setproctitle.c revision 53239 
1/*
2 * Copyright (c) 1995 Peter Wemm <peter@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, is permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice immediately at the beginning of the file, without modification,
10 *    this list of conditions, and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. Absolutely no warranty of function or purpose is made by the author
15 *    Peter Wemm.
16 *
17 * $FreeBSD: head/lib/libc/gen/setproctitle.c 53239 1999-11-16 20:31:58Z phk $
18 */
19
20#include <sys/types.h>
21#include <sys/param.h>
22#include <sys/exec.h>
23#include <sys/sysctl.h>
24
25#include <vm/vm.h>
26#include <vm/vm_param.h>
27#include <vm/pmap.h>
28
29#include <stdio.h>
30#include <string.h>
31#include <stdlib.h>
32#include <unistd.h>
33
34/*
35 * Older FreeBSD 2.0, 2.1 and 2.2 had different ps_strings structures and
36 * in different locations.
37 * 1: old_ps_strings at the very top of the stack.
38 * 2: old_ps_strings at SPARE_USRSPACE below the top of the stack.
39 * 3: ps_strings at the very top of the stack.
40 * This attempts to support a kernel built in the #2 and #3 era.
41 */
42
43struct old_ps_strings {
44	char	*old_ps_argvstr;
45	int	old_ps_nargvstr;
46	char	*old_ps_envstr;
47	int	old_ps_nenvstr;
48};
49#define	OLD_PS_STRINGS ((struct old_ps_strings *) \
50	(USRSTACK - SPARE_USRSPACE - sizeof(struct old_ps_strings)))
51
52#if defined(__STDC__)		/* from other parts of sendmail */
53#include <stdarg.h>
54#else
55#include <varargs.h>
56#endif
57
58
59#define SPT_BUFSIZE 2048	/* from other parts of sendmail */
60extern char * __progname;	/* is this defined in a .h anywhere? */
61
62static struct ps_strings *ps_strings;
63
64void
65#if defined(__STDC__)
66setproctitle(const char *fmt, ...)
67#else
68setproctitle(fmt, va_alist)
69	const char *fmt;
70	va_dcl
71#endif
72{
73	static char buf[SPT_BUFSIZE];
74	static char *ps_argv[2];
75	va_list ap;
76	size_t len;
77	unsigned long ul_ps_strings;
78	int oid[4];
79
80#if defined(__STDC__)
81	va_start(ap, fmt);
82#else
83	va_start(ap);
84#endif
85
86	buf[sizeof(buf) - 1] = '\0';
87	if (fmt) {
88
89		/* print program name heading for grep */
90		(void) snprintf(buf, sizeof(buf) - 1, "%s: ", __progname);
91
92		/*
93		 * can't use return from sprintf, as that is the count of how
94		 * much it wanted to write, not how much it actually did.
95		 */
96
97		len = strlen(buf);
98
99		/* print the argument string */
100		(void) vsnprintf(buf + len, sizeof(buf) - 1 - len, fmt, ap);
101	} else {
102		/* Idea from NetBSD - reset the title on fmt == NULL */
103		strncpy(buf, __progname, sizeof(buf) - 1);
104	}
105
106	va_end(ap);
107
108	/* Set the title into the kernel cached command line */
109	oid[0] = CTL_KERN;
110	oid[1] = KERN_PROC;
111	oid[2] = KERN_PROC_ARGS;
112	oid[3] = getpid();
113	sysctl(oid, 4, 0, 0, buf, strlen(buf) + 1);
114
115	if (ps_strings == NULL) {
116		len = sizeof(ul_ps_strings);
117		if (sysctlbyname("kern.ps_strings", &ul_ps_strings, &len, NULL,
118		    0) == -1)
119			ul_ps_strings = PS_STRINGS;
120		ps_strings = (struct ps_strings *)ul_ps_strings;
121	}
122
123	/* PS_STRINGS points to zeroed memory on a style #2 kernel */
124	if (ps_strings->ps_argvstr) {
125		/* style #3 */
126		ps_argv[0] = buf;
127		ps_argv[1] = NULL;
128		ps_strings->ps_nargvstr = 1;
129		ps_strings->ps_argvstr = ps_argv;
130	} else {
131		/* style #2 */
132		OLD_PS_STRINGS->old_ps_nargvstr = 1;
133		OLD_PS_STRINGS->old_ps_argvstr = buf;
134	}
135}
136