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b688fc87 WJ |
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 |