net: filter: split 'struct sk_filter' into socket and bpf parts

clean up names related to socket filtering and bpf in the following way:
- everything that deals with sockets keeps 'sk_*' prefix
- everything that is pure BPF is changed to 'bpf_*' prefix

split 'struct sk_filter' into
struct sk_filter {
	atomic_t        refcnt;
	struct rcu_head rcu;
	struct bpf_prog *prog;
};
and
struct bpf_prog {
        u32                     jited:1,
                                len:31;
        struct sock_fprog_kern  *orig_prog;
        unsigned int            (*bpf_func)(const struct sk_buff *skb,
                                            const struct bpf_insn *filter);
        union {
                struct sock_filter      insns[0];
                struct bpf_insn         insnsi[0];
                struct work_struct      work;
        };
};
so that 'struct bpf_prog' can be used independent of sockets and cleans up
'unattached' bpf use cases

split SK_RUN_FILTER macro into:
    SK_RUN_FILTER to be used with 'struct sk_filter *' and
    BPF_PROG_RUN to be used with 'struct bpf_prog *'

__sk_filter_release(struct sk_filter *) gains
__bpf_prog_release(struct bpf_prog *) helper function

also perform related renames for the functions that work
with 'struct bpf_prog *', since they're on the same lines:

sk_filter_size -> bpf_prog_size
sk_filter_select_runtime -> bpf_prog_select_runtime
sk_filter_free -> bpf_prog_free
sk_unattached_filter_create -> bpf_prog_create
sk_unattached_filter_destroy -> bpf_prog_destroy
sk_store_orig_filter -> bpf_prog_store_orig_filter
sk_release_orig_filter -> bpf_release_orig_filter
__sk_migrate_filter -> bpf_migrate_filter
__sk_prepare_filter -> bpf_prepare_filter

API for attaching classic BPF to a socket stays the same:
sk_attach_filter(prog, struct sock *)/sk_detach_filter(struct sock *)
and SK_RUN_FILTER(struct sk_filter *, ctx) to execute a program
which is used by sockets, tun, af_packet

API for 'unattached' BPF programs becomes:
bpf_prog_create(struct bpf_prog **)/bpf_prog_destroy(struct bpf_prog *)
and BPF_PROG_RUN(struct bpf_prog *, ctx) to execute a program
which is used by isdn, ppp, team, seccomp, ptp, xt_bpf, cls_bpf, test_bpf

Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index 5f48623..89e0345 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -1761,9 +1761,9 @@
 	return len + 1;
 }
 
-static struct sk_filter *generate_filter(int which, int *err)
+static struct bpf_prog *generate_filter(int which, int *err)
 {
-	struct sk_filter *fp;
+	struct bpf_prog *fp;
 	struct sock_fprog_kern fprog;
 	unsigned int flen = probe_filter_length(tests[which].u.insns);
 	__u8 test_type = tests[which].aux & TEST_TYPE_MASK;
@@ -1773,7 +1773,7 @@
 		fprog.filter = tests[which].u.insns;
 		fprog.len = flen;
 
-		*err = sk_unattached_filter_create(&fp, &fprog);
+		*err = bpf_prog_create(&fp, &fprog);
 		if (tests[which].aux & FLAG_EXPECTED_FAIL) {
 			if (*err == -EINVAL) {
 				pr_cont("PASS\n");
@@ -1798,7 +1798,7 @@
 		break;
 
 	case INTERNAL:
-		fp = kzalloc(sk_filter_size(flen), GFP_KERNEL);
+		fp = kzalloc(bpf_prog_size(flen), GFP_KERNEL);
 		if (fp == NULL) {
 			pr_cont("UNEXPECTED_FAIL no memory left\n");
 			*err = -ENOMEM;
@@ -1809,7 +1809,7 @@
 		memcpy(fp->insnsi, tests[which].u.insns_int,
 		       fp->len * sizeof(struct bpf_insn));
 
-		sk_filter_select_runtime(fp);
+		bpf_prog_select_runtime(fp);
 		break;
 	}
 
@@ -1817,21 +1817,21 @@
 	return fp;
 }
 
-static void release_filter(struct sk_filter *fp, int which)
+static void release_filter(struct bpf_prog *fp, int which)
 {
 	__u8 test_type = tests[which].aux & TEST_TYPE_MASK;
 
 	switch (test_type) {
 	case CLASSIC:
-		sk_unattached_filter_destroy(fp);
+		bpf_prog_destroy(fp);
 		break;
 	case INTERNAL:
-		sk_filter_free(fp);
+		bpf_prog_free(fp);
 		break;
 	}
 }
 
-static int __run_one(const struct sk_filter *fp, const void *data,
+static int __run_one(const struct bpf_prog *fp, const void *data,
 		     int runs, u64 *duration)
 {
 	u64 start, finish;
@@ -1840,7 +1840,7 @@
 	start = ktime_to_us(ktime_get());
 
 	for (i = 0; i < runs; i++)
-		ret = SK_RUN_FILTER(fp, data);
+		ret = BPF_PROG_RUN(fp, data);
 
 	finish = ktime_to_us(ktime_get());
 
@@ -1850,7 +1850,7 @@
 	return ret;
 }
 
-static int run_one(const struct sk_filter *fp, struct bpf_test *test)
+static int run_one(const struct bpf_prog *fp, struct bpf_test *test)
 {
 	int err_cnt = 0, i, runs = MAX_TESTRUNS;
 
@@ -1884,7 +1884,7 @@
 	int i, err_cnt = 0, pass_cnt = 0;
 
 	for (i = 0; i < ARRAY_SIZE(tests); i++) {
-		struct sk_filter *fp;
+		struct bpf_prog *fp;
 		int err;
 
 		pr_info("#%d %s ", i, tests[i].descr);