Home | History | Annotate | Line # | Download | only in pkill
pkill.c revision 1.33
      1 /*	$NetBSD: pkill.c,v 1.33 2022/10/29 08:17:16 simonb Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2002, 2022 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Andrew Doran.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 #ifndef lint
     34 __RCSID("$NetBSD: pkill.c,v 1.33 2022/10/29 08:17:16 simonb Exp $");
     35 #endif /* !lint */
     36 
     37 #include <sys/types.h>
     38 #include <sys/param.h>
     39 #include <sys/sysctl.h>
     40 #include <sys/proc.h>
     41 #include <sys/queue.h>
     42 #include <sys/resource.h>
     43 #include <sys/stat.h>
     44 
     45 #include <stdio.h>
     46 #include <stdlib.h>
     47 #include <limits.h>
     48 #include <string.h>
     49 #include <unistd.h>
     50 #include <signal.h>
     51 #include <regex.h>
     52 #include <ctype.h>
     53 #include <kvm.h>
     54 #include <err.h>
     55 #include <pwd.h>
     56 #include <grp.h>
     57 #include <errno.h>
     58 #include <paths.h>
     59 
     60 #define	STATUS_MATCH	0
     61 #define	STATUS_NOMATCH	1
     62 #define	STATUS_BADUSAGE	2
     63 #define	STATUS_ERROR	3
     64 
     65 enum listtype {
     66 	LT_GENERIC,
     67 	LT_USER,
     68 	LT_GROUP,
     69 	LT_TTY,
     70 	LT_PGRP,
     71 	LT_SID
     72 };
     73 
     74 struct list {
     75 	SLIST_ENTRY(list) li_chain;
     76 	long	li_number;
     77 };
     78 
     79 SLIST_HEAD(listhead, list);
     80 
     81 static struct kinfo_proc2	*plist;
     82 static char	*selected;
     83 static const char *delim = "\n";
     84 static int	nproc;
     85 static int	pgrep;
     86 static int	prenice;
     87 static int	signum = SIGTERM;
     88 static int	nicenum;
     89 static int	newest;
     90 static int	quiet;
     91 static int	inverse;
     92 static int	longfmt;
     93 static int	matchargs;
     94 static int	fullmatch;
     95 static int	cflags = REG_EXTENDED;
     96 static kvm_t	*kd;
     97 static pid_t	mypid;
     98 
     99 static struct listhead euidlist = SLIST_HEAD_INITIALIZER(list);
    100 static struct listhead ruidlist = SLIST_HEAD_INITIALIZER(list);
    101 static struct listhead rgidlist = SLIST_HEAD_INITIALIZER(list);
    102 static struct listhead pgrplist = SLIST_HEAD_INITIALIZER(list);
    103 static struct listhead ppidlist = SLIST_HEAD_INITIALIZER(list);
    104 static struct listhead tdevlist = SLIST_HEAD_INITIALIZER(list);
    105 static struct listhead sidlist = SLIST_HEAD_INITIALIZER(list);
    106 
    107 static void	usage(void) __dead;
    108 static int	killact(const struct kinfo_proc2 *);
    109 static int	reniceact(const struct kinfo_proc2 *);
    110 static int	grepact(const struct kinfo_proc2 *);
    111 static void	makelist(struct listhead *, enum listtype, char *);
    112 
    113 int
    114 main(int argc, char **argv)
    115 {
    116 	char buf[_POSIX2_LINE_MAX], **pargv, *q;
    117 	int i, j, ch, bestidx, rv, criteria;
    118 	int (*action)(const struct kinfo_proc2 *);
    119 	const struct kinfo_proc2 *kp;
    120 	struct list *li;
    121 	const char *p;
    122 	u_int32_t bestsec, bestusec;
    123 	regex_t reg;
    124 	regmatch_t regmatch;
    125 
    126 	setprogname(argv[0]);
    127 
    128 	if (strcmp(getprogname(), "pgrep") == 0) {
    129 		action = grepact;
    130 		pgrep = 1;
    131 	} else if (strcmp(getprogname(), "prenice") == 0) {
    132 		action = reniceact;
    133 		prenice = 1;
    134 	} else {
    135 		action = killact;
    136 		p = argv[1];
    137 
    138 		if (argc > 1 && p[0] == '-') {
    139 			p++;
