uml: network driver MTU cleanups

A bunch of MTU-related cleanups in the network code.

First, there is the addition of the notion of a maximally-sized packet, which
is the MTU plus headers.  This is used to size the skb that will receive a
packet.  This allows ether_adjust_skb to go away, as it was used to resize the
skb after it was allocated.

Since the skb passed into the low-level read routine is no longer resized, and
possibly reallocated, there, they (and the write routines) don't need to get
an sk_buff **.  They just need the sk_buff * now.  The callers of
ether_adjust_skb still need to do the skb_put, so that's now inlined.

The MAX_PACKET definitions in most of the drivers are gone.

The set_mtu methods were all the same and did nothing, so they can be
removed.

The ethertap driver had a typo which doubled the size of the packet rather
than adding two bytes to it.  It also wasn't defining its setup_size, causing
a zero-byte kmalloc and crash when the invalid pointer returned from kmalloc
was dereferenced.

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>

diff --git a/arch/um/drivers/daemon_kern.c b/arch/um/drivers/daemon_kern.c
index ac507bb..d53ff52 100644 (file)
--- a/arch/um/drivers/daemon_kern.c
+++ b/arch/um/drivers/daemon_kern.c
@@ -39,20 +39,15 @@ static void daemon_init(struct net_device *dev, void *data)
        printk("\n");
 }
 
-static int daemon_read(int fd, struct sk_buff **skb,
-                      struct uml_net_private *lp)
+static int daemon_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
 {
-       *skb = ether_adjust_skb(*skb, ETH_HEADER_OTHER);
-       if (*skb == NULL)
-               return -ENOMEM;
-       return net_recvfrom(fd, skb_mac_header(*skb),
-                           (*skb)->dev->mtu + ETH_HEADER_OTHER);
+       return net_recvfrom(fd, skb_mac_header(skb),
+                           skb->dev->mtu + ETH_HEADER_OTHER);
 }
 
-static int daemon_write(int fd, struct sk_buff **skb,
-                       struct uml_net_private *lp)
+static int daemon_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
 {
-       return daemon_user_write(fd, (*skb)->data, (*skb)->len,
+       return daemon_user_write(fd, skb->data, skb->len,
                                 (struct daemon_data *) &lp->user);
 }
 

diff --git a/arch/um/drivers/daemon_user.c b/arch/um/drivers/daemon_user.c
index 90983d4..f23c109 100644 (file)
--- a/arch/um/drivers/daemon_user.c
+++ b/arch/um/drivers/daemon_user.c
@@ -19,8 +19,6 @@
 #include "um_malloc.h"
 #include "user.h"
 
-#define MAX_PACKET (ETH_MAX_PACKET + ETH_HEADER_OTHER)
-
 enum request_type { REQ_NEW_CONTROL };
 
 #define SWITCH_MAGIC 0xfeedface
@@ -184,18 +182,13 @@ int daemon_user_write(int fd, void *buf, int len, struct daemon_data *pri)
        return net_sendto(fd, buf, len, data_addr, sizeof(*data_addr));
 }
 
-static int daemon_set_mtu(int mtu, void *data)
-{
-       return mtu;
-}
-
 const struct net_user_info daemon_user_info = {
        .init           = daemon_user_init,
        .open           = daemon_open,
        .close          = NULL,
        .remove         = daemon_remove,
-       .set_mtu        = daemon_set_mtu,
        .add_address    = NULL,
        .delete_address = NULL,
-       .max_packet     = MAX_PACKET - ETH_HEADER_OTHER
+       .mtu            = ETH_MAX_PACKET,
+       .max_packet     = ETH_MAX_PACKET + ETH_HEADER_OTHER,
 };

diff --git a/arch/um/drivers/mcast_kern.c b/arch/um/drivers/mcast_kern.c
index 5027b87..822092f 100644 (file)
--- a/arch/um/drivers/mcast_kern.c
+++ b/arch/um/drivers/mcast_kern.c
@@ -39,18 +39,15 @@ static void mcast_init(struct net_device *dev, void *data)
               dpri->addr, dpri->port, dpri->ttl);
 }
 
