1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 1995 Peter Wemm
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, 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 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include "namespace.h"
29 #include <sys/param.h>
30 #include <sys/elf_common.h>
31 #include <sys/exec.h>
32 #include <sys/sysctl.h>
33
34 #include <stdio.h>
35 #include <string.h>
36 #include <stdlib.h>
37 #include <unistd.h>
38 #include "un-namespace.h"
39
40 #include "libc_private.h"
41
42 /*
43 * Older FreeBSD 2.0, 2.1 and 2.2 had different ps_strings structures and
44 * in different locations.
45 * 1: old_ps_strings at the very top of the stack.
46 * 2: old_ps_strings at SPARE_USRSPACE below the top of the stack.
47 * 3: ps_strings at the very top of the stack.
48 * We only support a kernel providing #3 style ps_strings.
49 *
50 * For historical purposes, a definition of the old ps_strings structure
51 * and location is preserved below:
52 struct old_ps_strings {
53 char *old_ps_argvstr;
54 int old_ps_nargvstr;
55 char *old_ps_envstr;
56 int old_ps_nenvstr;
57 };
58 #define OLD_PS_STRINGS ((struct old_ps_strings *) \
59 (USRSTACK - SPARE_USRSPACE - sizeof(struct old_ps_strings)))
60 */
61
62 #include <stdarg.h>
63
64 #define SPT_BUFSIZE 2048 /* from other parts of sendmail */
65
66 static char *
setproctitle_internal(const char * fmt,va_list ap)67 setproctitle_internal(const char *fmt, va_list ap)
68 {
69 static struct ps_strings *ps_strings;
70 static char *buf = NULL;
71 static char *obuf = NULL;
72 static char **oargv;
73 static int oargc = -1;
74 static char *nargv[2] = { NULL, NULL };
75 char **nargvp;
76 int nargc;
77 int i;
78 size_t len;
79 unsigned long ul_ps_strings;
80
81 if (buf == NULL) {
82 buf = malloc(SPT_BUFSIZE);
83 if (buf == NULL)
84 return (NULL);
85 nargv[0] = buf;
86 }
87
88 if (obuf == NULL ) {
89 obuf = malloc(SPT_BUFSIZE);
90 if (obuf == NULL)
91 return (NULL);
92 *obuf = '\0';
93 }
94
95 if (fmt) {
96 buf[SPT_BUFSIZE - 1] = '\0';
97
98 if (fmt[0] == '-') {
99 /* skip program name prefix */
100 fmt++;
101 len = 0;
102 } else {
103 /* print program name heading for grep */
104 (void)snprintf(buf, SPT_BUFSIZE, "%s: ", _getprogname());
105 len = strlen(buf);
106 }
107
108 /* print the argument string */
109 (void)vsnprintf(buf + len, SPT_BUFSIZE - len, fmt, ap);
110
111 nargvp = nargv;
112 nargc = 1;
113 } else if (*obuf != '\0') {
114 /* Idea from NetBSD - reset the title on fmt == NULL */
115 nargvp = oargv;
116 nargc = oargc;
117 } else
118 /* Nothing to restore */
119 return (NULL);
120
121 if (ps_strings == NULL)
122 (void)_elf_aux_info(AT_PS_STRINGS, &ps_strings,
123 sizeof(ps_strings));
124
125 if (ps_strings == NULL) {
126 len = sizeof(ul_ps_strings);
127 if (sysctlbyname("kern.ps_strings", &ul_ps_strings, &len, NULL,
128 0) == -1)
129 return (NULL);
130 ps_strings = (struct ps_strings *)ul_ps_strings;
131 }
132
133 if (ps_strings == NULL)
134 return (NULL);
135
136 /*
137 * PS_STRINGS points to zeroed memory on a style #2 kernel.
138 * Should not happen.
139 */
140 if (ps_strings->ps_argvstr == NULL)
141 return (NULL);
142
143 /* style #3 */
144 if (oargc == -1) {
145 /* Record our original args */
146 oargc = ps_strings->ps_nargvstr;
147 oargv = ps_strings->ps_argvstr;
148 for (i = len = 0; i < oargc; i++) {
149 /*
150 * The program may have scribbled into its
151 * argv array, e.g., to remove some arguments.
152 * If that has happened, break out before
153 * trying to call strlen on a NULL pointer.
154 */
155 if (oargv[i] == NULL) {
156 oargc = i;
157 break;
158 }
159 snprintf(obuf + len, SPT_BUFSIZE - len, "%s%s",
160 len != 0 ? " " : "", oargv[i]);
161 if (len != 0)
162 len++;
163 len += strlen(oargv[i]);
164 if (len >= SPT_BUFSIZE)
165 break;
166 }
167 }
168 ps_strings->ps_nargvstr = nargc;
169 ps_strings->ps_argvstr = nargvp;
170
171 return (nargvp[0]);
172 }
173
174 static int fast_update = 0;
175
176 void
setproctitle_fast(const char * fmt,...)177 setproctitle_fast(const char *fmt, ...)
178 {
179 va_list ap;
180 char *buf;
181 int oid[4];
182
183 va_start(ap, fmt);
184 buf = setproctitle_internal(fmt, ap);
185 va_end(ap);
186
187 if (buf && !fast_update) {
188 /* Tell the kernel to start looking in user-space */
189 oid[0] = CTL_KERN;
190 oid[1] = KERN_PROC;
191 oid[2] = KERN_PROC_ARGS;
192 oid[3] = -1;
193 sysctl(oid, 4, 0, 0, "", 0);
194 fast_update = 1;
195 }
196 }
197
198 void
setproctitle(const char * fmt,...)199 setproctitle(const char *fmt, ...)
200 {
201 va_list ap;
202 char *buf;
203 int oid[4];
204
205 va_start(ap, fmt);
206 buf = setproctitle_internal(fmt, ap);
207 va_end(ap);
208
209 if (buf != NULL) {
210 /* Set the title into the kernel cached command line */
211 oid[0] = CTL_KERN;
212 oid[1] = KERN_PROC;
213 oid[2] = KERN_PROC_ARGS;
214 oid[3] = -1;
215 sysctl(oid, 4, 0, 0, buf, strlen(buf) + 1);
216 fast_update = 0;
217 }
218 }
219