    140 			i = (int)strtol(p, &q, 10);
    141 			if (*q == '\0') {
    142 				signum = i;
    143 				argv++;
    144 				argc--;
    145 			} else {
    146 				if (strncasecmp(p, "sig", 3) == 0)
    147 					p += 3;
    148 				for (i = 1; i < NSIG; i++)
    149 					if (strcasecmp(sys_signame[i], p) == 0)
    150 						break;
    151 				if (i != NSIG) {
    152 					signum = i;
    153 					argv++;
    154 					argc--;
    155 				}
    156 			}
    157 		}
    158 	}
    159 
    160 	criteria = 0;
    161 
    162 	if (prenice) {
    163 		if (argc < 2)
    164 			usage();
    165 
    166 		if (strcmp(argv[1], "-l") == 0) {
    167 			longfmt = 1;
    168 			argv++;
    169 			argc--;
    170 		}
    171 
    172 		if (argc < 2)
    173 			usage();
    174 
    175 		p = argv[1];
    176 
    177 		i = (int)strtol(p, &q, 10);
    178 		if (*q == '\0') {
    179 			nicenum = i;
    180 			argv++;
    181 			argc--;
    182 		} else
    183 			usage();
    184 	} else {
    185 		while ((ch = getopt(argc, argv, "G:P:U:d:fg:ilnqs:t:u:vx")) != -1)
    186 			switch (ch) {
    187 			case 'G':
    188 				makelist(&rgidlist, LT_GROUP, optarg);
    189 				criteria = 1;
    190 				break;
    191 			case 'P':
    192 				makelist(&ppidlist, LT_GENERIC, optarg);
    193 				criteria = 1;
    194 				break;
    195 			case 'U':
    196 				makelist(&ruidlist, LT_USER, optarg);
    197 				criteria = 1;
    198 				break;
    199 			case 'd':
    200 				if (!pgrep)
    201 					usage();
    202 				delim = optarg;
    203 				break;
    204 			case 'f':
    205 				matchargs = 1;
    206 				break;
    207 			case 'g':
    208 				makelist(&pgrplist, LT_PGRP, optarg);
    209 				criteria = 1;
    210 				break;
    211 			case 'i':
    212 				cflags |= REG_ICASE;
    213 				break;
    214 			case 'l':
    215 				longfmt = 1;
    216 				break;
    217 			case 'n':
    218 				newest = 1;
    219 				criteria = 1;
    220 				break;
    221 			case 'q':
    222 				if (!pgrep)
    223 					usage();
    224 				quiet = 1;
    225 				break;
    226 			case 's':
    227 				makelist(&sidlist, LT_SID, optarg);
    228 				criteria = 1;
    229 				break;
    230 			case 't':
    231 				makelist(&tdevlist, LT_TTY, optarg);
    232 				criteria = 1;
    233 				break;
    234 			case 'u':
    235 				makelist(&euidlist, LT_USER, optarg);
    236 				criteria = 1;
    237 				break;
    238 			case 'v':
    239 				inverse = 1;
    240 				break;
    241 			case 'x':
    242 				fullmatch = 1;
    243 				break;
    244 			default:
    245 				usage();
    246 				/* NOTREACHED */
    247 			}
    248 		argc -= optind;
    249 		argv += optind;
    250 	}
    251 
    252 	if (argc != 0)
    253 		criteria = 1;
    254 	if (!criteria)
    255 		usage();
    256 
    257 	mypid = getpid();
    258 
    259 	/*
    260 	 * Retrieve the list of running processes from the kernel.
    261 	 */
    262 	kd = kvm_openfiles(NULL, NULL, NULL, KVM_NO_FILES, buf);
    263 	if (kd == NULL)
    264 		errx(STATUS_ERROR, "Cannot open kernel files (%s)", buf);
    265 
    266 	plist = kvm_getproc2(kd, KERN_PROC_ALL, 0, sizeof(*plist), &nproc);
    267 	if (plist == NULL)
    268 		errx(STATUS_ERROR, "Cannot get process list (%s)",
    269 		    kvm_geterr(kd));
    270 
    271 	/*
    272 	 * Allocate memory which will be used to keep track of the
    273 	 * selection.
    274 	 */
    275 	if ((selected = calloc(sizeof(*selected), (size_t)nproc)) == NULL)
    276 		err(STATUS_ERROR, "Cannot allocate memory for %d processes",
    277 		    nproc);
    278 
    279 	/*
    280 	 * Refine the selection.
