| // SPDX-License-Identifier: GPL-2.0-only |
| /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com |
| */ |
| #include <linux/bpf.h> |
| #include <linux/rcupdate.h> |
| #include <linux/random.h> |
| #include <linux/smp.h> |
| #include <linux/topology.h> |
| #include <linux/ktime.h> |
| #include <linux/sched.h> |
| #include <linux/uidgid.h> |
| #include <linux/filter.h> |
| #include <linux/ctype.h> |
| |
| #include "../../lib/kstrtox.h" |
| |
| /* If kernel subsystem is allowing eBPF programs to call this function, |
| * inside its own verifier_ops->get_func_proto() callback it should return |
| * bpf_map_lookup_elem_proto, so that verifier can properly check the arguments |
| * |
| * Different map implementations will rely on rcu in map methods |
| * lookup/update/delete, therefore eBPF programs must run under rcu lock |
| * if program is allowed to access maps, so check rcu_read_lock_held in |
| * all three functions. |
| */ |
| BPF_CALL_2(bpf_map_lookup_elem, struct bpf_map *, map, void *, key) |
| { |
| WARN_ON_ONCE(!rcu_read_lock_held()); |
| return (unsigned long) map->ops->map_lookup_elem(map, key); |
| } |
| |
| const struct bpf_func_proto bpf_map_lookup_elem_proto = { |
| .func = bpf_map_lookup_elem, |
| .gpl_only = false, |
| .pkt_access = true, |
| .ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL, |
| .arg1_type = ARG_CONST_MAP_PTR, |
| .arg2_type = ARG_PTR_TO_MAP_KEY, |
| }; |
| |
| BPF_CALL_4(bpf_map_update_elem, struct bpf_map *, map, void *, key, |
| void *, value, u64, flags) |
| { |
| WARN_ON_ONCE(!rcu_read_lock_held()); |
| return map->ops->map_update_elem(map, key, value, flags); |
| } |
| |
| const struct bpf_func_proto bpf_map_update_elem_proto = { |
| .func = bpf_map_update_elem, |
| .gpl_only = false, |
| .pkt_access = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_CONST_MAP_PTR, |
| .arg2_type = ARG_PTR_TO_MAP_KEY, |
| .arg3_type = ARG_PTR_TO_MAP_VALUE, |
| .arg4_type = ARG_ANYTHING, |
| }; |
| |
| BPF_CALL_2(bpf_map_delete_elem, struct bpf_map *, map, void *, key) |
| { |
| WARN_ON_ONCE(!rcu_read_lock_held()); |
| return map->ops->map_delete_elem(map, key); |
| } |
| |
| const struct bpf_func_proto bpf_map_delete_elem_proto = { |
| .func = bpf_map_delete_elem, |
| .gpl_only = false, |
| .pkt_access = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_CONST_MAP_PTR, |
| .arg2_type = ARG_PTR_TO_MAP_KEY, |
| }; |
| |
| BPF_CALL_3(bpf_map_push_elem, struct bpf_map *, map, void *, value, u64, flags) |
| { |
| return map->ops->map_push_elem(map, value, flags); |
| } |
| |
| const struct bpf_func_proto bpf_map_push_elem_proto = { |
| .func = bpf_map_push_elem, |
| .gpl_only = false, |
| .pkt_access = true, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_CONST_MAP_PTR, |
| .arg2_type = ARG_PTR_TO_MAP_VALUE, |
| .arg3_type = ARG_ANYTHING, |
| }; |
| |
| BPF_CALL_2(bpf_map_pop_elem, struct bpf_map *, map, void *, value) |
| { |
| return map->ops->map_pop_elem(map, value); |
| } |
| |
| const struct bpf_func_proto bpf_map_pop_elem_proto = { |
| .func = bpf_map_pop_elem, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_CONST_MAP_PTR, |
| .arg2_type = ARG_PTR_TO_UNINIT_MAP_VALUE, |
| }; |
| |
| BPF_CALL_2(bpf_map_peek_elem, struct bpf_map *, map, void *, value) |
| { |
| return map->ops->map_peek_elem(map, value); |
| } |
| |
| const struct bpf_func_proto bpf_map_peek_elem_proto = { |
