Network API now allows for multiple network devices (although the

implementation allows for only one, and does so without compromising on
the efficiency of static allocation).

Link-layer protocols are cleanly separated from the device drivers.

Network-layer protocols are cleanly separated from individual network
devices.

Link-layer and network-layer protocols are cleanly separated from each
other.

1 files changed, 226 insertions, 0 deletions

diff --git a/src/net/ipv4.c b/src/net/ipv4.c
new file mode 100644
index 00000000..4200d234
--- /dev/null
+++ b/src/net/ipv4.c
@@ -0,0 +1,226 @@
+#include <string.h>
+#include <stdint.h>
+#include <byteswap.h>
+#include <gpxe/in.h>
+
+
+#include <ip.h>
+
+
+#include <gpxe/if_ether.h>
+#include <gpxe/pkbuff.h>
+#include <gpxe/netdevice.h>
+#include "../proto/uip/uip.h"
+
+/** @file
+ *
+ * IPv4 protocol
+ *
+ * The gPXE IP stack is currently implemented on top of the uIP
+ * protocol stack.  This file provides wrappers around uIP so that
+ * higher-level protocol implementations do not need to talk directly
+ * to uIP (which has a somewhat baroque API).
+ *
+ */
+
+/** An IPv4 routing table entry */
+struct ipv4_route {
+	/** Network address */
+	struct in_addr network;
+	/** Subnet mask */
+	struct in_addr netmask;
+	/** Gateway address */
+	struct in_addr gateway;
+	/** Gateway device */
+	struct in_addr gatewaydev;
+};
+
+enum {
+	STATIC_SINGLE_NETDEV_ROUTE = 0,
+	DEFAULT_ROUTE,
+	NUM_ROUTES
+};
+
+/** IPv4 routing table */
+static struct ipv4_route routing_table[NUM_ROUTES];
+
+#define routing_table_end ( routing_table + NUM_ROUTES )
+
+#if 0
+/**
+ * Set IP address
+ *
+ */
+void set_ipaddr ( struct in_addr address ) {
+	union {
+		struct in_addr address;
+		uint16_t uip_address[2];
+	} u;
+
+	u.address = address;
+	uip_sethostaddr ( u.uip_address );
+}
+
+/**
+ * Set netmask
+ *
+ */
+void set_netmask ( struct in_addr address ) {
+	union {
+		struct in_addr address;
+		uint16_t uip_address[2];
+	} u;
+
+	u.address = address;
+	uip_setnetmask ( u.uip_address );
+}
+
+/**
+ * Set default gateway
+ *
+ */
+void set_gateway ( struct in_addr address ) {
+	union {
+		struct in_addr address;
+		uint16_t uip_address[2];
+	} u;
+
+	u.address = address;
+	uip_setdraddr ( u.uip_address );
+}
+
+/**
+ * Run the TCP/IP stack
+ *
+ * Call this function in a loop in order to allow TCP/IP processing to
+ * take place.  This call takes the stack through a single iteration;
+ * it will typically be used in a loop such as
+ *
+ * @code
+ *
+ * struct tcp_connection *my_connection;
+ * ...
+ * tcp_connect ( my_connection );
+ * while ( ! my_connection->finished ) {
+ *   run_tcpip();
+ * }
+ *
+ * @endcode
+ *
+ * where @c my_connection->finished is set by one of the connection's
+ * #tcp_operations methods to indicate completion.
+ */
+void run_tcpip ( void ) {
+	void *data;
+	size_t len;
+	uint16_t type;
+	int i;
+	
+	if ( netdev_poll ( 1, &data, &len ) ) {
+		/* We have data */
+		memcpy ( uip_buf, data, len );
+		uip_len = len;
+		type = ntohs ( *( ( uint16_t * ) ( uip_buf + 12 ) ) );
+		if ( type == UIP_ETHTYPE_ARP ) {
+			uip_arp_arpin();
+		} else {
+			uip_arp_ipin();
+			uip_input();
+		}
+		if ( uip_len > 0 )
+			uip_transmit();
+	} else {
+		for ( i = 0 ; i < UIP_CONNS ; i++ ) {
+			uip_periodic ( i );
+			if ( uip_len > 0 )
+				uip_transmit();
+		}
+	}
+}
+#endif
+
+/**
+ * Process incoming IP packets
+ *
+ * @v pkb		Packet buffer
+ * @ret rc		Return status code
+ *
+ * This handles IP packets by handing them off to the uIP protocol
+ * stack.
+ */
+static int ipv4_rx ( struct pk_buff *pkb ) {
+
+	/* Transfer to uIP buffer.  Horrendously space-inefficient,
+	 * but will do as a proof-of-concept for now.
+	 */
+	memcpy ( uip_buf, pkb->data, pkb_len ( pkb ) );
+
+	/* Hand to uIP for processing */
+	uip_input ();
+	if ( uip_len > 0 ) {
+		pkb_empty ( pkb );
+		pkb_put ( pkb, uip_len );
+		memcpy ( pkb->data, uip_buf, uip_len );
+		if ( net_transmit ( pkb ) != 0 )
+			free_pkb ( pkb );
+	} else {
+		free_pkb ( pkb );
+	}
+	return 0;
+}
+
+/**
+ * Perform IP layer routing
+ *
+ * @v pkb	Packet buffer
+ * @ret source	Network-layer source address
+ * @ret dest	Network-layer destination address
+ * @ret rc	Return status code
+ */
+static int ipv4_route ( const struct pk_buff *pkb,
+			struct net_header *nethdr ) {
+	struct iphdr *iphdr = pkb->data;
+	struct in_addr *source = ( struct in_addr * ) nethdr->source_net_addr;
+	struct in_addr *dest = ( struct in_addr * ) nethdr->dest_net_addr;
+	struct ipv4_route *route;
+
+	/* Route IP packet according to routing table */
+	source->s_addr = INADDR_NONE;
+	dest->s_addr = iphdr->dest.s_addr;
+	for ( route = routing_table ; route < routing_table_end ; route++ ) {
+		if ( ( dest->s_addr & route->netmask.s_addr )
+		     == route->network.s_addr ) {
+			source->s_addr = route->gatewaydev.s_addr;
+			if ( route->gateway.s_addr )
+				dest->s_addr = route->gateway.s_addr;
+			break;
+		}
+	}
+
+	/* Set broadcast and multicast flags as applicable */
+	nethdr->dest_flags = 0;
+	if ( dest->s_addr == htonl ( INADDR_BROADCAST ) ) {
+		nethdr->dest_flags = NETADDR_FL_BROADCAST;
+	} else if ( IN_MULTICAST ( dest->s_addr ) ) {
+		nethdr->dest_flags = NETADDR_FL_MULTICAST;
+	}
+
+	return 0;
+}
+
+/** IPv4 protocol */
+struct net_protocol ipv4_protocol = {
+	.net_proto = ETH_P_IP,
+	.net_addr_len = sizeof ( struct in_addr ),
+	.rx = ipv4_rx,
+	.route = ipv4_route,
+};
+
+NET_PROTOCOL ( ipv4_protocol );
+
+/** IPv4 address for the static single net device */
+struct net_address static_single_ipv4_address = {
+	.net_protocol = &ipv4_protocol,
+};
+
+STATIC_SINGLE_NETDEV_ADDRESS ( static_single_ipv4_address );