| 1 | /* |
| 2 | * Copyright (c) 1989 The Regents of the University of California. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * Redistribution and use in source and binary forms, with or without |
| 6 | * modification, are permitted provided that the following conditions |
| 7 | * are met: |
| 8 | * 1. Redistributions of source code must retain the above copyright |
| 9 | * notice, this list of conditions and the following disclaimer. |
| 10 | * 2. Redistributions in binary form must reproduce the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer in the |
| 12 | * documentation and/or other materials provided with the distribution. |
| 13 | * 3. All advertising materials mentioning features or use of this software |
| 14 | * must display the following acknowledgement: |
| 15 | * This product includes software developed by the University of |
| 16 | * California, Berkeley and its contributors. |
| 17 | * 4. Neither the name of the University nor the names of its contributors |
| 18 | * may be used to endorse or promote products derived from this software |
| 19 | * without specific prior written permission. |
| 20 | * |
| 21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
| 22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 31 | * SUCH DAMAGE. |
| 32 | * |
| 33 | * @(#)kern_ktrace.c 7.15 (Berkeley) 6/21/91 |
| 34 | */ |
| 35 | |
| 36 | #ifdef KTRACE |
| 37 | |
| 38 | #include "param.h" |
| 39 | #include "proc.h" |
| 40 | #include "file.h" |
| 41 | #include "namei.h" |
| 42 | #include "vnode.h" |
| 43 | #include "ktrace.h" |
| 44 | #include "malloc.h" |
| 45 | #include "syslog.h" |
| 46 | |
| 47 | struct ktr_header * |
| 48 | ktrgetheader(type) |
| 49 | { |
| 50 | register struct ktr_header *kth; |
| 51 | struct proc *p = curproc; /* XXX */ |
| 52 | |
| 53 | MALLOC(kth, struct ktr_header *, sizeof (struct ktr_header), |
| 54 | M_TEMP, M_WAITOK); |
| 55 | kth->ktr_type = type; |
| 56 | microtime(&kth->ktr_time); |
| 57 | kth->ktr_pid = p->p_pid; |
| 58 | bcopy(p->p_comm, kth->ktr_comm, MAXCOMLEN); |
| 59 | return (kth); |
| 60 | } |
| 61 | |
| 62 | ktrsyscall(vp, code, narg, args) |
| 63 | struct vnode *vp; |
| 64 | int code, narg, args[]; |
| 65 | { |
| 66 | struct ktr_header *kth = ktrgetheader(KTR_SYSCALL); |
| 67 | struct ktr_syscall *ktp; |
| 68 | register len = sizeof(struct ktr_syscall) + (narg * sizeof(int)); |
| 69 | int *argp, i; |
| 70 | |
| 71 | MALLOC(ktp, struct ktr_syscall *, len, M_TEMP, M_WAITOK); |
| 72 | ktp->ktr_code = code; |
| 73 | ktp->ktr_narg = narg; |
| 74 | argp = (int *)((char *)ktp + sizeof(struct ktr_syscall)); |
| 75 | for (i = 0; i < narg; i++) |
| 76 | *argp++ = args[i]; |
| 77 | kth->ktr_buf = (caddr_t)ktp; |
| 78 | kth->ktr_len = len; |
| 79 | ktrwrite(vp, kth); |
| 80 | FREE(ktp, M_TEMP); |
| 81 | FREE(kth, M_TEMP); |
| 82 | } |
| 83 | |
| 84 | ktrsysret(vp, code, error, retval) |
| 85 | struct vnode *vp; |
| 86 | int code, error, retval; |
| 87 | { |
| 88 | struct ktr_header *kth = ktrgetheader(KTR_SYSRET); |
| 89 | struct ktr_sysret ktp; |
| 90 | |
| 91 | ktp.ktr_code = code; |
| 92 | ktp.ktr_error = error; |
