[PATCH] 2.5.9 TUN/TAP driver readv/writev support

From: Maksim (Max) (maxk@qualcomm.com)
Date: Tue Apr 23 2002 - 14:43:41 EST


Following patch adds proper support for readv/writev in TUN/TAP driver.
http://bluez.sourceforge.net/patches/tun-readv-writev-2.5.9.gz

Pleas apply

Thanks
Max

--- /opt/kernel/linux-2.5/drivers/net/tun.c Mon Apr 22 15:29:04 2002
+++ linux-2.5/drivers/net/tun.c Tue Apr 23 12:23:56 2002
@@ -1,6 +1,6 @@
 /*
  * TUN - Universal TUN/TAP device driver.
- * Copyright (C) 1999-2000 Maxim Krasnyansky <max_mk@yahoo.com>
+ * Copyright (C) 1999-2002 Maxim Krasnyansky <maxk@qualcomm.com>
*
  * 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
@@ -12,7 +12,7 @@
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  * GNU General Public License for more details.
  *
- * $Id: tun.c,v 1.12 2001/03/08 03:29:27 maxk Exp $
+ * $Id: tun.c,v 1.15 2002/03/01 02:44:24 maxk Exp $
  */
 
 /*
@@ -20,7 +20,7 @@
  * Modifications for 2.3.99-pre5 kernel.
  */
 
-#define TUN_VER "1.4"
+#define TUN_VER "1.5"
 
 #include <linux/config.h>
#include <linux/module.h>
@@ -181,50 +181,26 @@
 }
 
 /* Get packet from user space buffer(already verified) */
-static __inline__ ssize_t
-tun_get_user(struct tun_struct *tun, const struct iovec *iov,
- unsigned long count, size_t total)
+static __inline__ ssize_t tun_get_user(struct tun_struct *tun, struct iovec *iv, size_t count)
 {
         struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
- const struct iovec *vector = &iov[0];
- register const char *ptr = vector->iov_base;
- register int len = vector->iov_len;
         struct sk_buff *skb;
- ssize_t sent = 0;
+ size_t len = count;
 
         if (!(tun->flags & TUN_NO_PI)) {
                 if ((len -= sizeof(pi)) < 0)
                         return -EINVAL;
 
- copy_from_user(&pi, ptr, sizeof(pi));
- ptr += sizeof(pi);
-
- if (len == 0) {
- vector++;
- count--;
-
- ptr = vector->iov_base;
- len = vector->iov_len;
- }
+ memcpy_fromiovec((void *)&pi, iv, sizeof(pi));
         }
  
- if (!(skb = alloc_skb(total + 2, GFP_KERNEL))) {
+ if (!(skb = alloc_skb(len + 2, GFP_KERNEL))) {
                 tun->stats.rx_dropped++;
                 return -ENOMEM;
         }
 
         skb_reserve(skb, 2);
-
- while (count > 0) {
- copy_from_user(skb_put(skb, len), ptr, len);
- sent += len;
-
- vector++;
- count--;
-
- ptr = vector->iov_base;
- len = vector->iov_len;
- }
+ memcpy_fromiovec(skb_put(skb, len), iv, len);
 
         skb->dev = &tun->dev;
         switch (tun->flags & TUN_TYPE_MASK) {
@@ -243,60 +219,48 @@
         netif_rx_ni(skb);
    
         tun->stats.rx_packets++;
- tun->stats.rx_bytes += sent;
+ tun->stats.rx_bytes += len;
 
- return total;
+ return count;
 }
 
-/* Write */
-static ssize_t tun_chr_write(struct file * file, const char * buf,
- size_t count, loff_t *pos)
-{
- struct tun_struct *tun = (struct tun_struct *)file->private_data;
- struct iovec iov;
-
- if (!tun)
- return -EBADFD;
-
- DBG(KERN_INFO "%s: tun_chr_write %d\n", tun->name, count);
-
- if (verify_area(VERIFY_READ, buf, count))
- return -EFAULT;
-
- iov.iov_base = (char *) buf;
- iov.iov_len = count;
-
- return tun_get_user(tun, &iov, 1, count);
-}
-
 /* Writev */
-static ssize_t tun_chr_writev(struct file * file, const struct iovec *iov,
+static ssize_t tun_chr_writev(struct file * file, const struct iovec *iv,
                               unsigned long count, loff_t *pos)
 {
         struct tun_struct *tun = (struct tun_struct *)file->private_data;
- size_t total = 0;
         unsigned long i;
+ size_t len;
 
         if (!tun)
                 return -EBADFD;
 
