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-rw-r--r--system/net/Makefile11
-rw-r--r--system/net/pdp_net.c685
2 files changed, 696 insertions, 0 deletions
diff --git a/system/net/Makefile b/system/net/Makefile
new file mode 100644
index 0000000..53d1d61
--- /dev/null
+++ b/system/net/Makefile
@@ -0,0 +1,11 @@
+
+OBJECTS = pdp_net.o
+
+
+include ../../Makefile.config
+
+all: $(OBJECTS)
+
+clean:
+ rm -f *~
+ rm -f *.o
diff --git a/system/net/pdp_net.c b/system/net/pdp_net.c
new file mode 100644
index 0000000..04c97d6
--- /dev/null
+++ b/system/net/pdp_net.c
@@ -0,0 +1,685 @@
+
+#include "pdp_net.h"
+#include "pdp_debug.h"
+#include "pdp_post.h"
+#include "pdp_mem.h"
+
+#define D if (0) // DEBUG MSG
+#define DD if (0) // DROP DEBUG MSG
+
+/* shared internals */
+
+static int _is_udp_header(t_pdp_udp_header *header, unsigned int size)
+{
+ if (size < sizeof(t_pdp_udp_header)) return 0;
+ if (strcmp(header->signature, "PDP")) return 0;
+ if (PDP_UDP_VERSION != header->version) return 0;
+ return 1;
+}
+
+static void _make_udp_header(t_pdp_udp_header *header)
+{
+ strcpy(header->signature, "PDP");
+ header->version = PDP_UDP_VERSION;
+}
+
+
+
+
+/* R E C E I V E R */
+
+
+/* INTERNALS */
+
+static void _send_packet(t_pdp_udp_receiver *x)
+{
+ _make_udp_header(&x->x_resend_header);
+ PDP_ASSERT(x->x_resend_udp_packet_size <= sizeof(t_pdp_udp_header) + sizeof(x->x_resend_chunks));
+
+ /* send the packet */
+ if (-1 == sendto (x->x_socket, &x->x_resend_header, x->x_resend_udp_packet_size, 0,
+ (struct sockaddr *)&x->x_source_socket, x->x_sslen)){
+ pdp_post("pdp_netreceive: send failed");
+ }
+}
+
+static void _send_ack_new(t_pdp_udp_receiver *x)
+{
+ /* setup resend header */
+ x->x_resend_header.connection_id = x->x_connection_id;
+ x->x_resend_header.sequence_number = PDP_UDP_ACKNEW;
+ x->x_resend_udp_packet_size = sizeof(t_pdp_udp_header);
+
+ _send_packet(x);
+
+}
+
+
+static int _handle_PDP_UDP_NEW(t_pdp_udp_receiver *x)
+{
+ /* we've got a PDP_UDP_NEW packet, so prepare to receive the data */
+ t_pdp_udp_newpacket *np = (t_pdp_udp_newpacket *)x->x_buf;
+
+
+ //pdp_post("conn_id = %x", x->x_header.connection_id);
+ //pdp_post("size = %d", np->data_size);
+ //pdp_post("nb_chunks = %d", np->nb_chunks);
+ //pdp_post("chunk_size = %d", np->chunk_size);
+ //pdp_post("type = %s", np->type);
+
+ /* check if it is a resend of the PDP_UDP_NEW packet (if NEW_ACK didn't get through)
+ if not, prepare for reception */
+
+ if (x->x_connection_id != x->x_header.connection_id){
+
+
+ /* prepare for reception : TODO add some more checks here */
+
+ // setup type info
+ if (x->x_data_type) pdp_dealloc (x->x_data_type);
+ x->x_data_type = pdp_alloc(1 + strlen(np->type));
+ strcpy(x->x_data_type, np->type);
+
+ // setup data buffer
+ x->x_data_size = np->data_size;
+ if (x->x_data) pdp_dealloc (x->x_data);
