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Diffstat (limited to 'drivers/net/lguest_net.c')
-rw-r--r--drivers/net/lguest_net.c555
1 files changed, 0 insertions, 555 deletions
diff --git a/drivers/net/lguest_net.c b/drivers/net/lguest_net.c
deleted file mode 100644
index abce2ee8430..00000000000
--- a/drivers/net/lguest_net.c
+++ /dev/null
@@ -1,555 +0,0 @@
-/*D:500
- * The Guest network driver.
- *
- * This is very simple a virtual network driver, and our last Guest driver.
- * The only trick is that it can talk directly to multiple other recipients
- * (ie. other Guests on the same network). It can also be used with only the
- * Host on the network.
- :*/
-
-/* Copyright 2006 Rusty Russell <rusty@rustcorp.com.au> IBM Corporation
- *
- * 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.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- */
-//#define DEBUG
-#include <linux/netdevice.h>
-#include <linux/etherdevice.h>
-#include <linux/module.h>
-#include <linux/mm_types.h>
-#include <linux/io.h>
-#include <linux/lguest_bus.h>
-
-#define SHARED_SIZE PAGE_SIZE
-#define MAX_LANS 4
-#define NUM_SKBS 8
-
-/*M:011 Network code master Jeff Garzik points out numerous shortcomings in
- * this driver if it aspires to greatness.
- *
- * Firstly, it doesn't use "NAPI": the networking's New API, and is poorer for
- * it. As he says "NAPI means system-wide load leveling, across multiple
- * network interfaces. Lack of NAPI can mean competition at higher loads."
- *
- * He also points out that we don't implement set_mac_address, so users cannot
- * change the devices hardware address. When I asked why one would want to:
- * "Bonding, and situations where you /do/ want the MAC address to "leak" out
- * of the host onto the wider net."
- *
- * Finally, he would like module unloading: "It is not unrealistic to think of
- * [un|re|]loading the net support module in an lguest guest. And, adding
- * module support makes the programmer more responsible, because they now have
- * to learn to clean up after themselves. Any driver that cannot clean up
- * after itself is an incomplete driver in my book."
- :*/
-
-/*D:530 The "struct lguestnet_info" contains all the information we need to
- * know about the network device. */
-struct lguestnet_info
-{
- /* The mapped device page(s) (an array of "struct lguest_net"). */
- struct lguest_net *peer;
- /* The physical address of the device page(s) */
- unsigned long peer_phys;
- /* The size of the device page(s). */
- unsigned long mapsize;
-
- /* The lguest_device I come from */
- struct lguest_device *lgdev;
-
- /* My peerid (ie. my slot in the array). */
- unsigned int me;
-
- /* Receive queue: the network packets waiting to be filled. */
- struct sk_buff *skb[NUM_SKBS];
- struct lguest_dma dma[NUM_SKBS];
-};
-/*:*/
-
-/* How many bytes left in this page. */
-static unsigned int rest_of_page(void *data)
-{
- return PAGE_SIZE - ((unsigned long)data % PAGE_SIZE);
-}
-
-/*D:570 Each peer (ie. Guest or Host) on the network binds their receive
- * buffers to a different key: we simply use the physical address of the
- * device's memory page plus the peer number. The Host insists that all keys
- * be a multiple of 4, so we multiply the peer number by 4. */
-static unsigned long peer_key(struct lguestnet_info *info, unsigned peernum)
-{
- return info->peer_phys + 4 * peernum;
-}
-
-/* This is the routine which sets up a "struct lguest_dma" to point to a
- * network packet, similar to req_to_dma() in lguest_blk.c. The structure of a
- * "struct sk_buff" has grown complex over the years: it consists of a "head"
- * linear section pointed to by "skb->data", and possibly an array of
- * "fragments" in the case of a non-linear packet.
