/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2009 Robert N. M. Watson
* Copyright (c) 2009 Bjoern A. Zeeb <bz@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#define _WANT_PRISON
#define _WANT_UCRED
#define _WANT_VNET
#include <sys/_lock.h>
#include <sys/_mutex.h>
#include <sys/_task.h>
#include <sys/jail.h>
#include <sys/proc.h>
#include <sys/types.h>
#include <stdbool.h>
#include <net/vnet.h>
#include <kvm.h>
#include <limits.h>
#include <stdlib.h>
#include <unistd.h>
#include "kvm_private.h"
/*
* Set up libkvm to handle virtual network stack symbols by selecting a
* starting pid.
*/
int
_kvm_vnet_selectpid(kvm_t *kd, pid_t pid)
{
struct proc proc;
struct ucred cred;
struct prison prison;
struct vnet vnet;
struct kvm_nlist nl[] = {
/*
* Note: kvm_nlist strips the first '_' so add an extra one
* here to __{start,stop}_set_vnet.
*/
#define NLIST_START_VNET 0
{ .n_name = "___start_" VNET_SETNAME },
#define NLIST_STOP_VNET 1
{ .n_name = "___stop_" VNET_SETNAME },
#define NLIST_VNET_HEAD 2
{ .n_name = "vnet_head" },
#define NLIST_ALLPROC 3
{ .n_name = "allproc" },
#define NLIST_DUMPTID 4
{ .n_name = "dumptid" },
#define NLIST_PROC0 5
{ .n_name = "proc0" },
{ .n_name = NULL },
};
uintptr_t procp, credp;
#define VMCORE_VNET_OF_PROC0
#ifndef VMCORE_VNET_OF_PROC0
struct thread td;
uintptr_t tdp;
#endif
lwpid_t dumptid;
/*
* XXX: This only works for native kernels for now.
*/
if (!kvm_native(kd))
return (-1);
/*
* Locate and cache locations of important symbols
* using the internal version of _kvm_nlist, turning
* off initialization to avoid recursion in case of
* unresolveable symbols.
*/
if (_kvm_nlist(kd, nl, 0) != 0) {
/*
* XXX-BZ: ___start_/___stop_VNET_SETNAME may fail.
* For now do not report an error here as we are called
* internally and in `void context' until we merge the
* functionality to optionally activate this into programs.
* By that time we can properly fail and let the callers
* handle the error.
*/
/* _kvm_err(kd, kd->program, "%s: no namelist", __func__); */
return (-1);
}
/*
* Auto-detect if this is a crashdump by reading dumptid.
*/
dumptid = 0;
if (nl[NLIST_DUMPTID].n_value) {
if (kvm_read(kd, nl[NLIST_DUMPTID].n_value, &dumptid,
sizeof(dumptid)) != sizeof(dumptid)) {
_kvm_err(kd, kd->program, "%s: dumptid", __func__);
return (-1);
}
}
/*
* First, find the process for this pid. If we are working on a
* dump, either locate the thread dumptid is referring to or proc0.
* Based on either, take the address of the ucred.
*/
credp = 0;
procp = nl[NLIST_ALLPROC].n_value;
#ifdef VMCORE_VNET_OF_PROC0
if (dumptid > 0) {
procp = nl[NLIST_PROC0].n_value;
pid = 0;
}
#endif
while (procp != 0) {
if (kvm_read(kd, procp, &proc, sizeof(proc)) != sizeof(proc)) {
_kvm_err(kd, kd->program, "%s: proc", __func__);
return (-1);
}
#ifndef VMCORE_VNET_OF_PROC0
if (dumptid > 0) {
tdp = (uintptr_t)TAILQ_FIRST(&proc.p_threads);
while (tdp != 0) {
if (kvm_read(kd, tdp, &td, sizeof(td)) !=
sizeof(td)) {
_kvm_err(kd, kd->program, "%s: thread",
__func__);
return (-1);
}
if (td.td_tid == dumptid) {
credp = (uintptr_t)td.td_ucred;
break;
}
tdp = (uintptr_t)TAILQ_NEXT(&td, td_plist);
}
} else
#endif
if (proc.p_pid == pid)
credp = (uintptr_t)proc.p_ucred;
if (credp != 0)
break;
procp = (uintptr_t)LIST_NEXT(&proc, p_list);
}
if (credp == 0) {
_kvm_err(kd, kd->program, "%s: pid/tid not found", __func__);
return (-1);
}
if (kvm_read(kd, (uintptr_t)credp, &cred, sizeof(cred)) !=
sizeof(cred)) {
_kvm_err(kd, kd->program, "%s: cred", __func__);
return (-1);
}
if (cred.cr_prison == NULL) {
_kvm_err(kd, kd->program, "%s: no jail", __func__);
return (-1);
}
if (kvm_read(kd, (uintptr_t)cred.cr_prison, &prison, sizeof(prison)) !=
sizeof(prison)) {
_kvm_err(kd, kd->program, "%s: prison", __func__);
return (-1);
}
if (prison.pr_vnet == NULL) {
_kvm_err(kd, kd->program, "%s: no vnet", __func__);
return (-1);
}
if (kvm_read(kd, (uintptr_t)prison.pr_vnet, &vnet, sizeof(vnet)) !=
sizeof(vnet)) {
_kvm_err(kd, kd->program, "%s: vnet", __func__);
return (-1);
}
if (vnet.vnet_magic_n != VNET_MAGIC_N) {
_kvm_err(kd, kd->program, "%s: invalid vnet magic#", __func__);
return (-1);
}
kd->vnet_initialized = 1;
kd->vnet_start = nl[NLIST_START_VNET].n_value;
kd->vnet_stop = nl[NLIST_STOP_VNET].n_value;
kd->vnet_current = (uintptr_t)prison.pr_vnet;
kd->vnet_base = vnet.vnet_data_base;
return (0);
}
/*
* Check whether the vnet module has been initialized successfully
* or not, initialize it if permitted.
*/
int
_kvm_vnet_initialized(kvm_t *kd, int intialize)
{
if (kd->vnet_initialized || !intialize)
return (kd->vnet_initialized);
(void) _kvm_vnet_selectpid(kd, getpid());
return (kd->vnet_initialized);
}
/*
* Check whether the value is within the vnet symbol range and
* only if so adjust the offset relative to the current base.
*/
kvaddr_t
_kvm_vnet_validaddr(kvm_t *kd, kvaddr_t value)
{
if (value == 0)
return (value);
if (!kd->vnet_initialized)
return (value);
if (value < kd->vnet_start || value >= kd->vnet_stop)
return (value);
return (kd->vnet_base + value);
}
