--- /dev/null
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <byteswap.h>
+#include <errno.h>
+#include <ipxe/tcpip.h>
+#include <ipxe/iobuf.h>
+#include <ipxe/xfer.h>
+#include <ipxe/open.h>
+#include <ipxe/uri.h>
+#include <ipxe/netdevice.h>
+#include <ipxe/udp.h>
+
+/** @file
+ *
+ * UDP protocol
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+/**
+ * A UDP connection
+ *
+ */
+struct udp_connection {
+ /** Reference counter */
+ struct refcnt refcnt;
+ /** List of UDP connections */
+ struct list_head list;
+
+ /** Data transfer interface */
+ struct interface xfer;
+
+ /** Local socket address */
+ struct sockaddr_tcpip local;
+ /** Remote socket address */
+ struct sockaddr_tcpip peer;
+};
+
+/**
+ * List of registered UDP connections
+ */
+static LIST_HEAD ( udp_conns );
+
+/* Forward declatations */
+static struct interface_descriptor udp_xfer_desc;
+struct tcpip_protocol udp_protocol __tcpip_protocol;
+
+/**
+ * Check if local UDP port is available
+ *
+ * @v port Local port number
+ * @ret port Local port number, or negative error
+ */
+static int udp_port_available ( int port ) {
+ struct udp_connection *udp;
+
+ list_for_each_entry ( udp, &udp_conns, list ) {
+ if ( udp->local.st_port == htons ( port ) )
+ return -EADDRINUSE;
+ }
+ return port;
+}
+
+/**
+ * Open a UDP connection
+ *
+ * @v xfer Data transfer interface
+ * @v peer Peer socket address, or NULL
+ * @v local Local socket address, or NULL
+ * @v promisc Socket is promiscuous
+ * @ret rc Return status code
+ */
+static int udp_open_common ( struct interface *xfer,
+ struct sockaddr *peer, struct sockaddr *local,
+ int promisc ) {
+ struct sockaddr_tcpip *st_peer = ( struct sockaddr_tcpip * ) peer;
+ struct sockaddr_tcpip *st_local = ( struct sockaddr_tcpip * ) local;
+ struct udp_connection *udp;
+ int port;
+ int rc;
+
+ /* Allocate and initialise structure */
+ udp = zalloc ( sizeof ( *udp ) );
+ if ( ! udp )
+ return -ENOMEM;
+ DBGC ( udp, "UDP %p allocated\n", udp );
+ ref_init ( &udp->refcnt, NULL );
+ intf_init ( &udp->xfer, &udp_xfer_desc, &udp->refcnt );
+ if ( st_peer )
+ memcpy ( &udp->peer, st_peer, sizeof ( udp->peer ) );
+ if ( st_local )
+ memcpy ( &udp->local, st_local, sizeof ( udp->local ) );
+
+ /* Bind to local port */
+ if ( ! promisc ) {
+ port = tcpip_bind ( st_local, udp_port_available );
+ if ( port < 0 ) {
+ rc = port;
+ DBGC ( udp, "UDP %p could not bind: %s\n",
+ udp, strerror ( rc ) );
+ goto err;
+ }
+ udp->local.st_port = htons ( port );
+ DBGC ( udp, "UDP %p bound to port %d\n",
+ udp, ntohs ( udp->local.st_port ) );
+ }
+
+ /* Attach parent interface, transfer reference to connection
+ * list and return
+ */
+ intf_plug_plug ( &udp->xfer, xfer );
+ list_add ( &udp->list, &udp_conns );
+ return 0;
+
+ err:
+ ref_put ( &udp->refcnt );
+ return rc;
+}
+
+/**
+ * Open a UDP connection
+ *
+ * @v xfer Data transfer interface
+ * @v peer Peer socket address
+ * @v local Local socket address, or NULL
+ * @ret rc Return status code
+ */
+int udp_open ( struct interface *xfer, struct sockaddr *peer,
+ struct sockaddr *local ) {
+ return udp_open_common ( xfer, peer, local, 0 );
+}
+
+/**
+ * Open a promiscuous UDP connection
+ *
+ * @v xfer Data transfer interface
+ * @ret rc Return status code
+ *
+ * Promiscuous UDP connections are required in order to support the
+ * PXE API.
