+ sp = &session[s];
+
+ // DoS prevention: enforce a maximum number of packets per 0.1s for a session
+ if (config->max_packets > 0)
+ {
+ if (sess_local[s].last_packet_out == TIME)
+ {
+ int max = config->max_packets;
+
+ // All packets for throttled sessions are handled by the
+ // master, so further limit by using the throttle rate.
+ // A bit of a kludge, since throttle rate is in kbps,
+ // but should still be generous given our average DSL
+ // packet size is 200 bytes: a limit of 28kbps equates
+ // to around 180 packets per second.
+ if (!config->cluster_iam_master && sp->throttle_out && sp->throttle_out < max)
+ max = sp->throttle_out;
+
+ if (++sess_local[s].packets_out > max)
+ {
+ sess_local[s].packets_dropped++;
+ return;
+ }
+ }
+ else
+ {
+ if (sess_local[s].packets_dropped)
+ {
+ INC_STAT(tun_rx_dropped, sess_local[s].packets_dropped);
+ LOG(3, s, t, "Dropped %u/%u packets to %s for %suser %s\n",
+ sess_local[s].packets_dropped, sess_local[s].packets_out,
+ fmtaddr(ip, 0), sp->throttle_out ? "throttled " : "",
+ sp->user);
+ }
+
+ sess_local[s].last_packet_out = TIME;
+ sess_local[s].packets_out = 1;
+ sess_local[s].packets_dropped = 0;
+ }
+ }
+
+ // run access-list if any
+ if (session[s].filter_out && !ip_filter(buf, len, session[s].filter_out - 1))
+ return;
+
+ // adjust MSS on SYN and SYN,ACK packets with options
+ if ((ntohs(*(uint16_t *) (buf + 6)) & 0x1fff) == 0 && buf[9] == IPPROTO_TCP) // first tcp fragment
+ {
+ int ihl = (buf[0] & 0xf) * 4; // length of IP header
+ if (len >= ihl + 20 && (buf[ihl + 13] & TCP_FLAG_SYN) && ((buf[ihl + 12] >> 4) > 5))
+ adjust_tcp_mss(s, t, buf, len, buf + ihl);
+ }
+
+ if (sp->tbf_out)
+ {
+ // Are we throttling this session?
+ if (config->cluster_iam_master)
+ tbf_queue_packet(sp->tbf_out, data, size);
+ else
+ master_throttle_packet(sp->tbf_out, data, size);
+ return;
+ }
+
+ if (sp->walled_garden && !config->cluster_iam_master)
+ {
+ // We are walled-gardening this
+ master_garden_packet(s, data, size);
+ return;
+ }
+
+ // Add on L2TP header
+ {
+ bundleidt bid = 0;
+ if(session[s].bundle != 0 && bundle[session[s].bundle].num_of_links > 1)
+ {
+ bid = session[s].bundle;
+ s = bundle[bid].members[bundle[bid].current_ses = ++bundle[bid].current_ses % bundle[bid].num_of_links];
+ t = session[s].tunnel;
+ sp = &session[s];
+ LOG(4, s, t, "MPPP: (1)Session number becomes: %d\n", s);
+ if(len > MINFRAGLEN)
+ {
+ // Partition the packet to "bundle[b].num_of_links" fragments
+ bundlet *b = &bundle[bid];
+ uint32_t num_of_links = b->num_of_links;
+ uint32_t fraglen = len / num_of_links;
+ fraglen = (fraglen > session[s].mru ? session[s].mru : fraglen);
+ uint32_t last_fraglen = fraglen + len % num_of_links;
+ last_fraglen = (last_fraglen > session[s].mru ? len % num_of_links : last_fraglen);
+ uint32_t remain = len;
+
+ // send the first packet
+ uint8_t *p = makeppp(fragbuf, sizeof(fragbuf), buf, fraglen, s, t, PPPIP, 0, bid, MP_BEGIN);
+ if (!p) return;
+ tunnelsend(fragbuf, fraglen + (p-fragbuf), t); // send it...
+ // statistics
+ update_session_out_stat(s, sp, fraglen);
+ remain -= fraglen;
+ while (remain > last_fraglen)
+ {
+ s = b->members[b->current_ses = ++b->current_ses % num_of_links];
+ t = session[s].tunnel;
+ sp = &session[s];
+ LOG(4, s, t, "MPPP: (2)Session number becomes: %d\n", s);
+ p = makeppp(fragbuf, sizeof(fragbuf), buf+(len - remain), fraglen, s, t, PPPIP, 0, bid, 0);
+ if (!p) return;
+ tunnelsend(fragbuf, fraglen + (p-fragbuf), t); // send it...
