Merge branch 'bpf-updates'

Daniel Borkmann says:

====================
BPF updates

Some minor updates to {cls,act}_bpf to retrieve routing realms
and to make skb->priority writable.

Thanks!

v1 -> v2:
 - Dropped preclassify patch for now from the series as the
   rest is pretty much independent of it
 - Rest unchanged, only rebased and already posted Acked-by's kept
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

13 files changed, 63 insertions, 16 deletions

diff --git a/arch/arm/net/bpf_jit_32.c b/arch/arm/net/bpf_jit_32.c
index 876060bcceeb..0df5fd561513 100644
--- a/arch/arm/net/bpf_jit_32.c
+++ b/arch/arm/net/bpf_jit_32.c
@@ -1047,7 +1047,7 @@ void bpf_jit_compile(struct bpf_prog *fp)
 
 	set_memory_ro((unsigned long)header, header->pages);
 	fp->bpf_func = (void *)ctx.target;
-	fp->jited = true;
+	fp->jited = 1;
 out:
 	kfree(ctx.offsets);
 	return;
diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index c047598b09e0..a44e5293c6f5 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -744,7 +744,7 @@ void bpf_int_jit_compile(struct bpf_prog *prog)
 
 	set_memory_ro((unsigned long)header, header->pages);
 	prog->bpf_func = (void *)ctx.image;
-	prog->jited = true;
+	prog->jited = 1;
 out:
 	kfree(ctx.offset);
 }
diff --git a/arch/mips/net/bpf_jit.c b/arch/mips/net/bpf_jit.c
index 0c4a133f6216..77cb27309db2 100644
--- a/arch/mips/net/bpf_jit.c
+++ b/arch/mips/net/bpf_jit.c
@@ -1251,7 +1251,7 @@ void bpf_jit_compile(struct bpf_prog *fp)
 		bpf_jit_dump(fp->len, alloc_size, 2, ctx.target);
 
 	fp->bpf_func = (void *)ctx.target;
-	fp->jited = true;
+	fp->jited = 1;
 
 out:
 	kfree(ctx.offsets);
diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c
index 17cea18a09d3..04782164ee67 100644
--- a/arch/powerpc/net/bpf_jit_comp.c
+++ b/arch/powerpc/net/bpf_jit_comp.c
@@ -679,7 +679,7 @@ void bpf_jit_compile(struct bpf_prog *fp)
 		((u64 *)image)[1] = local_paca->kernel_toc;
 #endif
 		fp->bpf_func = (void *)image;
-		fp->jited = true;
+		fp->jited = 1;
 	}
 out:
 	kfree(addrs);
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index eeda051442c3..9a0c4c22e536 100644
--- a/arch/s390/net/bpf_jit_comp.c
+++ b/arch/s390/net/bpf_jit_comp.c
@@ -1310,7 +1310,7 @@ void bpf_int_jit_compile(struct bpf_prog *fp)
 	if (jit.prg_buf) {
 		set_memory_ro((unsigned long)header, header->pages);
 		fp->bpf_func = (void *) jit.prg_buf;
-		fp->jited = true;
+		fp->jited = 1;
 	}
 free_addrs:
 	kfree(jit.addrs);
diff --git a/arch/sparc/net/bpf_jit_comp.c b/arch/sparc/net/bpf_jit_comp.c
index f8b9f71b9a2b..22564f5f2364 100644
--- a/arch/sparc/net/bpf_jit_comp.c
+++ b/arch/sparc/net/bpf_jit_comp.c
@@ -812,7 +812,7 @@ cond_branch:			f_offset = addrs[i + filter[i].jf];
 	if (image) {
 		bpf_flush_icache(image, image + proglen);
 		fp->bpf_func = (void *)image;
-		fp->jited = true;
+		fp->jited = 1;
 	}
 out:
 	kfree(addrs);
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 70efcd0940f9..75991979f667 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -1109,7 +1109,7 @@ void bpf_int_jit_compile(struct bpf_prog *prog)
 		bpf_flush_icache(header, image + proglen);
 		set_memory_ro((unsigned long)header, header->pages);
 		prog->bpf_func = (void *)image;
-		prog->jited = true;
+		prog->jited = 1;
 	}
 out:
 	kfree(addrs);
diff --git a/include/linux/filter.h b/include/linux/filter.h
index fa2cab985e57..3d5fd24b321b 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -326,8 +326,11 @@ struct bpf_binary_header {
 
