// L2TPNS PPP Stuff
-char const *cvs_id_ppp = "$Id: ppp.c,v 1.75 2005/08/24 23:44:08 bodea Exp $";
+char const *cvs_id_ppp = "$Id: ppp.c,v 1.90 2005/12/15 14:18:16 bodea Exp $";
#include <stdio.h>
#include <string.h>
if (session[s].ip || !(r = radiusnew(s)))
{
// respond now, either no RADIUS available or already authenticated
- uint8_t b[MAXCONTROL];
+ uint8_t b[MAXETHER];
uint8_t id = p[1];
uint8_t *p = makeppp(b, sizeof(b), 0, 0, s, t, PPPPAP);
if (!p) return;
else if (length == 5)
{
int proto = ntohs(*(uint16_t *)(o + 2));
- int algo = *(uint8_t *)(o + 4);
+ int algo = *(o + 4);
LOG(4, 0, 0, " %s 0x%x 0x%x (%s)\n", ppp_lcp_option(type), proto, algo,
(proto == PPPCHAP && algo == 5) ? "CHAP MD5" : "UNSUPPORTED");
}
change_state(s, ccp, Dead);
}
-static uint8_t *ppp_rej(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype,
+static uint8_t *ppp_conf_rej(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype,
uint8_t **response, uint8_t *queued, uint8_t *packet, uint8_t *option)
{
if (!*response || **response != ConfigRej)
return queued + option[1];
}
-static uint8_t *ppp_nak(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype,
+static uint8_t *ppp_conf_nak(sessionidt s, uint8_t *buf, size_t blen, uint16_t mtype,
uint8_t **response, uint8_t *queued, uint8_t *packet, uint8_t *option,
uint8_t *value, size_t vlen)
{
if (*nak_sent < config->ppp_max_failure) // reject queued
return queued;
- return ppp_rej(s, buf, blen, mtype, response, 0, packet, option);
+ return ppp_conf_rej(s, buf, blen, mtype, response, 0, packet, option);
}
if (!*response)
{
if (*nak_sent >= config->ppp_max_failure)
- return ppp_rej(s, buf, blen, mtype, response, 0, packet, option);
+ return ppp_conf_rej(s, buf, blen, mtype, response, 0, packet, option);
queued = *response = makeppp(buf, blen, packet, 2, s, session[s].tunnel, mtype);
if (!queued)
return queued + vlen;
}
+static void ppp_code_rej(sessionidt s, tunnelidt t, uint16_t proto,
+ char *pname, uint8_t *p, uint16_t l, uint8_t *buf, size_t size)
+{
+ uint8_t *q;
+ int mru = session[s].mru;
+ if (mru < MINMTU) mru = MINMTU;
+ if (mru > size) mru = size;
+
+ l += 4;
+ if (l > mru) l = mru;
+
+ q = makeppp(buf, size, 0, 0, s, t, proto);
+ if (!q) return;
+
+ *q = CodeRej;
+ *(q + 1) = ++sess_local[s].lcp_ident;
+ *(uint16_t *)(q + 2) = htons(l);
+ memcpy(q + 4, p, l - 4);
+
+ LOG(2, s, t, "Unexpected %s code %s\n", pname, ppp_code(*p));
+ LOG(3, s, t, "%s: send %s\n", pname, ppp_code(*q));
+ if (config->debug > 3) dumplcp(q, l);
+
+ tunnelsend(buf, l + (q - buf), t);
+}
+
// Process LCP messages
void processlcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
{
- uint8_t b[MAXCONTROL];
+ uint8_t b[MAXETHER];
uint8_t *q = NULL;
uint32_t magicno = 0;
uint16_t hl;
if (session[s].die) // going down...
