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