/*
* Copyright (c) 2010, 2011, Oracle and/or its affiliates. All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*/
/*
* This compiles to a module that can be preloaded during a build. If this
* is preloaded, it interposes on time(2), gettimeofday(3C), and
* clock_gethrtime(3C) and returns a constant number of seconds since epoch
* when the execname matches one of the desired "programs" and TIME_CONSTANT
* contains an integer value to be returned.
*/
#include <stdlib.h>
#include <ucontext.h>
#include <dlfcn.h>
#include <strings.h>
#include <time.h>
/* The list of programs that we want to use a constant time. */
static char *programs[] = { "autogen", "bash", "cpp", "cc1", "date", "doxygen",
"erl", "javadoc", "ksh", "ksh93", "ld", "perl", "perl5.8.4", "perl5.10",
"ruby", "sh", "uil", NULL };
static int
stack_info(uintptr_t pc, int signo, void *arg)
{
Dl_info info;
void *sym;
if (dladdr1((void *)pc, &info, &sym, RTLD_DL_SYMENT) != NULL) {
if (strstr(info.dli_fname, ".so") == NULL)
*(char **)arg = (char *)info.dli_fname;
}
return (0);
}
static char *
my_execname()
{
static char *execname;
if (execname == NULL) {
ucontext_t ctx;
if (getcontext(&ctx) == 0)
walkcontext(&ctx, stack_info, &execname);
if (execname != NULL) {
char *s = strrchr(execname, '/');
if (s != NULL)
execname = ++s;
}
}
return (execname);
}
static time_t
time_constant()
{
char *execname = my_execname();
time_t result = -1;
if (execname != NULL) {
int i;
for (i = 0; programs[i] != NULL; i++)
if (strcmp(execname, programs[i]) == 0) {
static char *time_string;
if (time_string == NULL)
time_string = getenv("TIME_CONSTANT");
if (time_string != NULL)
result = atoll(time_string);
break;
}
}
return (result);
}
time_t
time(time_t *ptr)
{
time_t result = time_constant();
if (result == (time_t)-1) {
static time_t (*fptr)(time_t *);
if (fptr == NULL)
fptr = (time_t (*)(time_t *))dlsym(RTLD_NEXT, "time");
result = (fptr)(ptr);
} else if (ptr != NULL)
*ptr = result;
return (result);
}
int
gettimeofday(struct timeval *tp, void *tzp)
{
static int (*fptr)(struct timeval *, void *);
int result = -1;
if (fptr == NULL)
fptr = (int (*)(struct timeval *, void *))dlsym(RTLD_NEXT,
"gettimeofday");
if ((result = (fptr)(tp, tzp)) == 0) {
time_t curtime = time_constant();
if (curtime != (time_t)-1)
tp->tv_sec = curtime;
}
return (result);
}
int
clock_gettime(clockid_t clock_id, struct timespec *tp)
{
static int (*fptr)(clockid_t, struct timespec *);
int result = -1;
if (fptr == NULL)
fptr = (int (*)(clockid_t, struct timespec *))dlsym(RTLD_NEXT,
"clock_gettime");
if ((result = (fptr)(clock_id, tp)) == 0) {
time_t curtime = time_constant();
if (curtime != (time_t)-1)
tp->tv_sec = curtime;
}
return (result);
}