All of lore.kernel.org
 help / color / mirror / Atom feed
From: David Ahern <dsahern@kernel.org>
To: netdev@vger.kernel.org
Cc: davem@davemloft.net, kuba@kernel.org, brouer@redhat.com,
	toke@redhat.com, daniel@iogearbox.net, john.fastabend@gmail.com,
	ast@kernel.org, kafai@fb.com, songliubraving@fb.com, yhs@fb.com,
	andriin@fb.com, dsahern@gmail.com
Subject: [PATCH v2 bpf-next 1/5] devmap: Formalize map value as a named struct
Date: Wed, 27 May 2020 18:14:19 -0600	[thread overview]
Message-ID: <20200528001423.58575-2-dsahern@kernel.org> (raw)
In-Reply-To: <20200528001423.58575-1-dsahern@kernel.org>

From: David Ahern <dsahern@gmail.com>

Add 'struct devmap_val' to the bpf uapi 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 <dsahern@gmail.com>
---
 include/uapi/linux/bpf.h       |  5 ++++
 kernel/bpf/devmap.c            | 43 ++++++++++++++++++++--------------
 tools/include/uapi/linux/bpf.h |  5 ++++
 3 files changed, 35 insertions(+), 18 deletions(-)

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 54b93f8b49b8..d27302ecaa9c 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -3625,6 +3625,11 @@ struct xdp_md {
 	__u32 rx_queue_index;  /* rxq->queue_index  */
 };
 
+/* DEVMAP values */
+struct devmap_val {
+	__u32 ifindex;   /* device index */
+};
+
 enum sk_action {
 	SK_DROP = 0,
 	SK_PASS,
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index a51d9fb7a359..069a50113e26 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -66,6 +66,7 @@ struct bpf_dtab_netdev {
 	struct bpf_dtab *dtab;
 	struct rcu_head rcu;
 	unsigned int idx;
+	struct devmap_val val;
 };
 
 struct bpf_dtab {
@@ -110,7 +111,8 @@ static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr)
 
 	/* check sanity of attributes */
 	if (attr->max_entries == 0 || attr->key_size != 4 ||
-	    attr->value_size != 4 || attr->map_flags & ~DEV_CREATE_FLAG_MASK)
+	    attr->value_size > sizeof(struct devmap_val) ||
+	    attr->map_flags & ~DEV_CREATE_FLAG_MASK)
 		return -EINVAL;
 
 	/* Lookup returns a pointer straight to dev->ifindex, so make sure the
@@ -472,18 +474,15 @@ 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 +540,7 @@ 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 devmap_val *val,
 						    unsigned int idx)
 {
 	struct bpf_dtab_netdev *dev;
@@ -551,16 +550,18 @@ 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 +569,7 @@ 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 devmap_val val = { };
 	u32 i = *(u32 *)key;
 
 	if (unlikely(map_flags > BPF_EXIST))
@@ -578,10 +579,13 @@ 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 +613,15 @@ 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 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 +630,7 @@ 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;
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 54b93f8b49b8..d27302ecaa9c 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -3625,6 +3625,11 @@ struct xdp_md {
 	__u32 rx_queue_index;  /* rxq->queue_index  */
 };
 
+/* DEVMAP values */
+struct devmap_val {
+	__u32 ifindex;   /* device index */
+};
+
 enum sk_action {
 	SK_DROP = 0,
 	SK_PASS,
-- 
2.21.1 (Apple Git-122.3)


  reply	other threads:[~2020-05-28  0:14 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-28  0:14 [PATCH v2 bpf-next 0/5] bpf: Add support for XDP programs in DEVMAP entries David Ahern
2020-05-28  0:14 ` David Ahern [this message]
2020-05-28  7:01   ` [PATCH v2 bpf-next 1/5] devmap: Formalize map value as a named struct Andrii Nakryiko
2020-05-28 22:37     ` David Ahern
2020-05-28  0:14 ` [PATCH v2 bpf-next 2/5] bpf: Add support to attach bpf program to a devmap entry David Ahern
2020-05-28  7:01   ` Andrii Nakryiko
2020-05-28 22:40     ` David Ahern
2020-05-28 22:54       ` Andrii Nakryiko
2020-05-28  8:54   ` Toke Høiland-Jørgensen
2020-05-28  0:14 ` [PATCH v2 bpf-next 3/5] xdp: Add xdp_txq_info to xdp_buff David Ahern
2020-05-28  0:14 ` [PATCH v2 bpf-next 4/5] libbpf: Add SEC name for xdp programs attached to device map David Ahern
2020-05-28  7:04   ` Andrii Nakryiko
2020-05-28 22:49     ` David Ahern
2020-05-28  0:14 ` [PATCH v2 bpf-next 5/5] selftest: Add tests for XDP programs in devmap entries David Ahern
2020-05-28  7:08   ` Andrii Nakryiko
2020-05-28 10:25     ` Jesper Dangaard Brouer
2020-05-28 22:56       ` David Ahern
2020-05-28 22:54     ` David Ahern

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200528001423.58575-2-dsahern@kernel.org \
    --to=dsahern@kernel.org \
    --cc=andriin@fb.com \
    --cc=ast@kernel.org \
    --cc=brouer@redhat.com \
    --cc=daniel@iogearbox.net \
    --cc=davem@davemloft.net \
    --cc=dsahern@gmail.com \
    --cc=john.fastabend@gmail.com \
    --cc=kafai@fb.com \
    --cc=kuba@kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=songliubraving@fb.com \
    --cc=toke@redhat.com \
    --cc=yhs@fb.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.