uml: add VDE networking support

Added vde network backend in uml to introduce native Virtual Distributed
Ethernet support (using libvdeplug).

Signed-off-by: Luca Bigliardi <shammash@artha.org>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

5 files changed, 335 insertions, 2 deletions

diff --git a/arch/um/Kconfig.net b/arch/um/Kconfig.net
index 14a04ebdeae..66e50026ade 100644
--- a/arch/um/Kconfig.net
+++ b/arch/um/Kconfig.net
@@ -108,6 +108,28 @@ config UML_NET_DAEMON
         more than one without conflict.  If you don't need UML networking,
         say N.
 
+config UML_NET_VDE
+        bool "VDE transport"
+        depends on UML_NET
+        help
+        This User-Mode Linux network transport allows one or more running
+        UMLs on a single host to communicate with each other and also
+        with the rest of the world using Virtual Distributed Ethernet,
+        an improved fork of uml_switch.
+
+        You must have libvdeplug installed in order to build the vde
+        transport into UML.
+
+        To use this form of networking, you will need to run vde_switch
+        on the host.
+
+        For more information, see <http://wiki.virtualsquare.org/>
+        That site has a good overview of what VDE is and also examples
+        of the UML command line to use to enable VDE networking.
+
+        If you need UML networking with VDE,
+        say Y.
+
 config UML_NET_MCAST
         bool "Multicast transport"
         depends on UML_NET
diff --git a/arch/um/drivers/Makefile b/arch/um/drivers/Makefile
index de17d4c6e02..634968150bd 100644
--- a/arch/um/drivers/Makefile
+++ b/arch/um/drivers/Makefile
@@ -19,10 +19,16 @@ harddog-objs := harddog_kern.o harddog_user.o
 
 LDFLAGS_pcap.o := -r $(shell $(CC) $(CFLAGS) -print-file-name=libpcap.a)
 
-targets := pcap_kern.o pcap_user.o
+LDFLAGS_vde.o := -r $(shell $(CC) $(CFLAGS) -print-file-name=libvdeplug.a)
+
+targets := pcap_kern.o pcap_user.o vde_kern.o vde_user.o
 
 $(obj)/pcap.o: $(obj)/pcap_kern.o $(obj)/pcap_user.o
         $(LD) -r -dp -o $@ $^ $(LDFLAGS) $(LDFLAGS_pcap.o)
+
+$(obj)/vde.o: $(obj)/vde_kern.o $(obj)/vde_user.o
+        $(LD) -r -dp -o $@ $^ $(LDFLAGS) $(LDFLAGS_vde.o)
+
 #XXX: The call below does not work because the flags are added before the
 # object name, so nothing from the library gets linked.
 #$(call if_changed,ld)
@@ -37,6 +43,7 @@ obj-$(CONFIG_STDERR_CONSOLE) += stderr_console.o
 obj-$(CONFIG_UML_NET_SLIP) += slip.o slip_common.o
 obj-$(CONFIG_UML_NET_SLIRP) += slirp.o slip_common.o
 obj-$(CONFIG_UML_NET_DAEMON) += daemon.o 
+obj-$(CONFIG_UML_NET_VDE) += vde.o
 obj-$(CONFIG_UML_NET_MCAST) += mcast.o 
 obj-$(CONFIG_UML_NET_PCAP) += pcap.o
 obj-$(CONFIG_UML_NET) += net.o 
@@ -54,6 +61,6 @@ obj-$(CONFIG_BLK_DEV_COW_COMMON) += cow_user.o
 obj-$(CONFIG_UML_RANDOM) += random.o
 
 # pcap_user.o must be added explicitly.
-USER_OBJS := fd.o null.o pty.o tty.o xterm.o slip_common.o pcap_user.o
+USER_OBJS := fd.o null.o pty.o tty.o xterm.o slip_common.o pcap_user.o vde_user.o
 