return;
- LOG(*p == EchoReq ? 4 : 3, s, t, "LCP: recv %s\n", ppp_code(*p));
+ LOG((*p == EchoReq || *p == EchoReply) ? 4 : 3, s, t,
+ "LCP: recv %s\n", ppp_code(*p));
+
if (config->debug > 3) dumplcp(p, l);
if (*p == ConfigAck)
if (session[s].ppp.lcp == Opened)
lcp_restart(s);
- sendlcp(s, t, sess_local[s].lcp_authtype);
+ sendlcp(s, t);
change_state(s, lcp, RequestSent);
break;
switch (type)
{
case 1: // Maximum-Receive-Unit
- session[s].mru = ntohs(*(uint16_t *)(o + 2));
+ {
+ uint16_t mru = ntohs(*(uint16_t *)(o + 2));
+ if (mru >= MINMTU)
+ {
+ session[s].mru = mru;
+ break;
+ }
+
+ LOG(3, s, t, " Remote requesting MRU of %u. Rejecting.\n", mru);
+ mru = htons(MRU);
+ q = ppp_conf_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, (uint8_t *) &mru, sizeof(mru));
+ }
break;
case 2: // Async-Control-Character-Map
break;
LOG(3, s, t, " Remote requesting asyncmap. Rejecting.\n");
- q = ppp_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, asyncmap, sizeof(asyncmap));
+ q = ppp_conf_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, asyncmap, sizeof(asyncmap));
break;
case 3: // Authentication-Protocol
alen = add_lcp_auth(authproto, sizeof(authproto), config->radius_authprefer);
if (alen < 2) break; // paranoia
- q = ppp_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, authproto + 2, alen - 2);
+ q = ppp_conf_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, authproto + 2, alen - 2);
if (q && *response == ConfigNak &&
config->radius_authtypes != config->radius_authprefer)
{
// alternate type
alen = add_lcp_auth(authproto, sizeof(authproto), config->radius_authtypes & ~config->radius_authprefer);
if (alen < 2) break;
- q = ppp_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, authproto + 2, alen - 2);
+ q = ppp_conf_nak(s, b, sizeof(b), PPPLCP, &response, q, p, o, authproto + 2, alen - 2);
}
break;
default: // Reject any unknown options
LOG(3, s, t, " Rejecting unknown PPP LCP option %d\n", type);
- q = ppp_rej(s, b, sizeof(b), PPPLCP, &response, q, p, o);
+ q = ppp_conf_rej(s, b, sizeof(b), PPPLCP, &response, q, p, o);
}
x -= length;
o += length;
case Stopped:
initialise_restart_count(s, lcp);
- sendlcp(s, t, sess_local[s].lcp_authtype);
+ sendlcp(s, t);
if (*response == ConfigAck)
change_state(s, lcp, AckSent);
else
case Opened:
lcp_restart(s);
- sendlcp(s, t, sess_local[s].lcp_authtype);
+ sendlcp(s, t);
/* fallthrough */
case AckSent:
tunnelsend(b, l + (response - b), t);
}
- else if (*p == ConfigNak)
+ else if (*p == ConfigNak || *p == ConfigRej)
{
int x = l - 4;
uint8_t *o = (p + 4);
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);
+ if (*p == ConfigNak)
+ {
+ sess_local[s].ppp_mru = ntohs(*(uint16_t *)(o + 2));
+ LOG(3, s, t, " Remote requested MRU of %u\n", sess_local[s].ppp_mru);
+ }
+ else
+ {
+ sess_local[s].ppp_mru = 0;
+ LOG(3, s, t, " Remote rejected MRU negotiation\n");
+ }
+
break;
case 3: // Authentication-Protocol
if (authtype > 0)
break;
+ if (*p == ConfigNak)
{
int proto = ntohs(*(uint16_t *)(o + 2));
if (proto == PPPPAP)
proto);
}
}
+ else
+ {
+ LOG(2, s, t, "LCP: remote rejected auth negotiation\n");
+ authtype = 0; // shutdown
+ }
break;
default:
- LOG(2, s, t, " Remote NAKed LCP type %u?\n", type);
+ LOG(2, s, t, "LCP: remote sent %s for type %u?\n", ppp_code(*p), type);
break;
}
x -= length;
case RequestSent:
case AckSent:
initialise_restart_count(s, lcp);
- sendlcp(s, t, sess_local[s].lcp_authtype);
+ sendlcp(s, t);
break;
case AckReceived:
LOG(2, s, t, "LCP: ConfigNak in state %s? Sending ConfigReq\n", ppp_state(session[s].ppp.lcp));
- sendlcp(s, t, sess_local[s].lcp_authtype);
+ sendlcp(s, t);
break;
case Opened:
lcp_restart(s);
- sendlcp(s, t, sess_local[s].lcp_authtype);
+ sendlcp(s, t);
break;
default:
}
else if (*p == ProtocolRej)
{
- if (*(uint16_t *) (p+4) == htons(PPPIPV6CP))
+ uint16_t proto = 0;
+
+ if (l > 4)
+ {
+ proto = *(p+4);
+ if (l > 5 && !(proto & 1))
+ {
+ proto <<= 8;
+ proto |= *(p+5);
+ }
+ }
+
+ if (proto == PPPIPV6CP)
{
LOG(3, s, t, "IPv6 rejected\n");
change_state(s, ipv6cp, Closed);
}
else
{
- LOG(1, s, t, "Unexpected LCP protocol reject 0x%X\n",
- ntohs(*(uint16_t *) (p+4)));
- STAT(tunnel_rx_errors);
+ LOG(3, s, t, "LCP protocol reject: 0x%04X\n", proto);
}
}
else if (*p == EchoReq)
{
// Ignore it, last_packet time is set earlier than this.
