#include <linux/module.h>
#include <linux/types.h>
-#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/fcntl.h>
#include <linux/socket.h>
#include <linux/timer.h>
#include <asm/system.h>
#include <asm/uaccess.h>
+#include <asm/unaligned.h>
#include <linux/filter.h>
/* No hurry in this branch */
u8 *ptr = NULL;
if (k >= SKF_NET_OFF)
- ptr = skb->nh.raw + k - SKF_NET_OFF;
+ ptr = skb_network_header(skb) + k - SKF_NET_OFF;
else if (k >= SKF_LL_OFF)
- ptr = skb->mac.raw + k - SKF_LL_OFF;
+ ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
- if (ptr >= skb->head && ptr < skb->tail)
+ if (ptr >= skb->head && ptr < skb_tail_pointer(skb))
return ptr;
return NULL;
}
static inline void *load_pointer(struct sk_buff *skb, int k,
- unsigned int size, void *buffer)
+ unsigned int size, void *buffer)
{
if (k >= 0)
return skb_header_pointer(skb, k, size, buffer);
*/
for (pc = 0; pc < flen; pc++) {
fentry = &filter[pc];
-
+
switch (fentry->code) {
case BPF_ALU|BPF_ADD|BPF_X:
A += X;
load_w:
ptr = load_pointer(skb, k, 4, &tmp);
if (ptr != NULL) {
- A = ntohl(*(u32 *)ptr);
+ A = ntohl(get_unaligned((__be32 *)ptr));
continue;
}
break;
load_h:
ptr = load_pointer(skb, k, 2, &tmp);
if (ptr != NULL) {
- A = ntohs(*(u16 *)ptr);
+ A = ntohs(get_unaligned((__be16 *)ptr));
continue;
}
break;
*/
switch (k-SKF_AD_OFF) {
case SKF_AD_PROTOCOL:
- A = htons(skb->protocol);
+ A = ntohs(skb->protocol);
continue;
case SKF_AD_PKTTYPE:
A = skb->pkt_type;
return (BPF_CLASS(filter[flen - 1].code) == BPF_RET) ? 0 : -EINVAL;
}
+/**
+ * sk_filter_rcu_release: Release a socket filter by rcu_head
+ * @rcu: rcu_head that contains the sk_filter to free
+ */
+static void sk_filter_rcu_release(struct rcu_head *rcu)
+{
+ struct sk_filter *fp = container_of(rcu, struct sk_filter, rcu);
+
+ sk_filter_release(fp);
+}
+
+static void sk_filter_delayed_uncharge(struct sock *sk, struct sk_filter *fp)
+{
+ unsigned int size = sk_filter_len(fp);
+
+ atomic_sub(size, &sk->sk_omem_alloc);
+ call_rcu_bh(&fp->rcu, sk_filter_rcu_release);
+}
+
/**
* sk_attach_filter - attach a socket filter
* @fprog: the filter program
*/
int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk)
{
- struct sk_filter *fp;
+ struct sk_filter *fp, *old_fp;
unsigned int fsize = sizeof(struct sock_filter) * fprog->len;
int err;
if (!fp)
return -ENOMEM;
if (copy_from_user(fp->insns, fprog->filter, fsize)) {
- sock_kfree_s(sk, fp, fsize+sizeof(*fp));
+ sock_kfree_s(sk, fp, fsize+sizeof(*fp));
return -EFAULT;
}
fp->len = fprog->len;
err = sk_chk_filter(fp->insns, fp->len);
- if (!err) {
- struct sk_filter *old_fp;
-
- spin_lock_bh(&sk->sk_lock.slock);
- old_fp = sk->sk_filter;
- sk->sk_filter = fp;
- spin_unlock_bh(&sk->sk_lock.slock);
- fp = old_fp;
+ if (err) {
+ sk_filter_uncharge(sk, fp);
+ return err;
}
- if (fp)
- sk_filter_release(sk, fp);
- return err;
+ rcu_read_lock_bh();
+ old_fp = rcu_dereference(sk->sk_filter);
+ rcu_assign_pointer(sk->sk_filter, fp);
+ rcu_read_unlock_bh();
+
+ if (old_fp)
+ sk_filter_delayed_uncharge(sk, old_fp);
+ return 0;
+}
+
+int sk_detach_filter(struct sock *sk)
+{
+ int ret = -ENOENT;
+ struct sk_filter *filter;
+
+ rcu_read_lock_bh();
+ filter = rcu_dereference(sk->sk_filter);
+ if (filter) {
+ rcu_assign_pointer(sk->sk_filter, NULL);
+ sk_filter_delayed_uncharge(sk, filter);
+ ret = 0;
+ }
+ rcu_read_unlock_bh();
+ return ret;
}
EXPORT_SYMBOL(sk_chk_filter);