3 files changed, 118 insertions, 53 deletions

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 15d67635bb10..0476549841ac 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -64,6 +64,7 @@
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
 #include <net/rtnetlink.h>
+#include <net/sock.h>
 
 #include <asm/system.h>
 #include <asm/uaccess.h>
@@ -95,6 +96,8 @@ struct tun_file {
         wait_queue_head_t       read_wait;
 };
 
+struct tun_sock;
+
 struct tun_struct {
         struct tun_file         *tfile;
         unsigned int            flags;
@@ -107,12 +110,24 @@ struct tun_struct {
         struct fasync_struct    *fasync;
 
         struct tap_filter       txflt;
+        struct sock             *sk;
+        struct socket           socket;
 
 #ifdef TUN_DEBUG
         int debug;
 #endif
 };
 
+struct tun_sock {
+        struct sock             sk;
+        struct tun_struct       *tun;
+};
+
+static inline struct tun_sock *tun_sk(struct sock *sk)
+{
+        return container_of(sk, struct tun_sock, sk);
+}
+
 static int tun_attach(struct tun_struct *tun, struct file *file)
 {
         struct tun_file *tfile = file->private_data;
@@ -461,7 +476,8 @@ static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
 {
         struct tun_file *tfile = file->private_data;
         struct tun_struct *tun = __tun_get(tfile);
-        unsigned int mask = POLLOUT | POLLWRNORM;
+        struct sock *sk = tun->sk;
+        unsigned int mask = 0;
 
         if (!tun)
                 return POLLERR;
@@ -473,6 +489,11 @@ static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
         if (!skb_queue_empty(&tun->readq))
                 mask |= POLLIN | POLLRDNORM;
 
+        if (sock_writeable(sk) ||
+            (!test_and_set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags) &&
+             sock_writeable(sk)))
+                mask |= POLLOUT | POLLWRNORM;
+
         if (tun->dev->reg_state != NETREG_REGISTERED)
                 mask = POLLERR;
 
@@ -482,66 +503,35 @@ static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
 
 /* prepad is the amount to reserve at front.  len is length after that.
  * linear is a hint as to how much to copy (usually headers). */
-static struct sk_buff *tun_alloc_skb(size_t prepad, size_t len, size_t linear,
-                                     gfp_t gfp)
+static inline struct sk_buff *tun_alloc_skb(struct tun_struct *tun,
+                                            size_t prepad, size_t len,
+                                            size_t linear, int noblock)
 {
+        struct sock *sk = tun->sk;
         struct sk_buff *skb;
-        unsigned int i;
-
-        skb = alloc_skb(prepad + len, gfp|__GFP_NOWARN);
-        if (skb) {
-                skb_reserve(skb, prepad);
-                skb_put(skb, len);
-                return skb;
-        }
+        int err;
 
         /* Under a page?  Don't bother with paged skb. */
         if (prepad + len < PAGE_SIZE)
-                return NULL;
+                linear = len;
 
-        /* Start with a normal skb, and add pages. */
-        skb = alloc_skb(prepad + linear, gfp);
+        skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock,
+                                   &err);
         if (!skb)
-                return NULL;
+                return ERR_PTR(err);
 
         skb_reserve(skb, prepad);
         skb_put(skb, linear);
-
-        len -= linear;
-
-        for (i = 0; i < MAX_SKB_FRAGS; i++) {
-                skb_frag_t *f = &skb_shinfo(skb)->frags[i];
-
-                f->page = alloc_page(gfp|__GFP_ZERO);
-                if (!f->page)
-                        break;
-
-                f->page_offset = 0;
-                f->size = PAGE_SIZE;
-
-                skb->data_len += PAGE_SIZE;
-                skb->len += PAGE_SIZE;
-                skb->truesize += PAGE_SIZE;
-                skb_shinfo(skb)->nr_frags++;
-
-                if (len < PAGE_SIZE) {
-                        len = 0;
-                        break;
-                }
-                len -= PAGE_SIZE;
-        }
-
-        /* Too large, or alloc fail? */
-        if (unlikely(len)) {
-                kfree_skb(skb);
-                skb = NULL;
-        }
+        skb->data_len = len - linear;
+        skb->len += len - linear;
 