    281 	 */
    282 	for (; *argv != NULL; argv++) {
    283 		if ((rv = regcomp(&reg, *argv, cflags)) != 0) {
    284 			(void)regerror(rv, &reg, buf, sizeof(buf));
    285 			errx(STATUS_BADUSAGE,
    286 			    "Cannot compile regular expression `%s' (%s)",
    287 			    *argv, buf);
    288 		}
    289 
    290 		for (i = 0, kp = plist; i < nproc; i++, kp++) {
    291 			if ((kp->p_flag & P_SYSTEM) != 0 || kp->p_pid == mypid)
    292 				continue;
    293 
    294 			if ((pargv = kvm_getargv2(kd, kp, 0)) == NULL)
    295 				continue;
    296 			if (matchargs) {
    297 
    298 				j = 0;
    299 				while (j < (int)sizeof(buf) && *pargv != NULL) {
    300 					j += snprintf(buf + j, sizeof(buf) - j,
    301 					    pargv[1] != NULL ? "%s " : "%s",
    302 					    pargv[0]);
    303 					pargv++;
    304 				}
    305 			} else if (pargv[0] != NULL)
    306 				strlcpy(buf, pargv[0], sizeof(buf));
    307 			else
    308 				strlcpy(buf, kp->p_comm, sizeof(buf));
    309 
    310 			rv = regexec(&reg, buf, 1, &regmatch, 0);
    311 			if (rv == 0) {
    312 				if (fullmatch) {
    313 					if (regmatch.rm_so == 0 &&
    314 					    regmatch.rm_eo ==
    315 					    (regoff_t)strlen(buf))
    316 						selected[i] = 1;
    317 				} else
    318 					selected[i] = 1;
    319 			} else if (rv != REG_NOMATCH) {
    320 				(void)regerror(rv, &reg, buf, sizeof(buf));
    321 				errx(STATUS_ERROR,
    322 				    "Regular expression evaluation error (%s)",
    323 				    buf);
    324 			}
    325 		}
    326 
    327 		regfree(&reg);
    328 	}
    329 
    330 	for (i = 0, kp = plist; i < nproc; i++, kp++) {
    331 		if ((kp->p_flag & P_SYSTEM) != 0)
    332 			continue;
    333 
    334 		SLIST_FOREACH(li, &ruidlist, li_chain)
    335 			if (kp->p_ruid == (uid_t)li->li_number)
    336 				break;
    337 		if (SLIST_FIRST(&ruidlist) != NULL && li == NULL) {
    338 			selected[i] = 0;
    339 			continue;
    340 		}
    341 
    342 		SLIST_FOREACH(li, &rgidlist, li_chain)
    343 			if (kp->p_rgid == (gid_t)li->li_number)
    344 				break;
    345 		if (SLIST_FIRST(&rgidlist) != NULL && li == NULL) {
    346 			selected[i] = 0;
    347 			continue;
    348 		}
    349 
    350 		SLIST_FOREACH(li, &euidlist, li_chain)
    351 			if (kp->p_uid == (uid_t)li->li_number)
    352 				break;
    353 		if (SLIST_FIRST(&euidlist) != NULL && li == NULL) {
    354 			selected[i] = 0;
    355 			continue;
    356 		}
    357 
    358 		SLIST_FOREACH(li, &ppidlist, li_chain)
    359 			if ((uid_t)kp->p_ppid == (uid_t)li->li_number)
    360 				break;
    361 		if (SLIST_FIRST(&ppidlist) != NULL && li == NULL) {
    362 			selected[i] = 0;
    363 			continue;
    364 		}
    365 
    366 		SLIST_FOREACH(li, &pgrplist, li_chain)
    367 			if (kp->p__pgid == (pid_t)li->li_number)
    368 				break;
    369 		if (SLIST_FIRST(&pgrplist) != NULL && li == NULL) {
    370 			selected[i] = 0;
    371 			continue;
    372 		}
    373 
    374 		SLIST_FOREACH(li, &tdevlist, li_chain) {
    375 			if (li->li_number == -1 &&
    376 			    (kp->p_flag & P_CONTROLT) == 0)
    377 				break;
    378 			if (kp->p_tdev == (uid_t)li->li_number)
    379 				break;
    380 		}
    381 		if (SLIST_FIRST(&tdevlist) != NULL && li == NULL) {
    382 			selected[i] = 0;
    383 			continue;
    384 		}
    385 
    386 		SLIST_FOREACH(li, &sidlist, li_chain)
    387 			if (kp->p_sid == (pid_t)li->li_number)
    388 				break;
    389 		if (SLIST_FIRST(&sidlist) != NULL && li == NULL) {
    390 			selected[i] = 0;
    391 			continue;
    392 		}
    393 
    394 		if (argc == 0)
    395 			selected[i] = 1;
    396 	}
    397 
    398 	if (newest) {
    399 		bestsec = 0;
    400 		bestusec = 0;
    401 		bestidx = -1;
    402 
    403 		for (i = 0, kp = plist; i < nproc; i++, kp++) {
    404 			if (!selected[i])
    405 				continue;
    406 
    407 			if (kp->p_ustart_sec > bestsec ||
    408 			    (kp->p_ustart_sec == bestsec
    409 			    && kp->p_ustart_usec > bestusec)) {
    410 			    	bestsec = kp->p_ustart_sec;
    411 			    	bestusec = kp->p_ustart_usec;
    412 				bestidx = i;
    413 			}
    414 		}
    415 
    416 		(void)memset(selected, 0, (size_t)nproc);
    417 		if (bestidx != -1)
    418 			selected[bestidx] = 1;
    419 	}
    420 
    421 	/*
    422 	 * Take the appropriate action for each matched process, if any.
