1 files changed, 362 insertions, 0 deletions
diff --git a/net/sched/act_bpf.c b/net/sched/act_bpf.c
new file mode 100644
index 000000000..dc6a2d324
--- /dev/null
+++ b/net/sched/act_bpf.c
@@ -0,0 +1,362 @@
+/*
+ * Copyright (c) 2015 Jiri Pirko <jiri@resnulli.us>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#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/pkt_sched.h>
+
+#include <linux/tc_act/tc_bpf.h>
+#include <net/tc_act/tc_bpf.h>
+
+#define BPF_TAB_MASK		15
+#define ACT_BPF_NAME_LEN	256
+
+struct tcf_bpf_cfg {
+	struct bpf_prog *filter;
+	struct sock_filter *bpf_ops;
+	char *bpf_name;
+	u32 bpf_fd;
+	u16 bpf_num_ops;
+};
+
+static int tcf_bpf(struct sk_buff *skb, const struct tc_action *act,
+		   struct tcf_result *res)
+{
+	struct tcf_bpf *prog = act->priv;
+	int action, filter_res;
+
+	if (unlikely(!skb_mac_header_was_set(skb)))
+		return TC_ACT_UNSPEC;
+
+	spin_lock(&prog->tcf_lock);
+
+	prog->tcf_tm.lastuse = jiffies;
+	bstats_update(&prog->tcf_bstats, skb);
+
+	/* Needed here for accessing maps. */
+	rcu_read_lock();
+	filter_res = BPF_PROG_RUN(prog->filter, 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:
+		action = filter_res;
+		break;
+	case TC_ACT_SHOT:
+		action = filter_res;
+		prog->tcf_qstats.drops++;
+		break;
+	case TC_ACT_UNSPEC:
+		action = prog->tcf_action;
+		break;
+	default:
+		action = TC_ACT_UNSPEC;
+		break;
+	}
+
+	spin_unlock(&prog->tcf_lock);
+	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)
+{
+	if (nla_put_u32(skb, TCA_ACT_BPF_FD, prog->bpf_fd))
+		return -EMSGSIZE;
+
+	if (prog->bpf_name &&
+	    nla_put_string(skb, TCA_ACT_BPF_NAME, prog->bpf_name))
+		return -EMSGSIZE;
+
+	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 = act->priv;
+	struct tc_act_bpf opt = {
+		.index   = prog->tcf_index,
+		.refcnt  = prog->tcf_refcnt - ref,
+		.bindcnt = prog->tcf_bindcnt - bind,
+		.action  = prog->tcf_action,
+	};
+	struct tcf_t tm;
+	int ret;
+
+	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;
+
+	tm.install = jiffies_to_clock_t(jiffies - prog->tcf_tm.install);
+	tm.lastuse = jiffies_to_clock_t(jiffies - prog->tcf_tm.lastuse);
+	tm.expires = jiffies_to_clock_t(prog->tcf_tm.expires);
+
+	if (nla_put(skb, TCA_ACT_BPF_TM, sizeof(tm), &tm))
+		goto nla_put_failure;
+
+	return skb->len;
+
+nla_put_failure:
+	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 = kzalloc(bpf_size, GFP_KERNEL);
+	if (bpf_ops == NULL)
+		return -ENOMEM;
+
+	memcpy(bpf_ops, nla_data(tb[TCA_ACT_BPF_OPS]), bpf_size);
+
+	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;
+
+	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(bpf_fd);
+	if (IS_ERR(fp))
+		return PTR_ERR(fp);
+
+	if (fp->type != BPF_PROG_TYPE_SCHED_ACT) {
+		bpf_prog_put(fp);
+		return -EINVAL;
+	}
+
+	if (tb[TCA_ACT_BPF_NAME]) {
+		name = kmemdup(nla_data(tb[TCA_ACT_BPF_NAME]),
+			       nla_len(tb[TCA_ACT_BPF_NAME]),
+			       GFP_KERNEL);
+		if (!name) {
+			bpf_prog_put(fp);
+			return -ENOMEM;
+		}
+	}
+
+	cfg->bpf_fd = bpf_fd;
+	cfg->bpf_name = name;
+	cfg->filter = fp;
+
+	return 0;
+}
+
+static int tcf_bpf_init(struct net *net, struct nlattr *nla,
+			struct nlattr *est, struct tc_action *act,
+			int replace, int bind)
+{
+	struct nlattr *tb[TCA_ACT_BPF_MAX + 1];
+	struct tc_act_bpf *parm;
+	struct tcf_bpf *prog;
+	struct tcf_bpf_cfg cfg;
+	bool is_bpf, is_ebpf;
+	int ret;
+
+	if (!nla)
+		return -EINVAL;
+
+	ret = nla_parse_nested(tb, TCA_ACT_BPF_MAX, nla, act_bpf_policy);
+	if (ret < 0)
+		return ret;
+
+	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) ||
+	    !tb[TCA_ACT_BPF_PARMS])
+		return -EINVAL;
+
+	parm = nla_data(tb[TCA_ACT_BPF_PARMS]);
+
+	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)
+		return ret;
+
+	if (!tcf_hash_check(parm->index, act, bind)) {
+		ret = tcf_hash_create(parm->index, est, act,
+				      sizeof(*prog), bind);
+		if (ret < 0)
+			goto destroy_fp;
+
+		ret = ACT_P_CREATED;
+	} else {
+		/* Don't override defaults. */
+		if (bind)
+			goto destroy_fp;
+
+		tcf_hash_release(act, bind);
+		if (!replace) {
+			ret = -EEXIST;
+			goto destroy_fp;
+		}
+	}
+
+	prog = to_bpf(act);
+	spin_lock_bh(&prog->tcf_lock);
+
+	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;
+	if (cfg.bpf_fd)
+		prog->bpf_fd = cfg.bpf_fd;
+
+	prog->tcf_action = parm->action;
+	prog->filter = cfg.filter;
+
+	spin_unlock_bh(&prog->tcf_lock);
+
+	if (ret == ACT_P_CREATED)
+		tcf_hash_insert(act);
+
+	return ret;
+
+destroy_fp:
+	if (is_ebpf)
+		bpf_prog_put(cfg.filter);
+	else
+		bpf_prog_destroy(cfg.filter);
+
+	kfree(cfg.bpf_ops);
+	kfree(cfg.bpf_name);
+
+	return ret;
+}
+
+static void tcf_bpf_cleanup(struct tc_action *act, int bind)
+{
+	const struct tcf_bpf *prog = act->priv;
+
+	if (tcf_bpf_is_ebpf(prog))
+		bpf_prog_put(prog->filter);
+	else
+		bpf_prog_destroy(prog->filter);
+}
+
+static struct tc_action_ops act_bpf_ops __read_mostly = {
+	.kind		=	"bpf",
+	.type		=	TCA_ACT_BPF,
+	.owner		=	THIS_MODULE,
+	.act		=	tcf_bpf,
+	.dump		=	tcf_bpf_dump,
+	.cleanup	=	tcf_bpf_cleanup,
+	.init		=	tcf_bpf_init,
+};
+
+static int __init bpf_init_module(void)
+{
+	return tcf_register_action(&act_bpf_ops, BPF_TAB_MASK);
+}
+
+static void __exit bpf_cleanup_module(void)
+{
+	tcf_unregister_action(&act_bpf_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");