coap_connection_handler.c

00001 /*
00002  * Copyright (c) 2015-2017, Arm Limited and affiliates.
00003  * SPDX-License-Identifier: Apache-2.0
00004  *
00005  * Licensed under the Apache License, Version 2.0 (the "License");
00006  * you may not use this file except in compliance with the License.
00007  * You may obtain a copy of the License at
00008  *
00009  *     http://www.apache.org/licenses/LICENSE-2.0
00010  *
00011  * Unless required by applicable law or agreed to in writing, software
00012  * distributed under the License is distributed on an "AS IS" BASIS,
00013  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00014  * See the License for the specific language governing permissions and
00015  * limitations under the License.
00016  */
00017 
00018 #include <string.h>
00019 #include "coap_connection_handler.h"
00020 #include "coap_security_handler.h"
00021 #include "ns_list.h"
00022 #include "ns_trace.h"
00023 #include "nsdynmemLIB.h"
00024 #include "socket_api.h"
00025 #include "net_interface.h"
00026 #include "eventOS_event_timer.h"
00027 #include "coap_service_api_internal.h"
00028 
00029 #define TRACE_GROUP "ThCH"
00030 
00031 typedef enum session_state_e {
00032     SECURE_SESSION_HANDSHAKE_ONGOING = 0,
00033     SECURE_SESSION_OK,
00034     SECURE_SESSION_CLOSED
00035 }session_state_t;
00036 
00037 typedef struct internal_socket_s {
00038     coap_conn_handler_t *parent;
00039 
00040     uint32_t timeout_min;
00041     uint32_t timeout_max;
00042 
00043     uint16_t listen_port; // 0 for ephemeral-port sockets
00044 
00045     int16_t data_len;
00046     uint8_t *data;
00047 
00048     int8_t socket;  //positive value = socket id, negative value virtual socket id
00049     bool real_socket;
00050     uint8_t usage_counter;
00051     bool is_secure;
00052 
00053     bool bypass_link_sec;
00054 
00055     ns_list_link_t link;
00056 } internal_socket_t;
00057 
00058 const uint8_t COAP_MULTICAST_ADDR_LINK_LOCAL[16] = { 0xff, 0x02, [15] = 0xfd }; // ff02::fd, COAP link-local multicast (rfc7390)
00059 const uint8_t COAP_MULTICAST_ADDR_ADMIN_LOCAL[16] = { 0xff, 0x03, [15] = 0xfd }; // ff02::fd, COAP admin-local multicast (rfc7390)
00060 const uint8_t COAP_MULTICAST_ADDR_SITE_LOCAL[16] = { 0xff, 0x05, [15] = 0xfd }; // ff05::fd, COAP site-local multicast (rfc7390)
00061 
00062 static NS_LIST_DEFINE(socket_list, internal_socket_t, link);
00063 
00064 static uint8_t max_handshakes = MAX_ONGOING_HANDSHAKES;
00065 static uint8_t max_sessions = MAX_SECURE_SESSION_COUNT;
00066 
00067 static void timer_cb(void* param);
00068 
00069 static void recv_sckt_msg(void *cb_res);
00070 #ifdef COAP_SECURITY_AVAILABLE
00071 static void secure_recv_sckt_msg(void *cb_res);
00072 #endif
00073 
00074 #define TIMER_STATE_CANCELLED -1 /* cancelled */
00075 #define TIMER_STATE_NO_EXPIRY 0 /* none of the delays is expired */
00076 #define TIMER_STATE_INT_EXPIRY 1 /* the intermediate delay only is expired */
00077 #define TIMER_STATE_FIN_EXPIRY 2 /* the final delay is expired */
00078 
00079 typedef struct secure_timer_s {
00080     uint8_t id;
00081     timeout_t *timer;
00082     int8_t state;
00083     uint32_t fin_ms;
00084     uint32_t int_ms;
00085 } secure_timer_t;
00086 
00087 typedef struct secure_session {
00088     coap_security_t *sec_handler; //owned
00089     internal_socket_t *parent; //not owned
00090 
00091     ns_address_t remote_host;
00092     uint8_t local_address[16];
00093     // local port is fixed by socket
00094 
00095     secure_timer_t timer;
00096 
00097     session_state_t session_state;
00098     uint32_t last_contact_time;
00099     ns_list_link_t link;
00100 } secure_session_t;
00101 
00102 static NS_LIST_DEFINE(secure_session_list, secure_session_t, link);
00103 static int secure_session_sendto(int8_t socket_id, void *handle, const void *buf, size_t len);
00104 static int secure_session_recvfrom(int8_t socket_id, unsigned char *buf, size_t len);
00105 static void start_timer(int8_t timer_id, uint32_t int_ms, uint32_t fin_ms);
00106 static int timer_status(int8_t timer_id);
00107 
00108 static secure_session_t *secure_session_find_by_timer_id(int8_t timer_id)
00109 {
00110     secure_session_t *this = NULL;
00111     ns_list_foreach(secure_session_t, cur_ptr, &secure_session_list) {
00112         if (cur_ptr->timer.id == timer_id) {
00113             this = cur_ptr;
00114             break;
00115         }
00116     }
00117     return this;
00118 }
00119 
00120 static bool is_secure_session_valid(secure_session_t *session)
00121 {
00122     ns_list_foreach(secure_session_t, cur_ptr, &secure_session_list) {
00123         if (cur_ptr == session) {
00124             return true;
00125         }
00126     }
00127     return false;
00128 }
00129 
00130 static void secure_session_delete(secure_session_t *this)
00131 {
00132     if (this) {
00133         ns_list_remove(&secure_session_list, this);
00134         transactions_delete_all(this->remote_host.address, this->remote_host.identifier);
