mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-20 14:16:02 +00:00
![Willem de Bruijn](/assets/img/avatar_default.png)
Commite6afc8ace6
modified the udp receive path by pulling the udp header before queuing an skbuff onto the receive queue. Sunrpc also calls skb_recv_datagram to dequeue an skb from a udp socket. Modify this receive path to also no longer expect udp headers. Fixes:e6afc8ace6
("udp: remove headers from UDP packets before queueing") Reported-by: Franklin S Cooper Jr. <fcooper@ti.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Tested-by: Thierry Reding <treding@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net>
187 lines
4.5 KiB
C
187 lines
4.5 KiB
C
/*
|
|
* linux/net/sunrpc/socklib.c
|
|
*
|
|
* Common socket helper routines for RPC client and server
|
|
*
|
|
* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
|
|
*/
|
|
|
|
#include <linux/compiler.h>
|
|
#include <linux/netdevice.h>
|
|
#include <linux/gfp.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/types.h>
|
|
#include <linux/pagemap.h>
|
|
#include <linux/udp.h>
|
|
#include <linux/sunrpc/xdr.h>
|
|
#include <linux/export.h>
|
|
|
|
|
|
/**
|
|
* xdr_skb_read_bits - copy some data bits from skb to internal buffer
|
|
* @desc: sk_buff copy helper
|
|
* @to: copy destination
|
|
* @len: number of bytes to copy
|
|
*
|
|
* Possibly called several times to iterate over an sk_buff and copy
|
|
* data out of it.
|
|
*/
|
|
size_t xdr_skb_read_bits(struct xdr_skb_reader *desc, void *to, size_t len)
|
|
{
|
|
if (len > desc->count)
|
|
len = desc->count;
|
|
if (unlikely(skb_copy_bits(desc->skb, desc->offset, to, len)))
|
|
return 0;
|
|
desc->count -= len;
|
|
desc->offset += len;
|
|
return len;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_skb_read_bits);
|
|
|
|
/**
|
|
* xdr_skb_read_and_csum_bits - copy and checksum from skb to buffer
|
|
* @desc: sk_buff copy helper
|
|
* @to: copy destination
|
|
* @len: number of bytes to copy
|
|
*
|
|
* Same as skb_read_bits, but calculate a checksum at the same time.
|
|
*/
|
|
static size_t xdr_skb_read_and_csum_bits(struct xdr_skb_reader *desc, void *to, size_t len)
|
|
{
|
|
unsigned int pos;
|
|
__wsum csum2;
|
|
|
|
if (len > desc->count)
|
|
len = desc->count;
|
|
pos = desc->offset;
|
|
csum2 = skb_copy_and_csum_bits(desc->skb, pos, to, len, 0);
|
|
desc->csum = csum_block_add(desc->csum, csum2, pos);
|
|
desc->count -= len;
|
|
desc->offset += len;
|
|
return len;
|
|
}
|
|
|
|
/**
|
|
* xdr_partial_copy_from_skb - copy data out of an skb
|
|
* @xdr: target XDR buffer
|
|
* @base: starting offset
|
|
* @desc: sk_buff copy helper
|
|
* @copy_actor: virtual method for copying data
|
|
*
|
|
*/
|
|
ssize_t xdr_partial_copy_from_skb(struct xdr_buf *xdr, unsigned int base, struct xdr_skb_reader *desc, xdr_skb_read_actor copy_actor)
|
|
{
|
|
struct page **ppage = xdr->pages;
|
|
unsigned int len, pglen = xdr->page_len;
|
|
ssize_t copied = 0;
|
|
size_t ret;
|
|
|
|
len = xdr->head[0].iov_len;
|
|
if (base < len) {
|
|
len -= base;
|
|
ret = copy_actor(desc, (char *)xdr->head[0].iov_base + base, len);
|
|
copied += ret;
|
|
if (ret != len || !desc->count)
|
|
goto out;
|
|
base = 0;
|
|
} else
|
|
base -= len;
|
|
|
|
if (unlikely(pglen == 0))
|
|
goto copy_tail;
|
|
if (unlikely(base >= pglen)) {
|
|
base -= pglen;
|
|
goto copy_tail;
|
|
}
|
|
if (base || xdr->page_base) {
|
|
pglen -= base;
|
|
base += xdr->page_base;
|
|
ppage += base >> PAGE_SHIFT;
|
|
base &= ~PAGE_MASK;
|
|
}
|
|
do {
|
|
char *kaddr;
|
|
|
|
/* ACL likes to be lazy in allocating pages - ACLs
|
|
* are small by default but can get huge. */
|
|
if (unlikely(*ppage == NULL)) {
|
|
*ppage = alloc_page(GFP_ATOMIC);
|
|
if (unlikely(*ppage == NULL)) {
|
|
if (copied == 0)
|
|
copied = -ENOMEM;
|
|
goto out;
|
|
}
|
|
}
|
|
|
|
len = PAGE_SIZE;
|
|
kaddr = kmap_atomic(*ppage);
|
|
if (base) {
|
|
len -= base;
|
|
if (pglen < len)
|
|
len = pglen;
|
|
ret = copy_actor(desc, kaddr + base, len);
|
|
base = 0;
|
|
} else {
|
|
if (pglen < len)
|
|
len = pglen;
|
|
ret = copy_actor(desc, kaddr, len);
|
|
}
|
|
flush_dcache_page(*ppage);
|
|
kunmap_atomic(kaddr);
|
|
copied += ret;
|
|
if (ret != len || !desc->count)
|
|
goto out;
|
|
ppage++;
|
|
} while ((pglen -= len) != 0);
|
|
copy_tail:
|
|
len = xdr->tail[0].iov_len;
|
|
if (base < len)
|
|
copied += copy_actor(desc, (char *)xdr->tail[0].iov_base + base, len - base);
|
|
out:
|
|
return copied;
|
|
}
|
|
EXPORT_SYMBOL_GPL(xdr_partial_copy_from_skb);
|
|
|
|
/**
|
|
* csum_partial_copy_to_xdr - checksum and copy data
|
|
* @xdr: target XDR buffer
|
|
* @skb: source skb
|
|
*
|
|
* We have set things up such that we perform the checksum of the UDP
|
|
* packet in parallel with the copies into the RPC client iovec. -DaveM
|
|
*/
|
|
int csum_partial_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
|
|
{
|
|
struct xdr_skb_reader desc;
|
|
|
|
desc.skb = skb;
|
|
desc.offset = 0;
|
|
desc.count = skb->len - desc.offset;
|
|
|
|
if (skb_csum_unnecessary(skb))
|
|
goto no_checksum;
|
|
|
|
desc.csum = csum_partial(skb->data, desc.offset, skb->csum);
|
|
if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_and_csum_bits) < 0)
|
|
return -1;
|
|
if (desc.offset != skb->len) {
|
|
__wsum csum2;
|
|
csum2 = skb_checksum(skb, desc.offset, skb->len - desc.offset, 0);
|
|
desc.csum = csum_block_add(desc.csum, csum2, desc.offset);
|
|
}
|
|
if (desc.count)
|
|
return -1;
|
|
if (csum_fold(desc.csum))
|
|
return -1;
|
|
if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) &&
|
|
!skb->csum_complete_sw)
|
|
netdev_rx_csum_fault(skb->dev);
|
|
return 0;
|
|
no_checksum:
|
|
if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0)
|
|
return -1;
|
|
if (desc.count)
|
|
return -1;
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(csum_partial_copy_to_xdr);
|