// L2TPNS PPP Stuff
-// $Id: ppp.c,v 1.4 2004-05-24 04:26:01 fred_nerk Exp $
+
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.17 2004-10-29 04:01:53 bodea 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 int tunfd;
+extern char hostname[];
+extern u32 eth_tx;
extern time_t time_now;
extern struct configt *config;
+void sendccp(tunnelidt t, sessionidt s);
+
// Process PAP messages
void processpap(tunnelidt t, sessionidt s, u8 * p, u16 l)
{
char user[129];
char pass[129];
-#ifdef STAT_CALLS
- STAT(call_processpap);
-#endif
+
+ CSTAT(call_processpap);
+
log_hex(5, "PAP", p, l);
if (l < 4)
{
- log(1, 0, s, t, "Short PAP %u bytes", l);
+ log(1, 0, s, t, "Short PAP %u bytes\n", l);
STAT(tunnel_rx_errors);
return ;
}
// 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
+ *p = 2; // ACK
else
- *p = 3; // cant authorise
+ *p = 3; // cant authorise
p[1] = id;
- *(u16 *) (p + 2) = htons(5); // length
- p[4] = 0; // no message
+ *(u16 *) (p + 2) = htons(5); // length
+ p[4] = 0; // no message
if (session[s].ip)
{
- log(3, session[s].ip, s, t, "%d Already an IP allocated: %s (%d)\n", getpid(), inet_toa(htonl(session[s].ip)), session[s].ip_pool_index);
+ log(3, session[s].ip, s, t, "%d Already an IP allocated: %s (%d)\n", getpid(), inet_toa(htonl(session[s].ip)), session[s].ip_pool_index);
+ session[s].flags &= ~SF_IPCP_ACKED;
}
else
{
- log(1, 0, s, t, "No radius session available to authenticate session...\n");
+ log(1, 0, s, t, "No radius session available to authenticate session...\n");
}
log(3, 0, s, t, "Fallback response to PAP (%s)\n", (session[s].ip) ? "ACK" : "NAK");
tunnelsend(b, 5 + (p - b), t); // send it
}
else
- { // set up RADIUS request
+ {
+ // set up RADIUS request
u16 r = session[s].radius;
// Run PRE_AUTH plugins
u16 r;
u16 len;
-#ifdef STAT_CALLS
- STAT(call_processchap);
-#endif
+
+ CSTAT(call_processchap);
+
log_hex(5, "CHAP", p, l);
r = session[s].radius;
if (!r)
{
log(1, 0, s, t, "Unexpected CHAP message\n");
+
+// FIXME: Need to drop the session here.
+
STAT(tunnel_rx_errors);
return;
}
"EchoReq",
"EchoReply",
"DiscardRequest",
+ "IdentRequest",
};
-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);
- if (length == 0)
+ int type = o[0];
+ int length = o[1];
+ if (length < 2)
{
- log(4, 0, 0, 0, " Option length is 0...\n");
+ log(4, 0, 0, 0, " Option length is %d...\n", length);
break;
}
if (type == 0)
switch (type)
{
case 1: // Maximum-Receive-Unit
- log(4, 0, 0, 0, " %s %d\n", lcp_types[type], ntohs(*(u16 *)(o + 2)));
+ if (length == 4)
+ log(4, 0, 0, 0, " %s %d\n", lcp_types[type], ntohs(*(u16 *)(o + 2)));
+ else
+ log(4, 0, 0, 0, " %s odd length %d\n", lcp_types[type], length);
break;
case 3: // Authentication-Protocol
{
- int proto = ntohs(*(u16 *)(o + 2));
- log(4, 0, 0, 0, " %s %s\n", lcp_types[type],
- 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);
+ if (length == 4)
+ {
+ int proto = ntohs(*(u16 *)(o + 2));
+ log(4, 0, 0, 0, " %s 0x%x (%s)\n", lcp_types[type], proto,
+ proto == 0xC223 ? "CHAP" :
+ proto == 0xC023 ? "PAP" : "UNKNOWN");
+ }
+ else
+ log(4, 0, 0, 0, " %s odd length %d\n", lcp_types[type], length);
break;
}
case 4: // Quality-Protocol
log(4, 0, 0, 0, " %s %x\n", lcp_types[type], qp);
break;
}
+ case 5: // Magic-Number
+ {
+ if (length == 6)
+ {
+ u32 magicno = ntohl(*(u32 *)(o + 2));
+ log(4, 0, 0, 0, " %s %x\n", lcp_types[type], magicno);
+ }
+ else
+ log(4, 0, 0, 0, " %s odd length %d\n", lcp_types[type], length);
+ break;
+ }
case 7: // Protocol-Field-Compression
{
- u32 pfc = ntohl(*(u32 *)(o + 2));
- log(4, 0, 0, 0, " %s %x\n", lcp_types[type], pfc);