 struct bpf_prog {
 	u16			pages;		/* Number of allocated pages */
-	bool			jited;		/* Is our filter JIT'ed? */
-	bool			gpl_compatible;	/* Is our filter GPL compatible? */
+	kmemcheck_bitfield_begin(meta);
+	u16			jited:1,	/* Is our filter JIT'ed? */
+				gpl_compatible:1, /* Is filter GPL compatible? */
+				dst_needed:1;	/* Do we need dst entry? */
+	kmemcheck_bitfield_end(meta);
 	u32			len;		/* Number of filter blocks */
 	enum bpf_prog_type	type;		/* Type of BPF program */
 	struct bpf_prog_aux	*aux;		/* Auxiliary fields */
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 4ec0b5488294..564f1f091991 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -280,6 +280,13 @@ enum bpf_func_id {
 	 * Return: TC_ACT_REDIRECT
 	 */
 	BPF_FUNC_redirect,
+
+	/**
+	 * bpf_get_route_realm(skb) - retrieve a dst's tclassid
+	 * @skb: pointer to skb
+	 * Return: realm if != 0
+	 */
+	BPF_FUNC_get_route_realm,
 	__BPF_FUNC_MAX_ID,
 };
 
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 67c380cfa9ca..c8855c2a7a48 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -82,6 +82,8 @@ struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags)
 	if (fp == NULL)
 		return NULL;
 
+	kmemcheck_annotate_bitfield(fp, meta);
+
 	aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags);
 	if (aux == NULL) {
 		vfree(fp);
@@ -110,6 +112,8 @@ struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size,
 
 	fp = __vmalloc(size, gfp_flags, PAGE_KERNEL);
 	if (fp != NULL) {
+		kmemcheck_annotate_bitfield(fp, meta);
+
 		memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE);
 		fp->pages = size / PAGE_SIZE;
 
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 35bac8e8b071..5f35f420c12f 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -402,6 +402,8 @@ static void fixup_bpf_calls(struct bpf_prog *prog)
 			 */
 			BUG_ON(!prog->aux->ops->get_func_proto);
 
+			if (insn->imm == BPF_FUNC_get_route_realm)
+				prog->dst_needed = 1;
 			if (insn->imm == BPF_FUNC_tail_call) {
 				/* mark bpf_tail_call as different opcode
 				 * to avoid conditional branch in
@@ -553,10 +555,10 @@ static int bpf_prog_load(union bpf_attr *attr)
 		goto free_prog;
 
 	prog->orig_prog = NULL;
-	prog->jited = false;
+	prog->jited = 0;
 
 	atomic_set(&prog->aux->refcnt, 1);
-	prog->gpl_compatible = is_gpl;
+	prog->gpl_compatible = is_gpl ? 1 : 0;
 
 	/* find program type: socket_filter vs tracing_filter */
 	err = find_prog_type(type, prog);
diff --git a/net/core/filter.c b/net/core/filter.c
index 60e3fe7c59c0..53a5036fb32d 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -49,6 +49,7 @@
 #include <net/sch_generic.h>
 #include <net/cls_cgroup.h>
 #include <net/dst_metadata.h>
+#include <net/dst.h>
 
 /**
  *	sk_filter - run a packet through a socket filter
@@ -1001,7 +1002,7 @@ static struct bpf_prog *bpf_prepare_filter(struct bpf_prog *fp,
 	int err;
 
 	fp->bpf_func = NULL;
-	fp->jited = false;
+	fp->jited = 0;
 
 	err = bpf_check_classic(fp->insns, fp->len);
 	if (err) {
@@ -1478,6 +1479,25 @@ static const struct bpf_func_proto bpf_get_cgroup_classid_proto = {
 	.arg1_type      = ARG_PTR_TO_CTX,
 };
 
