File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c
new file mode 100644
index 0000000..3eef021
--- /dev/null
+++ b/net/sched/cls_bpf.c
@@ -0,0 +1,549 @@
+/*
+ * Berkeley Packet Filter based traffic classifier
+ *
+ * Might be used to classify traffic through flexible, user-defined and
+ * possibly JIT-ed BPF filters for traffic control as an alternative to
+ * ematches.
+ *
+ * (C) 2013 Daniel Borkmann <dborkman@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/skbuff.h>
+#include <linux/filter.h>
+#include <linux/bpf.h>
+
+#include <net/rtnetlink.h>
+#include <net/pkt_cls.h>
+#include <net/sock.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Daniel Borkmann <dborkman@redhat.com>");
+MODULE_DESCRIPTION("TC BPF based classifier");
+
+#define CLS_BPF_NAME_LEN 256
+
+struct cls_bpf_head {
+ struct list_head plist;
+ u32 hgen;
+ struct rcu_head rcu;
+};
+
+struct cls_bpf_prog {
+ struct bpf_prog *filter;
+ struct list_head link;
+ struct tcf_result res;
+ bool exts_integrated;
+ struct tcf_exts exts;
+ u32 handle;
+ union {
+ u32 bpf_fd;
+ u16 bpf_num_ops;
+ };
+ struct sock_filter *bpf_ops;
+ const char *bpf_name;
+ struct tcf_proto *tp;
+ struct rcu_head rcu;
+};
+
+static const struct nla_policy bpf_policy[TCA_BPF_MAX + 1] = {
+ [TCA_BPF_CLASSID] = { .type = NLA_U32 },
+ [TCA_BPF_FLAGS] = { .type = NLA_U32 },
+ [TCA_BPF_FD] = { .type = NLA_U32 },
+ [TCA_BPF_NAME] = { .type = NLA_NUL_STRING, .len = CLS_BPF_NAME_LEN },
+ [TCA_BPF_OPS_LEN] = { .type = NLA_U16 },
+ [TCA_BPF_OPS] = { .type = NLA_BINARY,
+ .len = sizeof(struct sock_filter) * BPF_MAXINSNS },
+};
+
+static int cls_bpf_exec_opcode(int code)
+{
+ switch (code) {
+ case TC_ACT_OK:
+ case TC_ACT_SHOT:
+ case TC_ACT_STOLEN:
+ case TC_ACT_REDIRECT:
+ case TC_ACT_UNSPEC:
+ return code;
+ default:
+ return TC_ACT_UNSPEC;
+ }
+}
+
+static int cls_bpf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
+ struct tcf_result *res)
+{
+ struct cls_bpf_head *head = rcu_dereference_bh(tp->root);
+ struct cls_bpf_prog *prog;
+#ifdef CONFIG_NET_CLS_ACT
+ bool at_ingress = G_TC_AT(skb->tc_verd) & AT_INGRESS;
+#else
+ bool at_ingress = false;
+#endif
+ int ret = -1;
+
+ if (unlikely(!skb_mac_header_was_set(skb)))
+ return -1;
+
+ /* Needed here for accessing maps. */
+ rcu_read_lock();
+ list_for_each_entry_rcu(prog, &head->plist, link) {
+ int filter_res;
+
+ qdisc_skb_cb(skb)->tc_classid = prog->res.classid;
+
+ if (at_ingress) {
+ /* It is safe to push/pull even if skb_shared() */
+ __skb_push(skb, skb->mac_len);
+ filter_res = BPF_PROG_RUN(prog->filter, skb);
+ __skb_pull(skb, skb->mac_len);
+ } else {
+ filter_res = BPF_PROG_RUN(prog->filter, skb);
+ }
+
+ if (prog->exts_integrated) {
+ res->class = prog->res.class;
+ res->classid = qdisc_skb_cb(skb)->tc_classid;
+
+ ret = cls_bpf_exec_opcode(filter_res);
+ if (ret == TC_ACT_UNSPEC)
+ continue;
+ break;
+ }
+
+ if (filter_res == 0)
+ continue;
+
+ *res = prog->res;
