void GeneralName::decode_from(class BER_Decoder& ber)
{
BER_Object obj = ber.get_next_object();
if((obj.class_tag != CONTEXT_SPECIFIC) &&
(obj.class_tag != (CONTEXT_SPECIFIC | CONSTRUCTED)))
throw Decoding_Error("Invalid class tag while decoding GeneralName");
const ASN1_Tag tag = obj.type_tag;
if(tag == 1 || tag == 2 || tag == 6)
{
m_name = Charset::transcode(ASN1::to_string(obj),LATIN1_CHARSET,LOCAL_CHARSET);
if(tag == 1)
{
m_type = "RFC822";
}
else if(tag == 2)
{
m_type = "DNS";
}
else if(tag == 6)
{
m_type = "URI";
}
}
else if(tag == 4)
{
X509_DN dn;
std::multimap<std::string, std::string> nam;
BER_Decoder dec(obj.value);
std::stringstream ss;
dn.decode_from(dec);
ss << dn;
m_name = ss.str();
m_type = "DN";
}
else if(tag == 7)
{
if(obj.value.size() == 8)
{
const std::vector<byte> ip(obj.value.begin(),obj.value.begin() + 4);
const std::vector<byte> net(obj.value.begin() + 4,obj.value.end());
m_type = "IP";
m_name = ipv4_to_string(load_be<u32bit>(ip.data(),0)) + "/" + ipv4_to_string(load_be<u32bit>(net.data(),0));
}
else if(obj.value.size() == 32)
{
throw Decoding_Error("Unsupported IPv6 name constraint");
}
else
{
throw Decoding_Error("Invalid IP name constraint size " +
std::to_string(obj.value.size()));
}
}
else
{
throw Decoding_Error("Found unknown GeneralName type");
}
}
/**
* Implements a very simple DHCP server.
*
* Server will always offer next available address to a DISCOVER command
* Server will NAK any REQUEST command which is not requesting the next available address
* Server will ACK any REQUEST command which is for the next available address, and then increment the next available address
*
* @param my_addr : local IP address for binding of server port.
*/
static void dhcp_thread( uint32_t thread_input )
{
wiced_packet_t* received_packet;
wiced_packet_t* transmit_packet;
wiced_ip_address_t local_ip_address;
wiced_ip_address_t netmask;
uint32_t next_available_ip_addr;
uint32_t ip_mask;
uint32_t subnet;
uint32_t netmask_htobe;
char* option_ptr;
wiced_dhcp_server_t* server = (wiced_dhcp_server_t*)thread_input;
uint8_t subnet_mask_option_buff[] = { 1, 4, 0, 0, 0, 0 };
uint8_t server_ip_addr_option_buff[] = { 54, 4, 0, 0, 0, 0 };
uint32_t* server_ip_addr_ptr = (uint32_t*)&server_ip_addr_option_buff[2];
uint8_t wpad_option_buff[ 2 + sizeof(WPAD_SAMPLE_URL)-1 ] = { 252, sizeof(WPAD_SAMPLE_URL)-1 };
/* Save local IP address to be sent in DHCP packets */
wiced_ip_get_ipv4_address(server->interface, &local_ip_address);
*server_ip_addr_ptr = htobe32( GET_IPV4_ADDRESS( local_ip_address ) );
/* Save the current netmask to be sent in DHCP packets as the 'subnet mask option' */
wiced_ip_get_netmask(server->interface, &netmask);
netmask_htobe = htobe32( GET_IPV4_ADDRESS(netmask) );
memcpy(&subnet_mask_option_buff[2], &netmask_htobe, 4);
/* Calculate the first available IP address which will be served - based on the netmask and the local IP */
ip_mask = ~( GET_IPV4_ADDRESS( netmask ) );
subnet = GET_IPV4_ADDRESS( local_ip_address ) & GET_IPV4_ADDRESS( netmask );
next_available_ip_addr = subnet | ( ( GET_IPV4_ADDRESS( local_ip_address ) + 1 ) & ip_mask );
/* Prepare the Web proxy auto discovery URL */
memcpy(&wpad_option_buff[2], WPAD_SAMPLE_URL, sizeof(WPAD_SAMPLE_URL)-1);
ipv4_to_string( (char*)&wpad_option_buff[2 + 7], *server_ip_addr_ptr);
/* Initialise the server quit flag */
server->quit = WICED_FALSE;
/* Loop endlessly */
while ( server->quit == WICED_FALSE )
{
uint16_t data_length;
uint16_t available_data_length;
dhcp_header_t* request_header;
/* Sleep until data is received from socket. */
if ( wiced_udp_receive( &server->socket, &received_packet, WICED_WAIT_FOREVER ) != WICED_SUCCESS )
{
continue;
}
/* Get a pointer to the data in the packet */
wiced_packet_get_data( received_packet, 0, (uint8_t**) &request_header, &data_length, &available_data_length );
