| // SPDX-License-Identifier: GPL-2.0+ |
| /* net/sched/act_ctinfo.c netfilter ctinfo connmark actions |
| * |
| * Copyright (c) 2019 Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk> |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/kernel.h> |
| #include <linux/skbuff.h> |
| #include <linux/rtnetlink.h> |
| #include <linux/pkt_cls.h> |
| #include <linux/ip.h> |
| #include <linux/ipv6.h> |
| #include <net/netlink.h> |
| #include <net/pkt_sched.h> |
| #include <net/act_api.h> |
| #include <net/pkt_cls.h> |
| #include <uapi/linux/tc_act/tc_ctinfo.h> |
| #include <net/tc_act/tc_ctinfo.h> |
| |
| #include <net/netfilter/nf_conntrack.h> |
| #include <net/netfilter/nf_conntrack_core.h> |
| #include <net/netfilter/nf_conntrack_ecache.h> |
| #include <net/netfilter/nf_conntrack_zones.h> |
| |
| static struct tc_action_ops act_ctinfo_ops; |
| static unsigned int ctinfo_net_id; |
| |
| static void tcf_ctinfo_dscp_set(struct nf_conn *ct, struct tcf_ctinfo *ca, |
| struct tcf_ctinfo_params *cp, |
| struct sk_buff *skb, int wlen, int proto) |
| { |
| u8 dscp, newdscp; |
| |
| newdscp = (((ct->mark & cp->dscpmask) >> cp->dscpmaskshift) << 2) & |
| ~INET_ECN_MASK; |
| |
| switch (proto) { |
| case NFPROTO_IPV4: |
| dscp = ipv4_get_dsfield(ip_hdr(skb)) & ~INET_ECN_MASK; |
| if (dscp != newdscp) { |
| if (likely(!skb_try_make_writable(skb, wlen))) { |
| ipv4_change_dsfield(ip_hdr(skb), |
| INET_ECN_MASK, |
| newdscp); |
| ca->stats_dscp_set++; |
| } else { |
| ca->stats_dscp_error++; |
| } |
| } |
| break; |
| case NFPROTO_IPV6: |
| dscp = ipv6_get_dsfield(ipv6_hdr(skb)) & ~INET_ECN_MASK; |
| if (dscp != newdscp) { |
| if (likely(!skb_try_make_writable(skb, wlen))) { |
| ipv6_change_dsfield(ipv6_hdr(skb), |
| INET_ECN_MASK, |
| newdscp); |
| ca->stats_dscp_set++; |
| } else { |
| ca->stats_dscp_error++; |
| } |
| } |
| break; |
| default: |
| break; |
| } |
| } |
| |
| static void tcf_ctinfo_cpmark_set(struct nf_conn *ct, struct tcf_ctinfo *ca, |
| struct tcf_ctinfo_params *cp, |
| struct sk_buff *skb) |
| { |
| ca->stats_cpmark_set++; |
| skb->mark = ct->mark & cp->cpmarkmask; |
| } |
| |
| static int tcf_ctinfo_act(struct sk_buff *skb, const struct tc_action *a, |
| struct tcf_result *res) |
| { |
| const struct nf_conntrack_tuple_hash *thash = NULL; |
| struct tcf_ctinfo *ca = to_ctinfo(a); |
| struct nf_conntrack_tuple tuple; |
| struct nf_conntrack_zone zone; |
| enum ip_conntrack_info ctinfo; |
| struct tcf_ctinfo_params *cp; |
| struct nf_conn *ct; |
| int proto, wlen; |
| int action; |
| |
| cp = rcu_dereference_bh(ca->params); |
| |
| tcf_lastuse_update(&ca->tcf_tm); |
| bstats_update(&ca->tcf_bstats, skb); |
| action = READ_ONCE(ca->tcf_action); |
| |
| wlen = skb_network_offset(skb); |
| switch (skb_protocol(skb, true)) { |
| case htons(ETH_P_IP): |
| wlen += sizeof(struct iphdr); |
| if (!pskb_may_pull(skb, wlen)) |
| goto out; |
| |
| proto = NFPROTO_IPV4; |
| break; |
| case htons(ETH_P_IPV6): |
