+ int x = l - 4;
+ uint8_t *o = (p + 4);
+ int authtype = -1;
+
+ 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
+ if (*p == ConfigNak)
+ {
+ if (length < 4) break;
+ 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;
+
+ if (length < 4) break;
+ 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 && length > 4 && *(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);
+ }
+ }
+ else
+ {
+ LOG(2, s, t, "LCP: remote rejected auth negotiation\n");
+ authtype = 0; // shutdown
+ }
+
+ break;
+
+ case 5: // Magic-Number
+ session[s].magic = 0;
+ if (*p == ConfigNak)
+ {
+ if (length < 6) break;
+ session[s].magic = ntohl(*(uint32_t *)(o + 2));
+ }
+
+ if (session[s].magic)
+ LOG(3, s, t, " Remote requested magic-no %x\n", session[s].magic);
+ else
+ LOG(3, s, t, " Remote rejected magic-no\n");
+
+ cluster_send_session(s);
+ break;
+
+ default:
+ LOG(2, s, t, "LCP: remote sent %s for type %u?\n", ppp_code(*p), type);
+ sessionshutdown(s, "Unable to negotiate LCP.", 3, 0);
+ return;
+ }
+ x -= length;
+ o += length;
+ }
+
+ if (!authtype)
+ {
+ sessionshutdown(s, "Unsupported authentication.", 3, 0);
+ return;
+ }
+
+ if (authtype > 0)
+ sess_local[s].lcp_authtype = authtype;
+
+ switch (session[s].ppp.lcp)
+ {
+ case Closed:
+ case Stopped:
+ {
+ uint8_t *response = makeppp(b, sizeof(b), p, 2, s, t, PPPLCP);
+ if (!response) return;
+ *response = TerminateAck;
+ *((uint16_t *) (response + 2)) = htons(l = 4);
+
+ LOG(3, s, t, "LCP: send %s\n", ppp_code(*response));
+ if (config->debug > 3) dumplcp(response, l);
+
+ tunnelsend(b, l + (response - b), t);
+ }
+ break;
+
+ case RequestSent:
+ case AckSent:
+ initialise_restart_count(s, lcp);
+ 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);
+ break;
+
+ case Opened:
+ lcp_restart(s);
+ sendlcp(s, t);
+ break;
+
+ default:
+ LOG(2, s, t, "LCP: ignoring %s in state %s\n", ppp_code(*p), ppp_state(session[s].ppp.lcp));
+ return;
+ }
+ }
+ else if (*p == TerminateReq)
+ {
+ *p = TerminateAck; // close
+ q = makeppp(b, sizeof(b), p, l, s, t, PPPLCP);
+ if (!q) return;
+
+ LOG(3, s, t, "LCP: send %s\n", ppp_code(*q));
+ if (config->debug > 3) dumplcp(q, l);
+
+ tunnelsend(b, l + (q - b), t); // send it
+ sessionshutdown(s, "Remote end closed connection.", 3, 0);
+ }
+ else if (*p == TerminateAck)
+ {
+ sessionshutdown(s, "Connection closed.", 3, 0);
+ }
+ else if (*p == ProtocolRej)
+ {
+ 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(3, s, t, "LCP protocol reject: 0x%04X\n", proto);
+ }
+ }
+ else if (*p == EchoReq)
+ {
+ *p = EchoReply; // reply
+ *(uint32_t *) (p + 4) = htonl(session[s].magic); // our magic number
+ q = makeppp(b, sizeof(b), p, l, s, t, PPPLCP);
+ if (!q) return;
+
+ LOG(4, s, t, "LCP: send %s\n", ppp_code(*q));
+ if (config->debug > 3) dumplcp(q, l);
+
projects / l2tpns.git / blobdiff