- *
- * Our receive buffers don't use fragments at all but outgoing skbs might, so
- * we handle it. */
-static void skb_to_dma(const struct sk_buff *skb, unsigned int headlen,
- struct lguest_dma *dma)
-{
- unsigned int i, seg;
-
- /* First, we put the linear region into the "struct lguest_dma". Each
- * entry can't go over a page boundary, so even though all our packets
- * are 1514 bytes or less, we might need to use two entries here: */
- for (i = seg = 0; i < headlen; seg++, i += rest_of_page(skb->data+i)) {
- dma->addr[seg] = virt_to_phys(skb->data + i);
- dma->len[seg] = min((unsigned)(headlen - i),
- rest_of_page(skb->data + i));
- }
-
- /* Now we handle the fragments: at least they're guaranteed not to go
- * over a page. skb_shinfo(skb) returns a pointer to the structure
- * which tells us about the number of fragments and the fragment
- * array. */
- for (i = 0; i < skb_shinfo(skb)->nr_frags; i++, seg++) {
- const skb_frag_t *f = &skb_shinfo(skb)->frags[i];
- /* Should not happen with MTU less than 64k - 2 * PAGE_SIZE. */
- if (seg == LGUEST_MAX_DMA_SECTIONS) {
- /* We will end up sending a truncated packet should
- * this ever happen. Plus, a cool log message! */
- printk("Woah dude! Megapacket!\n");
- break;
- }
- dma->addr[seg] = page_to_phys(f->page) + f->page_offset;
- dma->len[seg] = f->size;
- }
-
- /* If after all that we didn't use the entire "struct lguest_dma"
- * array, we terminate it with a 0 length. */
- if (seg < LGUEST_MAX_DMA_SECTIONS)
- dma->len[seg] = 0;
-}
-
-/*
- * Packet transmission.
- *
- * Our packet transmission is a little unusual. A real network card would just
- * send out the packet and leave the receivers to decide if they're interested.
- * Instead, we look through the network device memory page and see if any of
- * the ethernet addresses match the packet destination, and if so we send it to
- * that Guest.
- *
- * This is made a little more complicated in two cases. The first case is
- * broadcast packets: for that we send the packet to all Guests on the network,
- * one at a time. The second case is "promiscuous" mode, where a Guest wants
- * to see all the packets on the network. We need a way for the Guest to tell
- * us it wants to see all packets, so it sets the "multicast" bit on its
- * published MAC address, which is never valid in a real ethernet address.
- */
-#define PROMISC_BIT 0x01
-
-/* This is the callback which is summoned whenever the network device's
- * multicast or promiscuous state changes. If the card is in promiscuous mode,
- * we advertise that in our ethernet address in the device's memory. We do the
- * same if Linux wants any or all multicast traffic. */
-static void lguestnet_set_multicast(struct net_device *dev)
-{
- struct lguestnet_info *info = netdev_priv(dev);
-
- if ((dev->flags & (IFF_PROMISC|IFF_ALLMULTI)) || dev->mc_count)
- info->peer[info->me].mac[0] |= PROMISC_BIT;
- else
- info->peer[info->me].mac[0] &= ~PROMISC_BIT;
-}
-
-/* A simple test function to see if a peer wants to see all packets.*/
-static int promisc(struct lguestnet_info *info, unsigned int peer)
-{
- return info->peer[peer].mac[0] & PROMISC_BIT;
-}
-
-/* Another simple function to see if a peer's advertised ethernet address
- * matches a packet's destination ethernet address. */
-static int mac_eq(const unsigned char mac[ETH_ALEN],
- struct lguestnet_info *info, unsigned int peer)
-{
- /* Ignore multicast bit, which peer turns on to mean promisc. */
- if ((info->peer[peer].mac[0] & (~PROMISC_BIT)) != mac[0])
- return 0;
- return memcmp(mac+1, info->peer[peer].mac+1, ETH_ALEN-1) == 0;
-}
-
-/* This is the function which actually sends a packet once we've decided a
- * peer wants it: */
-static void transfer_packet(struct net_device *dev,
- struct sk_buff *skb,
- unsigned int peernum)
-{
- struct lguestnet_info *info = netdev_priv(dev);
- struct lguest_dma dma;
-
- /* We use our handy "struct lguest_dma" packing function to prepare
- * the skb for sending. */
- skb_to_dma(skb, skb_headlen(skb), &dma);
- pr_debug("xfer length %04x (%u)\n", htons(skb->len), skb->len);
-
- /* This is the actual send call which copies the packet. */
- lguest_send_dma(peer_key(info, peernum), &dma);
-
- /* Check that the entire packet was transmitted. If not, it could mean
- * that the other Guest registered a short receive buffer, but this
- * driver should never do that. More likely, the peer is dead. */
- if (dma.used_len != skb->len) {
- dev->stats.tx_carrier_errors++;
- pr_debug("Bad xfer to peer %i: %i of %i (dma %p/%i)\n",
- peernum, dma.used_len, skb->len,
- (void *)dma.addr[0], dma.len[0]);
- } else {
- /* On success we update the stats. */
- dev->stats.tx_bytes += skb->len;
- dev->stats.tx_packets++;
- }
-}
-
-/* Another helper function to tell is if a slot in the device memory is unused.
