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195 lines
4.5 KiB
195 lines
4.5 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* Copyright (c) 2020 Facebook */ |
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#include <linux/bpf.h> |
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#include <linux/fs.h> |
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#include <linux/filter.h> |
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#include <linux/kernel.h> |
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#include <linux/btf_ids.h> |
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struct bpf_iter_seq_map_info { |
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u32 map_id; |
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}; |
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static void *bpf_map_seq_start(struct seq_file *seq, loff_t *pos) |
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{ |
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struct bpf_iter_seq_map_info *info = seq->private; |
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struct bpf_map *map; |
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map = bpf_map_get_curr_or_next(&info->map_id); |
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if (!map) |
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return NULL; |
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if (*pos == 0) |
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++*pos; |
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return map; |
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} |
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static void *bpf_map_seq_next(struct seq_file *seq, void *v, loff_t *pos) |
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{ |
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struct bpf_iter_seq_map_info *info = seq->private; |
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++*pos; |
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++info->map_id; |
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bpf_map_put((struct bpf_map *)v); |
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return bpf_map_get_curr_or_next(&info->map_id); |
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} |
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struct bpf_iter__bpf_map { |
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__bpf_md_ptr(struct bpf_iter_meta *, meta); |
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__bpf_md_ptr(struct bpf_map *, map); |
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}; |
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DEFINE_BPF_ITER_FUNC(bpf_map, struct bpf_iter_meta *meta, struct bpf_map *map) |
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static int __bpf_map_seq_show(struct seq_file *seq, void *v, bool in_stop) |
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{ |
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struct bpf_iter__bpf_map ctx; |
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struct bpf_iter_meta meta; |
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struct bpf_prog *prog; |
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int ret = 0; |
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ctx.meta = &meta; |
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ctx.map = v; |
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meta.seq = seq; |
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prog = bpf_iter_get_info(&meta, in_stop); |
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if (prog) |
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ret = bpf_iter_run_prog(prog, &ctx); |
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return ret; |
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} |
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static int bpf_map_seq_show(struct seq_file *seq, void *v) |
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{ |
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return __bpf_map_seq_show(seq, v, false); |
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} |
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static void bpf_map_seq_stop(struct seq_file *seq, void *v) |
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{ |
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if (!v) |
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(void)__bpf_map_seq_show(seq, v, true); |
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else |
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bpf_map_put((struct bpf_map *)v); |
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} |
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static const struct seq_operations bpf_map_seq_ops = { |
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.start = bpf_map_seq_start, |
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.next = bpf_map_seq_next, |
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.stop = bpf_map_seq_stop, |
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.show = bpf_map_seq_show, |
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}; |
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BTF_ID_LIST(btf_bpf_map_id) |
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BTF_ID(struct, bpf_map) |
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static const struct bpf_iter_seq_info bpf_map_seq_info = { |
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.seq_ops = &bpf_map_seq_ops, |
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.init_seq_private = NULL, |
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.fini_seq_private = NULL, |
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.seq_priv_size = sizeof(struct bpf_iter_seq_map_info), |
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}; |
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static struct bpf_iter_reg bpf_map_reg_info = { |
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.target = "bpf_map", |
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.ctx_arg_info_size = 1, |
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.ctx_arg_info = { |
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{ offsetof(struct bpf_iter__bpf_map, map), |
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PTR_TO_BTF_ID_OR_NULL }, |
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}, |
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.seq_info = &bpf_map_seq_info, |
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}; |
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static int bpf_iter_attach_map(struct bpf_prog *prog, |
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union bpf_iter_link_info *linfo, |
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struct bpf_iter_aux_info *aux) |
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{ |
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u32 key_acc_size, value_acc_size, key_size, value_size; |
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struct bpf_map *map; |
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bool is_percpu = false; |
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int err = -EINVAL; |
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if (!linfo->map.map_fd) |
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return -EBADF; |
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map = bpf_map_get_with_uref(linfo->map.map_fd); |
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if (IS_ERR(map)) |
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return PTR_ERR(map); |
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if (map->map_type == BPF_MAP_TYPE_PERCPU_HASH || |
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map->map_type == BPF_MAP_TYPE_LRU_PERCPU_HASH || |
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map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) |
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is_percpu = true; |
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else if (map->map_type != BPF_MAP_TYPE_HASH && |
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map->map_type != BPF_MAP_TYPE_LRU_HASH && |
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map->map_type != BPF_MAP_TYPE_ARRAY) |
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goto put_map; |
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key_acc_size = prog->aux->max_rdonly_access; |
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value_acc_size = prog->aux->max_rdwr_access; |
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key_size = map->key_size; |
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if (!is_percpu) |
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value_size = map->value_size; |
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else |
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value_size = round_up(map->value_size, 8) * num_possible_cpus(); |
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if (key_acc_size > key_size || value_acc_size > value_size) { |
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err = -EACCES; |
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goto put_map; |
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} |
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aux->map = map; |
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return 0; |
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put_map: |
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bpf_map_put_with_uref(map); |
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return err; |
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} |
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static void bpf_iter_detach_map(struct bpf_iter_aux_info *aux) |
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{ |
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bpf_map_put_with_uref(aux->map); |
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} |
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void bpf_iter_map_show_fdinfo(const struct bpf_iter_aux_info *aux, |
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struct seq_file *seq) |
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{ |
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seq_printf(seq, "map_id:\t%u\n", aux->map->id); |
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} |
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int bpf_iter_map_fill_link_info(const struct bpf_iter_aux_info *aux, |
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struct bpf_link_info *info) |
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{ |
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info->iter.map.map_id = aux->map->id; |
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return 0; |
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} |
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DEFINE_BPF_ITER_FUNC(bpf_map_elem, struct bpf_iter_meta *meta, |
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struct bpf_map *map, void *key, void *value) |
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static const struct bpf_iter_reg bpf_map_elem_reg_info = { |
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.target = "bpf_map_elem", |
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.attach_target = bpf_iter_attach_map, |
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.detach_target = bpf_iter_detach_map, |
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.show_fdinfo = bpf_iter_map_show_fdinfo, |
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.fill_link_info = bpf_iter_map_fill_link_info, |
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.ctx_arg_info_size = 2, |
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.ctx_arg_info = { |
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{ offsetof(struct bpf_iter__bpf_map_elem, key), |
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PTR_TO_RDONLY_BUF_OR_NULL }, |
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{ offsetof(struct bpf_iter__bpf_map_elem, value), |
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PTR_TO_RDWR_BUF_OR_NULL }, |
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}, |
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}; |
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static int __init bpf_map_iter_init(void) |
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{ |
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int ret; |
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bpf_map_reg_info.ctx_arg_info[0].btf_id = *btf_bpf_map_id; |
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ret = bpf_iter_reg_target(&bpf_map_reg_info); |
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if (ret) |
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return ret; |
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return bpf_iter_reg_target(&bpf_map_elem_reg_info); |
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} |
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late_initcall(bpf_map_iter_init);
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