+ update_session_out_stat(s, sp, fraglen);
+ remain -= fraglen;
+ }
+ // send the last fragment
+ s = b->members[b->current_ses = ++b->current_ses % num_of_links];
+ t = session[s].tunnel;
+ sp = &session[s];
+ LOG(4, s, t, "MPPP: (2)Session number becomes: %d\n", s);
+ p = makeppp(fragbuf, sizeof(fragbuf), buf+(len - remain), remain, s, t, PPPIP, 0, bid, MP_END);
+ if (!p) return;
+ tunnelsend(fragbuf, remain + (p-fragbuf), t); // send it...
+ update_session_out_stat(s, sp, remain);
+ if (remain != last_fraglen)
+ LOG(3, s, t, "PROCESSIPOUT ERROR REMAIN != LAST_FRAGLEN, %d != %d\n", remain, last_fraglen);
+ }
+ else {
+ // Send it as one frame
+ uint8_t *p = makeppp(fragbuf, sizeof(fragbuf), buf, len, s, t, PPPIP, 0, bid, MP_BOTH_BITS);
+ if (!p) return;
+ tunnelsend(fragbuf, len + (p-fragbuf), t); // send it...
+ LOG(4, s, t, "MPPP: packet sent as one frame\n");
+ update_session_out_stat(s, sp, len);
+ }
+ }
+ else
+ {
+ uint8_t *p = makeppp(fragbuf, sizeof(fragbuf), buf, len, s, t, PPPIP, 0, 0, 0);
+ if (!p) return;
+ tunnelsend(fragbuf, len + (p-fragbuf), t); // send it...
+ update_session_out_stat(s, sp, len);
+ }
+ }
+
+ // Snooping this session, send it to intercept box
+ if (sp->snoop_ip && sp->snoop_port)
+ snoop_send_packet(buf, len, sp->snoop_ip, sp->snoop_port);
+
+ udp_tx += len;
+}
+
+// process outgoing (to tunnel) IPv6
+//
+static void processipv6out(uint8_t * buf, int len)
+{
+ sessionidt s;
+ sessiont *sp;
+ tunnelidt t;
+ in_addr_t ip;
+ struct in6_addr ip6;
+
+ uint8_t *data = buf; // Keep a copy of the originals.
+ int size = len;
+
+ uint8_t b[MAXETHER + 20];
+
+ CSTAT(processipv6out);
+
+ if (len < MIN_IP_SIZE)
+ {
+ LOG(1, 0, 0, "Short IPv6, %d bytes\n", len);
+ STAT(tunnel_tx_errors);
+ return;
+ }
+ if (len >= MAXETHER)
+ {
+ LOG(1, 0, 0, "Oversize IPv6 packet %d bytes\n", len);
+ STAT(tunnel_tx_errors);
+ return;
+ }
+
+ // Skip the tun header
+ buf += 4;
+ len -= 4;
+
+ // Got an IP header now
+ if (*(uint8_t *)(buf) >> 4 != 6)
+ {
+ LOG(1, 0, 0, "IP: Don't understand anything except IPv6\n");
+ return;
+ }
+
+ ip6 = *(struct in6_addr *)(buf+24);
+ s = sessionbyipv6(ip6);
+
+ if (s == 0)
+ {
+ ip = *(uint32_t *)(buf + 32);
+ s = sessionbyip(ip);
+ }
+
+ if (s == 0)
+ {
+ // Is this a packet for a session that doesn't exist?
+ static int rate = 0; // Number of ICMP packets we've sent this second.
+ static int last = 0; // Last time we reset the ICMP packet counter 'rate'.
+
+ if (last != time_now)
+ {
+ last = time_now;
+ rate = 0;
+ }
+
+ if (rate++ < config->icmp_rate) // Only send a max of icmp_rate per second.
+ {
+ // FIXME: Should send icmp6 host unreachable
+ }
+ return;
+ }
+ if (session[s].bundle && bundle[session[s].bundle].num_of_links > 1)
+ {
+ bundleidt bid = session[s].bundle;
+ s = bundle[bid].members[bundle[bid].current_ses = ++bundle[bid].current_ses % bundle[bid].num_of_links];
+ LOG(3, s, session[s].tunnel, "MPPP: Session number becomes: %u\n", s);
+ }
+ t = session[s].tunnel;
+ sp = &session[s];
+ sp->last_data = time_now;
+
+ // FIXME: add DoS prevention/filters?
+
+ if (sp->tbf_out)
+ {
projects / l2tpns.git / blobdiff