On 4/23/24 8:00 PM, Brad Cowie wrote:
Add ct zone id/flags/dir to bpf_ct_opts so that arbitrary ct zones
can be used for xdp/tc bpf ct helper functions bpf_{xdp,skb}_ct_alloc
and bpf_{xdp,skb}_ct_lookup.
Signed-off-by: Brad Cowie <brad@xxxxxxxxx>
---
v1 -> v2:
- Make ct zone flags/dir configurable
---
net/netfilter/nf_conntrack_bpf.c | 97 ++++++++++++++++++++------------
1 file changed, 61 insertions(+), 36 deletions(-)
diff --git a/net/netfilter/nf_conntrack_bpf.c b/net/netfilter/nf_conntrack_bpf.c
index d2492d050fe6..67f73b57089b 100644
--- a/net/netfilter/nf_conntrack_bpf.c
+++ b/net/netfilter/nf_conntrack_bpf.c
@@ -21,41 +21,44 @@
/* bpf_ct_opts - Options for CT lookup helpers
*
* Members:
- * @netns_id - Specify the network namespace for lookup
- * Values:
- * BPF_F_CURRENT_NETNS (-1)
- * Use namespace associated with ctx (xdp_md, __sk_buff)
- * [0, S32_MAX]
- * Network Namespace ID
- * @error - Out parameter, set for any errors encountered
- * Values:
- * -EINVAL - Passed NULL for bpf_tuple pointer
- * -EINVAL - opts->reserved is not 0
- * -EINVAL - netns_id is less than -1
- * -EINVAL - opts__sz isn't NF_BPF_CT_OPTS_SZ (12)
- * -EPROTO - l4proto isn't one of IPPROTO_TCP or IPPROTO_UDP
- * -ENONET - No network namespace found for netns_id
- * -ENOENT - Conntrack lookup could not find entry for tuple
- * -EAFNOSUPPORT - tuple__sz isn't one of sizeof(tuple->ipv4)
- * or sizeof(tuple->ipv6)
- * @l4proto - Layer 4 protocol
- * Values:
- * IPPROTO_TCP, IPPROTO_UDP
- * @dir: - connection tracking tuple direction.
- * @reserved - Reserved member, will be reused for more options in future
- * Values:
- * 0
+ * @netns_id - Specify the network namespace for lookup
+ * Values:
+ * BPF_F_CURRENT_NETNS (-1)
+ * Use namespace associated with ctx (xdp_md, __sk_buff)
+ * [0, S32_MAX]
+ * Network Namespace ID
+ * @error - Out parameter, set for any errors encountered
+ * Values:
+ * -EINVAL - Passed NULL for bpf_tuple pointer
+ * -EINVAL - netns_id is less than -1
+ * -EINVAL - opts__sz isn't NF_BPF_CT_OPTS_SZ (16)
+ * or NF_BPF_CT_OPTS_OLD_SZ (12)
+ * -EPROTO - l4proto isn't one of IPPROTO_TCP or IPPROTO_UDP
+ * -ENONET - No network namespace found for netns_id
+ * -ENOENT - Conntrack lookup could not find entry for tuple
+ * -EAFNOSUPPORT - tuple__sz isn't one of sizeof(tuple->ipv4)
+ * or sizeof(tuple->ipv6)
+ * @l4proto - Layer 4 protocol
+ * Values:
+ * IPPROTO_TCP, IPPROTO_UDP
+ * @dir: - connection tracking tuple direction.
Please avoid whitespace changes. It is unnecessary code churns.
+ * @ct_zone_id - connection tracking zone id.
+ * @ct_zone_flags - connection tracking zone flags.
+ * @ct_zone_dir - connection tracking zone direction.
*/
struct bpf_ct_opts {
s32 netns_id;
s32 error;
u8 l4proto;
u8 dir;
- u8 reserved[2];
+ u16 ct_zone_id;
+ u8 ct_zone_flags;
+ u8 ct_zone_dir;
The size is 16 now with 2 tail paddings.
It needs a "u8 reserved[2];" at the end and need to check its 0.
};
enum {
- NF_BPF_CT_OPTS_SZ = 12,
+ NF_BPF_CT_OPTS_SZ = 16,
+ NF_BPF_CT_OPTS_OLD_SZ = 12,
Avoid adding NF_BPF_CT_OPTS_OLD_SZ for now. I don't see how it may be useful.
};
static int bpf_nf_ct_tuple_parse(struct bpf_sock_tuple *bpf_tuple,
@@ -104,11 +107,13 @@ __bpf_nf_ct_alloc_entry(struct net *net, struct bpf_sock_tuple *bpf_tuple,
u32 timeout)
{
struct nf_conntrack_tuple otuple, rtuple;
+ struct nf_conntrack_zone ct_zone;
struct nf_conn *ct;
int err;
- if (!opts || !bpf_tuple || opts->reserved[0] || opts->reserved[1] ||
- opts_len != NF_BPF_CT_OPTS_SZ)
+ if (!opts || !bpf_tuple)
+ return ERR_PTR(-EINVAL);
+ if (!(opts_len == NF_BPF_CT_OPTS_SZ || opts_len == NF_BPF_CT_OPTS_OLD_SZ))
return ERR_PTR(-EINVAL);
if (unlikely(opts->netns_id < BPF_F_CURRENT_NETNS))
@@ -130,7 +135,16 @@ __bpf_nf_ct_alloc_entry(struct net *net, struct bpf_sock_tuple *bpf_tuple,
return ERR_PTR(-ENONET);
}
- ct = nf_conntrack_alloc(net, &nf_ct_zone_dflt, &otuple, &rtuple,
+ if (opts_len == NF_BPF_CT_OPTS_SZ) {
+ if (opts->ct_zone_dir == 0)
I don't know the details about the dir in ct_zone, so a question: a 0
ct_zone_dir is invalid and can be reused to mean NF_CT_DEFAULT_ZONE_DIR?
