1/*- 2 * Copyright (c) 2009 Robert N. M. Watson 3 * Copyright (c) 2009 Bjoern A. Zeeb <bz@FreeBSD.org> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28#include <sys/cdefs.h> 29__FBSDID("$FreeBSD: releng/10.3/lib/libkvm/kvm_vnet.c 217744 2011-01-23 11:08:28Z uqs $"); 30 31#include <sys/param.h> 32 33#define _WANT_PRISON 34#define _WANT_UCRED 35#define _WANT_VNET 36 37#include <sys/_lock.h> 38#include <sys/_mutex.h> 39#include <sys/_task.h> 40#include <sys/jail.h> 41#include <sys/proc.h> 42#include <sys/types.h> 43 44#include <net/vnet.h> 45 46#include <nlist.h> 47#include <kvm.h> 48#include <limits.h> 49#include <stdlib.h> 50#include <unistd.h> 51 52#include "kvm_private.h" 53 54/* 55 * Set up libkvm to handle virtual network stack symbols by selecting a 56 * starting pid. 57 */ 58int 59_kvm_vnet_selectpid(kvm_t *kd, pid_t pid) 60{ 61 struct proc proc; 62 struct ucred cred; 63 struct prison prison; 64 struct vnet vnet; 65 struct nlist nl[] = { 66 /* 67 * Note: kvm_nlist strips the first '_' so add an extra one 68 * here to __{start,stop}_set_vnet. 69 */ 70#define NLIST_START_VNET 0 71 { .n_name = "___start_" VNET_SETNAME }, 72#define NLIST_STOP_VNET 1 73 { .n_name = "___stop_" VNET_SETNAME }, 74#define NLIST_VNET_HEAD 2 75 { .n_name = "vnet_head" }, 76#define NLIST_ALLPROC 3 77 { .n_name = "allproc" }, 78#define NLIST_DUMPTID 4 79 { .n_name = "dumptid" }, 80#define NLIST_PROC0 5 81 { .n_name = "proc0" }, 82 { .n_name = NULL }, 83 }; 84 uintptr_t procp, credp; 85#define VMCORE_VNET_OF_PROC0 86#ifndef VMCORE_VNET_OF_PROC0 87 struct thread td; 88 uintptr_t tdp; 89#endif 90 lwpid_t dumptid; 91 92 /* 93 * Locate and cache locations of important symbols 94 * using the internal version of _kvm_nlist, turning 95 * off initialization to avoid recursion in case of 96 * unresolveable symbols. 97 */ 98 if (_kvm_nlist(kd, nl, 0) != 0) { 99 /* 100 * XXX-BZ: ___start_/___stop_VNET_SETNAME may fail. 101 * For now do not report an error here as we are called 102 * internally and in `void context' until we merge the 103 * functionality to optionally activate this into programs. 104 * By that time we can properly fail and let the callers 105 * handle the error. 106 */ 107 /* _kvm_err(kd, kd->program, "%s: no namelist", __func__); */ 108 return (-1); 109 } 110 111 /* 112 * Auto-detect if this is a crashdump by reading dumptid. 113 */ 114 dumptid = 0; 115 if (nl[NLIST_DUMPTID].n_value) { 116 if (kvm_read(kd, nl[NLIST_DUMPTID].n_value, &dumptid, 117 sizeof(dumptid)) != sizeof(dumptid)) { 118 _kvm_err(kd, kd->program, "%s: dumptid", __func__); 119 return (-1); 120 } 121 } 122 123 /* 124 * First, find the process for this pid. If we are working on a 125 * dump, either locate the thread dumptid is refering to or proc0. 126 * Based on either, take the address of the ucred. 