+ log(4, 0, 0, 0, " %s\n", lcp_types[type]);
break;
}
case 8: // Address-And-Control-Field-Compression
{
- u32 afc = ntohl(*(u32 *)(o + 2));
- log(4, 0, 0, 0, " %s %x\n", lcp_types[type], afc);
+ log(4, 0, 0, 0, " %s\n", lcp_types[type]);
break;
}
default:
{
u8 b[MAXCONTROL];
u8 *q = NULL;
+ u32 magicno = 0;
+
+
+ CSTAT(call_processlcp);
-#ifdef STAT_CALLS
- STAT(call_processlcp);
-#endif
log_hex(5, "LCP", p, l);
if (l < 4)
{
- log(1, session[s].ip, s, t, "Short LCP %d bytes", l);
+ log(1, session[s].ip, s, t, "Short LCP %d bytes\n", l);
STAT(tunnel_rx_errors);
return ;
}
if (*p == ConfigAck)
{
log(3, session[s].ip, s, t, "LCP: Discarding ConfigAck\n");
+ session[s].flags |= SESSIONLCPACK;
}
else if (*p == ConfigReq)
{
- signed int x = l - 1;
- char *o = (p + 1);
+ l = ntohs(*(u16 *)(p + 2));
+ 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)
{
case 1: // Maximum-Receive-Unit
session[s].mru = ntohs(*(u16 *)(o + 2));
break;
+ case 2: // asyncmap
+ log_hex(2, "PPP LCP Packet", p, l);
+ log(2, 0, 0, 0, "PPP LCP Packet type %d (%s len %d)\n", *p, ppp_lcp_types[(int)*p], ntohs( ((u16 *) p)[1]) );
+ break;
case 3: // Authentication-Protocol
{
int proto = ntohs(*(u16 *)(o + 2));
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);
}
case 5: // Magic-Number
{
-// u32 magicno = ntohl(*(u32 *)(o + 2));
+ magicno = ntohl(*(u32 *)(o + 2));
break;
}
case 4: // Quality-Protocol
- {
-// u32 qp = ntohl(*(u32 *)(o + 2));
- break;
- }
case 7: // Protocol-Field-Compression
- {
-// u32 pfc = ntohl(*(u32 *)(o + 2));
- break;
- }
case 8: // Address-And-Control-Field-Compression
- {
-// u32 afc = ntohl(*(u32 *)(o + 2));
break;
+ case 13: // CallBack option for LCP extention of win2000/routers L2TP client
+ case 17:
+ case 18:
+ {
+ // Reject LCP CallBack
+ log(2, session[s].ip, s, t, " PPP LCP Option type %d, len=%d\n", type, length);
+ memcpy(p + 4, o, length);
+ *(u16 *)(p + 2) = htons(length + 4);
+ *p = ConfigRej;
+ q = makeppp(b,sizeof(b), p, length + 4, t, s, PPPLCP);
+ tunnelsend(b, 12 + length + 4, t);
+ return;
}
+
default:
+ // Reject Unknown LCP Option to stop to send it again
log(2, session[s].ip, s, t, " Unknown PPP LCP Option type %d\n", type);
- break;
+ memcpy(p + 4, o, length);
+ *(u16 *)(p + 2) = htons(length + 4);
+ *p = ConfigRej;
+ q = makeppp(b,sizeof(b), p, length + 4, t, s, PPPLCP);
+ tunnelsend(b, 12 + length + 4, t);
+ return;
}
x -= length;
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);
+ // for win2k L2TP clients and LCP renegotiation of alive session
+ if (magicno || l == 4 || (session[s].mru && l == 8)) initlcp(t, s);
+ 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);
}
// Already built a ConfigNak... send it
log(3, session[s].ip, s, t, "Sending ConfigNak\n");
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++ = ConfigReq;
- *(u8 *)(q++) = 3;
- *(u8 *)(q++) = 4;
- *(u16 *)(q += 2) = htons(0xC023);
- tunnelsend(b, l + (q - b), t);
}
+
+ if (!(session[s].flags & SESSIONLCPACK))
+ initlcp(t, s);
}
else if (*p == ConfigNak)
{
}
else if (*p == TerminateReq)
{
- *p = TerminateAck; // close
- q = makeppp(b, p, l, t, s, PPPLCP);
+ *p = TerminateAck; // close
+ 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
}
- else if (*p == TerminateReq)
+ else if (*p == TerminateAck)
{
- sessionshutdown(s, "Remote end closed connection.");
+ sessionshutdown(s, "Connection closed.");
}
else if (*p == EchoReq)
{
- *p = EchoReply; // reply
+ *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
}
{
// Ignore it, last_packet time is set earlier than this.