/* Check DHCP command */
switch ( request_header->options[2] )
{
case DHCPDISCOVER:
{
dhcp_header_t* reply_header;
uint16_t available_space;
wiced_mac_t client_mac_address;
wiced_ip_address_t client_ip_address;
uint32_t temp;
/* Create reply packet */
if ( wiced_packet_create_udp( &server->socket, sizeof(dhcp_header_t), &transmit_packet, (uint8_t**) &reply_header, &available_space ) != WICED_SUCCESS )
{
/* Cannot reply - release incoming packet */
wiced_packet_delete( received_packet );
break;
}
/* Copy in the DHCP header content from the received discover packet into the reply packet */
memcpy( reply_header, request_header, sizeof(dhcp_header_t) - sizeof(reply_header->options) );
/* Finished with the received discover packet - release it */
wiced_packet_delete( received_packet );
/* Now construct the OFFER response */
reply_header->opcode = BOOTP_OP_REPLY;
/* Clear the DHCP options list */
memset( &reply_header->options, 0, sizeof( reply_header->options ) );
/* Record client MAC address */
memcpy( &client_mac_address, request_header->client_hardware_addr, sizeof( client_mac_address ) );
/* Check whether device is already cached */
if ( get_client_ip_address_from_cache( &client_mac_address, &client_ip_address ) != WICED_SUCCESS )
{
/* Address not found in cache. Use next available IP address */
client_ip_address.version = WICED_IPV4;
client_ip_address.ip.v4 = next_available_ip_addr;
}
/* Create the IP address for the Offer */
temp = htonl(client_ip_address.ip.v4);
memcpy( reply_header->your_ip_addr, &temp, sizeof( temp ) );
/* Copy the magic DHCP number */
memcpy( reply_header->magic, dhcp_magic_cookie, 4 );
/* Add options */
option_ptr = (char *) &reply_header->options;
option_ptr = MEMCAT( option_ptr, dhcp_offer_option_buff, 3 ); /* DHCP message type */
option_ptr = MEMCAT( option_ptr, server_ip_addr_option_buff, 6 ); /* Server identifier */
option_ptr = MEMCAT( option_ptr, lease_time_option_buff, 6 ); /* Lease Time */
option_ptr = MEMCAT( option_ptr, subnet_mask_option_buff, 6 ); /* Subnet Mask */
option_ptr = (char*)MEMCAT( option_ptr, wpad_option_buff, sizeof(wpad_option_buff) ); /* Web proxy auto discovery URL */
/* Copy the local IP into the Router & DNS server Options */
memcpy( option_ptr, server_ip_addr_option_buff, 6 ); /* Router (gateway) */
option_ptr[0] = 3; /* Router id */
option_ptr += 6;
memcpy( option_ptr, server_ip_addr_option_buff, 6 ); /* DNS server */
option_ptr[0] = 6; /* DNS server id */
option_ptr += 6;
option_ptr = MEMCAT( option_ptr, mtu_option_buff, 4 ); /* Interface MTU */
option_ptr[0] = (char) 0xff; /* end options */
option_ptr++;
/* Send OFFER reply packet */
wiced_packet_set_data_end( transmit_packet, (uint8_t*) option_ptr );
if ( wiced_udp_send( &server->socket, WICED_IP_BROADCAST, IPPORT_DHCPC, transmit_packet ) != WICED_SUCCESS )
{
wiced_packet_delete( transmit_packet );
}
}
break;
case DHCPREQUEST:
{
/* REQUEST command - send back ACK or NAK */
uint32_t temp;
uint32_t* server_id_req;
dhcp_header_t* reply_header;
uint16_t available_space;
wiced_mac_t client_mac_address;
wiced_ip_address_t given_ip_address;
wiced_ip_address_t requested_ip_address;
wiced_bool_t next_avail_ip_address_used = WICED_FALSE;
/* Check that the REQUEST is for this server */
server_id_req = (uint32_t*) find_option( request_header, 54 );
if ( ( server_id_req != NULL ) && ( GET_IPV4_ADDRESS( local_ip_address ) != htobe32(*server_id_req) ) )
{
break; /* Server ID does not match local IP address */
}
/* Create reply packet */
if ( wiced_packet_create_udp( &server->socket, sizeof(dhcp_header_t), &transmit_packet, (uint8_t**) &reply_header, &available_space ) != WICED_SUCCESS )
{
/* Cannot reply - release incoming packet */
wiced_packet_delete( received_packet );
break;
}
/* Copy in the DHCP header content from the received request packet into the reply packet */
