diff options
Diffstat (limited to 'net/netfilter/nf_conntrack_bpf.c')
-rw-r--r-- | net/netfilter/nf_conntrack_bpf.c | 365 |
1 files changed, 276 insertions, 89 deletions
diff --git a/net/netfilter/nf_conntrack_bpf.c b/net/netfilter/nf_conntrack_bpf.c index bc4d5cd63a94..1cd87b28c9b0 100644 --- a/net/netfilter/nf_conntrack_bpf.c +++ b/net/netfilter/nf_conntrack_bpf.c @@ -55,57 +55,131 @@ enum { NF_BPF_CT_OPTS_SZ = 12, }; -static struct nf_conn *__bpf_nf_ct_lookup(struct net *net, - struct bpf_sock_tuple *bpf_tuple, - u32 tuple_len, u8 protonum, - s32 netns_id, u8 *dir) +static int bpf_nf_ct_tuple_parse(struct bpf_sock_tuple *bpf_tuple, + u32 tuple_len, u8 protonum, u8 dir, + struct nf_conntrack_tuple *tuple) { - struct nf_conntrack_tuple_hash *hash; - struct nf_conntrack_tuple tuple; - struct nf_conn *ct; + union nf_inet_addr *src = dir ? &tuple->dst.u3 : &tuple->src.u3; + union nf_inet_addr *dst = dir ? &tuple->src.u3 : &tuple->dst.u3; + union nf_conntrack_man_proto *sport = dir ? (void *)&tuple->dst.u + : &tuple->src.u; + union nf_conntrack_man_proto *dport = dir ? &tuple->src.u + : (void *)&tuple->dst.u; if (unlikely(protonum != IPPROTO_TCP && protonum != IPPROTO_UDP)) - return ERR_PTR(-EPROTO); - if (unlikely(netns_id < BPF_F_CURRENT_NETNS)) - return ERR_PTR(-EINVAL); + return -EPROTO; + + memset(tuple, 0, sizeof(*tuple)); - memset(&tuple, 0, sizeof(tuple)); switch (tuple_len) { case sizeof(bpf_tuple->ipv4): - tuple.src.l3num = AF_INET; - tuple.src.u3.ip = bpf_tuple->ipv4.saddr; - tuple.src.u.tcp.port = bpf_tuple->ipv4.sport; - tuple.dst.u3.ip = bpf_tuple->ipv4.daddr; - tuple.dst.u.tcp.port = bpf_tuple->ipv4.dport; + tuple->src.l3num = AF_INET; + src->ip = bpf_tuple->ipv4.saddr; + sport->tcp.port = bpf_tuple->ipv4.sport; + dst->ip = bpf_tuple->ipv4.daddr; + dport->tcp.port = bpf_tuple->ipv4.dport; break; case sizeof(bpf_tuple->ipv6): - tuple.src.l3num = AF_INET6; - memcpy(tuple.src.u3.ip6, bpf_tuple->ipv6.saddr, sizeof(bpf_tuple->ipv6.saddr)); - tuple.src.u.tcp.port = bpf_tuple->ipv6.sport; - memcpy(tuple.dst.u3.ip6, bpf_tuple->ipv6.daddr, sizeof(bpf_tuple->ipv6.daddr)); - tuple.dst.u.tcp.port = bpf_tuple->ipv6.dport; + tuple->src.l3num = AF_INET6; + memcpy(src->ip6, bpf_tuple->ipv6.saddr, sizeof(bpf_tuple->ipv6.saddr)); + sport->tcp.port = bpf_tuple->ipv6.sport; + memcpy(dst->ip6, bpf_tuple->ipv6.daddr, sizeof(bpf_tuple->ipv6.daddr)); + dport->tcp.port = bpf_tuple->ipv6.dport; break; default: - return ERR_PTR(-EAFNOSUPPORT); + return -EAFNOSUPPORT; + } + tuple->dst.protonum = protonum; + tuple->dst.dir = dir; + + return 0; +} + +static struct nf_conn * +__bpf_nf_ct_alloc_entry(struct net *net, struct bpf_sock_tuple *bpf_tuple, + u32 tuple_len, struct bpf_ct_opts *opts, u32 opts_len, + u32 timeout) +{ + struct nf_conntrack_tuple otuple, rtuple; + struct nf_conn *ct; + int err; + + if (!opts || !bpf_tuple || opts->reserved[0] || opts->reserved[1] || + opts_len != NF_BPF_CT_OPTS_SZ) + return ERR_PTR(-EINVAL); + + if (unlikely(opts->netns_id < BPF_F_CURRENT_NETNS)) + return ERR_PTR(-EINVAL); + + err = bpf_nf_ct_tuple_parse(bpf_tuple, tuple_len, opts->l4proto, + IP_CT_DIR_ORIGINAL, &otuple); + if (err < 0) + return ERR_PTR(err); + + err = bpf_nf_ct_tuple_parse(bpf_tuple, tuple_len, opts->l4proto, + IP_CT_DIR_REPLY, &rtuple); + if (err < 0) + return ERR_PTR(err); + + if (opts->netns_id >= 0) { + net = get_net_ns_by_id(net, opts->netns_id); + if (unlikely(!net)) + return ERR_PTR(-ENONET); } - tuple.dst.protonum = protonum; + ct = nf_conntrack_alloc(net, &nf_ct_zone_dflt, &otuple, &rtuple, + GFP_ATOMIC); + if (IS_ERR(ct)) + goto out; + + memset(&ct->proto, 0, sizeof(ct->proto)); + __nf_ct_set_timeout(ct, timeout * HZ); + ct->status |= IPS_CONFIRMED; + +out: + if (opts->netns_id >= 0) + put_net(net); + + return ct; +} + +static struct nf_conn *__bpf_nf_ct_lookup(struct net *net, + struct bpf_sock_tuple *bpf_tuple, + u32 tuple_len, struct bpf_ct_opts *opts, + u32 opts_len) +{ + struct nf_conntrack_tuple_hash *hash; + struct nf_conntrack_tuple tuple; + struct nf_conn *ct; + int err; + + if (!opts || !bpf_tuple || opts->reserved[0] || opts->reserved[1] || + opts_len != NF_BPF_CT_OPTS_SZ) + return ERR_PTR(-EINVAL); + if (unlikely(opts->l4proto != IPPROTO_TCP && opts->l4proto != IPPROTO_UDP)) + return ERR_PTR(-EPROTO); + if (unlikely(opts->netns_id < BPF_F_CURRENT_NETNS)) + return ERR_PTR(-EINVAL); + + err = bpf_nf_ct_tuple_parse(bpf_tuple, tuple_len, opts->l4proto, + IP_CT_DIR_ORIGINAL, &tuple); + if (err < 0) + return ERR_PTR(err); - if (netns_id >= 0) { - net = get_net_ns_by_id(net, netns_id); + if (opts->netns_id >= 0) { + net = get_net_ns_by_id(net, opts->netns_id); if (unlikely(!net)) return ERR_PTR(-ENONET); } hash = nf_conntrack_find_get(net, &nf_ct_zone_dflt, &tuple); - if (netns_id >= 0) + if (opts->netns_id >= 0) put_net(net); if (!hash) return ERR_PTR(-ENOENT); ct = nf_ct_tuplehash_to_ctrack(hash); - if (dir) - *dir = NF_CT_DIRECTION(hash); + opts->dir = NF_CT_DIRECTION(hash); return ct; } @@ -114,6 +188,43 @@ __diag_push(); __diag_ignore_all("-Wmissing-prototypes", "Global functions as their definitions will be in nf_conntrack BTF"); +struct nf_conn___init { + struct nf_conn ct; +}; + +/* bpf_xdp_ct_alloc - Allocate a new CT entry + * + * Parameters: + * @xdp_ctx - Pointer to ctx (xdp_md) in XDP program + * Cannot be NULL + * @bpf_tuple - Pointer to memory representing the tuple to look up + * Cannot be NULL + * @tuple__sz - Length of the tuple structure + * Must be one of sizeof(bpf_tuple->ipv4) or + * sizeof(bpf_tuple->ipv6) + * @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) + */ +struct nf_conn___init * +bpf_xdp_ct_alloc(struct xdp_md *xdp_ctx, struct bpf_sock_tuple *bpf_tuple, + u32 tuple__sz, struct bpf_ct_opts *opts, u32 opts__sz) +{ + struct xdp_buff *ctx = (struct xdp_buff *)xdp_ctx; + struct nf_conn *nfct; + + nfct = __bpf_nf_ct_alloc_entry(dev_net(ctx->rxq->dev), bpf_tuple, tuple__sz, + opts, opts__sz, 10); + if (IS_ERR(nfct)) { + if (opts) + opts->error = PTR_ERR(nfct); + return NULL; + } + + return (struct nf_conn___init *)nfct; +} + /* bpf_xdp_ct_lookup - Lookup CT entry for the given tuple, and acquire a * reference to it * @@ -138,25 +249,50 @@ bpf_xdp_ct_lookup(struct xdp_md *xdp_ctx, struct bpf_sock_tuple *bpf_tuple, struct net *caller_net; struct nf_conn *nfct; - BUILD_BUG_ON(sizeof(struct bpf_ct_opts) != NF_BPF_CT_OPTS_SZ); - - if (!opts) - return NULL; - if (!bpf_tuple || opts->reserved[0] || opts->reserved[1] || - opts__sz != NF_BPF_CT_OPTS_SZ) { - opts->error = -EINVAL; - return NULL; - } caller_net = dev_net(ctx->rxq->dev); - nfct = __bpf_nf_ct_lookup(caller_net, bpf_tuple, tuple__sz, opts->l4proto, - opts->netns_id, &opts->dir); + nfct = __bpf_nf_ct_lookup(caller_net, bpf_tuple, tuple__sz, opts, opts__sz); if (IS_ERR(nfct)) { - opts->error = PTR_ERR(nfct); + if (opts) + opts->error = PTR_ERR(nfct); return NULL; } return nfct; } +/* bpf_skb_ct_alloc - Allocate a new CT entry + * + * Parameters: + * @skb_ctx - Pointer to ctx (__sk_buff) in TC program + * Cannot be NULL + * @bpf_tuple - Pointer to memory representing the tuple to look up + * Cannot be NULL + * @tuple__sz - Length of the tuple structure + * Must be one of sizeof(bpf_tuple->ipv4) or + * sizeof(bpf_tuple->ipv6) + * @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) + */ +struct nf_conn___init * +bpf_skb_ct_alloc(struct __sk_buff *skb_ctx, struct bpf_sock_tuple *bpf_tuple, + u32 tuple__sz, struct bpf_ct_opts *opts, u32 opts__sz) +{ + struct sk_buff *skb = (struct sk_buff *)skb_ctx; + struct nf_conn *nfct; + struct net *net; + + net = skb->dev ? dev_net(skb->dev) : sock_net(skb->sk); + nfct = __bpf_nf_ct_alloc_entry(net, bpf_tuple, tuple__sz, opts, opts__sz, 10); + if (IS_ERR(nfct)) { + if (opts) + opts->error = PTR_ERR(nfct); + return NULL; + } + + return (struct nf_conn___init *)nfct; +} + /* bpf_skb_ct_lookup - Lookup CT entry for the given tuple, and acquire a * reference to it * @@ -181,20 +317,31 @@ bpf_skb_ct_lookup(struct __sk_buff *skb_ctx, struct bpf_sock_tuple *bpf_tuple, struct net *caller_net; struct nf_conn *nfct; - BUILD_BUG_ON(sizeof(struct bpf_ct_opts) != NF_BPF_CT_OPTS_SZ); - - if (!opts) - return NULL; - if (!bpf_tuple || opts->reserved[0] || opts->reserved[1] || - opts__sz != NF_BPF_CT_OPTS_SZ) { - opts->error = -EINVAL; - return NULL; - } caller_net = skb->dev ? dev_net(skb->dev) : sock_net(skb->sk); - nfct = __bpf_nf_ct_lookup(caller_net, bpf_tuple, tuple__sz, opts->l4proto, - opts->netns_id, &opts->dir); + nfct = __bpf_nf_ct_lookup(caller_net, bpf_tuple, tuple__sz, opts, opts__sz); if (IS_ERR(nfct)) { - opts->error = PTR_ERR(nfct); + if (opts) + opts->error = PTR_ERR(nfct); + return NULL; + } + return nfct; +} + +/* bpf_ct_insert_entry - Add the provided entry into a CT map + * + * This must be invoked for referenced PTR_TO_BTF_ID. + * + * @nfct - Pointer to referenced nf_conn___init object, obtained + * using bpf_xdp_ct_alloc or bpf_skb_ct_alloc. + */ +struct nf_conn *bpf_ct_insert_entry(struct nf_conn___init *nfct_i) +{ + struct nf_conn *nfct = (struct nf_conn *)nfct_i; + int err; + + err = nf_conntrack_hash_check_insert(nfct); + if (err < 0) { + nf_conntrack_free(nfct); return NULL; } return nfct; @@ -217,50 +364,90 @@ void bpf_ct_release(struct nf_conn *nfct) nf_ct_put(nfct); } +/* bpf_ct_set_timeout - Set timeout of allocated nf_conn + * + * Sets the default timeout of newly allocated nf_conn before insertion. + * This helper must be invoked for refcounted pointer to nf_conn___init. + * + * Parameters: + * @nfct - Pointer to referenced nf_conn object, obtained using + * bpf_xdp_ct_alloc or bpf_skb_ct_alloc. + * @timeout - Timeout in msecs. + */ +void bpf_ct_set_timeout(struct nf_conn___init *nfct, u32 timeout) +{ + __nf_ct_set_timeout((struct nf_conn *)nfct, msecs_to_jiffies(timeout)); +} + +/* bpf_ct_change_timeout - Change timeout of inserted nf_conn + * + * Change timeout associated of the inserted or looked up nf_conn. + * This helper must be invoked for refcounted pointer to nf_conn. + * + * Parameters: + * @nfct - Pointer to referenced nf_conn object, obtained using + * bpf_ct_insert_entry, bpf_xdp_ct_lookup, or bpf_skb_ct_lookup. + * @timeout - New timeout in msecs. + */ +int bpf_ct_change_timeout(struct nf_conn *nfct, u32 timeout) +{ + return __nf_ct_change_timeout(nfct, 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 - 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, u32 status) +{ + return nf_ct_change_status_common((struct nf_conn *)nfct, 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 - 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, u32 status) +{ + return nf_ct_change_status_common(nfct, status); +} + __diag_pop() -BTF_SET_START(nf_ct_xdp_check_kfunc_ids) -BTF_ID(func, bpf_xdp_ct_lookup) -BTF_ID(func, bpf_ct_release) -BTF_SET_END(nf_ct_xdp_check_kfunc_ids) - -BTF_SET_START(nf_ct_tc_check_kfunc_ids) -BTF_ID(func, bpf_skb_ct_lookup) -BTF_ID(func, bpf_ct_release) -BTF_SET_END(nf_ct_tc_check_kfunc_ids) - -BTF_SET_START(nf_ct_acquire_kfunc_ids) -BTF_ID(func, bpf_xdp_ct_lookup) -BTF_ID(func, bpf_skb_ct_lookup) -BTF_SET_END(nf_ct_acquire_kfunc_ids) - -BTF_SET_START(nf_ct_release_kfunc_ids) -BTF_ID(func, bpf_ct_release) -BTF_SET_END(nf_ct_release_kfunc_ids) - -/* Both sets are identical */ -#define nf_ct_ret_null_kfunc_ids nf_ct_acquire_kfunc_ids - -static const struct btf_kfunc_id_set nf_conntrack_xdp_kfunc_set = { - .owner = THIS_MODULE, - .check_set = &nf_ct_xdp_check_kfunc_ids, - .acquire_set = &nf_ct_acquire_kfunc_ids, - .release_set = &nf_ct_release_kfunc_ids, - .ret_null_set = &nf_ct_ret_null_kfunc_ids, -}; +BTF_SET8_START(nf_ct_kfunc_set) +BTF_ID_FLAGS(func, bpf_xdp_ct_alloc, KF_ACQUIRE | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_xdp_ct_lookup, KF_ACQUIRE | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_skb_ct_alloc, KF_ACQUIRE | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_skb_ct_lookup, KF_ACQUIRE | KF_RET_NULL) +BTF_ID_FLAGS(func, bpf_ct_insert_entry, KF_ACQUIRE | KF_RET_NULL | KF_RELEASE) +BTF_ID_FLAGS(func, bpf_ct_release, KF_RELEASE) +BTF_ID_FLAGS(func, bpf_ct_set_timeout, KF_TRUSTED_ARGS) +BTF_ID_FLAGS(func, bpf_ct_change_timeout, KF_TRUSTED_ARGS) +BTF_ID_FLAGS(func, bpf_ct_set_status, KF_TRUSTED_ARGS) +BTF_ID_FLAGS(func, bpf_ct_change_status, KF_TRUSTED_ARGS) +BTF_SET8_END(nf_ct_kfunc_set) -static const struct btf_kfunc_id_set nf_conntrack_tc_kfunc_set = { - .owner = THIS_MODULE, - .check_set = &nf_ct_tc_check_kfunc_ids, - .acquire_set = &nf_ct_acquire_kfunc_ids, - .release_set = &nf_ct_release_kfunc_ids, - .ret_null_set = &nf_ct_ret_null_kfunc_ids, +static const struct btf_kfunc_id_set nf_conntrack_kfunc_set = { + .owner = THIS_MODULE, + .set = &nf_ct_kfunc_set, }; int register_nf_conntrack_bpf(void) { int ret; - ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP, &nf_conntrack_xdp_kfunc_set); - return ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &nf_conntrack_tc_kfunc_set); + ret = register_btf_kfunc_id_set(BPF_PROG_TYPE_XDP, &nf_conntrack_kfunc_set); + return ret ?: register_btf_kfunc_id_set(BPF_PROG_TYPE_SCHED_CLS, &nf_conntrack_kfunc_set); } |