| /* |
| * Copyright (C) 2017-2018 Netronome Systems, Inc. |
| * |
| * This software is licensed under the GNU General License Version 2, |
| * June 1991 as shown in the file COPYING in the top-level directory of this |
| * source tree. |
| * |
| * THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" |
| * WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, |
| * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| * FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE |
| * OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME |
| * THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. |
| */ |
| |
| #include <linux/bpf.h> |
| #include <linux/bpf_verifier.h> |
| #include <linux/bug.h> |
| #include <linux/kdev_t.h> |
| #include <linux/list.h> |
| #include <linux/lockdep.h> |
| #include <linux/netdevice.h> |
| #include <linux/printk.h> |
| #include <linux/proc_ns.h> |
| #include <linux/rhashtable.h> |
| #include <linux/rtnetlink.h> |
| #include <linux/rwsem.h> |
| |
| /* Protects offdevs, members of bpf_offload_netdev and offload members |
| * of all progs. |
| * RTNL lock cannot be taken when holding this lock. |
| */ |
| static DECLARE_RWSEM(bpf_devs_lock); |
| |
| struct bpf_offload_dev { |
| struct list_head netdevs; |
| }; |
| |
| struct bpf_offload_netdev { |
| struct rhash_head l; |
| struct net_device *netdev; |
| struct bpf_offload_dev *offdev; |
| struct list_head progs; |
| struct list_head maps; |
| struct list_head offdev_netdevs; |
| }; |
| |
| static const struct rhashtable_params offdevs_params = { |
| .nelem_hint = 4, |
| .key_len = sizeof(struct net_device *), |
| .key_offset = offsetof(struct bpf_offload_netdev, netdev), |
| .head_offset = offsetof(struct bpf_offload_netdev, l), |
| .automatic_shrinking = true, |
| }; |
| |
| static struct rhashtable offdevs; |
| static bool offdevs_inited; |
| |
| static int bpf_dev_offload_check(struct net_device *netdev) |
| { |
| if (!netdev) |
| return -EINVAL; |
| if (!netdev->netdev_ops->ndo_bpf) |
| return -EOPNOTSUPP; |
| return 0; |
| } |
| |
| static struct bpf_offload_netdev * |
| bpf_offload_find_netdev(struct net_device *netdev) |
| { |
| lockdep_assert_held(&bpf_devs_lock); |
| |
| if (!offdevs_inited) |
| return NULL; |
| return rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params); |
| } |
| |
| int bpf_prog_offload_init(struct bpf_prog *prog, union bpf_attr *attr) |
| { |
| struct bpf_offload_netdev *ondev; |
| struct bpf_prog_offload *offload; |
| int err; |
| |
| if (attr->prog_type != BPF_PROG_TYPE_SCHED_CLS && |
| attr->prog_type != BPF_PROG_TYPE_XDP) |
| return -EINVAL; |
| |
| if (attr->prog_flags) |
| return -EINVAL; |
| |
| offload = kzalloc(sizeof(*offload), GFP_USER); |
| if (!offload) |
| return -ENOMEM; |
| |
| offload->prog = prog; |
| |
| offload->netdev = dev_get_by_index(current->nsproxy->net_ns, |
| attr->prog_ifindex); |
| err = bpf_dev_offload_check(offload->netdev); |
| if (err) |
| goto err_maybe_put; |
| |
| down_write(&bpf_devs_lock); |
| ondev = bpf_offload_find_netdev(offload->netdev); |
| if (!ondev) { |
| err = -EINVAL; |
| goto err_unlock; |
| } |
| prog->aux->offload = offload; |
| list_add_tail(&offload->offloads, &ondev->progs); |
| dev_put(offload->netdev); |
| up_write(&bpf_devs_lock); |
| |
| return 0; |
| err_unlock: |
| up_write(&bpf_devs_lock); |
| err_maybe_put: |
| if (offload->netdev) |
| dev_put(offload->netdev); |
| kfree(offload); |
| return err; |
| } |
| |
| static int __bpf_offload_ndo(struct bpf_prog *prog, enum bpf_netdev_command cmd, |