| wlen += sizeof(struct ipv6hdr); |
| if (!pskb_may_pull(skb, wlen)) |
| goto out; |
| |
| proto = NFPROTO_IPV6; |
| break; |
| default: |
| goto out; |
| } |
| |
| ct = nf_ct_get(skb, &ctinfo); |
| if (!ct) { /* look harder, usually ingress */ |
| if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), |
| proto, cp->net, &tuple)) |
| goto out; |
| zone.id = cp->zone; |
| zone.dir = NF_CT_DEFAULT_ZONE_DIR; |
| |
| thash = nf_conntrack_find_get(cp->net, &zone, &tuple); |
| if (!thash) |
| goto out; |
| |
| ct = nf_ct_tuplehash_to_ctrack(thash); |
| } |
| |
| if (cp->mode & CTINFO_MODE_DSCP) |
| if (!cp->dscpstatemask || (ct->mark & cp->dscpstatemask)) |
| tcf_ctinfo_dscp_set(ct, ca, cp, skb, wlen, proto); |
| |
| if (cp->mode & CTINFO_MODE_CPMARK) |
| tcf_ctinfo_cpmark_set(ct, ca, cp, skb); |
| |
| if (thash) |
| nf_ct_put(ct); |
| out: |
| return action; |
| } |
| |
| static const struct nla_policy ctinfo_policy[TCA_CTINFO_MAX + 1] = { |
| [TCA_CTINFO_ACT] = { .type = NLA_EXACT_LEN, |
| .len = sizeof(struct |
| tc_ctinfo) }, |
| [TCA_CTINFO_ZONE] = { .type = NLA_U16 }, |
| [TCA_CTINFO_PARMS_DSCP_MASK] = { .type = NLA_U32 }, |
| [TCA_CTINFO_PARMS_DSCP_STATEMASK] = { .type = NLA_U32 }, |
| [TCA_CTINFO_PARMS_CPMARK_MASK] = { .type = NLA_U32 }, |
| }; |
| |
| static int tcf_ctinfo_init(struct net *net, struct nlattr *nla, |
| struct nlattr *est, struct tc_action **a, |
| int ovr, int bind, bool rtnl_held, |
| struct tcf_proto *tp, u32 flags, |
| struct netlink_ext_ack *extack) |
| { |
| struct tc_action_net *tn = net_generic(net, ctinfo_net_id); |
| u32 dscpmask = 0, dscpstatemask, index; |
| struct nlattr *tb[TCA_CTINFO_MAX + 1]; |
| struct tcf_ctinfo_params *cp_new; |
| struct tcf_chain *goto_ch = NULL; |
| struct tc_ctinfo *actparm; |
| struct tcf_ctinfo *ci; |
| u8 dscpmaskshift; |
| int ret = 0, err; |
| |
| if (!nla) { |
| NL_SET_ERR_MSG_MOD(extack, "ctinfo requires attributes to be passed"); |
| return -EINVAL; |
| } |
| |
| err = nla_parse_nested(tb, TCA_CTINFO_MAX, nla, ctinfo_policy, extack); |
| if (err < 0) |
| return err; |
| |
| if (!tb[TCA_CTINFO_ACT]) { |
| NL_SET_ERR_MSG_MOD(extack, |
| "Missing required TCA_CTINFO_ACT attribute"); |
| return -EINVAL; |
| } |
| actparm = nla_data(tb[TCA_CTINFO_ACT]); |
| |
| /* do some basic validation here before dynamically allocating things */ |
| /* that we would otherwise have to clean up. */ |
| if (tb[TCA_CTINFO_PARMS_DSCP_MASK]) { |
| dscpmask = nla_get_u32(tb[TCA_CTINFO_PARMS_DSCP_MASK]); |
| /* need contiguous 6 bit mask */ |
| dscpmaskshift = dscpmask ? __ffs(dscpmask) : 0; |
| if ((~0 & (dscpmask >> dscpmaskshift)) != 0x3f) { |
| NL_SET_ERR_MSG_ATTR(extack, |
| tb[TCA_CTINFO_PARMS_DSCP_MASK], |
| "dscp mask must be 6 contiguous bits"); |
| return -EINVAL; |
| } |
| dscpstatemask = tb[TCA_CTINFO_PARMS_DSCP_STATEMASK] ? |
| nla_get_u32(tb[TCA_CTINFO_PARMS_DSCP_STATEMASK]) : 0; |
| /* mask & statemask must not overlap */ |
| if (dscpmask & dscpstatemask) { |
