From ef69aa3a986ef94f01ce8b5b619f550db54432fe Mon Sep 17 00:00:00 2001 From: Lorenzo Bianconi Date: Thu, 21 Jul 2022 15:42:41 +0200 Subject: net: netfilter: Add kfuncs to set and change CT status Introduce bpf_ct_set_status and bpf_ct_change_status kfunc helpers in order to set nf_conn field of allocated entry or update nf_conn status field of existing inserted entry. Use nf_ct_change_status_common to share the permitted status field changes between netlink and BPF side by refactoring ctnetlink_change_status. It is required to introduce two kfuncs taking nf_conn___init and nf_conn instead of sharing one because KF_TRUSTED_ARGS flag causes strict type checking. This would disallow passing nf_conn___init to kfunc taking nf_conn, and vice versa. We cannot remove the KF_TRUSTED_ARGS flag as we only want to accept refcounted pointers and not e.g. ct->master. Hence, bpf_ct_set_* kfuncs are meant to be used on allocated CT, and bpf_ct_change_* kfuncs are meant to be used on inserted or looked up CT entry. Signed-off-by: Lorenzo Bianconi Co-developed-by: Kumar Kartikeya Dwivedi Signed-off-by: Kumar Kartikeya Dwivedi Link: https://lore.kernel.org/r/20220721134245.2450-10-memxor@gmail.com Signed-off-by: Alexei Starovoitov --- net/netfilter/nf_conntrack_netlink.c | 39 ++---------------------------------- 1 file changed, 2 insertions(+), 37 deletions(-) (limited to 'net/netfilter/nf_conntrack_netlink.c') diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c index b1de07c73845..e02832ef9b9f 100644 --- a/net/netfilter/nf_conntrack_netlink.c +++ b/net/netfilter/nf_conntrack_netlink.c @@ -1890,45 +1890,10 @@ ctnetlink_parse_nat_setup(struct nf_conn *ct, } #endif -static void -__ctnetlink_change_status(struct nf_conn *ct, unsigned long on, - unsigned long off) -{ - unsigned int bit; - - /* Ignore these unchangable bits */ - on &= ~IPS_UNCHANGEABLE_MASK; - off &= ~IPS_UNCHANGEABLE_MASK; - - for (bit = 0; bit < __IPS_MAX_BIT; bit++) { - if (on & (1 << bit)) - set_bit(bit, &ct->status); - else if (off & (1 << bit)) - clear_bit(bit, &ct->status); - } -} - static int ctnetlink_change_status(struct nf_conn *ct, const struct nlattr * const cda[]) { - unsigned long d; - unsigned int status = ntohl(nla_get_be32(cda[CTA_STATUS])); - d = ct->status ^ status; - - if (d & (IPS_EXPECTED|IPS_CONFIRMED|IPS_DYING)) - /* unchangeable */ - return -EBUSY; - - if (d & IPS_SEEN_REPLY && !(status & IPS_SEEN_REPLY)) - /* SEEN_REPLY bit can only be set */ - return -EBUSY; - - if (d & IPS_ASSURED && !(status & IPS_ASSURED)) - /* ASSURED bit can only be set */ - return -EBUSY; - - __ctnetlink_change_status(ct, status, 0); - return 0; + return nf_ct_change_status_common(ct, ntohl(nla_get_be32(cda[CTA_STATUS]))); } static int @@ -2825,7 +2790,7 @@ ctnetlink_update_status(struct nf_conn *ct, const struct nlattr * const cda[]) * unchangeable bits but do not error out. Also user programs * are allowed to clear the bits that they are allowed to change. */ - __ctnetlink_change_status(ct, status, ~status); + __nf_ct_change_status(ct, status, ~status); return 0; } -- cgit