00135         if( this->sec_handler ){
00136             coap_security_destroy(this->sec_handler);
00137             this->sec_handler = NULL;
00138         }
00139         if(this->timer.timer){
00140             eventOS_timeout_cancel(this->timer.timer);
00141         }
00142         ns_dyn_mem_free(this);
00143         this = NULL;
00144     }
00145 
00146     return;
00147 }
00148 
00149 static int8_t virtual_socket_id_allocate()
00150 {
00151     int8_t new_virtual_socket_id = -1; // must not overlap with real socket id's
00152     ns_list_foreach(internal_socket_t, cur_ptr, &socket_list) {
00153         if (cur_ptr->socket <= new_virtual_socket_id) {
00154             new_virtual_socket_id = cur_ptr->socket - 1;
00155         }
00156     }
00157     return new_virtual_socket_id;
00158 }
00159 
00160 static secure_session_t *secure_session_create(internal_socket_t *parent, const uint8_t *address_ptr, uint16_t port, SecureConnectionMode secure_mode)
00161 {
00162     uint8_t handshakes = 0;
00163     if(!address_ptr){
00164         return NULL;
00165     }
00166 
00167     if(max_sessions <= ns_list_count(&secure_session_list)){
00168         // Seek & destroy oldest session where close notify have been sent
00169         secure_session_t *to_be_removed = NULL;
00170         ns_list_foreach(secure_session_t, cur_ptr, &secure_session_list) {
00171             if(cur_ptr->session_state == SECURE_SESSION_CLOSED){
00172                 if(!to_be_removed || cur_ptr->last_contact_time < to_be_removed->last_contact_time){
00173                     to_be_removed = cur_ptr;
00174                 }
00175             }
00176         }
00177         if(!to_be_removed){
00178             return NULL;
00179         }
00180 
00181         secure_session_delete(to_be_removed);
00182     }
00183 
00184     // Count for ongoing handshakes
00185     ns_list_foreach(secure_session_t, cur_ptr, &secure_session_list) {
00186         if(cur_ptr->session_state == SECURE_SESSION_HANDSHAKE_ONGOING){
00187             handshakes++;
00188         }
00189     }
00190     if(handshakes >= max_handshakes) {
00191         return NULL;
00192     }
00193 
00194     secure_session_t *this = ns_dyn_mem_alloc(sizeof(secure_session_t));
00195     if (!this) {
00196         return NULL;
00197     }
00198     memset(this, 0, sizeof(secure_session_t));
00199 
00200     uint8_t timer_id = 1;
00201 
00202     while(secure_session_find_by_timer_id(timer_id)){
00203         if(timer_id == 0xff){
00204             ns_dyn_mem_free(this);
00205             return NULL;
00206         }
00207         timer_id++;
00208     }
00209     this->last_contact_time = coap_service_get_internal_timer_ticks();
00210     this->timer.id = timer_id;
00211     this->remote_host.type = ADDRESS_IPV6;
00212     memcpy(this->remote_host.address, address_ptr, 16);
00213     this->remote_host.identifier = port;
00214 
00215     this->sec_handler = coap_security_create(parent->socket, this->timer.id, this, secure_mode,
00216                                                &secure_session_sendto, &secure_session_recvfrom, &start_timer, &timer_status);
00217     if( !this->sec_handler ){
00218         ns_dyn_mem_free(this);
00219         return NULL;
00220     }
00221     this->parent = parent;
00222 
00223     this->session_state = SECURE_SESSION_HANDSHAKE_ONGOING;
00224     ns_list_add_to_start(&secure_session_list, this);
00225 
00226     return this;
00227 }
00228 
00229 
00230 static void clear_secure_sessions(internal_socket_t *this){
00231     if( this ){
00232         ns_list_foreach_safe(secure_session_t, cur_ptr, &secure_session_list) {
00233             if( cur_ptr->parent == this ){
00234                 coap_security_send_close_alert( cur_ptr->sec_handler );
00235                 secure_session_delete(cur_ptr);
00236             }
00237         }
00238     }
00239 }
00240 
00241 static secure_session_t *secure_session_find(internal_socket_t *parent, const uint8_t *address_ptr, uint16_t port)
00242 {
00243     secure_session_t *this = NULL;
00244     ns_list_foreach(secure_session_t, cur_ptr, &secure_session_list) {
00245         if( cur_ptr->sec_handler ){
00246             if (cur_ptr->parent == parent && cur_ptr->remote_host.identifier == port &&
00247                 memcmp(cur_ptr->remote_host.address, address_ptr, 16) == 0) {
00248                 this = cur_ptr;
00249                 break;
00250             }
00251         }
00252     }
00253     return this;
00254 }
00255 
00256 static void coap_multicast_group_join_or_leave(int8_t socket_id, uint8_t opt_name, int8_t interface_id)
00257 {
00258     ns_ipv6_mreq_t ns_ipv6_mreq;
00259     int8_t ret_val;
00260 
00261     // Join or leave COAP multicast groups
00262     ns_ipv6_mreq.ipv6mr_interface = interface_id;
00263 
00264     memcpy(ns_ipv6_mreq.ipv6mr_multiaddr, COAP_MULTICAST_ADDR_LINK_LOCAL, 16);
00265     ret_val = socket_setsockopt(socket_id, SOCKET_IPPROTO_IPV6, opt_name, &ns_ipv6_mreq, sizeof(ns_ipv6_mreq));