+ x->x_data = pdp_alloc(x->x_data_size);
+ memset(x->x_data, 0, x->x_data_size); // clear for debug
+
+ // setup connection info
+ x->x_connection_id = x->x_header.connection_id;
+ x->x_nb_chunks = np->nb_chunks;
+ x->x_chunk_size = np->chunk_size;
+
+ /* setup chunk list */
+ if (x->x_chunk_list) pdp_dealloc(x->x_chunk_list);
+ x->x_chunk_list = pdp_alloc(sizeof(unsigned int)*x->x_nb_chunks);
+ memset(x->x_chunk_list, 0, sizeof(unsigned int)*x->x_nb_chunks);
+
+ x->x_receive_finished = 0; // we're in a receiving state
+ x->x_packet_transferred = 0; // we didn't pass the packet yet
+ }
+
+ /* send ACK */
+ _send_ack_new(x);
+
+
+
+ return 1;
+}
+
+static void _handle_PDP_UDP_DONE(t_pdp_udp_receiver *x)
+{
+ unsigned int chunk;
+ unsigned int missing;
+ unsigned int i;
+ unsigned int resend_packet_size;
+
+
+ /* check the connection id */
+ if (x->x_connection_id != x->x_header.connection_id) return;
+
+ /* determine how many packets are missing */
+ missing = 0;
+ for (i=0; i<x->x_nb_chunks; i++)
+ if (!x->x_chunk_list[i]) missing++;
+
+ D pdp_post ("last packet %x had %d/%d dropped chunks", x->x_connection_id, missing, x->x_nb_chunks);
+
+
+ /* build the resend request (chunk list )*/
+ if (missing > RESEND_MAX_CHUNKS) missing = RESEND_MAX_CHUNKS;
+ chunk = 0;
+ i = missing;
+ while(i--){
+ while (x->x_chunk_list[chunk]) chunk++; // find next missing chunk
+ x->x_resend_chunks[i] = chunk++; // store it in list
+ }
+
+ /* set the packet size to include the list */
+ x->x_resend_udp_packet_size = sizeof(t_pdp_udp_header)
+ + missing * sizeof(unsigned int);
+
+ /* setup resend header */
+ strcpy((char *)&x->x_resend_header, "PDP");
+ x->x_resend_header.version = PDP_UDP_VERSION;
+ x->x_resend_header.connection_id = x->x_connection_id;
+ x->x_resend_header.sequence_number = PDP_UDP_RESEND;
+
+ D pdp_post("pdp_netreceive: sending RESEND response for %u chunks", missing);
+
+ /* send out */
+ _send_packet(x);
+
+ /* indicate we're done if there's no chunks missing */
+ if (!missing) x->x_receive_finished = 1;
+
+}
+
+
+static int _handle_UDP_DATA(t_pdp_udp_receiver *x)
+{
+ unsigned int seq = x->x_header.sequence_number;
+ unsigned int offset = x->x_chunk_size * seq;
+
+ /* ignore the packet if we're not expecting it */
+ if ((!x->x_connection_id) || (x->x_connection_id != x->x_header.connection_id)){
+ //pdp_post("pdp_netreceive: got invalid data packet: transmission id %x is not part of current transmisson %x",
+ // x->x_header.connection_id, x->x_connection_id);
+ return 0;
+ }
+
+ /* check if it is valid */
+ if (seq >= x->x_nb_chunks){
+ pdp_post("pdp_netreceive: got invalid data packet: sequence number %u out of bound (nb_chunks=%u)",
+ seq, x->x_nb_chunks);
+ return 0;
+ }
+
+ /* final check */
+ PDP_ASSERT(offset + x->x_buf_size <= x->x_data_size);
+
+ /* write & log it */
