On 4/30/24 9:59 PM, Brad Cowie wrote:
On Fri, 26 Apr 2024 at 11:27, Martin KaFai Lau <martin.lau@xxxxxxxxx> wrote:
On 4/23/24 8:00 PM, Brad Cowie wrote:
};
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?
ct_zone_dir is a bitmask that can have two different bits set,
NF_CT_ZONE_DIR_ORIG (1) and NF_CT_ZONE_DIR_REPL (2).
The comparison function nf_ct_zone_matches_dir() in nf_conntrack_zones.h
checks if ct_zone_dir & (1 << ip_conntrack_dir dir). ip_conntrack_dir
has two possible values IP_CT_DIR_ORIGINAL (0) and IP_CT_DIR_REPLY (1).
If ct_zone_dir has a value of 0, this makes nf_ct_zone_matches_dir()
always return false which makes nf_ct_zone_id() always return
NF_CT_DEFAULT_ZONE_ID instead of the specified ct zone id.
I chose to override ct_zone_dir here and set NF_CT_DEFAULT_ZONE_DIR (3),
to make the behaviour more obvious when a user calls the bpf ct helper
kfuncs while only setting ct_zone_id but not ct_zone_dir.
Ok. make sense.
+ 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.
Could I ask for clarification here, do you mean changing this
else statement to:
+ } else if (opts->ct_zone_id == 0) {
Or should I be setting opts->ct_zone_id = 0 inside the else block?
Testing non zero inside the else and return error instead of silently ignoring
it and then use nf_ct_zone_dflt:
} else {
if (opts->ct_zone_id)
/* don't ignore the opts->ct_zone_id */
return ERR_PTR(-EINVAL);
ct_zone = nf_ct_zone_dflt;
}