}
+ else if (*p == IdentRequest)
+ {
+ *p = CodeRej;
+ if (l > MAXCONTROL)
+ {
+ log(1, 0, s, t, "Truncated Ident Packet (length=%d) to 1400 bytes\n", l);
+ l = 1400;
+ }
+ q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
+ if (!q)
+ {
+ log(3, session[s].ip, s, t, "Failed to create IdentRej.\n");
+ return;
+ }
+ log_hex(5, "LCPIdentRej", q, l + 4);
+ tunnelsend(b, 12 + 4 + l, t);
+ }
else
{
log(1, session[s].ip, s, t, "Unexpected LCP code %d\n", *p);
// Process IPCP messages
void processipcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
{
-#ifdef STAT_CALLS
- STAT(call_processipcp);
-#endif
+
+ CSTAT(call_processipcp);
+
log_hex(5, "IPCP", p, l);
if (l < 5)
{
- log(1, 0, s, t, "Short IPCP %d bytes", l);
+ log(1, 0, s, t, "Short IPCP %d bytes\n", l);
STAT(tunnel_rx_errors);
return ;
}
if (*p == ConfigAck)
- { // happy with our IPCP
+ {
+ // happy with our IPCP
u16 r = session[s].radius;
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
- return ; // done
+ }
+ session[s].flags |= SF_IPCP_ACKED;
+
+ log(3, session[s].ip, s, t, "IPCP Acked, session is now active\n");
+ return;
}
if (*p != ConfigReq)
{
STAT(tunnel_rx_errors);
return ;
}
+ log(4, session[s].ip, s, t, "IPCP ConfigReq received\n");
if (ntohs(*(u16 *) (p + 2)) > l)
{
log(1, 0, s, t, "Length mismatch IPCP %d/%d\n", ntohs(*(u16 *) (p + 2)), l);
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
{
u8 *i,
*q;
+ l = ntohs(*(u16 *) (p + 2)); // We must use length from IPCP len field
q = p + 4;
i = p + l;
while (q < i && q[1])
q += q[1];
}
if (q < i)
- { // reject
+ {
+ // reject
u16 n = 4;
i = p + l;
- q = makeppp(b, p, l, t, s, PPPIPCP);
+ if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP)))
+ {
+ log(2, 0, s, t, "Failed to send IPCP ConfigRej\n");
+ return;
+ }
*q = ConfigRej;
p += 4;
while (p < i && p[1])
p += p[1];
}
*(u16 *) (q + 2) = htons(n);
+ log(4, session[s].ip, s, t, "Sending ConfigRej\n");
tunnelsend(b, n + (q - b), t); // send it
}
else
{
+ log(4, session[s].ip, s, t, "Sending ConfigAck\n");
*p = ConfigAck;
- i = findppp(p, 0x81); // Primary DNS address
- if (i)
+ if ((i = findppp(p, 0x81))) // Primary DNS address
{
if (*(u32 *) (i + 2) != htonl(session[s].dns1))
{
*(u32 *) (i + 2) = htonl(session[s].dns1);
*p = ConfigNak;
+ log(5, session[s].ip, s, t, " DNS1 = %s\n", inet_toa(session[s].dns1));
}
}
- i = findppp(p, 0x83); // Secondary DNS address (TBA, is it)
- if (i)
+ if ((i = findppp(p, 0x83))) // Secondary DNS address (TBA, is it)
{
if (*(u32 *) (i + 2) != htonl(session[s].dns2))
{
*(u32 *) (i + 2) = htonl(session[s].dns2);
*p = ConfigNak;
+ log(5, session[s].ip, s, t, " DNS2 = %s\n", inet_toa(session[s].dns1));
}
}
- i = findppp(p, 3); // IP address
+ i = findppp(p, 3); // IP address
if (!i || i[1] != 6)
{
log(1, 0, s, t, "No IP in IPCP request\n");
{
*(u32 *) (i + 2) = htonl(session[s].ip);
*p = ConfigNak;
+ log(4, session[s].ip, s, t, " No, a ConfigNak, client is requesting IP - sending %s\n",
+ inet_toa(htonl(session[s].ip)));
+ }
+ if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP)))
+ {
+ log(2, 0, s, t, " Failed to send IPCP packet.\n");
+ return;
}
- q = makeppp(b, p, l, t, s, PPPIPCP);
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)
{
-#ifdef STAT_CALLS
- STAT(call_processipin);
-#endif
+ ipt ip;
+
+ CSTAT(call_processipin);
+
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
