blob: a5c334ac99d26d25789a5e22ce1173edfbb2710a [file] [log] [blame]
/**
* @file daemon/opd_pipe.c
* Functions handling the $SESSIONDIR/opd_pipe FIFO special file.
* NOTE: This code is dealing with potentially insecure input.
*
* @remark Copyright 2008 OProfile authors
* @remark Read the file COPYING
*
* @author Daniel Hansel
*/
#include "opd_pipe.h"
#include "opd_printf.h"
#include "op_config.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include <sys/stat.h>
static int fifo;
void opd_create_pipe(void)
{
mode_t orig_umask = umask(0111);
if (mkfifo(op_pipe_file, 0666) == -1) {
if (errno != EEXIST) {
perror("oprofiled: couldn't create pipe: ");
exit(EXIT_FAILURE);
}
}
umask(orig_umask);
}
void opd_open_pipe(void)
{
fifo = open(op_pipe_file, O_RDONLY | O_NONBLOCK);
if (fifo == -1) {
perror("oprofiled: couldn't open pipe: ");
exit(EXIT_FAILURE);
}
}
void opd_close_pipe(void)
{
close(fifo);
}
int is_jitconv_requested(void)
{
/* number of dropped (unknown) requests */
static long nr_drops = 0;
/* modulus to output only a few warnings to avoid flooding oprofiled.log */
static int mod_cnt_drops = 1;
FILE * fd;
char line[256];
int i, ret = 0;
/* get a file descriptor to the pipe */
fd = fdopen(fifo, "r");
if (fd == NULL) {
perror("oprofiled: couldn't create file descriptor: ");
exit(EXIT_FAILURE);
}
/* read up to 99 lines to check for 'do_jitconv' */
for (i = 0; i < 99; i++) {
/* just break if no new line is found */
if (fgets(line, 256, fd) == NULL)
break;
line[strlen(line) - 1] = '\0';
if (strstr(line, "do_jitconv") != NULL) {
ret = 1;
} else {
nr_drops++;
if (nr_drops % mod_cnt_drops == 0) {
printf(
"Warning: invalid pipe request received (dropped request(s): %ld)\n",
nr_drops);
/* increase modulus to avoid flooding log file */
mod_cnt_drops *= 5;
}
}
}
return ret;
}