// L2TPNS PPP Stuff
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.51 2005-05-07 11:57:53 bodea Exp $";
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.61 2005-05-13 09:23:00 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)
LOG(1, s, t, "Short PAP %u bytes\n", l);
STAT(tunnel_rx_errors);
sessionshutdown(s, "Short PAP packet.", 3, 0);
- return ;
+ 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);
sessionshutdown(s, "PAP length mismatch.", 3, 0);
- return ;
+ return;
}
l = hl;
LOG(1, s, t, "Unexpected PAP code %d\n", *p);
STAT(tunnel_rx_errors);
sessionshutdown(s, "Unexpected PAP code.", 3, 0);
- return ;
+ 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
if (*p == ConfigAck)
{
- LOG(3, s, t, "LCP: Discarding ConfigAck\n");
+ int x = l - 4;
+ uint8_t *o = (p + 4);
+
+ LOG(3, s, t, "LCP: ConfigAck (%d bytes)...\n", l);
+ if (config->debug > 3) dumplcp(p, l);
+
+ while (x > 2)
+ {
+ int type = o[0];
+ int length = o[1];
+
+ if (length == 0 || type == 0 || x < length) break;
+ switch (type)
+ {
+ case 3: // Authentication-Protocol
+ {
+ int proto = ntohs(*(uint16_t *)(o + 2));
+ if (proto == PPPCHAP && *(o + 4) == 5)
+ sendchap(t, s);
+ }
+
+ break;
+ }
+ x -= length;
+ o += length;
+ }
+
session[s].flags |= SF_LCP_ACKED;
}
else if (*p == ConfigReq)
*q++ = 6;
memset(q, 0, 4); // asyncmap 0
q += 4;
- *((uint16_t *) (response + 2)) = htons(q - response); // LCP header length
break;
case 3: // Authentication-Protocol
{
int proto = ntohs(*(uint16_t *)(o + 2));
char proto_name[] = "0x0000";
+ uint8_t *a;
if (proto == PPPPAP)
{
q += 4;
}
- if ((q - b + 5) > sizeof(b)) // 5 is the larger (CHAP+MD5) of the two NAKs
+ 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;
}
- *q++ = type;
- if (config->radius_authprefer == AUTHCHAP)
- {
- *q++ = 5;
- *(uint16_t *) q = htons(PPPCHAP); q += 2;
- *q++ = 5; // MD5
- }
- else
+ q = a;
+
+ if (config->radius_authtypes != config->radius_authprefer)
{
- *q++ = 4;
- *(uint16_t *) q = htons(PPPPAP); q += 2;
+ 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;
memcpy(q, o, length);
q += length;
- *((uint16_t *) (response + 2)) = htons(q - response); // LCP header length
}
x -= length;
o += length;
}
- if (!response)
+ if (response)
{
- // Send back a ConfigAck
- q = response = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
- if (!q) return;
- *q = ConfigAck;
+ l = q - response; // LCP packet length
+ *((uint16_t *) (response + 2)) = htons(l); // update header
+ }
+ else
+ {
+ // Send packet back as ConfigAck
+ response = makeppp(b, sizeof(b), p, l, t, s, PPPLCP);
+ if (!response) return;
+ *response = ConfigAck;
}
LOG(3, s, t, "Sending %s\n", ppp_lcp_type(*response));
- tunnelsend(b, l + (q - b), t);
+ tunnelsend(b, l + response - 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 = -1;
+
+ 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 > 0)
+ 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);
+ }
+ }
+
+ break;
+
+ default:
+ LOG(2, s, t, " Remote NAKed LCP type %u?\n", type);
+ break;
+ }
+ x -= length;
+ o += length;
+ }
+
+ if (!authtype)
+ {
+ sessionshutdown(s, "Unsupported authentication.", 3, 0);
+ return;
+ }
+
+ if (authtype == -1)
+ authtype = config->radius_authprefer;
+
+ sendlcp(t, s, authtype);
}
else if (*p == TerminateReq)
{
{
LOG(1, s, t, "Unexpected LCP code %d\n", *p);
STAT(tunnel_rx_errors);
- return ;
}
}
return b;
}
-// Send initial LCP ConfigReq for preferred authentication type, set magic no and MRU
-void initlcp(tunnelidt t, sessionidt s)
+static uint8_t *add_lcp_auth(uint8_t *b, int size, int authtype)
+{
+ 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;
return;
LOG(4, s, t, "Sending LCP ConfigReq for %s\n",
- config->radius_authprefer == AUTHCHAP ? "CHAP" : "PAP");
+ authtype == AUTHCHAP ? "CHAP" : "PAP");
if (!session[s].mru)
session[s].mru = DEFAULT_MRU;
*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++ = 3; // Authentication-Protocol
- if (config->radius_authprefer == AUTHCHAP)
- {
- *l++ = 5; // length
- *(uint16_t *) l = htons(PPPCHAP); l += 2;
- *l++ = 5; // MD5
- }
- else
- {
- *l++ = 4; // length
- *(uint16_t *) l = htons(PPPPAP); 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);
projects / l2tpns.git / blobdiff