         return skb;
 }
 
 /* Get packet from user space buffer */
-static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
+static __inline__ ssize_t tun_get_user(struct tun_struct *tun,
+                                       struct iovec *iv, size_t count,
+                                       int noblock)
 {
         struct tun_pi pi = { 0, cpu_to_be16(ETH_P_IP) };
         struct sk_buff *skb;
@@ -573,9 +563,11 @@ static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv,
                         return -EINVAL;
         }
 
-        if (!(skb = tun_alloc_skb(align, len, gso.hdr_len, GFP_KERNEL))) {
-                tun->dev->stats.rx_dropped++;
-                return -ENOMEM;
+        skb = tun_alloc_skb(tun, align, len, gso.hdr_len, noblock);
+        if (IS_ERR(skb)) {
+                if (PTR_ERR(skb) != -EAGAIN)
+                        tun->dev->stats.rx_dropped++;
+                return PTR_ERR(skb);
         }
 
         if (skb_copy_datagram_from_iovec(skb, 0, iv, len)) {
@@ -661,7 +653,8 @@ static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv,
 static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
                               unsigned long count, loff_t pos)
 {
-        struct tun_struct *tun = tun_get(iocb->ki_filp);
+        struct file *file = iocb->ki_filp;
+        struct tun_struct *tun = file->private_data;
         ssize_t result;
 
         if (!tun)
@@ -669,7 +662,8 @@ static ssize_t tun_chr_aio_write(struct kiocb *iocb, const struct iovec *iv,
 
         DBG(KERN_INFO "%s: tun_chr_write %ld\n", tun->dev->name, count);
 
-        result = tun_get_user(tun, (struct iovec *) iv, iov_length(iv, count));
+        result = tun_get_user(tun, (struct iovec *)iv, iov_length(iv, count),
+                              file->f_flags & O_NONBLOCK);
 
         tun_put(tun);
         return result;
@@ -828,11 +822,40 @@ static struct rtnl_link_ops tun_link_ops __read_mostly = {
         .validate       = tun_validate,
 };
 
+static void tun_sock_write_space(struct sock *sk)
+{
+        struct tun_struct *tun;
+
+        if (!sock_writeable(sk))
+                return;
+
+        if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
+                wake_up_interruptible_sync(sk->sk_sleep);
+
+        if (!test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags))
+                return;
+
+        tun = container_of(sk, struct tun_sock, sk)->tun;
+        kill_fasync(&tun->fasync, SIGIO, POLL_OUT);
+}
+
+static void tun_sock_destruct(struct sock *sk)
+{
+        dev_put(container_of(sk, struct tun_sock, sk)->tun->dev);
+}
+
+static struct proto tun_proto = {
+        .name           = "tun",
+        .owner          = THIS_MODULE,
+        .obj_size       = sizeof(struct tun_sock),
+};
 
 static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
 {
+        struct sock *sk;
         struct tun_struct *tun;
         struct net_device *dev;
+        struct tun_file *tfile = file->private_data;
         int err;
 
         dev = __dev_get_by_name(net, ifr->ifr_name);
@@ -885,14 +908,31 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
                 tun->flags = flags;
                 tun->txflt.count = 0;
 
+                err = -ENOMEM;
+                sk = sk_alloc(net, AF_UNSPEC, GFP_KERNEL, &tun_proto);
+                if (!sk)
+                        goto err_free_dev;
+
+                /* This ref count is for tun->sk. */
+                dev_hold(dev);
+                sock_init_data(&tun->socket, sk);
+                sk->sk_write_space = tun_sock_write_space;
+                sk->sk_destruct = tun_sock_destruct;
+                sk->sk_sndbuf = INT_MAX;
+                sk->sk_sleep = &tfile->read_wait;
+
+                tun->sk = sk;
+                container_of(sk, struct tun_sock, sk)->tun = tun;
+
                 tun_net_init(dev);
 
                 if (strchr(dev->name, '%')) {
                         err = dev_alloc_name(dev, dev->name);
                         if (err < 0)
-                                goto err_free_dev;
+                                goto err_free_sk;
                 }
 