- * Since we always set the Local Assignment bit in the ethernet address, the
- * first byte can never be 0. */
-static int unused_peer(const struct lguest_net peer[], unsigned int num)
-{
- return peer[num].mac[0] == 0;
-}
-
-/* Finally, here is the routine which handles an outgoing packet. It's called
- * "start_xmit" for traditional reasons. */
-static int lguestnet_start_xmit(struct sk_buff *skb, struct net_device *dev)
-{
- unsigned int i;
- int broadcast;
- struct lguestnet_info *info = netdev_priv(dev);
- /* Extract the destination ethernet address from the packet. */
- const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest;
- DECLARE_MAC_BUF(mac);
-
- pr_debug("%s: xmit %s\n", dev->name, print_mac(mac, dest));
-
- /* If it's a multicast packet, we broadcast to everyone. That's not
- * very efficient, but there are very few applications which actually
- * use multicast, which is a shame really.
- *
- * As etherdevice.h points out: "By definition the broadcast address is
- * also a multicast address." So we don't have to test for broadcast
- * packets separately. */
- broadcast = is_multicast_ether_addr(dest);
-
- /* Look through all the published ethernet addresses to see if we
- * should send this packet. */
- for (i = 0; i < info->mapsize/sizeof(struct lguest_net); i++) {
- /* We don't send to ourselves (we actually can't SEND_DMA to
- * ourselves anyway), and don't send to unused slots.*/
- if (i == info->me || unused_peer(info->peer, i))
- continue;
-
- /* If it's broadcast we send it. If they want every packet we
- * send it. If the destination matches their address we send
- * it. Otherwise we go to the next peer. */
- if (!broadcast && !promisc(info, i) && !mac_eq(dest, info, i))
- continue;
-
- pr_debug("lguestnet %s: sending from %i to %i\n",
- dev->name, info->me, i);
- /* Our routine which actually does the transfer. */
- transfer_packet(dev, skb, i);
- }
-
- /* An xmit routine is expected to dispose of the packet, so we do. */
- dev_kfree_skb(skb);
-
- /* As per kernel convention, 0 means success. This is why I love
- * networking: even if we never sent to anyone, that's still
- * success! */
- return 0;
-}
-
-/*D:560
- * Packet receiving.
- *
- * First, here's a helper routine which fills one of our array of receive
- * buffers: */
-static int fill_slot(struct net_device *dev, unsigned int slot)
-{
- struct lguestnet_info *info = netdev_priv(dev);
-
- /* We can receive ETH_DATA_LEN (1500) byte packets, plus a standard
- * ethernet header of ETH_HLEN (14) bytes. */
- info->skb[slot] = netdev_alloc_skb(dev, ETH_HLEN + ETH_DATA_LEN);
- if (!info->skb[slot]) {
- printk("%s: could not fill slot %i\n", dev->name, slot);
- return -ENOMEM;
- }
-
- /* skb_to_dma() is a helper which sets up the "struct lguest_dma" to
- * point to the data in the skb: we also use it for sending out a
- * packet. */
- skb_to_dma(info->skb[slot], ETH_HLEN + ETH_DATA_LEN, &info->dma[slot]);
-
- /* This is a Write Memory Barrier: it ensures that the entry in the
- * receive buffer array is written *before* we set the "used_len" entry
- * to 0. If the Host were looking at the receive buffer array from a
- * different CPU, it could potentially see "used_len = 0" and not see
- * the updated receive buffer information. This would be a horribly
- * nasty bug, so make sure the compiler and CPU know this has to happen
- * first. */
- wmb();
- /* Writing 0 to "used_len" tells the Host it can use this receive
- * buffer now. */