| struct netdev_bpf *data) |
| { |
| struct bpf_prog_offload *offload = prog->aux->offload; |
| struct net_device *netdev; |
| |
| ASSERT_RTNL(); |
| |
| if (!offload) |
| return -ENODEV; |
| netdev = offload->netdev; |
| |
| data->command = cmd; |
| |
| return netdev->netdev_ops->ndo_bpf(netdev, data); |
| } |
| |
| int bpf_prog_offload_verifier_prep(struct bpf_verifier_env *env) |
| { |
| struct netdev_bpf data = {}; |
| int err; |
| |
| data.verifier.prog = env->prog; |
| |
| rtnl_lock(); |
| err = __bpf_offload_ndo(env->prog, BPF_OFFLOAD_VERIFIER_PREP, &data); |
| if (err) |
| goto exit_unlock; |
| |
| env->prog->aux->offload->dev_ops = data.verifier.ops; |
| env->prog->aux->offload->dev_state = true; |
| exit_unlock: |
| rtnl_unlock(); |
| return err; |
| } |
| |
| int bpf_prog_offload_verify_insn(struct bpf_verifier_env *env, |
| int insn_idx, int prev_insn_idx) |
| { |
| struct bpf_prog_offload *offload; |
| int ret = -ENODEV; |
| |
| down_read(&bpf_devs_lock); |
| offload = env->prog->aux->offload; |
| if (offload) |
| ret = offload->dev_ops->insn_hook(env, insn_idx, prev_insn_idx); |
| up_read(&bpf_devs_lock); |
| |
| return ret; |
| } |
| |
| static void __bpf_prog_offload_destroy(struct bpf_prog *prog) |
| { |
| struct bpf_prog_offload *offload = prog->aux->offload; |
| struct netdev_bpf data = {}; |
| |
| data.offload.prog = prog; |
| |
| if (offload->dev_state) |
| WARN_ON(__bpf_offload_ndo(prog, BPF_OFFLOAD_DESTROY, &data)); |
| |
| /* Make sure BPF_PROG_GET_NEXT_ID can't find this dead program */ |
| bpf_prog_free_id(prog, true); |
| |
| list_del_init(&offload->offloads); |
| kfree(offload); |
| prog->aux->offload = NULL; |
| } |
| |
| void bpf_prog_offload_destroy(struct bpf_prog *prog) |
| { |
| rtnl_lock(); |
| down_write(&bpf_devs_lock); |
| if (prog->aux->offload) |
| __bpf_prog_offload_destroy(prog); |
| up_write(&bpf_devs_lock); |
| rtnl_unlock(); |
| } |
| |
| static int bpf_prog_offload_translate(struct bpf_prog *prog) |
| { |
| struct netdev_bpf data = {}; |
| int ret; |
| |
| data.offload.prog = prog; |
| |
| rtnl_lock(); |
| ret = __bpf_offload_ndo(prog, BPF_OFFLOAD_TRANSLATE, &data); |
| rtnl_unlock(); |
| |
| return ret; |
| } |
| |
| static unsigned int bpf_prog_warn_on_exec(const void *ctx, |
| const struct bpf_insn *insn) |
| { |
| WARN(1, "attempt to execute device eBPF program on the host!"); |
| return 0; |
| } |
| |
| int bpf_prog_offload_compile(struct bpf_prog *prog) |
| { |
| prog->bpf_func = bpf_prog_warn_on_exec; |
| |
| return bpf_prog_offload_translate(prog); |
| } |
| |
| struct ns_get_path_bpf_prog_args { |
| struct bpf_prog *prog; |
| struct bpf_prog_info *info; |
| }; |
| |
| static struct ns_common *bpf_prog_offload_info_fill_ns(void *private_data) |
| { |
| struct ns_get_path_bpf_prog_args *args = private_data; |
| struct bpf_prog_aux *aux = args->prog->aux; |
| struct ns_common *ns; |
| struct net *net; |
| |
| rtnl_lock(); |
| down_read(&bpf_devs_lock); |
| |
| if (aux->offload) { |
| args->info->ifindex = aux->offload->netdev->ifindex; |
| net = dev_net(aux->offload->netdev); |
| get_net(net); |
| ns = &net->ns; |
| } else { |
| args->info->ifindex = 0; |
| ns = NULL; |
| } |
| |
| up_read(&bpf_devs_lock); |
| rtnl_unlock(); |
| |
| return ns; |
| } |
| |
| int bpf_prog_offload_info_fill(struct bpf_prog_info *info, |
| struct bpf_prog *prog) |
| { |
| struct ns_get_path_bpf_prog_args args = { |
| .prog = prog, |
| .info = info, |
| }; |
