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xbpf.c
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xbpf.c
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typedef int bool;
#define true 1;
#define false 0;
#include <stdio.h>
#include <uk/netdev_core.h>
#include <string.h>
#include <stdlib.h>
//#include <stdbool.h>
#include <stdarg.h>
#include <inttypes.h>
//#include <sys/mman.h>
#include "ubpf_int.h"
#include "endian.h"
#include <unistd.h>
#include <errno.h>
#include "ubpf.h"
#include "uthash.h"
#include "xbpf.h"
#include "bpf-binary.h"
#define MAX_EXT_FUNCS 64
static bool validate(const struct ubpf_vm *vm, const struct ebpf_inst *insts, uint32_t num_insts, char **errmsg);
static bool bounds_check(void *addr, int size, const char *type, uint16_t cur_pc, void *mem, size_t mem_len, void *stack);
struct ubpf_vm *ebpf_vm = 0x0;
/*
*/
typedef struct {
uint16_t eth_type;
uint16_t proto;
} key_t;
typedef struct {
key_t key;
int value;
UT_hash_handle hh;
} el_t;
enum bpf_map_type {
BPF_MAP_TYPE_UNSPEC,
BPF_MAP_TYPE_HASH,
BPF_MAP_TYPE_ARRAY,
BPF_MAP_TYPE_PROG_ARRAY,
BPF_MAP_TYPE_PERF_EVENT_ARRAY,
BPF_MAP_TYPE_PERCPU_HASH,
BPF_MAP_TYPE_PERCPU_ARRAY,
BPF_MAP_TYPE_STACK_TRACE,
BPF_MAP_TYPE_CGROUP_ARRAY,
BPF_MAP_TYPE_LRU_HASH,
BPF_MAP_TYPE_LRU_PERCPU_HASH,
};
struct xbpf_map {
enum bpf_map_type type;
unsigned int key_size;
unsigned int value_size;
unsigned int max_entries;
unsigned int map_flags;
el_t * el;
};
/*
*/
struct xbpf_map xbpf_map = {0};
void *xbpf_map_lookup_elem(struct xbpf_map *map, const void *key);
int xbpf_map_update_elem(struct xbpf_map *map, const void *key, const void *value, uint64_t flags);
struct ubpf_vm *
ubpf_create(void)
{
struct ubpf_vm *vm = calloc(1, sizeof(*vm));
if (vm == NULL) {
return NULL;
}
vm->ext_funcs = calloc(MAX_EXT_FUNCS, sizeof(*vm->ext_funcs));
if (vm->ext_funcs == NULL) {
ubpf_destroy(vm);
return NULL;
}
vm->ext_func_names = calloc(MAX_EXT_FUNCS, sizeof(*vm->ext_func_names));
if (vm->ext_func_names == NULL) {
ubpf_destroy(vm);
return NULL;
}
return vm;
}
void
ubpf_destroy(struct ubpf_vm *vm)
{
/*
if (vm->jitted) {
munmap(vm->jitted, vm->jitted_size);
}
*/
free(vm->insts);
free(vm->ext_funcs);
free(vm->ext_func_names);
free(vm);
}
int
ubpf_register(struct ubpf_vm *vm, unsigned int idx, const char *name, void *fn)
{
if (idx >= MAX_EXT_FUNCS) {
return -1;
}
vm->ext_funcs[idx] = (ext_func)fn;
vm->ext_func_names[idx] = name;
return 0;
}
unsigned int
ubpf_lookup_registered_function(struct ubpf_vm *vm, const char *name)
{
int i;
for (i = 0; i < MAX_EXT_FUNCS; i++) {
const char *other = vm->ext_func_names[i];
if (other && !strcmp(other, name)) {
return i;
}
}
return -1;
}
int
ubpf_load(struct ubpf_vm *vm, const void *code, uint32_t code_len, char **errmsg)
{
*errmsg = NULL;
if (vm->insts) {
*errmsg = ubpf_error("code has already been loaded into this VM");
return -1;
}
if (code_len % 8 != 0) {