00266 
00267     memcpy(ns_ipv6_mreq.ipv6mr_multiaddr, COAP_MULTICAST_ADDR_ADMIN_LOCAL, 16);
00268     ret_val |= socket_setsockopt(socket_id, SOCKET_IPPROTO_IPV6, opt_name, &ns_ipv6_mreq, sizeof(ns_ipv6_mreq));
00269 
00270     memcpy(ns_ipv6_mreq.ipv6mr_multiaddr, COAP_MULTICAST_ADDR_SITE_LOCAL, 16);
00271     ret_val |= socket_setsockopt(socket_id, SOCKET_IPPROTO_IPV6, opt_name, &ns_ipv6_mreq, sizeof(ns_ipv6_mreq));
00272 
00273     if (ret_val) {
00274         tr_error("Multicast group access failed, err=%d, name=%d", ret_val, opt_name);
00275     }
00276 }
00277 
00278 static internal_socket_t *int_socket_create(uint16_t listen_port, bool use_ephemeral_port, bool is_secure, bool real_socket, bool bypassSec, int8_t socket_interface_selection, bool multicast_registration)
00279 {
00280     internal_socket_t *this = ns_dyn_mem_alloc(sizeof(internal_socket_t));
00281 
00282     if (!this) {
00283         return NULL;
00284     }
00285     memset(this, 0, sizeof(internal_socket_t));
00286 
00287     this->data_len = 0;
00288     this->data = NULL;
00289 
00290     this->is_secure = is_secure;
00291     this->usage_counter = 1;
00292 
00293     this->listen_port = listen_port;
00294     this->real_socket = real_socket;
00295     this->bypass_link_sec = bypassSec;
00296     this->socket = -1;
00297     if( real_socket ){
00298         if( use_ephemeral_port ){ //socket_api creates ephemeral port if the one provided is 0
00299             listen_port = 0;
00300         }
00301         if( !is_secure ){
00302             this->socket = socket_open(SOCKET_UDP, listen_port, recv_sckt_msg);
00303         }else{
00304 #ifdef COAP_SECURITY_AVAILABLE
00305             this->socket = socket_open(SOCKET_UDP, listen_port, secure_recv_sckt_msg);
00306 #else
00307             tr_err("Secure CoAP unavailable - SSL library not configured, possibly due to lack of entropy source");
00308 #endif
00309         }
00310         // Socket create failed
00311         if(this->socket < 0){
00312             ns_dyn_mem_free(this);
00313             return NULL;
00314         }
00315 
00316         socket_setsockopt(this->socket, SOCKET_IPPROTO_IPV6, SOCKET_LINK_LAYER_SECURITY, &(const int8_t) {bypassSec ? 0 : 1}, sizeof(int8_t));
00317 
00318         // XXX API for this? May want to get clever to do recommended first query = 1 hop, retries = whole PAN
00319         socket_setsockopt(this->socket, SOCKET_IPPROTO_IPV6, SOCKET_IPV6_MULTICAST_HOPS, &(const int16_t) {16}, sizeof(int16_t));
00320 
00321         // Set socket option to receive packet info
00322         socket_setsockopt(this->socket, SOCKET_IPPROTO_IPV6, SOCKET_IPV6_RECVPKTINFO, &(const bool) {1}, sizeof(bool));
00323         if (socket_interface_selection > 0) {
00324             // Interface selection requested as socket_interface_selection set
00325             socket_setsockopt(this->socket, SOCKET_IPPROTO_IPV6, SOCKET_INTERFACE_SELECT, &socket_interface_selection, sizeof(socket_interface_selection));
00326         }
00327 
00328         if (multicast_registration) {
00329             coap_multicast_group_join_or_leave(this->socket, SOCKET_IPV6_JOIN_GROUP, socket_interface_selection);
00330         }
00331     } else {
00332         this->socket = virtual_socket_id_allocate();
00333     }
00334 
00335     ns_list_add_to_start(&socket_list, this);
00336     return this;
00337 }
00338 
00339 static void int_socket_delete(internal_socket_t *this)
00340 {
00341     if (this) {
00342         this->usage_counter--;
00343         if(this->usage_counter == 0){
00344             clear_secure_sessions(this);
00345             socket_close(this->socket);
00346             ns_list_remove(&socket_list, this);
00347             if( this->data ){
00348                 ns_dyn_mem_free(this->data);
00349                 this->data = NULL;
00350             }
00351             if(this->parent){
00352                 ns_dyn_mem_free(this->parent);
00353             }
00354             ns_dyn_mem_free(this);
00355         }
00356     }
00357 }
00358 
00359 static internal_socket_t *int_socket_find_by_socket_id(int8_t id)
00360 {
00361     internal_socket_t *this = NULL;
00362     ns_list_foreach(internal_socket_t, cur_ptr, &socket_list) {
00363         if( cur_ptr->socket == id ) {
00364             this = cur_ptr;
00365             break;
00366         }
00367     }
00368     return this;
00369 }
00370 
00371 static internal_socket_t *int_socket_find(uint16_t port, bool is_secure, bool is_real_socket, bool bypassSec)
00372 {
00373     (void) bypassSec;
00374 
00375     internal_socket_t *this = NULL;
00376     ns_list_foreach(internal_socket_t, cur_ptr, &socket_list) {
00377         if( cur_ptr->listen_port == port && cur_ptr->real_socket == is_real_socket &&
00378             is_secure == cur_ptr->is_secure /*&& bypass_link_sec == bypassSec*/) {
00379             this = cur_ptr;
00380             break;
00381         }
00382     }
00383     return this;
00384 }
00385 