 include arch/um/scripts/Makefile.rules
diff --git a/arch/um/drivers/vde.h b/arch/um/drivers/vde.h
new file mode 100644
index 00000000000..fc3a05902ba
--- /dev/null
+++ b/arch/um/drivers/vde.h
@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2007 Luca Bigliardi (shammash@artha.org).
+ * Licensed under the GPL.
+ */
+
+#ifndef __UM_VDE_H__
+#define __UM_VDE_H__
+
+struct vde_data {
+        char *vde_switch;
+        char *descr;
+        void *args;
+        void *conn;
+        void *dev;
+};
+
+struct vde_init {
+        char *vde_switch;
+        char *descr;
+        int port;
+        char *group;
+        int mode;
+};
+
+extern const struct net_user_info vde_user_info;
+
+extern void vde_init_libstuff(struct vde_data *vpri, struct vde_init *init);
+
+extern int vde_user_read(void *conn, void *buf, int len);
+extern int vde_user_write(void *conn, void *buf, int len);
+
+#endif
diff --git a/arch/um/drivers/vde_kern.c b/arch/um/drivers/vde_kern.c
new file mode 100644
index 00000000000..eb8cf31b820
--- /dev/null
+++ b/arch/um/drivers/vde_kern.c
@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) 2007 Luca Bigliardi (shammash@artha.org).
+ * Licensed under the GPL.
+ *
+ * Transport usage:
+ *  ethN=vde,<vde_switch>,<mac addr>,<port>,<group>,<mode>,<description>
+ *
+ */
+
+#include "linux/kernel.h"
+#include "linux/init.h"
+#include "linux/netdevice.h"
+#include "linux/etherdevice.h"
+#include "net_kern.h"
+#include "net_user.h"
+#include "vde.h"
+
+static void vde_init(struct net_device *dev, void *data)
+{
+        struct vde_init *init = data;
+        struct uml_net_private *pri;
+        struct vde_data *vpri;
+
+        pri = dev->priv;
+        vpri = (struct vde_data *) pri->user;
+
+        vpri->vde_switch = init->vde_switch;
+        vpri->descr = init->descr ? init->descr : "UML vde_transport";
+        vpri->args = NULL;
+        vpri->conn = NULL;
+        vpri->dev = dev;
+
+        printk(KERN_INFO "vde backend - %s, ", vpri->vde_switch ?
+               vpri->vde_switch : "(default socket)");
+
+        vde_init_libstuff(vpri, init);
+
+        printk(KERN_INFO "\n");
+}
+
+static int vde_read(int fd, struct sk_buff **skb, struct uml_net_private *lp)
+{
+        struct vde_data *pri = (struct vde_data *) &lp->user;
+
+        if (pri->conn != NULL) {
+                *skb = ether_adjust_skb(*skb, ETH_HEADER_OTHER);
+                if (*skb == NULL)
+                        return -ENOMEM;
+
+                return vde_user_read(pri->conn, skb_mac_header(*skb),
+                                     (*skb)->dev->mtu + ETH_HEADER_OTHER);
+        }
+
+        printk(KERN_ERR "vde_read - we have no VDECONN to read from");
+        return -EBADF;
+}
+
+static int vde_write(int fd, struct sk_buff **skb, struct uml_net_private *lp)
+{
+        struct vde_data *pri = (struct vde_data *) &lp->user;
+
+        if (pri->conn != NULL)
+                return vde_user_write((void *)pri->conn, (*skb)->data,
+                                      (*skb)->len);
+
+        printk(KERN_ERR "vde_write - we have no VDECONN to write to");
+        return -EBADF;
+}
+
+static const struct net_kern_info vde_kern_info = {
+        .init                   = vde_init,
+        .protocol               = eth_protocol,
+        .read                   = vde_read,
+        .write                  = vde_write,
+};
+
+static int vde_setup(char *str, char **mac_out, void *data)
+{
+        struct vde_init *init = data;
+        char *remain, *port_str = NULL, *mode_str = NULL, *last;
+
+        *init = ((struct vde_init)
+                { .vde_switch           = NULL,
+                  .descr                = NULL,
+                  .port                 = 0,
+                  .group                = NULL,
+                  .mode                 = 0 });
+
+        remain = split_if_spec(str, &init->vde_switch, mac_out, &port_str,
+                                &init->group, &mode_str, &init->descr, NULL);
+
+        if (remain != NULL)
+                printk(KERN_WARNING "vde_setup - Ignoring extra data :"
+                       "'%s'\n", remain);
+
+        if (port_str != NULL) {
+                init->port = simple_strtoul(port_str, &last, 10);
+                if ((*last != '\0') || (last == port_str)) {
+                        printk(KERN_ERR "vde_setup - Bad port : '%s'\n",
+                                                port_str);
+                        return 0;
+                }
+        }
+
+        if (mode_str != NULL) {
+                init->mode = simple_strtoul(mode_str, &last, 8);
