// L2TPNS PPP Stuff
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.42 2005/01/25 04:19:06 bodea Exp $";
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.54 2005/05/10 00:56:12 bodea Exp $";
#include <stdio.h>
#include <string.h>
extern configt *config;
static void initccp(tunnelidt t, sessionidt s);
+static uint8_t *add_lcp_auth(uint8_t *b, int size, int authtype);
// Process PAP messages
void processpap(tunnelidt t, sessionidt s, uint8_t *p, uint16_t l)
{
- char user[129];
- char pass[129];
+ char user[MAXUSER];
+ char pass[MAXPASS];
uint16_t hl;
CSTAT(processpap);
{
LOG(1, s, t, "Short PAP %u bytes\n", l);
STAT(tunnel_rx_errors);
- return ;
+ sessionshutdown(s, "Short PAP packet.", 3, 0);
+ return;
}
if ((hl = ntohs(*(uint16_t *) (p + 2))) > l)
{
LOG(1, s, t, "Length mismatch PAP %u/%u\n", hl, l);
STAT(tunnel_rx_errors);
- return ;
+ sessionshutdown(s, "PAP length mismatch.", 3, 0);
+ return;
}
l = hl;
{
LOG(1, s, t, "Unexpected PAP code %d\n", *p);
STAT(tunnel_rx_errors);
- return ;
+ sessionshutdown(s, "Unexpected PAP code.", 3, 0);
+ return;
}
{
uint8_t *b = p;
b += 4;
+ user[0] = pass[0] = 0;
if (*b && *b < sizeof(user))
+ {
memcpy(user, b + 1, *b);
- user[*b] = 0;
- b += 1 + *b;
- if (*b && *b < sizeof(pass))
- memcpy(pass, b + 1, *b);
- pass[*b] = 0;
+ user[*b] = 0;
+ b += 1 + *b;
+ if (*b && *b < sizeof(pass))
+ {
+ memcpy(pass, b + 1, *b);
+ pass[*b] = 0;
+ }
+ }
LOG(3, s, t, "PAP login %s/%s\n", user, pass);
}
- if (session[s].ip || !session[s].radius)
+ if (session[s].ip || !sess_local[s].radius)
{
// respond now, either no RADIUS available or already authenticated
uint8_t b[MAXCONTROL];
}
LOG(3, s, t, "Fallback response to PAP (%s)\n", (session[s].ip) ? "ACK" : "NAK");
tunnelsend(b, 5 + (p - b), t); // send it
+ sessionshutdown(s, "PAP authentication failed.", 3, 0);
}
else
{
// set up RADIUS request
- uint16_t r = session[s].radius;
+ uint16_t r = sess_local[s].radius;
// Run PRE_AUTH plugins
struct param_pre_auth packet = { &tunnel[t], &session[s], strdup(user), strdup(pass), PPPPAP, 1 };
CSTAT(processchap);
LOG_HEX(5, "CHAP", p, l);
- r = session[s].radius;
+ r = sess_local[s].radius;
if (!r)
{
LOG(1, s, t, "Unexpected CHAP message\n");
STAT(tunnel_rx_errors);
+ sessionshutdown(s, "Unexpected CHAP message.", 3, 0);
return;
}
{
LOG(1, s, t, "Short CHAP %u bytes\n", l);
STAT(tunnel_rx_errors);
- return ;
+ sessionshutdown(s, "Short CHAP packet.", 3, 0);
+ return;
}
if ((hl = ntohs(*(uint16_t *) (p + 2))) > l)
{
LOG(1, s, t, "Length mismatch CHAP %u/%u\n", hl, l);
STAT(tunnel_rx_errors);
- return ;
+ sessionshutdown(s, "CHAP length mismatch.", 3, 0);
+ return;
}
l = hl;
{
LOG(1, s, t, "Unexpected CHAP response code %d\n", *p);
STAT(tunnel_rx_errors);
+ sessionshutdown(s, "CHAP length mismatch.", 3, 0);
return;
}
if (p[1] != radius[r].id)
{
LOG(1, s, t, "Wrong CHAP response ID %d (should be %d) (%d)\n", p[1], radius[r].id, r);
