// L2TPNS PPP Stuff
-// $Id: ppp.c,v 1.4 2004/05/24 04:26:01 fred_nerk Exp $
+// $Id: ppp.c,v 1.5 2004/06/23 03:52:24 fred_nerk Exp $
#include <stdio.h>
#include <string.h>
#include "constants.h"
#include "plugin.h"
#include "util.h"
+#include "tbf.h"
+#include "cluster.h"
extern tunnelt *tunnel;
extern sessiont *session;
extern radiust *radius;
extern int tapfd;
-extern char hostname[1000];
-extern struct Tstats *_statistics;
-extern unsigned long eth_tx;
+extern char hostname[];
+extern u32 eth_tx;
extern time_t time_now;
extern struct configt *config;
// respond now, either no RADIUS available or already authenticated
u8 b[MAXCONTROL];
u8 id = p[1];
- u8 *p = makeppp(b, 0, 0, t, s, PPPPAP);
+ u8 *p = makeppp(b, sizeof(b), 0, 0, t, s, PPPPAP);
+ if (!p) { // Failed to make ppp header!
+ log(1,0,0,0, "Failed to make PPP header in process pap!\n");
+ return;
+ }
if (session[s].ip)
*p = 2; // ACK
else
if (!r)
{
log(1, 0, s, t, "Unexpected CHAP message\n");
+
+// FIXME: Need to drop the session here.
+
STAT(tunnel_rx_errors);
return;
}
"DiscardRequest",
};
-void dumplcp(char *p, int l)
+void dumplcp(u8 *p, int l)
{
- signed int x = l - 3;
- char *o = (p + 3);
+ signed int x = l - 4;
+ u8 *o = (p + 4);
log_hex(5, "PPP LCP Packet", p, l);
- log(4, 0, 0, 0, "PPP LCP Packet type %d (%s)\n", *p, ppp_lcp_types[(int)*p]);
+ log(4, 0, 0, 0, "PPP LCP Packet type %d (%s len %d)\n", *p, ppp_lcp_types[(int)*p], ntohs( ((u16 *) p)[1]) );
log(4, 0, 0, 0, "Length: %d\n", l);
if (*p != ConfigReq && *p != ConfigRej && *p != ConfigAck)
return;
while (x > 2)
{
- int type = *(u8 *)(o);
- int length = *(u8 *)(o + 1);
+ int type = o[0];
+ int length = o[1];
if (length == 0)
{
log(4, 0, 0, 0, " Option length is 0...\n");
proto == 0xC223 ? "CHAP" : "PAP");
break;
}
- case 5: // Magic-Number
- {
- u32 magicno = ntohl(*(u32 *)(o + 2));
- log(4, 0, 0, 0, " %s %x\n", lcp_types[type], magicno);
- break;
- }
case 4: // Quality-Protocol
{
u32 qp = ntohl(*(u32 *)(o + 2));
log(4, 0, 0, 0, " %s %x\n", lcp_types[type], qp);
break;
}
+ case 5: // Magic-Number
+ {
+ u32 magicno = ntohl(*(u32 *)(o + 2));
+ log(4, 0, 0, 0, " %s %x\n", lcp_types[type], magicno);
+ break;
+ }
case 7: // Protocol-Field-Compression
{
u32 pfc = ntohl(*(u32 *)(o + 2));
}
else if (*p == ConfigReq)
{
- signed int x = l - 1;
- char *o = (p + 1);
+ signed int x = l - 4;
+ u8 *o = (p + 4);
log(3, session[s].ip, s, t, "LCP: ConfigReq (%d bytes)...\n", l);
+ dumplcp(p, l);
while (x > 2)
{
- int type = *(u8 *)(o);
- int length = *(u8 *)(o + 1);
+ int type = o[0];
+ int length = o[1];
if (length == 0 || type == 0) break;
switch (type)
{
if (!q)
{
- q = makeppp(b, p, l, t, s, PPPLCP);
+ q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
+ if (!q) {
+ log(2, session[s].ip, s, t, " Failed to send packet.\n");
+ break;
+ }
*q++ = ConfigNak;
}
memcpy(q, o, length);
{
// Send back a ConfigAck
log(3, session[s].ip, s, t, "ConfigReq accepted, sending as Ack\n");
- q = makeppp(b, p, l, t, s, PPPLCP);
+ q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
+ if (!q) {
+ log(3, session[s].ip, s, t, " failed to create packet.\n");
+ return;
+ }
*q = ConfigAck;
tunnelsend(b, l + (q - b), t);
}
tunnelsend(b, l + (q - b), t);
log(3, session[s].ip, s, t, "Sending ConfigReq, requesting PAP login\n");
- q = makeppp(b, NULL, 0, t, s, PPPLCP);
+ q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP);
*q++ = ConfigReq;
*(u8 *)(q++) = 3;
*(u8 *)(q++) = 4;
else if (*p == TerminateReq)
{
*p = TerminateAck; // close