| NL_SET_ERR_MSG_ATTR(extack, |
| tb[TCA_CTINFO_PARMS_DSCP_STATEMASK], |
| "dscp statemask must not overlap dscp mask"); |
| return -EINVAL; |
| } |
| } |
| |
| /* done the validation:now to the actual action allocation */ |
| index = actparm->index; |
| err = tcf_idr_check_alloc(tn, &index, a, bind); |
| if (!err) { |
| ret = tcf_idr_create(tn, index, est, a, |
| &act_ctinfo_ops, bind, false, 0); |
| if (ret) { |
| tcf_idr_cleanup(tn, index); |
| return ret; |
| } |
| ret = ACT_P_CREATED; |
| } else if (err > 0) { |
| if (bind) /* don't override defaults */ |
| return 0; |
| if (!ovr) { |
| tcf_idr_release(*a, bind); |
| return -EEXIST; |
| } |
| } else { |
| return err; |
| } |
| |
| err = tcf_action_check_ctrlact(actparm->action, tp, &goto_ch, extack); |
| if (err < 0) |
| goto release_idr; |
| |
| ci = to_ctinfo(*a); |
| |
| cp_new = kzalloc(sizeof(*cp_new), GFP_KERNEL); |
| if (unlikely(!cp_new)) { |
| err = -ENOMEM; |
| goto put_chain; |
| } |
| |
| cp_new->net = net; |
| cp_new->zone = tb[TCA_CTINFO_ZONE] ? |
| nla_get_u16(tb[TCA_CTINFO_ZONE]) : 0; |
| if (dscpmask) { |
| cp_new->dscpmask = dscpmask; |
| cp_new->dscpmaskshift = dscpmaskshift; |
| cp_new->dscpstatemask = dscpstatemask; |
| cp_new->mode |= CTINFO_MODE_DSCP; |
| } |
| |
| if (tb[TCA_CTINFO_PARMS_CPMARK_MASK]) { |
| cp_new->cpmarkmask = |
| nla_get_u32(tb[TCA_CTINFO_PARMS_CPMARK_MASK]); |
| cp_new->mode |= CTINFO_MODE_CPMARK; |
| } |
| |
| spin_lock_bh(&ci->tcf_lock); |
| goto_ch = tcf_action_set_ctrlact(*a, actparm->action, goto_ch); |
| cp_new = rcu_replace_pointer(ci->params, cp_new, |
| lockdep_is_held(&ci->tcf_lock)); |
| spin_unlock_bh(&ci->tcf_lock); |
| |
| if (goto_ch) |
| tcf_chain_put_by_act(goto_ch); |
| if (cp_new) |
| kfree_rcu(cp_new, rcu); |
| |
| return ret; |
| |
| put_chain: |
| if (goto_ch) |
| tcf_chain_put_by_act(goto_ch); |
| release_idr: |
| tcf_idr_release(*a, bind); |
| return err; |
| } |
| |
| static int tcf_ctinfo_dump(struct sk_buff *skb, struct tc_action *a, |
| int bind, int ref) |
| { |
| struct tcf_ctinfo *ci = to_ctinfo(a); |
| struct tc_ctinfo opt = { |
| .index = ci->tcf_index, |
| .refcnt = refcount_read(&ci->tcf_refcnt) - ref, |
| .bindcnt = atomic_read(&ci->tcf_bindcnt) - bind, |
| }; |
| unsigned char *b = skb_tail_pointer(skb); |
| struct tcf_ctinfo_params *cp; |
| struct tcf_t t; |
| |
| spin_lock_bh(&ci->tcf_lock); |
| cp = rcu_dereference_protected(ci->params, |
| lockdep_is_held(&ci->tcf_lock)); |
| |
| tcf_tm_dump(&t, &ci->tcf_tm); |
| if (nla_put_64bit(skb, TCA_CTINFO_TM, sizeof(t), &t, TCA_CTINFO_PAD)) |
| goto nla_put_failure; |
| |
| opt.action = ci->tcf_action; |
| if (nla_put(skb, TCA_CTINFO_ACT, sizeof(opt), &opt)) |
| goto nla_put_failure; |
| |
| if (nla_put_u16(skb, TCA_CTINFO_ZONE, cp->zone)) |
| goto nla_put_failure; |
| |
| if (cp->mode & CTINFO_MODE_DSCP) { |
| if (nla_put_u32(skb, TCA_CTINFO_PARMS_DSCP_MASK, |
| cp->dscpmask)) |
| goto nla_put_failure; |
| if (nla_put_u32(skb, TCA_CTINFO_PARMS_DSCP_STATEMASK, |