- for (i = 0; i < count; i++) {
- if (verify_area(VERIFY_READ, iov[i].iov_base, iov[i].iov_len))
+ DBG(KERN_INFO "%s: tun_chr_write %d\n", tun->name, count);
+
+ for (i = 0, len = 0; i < count; i++) {
+ if (verify_area(VERIFY_READ, iv[i].iov_base, iv[i].iov_len))
                         return -EFAULT;
- total += iov[i].iov_len;
+ len += iv[i].iov_len;
         }
 
- return tun_get_user(tun, iov, count, total);
+ return tun_get_user(tun, (struct iovec *) iv, len);
+}
+
+/* Write */
+static ssize_t tun_chr_write(struct file * file, const char * buf,
+ size_t count, loff_t *pos)
+{
+ struct iovec iv = { (void *) buf, count };
+ return tun_chr_writev(file, &iv, 1, pos);
 }
 
-/* Put packet to user space buffer(already verified) */
+/* Put packet to the user space buffer (already verified) */
 static __inline__ ssize_t tun_put_user(struct tun_struct *tun,
                                        struct sk_buff *skb,
- char *buf, int count)
+ struct iovec *iv, int len)
 {
         struct tun_pi pi = { 0, skb->protocol };
- int len = count, total = 0;
- char *ptr = buf;
+ ssize_t total = 0;
 
         if (!(tun->flags & TUN_NO_PI)) {
                 if ((len -= sizeof(pi)) < 0)
@@ -307,14 +271,13 @@
                         pi.flags |= TUN_PKT_STRIP;
                 }
  
- copy_to_user(ptr, &pi, sizeof(pi));
-
+ memcpy_toiovec(iv, (void *) &pi, sizeof(pi));
                 total += sizeof(pi);
- ptr += sizeof(pi);
         }
 
- len = MIN(skb->len, len);
- copy_to_user(ptr, skb->data, len);
+ len = MIN(skb->len, len);
+
+ skb_copy_datagram_iovec(skb, 0, iv, len);
         total += len;
 
         tun->stats.tx_packets++;
@@ -323,22 +286,29 @@
         return total;
 }
 
-/* Read */
-static ssize_t tun_chr_read(struct file * file, char * buf,
- size_t count, loff_t *pos)
+/* Readv */
+static ssize_t tun_chr_readv(struct file *file, const struct iovec *iv,
+ unsigned long count, loff_t *pos)
 {
         struct tun_struct *tun = (struct tun_struct *)file->private_data;
         DECLARE_WAITQUEUE(wait, current);
         struct sk_buff *skb;
- ssize_t ret = 0;
+ ssize_t len, ret = 0;
+ unsigned long i;
 
         if (!tun)
                 return -EBADFD;
 
         DBG(KERN_INFO "%s: tun_chr_read\n", tun->name);
 
+ for (i = 0, len = 0; i < count; i++) {
+ if (verify_area(VERIFY_WRITE, iv[i].iov_base, iv[i].iov_len))
+ return -EFAULT;
+ len += iv[i].iov_len;
+ }
+
         add_wait_queue(&tun->read_wait, &wait);
- while (count) {
+ while (len) {
                 current->state = TASK_INTERRUPTIBLE;
 
                 /* Read frames from the queue */
@@ -358,10 +328,7 @@
                 }
                 netif_start_queue(&tun->dev);
 
- if (!verify_area(VERIFY_WRITE, buf, count))
- ret = tun_put_user(tun, skb, buf, count);
- else
- ret = -EFAULT;
+ ret = tun_put_user(tun, skb, (struct iovec *) iv, len);
 
                 kfree_skb(skb);
                 break;
@@ -373,6 +340,14 @@
         return ret;
 }
 
+/* Read */
+static ssize_t tun_chr_read(struct file * file, char * buf,
+ size_t count, loff_t *pos)
+{
+ struct iovec iv = { buf, count };
+ return tun_chr_readv(file, &iv, 1, pos);
+}
+
 static int tun_set_iff(struct file *file, struct ifreq *ifr)
 {
         struct tun_struct *tun;
@@ -592,6 +567,7 @@
         owner: THIS_MODULE,
         llseek: no_llseek,
         read: tun_chr_read,
+ readv: tun_chr_readv,
         write: tun_chr_write,
         writev: tun_chr_writev,
         poll: tun_chr_poll,
@@ -611,7 +587,7 @@
 int __init tun_init(void)
 {
         printk(KERN_INFO "Universal TUN/TAP device driver %s "
- "(C)1999-2001 Maxim Krasnyansky\n", TUN_VER);
+ "(C)1999-2002 Maxim Krasnyansky\n", TUN_VER);
 
         if (misc_register(&tun_miscdev)) {
                 printk(KERN_ERR "tun: Can't register misc device %d\n", TUN_MINOR);

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This archive was generated by hypermail 2b29 : Tue Apr 23 2002 - 22:00:36 EST