Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c
new file mode 100644
index 0000000..2ffc317
--- /dev/null
+++ b/drivers/net/loopback.c
@@ -0,0 +1,233 @@
+/*
+ * INET An implementation of the TCP/IP protocol suite for the LINUX
+ * operating system. INET is implemented using the BSD Socket
+ * interface as the means of communication with the user level.
+ *
+ * Pseudo-driver for the loopback interface.
+ *
+ * Version: @(#)loopback.c 1.0.4b 08/16/93
+ *
+ * Authors: Ross Biro, <bir7@leland.Stanford.Edu>
+ * Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ * Donald Becker, <becker@scyld.com>
+ *
+ * Alan Cox : Fixed oddments for NET3.014
+ * Alan Cox : Rejig for NET3.029 snap #3
+ * Alan Cox : Fixed NET3.029 bugs and sped up
+ * Larry McVoy : Tiny tweak to double performance
+ * Alan Cox : Backed out LMV's tweak - the linux mm
+ * can't take it...
+ * Michael Griffith: Don't bother computing the checksums
+ * on packets received on the loopback
+ * interface.
+ * Alexey Kuznetsov: Potential hang under some extreme
+ * cases removed.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#include <linux/kernel.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/fs.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/socket.h>
+#include <linux/errno.h>
+#include <linux/fcntl.h>
+#include <linux/in.h>
+#include <linux/init.h>
+
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/ethtool.h>
+#include <net/sock.h>
+#include <net/checksum.h>
+#include <linux/if_ether.h> /* For the statistics structure. */
+#include <linux/if_arp.h> /* For ARPHRD_ETHER */
+#include <linux/ip.h>
+#include <linux/tcp.h>
+#include <linux/percpu.h>
+
+static DEFINE_PER_CPU(struct net_device_stats, loopback_stats);
+
+#define LOOPBACK_OVERHEAD (128 + MAX_HEADER + 16 + 16)
+
+/* KISS: just allocate small chunks and copy bits.
+ *
+ * So, in fact, this is documentation, explaining what we expect
+ * of largesending device modulo TCP checksum, which is ignored for loopback.
+ */
+
+static void emulate_large_send_offload(struct sk_buff *skb)
+{
+ struct iphdr *iph = skb->nh.iph;
+ struct tcphdr *th = (struct tcphdr*)(skb->nh.raw + (iph->ihl * 4));
+ unsigned int doffset = (iph->ihl + th->doff) * 4;
+ unsigned int mtu = skb_shinfo(skb)->tso_size + doffset;
+ unsigned int offset = 0;
+ u32 seq = ntohl(th->seq);
+ u16 id = ntohs(iph->id);
+
+ while (offset + doffset < skb->len) {
+ unsigned int frag_size = min(mtu, skb->len - offset) - doffset;
+ struct sk_buff *nskb = alloc_skb(mtu + 32, GFP_ATOMIC);
+
+ if (!nskb)
+ break;
+ skb_reserve(nskb, 32);
+ nskb->mac.raw = nskb->data - 14;
+ nskb->nh.raw = nskb->data;
+ iph = nskb->nh.iph;
+ memcpy(nskb->data, skb->nh.raw, doffset);
+ if (skb_copy_bits(skb,
+ doffset + offset,
+ nskb->data + doffset,
+ frag_size))
+ BUG();
+ skb_put(nskb, doffset + frag_size);
+ nskb->ip_summed = CHECKSUM_UNNECESSARY;
+ nskb->dev = skb->dev;
+ nskb->priority = skb->priority;
+ nskb->protocol = skb->protocol;
+ nskb->dst = dst_clone(skb->dst);
+ memcpy(nskb->cb, skb->cb, sizeof(skb->cb));
+ nskb->pkt_type = skb->pkt_type;
+
+ th = (struct tcphdr*)(nskb->nh.raw + iph->ihl*4);
+ iph->tot_len = htons(frag_size + doffset);
+ iph->id = htons(id);
+ iph->check = 0;
+ iph->check = ip_fast_csum((unsigned char *) iph, iph->ihl);
+ th->seq = htonl(seq);
+ if (offset + doffset + frag_size < skb->len)
+ th->fin = th->psh = 0;
+ netif_rx(nskb);
+ offset += frag_size;
+ seq += frag_size;
+ id++;
+ }
+
+ dev_kfree_skb(skb);
+}
+
+/*
+ * The higher levels take care of making this non-reentrant (it's
+ * called with bh's disabled).