memcpy( reply_header, request_header, sizeof(dhcp_header_t) - sizeof(reply_header->options) );
/* Record client MAC address */
memcpy( &client_mac_address, request_header->client_hardware_addr, sizeof( client_mac_address ) );
/* Locate the requested address in the options and keep requested address */
requested_ip_address.version = WICED_IPV4;
requested_ip_address.ip.v4 = ntohl(*(uint32_t*)find_option( request_header, 50 ));
/* Delete received packet. We don't need it anymore */
wiced_packet_delete( received_packet );
reply_header->opcode = BOOTP_OP_REPLY;
/* Blank options list */
memset( &reply_header->options, 0, sizeof( reply_header->options ) );
/* Copy DHCP magic number into packet */
memcpy( reply_header->magic, dhcp_magic_cookie, 4 );
option_ptr = (char *) &reply_header->options;
/* Check if device is cache. If it is, give the previous IP address. Otherwise give the next available IP address */
if ( get_client_ip_address_from_cache( &client_mac_address, &given_ip_address ) != WICED_SUCCESS )
{
/* Address not found in cache. Use next available IP address */
next_avail_ip_address_used = WICED_TRUE;
given_ip_address.version = WICED_IPV4;
given_ip_address.ip.v4 = next_available_ip_addr;
}
/* Check if the requested IP address matches one we have assigned */
if ( memcmp( &requested_ip_address.ip.v4, &given_ip_address.ip.v4, sizeof( requested_ip_address.ip.v4 ) ) != 0 )
{
/* Request is not for the assigned IP - force client to take next available IP by sending NAK */
/* Add appropriate options */
option_ptr = (char*)MEMCAT( option_ptr, dhcp_nak_option_buff, 3 ); /* DHCP message type */
option_ptr = (char*)MEMCAT( option_ptr, server_ip_addr_option_buff, 6 ); /* Server identifier */
memset( reply_header->your_ip_addr, 0, sizeof( reply_header->your_ip_addr ) ); /* Clear IP addr */
}
else
{
/* Request is for next available IP */
/* Add appropriate options */
option_ptr = (char*)MEMCAT( option_ptr, dhcp_ack_option_buff, 3 ); /* DHCP message type */
option_ptr = (char*)MEMCAT( option_ptr, server_ip_addr_option_buff, 6 ); /* Server identifier */
option_ptr = (char*)MEMCAT( option_ptr, lease_time_option_buff, 6 ); /* Lease Time */
option_ptr = (char*)MEMCAT( option_ptr, subnet_mask_option_buff, 6 ); /* Subnet Mask */
option_ptr = (char*)MEMCAT( option_ptr, wpad_option_buff, sizeof(wpad_option_buff) ); /* Web proxy auto discovery URL */
/* Copy the local IP into the Router & DNS server Options */
memcpy( option_ptr, server_ip_addr_option_buff, 6 ); /* Router (gateway) */
option_ptr[0] = 3; /* Router id */
option_ptr += 6;
memcpy( option_ptr, server_ip_addr_option_buff, 6 ); /* DNS server */
option_ptr[0] = 6; /* DNS server id */
option_ptr += 6;
option_ptr = (char*)MEMCAT( option_ptr, mtu_option_buff, 4 ); /* Interface MTU */
/* Create the IP address for the Offer */
temp = htonl(given_ip_address.ip.v4);
memcpy( reply_header->your_ip_addr, &temp, sizeof( temp ) );
/* Increment next available IP address only if not found in cache */
if ( next_avail_ip_address_used == WICED_TRUE )
{
do
{
next_available_ip_addr = subnet | ( ( next_available_ip_addr + 1 ) & ip_mask );
} while ( next_available_ip_addr == GET_IPV4_ADDRESS(local_ip_address) );
}
/* Cache client */
add_client_to_cache( &client_mac_address, &given_ip_address );
}
option_ptr[0] = (char) 0xff; /* end options */
option_ptr++;
/* Send reply packet */
wiced_packet_set_data_end( transmit_packet, (uint8_t*) option_ptr );
if ( wiced_udp_send( &server->socket, WICED_IP_BROADCAST, IPPORT_DHCPC, transmit_packet ) != WICED_SUCCESS )
{
wiced_packet_delete( transmit_packet );
}
}
break;
default:
/* Unknown packet type - release received packet */
wiced_packet_delete( received_packet );
break;
}
}
/* Server loop has exited due to quit flag */
/* Delete DHCP socket */
wiced_udp_delete_socket( &server->socket );
WICED_END_OF_CURRENT_THREAD( );
}