| cp->dscpstatemask)) |
| goto nla_put_failure; |
| } |
| |
| if (cp->mode & CTINFO_MODE_CPMARK) { |
| if (nla_put_u32(skb, TCA_CTINFO_PARMS_CPMARK_MASK, |
| cp->cpmarkmask)) |
| goto nla_put_failure; |
| } |
| |
| if (nla_put_u64_64bit(skb, TCA_CTINFO_STATS_DSCP_SET, |
| ci->stats_dscp_set, TCA_CTINFO_PAD)) |
| goto nla_put_failure; |
| |
| if (nla_put_u64_64bit(skb, TCA_CTINFO_STATS_DSCP_ERROR, |
| ci->stats_dscp_error, TCA_CTINFO_PAD)) |
| goto nla_put_failure; |
| |
| if (nla_put_u64_64bit(skb, TCA_CTINFO_STATS_CPMARK_SET, |
| ci->stats_cpmark_set, TCA_CTINFO_PAD)) |
| goto nla_put_failure; |
| |
| spin_unlock_bh(&ci->tcf_lock); |
| return skb->len; |
| |
| nla_put_failure: |
| spin_unlock_bh(&ci->tcf_lock); |
| nlmsg_trim(skb, b); |
| return -1; |
| } |
| |
| static int tcf_ctinfo_walker(struct net *net, struct sk_buff *skb, |
| struct netlink_callback *cb, int type, |
| const struct tc_action_ops *ops, |
| struct netlink_ext_ack *extack) |
| { |
| struct tc_action_net *tn = net_generic(net, ctinfo_net_id); |
| |
| return tcf_generic_walker(tn, skb, cb, type, ops, extack); |
| } |
| |
| static int tcf_ctinfo_search(struct net *net, struct tc_action **a, u32 index) |
| { |
| struct tc_action_net *tn = net_generic(net, ctinfo_net_id); |
| |
| return tcf_idr_search(tn, a, index); |
| } |
| |
| static void tcf_ctinfo_cleanup(struct tc_action *a) |
| { |
| struct tcf_ctinfo *ci = to_ctinfo(a); |
| struct tcf_ctinfo_params *cp; |
| |
| cp = rcu_dereference_protected(ci->params, 1); |
| if (cp) |
| kfree_rcu(cp, rcu); |
| } |
| |
| static struct tc_action_ops act_ctinfo_ops = { |
| .kind = "ctinfo", |
| .id = TCA_ID_CTINFO, |
| .owner = THIS_MODULE, |
| .act = tcf_ctinfo_act, |
| .dump = tcf_ctinfo_dump, |
| .init = tcf_ctinfo_init, |
| .cleanup= tcf_ctinfo_cleanup, |
| .walk = tcf_ctinfo_walker, |
| .lookup = tcf_ctinfo_search, |
| .size = sizeof(struct tcf_ctinfo), |
| }; |
| |
| static __net_init int ctinfo_init_net(struct net *net) |
| { |
| struct tc_action_net *tn = net_generic(net, ctinfo_net_id); |
| |
| return tc_action_net_init(net, tn, &act_ctinfo_ops); |
| } |
| |
| static void __net_exit ctinfo_exit_net(struct list_head *net_list) |
| { |
| tc_action_net_exit(net_list, ctinfo_net_id); |
| } |
| |
| static struct pernet_operations ctinfo_net_ops = { |
| .init = ctinfo_init_net, |
| .exit_batch = ctinfo_exit_net, |
| .id = &ctinfo_net_id, |
| .size = sizeof(struct tc_action_net), |
| }; |
| |
| static int __init ctinfo_init_module(void) |
| { |
| return tcf_register_action(&act_ctinfo_ops, &ctinfo_net_ops); |
| } |
| |
| static void __exit ctinfo_cleanup_module(void) |
| { |
| tcf_unregister_action(&act_ctinfo_ops, &ctinfo_net_ops); |
| } |
| |
| module_init(ctinfo_init_module); |
| module_exit(ctinfo_cleanup_module); |
| MODULE_AUTHOR("Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>"); |
| MODULE_DESCRIPTION("Connection tracking mark actions"); |
| MODULE_LICENSE("GPL"); |