[bpf-next,v3,2/3] bpf: Expand map key argument of bpf_redirect_map to u64

Commit Message

Toke Høiland-Jørgensen Nov. 8, 2022, 2:06 p.m. UTC

For queueing packets in XDP we want to add a new redirect map type with
support for 64-bit indexes. To prepare fore this, expand the width of the
'key' argument to the bpf_redirect_map() helper. Since BPF registers are
always 64-bit, this should be safe to do after the fact.

Acked-by: Song Liu <[e-mail]>
Reviewed-by: Stanislav Fomichev <[e-mail]>
Signed-off-by: Toke Høiland-Jørgensen <[e-mail]>
---
 include/linux/bpf.h      |  2 +-
 include/linux/filter.h   | 12 ++++++------
 include/uapi/linux/bpf.h |  2 +-
 kernel/bpf/cpumap.c      |  4 ++--
 kernel/bpf/devmap.c      |  4 ++--
 kernel/bpf/verifier.c    |  2 +-
 net/core/filter.c        |  4 ++--
 net/xdp/xskmap.c         |  4 ++--
 8 files changed, 17 insertions(+), 17 deletions(-)

Patch

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 798aec816970..863a5db1e370 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -135,7 +135,7 @@  struct bpf_map_ops {
 	struct bpf_local_storage __rcu ** (*map_owner_storage_ptr)(void *owner);
 
 	/* Misc helpers.*/
-	int (*map_redirect)(struct bpf_map *map, u32 ifindex, u64 flags);
+	int (*map_redirect)(struct bpf_map *map, u64 key, u64 flags);
 
 	/* map_meta_equal must be implemented for maps that can be
 	 * used as an inner map.  It is a runtime check to ensure
diff --git a/include/linux/filter.h b/include/linux/filter.h
index efc42a6e3aed..e6c1c277ffdc 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -643,13 +643,13 @@  struct bpf_nh_params {
 };
 
 struct bpf_redirect_info {
-	u32 flags;
-	u32 tgt_index;
+	u64 tgt_index;
 	void *tgt_value;
 	struct bpf_map *map;
+	u32 flags;
+	u32 kern_flags;
 	u32 map_id;
 	enum bpf_map_type map_type;
-	u32 kern_flags;
 	struct bpf_nh_params nh;
 };
 
@@ -1504,7 +1504,7 @@  static inline bool bpf_sk_lookup_run_v6(struct net *net, int protocol,
 }
 #endif /* IS_ENABLED(CONFIG_IPV6) */
 
-static __always_inline int __bpf_xdp_redirect_map(struct bpf_map *map, u32 ifindex,
+static __always_inline int __bpf_xdp_redirect_map(struct bpf_map *map, u64 index,
 						  u64 flags, const u64 flag_mask,
 						  void *lookup_elem(struct bpf_map *map, u32 key))
 {
@@ -1515,7 +1515,7 @@  static __always_inline int __bpf_xdp_redirect_map(struct bpf_map *map, u32 ifind
 	if (unlikely(flags & ~(action_mask | flag_mask)))
 		return XDP_ABORTED;
 
-	ri->tgt_value = lookup_elem(map, ifindex);
+	ri->tgt_value = lookup_elem(map, index);
 	if (unlikely(!ri->tgt_value) && !(flags & BPF_F_BROADCAST)) {
 		/* If the lookup fails we want to clear out the state in the
 		 * redirect_info struct completely, so that if an eBPF program
@@ -1527,7 +1527,7 @@  static __always_inline int __bpf_xdp_redirect_map(struct bpf_map *map, u32 ifind
 		return flags & action_mask;
 	}
 
-	ri->tgt_index = ifindex;
+	ri->tgt_index = index;
 	ri->map_id = map->id;
 	ri->map_type = map->map_type;
 