STAT(tunnel_rx_errors);
- return ;
+ sessionshutdown(s, "Unexpected CHAP response ID.", 3, 0);
+ return;
}
if (l < 5 || p[4] != 16)
{
LOG(1, s, t, "Bad CHAP response length %d\n", l < 5 ? -1 : p[4]);
STAT(tunnel_rx_errors);
- return ;
+ sessionshutdown(s, "Bad CHAP response length.", 3, 0);
+ return;
}
l -= 5;
{
LOG(1, s, t, "CHAP user too long %d\n", l - 16);
STAT(tunnel_rx_errors);
- return ;
+ sessionshutdown(s, "CHAP username too long.", 3, 0);
+ return;
}
// Run PRE_AUTH plugins
{
int proto = ntohs(*(uint16_t *)(o + 2));
LOG(4, 0, 0, " %s 0x%x (%s)\n", lcp_type(type), proto,
- proto == PPPCHAP ? "CHAP" :
- proto == PPPPAP ? "PAP" : "UNKNOWN");
+ proto == PPPPAP ? "PAP" : "UNSUPPORTED");
+ }
+ else if (length == 5)
+ {
+ int proto = ntohs(*(uint16_t *)(o + 2));
+ int algo = *(uint8_t *)(o + 4);
+ LOG(4, 0, 0, " %s 0x%x 0x%x (%s)\n", lcp_type(type), proto, algo,
+ (proto == PPPCHAP && algo == 5) ? "CHAP MD5" : "UNSUPPORTED");
}
else
LOG(4, 0, 0, " %s odd length %d\n", lcp_type(type), length);
{
int proto = ntohs(*(uint16_t *)(o + 2));
char proto_name[] = "0x0000";
+ uint8_t *a;
+
if (proto == PPPPAP)
- break;
+ {
+ if (config->radius_authtypes & AUTHPAP)
+ break;
- if (response && *response != ConfigNak) // rej already queued
- break;
+ strcpy(proto_name, "PAP");
+ }
+ else if (proto == PPPCHAP)
+ {
+ if (config->radius_authtypes & AUTHCHAP
+ && *(o + 4) == 5) // MD5
+ break;
- if (proto == PPPCHAP)
strcpy(proto_name, "CHAP");
+ }
else
sprintf(proto_name, "%#4.4x", proto);
+ if (response && *response != ConfigNak) // rej already queued
+ break;
+
LOG(2, s, t, " Remote requesting %s authentication. Rejecting.\n", proto_name);
if (!response)
q += 4;
}
- if ((q - b + length) > sizeof(b))
+ a = add_lcp_auth(q, sizeof(b) - (q - b), config->radius_authprefer);
+ if (!a)
{
LOG(2, s, t, "LCP overflow for %s ConfigNak.\n", proto_name);
break;
}
- memcpy(q, o, length);
- *(uint16_t *)(q += 2) = htons(PPPPAP); // NAK -> Use PAP instead
- q += length;
- *((uint16_t *) (response + 2)) = htons(q - response);
+ q = a;
+
+ if (config->radius_authtypes != config->radius_authprefer)
+ {
+ a = add_lcp_auth(q, sizeof(b) - (q - b), config->radius_authtypes & ~config->radius_authprefer);
+ if (!a)
+ {
+ LOG(2, s, t, "LCP overflow for %s ConfigNak.\n", proto_name);
+ break;
+ }
+
+ q = a;
+ }
+
+ *((uint16_t *) (response + 2)) = htons(q - response); // LCP header length
+ break;
}
break;
tunnelsend(b, l + (q - b), t);
if (!(session[s].flags & SF_LCP_ACKED))
- initlcp(t, s);
+ sendlcp(t, s, config->radius_authprefer);
}
else if (*p == ConfigNak)
{
- LOG(1, s, t, "Remote end sent a ConfigNak. Ignoring\n");
+ int x = l - 4;
+ uint8_t *o = (p + 4);
+ int authtype = 0;
+
+ LOG(3, s, t, "LCP: ConfigNak (%d bytes)...\n", l);
if (config->debug > 3) dumplcp(p, l);
- return ;
+
+ while (x > 2)
+ {
+ int type = o[0];