    423 	 */
    424 	for (i = 0, rv = 0, kp = plist; i < nproc; i++, kp++) {
    425 		if (kp->p_pid == mypid)
    426 			continue;
    427 		if (selected[i]) {
    428 			if (inverse)
    429 				continue;
    430 		} else if (!inverse)
    431 			continue;
    432 
    433 		if ((kp->p_flag & P_SYSTEM) != 0)
    434 			continue;
    435 
    436 		rv |= (*action)(kp);
    437 	}
    438 
    439 	return rv ? STATUS_MATCH : STATUS_NOMATCH;
    440 }
    441 
    442 static void
    443 usage(void)
    444 {
    445 	const char *ustr;
    446 
    447 	if (prenice)
    448 		fprintf(stderr, "Usage: %s [-l] priority pattern ...\n",
    449 		    getprogname());
    450 	else {
    451 		if (pgrep)
    452 			ustr = "[-filnqvx] [-d delim]";
    453 		else
    454 			ustr = "[-signal] [-filnvx]";
    455 
    456 		(void)fprintf(stderr,
    457 		    "Usage: %s %s [-G gid] [-g pgrp] [-P ppid] [-s sid] "
    458 			   "[-t tty]\n"
    459 		    "             [-U uid] [-u euid] pattern ...\n",
    460 			      getprogname(), ustr);
    461 	}
    462 
    463 	exit(STATUS_BADUSAGE);
    464 }
    465 
    466 static int
    467 killact(const struct kinfo_proc2 *kp)
    468 {
    469 	if (longfmt)
    470 		grepact(kp);
    471 	if (kill(kp->p_pid, signum) == -1) {
    472 
    473 		/*
    474 		 * Check for ESRCH, which indicates that the process
    475 		 * disappeared between us matching it and us
    476 		 * signalling it; don't issue a warning about it.
    477 		 */
    478 		if (errno != ESRCH)
    479 			warn("signalling pid %d", (int)kp->p_pid);
    480 
    481 		/*
    482 		 * Return 0 to indicate that the process should not be
    483 		 * considered a match, since we didn't actually get to
    484 		 * signal it.
    485 		 */
    486 		return 0;
    487 	}
    488 
    489 	return 1;
    490 }
    491 
    492 static int
    493 reniceact(const struct kinfo_proc2 *kp)
    494 {
    495 	int oldprio;
    496 
    497 	if (longfmt)
    498 		grepact(kp);
    499 
    500 	errno = 0;
    501 	if ((oldprio = getpriority(PRIO_PROCESS, kp->p_pid)) == -1 &&
    502 	    errno != 0) {
    503 		warn("%d: getpriority", kp->p_pid);
    504 		return 0;
    505 	}
    506 
    507 	if (setpriority(PRIO_PROCESS, kp->p_pid, nicenum) == -1) {
    508 		warn("%d: setpriority", kp->p_pid);
    509 		return 0;
    510 	}
    511 
    512 	(void)printf("%d: old priority %d, new priority %d\n",
    513 	    kp->p_pid, oldprio, nicenum);
    514 
    515 	return 1;
    516 }
    517 
    518 static int
    519 grepact(const struct kinfo_proc2 *kp)
    520 {
    521 	char **argv;
    522 
    523 	if (quiet)
    524 		return 1;
    525 
    526 	if (longfmt && matchargs) {
    527 
    528 		/*
    529 		 * If kvm_getargv2() failed the process has probably
    530 		 * disappeared.  Return 0 to indicate that the process
    531 		 * should not be considered a match, since we are no
    532 		 * longer in a position to output it as a match.
