parsePacket(PPPoEPacket *packet, ParseFunc *func, void *extra)
+{
+ UINT16_t len = ntohs(packet->length);
+ unsigned char *curTag;
+ UINT16_t tagType, tagLen;
+
+ if (PPPOE_VER(packet->vertype) != 1) {
+ error("Invalid PPPoE version (%d)", PPPOE_VER(packet->vertype));
+ return -1;
+ }
+ if (PPPOE_TYPE(packet->vertype) != 1) {
+ error("Invalid PPPoE type (%d)", PPPOE_TYPE(packet->vertype));
+ return -1;
+ }
+
+ /* Do some sanity checks on packet */
+ if (len > ETH_JUMBO_LEN - PPPOE_OVERHEAD) { /* 6-byte overhead for PPPoE header */
+ error("Invalid PPPoE packet length (%u)", len);
+ return -1;
+ }
+
+ /* Step through the tags */
+ curTag = packet->payload;
+ while (curTag - packet->payload + TAG_HDR_SIZE <= len) {
+ /* Alignment is not guaranteed, so do this by hand... */
+ tagType = (curTag[0] << 8) + curTag[1];
+ tagLen = (curTag[2] << 8) + curTag[3];
+ if (tagType == TAG_END_OF_LIST) {
+ return 0;
+ }
+ if ((curTag - packet->payload) + tagLen + TAG_HDR_SIZE > len) {
+ error("Invalid PPPoE tag length (%u)", tagLen);
+ return -1;
+ }
+ func(tagType, tagLen, curTag+TAG_HDR_SIZE, extra);
+ curTag = curTag + TAG_HDR_SIZE + tagLen;
+ }
+ return 0;
+}
+
+/***********************************************************************
+*%FUNCTION: sendPADT
+*%ARGUMENTS:
+* conn -- PPPoE connection
+* msg -- if non-NULL, extra error message to include in PADT packet.
+*%RETURNS:
+* Nothing
+*%DESCRIPTION:
+* Sends a PADT packet
+***********************************************************************/
+void
+sendPADT(PPPoEConnection *conn, char const *msg)
+{
+ PPPoEPacket packet;
+ unsigned char *cursor = packet.payload;
+
+ UINT16_t plen = 0;
+
+ /* Do nothing if no session established yet */
+ if (!conn->session) return;
+
+ /* Do nothing if no discovery socket */
+ if (conn->discoverySocket < 0) return;
+
+ memcpy(packet.ethHdr.h_dest, conn->peerEth, ETH_ALEN);
+ memcpy(packet.ethHdr.h_source, conn->myEth, ETH_ALEN);
+
+ packet.ethHdr.h_proto = htons(Eth_PPPOE_Discovery);
+ packet.vertype = PPPOE_VER_TYPE(1, 1);
+ packet.code = CODE_PADT;
+ packet.session = conn->session;
+
+ /* Reset Session to zero so there is no possibility of
+ recursive calls to this function by any signal handler */
+ conn->session = 0;
+
+ /* If we're using Host-Uniq, copy it over */
+ if (conn->hostUniq.length) {
+ int len = ntohs(conn->hostUniq.length);
+ memcpy(cursor, &conn->hostUniq, len + TAG_HDR_SIZE);
+ cursor += len + TAG_HDR_SIZE;
+ plen += len + TAG_HDR_SIZE;
+ }
+
+ /* Copy error message */
+ if (msg) {
+ PPPoETag err;
+ size_t elen = strlen(msg);
+ err.type = htons(TAG_GENERIC_ERROR);
+ err.length = htons(elen);
+ strcpy(err.payload, msg);
+ memcpy(cursor, &err, elen + TAG_HDR_SIZE);
+ cursor += elen + TAG_HDR_SIZE;
+ plen += elen + TAG_HDR_SIZE;
+ }
+
+ /* Copy cookie and relay-ID if needed */
+ if (conn->cookie.type) {
+ CHECK_ROOM(cursor, packet.payload,
+ ntohs(conn->cookie.length) + TAG_HDR_SIZE);
+ memcpy(cursor, &conn->cookie, ntohs(conn->cookie.length) + TAG_HDR_SIZE);
+ cursor += ntohs(conn->cookie.length) + TAG_HDR_SIZE;
+ plen += ntohs(conn->cookie.length) + TAG_HDR_SIZE;
+ }
+
+ if (conn->relayId.type) {
+ CHECK_ROOM(cursor, packet.payload,
+ ntohs(conn->relayId.length) + TAG_HDR_SIZE);
+ memcpy(cursor, &conn->relayId, ntohs(conn->relayId.length) + TAG_HDR_SIZE);
