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