-static int mcast_read(int fd, struct sk_buff **skb, struct uml_net_private *lp)
+static int mcast_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
 {
-       *skb = ether_adjust_skb(*skb, ETH_HEADER_OTHER);
-       if (*skb == NULL)
-               return -ENOMEM;
-       return net_recvfrom(fd, skb_mac_header(*skb),
-                           (*skb)->dev->mtu + ETH_HEADER_OTHER);
+       return net_recvfrom(fd, skb_mac_header(skb),
+                           skb->dev->mtu + ETH_HEADER_OTHER);
 }
 
-static int mcast_write(int fd, struct sk_buff **skb, struct uml_net_private *lp)
+static int mcast_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
 {
-       return mcast_user_write(fd, (*skb)->data, (*skb)->len,
+       return mcast_user_write(fd, skb->data, skb->len,
                                (struct mcast_data *) &lp->user);
 }
 

diff --git a/arch/um/drivers/mcast_user.c b/arch/um/drivers/mcast_user.c
index e427b53..5f647d7 100644 (file)
--- a/arch/um/drivers/mcast_user.c
+++ b/arch/um/drivers/mcast_user.c
@@ -20,8 +20,6 @@
 #include "um_malloc.h"
 #include "user.h"
 
-#define MAX_PACKET (ETH_MAX_PACKET + ETH_HEADER_OTHER)
-
 static struct sockaddr_in *new_addr(char *addr, unsigned short port)
 {
        struct sockaddr_in *sin;
@@ -154,18 +152,13 @@ int mcast_user_write(int fd, void *buf, int len, struct mcast_data *pri)
        return net_sendto(fd, buf, len, data_addr, sizeof(*data_addr));
 }
 
-static int mcast_set_mtu(int mtu, void *data)
-{
-       return mtu;
-}
-
 const struct net_user_info mcast_user_info = {
        .init           = mcast_user_init,
        .open           = mcast_open,
        .close          = mcast_close,
        .remove         = mcast_remove,
-       .set_mtu        = mcast_set_mtu,
        .add_address    = NULL,
        .delete_address = NULL,
-       .max_packet     = MAX_PACKET - ETH_HEADER_OTHER
+       .mtu            = ETH_MAX_PACKET,
+       .max_packet     = ETH_MAX_PACKET + ETH_HEADER_OTHER,
 };

diff --git a/arch/um/drivers/net_kern.c b/arch/um/drivers/net_kern.c
index b097a24..59811cc 100644 (file)
--- a/arch/um/drivers/net_kern.c
+++ b/arch/um/drivers/net_kern.c
@@ -41,16 +41,16 @@ static int uml_net_rx(struct net_device *dev)
        struct sk_buff *skb;
 
        /* If we can't allocate memory, try again next round. */
-       skb = dev_alloc_skb(dev->mtu);
+       skb = dev_alloc_skb(lp->max_packet);
        if (skb == NULL) {
                lp->stats.rx_dropped++;
                return 0;
        }
 
        skb->dev = dev;
-       skb_put(skb, dev->mtu);
+       skb_put(skb, lp->max_packet);
        skb_reset_mac_header(skb);
-       pkt_len = (*lp->read)(lp->fd, &skb, lp);
+       pkt_len = (*lp->read)(lp->fd, skb, lp);
 
        if (pkt_len > 0) {
                skb_trim(skb, pkt_len);
@@ -178,7 +178,7 @@ static int uml_net_start_xmit(struct sk_buff *skb, struct net_device *dev)
 
        spin_lock_irqsave(&lp->lock, flags);
 
-       len = (*lp->write)(lp->fd, &skb, lp);
+       len = (*lp->write)(lp->fd, skb, lp);
 
        if (len == skb->len) {
                lp->stats.tx_packets++;
@@ -240,22 +240,9 @@ static int uml_net_set_mac(struct net_device *dev, void *addr)
 
 static int uml_net_change_mtu(struct net_device *dev, int new_mtu)
 {
-       struct uml_net_private *lp = dev->priv;
-       int err = 0;
-
-       spin_lock_irq(&lp->lock);
-
-       new_mtu = (*lp->set_mtu)(new_mtu, &lp->user);
-       if (new_mtu < 0) {
-               err = new_mtu;
-               goto out;
-       }
-
        dev->mtu = new_mtu;
 