- info->dma[slot].used_len = 0;
- return 0;
-}
-
-/* This is the actual receive routine. When we receive an interrupt from the
- * Host to tell us a packet has been delivered, we arrive here: */
-static irqreturn_t lguestnet_rcv(int irq, void *dev_id)
-{
- struct net_device *dev = dev_id;
- struct lguestnet_info *info = netdev_priv(dev);
- unsigned int i, done = 0;
-
- /* Look through our entire receive array for an entry which has data
- * in it. */
- for (i = 0; i < ARRAY_SIZE(info->dma); i++) {
- unsigned int length;
- struct sk_buff *skb;
-
- length = info->dma[i].used_len;
- if (length == 0)
- continue;
-
- /* We've found one! Remember the skb (we grabbed the length
- * above), and immediately refill the slot we've taken it
- * from. */
- done++;
- skb = info->skb[i];
- fill_slot(dev, i);
-
- /* This shouldn't happen: micropackets could be sent by a
- * badly-behaved Guest on the network, but the Host will never
- * stuff more data in the buffer than the buffer length. */
- if (length < ETH_HLEN || length > ETH_HLEN + ETH_DATA_LEN) {
- pr_debug(KERN_WARNING "%s: unbelievable skb len: %i\n",
- dev->name, length);
- dev_kfree_skb(skb);
- continue;
- }
-
- /* skb_put(), what a great function! I've ranted about this
- * function before (http://lkml.org/lkml/1999/9/26/24). You
- * call it after you've added data to the end of an skb (in
- * this case, it was the Host which wrote the data). */
- skb_put(skb, length);
-
- /* The ethernet header contains a protocol field: we use the
- * standard helper to extract it, and place the result in
- * skb->protocol. The helper also sets up skb->pkt_type and
- * eats up the ethernet header from the front of the packet. */
- skb->protocol = eth_type_trans(skb, dev);
-
- /* If this device doesn't need checksums for sending, we also
- * don't need to check the packets when they come in. */
- if (dev->features & NETIF_F_NO_CSUM)
- skb->ip_summed = CHECKSUM_UNNECESSARY;
-
- /* As a last resort for debugging the driver or the lguest I/O
- * subsystem, you can uncomment the "#define DEBUG" at the top
- * of this file, which turns all the pr_debug() into printk()
- * and floods the logs. */
- pr_debug("Receiving skb proto 0x%04x len %i type %i\n",
- ntohs(skb->protocol), skb->len, skb->pkt_type);
-
- /* Update the packet and byte counts (visible from ifconfig,
- * and good for debugging). */
- dev->stats.rx_bytes += skb->len;
- dev->stats.rx_packets++;
-
- /* Hand our fresh network packet into the stack's "network
- * interface receive" routine. That will free the packet
- * itself when it's finished. */
- netif_rx(skb);
- }
-
- /* If we found any packets, we assume the interrupt was for us. */
- return done ? IRQ_HANDLED : IRQ_NONE;
-}
-
-/*D:550 This is where we start: when the device is brought up by dhcpd or
- * ifconfig. At this point we advertise our MAC address to the rest of the
- * network, and register receive buffers ready for incoming packets. */
-static int lguestnet_open(struct net_device *dev)
-{
- int i;
- struct lguestnet_info *info = netdev_priv(dev);
-
- /* Copy our MAC address into the device page, so others on the network
- * can find us. */
- memcpy(info->peer[info->me].mac, dev->dev_addr, ETH_ALEN);
-
- /* We might already be in promisc mode (dev->flags & IFF_PROMISC). Our
- * set_multicast callback handles this already, so we call it now. */
- lguestnet_set_multicast(dev);
-
- /* Allocate packets and put them into our "struct lguest_dma" array.
