net: filter: move load_pointer() into filter.h

load_pointer() is already a static inline function.
Let's move it into filter.h so BPF JIT implementations can reuse this
function.

Since we're exporting this function, let's also rename it to
bpf_load_pointer() for clarity.

Signed-off-by: Zi Shen Lim <zlim.lnx@gmail.com>
Reviewed-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 16 insertions, 12 deletions

diff --git a/include/linux/filter.h b/include/linux/filter.h
index a7e3c48d73a7..b885dcb7eaca 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -6,6 +6,7 @@
 
 #include <linux/atomic.h>
 #include <linux/compat.h>
+#include <linux/skbuff.h>
 #include <linux/workqueue.h>
 #include <uapi/linux/filter.h>
 
@@ -406,6 +407,18 @@ static inline u16 bpf_anc_helper(const struct sock_filter *ftest)
         }
 }
 
+void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb,
+                                           int k, unsigned int size);
+
+static inline void *bpf_load_pointer(const struct sk_buff *skb, int k,
+                                     unsigned int size, void *buffer)
+{
+        if (k >= 0)
+                return skb_header_pointer(skb, k, size, buffer);
+
+        return bpf_internal_load_pointer_neg_helper(skb, k, size);
+}
+
 #ifdef CONFIG_BPF_JIT
 #include <stdarg.h>
 #include <linux/linkage.h>
diff --git a/net/core/filter.c b/net/core/filter.c
index 1dbf6462f766..87af1e3e56c0 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -84,15 +84,6 @@ void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, uns
         return NULL;
 }
 
-static inline void *load_pointer(const struct sk_buff *skb, int k,
-                                 unsigned int size, void *buffer)
-{
-        if (k >= 0)
-                return skb_header_pointer(skb, k, size, buffer);
-
-        return bpf_internal_load_pointer_neg_helper(skb, k, size);
-}
-
 /**
  *      sk_filter - run a packet through a socket filter
  *      @sk: sock associated with &sk_buff
@@ -537,7 +528,7 @@ load_word:
                  *   BPF_R0 - 8/16/32-bit skb data converted to cpu endianness
                  */
 
-                ptr = load_pointer((struct sk_buff *) (unsigned long) CTX, off, 4, &tmp);
+                ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 4, &tmp);
                 if (likely(ptr != NULL)) {
                         BPF_R0 = get_unaligned_be32(ptr);
                         CONT;
@@ -547,7 +538,7 @@ load_word:
         LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + imm32)) */
                 off = IMM;
 load_half:
-                ptr = load_pointer((struct sk_buff *) (unsigned long) CTX, off, 2, &tmp);
+                ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 2, &tmp);
                 if (likely(ptr != NULL)) {
                         BPF_R0 = get_unaligned_be16(ptr);
                         CONT;
@@ -557,7 +548,7 @@ load_half:
         LD_ABS_B: /* BPF_R0 = *(u8 *) (skb->data + imm32) */
                 off = IMM;
 load_byte:
-                ptr = load_pointer((struct sk_buff *) (unsigned long) CTX, off, 1, &tmp);
+                ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 1, &tmp);
                 if (likely(ptr != NULL)) {
                         BPF_R0 = *(u8 *)ptr;
                         CONT;