00386 static int send_to_real_socket(int8_t socket_id, const ns_address_t *address, const uint8_t source_address[static 16], const void *buffer, uint16_t length)
00387 {
00388     ns_iovec_t msg_iov = {
00389         .iov_base = (void *) buffer,
00390         .iov_len = length
00391     };
00392     ns_msghdr_t msghdr = {
00393         .msg_name = (void *) address,
00394         .msg_namelen = sizeof(ns_address_t),
00395         .msg_iov = &msg_iov,
00396         .msg_iovlen = 1
00397     };
00398 
00399     if (memcmp(source_address, ns_in6addr_any, 16)) {
00400         uint8_t ancillary_databuffer[NS_CMSG_SPACE(sizeof(ns_in6_pktinfo_t))];
00401         ns_cmsghdr_t *cmsg;
00402         ns_in6_pktinfo_t *pktinfo;
00403 
00404         tr_debug("send from source address %s", trace_array(source_address, 16));
00405         msghdr.msg_control = ancillary_databuffer;
00406         msghdr.msg_controllen = sizeof(ancillary_databuffer);
00407 
00408         cmsg = NS_CMSG_FIRSTHDR(&msghdr);
00409         cmsg->cmsg_type = SOCKET_IPV6_PKTINFO;
00410         cmsg->cmsg_level = SOCKET_IPPROTO_IPV6;
00411         cmsg->cmsg_len = NS_CMSG_LEN(sizeof(ns_in6_pktinfo_t));
00412 
00413         pktinfo = (ns_in6_pktinfo_t*)NS_CMSG_DATA(cmsg);
00414         pktinfo->ipi6_ifindex = 0;
00415         memcpy(pktinfo->ipi6_addr, source_address, 16);
00416     }
00417 
00418     return socket_sendmsg(socket_id, &msghdr, 0);
00419 }
00420 
00421 static int secure_session_sendto(int8_t socket_id, void *handle, const void *buf, size_t len)
00422 {
00423     secure_session_t *session = handle;
00424     internal_socket_t *sock = int_socket_find_by_socket_id(socket_id);
00425     if(!sock){
00426         return -1;
00427     }
00428     if(!sock->real_socket){
00429         // Send to virtual socket cb
00430         int ret = sock->parent->_send_cb(sock->socket, session->remote_host.address, session->remote_host.identifier, buf, len);
00431         if( ret < 0 )
00432             return ret;
00433         return len;
00434     }
00435 
00436     int opt_name = SOCKET_IPV6_PREFER_SRC_6LOWPAN_SHORT;
00437     int8_t securityLinkLayer = 1;
00438     if (sock->bypass_link_sec) {
00439         securityLinkLayer = 0;
00440     }
00441     socket_setsockopt(sock->socket, SOCKET_IPPROTO_IPV6, SOCKET_IPV6_ADDR_PREFERENCES, &opt_name, sizeof(int));
00442     socket_setsockopt(sock->socket, SOCKET_IPPROTO_IPV6, SOCKET_LINK_LAYER_SECURITY, &securityLinkLayer, sizeof(int8_t));
00443     //For some reason socket_sendto returns 0 in success, while other socket impls return number of bytes sent!!!
00444     //TODO: check if address_ptr is valid and use that instead if it is
00445 
00446     int ret = send_to_real_socket(sock->socket, &session->remote_host, session->local_address, buf, len);
00447     if (ret < 0) {
00448         return ret;
00449     }
00450     return len;
00451 }
00452 
00453 static int secure_session_recvfrom(int8_t socket_id, unsigned char *buf, size_t len)
00454 {
00455     (void)len;
00456     internal_socket_t *sock = int_socket_find_by_socket_id(socket_id);
00457     if (sock->data && sock->data_len > 0) {
00458         memcpy( buf, sock->data, sock->data_len );
00459         int l = sock->data_len;
00460         ns_dyn_mem_free(sock->data);
00461         sock->data = NULL;
00462         sock->data_len = 0;
00463         return l;
00464     }
00465     return MBEDTLS_ERR_SSL_WANT_READ;
00466 }
00467 
00468 /**
00469  * Callback timer. Maybe called in interrupt context
00470  * so keep it simple.
00471  * TODO - might be better to use an event timer in conjunction with
00472  * CoAP tasklet
00473  */
00474 static void timer_cb(void *param)
00475 {
00476     secure_session_t *sec = param;
00477 
00478     if( sec && is_secure_session_valid(sec)){
00479         if(sec->timer.fin_ms > sec->timer.int_ms){
00480             /* Intermediate expiry */
00481             sec->timer.fin_ms -= sec->timer.int_ms;
00482             sec->timer.state = TIMER_STATE_INT_EXPIRY;
00483             int error = coap_security_handler_continue_connecting(sec->sec_handler);
00484             if(MBEDTLS_ERR_SSL_TIMEOUT == error) {
00485                 //TODO: How do we handle timeouts?
00486                 secure_session_delete(sec);
00487             }
00488             else{
00489                 sec->timer.timer = eventOS_timeout_ms(timer_cb, sec->timer.int_ms, (void*)sec);
00490             }
00491         }
00492         else{
00493             /* We have counted the number of cycles - finish */
00494             eventOS_timeout_cancel(sec->timer.timer);
00495             sec->timer.fin_ms = 0;
00496             sec->timer.int_ms = 0;
00497             sec->timer.timer = NULL;
00498             sec->timer.state = TIMER_STATE_FIN_EXPIRY;
00499             int error = coap_security_handler_continue_connecting(sec->sec_handler);
00500             if(MBEDTLS_ERR_SSL_TIMEOUT == error) {
00501                 //TODO: How do we handle timeouts?