| 93 | ktp.ktr_retval = retval; /* what about val2 ? */ |
| 94 | |
| 95 | kth->ktr_buf = (caddr_t)&ktp; |
| 96 | kth->ktr_len = sizeof(struct ktr_sysret); |
| 97 | |
| 98 | ktrwrite(vp, kth); |
| 99 | FREE(kth, M_TEMP); |
| 100 | } |
| 101 | |
| 102 | ktrnamei(vp, path) |
| 103 | struct vnode *vp; |
| 104 | char *path; |
| 105 | { |
| 106 | struct ktr_header *kth = ktrgetheader(KTR_NAMEI); |
| 107 | |
| 108 | kth->ktr_len = strlen(path); |
| 109 | kth->ktr_buf = path; |
| 110 | |
| 111 | ktrwrite(vp, kth); |
| 112 | FREE(kth, M_TEMP); |
| 113 | } |
| 114 | |
| 115 | ktrgenio(vp, fd, rw, iov, len, error) |
| 116 | struct vnode *vp; |
| 117 | int fd; |
| 118 | enum uio_rw rw; |
| 119 | register struct iovec *iov; |
| 120 | { |
| 121 | struct ktr_header *kth = ktrgetheader(KTR_GENIO); |
| 122 | register struct ktr_genio *ktp; |
| 123 | register caddr_t cp; |
| 124 | register int resid = len, cnt; |
| 125 | |
| 126 | if (error) |
| 127 | return; |
| 128 | MALLOC(ktp, struct ktr_genio *, sizeof(struct ktr_genio) + len, |
| 129 | M_TEMP, M_WAITOK); |
| 130 | ktp->ktr_fd = fd; |
| 131 | ktp->ktr_rw = rw; |
| 132 | cp = (caddr_t)((char *)ktp + sizeof (struct ktr_genio)); |
| 133 | while (resid > 0) { |
| 134 | if ((cnt = iov->iov_len) > resid) |
| 135 | cnt = resid; |
| 136 | if (copyin(iov->iov_base, cp, (unsigned)cnt)) |
| 137 | goto done; |
| 138 | cp += cnt; |
| 139 | resid -= cnt; |
| 140 | iov++; |
| 141 | } |
| 142 | kth->ktr_buf = (caddr_t)ktp; |
| 143 | kth->ktr_len = sizeof (struct ktr_genio) + len; |
| 144 | |
| 145 | ktrwrite(vp, kth); |
| 146 | done: |
| 147 | FREE(kth, M_TEMP); |
| 148 | FREE(ktp, M_TEMP); |
| 149 | } |
| 150 | |
| 151 | ktrpsig(vp, sig, action, mask, code) |
| 152 | struct vnode *vp; |
| 153 | sig_t action; |
| 154 | { |
| 155 | struct ktr_header *kth = ktrgetheader(KTR_PSIG); |
| 156 | struct ktr_psig kp; |
| 157 | |
| 158 | kp.signo = (char)sig; |
| 159 | kp.action = action; |
| 160 | kp.mask = mask; |
| 161 | kp.code = code; |
| 162 | kth->ktr_buf = (caddr_t)&kp; |
| 163 | kth->ktr_len = sizeof (struct ktr_psig); |
| 164 | |
| 165 | ktrwrite(vp, kth); |
| 166 | FREE(kth, M_TEMP); |
| 167 | } |
| 168 | |
| 169 | /* Interface and common routines */ |
| 170 | |
| 171 | /* |
| 172 | * ktrace system call |
| 173 | */ |
| 174 | /* ARGSUSED */ |
| 175 | ktrace(curp, uap, retval) |
| 176 | struct proc *curp; |
| 177 | register struct args { |
| 178 | char *fname; |
| 179 | int ops; |
| 180 | int facs; |
| 181 | int pid; |
| 182 | } *uap; |
| 183 | int *retval; |
| 184 | { |
| 185 | register struct vnode *vp = NULL; |
| 186 | register struct proc *p; |
| 187 | struct pgrp *pg; |
| 188 | int facs = uap->facs & ~KTRFAC_ROOT; |
| 189 | int ops = KTROP(uap->ops); |
| 190 | int descend = uap->ops & KTRFLAG_DESCEND; |
| 191 | int ret = 0; |
| 192 | int error = 0; |
| 193 | struct nameidata nd; |
| 194 | |
| 195 | if (ops != KTROP_CLEAR) { |
| 196 | /* |
| 197 | * an operation which requires a file argument. |
| 198 | */ |
| 199 | nd.ni_segflg = UIO_USERSPACE; |
| 200 | nd.ni_dirp = uap->fname; |
| 201 | if (error = vn_open(&nd, curp, FREAD|FWRITE, 0)) |
