--- /dev/null
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <byteswap.h>
+#include <ipxe/iobuf.h>
+#include <ipxe/tables.h>
+#include <ipxe/ipstat.h>
+#include <ipxe/netdevice.h>
+#include <ipxe/tcpip.h>
+
+/** @file
+ *
+ * Transport-network layer interface
+ *
+ * This file contains functions and utilities for the
+ * TCP/IP transport-network layer interface
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+/**
+ * Process a received TCP/IP packet
+ *
+ * @v iobuf I/O buffer
+ * @v netdev Network device
+ * @v tcpip_proto Transport-layer protocol number
+ * @v st_src Partially-filled source address
+ * @v st_dest Partially-filled destination address
+ * @v pshdr_csum Pseudo-header checksum
+ * @v stats IP statistics
+ * @ret rc Return status code
+ *
+ * This function expects a transport-layer segment from the network
+ * layer. The network layer should fill in as much as it can of the
+ * source and destination addresses (i.e. it should fill in the
+ * address family and the network-layer addresses, but leave the ports
+ * and the rest of the structures as zero).
+ */
+int tcpip_rx ( struct io_buffer *iobuf, struct net_device *netdev,
+ uint8_t tcpip_proto, struct sockaddr_tcpip *st_src,
+ struct sockaddr_tcpip *st_dest, uint16_t pshdr_csum,
+ struct ip_statistics *stats ) {
+ struct tcpip_protocol *tcpip;
+
+ /* Hand off packet to the appropriate transport-layer protocol */
+ for_each_table_entry ( tcpip, TCPIP_PROTOCOLS ) {
+ if ( tcpip->tcpip_proto == tcpip_proto ) {
+ DBG ( "TCP/IP received %s packet\n", tcpip->name );
+ stats->in_delivers++;
+ return tcpip->rx ( iobuf, netdev, st_src, st_dest,
+ pshdr_csum );
+ }
+ }
+
+ DBG ( "Unrecognised TCP/IP protocol %d\n", tcpip_proto );
+ stats->in_unknown_protos++;
+ free_iob ( iobuf );
+ return -EPROTONOSUPPORT;
+}
+
+/**
+ * Find TCP/IP network-layer protocol
+ *
+ * @v st_dest Destination address
+ * @ret tcpip_net TCP/IP network-layer protocol, or NULL if not found
+ */
+static struct tcpip_net_protocol *
+tcpip_net_protocol ( struct sockaddr_tcpip *st_dest ) {
+ struct tcpip_net_protocol *tcpip_net;
+
+ for_each_table_entry ( tcpip_net, TCPIP_NET_PROTOCOLS ) {
+ if ( tcpip_net->sa_family == st_dest->st_family )
+ return tcpip_net;
+ }
+
+ DBG ( "Unrecognised TCP/IP address family %d\n", st_dest->st_family );
+ return NULL;
+}
+
+/**
+ * Transmit a TCP/IP packet
+ *
+ * @v iobuf I/O buffer
+ * @v tcpip_protocol Transport-layer protocol
+ * @v st_src Source address, or NULL to use route default
+ * @v st_dest Destination address
+ * @v netdev Network device to use if no route found, or NULL
+ * @v trans_csum Transport-layer checksum to complete, or NULL
+ * @ret rc Return status code
+ */
+int tcpip_tx ( struct io_buffer *iobuf, struct tcpip_protocol *tcpip_protocol,
+ struct sockaddr_tcpip *st_src, struct sockaddr_tcpip *st_dest,
+ struct net_device *netdev, uint16_t *trans_csum ) {
+ struct tcpip_net_protocol *tcpip_net;
+
+ /* Hand off packet to the appropriate network-layer protocol */
+ tcpip_net = tcpip_net_protocol ( st_dest );
+ if ( tcpip_net ) {
+ DBG ( "TCP/IP sending %s packet\n", tcpip_net->name );
+ return tcpip_net->tx ( iobuf, tcpip_protocol, st_src, st_dest,
+ netdev, trans_csum );
+ }
+
+ free_iob ( iobuf );
+ return -EAFNOSUPPORT;
+}
+
+/**
+ * Determine transmitting network device
+ *
+ * @v st_dest Destination address
+ * @ret netdev Network device, or NULL
+ */
+struct net_device * tcpip_netdev ( struct sockaddr_tcpip *st_dest ) {
+ struct tcpip_net_protocol *tcpip_net;
+
+ /* Hand off to the appropriate network-layer protocol */
+ tcpip_net = tcpip_net_protocol ( st_dest );