| .func = bpf_map_peek_elem, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_CONST_MAP_PTR, |
| .arg2_type = ARG_PTR_TO_UNINIT_MAP_VALUE, |
| }; |
| |
| const struct bpf_func_proto bpf_get_prandom_u32_proto = { |
| .func = bpf_user_rnd_u32, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| }; |
| |
| BPF_CALL_0(bpf_get_smp_processor_id) |
| { |
| return smp_processor_id(); |
| } |
| |
| const struct bpf_func_proto bpf_get_smp_processor_id_proto = { |
| .func = bpf_get_smp_processor_id, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| }; |
| |
| BPF_CALL_0(bpf_get_numa_node_id) |
| { |
| return numa_node_id(); |
| } |
| |
| const struct bpf_func_proto bpf_get_numa_node_id_proto = { |
| .func = bpf_get_numa_node_id, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| }; |
| |
| BPF_CALL_0(bpf_ktime_get_ns) |
| { |
| /* NMI safe access to clock monotonic */ |
| return ktime_get_mono_fast_ns(); |
| } |
| |
| const struct bpf_func_proto bpf_ktime_get_ns_proto = { |
| .func = bpf_ktime_get_ns, |
| .gpl_only = true, |
| .ret_type = RET_INTEGER, |
| }; |
| |
| BPF_CALL_0(bpf_get_current_pid_tgid) |
| { |
| struct task_struct *task = current; |
| |
| if (unlikely(!task)) |
| return -EINVAL; |
| |
| return (u64) task->tgid << 32 | task->pid; |
| } |
| |
| const struct bpf_func_proto bpf_get_current_pid_tgid_proto = { |
| .func = bpf_get_current_pid_tgid, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| }; |
| |
| BPF_CALL_0(bpf_get_current_uid_gid) |
| { |
| struct task_struct *task = current; |
| kuid_t uid; |
| kgid_t gid; |
| |
| if (unlikely(!task)) |
| return -EINVAL; |
| |
| current_uid_gid(&uid, &gid); |
| return (u64) from_kgid(&init_user_ns, gid) << 32 | |
| from_kuid(&init_user_ns, uid); |
| } |
| |
| const struct bpf_func_proto bpf_get_current_uid_gid_proto = { |
| .func = bpf_get_current_uid_gid, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| }; |
| |
| BPF_CALL_2(bpf_get_current_comm, char *, buf, u32, size) |
| { |
| struct task_struct *task = current; |
| |
| if (unlikely(!task)) |
| goto err_clear; |
| |
| strncpy(buf, task->comm, size); |
| |
| /* Verifier guarantees that size > 0. For task->comm exceeding |
| * size, guarantee that buf is %NUL-terminated. Unconditionally |
| * done here to save the size test. |
| */ |
| buf[size - 1] = 0; |
| return 0; |
| err_clear: |
| memset(buf, 0, size); |
| return -EINVAL; |
| } |
| |
| const struct bpf_func_proto bpf_get_current_comm_proto = { |
| .func = bpf_get_current_comm, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| .arg1_type = ARG_PTR_TO_UNINIT_MEM, |
| .arg2_type = ARG_CONST_SIZE, |
| }; |
| |
| #if defined(CONFIG_QUEUED_SPINLOCKS) || defined(CONFIG_BPF_ARCH_SPINLOCK) |
| |
| static inline void __bpf_spin_lock(struct bpf_spin_lock *lock) |
| { |
| arch_spinlock_t *l = (void *)lock; |
| union { |
| __u32 val; |
| arch_spinlock_t lock; |
| } u = { .lock = __ARCH_SPIN_LOCK_UNLOCKED }; |
| |
| compiletime_assert(u.val == 0, "__ARCH_SPIN_LOCK_UNLOCKED not 0"); |
| BUILD_BUG_ON(sizeof(*l) != sizeof(__u32)); |
| BUILD_BUG_ON(sizeof(*lock) != sizeof(__u32)); |
| arch_spin_lock(l); |
| } |
| |
| static inline void __bpf_spin_unlock(struct bpf_spin_lock *lock) |
| { |
| arch_spinlock_t *l = (void *)lock; |
| |
| arch_spin_unlock(l); |
| } |
| |
| #else |
| |
| static inline void __bpf_spin_lock(struct bpf_spin_lock *lock) |
| { |
| atomic_t *l = (void *)lock; |
| |
