From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- net/sched/cls_bpf.c | 706 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 706 insertions(+) create mode 100644 net/sched/cls_bpf.c (limited to 'net/sched/cls_bpf.c') diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c new file mode 100644 index 000000000..0320e11eb --- /dev/null +++ b/net/sched/cls_bpf.c @@ -0,0 +1,706 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 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 + */ + +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Daniel Borkmann "); +MODULE_DESCRIPTION("TC BPF based classifier"); + +#define CLS_BPF_NAME_LEN 256 +#define CLS_BPF_SUPPORTED_GEN_FLAGS \ + (TCA_CLS_FLAGS_SKIP_HW | TCA_CLS_FLAGS_SKIP_SW) + +struct cls_bpf_head { + struct list_head plist; + struct idr handle_idr; + struct rcu_head rcu; +}; + +struct cls_bpf_prog { + struct bpf_prog *filter; + struct list_head link; + struct tcf_result res; + bool exts_integrated; + u32 gen_flags; + unsigned int in_hw_count; + struct tcf_exts exts; + u32 handle; + u16 bpf_num_ops; + struct sock_filter *bpf_ops; + const char *bpf_name; + struct tcf_proto *tp; + struct rcu_work rwork; +}; + +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_FLAGS_GEN] = { .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_TRAP: + 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); + bool at_ingress = skb_at_tc_ingress(skb); + struct cls_bpf_prog *prog; + int ret = -1; + + list_for_each_entry_rcu(prog, &head->plist, link) { + int filter_res; + + qdisc_skb_cb(skb)->tc_classid = prog->res.classid; + + if (tc_skip_sw(prog->gen_flags)) { + filter_res = prog->exts_integrated ? TC_ACT_UNSPEC : 0; + } else if (at_ingress) { + /* It is safe to push/pull even if skb_shared() */ + __skb_push(skb, skb->mac_len); + bpf_compute_data_pointers(skb); + filter_res = bpf_prog_run(prog->filter, skb); + __skb_pull(skb, skb->mac_len); + } else { + bpf_compute_data_pointers(skb); + filter_res = bpf_prog_run(prog->filter, skb); + } + if (unlikely(!skb->tstamp && skb->mono_delivery_time)) + skb->mono_delivery_time = 0; + + if (prog->exts_integrated) { + res->class = 0; + res->classid = TC_H_MAJ(prog->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; + if (filter_res != -1) { + res->class = 0; + res->classid = filter_res; + } else { + *res = prog->res; + } + + ret = tcf_exts_exec(skb, &prog->exts, res); + if (ret < 0) + continue; + + break; + } + + return ret; +} + +static bool cls_bpf_is_ebpf(const struct cls_bpf_prog *prog) +{ + return !prog->bpf_ops; +} + +static int cls_bpf_offload_cmd(struct tcf_proto *tp, struct cls_bpf_prog *prog, + struct cls_bpf_prog *oldprog, + struct netlink_ext_ack *extack) +{ + struct tcf_block *block = tp->chain->block; + struct tc_cls_bpf_offload cls_bpf = {}; + struct cls_bpf_prog *obj; + bool skip_sw; + int err; + + skip_sw = prog && tc_skip_sw(prog->gen_flags); + obj = prog ?: oldprog; + + tc_cls_common_offload_init(&cls_bpf.common, tp, obj->gen_flags, extack); + cls_bpf.command = TC_CLSBPF_OFFLOAD; + cls_bpf.exts = &obj->exts; + cls_bpf.prog = prog ? prog->filter : NULL; + cls_bpf.oldprog = oldprog ? oldprog->filter : NULL; + cls_bpf.name = obj->bpf_name; + cls_bpf.exts_integrated = obj->exts_integrated; + + if (oldprog && prog) + err = tc_setup_cb_replace(block, tp, TC_SETUP_CLSBPF, &cls_bpf, + skip_sw, &oldprog->gen_flags, + &oldprog->in_hw_count, + &prog->gen_flags, &prog->in_hw_count, + true); + else if (prog) + err = tc_setup_cb_add(block, tp, TC_SETUP_CLSBPF, &cls_bpf, + skip_sw, &prog->gen_flags, + &prog->in_hw_count, true); + else + err = tc_setup_cb_destroy(block, tp, TC_SETUP_CLSBPF, &cls_bpf, + skip_sw, &oldprog->gen_flags, + &oldprog->in_hw_count, true); + + if (prog && err) { + cls_bpf_offload_cmd(tp, oldprog, prog, extack); + return err; + } + + if (prog && skip_sw && !