+ */
+static int loopback_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct net_device_stats *lb_stats;
+
+ skb_orphan(skb);
+
+ skb->protocol=eth_type_trans(skb,dev);
+ skb->dev=dev;
+#ifndef LOOPBACK_MUST_CHECKSUM
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+#endif
+
+ if (skb_shinfo(skb)->tso_size) {
+ BUG_ON(skb->protocol != htons(ETH_P_IP));
+ BUG_ON(skb->nh.iph->protocol != IPPROTO_TCP);
+
+ emulate_large_send_offload(skb);
+ return 0;
+ }
+
+ dev->last_rx = jiffies;
+
+ lb_stats = &per_cpu(loopback_stats, get_cpu());
+ lb_stats->rx_bytes += skb->len;
+ lb_stats->tx_bytes += skb->len;
+ lb_stats->rx_packets++;
+ lb_stats->tx_packets++;
+ put_cpu();
+
+ netif_rx(skb);
+
+ return(0);
+}
+
+static struct net_device_stats *get_stats(struct net_device *dev)
+{
+ struct net_device_stats *stats = dev->priv;
+ int i;
+
+ if (!stats) {
+ return NULL;
+ }
+
+ memset(stats, 0, sizeof(struct net_device_stats));
+
+ for (i=0; i < NR_CPUS; i++) {
+ struct net_device_stats *lb_stats;
+
+ if (!cpu_possible(i))
+ continue;
+ lb_stats = &per_cpu(loopback_stats, i);
+ stats->rx_bytes += lb_stats->rx_bytes;
+ stats->tx_bytes += lb_stats->tx_bytes;
+ stats->rx_packets += lb_stats->rx_packets;
+ stats->tx_packets += lb_stats->tx_packets;
+ }
+
+ return stats;
+}
+
+static u32 loopback_get_link(struct net_device *dev)
+{
+ return 1;
+}
+
+static struct ethtool_ops loopback_ethtool_ops = {
+ .get_link = loopback_get_link,
+ .get_tso = ethtool_op_get_tso,
+ .set_tso = ethtool_op_set_tso,
+};
+
+struct net_device loopback_dev = {
+ .name = "lo",
+ .mtu = (16 * 1024) + 20 + 20 + 12,
+ .hard_start_xmit = loopback_xmit,
+ .hard_header = eth_header,
+ .hard_header_cache = eth_header_cache,
+ .header_cache_update = eth_header_cache_update,
+ .hard_header_len = ETH_HLEN, /* 14 */
+ .addr_len = ETH_ALEN, /* 6 */
+ .tx_queue_len = 0,
+ .type = ARPHRD_LOOPBACK, /* 0x0001*/
+ .rebuild_header = eth_rebuild_header,
+ .flags = IFF_LOOPBACK,
+ .features = NETIF_F_SG|NETIF_F_FRAGLIST
+ |NETIF_F_NO_CSUM|NETIF_F_HIGHDMA
+ |NETIF_F_LLTX,
+ .ethtool_ops = &loopback_ethtool_ops,
+};
+
+/* Setup and register the of the LOOPBACK device. */
+int __init loopback_init(void)
+{
+ struct net_device_stats *stats;
+
+ /* Can survive without statistics */
+ stats = kmalloc(sizeof(struct net_device_stats), GFP_KERNEL);
+ if (stats) {
+ memset(stats, 0, sizeof(struct net_device_stats));
+ loopback_dev.priv = stats;
+ loopback_dev.get_stats = &get_stats;
+ }
+
+ return register_netdev(&loopback_dev);
+};
+
+EXPORT_SYMBOL(loopback_dev);
