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-rw-r--r--net/sched/act_bpf.c457
1 files changed, 457 insertions, 0 deletions
diff --git a/net/sched/act_bpf.c b/net/sched/act_bpf.c
new file mode 100644
index 000000000..78f1cd70c
--- /dev/null
+++ b/net/sched/act_bpf.c
@@ -0,0 +1,457 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2015 Jiri Pirko <jiri@resnulli.us>
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/rtnetlink.h>
+#include <linux/filter.h>
+#include <linux/bpf.h>
+
+#include <net/netlink.h>
+#include <net/sock.h>
+#include <net/pkt_sched.h>
+#include <net/pkt_cls.h>
+
+#include <linux/tc_act/tc_bpf.h>
+#include <net/tc_act/tc_bpf.h>
+
+#define ACT_BPF_NAME_LEN 256
+
+struct tcf_bpf_cfg {
+ struct bpf_prog *filter;
+ struct sock_filter *bpf_ops;
+ const char *bpf_name;
+ u16 bpf_num_ops;
+ bool is_ebpf;
+};
+
+static unsigned int bpf_net_id;
+static struct tc_action_ops act_bpf_ops;
+
+static int tcf_bpf_act(struct sk_buff *skb, const struct tc_action *act,
+ struct tcf_result *res)
+{
+ bool at_ingress = skb_at_tc_ingress(skb);
+ struct tcf_bpf *prog = to_bpf(act);
+ struct bpf_prog *filter;
+ int action, filter_res;
+
+ tcf_lastuse_update(&prog->tcf_tm);
+ bstats_cpu_update(this_cpu_ptr(prog->common.cpu_bstats), skb);
+
+ rcu_read_lock();
+ filter = rcu_dereference(prog->filter);
+ if (at_ingress) {
+ __skb_push(skb, skb->mac_len);
+ bpf_compute_data_pointers(skb);
+ filter_res = BPF_PROG_RUN(filter, skb);
+ __skb_pull(skb, skb->mac_len);
+ } else {
+ bpf_compute_data_pointers(skb);
+ filter_res = BPF_PROG_RUN(filter, skb);
+ }
+ if (skb_sk_is_prefetched(skb) && filter_res != TC_ACT_OK)
+ skb_orphan(skb);
+ rcu_read_unlock();
+
+ /* A BPF program may overwrite the default action opcode.
+ * Similarly as in cls_bpf, if filter_res == -1 we use the
+ * default action specified from tc.
+ *
+ * In case a different well-known TC_ACT opcode has been
+ * returned, it will overwrite the default one.
+ *
+ * For everything else that is unkown, TC_ACT_UNSPEC is
+ * returned.
+ */
+ switch (filter_res) {
+ case TC_ACT_PIPE:
+ case TC_ACT_RECLASSIFY:
+ case TC_ACT_OK:
+ case TC_ACT_REDIRECT:
+ action = filter_res;
+ break;
+ case TC_ACT_SHOT:
+ action = filter_res;
+ qstats_drop_inc(this_cpu_ptr(prog->common.cpu_qstats));
+ break;
+ case TC_ACT_UNSPEC:
+ action = prog->tcf_action;
+ break;
+ default:
+ action = TC_ACT_UNSPEC;
+ break;
+ }
+
+ return action;
+}
+
+static bool tcf_bpf_is_ebpf(const struct tcf_bpf *prog)
+{
+ return !prog->bpf_ops;
+}
+
+static int tcf_bpf_dump_bpf_info(const struct tcf_bpf *prog,
+ struct sk_buff *skb)
+{
+ struct nlattr *nla;
+
+ if (nla_put_u16(skb, TCA_ACT_BPF_OPS_LEN, prog->bpf_num_ops))
+ return -EMSGSIZE;
+