- * If we fail to allocate all the packets we could still limp along,
- * but it's a sign of real stress so we should probably give up now. */
- for (i = 0; i < ARRAY_SIZE(info->dma); i++) {
- if (fill_slot(dev, i) != 0)
- goto cleanup;
- }
-
- /* Finally we tell the Host where our array of "struct lguest_dma"
- * receive buffers is, binding it to the key corresponding to the
- * device's physical memory plus our peerid. */
- if (lguest_bind_dma(peer_key(info,info->me), info->dma,
- NUM_SKBS, lgdev_irq(info->lgdev)) != 0)
- goto cleanup;
- return 0;
-
-cleanup:
- while (--i >= 0)
- dev_kfree_skb(info->skb[i]);
- return -ENOMEM;
-}
-/*:*/
-
-/* The close routine is called when the device is no longer in use: we clean up
- * elegantly. */
-static int lguestnet_close(struct net_device *dev)
-{
- unsigned int i;
- struct lguestnet_info *info = netdev_priv(dev);
-
- /* Clear all trace of our existence out of the device memory by setting
- * the slot which held our MAC address to 0 (unused). */
- memset(&info->peer[info->me], 0, sizeof(info->peer[info->me]));
-
- /* Unregister our array of receive buffers */
- lguest_unbind_dma(peer_key(info, info->me), info->dma);
- for (i = 0; i < ARRAY_SIZE(info->dma); i++)
- dev_kfree_skb(info->skb[i]);
- return 0;
-}
-
-/*D:510 The network device probe function is basically a standard ethernet
- * device setup. It reads the "struct lguest_device_desc" and sets the "struct
- * net_device". Oh, the line-by-line excitement! Let's skip over it. :*/
-static int lguestnet_probe(struct lguest_device *lgdev)
-{
- int err, irqf = IRQF_SHARED;
- struct net_device *dev;
- struct lguestnet_info *info;
- struct lguest_device_desc *desc = &lguest_devices[lgdev->index];
-
- pr_debug("lguest_net: probing for device %i\n", lgdev->index);
-
- dev = alloc_etherdev(sizeof(struct lguestnet_info));
- if (!dev)
- return -ENOMEM;
-
- /* Ethernet defaults with some changes */
- ether_setup(dev);
- dev->set_mac_address = NULL;
-
- dev->dev_addr[0] = 0x02; /* set local assignment bit (IEEE802) */
- dev->dev_addr[1] = 0x00;
- memcpy(&dev->dev_addr[2], &lguest_data.guestid, 2);
- dev->dev_addr[4] = 0x00;
- dev->dev_addr[5] = 0x00;
-
- dev->open = lguestnet_open;
- dev->stop = lguestnet_close;
- dev->hard_start_xmit = lguestnet_start_xmit;
-
- /* We don't actually support multicast yet, but turning on/off
- * promisc also calls dev->set_multicast_list. */
- dev->set_multicast_list = lguestnet_set_multicast;
- SET_NETDEV_DEV(dev, &lgdev->dev);
-
- /* The network code complains if you have "scatter-gather" capability
- * if you don't also handle checksums (it seem that would be
- * "illogical"). So we use a lie of omission and don't tell it that we
- * can handle scattered packets unless we also don't want checksums,
- * even though to us they're completely independent. */
- if (desc->features & LGUEST_NET_F_NOCSUM)
- dev->features = NETIF_F_SG|NETIF_F_NO_CSUM;
-
- info = netdev_priv(dev);
- info->mapsize = PAGE_SIZE * desc->num_pages;
- info->peer_phys = ((unsigned long)desc->pfn << PAGE_SHIFT);
- info->lgdev = lgdev;
- info->peer = lguest_map(info->peer_phys, desc->num_pages);
- if (!info->peer) {
- err = -ENOMEM;
- goto free;
- }
-
- /* This stores our peerid (upper bits reserved for future). */
- info->me = (desc->features & (info->mapsize-1));
-
- err = register_netdev(dev);
- if (err) {
- pr_debug("lguestnet: registering device failed\n");
- goto unmap;
- }
-
- if (lguest_devices[lgdev->index].features & LGUEST_DEVICE_F_RANDOMNESS)
- irqf |= IRQF_SAMPLE_RANDOM;
- if (request_irq(lgdev_irq(lgdev), lguestnet_rcv, irqf, "lguestnet",
- dev) != 0) {
- pr_debug("lguestnet: cannot get irq %i\n", lgdev_irq(lgdev));
- goto unregister;
- }
-
- pr_debug("lguestnet: registered device %s\n", dev->name);
- /* Finally, we put the "struct net_device" in the generic "struct
- * lguest_device"s private pointer. Again, it's not necessary, but
- * makes sure the cool kernel kids don't tease us. */
- lgdev->private = dev;
- return 0;
-
-unregister:
- unregister_netdev(dev);
-unmap:
- lguest_unmap(info->peer);
-free:
- free_netdev(dev);
- return err;
-}
-
-static struct lguest_driver lguestnet_drv = {
- .name = "lguestnet",
- .owner = THIS_MODULE,
- .device_type = LGUEST_DEVICE_T_NET,
- .probe = lguestnet_probe,
-};
-
-static __init int lguestnet_init(void)
-{
- return register_lguest_driver(&lguestnet_drv);
-}
-module_init(lguestnet_init);
-
-MODULE_DESCRIPTION("Lguest network driver");
-MODULE_LICENSE("GPL");
-
-/*D:580
- * This is the last of the Drivers, and with this we have covered the many and
- * wonderous and fine (and boring) details of the Guest.
- *
- * "make Launcher" beckons, where we answer questions like "Where do Guests
- * come from?", and "What do you do when someone asks for optimization?"
- */