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