1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2009 Robert N. M. Watson 5 * Copyright (c) 2009 Bjoern A. Zeeb <bz@FreeBSD.org> 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 #include <sys/cdefs.h> 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 <stdbool.h> 45 #include <net/vnet.h> 46 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 */ 58 int 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 kvm_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 * XXX: This only works for native kernels for now. 94 */ 95 if (!kvm_native(kd)) 96 return (-1); 97 98 /* 99 * Locate and cache locations of important symbols 100 * using the internal version of _kvm_nlist, turning 101 * off initialization to avoid recursion in case of 102 * unresolveable symbols. 103 */ 104 if (_kvm_nlist(kd, nl, 0) != 0) { 105 /* 106 * XXX-BZ: ___start_/___stop_VNET_SETNAME may fail. 107 * For now do not report an error here as we are called 108 * internally and in `void context' until we merge the 109 * functionality to optionally activate this into programs. 110 * By that time we can properly fail and let the callers 111 * handle the error. 112 */ 113 /* _kvm_err(kd, kd->program, "%s: no namelist", __func__); */ 114 return (-1); 115 } 116 117 /* 118 * Auto-detect if this is a crashdump by reading dumptid. 119 */ 120 dumptid = 0; 121 if (nl[NLIST_DUMPTID].n_value) { 122 if (kvm_read(kd, nl[NLIST_DUMPTID].n_value, &dumptid, 123 sizeof(dumptid)) != sizeof(dumptid)) { 124 _kvm_err(kd, kd->program, "%s: dumptid", __func__); 125 return (-1); 126 } 127 } 128 129 /* 130 * First, find the process for this pid. If we are working on a 131 * dump, either locate the thread dumptid is referring to or proc0. 132 * Based on either, take the address of the ucred. 133 */ 134 credp = 0; 135 136 procp = nl[NLIST_ALLPROC].n_value; 137 #ifdef VMCORE_VNET_OF_PROC0 138 if (dumptid > 0) { 139 procp = nl[NLIST_PROC0].n_value; 140 pid = 0; 141 } 142 #endif 143 while (procp != 0) { 144 if (kvm_read(kd, procp, &proc, sizeof(proc)) != sizeof(proc)) { 145 _kvm_err(kd, kd->program, "%s: proc", __func__); 146 return (-1); 147 } 148 #ifndef VMCORE_VNET_OF_PROC0 149 if (dumptid > 0) { 150 tdp = (uintptr_t)TAILQ_FIRST(&proc.p_threads); 151 while (tdp != 0) { 152 if (kvm_read(kd, tdp, &td, sizeof(td)) != 153 sizeof(td)) { 154 _kvm_err(kd, kd->program, "%s: thread", 155 __func__); 156 return (-1); 157 } 158 if (td.td_tid == dumptid) { 159 credp = (uintptr_t)td.td_ucred; 160 break; 161 } 162 tdp = (uintptr_t)TAILQ_NEXT(&td, td_plist); 163 } 164 } else 165 #endif 166 if (proc.p_pid == pid) 167 credp = (uintptr_t)proc.p_ucred; 168 if (credp != 0) 169 break; 170 procp = (uintptr_t)LIST_NEXT(&proc, p_list); 171 } 172 if (credp == 0) { 173 _kvm_err(kd, kd->program, "%s: pid/tid not found", __func__); 174 return (-1); 175 } 176 if (kvm_read(kd, (uintptr_t)credp, &cred, sizeof(cred)) != 177 sizeof(cred)) { 178 _kvm_err(kd, kd->program, "%s: cred", __func__); 179 return (-1); 180 } 181 if (cred.cr_prison == NULL) { 182 _kvm_err(kd, kd->program, "%s: no jail", __func__); 183 return (-1); 184 } 185 if (kvm_read(kd, (uintptr_t)cred.cr_prison, &prison, sizeof(prison)) != 186 sizeof(prison)) { 187 _kvm_err(kd, kd->program, "%s: prison", __func__); 188 return (-1); 189 } 190 if (prison.pr_vnet == NULL) { 191 _kvm_err(kd, kd->program, "%s: no vnet", __func__); 192 return (-1); 193 } 194 if (kvm_read(kd, (uintptr_t)prison.pr_vnet, &vnet, sizeof(vnet)) != 195 sizeof(vnet)) { 196 _kvm_err(kd, kd->program, "%s: vnet", __func__); 197 return (-1); 198 } 199 if (vnet.vnet_magic_n != VNET_MAGIC_N) { 200 _kvm_err(kd, kd->program, "%s: invalid vnet magic#", __func__); 201 return (-1); 202 } 203 kd->vnet_initialized = 1; 204 kd->vnet_start = nl[NLIST_START_VNET].n_value; 205 kd->vnet_stop = nl[NLIST_STOP_VNET].n_value; 206 kd->vnet_current = (uintptr_t)prison.pr_vnet; 207 kd->vnet_base = vnet.vnet_data_base; 208 return (0); 209 } 210 211 /* 212 * Check whether the vnet module has been initialized successfully 213 * or not, initialize it if permitted. 214 */ 215 int 216 _kvm_vnet_initialized(kvm_t *kd, int intialize) 217 { 218 219 if (kd->vnet_initialized || !intialize) 220 return (kd->vnet_initialized); 221 222 (void) _kvm_vnet_selectpid(kd, getpid()); 223 224 return (kd->vnet_initialized); 225 } 226 227 /* 228 * Check whether the value is within the vnet symbol range and 229 * only if so adjust the offset relative to the current base. 230 */ 231 kvaddr_t 232 _kvm_vnet_validaddr(kvm_t *kd, kvaddr_t value) 233 { 234 235 if (value == 0) 236 return (value); 237 238 if (!kd->vnet_initialized) 239 return (value); 240 241 if (value < kd->vnet_start || value >= kd->vnet_stop) 242 return (value); 243 244 return (kd->vnet_base + value); 245 } 246