+ */
+int udp_open_promisc ( struct interface *xfer ) {
+ return udp_open_common ( xfer, NULL, NULL, 1 );
+}
+
+/**
+ * Close a UDP connection
+ *
+ * @v udp UDP connection
+ * @v rc Reason for close
+ */
+static void udp_close ( struct udp_connection *udp, int rc ) {
+
+ /* Close data transfer interface */
+ intf_shutdown ( &udp->xfer, rc );
+
+ /* Remove from list of connections and drop list's reference */
+ list_del ( &udp->list );
+ ref_put ( &udp->refcnt );
+
+ DBGC ( udp, "UDP %p closed\n", udp );
+}
+
+/**
+ * Transmit data via a UDP connection to a specified address
+ *
+ * @v udp UDP connection
+ * @v iobuf I/O buffer
+ * @v src Source address, or NULL to use default
+ * @v dest Destination address, or NULL to use default
+ * @v netdev Network device, or NULL to use default
+ * @ret rc Return status code
+ */
+static int udp_tx ( struct udp_connection *udp, struct io_buffer *iobuf,
+ struct sockaddr_tcpip *src, struct sockaddr_tcpip *dest,
+ struct net_device *netdev ) {
+ struct udp_header *udphdr;
+ size_t len;
+ int rc;
+
+ /* Check we can accommodate the header */
+ if ( ( rc = iob_ensure_headroom ( iobuf,
+ MAX_LL_NET_HEADER_LEN ) ) != 0 ) {
+ free_iob ( iobuf );
+ return rc;
+ }
+
+ /* Fill in default values if not explicitly provided */
+ if ( ! src )
+ src = &udp->local;
+ if ( ! dest )
+ dest = &udp->peer;
+
+ /* Add the UDP header */
+ udphdr = iob_push ( iobuf, sizeof ( *udphdr ) );
+ len = iob_len ( iobuf );
+ udphdr->dest = dest->st_port;
+ udphdr->src = src->st_port;
+ udphdr->len = htons ( len );
+ udphdr->chksum = 0;
+ udphdr->chksum = tcpip_chksum ( udphdr, len );
+
+ /* Dump debugging information */
+ DBGC2 ( udp, "UDP %p TX %d->%d len %d\n", udp,
+ ntohs ( udphdr->src ), ntohs ( udphdr->dest ),
+ ntohs ( udphdr->len ) );
+
+ /* Send it to the next layer for processing */
+ if ( ( rc = tcpip_tx ( iobuf, &udp_protocol, src, dest, netdev,
+ &udphdr->chksum ) ) != 0 ) {
+ DBGC ( udp, "UDP %p could not transmit packet: %s\n",
+ udp, strerror ( rc ) );
+ return rc;
+ }
+
+ return 0;
+}
+
+/**
+ * Identify UDP connection by local address
+ *
+ * @v local Local address
+ * @ret udp UDP connection, or NULL
+ */
+static struct udp_connection * udp_demux ( struct sockaddr_tcpip *local ) {
+ static const struct sockaddr_tcpip empty_sockaddr = { .pad = { 0, } };
+ struct udp_connection *udp;
+
+ list_for_each_entry ( udp, &udp_conns, list ) {
+ if ( ( ( udp->local.st_family == local->st_family ) ||
+ ( udp->local.st_family == 0 ) ) &&
+ ( ( udp->local.st_port == local->st_port ) ||
+ ( udp->local.st_port == 0 ) ) &&
+ ( ( memcmp ( udp->local.pad, local->pad,
+ sizeof ( udp->local.pad ) ) == 0 ) ||
+ ( memcmp ( udp->local.pad, empty_sockaddr.pad,
+ sizeof ( udp->local.pad ) ) == 0 ) ) ) {
+ return udp;
+ }
+ }
+ return NULL;
+}
+
+/**
+ * Process a received packet
+ *
+ * @v iobuf I/O buffer
+ * @v netdev Network device
+ * @v st_src Partially-filled source address
+ * @v st_dest Partially-filled destination address
+ * @v pshdr_csum Pseudo-header checksum
+ * @ret rc Return status code
+ */
+static int udp_rx ( struct io_buffer *iobuf,
+ struct net_device *netdev __unused,
+ struct sockaddr_tcpip *st_src,
+ struct sockaddr_tcpip *st_dest, uint16_t pshdr_csum ) {
+ struct udp_header *udphdr = iobuf->data;
+ struct udp_connection *udp;
+ struct xfer_metadata meta;
+ size_t ulen;
+ unsigned int csum;
+ int rc = 0;
+
+ /* Sanity check packet */
+ if ( iob_len ( iobuf ) < sizeof ( *udphdr ) ) {
+ DBG ( "UDP packet too short at %zd bytes (min %zd bytes)\n",
+ iob_len ( iobuf ), sizeof ( *udphdr ) );
+
+ rc = -EINVAL;
+ goto done;
+ }
+ ulen = ntohs ( udphdr->len );
+ if ( ulen < sizeof ( *udphdr ) ) {
+ DBG ( "UDP length too short at %zd bytes "
+ "(header is %zd bytes)\n", ulen, sizeof ( *udphdr ) );
+ rc = -EINVAL;
+ goto done;
+ }
+ if ( ulen > iob_len ( iobuf ) ) {
+ DBG ( "UDP length too long at %zd bytes (packet is %zd "
+ "bytes)\n", ulen, iob_len ( iobuf ) );
+ rc = -EINVAL;
+ goto done;
+ }
+ if ( udphdr->chksum ) {