}
- else
+ else if (*p != CodeRej)
{
- int code = *p;
- int mru = session[s].mru;
- if (!mru)
- mru = DEFAULT_MRU;
-
- if (l > mru) l = mru;
-
- *p = CodeRej;
- q = makeppp(b, sizeof(b), p, l, s, t, PPPLCP);
- if (!q) return;
-
- LOG(2, s, t, "Unexpected LCP code %s\n", ppp_code(code));
- LOG(3, s, t, "LCP: send %s\n", ppp_code(*q));
- if (config->debug > 3) dumplcp(q, l);
-
- tunnelsend(b, l + (q - b), t);
+ ppp_code_rej(s, t, PPPLCP, "LCP", p, l, b, sizeof(b));
}
}
change_state(s, ipcp, Opened);
- if (!session[s].walled_garden)
+ if (!(session[s].walled_garden || session[s].flags & SESSION_STARTED))
{
uint16_t r = radiusnew(s);
if (r)
+ {
radiussend(r, RADIUSSTART); // send radius start
+
+ // don't send further Start records if IPCP is restarted
+ session[s].flags |= SESSION_STARTED;
+ cluster_send_session(s);
+ }
}
// start IPv6 if configured and still in passive state
// Process IPCP messages
void processipcp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
{
- uint8_t b[MAXCONTROL];
+ uint8_t b[MAXETHER];
uint8_t *q = 0;
uint16_t hl;
if (memcmp(o + 2, &addr, (sizeof addr)))
{
uint8_t *oq = q;
- q = ppp_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr));
+ q = ppp_conf_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr));
if (!q || (q != oq && *response == ConfigRej))
{
sessionshutdown(s, "Can't negotiate IPCP.", 3, 0);
addr = htonl(session[s].dns1);
if (memcmp(o + 2, &addr, (sizeof addr)))
{
- q = ppp_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr));
+ q = ppp_conf_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr));
if (!q) return;
}
case 131: // secondary DNS
if (o[1] != 6 || o[1] > length) return;
- addr = htonl(session[s].dns1);
+ addr = htonl(session[s].dns2);
if (memcmp(o + 2, &addr, sizeof(addr)))
{
- q = ppp_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr));
+ q = ppp_conf_nak(s, b, sizeof(b), PPPIPCP, &response, q, p, o, (uint8_t *) &addr, sizeof(addr));
if (!q) return;
}
default:
LOG(2, s, t, " Rejecting PPP IPCP Option type %d\n", *o);
- q = ppp_rej(s, b, sizeof(b), PPPIPCP, &response, q, p, o);
+ q = ppp_conf_rej(s, b, sizeof(b), PPPIPCP, &response, q, p, o);
if (!q) return;
}
tunnelsend(b, l + (q - b), t);
change_state(s, ipcp, Stopped);
}
- else
+ else if (*p != CodeRej)
{
- int code = *p;
- int mru = session[s].mru;
- if (!mru)
- mru = DEFAULT_MRU;
-
- if (l > mru) l = mru;
-
- *p = CodeRej;
- q = makeppp(b, sizeof(b), p, l, s, t, PPPIPCP);
- if (!q) return;
-
- LOG(2, s, t, "Unexpected IPCP code %s\n", ppp_code(code));
- LOG(3, s, t, "IPCP: send %s\n", ppp_code(*q));
- tunnelsend(b, l + (q - b), t);
+ ppp_code_rej(s, t, PPPIPCP, "IPCP", p, l, b, sizeof(b));
}
}
// Process IPV6CP messages
void processipv6cp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
{
- uint8_t b[MAXCONTROL];
+ uint8_t b[MAXETHER];
uint8_t *q = 0;
uint16_t hl;
LOG(3, s, t, "IPV6CP: recv %s\n", ppp_code(*p));