+ if ( tcpip_net )
+ return tcpip_net->netdev ( st_dest );
+
+ return NULL;
+}
+
+/**
+ * Determine maximum transmission unit
+ *
+ * @v st_dest Destination address
+ * @ret mtu Maximum transmission unit
+ */
+size_t tcpip_mtu ( struct sockaddr_tcpip *st_dest ) {
+ struct tcpip_net_protocol *tcpip_net;
+ struct net_device *netdev;
+ size_t mtu;
+
+ /* Find appropriate network-layer protocol */
+ tcpip_net = tcpip_net_protocol ( st_dest );
+ if ( ! tcpip_net )
+ return 0;
+
+ /* Find transmitting network device */
+ netdev = tcpip_net->netdev ( st_dest );
+ if ( ! netdev )
+ return 0;
+
+ /* Calculate MTU */
+ mtu = ( netdev->max_pkt_len - netdev->ll_protocol->ll_header_len -
+ tcpip_net->header_len );
+
+ return mtu;
+}
+
+/**
+ * Calculate continued TCP/IP checkum
+ *
+ * @v partial Checksum of already-summed data, in network byte order
+ * @v data Data buffer
+ * @v len Length of data buffer
+ * @ret cksum Updated checksum, in network byte order
+ *
+ * Calculates a TCP/IP-style 16-bit checksum over the data block. The
+ * checksum is returned in network byte order.
+ *
+ * This function may be used to add new data to an existing checksum.
+ * The function assumes that both the old data and the new data start
+ * on even byte offsets; if this is not the case then you will need to
+ * byte-swap either the input partial checksum, the output checksum,
+ * or both. Deciding which to swap is left as an exercise for the
+ * interested reader.
+ */
+uint16_t generic_tcpip_continue_chksum ( uint16_t partial,
+ const void *data, size_t len ) {
+ unsigned int cksum = ( ( ~partial ) & 0xffff );
+ unsigned int value;
+ unsigned int i;
+
+ for ( i = 0 ; i < len ; i++ ) {
+ value = * ( ( uint8_t * ) data + i );
+ if ( i & 1 ) {
+ /* Odd bytes: swap on little-endian systems */
+ value = be16_to_cpu ( value );
+ } else {
+ /* Even bytes: swap on big-endian systems */
+ value = le16_to_cpu ( value );
+ }
+ cksum += value;
+ if ( cksum > 0xffff )
+ cksum -= 0xffff;
+ }
+
+ return ( ~cksum );
+}
+
+/**
+ * Calculate TCP/IP checkum
+ *
+ * @v data Data buffer
+ * @v len Length of data buffer
+ * @ret cksum Checksum, in network byte order
+ *
+ * Calculates a TCP/IP-style 16-bit checksum over the data block. The
+ * checksum is returned in network byte order.
+ */
+uint16_t tcpip_chksum ( const void *data, size_t len ) {
+ return tcpip_continue_chksum ( TCPIP_EMPTY_CSUM, data, len );
+}
+
+/**
+ * Bind to local TCP/IP port
+ *
+ * @v st_local Local TCP/IP socket address, or NULL
+ * @v available Function to check port availability
+ * @ret port Local port number, or negative error
+ */
+int tcpip_bind ( struct sockaddr_tcpip *st_local,
+ int ( * available ) ( int port ) ) {
+ uint16_t flags = 0;
+ uint16_t try_port = 0;
+ uint16_t min_port;
+ uint16_t max_port;
+ unsigned int offset;
+ unsigned int i;
+
+ /* Extract parameters from local socket address */
+ if ( st_local ) {
+ flags = st_local->st_flags;
+ try_port = ntohs ( st_local->st_port );
+ }
+
+ /* If an explicit port is specified, check its availability */
+ if ( try_port )
+ return available ( try_port );
+
+ /* Otherwise, find an available port in the range [1,1023] or
+ * [1025,65535] as appropriate.
+ */
+ min_port = ( ( ( ! flags ) & TCPIP_BIND_PRIVILEGED ) + 1 );
+ max_port = ( ( flags & TCPIP_BIND_PRIVILEGED ) - 1 );
+ offset = random();
+ for ( i = 0 ; i <= max_port ; i++ ) {
+ try_port = ( ( i + offset ) & max_port );
+ if ( try_port < min_port )
+ continue;
+ if ( available ( try_port ) < 0 )
+ continue;
+ return try_port;
+ }
+ return -EADDRINUSE;
+}
Code Review / kvmfornfv.git / blobdiff