+ nla = nla_reserve(skb, TCA_ACT_BPF_OPS, prog->bpf_num_ops *
+ sizeof(struct sock_filter));
+ if (nla == NULL)
+ return -EMSGSIZE;
+
+ memcpy(nla_data(nla), prog->bpf_ops, nla_len(nla));
+
+ return 0;
+}
+
+static int tcf_bpf_dump_ebpf_info(const struct tcf_bpf *prog,
+ struct sk_buff *skb)
+{
+ struct nlattr *nla;
+
+ if (prog->bpf_name &&
+ nla_put_string(skb, TCA_ACT_BPF_NAME, prog->bpf_name))
+ return -EMSGSIZE;
+
+ if (nla_put_u32(skb, TCA_ACT_BPF_ID, prog->filter->aux->id))
+ return -EMSGSIZE;
+
+ nla = nla_reserve(skb, TCA_ACT_BPF_TAG, sizeof(prog->filter->tag));
+ if (nla == NULL)
+ return -EMSGSIZE;
+
+ memcpy(nla_data(nla), prog->filter->tag, nla_len(nla));
+
+ return 0;
+}
+
+static int tcf_bpf_dump(struct sk_buff *skb, struct tc_action *act,
+ int bind, int ref)
+{
+ unsigned char *tp = skb_tail_pointer(skb);
+ struct tcf_bpf *prog = to_bpf(act);
+ struct tc_act_bpf opt = {
+ .index = prog->tcf_index,
+ .refcnt = refcount_read(&prog->tcf_refcnt) - ref,
+ .bindcnt = atomic_read(&prog->tcf_bindcnt) - bind,
+ };
+ struct tcf_t tm;
+ int ret;
+
+ spin_lock_bh(&prog->tcf_lock);
+ opt.action = prog->tcf_action;
+ if (nla_put(skb, TCA_ACT_BPF_PARMS, sizeof(opt), &opt))
+ goto nla_put_failure;
+
+ if (tcf_bpf_is_ebpf(prog))
+ ret = tcf_bpf_dump_ebpf_info(prog, skb);
+ else
+ ret = tcf_bpf_dump_bpf_info(prog, skb);
+ if (ret)
+ goto nla_put_failure;
+
+ tcf_tm_dump(&tm, &prog->tcf_tm);
+ if (nla_put_64bit(skb, TCA_ACT_BPF_TM, sizeof(tm), &tm,
+ TCA_ACT_BPF_PAD))
+ goto nla_put_failure;
+
+ spin_unlock_bh(&prog->tcf_lock);
+ return skb->len;
+
+nla_put_failure:
+ spin_unlock_bh(&prog->tcf_lock);
+ nlmsg_trim(skb, tp);
+ return -1;
+}
+
+static const struct nla_policy act_bpf_policy[TCA_ACT_BPF_MAX + 1] = {
+ [TCA_ACT_BPF_PARMS] = { .len = sizeof(struct tc_act_bpf) },
+ [TCA_ACT_BPF_FD] = { .type = NLA_U32 },
+ [TCA_ACT_BPF_NAME] = { .type = NLA_NUL_STRING,
+ .len = ACT_BPF_NAME_LEN },
+ [TCA_ACT_BPF_OPS_LEN] = { .type = NLA_U16 },
+ [TCA_ACT_BPF_OPS] = { .type = NLA_BINARY,
+ .len = sizeof(struct sock_filter) * BPF_MAXINSNS },
+};
+
+static int tcf_bpf_init_from_ops(struct nlattr **tb, struct tcf_bpf_cfg *cfg)
+{
+ struct sock_filter *bpf_ops;
+ struct sock_fprog_kern fprog_tmp;
+ struct bpf_prog *fp;
+ u16 bpf_size, bpf_num_ops;
+ int ret;
+
+ bpf_num_ops = nla_get_u16(tb[TCA_ACT_BPF_OPS_LEN]);
+ if (bpf_num_ops > BPF_MAXINSNS || bpf_num_ops == 0)
+ return -EINVAL;
+
+ bpf_size = bpf_num_ops * sizeof(*bpf_ops);
+ if (bpf_size != nla_len(tb[TCA_ACT_BPF_OPS]))
+ return -EINVAL;
+
+ bpf_ops = kmemdup(nla_data(tb[TCA_ACT_BPF_OPS]), bpf_size, GFP_KERNEL);
+ if (bpf_ops == NULL)
+ return -ENOMEM;
+
+ fprog_tmp.len = bpf_num_ops;
+ fprog_tmp.filter = bpf_ops;
+
+ ret = bpf_prog_create(&fp, &fprog_tmp);