    533 		 */
    534 		if ((argv = kvm_getargv2(kd, kp, 0)) == NULL)
    535 			return 0;
    536 
    537 		(void)printf("%d ", (int)kp->p_pid);
    538 		for (; *argv != NULL; argv++) {
    539 			(void)printf("%s", *argv);
    540 			if (argv[1] != NULL)
    541 				(void)putchar(' ');
    542 		}
    543 	} else if (longfmt)
    544 		(void)printf("%d %s", (int)kp->p_pid, kp->p_comm);
    545 	else
    546 		(void)printf("%d", (int)kp->p_pid);
    547 
    548 	(void)printf("%s", delim);
    549 
    550 	return 1;
    551 }
    552 
    553 static void
    554 makelist(struct listhead *head, enum listtype type, char *src)
    555 {
    556 	struct list *li;
    557 	struct passwd *pw;
    558 	struct group *gr;
    559 	struct stat st;
    560 	char *sp, *ep, buf[MAXPATHLEN];
    561 	const char *p;
    562 	int empty;
    563 	const char *prefix = _PATH_DEV;
    564 
    565 	empty = 1;
    566 
    567 	while ((sp = strsep(&src, ",")) != NULL) {
    568 		if (*sp == '\0')
    569 			usage();
    570 
    571 		if ((li = malloc(sizeof(*li))) == NULL)
    572 			err(STATUS_ERROR, "Cannot allocate %zu bytes",
    573 			    sizeof(*li));
    574 		SLIST_INSERT_HEAD(head, li, li_chain);
    575 		empty = 0;
    576 
    577 		li->li_number = (uid_t)strtol(sp, &ep, 0);
    578 		if (*ep == '\0' && type != LT_TTY) {
    579 			switch (type) {
    580 			case LT_PGRP:
    581 				if (li->li_number == 0)
    582 					li->li_number = getpgrp();
    583 				break;
    584 			case LT_SID:
    585 				if (li->li_number == 0)
    586 					li->li_number = getsid(mypid);
    587 				break;
    588 			default:
    589 				break;
    590 			}
    591 			continue;
    592 		}
    593 
    594 		switch (type) {
    595 		case LT_USER:
    596 			if ((pw = getpwnam(sp)) == NULL)
    597 				errx(STATUS_BADUSAGE, "Unknown user `%s'",
    598 				    sp);
    599 			li->li_number = pw->pw_uid;
    600 			break;
    601 		case LT_GROUP:
    602 			if ((gr = getgrnam(sp)) == NULL)
    603 				errx(STATUS_BADUSAGE, "Unknown group `%s'",
    604 				    sp);
    605 			li->li_number = gr->gr_gid;
    606 			break;
    607 		case LT_TTY:
    608 			p = sp;
    609 			if (*sp == '/')
    610 				prefix = "";
    611 			else if (strcmp(sp, "-") == 0) {
    612 				li->li_number = -1;
    613 				break;
    614 			} else if (strcmp(sp, "co") == 0)
    615 				p = "console";
    616 			else if (strncmp(sp, "tty", 3) == 0)
    617 				/* all set */;
    618 			else if (strncmp(sp, "pts/", 4) == 0)
    619 				/* all set */;
    620 			else if (*ep != '\0' || (strlen(sp) == 2 && *sp == '0'))
    621 				prefix = _PATH_TTY;
    622 			else
    623 				prefix = _PATH_DEV_PTS;
    624 
    625 			(void)snprintf(buf, sizeof(buf), "%s%s", prefix, p);
    626 
    627 			if (stat(buf, &st) == -1) {
    628 				if (errno == ENOENT)
    629 					errx(STATUS_BADUSAGE,
    630 					    "No such tty: `%s'", buf);
    631 				err(STATUS_ERROR, "Cannot access `%s'", buf);
    632 			}
    633 
    634 			if ((st.st_mode & S_IFCHR) == 0)
    635 				errx(STATUS_BADUSAGE, "Not a tty: `%s'", buf);
    636 
    637 			li->li_number = st.st_rdev;
    638 			break;
    639 		default:
    640 			usage();
    641 		}
    642 	}
    643 
    644 	if (empty)
    645 		usage();
    646 }
    647