void process_outgoing_tun (struct context *c) { struct gc_arena gc = gc_new (); /* * Set up for write() call to TUN/TAP * device. */ if (c->c2.to_tun.len <= 0) return; perf_push (PERF_PROC_OUT_TUN); /* * The --mssfix option requires * us to examine the IPv4 header. */ process_ipv4_header (c, PIPV4_MSSFIX|PIPV4_EXTRACT_DHCP_ROUTER|PIPV4_OUTGOING, &c->c2.to_tun); if (c->c2.to_tun.len <= MAX_RW_SIZE_TUN (&c->c2.frame)) { /* * Write to TUN/TAP device. */ int size; #ifdef LOG_RW if (c->c2.log_rw) fprintf (stderr, "w"); #endif dmsg (D_TUN_RW, "TUN WRITE [%d]", BLEN (&c->c2.to_tun)); #ifdef PACKET_TRUNCATION_CHECK ipv4_packet_size_verify (BPTR (&c->c2.to_tun), BLEN (&c->c2.to_tun), TUNNEL_TYPE (c->c1.tuntap), "WRITE_TUN", &c->c2.n_trunc_tun_write); #endif #ifdef TUN_PASS_BUFFER size = write_tun_buffered (c->c1.tuntap, &c->c2.to_tun); #else size = write_tun (c->c1.tuntap, BPTR (&c->c2.to_tun), BLEN (&c->c2.to_tun)); #endif if (size > 0) c->c2.tun_write_bytes += size; check_status (size, "write to TUN/TAP", NULL, c->c1.tuntap); /* check written packet size */ if (size > 0) { /* Did we write a different size packet than we intended? */ if (size != BLEN (&c->c2.to_tun)) msg (D_LINK_ERRORS, "TUN/TAP packet was destructively fragmented on write to %s (tried=%d,actual=%d)", c->c1.tuntap->actual_name, BLEN (&c->c2.to_tun), size); /* indicate activity regarding --inactive parameter */ register_activity (c, size); } } else { /* * This should never happen, probably indicates some kind * of MTU mismatch. */ msg (D_LINK_ERRORS, "tun packet too large on write (tried=%d,max=%d)", c->c2.to_tun.len, MAX_RW_SIZE_TUN (&c->c2.frame)); } buf_reset (&c->c2.to_tun); perf_pop (); gc_free (&gc); }
void process_incoming_link (struct context *c) { struct gc_arena gc = gc_new (); bool decrypt_status; struct link_socket_info *lsi = get_link_socket_info (c); const uint8_t *orig_buf = c->c2.buf.data; perf_push (PERF_PROC_IN_LINK); if (c->c2.buf.len > 0) { c->c2.link_read_bytes += c->c2.buf.len; link_read_bytes_global += c->c2.buf.len; c->c2.original_recv_size = c->c2.buf.len; #ifdef ENABLE_MANAGEMENT if (management) { management_bytes_in (management, c->c2.buf.len); #ifdef MANAGEMENT_DEF_AUTH management_bytes_server (management, &c->c2.link_read_bytes, &c->c2.link_write_bytes, &c->c2.mda_context); #endif } #endif } else c->c2.original_recv_size = 0; #ifdef ENABLE_DEBUG /* take action to corrupt packet if we are in gremlin test mode */ if (c->options.gremlin) { if (!ask_gremlin (c->options.gremlin)) c->c2.buf.len = 0; corrupt_gremlin (&c->c2.buf, c->options.gremlin); } #endif /* log incoming packet */ #ifdef LOG_RW if (c->c2.log_rw) fprintf (stderr, "R"); #endif msg (D_LINK_RW, "%s READ [%d] from %s: %s", proto2ascii (lsi->proto, true), BLEN (&c->c2.buf), print_link_socket_actual (&c->c2.from, &gc), PROTO_DUMP (&c->c2.buf, &gc)); /* * Good, non-zero length packet received. * Commence multi-stage processing of packet, * such as authenticate, decrypt, decompress. * If any stage fails, it sets buf.len to 0 or -1, * telling downstream stages to ignore the packet. */ if (c->c2.buf.len > 0) { if (!link_socket_verify_incoming_addr (&c->c2.buf, lsi, &c->c2.from)) link_socket_bad_incoming_addr (&c->c2.buf, lsi, &c->c2.from); #ifdef USE_CRYPTO #ifdef USE_SSL if (c->c2.tls_multi) { /* * If tls_pre_decrypt returns true, it means the incoming * packet was a good TLS control channel packet. If so, TLS code * will deal with the packet and set buf.len to 0 so downstream * stages ignore it. * * If the packet is a data channel packet, tls_pre_decrypt * will load crypto_options with the correct encryption key * and return false. */ /*tls_mutex_lock (c->c2.tls_multi);*/ if (tls_pre_decrypt (c->c2.tls_multi, &c->c2.from, &c->c2.buf, &c->c2.crypto_options)) { interval_action (&c->c2.tmp_int); /* reset packet received timer if TLS packet */ if (c->options.ping_rec_timeout) event_timeout_reset (&c->c2.ping_rec_interval); } } #if P2MP_SERVER /* * Drop non-TLS packet if client-connect script/plugin has not * yet succeeded. */ if (c->c2.context_auth != CAS_SUCCEEDED) c->c2.buf.len = 0; #endif #endif /* USE_SSL */ /* authenticate and decrypt the incoming packet */ decrypt_status = openvpn_decrypt (&c->c2.buf, c->c2.buffers->decrypt_buf, &c->c2.crypto_options, &c->c2.frame); #ifdef USE_SSL if (c->c2.tls_multi) { /*tls_mutex_unlock (c->c2.tls_multi);*/ } #endif if (!decrypt_status && link_socket_connection_oriented (c->c2.link_socket)) { /* decryption errors are fatal in TCP mode */ c->sig->signal_received = SIGUSR1; /* SOFT-SIGUSR1 -- decryption error in TCP mode */ c->sig->signal_text = "decryption-error"; msg (D_STREAM_ERRORS, "Fatal decryption error (process_incoming_link), restarting"); goto done; } #endif /* USE_CRYPTO */ #ifdef ENABLE_FRAGMENT if (c->c2.fragment) fragment_incoming (c->c2.fragment, &c->c2.buf, &c->c2.frame_fragment); #endif #ifdef USE_LZO /* decompress the incoming packet */ if (lzo_defined (&c->c2.lzo_compwork)) lzo_decompress (&c->c2.buf, c->c2.buffers->lzo_decompress_buf, &c->c2.lzo_compwork, &c->c2.frame); #endif #ifdef PACKET_TRUNCATION_CHECK /* if (c->c2.buf.len > 1) --c->c2.buf.len; */ ipv4_packet_size_verify (BPTR (&c->c2.buf), BLEN (&c->c2.buf), TUNNEL_TYPE (c->c1.tuntap), "POST_DECRYPT", &c->c2.n_trunc_post_decrypt); #endif /* * Set our "official" outgoing address, since * if buf.len is non-zero, we know the packet * authenticated. In TLS mode we do nothing * because TLS mode takes care of source address * authentication. * * Also, update the persisted version of our packet-id. */ if (!TLS_MODE (c)) link_socket_set_outgoing_addr (&c->c2.buf, lsi, &c->c2.from, NULL, c->c2.es); /* reset packet received timer */ if (c->options.ping_rec_timeout && c->c2.buf.len > 0) event_timeout_reset (&c->c2.ping_rec_interval); /* increment authenticated receive byte count */ if (c->c2.buf.len > 0) { c->c2.link_read_bytes_auth += c->c2.buf.len; c->c2.max_recv_size_local = max_int (c->c2.original_recv_size, c->c2.max_recv_size_local); } /* Did we just receive an openvpn ping packet? */ if (is_ping_msg (&c->c2.buf)) { dmsg (D_PING, "RECEIVED PING PACKET"); c->c2.buf.len = 0; /* drop packet */ } #ifdef ENABLE_OCC /* Did we just receive an OCC packet? */ if (is_occ_msg (&c->c2.buf)) process_received_occ_msg (c); #endif buffer_turnover (orig_buf, &c->c2.to_tun, &c->c2.buf, &c->c2.buffers->read_link_buf); /* to_tun defined + unopened tuntap can cause deadlock */ if (!tuntap_defined (c->c1.tuntap)) c->c2.to_tun.len = 0; } else { buf_reset (&c->c2.to_tun); } done: perf_pop (); gc_free (&gc); }
void process_incoming_link_part2 (struct context *c, struct link_socket_info *lsi, const uint8_t *orig_buf) { if (c->c2.buf.len > 0) { #ifdef ENABLE_FRAGMENT if (c->c2.fragment) fragment_incoming (c->c2.fragment, &c->c2.buf, &c->c2.frame_fragment); #endif #ifdef USE_COMP /* decompress the incoming packet */ if (c->c2.comp_context) (*c->c2.comp_context->alg.decompress)(&c->c2.buf, c->c2.buffers->decompress_buf, c->c2.comp_context, &c->c2.frame); #endif #ifdef PACKET_TRUNCATION_CHECK /* if (c->c2.buf.len > 1) --c->c2.buf.len; */ ipv4_packet_size_verify (BPTR (&c->c2.buf), BLEN (&c->c2.buf), TUNNEL_TYPE (c->c1.tuntap), "POST_DECRYPT", &c->c2.n_trunc_post_decrypt); #endif /* * Set our "official" outgoing address, since * if buf.len is non-zero, we know the packet * authenticated. In TLS mode we do nothing * because TLS mode takes care of source address * authentication. * * Also, update the persisted version of our packet-id. */ if (!TLS_MODE (c)) link_socket_set_outgoing_addr (&c->c2.buf, lsi, &c->c2.from, NULL, c->c2.es); /* reset packet received timer */ if (c->options.ping_rec_timeout && c->c2.buf.len > 0) event_timeout_reset (&c->c2.ping_rec_interval); /* increment authenticated receive byte count */ if (c->c2.buf.len > 0) { c->c2.link_read_bytes_auth += c->c2.buf.len; c->c2.max_recv_size_local = max_int (c->c2.original_recv_size, c->c2.max_recv_size_local); } /* Did we just receive an openvpn ping packet? */ if (is_ping_msg (&c->c2.buf)) { dmsg (D_PING, "RECEIVED PING PACKET"); c->c2.buf.len = 0; /* drop packet */ } #ifdef ENABLE_OCC /* Did we just receive an OCC packet? */ if (is_occ_msg (&c->c2.buf)) process_received_occ_msg (c); #endif buffer_turnover (orig_buf, &c->c2.to_tun, &c->c2.buf, &c->c2.buffers->read_link_buf); /* to_tun defined + unopened tuntap can cause deadlock */ if (!tuntap_defined (c->c1.tuntap)) c->c2.to_tun.len = 0; } else { buf_reset (&c->c2.to_tun); } }