+ int length = o[1];
+
+ if (length == 0 || type == 0 || x < length) break;
+ switch (type)
+ {
+ case 1: // Maximum-Receive-Unit
+ session[s].mru = ntohs(*(uint16_t *)(o + 2));
+ LOG(3, s, t, " Remote requested MRU of %u\n", session[s].mru);
+ break;
+
+ case 3: // Authentication-Protocol
+ if (authtype)
+ break;
+
+ {
+ int proto = ntohs(*(uint16_t *)(o + 2));
+ if (proto == PPPPAP)
+ {
+ authtype = config->radius_authtypes & AUTHPAP;
+ LOG(3, s, t, " Remote requested PAP authentication...%sing\n",
+ authtype ? "accept" : "reject");
+ }
+ else if (proto == PPPCHAP && *(o + 4) == 5)
+ {
+ authtype = config->radius_authtypes & AUTHCHAP;
+ LOG(3, s, t, " Remote requested CHAP authentication...%sing\n",
+ authtype ? "accept" : "reject");
+ }
+ else
+ {
+ LOG(3, s, t, " Rejecting unsupported authentication %#4x\n",
+ proto);
+ }
+ }
+
+ if (!authtype)
+ {
+ sessionshutdown(s, "Unsupported authentication.", 3, 0);
+ return;
+ }
+
+ break;
+
+ default:
+ LOG(2, s, t, " Remote NAKed LCP type %u?\n", type);
+ break;
+ }
+ }
+
+ if (!authtype)
+ authtype = config->radius_authprefer;
+
+ sendlcp(t, s, authtype);
}
else if (*p == TerminateReq)
{
q = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
if (!q) return;
tunnelsend(b, l + (q - b), t); // send it
- sessionshutdown(s, "Remote end closed connection.");
+ sessionshutdown(s, "Remote end closed connection.", 3, 0);
}
else if (*p == TerminateAck)
{
- sessionshutdown(s, "Connection closed.");
+ sessionshutdown(s, "Connection closed.", 3, 0);
}
else if (*p == ProtocolRej)
{
{
LOG(1, s, t, "Unexpected LCP code %d\n", *p);
STAT(tunnel_rx_errors);
- return ;
}
}
if (*p == ConfigAck)
{
// happy with our IPCP
- uint16_t r = session[s].radius;
+ uint16_t r = sess_local[s].radius;
if ((!r || radius[r].state == RADIUSIPCP) && !session[s].walled_garden)
{
if (!r)
// Add on the tun header
p -= 4;
- *(uint32_t *) p = htonl(0x00000800);
+ *(uint32_t *) p = htonl(PKTIP);
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.
+ // Are we throttled and a slave?
+ if (session[s].tbf_in && !config->cluster_iam_master) {
+ // Pass it to the master for handling.
+ master_throttle_packet(session[s].tbf_in, p, l);
return;
}
- if (session[s].tbf_in && config->cluster_iam_master) { // Are we throttled and a master?? actually handle the throttled packets.
+ // Are we throttled and a master??
+ if (session[s].tbf_in && config->cluster_iam_master) {
+ // Actually handle the throttled packets.
tbf_queue_packet(session[s].tbf_in, p, l);
return;
}
// Add on the tun header
p -= 4;
- *(uint32_t *)p = htonl(PKTIPV6);
+ *(uint32_t *) p = htonl(PKTIPV6);
l += 4;
// Are we throttled and a slave?
return;
}
- // Are we throttled and a master?? actually handle the throttled
- // packets.
+ // Are we throttled and a master??
if (session[s].tbf_in && config->cluster_iam_master) {
+ // Actually handle the throttled packets.
