547 lines
12 KiB
C
547 lines
12 KiB
C
// 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 <linux/jiffies.h>
|
|
#include <linux/pid_namespace.h>
|
|
#include <linux/proc_ns.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_pop_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);
|
|
|
|
notrace BPF_CALL_1(bpf_spin_lock, struct bpf_spin_lock *, lock)
|
|
{
|
|
unsigned long flags;
|
|
|
|
local_irq_save(flags);
|
|
__bpf_spin_lock(lock);
|
|
__this_cpu_write(irqsave_flags, flags);
|
|
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,
|
|
};
|
|
|
|
notrace BPF_CALL_1(bpf_spin_unlock, struct bpf_spin_lock *, lock)
|
|
{
|
|
unsigned long flags;
|
|
|
|
flags = __this_cpu_read(irqsave_flags);
|
|
__bpf_spin_unlock(lock);
|
|
local_irq_restore(flags);
|
|
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(lock);
|
|
copy_map_value(map, dst, src);
|
|
____bpf_spin_unlock(lock);
|
|
preempt_enable();
|
|
}
|
|
|
|
BPF_CALL_0(bpf_jiffies64)
|
|
{
|
|
return get_jiffies_64();
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_jiffies64_proto = {
|
|
.func = bpf_jiffies64,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
};
|
|
|
|
#ifdef CONFIG_CGROUPS
|
|
BPF_CALL_0(bpf_get_current_cgroup_id)
|
|
{
|
|
struct cgroup *cgrp = task_dfl_cgroup(current);
|
|
|
|
return cgroup_id(cgrp);
|
|
}
|
|
|
|
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
|
|
|
|
BPF_CALL_4(bpf_get_ns_current_pid_tgid, u64, dev, u64, ino,
|
|
struct bpf_pidns_info *, nsdata, u32, size)
|
|
{
|
|
struct task_struct *task = current;
|
|
struct pid_namespace *pidns;
|
|
int err = -EINVAL;
|
|
|
|
if (unlikely(size != sizeof(struct bpf_pidns_info)))
|
|
goto clear;
|
|
|
|
if (unlikely((u64)(dev_t)dev != dev))
|
|
goto clear;
|
|
|
|
if (unlikely(!task))
|
|
goto clear;
|
|
|
|
pidns = task_active_pid_ns(task);
|
|
if (unlikely(!pidns)) {
|
|
err = -ENOENT;
|
|
goto clear;
|
|
}
|
|
|
|
if (!ns_match(&pidns->ns, (dev_t)dev, ino))
|
|
goto clear;
|
|
|
|
nsdata->pid = task_pid_nr_ns(task, pidns);
|
|
nsdata->tgid = task_tgid_nr_ns(task, pidns);
|
|
return 0;
|
|
clear:
|
|
memset((void *)nsdata, 0, (size_t) size);
|
|
return err;
|
|
}
|
|
|
|
const struct bpf_func_proto bpf_get_ns_current_pid_tgid_proto = {
|
|
.func = bpf_get_ns_current_pid_tgid,
|
|
.gpl_only = false,
|
|
.ret_type = RET_INTEGER,
|
|
.arg1_type = ARG_ANYTHING,
|
|
.arg2_type = ARG_ANYTHING,
|
|
.arg3_type = ARG_PTR_TO_UNINIT_MEM,
|
|
.arg4_type = ARG_CONST_SIZE,
|
|
};
|