From: Lorenzo Bianconi <lorenzo@xxxxxxxxxx> 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 __ref suffix on the parameter name causes strict type checking. This would disallow passing nf_conn___init to kfunc taking nf_conn, and vice versa. We cannot remove the __ref suffix 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 <lorenzo@xxxxxxxxxx> Co-developed-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx> --- include/net/netfilter/nf_conntrack_core.h | 2 ++ net/netfilter/nf_conntrack_bpf.c | 37 +++++++++++++++++++++ net/netfilter/nf_conntrack_core.c | 40 +++++++++++++++++++++++ net/netfilter/nf_conntrack_netlink.c | 39 ++-------------------- 4 files changed, 81 insertions(+), 37 deletions(-) diff --git a/include/net/netfilter/nf_conntrack_core.h b/include/net/netfilter/nf_conntrack_core.h index 3b0f7d0eebae..3cd3a6e631aa 100644 --- a/include/net/netfilter/nf_conntrack_core.h +++ b/include/net/netfilter/nf_conntrack_core.h @@ -98,6 +98,8 @@ static inline void __nf_ct_set_timeout(struct nf_conn *ct, u64 timeout) } int __nf_ct_change_timeout(struct nf_conn *ct, u64 cta_timeout); +void __nf_ct_change_status(struct nf_conn *ct, unsigned long on, unsigned long off); +int nf_ct_change_status_common(struct nf_conn *ct, unsigned int status); #endif diff --git a/net/netfilter/nf_conntrack_bpf.c b/net/netfilter/nf_conntrack_bpf.c index db04874da950..6975dda77173 100644 --- a/net/netfilter/nf_conntrack_bpf.c +++ b/net/netfilter/nf_conntrack_bpf.c @@ -394,6 +394,39 @@ int bpf_ct_change_timeout(struct nf_conn *nfct__ref, u32 timeout) return __nf_ct_change_timeout(nfct__ref, msecs_to_jiffies(timeout)); } +/* bpf_ct_set_status - Set status field of allocated nf_conn + * + * Set the status field of the newly allocated nf_conn before insertion. + * This must be invoked for referenced PTR_TO_BTF_ID to nf_conn___init. + * + * Parameters: + * @nfct__ref - Pointer to referenced nf_conn object, obtained using + * bpf_xdp_ct_alloc or bpf_skb_ct_alloc. + * @status - New status value. + */ +int bpf_ct_set_status(const struct nf_conn___init *nfct__ref, u32 status) +{ + return nf_ct_change_status_common((struct nf_conn *)nfct__ref, status); +} + +/* bpf_ct_change_status - Change status of inserted nf_conn + * + * Change the status field of the provided connection tracking entry. + * This must be invoked for referenced PTR_TO_BTF_ID to nf_conn. + * + * Parameters: + * @nfct__ref - Pointer to referenced nf_conn object, obtained using + * bpf_ct_insert_entry, bpf_xdp_ct_lookup or bpf_skb_ct_lookup. + * @status - New status value. + */ +int bpf_ct_change_status(struct nf_conn *nfct__ref, u32 status) +{ + /* We need a different kfunc because __ref suffix makes type matching + * strict, so normal nf_conn cannot be passed to bpf_ct_set_status. + */ + return nf_ct_change_status_common(nfct__ref, status); +} + __diag_pop() BTF_SET_START(nf_ct_xdp_check_kfunc_ids) @@ -403,6 +436,8 @@ BTF_ID(func, bpf_ct_insert_entry) BTF_ID(func, bpf_ct_release) BTF_ID(func, bpf_ct_set_timeout); BTF_ID(func, bpf_ct_change_timeout); +BTF_ID(func, bpf_ct_set_status); +BTF_ID(func, bpf_ct_change_status); BTF_SET_END(nf_ct_xdp_check_kfunc_ids) BTF_SET_START(nf_ct_tc_check_kfunc_ids) @@ -412,6 +447,8 @@ BTF_ID(func, bpf_ct_insert_entry) BTF_ID(func, bpf_ct_release) BTF_ID(func, bpf_ct_set_timeout); BTF_ID(func, bpf_ct_change_timeout); +BTF_ID(func, bpf_ct_set_status); +BTF_ID(func, bpf_ct_change_status); BTF_SET_END(nf_ct_tc_check_kfunc_ids) BTF_SET_START(nf_ct_acquire_kfunc_ids) diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c index 572f59a5e936..66a0aa8dbc3b 100644 --- a/net/netfilter/nf_conntrack_core.c +++ b/net/netfilter/nf_conntrack_core.c @@ -2807,4 +2807,44 @@ int __nf_ct_change_timeout(struct nf_conn *ct, u64 timeout) } EXPORT_SYMBOL_GPL(__nf_ct_change_timeout); +void __nf_ct_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); + } +} +EXPORT_SYMBOL_GPL(__nf_ct_change_status); + +int nf_ct_change_status_common(struct nf_conn *ct, unsigned int status) +{ + unsigned long d; + + 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; + + __nf_ct_change_status(ct, status, 0); + return 0; +} +EXPORT_SYMBOL_GPL(nf_ct_change_status_common); + #endif 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; } -- 2.36.1