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 <sys/cdefs.h> 29 #include "namespace.h" 30 #include <sys/param.h> 31 #include <sys/elf_common.h> 32 #include <sys/exec.h> 33 #include <sys/sysctl.h> 34 35 #include <stdio.h> 36 #include <string.h> 37 #include <stdlib.h> 38 #include <unistd.h> 39 #include "un-namespace.h" 40 41 #include "libc_private.h" 42 43 /* 44 * Older FreeBSD 2.0, 2.1 and 2.2 had different ps_strings structures and 45 * in different locations. 46 * 1: old_ps_strings at the very top of the stack. 47 * 2: old_ps_strings at SPARE_USRSPACE below the top of the stack. 48 * 3: ps_strings at the very top of the stack. 49 * We only support a kernel providing #3 style ps_strings. 50 * 51 * For historical purposes, a definition of the old ps_strings structure 52 * and location is preserved below: 53 struct old_ps_strings { 54 char *old_ps_argvstr; 55 int old_ps_nargvstr; 56 char *old_ps_envstr; 57 int old_ps_nenvstr; 58 }; 59 #define OLD_PS_STRINGS ((struct old_ps_strings *) \ 60 (USRSTACK - SPARE_USRSPACE - sizeof(struct old_ps_strings))) 61 */ 62 63 #include <stdarg.h> 64 65 #define SPT_BUFSIZE 2048 /* from other parts of sendmail */ 66 67 static char * 68 setproctitle_internal(const char *fmt, va_list ap) 69 { 70 static struct ps_strings *ps_strings; 71 static char *buf = NULL; 72 static char *obuf = NULL; 73 static char **oargv; 74 static int oargc = -1; 75 static char *nargv[2] = { NULL, NULL }; 76 char **nargvp; 77 int nargc; 78 int i; 79 size_t len; 80 unsigned long ul_ps_strings; 81 82 if (buf == NULL) { 83 buf = malloc(SPT_BUFSIZE); 84 if (buf == NULL) 85 return (NULL); 86 nargv[0] = buf; 87 } 88 89 if (obuf == NULL ) { 90 obuf = malloc(SPT_BUFSIZE); 91 if (obuf == NULL) 92 return (NULL); 93 *obuf = '\0'; 94 } 95 96 if (fmt) { 97 buf[SPT_BUFSIZE - 1] = '\0'; 98 99 if (fmt[0] == '-') { 100 /* skip program name prefix */ 101 fmt++; 102 len = 0; 103 } else { 104 /* print program name heading for grep */ 105 (void)snprintf(buf, SPT_BUFSIZE, "%s: ", _getprogname()); 106 len = strlen(buf); 107 } 108 109 /* print the argument string */ 110 (void)vsnprintf(buf + len, SPT_BUFSIZE - len, fmt, ap); 111 112 nargvp = nargv; 113 nargc = 1; 114 } else if (*obuf != '\0') { 115 /* Idea from NetBSD - reset the title on fmt == NULL */ 116 nargvp = oargv; 117 nargc = oargc; 118 } else 119 /* Nothing to restore */ 120 return (NULL); 121 122 if (ps_strings == NULL) 123 (void)_elf_aux_info(AT_PS_STRINGS, &ps_strings, 124 sizeof(ps_strings)); 125 126 if (ps_strings == NULL) { 127 len = sizeof(ul_ps_strings); 128 if (sysctlbyname("kern.ps_strings", &ul_ps_strings, &len, NULL, 129 0) == -1) 130 return (NULL); 131 ps_strings = (struct ps_strings *)ul_ps_strings; 132 } 133 134 if (ps_strings == NULL) 135 return (NULL); 136 137 /* 138 * PS_STRINGS points to zeroed memory on a style #2 kernel. 139 * Should not happen. 140 */ 141 if (ps_strings->ps_argvstr == NULL) 142 return (NULL); 143 144 /* style #3 */ 145 if (oargc == -1) { 146 /* Record our original args */ 147 oargc = ps_strings->ps_nargvstr; 148 oargv = ps_strings->ps_argvstr; 149 for (i = len = 0; i < oargc; i++) { 150 /* 151 * The program may have scribbled into its 152 * argv array, e.g., to remove some arguments. 153 * If that has happened, break out before 154 * trying to call strlen on a NULL pointer. 155 */ 156 if (oargv[i] == NULL) { 157 oargc = i; 158 break; 159 } 160 snprintf(obuf + len, SPT_BUFSIZE - len, "%s%s", 161 len != 0 ? " " : "", oargv[i]); 162 if (len != 0) 163 len++; 164 len += strlen(oargv[i]); 165 if (len >= SPT_BUFSIZE) 166 break; 167 } 168 } 169 ps_strings->ps_nargvstr = nargc; 170 ps_strings->ps_argvstr = nargvp; 171 172 return (nargvp[0]); 173 } 174 175 static int fast_update = 0; 176 177 void 178 setproctitle_fast(const char *fmt, ...) 179 { 180 va_list ap; 181 char *buf; 182 int oid[4]; 183 184 va_start(ap, fmt); 185 buf = setproctitle_internal(fmt, ap); 186 va_end(ap); 187 188 if (buf && !fast_update) { 189 /* Tell the kernel to start looking in user-space */ 190 oid[0] = CTL_KERN; 191 oid[1] = KERN_PROC; 192 oid[2] = KERN_PROC_ARGS; 193 oid[3] = -1; 194 sysctl(oid, 4, 0, 0, "", 0); 195 fast_update = 1; 196 } 197 } 198 199 void 200 setproctitle(const char *fmt, ...) 201 { 202 va_list ap; 203 char *buf; 204 int oid[4]; 205 206 va_start(ap, fmt); 207 buf = setproctitle_internal(fmt, ap); 208 va_end(ap); 209 210 if (buf != NULL) { 211 /* Set the title into the kernel cached command line */ 212 oid[0] = CTL_KERN; 213 oid[1] = KERN_PROC; 214 oid[2] = KERN_PROC_ARGS; 215 oid[3] = -1; 216 sysctl(oid, 4, 0, 0, buf, strlen(buf) + 1); 217 fast_update = 0; 218 } 219 } 220