| struct bpf_prog_aux *aux = prog->aux; |
| struct inode *ns_inode; |
| struct path ns_path; |
| char __user *uinsns; |
| void *res; |
| u32 ulen; |
| |
| res = ns_get_path_cb(&ns_path, bpf_prog_offload_info_fill_ns, &args); |
| if (IS_ERR(res)) { |
| if (!info->ifindex) |
| return -ENODEV; |
| return PTR_ERR(res); |
| } |
| |
| down_read(&bpf_devs_lock); |
| |
| if (!aux->offload) { |
| up_read(&bpf_devs_lock); |
| return -ENODEV; |
| } |
| |
| ulen = info->jited_prog_len; |
| info->jited_prog_len = aux->offload->jited_len; |
| if (info->jited_prog_len & ulen) { |
| uinsns = u64_to_user_ptr(info->jited_prog_insns); |
| ulen = min_t(u32, info->jited_prog_len, ulen); |
| if (copy_to_user(uinsns, aux->offload->jited_image, ulen)) { |
| up_read(&bpf_devs_lock); |
| return -EFAULT; |
| } |
| } |
| |
| up_read(&bpf_devs_lock); |
| |
| ns_inode = ns_path.dentry->d_inode; |
| info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev); |
| info->netns_ino = ns_inode->i_ino; |
| path_put(&ns_path); |
| |
| return 0; |
| } |
| |
| const struct bpf_prog_ops bpf_offload_prog_ops = { |
| }; |
| |
| static int bpf_map_offload_ndo(struct bpf_offloaded_map *offmap, |
| enum bpf_netdev_command cmd) |
| { |
| struct netdev_bpf data = {}; |
| struct net_device *netdev; |
| |
| ASSERT_RTNL(); |
| |
| data.command = cmd; |
| data.offmap = offmap; |
| /* Caller must make sure netdev is valid */ |
| netdev = offmap->netdev; |
| |
| return netdev->netdev_ops->ndo_bpf(netdev, &data); |
| } |
| |
| struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr) |
| { |
| struct net *net = current->nsproxy->net_ns; |
| struct bpf_offload_netdev *ondev; |
| struct bpf_offloaded_map *offmap; |
| int err; |
| |
| if (!capable(CAP_SYS_ADMIN)) |
| return ERR_PTR(-EPERM); |
| if (attr->map_type != BPF_MAP_TYPE_ARRAY && |
| attr->map_type != BPF_MAP_TYPE_HASH) |
| return ERR_PTR(-EINVAL); |
| |
| offmap = kzalloc(sizeof(*offmap), GFP_USER); |
| if (!offmap) |
| return ERR_PTR(-ENOMEM); |
| |
| bpf_map_init_from_attr(&offmap->map, attr); |
| |
| rtnl_lock(); |
| down_write(&bpf_devs_lock); |
| offmap->netdev = __dev_get_by_index(net, attr->map_ifindex); |
| err = bpf_dev_offload_check(offmap->netdev); |
| if (err) |
| goto err_unlock; |
| |
| ondev = bpf_offload_find_netdev(offmap->netdev); |
| if (!ondev) { |
| err = -EINVAL; |
| goto err_unlock; |
| } |
| |
| err = bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_ALLOC); |
| if (err) |
| goto err_unlock; |
| |
| list_add_tail(&offmap->offloads, &ondev->maps); |
| up_write(&bpf_devs_lock); |
| rtnl_unlock(); |
| |
| return &offmap->map; |
| |
| err_unlock: |
| up_write(&bpf_devs_lock); |
| rtnl_unlock(); |
| kfree(offmap); |
| return ERR_PTR(err); |
| } |
| |
| static void __bpf_map_offload_destroy(struct bpf_offloaded_map *offmap) |
| { |
| WARN_ON(bpf_map_offload_ndo(offmap, BPF_OFFLOAD_MAP_FREE)); |
| /* Make sure BPF_MAP_GET_NEXT_ID can't find this dead map */ |
| bpf_map_free_id(&offmap->map, true); |
| list_del_init(&offmap->offloads); |
| offmap->netdev = NULL; |
| } |
| |
| void bpf_map_offload_map_free(struct bpf_map *map) |
| { |
| struct bpf_offloaded_map *offmap = map_to_offmap(map); |
| |
| rtnl_lock(); |
| down_write(&bpf_devs_lock); |
| if (offmap->netdev) |
| __bpf_map_offload_destroy(offmap); |
| up_write(&bpf_devs_lock); |
| rtnl_unlock(); |
| |
| kfree(offmap); |
| } |
| |
| int bpf_map_offload_lookup_elem(struct bpf_map *map, void *key, void *value) |
| { |
| struct bpf_offloaded_map *offmap = map_to_offmap(map); |