+                if ((*last != '\0') || (last == mode_str)) {
+                        printk(KERN_ERR "vde_setup - Bad mode : '%s'\n",
+                                                mode_str);
+                        return 0;
+                }
+        }
+
+        printk(KERN_INFO "Configured vde device: %s\n", init->vde_switch ?
+               init->vde_switch : "(default socket)");
+
+        return 1;
+}
+
+static struct transport vde_transport = {
+        .list           = LIST_HEAD_INIT(vde_transport.list),
+        .name           = "vde",
+        .setup          = vde_setup,
+        .user           = &vde_user_info,
+        .kern           = &vde_kern_info,
+        .private_size   = sizeof(struct vde_data),
+        .setup_size     = sizeof(struct vde_init),
+};
+
+static int register_vde(void)
+{
+        register_transport(&vde_transport);
+        return 0;
+}
+
+late_initcall(register_vde);
diff --git a/arch/um/drivers/vde_user.c b/arch/um/drivers/vde_user.c
new file mode 100644
index 00000000000..d3b5a065fc5
--- /dev/null
+++ b/arch/um/drivers/vde_user.c
@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) 2007 Luca Bigliardi (shammash@artha.org).
+ * Licensed under the GPL.
+ */
+
+#include <errno.h>
+#include <unistd.h>
+#include <libvdeplug.h>
+#include "net_user.h"
+#include "kern_util.h"
+#include "kern_constants.h"
+#include "user.h"
+#include "os.h"
+#include "um_malloc.h"
+#include "vde.h"
+
+#define MAX_PACKET (ETH_MAX_PACKET + ETH_HEADER_OTHER)
+
+static int vde_user_init(void *data, void *dev)
+{
+        struct vde_data *pri = data;
+        VDECONN *conn = NULL;
+        int err = -EINVAL;
+
+        pri->dev = dev;
+
+        conn = vde_open(pri->vde_switch, pri->descr, pri->args);
+
+        if (conn == NULL) {
+                err = -errno;
+                printk(UM_KERN_ERR "vde_user_init: vde_open failed, "
+                       "errno = %d\n", errno);
+                return err;
+        }
+
+        printk(UM_KERN_INFO "vde backend - connection opened\n");
+
+        pri->conn = conn;
+
+        return 0;
+}
+
+static int vde_user_open(void *data)
+{
+        struct vde_data *pri = data;
+
+        if (pri->conn != NULL)
+                return vde_datafd(pri->conn);
+
+        printk(UM_KERN_WARNING "vde_open - we have no VDECONN to open");
+        return -EINVAL;
+}
+
+static void vde_remove(void *data)
+{
+        struct vde_data *pri = data;
+
+        if (pri->conn != NULL) {
+                printk(UM_KERN_INFO "vde backend - closing connection\n");
+                vde_close(pri->conn);
+                pri->conn = NULL;
+                kfree(pri->args);
+                pri->args = NULL;
+                return;
+        }
+
+        printk(UM_KERN_WARNING "vde_remove - we have no VDECONN to remove");
+}
+
+static int vde_set_mtu(int mtu, void *data)
+{
+        return mtu;
+}
+
+const struct net_user_info vde_user_info = {
+        .init           = vde_user_init,
+        .open           = vde_user_open,
+        .close          = NULL,
+        .remove         = vde_remove,
+        .set_mtu        = vde_set_mtu,
+        .add_address    = NULL,
+        .delete_address = NULL,
+        .max_packet     = MAX_PACKET - ETH_HEADER_OTHER
+};
+
+void vde_init_libstuff(struct vde_data *vpri, struct vde_init *init)
+{
+        struct vde_open_args *args;
+
+        vpri->args = kmalloc(sizeof(struct vde_open_args), UM_GFP_KERNEL);
+        if (vpri->args == NULL) {
+                printk(UM_KERN_ERR "vde_init_libstuff - vde_open_args"
+                       "allocation failed");
+                return;
+        }
+
+        args = vpri->args;
+
+        args->port = init->port;
+        args->group = init->group;
+        args->mode = init->mode ? init->mode : 0700;
+
+        args->port ?  printk(UM_KERN_INFO "port %d", args->port) :
+                printk(UM_KERN_INFO "undefined port");
+}
+
+int vde_user_read(void *conn, void *buf, int len)
+{
+        VDECONN *vconn = conn;
+        int rv;
+
+        if (vconn == NULL)
+                return 0;
+
+        rv = vde_recv(vconn, buf, len, 0);
+        if (rv < 0) {
+                if (errno == EAGAIN)
+                        return 0;
+                return -errno;
+        }
+        else if (rv == 0)
+                return -ENOTCONN;
+
+        return rv;
+}
+
+int vde_user_write(void *conn, void *buf, int len)
+{
+        VDECONN *vconn = conn;
+
+        if (vconn == NULL)
+                return 0;
+
+        return vde_send(vconn, buf, len, 0);
+}
+