freebsd-dev/lib/libc/gen/setproctitle.c
Alfred Perlstein 9470460d7a Don't segfault if setproctitle(3) is called with NULL initially.
The old buffer was not being initialized and a later str*() op on
it would cause a crash if it wasn't initialized by a previous
call to setproctitle(3) with an actual string.

Noticed by: Ashley Penney <ashp@unloved.org>
2003-07-01 09:45:35 +00:00

177 lines
4.3 KiB
C

/*
* Copyright (c) 1995 Peter Wemm <peter@freebsd.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, is permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice immediately at the beginning of the file, without modification,
* this list of conditions, and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Absolutely no warranty of function or purpose is made by the author
* Peter Wemm.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "namespace.h"
#include <sys/types.h>
#include <sys/param.h>
#include <sys/exec.h>
#include <sys/sysctl.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include "un-namespace.h"
#include "libc_private.h"
/*
* Older FreeBSD 2.0, 2.1 and 2.2 had different ps_strings structures and
* in different locations.
* 1: old_ps_strings at the very top of the stack.
* 2: old_ps_strings at SPARE_USRSPACE below the top of the stack.
* 3: ps_strings at the very top of the stack.
* This attempts to support a kernel built in the #2 and #3 era.
*/
struct old_ps_strings {
char *old_ps_argvstr;
int old_ps_nargvstr;
char *old_ps_envstr;
int old_ps_nenvstr;
};
#define OLD_PS_STRINGS ((struct old_ps_strings *) \
(USRSTACK - SPARE_USRSPACE - sizeof(struct old_ps_strings)))
#include <stdarg.h>
#define SPT_BUFSIZE 2048 /* from other parts of sendmail */
void
setproctitle(const char *fmt, ...)
{
static struct ps_strings *ps_strings;
static char *buf = NULL;
static char *obuf = NULL;
static char **oargv, *kbuf;
static int oargc = -1;
static char *nargv[2] = { NULL, NULL };
char **nargvp;
int nargc;
int i;
va_list ap;
size_t len;
unsigned long ul_ps_strings;
int oid[4];
if (buf == NULL) {
buf = malloc(SPT_BUFSIZE);
if (buf == NULL)
return;
nargv[0] = buf;
}
if (obuf == NULL ) {
obuf = malloc(SPT_BUFSIZE);
if (obuf == NULL)
return;
*obuf = '\0';
}
va_start(ap, fmt);
if (fmt) {
buf[SPT_BUFSIZE - 1] = '\0';
if (fmt[0] == '-') {
/* skip program name prefix */
fmt++;
len = 0;
} else {
/* print program name heading for grep */
(void)snprintf(buf, SPT_BUFSIZE, "%s: ", _getprogname());
len = strlen(buf);
}
/* print the argument string */
(void) vsnprintf(buf + len, SPT_BUFSIZE - len, fmt, ap);
nargvp = nargv;
nargc = 1;
kbuf = buf;
} else if (*obuf != '\0') {
/* Idea from NetBSD - reset the title on fmt == NULL */
nargvp = oargv;
nargc = oargc;
kbuf = obuf;
} else
/* Nothing to restore */
return;
va_end(ap);
/* Set the title into the kernel cached command line */
oid[0] = CTL_KERN;
oid[1] = KERN_PROC;
oid[2] = KERN_PROC_ARGS;
oid[3] = getpid();
sysctl(oid, 4, 0, 0, kbuf, strlen(kbuf) + 1);
if (ps_strings == NULL) {
len = sizeof(ul_ps_strings);
if (sysctlbyname("kern.ps_strings", &ul_ps_strings, &len, NULL,
0) == -1)
ul_ps_strings = PS_STRINGS;
ps_strings = (struct ps_strings *)ul_ps_strings;
}
/* PS_STRINGS points to zeroed memory on a style #2 kernel */
if (ps_strings->ps_argvstr) {
/* style #3 */
if (oargc == -1) {
/* Record our original args */
oargc = ps_strings->ps_nargvstr;
oargv = ps_strings->ps_argvstr;
for (i = len = 0; i < oargc; i++) {
/*
* The program may have scribbled into its
* argv array, e.g., to remove some arguments.
* If that has happened, break out before
* trying to call strlen on a NULL pointer.
*/
if (oargv[i] == NULL) {
oargc = i;
break;
}
snprintf(obuf + len, SPT_BUFSIZE - len, "%s%s",
len ? " " : "", oargv[i]);
if (len)
len++;
len += strlen(oargv[i]);
if (len >= SPT_BUFSIZE)
break;
}
}
ps_strings->ps_nargvstr = nargc;
ps_strings->ps_argvstr = nargvp;
} else {
/* style #2 - we can only restore our first arg :-( */
if (*obuf == '\0')
strncpy(obuf, OLD_PS_STRINGS->old_ps_argvstr,
SPT_BUFSIZE - 1);
OLD_PS_STRINGS->old_ps_nargvstr = 1;
OLD_PS_STRINGS->old_ps_argvstr = nargvp[0];
}
}