| int ret = -ENODEV; |
| |
| down_read(&bpf_devs_lock); |
| if (offmap->netdev) |
| ret = offmap->dev_ops->map_lookup_elem(offmap, key, value); |
| up_read(&bpf_devs_lock); |
| |
| return ret; |
| } |
| |
| int bpf_map_offload_update_elem(struct bpf_map *map, |
| void *key, void *value, u64 flags) |
| { |
| struct bpf_offloaded_map *offmap = map_to_offmap(map); |
| int ret = -ENODEV; |
| |
| if (unlikely(flags > BPF_EXIST)) |
| return -EINVAL; |
| |
| down_read(&bpf_devs_lock); |
| if (offmap->netdev) |
| ret = offmap->dev_ops->map_update_elem(offmap, key, value, |
| flags); |
| up_read(&bpf_devs_lock); |
| |
| return ret; |
| } |
| |
| int bpf_map_offload_delete_elem(struct bpf_map *map, void *key) |
| { |
| struct bpf_offloaded_map *offmap = map_to_offmap(map); |
| int ret = -ENODEV; |
| |
| down_read(&bpf_devs_lock); |
| if (offmap->netdev) |
| ret = offmap->dev_ops->map_delete_elem(offmap, key); |
| up_read(&bpf_devs_lock); |
| |
| return ret; |
| } |
| |
| int bpf_map_offload_get_next_key(struct bpf_map *map, void *key, void *next_key) |
| { |
| struct bpf_offloaded_map *offmap = map_to_offmap(map); |
| int ret = -ENODEV; |
| |
| down_read(&bpf_devs_lock); |
| if (offmap->netdev) |
| ret = offmap->dev_ops->map_get_next_key(offmap, key, next_key); |
| up_read(&bpf_devs_lock); |
| |
| return ret; |
| } |
| |
| struct ns_get_path_bpf_map_args { |
| struct bpf_offloaded_map *offmap; |
| struct bpf_map_info *info; |
| }; |
| |
| static struct ns_common *bpf_map_offload_info_fill_ns(void *private_data) |
| { |
| struct ns_get_path_bpf_map_args *args = private_data; |
| struct ns_common *ns; |
| struct net *net; |
| |
| rtnl_lock(); |
| down_read(&bpf_devs_lock); |
| |
| if (args->offmap->netdev) { |
| args->info->ifindex = args->offmap->netdev->ifindex; |
| net = dev_net(args->offmap->netdev); |
| get_net(net); |
| ns = &net->ns; |
| } else { |
| args->info->ifindex = 0; |
| ns = NULL; |
| } |
| |
| up_read(&bpf_devs_lock); |
| rtnl_unlock(); |
| |
| return ns; |
| } |
| |
| int bpf_map_offload_info_fill(struct bpf_map_info *info, struct bpf_map *map) |
| { |
| struct ns_get_path_bpf_map_args args = { |
| .offmap = map_to_offmap(map), |
| .info = info, |
| }; |
| struct inode *ns_inode; |
| struct path ns_path; |
| void *res; |
| |
| res = ns_get_path_cb(&ns_path, bpf_map_offload_info_fill_ns, &args); |
| if (IS_ERR(res)) { |
| if (!info->ifindex) |
| return -ENODEV; |
| return PTR_ERR(res); |
| } |
| |
| ns_inode = ns_path.dentry->d_inode; |
| info->netns_dev = new_encode_dev(ns_inode->i_sb->s_dev); |
| info->netns_ino = ns_inode->i_ino; |
| path_put(&ns_path); |
| |
| return 0; |
| } |
| |
| static bool __bpf_offload_dev_match(struct bpf_prog *prog, |
| struct net_device *netdev) |
| { |
| struct bpf_offload_netdev *ondev1, *ondev2; |
| struct bpf_prog_offload *offload; |
| |
| if (!bpf_prog_is_dev_bound(prog->aux)) |
| return false; |
| |
| offload = prog->aux->offload; |
| if (!offload) |
| return false; |
| if (offload->netdev == netdev) |
| return true; |
| |
| ondev1 = bpf_offload_find_netdev(offload->netdev); |
| ondev2 = bpf_offload_find_netdev(netdev); |
| |
| return ondev1 && ondev2 && ondev1->offdev == ondev2->offdev; |
| } |
| |
| bool bpf_offload_dev_match(struct bpf_prog *prog, struct net_device *netdev) |
| { |
| bool ret; |
| |
| down_read(&bpf_devs_lock); |
| ret = __bpf_offload_dev_match(prog, netdev); |
| up_read(&bpf_devs_lock); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(bpf_offload_dev_match); |
| |