+ opts->ct_zone_dir = NF_CT_DEFAULT_ZONE_DIR;
+ nf_ct_zone_init(&ct_zone,
+ opts->ct_zone_id, opts->ct_zone_dir, opts->ct_zone_flags);
+ } else {
Better enforce "ct_zone_id == 0" also instead of ignoring it.
+ ct_zone = nf_ct_zone_dflt;
+ }
+
+ ct = nf_conntrack_alloc(net, &ct_zone, &otuple, &rtuple,
GFP_ATOMIC);
if (IS_ERR(ct))
goto out;
@@ -152,11 +166,13 @@ static struct nf_conn *__bpf_nf_ct_lookup(struct net *net,
{
struct nf_conntrack_tuple_hash *hash;
struct nf_conntrack_tuple tuple;
+ struct nf_conntrack_zone ct_zone;
struct nf_conn *ct;
int err;
- if (!opts || !bpf_tuple || opts->reserved[0] || opts->reserved[1] ||
- opts_len != NF_BPF_CT_OPTS_SZ)
+ if (!opts || !bpf_tuple)
+ return ERR_PTR(-EINVAL);
+ if (!(opts_len == NF_BPF_CT_OPTS_SZ || opts_len == NF_BPF_CT_OPTS_OLD_SZ))
return ERR_PTR(-EINVAL);
if (unlikely(opts->l4proto != IPPROTO_TCP && opts->l4proto != IPPROTO_UDP))
return ERR_PTR(-EPROTO);
@@ -174,7 +190,16 @@ static struct nf_conn *__bpf_nf_ct_lookup(struct net *net,
return ERR_PTR(-ENONET);
}
- hash = nf_conntrack_find_get(net, &nf_ct_zone_dflt, &tuple);
+ if (opts_len == NF_BPF_CT_OPTS_SZ) {
+ if (opts->ct_zone_dir == 0)
+ opts->ct_zone_dir = NF_CT_DEFAULT_ZONE_DIR;
+ nf_ct_zone_init(&ct_zone,
+ opts->ct_zone_id, opts->ct_zone_dir, opts->ct_zone_flags);
+ } else {
+ ct_zone = nf_ct_zone_dflt;
+ }
+
+ hash = nf_conntrack_find_get(net, &ct_zone, &tuple);
if (opts->netns_id >= 0)
put_net(net);
if (!hash)
@@ -245,7 +270,7 @@ __bpf_kfunc_start_defs();
* @opts - Additional options for allocation (documented above)
* Cannot be NULL
* @opts__sz - Length of the bpf_ct_opts structure
- * Must be NF_BPF_CT_OPTS_SZ (12)
+ * Must be NF_BPF_CT_OPTS_SZ (16)
*/
__bpf_kfunc struct nf_conn___init *
bpf_xdp_ct_alloc(struct xdp_md *xdp_ctx, struct bpf_sock_tuple *bpf_tuple,
@@ -279,7 +304,7 @@ bpf_xdp_ct_alloc(struct xdp_md *xdp_ctx, struct bpf_sock_tuple *bpf_tuple,
* @opts - Additional options for lookup (documented above)
* Cannot be NULL
* @opts__sz - Length of the bpf_ct_opts structure
- * Must be NF_BPF_CT_OPTS_SZ (12)
+ * Must be NF_BPF_CT_OPTS_SZ (16)
Either 16 or 12. Same for below.
*/
__bpf_kfunc struct nf_conn *
bpf_xdp_ct_lookup(struct xdp_md *xdp_ctx, struct bpf_sock_tuple *bpf_tuple,
@@ -312,7 +337,7 @@ bpf_xdp_ct_lookup(struct xdp_md *xdp_ctx, struct bpf_sock_tuple *bpf_tuple,
* @opts - Additional options for allocation (documented above)
* Cannot be NULL
* @opts__sz - Length of the bpf_ct_opts structure
- * Must be NF_BPF_CT_OPTS_SZ (12)
+ * Must be NF_BPF_CT_OPTS_SZ (16)
*/
__bpf_kfunc struct nf_conn___init *
bpf_skb_ct_alloc(struct __sk_buff *skb_ctx, struct bpf_sock_tuple *bpf_tuple,
@@ -347,7 +372,7 @@ bpf_skb_ct_alloc(struct __sk_buff *skb_ctx, struct bpf_sock_tuple *bpf_tuple,
* @opts - Additional options for lookup (documented above)
* Cannot be NULL
* @opts__sz - Length of the bpf_ct_opts structure
- * Must be NF_BPF_CT_OPTS_SZ (12)
+ * Must be NF_BPF_CT_OPTS_SZ (16)
*/
__bpf_kfunc struct nf_conn *
bpf_skb_ct_lookup(struct __sk_buff *skb_ctx, struct bpf_sock_tuple *bpf_tuple,
