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/*
* Copyright (C) 2014-2018 Firejail Authors
*
* This file is part of firejail project
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "firejail.h"
#include <sched.h>
#include <unistd.h>
#include <sys/stat.h>
// converts a numeric cpu value in the corresponding bit mask
static void set_cpu(const char *str) {
if (strlen(str) == 0)
return;
int val = atoi(str);
if (val < 0 || val >= 32) {
fprintf(stderr, "Error: invalid cpu number. Accepted values are between 0 and 31.\n");
exit(1);
}
uint32_t mask = 1;
int i;
for (i = 0; i < val; i++, mask <<= 1);
cfg.cpus |= mask;
}
void read_cpu_list(const char *str) {
EUID_ASSERT();
char *tmp = strdup(str);
if (tmp == NULL)
errExit("strdup");
char *ptr = tmp;
while (*ptr != '\0') {
if (*ptr == ',' || isdigit(*ptr))
;
else {
fprintf(stderr, "Error: invalid cpu list\n");
exit(1);
}
ptr++;
}
char *start = tmp;
ptr = tmp;
while (*ptr != '\0') {
if (*ptr == ',') {
*ptr = '\0';
set_cpu(start);
start = ptr + 1;
}
ptr++;
}
set_cpu(start);
free(tmp);
}
void save_cpu(void) {
if (cfg.cpus == 0)
return;
FILE *fp = fopen(RUN_CPU_CFG, "w");
if (fp) {
fprintf(fp, "%x\n", cfg.cpus);
SET_PERMS_STREAM(fp, 0, 0, 0600);
fclose(fp);
}
else {
fprintf(stderr, "Error: cannot save cpu affinity mask\n");
exit(1);
}
}
void load_cpu(const char *fname) {
if (!fname)
return;
FILE *fp = fopen(fname, "r");
if (fp) {
unsigned tmp;
int rv = fscanf(fp, "%x", &tmp);
if (rv)
cfg.cpus = (uint32_t) tmp;
fclose(fp);
}
else
fwarning("cannot load cpu affinity mask\n");
}
void set_cpu_affinity(void) {
// set cpu affinity
cpu_set_t mask;
CPU_ZERO(&mask);
int i;
uint32_t m = 1;
for (i = 0; i < 32; i++, m <<= 1) {
if (cfg.cpus & m)
CPU_SET(i, &mask);
}
if (sched_setaffinity(0, sizeof(mask), &mask) == -1)
fwarning("cannot set cpu affinity\n");
// verify cpu affinity
cpu_set_t mask2;
CPU_ZERO(&mask2);
if (sched_getaffinity(0, sizeof(mask2), &mask2) == -1)
fwarning("cannot verify cpu affinity\n");
else if (arg_debug) {
if (CPU_EQUAL(&mask, &mask2))
printf("CPU affinity set\n");
else
printf("CPU affinity not set\n");
}
}
static void print_cpu(int pid) {
char *file;
if (asprintf(&file, "/proc/%d/status", pid) == -1) {
errExit("asprintf");
exit(1);
}
EUID_ROOT(); // grsecurity
FILE *fp = fopen(file, "r");
EUID_USER(); // grsecurity
if (!fp) {
printf(" Error: cannot open %s\n", file);
free(file);
return;
}
#define MAXBUF 4096
char buf[MAXBUF];
while (fgets(buf, MAXBUF, fp)) {
if (strncmp(buf, "Cpus_allowed_list:", 18) == 0) {
printf(" %s", buf);
fflush(0);
free(file);
fclose(fp);
return;
}
}
fclose(fp);
free(file);
}
// allow any user to run --cpu.print
void cpu_print_filter(pid_t pid) {
EUID_ASSERT();
// in case the pid is that of a firejail process, use the pid of the first child process
pid = switch_to_child(pid);
// now check if the pid belongs to a firejail sandbox
if (invalid_sandbox(pid)) {
fprintf(stderr, "Error: no valid sandbox\n");
exit(1);
}
print_cpu(pid);
exit(0);
}
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