- if (!config->ipv6_prefix.s6_addr[0])
- {
- LOG(2, s, t, "IPV6CP: %s rejected (not configured)\n", ppp_code(*p));
- *p = ProtocolRej;
- q = makeppp(b, sizeof(b), p, l, s, t, PPPIPV6CP);
- if (!q) return;
- tunnelsend(b, l + (q - b), t);
- return;
- }
-
if (!session[s].ip)
{
LOG(3, s, t, "IPV6CP: no IPv4 address (IPCP in state %s)\n", ppp_state(session[s].ppp.ipcp));
if (memcmp(o + 2, ident, sizeof(ident)))
{
- q = ppp_nak(s, b, sizeof(b), PPPIPV6CP, &response, q, p, o, ident, sizeof(ident));
+ q = ppp_conf_nak(s, b, sizeof(b), PPPIPV6CP, &response, q, p, o, ident, sizeof(ident));
if (!q) return;
}
default:
LOG(2, s, t, " Rejecting PPP IPV6CP Option type %d\n", *o);
- q = ppp_rej(s, b, sizeof(b), PPPIPV6CP, &response, q, p, o);
+ q = ppp_conf_rej(s, b, sizeof(b), PPPIPV6CP, &response, q, p, o);
if (!q) return;
}
tunnelsend(b, l + (q - b), t);
change_state(s, ipv6cp, Stopped);
}
- else
+ else if (*p != CodeRej)
{
- int code = *p;
- int mru = session[s].mru;
- if (!mru)
- mru = DEFAULT_MRU;
-
- if (l > mru) l = mru;
-
- *p = CodeRej;
- q = makeppp(b, sizeof(b), p, l, s, t, PPPIPV6CP);
- if (!q) return;
-
- LOG(2, s, t, "Unexpected IPV6CP code %s\n", ppp_code(code));
- LOG(3, s, t, "IPV6CP: send %s\n", ppp_code(*q));
- tunnelsend(b, l + (q - b), t);
+ ppp_code_rej(s, t, PPPIPV6CP, "IPV6CP", p, l, b, sizeof(b));
}
}
LOG_HEX(5, "IP", p, l);
+ if (l < 20)
+ {
+ LOG(1, s, t, "IP packet too short %d\n", l);
+ STAT(tunnel_rx_errors);
+ return ;
+ }
+
ip = ntohl(*(uint32_t *)(p + 12));
if (l > MAXETHER)
if (session[s].filter_in && !ip_filter(p, l, session[s].filter_in - 1))
return;
+ // adjust MSS on SYN and SYN,ACK packets with options
+ if ((ntohs(*(uint16_t *) (p + 6)) & 0x1fff) == 0 && p[9] == IPPROTO_TCP) // first tcp fragment
+ {
+ int ihl = (p[0] & 0xf) * 4; // length of IP header
+ if (l >= ihl + 20 && (p[ihl + 13] & TCP_FLAG_SYN) && ((p[ihl + 12] >> 4) > 5))
+ adjust_tcp_mss(s, t, p, l, p + ihl);
+ }
+
// Add on the tun header
p -= 4;
*(uint32_t *) p = htonl(PKTIP);
// Process CCP messages
void processccp(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l)
{
- uint8_t b[MAXCONTROL];
+ uint8_t b[MAXETHER];
uint8_t *q;
CSTAT(processccp);
tunnelsend(b, l + (q - b), t);
change_state(s, ccp, Stopped);
}
- else
+ else if (*p != CodeRej)
{
- int code = *p;
- int mru = session[s].mru;
- if (!mru)
- mru = DEFAULT_MRU;
-
- if (l > mru) l = mru;
-
- *p = CodeRej;
- q = makeppp(b, sizeof(b), p, l, s, t, PPPCCP);
- if (!q) return;
-
- LOG(2, s, t, "Unexpected CCP code %s\n", ppp_code(code));
- LOG(3, s, t, "CCP: send %s\n", ppp_code(*q));
- tunnelsend(b, l + (q - b), t);
+ ppp_code_rej(s, t, PPPCCP, "CCP", p, l, b, sizeof(b));
}
}
// send a CHAP challenge
void sendchap(sessionidt s, tunnelidt t)
{
- uint8_t b[MAXCONTROL];
+ uint8_t b[MAXETHER];
uint16_t r;
uint8_t *q;
{
if (size < 12) // Need more space than this!!