- out:
-       spin_unlock_irq(&lp->lock);
-       return err;
+       return 0;
 }
 
 static void uml_net_get_drvinfo(struct net_device *dev,
@@ -427,6 +414,7 @@ static void eth_configure(int n, void *init, char *mac,
                  .dev                  = dev,
                  .fd                   = -1,
                  .mac                  = { 0xfe, 0xfd, 0x0, 0x0, 0x0, 0x0},
+                 .max_packet           = transport->user->max_packet,
                  .protocol             = transport->kern->protocol,
                  .open                 = transport->user->open,
                  .close                = transport->user->close,
@@ -434,8 +422,7 @@ static void eth_configure(int n, void *init, char *mac,
                  .read                 = transport->kern->read,
                  .write                = transport->kern->write,
                  .add_address          = transport->user->add_address,
-                 .delete_address       = transport->user->delete_address,
-                 .set_mtu              = transport->user->set_mtu });
+                 .delete_address       = transport->user->delete_address });
 
        init_timer(&lp->tl);
        spin_lock_init(&lp->lock);
@@ -447,7 +434,7 @@ static void eth_configure(int n, void *init, char *mac,
                goto out_unregister;
 
        set_ether_mac(dev, device->mac);
-       dev->mtu = transport->user->max_packet;
+       dev->mtu = transport->user->mtu;
        dev->open = uml_net_open;
        dev->hard_start_xmit = uml_net_start_xmit;
        dev->stop = uml_net_close;
@@ -807,19 +794,6 @@ static void close_devices(void)
 
 __uml_exitcall(close_devices);
 
-struct sk_buff *ether_adjust_skb(struct sk_buff *skb, int extra)
-{
-       if ((skb != NULL) && (skb_tailroom(skb) < extra)) {
-               struct sk_buff *skb2;
-
-               skb2 = skb_copy_expand(skb, 0, extra, GFP_ATOMIC);
-               dev_kfree_skb(skb);
-               skb = skb2;
-       }
-       if (skb != NULL) skb_put(skb, extra);
-       return skb;
-}
-
 void iter_addresses(void *d, void (*cb)(unsigned char *, unsigned char *,
                                        void *),
                    void *arg)

diff --git a/arch/um/drivers/pcap_kern.c b/arch/um/drivers/pcap_kern.c
index da0403e..3a750dd 100644 (file)
--- a/arch/um/drivers/pcap_kern.c
+++ b/arch/um/drivers/pcap_kern.c
@@ -31,19 +31,14 @@ void pcap_init(struct net_device *dev, void *data)
        printk("pcap backend, host interface %s\n", ppri->host_if);
 }
 
-static int pcap_read(int fd, struct sk_buff **skb,
-                      struct uml_net_private *lp)
+static int pcap_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
 {
-       *skb = ether_adjust_skb(*skb, ETH_HEADER_OTHER);
-       if (*skb == NULL)
-               return -ENOMEM;
-
-       return pcap_user_read(fd, skb_mac_header(*skb),
-                             (*skb)->dev->mtu + ETH_HEADER_OTHER,
+       return pcap_user_read(fd, skb_mac_header(skb),
+                             skb->dev->mtu + ETH_HEADER_OTHER,
                              (struct pcap_data *) &lp->user);
 }
 
-static int pcap_write(int fd, struct sk_buff **skb, struct uml_net_private *lp)
+static int pcap_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
 {
        return -EPERM;
 }

diff --git a/arch/um/drivers/pcap_user.c b/arch/um/drivers/pcap_user.c
index cf996b8..e980935 100644 (file)
--- a/arch/um/drivers/pcap_user.c
+++ b/arch/um/drivers/pcap_user.c
@@ -13,8 +13,6 @@
 #include "um_malloc.h"
 #include "user.h"
 
