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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /net/sched/act_bpf.c
Initial import
Diffstat (limited to 'net/sched/act_bpf.c')
-rw-r--r--net/sched/act_bpf.c362
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");