5430f7f2bc
We finally got the OK from all contributors with non-trivial commits to relicense systemd from GPL2+ to LGPL2.1+. Some udev bits continue to be GPL2+ for now, but we are looking into relicensing them too, to allow free copy/paste of all code within systemd. The bits that used to be MIT continue to be MIT. The big benefit of the relicensing is that closed source code may now link against libsystemd-login.so and friends.
149 lines
5 KiB
C
149 lines
5 KiB
C
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
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/***
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This file is part of systemd.
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Copyright 2010 Lennart Poettering
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systemd is free software; you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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systemd is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with systemd; If not, see <http://www.gnu.org/licenses/>.
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***/
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#include <unistd.h>
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#include <fcntl.h>
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#include <errno.h>
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#include <string.h>
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#include <sys/stat.h>
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#include "log.h"
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#include "util.h"
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#include "mkdir.h"
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#define POOL_SIZE_MIN 512
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int main(int argc, char *argv[]) {
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int seed_fd = -1, random_fd = -1;
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int ret = EXIT_FAILURE;
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void* buf;
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size_t buf_size = 0;
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ssize_t r;
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FILE *f;
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if (argc != 2) {
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log_error("This program requires one argument.");
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return EXIT_FAILURE;
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}
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log_set_target(LOG_TARGET_AUTO);
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log_parse_environment();
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log_open();
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umask(0022);
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/* Read pool size, if possible */
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if ((f = fopen("/proc/sys/kernel/random/poolsize", "re"))) {
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if (fscanf(f, "%zu", &buf_size) > 0) {
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/* poolsize is in bits on 2.6, but we want bytes */
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buf_size /= 8;
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}
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fclose(f);
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}
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if (buf_size <= POOL_SIZE_MIN)
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buf_size = POOL_SIZE_MIN;
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if (!(buf = malloc(buf_size))) {
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log_error("Failed to allocate buffer.");
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goto finish;
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}
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if (mkdir_parents(RANDOM_SEED, 0755) < 0) {
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log_error("Failed to create directories parents of %s: %m", RANDOM_SEED);
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goto finish;
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}
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/* When we load the seed we read it and write it to the device
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* and then immediately update the saved seed with new data,
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* to make sure the next boot gets seeded differently. */
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if (streq(argv[1], "load")) {
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if ((seed_fd = open(RANDOM_SEED, O_RDWR|O_CLOEXEC|O_NOCTTY|O_CREAT, 0600)) < 0) {
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if ((seed_fd = open(RANDOM_SEED, O_RDONLY|O_CLOEXEC|O_NOCTTY)) < 0) {
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log_error("Failed to open random seed: %m");
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goto finish;
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}
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}
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if ((random_fd = open("/dev/urandom", O_RDWR|O_CLOEXEC|O_NOCTTY, 0600)) < 0) {
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if ((random_fd = open("/dev/urandom", O_WRONLY|O_CLOEXEC|O_NOCTTY, 0600)) < 0) {
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log_error("Failed to open /dev/urandom: %m");
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goto finish;
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}
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}
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if ((r = loop_read(seed_fd, buf, buf_size, false)) <= 0) {
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if (r != 0)
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log_error("Failed to read seed file: %m");
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} else {
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lseek(seed_fd, 0, SEEK_SET);
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if ((r = loop_write(random_fd, buf, (size_t) r, false)) <= 0)
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log_error("Failed to write seed to /dev/random: %s", r < 0 ? strerror(errno) : "short write");
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}
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} else if (streq(argv[1], "save")) {
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if ((seed_fd = open(RANDOM_SEED, O_WRONLY|O_CLOEXEC|O_NOCTTY|O_CREAT, 0600)) < 0) {
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log_error("Failed to open random seed: %m");
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goto finish;
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}
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if ((random_fd = open("/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOCTTY)) < 0) {
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log_error("Failed to open /dev/urandom: %m");
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goto finish;
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}
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} else {
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log_error("Unknown verb %s.", argv[1]);
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goto finish;
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}
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/* This is just a safety measure. Given that we are root and
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* most likely created the file ourselves the mode and owner
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* should be correct anyway. */
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fchmod(seed_fd, 0600);
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fchown(seed_fd, 0, 0);
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if ((r = loop_read(random_fd, buf, buf_size, false)) <= 0)
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log_error("Failed to read new seed from /dev/urandom: %s", r < 0 ? strerror(errno) : "EOF");
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else {
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if ((r = loop_write(seed_fd, buf, (size_t) r, false)) <= 0)
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log_error("Failed to write new random seed file: %s", r < 0 ? strerror(errno) : "short write");
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}
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ret = EXIT_SUCCESS;
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finish:
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if (random_fd >= 0)
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close_nointr_nofail(random_fd);
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if (seed_fd >= 0)
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close_nointr_nofail(seed_fd);
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free(buf);
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return ret;
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}
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