From 7f1c04269fe7b3293dea38ea65da4fd6614d6f80 Mon Sep 17 00:00:00 2001 From: David Ahern Date: Fri, 29 May 2020 16:07:12 -0600 Subject: devmap: Formalize map value as a named struct MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add 'struct bpf_devmap_val' to formalize the expected values that can be passed in for a DEVMAP. Update devmap code to use the struct. Signed-off-by: David Ahern Signed-off-by: Alexei Starovoitov Acked-by: Toke Høiland-Jørgensen Link: https://lore.kernel.org/bpf/20200529220716.75383-2-dsahern@kernel.org Signed-off-by: Alexei Starovoitov --- kernel/bpf/devmap.c | 45 ++++++++++++++++++++++++++++----------------- 1 file changed, 28 insertions(+), 17 deletions(-) (limited to 'kernel/bpf/devmap.c') diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index a51d9fb7a359..a1459de0914e 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -60,12 +60,18 @@ struct xdp_dev_bulk_queue { unsigned int count; }; +/* DEVMAP values */ +struct bpf_devmap_val { + u32 ifindex; /* device index */ +}; + struct bpf_dtab_netdev { struct net_device *dev; /* must be first member, due to tracepoint */ struct hlist_node index_hlist; struct bpf_dtab *dtab; struct rcu_head rcu; unsigned int idx; + struct bpf_devmap_val val; }; struct bpf_dtab { @@ -472,18 +478,15 @@ int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb, static void *dev_map_lookup_elem(struct bpf_map *map, void *key) { struct bpf_dtab_netdev *obj = __dev_map_lookup_elem(map, *(u32 *)key); - struct net_device *dev = obj ? obj->dev : NULL; - return dev ? &dev->ifindex : NULL; + return obj ? &obj->val : NULL; } static void *dev_map_hash_lookup_elem(struct bpf_map *map, void *key) { struct bpf_dtab_netdev *obj = __dev_map_hash_lookup_elem(map, *(u32 *)key); - struct net_device *dev = obj ? obj->dev : NULL; - - return dev ? &dev->ifindex : NULL; + return obj ? &obj->val : NULL; } static void __dev_map_entry_free(struct rcu_head *rcu) @@ -541,7 +544,7 @@ static int dev_map_hash_delete_elem(struct bpf_map *map, void *key) static struct bpf_dtab_netdev *__dev_map_alloc_node(struct net *net, struct bpf_dtab *dtab, - u32 ifindex, + struct bpf_devmap_val *val, unsigned int idx) { struct bpf_dtab_netdev *dev; @@ -551,16 +554,18 @@ static struct bpf_dtab_netdev *__dev_map_alloc_node(struct net *net, if (!dev) return ERR_PTR(-ENOMEM); - dev->dev = dev_get_by_index(net, ifindex); - if (!dev->dev) { - kfree(dev); - return ERR_PTR(-EINVAL); - } + dev->dev = dev_get_by_index(net, val->ifindex); + if (!dev->dev) + goto err_out; dev->idx = idx; dev->dtab = dtab; + dev->val.ifindex = val->ifindex; return dev; +err_out: + kfree(dev); + return ERR_PTR(-EINVAL); } static int __dev_map_update_elem(struct net *net, struct bpf_map *map, @@ -568,7 +573,7 @@ static int __dev_map_update_elem(struct net *net, struct bpf_map *map, { struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map); struct bpf_dtab_netdev *dev, *old_dev; - u32 ifindex = *(u32 *)value; + struct bpf_devmap_val val = { }; u32 i = *(u32 *)key; if (unlikely(map_flags > BPF_EXIST)) @@ -578,10 +583,13 @@ static int __dev_map_update_elem(struct net *net, struct bpf_map *map, if (unlikely(map_flags == BPF_NOEXIST)) return -EEXIST; - if (!ifindex) { + /* already verified value_size <= sizeof val */ + memcpy(&val, value, map->value_size); + + if (!val.ifindex) { dev = NULL; } else { - dev = __dev_map_alloc_node(net, dtab, ifindex, i); + dev = __dev_map_alloc_node(net, dtab, &val, i); if (IS_ERR(dev)) return PTR_ERR(dev); } @@ -609,12 +617,15 @@ static int __dev_map_hash_update_elem(struct net *net, struct bpf_map *map, { struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map); struct bpf_dtab_netdev *dev, *old_dev; - u32 ifindex = *(u32 *)value; + struct bpf_devmap_val val = { }; u32 idx = *(u32 *)key; unsigned long flags; int err = -EEXIST; - if (unlikely(map_flags > BPF_EXIST || !ifindex)) + /* already verified value_size <= sizeof val */ + memcpy(&val, value, map->value_size); + + if (unlikely(map_flags > BPF_EXIST || !val.ifindex)) return -EINVAL; spin_lock_irqsave(&dtab->index_lock, flags); @@ -623,7 +634,7 @@ static int __dev_map_hash_update_elem(struct net *net, struct bpf_map *map, if (old_dev && (map_flags & BPF_NOEXIST)) goto out_err; - dev = __dev_map_alloc_node(net, dtab, ifindex, idx); + dev = __dev_map_alloc_node(net, dtab, &val, idx); if (IS_ERR(dev)) { err = PTR_ERR(dev); goto out_err; -- cgit v1.2.3-59-g8ed1b