diff options
Diffstat (limited to 'lib/libkvm/kvm_vnet.c')
| -rw-r--r-- | lib/libkvm/kvm_vnet.c | 237 |
1 files changed, 237 insertions, 0 deletions
diff --git a/lib/libkvm/kvm_vnet.c b/lib/libkvm/kvm_vnet.c new file mode 100644 index 0000000..13f7cf4 --- /dev/null +++ b/lib/libkvm/kvm_vnet.c @@ -0,0 +1,237 @@ +/*- + * 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 <sys/vimage.h> + +#include <net/vnet.h> + +#include <nlist.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 thread td; + struct ucred cred; + struct prison prison; + struct vnet vnet; + struct 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, tdp, credp; + lwpid_t dumptid; + + /* + * 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 workig on a dump, + * either locate the thread dumptid is refering to or proc0. + * Based on either, take the address of the ucred. + */ + credp = 0; + + procp = nl[NLIST_ALLPROC].n_value; +#define VMCORE_VNET_OF_PROC0 +#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 = (uintptr_t)vnet.vnet_data_mem - kd->vnet_start; + return (0); +} + +/* + * Check whether the vnet module has been initialized sucessfully + * or not, intialize 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. + */ +uintptr_t +_kvm_vnet_validaddr(kvm_t *kd, uintptr_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); +} |
