490 lines
11 KiB
C
490 lines
11 KiB
C
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// SPDX-License-Identifier: GPL-2.0-only
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/* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
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*/
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#include <linux/bpf.h>
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#include <linux/rcupdate.h>
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#include <linux/random.h>
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#include <linux/smp.h>
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#include <linux/topology.h>
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#include <linux/ktime.h>
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#include <linux/sched.h>
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#include <linux/uidgid.h>
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#include <linux/filter.h>
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#include <linux/ctype.h>
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#include "../../lib/kstrtox.h"
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/* If kernel subsystem is allowing eBPF programs to call this function,
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* inside its own verifier_ops->get_func_proto() callback it should return
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* bpf_map_lookup_elem_proto, so that verifier can properly check the arguments
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*
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* Different map implementations will rely on rcu in map methods
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* lookup/update/delete, therefore eBPF programs must run under rcu lock
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* if program is allowed to access maps, so check rcu_read_lock_held in
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* all three functions.
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*/
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BPF_CALL_2(bpf_map_lookup_elem, struct bpf_map *, map, void *, key)
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{
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WARN_ON_ONCE(!rcu_read_lock_held());
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return (unsigned long) map->ops->map_lookup_elem(map, key);
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}
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const struct bpf_func_proto bpf_map_lookup_elem_proto = {
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.func = bpf_map_lookup_elem,
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.gpl_only = false,
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.pkt_access = true,
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.ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
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.arg1_type = ARG_CONST_MAP_PTR,
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.arg2_type = ARG_PTR_TO_MAP_KEY,
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};
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BPF_CALL_4(bpf_map_update_elem, struct bpf_map *, map, void *, key,
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void *, value, u64, flags)
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{
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WARN_ON_ONCE(!rcu_read_lock_held());
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return map->ops->map_update_elem(map, key, value, flags);
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}
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const struct bpf_func_proto bpf_map_update_elem_proto = {
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.func = bpf_map_update_elem,
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.gpl_only = false,
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.pkt_access = true,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_CONST_MAP_PTR,
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.arg2_type = ARG_PTR_TO_MAP_KEY,
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.arg3_type = ARG_PTR_TO_MAP_VALUE,
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.arg4_type = ARG_ANYTHING,
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};
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BPF_CALL_2(bpf_map_delete_elem, struct bpf_map *, map, void *, key)
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{
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WARN_ON_ONCE(!rcu_read_lock_held());
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return map->ops->map_delete_elem(map, key);
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}
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const struct bpf_func_proto bpf_map_delete_elem_proto = {
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.func = bpf_map_delete_elem,
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.gpl_only = false,
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.pkt_access = true,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_CONST_MAP_PTR,
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.arg2_type = ARG_PTR_TO_MAP_KEY,
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};
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BPF_CALL_3(bpf_map_push_elem, struct bpf_map *, map, void *, value, u64, flags)
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{
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return map->ops->map_push_elem(map, value, flags);
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}
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const struct bpf_func_proto bpf_map_push_elem_proto = {
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.func = bpf_map_push_elem,
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.gpl_only = false,
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.pkt_access = true,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_CONST_MAP_PTR,
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.arg2_type = ARG_PTR_TO_MAP_VALUE,
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.arg3_type = ARG_ANYTHING,
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};
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BPF_CALL_2(bpf_map_pop_elem, struct bpf_map *, map, void *, value)
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{
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return map->ops->map_pop_elem(map, value);
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}
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const struct bpf_func_proto bpf_map_pop_elem_proto = {
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.func = bpf_map_pop_elem,