+ csum = tcpip_continue_chksum ( pshdr_csum, iobuf->data, ulen );
+ if ( csum != 0 ) {
+ DBG ( "UDP checksum incorrect (is %04x including "
+ "checksum field, should be 0000)\n", csum );
+ rc = -EINVAL;
+ goto done;
+ }
+ }
+
+ /* Parse parameters from header and strip header */
+ st_src->st_port = udphdr->src;
+ st_dest->st_port = udphdr->dest;
+ udp = udp_demux ( st_dest );
+ iob_unput ( iobuf, ( iob_len ( iobuf ) - ulen ) );
+ iob_pull ( iobuf, sizeof ( *udphdr ) );
+
+ /* Dump debugging information */
+ DBGC2 ( udp, "UDP %p RX %d<-%d len %zd\n", udp,
+ ntohs ( udphdr->dest ), ntohs ( udphdr->src ), ulen );
+
+ /* Ignore if no matching connection found */
+ if ( ! udp ) {
+ DBG ( "No UDP connection listening on port %d\n",
+ ntohs ( udphdr->dest ) );
+ rc = -ENOTCONN;
+ goto done;
+ }
+
+ /* Pass data to application */
+ memset ( &meta, 0, sizeof ( meta ) );
+ meta.src = ( struct sockaddr * ) st_src;
+ meta.dest = ( struct sockaddr * ) st_dest;
+ rc = xfer_deliver ( &udp->xfer, iob_disown ( iobuf ), &meta );
+
+ done:
+ free_iob ( iobuf );
+ return rc;
+}
+
+struct tcpip_protocol udp_protocol __tcpip_protocol = {
+ .name = "UDP",
+ .rx = udp_rx,
+ .tcpip_proto = IP_UDP,
+};
+
+/***************************************************************************
+ *
+ * Data transfer interface
+ *
+ ***************************************************************************
+ */
+
+/**
+ * Allocate I/O buffer for UDP
+ *
+ * @v udp UDP connection
+ * @v len Payload size
+ * @ret iobuf I/O buffer, or NULL
+ */
+static struct io_buffer * udp_xfer_alloc_iob ( struct udp_connection *udp,
+ size_t len ) {
+ struct io_buffer *iobuf;
+
+ iobuf = alloc_iob ( MAX_LL_NET_HEADER_LEN + len );
+ if ( ! iobuf ) {
+ DBGC ( udp, "UDP %p cannot allocate buffer of length %zd\n",
+ udp, len );
+ return NULL;
+ }
+ iob_reserve ( iobuf, MAX_LL_NET_HEADER_LEN );
+ return iobuf;
+}
+
+/**
+ * Deliver datagram as I/O buffer
+ *
+ * @v udp UDP connection
+ * @v iobuf Datagram I/O buffer
+ * @v meta Data transfer metadata
+ * @ret rc Return status code
+ */
+static int udp_xfer_deliver ( struct udp_connection *udp,
+ struct io_buffer *iobuf,
+ struct xfer_metadata *meta ) {
+
+ /* Transmit data, if possible */
+ return udp_tx ( udp, iobuf, ( ( struct sockaddr_tcpip * ) meta->src ),
+ ( ( struct sockaddr_tcpip * ) meta->dest ),
+ meta->netdev );
+}
+
+/** UDP data transfer interface operations */
+static struct interface_operation udp_xfer_operations[] = {
+ INTF_OP ( xfer_deliver, struct udp_connection *, udp_xfer_deliver ),
+ INTF_OP ( xfer_alloc_iob, struct udp_connection *, udp_xfer_alloc_iob ),
+ INTF_OP ( intf_close, struct udp_connection *, udp_close ),
+};
+
+/** UDP data transfer interface descriptor */
+static struct interface_descriptor udp_xfer_desc =
+ INTF_DESC ( struct udp_connection, xfer, udp_xfer_operations );
+
+/***************************************************************************
+ *
+ * Openers
+ *
+ ***************************************************************************
+ */
+
+/** UDP IPv4 socket opener */
+struct socket_opener udp_ipv4_socket_opener __socket_opener = {
+ .semantics = UDP_SOCK_DGRAM,
+ .family = AF_INET,
+ .open = udp_open,
+};
+
+/** UDP IPv6 socket opener */
+struct socket_opener udp_ipv6_socket_opener __socket_opener = {
+ .semantics = UDP_SOCK_DGRAM,
+ .family = AF_INET6,
+ .open = udp_open,
+};
+
+/** Linkage hack */
+int udp_sock_dgram = UDP_SOCK_DGRAM;
+
+/**
+ * Open UDP URI
+ *
+ * @v xfer Data transfer interface
+ * @v uri URI
+ * @ret rc Return status code
+ */
+static int udp_open_uri ( struct interface *xfer, struct uri *uri ) {
+ struct sockaddr_tcpip peer;
+
+ /* Sanity check */
+ if ( ! uri->host )
+ return -EINVAL;
+
+ memset ( &peer, 0, sizeof ( peer ) );
+ peer.st_port = htons ( uri_port ( uri, 0 ) );
+ return xfer_open_named_socket ( xfer, SOCK_DGRAM,
+ ( struct sockaddr * ) &peer,
+ uri->host, NULL );
+}
+
+/** UDP URI opener */
+struct uri_opener udp_uri_opener __uri_opener = {
+ .scheme = "udp",
+ .open = udp_open_uri,
+};
Code Review / kvmfornfv.git / blobdiff