+ if (filter_res != -1)
+ res->classid = filter_res;
+
+ ret = tcf_exts_exec(skb, &prog->exts, res);
+ if (ret < 0)
+ continue;
+
+ break;
+ }
+ rcu_read_unlock();
+
+ return ret;
+}
+
+static bool cls_bpf_is_ebpf(const struct cls_bpf_prog *prog)
+{
+ return !prog->bpf_ops;
+}
+
+static int cls_bpf_init(struct tcf_proto *tp)
+{
+ struct cls_bpf_head *head;
+
+ head = kzalloc(sizeof(*head), GFP_KERNEL);
+ if (head == NULL)
+ return -ENOBUFS;
+
+ INIT_LIST_HEAD_RCU(&head->plist);
+ rcu_assign_pointer(tp->root, head);
+
+ return 0;
+}
+
+static void cls_bpf_delete_prog(struct tcf_proto *tp, struct cls_bpf_prog *prog)
+{
+ tcf_exts_destroy(&prog->exts);
+
+ if (cls_bpf_is_ebpf(prog))
+ bpf_prog_put(prog->filter);
+ else
+ bpf_prog_destroy(prog->filter);
+
+ kfree(prog->bpf_name);
+ kfree(prog->bpf_ops);
+ kfree(prog);
+}
+
+static void __cls_bpf_delete_prog(struct rcu_head *rcu)
+{
+ struct cls_bpf_prog *prog = container_of(rcu, struct cls_bpf_prog, rcu);
+
+ cls_bpf_delete_prog(prog->tp, prog);
+}
+
+static int cls_bpf_delete(struct tcf_proto *tp, unsigned long arg)
+{
+ struct cls_bpf_prog *prog = (struct cls_bpf_prog *) arg;
+
+ list_del_rcu(&prog->link);
+ tcf_unbind_filter(tp, &prog->res);
+ call_rcu(&prog->rcu, __cls_bpf_delete_prog);
+
+ return 0;
+}
+
+static bool cls_bpf_destroy(struct tcf_proto *tp, bool force)
+{
+ struct cls_bpf_head *head = rtnl_dereference(tp->root);
+ struct cls_bpf_prog *prog, *tmp;
+
+ if (!force && !list_empty(&head->plist))
+ return false;
+
+ list_for_each_entry_safe(prog, tmp, &head->plist, link) {
+ list_del_rcu(&prog->link);
+ tcf_unbind_filter(tp, &prog->res);
+ call_rcu(&prog->rcu, __cls_bpf_delete_prog);
+ }
+
+ kfree_rcu(head, rcu);
+ return true;
+}
+
+static unsigned long cls_bpf_get(struct tcf_proto *tp, u32 handle)
+{
+ struct cls_bpf_head *head = rtnl_dereference(tp->root);
+ struct cls_bpf_prog *prog;
+ unsigned long ret = 0UL;
+
+ list_for_each_entry(prog, &head->plist, link) {
+ if (prog->handle == handle) {
+ ret = (unsigned long) prog;
+ break;
+ }
+ }
+
+ return ret;
+}
+
+static int cls_bpf_prog_from_ops(struct nlattr **tb, struct cls_bpf_prog *prog)
+{
+ 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_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_BPF_OPS]))
+ return -EINVAL;
+
+ bpf_ops = kzalloc(bpf_size, GFP_KERNEL);
+ if (bpf_ops == NULL)
+ return -ENOMEM;
+
+ memcpy(bpf_ops, nla_data(tb[TCA_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;
+ }
+
+ prog->bpf_ops = bpf_ops;
+ prog->bpf_num_ops = bpf_num_ops;
+ prog->bpf_name = NULL;
+ prog->filter = fp;
+
+ return 0;
+}
+
+static int cls_bpf_prog_from_efd(struct nlattr **tb, struct cls_bpf_prog *prog,
+ const struct tcf_proto *tp)
+{
+ struct bpf_prog *fp;
+ char *name = NULL;
+ u32 bpf_fd;
+
+ bpf_fd = nla_get_u32(tb[TCA_BPF_FD]);
+
+ fp = bpf_prog_get(bpf_fd);
+ if (IS_ERR(fp))
+ return PTR_ERR(fp);
+
+ if (fp->type != BPF_PROG_TYPE_SCHED_CLS) {
+ bpf_prog_put(fp);
