Merge branch 'bpf-next'

Daniel Borkmann says:

====================
BPF update

This set adds IPv6 support for bpf_skb_{set,get}_tunnel_key() helper.
It also exports flags to user space that are being used in helpers and
weren't exported thus far. For more details, please see the individual
patches.
====================

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

include/uapi/linux/bpf.h

@@ -273,6 +273,25 @@ enum bpf_func_id {
 	__BPF_FUNC_MAX_ID,
 };
 
+/* All flags used by eBPF helper functions, placed here. */
+
+/* BPF_FUNC_skb_store_bytes flags. */
+#define BPF_F_RECOMPUTE_CSUM		(1ULL << 0)
+
+/* BPF_FUNC_l3_csum_replace and BPF_FUNC_l4_csum_replace flags.
+ * First 4 bits are for passing the header field size.
+ */
+#define BPF_F_HDR_FIELD_MASK		0xfULL
+
+/* BPF_FUNC_l4_csum_replace flags. */
+#define BPF_F_PSEUDO_HDR		(1ULL << 4)
+
+/* BPF_FUNC_clone_redirect and BPF_FUNC_redirect flags. */
+#define BPF_F_INGRESS			(1ULL << 0)
+
+/* BPF_FUNC_skb_set_tunnel_key and BPF_FUNC_skb_get_tunnel_key flags. */
+#define BPF_F_TUNINFO_IPV6		(1ULL << 0)
+
 /* user accessible mirror of in-kernel sk_buff.
  * new fields can only be added to the end of this structure
  */
@@ -296,7 +315,12 @@ struct __sk_buff {
 
 struct bpf_tunnel_key {
 	__u32 tunnel_id;
-	__u32 remote_ipv4;
+	union {
+		__u32 remote_ipv4;
+		__u32 remote_ipv6[4];
+	};
+	__u8 tunnel_tos;
+	__u8 tunnel_ttl;
 };
 
 #endif /* _UAPI__LINUX_BPF_H__ */

net/core/filter.c

@@ -1328,8 +1328,7 @@ int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk)
 	return 0;
 }
 
-#define BPF_RECOMPUTE_CSUM(flags)	((flags) & 1)
-#define BPF_LDST_LEN			16U
+#define BPF_LDST_LEN 16U
 
 static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 flags)
 {
@@ -1340,6 +1339,9 @@ static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 flags)
 	char buf[BPF_LDST_LEN];
 	void *ptr;
 
+	if (unlikely(flags & ~(BPF_F_RECOMPUTE_CSUM)))
+		return -EINVAL;
+
 	/* bpf verifier guarantees that:
 	 * 'from' pointer points to bpf program stack
 	 * 'len' bytes of it were initialized
@@ -1359,7 +1361,7 @@ static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 flags)
 	if (unlikely(!ptr))
 		return -EFAULT;
 
-	if (BPF_RECOMPUTE_CSUM(flags))
+	if (flags & BPF_F_RECOMPUTE_CSUM)
 		skb_postpull_rcsum(skb, ptr, len);
 
 	memcpy(ptr, from, len);
@@ -1368,7 +1370,7 @@ static u64 bpf_skb_store_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 flags)
 		/* skb_store_bits cannot return -EFAULT here */
 		skb_store_bits(skb, offset, ptr, len);
 
-	if (BPF_RECOMPUTE_CSUM(flags))
+	if (flags & BPF_F_RECOMPUTE_CSUM)
 		skb_postpush_rcsum(skb, ptr, len);
 
 	return 0;
@@ -1415,15 +1417,14 @@ const struct bpf_func_proto bpf_skb_load_bytes_proto = {
 	.arg4_type	= ARG_CONST_STACK_SIZE,
 };
 
-#define BPF_HEADER_FIELD_SIZE(flags)	((flags) & 0x0f)
-#define BPF_IS_PSEUDO_HEADER(flags)	((flags) & 0x10)
-
 static u64 bpf_l3_csum_replace(u64 r1, u64 r2, u64 from, u64 to, u64 flags)
 {
 	struct sk_buff *skb = (struct sk_buff *) (long) r1;
 	int offset = (int) r2;
 	__sum16 sum, *ptr;
 
+	if (unlikely(flags & ~(BPF_F_HDR_FIELD_MASK)))
+		return -EINVAL;
 	if (unlikely((u32) offset > 0xffff))
 		return -EFAULT;
 