{
- static int backtrace_count = 0;
LOG(0, s, t, "makeppp buffer too small for L2TP header (size=%d)\n", size);
- log_backtrace(backtrace_count, 5)
return NULL;
}
*(uint16_t *) (b + 2) = htons(tunnel[t].far); // tunnel
*(uint16_t *) (b + 4) = htons(session[s].far); // session
b += 6;
- if (mtype == PPPLCP || !(session[s].l2tp_flags & SESSIONACFC))
+ if (mtype == PPPLCP || !(session[s].flags & SESSION_ACFC))
{
*(uint16_t *) b = htons(0xFF03); // HDLC header
b += 2;
}
- if (mtype < 0x100 && session[s].l2tp_flags & SESSIONPFC)
+ if (mtype < 0x100 && session[s].flags & SESSION_PFC)
*b++ = mtype;
else
{
if (l + 12 > size)
{
- static int backtrace_count = 0;
LOG(2, s, t, "makeppp would overflow buffer (size=%d, header+payload=%d)\n", size, l + 12);
- log_backtrace(backtrace_count, 5)
return NULL;
}
}
// Send initial LCP ConfigReq for MRU, authentication type and magic no
-void sendlcp(sessionidt s, tunnelidt t, int authtype)
+void sendlcp(sessionidt s, tunnelidt t)
{
uint8_t b[500], *q, *l;
+ int authtype = sess_local[s].lcp_authtype;
if (!(q = makeppp(b, sizeof(b), NULL, 0, s, t, PPPLCP)))
return;
authtype ? (authtype == AUTHCHAP ? "CHAP" : "PAP") : "",
authtype ? ")" : "");
- if (!session[s].mru)
- session[s].mru = DEFAULT_MRU;
-
l = q;
*l++ = ConfigReq;
- *l++ = (time_now % 255) + 1; // ID
+ *l++ = ++sess_local[s].lcp_ident; // 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;
+ if (sess_local[s].ppp_mru)
+ {
+ *l++ = 1; *l++ = 4; // Maximum-Receive-Unit (length 4)
+ *(uint16_t *) l = htons(sess_local[s].ppp_mru); l += 2;
+ }
if (authtype)
l += add_lcp_auth(l, sizeof(b) - (l - b), authtype);
if (config->debug > 3) dumplcp(q, l - q);
tunnelsend(b, (l - b), t);
+ restart_timer(s, lcp);
}
// Send CCP request for no compression
LOG(3, s, t, "CCP: send ConfigReq (no compression)\n");
*q = ConfigReq;
- *(uint8_t *)(q + 1) = (time_now % 255) + 1; // ID
+ *(q + 1) = ++sess_local[s].lcp_ident; // ID
*(uint16_t *)(q + 2) = htons(4); // Length
LOG_HEX(5, "PPPCCP", q, 4);
tunnelsend(b, (q - b) + 4 , t);
+ restart_timer(s, ccp);
+}
+
+// Reject unknown/unconfigured protocols
+void protoreject(sessionidt s, tunnelidt t, uint8_t *p, uint16_t l, uint16_t proto)
+{
+
+ uint8_t buf[MAXETHER];
+ uint8_t *q;
+ int mru = session[s].mru;
+ if (mru < MINMTU) mru = MINMTU;
+ if (mru > sizeof(buf)) mru = sizeof(buf);
+
+ l += 6;
+ if (l > mru) l = mru;
+
+ q = makeppp(buf, sizeof(buf), 0, 0, s, t, PPPLCP);
+ if (!q) return;
+
+ *q = ProtocolRej;
+ *(q + 1) = ++sess_local[s].lcp_ident;
+ *(uint16_t *)(q + 2) = htons(l);
+ *(uint16_t *)(q + 4) = htons(proto);
+ memcpy(q + 6, p, l - 6);
+
+ if (proto == PPPIPV6CP)
+ LOG(3, s, t, "LCP: send ProtocolRej (IPV6CP: not configured)\n");
+ else
+ LOG(2, s, t, "LCP: sent ProtocolRej (0x%04X: unsupported)\n", proto);
+
+ tunnelsend(buf, l + (q - buf), t);
}
projects / l2tpns.git / blobdiff