| BUILD_BUG_ON(sizeof(*l) != sizeof(*lock)); |
| do { |
| atomic_cond_read_relaxed(l, !VAL); |
| } while (atomic_xchg(l, 1)); |
| } |
| |
| static inline void __bpf_spin_unlock(struct bpf_spin_lock *lock) |
| { |
| atomic_t *l = (void *)lock; |
| |
| atomic_set_release(l, 0); |
| } |
| |
| #endif |
| |
| static DEFINE_PER_CPU(unsigned long, irqsave_flags); |
| |
| static inline void __bpf_spin_lock_irqsave(struct bpf_spin_lock *lock) |
| { |
| unsigned long flags; |
| |
| local_irq_save(flags); |
| __bpf_spin_lock(lock); |
| __this_cpu_write(irqsave_flags, flags); |
| } |
| |
| NOTRACE_BPF_CALL_1(bpf_spin_lock, struct bpf_spin_lock *, lock) |
| { |
| __bpf_spin_lock_irqsave(lock); |
| return 0; |
| } |
| |
| const struct bpf_func_proto bpf_spin_lock_proto = { |
| .func = bpf_spin_lock, |
| .gpl_only = false, |
| .ret_type = RET_VOID, |
| .arg1_type = ARG_PTR_TO_SPIN_LOCK, |
| }; |
| |
| static inline void __bpf_spin_unlock_irqrestore(struct bpf_spin_lock *lock) |
| { |
| unsigned long flags; |
| |
| flags = __this_cpu_read(irqsave_flags); |
| __bpf_spin_unlock(lock); |
| local_irq_restore(flags); |
| } |
| |
| NOTRACE_BPF_CALL_1(bpf_spin_unlock, struct bpf_spin_lock *, lock) |
| { |
| __bpf_spin_unlock_irqrestore(lock); |
| return 0; |
| } |
| |
| const struct bpf_func_proto bpf_spin_unlock_proto = { |
| .func = bpf_spin_unlock, |
| .gpl_only = false, |
| .ret_type = RET_VOID, |
| .arg1_type = ARG_PTR_TO_SPIN_LOCK, |
| }; |
| |
| void copy_map_value_locked(struct bpf_map *map, void *dst, void *src, |
| bool lock_src) |
| { |
| struct bpf_spin_lock *lock; |
| |
| if (lock_src) |
| lock = src + map->spin_lock_off; |
| else |
| lock = dst + map->spin_lock_off; |
| preempt_disable(); |
| __bpf_spin_lock_irqsave(lock); |
| copy_map_value(map, dst, src); |
| __bpf_spin_unlock_irqrestore(lock); |
| preempt_enable(); |
| } |
| |
| #ifdef CONFIG_CGROUPS |
| BPF_CALL_0(bpf_get_current_cgroup_id) |
| { |
| struct cgroup *cgrp = task_dfl_cgroup(current); |
| |
| return cgrp->kn->id.id; |
| } |
| |
| const struct bpf_func_proto bpf_get_current_cgroup_id_proto = { |
| .func = bpf_get_current_cgroup_id, |
| .gpl_only = false, |
| .ret_type = RET_INTEGER, |
| }; |
| |
| #ifdef CONFIG_CGROUP_BPF |
| DECLARE_PER_CPU(struct bpf_cgroup_storage*, |
| bpf_cgroup_storage[MAX_BPF_CGROUP_STORAGE_TYPE]); |
| |
| BPF_CALL_2(bpf_get_local_storage, struct bpf_map *, map, u64, flags) |
| { |
| /* flags argument is not used now, |
| * but provides an ability to extend the API. |
| * verifier checks that its value is correct. |
| */ |
| enum bpf_cgroup_storage_type stype = cgroup_storage_type(map); |
| struct bpf_cgroup_storage *storage; |
| void *ptr; |
| |
| storage = this_cpu_read(bpf_cgroup_storage[stype]); |
| |
| if (stype == BPF_CGROUP_STORAGE_SHARED) |
| ptr = &READ_ONCE(storage->buf)->data[0]; |
| else |
| ptr = this_cpu_ptr(storage->percpu_buf); |
| |
| return (unsigned long)ptr; |
| } |
| |
| const struct bpf_func_proto bpf_get_local_storage_proto = { |
| .func = bpf_get_local_storage, |
| .gpl_only = false, |
| .ret_type = RET_PTR_TO_MAP_VALUE, |
| .arg1_type = ARG_CONST_MAP_PTR, |
| .arg2_type = ARG_ANYTHING, |
| }; |
| #endif |
| |
| #define BPF_STRTOX_BASE_MASK 0x1F |
| |
| static int __bpf_strtoull(const char *buf, size_t buf_len, u64 flags, |
| unsigned long long *res, bool *is_negative) |
| { |
| 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 |