00502                 secure_session_delete(sec);
00503             }
00504         }
00505     }
00506 }
00507 
00508 static void start_timer(int8_t timer_id, uint32_t int_ms, uint32_t fin_ms)
00509 {
00510     secure_session_t *sec = secure_session_find_by_timer_id(timer_id);
00511     if( sec ){
00512         if ((int_ms > 0) && (fin_ms > 0)) {
00513             sec->timer.int_ms = int_ms;
00514             sec->timer.fin_ms = fin_ms;
00515             sec->timer.state = TIMER_STATE_NO_EXPIRY;
00516             if(sec->timer.timer){
00517                 eventOS_timeout_cancel(sec->timer.timer);
00518             }
00519             sec->timer.timer = eventOS_timeout_ms(timer_cb, int_ms, sec);
00520         } else if (fin_ms == 0) {
00521             /* fin_ms == 0 means cancel the timer */
00522             sec->timer.state = TIMER_STATE_CANCELLED;
00523             eventOS_timeout_cancel(sec->timer.timer);
00524             sec->timer.fin_ms = 0;
00525             sec->timer.int_ms = 0;
00526             sec->timer.timer = NULL;
00527         }
00528     }
00529 }
00530 
00531 static int timer_status(int8_t timer_id)
00532 {
00533     secure_session_t *sec = secure_session_find_by_timer_id(timer_id);
00534     if( sec ){
00535         return (int)sec->timer.state;
00536     }
00537     return TIMER_STATE_CANCELLED;
00538 }
00539 
00540 static int read_data(socket_callback_t *sckt_data, internal_socket_t *sock, ns_address_t *src_address, uint8_t dst_address[static 16], int8_t *interface)
00541 {
00542     sock->data_len = 0;
00543     if (sckt_data->event_type == SOCKET_DATA && sckt_data->d_len > 0) {
00544         uint8_t ancillary_databuffer[NS_CMSG_SPACE(sizeof(ns_in6_pktinfo_t))];
00545         ns_iovec_t msg_iov;
00546         ns_msghdr_t msghdr;
00547         ns_in6_pktinfo_t *pkt = NULL;
00548 
00549         if (sock->data) {
00550             ns_dyn_mem_free(sock->data);
00551             sock->data = NULL;
00552         }
00553 
00554         sock->data = ns_dyn_mem_temporary_alloc(sckt_data->d_len);
00555         if (!sock->data) {
00556             sock->data = NULL;
00557             return -1;
00558         }
00559 
00560         msghdr.msg_name = src_address;
00561         msghdr.msg_namelen = sizeof(ns_address_t);
00562         msghdr.msg_iov = &msg_iov;
00563         msghdr.msg_iovlen = 1;
00564         msghdr.msg_control = ancillary_databuffer;
00565         msghdr.msg_controllen = sizeof(ancillary_databuffer);
00566 
00567         msg_iov.iov_base = sock->data;
00568         msg_iov.iov_len = sckt_data->d_len;
00569 
00570         sock->data_len = socket_recvmsg(sckt_data->socket_id, &msghdr, 0);
00571 
00572         if (sock->data_len > 0) {
00573             ns_cmsghdr_t *cmsg = NS_CMSG_FIRSTHDR(&msghdr);
00574 
00575             while (cmsg) {
00576                 switch (cmsg->cmsg_type) {
00577                     case SOCKET_IPV6_PKTINFO:
00578                         pkt = (ns_in6_pktinfo_t*)NS_CMSG_DATA(cmsg);
00579                         break;
00580                     default:
00581                         break;
00582                 }
00583                 cmsg = NS_CMSG_NXTHDR(&msghdr, cmsg);
00584             }
00585             if (pkt) {
00586                 memcpy(dst_address, pkt->ipi6_addr, 16);
00587                 *interface = pkt->ipi6_ifindex;
00588             } else {
00589                 goto return_failure;
00590             }
00591         } else {
00592             goto return_failure;
00593         }
00594     } else {
00595         goto return_failure;
00596     }
00597 
00598     return 0;
00599 
00600 return_failure:
00601     ns_dyn_mem_free(sock->data);
00602     sock->data = NULL;
00603     sock->data_len = 0;
00604     return -1;
00605 
00606 
00607 }
00608 
00609 #ifdef COAP_SECURITY_AVAILABLE
00610 static void secure_recv_sckt_msg(void *cb_res)
00611 {
00612     socket_callback_t *sckt_data = cb_res;
00613     internal_socket_t *sock = int_socket_find_by_socket_id(sckt_data->socket_id);
00614     ns_address_t src_address;
00615     uint8_t dst_address[16] = {0};
00616     memset(&src_address, 0, sizeof(ns_address_t));
00617     int8_t interface_id = -1;
00618 
00619     if (sock && read_data(sckt_data, sock, &src_address, dst_address, &interface_id) == 0) {
00620         /* If received from multicast address, reject */
00621         if (*(dst_address) == 0xFF) {
00622             return;
00623         }
00624         secure_session_t *session = secure_session_find(sock, src_address.address, src_address.identifier);
00625 
00626         // Create session
00627         if (!session) {
00628             coap_security_keys_t keys;
00629             memset(&keys, 0, sizeof(coap_security_keys_t));
00630 
00631             if (sock->parent->_get_password_cb && 0 == sock->parent->_get_password_cb(sock->socket, src_address.address, src_address.identifier, &keys)) {
00632                 session = secure_session_create(sock, src_address.address, src_address.identifier, keys.mode);
00633                 if (!session) {
00634                     tr_err("secure_recv_sckt_msg session creation failed - OOM");
00635                     ns_dyn_mem_free(keys._key);
00636                     return;
00637                 }
00638                 //TODO: error handling
00639             } else {
00640                 return;
00641             }
00642 
00643             // Record the destination. We are not strict on local address - all
00644             // session_find calls match only on remote address and port. But we
00645             // record the last-used destination address to use it as the source of
00646             // outgoing packets.
