#include <stdint.h>
#include <string.h>
#include <assert.h>
#include <byteswap.h>
#include <latch.h>
#include <errno.h>
#include <gpxe/in.h>
#include <gpxe/ip.h>
#include <gpxe/udp.h>
#include <gpxe/init.h>
#include <gpxe/pkbuff.h>
#include <gpxe/netdevice.h>
#include <gpxe/interface.h>
/** @file
*
* UDP protocol
*/
void copy_sockaddr ( struct sockaddr *source, struct sockaddr *dest );
/**
* Open a UDP connection
*
* @v conn UDP connection
* @v peer Destination socket address
*
* This function stores the socket address within the connection
*/
void udp_connect ( struct udp_connection *conn, struct sockaddr *peer ) {
copy_sockaddr ( peer, &conn->sin );
/**
* Not sure if this should add the connection to udp_conns; If it does, uncomment the following code
*/
// list_add ( &conn->list, &udp_conns );
}
/**
* Initialize a UDP connection
*
* @v conn UDP connection
* @v udp_op UDP operations
*/
void udp_init ( struct udp_connection *conn, struct udp_operations *udp_op ) {
conn->local_port = 0;
conn->tx_pkb = NULL;
if ( udp_op != NULL ) {
conn->udp_op = udp_op;
}
}
/**
* Allocate space to the UDP buffer
*
* @v conn UDP connection
* @v len Length to allocate
* @ret rc Status
*
* Allocate "len" amount of space in the transmit buffer
*/
int udp_buf_alloc ( struct udp_connection *conn, size_t len ) {
if ( conn->tx_pkb != NULL ) {
free_pkb ( conn->tx_pkb );
conn->tx_pkb = NULL;
}
conn->tx_pkb = alloc_pkb ( len < UDP_MIN_TXPKB ? UDP_MIN_TXPKB : len );
return !conn ? -ENOMEM : 0;
}
/**
* Send data via a UDP connection
*
* @v conn UDP connection
* @v data Data to send
* @v len Length of data
*
* This function fills up the UDP headers and sends the data. Discover the network protocol to
* use through the sa_family field in the destination socket address.
*/
int udp_send ( struct udp_connection *conn, const void *data, size_t len ) {
struct udp_header *udphdr; /* UDP header */
struct sockaddr *sock = &conn->sin; /* Destination sockaddr */
int rc;
/* Copy data into packet buffer if necessary */
if ( data != conn->tx_pkb->data ) {
/* Allocate a buffer */
if ( ( rc = udp_buf_alloc ( conn, len + UDP_MAX_HLEN ) ) != 0 ) {
DBG ( "Error allocating buffer" );
return rc;
}
/* Reserve space for the headers and copy contents */
pkb_reserve ( conn->tx_pkb, UDP_MAX_HLEN );
memcpy ( pkb_put ( conn->tx_pkb, len ), data, len );
}
/* Add the UDP header */
udphdr = pkb_push ( conn->tx_pkb, UDP_HLEN );
if ( sock->sa_family == AF_INET )
udphdr->dest_port = sock->sin.sin_port;
else
udphdr->dest_port = sock->sin6.sin6_port;
udphdr->source_port = conn->local_port;
udphdr->len = htons ( pkb_len ( conn->tx_pkb ) );
udphdr->chksum = calc_chksum ( udphdr, UDP_HLEN );
/* Print UDP header for debugging */
DBG ( "UDP header at %#x + %d\n", udphdr, UDP_HDR_LEN );
DBG ( "\tSource Port = %d\n", udphdr->source_port );
DBG ( "\tDestination Port = %d\n", udphdr->dest_port );
DBG ( "\tLength = %d\n", udphdr->len );
DBG ( "\tChecksum = %d\n", udphdr->chksum );
DBG ( "\tChecksum located at %#x\n", &udphdr->chksum );
return trans_tx ( conn->tx_pkb, IP_UDP, sock );
}
/**
* Send data to a specified address
*
* @v conn UDP connection
* @v peer Destination address
* @v data Data to send
* @v len Length of data
*/
int udp_sendto ( struct udp_connection *conn, struct sockaddr *peer,
const void *data, size_t len ) {
struct sockaddr tempsock;
copy_sockaddr ( &conn->sin, &tempsock );
copy_sockaddr ( peer, &conn->sin );
int rc = udp_send ( conn, data, len );
copy_sockaddr ( &tempsock, &conn->sin );
return rc;
}
/**
* Close a UDP connection
*
* @v conn UDP connection
*/
void udp_close ( struct udp_connection *conn ) {
list_del ( &conn->list );
}
/**
* Open a local port
*
* @v conn UDP connection
* @v local_port Local port on which to open connection
*
* This does not support the 0 port option correctly yet
*/
int udp_open ( struct udp_connection *conn, uint16_t local_port ) {
struct udp_connection *connr;
uint16_t min_port = 0xffff;
list_for_each_entry ( connr, &udp_conns, list ) {
if ( connr->local_port == local_port ) {
return -EISCONN; /* CHECK THE ERROR NUMBER */
}
if ( min_port > connr->local_port ) {
min_port = connr->local_port;
}
}
conn->local_port = local_port == 0 ? min_port > 1024 ? 1024 : min_port + 1 : local_port; // FAULTY!!!
list_add ( &conn->list, &udp_conns );
return 0;
}
/**
* Process a received packet
*
* @v pkb Packet buffer
* @v src_net_addr Source network address
* @v dest_net_addr Destination network address
*/
void udp_rx ( struct pk_buff *pkb, struct in_addr *src_net_addr __unused,
struct in_addr *dest_net_addr __unused ) {
struct udp_header *udphdr = pkb->data;
struct udp_connection *conn;
/* todo: Compute and verify checksum */
/* Print UDP header for debugging */
DBG ( "UDP header at %#x + %d\n", udphdr, UDP_HDR_LEN );
DBG ( "\tSource Port = %d\n", udphdr->source_port );
DBG ( "\tDestination Port = %d\n", udphdr->dest_port );
DBG ( "\tLength = %d\n", udphdr->len );
DBG ( "\tChecksum = %d\n", udphdr->chksum );
DBG ( "\tChecksum located at %#x\n", &udphdr->chksum );
/* Demux the connection */
list_for_each_entry ( conn, &udp_conns, list ) {
if ( conn->local_port == udphdr->dest_port ) {
goto conn;
}
}
return;
conn:
/** Strip off the UDP header */
pkb_pull ( pkb, UDP_HLEN );
/** Allocate max possible buffer space to the tx buffer */
conn->tx_pkb = alloc_pkb ( UDP_MAX_TXPKB );
pkb_reserve ( conn->tx_pkb, UDP_MAX_HLEN );
/** Call the application's callback */
conn->udp_op->newdata ( conn, pkb->data, ntohs ( udphdr->len ) - UDP_HLEN );
}
struct trans_protocol udp_protocol = {
.name = "UDP",
.rx = udp_rx,
.trans_proto = IP_UDP,
};
TRANS_PROTOCOL ( udp_protocol );
/**
* Internal functions
*/
void copy_sockaddr ( struct sockaddr *source, struct sockaddr *dest ) {
memcpy ( dest, source, sizeof ( struct sockaddr ) );
}
