diff options
Diffstat (limited to 'net/sched/cls_flow.c')
| -rw-r--r-- | net/sched/cls_flow.c | 721 |
1 files changed, 721 insertions, 0 deletions
diff --git a/net/sched/cls_flow.c b/net/sched/cls_flow.c new file mode 100644 index 0000000000..6ab317b48d --- /dev/null +++ b/net/sched/cls_flow.c @@ -0,0 +1,721 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * net/sched/cls_flow.c Generic flow classifier + * + * Copyright (c) 2007, 2008 Patrick McHardy <kaber@trash.net> + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/list.h> +#include <linux/jhash.h> +#include <linux/random.h> +#include <linux/pkt_cls.h> +#include <linux/skbuff.h> +#include <linux/in.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <linux/if_vlan.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <net/inet_sock.h> + +#include <net/pkt_cls.h> +#include <net/ip.h> +#include <net/route.h> +#include <net/flow_dissector.h> +#include <net/tc_wrapper.h> + +#if IS_ENABLED(CONFIG_NF_CONNTRACK) +#include <net/netfilter/nf_conntrack.h> +#endif + +struct flow_head { + struct list_head filters; + struct rcu_head rcu; +}; + +struct flow_filter { + struct list_head list; + struct tcf_exts exts; + struct tcf_ematch_tree ematches; + struct tcf_proto *tp; + struct timer_list perturb_timer; + u32 perturb_period; + u32 handle; + + u32 nkeys; + u32 keymask; + u32 mode; + u32 mask; + u32 xor; + u32 rshift; + u32 addend; + u32 divisor; + u32 baseclass; + u32 hashrnd; + struct rcu_work rwork; +}; + +static inline u32 addr_fold(void *addr) +{ + unsigned long a = (unsigned long)addr; + + return (a & 0xFFFFFFFF) ^ (BITS_PER_LONG > 32 ? a >> 32 : 0); +} + +static u32 flow_get_src(const struct sk_buff *skb, const struct flow_keys *flow) +{ + __be32 src = flow_get_u32_src(flow); + + if (src) + return ntohl(src); + + return addr_fold(skb->sk); +} + +static u32 flow_get_dst(const struct sk_buff *skb, const struct flow_keys *flow) +{ + __be32 dst = flow_get_u32_dst(flow); + + if (dst) + return ntohl(dst); + + return addr_fold(skb_dst(skb)) ^ (__force u16)skb_protocol(skb, true); +} + +static u32 flow_get_proto(const struct sk_buff *skb, + const struct flow_keys *flow) +{ + return flow->basic.ip_proto; +} + +static u32 flow_get_proto_src(const struct sk_buff *skb, + const struct flow_keys *flow) +{ + if (flow->ports.ports) + return ntohs(flow->ports.src); + + return addr_fold(skb->sk); +} + +static u32 flow_get_proto_dst(const struct sk_buff *skb, + const struct flow_keys *flow) +{ + if (flow->ports.ports) + return ntohs(flow->ports.dst); + + return addr_fold(skb_dst(skb)) ^ (__force u16)skb_protocol(skb, true); +} + +static u32 flow_get_iif(const struct sk_buff *skb) +{ + return skb->skb_iif; +} + +static u32 flow_get_priority(const struct sk_buff *skb) +{ + return skb->priority; +} + +static u32 flow_get_mark(const struct sk_buff *skb) +{ + return skb->mark; +} + +static u32 flow_get_nfct(const struct sk_buff *skb) +{ +#if IS_ENABLED(CONFIG_NF_CONNTRACK) + return addr_fold(skb_nfct(skb)); +#else + return 0; +#endif +} + +#if IS_ENABLED(CONFIG_NF_CONNTRACK) +#define CTTUPLE(skb, member) \ +({ \ + enum ip_conntrack_info ctinfo; \ + const struct nf_conn *ct = nf_ct_get(skb, &ctinfo); \ + if (ct == NULL) \ + goto fallback; \ + ct->tuplehash[CTINFO2DIR(ctinfo)].tuple.member; \ +}) +#else +#define CTTUPLE(skb, member) \ +({ \ + goto fallback; \ + 0; \ +}) +#endif + +static u32 flow_get_nfct_src(const struct sk_buff *skb, + const struct flow_keys *flow) +{ + switch (skb_protocol(skb, true)) { + case htons(ETH_P_IP): + return ntohl(CTTUPLE(skb, src.u3.ip)); + case htons(ETH_P_IPV6): + return ntohl(CTTUPLE(skb, src.u3.ip6[3])); + } +fallback: + return flow_get_src(skb, flow); +} + +static u32 flow_get_nfct_dst(const struct sk_buff *skb, + const struct flow_keys *flow) +{ + switch (skb_protocol(skb, true)) { + case htons(ETH_P_IP): + return ntohl(CTTUPLE(skb, dst.u3.ip)); + case htons(ETH_P_IPV6): + return ntohl(CTTUPLE(skb, dst.u3.ip6[3])); + } +fallback: + return flow_get_dst(skb, flow); +} + +static u32 flow_get_nfct_proto_src(const struct sk_buff *skb, + const struct flow_keys *flow) +{ + return ntohs(CTTUPLE(skb, src.u.all)); +fallback: + return flow_get_proto_src(skb, flow); +} + +static u32 flow_get_nfct_proto_dst(const struct sk_buff *skb, + const struct flow_keys *flow) +{ + return ntohs(CTTUPLE(skb, dst.u.all)); +fallback: + return flow_get_proto_dst(skb, flow); +} + +static u32 flow_get_rtclassid(const struct sk_buff *skb) +{ +#ifdef CONFIG_IP_ROUTE_CLASSID + if (skb_dst(skb)) + return skb_dst(skb)->tclassid; +#endif + return 0; +} + +static u32 flow_get_skuid(const struct sk_buff *skb) +{ + struct sock *sk = skb_to_full_sk(skb); + + if (sk && sk->sk_socket && sk->sk_socket->file) { + kuid_t skuid = sk->sk_socket->file->f_cred->fsuid; + + return from_kuid(&init_user_ns, skuid); + } + return 0; +} + +static u32 flow_get_skgid(const struct sk_buff *skb) +{ + struct sock *sk = skb_to_full_sk(skb); + + if (sk && sk->sk_socket && sk->sk_socket->file) { + kgid_t skgid = sk->sk_socket->file->f_cred->fsgid; + + return from_kgid(&init_user_ns, skgid); + } + return 0; +} + +static u32 flow_get_vlan_tag(const struct sk_buff *skb) +{ + u16 tag; + + if (vlan_get_tag(skb, &tag) < 0) + return 0; + return tag & VLAN_VID_MASK; +} + +static u32 flow_get_rxhash(struct sk_buff *skb) +{ + return skb_get_hash(skb); +} + +static u32 flow_key_get(struct sk_buff *skb, int key, struct flow_keys *flow) +{ + switch (key) { + case FLOW_KEY_SRC: + return flow_get_src(skb, flow); + case FLOW_KEY_DST: + return flow_get_dst(skb, flow); + case FLOW_KEY_PROTO: + return flow_get_proto(skb, flow); + case FLOW_KEY_PROTO_SRC: + return flow_get_proto_src(skb, flow); + case FLOW_KEY_PROTO_DST: + return flow_get_proto_dst(skb, flow); + case FLOW_KEY_IIF: + return flow_get_iif(skb); + case FLOW_KEY_PRIORITY: + return flow_get_priority(skb); + case FLOW_KEY_MARK: + return flow_get_mark(skb); + case FLOW_KEY_NFCT: + return flow_get_nfct(skb); + case FLOW_KEY_NFCT_SRC: + return flow_get_nfct_src(skb, flow); + case FLOW_KEY_NFCT_DST: + return flow_get_nfct_dst(skb, flow); + case FLOW_KEY_NFCT_PROTO_SRC: + return flow_get_nfct_proto_src(skb, flow); + case FLOW_KEY_NFCT_PROTO_DST: + return flow_get_nfct_proto_dst(skb, flow); + case FLOW_KEY_RTCLASSID: + return flow_get_rtclassid(skb); + case FLOW_KEY_SKUID: + return flow_get_skuid(skb); + case FLOW_KEY_SKGID: + return flow_get_skgid(skb); + case FLOW_KEY_VLAN_TAG: + return flow_get_vlan_tag(skb); + case FLOW_KEY_RXHASH: + return flow_get_rxhash(skb); + default: + WARN_ON(1); + return 0; + } +} + +#define FLOW_KEYS_NEEDED ((1 << FLOW_KEY_SRC) | \ + (1 << FLOW_KEY_DST) | \ + (1 << FLOW_KEY_PROTO) | \ + (1 << FLOW_KEY_PROTO_SRC) | \ + (1 << FLOW_KEY_PROTO_DST) | \ + (1 << FLOW_KEY_NFCT_SRC) | \ + (1 << FLOW_KEY_NFCT_DST) | \ + (1 << FLOW_KEY_NFCT_PROTO_SRC) | \ + (1 << FLOW_KEY_NFCT_PROTO_DST)) + +TC_INDIRECT_SCOPE int flow_classify(struct sk_buff *skb, + const struct tcf_proto *tp, + struct tcf_result *res) +{ + struct flow_head *head = rcu_dereference_bh(tp->root); + struct flow_filter *f; + u32 keymask; + u32 classid; + unsigned int n, key; + int r; + + list_for_each_entry_rcu(f, &head->filters, list) { + u32 keys[FLOW_KEY_MAX + 1]; + struct flow_keys flow_keys; + + if (!tcf_em_tree_match(skb, &f->ematches, NULL)) + continue; + + keymask = f->keymask; + if (keymask & FLOW_KEYS_NEEDED) + skb_flow_dissect_flow_keys(skb, &flow_keys, 0); + + for (n = 0; n < f->nkeys; n++) { + key = ffs(keymask) - 1; + keymask &= ~(1 << key); + keys[n] = flow_key_get(skb, key, &flow_keys); + } + + if (f->mode == FLOW_MODE_HASH) + classid = jhash2(keys, f->nkeys, f->hashrnd); + else { + classid = keys[0]; + classid = (classid & f->mask) ^ f->xor; + classid = (classid >> f->rshift) + f->addend; + } + + if (f->divisor) + classid %= f->divisor; + + res->class = 0; + res->classid = TC_H_MAKE(f->baseclass, f->baseclass + classid); + + r = tcf_exts_exec(skb, &f->exts, res); + if (r < 0) + continue; + return r; + } + return -1; +} + +static void flow_perturbation(struct timer_list *t) +{ + struct flow_filter *f = from_timer(f, t, perturb_timer); + + get_random_bytes(&f->hashrnd, 4); + if (f->perturb_period) + mod_timer(&f->perturb_timer, jiffies + f->perturb_period); +} + +static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = { + [TCA_FLOW_KEYS] = { .type = NLA_U32 }, + [TCA_FLOW_MODE] = { .type = NLA_U32 }, + [TCA_FLOW_BASECLASS] = { .type = NLA_U32 }, + [TCA_FLOW_RSHIFT] = { .type = NLA_U32 }, + [TCA_FLOW_ADDEND] = { .type = NLA_U32 }, + [TCA_FLOW_MASK] = { .type = NLA_U32 }, + [TCA_FLOW_XOR] = { .type = NLA_U32 }, + [TCA_FLOW_DIVISOR] = { .type = NLA_U32 }, + [TCA_FLOW_ACT] = { .type = NLA_NESTED }, + [TCA_FLOW_POLICE] = { .type = NLA_NESTED }, + [TCA_FLOW_EMATCHES] = { .type = NLA_NESTED }, + [TCA_FLOW_PERTURB] = { .type = NLA_U32 }, +}; + +static void __flow_destroy_filter(struct flow_filter *f) +{ + timer_shutdown_sync(&f->perturb_timer); + tcf_exts_destroy(&f->exts); + tcf_em_tree_destroy(&f->ematches); + tcf_exts_put_net(&f->exts); + kfree(f); +} + +static void flow_destroy_filter_work(struct work_struct *work) +{ + struct flow_filter *f = container_of(to_rcu_work(work), + struct flow_filter, + rwork); + rtnl_lock(); + __flow_destroy_filter(f); + rtnl_unlock(); +} + +static int flow_change(struct net *net, struct sk_buff *in_skb, + struct tcf_proto *tp, unsigned long base, + u32 handle, struct nlattr **tca, + void **arg, u32 flags, + struct netlink_ext_ack *extack) +{ + struct flow_head *head = rtnl_dereference(tp->root); + struct flow_filter *fold, *fnew; + struct nlattr *opt = tca[TCA_OPTIONS]; + struct nlattr *tb[TCA_FLOW_MAX + 1]; + unsigned int nkeys = 0; + unsigned int perturb_period = 0; + u32 baseclass = 0; + u32 keymask = 0; + u32 mode; + int err; + + if (opt == NULL) + return -EINVAL; + + err = nla_parse_nested_deprecated(tb, TCA_FLOW_MAX, opt, flow_policy, + NULL); + if (err < 0) + return err; + + if (tb[TCA_FLOW_BASECLASS]) { + baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]); + if (TC_H_MIN(baseclass) == 0) + return -EINVAL; + } + + if (tb[TCA_FLOW_KEYS]) { + keymask = nla_get_u32(tb[TCA_FLOW_KEYS]); + + nkeys = hweight32(keymask); + if (nkeys == 0) + return -EINVAL; + + if (fls(keymask) - 1 > FLOW_KEY_MAX) + return -EOPNOTSUPP; + + if ((keymask & (FLOW_KEY_SKUID|FLOW_KEY_SKGID)) && + sk_user_ns(NETLINK_CB(in_skb).sk) != &init_user_ns) + return -EOPNOTSUPP; + } + + fnew = kzalloc(sizeof(*fnew), GFP_KERNEL); + if (!fnew) + return -ENOBUFS; + + err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &fnew->ematches); + if (err < 0) + goto err1; + + err = tcf_exts_init(&fnew->exts, net, TCA_FLOW_ACT, TCA_FLOW_POLICE); + if (err < 0) + goto err2; + + err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &fnew->exts, flags, + extack); + if (err < 0) + goto err2; + + fold = *arg; + if (fold) { + err = -EINVAL; + if (fold->handle != handle && handle) + goto err2; + + /* Copy fold into fnew */ + fnew->tp = fold->tp; + fnew->handle = fold->handle; + fnew->nkeys = fold->nkeys; + fnew->keymask = fold->keymask; + fnew->mode = fold->mode; + fnew->mask = fold->mask; + fnew->xor = fold->xor; + fnew->rshift = fold->rshift; + fnew->addend = fold->addend; + fnew->divisor = fold->divisor; + fnew->baseclass = fold->baseclass; + fnew->hashrnd = fold->hashrnd; + + mode = fold->mode; + if (tb[TCA_FLOW_MODE]) + mode = nla_get_u32(tb[TCA_FLOW_MODE]); + if (mode != FLOW_MODE_HASH && nkeys > 1) + goto err2; + + if (mode == FLOW_MODE_HASH) + perturb_period = fold->perturb_period; + if (tb[TCA_FLOW_PERTURB]) { + if (mode != FLOW_MODE_HASH) + goto err2; + perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ; + } + } else { + err = -EINVAL; + if (!handle) + goto err2; + if (!tb[TCA_FLOW_KEYS]) + goto err2; + + mode = FLOW_MODE_MAP; + if (tb[TCA_FLOW_MODE]) + mode = nla_get_u32(tb[TCA_FLOW_MODE]); + if (mode != FLOW_MODE_HASH && nkeys > 1) + goto err2; + + if (tb[TCA_FLOW_PERTURB]) { + if (mode != FLOW_MODE_HASH) + goto err2; + perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ; + } + + if (TC_H_MAJ(baseclass) == 0) { + struct Qdisc *q = tcf_block_q(tp->chain->block); + + baseclass = TC_H_MAKE(q->handle, baseclass); + } + if (TC_H_MIN(baseclass) == 0) + baseclass = TC_H_MAKE(baseclass, 1); + + fnew->handle = handle; + fnew->mask = ~0U; + fnew->tp = tp; + get_random_bytes(&fnew->hashrnd, 4); + } + + timer_setup(&fnew->perturb_timer, flow_perturbation, TIMER_DEFERRABLE); + + tcf_block_netif_keep_dst(tp->chain->block); + + if (tb[TCA_FLOW_KEYS]) { + fnew->keymask = keymask; + fnew->nkeys = nkeys; + } + + fnew->mode = mode; + + if (tb[TCA_FLOW_MASK]) + fnew->mask = nla_get_u32(tb[TCA_FLOW_MASK]); + if (tb[TCA_FLOW_XOR]) + fnew->xor = nla_get_u32(tb[TCA_FLOW_XOR]); + if (tb[TCA_FLOW_RSHIFT]) + fnew->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]); + if (tb[TCA_FLOW_ADDEND]) + fnew->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]); + + if (tb[TCA_FLOW_DIVISOR]) + fnew->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]); + if (baseclass) + fnew->baseclass = baseclass; + + fnew->perturb_period = perturb_period; + if (perturb_period) + mod_timer(&fnew->perturb_timer, jiffies + perturb_period); + + if (!*arg) + list_add_tail_rcu(&fnew->list, &head->filters); + else + list_replace_rcu(&fold->list, &fnew->list); + + *arg = fnew; + + if (fold) { + tcf_exts_get_net(&fold->exts); + tcf_queue_work(&fold->rwork, flow_destroy_filter_work); + } + return 0; + +err2: + tcf_exts_destroy(&fnew->exts); + tcf_em_tree_destroy(&fnew->ematches); +err1: + kfree(fnew); + return err; +} + +static int flow_delete(struct tcf_proto *tp, void *arg, bool *last, + bool rtnl_held, struct netlink_ext_ack *extack) +{ + struct flow_head *head = rtnl_dereference(tp->root); + struct flow_filter *f = arg; + + list_del_rcu(&f->list); + tcf_exts_get_net(&f->exts); + tcf_queue_work(&f->rwork, flow_destroy_filter_work); + *last = list_empty(&head->filters); + return 0; +} + +static int flow_init(struct tcf_proto *tp) +{ + struct flow_head *head; + + head = kzalloc(sizeof(*head), GFP_KERNEL); + if (head == NULL) + return -ENOBUFS; + INIT_LIST_HEAD(&head->filters); + rcu_assign_pointer(tp->root, head); + return 0; +} + +static void flow_destroy(struct tcf_proto *tp, bool rtnl_held, + struct netlink_ext_ack *extack) +{ + struct flow_head *head = rtnl_dereference(tp->root); + struct flow_filter *f, *next; + + list_for_each_entry_safe(f, next, &head->filters, list) { + list_del_rcu(&f->list); + if (tcf_exts_get_net(&f->exts)) + tcf_queue_work(&f->rwork, flow_destroy_filter_work); + else + __flow_destroy_filter(f); + } + kfree_rcu(head, rcu); +} + +static void *flow_get(struct tcf_proto *tp, u32 handle) +{ + struct flow_head *head = rtnl_dereference(tp->root); + struct flow_filter *f; + + list_for_each_entry(f, &head->filters, list) + if (f->handle == handle) + return f; + return NULL; +} + +static int flow_dump(struct net *net, struct tcf_proto *tp, void *fh, + struct sk_buff *skb, struct tcmsg *t, bool rtnl_held) +{ + struct flow_filter *f = fh; + struct nlattr *nest; + + if (f == NULL) + return skb->len; + + t->tcm_handle = f->handle; + + nest = nla_nest_start_noflag(skb, TCA_OPTIONS); + if (nest == NULL) + goto nla_put_failure; + + if (nla_put_u32(skb, TCA_FLOW_KEYS, f->keymask) || + nla_put_u32(skb, TCA_FLOW_MODE, f->mode)) + goto nla_put_failure; + + if (f->mask != ~0 || f->xor != 0) { + if (nla_put_u32(skb, TCA_FLOW_MASK, f->mask) || + nla_put_u32(skb, TCA_FLOW_XOR, f->xor)) + goto nla_put_failure; + } + if (f->rshift && + nla_put_u32(skb, TCA_FLOW_RSHIFT, f->rshift)) + goto nla_put_failure; + if (f->addend && + nla_put_u32(skb, TCA_FLOW_ADDEND, f->addend)) + goto nla_put_failure; + + if (f->divisor && + nla_put_u32(skb, TCA_FLOW_DIVISOR, f->divisor)) + goto nla_put_failure; + if (f->baseclass && + nla_put_u32(skb, TCA_FLOW_BASECLASS, f->baseclass)) + goto nla_put_failure; + + if (f->perturb_period && + nla_put_u32(skb, TCA_FLOW_PERTURB, f->perturb_period / HZ)) + goto nla_put_failure; + + if (tcf_exts_dump(skb, &f->exts) < 0) + goto nla_put_failure; +#ifdef CONFIG_NET_EMATCH + if (f->ematches.hdr.nmatches && + tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0) + goto nla_put_failure; +#endif + nla_nest_end(skb, nest); + + if (tcf_exts_dump_stats(skb, &f->exts) < 0) + goto nla_put_failure; + + return skb->len; + +nla_put_failure: + nla_nest_cancel(skb, nest); + return -1; +} + +static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg, + bool rtnl_held) +{ + struct flow_head *head = rtnl_dereference(tp->root); + struct flow_filter *f; + + list_for_each_entry(f, &head->filters, list) { + if (!tc_cls_stats_dump(tp, arg, f)) + break; + } +} + +static struct tcf_proto_ops cls_flow_ops __read_mostly = { + .kind = "flow", + .classify = flow_classify, + .init = flow_init, + .destroy = flow_destroy, + .change = flow_change, + .delete = flow_delete, + .get = flow_get, + .dump = flow_dump, + .walk = flow_walk, + .owner = THIS_MODULE, +}; + +static int __init cls_flow_init(void) +{ + return register_tcf_proto_ops(&cls_flow_ops); +} + +static void __exit cls_flow_exit(void) +{ + unregister_tcf_proto_ops(&cls_flow_ops); +} + +module_init(cls_flow_init); +module_exit(cls_flow_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); +MODULE_DESCRIPTION("TC flow classifier"); |