numam-dpdk/lib/librte_bpf/bpf_load.c
Konstantin Ananyev 60702e8c7c bpf: add extra information for external symbol definitions
Extend struct rte_bpf_xsym with new fields to provide information about:
 - for variables - type and size
 - for functions - number of arguments and type/size of each argument
   and return value

Such information would allow validate code to perform
more extensive checking on input BPF program and catch
misbehaving BPF code.

That change would cause ABI/API breakage for librte_bpf.

Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
2018-07-12 09:37:16 +02:00

149 lines
2.9 KiB
C

/* SPDX-License-Identifier: BSD-3-Clause
* Copyright(c) 2018 Intel Corporation
*/
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <stdint.h>
#include <unistd.h>
#include <inttypes.h>
#include <rte_common.h>
#include <rte_log.h>
#include <rte_debug.h>
#include <rte_memory.h>
#include <rte_eal.h>
#include <rte_byteorder.h>
#include <rte_errno.h>
#include "bpf_impl.h"
static struct rte_bpf *
bpf_load(const struct rte_bpf_prm *prm)
{
uint8_t *buf;
struct rte_bpf *bpf;
size_t sz, bsz, insz, xsz;
xsz = prm->nb_xsym * sizeof(prm->xsym[0]);
insz = prm->nb_ins * sizeof(prm->ins[0]);
bsz = sizeof(bpf[0]);
sz = insz + xsz + bsz;
buf = mmap(NULL, sz, PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (buf == MAP_FAILED)
return NULL;
bpf = (void *)buf;
bpf->sz = sz;
memcpy(&bpf->prm, prm, sizeof(bpf->prm));
memcpy(buf + bsz, prm->xsym, xsz);
memcpy(buf + bsz + xsz, prm->ins, insz);
bpf->prm.xsym = (void *)(buf + bsz);
bpf->prm.ins = (void *)(buf + bsz + xsz);
return bpf;
}
/*
* Check that user provided external symbol.
*/
static int
bpf_check_xsym(const struct rte_bpf_xsym *xsym)
{
uint32_t i;
if (xsym->name == NULL)
return -EINVAL;
if (xsym->type == RTE_BPF_XTYPE_VAR) {
if (xsym->var.desc.type == RTE_BPF_ARG_UNDEF)
return -EINVAL;
} else if (xsym->type == RTE_BPF_XTYPE_FUNC) {
if (xsym->func.nb_args > EBPF_FUNC_MAX_ARGS)
return -EINVAL;
/* check function arguments */
for (i = 0; i != xsym->func.nb_args; i++) {
if (xsym->func.args[i].type == RTE_BPF_ARG_UNDEF)
return -EINVAL;
}
/* check return value info */
if (xsym->func.ret.type != RTE_BPF_ARG_UNDEF &&
xsym->func.ret.size == 0)
return -EINVAL;
} else
return -EINVAL;
return 0;
}
__rte_experimental struct rte_bpf *
rte_bpf_load(const struct rte_bpf_prm *prm)
{
struct rte_bpf *bpf;
int32_t rc;
uint32_t i;
if (prm == NULL || prm->ins == NULL ||
(prm->nb_xsym != 0 && prm->xsym == NULL)) {
rte_errno = EINVAL;
return NULL;
}
rc = 0;
for (i = 0; i != prm->nb_xsym && rc == 0; i++)
rc = bpf_check_xsym(prm->xsym + i);
if (rc != 0) {
rte_errno = -rc;
RTE_BPF_LOG(ERR, "%s: %d-th xsym is invalid\n", __func__, i);
return NULL;
}
bpf = bpf_load(prm);
if (bpf == NULL) {
rte_errno = ENOMEM;
return NULL;
}
rc = bpf_validate(bpf);
if (rc == 0) {
bpf_jit(bpf);
if (mprotect(bpf, bpf->sz, PROT_READ) != 0)
rc = -ENOMEM;
}
if (rc != 0) {
rte_bpf_destroy(bpf);
rte_errno = -rc;
return NULL;
}
return bpf;
}
__rte_experimental __attribute__ ((weak)) struct rte_bpf *
rte_bpf_elf_load(const struct rte_bpf_prm *prm, const char *fname,
const char *sname)
{
if (prm == NULL || fname == NULL || sname == NULL) {
rte_errno = EINVAL;
return NULL;
}
RTE_BPF_LOG(ERR, "%s() is not supported with current config\n"
"rebuild with libelf installed\n",
__func__);
rte_errno = ENOTSUP;
return NULL;
}