- q = makeppp(b, p, l, t, s, PPPLCP);
+ q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
+ if (!q) {
+ log(3, session[s].ip, s, t, "Failed to create PPP packet in processlcp.\n");
+ return;
+ }
log(3, session[s].ip, s, t, "LCP: Received TerminateReq. Sending TerminateAck\n");
sessionshutdown(s, "Remote end closed connection.");
tunnelsend(b, l + (q - b), t); // send it
{
*p = EchoReply; // reply
*(u32 *) (p + 4) = htonl(session[s].magic); // our magic number
- q = makeppp(b, p, l, t, s, PPPLCP);
+ q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
+ if (!q) {
+ log(3, session[s].ip, s, t, " failed to send EchoReply.\n");
+ return;
+ }
log(5, session[s].ip, s, t, "LCP: Received EchoReq. Sending EchoReply\n");
tunnelsend(b, l + (q - b), t); // send it
}
if (*p == ConfigAck)
{ // happy with our IPCP
u16 r = session[s].radius;
- if ((!r || radius[r].state == RADIUSIPCP) && !session[s].walled_garden)
+ if ((!r || radius[r].state == RADIUSIPCP) && !session[s].walled_garden) {
if (!r)
r = radiusnew(s);
if (r)
radiussend(r, RADIUSSTART); // send radius start, having got IPCP at last
+ }
+ session[s].flags |= SF_IPCP_ACKED;
+
return ; // done
}
if (*p != ConfigReq)
if (!session[s].ip)
{
log(3, 0, s, t, "Waiting on radius reply\n");
- return ; // have to wait on RADIUS eply
+ return ; // have to wait on RADIUS reply
}
// form a config reply quoting the IP in the session
{
{ // reject
u16 n = 4;
i = p + l;
- q = makeppp(b, p, l, t, s, PPPIPCP);
+ q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP);
+ if (!q) {
+ log(2, 0, s, t, "Failed to send IPCP.\n");
+ return;
+ }
*q = ConfigRej;
p += 4;
while (p < i && p[1])
*(u32 *) (i + 2) = htonl(session[s].ip);
*p = ConfigNak;
}
- q = makeppp(b, p, l, t, s, PPPIPCP);
+ q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP);
+ if (!q) {
+ log(2, 0, s, t, " Failed to send IPCP packet.\n");
+ return;
+ }
tunnelsend(b, l + (q - b), t); // send it
}
}
}
// process IP packet received
+//
+// This MUST be called with at least 4 byte behind 'p'.
+// (i.e. this routine writes to p[-4]).
void processipin(tunnelidt t, sessionidt s, u8 * p, u16 l)
{
+ ipt ip;
+
#ifdef STAT_CALLS
STAT(call_processipin);
#endif
log_hex(5, "IP", p, l);
+ ip = ntohl(*(u32 *)(p + 12));
+
if (l > MAXETHER)
{
- log(1, *(u32 *)(p + 12), s, t, "IP packet too long %d\n", l);
+ log(1, ip, s, t, "IP packet too long %d\n", l);
STAT(tunnel_rx_errors);
return ;
}
- session[s].cin += l;
- session[s].total_cin += l;
- session[s].pin++;
- eth_tx += l;
+ // no spoof (do sessionbyip to handled statically routed subnets)
+ if (ip != session[s].ip && sessionbyip(htonl(ip)) != s)
+ {
+ log(5, ip, s, t, "Dropping packet with spoofed IP %s\n", inet_toa(htonl(ip)));
+ return;
+ }
// Add on the tun header
p -= 4;
*(u32 *)p = htonl(0x00000800);
l += 4;
+ if (session[s].tbf_in && !config->cluster_iam_master) { // Are we throttled and a slave?
+ master_throttle_packet(session[s].tbf_in, p, l); // Pass it to the master for handling.
+ return;
+ }
+
+ session[s].cin += l - 4;
+ session[s].total_cin += l - 4;
+ sess_count[s].cin += l - 4;
+
+ session[s].pin++;
+ eth_tx += l - 4;
+
+ if (session[s].snoop_ip && session[s].snoop_port)
+ {
+ // Snooping this session, send it to ASIO
+ snoop_send_packet(p, l, session[s].snoop_ip, session[s].snoop_port);
+ }
+ STAT(tap_tx_packets);
+ INC_STAT(tap_tx_bytes, l);
+
+ if (session[s].tbf_in && config->cluster_iam_master) { // Are we throttled and a master?? actually handle the throttled packets.
