1/* $OpenBSD: procname.c,v 1.20 2022/02/22 17:35:01 deraadt Exp $ */
2
3/*
4 * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
15 * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
16 * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19#include <sys/types.h>
20#include <sys/signal.h>
21#include <sys/proc.h>
22#include <sys/sysctl.h>
23#include <sys/stat.h>
24
25#include <errno.h>
26#include <stdlib.h>
27#include <string.h>
28#include <unistd.h>
29
30#ifndef nitems
31#define nitems(_a) (sizeof((_a)) / sizeof((_a)[0]))
32#endif
33
34#define is_runnable(p) \
35	((p)->p_stat == SRUN || (p)->p_stat == SIDL || (p)->p_stat == SONPROC)
36#define is_stopped(p) \
37	((p)->p_stat == SSTOP || (p)->p_stat == SDEAD)
38
39static struct kinfo_proc *cmp_procs(struct kinfo_proc *, struct kinfo_proc *);
40char	*get_proc_name(int, char *);
41char	*get_proc_cwd(int);
42
43static struct kinfo_proc *
44cmp_procs(struct kinfo_proc *p1, struct kinfo_proc *p2)
45{
46	if (is_runnable(p1) && !is_runnable(p2))
47		return (p1);
48	if (!is_runnable(p1) && is_runnable(p2))
49		return (p2);
50
51	if (is_stopped(p1) && !is_stopped(p2))
52		return (p1);
53	if (!is_stopped(p1) && is_stopped(p2))
54		return (p2);
55
56	if (p1->p_estcpu > p2->p_estcpu)
57		return (p1);
58	if (p1->p_estcpu < p2->p_estcpu)
59		return (p2);
60
61	if (p1->p_slptime < p2->p_slptime)
62		return (p1);
63	if (p1->p_slptime > p2->p_slptime)
64		return (p2);
65
66	if ((p1->p_flag & P_SINTR) && !(p2->p_flag & P_SINTR))
67		return (p1);
68	if (!(p1->p_flag & P_SINTR) && (p2->p_flag & P_SINTR))
69		return (p2);
70
71	if (strcmp(p1->p_comm, p2->p_comm) < 0)
72		return (p1);
73	if (strcmp(p1->p_comm, p2->p_comm) > 0)
74		return (p2);
75
76	if (p1->p_pid > p2->p_pid)
77		return (p1);
78	return (p2);
79}
80
81char *
82get_proc_name(int fd, char *tty)
83{
84	int		 mib[6] = { CTL_KERN, KERN_PROC, KERN_PROC_PGRP, 0,
85				    sizeof(struct kinfo_proc), 0 };
86	struct stat	 sb;
87	size_t		 len;
88	struct kinfo_proc *buf, *newbuf, *bestp;
89	u_int		 i;
90	char		*name;
91
92	buf = NULL;
93
94	if (stat(tty, &sb) == -1)
95		return (NULL);
96	if ((mib[3] = tcgetpgrp(fd)) == -1)
97		return (NULL);
98
99retry:
100	if (sysctl(mib, nitems(mib), NULL, &len, NULL, 0) == -1)
101		goto error;
102	len = (len * 5) / 4;
103
104	if ((newbuf = realloc(buf, len)) == NULL)
105		goto error;
106	buf = newbuf;
107
108	mib[5] = (int)(len / sizeof(struct kinfo_proc));
109	if (sysctl(mib, nitems(mib), buf, &len, NULL, 0) == -1) {
110		if (errno == ENOMEM)
111			goto retry;
112		goto error;
113	}
114
115	bestp = NULL;
116	for (i = 0; i < len / sizeof (struct kinfo_proc); i++) {
117		if ((dev_t)buf[i].p_tdev != sb.st_rdev)
118			continue;
119		if (bestp == NULL)
120			bestp = &buf[i];
121		else
122			bestp = cmp_procs(&buf[i], bestp);
123	}
124
125	name = NULL;
126	if (bestp != NULL)
127		name = strdup(bestp->p_comm);
128
129	free(buf);
130	return (name);
131
132error:
133	free(buf);
134	return (NULL);
135}
136
137char *
138get_proc_cwd(int fd)
139{
140        int             name[] = { CTL_KERN, KERN_PROC_CWD, 0 };
141        static char     path[PATH_MAX];
142        size_t          pathlen = sizeof path;
143
144        if ((name[2] = tcgetpgrp(fd)) == -1)
145                return (NULL);
146        if (sysctl(name, 3, path, &pathlen, NULL, 0) != 0)
147                return (NULL);
148        return (path);
149}
150