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 * $Id: ktrace.c,v 1.1 94/10/19 18:36:43 bill Exp $
34 */
35
36
37 #include "sys/param.h"
38 #include "sys/uio.h"
39 #include "sys/file.h"
40 #include "sys/syslog.h"
41 #include "sys/errno.h"
42 #include "proc.h"
43 #include "sys/ktrace.h"
44 #include "malloc.h"
45
46 #include "namei.h"
47 #include "vnode.h"
48
49 #include "prototypes.h"
50
51 struct ktr_header *
ktrgetheader(type)52 ktrgetheader(type)
53 {
54 register struct ktr_header *kth;
55 struct proc *p = curproc; /* XXX */
56
57 MALLOC(kth, struct ktr_header *, sizeof (struct ktr_header),
58 M_TEMP, M_WAITOK);
59 kth->ktr_type = type;
60 microtime(&kth->ktr_time);
61 kth->ktr_pid = p->p_pid;
62 memcpy(kth->ktr_comm, p->p_comm, MAXCOMLEN);
63 return (kth);
64 }
65
66 ktrsyscall(vp, code, narg, args)
67 struct vnode *vp;
68 int code, narg, args[];
69 {
70 struct ktr_header *kth = ktrgetheader(KTR_SYSCALL);
71 struct ktr_syscall *ktp;
72 register len = sizeof(struct ktr_syscall) + (narg * sizeof(int));
73 int *argp, i;
74
75 MALLOC(ktp, struct ktr_syscall *, len, M_TEMP, M_WAITOK);
76 ktp->ktr_code = code;
77 ktp->ktr_narg = narg;
78 argp = (int *)((char *)ktp + sizeof(struct ktr_syscall));
79 for (i = 0; i < narg; i++)
80 *argp++ = args[i];
81 kth->ktr_buf = (caddr_t)ktp;
82 kth->ktr_len = len;
83 ktrwrite(vp, kth);
84 FREE(ktp, M_TEMP);
85 FREE(kth, M_TEMP);
86 }
87
88 ktrsysret(vp, code, error, retval)
89 struct vnode *vp;
90 int code, error, retval;
91 {
92 struct ktr_header *kth = ktrgetheader(KTR_SYSRET);
93 struct ktr_sysret ktp;
94
95 ktp.ktr_code = code;
96 ktp.ktr_error = error;
97 ktp.ktr_retval = retval; /* what about val2 ? */
98
99 kth->ktr_buf = (caddr_t)&ktp;
100 kth->ktr_len = sizeof(struct ktr_sysret);
101
102 ktrwrite(vp, kth);
103 FREE(kth, M_TEMP);
104 }
105
106 ktrnamei(vp, path)
107 struct vnode *vp;
108 char *path;
109 {
110 struct ktr_header *kth = ktrgetheader(KTR_NAMEI);
111
112 kth->ktr_len = strlen(path);
113 kth->ktr_buf = path;
114
115 ktrwrite(vp, kth);
116 FREE(kth, M_TEMP);
117 }
118
119 ktrgenio(vp, fd, rw, iov, len, error)
120 struct vnode *vp;
121 int fd;
122 enum uio_rw rw;
123 register struct iovec *iov;
124 {
125 struct ktr_header *kth = ktrgetheader(KTR_GENIO);
126 register struct ktr_genio *ktp;
127 register caddr_t cp;
128 register int resid = len, cnt;
129
130 if (error)
131 return;
132 MALLOC(ktp, struct ktr_genio *, sizeof(struct ktr_genio) + len,
133 M_TEMP, M_WAITOK);
134 ktp->ktr_fd = fd;
135 ktp->ktr_rw = rw;
136 cp = (caddr_t)((char *)ktp + sizeof (struct ktr_genio));
137 while (resid > 0) {
138 if ((cnt = iov->iov_len) > resid)
139 cnt = resid;
140 if (copyin(curproc, iov->iov_base, cp, (unsigned)cnt))
141 goto done;
142 cp += cnt;
143 resid -= cnt;
144 iov++;
145 }
146 kth->ktr_buf = (caddr_t)ktp;
147 kth->ktr_len = sizeof (struct ktr_genio) + len;
148
149 ktrwrite(vp, kth);
150 done:
151 FREE(kth, M_TEMP);
152 FREE(ktp, M_TEMP);
153 }
154
155 ktrpsig(vp, sig, action, mask, code)
156 struct vnode *vp;
157 sig_t action;
158 {
159 struct ktr_header *kth = ktrgetheader(KTR_PSIG);
160 struct ktr_psig kp;
161
162 kp.signo = (char)sig;
163 kp.action = action;
164 kp.mask = mask;
165 kp.code = code;
166 kth->ktr_buf = (caddr_t)&kp;
167 kth->ktr_len = sizeof (struct ktr_psig);
168
169 ktrwrite(vp, kth);
170 FREE(kth, M_TEMP);
171 }
172
173 ktrvm(vp, func, a1, a2, a3, a4)
174 struct vnode *vp;
175 {
176 struct ktr_header *kth = ktrgetheader(KTR_VM);
177 struct ktr_vm kv;
178
179 kv.func = func;
180 kv.args[0] = a1;
181 kv.args[1] = a2;
182 kv.args[2] = a3;
183 kv.args[3] = a4;
184 kth->ktr_buf = (caddr_t)&kv;
185 kth->ktr_len = sizeof (struct ktr_vm);
186
187 ktrwrite(vp, kth);