| 202 | return (error); |
| 203 | vp = nd.ni_vp; |
| 204 | VOP_UNLOCK(vp); |
| 205 | if (vp->v_type != VREG) { |
| 206 | (void) vn_close(vp, FREAD|FWRITE, curp->p_ucred, curp); |
| 207 | return (EACCES); |
| 208 | } |
| 209 | } |
| 210 | /* |
| 211 | * Clear all uses of the tracefile |
| 212 | */ |
| 213 | if (ops == KTROP_CLEARFILE) { |
| 214 | for (p = allproc; p != NULL; p = p->p_nxt) { |
| 215 | if (p->p_tracep == vp) { |
| 216 | if (ktrcanset(curp, p)) { |
| 217 | p->p_tracep = NULL; |
| 218 | p->p_traceflag = 0; |
| 219 | (void) vn_close(vp, FREAD|FWRITE, |
| 220 | p->p_ucred, p); |
| 221 | } else |
| 222 | error = EPERM; |
| 223 | } |
| 224 | } |
| 225 | goto done; |
| 226 | } |
| 227 | /* |
| 228 | * need something to (un)trace (XXX - why is this here?) |
| 229 | */ |
| 230 | if (!facs) { |
| 231 | error = EINVAL; |
| 232 | goto done; |
| 233 | } |
| 234 | /* |
| 235 | * do it |
| 236 | */ |
| 237 | if (uap->pid < 0) { |
| 238 | /* |
| 239 | * by process group |
| 240 | */ |
| 241 | pg = pgfind(-uap->pid); |
| 242 | if (pg == NULL) { |
| 243 | error = ESRCH; |
| 244 | goto done; |
| 245 | } |
| 246 | for (p = pg->pg_mem; p != NULL; p = p->p_pgrpnxt) |
| 247 | if (descend) |
| 248 | ret |= ktrsetchildren(curp, p, ops, facs, vp); |
| 249 | else |
| 250 | ret |= ktrops(curp, p, ops, facs, vp); |
| 251 | |
| 252 | } else { |
| 253 | /* |
| 254 | * by pid |
| 255 | */ |
| 256 | p = pfind(uap->pid); |
| 257 | if (p == NULL) { |
| 258 | error = ESRCH; |
| 259 | goto done; |
| 260 | } |
| 261 | if (descend) |
| 262 | ret |= ktrsetchildren(curp, p, ops, facs, vp); |
| 263 | else |
| 264 | ret |= ktrops(curp, p, ops, facs, vp); |
| 265 | } |
| 266 | if (!ret) |
| 267 | error = EPERM; |
| 268 | done: |
| 269 | if (vp != NULL) |
| 270 | (void) vn_close(vp, FWRITE, curp->p_ucred, curp); |
| 271 | return (error); |
| 272 | } |
| 273 | |
| 274 | ktrops(curp, p, ops, facs, vp) |
| 275 | struct proc *curp, *p; |
| 276 | struct vnode *vp; |
| 277 | { |
| 278 | |
| 279 | if (!ktrcanset(curp, p)) |
| 280 | return (0); |
| 281 | if (ops == KTROP_SET) { |
| 282 | if (p->p_tracep != vp) { |
| 283 | /* |
| 284 | * if trace file already in use, relinquish |
| 285 | */ |
| 286 | if (p->p_tracep != NULL) |
| 287 | vrele(p->p_tracep); |
| 288 | VREF(vp); |
| 289 | p->p_tracep = vp; |
| 290 | } |
| 291 | p->p_traceflag |= facs; |
| 292 | if (curp->p_ucred->cr_uid == 0) |
| 293 | p->p_traceflag |= KTRFAC_ROOT; |
| 294 | } else { |
| 295 | /* KTROP_CLEAR */ |
| 296 | if (((p->p_traceflag &= ~facs) & KTRFAC_MASK) == 0) { |
| 297 | /* no more tracing */ |
| 298 | p->p_traceflag = 0; |
| 299 | if (p->p_tracep != NULL) { |
| 300 | vrele(p->p_tracep); |
| 301 | p->p_tracep = NULL; |
| 302 | } |
| 303 | } |
| 304 | } |
| 305 | |
| 306 | return (1); |
| 307 | } |
| 308 | |
| 309 | ktrsetchildren(curp, top, ops, facs, vp) |
| 310 | struct proc *curp, *top; |
| 311 | struct vnode *vp; |
| 312 | { |
| 313 | register struct proc *p; |
| 314 | register int ret = 0; |
| 315 | |
| 316 | p = top; |
| 317 | for (;;) { |
| 318 | ret |= ktrops(curp, p, ops, facs, vp); |