@@ -1435,7 +1436,7 @@ static u64 bpf_l3_csum_replace(u64 r1, u64 r2, u64 from, u64 to, u64 flags)
 	if (unlikely(!ptr))
 		return -EFAULT;
 
-	switch (BPF_HEADER_FIELD_SIZE(flags)) {
+	switch (flags & BPF_F_HDR_FIELD_MASK) {
 	case 2:
 		csum_replace2(ptr, from, to);
 		break;
@@ -1467,10 +1468,12 @@ const struct bpf_func_proto bpf_l3_csum_replace_proto = {
 static u64 bpf_l4_csum_replace(u64 r1, u64 r2, u64 from, u64 to, u64 flags)
 {
 	struct sk_buff *skb = (struct sk_buff *) (long) r1;
-	bool is_pseudo = !!BPF_IS_PSEUDO_HEADER(flags);
+	bool is_pseudo = flags & BPF_F_PSEUDO_HDR;
 	int offset = (int) r2;
 	__sum16 sum, *ptr;
 
+	if (unlikely(flags & ~(BPF_F_PSEUDO_HDR | BPF_F_HDR_FIELD_MASK)))
+		return -EINVAL;
 	if (unlikely((u32) offset > 0xffff))
 		return -EFAULT;
 
@@ -1482,7 +1485,7 @@ static u64 bpf_l4_csum_replace(u64 r1, u64 r2, u64 from, u64 to, u64 flags)
 	if (unlikely(!ptr))
 		return -EFAULT;
 
-	switch (BPF_HEADER_FIELD_SIZE(flags)) {
+	switch (flags & BPF_F_HDR_FIELD_MASK) {
 	case 2:
 		inet_proto_csum_replace2(ptr, skb, from, to, is_pseudo);
 		break;
@@ -1511,13 +1514,14 @@ const struct bpf_func_proto bpf_l4_csum_replace_proto = {
 	.arg5_type	= ARG_ANYTHING,
 };
 
-#define BPF_IS_REDIRECT_INGRESS(flags)	((flags) & 1)
-
 static u64 bpf_clone_redirect(u64 r1, u64 ifindex, u64 flags, u64 r4, u64 r5)
 {
 	struct sk_buff *skb = (struct sk_buff *) (long) r1, *skb2;
 	struct net_device *dev;
 
+	if (unlikely(flags & ~(BPF_F_INGRESS)))
+		return -EINVAL;
+
 	dev = dev_get_by_index_rcu(dev_net(skb->dev), ifindex);
 	if (unlikely(!dev))
 		return -EINVAL;
@@ -1526,7 +1530,7 @@ static u64 bpf_clone_redirect(u64 r1, u64 ifindex, u64 flags, u64 r4, u64 r5)
 	if (unlikely(!skb2))
 		return -ENOMEM;
 
-	if (BPF_IS_REDIRECT_INGRESS(flags)) {
+	if (flags & BPF_F_INGRESS) {
 		if (skb_at_tc_ingress(skb2))
 			skb_postpush_rcsum(skb2, skb_mac_header(skb2),
 					   skb2->mac_len);
@@ -1553,12 +1557,17 @@ struct redirect_info {
 };
 
 static DEFINE_PER_CPU(struct redirect_info, redirect_info);
+
 static u64 bpf_redirect(u64 ifindex, u64 flags, u64 r3, u64 r4, u64 r5)
 {
 	struct redirect_info *ri = this_cpu_ptr(&redirect_info);
 
+	if (unlikely(flags & ~(BPF_F_INGRESS)))
+		return TC_ACT_SHOT;
+
 	ri->ifindex = ifindex;
 	ri->flags = flags;
+
 	return TC_ACT_REDIRECT;
 }
 
@@ -1574,7 +1583,7 @@ int skb_do_redirect(struct sk_buff *skb)
 		return -EINVAL;
 	}
 
-	if (BPF_IS_REDIRECT_INGRESS(ri->flags)) {
+	if (ri->flags & BPF_F_INGRESS) {
 		if (skb_at_tc_ingress(skb))
 			skb_postpush_rcsum(skb, skb_mac_header(skb),
 					   skb->mac_len);
@@ -1671,19 +1680,49 @@ bool bpf_helper_changes_skb_data(void *func)
 	return false;
 }
 