00647             memcpy(session->local_address, dst_address, 16);
00648 
00649             session->last_contact_time = coap_service_get_internal_timer_ticks();
00650             // Start handshake
00651             if (!coap_security_handler_is_started(session->sec_handler)) {
00652                 coap_security_handler_connect_non_blocking(session->sec_handler, true, DTLS, keys, sock->timeout_min, sock->timeout_max);
00653                 ns_dyn_mem_free(keys._key);
00654 
00655             }
00656         } else {
00657             //Continue handshake
00658             if (session->session_state == SECURE_SESSION_HANDSHAKE_ONGOING) {
00659                 int ret = coap_security_handler_continue_connecting(session->sec_handler);
00660                 // Handshake done
00661                 if (ret == 0) {
00662                     eventOS_timeout_cancel(session->timer.timer);
00663                     session->timer.timer = NULL;
00664                     session->session_state = SECURE_SESSION_OK;
00665                     if( sock->parent->_security_done_cb ){
00666                         sock->parent->_security_done_cb(sock->socket, src_address.address,
00667                                                        src_address.identifier,
00668                                                        (void *)coap_security_handler_keyblock(session->sec_handler));
00669                     }
00670                 } else if (ret < 0){
00671                     // error handling
00672                     // TODO: here we also should clear CoAP retransmission buffer and inform that CoAP request sending is failed.
00673                     secure_session_delete(session);
00674                 }
00675             //Session valid
00676             } else {
00677                 unsigned char *data = ns_dyn_mem_temporary_alloc(sock->data_len);
00678                 int len = 0;
00679                 len = coap_security_handler_read(session->sec_handler, data, sock->data_len);
00680                 if( len < 0 ){
00681                     if (len != MBEDTLS_ERR_SSL_WANT_READ && len != MBEDTLS_ERR_SSL_WANT_WRITE &&
00682                             len != MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE) {
00683                         secure_session_delete(session);
00684                     }
00685                     ns_dyn_mem_free(data);
00686                 } else {
00687                     if (sock->parent->_recv_cb) {
00688                         sock->parent->_recv_cb(sock->socket, interface_id, src_address.address, src_address.identifier, dst_address, data, len);
00689                     }
00690                     ns_dyn_mem_free(data);
00691                 }
00692             }
00693         }
00694     }
00695 }
00696 #endif
00697 
00698 static void recv_sckt_msg(void *cb_res)
00699 {
00700     socket_callback_t *sckt_data = cb_res;
00701     internal_socket_t *sock = int_socket_find_by_socket_id(sckt_data->socket_id);
00702     ns_address_t src_address;
00703     uint8_t dst_address[16];
00704     int8_t interface_id = -1;
00705 
00706     if (sock && read_data(sckt_data, sock, &src_address, dst_address, &interface_id) == 0) {
00707         if (sock->parent && sock->parent->_recv_cb) {
00708             sock->parent->_recv_cb(sock->socket, interface_id, src_address.address, src_address.identifier, dst_address, sock->data, sock->data_len);
00709         }
00710         ns_dyn_mem_free(sock->data);
00711         sock->data = NULL;
00712     }
00713 }
00714 
00715 int coap_connection_handler_virtual_recv(coap_conn_handler_t *handler, uint8_t address[static 16], uint16_t port, uint8_t *data_ptr, uint16_t data_len)
00716 {
00717     int8_t interface_id = -1;
00718 
00719     if(!handler || !handler->socket) {
00720         return -1;
00721     }
00722     internal_socket_t *sock = handler->socket;
00723     sock->data_len = data_len;
00724     if (sock->data) {
00725         ns_dyn_mem_free(sock->data);
00726         sock->data = NULL;
00727     }
00728     sock->data = ns_dyn_mem_temporary_alloc(data_len);
00729     if (data_len > 0 && !sock->data) {
00730         return -1;
00731     }
00732     if (data_ptr) {
00733         memcpy(sock->data, data_ptr, data_len);
00734     } else {
00735         if (sock->data) {
00736             ns_dyn_mem_free(sock->data);
00737             sock->data = NULL;
00738         }
00739     }
00740 
00741     if (handler->socket->is_secure) {
00742         coap_security_keys_t keys;
00743         memset(&keys, 0, sizeof(coap_security_keys_t));
00744 
00745         secure_session_t *session = secure_session_find(sock, address, port);
00746         if (!session) {
00747             if (sock->parent->_get_password_cb && 0 == sock->parent->_get_password_cb(sock->socket, address, port, &keys)) {
00748                 session = secure_session_create(sock, address, port, keys.mode);
00749                 if (!session) {
00750                     tr_err("coap_connection_handler_virtual_recv session creation failed - OOM");
00751                     ns_dyn_mem_free(keys._key);
00752                     return -1;
00753                 }
00754                 coap_security_handler_connect_non_blocking(session->sec_handler, true, DTLS, keys, handler->socket->timeout_min, handler->socket->timeout_max);
00755                 ns_dyn_mem_free(keys._key);
00756                 return 0;
00757             } else {
00758                 return -1;
00759             }
00760         }
00761 
00762         session->last_contact_time = coap_service_get_internal_timer_ticks();
00763 
00764         if (coap_security_handler_is_started(session->sec_handler)) {
00765             if (session->session_state == SECURE_SESSION_HANDSHAKE_ONGOING) {
00766                 int ret = coap_security_handler_continue_connecting(session->sec_handler);
00767                 if(ret == 0){
00768                     session->session_state = SECURE_SESSION_OK;
00769                     if( handler->_security_done_cb ){
00770                         handler->_security_done_cb(sock->socket,
00771                                                   address, port,
00772                                                   (void *)coap_security_handler_keyblock(session->sec_handler));
00773                     }
00774                     return 0;
00775                 }
00776                 else if (ret < 0) {
00777                     // error handling
00778                     // TODO: here we also should clear CoAP retransmission buffer and inform that CoAP request sending is failed.