+ cursor += ntohs(conn->relayId.length) + TAG_HDR_SIZE;
+ plen += ntohs(conn->relayId.length) + TAG_HDR_SIZE;
+ }
+
+ packet.length = htons(plen);
+ sendPacket(conn, conn->discoverySocket, &packet, (int) (plen + HDR_SIZE));
+ info("Sent PADT");
+}
+
+#define EH(x) (x)[0], (x)[1], (x)[2], (x)[3], (x)[4], (x)[5]
+
+/* Print out a PPPOE packet for debugging */
+void pppoe_printpkt(PPPoEPacket *packet,
+ void (*printer)(void *, char *, ...), void *arg)
+{
+ int len = ntohs(packet->length);
+ int i, tag, tlen, text;
+
+ switch (ntohs(packet->ethHdr.h_proto)) {
+ case ETH_PPPOE_DISCOVERY:
+ printer(arg, "PPPOE Discovery V%dT%d ", PPPOE_VER(packet->vertype),
+ PPPOE_TYPE(packet->vertype));
+ switch (packet->code) {
+ case CODE_PADI:
+ printer(arg, "PADI");
+ break;
+ case CODE_PADO:
+ printer(arg, "PADO");
+ break;
+ case CODE_PADR:
+ printer(arg, "PADR");
+ break;
+ case CODE_PADS:
+ printer(arg, "PADS");
+ break;
+ case CODE_PADT:
+ printer(arg, "PADT");
+ break;
+ default:
+ printer(arg, "unknown code %x", packet->code);
+ }
+ printer(arg, " session 0x%x length %d\n", ntohs(packet->session), len);
+ break;
+ case ETH_PPPOE_SESSION:
+ printer(arg, "PPPOE Session V%dT%d", PPPOE_VER(packet->vertype),
+ PPPOE_TYPE(packet->vertype));
+ printer(arg, " code 0x%x session 0x%x length %d\n", packet->code,
+ ntohs(packet->session), len);
+ break;
+ default:
+ printer(arg, "Unknown ethernet frame with proto = 0x%x\n",
+ ntohs(packet->ethHdr.h_proto));
+ }
+
+ printer(arg, " dst %02x:%02x:%02x:%02x:%02x:%02x ", EH(packet->ethHdr.h_dest));
+ printer(arg, " src %02x:%02x:%02x:%02x:%02x:%02x\n", EH(packet->ethHdr.h_source));
+ if (ntohs(packet->ethHdr.h_proto) != ETH_PPPOE_DISCOVERY)
+ return;
+
+ for (i = 0; i + TAG_HDR_SIZE <= len; i += tlen) {
+ tag = (packet->payload[i] << 8) + packet->payload[i+1];
+ tlen = (packet->payload[i+2] << 8) + packet->payload[i+3];
+ if (i + tlen + TAG_HDR_SIZE > len)
+ break;
+ text = 0;
+ i += TAG_HDR_SIZE;
+ printer(arg, " [");
+ switch (tag) {
+ case TAG_END_OF_LIST:
+ printer(arg, "end-of-list");
+ break;
+ case TAG_SERVICE_NAME:
+ printer(arg, "service-name");
+ text = 1;
+ break;
+ case TAG_AC_NAME:
+ printer(arg, "AC-name");
+ text = 1;
+ break;
+ case TAG_HOST_UNIQ:
+ printer(arg, "host-uniq");
+ break;
+ case TAG_AC_COOKIE:
+ printer(arg, "AC-cookie");
+ break;
+ case TAG_VENDOR_SPECIFIC:
+ printer(arg, "vendor-specific");
+ break;
+ case TAG_RELAY_SESSION_ID:
+ printer(arg, "relay-session-id");
+ break;
+ case TAG_PPP_MAX_PAYLOAD:
+ printer(arg, "PPP-max-payload");
+ break;
+ case TAG_SERVICE_NAME_ERROR:
+ printer(arg, "service-name-error");
+ text = 1;
+ break;
+ case TAG_AC_SYSTEM_ERROR:
+ printer(arg, "AC-system-error");
+ text = 1;
+ break;
+ case TAG_GENERIC_ERROR:
+ printer(arg, "generic-error");
+ text = 1;
+ break;
+ default:
+ printer(arg, "unknown tag 0x%x", tag);
+ }
+ if (tlen) {
+ if (text)
+ printer(arg, " %.*v", tlen, &packet->payload[i]);
+ else if (tlen <= 32)
+ printer(arg, " %.*B", tlen, &packet->payload[i]);
+ else
+ printer(arg, " %.32B... (length %d)",
+ &packet->payload[i], tlen);
+ }
+ printer(arg, "]");
+ }
+ printer(arg, "\n");
+}
+
+void pppoe_log_packet(const char *prefix, PPPoEPacket *packet)
+{
+ init_pr_log(prefix, LOG_DEBUG);
+ pppoe_printpkt(packet, pr_log, NULL);
+ end_pr_log();
+}
projects / ppp.git / blobdiff