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.gpl_only = false,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_CONST_MAP_PTR,
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.arg2_type = ARG_PTR_TO_UNINIT_MAP_VALUE,
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};
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BPF_CALL_2(bpf_map_peek_elem, struct bpf_map *, map, void *, value)
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{
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return map->ops->map_peek_elem(map, value);
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}
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const struct bpf_func_proto bpf_map_peek_elem_proto = {
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.func = bpf_map_pop_elem,
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.gpl_only = false,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_CONST_MAP_PTR,
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.arg2_type = ARG_PTR_TO_UNINIT_MAP_VALUE,
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};
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const struct bpf_func_proto bpf_get_prandom_u32_proto = {
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.func = bpf_user_rnd_u32,
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.gpl_only = false,
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.ret_type = RET_INTEGER,
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};
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BPF_CALL_0(bpf_get_smp_processor_id)
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{
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return smp_processor_id();
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}
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const struct bpf_func_proto bpf_get_smp_processor_id_proto = {
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.func = bpf_get_smp_processor_id,
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.gpl_only = false,
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.ret_type = RET_INTEGER,
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};
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BPF_CALL_0(bpf_get_numa_node_id)
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{
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return numa_node_id();
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}
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const struct bpf_func_proto bpf_get_numa_node_id_proto = {
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.func = bpf_get_numa_node_id,
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.gpl_only = false,
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.ret_type = RET_INTEGER,
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};
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BPF_CALL_0(bpf_ktime_get_ns)
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{
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/* NMI safe access to clock monotonic */
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return ktime_get_mono_fast_ns();
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}
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const struct bpf_func_proto bpf_ktime_get_ns_proto = {
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.func = bpf_ktime_get_ns,
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.gpl_only = true,
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.ret_type = RET_INTEGER,
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};
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BPF_CALL_0(bpf_get_current_pid_tgid)
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{
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struct task_struct *task = current;
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if (unlikely(!task))
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return -EINVAL;
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return (u64) task->tgid << 32 | task->pid;
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}
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const struct bpf_func_proto bpf_get_current_pid_tgid_proto = {
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.func = bpf_get_current_pid_tgid,
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.gpl_only = false,
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.ret_type = RET_INTEGER,
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};
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BPF_CALL_0(bpf_get_current_uid_gid)
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{
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struct task_struct *task = current;
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kuid_t uid;
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kgid_t gid;
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if (unlikely(!task))
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return -EINVAL;
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current_uid_gid(&uid, &gid);
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return (u64) from_kgid(&init_user_ns, gid) << 32 |
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from_kuid(&init_user_ns, uid);
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}
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const struct bpf_func_proto bpf_get_current_uid_gid_proto = {
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.func = bpf_get_current_uid_gid,
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.gpl_only = false,
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.ret_type = RET_INTEGER,
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};
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BPF_CALL_2(bpf_get_current_comm, char *, buf, u32, size)
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{
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struct task_struct *task = current;
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if (unlikely(!task))
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goto err_clear;
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strncpy(buf, task->comm, size);
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/* Verifier guarantees that size > 0. For task->comm exceeding
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* size, guarantee that buf is %NUL-terminated. Unconditionally
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* done here to save the size test.
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*/
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buf[size - 1] = 0;
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return 0;
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err_clear:
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memset(buf, 0, size);
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return -EINVAL;
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}
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const struct bpf_func_proto bpf_get_current_comm_proto = {
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.func = bpf_get_current_comm,
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.gpl_only = false,
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.ret_type = RET_INTEGER,
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.arg1_type = ARG_PTR_TO_UNINIT_MEM,
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.arg2_type = ARG_CONST_SIZE,
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};
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#if defined(CONFIG_QUEUED_SPINLOCKS) || defined(CONFIG_BPF_ARCH_SPINLOCK)
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static inline void __bpf_spin_lock(struct bpf_spin_lock *lock)
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{
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arch_spinlock_t *l = (void *)lock;
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union {
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__u32 val;
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arch_spinlock_t lock;
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} u = { .lock = __ARCH_SPIN_LOCK_UNLOCKED };
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compiletime_assert(u.val == 0, "__ARCH_SPIN_LOCK_UNLOCKED not 0");
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BUILD_BUG_ON(sizeof(*l) != sizeof(__u32));
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BUILD_BUG_ON(sizeof(*lock) != sizeof(__u32));
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arch_spin_lock(l);
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}
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static inline void __bpf_spin_unlock(struct bpf_spin_lock *lock)
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{
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arch_spinlock_t *l = (void *)lock;
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arch_spin_unlock(l);
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}
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#else
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static inline void __bpf_spin_lock(struct bpf_spin_lock *lock)
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{
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atomic_t *l = (void *)lock;
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BUILD_BUG_ON(sizeof(*l) != sizeof(*lock));
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do {
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atomic_cond_read_relaxed(l, !VAL);
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} while (atomic_xchg(l, 1));
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}
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static inline void __bpf_spin_unlock(struct bpf_spin_lock *lock)
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{
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atomic_t *l = (void *)lock;
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atomic_set_release(l, 0);
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}
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#endif
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static DEFINE_PER_CPU(unsigned long, irqsave_flags);
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notrace BPF_CALL_1(bpf_spin_lock, struct bpf_spin_lock *, lock)
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{
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unsigned long flags;
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local_irq_save(flags);
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__bpf_spin_lock(lock);
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__this_cpu_write(irqsave_flags, flags);
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return 0;
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}
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const struct bpf_func_proto bpf_spin_lock_proto = {
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.func = bpf_spin_lock,
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.gpl_only = false,
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.ret_type = RET_VOID,
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.arg1_type = ARG_PTR_TO_SPIN_LOCK,
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};
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notrace BPF_CALL_1(bpf_spin_unlock, struct bpf_spin_lock *, lock)
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{
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unsigned long flags;
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flags = __this_cpu_read(irqsave_flags);
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__bpf_spin_unlock(lock);
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local_irq_restore(flags);
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return 0;
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}
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const struct bpf_func_proto bpf_spin_unlock_proto = {
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.func = bpf_spin_unlock,
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.gpl_only = false,
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.ret_type = RET_VOID,
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.arg1_type = ARG_PTR_TO_SPIN_LOCK,
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};
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void copy_map_value_locked(struct bpf_map *map, void *dst, void *src,
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bool lock_src)
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{
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struct bpf_spin_lock *lock;
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if (lock_src)
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lock = src + map->spin_lock_off;
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else
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lock = dst + map->spin_lock_off;
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preempt_disable();
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____bpf_spin_lock(lock);
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copy_map_value(map, dst, src);
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____bpf_spin_unlock(lock);
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preempt_enable();
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}
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#ifdef CONFIG_CGROUPS
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BPF_CALL_0(bpf_get_current_cgroup_id)
