xref: /openbsd/usr.bin/tmux/procname.c (revision cecf84d4)
1 /* $OpenBSD: procname.c,v 1.14 2015/01/16 06:40:13 deraadt Exp $ */
2 
3 /*
4  * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
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/param.h>	/* MAXCOMLEN */
20 #include <sys/types.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 
39 struct kinfo_proc	*cmp_procs(struct kinfo_proc *, struct kinfo_proc *);
40 char			*get_proc_name(int, char *);
41 
42 struct kinfo_proc *
43 cmp_procs(struct kinfo_proc *p1, struct kinfo_proc *p2)
44 {
45 	if (is_runnable(p1) && !is_runnable(p2))
46 		return (p1);
47 	if (!is_runnable(p1) && is_runnable(p2))
48 		return (p2);
49 
50 	if (is_stopped(p1) && !is_stopped(p2))
51 		return (p1);
52 	if (!is_stopped(p1) && is_stopped(p2))
53 		return (p2);
54 
55 	if (p1->p_estcpu > p2->p_estcpu)
56 		return (p1);
57 	if (p1->p_estcpu < p2->p_estcpu)
58 		return (p2);
59 
60 	if (p1->p_slptime < p2->p_slptime)
61 		return (p1);
62 	if (p1->p_slptime > p2->p_slptime)
63 		return (p2);
64 
65 	if ((p1->p_flag & P_SINTR) && !(p2->p_flag & P_SINTR))
66 		return (p1);
67 	if (!(p1->p_flag & P_SINTR) && (p2->p_flag & P_SINTR))
68 		return (p2);
69 
70 	if (strcmp(p1->p_comm, p2->p_comm) < 0)
71 		return (p1);
72 	if (strcmp(p1->p_comm, p2->p_comm) > 0)
73 		return (p2);
74 
75 	if (p1->p_pid > p2->p_pid)
76 		return (p1);
77 	return (p2);
78 }
79 
80 char *
81 get_proc_name(int fd, char *tty)
82 {
83 	int		 mib[6] = { CTL_KERN, KERN_PROC, KERN_PROC_PGRP, 0,
84 				    sizeof(struct kinfo_proc), 0 };
85 	struct stat	 sb;
86 	size_t		 len;
87 	struct kinfo_proc *buf, *newbuf, *bestp;
88 	u_int		 i;
89 	char		*name;
90 
91 	buf = NULL;
92 
93 	if (stat(tty, &sb) == -1)
94 		return (NULL);
95 	if ((mib[3] = tcgetpgrp(fd)) == -1)
96 		return (NULL);
97 
98 retry:
99 	if (sysctl(mib, nitems(mib), NULL, &len, NULL, 0) == -1)
100 		goto error;
101 	len = (len * 5) / 4;
102 
103 	if ((newbuf = realloc(buf, len)) == NULL)
104 		goto error;
105 	buf = newbuf;
106 
107 	mib[5] = (int)(len / sizeof(struct kinfo_proc));
108 	if (sysctl(mib, nitems(mib), buf, &len, NULL, 0) == -1) {
109 		if (errno == ENOMEM)
110 			goto retry;
111 		goto error;
112 	}
113 
114 	bestp = NULL;
115 	for (i = 0; i < len / sizeof (struct kinfo_proc); i++) {
116 		if ((dev_t)buf[i].p_tdev != sb.st_rdev)
117 			continue;
118 		if (bestp == NULL)
119 			bestp = &buf[i];
120 		else
121 			bestp = cmp_procs(&buf[i], bestp);
122 	}
123 
124 	name = NULL;
125 	if (bestp != NULL)
126 		name = strdup(bestp->p_comm);
127 
128 	free(buf);
129 	return (name);
130 
131 error:
132 	free(buf);
133 	return (NULL);
134 }
135