+static u64 bpf_get_route_realm(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5)
+{
+#ifdef CONFIG_IP_ROUTE_CLASSID
+	const struct dst_entry *dst;
+
+	dst = skb_dst((struct sk_buff *) (unsigned long) r1);
+	if (dst)
+		return dst->tclassid;
+#endif
+	return 0;
+}
+
+static const struct bpf_func_proto bpf_get_route_realm_proto = {
+	.func           = bpf_get_route_realm,
+	.gpl_only       = false,
+	.ret_type       = RET_INTEGER,
+	.arg1_type      = ARG_PTR_TO_CTX,
+};
+
 static u64 bpf_skb_vlan_push(u64 r1, u64 r2, u64 vlan_tci, u64 r4, u64 r5)
 {
 	struct sk_buff *skb = (struct sk_buff *) (long) r1;
@@ -1648,6 +1668,8 @@ tc_cls_act_func_proto(enum bpf_func_id func_id)
 		return bpf_get_skb_set_tunnel_key_proto();
 	case BPF_FUNC_redirect:
 		return &bpf_redirect_proto;
+	case BPF_FUNC_get_route_realm:
+		return &bpf_get_route_realm_proto;
 	default:
 		return sk_filter_func_proto(func_id);
 	}
@@ -1699,6 +1721,7 @@ static bool tc_cls_act_is_valid_access(int off, int size,
 		switch (off) {
 		case offsetof(struct __sk_buff, mark):
 		case offsetof(struct __sk_buff, tc_index):
+		case offsetof(struct __sk_buff, priority):
 		case offsetof(struct __sk_buff, cb[0]) ...
 			offsetof(struct __sk_buff, cb[4]):
 			break;
@@ -1740,8 +1763,12 @@ static u32 bpf_net_convert_ctx_access(enum bpf_access_type type, int dst_reg,
 	case offsetof(struct __sk_buff, priority):
 		BUILD_BUG_ON(FIELD_SIZEOF(struct sk_buff, priority) != 4);
 
-		*insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg,
-				      offsetof(struct sk_buff, priority));
+		if (type == BPF_WRITE)
+			*insn++ = BPF_STX_MEM(BPF_W, dst_reg, src_reg,
+					      offsetof(struct sk_buff, priority));
+		else
+			*insn++ = BPF_LDX_MEM(BPF_W, dst_reg, src_reg,
+					      offsetof(struct sk_buff, priority));
 		break;
 
 	case offsetof(struct __sk_buff, ingress_ifindex):
diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c
index 7eeffaf69c75..5faaa5425f7b 100644
--- a/net/sched/cls_bpf.c
+++ b/net/sched/cls_bpf.c
@@ -262,7 +262,8 @@ static int cls_bpf_prog_from_ops(struct nlattr **tb, struct cls_bpf_prog *prog)
 	return 0;
 }
 
-static int cls_bpf_prog_from_efd(struct nlattr **tb, struct cls_bpf_prog *prog)
+static int cls_bpf_prog_from_efd(struct nlattr **tb, struct cls_bpf_prog *prog,
+				 const struct tcf_proto *tp)
 {
 	struct bpf_prog *fp;
 	char *name = NULL;
@@ -294,6 +295,9 @@ static int cls_bpf_prog_from_efd(struct nlattr **tb, struct cls_bpf_prog *prog)
 	prog->bpf_name = name;
 	prog->filter = fp;
 
+	if (fp->dst_needed)
+		netif_keep_dst(qdisc_dev(tp->q));
+
 	return 0;
 }
 
@@ -330,7 +334,7 @@ static int cls_bpf_modify_existing(struct net *net, struct tcf_proto *tp,
 	prog->exts_integrated = have_exts;
 
 	ret = is_bpf ? cls_bpf_prog_from_ops(tb, prog) :
-		       cls_bpf_prog_from_efd(tb, prog);
+		       cls_bpf_prog_from_efd(tb, prog, tp);
 	if (ret < 0) {
 		tcf_exts_destroy(&exts);
 		return ret;