127 */ 128 credp = 0; 129 130 procp = nl[NLIST_ALLPROC].n_value; 131#ifdef VMCORE_VNET_OF_PROC0 132 if (dumptid > 0) { 133 procp = nl[NLIST_PROC0].n_value; 134 pid = 0; 135 } 136#endif 137 while (procp != 0) { 138 if (kvm_read(kd, procp, &proc, sizeof(proc)) != sizeof(proc)) { 139 _kvm_err(kd, kd->program, "%s: proc", __func__); 140 return (-1); 141 } 142#ifndef VMCORE_VNET_OF_PROC0 143 if (dumptid > 0) { 144 tdp = (uintptr_t)TAILQ_FIRST(&proc.p_threads); 145 while (tdp != 0) { 146 if (kvm_read(kd, tdp, &td, sizeof(td)) != 147 sizeof(td)) { 148 _kvm_err(kd, kd->program, "%s: thread", 149 __func__); 150 return (-1); 151 } 152 if (td.td_tid == dumptid) { 153 credp = (uintptr_t)td.td_ucred; 154 break; 155 } 156 tdp = (uintptr_t)TAILQ_NEXT(&td, td_plist); 157 } 158 } else 159#endif 160 if (proc.p_pid == pid) 161 credp = (uintptr_t)proc.p_ucred; 162 if (credp != 0) 163 break; 164 procp = (uintptr_t)LIST_NEXT(&proc, p_list); 165 } 166 if (credp == 0) { 167 _kvm_err(kd, kd->program, "%s: pid/tid not found", __func__); 168 return (-1); 169 } 170 if (kvm_read(kd, (uintptr_t)credp, &cred, sizeof(cred)) != 171 sizeof(cred)) { 172 _kvm_err(kd, kd->program, "%s: cred", __func__); 173 return (-1); 174 } 175 if (cred.cr_prison == NULL) { 176 _kvm_err(kd, kd->program, "%s: no jail", __func__); 177 return (-1); 178 } 179 if (kvm_read(kd, (uintptr_t)cred.cr_prison, &prison, sizeof(prison)) != 180 sizeof(prison)) { 181 _kvm_err(kd, kd->program, "%s: prison", __func__); 182 return (-1); 183 } 184 if (prison.pr_vnet == NULL) { 185 _kvm_err(kd, kd->program, "%s: no vnet", __func__); 186 return (-1); 187 } 188 if (kvm_read(kd, (uintptr_t)prison.pr_vnet, &vnet, sizeof(vnet)) != 189 sizeof(vnet)) { 190 _kvm_err(kd, kd->program, "%s: vnet", __func__); 191 return (-1); 192 } 193 if (vnet.vnet_magic_n != VNET_MAGIC_N) { 194 _kvm_err(kd, kd->program, "%s: invalid vnet magic#", __func__); 195 return (-1); 196 } 197 kd->vnet_initialized = 1; 198 kd->vnet_start = nl[NLIST_START_VNET].n_value; 199 kd->vnet_stop = nl[NLIST_STOP_VNET].n_value; 200 kd->vnet_current = (uintptr_t)prison.pr_vnet; 201 kd->vnet_base = vnet.vnet_data_base; 202 return (0); 203} 204 205/* 206 * Check whether the vnet module has been initialized sucessfully 207 * or not, intialize it if permitted. 208 */ 209int 210_kvm_vnet_initialized(kvm_t *kd, int intialize) 211{ 212 213 if (kd->vnet_initialized || !intialize) 214 return (kd->vnet_initialized); 215 216 (void) _kvm_vnet_selectpid(kd, getpid()); 217 218 return (kd->vnet_initialized); 219} 220 221/* 222 * Check whether the value is within the vnet symbol range and 223 * only if so adjust the offset relative to the current base. 224 */ 225uintptr_t 226_kvm_vnet_validaddr(kvm_t *kd, uintptr_t value) 227{ 228 229 if (value == 0) 230 return (value); 231 232 if (!kd->vnet_initialized) 233 return (value); 234 235 if (value < kd->vnet_start || value >= kd->vnet_stop) 236 return (value); 237 238 return (kd->vnet_base + value); 239} 240