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 94659f6b3395..9fd462e2f8c0 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -2647,7 +2647,7 @@  union bpf_attr {
  * 	Return
  * 		0 on success, or a negative error in case of failure.
  *
- * long bpf_redirect_map(struct bpf_map *map, u32 key, u64 flags)
+ * long bpf_redirect_map(struct bpf_map *map, u64 key, u64 flags)
  * 	Description
  * 		Redirect the packet to the endpoint referenced by *map* at
  * 		index *key*. Depending on its type, this *map* can contain
diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
index bb03fdba73bb..fa9dc11d5d64 100644
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c
@@ -664,9 +664,9 @@  static int cpu_map_get_next_key(struct bpf_map *map, void *key, void *next_key)
 	return 0;
 }
 
-static int cpu_map_redirect(struct bpf_map *map, u32 ifindex, u64 flags)
+static int cpu_map_redirect(struct bpf_map *map, u64 index, u64 flags)
 {
-	return __bpf_xdp_redirect_map(map, ifindex, flags, 0,
+	return __bpf_xdp_redirect_map(map, index, flags, 0,
 				      __cpu_map_lookup_elem);
 }
 
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index f9a87dcc5535..d01e4c55b376 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -992,14 +992,14 @@  static int dev_map_hash_update_elem(struct bpf_map *map, void *key, void *value,
 					 map, key, value, map_flags);
 }
 
-static int dev_map_redirect(struct bpf_map *map, u32 ifindex, u64 flags)
+static int dev_map_redirect(struct bpf_map *map, u64 ifindex, u64 flags)
 {
 	return __bpf_xdp_redirect_map(map, ifindex, flags,
 				      BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS,
 				      __dev_map_lookup_elem);
 }
 
-static int dev_hash_map_redirect(struct bpf_map *map, u32 ifindex, u64 flags)
+static int dev_hash_map_redirect(struct bpf_map *map, u64 ifindex, u64 flags)
 {
 	return __bpf_xdp_redirect_map(map, ifindex, flags,
 				      BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS,
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index d3b75aa0c54d..f81b70a8d4ea 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -14366,7 +14366,7 @@  static int do_misc_fixups(struct bpf_verifier_env *env)
 			BUILD_BUG_ON(!__same_type(ops->map_peek_elem,
 				     (int (*)(struct bpf_map *map, void *value))NULL));
 			BUILD_BUG_ON(!__same_type(ops->map_redirect,
-				     (int (*)(struct bpf_map *map, u32 ifindex, u64 flags))NULL));
+				     (int (*)(struct bpf_map *map, u64 index, u64 flags))NULL));
 			BUILD_BUG_ON(!__same_type(ops->map_for_each_callback,
 				     (int (*)(struct bpf_map *map,
 					      bpf_callback_t callback_fn,
diff --git a/net/core/filter.c b/net/core/filter.c
index cb3b635e35be..d062f85794f7 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4414,10 +4414,10 @@  static const struct bpf_func_proto bpf_xdp_redirect_proto = {
 	.arg2_type      = ARG_ANYTHING,
 };
 
-BPF_CALL_3(bpf_xdp_redirect_map, struct bpf_map *, map, u32, ifindex,
+BPF_CALL_3(bpf_xdp_redirect_map, struct bpf_map *, map, u64, key,
 	   u64, flags)
 {
-	return map->ops->map_redirect(map, ifindex, flags);
+	return map->ops->map_redirect(map, key, flags);
 }
 
 static const struct bpf_func_proto bpf_xdp_redirect_map_proto = {
diff --git a/net/xdp/xskmap.c b/net/xdp/xskmap.c
index acc8e52a4f5f..771d0fa90ef5 100644
--- a/net/xdp/xskmap.c
+++ b/net/xdp/xskmap.c
@@ -231,9 +231,9 @@  static int xsk_map_delete_elem(struct bpf_map *map, void *key)
 	return 0;
 }
 
-static int xsk_map_redirect(struct bpf_map *map, u32 ifindex, u64 flags)
+static int xsk_map_redirect(struct bpf_map *map, u64 index, u64 flags)
 {
-	return __bpf_xdp_redirect_map(map, ifindex, flags, 0,
+	return __bpf_xdp_redirect_map(map, index, flags, 0,
 				      __xsk_map_lookup_elem);
 }