+static unsigned short bpf_tunnel_key_af(u64 flags)
+{
+	return flags & BPF_F_TUNINFO_IPV6 ? AF_INET6 : AF_INET;
+}
+
 static u64 bpf_skb_get_tunnel_key(u64 r1, u64 r2, u64 size, u64 flags, u64 r5)
 {
 	struct sk_buff *skb = (struct sk_buff *) (long) r1;
 	struct bpf_tunnel_key *to = (struct bpf_tunnel_key *) (long) r2;
-	struct ip_tunnel_info *info = skb_tunnel_info(skb);
+	const struct ip_tunnel_info *info = skb_tunnel_info(skb);
+	u8 compat[sizeof(struct bpf_tunnel_key)];
 
-	if (unlikely(size != sizeof(struct bpf_tunnel_key) || flags || !info))
-		return -EINVAL;
-	if (ip_tunnel_info_af(info) != AF_INET)
+	if (unlikely(!info || (flags & ~(BPF_F_TUNINFO_IPV6))))
 		return -EINVAL;
+	if (ip_tunnel_info_af(info) != bpf_tunnel_key_af(flags))
+		return -EPROTO;
+	if (unlikely(size != sizeof(struct bpf_tunnel_key))) {
+		switch (size) {
+		case offsetof(struct bpf_tunnel_key, remote_ipv6[1]):
+			/* Fixup deprecated structure layouts here, so we have
+			 * a common path later on.
+			 */
+			if (ip_tunnel_info_af(info) != AF_INET)
+				return -EINVAL;
+			to = (struct bpf_tunnel_key *)compat;
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
 
 	to->tunnel_id = be64_to_cpu(info->key.tun_id);
-	to->remote_ipv4 = be32_to_cpu(info->key.u.ipv4.src);
+	to->tunnel_tos = info->key.tos;
+	to->tunnel_ttl = info->key.ttl;
+
+	if (flags & BPF_F_TUNINFO_IPV6)
+		memcpy(to->remote_ipv6, &info->key.u.ipv6.src,
+		       sizeof(to->remote_ipv6));
+	else
+		to->remote_ipv4 = be32_to_cpu(info->key.u.ipv4.src);
+
+	if (unlikely(size != sizeof(struct bpf_tunnel_key)))
+		memcpy((void *)(long) r2, to, size);
 
 	return 0;
 }
@@ -1705,10 +1744,25 @@ static u64 bpf_skb_set_tunnel_key(u64 r1, u64 r2, u64 size, u64 flags, u64 r5)
 	struct sk_buff *skb = (struct sk_buff *) (long) r1;
 	struct bpf_tunnel_key *from = (struct bpf_tunnel_key *) (long) r2;
 	struct metadata_dst *md = this_cpu_ptr(md_dst);
+	u8 compat[sizeof(struct bpf_tunnel_key)];
 	struct ip_tunnel_info *info;
 
-	if (unlikely(size != sizeof(struct bpf_tunnel_key) || flags))
+	if (unlikely(flags & ~(BPF_F_TUNINFO_IPV6)))
 		return -EINVAL;
+	if (unlikely(size != sizeof(struct bpf_tunnel_key))) {
+		switch (size) {
+		case offsetof(struct bpf_tunnel_key, remote_ipv6[1]):
+			/* Fixup deprecated structure layouts here, so we have
+			 * a common path later on.
+			 */
+			memcpy(compat, from, size);
+			memset(compat + size, 0, sizeof(compat) - size);
+			from = (struct bpf_tunnel_key *)compat;
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
 
 	skb_dst_drop(skb);
 	dst_hold((struct dst_entry *) md);
@@ -1716,9 +1770,19 @@ static u64 bpf_skb_set_tunnel_key(u64 r1, u64 r2, u64 size, u64 flags, u64 r5)
 
 	info = &md->u.tun_info;
 	info->mode = IP_TUNNEL_INFO_TX;
+
 	info->key.tun_flags = TUNNEL_KEY;
 	info->key.tun_id = cpu_to_be64(from->tunnel_id);
-	info->key.u.ipv4.dst = cpu_to_be32(from->remote_ipv4);
+	info->key.tos = from->tunnel_tos;
+	info->key.ttl = from->tunnel_ttl;
+
+	if (flags & BPF_F_TUNINFO_IPV6) {
+		info->mode |= IP_TUNNEL_INFO_IPV6;
+		memcpy(&info->key.u.ipv6.dst, from->remote_ipv6,
+		       sizeof(from->remote_ipv6));
+	} else {
+		info->key.u.ipv4.dst = cpu_to_be32(from->remote_ipv4);
+	}
 
 	return 0;
 }