// L2TPNS PPP Stuff
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.7 2004/07/08 16:54:35 bodea Exp $";
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.18 2004/11/03 13:22:39 bodea Exp $";
#include <stdio.h>
#include <string.h>
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)
+void processpap(tunnelidt t, sessionidt s, u8 *p, u16 l)
{
char user[129];
char pass[129];
-
+ u16 hl;
CSTAT(call_processpap);
STAT(tunnel_rx_errors);
return ;
}
- if (*p != 1)
+
+ if ((hl = ntohs(*(u16 *) (p + 2))) > l)
{
- log(1, 0, s, t, "Unexpected PAP code %d\n", *p);
+ log(1, 0, s, t, "Length mismatch PAP %u/%u\n", hl, l);
STAT(tunnel_rx_errors);
return ;
}
- if (ntohs(*(u16 *) (p + 2)) > l)
+ l = hl;
+
+ if (*p != 1)
{
- log(1, 0, s, t, "Length mismatch PAP %d/%d\n", ntohs(*(u16 *) (p + 2)), l);
+ log(1, 0, s, t, "Unexpected PAP code %d\n", *p);
STAT(tunnel_rx_errors);
return ;
}
+
{
u8 *b = p;
b += 4;
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
}
// Process CHAP messages
-void processchap(tunnelidt t, sessionidt s, u8 * p, u16 l)
+void processchap(tunnelidt t, sessionidt s, u8 *p, u16 l)
{
u16 r;
- u16 len;
-
+ u16 hl;
CSTAT(call_processchap);
STAT(tunnel_rx_errors);
return;
}
+
+ if (l < 4)
+ {
+ log(1, 0, s, t, "Short CHAP %u bytes\n", l);
+ STAT(tunnel_rx_errors);
+ return ;
+ }
+
+ if ((hl = ntohs(*(u16 *) (p + 2))) > l)
+ {
+ log(1, 0, s, t, "Length mismatch CHAP %u/%u\n", hl, l);
+ STAT(tunnel_rx_errors);
+ return ;
+ }
+ l = hl;
+
if (*p != 2)
{
log(1, 0, s, t, "Unexpected CHAP response code %d\n", *p);
STAT(tunnel_rx_errors);
return ;
}
- len = ntohs(*(u16 *) (p + 2));
- if (len > l)
- {
- log(1, 0, s, t, "Bad CHAP length %d\n", len);
- STAT(tunnel_rx_errors);
- return ;
- }
- if (p[4] != 16)
+
+ if (l < 5 || p[4] != 16)
{
- log(1, 0, s, t, "Bad CHAP response length %d\n", p[4]);
+ log(1, 0, s, t, "Bad CHAP response length %d\n", l < 5 ? -1 : p[4]);
STAT(tunnel_rx_errors);
return ;
}
- if (len - 21 >= sizeof(session[s].user))
+
+ l -= 5;
+ p += 5;
+ if (l < 16 || l - 16 >= sizeof(session[s].user))
{
- log(1, 0, s, t, "CHAP user too long %d\n", len - 21);
+ log(1, 0, s, t, "CHAP user too long %d\n", l - 16);
STAT(tunnel_rx_errors);
return ;
}
{
struct param_pre_auth packet = { &tunnel[t], &session[s], NULL, NULL, PPPCHAP, 1 };
- packet.username = calloc(len-20, 1);
+ packet.username = calloc(l - 16 + 1, 1);
packet.password = calloc(16, 1);
- memcpy(packet.username, p + 21, len - 21);
- memcpy(packet.password, p + 5, 16);
+ memcpy(packet.username, p + 16, l - 16);
+ memcpy(packet.password, p, 16);
run_plugins(PLUGIN_PRE_AUTH, &packet);
if (!packet.continue_auth)
"EchoReq",
"EchoReply",
"DiscardRequest",
+ "IdentRequest",
};
void dumplcp(u8 *p, int l)
{
- signed int x = l - 4;
+ int x = l - 4;
u8 *o = (p + 4);
log_hex(5, "PPP LCP Packet", p, l);
{
int type = o[0];
int length = o[1];
- if (length == 0)
+ 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");
+ 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
}
case 5: // Magic-Number
{
- u32 magicno = ntohl(*(u32 *)(o + 2));
- log(4, 0, 0, 0, " %s %x\n", lcp_types[type], magicno);
+ 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:
}
// Process LCP messages
-void processlcp(tunnelidt t, sessionidt s, u8 * p, u16 l)
+void processlcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
{
u8 b[MAXCONTROL];
u8 *q = NULL;
-
+ u32 magicno = 0;
+ u16 hl;
CSTAT(call_processlcp);
STAT(tunnel_rx_errors);
return ;
}
+
+ if ((hl = ntohs(*(u16 *) (p + 2))) > l)
+ {
+ log(1, 0, s, t, "Length mismatch LCP %u/%u\n", hl, l);
+ STAT(tunnel_rx_errors);
+ return ;
+ }
+ l = hl;
+
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 - 4;
+ int x = l - 4;
u8 *o = (p + 4);
log(3, session[s].ip, s, t, "LCP: ConfigReq (%d bytes)...\n", l);
- dumplcp(p, l);
+ if (config->debug > 3) dumplcp(p, l);
while (x > 2)
{
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));
}
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");