*errmsg = ubpf_error("code_len must be a multiple of 8");
return -1;
}
if (!validate(vm, code, code_len/8, errmsg)) {
return -1;
}
vm->insts = malloc(code_len);
if (vm->insts == NULL) {
*errmsg = ubpf_error("out of memory");
return -1;
}
memcpy(vm->insts, code, code_len);
vm->num_insts = code_len/sizeof(vm->insts[0]);
return 0;
}
static uint32_t
u32(uint64_t x)
{
return x;
}
uint64_t
ubpf_exec(const struct ubpf_vm *vm, void *mem, size_t mem_len)
{
uint16_t pc = 0;
const struct ebpf_inst *insts = vm->insts;
uint64_t reg[16];
uint64_t stack[(STACK_SIZE+7)/8];
if (!insts) {
/* Code must be loaded before we can execute */
return UINT64_MAX-1;
}
reg[1] = (uintptr_t)mem;
reg[10] = (uintptr_t)stack + sizeof(stack);
while (1) {
const uint16_t cur_pc = pc;
struct ebpf_inst inst = insts[pc++];
switch (inst.opcode) {
case EBPF_OP_ADD_IMM:
reg[inst.dst] += inst.imm;
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_ADD_REG:
reg[inst.dst] += reg[inst.src];
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_SUB_IMM:
reg[inst.dst] -= inst.imm;
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_SUB_REG:
reg[inst.dst] -= reg[inst.src];
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_MUL_IMM:
reg[inst.dst] *= inst.imm;
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_MUL_REG:
reg[inst.dst] *= reg[inst.src];
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_DIV_IMM:
reg[inst.dst] = u32(reg[inst.dst]) / u32(inst.imm);
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_DIV_REG:
if (reg[inst.src] == 0) {
fprintf(stderr, "uBPF error: division by zero at PC %u\n", cur_pc);
return UINT64_MAX-2;
}
reg[inst.dst] = u32(reg[inst.dst]) / u32(reg[inst.src]);
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_OR_IMM:
reg[inst.dst] |= inst.imm;
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_OR_REG:
reg[inst.dst] |= reg[inst.src];
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_AND_IMM:
reg[inst.dst] &= inst.imm;
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_AND_REG:
reg[inst.dst] &= reg[inst.src];
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_LSH_IMM:
reg[inst.dst] <<= inst.imm;
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_LSH_REG:
reg[inst.dst] <<= reg[inst.src];
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_RSH_IMM:
reg[inst.dst] = u32(reg[inst.dst]) >> inst.imm;
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_RSH_REG:
reg[inst.dst] = u32(reg[inst.dst]) >> reg[inst.src];
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_NEG:
reg[inst.dst] = -reg[inst.dst];
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_MOD_IMM:
reg[inst.dst] = u32(reg[inst.dst]) % u32(inst.imm);
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_MOD_REG:
if (reg[inst.src] == 0) {
fprintf(stderr, "uBPF error: division by zero at PC %u\n", cur_pc);
return UINT64_MAX-3;
}
reg[inst.dst] = u32(reg[inst.dst]) % u32(reg[inst.src]);
break;
case EBPF_OP_XOR_IMM:
reg[inst.dst] ^= inst.imm;
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_XOR_REG:
reg[inst.dst] ^= reg[inst.src];
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_MOV_IMM:
reg[inst.dst] = inst.imm;
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_MOV_REG:
reg[inst.dst] = reg[inst.src];
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_ARSH_IMM:
reg[inst.dst] = (int32_t)reg[inst.dst] >> inst.imm;
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_ARSH_REG:
reg[inst.dst] = (int32_t)reg[inst.dst] >> u32(reg[inst.src]);
reg[inst.dst] &= UINT32_MAX;
break;
case EBPF_OP_LE:
if (inst.imm == 16) {
reg[inst.dst] = htole16(reg[inst.dst]);
} else if (inst.imm == 32) {
reg[inst.dst] = htole32(reg[inst.dst]);
} else if (inst.imm == 64) {
reg[inst.dst] = htole64(reg[inst.dst]);
}
break;
case EBPF_OP_BE:
if (inst.imm == 16) {
reg[inst.dst] = htobe16(reg[inst.dst]);
} else if (inst.imm == 32) {
reg[inst.dst] = htobe32(reg[inst.dst]);
} else if (inst.imm == 64) {
reg[inst.dst] = htobe64(reg[inst.dst]);
}
break;
case EBPF_OP_ADD64_IMM:
reg[inst.dst] += inst.imm;
break;
case EBPF_OP_ADD64_REG:
reg[inst.dst] += reg[inst.src];
break;
case EBPF_OP_SUB64_IMM:
reg[inst.dst] -= inst.imm;
break;
case EBPF_OP_SUB64_REG:
reg[inst.dst] -= reg[inst.src];
break;
case EBPF_OP_MUL64_IMM:
reg[inst.dst] *= inst.imm;
break;
case EBPF_OP_MUL64_REG:
reg[inst.dst] *= reg[inst.src];
break;
case EBPF_OP_DIV64_IMM:
reg[inst.dst] /= inst.imm;
break;
case EBPF_OP_DIV64_REG:
if (reg[inst.src] == 0) {
fprintf(stderr, "uBPF error: division by zero at PC %u\n", cur_pc);
return UINT64_MAX-4;
}
reg[inst.dst] /= reg[inst.src];
break;
case EBPF_OP_OR64_IMM:
reg[inst.dst] |= inst.imm;
break;
case EBPF_OP_OR64_REG:
reg[inst.dst] |= reg[inst.src];
break;
case EBPF_OP_AND64_IMM:
reg[inst.dst] &= inst.imm;
break;
case EBPF_OP_AND64_REG:
reg[inst.dst] &= reg[inst.src];
break;
case EBPF_OP_LSH64_IMM:
reg[inst.dst] <<= inst.imm;
break;
case EBPF_OP_LSH64_REG:
reg[inst.dst] <<= reg[inst.src];
break;
case EBPF_OP_RSH64_IMM:
reg[inst.dst] >>= inst.imm;
break;
case EBPF_OP_RSH64_REG:
reg[inst.dst] >>= reg[inst.src];
break;
case EBPF_OP_NEG64:
reg[inst.dst] = -reg[inst.dst];
break;
case EBPF_OP_MOD64_IMM:
reg[inst.dst] %= inst.imm;
break;
case EBPF_OP_MOD64_REG:
if (reg[inst.src] == 0) {
fprintf(stderr, "uBPF error: division by zero at PC %u\n", cur_pc);
return UINT64_MAX-5;
}
reg[inst.dst] %= reg[inst.src];
break;
case EBPF_OP_XOR64_IMM:
reg[inst.dst] ^= inst.imm;
break;
case EBPF_OP_XOR64_REG:
reg[inst.dst] ^= reg[inst.src];
break;
case EBPF_OP_MOV64_IMM:
reg[inst.dst] = inst.imm;
break;
case EBPF_OP_MOV64_REG:
reg[inst.dst] = reg[inst.src];
break;
case EBPF_OP_ARSH64_IMM:
reg[inst.dst] = (int64_t)reg[inst.dst] >> inst.imm;
break;
case EBPF_OP_ARSH64_REG:
reg[inst.dst] = (int64_t)reg[inst.dst] >> reg[inst.src];
break;
/*
* HACK runtime bounds check
*
* Needed since we don't have a verifier yet.