+ memcpy(x->x_data + offset, x->x_buf, x->x_buf_size);
+ x->x_chunk_list[seq] = 1;
+ return 1;
+
+}
+
+/* INTERFACE */
+
+/* setup */
+t_pdp_udp_receiver *pdp_udp_receiver_new(int port)
+{
+ t_pdp_udp_receiver *x = pdp_alloc(sizeof(*x));
+ memset(x, 0, sizeof(*x));
+
+ /* init */
+ x->x_data = 0;
+ x->x_data_type = 0;
+ x->x_data_size = 0;
+ x->x_chunk_list = 0;
+ x->x_receive_finished = 0;
+ x->x_packet_transferred = 0;
+ x->x_zero_terminator = 0;
+
+ x->x_socket = socket(PF_INET, SOCK_DGRAM, 0);
+ x->x_connection_id = 0; /* zero for bootstrap (0 == an invalid id) */
+ x->x_sslen = sizeof(struct sockaddr_in);
+
+ /* bind socket */
+ x->x_sa.sin_port = htons(port);
+ x->x_sa.sin_addr.s_addr = 0;
+ if (-1 != bind (x->x_socket, (struct sockaddr *)&x->x_sa,
+ sizeof(struct sockaddr_in))) return x;
+
+ /* suicide if find failed */
+ else {
+ pdp_dealloc(x);
+ return 0;
+ }
+}
+void pdp_udp_receiver_free(t_pdp_udp_receiver *x)
+{
+ if (!x) return;
+ if (x->x_socket != 1) close (x->x_socket);
+ if (x->x_data) pdp_dealloc(x->x_data);
+ if (x->x_data_type) pdp_dealloc (x->x_data_type);
+ if (x->x_chunk_list) pdp_dealloc (x->x_chunk_list);
+}
+
+void pdp_udp_receiver_reset(t_pdp_udp_receiver *x)
+{
+ x->x_connection_id = 0;
+}
+
+
+/* receive loop, returns 1 on success, -1 on error, 0 on timeout */
+int pdp_udp_receiver_receive(t_pdp_udp_receiver *x, unsigned int timeout_ms)
+{
+ /* listen for packets */
+
+ unsigned int size;
+ struct timeval tv = {0,1000 * timeout_ms};
+ fd_set inset;
+ FD_ZERO(&inset);
+ FD_SET(x->x_socket, &inset);
+ switch(select (x->x_socket+1, &inset, NULL, NULL, &tv)){
+ case -1:
+ return -1; /* select error */
+ case 0:
+ return 0; /* select time out */
+ default:
+ break; /* data ready */
+ }
+
+ /* this won't block, since there's data available */
+ if (-1 == (int)(size = recvfrom(x->x_socket, (void *)&x->x_header,
+ PDP_UDP_BUFSIZE+sizeof(x->x_header), 0,
+ (struct sockaddr *)&x->x_source_socket, &x->x_sslen))) return -1;
+
+ /* store the data size of the packet */
+ x->x_buf_size = size - sizeof(t_pdp_udp_header);
+
+ /* parse the udp packet */
+ if (_is_udp_header(&x->x_header, size)){
+
+ /* it is a control packet */
+ if ((int)x->x_header.sequence_number < 0){
+
+ switch (x->x_header.sequence_number){
+ case PDP_UDP_NEW:
+ _handle_PDP_UDP_NEW(x);
+ break;
+
+ case PDP_UDP_DONE:
+ _handle_PDP_UDP_DONE(x);
+
+ /* check if we got a complete packet
+ and signal arrival if we haven't done this already */
+ if (x->x_receive_finished && !x->x_packet_transferred){
+ x->x_packet_transferred = 1;
+ return 1; // data complete, please receive
+ }
+ break;
+
+ default:
+ pdp_post("got unknown msg");
+ break;
+ }
+ }
+
+ /* it is a data packet */
+ else {
+ _handle_UDP_DATA(x);
+ }
+
+
+ }
+
+ else {
+ pdp_post("pdp_netreceive: got invalid UDP packet (size = %d)", size);
+ }
+
+ return 0; //no major event, please poll again
