1 /* 2 * Copyright (c) 1995 Peter Wemm <peter@freebsd.org> 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 * $FreeBSD: src/lib/libc/gen/setproctitle.c,v 1.12.2.2 2000/12/10 20:27:08 jdp Exp $ 18 * $DragonFly: src/lib/libc/gen/setproctitle.c,v 1.3 2004/02/02 05:43:14 dillon Exp $ 19 */ 20 21 #include <sys/types.h> 22 #include <sys/param.h> 23 #include <sys/exec.h> 24 #include <sys/sysctl.h> 25 26 #include <vm/vm.h> 27 #include <vm/vm_param.h> 28 #include <vm/pmap.h> 29 30 #include <stdio.h> 31 #include <string.h> 32 #include <stdlib.h> 33 #include <unistd.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 * This attempts to support a kernel built in the #2 and #3 era. 42 */ 43 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 #include <stdarg.h> 54 55 #define SPT_BUFSIZE 2048 /* from other parts of sendmail */ 56 extern char * __progname; /* is this defined in a .h anywhere? */ 57 58 void 59 setproctitle(const char *fmt, ...) 60 { 61 static struct ps_strings *ps_strings; 62 static char buf[SPT_BUFSIZE]; 63 static char obuf[SPT_BUFSIZE]; 64 static char **oargv, *kbuf; 65 static int oargc = -1; 66 static char *nargv[2] = { buf, NULL }; 67 char **nargvp; 68 int nargc; 69 int i; 70 va_list ap; 71 size_t len; 72 unsigned long ul_ps_strings; 73 int oid[4]; 74 75 va_start(ap, fmt); 76 77 if (fmt) { 78 buf[sizeof(buf) - 1] = '\0'; 79 80 if (fmt[0] == '-') { 81 /* skip program name prefix */ 82 fmt++; 83 len = 0; 84 } else { 85 /* print program name heading for grep */ 86 (void) snprintf(buf, sizeof(buf), "%s: ", __progname); 87 len = strlen(buf); 88 } 89 90 /* print the argument string */ 91 (void) vsnprintf(buf + len, sizeof(buf) - len, fmt, ap); 92 93 nargvp = nargv; 94 nargc = 1; 95 kbuf = buf; 96 } else if (*obuf != '\0') { 97 /* Idea from NetBSD - reset the title on fmt == NULL */ 98 nargvp = oargv; 99 nargc = oargc; 100 kbuf = obuf; 101 } else 102 /* Nothing to restore */ 103 return; 104 105 va_end(ap); 106 107 /* Set the title into the kernel cached command line */ 108 oid[0] = CTL_KERN; 109 oid[1] = KERN_PROC; 110 oid[2] = KERN_PROC_ARGS; 111 oid[3] = getpid(); 112 sysctl(oid, 4, 0, 0, kbuf, strlen(kbuf) + 1); 113 114 #ifdef __i386__ 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 ul_ps_strings = PS_STRINGS; 120 ps_strings = (struct ps_strings *)ul_ps_strings; 121 } 122 123 /* PS_STRINGS points to zeroed memory on a style #2 kernel */ 124 if (ps_strings->ps_argvstr) { 125 /* style #3 */ 126 if (oargc == -1) { 127 /* Record our original args */ 128 oargc = ps_strings->ps_nargvstr; 129 oargv = ps_strings->ps_argvstr; 130 for (i = len = 0; i < oargc; i++) { 131 /* 132 * The program may have scribbled into its 133 * argv array, e.g., to remove some arguments. 134 * If that has happened, break out before 135 * trying to call strlen on a NULL pointer. 136 */ 137 if (oargv[i] == NULL) { 138 oargc = i; 139 break; 140 } 141 snprintf(obuf + len, sizeof(obuf) - len, "%s%s", 142 len ? " " : "", oargv[i]); 143 if (len) 144 len++; 145 len += strlen(oargv[i]); 146 if (len >= sizeof(obuf)) 147 break; 148 } 149 } 150 ps_strings->ps_nargvstr = nargc; 151 ps_strings->ps_argvstr = nargvp; 152 } else { 153 /* style #2 - we can only restore our first arg :-( */ 154 if (*obuf == '\0') 155 strncpy(obuf, OLD_PS_STRINGS->old_ps_argvstr, 156 sizeof(obuf) - 1); 157 OLD_PS_STRINGS->old_ps_nargvstr = 1; 158 OLD_PS_STRINGS->old_ps_argvstr = nargvp[0]; 159 } 160 #endif 161 } 162