-#define MAX_PACKET (ETH_MAX_PACKET + ETH_HEADER_OTHER)
-
 #define PCAP_FD(p) (*(int *)(p))
 
 static int pcap_user_init(void *data, void *dev)
@@ -23,7 +21,8 @@ static int pcap_user_init(void *data, void *dev)
        pcap_t *p;
        char errors[PCAP_ERRBUF_SIZE];
 
-       p = pcap_open_live(pri->host_if, MAX_PACKET, pri->promisc, 0, errors);
+       p = pcap_open_live(pri->host_if, ETH_MAX_PACKET + ETH_HEADER_OTHER,
+                          pri->promisc, 0, errors);
        if (p == NULL) {
                printk(UM_KERN_ERR "pcap_user_init : pcap_open_live failed - "
                       "'%s'\n", errors);
@@ -133,8 +132,8 @@ const struct net_user_info pcap_user_info = {
        .open           = pcap_open,
        .close          = NULL,
        .remove         = pcap_remove,
-       .set_mtu        = NULL,
        .add_address    = NULL,
        .delete_address = NULL,
-       .max_packet     = MAX_PACKET - ETH_HEADER_OTHER
+       .mtu            = ETH_MAX_PACKET,
+       .max_packet     = ETH_MAX_PACKET + ETH_HEADER_OTHER,
 };

diff --git a/arch/um/drivers/slip_kern.c b/arch/um/drivers/slip_kern.c
index 05ed351..ae67e71 100644 (file)
--- a/arch/um/drivers/slip_kern.c
+++ b/arch/um/drivers/slip_kern.c
@@ -47,17 +47,15 @@ static unsigned short slip_protocol(struct sk_buff *skbuff)
        return htons(ETH_P_IP);
 }
 
-static int slip_read(int fd, struct sk_buff **skb,
-                      struct uml_net_private *lp)
+static int slip_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
 {
-       return slip_user_read(fd, skb_mac_header(*skb), (*skb)->dev->mtu,
+       return slip_user_read(fd, skb_mac_header(skb), skb->dev->mtu,
                              (struct slip_data *) &lp->user);
 }
 
-static int slip_write(int fd, struct sk_buff **skb,
-                     struct uml_net_private *lp)
+static int slip_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
 {
-       return slip_user_write(fd, (*skb)->data, (*skb)->len,
+       return slip_user_write(fd, skb->data, skb->len,
                               (struct slip_data *) &lp->user);
 }
 

diff --git a/arch/um/drivers/slip_user.c b/arch/um/drivers/slip_user.c
index d78f324..5f06204 100644 (file)
--- a/arch/um/drivers/slip_user.c
+++ b/arch/um/drivers/slip_user.c
@@ -230,11 +230,6 @@ int slip_user_write(int fd, void *buf, int len, struct slip_data *pri)
        return slip_proto_write(fd, buf, len, &pri->slip);
 }
 
-static int slip_set_mtu(int mtu, void *data)
-{
-       return mtu;
-}
-
 static void slip_add_addr(unsigned char *addr, unsigned char *netmask,
                          void *data)
 {
@@ -260,8 +255,8 @@ const struct net_user_info slip_user_info = {
        .open           = slip_open,
        .close          = slip_close,
        .remove         = NULL,
-       .set_mtu        = slip_set_mtu,
        .add_address    = slip_add_addr,
        .delete_address = slip_del_addr,
-       .max_packet     = BUF_SIZE
+       .mtu            = BUF_SIZE,
+       .max_packet     = BUF_SIZE,
 };

diff --git a/arch/um/drivers/slirp_kern.c b/arch/um/drivers/slirp_kern.c
index b208d5e..240ee65 100644 (file)
--- a/arch/um/drivers/slirp_kern.c
+++ b/arch/um/drivers/slirp_kern.c
@@ -52,18 +52,16 @@ static unsigned short slirp_protocol(struct sk_buff *skbuff)
        return htons(ETH_P_IP);
 }
 