188 FREE(kth, M_TEMP);
189 }
190
191 ktrbio(vp, func, a1, a2)
192 struct vnode *vp;
193 {
194 struct ktr_header *kth = ktrgetheader(KTR_BIO);
195 struct ktr_bio kb;
196
197 kb.func = func;
198 kb.args[0] = a1;
199 kb.args[1] = a2;
200 kth->ktr_buf = (caddr_t)&kb;
201 kth->ktr_len = sizeof (struct ktr_bio);
202
203 ktrwrite(vp, kth);
204 FREE(kth, M_TEMP);
205 }
206
207 /* Interface and common routines */
208
209 /*
210 * ktrace system call
211 */
212 /* ARGSUSED */
213 ktrace(curp, uap, retval)
214 struct proc *curp;
215 register struct args {
216 char *fname;
217 int ops;
218 int facs;
219 int pid;
220 } *uap;
221 int *retval;
222 {
223 register struct vnode *vp = NULL;
224 register struct proc *p;
225 struct pgrp *pg;
226 int facs = uap->facs & ~KTRFAC_ROOT;
227 int ops = KTROP(uap->ops);
228 int descend = uap->ops & KTRFLAG_DESCEND;
229 int ret = 0;
230 int error = 0;
231 struct nameidata nd;
232
233 if (ops != KTROP_CLEAR) {
234 /*
235 * an operation which requires a file argument.
236 */
237 nd.ni_segflg = UIO_USERSPACE;
238 nd.ni_dirp = uap->fname;
239 if (error = vn_open(&nd, curp, FREAD|FWRITE, 0))
240 return (error);
241 vp = nd.ni_vp;
242 VOP_UNLOCK(vp);
243 if (vp->v_type != VREG) {
244 (void) vn_close(vp, FREAD|FWRITE, curp->p_ucred, curp);
245 return (EACCES);
246 }
247 }
248 /*
249 * Clear all uses of the tracefile
250 */
251 if (ops == KTROP_CLEARFILE) {
252 for (p = allproc; p != NULL; p = p->p_nxt) {
253 if (p->p_tracep == vp) {
254 if (ktrcanset(curp, p)) {
255 p->p_tracep = NULL;
256 p->p_traceflag = 0;
257 (void) vn_close(vp, FREAD|FWRITE,
258 p->p_ucred, p);
259 } else
260 error = EPERM;
261 }
262 }
263 goto done;
264 }
265 /*
266 * need something to (un)trace (XXX - why is this here?)
267 */
268 if (!facs) {
269 error = EINVAL;
270 goto done;
271 }
272 /*
273 * do it
274 */
275 if (uap->pid < 0) {
276 /*
277 * by process group
278 */
279 pg = pgfind(-uap->pid);
280 if (pg == NULL) {
281 error = ESRCH;
282 goto done;
283 }
284 for (p = pg->pg_mem; p != NULL; p = p->p_pgrpnxt)
285 if (descend)
286 ret |= ktrsetchildren(curp, p, ops, facs, vp);
287 else
288 ret |= ktrops(curp, p, ops, facs, vp);
289
290 } else {
291 /*
292 * by pid
293 */
294 p = pfind(uap->pid);
295 if (p == NULL) {
296 error = ESRCH;
297 goto done;
298 }
299 if (descend)
300 ret |= ktrsetchildren(curp, p, ops, facs, vp);
301 else
302 ret |= ktrops(curp, p, ops, facs, vp);
303 }
304 if (!ret)
305 error = EPERM;
306 done:
307 if (vp != NULL)
308 (void) vn_close(vp, FWRITE, curp->p_ucred, curp);
309 return (error);
310 }
311
312 ktrops(curp, p, ops, facs, vp)
313 struct proc *curp, *p;
314 struct vnode *vp;
315 {
316
317 if (!ktrcanset(curp, p))
318 return (0);
319 if (ops == KTROP_SET) {
320 if (p->p_tracep != vp) {
321 /*
322 * if trace file already in use, relinquish
323 */
324 if (p->p_tracep != NULL)
325 vrele(p->p_tracep);
326 VREF(vp);
327 p->p_tracep = vp;
328 }
329 p->p_traceflag |= facs;
330 if (curp->p_ucred->cr_uid == 0)
331 p->p_traceflag |= KTRFAC_ROOT;
332 } else {
333 /* KTROP_CLEAR */
334 if (((p->p_traceflag &= ~facs) & KTRFAC_MASK) == 0) {
335 /* no more tracing */
336 p->p_traceflag = 0;
337 if (p->p_tracep != NULL) {
338 vrele(p->p_tracep);
339 p->p_tracep = NULL;
340 }
341 }
342 }
343
344 return (1);
345 }
346
347 ktrsetchildren(curp, top, ops, facs, vp)
348 struct proc *curp, *top;
349 struct vnode *vp;
350 {
351 register struct proc *p;
352 register int ret = 0;
353
354 p = top;
355 for (;;) {
356 ret |= ktrops(curp, p, ops, facs, vp);
357 /*
358 * If this process has children, descend to them next,
359 * otherwise do any siblings, and if done with this level,
360 * follow back up the tree (but not past top).