+ return -EINVAL;
+ }
+
+ if (tb[TCA_BPF_NAME]) {
+ name = kmemdup(nla_data(tb[TCA_BPF_NAME]),
+ nla_len(tb[TCA_BPF_NAME]),
+ GFP_KERNEL);
+ if (!name) {
+ bpf_prog_put(fp);
+ return -ENOMEM;
+ }
+ }
+
+ prog->bpf_ops = NULL;
+ prog->bpf_fd = bpf_fd;
+ prog->bpf_name = name;
+ prog->filter = fp;
+
+ if (fp->dst_needed)
+ netif_keep_dst(qdisc_dev(tp->q));
+
+ return 0;
+}
+
+static int cls_bpf_modify_existing(struct net *net, struct tcf_proto *tp,
+ struct cls_bpf_prog *prog,
+ unsigned long base, struct nlattr **tb,
+ struct nlattr *est, bool ovr)
+{
+ bool is_bpf, is_ebpf, have_exts = false;
+ struct tcf_exts exts;
+ int ret;
+
+ is_bpf = tb[TCA_BPF_OPS_LEN] && tb[TCA_BPF_OPS];
+ is_ebpf = tb[TCA_BPF_FD];
+ if ((!is_bpf && !is_ebpf) || (is_bpf && is_ebpf))
+ return -EINVAL;
+
+ tcf_exts_init(&exts, TCA_BPF_ACT, TCA_BPF_POLICE);
+ ret = tcf_exts_validate(net, tp, tb, est, &exts, ovr);
+ if (ret < 0)
+ return ret;
+
+ if (tb[TCA_BPF_FLAGS]) {
+ u32 bpf_flags = nla_get_u32(tb[TCA_BPF_FLAGS]);
+
+ if (bpf_flags & ~TCA_BPF_FLAG_ACT_DIRECT) {
+ tcf_exts_destroy(&exts);
+ return -EINVAL;
+ }
+
+ have_exts = bpf_flags & TCA_BPF_FLAG_ACT_DIRECT;
+ }
+
+ prog->exts_integrated = have_exts;
+
+ ret = is_bpf ? cls_bpf_prog_from_ops(tb, prog) :
+ cls_bpf_prog_from_efd(tb, prog, tp);
+ if (ret < 0) {
+ tcf_exts_destroy(&exts);
+ return ret;
+ }
+
+ if (tb[TCA_BPF_CLASSID]) {
+ prog->res.classid = nla_get_u32(tb[TCA_BPF_CLASSID]);
+ tcf_bind_filter(tp, &prog->res, base);
+ }
+
+ tcf_exts_change(tp, &prog->exts, &exts);
+ return 0;
+}
+
+static u32 cls_bpf_grab_new_handle(struct tcf_proto *tp,
+ struct cls_bpf_head *head)
+{
+ unsigned int i = 0x80000000;
+ u32 handle;
+
+ do {
+ if (++head->hgen == 0x7FFFFFFF)
+ head->hgen = 1;
+ } while (--i > 0 && cls_bpf_get(tp, head->hgen));
+
+ if (unlikely(i == 0)) {
+ pr_err("Insufficient number of handles\n");
+ handle = 0;
+ } else {
+ handle = head->hgen;
+ }
+
+ return handle;
+}
+
+static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
+ struct tcf_proto *tp, unsigned long base,
+ u32 handle, struct nlattr **tca,
+ unsigned long *arg, bool ovr)
+{
+ struct cls_bpf_head *head = rtnl_dereference(tp->root);
+ struct cls_bpf_prog *oldprog = (struct cls_bpf_prog *) *arg;
+ struct nlattr *tb[TCA_BPF_MAX + 1];
+ struct cls_bpf_prog *prog;
+ int ret;
+
+ if (tca[TCA_OPTIONS] == NULL)
+ return -EINVAL;
+
+ ret = nla_parse_nested(tb, TCA_BPF_MAX, tca[TCA_OPTIONS], bpf_policy);
+ if (ret < 0)
+ return ret;
+
+ prog = kzalloc(sizeof(*prog), GFP_KERNEL);
+ if (!prog)
+ return -ENOBUFS;
+
+ tcf_exts_init(&prog->exts, TCA_BPF_ACT, TCA_BPF_POLICE);
+
+ if (oldprog) {
+ if (handle && oldprog->handle != handle) {
+ ret = -EINVAL;
+ goto errout;
+ }
+ }
+
+ if (handle == 0)
+ prog->handle = cls_bpf_grab_new_handle(tp, head);
+ else
+ prog->handle = handle;
+ if (prog->handle == 0) {
+ ret = -EINVAL;
+ goto errout;
+ }
+
+ ret = cls_bpf_modify_existing(net, tp, prog, base, tb, tca[TCA_RATE], ovr);