00779                     secure_session_delete(session);
00780                 }
00781                 //TODO: error handling
00782             } else {
00783                 unsigned char *data = ns_dyn_mem_temporary_alloc(sock->data_len);
00784                 int len = 0;
00785                 len = coap_security_handler_read(session->sec_handler, data, sock->data_len);
00786                 if (len < 0) {
00787                     if (len != MBEDTLS_ERR_SSL_WANT_READ && len != MBEDTLS_ERR_SSL_WANT_WRITE &&
00788                             len != MBEDTLS_ERR_SSL_UNEXPECTED_MESSAGE) {
00789                         secure_session_delete(session);
00790                     }
00791                     ns_dyn_mem_free(data);
00792                     return 0;
00793                 } else {
00794                     if (sock->parent->_recv_cb) {
00795                         sock->parent->_recv_cb(sock->socket, interface_id, address, port, ns_in6addr_any, data, len);
00796                     }
00797                     ns_dyn_mem_free(data);
00798                     data = NULL;
00799                 }
00800                 return 0;
00801             }
00802         }
00803     } else {
00804         /* unsecure*/
00805         if (sock->parent->_recv_cb) {
00806             sock->parent->_recv_cb(sock->socket, interface_id, address, port, ns_in6addr_any, sock->data, sock->data_len);
00807         }
00808         if (sock->data) {
00809             ns_dyn_mem_free(sock->data);
00810             sock->data = NULL;
00811         }
00812         return 0;
00813     }
00814     return -1;
00815 }
00816 
00817 coap_conn_handler_t *connection_handler_create(receive_from_socket_cb *recv_from_cb,
00818                                                  send_to_socket_cb *send_to_cb,
00819                                                  get_pw_cb *pw_cb,
00820                                                  security_done_cb *done_cb )
00821 {
00822     if(recv_from_cb == NULL) {
00823         return NULL;
00824     }
00825 
00826     coap_conn_handler_t *handler = ns_dyn_mem_alloc(sizeof(coap_conn_handler_t));
00827     if(!handler){
00828         return NULL;
00829     }
00830     memset(handler, 0, sizeof(coap_conn_handler_t));
00831     handler->socket = NULL;
00832     handler->_recv_cb = recv_from_cb;
00833     handler->_send_cb = send_to_cb;
00834 
00835     handler->_get_password_cb = pw_cb;
00836     handler->_security_done_cb = done_cb;
00837 
00838     return handler;
00839 }
00840 
00841 void connection_handler_destroy(coap_conn_handler_t *handler, bool multicast_group_leave)
00842 {
00843     if(handler){
00844         if (multicast_group_leave) {
00845             coap_multicast_group_join_or_leave(handler->socket->socket, SOCKET_IPV6_LEAVE_GROUP, handler->socket_interface_selection);
00846         }
00847         if (handler->security_keys) {
00848             ns_dyn_mem_free(handler->security_keys);
00849         }
00850        int_socket_delete(handler->socket);
00851        ns_dyn_mem_free(handler);
00852     }
00853 }
00854 
00855 void connection_handler_close_secure_connection( coap_conn_handler_t *handler, uint8_t destination_addr_ptr[static 16], uint16_t port )
00856 {
00857     if (handler) {
00858         if (handler->socket && handler->socket->is_secure) {
00859             secure_session_t *session = secure_session_find( handler->socket, destination_addr_ptr, port );
00860             if (session) {
00861                 coap_security_send_close_alert( session->sec_handler );
00862                 session->session_state = SECURE_SESSION_CLOSED;
00863                 session->last_contact_time = coap_service_get_internal_timer_ticks();
00864             }
00865         }
00866     }
00867 }
00868 
00869 int coap_connection_handler_open_connection(coap_conn_handler_t *handler, uint16_t listen_port, bool use_ephemeral_port, bool is_secure, bool is_real_socket, bool bypassSec)
00870 {
00871     if (!handler) {
00872         return -1;
00873     }
00874     //virtual socket must have send callback
00875     if (!is_real_socket && !handler->_send_cb) {
00876         return -1;
00877     }
00878     if (handler->socket) {
00879         int_socket_delete(handler->socket);
00880     }
00881 
00882     internal_socket_t *current = !use_ephemeral_port?int_socket_find(listen_port, is_secure, is_real_socket, bypassSec):NULL;
00883     if (!current) {
00884         handler->socket = int_socket_create(listen_port, use_ephemeral_port, is_secure, is_real_socket, bypassSec, handler->socket_interface_selection, handler->registered_to_multicast);
00885         if (!handler->socket) {
00886             return -1;
00887         }
00888         handler->socket->parent = ns_dyn_mem_alloc(sizeof(coap_conn_handler_t));
00889         if (!handler->socket->parent) {
00890             int_socket_delete(handler->socket);
00891             return -1;
00892         }
00893         *handler->socket->parent = *handler;
00894     } else {
00895         current->usage_counter++;
00896         handler->socket = current;
00897     }
00898     return 0;
00899 }
00900 