361 */
362 if (p->p_cptr)
363 p = p->p_cptr;
364 else if (p == top)
365 return (ret);
366 else if (p->p_osptr)
367 p = p->p_osptr;
368 else for (;;) {
369 p = p->p_pptr;
370 if (p == top)
371 return (ret);
372 if (p->p_osptr) {
373 p = p->p_osptr;
374 break;
375 }
376 }
377 }
378 /*NOTREACHED*/
379 }
380
381 ktrwrite(vp, kth)
382 struct vnode *vp;
383 register struct ktr_header *kth;
384 {
385 struct uio auio;
386 struct iovec aiov[2];
387 register struct proc *p = curproc; /* XXX */
388 int error;
389
390 if (vp == NULL || p->p_traceflag & 0x20000000)
391 return;
392 p->p_traceflag |= 0x20000000;
393 auio.uio_iov = &aiov[0];
394 auio.uio_offset = 0;
395 auio.uio_segflg = UIO_SYSSPACE;
396 auio.uio_rw = UIO_WRITE;
397 aiov[0].iov_base = (caddr_t)kth;
398 aiov[0].iov_len = sizeof(struct ktr_header);
399 auio.uio_resid = sizeof(struct ktr_header);
400 auio.uio_iovcnt = 1;
401 auio.uio_procp = (struct proc *)0;
402 if (kth->ktr_len > 0) {
403 auio.uio_iovcnt++;
404 aiov[1].iov_base = kth->ktr_buf;
405 aiov[1].iov_len = kth->ktr_len;
406 auio.uio_resid += kth->ktr_len;
407 }
408 VOP_LOCK(vp);
409 error = VOP_WRITE(vp, &auio, IO_UNIT|IO_APPEND, p->p_ucred);
410 VOP_UNLOCK(vp);
411 p->p_traceflag &= ~0x20000000;
412 if (!error)
413 return;
414 /*
415 * If error encountered, give up tracing on this vnode.
416 */
417 log(LOG_NOTICE, "ktrace write failed, errno %d, tracing stopped\n",
418 error);
419 for (p = allproc; p != NULL; p = p->p_nxt) {
420 if (p->p_tracep == vp) {
421 p->p_tracep = NULL;
422 p->p_traceflag = 0;
423 vrele(vp);
424 }
425 }
426 }
427
428 /*
429 * Return true if caller has permission to set the ktracing state
430 * of target. Essentially, the target can't possess any
431 * more permissions than the caller. KTRFAC_ROOT signifies that
432 * root previously set the tracing status on the target process, and
433 * so, only root may further change it.
434 *
435 * TODO: check groups. use caller effective gid.
436 */
437 ktrcanset(callp, targetp)
438 struct proc *callp, *targetp;
439 {
440 register struct pcred *caller = callp->p_cred;
441 register struct pcred *target = targetp->p_cred;
442
443 if ((caller->pc_ucred->cr_uid == target->p_ruid &&
444 target->p_ruid == target->p_svuid &&
445 caller->p_rgid == target->p_rgid && /* XXX */
446 target->p_rgid == target->p_svgid &&
447 (targetp->p_traceflag & KTRFAC_ROOT) == 0) ||
448 caller->pc_ucred->cr_uid == 0)
449 return (1);
450
451 return (0);
452 }
453
454 /* if ktrace inherited, copy flags and add reference to trace vnode */
455 void
ktrace_fork(struct proc * p1,struct proc * p2)456 ktrace_fork(struct proc *p1, struct proc *p2) {
457 if (p1->p_traceflag&KTRFAC_INHERIT) {
458 p2->p_traceflag = p1->p_traceflag;
459 if ((p2->p_tracep = p1->p_tracep) != NULL)
460 VREF(p2->p_tracep);
461 } else {
462 p2->p_traceflag = 0;
463 p2->p_tracep = NULL;
464 }
465 }
466
467 /* ktrace'd process terminating, detach from traced vnode */
ktrace_exit(struct proc * p)468 ktrace_exit(struct proc *p) {
469
470 p->p_traceflag = 0;
471 vrele(p->p_tracep);
472 }
473