-static int slirp_read(int fd, struct sk_buff **skb,
-                      struct uml_net_private *lp)
+static int slirp_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
 {
-       return slirp_user_read(fd, skb_mac_header(*skb), (*skb)->dev->mtu,
-                             (struct slirp_data *) &lp->user);
+       return slirp_user_read(fd, skb_mac_header(skb), skb->dev->mtu,
+                              (struct slirp_data *) &lp->user);
 }
 
-static int slirp_write(int fd, struct sk_buff **skb,
-                     struct uml_net_private *lp)
+static int slirp_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
 {
-       return slirp_user_write(fd, (*skb)->data, (*skb)->len,
-                              (struct slirp_data *) &lp->user);
+       return slirp_user_write(fd, skb->data, skb->len,
+                               (struct slirp_data *) &lp->user);
 }
 
 const struct net_kern_info slirp_kern_info = {

diff --git a/arch/um/drivers/slirp_user.c b/arch/um/drivers/slirp_user.c
index a4755bc..1865089 100644 (file)
--- a/arch/um/drivers/slirp_user.c
+++ b/arch/um/drivers/slirp_user.c
@@ -124,18 +124,13 @@ int slirp_user_write(int fd, void *buf, int len, struct slirp_data *pri)
        return slip_proto_write(fd, buf, len, &pri->slip);
 }
 
-static int slirp_set_mtu(int mtu, void *data)
-{
-       return mtu;
-}
-
 const struct net_user_info slirp_user_info = {
        .init           = slirp_user_init,
        .open           = slirp_open,
        .close          = slirp_close,
        .remove         = NULL,
-       .set_mtu        = slirp_set_mtu,
        .add_address    = NULL,
        .delete_address = NULL,
-       .max_packet     = BUF_SIZE
+       .mtu            = BUF_SIZE,
+       .max_packet     = BUF_SIZE,
 };

diff --git a/arch/um/drivers/vde_kern.c b/arch/um/drivers/vde_kern.c
index c5d0168..add7e72 100644 (file)
--- a/arch/um/drivers/vde_kern.c
+++ b/arch/um/drivers/vde_kern.c
@@ -36,30 +36,25 @@ static void vde_init(struct net_device *dev, void *data)
        printk("\n");
 }
 
-static int vde_read(int fd, struct sk_buff **skb, struct uml_net_private *lp)
+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);
-       }
+       if (pri->conn != NULL)
+               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)
+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);
+               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;

diff --git a/arch/um/drivers/vde_user.c b/arch/um/drivers/vde_user.c
index 7533cd3..d9941fe 100644 (file)
--- a/arch/um/drivers/vde_user.c
+++ b/arch/um/drivers/vde_user.c
@@ -12,8 +12,6 @@
 #include "user.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;
@@ -65,20 +63,15 @@ static void vde_remove(void *data)
        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
+       .mtu            = ETH_MAX_PACKET,
+       .max_packet     = ETH_MAX_PACKET + ETH_HEADER_OTHER,
 };
 
 void vde_init_libstuff(struct vde_data *vpri, struct vde_init *init)

diff --git a/arch/um/include/net_kern.h b/arch/um/include/net_kern.h
index 9237056..d843c79 100644 (file)
--- a/arch/um/include/net_kern.h
+++ b/arch/um/include/net_kern.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2002 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
@@ -30,24 +30,24 @@ struct uml_net_private {
        struct work_struct work;
        int fd;
        unsigned char mac[ETH_ALEN];
+       int max_packet;
        unsigned short (*protocol)(struct sk_buff *);
        int (*open)(void *);
        void (*close)(int, void *);
        void (*remove)(void *);
-       int (*read)(int, struct sk_buff **skb, struct uml_net_private *);
-       int (*write)(int, struct sk_buff **skb, struct uml_net_private *);
+       int (*read)(int, struct sk_buff *skb, struct uml_net_private *);
+       int (*write)(int, struct sk_buff *skb, struct uml_net_private *);
 
