1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 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 __FBSDID("$FreeBSD$"); 32 33 #include <sys/param.h> 34 35 #define _WANT_PRISON 36 #define _WANT_UCRED 37 #define _WANT_VNET 38 39 #include <sys/_lock.h> 40 #include <sys/_mutex.h> 41 #include <sys/_task.h> 42 #include <sys/jail.h> 43 #include <sys/proc.h> 44 #include <sys/types.h> 45 46 #include <net/vnet.h> 47 48 #include <kvm.h> 49 #include <limits.h> 50 #include <stdlib.h> 51 #include <unistd.h> 52 53 #include "kvm_private.h" 54 55 /* 56 * Set up libkvm to handle virtual network stack symbols by selecting a 57 * starting pid. 58 */ 59 int 60 _kvm_vnet_selectpid(kvm_t *kd, pid_t pid) 61 { 62 struct proc proc; 63 struct ucred cred; 64 struct prison prison; 65 struct vnet vnet; 66 struct kvm_nlist nl[] = { 67 /* 68 * Note: kvm_nlist strips the first '_' so add an extra one 69 * here to __{start,stop}_set_vnet. 70 */ 71 #define NLIST_START_VNET 0 72 { .n_name = "___start_" VNET_SETNAME }, 73 #define NLIST_STOP_VNET 1 74 { .n_name = "___stop_" VNET_SETNAME }, 75 #define NLIST_VNET_HEAD 2 76 { .n_name = "vnet_head" }, 77 #define NLIST_ALLPROC 3 78 { .n_name = "allproc" }, 79 #define NLIST_DUMPTID 4 80 { .n_name = "dumptid" }, 81 #define NLIST_PROC0 5 82 { .n_name = "proc0" }, 83 { .n_name = NULL }, 84 }; 85 uintptr_t procp, credp; 86 #define VMCORE_VNET_OF_PROC0 87 #ifndef VMCORE_VNET_OF_PROC0 88 struct thread td; 89 uintptr_t tdp; 90 #endif 91 lwpid_t dumptid; 92 93 /* 94 * XXX: This only works for native kernels for now. 95 */ 96 if (!kvm_native(kd)) 97 return (-1); 98 99 /* 100 * Locate and cache locations of important symbols 101 * using the internal version of _kvm_nlist, turning 102 * off initialization to avoid recursion in case of 103 * unresolveable symbols. 104 */ 105 if (_kvm_nlist(kd, nl, 0) != 0) { 106 /* 107 * XXX-BZ: ___start_/___stop_VNET_SETNAME may fail. 108 * For now do not report an error here as we are called 109 * internally and in `void context' until we merge the 110 * functionality to optionally activate this into programs. 111 * By that time we can properly fail and let the callers 112 * handle the error. 113 */ 114 /* _kvm_err(kd, kd->program, "%s: no namelist", __func__); */ 115 return (-1); 116 } 117 118 /* 119 * Auto-detect if this is a crashdump by reading dumptid. 120 */ 121 dumptid = 0; 122 if (nl[NLIST_DUMPTID].n_value) { 123 if (kvm_read(kd, nl[NLIST_DUMPTID].n_value, &dumptid, 124 sizeof(dumptid)) != sizeof(dumptid)) { 125 _kvm_err(kd, kd->program, "%s: dumptid", __func__); 126 return (-1); 127 } 128 } 129 130 /* 131 * First, find the process for this pid. If we are working on a 132 * dump, either locate the thread dumptid is referring to or proc0. 133 * Based on either, take the address of the ucred. 134 */ 135 credp = 0; 136 137 procp = nl[NLIST_ALLPROC].n_value; 138 #ifdef VMCORE_VNET_OF_PROC0 139 if (dumptid > 0) { 140 procp = nl[NLIST_PROC0].n_value; 141 pid = 0; 142 } 143 #endif 144 while (procp != 0) { 145 if (kvm_read(kd, procp, &proc, sizeof(proc)) != sizeof(proc)) { 146 _kvm_err(kd, kd->program, "%s: proc", __func__); 147 return (-1); 148 } 149 #ifndef VMCORE_VNET_OF_PROC0 150 if (dumptid > 0) { 151 tdp = (uintptr_t)TAILQ_FIRST(&proc.p_threads); 152 while (tdp != 0) { 153 if (kvm_read(kd, tdp, &td, sizeof(td)) != 154 sizeof(td)) { 155 _kvm_err(kd, kd->program, "%s: thread", 156 __func__); 157 return (-1); 158 } 159 if (td.td_tid == dumptid) { 160 credp = (uintptr_t)td.td_ucred; 161 break; 162 } 163 tdp = (uintptr_t)TAILQ_NEXT(&td, td_plist); 164 } 165 } else 166 #endif 167 if (proc.p_pid == pid) 168 credp = (uintptr_t)proc.p_ucred; 169 if (credp != 0) 170 break; 171 procp = (uintptr_t)LIST_NEXT(&proc, p_list); 172 } 173 if (credp == 0) { 174 _kvm_err(kd, kd->program, "%s: pid/tid not found", __func__); 175 return (-1); 176 } 177 if (kvm_read(kd, (uintptr_t)credp, &cred, sizeof(cred)) != 178 sizeof(cred)) { 179 _kvm_err(kd, kd->program, "%s: cred", __func__); 180 return (-1); 181 } 182 if (cred.cr_prison == NULL) { 183 _kvm_err(kd, kd->program, "%s: no jail", __func__); 184 return (-1); 185 } 186 if (kvm_read(kd, (uintptr_t)cred.cr_prison, &prison, sizeof(prison)) != 187 sizeof(prison)) { 188 _kvm_err(kd, kd->program, "%s: prison", __func__); 189 return (-1); 190 } 191 if (prison.pr_vnet == NULL) { 192 _kvm_err(kd, kd->program, "%s: no vnet", __func__); 193 return (-1); 194 } 195 if (kvm_read(kd, (uintptr_t)prison.pr_vnet, &vnet, sizeof(vnet)) != 196 sizeof(vnet)) { 197 _kvm_err(kd, kd->program, "%s: vnet", __func__); 198 return (-1); 199 } 200 if (vnet.vnet_magic_n != VNET_MAGIC_N) { 201 _kvm_err(kd, kd->program, "%s: invalid vnet magic#", __func__); 202 return (-1); 203 } 204 kd->vnet_initialized = 1; 205 kd->vnet_start = nl[NLIST_START_VNET].n_value; 206 kd->vnet_stop = nl[NLIST_STOP_VNET].n_value; 207 kd->vnet_current = (uintptr_t)prison.pr_vnet; 208 kd->vnet_base = vnet.vnet_data_base; 209 return (0); 210 } 211 212 /* 213 * Check whether the vnet module has been initialized successfully 214 * or not, initialize it if permitted. 215 */ 216 int 217 _kvm_vnet_initialized(kvm_t *kd, int intialize) 218 { 219 220 if (kd->vnet_initialized || !intialize) 221 return (kd->vnet_initialized); 222 223 (void) _kvm_vnet_selectpid(kd, getpid()); 224 225 return (kd->vnet_initialized); 226 } 227 228 /* 229 * Check whether the value is within the vnet symbol range and 230 * only if so adjust the offset relative to the current base. 231 */ 232 kvaddr_t 233 _kvm_vnet_validaddr(kvm_t *kd, kvaddr_t value) 234 { 235 236 if (value == 0) 237 return (value); 238 239 if (!kd->vnet_initialized) 240 return (value); 241 242 if (value < kd->vnet_start || value >= kd->vnet_stop) 243 return (value); 244 245 return (kd->vnet_base + value); 246 } 247