+ if (ret < 0) {
+ kfree(bpf_ops);
+ return ret;
+ }
+
+ cfg->bpf_ops = bpf_ops;
+ cfg->bpf_num_ops = bpf_num_ops;
+ cfg->filter = fp;
+ cfg->is_ebpf = false;
+
+ return 0;
+}
+
+static int tcf_bpf_init_from_efd(struct nlattr **tb, struct tcf_bpf_cfg *cfg)
+{
+ struct bpf_prog *fp;
+ char *name = NULL;
+ u32 bpf_fd;
+
+ bpf_fd = nla_get_u32(tb[TCA_ACT_BPF_FD]);
+
+ fp = bpf_prog_get_type(bpf_fd, BPF_PROG_TYPE_SCHED_ACT);
+ if (IS_ERR(fp))
+ return PTR_ERR(fp);
+
+ if (tb[TCA_ACT_BPF_NAME]) {
+ name = nla_memdup(tb[TCA_ACT_BPF_NAME], GFP_KERNEL);
+ if (!name) {
+ bpf_prog_put(fp);
+ return -ENOMEM;
+ }
+ }
+
+ cfg->bpf_name = name;
+ cfg->filter = fp;
+ cfg->is_ebpf = true;
+
+ return 0;
+}
+
+static void tcf_bpf_cfg_cleanup(const struct tcf_bpf_cfg *cfg)
+{
+ struct bpf_prog *filter = cfg->filter;
+
+ if (filter) {
+ if (cfg->is_ebpf)
+ bpf_prog_put(filter);
+ else
+ bpf_prog_destroy(filter);
+ }
+
+ kfree(cfg->bpf_ops);
+ kfree(cfg->bpf_name);
+}
+
+static void tcf_bpf_prog_fill_cfg(const struct tcf_bpf *prog,
+ struct tcf_bpf_cfg *cfg)
+{
+ cfg->is_ebpf = tcf_bpf_is_ebpf(prog);
+ /* updates to prog->filter are prevented, since it's called either
+ * with tcf lock or during final cleanup in rcu callback
+ */
+ cfg->filter = rcu_dereference_protected(prog->filter, 1);
+
+ cfg->bpf_ops = prog->bpf_ops;
+ cfg->bpf_name = prog->bpf_name;
+}
+
+static int tcf_bpf_init(struct net *net, struct nlattr *nla,
+ struct nlattr *est, struct tc_action **act,
+ int replace, int bind, bool rtnl_held,
+ struct tcf_proto *tp, u32 flags,
+ struct netlink_ext_ack *extack)
+{
+ struct tc_action_net *tn = net_generic(net, bpf_net_id);
+ struct nlattr *tb[TCA_ACT_BPF_MAX + 1];
+ struct tcf_chain *goto_ch = NULL;
+ struct tcf_bpf_cfg cfg, old;
+ struct tc_act_bpf *parm;
+ struct tcf_bpf *prog;
+ bool is_bpf, is_ebpf;
+ int ret, res = 0;
+ u32 index;
+
+ if (!nla)
+ return -EINVAL;
+
+ ret = nla_parse_nested_deprecated(tb, TCA_ACT_BPF_MAX, nla,
+ act_bpf_policy, NULL);
+ if (ret < 0)
+ return ret;
+
+ if (!tb[TCA_ACT_BPF_PARMS])
+ return -EINVAL;
+
+ parm = nla_data(tb[TCA_ACT_BPF_PARMS]);
+ index = parm->index;
+ ret = tcf_idr_check_alloc(tn, &index, act, bind);
+ if (!ret) {
+ ret = tcf_idr_create(tn, index, est, act,
+ &act_bpf_ops, bind, true, flags);
+ if (ret < 0) {
+ tcf_idr_cleanup(tn, index);
+ return ret;
+ }
+
+ res = ACT_P_CREATED;
+ } else if (ret > 0) {
+ /* Don't override defaults. */
+ if (bind)
+ return 0;
+
+ if (!replace) {
+ tcf_idr_release(*act, bind);
+ return -EEXIST;
+ }
+ } else {
+ return ret;
+ }
+
+ ret = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
+ if (ret < 0)
+ goto release_idr;
+
+ is_bpf = tb[TCA_ACT_BPF_OPS_LEN] && tb[TCA_ACT_BPF_OPS];