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{
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struct cgroup *cgrp = task_dfl_cgroup(current);
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return cgrp->kn->id.id;
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}
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const struct bpf_func_proto bpf_get_current_cgroup_id_proto = {
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.func = bpf_get_current_cgroup_id,
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.gpl_only = false,
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.ret_type = RET_INTEGER,
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};
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#ifdef CONFIG_CGROUP_BPF
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DECLARE_PER_CPU(struct bpf_cgroup_storage*,
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bpf_cgroup_storage[MAX_BPF_CGROUP_STORAGE_TYPE]);
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BPF_CALL_2(bpf_get_local_storage, struct bpf_map *, map, u64, flags)
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{
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/* flags argument is not used now,
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* but provides an ability to extend the API.
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* verifier checks that its value is correct.
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*/
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enum bpf_cgroup_storage_type stype = cgroup_storage_type(map);
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struct bpf_cgroup_storage *storage;
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void *ptr;
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storage = this_cpu_read(bpf_cgroup_storage[stype]);
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if (stype == BPF_CGROUP_STORAGE_SHARED)
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ptr = &READ_ONCE(storage->buf)->data[0];
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else
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ptr = this_cpu_ptr(storage->percpu_buf);
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return (unsigned long)ptr;
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}
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const struct bpf_func_proto bpf_get_local_storage_proto = {
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.func = bpf_get_local_storage,
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.gpl_only = false,
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.ret_type = RET_PTR_TO_MAP_VALUE,
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.arg1_type = ARG_CONST_MAP_PTR,
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.arg2_type = ARG_ANYTHING,
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};
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#endif
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#define BPF_STRTOX_BASE_MASK 0x1F
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static int __bpf_strtoull(const char *buf, size_t buf_len, u64 flags,
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unsigned long long *res, bool *is_negative)
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|
|
{
|
||
|
|
unsigned int base = flags & BPF_STRTOX_BASE_MASK;
|
||
|
|
const char *cur_buf = buf;
|
||
|
|
size_t cur_len = buf_len;
|
||
|
|
unsigned int consumed;
|
||
|
|
size_t val_len;
|
||
|
|
char str[64];
|
||
|
|
|
||
|
|
if (!buf || !buf_len || !res || !is_negative)
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
if (base != 0 && base != 8 && base != 10 && base != 16)
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
if (flags & ~BPF_STRTOX_BASE_MASK)
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
while (cur_buf < buf + buf_len && isspace(*cur_buf))
|
||
|
|
++cur_buf;
|
||
|
|
|
||
|
|
*is_negative = (cur_buf < buf + buf_len && *cur_buf == '-');
|
||
|
|
if (*is_negative)
|
||
|
|
++cur_buf;
|
||
|
|
|
||
|
|
consumed = cur_buf - buf;
|
||
|
|
cur_len -= consumed;
|
||
|
|
if (!cur_len)
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
cur_len = min(cur_len, sizeof(str) - 1);
|
||
|
|
memcpy(str, cur_buf, cur_len);
|
||
|
|
str[cur_len] = '\0';
|
||
|
|
cur_buf = str;
|
||
|
|
|
||
|
|
cur_buf = _parse_integer_fixup_radix(cur_buf, &base);
|
||
|
|
val_len = _parse_integer(cur_buf, base, res);
|
||
|
|
|
||
|
|
if (val_len & KSTRTOX_OVERFLOW)
|
||
|
|
return -ERANGE;
|
||
|
|
|
||
|
|
if (val_len == 0)
|
||
|
|
return -EINVAL;
|
||
|
|
|
||
|
|
cur_buf += val_len;
|
||
|
|
consumed += cur_buf - str;
|
||
|
|
|
||
|
|
return consumed;
|
||
|
|
}
|
||
|
|
|
||
|
|
static int __bpf_strtoll(const char *buf, size_t buf_len, u64 flags,
|
||
|
|
long long *res)
|
||
|
|
{
|
||
|
|
unsigned long long _res;
|
||
|
|
bool is_negative;
|
||
|
|
int err;
|
||
|
|
|
||
|
|
err = __bpf_strtoull(buf, buf_len, flags, &_res, &is_negative);
|
||
|
|
if (err < 0)
|
||
|
|
return err;
|
||
|
|
if (is_negative) {
|
||
|
|
if ((long long)-_res > 0)
|
||
|
|
return -ERANGE;
|
||
|
|
*res = -_res;
|
||
|
|
} else {
|
||
|
|
if ((long long)_res < 0)
|
||
|
|
return -ERANGE;
|
||
|
|
*res = _res;
|
||
|
|
}
|
||
|
|
return err;
|
||
|
|
}
|
||
|
|
|
||
|
|
BPF_CALL_4(bpf_strtol, const char *, buf, size_t, buf_len, u64, flags,
|
||
|
|
long *, res)
|
||
|
|
{
|
||
|
|
long long _res;
|
||
|
|
int err;
|
||
|
|
|
||
|
|
err = __bpf_strtoll(buf, buf_len, flags, &_res);
|
||
|
|
if (err < 0)
|
||
|
|
return err;
|
||
|
|
if (_res != (long)_res)
|
||
|
|
return -ERANGE;
|
||
|
|
*res = _res;
|
||
|
|
return err;
|
||
|
|
}
|
||
|
|
|
||
|
|
const struct bpf_func_proto bpf_strtol_proto = {
|
||
|
|
.func = bpf_strtol,
|
||
|
|
.gpl_only = false,
|
||
|
|
.ret_type = RET_INTEGER,
|
||
|
|
.arg1_type = ARG_PTR_TO_MEM,
|
||
|
|
.arg2_type = ARG_CONST_SIZE,
|
||
|
|
.arg3_type = ARG_ANYTHING,
|
||
|
|
.arg4_type = ARG_PTR_TO_LONG,
|
||
|
|
};
|
||
|
|
|
||
|
|
BPF_CALL_4(bpf_strtoul, const char *, buf, size_t, buf_len, u64, flags,
|
||
|
|
unsigned long *, res)
|
||
|
|
{
|
||
|
|
unsigned long long _res;
|
||
|
|
bool is_negative;
|
||
|
|
int err;
|
||
|
|
|
||
|
|
err = __bpf_strtoull(buf, buf_len, flags, &_res, &is_negative);
|
||
|
|
if (err < 0)
|
||
|
|
return err;
|
||
|
|
if (is_negative)
|
||
|
|
return -EINVAL;
|
||
|
|
if (_res != (unsigned long)_res)
|
||
|
|
return -ERANGE;
|
||
|
|
*res = _res;
|
||
|
|
return err;
|
||
|
|
}
|
||
|
|
|
||
|
|
const struct bpf_func_proto bpf_strtoul_proto = {
|
||
|
|
.func = bpf_strtoul,
|
||
|
|
.gpl_only = false,
|
||
|
|
.ret_type = RET_INTEGER,
|
||
|
|
.arg1_type = ARG_PTR_TO_MEM,
|
||
|
|
.arg2_type = ARG_CONST_SIZE,
|
||
|
|
.arg3_type = ARG_ANYTHING,
|
||
|
|
.arg4_type = ARG_PTR_TO_LONG,
|
||
|
|
};
|
||
|
|
#endif
|