(prog->gen_flags & TCA_CLS_FLAGS_IN_HW)) + return -EINVAL; + + return 0; +} + +static u32 cls_bpf_flags(u32 flags) +{ + return flags & CLS_BPF_SUPPORTED_GEN_FLAGS; +} + +static int cls_bpf_offload(struct tcf_proto *tp, struct cls_bpf_prog *prog, + struct cls_bpf_prog *oldprog, + struct netlink_ext_ack *extack) +{ + if (prog && oldprog && + cls_bpf_flags(prog->gen_flags) != + cls_bpf_flags(oldprog->gen_flags)) + return -EINVAL; + + if (prog && tc_skip_hw(prog->gen_flags)) + prog = NULL; + if (oldprog && tc_skip_hw(oldprog->gen_flags)) + oldprog = NULL; + if (!prog && !oldprog) + return 0; + + return cls_bpf_offload_cmd(tp, prog, oldprog, extack); +} + +static void cls_bpf_stop_offload(struct tcf_proto *tp, + struct cls_bpf_prog *prog, + struct netlink_ext_ack *extack) +{ + int err; + + err = cls_bpf_offload_cmd(tp, NULL, prog, extack); + if (err) + pr_err("Stopping hardware offload failed: %d\n", err); +} + +static void cls_bpf_offload_update_stats(struct tcf_proto *tp, + struct cls_bpf_prog *prog) +{ + struct tcf_block *block = tp->chain->block; + struct tc_cls_bpf_offload cls_bpf = {}; + + tc_cls_common_offload_init(&cls_bpf.common, tp, prog->gen_flags, NULL); + cls_bpf.command = TC_CLSBPF_STATS; + cls_bpf.exts = &prog->exts; + cls_bpf.prog = prog->filter; + cls_bpf.name = prog->bpf_name; + cls_bpf.exts_integrated = prog->exts_integrated; + + tc_setup_cb_call(block, TC_SETUP_CLSBPF, &cls_bpf, false, true); +} + +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); + idr_init(&head->handle_idr); + rcu_assign_pointer(tp->root, head); + + return 0; +} + +static void cls_bpf_free_parms(struct cls_bpf_prog *prog) +{ + 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); +} + +static void __cls_bpf_delete_prog(struct cls_bpf_prog *prog) +{ + tcf_exts_destroy(&prog->exts); + tcf_exts_put_net(&prog->exts); + + cls_bpf_free_parms(prog); + kfree(prog); +} + +static void cls_bpf_delete_prog_work(struct work_struct *work) +{ + struct cls_bpf_prog *prog = container_of(to_rcu_work(work), + struct cls_bpf_prog, + rwork); + rtnl_lock(); + __cls_bpf_delete_prog(prog); + rtnl_unlock(); +} + +static void __cls_bpf_delete(struct tcf_proto *tp, struct cls_bpf_prog *prog, + struct netlink_ext_ack *extack) +{ + struct cls_bpf_head *head = rtnl_dereference(tp->root); + + idr_remove(&head->handle_idr, prog->handle); + cls_bpf_stop_offload(tp, prog, extack); + list_del_rcu(&prog->link); + tcf_unbind_filter(tp, &prog->res); + if (tcf_exts_get_net(&prog->exts)) + tcf_queue_work(&prog->rwork, cls_bpf_delete_prog_work); + else + __cls_bpf_delete_prog(prog); +} + +static int cls_bpf_delete(struct tcf_proto *tp, void *arg, bool *last, + bool rtnl_held, struct netlink_ext_ack *extack) +{ + struct cls_bpf_head *head = rtnl_dereference(tp->root); + + __cls_bpf_delete(tp, arg, extack); + *last = list_empty(&head->plist); + return 0; +} + +static void cls_bpf_destroy(struct tcf_proto *tp, bool rtnl_held, + struct netlink_ext_ack *extack) +{ + struct cls_bpf_head *head = rtnl_dereference(tp->root); + struct cls_bpf_prog *prog, *tmp; + + list_for_each_entry_safe(prog, tmp, &head->plist, link) + __cls_bpf_delete(tp, prog, extack); + + idr_destroy(&head->handle_idr); + kfree_rcu(head, rcu); +} + +static void *cls_bpf_get(struct tcf_proto *tp, u32 handle) +{ + struct cls_bpf_head *head = rtnl_dereference(tp->root); + struct cls_bpf_prog *prog; + + list_for_each_entry(prog, &head->plist, link) { + if (prog->handle == handle) + return prog; + } + + return NULL; +} + +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 = kmemdup(nla_data(tb[TCA_BPF_OPS]), bpf_size, GFP_KERNEL); + if (bpf_ops == NULL) + return -ENOMEM; + + 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, + u32 gen_flags, const struct tcf_proto *tp) +{ + struct bpf_prog *fp; + char *name = NULL; + bool skip_sw; + u32 bpf_fd; + + bpf_fd = nla_get_u32(tb[TCA_BPF_FD]); + skip_sw = gen_flags & TCA_CLS_FLAGS_SKIP_SW; + + fp = bpf_prog_get_type_dev(bpf_fd, BPF_PROG_TYPE_SCHED_CLS, skip_sw); + if (IS_ERR(fp)) + return PTR_ERR(fp); + + if (tb[TCA_BPF_NAME]) { + name = nla_memdup(tb[TCA_BPF_NAME], GFP_KERNEL); + if (!name) { + bpf_prog_put(fp); + return -ENOMEM; + } + } + + prog->bpf_ops = NULL; + prog->bpf_name = name; + prog->filter = fp; + + if (fp->dst_needed) + tcf_block_netif_keep_dst(tp->chain->block); + + return 0; +} + +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, + void **arg, u32 flags, + struct netlink_ext_ack *extack) +{ + struct cls_bpf_head *head = rtnl_dereference(tp->root); + bool is_bpf, is_ebpf, have_exts = false; + struct cls_bpf_prog *oldprog = *arg; + struct nlattr *tb[TCA_BPF_MAX + 1]; + bool bound_to_filter = false; + struct cls_bpf_prog *prog; + u32 gen_flags = 0; + int ret; + + if (tca[TCA_OPTIONS] == NULL) + return -EINVAL; + + ret = nla_parse_nested_deprecated(tb, TCA_BPF_MAX, tca[TCA_OPTIONS], + bpf_policy, NULL); + if (ret < 0) + return ret; + + prog = kzalloc(sizeof(*prog), GFP_KERNEL); + if (!prog) + return -ENOBUFS; + + ret = tcf_exts_init(&prog->exts, net, TCA_BPF_ACT, TCA_BPF_POLICE); + if (ret < 0) + goto errout; + + if (oldprog) { + if (handle && oldprog->handle != handle) { + ret = -EINVAL; + goto errout; + } + } + + if (handle == 0) { + handle = 1; + ret = idr_alloc_u32(&head->handle_idr, prog, &handle, + INT_MAX, GFP_KERNEL); + } else if (!oldprog) { + ret = idr_alloc_u32(&head->handle_idr, prog, &handle, + handle, GFP_KERNEL); + } + + if (ret) + goto errout; + prog->handle = handle; + + 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)) { + ret = -EINVAL; + goto errout_idr; + } + + ret = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &prog->exts, + flags, extack); + if (ret < 0) + goto errout_idr; + + if (tb[TCA_BPF_FLAGS]) { + u32 bpf_flags = nla_get_u32(tb[TCA_BPF_FLAGS]); + + if (bpf_flags & ~TCA_BPF_FLAG_ACT_DIRECT) { + ret = -EINVAL; + goto errout_idr; + } + + have_exts = bpf_flags & TCA_BPF_FLAG_ACT_DIRECT; + } + if (tb[TCA_BPF_FLAGS_GEN]) { + gen_flags = nla_get_u32(tb[TCA_BPF_FLAGS_GEN]); + if (gen_flags & ~CLS_BPF_SUPPORTED_GEN_FLAGS || + !tc_flags_valid(gen_flags)) { + ret = -EINVAL; + goto errout_idr; + } + } + + prog->exts_integrated = have_exts; + prog->gen_flags = gen_flags; + + ret = is_bpf ? cls_bpf_prog_from_ops(tb, prog) : + cls_bpf_prog_from_efd(tb, prog, gen_flags, tp); + if (ret < 0) + goto errout_idr; + + if (tb[TCA_BPF_CLASSID]) { + prog->res.classid = nla_get_u32(tb[TCA_BPF_CLASSID]); + tcf_bind_filter(tp, &prog->res, base); + bound_to_filter = true; + } + + ret = cls_bpf_offload(tp, prog, oldprog, extack); + if (ret) + goto errout_parms; + + if (!tc_in_hw(prog->gen_flags)) + prog->gen_flags |= TCA_CLS_FLAGS_NOT_IN_HW; + + if (oldprog) { + idr_replace(&head->handle_idr, prog, handle); + list_replace_rcu(&oldprog->link, &prog->link); + tcf_unbind_filter(tp, &oldprog->res); + tcf_exts_get_net(&oldprog->exts); + tcf_queue_work(&oldprog->rwork, cls_bpf_delete_prog_work); + } else { + list_add_rcu(&prog->link, &head->plist); + } + + *arg = prog; + return 0; + +errout_parms: + if (bound_to_filter) + tcf_unbind_filter(tp, &prog->res); + cls_bpf_free_parms(prog); +errout_idr: + if (!oldprog) + idr_remove(&head->handle_idr, prog->handle); +errout: + tcf_exts_destroy(&prog->exts); + 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) +{ + struct nlattr *nla; + + if (prog->bpf_name && + nla_put_string(skb, TCA_BPF_NAME, prog->bpf_name)) + return -EMSGSIZE; + + if (nla_put_u32(skb, TCA_BPF_ID, prog->filter->aux->id)) + return -EMSGSIZE; + + nla = nla_reserve(skb, TCA_BPF_TAG, sizeof(prog->filter->tag)); + if (nla == NULL) + return -EMSGSIZE; + + memcpy(nla_data(nla), prog->filter->tag, nla_len(nla)); + + return 0; +} + +static int cls_bpf_dump(struct net *net, struct tcf_proto *tp, void *fh, + struct sk_buff *skb, struct tcmsg *tm, bool rtnl_held) +{ + struct cls_bpf_prog *prog = fh; + struct nlattr *nest; + u32 bpf_flags = 0; + int ret; + + if (prog == NULL) + return skb->len; + + tm->tcm_handle = prog->handle; + + cls_bpf_offload_update_stats(tp, prog); + + nest = nla_nest_start_noflag(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; + if (prog->gen_flags && + nla_put_u32(skb, TCA_BPF_FLAGS_GEN, prog->gen_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_bind_class(void *fh, u32 classid, unsigned long cl, + void *q, unsigned long base) +{ + struct cls_bpf_prog *prog = fh; + + tc_cls_bind_class(classid, cl, q, &prog->res, base); +} + +static void cls_bpf_walk(struct tcf_proto *tp, struct tcf_walker *arg, + bool rtnl_held) +{ + struct cls_bpf_head *head = rtnl_dereference(tp->root); + struct cls_bpf_prog *prog; + + list_for_each_entry(prog, &head->plist, link) { + if (!tc_cls_stats_dump(tp, arg, prog)) + break; + } +} + +static int cls_bpf_reoffload(struct tcf_proto *tp, bool add, flow_setup_cb_t *cb, + void *cb_priv, struct netlink_ext_ack *extack) +{ + struct cls_bpf_head *head = rtnl_dereference(tp->root); + struct tcf_block *block = tp->chain->block; + struct tc_cls_bpf_offload cls_bpf = {}; + struct cls_bpf_prog *prog; + int err; + + list_for_each_entry(prog, &head->plist, link) { + if (tc_skip_hw(prog->gen_flags)) + continue; + + tc_cls_common_offload_init(&cls_bpf.common, tp, prog->gen_flags, + extack); + cls_bpf.command = TC_CLSBPF_OFFLOAD; + cls_bpf.exts = &prog->exts; + cls_bpf.prog = add ? prog->filter : NULL; + cls_bpf.oldprog = add ? NULL : prog->filter; + cls_bpf.name = prog->bpf_name; + cls_bpf.exts_integrated = prog->exts_integrated; + + err = tc_setup_cb_reoffload(block, tp, add, cb, TC_SETUP_CLSBPF, + &cls_bpf, cb_priv, &prog->gen_flags, + &prog->in_hw_count); + if (err) + return err; + } + + return 0; +} + +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, + .reoffload = cls_bpf_reoffload, + .dump = cls_bpf_dump, + .bind_class = cls_bpf_bind_class, +}; + +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); -- cgit v1.2.3