+ snoop_send_packet(p, l, session[s].snoop_ip, session[s].snoop_port);
+ }
+ STAT(tun_tx_packets);
+ INC_STAT(tun_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);
+ STAT(tun_tx_errors);
+ log(0, 0, s, t, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n",
+ l, strerror(errno), tunfd, 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(tunfd, buf, len) < 0)
{
- // Snooping this session, send it to ASIO
- snoop_send_packet(p, l);
+ STAT(tun_tx_errors);
+ log(0, 0, 0, 0, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n",
+ len, strerror(errno), tunfd, 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)
{
-#ifdef STAT_CALLS
- STAT(call_processccp);
-#endif
+
+ CSTAT(call_processccp);
+
log_hex(5, "CCP", p, l);
if (l < 2 || (*p != ConfigReq && *p != TerminateReq))
{
- log(1, 0, s, t, "Unexpecetd CCP request code %d\n", *p);
+ log(1, 0, s, t, "Unexpected CCP request code %d\n", *p);
STAT(tunnel_rx_errors);
return ;
}
}
else
{
- *p = ConfigRej; // reject
+ *p = ConfigRej; // reject
+ sendccp(t, s);
}
}
else
- *p = TerminateAck; // close
- q = makeppp(b, p, l, t, s, PPPCCP);
+ *p = TerminateAck; // close
+ if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPCCP)))
+ {
+ log(1,0,0,0, "Failed to send CCP packet.\n");
+ return;
+ }
tunnelsend(b, l + (q - b), t); // send it
}
}
u8 b[MAXCONTROL];
u16 r = session[s].radius;
u8 *q;
-#ifdef STAT_CALLS
- STAT(call_sendchap);
-#endif
+
+ CSTAT(call_sendchap);
+
if (!r)
{
log(1, 0, s, t, "No RADIUS to send challenge\n");
return ;
}
log(1, 0, s, t, "Send CHAP challenge\n");
- { // new challenge
+ {
+ // new challenge
int n;
for (n = 0; n < 15; n++)
radius[r].auth[n] = rand();
}
- radius[r].chap = 1; // CHAP not PAP
+ radius[r].chap = 1; // CHAP not PAP
radius[r].id++;
if (radius[r].state != RADIUSCHAP)
radius[r].try = 0;
STAT(tunnel_tx_errors);
return ;
}
- q = makeppp(b, 0, 0, t, s, PPPCHAP);
- *q = 1; // challenhe
- q[1] = radius[r].id; // ID
- q[4] = 16; // length
- memcpy(q + 5, radius[r].auth, 16); // challenge
- strcpy(q + 21, hostname); // our name
+ 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; // challenge
+ q[1] = radius[r].id; // ID
+ q[4] = 16; // length
+ memcpy(q + 5, radius[r].auth, 16); // challenge
+ strcpy(q + 21, hostname); // our name
*(u16 *) (q + 2) = htons(strlen(hostname) + 21); // length
tunnelsend(b, strlen(hostname) + 21 + (q - b), t); // send it
}
// 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;
while (l)
{
if (l < b[1] || !b[1])
- return 0; // faulty
+ return 0; // faulty
if (*b == mtype)
return b;
l -= b[1];
{
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
- *(u16 *)(q + 2) = htons(8); // Length
- *(u8 *)(q + 4) = 3;
- *(u8 *)(q + 5) = 4;
- *(u16 *)(q + 6) = htons(0xC023); // PAP
- tunnelsend(b, 12 + 8, t);
+ *(u16 *)(q + 2) = htons(14); // Length
+ *(u8 *)(q + 4) = 5;
+ *(u8 *)(q + 5) = 6;
+ *(u32 *)(q + 6) = htonl(session[s].magic);
+ *(u8 *)(q + 10) = 3;
+ *(u8 *)(q + 11) = 4;
+ *(u16 *)(q + 12) = htons(0xC023); // PAP
+ tunnelsend(b, 12 + 14, t);
+}
+
+// Send CCP reply
+void sendccp(tunnelidt t, sessionidt s)
+{
+ char *q, b[500] = {0};
+
+ q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPCCP);
+ *q = ConfigReq;
+ *(u8 *)(q + 1) = (time_now % 255) + 1; // ID
+ *(u16 *)(q + 2) = htons(4); // Length
+ log_hex(5, "PPPCCP", q, 4);
+ tunnelsend(b, (q - b) + 4 , t);
}
projects / l2tpns.git / blobdiff