1 /*
2 * Copyright (c) 1995 Peter Wemm <[email protected]>
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
18 #include <sys/cdefs.h>
19 __FBSDID("$FreeBSD$");
20
21 #include "namespace.h"
22 #include <sys/param.h>
23 #include <sys/elf_common.h>
24 #include <sys/exec.h>
25 #include <sys/sysctl.h>
26
27 #include <stdio.h>
28 #include <string.h>
29 #include <stdlib.h>
30 #include <unistd.h>
31 #include "un-namespace.h"
32
33 #include "libc_private.h"
34
35 /*
36 * Older FreeBSD 2.0, 2.1 and 2.2 had different ps_strings structures and
37 * in different locations.
38 * 1: old_ps_strings at the very top of the stack.
39 * 2: old_ps_strings at SPARE_USRSPACE below the top of the stack.
40 * 3: ps_strings at the very top of the stack.
41 * We only support a kernel providing #3 style ps_strings.
42 *
43 * For historical purposes, a definition of the old ps_strings structure
44 * and location is preserved below:
45 struct old_ps_strings {
46 char *old_ps_argvstr;
47 int old_ps_nargvstr;
48 char *old_ps_envstr;
49 int old_ps_nenvstr;
50 };
51 #define OLD_PS_STRINGS ((struct old_ps_strings *) \
52 (USRSTACK - SPARE_USRSPACE - sizeof(struct old_ps_strings)))
53 */
54
55 #include <stdarg.h>
56
57 #define SPT_BUFSIZE 2048 /* from other parts of sendmail */
58
59 static char *
setproctitle_internal(const char * fmt,va_list ap)60 setproctitle_internal(const char *fmt, va_list ap)
61 {
62 static struct ps_strings *ps_strings;
63 static char *buf = NULL;
64 static char *obuf = NULL;
65 static char **oargv;
66 static int oargc = -1;
67 static char *nargv[2] = { NULL, NULL };
68 char **nargvp;
69 int nargc;
70 int i;
71 size_t len;
72 unsigned long ul_ps_strings;
73
74 if (buf == NULL) {
75 buf = malloc(SPT_BUFSIZE);
76 if (buf == NULL)
77 return (NULL);
78 nargv[0] = buf;
79 }
80
81 if (obuf == NULL ) {
82 obuf = malloc(SPT_BUFSIZE);
83 if (obuf == NULL)
84 return (NULL);
85 *obuf = '\0';
86 }
87
88 if (fmt) {
89 buf[SPT_BUFSIZE - 1] = '\0';
90
91 if (fmt[0] == '-') {
92 /* skip program name prefix */
93 fmt++;
94 len = 0;
95 } else {
96 /* print program name heading for grep */
97 (void)snprintf(buf, SPT_BUFSIZE, "%s: ", _getprogname());
98 len = strlen(buf);
99 }
100
101 /* print the argument string */
102 (void)vsnprintf(buf + len, SPT_BUFSIZE - len, fmt, ap);
103
104 nargvp = nargv;
105 nargc = 1;
106 } else if (*obuf != '\0') {
107 /* Idea from NetBSD - reset the title on fmt == NULL */
108 nargvp = oargv;
109 nargc = oargc;
110 } else
111 /* Nothing to restore */
112 return (NULL);
113
114 if (ps_strings == NULL)
115 (void)_elf_aux_info(AT_PS_STRINGS, &ps_strings,
116 sizeof(ps_strings));
117
118 if (ps_strings == NULL) {
119 len = sizeof(ul_ps_strings);
120 if (sysctlbyname("kern.ps_strings", &ul_ps_strings, &len, NULL,
121 0) == -1)
122 return (NULL);
123 ps_strings = (struct ps_strings *)ul_ps_strings;
124 }
125
126 if (ps_strings == NULL)
127 return (NULL);
128
129 /*
130 * PS_STRINGS points to zeroed memory on a style #2 kernel.
131 * Should not happen.
132 */
133 if (ps_strings->ps_argvstr == NULL)
134 return (NULL);
135
136 /* style #3 */
137 if (oargc == -1) {
138 /* Record our original args */
139 oargc = ps_strings->ps_nargvstr;
140 oargv = ps_strings->ps_argvstr;
141 for (i = len = 0; i < oargc; i++) {
142 /*
143 * The program may have scribbled into its
144 * argv array, e.g., to remove some arguments.
145 * If that has happened, break out before
146 * trying to call strlen on a NULL pointer.
147 */
148 if (oargv[i] == NULL) {
149 oargc = i;
150 break;
151 }
152 snprintf(obuf + len, SPT_BUFSIZE - len, "%s%s",
153 len != 0 ? " " : "", oargv[i]);
154 if (len != 0)
155 len++;
156 len += strlen(oargv[i]);
157 if (len >= SPT_BUFSIZE)
158 break;
159 }
160 }
161 ps_strings->ps_nargvstr = nargc;
162 ps_strings->ps_argvstr = nargvp;
163
164 return (nargvp[0]);
165 }
166
167 static int fast_update = 0;
168
169 void
setproctitle_fast(const char * fmt,...)170 setproctitle_fast(const char *fmt, ...)
171 {
172 va_list ap;
173 char *buf;
174 int oid[4];
175
176 va_start(ap, fmt);
177 buf = setproctitle_internal(fmt, ap);
178 va_end(ap);
179
180 if (buf && !fast_update) {
181 /* Tell the kernel to start looking in user-space */
182 oid[0] = CTL_KERN;
183 oid[1] = KERN_PROC;
184 oid[2] = KERN_PROC_ARGS;
185 oid[3] = -1;
186 sysctl(oid, 4, 0, 0, "", 0);
187 fast_update = 1;
188 }
189 }
190
191 void
setproctitle(const char * fmt,...)192 setproctitle(const char *fmt, ...)
193 {
194 va_list ap;
195 char *buf;
196 int oid[4];
197
198 va_start(ap, fmt);
199 buf = setproctitle_internal(fmt, ap);
200 va_end(ap);
201
202 if (buf != NULL) {
203 /* Set the title into the kernel cached command line */
204 oid[0] = CTL_KERN;
205 oid[1] = KERN_PROC;
206 oid[2] = KERN_PROC_ARGS;
207 oid[3] = -1;
208 sysctl(oid, 4, 0, 0, buf, strlen(buf) + 1);
209 fast_update = 0;
210 }
211 }
212