bpf: Expand map key argument of bpf_redirect_map to u64

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 <song@kernel.org>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20221108140601.149971-3-toke@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 49f9d2b..54462dd 100644 (file)
--- 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 787d35d..bf70197 100644 (file)
--- 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 6580448..ab86145 100644 (file)
--- 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 6b6a78c..e0b2d01 100644 (file)
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c
@@ -667,9 +667,9 @@ 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 f9a87dc..d01e4c5 100644 (file)
--- 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 5e74f46..be24774 100644 (file)
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -14384,7 +14384,7 @@ 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 37fad5a..754dd01 100644 (file)
--- 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 acc8e52..771d0fa 100644 (file)
--- 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);
 }