+
+}
+
+/* get meta & data */
+char *pdp_udp_receiver_type(t_pdp_udp_receiver *x){return x->x_data_type;}
+unsigned int pdp_udp_receiver_size(t_pdp_udp_receiver *x){return x->x_data_size;}
+void *pdp_udp_receiver_data(t_pdp_udp_receiver *x){return x->x_data;}
+
+
+/* S E N D E R */
+
+/* INTERNALS */
+
+static void _sleep(t_pdp_udp_sender *x)
+{
+ int sleep_period = x->x_sleep_period;
+
+ if (sleep_period) {
+ if (!x->x_sleep_count++) usleep(x->x_sleepgrain_us);
+ x->x_sleep_count %= sleep_period;
+ }
+}
+
+static void _send(t_pdp_udp_sender *x)
+{
+ //post("sending %u data bytes", x->x_buf_size);
+
+ _make_udp_header(&x->x_header);
+
+ PDP_ASSERT (x->x_buf_size <= PDP_UDP_BUFSIZE);
+
+ if (-1 == sendto (x->x_socket, &x->x_header, x->x_buf_size + sizeof(t_pdp_udp_header),
+ 0, (struct sockaddr *)&x->x_sa, sizeof(struct sockaddr_in)))
+ pdp_post("pdp_netsend: send FAILED");
+
+ _sleep(x);
+
+}
+
+
+static void _prepare_for_new_transmission(t_pdp_udp_sender *x, char *type, unsigned int size, void *data)
+{
+ unsigned int i;
+
+ /* setup data for transmission */
+ x->x_data_type = type;
+ x->x_data_size = size;
+ x->x_data = data;
+ x->x_chunk_size = x->x_udp_payload_size;
+ x->x_nb_chunks = (x->x_data_size - 1) / x->x_chunk_size + 1;
+
+ /* generate a connection id (non-zero) */
+ while (!(x->x_connection_id = rand()));
+
+ /* setup chunk list to contain all chunks */
+ if (x->x_chunk_list) free (x->x_chunk_list);
+ x->x_chunk_list_size = x->x_nb_chunks;
+ x->x_chunk_list = malloc(sizeof(unsigned int)*x->x_chunk_list_size);
+ for (i=0; i<x->x_chunk_list_size; i++) x->x_chunk_list[i] = i;
+
+}
+
+static void _send_header_packet(t_pdp_udp_sender *x)
+{
+ t_pdp_udp_newpacket *np = (t_pdp_udp_newpacket *)x->x_buf; /* buf contains the PDP_UDP_NEW body */
+
+ /* init packet */
+ x->x_header.sequence_number = PDP_UDP_NEW;
+ x->x_header.connection_id = x->x_connection_id;
+ np->data_size = x->x_data_size;
+ np->nb_chunks = x->x_nb_chunks;
+ np->chunk_size = x->x_chunk_size;
+ strcpy(np->type, x->x_data_type);
+ x->x_buf_size = sizeof(*np) + strlen(np->type) + 1;
+ PDP_ASSERT(x->x_buf_size <= PDP_UDP_BUFSIZE);
+
+ /* send the packet */
+ _send(x);
+}
+
+/* saend the chunks in the chunk list */
+static void _send_chunks(t_pdp_udp_sender *x){
+ unsigned int i;
+ unsigned int count = 0;
+
+ /* send chunks: this requires header is setup ok (sig,ver,connid)*/
+ for (i=0; i<x->x_chunk_list_size; i++){
+ unsigned int offset;
+ unsigned int current_chunk_size;
+ unsigned int seq = x->x_chunk_list[i];
+
+ PDP_ASSERT(seq < x->x_nb_chunks);
+ x->x_header.sequence_number = seq; // store chunk number
+
+ /* get current chunk offset */
+ offset = seq * x->x_chunk_size;
+ PDP_ASSERT(offset < x->x_data_size);
+
+
+ /* get current chunk size */
+ current_chunk_size = (offset + x->x_chunk_size > x->x_data_size) ?