+                err = -EINVAL;
                 err = register_netdevice(tun->dev);
                 if (err < 0)
                         goto err_free_dev;
@@ -928,6 +968,8 @@ static int tun_set_iff(struct net *net, struct file *file, struct ifreq *ifr)
         strcpy(ifr->ifr_name, tun->dev->name);
         return 0;
 
+ err_free_sk:
+        sock_put(sk);
  err_free_dev:
         free_netdev(dev);
  failed:
@@ -1012,6 +1054,7 @@ static int tun_chr_ioctl(struct inode *inode, struct file *file,
         struct tun_struct *tun;
         void __user* argp = (void __user*)arg;
         struct ifreq ifr;
+        int sndbuf;
         int ret;
 
         if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
@@ -1151,6 +1194,22 @@ static int tun_chr_ioctl(struct inode *inode, struct file *file,
                 ret = dev_set_mac_address(tun->dev, &ifr.ifr_hwaddr);
                 rtnl_unlock();
                 break;
+
+        case TUNGETSNDBUF:
+                sndbuf = tun->sk->sk_sndbuf;
+                if (copy_to_user(argp, &sndbuf, sizeof(sndbuf)))
+                        ret = -EFAULT;
+                break;
+
+        case TUNSETSNDBUF:
+                if (copy_from_user(&sndbuf, argp, sizeof(sndbuf))) {
+                        ret = -EFAULT;
+                        break;
+                }
+
+                tun->sk->sk_sndbuf = sndbuf;
+                break;
+
         default:
                 ret = -EINVAL;
                 break;
@@ -1218,8 +1277,10 @@ static int tun_chr_close(struct inode *inode, struct file *file)
                 __tun_detach(tun);
 
                 /* If desireable, unregister the netdevice. */
-                if (!(tun->flags & TUN_PERSIST))
+                if (!(tun->flags & TUN_PERSIST)) {
+                        sock_put(tun->sk);
                         unregister_netdevice(tun->dev);
+                }
 
                 rtnl_unlock();
         }
diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c
index c8f8d5904f5e..c03c10d7fb6b 100644
--- a/fs/compat_ioctl.c
+++ b/fs/compat_ioctl.c
@@ -1988,6 +1988,8 @@ COMPATIBLE_IOCTL(TUNSETGROUP)
 COMPATIBLE_IOCTL(TUNGETFEATURES)
 COMPATIBLE_IOCTL(TUNSETOFFLOAD)
 COMPATIBLE_IOCTL(TUNSETTXFILTER)
+COMPATIBLE_IOCTL(TUNGETSNDBUF)
+COMPATIBLE_IOCTL(TUNSETSNDBUF)
 /* Big V */
 COMPATIBLE_IOCTL(VT_SETMODE)
 COMPATIBLE_IOCTL(VT_GETMODE)
diff --git a/include/linux/if_tun.h b/include/linux/if_tun.h
index 8529f57ba263..049d6c9428db 100644
--- a/include/linux/if_tun.h
+++ b/include/linux/if_tun.h
@@ -46,6 +46,8 @@
 #define TUNSETOFFLOAD  _IOW('T', 208, unsigned int)
 #define TUNSETTXFILTER _IOW('T', 209, unsigned int)
 #define TUNGETIFF      _IOR('T', 210, unsigned int)
+#define TUNGETSNDBUF   _IOR('T', 211, int)
+#define TUNSETSNDBUF   _IOW('T', 212, int)
 
 /* TUNSETIFF ifr flags */
 #define IFF_TUN         0x0001