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 __FBSDID("$FreeBSD$"); 30 31 #include "namespace.h" 32 #include <sys/param.h> 33 #include <sys/elf_common.h> 34 #include <sys/exec.h> 35 #include <sys/sysctl.h> 36 37 #include <stdio.h> 38 #include <string.h> 39 #include <stdlib.h> 40 #include <unistd.h> 41 #include "un-namespace.h" 42 43 #include "libc_private.h" 44 45 /* 46 * Older FreeBSD 2.0, 2.1 and 2.2 had different ps_strings structures and 47 * in different locations. 48 * 1: old_ps_strings at the very top of the stack. 49 * 2: old_ps_strings at SPARE_USRSPACE below the top of the stack. 50 * 3: ps_strings at the very top of the stack. 51 * We only support a kernel providing #3 style ps_strings. 52 * 53 * For historical purposes, a definition of the old ps_strings structure 54 * and location is preserved below: 55 struct old_ps_strings { 56 char *old_ps_argvstr; 57 int old_ps_nargvstr; 58 char *old_ps_envstr; 59 int old_ps_nenvstr; 60 }; 61 #define OLD_PS_STRINGS ((struct old_ps_strings *) \ 62 (USRSTACK - SPARE_USRSPACE - sizeof(struct old_ps_strings))) 63 */ 64 65 #include <stdarg.h> 66 67 #define SPT_BUFSIZE 2048 /* from other parts of sendmail */ 68 69 static char * 70 setproctitle_internal(const char *fmt, va_list ap) 71 { 72 static struct ps_strings *ps_strings; 73 static char *buf = NULL; 74 static char *obuf = NULL; 75 static char **oargv; 76 static int oargc = -1; 77 static char *nargv[2] = { NULL, NULL }; 78 char **nargvp; 79 int nargc; 80 int i; 81 size_t len; 82 unsigned long ul_ps_strings; 83 84 if (buf == NULL) { 85 buf = malloc(SPT_BUFSIZE); 86 if (buf == NULL) 87 return (NULL); 88 nargv[0] = buf; 89 } 90 91 if (obuf == NULL ) { 92 obuf = malloc(SPT_BUFSIZE); 93 if (obuf == NULL) 94 return (NULL); 95 *obuf = '\0'; 96 } 97 98 if (fmt) { 99 buf[SPT_BUFSIZE - 1] = '\0'; 100 101 if (fmt[0] == '-') { 102 /* skip program name prefix */ 103 fmt++; 104 len = 0; 105 } else { 106 /* print program name heading for grep */ 107 (void)snprintf(buf, SPT_BUFSIZE, "%s: ", _getprogname()); 108 len = strlen(buf); 109 } 110 111 /* print the argument string */ 112 (void)vsnprintf(buf + len, SPT_BUFSIZE - len, fmt, ap); 113 114 nargvp = nargv; 115 nargc = 1; 116 } else if (*obuf != '\0') { 117 /* Idea from NetBSD - reset the title on fmt == NULL */ 118 nargvp = oargv; 119 nargc = oargc; 120 } else 121 /* Nothing to restore */ 122 return (NULL); 123 124 if (ps_strings == NULL) 125 (void)_elf_aux_info(AT_PS_STRINGS, &ps_strings, 126 sizeof(ps_strings)); 127 128 if (ps_strings == NULL) { 129 len = sizeof(ul_ps_strings); 130 if (sysctlbyname("kern.ps_strings", &ul_ps_strings, &len, NULL, 131 0) == -1) 132 return (NULL); 133 ps_strings = (struct ps_strings *)ul_ps_strings; 134 } 135 136 if (ps_strings == NULL) 137 return (NULL); 138 139 /* 140 * PS_STRINGS points to zeroed memory on a style #2 kernel. 141 * Should not happen. 142 */ 143 if (ps_strings->ps_argvstr == NULL) 144 return (NULL); 145 146 /* style #3 */ 147 if (oargc == -1) { 148 /* Record our original args */ 149 oargc = ps_strings->ps_nargvstr; 150 oargv = ps_strings->ps_argvstr; 151 for (i = len = 0; i < oargc; i++) { 152 /* 153 * The program may have scribbled into its 154 * argv array, e.g., to remove some arguments. 155 * If that has happened, break out before 156 * trying to call strlen on a NULL pointer. 157 */ 158 if (oargv[i] == NULL) { 159 oargc = i; 160 break; 161 } 162 snprintf(obuf + len, SPT_BUFSIZE - len, "%s%s", 163 len != 0 ? " " : "", oargv[i]); 164 if (len != 0) 165 len++; 166 len += strlen(oargv[i]); 167 if (len >= SPT_BUFSIZE) 168 break; 169 } 170 } 171 ps_strings->ps_nargvstr = nargc; 172 ps_strings->ps_argvstr = nargvp; 173 174 return (nargvp[0]); 175 } 176 177 static int fast_update = 0; 178 179 void 180 setproctitle_fast(const char *fmt, ...) 181 { 182 va_list ap; 183 char *buf; 184 int oid[4]; 185 186 va_start(ap, fmt); 187 buf = setproctitle_internal(fmt, ap); 188 va_end(ap); 189 190 if (buf && !fast_update) { 191 /* Tell the kernel to start looking in user-space */ 192 oid[0] = CTL_KERN; 193 oid[1] = KERN_PROC; 194 oid[2] = KERN_PROC_ARGS; 195 oid[3] = -1; 196 sysctl(oid, 4, 0, 0, "", 0); 197 fast_update = 1; 198 } 199 } 200 201 void 202 setproctitle(const char *fmt, ...) 203 { 204 va_list ap; 205 char *buf; 206 int oid[4]; 207 208 va_start(ap, fmt); 209 buf = setproctitle_internal(fmt, ap); 210 va_end(ap); 211 212 if (buf != NULL) { 213 /* Set the title into the kernel cached command line */ 214 oid[0] = CTL_KERN; 215 oid[1] = KERN_PROC; 216 oid[2] = KERN_PROC_ARGS; 217 oid[3] = -1; 218 sysctl(oid, 4, 0, 0, buf, strlen(buf) + 1); 219 fast_update = 0; 220 } 221 } 222