tbf_queue_packet(session[s].tbf_in, p, l);
return;
}
if (tun_write(p, l) < 0)
{
STAT(tun_tx_errors);
- LOG(0, s, t, "Error writing %d bytes to TUN device: %s" " (tunfd=%d, p=%p)\n",
+ LOG(0, s, t, "Error writing %d bytes to TUN device: %s (tunfd=%d, p=%p)\n",
l, strerror(errno), tunfd, p);
+
+ return;
}
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);
+ snoop_send_packet(p + 4, l - 4, session[s].snoop_ip, session[s].snoop_port);
}
session[s].cin += l - 4;
tunnelsend(b, l + (q - b), t); // send it
}
-// send a CHAP PP packet
+// send a CHAP challenge
void sendchap(tunnelidt t, sessionidt s)
{
uint8_t b[MAXCONTROL];
- uint16_t r = session[s].radius;
+ uint16_t r = sess_local[s].radius;
uint8_t *q;
CSTAT(sendchap);
LOG(1, s, t, "Send CHAP challenge\n");
- // new challenge
- random_data(radius[r].auth, sizeof(radius[r].auth));
radius[r].chap = 1; // CHAP not PAP
radius[r].id++;
if (radius[r].state != RADIUSCHAP)
radius[r].retry = backoff(radius[r].try++);
if (radius[r].try > 5)
{
- sessionshutdown(s, "Timeout CHAP");
+ sessionshutdown(s, "CHAP timeout.", 3, 0);
STAT(tunnel_tx_errors);
return ;
}
*q = 1; // challenge
q[1] = radius[r].id; // ID
- q[4] = 16; // length
+ q[4] = 16; // value size (size of challenge)
memcpy(q + 5, radius[r].auth, 16); // challenge
strcpy(q + 21, hostname); // our name
*(uint16_t *) (q + 2) = htons(strlen(hostname) + 21); // length
return b;
}
-// Send initial LCP ConfigReq for PAP, set magic no.
-void initlcp(tunnelidt t, sessionidt s)
+static uint8_t *add_lcp_auth(uint8_t *b, int size, int authtype)
{
- char b[500], *q;
+ if ((authtype == AUTHCHAP && size < 5) || size < 4)
+ return 0;
+
+ *b++ = 3; // Authentication-Protocol
+ if (authtype == AUTHCHAP)
+ {
+ *b++ = 5; // length
+ *(uint16_t *) b = htons(PPPCHAP); b += 2;
+ *b++ = 5; // MD5
+ }
+ else if (authtype == AUTHPAP)
+ {
+ *b++ = 4; // length
+ *(uint16_t *) b = htons(PPPPAP); b += 2;
+ }
+ else
+ {
+ LOG(0, 0, 0, "add_lcp_auth called with unsupported auth type %d\n", authtype);
+ }
+
+ return b;
+}
+
+// Send initial LCP ConfigReq for MRU, authentication type and magic no
+void sendlcp(tunnelidt t, sessionidt s, int authtype)
+{
+ char b[500], *q, *l;
if (!(q = makeppp(b, sizeof(b), NULL, 0, t, s, PPPLCP)))
return;
- LOG(4, s, t, "Sending LCP ConfigReq for PAP\n");
- *q = ConfigReq;
- *(uint8_t *)(q + 1) = (time_now % 255) + 1; // ID
- *(uint16_t *)(q + 2) = htons(14); // Length
- *(uint8_t *)(q + 4) = 5;
- *(uint8_t *)(q + 5) = 6;
- *(uint32_t *)(q + 6) = htonl(session[s].magic);
- *(uint8_t *)(q + 10) = 3;
- *(uint8_t *)(q + 11) = 4;
- *(uint16_t *)(q + 12) = htons(PPPPAP); // PAP
-
- LOG_HEX(5, "PPPLCP", q, 14);
- tunnelsend(b, (q - b) + 14, t);
+ LOG(4, s, t, "Sending LCP ConfigReq for %s\n",
+ config->radius_authprefer == AUTHCHAP ? "CHAP" : "PAP");
+
+ if (!session[s].mru)
+ session[s].mru = DEFAULT_MRU;
+
+ l = q;
+ *l++ = ConfigReq;
+ *l++ = (time_now % 255) + 1; // ID
+
+ l += 2; //Save space for length
+
+ *l++ = 1; *l++ = 4; // Maximum-Receive-Unit (length 4)
+ *(uint16_t *) l = htons(session[s].mru); l += 2;
+
+ l = add_lcp_auth(l, sizeof(b) - (l - b), authtype);
+
+ *l++ = 5; *l++ = 6; // Magic-Number (length 6)
+ *(uint32_t *) l = htonl(session[s].magic);
+ l += 4;
+
+ *(uint16_t *)(q + 2) = htons(l - q); // Length
+
+ LOG_HEX(5, "PPPLCP", q, l - q);
+ tunnelsend(b, (l - b), t);
}
// Send CCP request for no compression
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