| 319 | /* |
| 320 | * If this process has children, descend to them next, |
| 321 | * otherwise do any siblings, and if done with this level, |
| 322 | * follow back up the tree (but not past top). |
| 323 | */ |
| 324 | if (p->p_cptr) |
| 325 | p = p->p_cptr; |
| 326 | else if (p == top) |
| 327 | return (ret); |
| 328 | else if (p->p_osptr) |
| 329 | p = p->p_osptr; |
| 330 | else for (;;) { |
| 331 | p = p->p_pptr; |
| 332 | if (p == top) |
| 333 | return (ret); |
| 334 | if (p->p_osptr) { |
| 335 | p = p->p_osptr; |
| 336 | break; |
| 337 | } |
| 338 | } |
| 339 | } |
| 340 | /*NOTREACHED*/ |
| 341 | } |
| 342 | |
| 343 | ktrwrite(vp, kth) |
| 344 | struct vnode *vp; |
| 345 | register struct ktr_header *kth; |
| 346 | { |
| 347 | struct uio auio; |
| 348 | struct iovec aiov[2]; |
| 349 | register struct proc *p = curproc; /* XXX */ |
| 350 | int error; |
| 351 | |
| 352 | if (vp == NULL) |
| 353 | return; |
| 354 | auio.uio_iov = &aiov[0]; |
| 355 | auio.uio_offset = 0; |
| 356 | auio.uio_segflg = UIO_SYSSPACE; |
| 357 | auio.uio_rw = UIO_WRITE; |
| 358 | aiov[0].iov_base = (caddr_t)kth; |
| 359 | aiov[0].iov_len = sizeof(struct ktr_header); |
| 360 | auio.uio_resid = sizeof(struct ktr_header); |
| 361 | auio.uio_iovcnt = 1; |
| 362 | auio.uio_procp = (struct proc *)0; |
| 363 | if (kth->ktr_len > 0) { |
| 364 | auio.uio_iovcnt++; |
| 365 | aiov[1].iov_base = kth->ktr_buf; |
| 366 | aiov[1].iov_len = kth->ktr_len; |
| 367 | auio.uio_resid += kth->ktr_len; |
| 368 | } |
| 369 | VOP_LOCK(vp); |
| 370 | error = VOP_WRITE(vp, &auio, IO_UNIT|IO_APPEND, p->p_ucred); |
| 371 | VOP_UNLOCK(vp); |
| 372 | if (!error) |
| 373 | return; |
| 374 | /* |
| 375 | * If error encountered, give up tracing on this vnode. |
| 376 | */ |
| 377 | log(LOG_NOTICE, "ktrace write failed, errno %d, tracing stopped\n", |
| 378 | error); |
| 379 | for (p = allproc; p != NULL; p = p->p_nxt) { |
| 380 | if (p->p_tracep == vp) { |
| 381 | p->p_tracep = NULL; |
| 382 | p->p_traceflag = 0; |
| 383 | vrele(vp); |
| 384 | } |
| 385 | } |
| 386 | } |
| 387 | |
| 388 | /* |
| 389 | * Return true if caller has permission to set the ktracing state |
| 390 | * of target. Essentially, the target can't possess any |
| 391 | * more permissions than the caller. KTRFAC_ROOT signifies that |
| 392 | * root previously set the tracing status on the target process, and |
| 393 | * so, only root may further change it. |
| 394 | * |
| 395 | * TODO: check groups. use caller effective gid. |
| 396 | */ |
| 397 | ktrcanset(callp, targetp) |
| 398 | struct proc *callp, *targetp; |
| 399 | { |
| 400 | register struct pcred *caller = callp->p_cred; |
| 401 | register struct pcred *target = targetp->p_cred; |
| 402 | |
| 403 | if ((caller->pc_ucred->cr_uid == target->p_ruid && |
| 404 | target->p_ruid == target->p_svuid && |
| 405 | caller->p_rgid == target->p_rgid && /* XXX */ |
| 406 | target->p_rgid == target->p_svgid && |
| 407 | (targetp->p_traceflag & KTRFAC_ROOT) == 0) || |
| 408 | caller->pc_ucred->cr_uid == 0) |
| 409 | return (1); |
| 410 | |
| 411 | return (0); |
| 412 | } |
| 413 | |
| 414 | #endif |