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Diffstat (limited to 'include/pdp_net.h')
| -rw-r--r-- | include/pdp_net.h | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/include/pdp_net.h b/include/pdp_net.h new file mode 100644 index 0000000..ddc3f7f --- /dev/null +++ b/include/pdp_net.h @@ -0,0 +1,197 @@ +#ifndef __PDP_UDP_H_ +#define __PDP_UDP_H_ + +/* + * Pure Data Packet header: UDP protocol for raw packets + * Copyright (c) by Tom Schouten <pdp@zzz.kotnet.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + */ + +/* + + This file contains the specification of the pdp UDP transport protocol. + It is a very basic binary protocol, not very fool proof. + + The protocol: + + A header packet is transmitted first. This contains mime type information, + and the size of and number of packets to be received. + + The connection id: + + Currently it is just a random number from the libc rand() function + this should be accurate enough. + + +*/ + +#include <sys/socket.h> +#include <netinet/in.h> +#include <arpa/inet.h> +#include <unistd.h> +#include <pthread.h> +#include <netdb.h> +#include <stdlib.h> +#include <stdio.h> +#include <string.h> + +/* some defs */ +#define MAX_UDP_PACKET 1472 +#define RESEND_MAX_CHUNKS ((MAX_UDP_PACKET - sizeof(t_pdp_udp_header))/sizeof(unsigned int)) + +#define PDP_UDP_VERSION 1 + +/* a pdp udp packet is prepended with this header */ + +typedef struct _pdp_udp_header +{ + char signature[4]; /* must be "PDP" */; + unsigned int version; /* protocol version */ + unsigned int connection_id; /* the 'connection' id */ + unsigned int sequence_number; /* sequence number. negative: control packet: body contains meta info */ + +} t_pdp_udp_header; + +/* the data part for a new connection */ + +#define PDP_UDP_NEW -1 /* start a new transmission */ +typedef struct _pdp_udp_new +{ + unsigned int data_size; /* the size of the packets */ + unsigned int nb_chunks; /* number of chunks in pdp to be transmitted */ + unsigned int chunk_size; /* the maximum chunk size */ + char type[0]; /* the packet type */ + + // the tail part is the mime type, for creation and reassembly +} t_pdp_udp_newpacket; + +#define PDP_UDP_DONE -2 /* transmission is done */ + +#define PDP_UDP_RESEND -3 /* request retransmission of certain chunks. empty: transmission ok */ +#define PDP_UDP_ACKNEW -4 /* acknowledge reception of new packet header */ + + +/* receiver and sender classes (transport layer) */ + +#define PDP_UDP_BUFSIZE 0xF000 + +/* RECEIVER */ +typedef struct _pdp_udp_receiver +{ + + // buffer for receiving + t_pdp_udp_header x_header; //pdp over udp header + char x_buf[PDP_UDP_BUFSIZE]; //send buffer + unsigned int x_zero_terminator; // to prevent runaway strings + unsigned int x_buf_size; //size of the received data in the buffer (excluding the header) + + // buffer for sending + t_pdp_udp_header x_resend_header; // header of the resend packet + unsigned int x_resend_chunks[RESEND_MAX_CHUNKS]; // body contains the chunks to resend + unsigned int x_resend_udp_packet_size; + + // transmission info + unsigned int x_connection_id; + unsigned int x_nb_chunks; + unsigned int x_chunk_size; + unsigned int *x_chunk_list; + char *x_data_type; + unsigned int x_data_size; + void *x_data; + struct sockaddr_in x_source_socket; + int x_sslen; + int x_receive_finished; + int x_packet_transferred; + + int x_socket; //socket used for sending + struct sockaddr_in x_sa; //address struct + +} t_pdp_udp_receiver; + +/* setup */ +t_pdp_udp_receiver *pdp_udp_receiver_new(int port); +void pdp_udp_receiver_free(t_pdp_udp_receiver *x); + +/* reset connection (wait for new packet) */ +void pdp_udp_receiver_reset(t_pdp_udp_receiver *x); + +/* receive, returns 1 on success, 0 on timeout, -1 on error */ +int pdp_udp_receiver_receive(t_pdp_udp_receiver *x, unsigned int timeout_ms); + +/* get meta & data */ +char *pdp_udp_receiver_type(t_pdp_udp_receiver *x); +unsigned int pdp_udp_receiver_size(t_pdp_udp_receiver *x); +void *pdp_udp_receiver_data(t_pdp_udp_receiver *x); + + + +/* SENDER */ +typedef struct _pdp_udp_sender +{ + // desired udp packet size + unsigned int x_udp_payload_size; + + // current packet && communication info + unsigned int x_connection_id; + char *x_data_type; + void *x_data; + unsigned int x_data_size; + unsigned int x_chunk_size; + unsigned int *x_chunk_list; + unsigned int x_nb_chunks; + unsigned int x_chunk_list_size; + + // connection data + int x_socket; //socket used for sending + struct sockaddr_in x_sa; //address struct + unsigned int x_sleepgrain_us; //pause between sends (the poor man's flow control) (0 == no sleep) + unsigned int x_sleep_count; + unsigned int x_sleep_period; + unsigned int x_timeout_us; + + // temp buffer for sending + t_pdp_udp_header x_header; + char x_buf[PDP_UDP_BUFSIZE]; + unsigned int x_buf_size; + + // temp buffer for receiving + t_pdp_udp_header x_resend_header; + unsigned int x_resend_chunks[RESEND_MAX_CHUNKS]; + unsigned int x_resend_items; + + +} t_pdp_udp_sender; + +/* some flow control variables */ +void pdp_udp_sender_timeout_us(t_pdp_udp_sender *x, unsigned int timeout_us); +void pdp_udp_sender_sleepgrain_us(t_pdp_udp_sender *x, unsigned int sleepgrain_us); +void pdp_udp_sender_sleepperiod(t_pdp_udp_sender *x, unsigned int sleepperiod); +void pdp_udp_sender_udp_packet_size(t_pdp_udp_sender *x, unsigned int udp_packet_size); + +/* setup */ +t_pdp_udp_sender *pdp_udp_sender_new(void); +void pdp_udp_sender_free(t_pdp_udp_sender *x); + +/* connect */ +void pdp_udp_sender_connect(t_pdp_udp_sender *x, char *host, unsigned int port); + +/* send, returns 1 on success, 0 on error */ +int pdp_udp_sender_send(t_pdp_udp_sender *x, char* type, unsigned int size, void *data); + + + +#endif |