*/
#define BOUNDS_CHECK_LOAD(size) \
do { \
if (!bounds_check((void *)reg[inst.src] + inst.offset, size, "load", cur_pc, mem, mem_len, stack)) { \
return UINT64_MAX-6; \
} \
} while (0)
#define BOUNDS_CHECK_STORE(size) \
do { \
if (!bounds_check((void *)reg[inst.dst] + inst.offset, size, "store", cur_pc, mem, mem_len, stack)) { \
return UINT64_MAX-7; \
} \
} while (0)
case EBPF_OP_LDXW:
BOUNDS_CHECK_LOAD(4);
reg[inst.dst] = *(uint32_t *)(uintptr_t)(reg[inst.src] + inst.offset);
break;
case EBPF_OP_LDXH:
BOUNDS_CHECK_LOAD(2);
reg[inst.dst] = *(uint16_t *)(uintptr_t)(reg[inst.src] + inst.offset);
break;
case EBPF_OP_LDXB:
BOUNDS_CHECK_LOAD(1);
reg[inst.dst] = *(uint8_t *)(uintptr_t)(reg[inst.src] + inst.offset);
break;
case EBPF_OP_LDXDW:
BOUNDS_CHECK_LOAD(8);
reg[inst.dst] = *(uint64_t *)(uintptr_t)(reg[inst.src] + inst.offset);
break;
case EBPF_OP_STW:
BOUNDS_CHECK_STORE(4);
*(uint32_t *)(uintptr_t)(reg[inst.dst] + inst.offset) = inst.imm;
break;
case EBPF_OP_STH:
BOUNDS_CHECK_STORE(2);
*(uint16_t *)(uintptr_t)(reg[inst.dst] + inst.offset) = inst.imm;
break;
case EBPF_OP_STB:
BOUNDS_CHECK_STORE(1);
*(uint8_t *)(uintptr_t)(reg[inst.dst] + inst.offset) = inst.imm;
break;
case EBPF_OP_STDW:
BOUNDS_CHECK_STORE(8);
*(uint64_t *)(uintptr_t)(reg[inst.dst] + inst.offset) = inst.imm;
break;
case EBPF_OP_STXW:
BOUNDS_CHECK_STORE(4);
*(uint32_t *)(uintptr_t)(reg[inst.dst] + inst.offset) = reg[inst.src];
break;
case EBPF_OP_STXH:
BOUNDS_CHECK_STORE(2);
*(uint16_t *)(uintptr_t)(reg[inst.dst] + inst.offset) = reg[inst.src];
break;
case EBPF_OP_STXB:
BOUNDS_CHECK_STORE(1);
*(uint8_t *)(uintptr_t)(reg[inst.dst] + inst.offset) = reg[inst.src];
break;
case EBPF_OP_STXDW:
BOUNDS_CHECK_STORE(8);
*(uint64_t *)(uintptr_t)(reg[inst.dst] + inst.offset) = reg[inst.src];
break;
case EBPF_OP_LDDW:
reg[inst.dst] = (uint32_t)inst.imm | ((uint64_t)insts[pc++].imm << 32);
break;
case EBPF_OP_JA:
pc += inst.offset;
break;
case EBPF_OP_JEQ_IMM:
if (reg[inst.dst] == inst.imm) {
pc += inst.offset;
}
break;
case EBPF_OP_JEQ_REG:
if (reg[inst.dst] == reg[inst.src]) {
pc += inst.offset;
}
break;
case EBPF_OP_JGT_IMM:
if (reg[inst.dst] > (uint32_t)inst.imm) {
pc += inst.offset;
}
break;
case EBPF_OP_JGT_REG:
if (reg[inst.dst] > reg[inst.src]) {
pc += inst.offset;
}
break;
case EBPF_OP_JGE_IMM:
if (reg[inst.dst] >= (uint32_t)inst.imm) {
pc += inst.offset;
}
break;
case EBPF_OP_JGE_REG:
if (reg[inst.dst] >= reg[inst.src]) {
pc += inst.offset;
}
break;
case EBPF_OP_JLT_IMM:
if (reg[inst.dst] < (uint32_t)inst.imm) {
pc += inst.offset;
}
break;
case EBPF_OP_JLT_REG:
if (reg[inst.dst] < reg[inst.src]) {
pc += inst.offset;
}
break;
case EBPF_OP_JLE_IMM:
if (reg[inst.dst] <= (uint32_t)inst.imm) {
pc += inst.offset;
}
break;
case EBPF_OP_JLE_REG:
if (reg[inst.dst] <= reg[inst.src]) {
pc += inst.offset;
}
break;
case EBPF_OP_JSET_IMM:
if (reg[inst.dst] & inst.imm) {
pc += inst.offset;
}
break;
case EBPF_OP_JSET_REG:
if (reg[inst.dst] & reg[inst.src]) {
pc += inst.offset;
}
break;
case EBPF_OP_JNE_IMM:
if (reg[inst.dst] != inst.imm) {
pc += inst.offset;
}
break;
case EBPF_OP_JNE_REG:
if (reg[inst.dst] != reg[inst.src]) {
pc += inst.offset;
}
break;
case EBPF_OP_JSGT_IMM:
if ((int64_t)reg[inst.dst] > inst.imm) {
pc += inst.offset;
}
break;
case EBPF_OP_JSGT_REG:
if ((int64_t)reg[inst.dst] > (int64_t)reg[inst.src]) {
pc += inst.offset;
}
break;
case EBPF_OP_JSGE_IMM:
if ((int64_t)reg[inst.dst] >= inst.imm) {
pc += inst.offset;
}
break;
case EBPF_OP_JSGE_REG:
if ((int64_t)reg[inst.dst] >= (int64_t)reg[inst.src]) {
pc += inst.offset;
}
break;
case EBPF_OP_JSLT_IMM:
if ((int64_t)reg[inst.dst] < inst.imm) {
pc += inst.offset;
}
break;
case EBPF_OP_JSLT_REG:
if ((int64_t)reg[inst.dst] < (int64_t)reg[inst.src]) {
pc += inst.offset;
}
break;
case EBPF_OP_JSLE_IMM:
if ((int64_t)reg[inst.dst] <= inst.imm) {
pc += inst.offset;
}
break;
case EBPF_OP_JSLE_REG:
if ((int64_t)reg[inst.dst] <= (int64_t)reg[inst.src]) {
pc += inst.offset;
}
break;
case EBPF_OP_EXIT:
return reg[0];
case EBPF_OP_CALL:
reg[0] = vm->ext_funcs[inst.imm](reg[1], reg[2], reg[3], reg[4], reg[5]);
break;
}
}
}
static bool
validate(const struct ubpf_vm *vm, const struct ebpf_inst *insts, uint32_t num_insts, char **errmsg)
{
if (num_insts >= MAX_INSTS) {
*errmsg = ubpf_error("too many instructions (max %u)", MAX_INSTS);
return false;
}
if (num_insts == 0 || insts[num_insts-1].opcode != EBPF_OP_EXIT) {
*errmsg = ubpf_error("no exit at end of instructions");
return false;
}
int i;
for (i = 0; i < num_insts; i++) {
struct ebpf_inst inst = insts[i];
bool store = false;
switch (inst.opcode) {
case EBPF_OP_ADD_IMM:
case EBPF_OP_ADD_REG:
case EBPF_OP_SUB_IMM:
case EBPF_OP_SUB_REG:
case EBPF_OP_MUL_IMM:
case EBPF_OP_MUL_REG:
case EBPF_OP_DIV_REG:
case EBPF_OP_OR_IMM:
case EBPF_OP_OR_REG:
case EBPF_OP_AND_IMM:
case EBPF_OP_AND_REG:
case EBPF_OP_LSH_IMM:
case EBPF_OP_LSH_REG:
case EBPF_OP_RSH_IMM:
case EBPF_OP_RSH_REG:
case EBPF_OP_NEG:
case EBPF_OP_MOD_REG:
case EBPF_OP_XOR_IMM:
case EBPF_OP_XOR_REG:
case EBPF_OP_MOV_IMM:
case EBPF_OP_MOV_REG:
case EBPF_OP_ARSH_IMM:
case EBPF_OP_ARSH_REG:
break;
case EBPF_OP_LE:
case EBPF_OP_BE:
if (inst.imm != 16 && inst.imm != 32 && inst.imm != 64) {
*errmsg = ubpf_error("invalid endian immediate at PC %d", i);
return false;
}
break;
case EBPF_OP_ADD64_IMM:
case EBPF_OP_ADD64_REG:
case EBPF_OP_SUB64_IMM:
case EBPF_OP_SUB64_REG:
case EBPF_OP_MUL64_IMM:
case EBPF_OP_MUL64_REG:
case EBPF_OP_DIV64_REG:
case EBPF_OP_OR64_IMM:
case EBPF_OP_OR64_REG:
case EBPF_OP_AND64_IMM:
case EBPF_OP_AND64_REG:
case EBPF_OP_LSH64_IMM:
case EBPF_OP_LSH64_REG:
case EBPF_OP_RSH64_IMM:
case EBPF_OP_RSH64_REG:
case EBPF_OP_NEG64:
case EBPF_OP_MOD64_REG:
case EBPF_OP_XOR64_IMM:
case EBPF_OP_XOR64_REG:
case EBPF_OP_MOV64_IMM:
case EBPF_OP_MOV64_REG:
case EBPF_OP_ARSH64_IMM:
case EBPF_OP_ARSH64_REG:
break;
case EBPF_OP_LDXW:
case EBPF_OP_LDXH:
case EBPF_OP_LDXB:
case EBPF_OP_LDXDW:
break;
case EBPF_OP_STW:
case EBPF_OP_STH:
case EBPF_OP_STB:
case EBPF_OP_STDW:
case EBPF_OP_STXW:
case EBPF_OP_STXH:
case EBPF_OP_STXB:
case EBPF_OP_STXDW:
store = true;
break;
case EBPF_OP_LDDW:
if (i + 1 >= num_insts || insts[i+1].opcode != 0) {
*errmsg = ubpf_error("incomplete lddw at PC %d", i);
return false;
}
i++; /* Skip next instruction */
break;
case EBPF_OP_JA:
case EBPF_OP_JEQ_REG:
case EBPF_OP_JEQ_IMM:
case EBPF_OP_JGT_REG:
case EBPF_OP_JGT_IMM:
case EBPF_OP_JGE_REG:
case EBPF_OP_JGE_IMM:
case EBPF_OP_JLT_REG:
case EBPF_OP_JLT_IMM:
case EBPF_OP_JLE_REG:
case EBPF_OP_JLE_IMM:
case EBPF_OP_JSET_REG:
case EBPF_OP_JSET_IMM:
case EBPF_OP_JNE_REG:
case EBPF_OP_JNE_IMM:
case EBPF_OP_JSGT_IMM:
case EBPF_OP_JSGT_REG:
case EBPF_OP_JSGE_IMM:
case EBPF_OP_JSGE_REG:
case EBPF_OP_JSLT_IMM:
case EBPF_OP_JSLT_REG:
case EBPF_OP_JSLE_IMM:
case EBPF_OP_JSLE_REG:
if (inst.offset == -1) {
*errmsg = ubpf_error("infinite loop at PC %d", i);
return false;
}
int new_pc = i + 1 + inst.offset;
if (new_pc < 0 || new_pc >= num_insts) {
*errmsg = ubpf_error("jump out of bounds at PC %d", i);
return false;
} else if (insts[new_pc].opcode == 0) {
*errmsg = ubpf_error("jump to middle of lddw at PC %d", i);
return false;
}
break;
case EBPF_OP_CALL:
if (inst.imm < 0 || inst.imm >= MAX_EXT_FUNCS) {
*errmsg = ubpf_error("invalid call immediate at PC %d", i);
return false;
}
if (!vm->ext_funcs[inst.imm]) {
*errmsg = ubpf_error("call to nonexistent function %u at PC %d", inst.imm, i);
return false;
}
break;
case EBPF_OP_EXIT:
break;
case EBPF_OP_DIV_IMM:
case EBPF_OP_MOD_IMM:
case EBPF_OP_DIV64_IMM:
case EBPF_OP_MOD64_IMM:
if (inst.imm == 0) {
*errmsg = ubpf_error("division by zero at PC %d", i);
return false;
}
break;
default:
*errmsg = ubpf_error("unknown opcode 0x%02x at PC %d", inst.opcode, i);
return false;
}
if (inst.src > 10) {
*errmsg = ubpf_error("invalid source register at PC %d", i);
return false;
}
if (inst.dst > 9 && !(store && inst.dst == 10)) {
*errmsg = ubpf_error("invalid destination register at PC %d", i);
return false;
}
}
return true;
}
static bool
bounds_check(void *addr, int size, const char *type, uint16_t cur_pc, void *mem, size_t mem_len, void *stack)
{
if (mem && (addr >= mem && (addr + size) <= (mem + mem_len))) {
/* Context access */
return true;
} else if (addr >= stack && (addr + size) <= (stack + STACK_SIZE)) {
/* Stack access */
return true;
} else {
fprintf(stderr, "uBPF error: out of bounds memory %s at PC %u, addr %p, size %d\n", type, cur_pc, addr, size);
fprintf(stderr, "mem %p/%zd stack %p/%d\n", mem, mem_len, stack, STACK_SIZE);
return false;
}
}
char *
ubpf_error(const char *fmt, ...)