| bool bpf_offload_prog_map_match(struct bpf_prog *prog, struct bpf_map *map) |
| { |
| struct bpf_offloaded_map *offmap; |
| bool ret; |
| |
| if (!bpf_map_is_dev_bound(map)) |
| return bpf_map_offload_neutral(map); |
| offmap = map_to_offmap(map); |
| |
| down_read(&bpf_devs_lock); |
| ret = __bpf_offload_dev_match(prog, offmap->netdev); |
| up_read(&bpf_devs_lock); |
| |
| return ret; |
| } |
| |
| int bpf_offload_dev_netdev_register(struct bpf_offload_dev *offdev, |
| struct net_device *netdev) |
| { |
| struct bpf_offload_netdev *ondev; |
| int err; |
| |
| ondev = kzalloc(sizeof(*ondev), GFP_KERNEL); |
| if (!ondev) |
| return -ENOMEM; |
| |
| ondev->netdev = netdev; |
| ondev->offdev = offdev; |
| INIT_LIST_HEAD(&ondev->progs); |
| INIT_LIST_HEAD(&ondev->maps); |
| |
| down_write(&bpf_devs_lock); |
| err = rhashtable_insert_fast(&offdevs, &ondev->l, offdevs_params); |
| if (err) { |
| netdev_warn(netdev, "failed to register for BPF offload\n"); |
| goto err_unlock_free; |
| } |
| |
| list_add(&ondev->offdev_netdevs, &offdev->netdevs); |
| up_write(&bpf_devs_lock); |
| return 0; |
| |
| err_unlock_free: |
| up_write(&bpf_devs_lock); |
| kfree(ondev); |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_register); |
| |
| void bpf_offload_dev_netdev_unregister(struct bpf_offload_dev *offdev, |
| struct net_device *netdev) |
| { |
| struct bpf_offload_netdev *ondev, *altdev; |
| struct bpf_offloaded_map *offmap, *mtmp; |
| struct bpf_prog_offload *offload, *ptmp; |
| |
| ASSERT_RTNL(); |
| |
| down_write(&bpf_devs_lock); |
| ondev = rhashtable_lookup_fast(&offdevs, &netdev, offdevs_params); |
| if (WARN_ON(!ondev)) |
| goto unlock; |
| |
| WARN_ON(rhashtable_remove_fast(&offdevs, &ondev->l, offdevs_params)); |
| list_del(&ondev->offdev_netdevs); |
| |
| /* Try to move the objects to another netdev of the device */ |
| altdev = list_first_entry_or_null(&offdev->netdevs, |
| struct bpf_offload_netdev, |
| offdev_netdevs); |
| if (altdev) { |
| list_for_each_entry(offload, &ondev->progs, offloads) |
| offload->netdev = altdev->netdev; |
| list_splice_init(&ondev->progs, &altdev->progs); |
| |
| list_for_each_entry(offmap, &ondev->maps, offloads) |
| offmap->netdev = altdev->netdev; |
| list_splice_init(&ondev->maps, &altdev->maps); |
| } else { |
| list_for_each_entry_safe(offload, ptmp, &ondev->progs, offloads) |
| __bpf_prog_offload_destroy(offload->prog); |
| list_for_each_entry_safe(offmap, mtmp, &ondev->maps, offloads) |
| __bpf_map_offload_destroy(offmap); |
| } |
| |
| WARN_ON(!list_empty(&ondev->progs)); |
| WARN_ON(!list_empty(&ondev->maps)); |
| kfree(ondev); |
| unlock: |
| up_write(&bpf_devs_lock); |
| } |
| EXPORT_SYMBOL_GPL(bpf_offload_dev_netdev_unregister); |
| |
| struct bpf_offload_dev *bpf_offload_dev_create(void) |
| { |
| struct bpf_offload_dev *offdev; |
| int err; |
| |
| down_write(&bpf_devs_lock); |
| if (!offdevs_inited) { |
| err = rhashtable_init(&offdevs, &offdevs_params); |
| if (err) { |
| up_write(&bpf_devs_lock); |
| return ERR_PTR(err); |
| } |
| offdevs_inited = true; |
| } |
| up_write(&bpf_devs_lock); |
| |
| offdev = kzalloc(sizeof(*offdev), GFP_KERNEL); |
| if (!offdev) |
| return ERR_PTR(-ENOMEM); |
| |
| INIT_LIST_HEAD(&offdev->netdevs); |
| |
| return offdev; |
| } |
| EXPORT_SYMBOL_GPL(bpf_offload_dev_create); |
| |
| void bpf_offload_dev_destroy(struct bpf_offload_dev *offdev) |
| { |
| WARN_ON(!list_empty(&offdev->netdevs)); |
| kfree(offdev); |
| } |
| EXPORT_SYMBOL_GPL(bpf_offload_dev_destroy); |