+ if (ret < 0)
+ goto errout;
+
+ if (oldprog) {
+ list_replace_rcu(&oldprog->link, &prog->link);
+ tcf_unbind_filter(tp, &oldprog->res);
+ call_rcu(&oldprog->rcu, __cls_bpf_delete_prog);
+ } else {
+ list_add_rcu(&prog->link, &head->plist);
+ }
+
+ *arg = (unsigned long) prog;
+ return 0;
+errout:
+ kfree(prog);
+
+ return ret;
+}
+
+static int cls_bpf_dump_bpf_info(const struct cls_bpf_prog *prog,
+ struct sk_buff *skb)
+{
+ struct nlattr *nla;
+
+ if (nla_put_u16(skb, TCA_BPF_OPS_LEN, prog->bpf_num_ops))
+ return -EMSGSIZE;
+
+ nla = nla_reserve(skb, TCA_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 cls_bpf_dump_ebpf_info(const struct cls_bpf_prog *prog,
+ struct sk_buff *skb)
+{
+ if (nla_put_u32(skb, TCA_BPF_FD, prog->bpf_fd))
+ return -EMSGSIZE;
+
+ if (prog->bpf_name &&
+ nla_put_string(skb, TCA_BPF_NAME, prog->bpf_name))
+ return -EMSGSIZE;
+
+ return 0;
+}
+
+static int cls_bpf_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
+ struct sk_buff *skb, struct tcmsg *tm)
+{
+ struct cls_bpf_prog *prog = (struct cls_bpf_prog *) fh;
+ struct nlattr *nest;
+ u32 bpf_flags = 0;
+ int ret;
+
+ if (prog == NULL)
+ return skb->len;
+
+ tm->tcm_handle = prog->handle;
+
+ nest = nla_nest_start(skb, TCA_OPTIONS);
+ if (nest == NULL)
+ goto nla_put_failure;
+
+ if (prog->res.classid &&
+ nla_put_u32(skb, TCA_BPF_CLASSID, prog->res.classid))
+ goto nla_put_failure;
+
+ if (cls_bpf_is_ebpf(prog))
+ ret = cls_bpf_dump_ebpf_info(prog, skb);
+ else
+ ret = cls_bpf_dump_bpf_info(prog, skb);
+ if (ret)
+ goto nla_put_failure;
+
+ if (tcf_exts_dump(skb, &prog->exts) < 0)
+ goto nla_put_failure;
+
+ if (prog->exts_integrated)
+ bpf_flags |= TCA_BPF_FLAG_ACT_DIRECT;
+ if (bpf_flags && nla_put_u32(skb, TCA_BPF_FLAGS, bpf_flags))
+ goto nla_put_failure;
+
+ nla_nest_end(skb, nest);
+
+ if (tcf_exts_dump_stats(skb, &prog->exts) < 0)
+ goto nla_put_failure;
+
+ return skb->len;
+
+nla_put_failure:
+ nla_nest_cancel(skb, nest);
+ return -1;
+}
+
+static void cls_bpf_walk(struct tcf_proto *tp, struct tcf_walker *arg)
+{
+ struct cls_bpf_head *head = rtnl_dereference(tp->root);
+ struct cls_bpf_prog *prog;
+
+ list_for_each_entry(prog, &head->plist, link) {
+ if (arg->count < arg->skip)
+ goto skip;
+ if (arg->fn(tp, (unsigned long) prog, arg) < 0) {
+ arg->stop = 1;
+ break;
+ }
+skip:
+ arg->count++;
+ }
+}
+
+static struct tcf_proto_ops cls_bpf_ops __read_mostly = {
+ .kind = "bpf",
+ .owner = THIS_MODULE,
+ .classify = cls_bpf_classify,
+ .init = cls_bpf_init,
+ .destroy = cls_bpf_destroy,
+ .get = cls_bpf_get,
+ .change = cls_bpf_change,
+ .delete = cls_bpf_delete,
+ .walk = cls_bpf_walk,
+ .dump = cls_bpf_dump,
+};
+
+static int __init cls_bpf_init_mod(void)
+{
+ return register_tcf_proto_ops(&cls_bpf_ops);
+}
+
+static void __exit cls_bpf_exit_mod(void)
+{
+ unregister_tcf_proto_ops(&cls_bpf_ops);
+}
+
+module_init(cls_bpf_init_mod);
+module_exit(cls_bpf_exit_mod);