+ (x->x_data_size - offset) : x->x_chunk_size;
+ x->x_buf_size = current_chunk_size;
+ PDP_ASSERT(x->x_buf_size <= PDP_UDP_BUFSIZE);
+
+ /* copy chunk to transmission buffer & send */
+ PDP_ASSERT(offset + current_chunk_size <= x->x_data_size);
+ memcpy(x->x_buf, x->x_data + offset, current_chunk_size);
+
+
+ /* send the chunk */
+ _send(x);
+ count++;
+
+ }
+ D pdp_post("sent %d chunks, id=%x", count,x->x_connection_id);
+}
+
+/* send a DONE packet */
+static void _send_done(t_pdp_udp_sender *x){
+ x->x_header.sequence_number = PDP_UDP_DONE;
+ x->x_buf_size = 0;
+ _send(x);
+}
+static int _receive_packet(t_pdp_udp_sender *x, int desired_type)
+/* 0 == timeout, -1 == error, 1 == got packet */
+{
+ unsigned int size;
+ int type;
+
+ struct timeval tv;
+ fd_set inset;
+ int sr;
+
+
+ while (1){
+ int retval;
+
+ /* wait for incoming */
+ tv.tv_sec = 0;
+ tv.tv_usec = x->x_timeout_us;
+ FD_ZERO(&inset);
+ FD_SET(x->x_socket, &inset);
+ switch (select (x->x_socket+1, &inset, NULL, NULL, &tv)){
+ case -1:
+ return -1; /* select error */
+ case 0:
+ return 0; /* select time out */
+ default:
+ break; /* data ready */
+ }
+
+ /* read packet */
+ if (-1 == (int)(size = recv(x->x_socket, (void *)&x->x_resend_header, MAX_UDP_PACKET, 0))){
+ pdp_post("pdp_netsend: error while reading from socket");
+ return -1;
+ }
+
+ /* check if it is a valid PDP_UDP packet */
+ if (!_is_udp_header(&x->x_resend_header, size)){
+ pdp_post("pdp_netsend: ignoring invalid UDP packet (size = %u)", size);
+ continue;
+ }
+
+
+ /* check connection id */
+ if (x->x_connection_id != x->x_resend_header.connection_id){
+ D pdp_post("pdp_netsend: ignoring ghost packet id=%x, current id=%x",
+ x->x_resend_header.connection_id, x->x_connection_id);
+ continue;
+ }
+
+ /* check type */
+ type = x->x_resend_header.sequence_number;
+ if (type != desired_type) continue;
+
+
+ /* setup data buffer for known packets */
+ switch(type){
+ case PDP_UDP_RESEND:
+ x->x_resend_items = (size - sizeof(t_pdp_udp_header)) / sizeof(unsigned int);
+ break;
+ default:
+ break;
+ }
+
+ return 1;
+ }
+
+}
+
+/* get the resend list */
+static int _need_resend(t_pdp_udp_sender *x) {
+
+ int retries = 3;
+ int retval;
+ while (retries--){
+
+ /* send a DONE msg */
+ _send_done(x);
+
+ /* wait for ACK */
+ switch(_receive_packet(x, PDP_UDP_RESEND)){
+ case 0:
+ /* timeout, retry */
+ continue;
+ case -1:
+ /* error */
+ goto move_on;
+
+ default:
+ /* got PDP_UDP_RESEND packet: setup resend list */
+ if (x->x_resend_items > x->x_nb_chunks){
+ pdp_post("pdp_netsend: WARNING: chunk list size (%d) is too big, ignoring RESEND request",
+ x->x_resend_items);
+ x->x_resend_items = 0;
+ continue;
+ }
+ x->x_chunk_list_size = x->x_resend_items;
+
+ memcpy(x->x_chunk_list, x->x_resend_chunks, sizeof(unsigned int) * x->x_resend_items);
+ D pdp_post("got RESEND request for %d chunks (id %x)", x->x_resend_items,x->x_connection_id);
+
+ return x->x_chunk_list_size > 0;
+ }
+
+ }
+
+ /* timeout */
+ move_on:
+ x->x_chunk_list_size = 0;
+ return 0;
+
+
+}
+
+
+/* INTERFACE */
+
+
+/* some flow control hacks */
+
+void pdp_udp_sender_timeout_us(t_pdp_udp_sender *x, unsigned int timeout_us)
+{
+ x->x_timeout_us = timeout_us;
+}
+
+