        void (*add_address)(unsigned char *, unsigned char *, void *);
        void (*delete_address)(unsigned char *, unsigned char *, void *);
-       int (*set_mtu)(int mtu, void *);
        char user[0];
 };
 
 struct net_kern_info {
        void (*init)(struct net_device *, void *);
        unsigned short (*protocol)(struct sk_buff *);
-       int (*read)(int, struct sk_buff **skb, struct uml_net_private *);
-       int (*write)(int, struct sk_buff **skb, struct uml_net_private *);
+       int (*read)(int, struct sk_buff *skb, struct uml_net_private *);
+       int (*write)(int, struct sk_buff *skb, struct uml_net_private *);
 };
 
 struct transport {
@@ -62,7 +62,6 @@ struct transport {
 
 extern struct net_device *ether_init(int);
 extern unsigned short ether_protocol(struct sk_buff *);
-extern struct sk_buff *ether_adjust_skb(struct sk_buff *skb, int extra);
 extern int tap_setup_common(char *str, char *type, char **dev_name,
                            char **mac_out, char **gate_addr);
 extern void register_transport(struct transport *new);

diff --git a/arch/um/include/net_user.h b/arch/um/include/net_user.h
index cfe7c50..63bee15 100644 (file)
--- a/arch/um/include/net_user.h
+++ b/arch/um/include/net_user.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
@@ -18,10 +18,10 @@ struct net_user_info {
        int (*open)(void *);
        void (*close)(int, void *);
        void (*remove)(void *);
-       int (*set_mtu)(int mtu, void *);
        void (*add_address)(unsigned char *, unsigned char *, void *);
        void (*delete_address)(unsigned char *, unsigned char *, void *);
        int max_packet;
+       int mtu;
 };
 
 extern void ether_user_init(void *data, void *dev);

diff --git a/arch/um/os-Linux/drivers/ethertap_kern.c b/arch/um/os-Linux/drivers/ethertap_kern.c
index 542bcc5..04f11b9 100644 (file)
--- a/arch/um/os-Linux/drivers/ethertap_kern.c
+++ b/arch/um/os-Linux/drivers/ethertap_kern.c
@@ -36,35 +36,24 @@ static void etap_init(struct net_device *dev, void *data)
        printk("\n");
 }
 
-static int etap_read(int fd, struct sk_buff **skb, struct uml_net_private *lp)
+static int etap_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
 {
        int len;
 
-       *skb = ether_adjust_skb(*skb, ETH_HEADER_ETHERTAP);
-       if (*skb == NULL)
-               return -ENOMEM;
-       len = net_recvfrom(fd, skb_mac_header(*skb),
-                          (*skb)->dev->mtu + 2 * ETH_HEADER_ETHERTAP);
+       len = net_recvfrom(fd, skb_mac_header(skb),
+                          skb->dev->mtu + 2 + ETH_HEADER_ETHERTAP);
        if (len <= 0)
-               return len;
-       skb_pull(*skb, 2);
+               return(len);
+
+       skb_pull(skb, 2);
        len -= 2;
        return len;
 }
 
-static int etap_write(int fd, struct sk_buff **skb, struct uml_net_private *lp)
+static int etap_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
 {
-       if (skb_headroom(*skb) < 2) {
-               struct sk_buff *skb2;
-
-               skb2 = skb_realloc_headroom(*skb, 2);
-               dev_kfree_skb(*skb);
-               if (skb2 == NULL)
-                       return -ENOMEM;
-               *skb = skb2;
-       }
-       skb_push(*skb, 2);
-       return net_send(fd, (*skb)->data, (*skb)->len);
+       skb_push(skb, 2);
+       return net_send(fd, skb->data, skb->len);
 }
 
 const struct net_kern_info ethertap_kern_info = {
@@ -99,6 +88,7 @@ static struct transport ethertap_transport = {
        .user           = &ethertap_user_info,
        .kern           = &ethertap_kern_info,
        .private_size   = sizeof(struct ethertap_data),
+       .setup_size     = sizeof(struct ethertap_init),
 };
 
 static int register_ethertap(void)

diff --git a/arch/um/os-Linux/drivers/ethertap_user.c b/arch/um/os-Linux/drivers/ethertap_user.c
index 29404b9..4ff5536 100644 (file)
--- a/arch/um/os-Linux/drivers/ethertap_user.c
+++ b/arch/um/os-Linux/drivers/ethertap_user.c
@@ -222,11 +222,6 @@ static void etap_close(int fd, void *data)
        pri->control_fd = -1;
 }
 