00901 int coap_connection_handler_send_data(coap_conn_handler_t *handler, const ns_address_t *dest_addr, const uint8_t src_address[static 16], uint8_t *data_ptr, uint16_t data_len, bool bypass_link_sec)
00902 {
00903     if (!handler || !handler->socket || !dest_addr) {
00904         return -1;
00905     }
00906 
00907     /* Secure send */
00908     if (handler->socket->is_secure) {
00909         handler->socket->bypass_link_sec = bypass_link_sec;
00910         secure_session_t *session = secure_session_find(handler->socket, dest_addr->address, dest_addr->identifier);
00911         if (!session) {
00912             coap_security_keys_t security_material;
00913             int ret_val = 0;
00914 
00915             memset(&security_material, 0, sizeof(coap_security_keys_t));
00916 
00917             if (!handler->_get_password_cb || 0 != handler->_get_password_cb(handler->socket->socket, (uint8_t*)dest_addr->address, dest_addr->identifier, &security_material)) {
00918                 return -1;
00919             }
00920 
00921             session = secure_session_create(handler->socket, dest_addr->address, dest_addr->identifier, security_material.mode);
00922             if (!session || (0 > coap_security_handler_connect_non_blocking(session->sec_handler, false, DTLS, security_material, handler->socket->timeout_min, handler->socket->timeout_max))) {
00923                 ret_val = -1;
00924             }
00925 
00926             ns_dyn_mem_free(security_material._key);
00927             return ret_val;
00928 
00929         } else if (session->session_state == SECURE_SESSION_OK) {
00930             session->last_contact_time = coap_service_get_internal_timer_ticks();
00931             if (0 > coap_security_handler_send_message(session->sec_handler, data_ptr, data_len )) {
00932                 return -1;
00933             }
00934         }
00935     /* Unsecure */
00936     } else {
00937         /* Virtual socket */
00938         if (!handler->socket->real_socket && handler->_send_cb) {
00939             if (handler->_send_cb((int8_t)handler->socket->socket, dest_addr->address, dest_addr->identifier, data_ptr, data_len) < 0) {
00940                 return -1;
00941             }
00942         } else {
00943             int opt_name = SOCKET_IPV6_PREFER_SRC_6LOWPAN_SHORT;
00944             int8_t securityLinkLayer = 1;
00945             if (bypass_link_sec) {
00946                 securityLinkLayer = 0;
00947             }
00948 
00949             socket_setsockopt(handler->socket->socket, SOCKET_IPPROTO_IPV6, SOCKET_IPV6_ADDR_PREFERENCES, &opt_name, sizeof(int));
00950             socket_setsockopt(handler->socket->socket, SOCKET_IPPROTO_IPV6, SOCKET_LINK_LAYER_SECURITY, &securityLinkLayer, sizeof(int8_t));
00951 
00952             if (0 > send_to_real_socket(handler->socket->socket, dest_addr, src_address, data_ptr, data_len)) {
00953                 return -1;
00954             }
00955         }
00956     }
00957 
00958     return 1;
00959 }
00960 
00961 bool coap_connection_handler_socket_belongs_to(coap_conn_handler_t *handler, int8_t socket_id)
00962 {
00963     if( !handler || !handler->socket){
00964         return false;
00965     }
00966 
00967     if( handler->socket->socket == socket_id){
00968         return true;
00969     }
00970     return false;
00971 }
00972 
00973 int8_t coap_connection_handler_set_timeout(coap_conn_handler_t *handler, uint32_t min, uint32_t max)
00974 {
00975     if(!handler || !handler->socket){
00976         return -1;
00977     }
00978     handler->socket->timeout_max = max;
00979     handler->socket->timeout_min = min;
00980 
00981     return 0;
00982 }
00983 
00984 int8_t coap_connection_handler_handshake_limits_set(uint8_t handshakes_limit, uint8_t connections_limit)
00985 {
00986     if (!handshakes_limit || !connections_limit) {
00987         return -1;
00988     }
00989     max_handshakes = handshakes_limit;
00990     max_sessions = connections_limit;
00991 
00992     return 0;
00993 }
00994 
00995 /* No need to call every second - call rather like every minute (SECURE_SESSION_CLEAN_INTERVAL sets this) */
00996 void coap_connection_handler_exec(uint32_t time)
00997 {
00998     if(ns_list_count(&secure_session_list)){
00999         // Seek & destroy old sessions where close notify have been sent
01000         ns_list_foreach(secure_session_t, cur_ptr, &secure_session_list) {
01001             if(cur_ptr->session_state == SECURE_SESSION_CLOSED) {
01002                 if((cur_ptr->last_contact_time +  CLOSED_SECURE_SESSION_TIMEOUT) <= time){
01003                     secure_session_delete(cur_ptr);
01004                 }
01005             } else if(cur_ptr->session_state == SECURE_SESSION_OK){
01006                 if((cur_ptr->last_contact_time +  OPEN_SECURE_SESSION_TIMEOUT) <= time){
01007                     secure_session_delete(cur_ptr);
01008                 }
01009             } else if(cur_ptr->session_state == SECURE_SESSION_HANDSHAKE_ONGOING){
01010                 if((cur_ptr->last_contact_time +  ONGOING_HANDSHAKE_TIMEOUT) <= time){
01011                     secure_session_delete(cur_ptr);
01012                 }
01013             }
01014         }
01015     }
01016 }