From d23b8ad8ab23f5a18b91e2396fb63d10f66b08d6 Mon Sep 17 00:00:00 2001 From: Jiri Pirko Date: Thu, 15 Jan 2015 09:52:39 +0100 Subject: [PATCH] tc: add BPF based action This action provides a possibility to exec custom BPF code. Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller --- include/net/tc_act/tc_bpf.h | 25 ++++ include/uapi/linux/tc_act/Kbuild | 1 + include/uapi/linux/tc_act/tc_bpf.h | 31 +++++ net/sched/Kconfig | 12 ++ net/sched/Makefile | 1 + net/sched/act_bpf.c | 205 +++++++++++++++++++++++++++++ 6 files changed, 275 insertions(+) create mode 100644 include/net/tc_act/tc_bpf.h create mode 100644 include/uapi/linux/tc_act/tc_bpf.h create mode 100644 net/sched/act_bpf.c diff --git a/include/net/tc_act/tc_bpf.h b/include/net/tc_act/tc_bpf.h new file mode 100644 index 000000000000..86a070ffc930 --- /dev/null +++ b/include/net/tc_act/tc_bpf.h @@ -0,0 +1,25 @@ +/* + * Copyright (c) 2015 Jiri Pirko + * + * 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. + */ + +#ifndef __NET_TC_BPF_H +#define __NET_TC_BPF_H + +#include +#include + +struct tcf_bpf { + struct tcf_common common; + struct bpf_prog *filter; + struct sock_filter *bpf_ops; + u16 bpf_num_ops; +}; +#define to_bpf(a) \ + container_of(a->priv, struct tcf_bpf, common) + +#endif /* __NET_TC_BPF_H */ diff --git a/include/uapi/linux/tc_act/Kbuild b/include/uapi/linux/tc_act/Kbuild index b057da2b87a4..19d5219b0b99 100644 --- a/include/uapi/linux/tc_act/Kbuild +++ b/include/uapi/linux/tc_act/Kbuild @@ -8,3 +8,4 @@ header-y += tc_nat.h header-y += tc_pedit.h header-y += tc_skbedit.h header-y += tc_vlan.h +header-y += tc_bpf.h diff --git a/include/uapi/linux/tc_act/tc_bpf.h b/include/uapi/linux/tc_act/tc_bpf.h new file mode 100644 index 000000000000..5288bd77e63b --- /dev/null +++ b/include/uapi/linux/tc_act/tc_bpf.h @@ -0,0 +1,31 @@ +/* + * Copyright (c) 2015 Jiri Pirko + * + * 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. + */ + +#ifndef __LINUX_TC_BPF_H +#define __LINUX_TC_BPF_H + +#include + +#define TCA_ACT_BPF 13 + +struct tc_act_bpf { + tc_gen; +}; + +enum { + TCA_ACT_BPF_UNSPEC, + TCA_ACT_BPF_TM, + TCA_ACT_BPF_PARMS, + TCA_ACT_BPF_OPS_LEN, + TCA_ACT_BPF_OPS, + __TCA_ACT_BPF_MAX, +}; +#define TCA_ACT_BPF_MAX (__TCA_ACT_BPF_MAX - 1) + +#endif diff --git a/net/sched/Kconfig b/net/sched/Kconfig index c54c9d9d1ffb..466943551581 100644 --- a/net/sched/Kconfig +++ b/net/sched/Kconfig @@ -698,6 +698,18 @@ config NET_ACT_VLAN To compile this code as a module, choose M here: the module will be called act_vlan. +config NET_ACT_BPF + tristate "BPF based action" + depends on NET_CLS_ACT + ---help--- + Say Y here to execute BPF code on packets. The BPF code will decide + if the packet should be dropped or not. + + If unsure, say N. + + To compile this code as a module, choose M here: the + module will be called act_bpf. + config NET_CLS_IND bool "Incoming device classification" depends on NET_CLS_U32 || NET_CLS_FW diff --git a/net/sched/Makefile b/net/sched/Makefile index 679f24ae7f93..7ca2b4e76312 100644 --- a/net/sched/Makefile +++ b/net/sched/Makefile @@ -17,6 +17,7 @@ obj-$(CONFIG_NET_ACT_SIMP) += act_simple.o obj-$(CONFIG_NET_ACT_SKBEDIT) += act_skbedit.o obj-$(CONFIG_NET_ACT_CSUM) += act_csum.o obj-$(CONFIG_NET_ACT_VLAN) += act_vlan.o +obj-$(CONFIG_NET_ACT_BPF) += act_bpf.o obj-$(CONFIG_NET_SCH_FIFO) += sch_fifo.o obj-$(CONFIG_NET_SCH_CBQ) += sch_cbq.o obj-$(CONFIG_NET_SCH_HTB) += sch_htb.o diff --git a/net/sched/act_bpf.c b/net/sched/act_bpf.c new file mode 100644 index 000000000000..1bd257e473a9 --- /dev/null +++ b/net/sched/act_bpf.c @@ -0,0 +1,205 @@ +/* + * Copyright (c) 2015 Jiri Pirko + * + * 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 +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#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); + 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 "); +MODULE_DESCRIPTION("TC BPF based action"); +MODULE_LICENSE("GPL v2"); -- 2.20.1