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 * 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 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 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