+ tbf_queue_packet(session[s].tbf_in, p, l);
+ return;
+ }
+
// send to ethernet
- if (write(tapfd, p, l) < 0)
+ if (tun_write(p, l) < 0)
{
STAT(tap_tx_errors);
log(0, 0, s, t, "Error writing %d bytes to TAP device: %s (tapfd=%d, p=%p)\n",
l, strerror(errno), tapfd, p);
}
- if (session[s].snoop)
+}
+
+//
+// Helper routine for the TBF filters.
+// Used to send queued data in from the user.
+//
+void send_ipin(sessionidt s, u8 *buf, int len)
+{
+ log_hex(5, "IP in throttled", buf, len);
+ if (write(tapfd, buf, len) < 0)
{
- // Snooping this session, send it to ASIO
- snoop_send_packet(p, l);
+ STAT(tap_tx_errors);
+ log(0, 0, 0, 0, "Error writing %d bytes to TAP device: %s (tapfd=%d, p=%p)\n",
+ len, strerror(errno), tapfd, buf);
}
- STAT(tap_tx_packets);
- INC_STAT(tap_tx_bytes, l);
+
+ // Increment packet counters
+ session[s].cin += len - 4;
+ session[s].total_cin += len - 4;
+ sess_count[s].cin += len - 4;
+
+ session[s].pin++;
+ eth_tx += len - 4;
}
+
// Process LCP messages
void processccp(tunnelidt t, sessionidt s, u8 * p, u16 l)
{
}
else
*p = TerminateAck; // close
- q = makeppp(b, p, l, t, s, PPPCCP);
+ q = makeppp(b, sizeof(b), p, l, t, s, PPPCCP);
+ if (!q) {
+ log(1,0,0,0, "Failed to send CCP packet.\n");
+ return;
+ }
tunnelsend(b, l + (q - b), t); // send it
}
}
STAT(tunnel_tx_errors);
return ;
}
- q = makeppp(b, 0, 0, t, s, PPPCHAP);
+ q = makeppp(b, sizeof(b), 0, 0, t, s, PPPCHAP);
+ if (!q) {
+ log(1, 0, s, t, "failed to send CHAP challenge.\n");
+ return;
+ }
*q = 1; // challenhe
q[1] = radius[r].id; // ID
q[4] = 16; // length
// fill in a L2TP message with a PPP frame,
// copies existing PPP message and changes magic number if seen
// returns start of PPP frame
-u8 *makeppp(u8 * b, u8 * p, int l, tunnelidt t, sessionidt s, u16 mtype)
+u8 *makeppp(u8 * b, int size, u8 * p, int l, tunnelidt t, sessionidt s, u16 mtype)
{
+
+ if (size < 12)
+ return NULL; // Need more space than this!!
+
*(u16 *) (b + 0) = htons(0x0002); // L2TP with no options
*(u16 *) (b + 2) = htons(tunnel[t].far); // tunnel
*(u16 *) (b + 4) = htons(session[s].far); // session
b += 6;
- if (mtype != PPPLCP && !(session[s].flags & SESSIONACFC))
+ if (mtype != PPPLCP && !(session[s].l2tp_flags & SESSIONACFC))
{
*(u16 *) b = htons(0xFF03); // HDLC header
b += 2;
}
- if (mtype < 0x100 && session[s].flags & SESSIONPFC)
+ if (mtype < 0x100 && session[s].l2tp_flags & SESSIONPFC)
*b++ = mtype;
else
{
*(u16 *) b = htons(mtype);
b += 2;
}
+
+ if (l + 12 > size) {
+ log(3,0,0,0, "Would have overflowed the buffer in makeppp: size %d, len %d.\n", size, l);
+ return NULL; // Run out of room to hold the packet!
+ }
if (p && l)
memcpy(b, p, l);
return b;
{
char b[500] = {0}, *q;
- q = makeppp(b, NULL, 0, t, s, PPPLCP);
+ q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP);
+ if (!q) {
+ log(1, 0, s, t, "Failed to send LCP ConfigReq.\n");
+ return;
+ }
log(4, 0, s, t, "Sending LCP ConfigReq for PAP\n");
*q = ConfigReq;
*(u8 *)(q + 1) = (time_now % 255) + 1; // ID
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