diff options
Diffstat (limited to 'net/sched/act_bpf.c')
| -rw-r--r-- | net/sched/act_bpf.c | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/net/sched/act_bpf.c b/net/sched/act_bpf.c new file mode 100644 index 00000000000..82c5d7fc198 --- /dev/null +++ b/net/sched/act_bpf.c @@ -0,0 +1,208 @@ +/* + * 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 <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 + +static int tcf_bpf(struct sk_buff *skb, const struct tc_action *a, + struct tcf_result *res) +{ + struct tcf_bpf *b = a->priv; + int action; + int filter_res; + + spin_lock(&b->tcf_lock); + b->tcf_tm.lastuse = jiffies; + bstats_update(&b->tcf_bstats, skb); + action = b->tcf_action; + + filter_res = BPF_PROG_RUN(b->filter, skb); + if (filter_res == 0) { + /* Return code 0 from the BPF program + * is being interpreted as a drop here. + */ + action = TC_ACT_SHOT; + b->tcf_qstats.drops++; + } + + spin_unlock(&b->tcf_lock); + return action; +} + +static int tcf_bpf_dump(struct sk_buff *skb, struct tc_action *a, + int bind, int ref) +{ + unsigned char *tp = skb_tail_pointer(skb); + struct tcf_bpf *b = a->priv; + struct tc_act_bpf opt = { + .index = b->tcf_index, + .refcnt = b->tcf_refcnt - ref, + .bindcnt = b->tcf_bindcnt - bind, + .action = b->tcf_action, + }; + struct tcf_t t; + struct nlattr *nla; + + if (nla_put(skb, TCA_ACT_BPF_PARMS, sizeof(opt), &opt)) + goto nla_put_failure; + + if (nla_put_u16(skb, TCA_ACT_BPF_OPS_LEN, b->bpf_num_ops)) + goto nla_put_failure; + + nla = nla_reserve(skb, TCA_ACT_BPF_OPS, b->bpf_num_ops * + sizeof(struct sock_filter)); + if (!nla) + goto nla_put_failure; + + memcpy(nla_data(nla), b->bpf_ops, nla_len(nla)); + + t.install = jiffies_to_clock_t(jiffies - b->tcf_tm.install); + t.lastuse = jiffies_to_clock_t(jiffies - b->tcf_tm.lastuse); + t.expires = jiffies_to_clock_t(b->tcf_tm.expires); + if (nla_put(skb, TCA_ACT_BPF_TM, sizeof(t), &t)) + 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_OPS_LEN] = { .type = NLA_U16 }, + [TCA_ACT_BPF_OPS] = { .type = NLA_BINARY, + .len = sizeof(struct sock_filter) * BPF_MAXINSNS }, +}; + +static int tcf_bpf_init(struct net *net, struct nlattr *nla, + struct nlattr *est, struct tc_action *a, + int ovr, int bind) +{ + struct nlattr *tb[TCA_ACT_BPF_MAX + 1]; + struct tc_act_bpf *parm; + struct tcf_bpf *b; + u16 bpf_size, bpf_num_ops; + struct sock_filter *bpf_ops; + struct sock_fprog_kern tmp; + struct bpf_prog *fp; + int ret; + + if (!nla) + return -EINVAL; + + ret = nla_parse_nested(tb, TCA_ACT_BPF_MAX, nla, act_bpf_policy); + if (ret < 0) + return ret; + + if (!tb[TCA_ACT_BPF_PARMS] || + !tb[TCA_ACT_BPF_OPS_LEN] || !tb[TCA_ACT_BPF_OPS]) + return -EINVAL; + parm = nla_data(tb[TCA_ACT_BPF_PARMS]); + + 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) + return -ENOMEM; + + memcpy(bpf_ops, nla_data(tb[TCA_ACT_BPF_OPS]), bpf_size); + + tmp.len = bpf_num_ops; + tmp.filter = bpf_ops; + + ret = bpf_prog_create(&fp, &tmp); + if (ret) + goto free_bpf_ops; + + if (!tcf_hash_check(parm->index, a, bind)) { + ret = tcf_hash_create(parm->index, est, a, sizeof(*b), bind); + if (ret) + goto destroy_fp; + + ret = ACT_P_CREATED; + } else { + if (bind) + goto destroy_fp; + tcf_hash_release(a, bind); + if (!ovr) { + ret = -EEXIST; + goto destroy_fp; + } + } + + b = to_bpf(a); + spin_lock_bh(&b->tcf_lock); + b->tcf_action = parm->action; + b->bpf_num_ops = bpf_num_ops; + b->bpf_ops = bpf_ops; + b->filter = fp; + spin_unlock_bh(&b->tcf_lock); + + if (ret == ACT_P_CREATED) + tcf_hash_insert(a); + return ret; + +destroy_fp: + bpf_prog_destroy(fp); +free_bpf_ops: + kfree(bpf_ops); + return ret; +} + +static void tcf_bpf_cleanup(struct tc_action *a, int bind) +{ + struct tcf_bpf *b = a->priv; + + bpf_prog_destroy(b->filter); +} + +static struct tc_action_ops act_bpf_ops = { + .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"); 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