+ is_ebpf = tb[TCA_ACT_BPF_FD];
+
+ if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf)) {
+ ret = -EINVAL;
+ goto put_chain;
+ }
+
+ memset(&cfg, 0, sizeof(cfg));
+
+ ret = is_bpf ? tcf_bpf_init_from_ops(tb, &cfg) :
+ tcf_bpf_init_from_efd(tb, &cfg);
+ if (ret < 0)
+ goto put_chain;
+
+ prog = to_bpf(*act);
+
+ spin_lock_bh(&prog->tcf_lock);
+ if (res != ACT_P_CREATED)
+ tcf_bpf_prog_fill_cfg(prog, &old);
+
+ prog->bpf_ops = cfg.bpf_ops;
+ prog->bpf_name = cfg.bpf_name;
+
+ if (cfg.bpf_num_ops)
+ prog->bpf_num_ops = cfg.bpf_num_ops;
+
+ goto_ch = tcf_action_set_ctrlact(*act, parm->action, goto_ch);
+ rcu_assign_pointer(prog->filter, cfg.filter);
+ spin_unlock_bh(&prog->tcf_lock);
+
+ if (goto_ch)
+ tcf_chain_put_by_act(goto_ch);
+
+ if (res != ACT_P_CREATED) {
+ /* make sure the program being replaced is no longer executing */
+ synchronize_rcu();
+ tcf_bpf_cfg_cleanup(&old);
+ }
+
+ return res;
+
+put_chain:
+ if (goto_ch)
+ tcf_chain_put_by_act(goto_ch);
+
+release_idr:
+ tcf_idr_release(*act, bind);
+ return ret;
+}
+
+static void tcf_bpf_cleanup(struct tc_action *act)
+{
+ struct tcf_bpf_cfg tmp;
+
+ tcf_bpf_prog_fill_cfg(to_bpf(act), &tmp);
+ tcf_bpf_cfg_cleanup(&tmp);
+}
+
+static int tcf_bpf_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, bpf_net_id);
+
+ return tcf_generic_walker(tn, skb, cb, type, ops, extack);
+}
+
+static int tcf_bpf_search(struct net *net, struct tc_action **a, u32 index)
+{
+ struct tc_action_net *tn = net_generic(net, bpf_net_id);
+
+ return tcf_idr_search(tn, a, index);
+}
+
+static struct tc_action_ops act_bpf_ops __read_mostly = {
+ .kind = "bpf",
+ .id = TCA_ID_BPF,
+ .owner = THIS_MODULE,
+ .act = tcf_bpf_act,
+ .dump = tcf_bpf_dump,
+ .cleanup = tcf_bpf_cleanup,
+ .init = tcf_bpf_init,
+ .walk = tcf_bpf_walker,
+ .lookup = tcf_bpf_search,
+ .size = sizeof(struct tcf_bpf),
+};
+
+static __net_init int bpf_init_net(struct net *net)
+{
+ struct tc_action_net *tn = net_generic(net, bpf_net_id);
+
+ return tc_action_net_init(net, tn, &act_bpf_ops);
+}
+
+static void __net_exit bpf_exit_net(struct list_head *net_list)
+{
+ tc_action_net_exit(net_list, bpf_net_id);
+}
+
+static struct pernet_operations bpf_net_ops = {
+ .init = bpf_init_net,
+ .exit_batch = bpf_exit_net,
+ .id = &bpf_net_id,
+ .size = sizeof(struct tc_action_net),
+};
+
+static int __init bpf_init_module(void)
+{
+ return tcf_register_action(&act_bpf_ops, &bpf_net_ops);
+}
+
+static void __exit bpf_cleanup_module(void)
+{
+ tcf_unregister_action(&act_bpf_ops, &bpf_net_ops);
+}
+
+module_init(bpf_init_module);
+module_exit(bpf_cleanup_module);
+
+MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
+MODULE_DESCRIPTION("TC BPF based action");
+MODULE_LICENSE("GPL v2");