+void pdp_udp_sender_sleepgrain_us(t_pdp_udp_sender *x, unsigned int sleepgrain_us)
+{
+ x->x_sleepgrain_us = sleepgrain_us;
+}
+
+void pdp_udp_sender_sleepperiod(t_pdp_udp_sender *x, unsigned int sleepperiod)
+{
+ x->x_sleep_period = sleepperiod;
+}
+
+
+void pdp_udp_sender_udp_packet_size(t_pdp_udp_sender *x, unsigned int udp_packet_size)
+{
+ int i = (int)udp_packet_size - sizeof(t_pdp_udp_header);
+ if (i < 1024) i = 1024;
+ if (i > PDP_UDP_BUFSIZE) i = PDP_UDP_BUFSIZE;
+ x->x_udp_payload_size = i;
+}
+
+void pdp_udp_sender_connect(t_pdp_udp_sender *x, char *host, unsigned int port)
+{
+ struct hostent *hp;
+
+ hp = gethostbyname(host);
+ if (!hp){
+ pdp_post("pdp_udp_sender: host %s not found", host);
+ }
+ else{
+ /* host ok, setup address */
+ x->x_sa.sin_family = AF_INET;
+ x->x_sa.sin_port = htons(port);
+ memcpy((char *)&x->x_sa.sin_addr, (char *)hp->h_addr, hp->h_length);
+
+ /* create the a socket if necessary */
+ if (x->x_socket == -1){
+ if (-1 == (x->x_socket = socket(PF_INET, SOCK_DGRAM, 0))){
+ pdp_post("pdp_udp_sender: can't create socket");
+ }
+ if (1){
+ int on = 1;
+ if (setsockopt(x->x_socket,SOL_SOCKET,SO_BROADCAST,(char *)&on,sizeof(on))<0)
+ pdp_post("pdp_udp_sender: can't set broadcast flag");
+ }
+ }
+ }
+}
+
+/* setup */
+t_pdp_udp_sender *pdp_udp_sender_new(void)
+{
+ t_pdp_udp_sender *x = pdp_alloc(sizeof(*x));
+ memset(x,0,sizeof(*x));
+
+ x->x_chunk_list = 0;
+
+ /* no connection */
+ x->x_socket = -1;
+
+
+ /* set flow control */
+ pdp_udp_sender_timeout_us(x, 50000);
+ x->x_sleep_count = 0;
+ pdp_udp_sender_sleepgrain_us(x, 0);
+ pdp_udp_sender_sleepperiod(x, 50);
+ pdp_udp_sender_udp_packet_size(x, 1472); //optimal udp packet size (ip: 1500 = 28 + 1472)
+
+
+ return x;
+}
+
+void pdp_udp_sender_free(t_pdp_udp_sender *x)
+{
+ int i;
+ void* retval;
+ if (x->x_socket != -1) close(x->x_socket);
+ if (x->x_chunk_list) free (x->x_chunk_list);
+}
+
+/* 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)
+{
+
+ /* SEND A PACKET */
+
+ /* get the type and data from caller */
+ /* send header packet and make sure it has arrived */
+ /* send a chunk burst */
+ /* send done packet and get the resend list */
+ /* repeat until send list is empty */
+
+
+ int hs_retry = 5; // retry count for initial handshake
+ int rs_retry = 5; // retry count for resends
+
+ /* check if we have a target */
+ if (-1 == x->x_socket) goto transerror;
+
+ /* setup internal state */
+ _prepare_for_new_transmission(x,type,size,data);
+
+ /* handshake a new transmission */
+ do {
+ if (!(hs_retry--)) break;
+ // pdp_post("handshake retry %d for packet %x", hscount, x->x_connection_id);
+ _send_header_packet(x);
+ } while (!_receive_packet(x, PDP_UDP_ACKNEW));
+
+
+ /* exit if no handshake was possible */
+ if (hs_retry < 0){
+ DD pdp_post("pdp_netsend: DROP: receiver does not accept new transmission");
+ goto transerror;
+ }
+
+ /* transmission loop */
+ do {
+ if (!(rs_retry--)) break;
+ _send_chunks(x);
+ } while (_need_resend(x));
+
+ /* exit if transmission was not successful */
+ if (rs_retry < 0){
+ DD pdp_post("pdp_netsend: DROP: receiver did not confirm reception");
+ goto transerror;
+ }
+
+ /* send successful */
+ return 1;
+
+ transerror:
+ /* transmission error */
+ return 0;
+}