-static int etap_set_mtu(int mtu, void *data)
-{
-       return mtu;
-}
-
 static void etap_add_addr(unsigned char *addr, unsigned char *netmask,
                          void *data)
 {
@@ -254,8 +249,8 @@ const struct net_user_info ethertap_user_info = {
        .open           = etap_open,
        .close          = etap_close,
        .remove         = NULL,
-       .set_mtu        = etap_set_mtu,
        .add_address    = etap_add_addr,
        .delete_address = etap_del_addr,
-       .max_packet     = MAX_PACKET - ETH_HEADER_ETHERTAP
+       .mtu            = ETH_MAX_PACKET,
+       .max_packet     = ETH_MAX_PACKET + ETH_HEADER_ETHERTAP,
 };

diff --git a/arch/um/os-Linux/drivers/tuntap_kern.c b/arch/um/os-Linux/drivers/tuntap_kern.c
index 9ade1f8..9d38480 100644 (file)
--- a/arch/um/os-Linux/drivers/tuntap_kern.c
+++ b/arch/um/os-Linux/drivers/tuntap_kern.c
@@ -35,20 +35,15 @@ static void tuntap_init(struct net_device *dev, void *data)
        printk("\n");
 }
 
-static int tuntap_read(int fd, struct sk_buff **skb,
-                      struct uml_net_private *lp)
+static int tuntap_read(int fd, struct sk_buff *skb, struct uml_net_private *lp)
 {
-       *skb = ether_adjust_skb(*skb, ETH_HEADER_OTHER);
-       if (*skb == NULL)
-               return -ENOMEM;
-       return net_read(fd, skb_mac_header(*skb),
-                       (*skb)->dev->mtu + ETH_HEADER_OTHER);
+       return net_read(fd, skb_mac_header(skb),
+                       skb->dev->mtu + ETH_HEADER_OTHER);
 }
 
-static int tuntap_write(int fd, struct sk_buff **skb,
-                       struct uml_net_private *lp)
+static int tuntap_write(int fd, struct sk_buff *skb, struct uml_net_private *lp)
 {
-       return net_write(fd, (*skb)->data, (*skb)->len);
+       return net_write(fd, skb->data, skb->len);
 }
 
 const struct net_kern_info tuntap_kern_info = {

diff --git a/arch/um/os-Linux/drivers/tuntap_user.c b/arch/um/os-Linux/drivers/tuntap_user.c
index 10714a4..6c55d3c 100644 (file)
--- a/arch/um/os-Linux/drivers/tuntap_user.c
+++ b/arch/um/os-Linux/drivers/tuntap_user.c
@@ -18,8 +18,6 @@
 #include "tuntap.h"
 #include "user.h"
 
-#define MAX_PACKET ETH_MAX_PACKET
-
 static int tuntap_user_init(void *data, void *dev)
 {
        struct tuntap_data *pri = data;
@@ -206,18 +204,13 @@ static void tuntap_close(int fd, void *data)
        pri->fd = -1;
 }
 
-static int tuntap_set_mtu(int mtu, void *data)
-{
-       return mtu;
-}
-
 const struct net_user_info tuntap_user_info = {
        .init           = tuntap_user_init,
        .open           = tuntap_open,
        .close          = tuntap_close,
        .remove         = NULL,
-       .set_mtu        = tuntap_set_mtu,
        .add_address    = tuntap_add_addr,
        .delete_address = tuntap_del_addr,
-       .max_packet     = MAX_PACKET
+       .mtu            = ETH_MAX_PACKET,
+       .max_packet     = ETH_MAX_PACKET + ETH_HEADER_OTHER,
 };