{
char *msg;
va_list ap;
va_start(ap, fmt);
if (vasprintf(&msg, fmt, ap) < 0) {
msg = NULL;
}
va_end(ap);
return msg;
}
static void register_functions(struct ubpf_vm *vm);
struct ubpf_vm * do_prepare_ebpf()
{
size_t code_len;
void *code;
bool use_hard_coded_bpf = 0;
code_len = testc_bin_len;
code = testc_bin;
use_hard_coded_bpf = 1;
size_t mem_len = 0;
void *mem = NULL;
struct ubpf_vm *vm = ubpf_create();
if (!vm) {
fprintf(stderr, "Failed to create VM\n");
return 1;
}
register_functions(vm);
char *errmsg;
int rv;
rv = ubpf_load(vm, code, code_len, &errmsg);
if (rv < 0) {
fprintf(stderr, "Failed to load code: %s\n", errmsg);
free(errmsg);
ubpf_destroy(vm);
return 0x0;
}
// trial init
xbpf_map.key_size = sizeof(key_t);
xbpf_map.value_size = 4;
xbpf_map.el = NULL;
return vm;
}
void count_pkt(void *mem)
{
typedef struct {
uint8_t eth_src[6];
uint8_t eth_dst[6];
uint16_t eth_type;
} eth_hdr_t ;
typedef struct {
uint8_t ver_ihl;
uint8_t tos;
uint16_t total_length;
uint16_t id;
uint16_t frag;
uint8_t ttl;
uint8_t proto;
uint16_t csum;
uint32_t src;
uint32_t dst;
} ipv4_hdr_t;
uint16_t eth_type = be16toh(((eth_hdr_t *)mem)->eth_type);
uint16_t proto = 0;
if (eth_type == 0x0800){
proto = be16toh(((ipv4_hdr_t *)(mem + 14))->proto);
}
key_t key = { eth_type, proto };
el_t * p;
int count = 0;
p = xbpf_map_lookup_elem(&xbpf_map, &key);
if (p) {
count = p->value;
count += 1;
}
xbpf_map_update_elem(&xbpf_map, &key, &count, 0);
}
int do_exec_ebpf(struct ubpf_vm *vm, void *mem, size_t mem_len)
{
uint64_t ret;
ret = ubpf_exec(vm, mem, mem_len);
printf("0x%"PRIx64"\n", ret);
//ubpf_destroy(vm);
// dummy call for pkt counting
// should go into ebpf
count_pkt(mem);
return ret;
}
static uint64_t
gather_bytes(uint8_t a, uint8_t b, uint8_t c, uint8_t d, uint8_t e)
{
return ((uint64_t)a << 32) |
((uint32_t)b << 24) |
((uint32_t)c << 16) |
((uint16_t)d << 8) |
e;
}
static uint32_t
timestwo(uint32_t x)
{
return x*x;
}
static void
register_functions(struct ubpf_vm *vm)
{
ubpf_register(vm, 0, "gather_bytes", gather_bytes);
ubpf_register(vm, 4, "strcmp_ext", strcmp);
ubpf_register(vm, 5, "timestwo", timestwo);
}
// helper function to recalculate the l3 checksum for ipv4
int fix_ip_checksum(void* vdata, size_t length) {
struct eth_hdr {
uint8_t eth_src[6];
uint8_t eth_dst[6];
uint16_t eth_type;
};
struct ipv4_hdr {
uint8_t ver_ihl;
uint8_t tos;
uint16_t total_length;
uint16_t id;
uint16_t frag;
uint8_t ttl;
uint8_t proto;
uint16_t csum;
uint32_t src;
uint32_t dst;
};
struct eth_hdr * eh;
struct ipv4_hdr * ih;
// Cast the data pointer to one that can be indexed.
char* data=(char*)vdata;
uint16_t eth_type = ((struct eth_hdr *)data)->eth_type;
// return immediately if not IPv4
if (((struct eth_hdr *)data)->eth_type != htobe16(0x0800)) {
uk_pr_err("skip pkt type %04x\n", be16toh(((struct eth_hdr *)data)->eth_type));
return 0;
}
data += sizeof(struct eth_hdr);
uint16_t total_length = be16toh(((struct ipv4_hdr *)data)->total_length);
int ipv4_header_length = (((struct ipv4_hdr *)data)->ver_ihl & 0x07) * 4; // bytes not bits
uint16_t old_csum = ((struct ipv4_hdr *)data)->csum;
// reset checksum
((struct ipv4_hdr *)data)->csum = 0x00;
// make sure length >= total_length, otherwise error
if (length-14 != total_length) {