+ // 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) {
+ if (!q)
+ {
log(3, session[s].ip, s, t, " failed to create packet.\n");
return;
}
// 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, sizeof(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)
{
log(1, session[s].ip, s, t, "Remote end sent a ConfigNak. Ignoring\n");
- dumplcp(p, l);
+ if (config->debug > 3) dumplcp(p, l);
return ;
}
else if (*p == TerminateReq)
{
- *p = TerminateAck; // close
+ *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");
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, sizeof(b), p, l, t, s, PPPLCP);
if (!q) {
{
// 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)
+void processipcp(tunnelidt t, sessionidt s, u8 *p, u16 l)
{
+ u16 hl;
CSTAT(call_processipcp);
STAT(tunnel_rx_errors);
return ;
}
+
+ if ((hl = ntohs(*(u16 *) (p + 2))) > l)
+ {
+ log(1, 0, s, t, "Length mismatch IPCP %u/%u\n", hl, l);
+ STAT(tunnel_rx_errors);
+ return ;
+ }
+ l = hl;
+
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 || radius[r].state == RADIUSIPCP) && !session[s].walled_garden)
+ {
if (!r)
r = radiusnew(s);
if (r)
}
session[s].flags |= SF_IPCP_ACKED;
- return ; // done
+ log(3, session[s].ip, s, t, "IPCP Acked, session is now active\n");
+ return;
}
if (*p != ConfigReq)
{
STAT(tunnel_rx_errors);
return ;
}
- if (ntohs(*(u16 *) (p + 2)) > l)
- {
- log(1, 0, s, t, "Length mismatch IPCP %d/%d\n", ntohs(*(u16 *) (p + 2)), l);
- STAT(tunnel_rx_errors);
- return ;
- }
+ log(4, session[s].ip, s, t, "IPCP ConfigReq received\n");
+
if (!session[s].ip)
{
log(3, 0, s, t, "Waiting on radius reply\n");
- return ; // have to wait on RADIUS reply
+ return; // have to wait on RADIUS reply
}
// form a config reply quoting the IP in the session
{
q += q[1];
}
if (q < i)
- { // reject
+ {
+ // reject
u16 n = 4;
i = p + l;
- q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP);
- if (!q) {
- log(2, 0, s, t, "Failed to send IPCP.\n");
+ 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 += 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)));
}
- q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP);
- if (!q) {
+ if (!(q = makeppp(b, sizeof(b), p, l, t, s, PPPIPCP)))
+ {
log(2, 0, s, t, " Failed to send IPCP packet.\n");
return;
}
//
// 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)
+void processipin(tunnelidt t, sessionidt s, u8 *p, u16 l)
{
ipt ip;
-
CSTAT(call_processipin);
log_hex(5, "IP", p, l);
if (session[s].snoop_ip && session[s].snoop_port)
{
- // Snooping this session, send it to ASIO
+ // Snooping this session
snoop_send_packet(p, l, session[s].snoop_ip, session[s].snoop_port);
}
STAT(tun_tx_packets);
// Process LCP messages
-void processccp(tunnelidt t, sessionidt s, u8 * p, u16 l)
+void processccp(tunnelidt t, sessionidt s, u8 *p, u16 l)
{
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, sizeof(b), p, l, t, s, PPPCCP);
- if (!q) {
+ *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;
}
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;
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
- memcpy(q + 5, radius[r].auth, 16); // challenge
- strcpy(q + 21, hostname); // our name
+ *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, int size, 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 + 2) = htons(tunnel[t].far); // tunnel
*(u16 *) (b + 4) = htons(session[s].far); // session
b += 6;
- if (mtype != PPPLCP && !(session[s].l2tp_flags & SESSIONACFC))
+ if (mtype == PPPLCP || !(session[s].l2tp_flags & SESSIONACFC))
{
*(u16 *) b = htons(0xFF03); // HDLC header
b += 2;
}
// find a PPP option, returns point to option, or 0 if not found
-u8 *findppp(u8 * b, u8 mtype)
+u8 *findppp(u8 *b, u8 mtype)
{
u16 l = ntohs(*(u16 *) (b + 2));
if (l < 4)
while (l)
{
if (l < b[1] || !b[1])
- return 0; // faulty
+ return 0; // faulty
if (*b == mtype)
return b;
l -= b[1];
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