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random-seed: a few modernizations

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This commit is contained in:
Lennart Poettering 2013-08-13 22:01:55 +02:00
parent d67ca9ab84
commit ce17947045
1 changed files with 52 additions and 35 deletions
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87
src/random-seed/random-seed.c
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@ -32,11 +32,11 @@
#define POOL_SIZE_MIN 512
int main(int argc, char *argv[]) {
int seed_fd = -1, random_fd = -1;
int ret = EXIT_FAILURE;
void* buf;
_cleanup_close_ int seed_fd = -1, random_fd = -1;
_cleanup_free_ void* buf = NULL;
size_t buf_size = 0;
ssize_t r;
ssize_t k;
int r;
FILE *f;
if (argc != 2) {
@ -51,7 +51,8 @@ int main(int argc, char *argv[]) {
umask(0022);
/* Read pool size, if possible */
if ((f = fopen("/proc/sys/kernel/random/poolsize", "re"))) {
f = fopen("/proc/sys/kernel/random/poolsize", "re");
if (f) {
if (fscanf(f, "%zu", &buf_size) > 0) {
/* poolsize is in bits on 2.6, but we want bytes */
buf_size /= 8;
@ -63,13 +64,15 @@ int main(int argc, char *argv[]) {
if (buf_size <= POOL_SIZE_MIN)
buf_size = POOL_SIZE_MIN;
if (!(buf = malloc(buf_size))) {
log_error("Failed to allocate buffer.");
buf = malloc(buf_size);
if (!buf) {
r = log_oom();
goto finish;
}
if (mkdir_parents_label(RANDOM_SEED, 0755) < 0) {
log_error("Failed to create directories parents of %s: %m", RANDOM_SEED);
r = mkdir_parents_label(RANDOM_SEED, 0755);
if (r < 0) {
log_error("Failed to create parent directory of " RANDOM_SEED ": %s", strerror(-r));
goto finish;
}
@ -79,45 +82,64 @@ int main(int argc, char *argv[]) {
if (streq(argv[1], "load")) {
if ((seed_fd = open(RANDOM_SEED, O_RDWR|O_CLOEXEC|O_NOCTTY|O_CREAT, 0600)) < 0) {
if ((seed_fd = open(RANDOM_SEED, O_RDONLY|O_CLOEXEC|O_NOCTTY)) < 0) {
seed_fd = open(RANDOM_SEED, O_RDWR|O_CLOEXEC|O_NOCTTY|O_CREAT, 0600);
if (seed_fd < 0) {
seed_fd = open(RANDOM_SEED, O_RDONLY|O_CLOEXEC|O_NOCTTY);
if (seed_fd < 0) {
log_error("Failed to open random seed: %m");
r = -errno;
goto finish;
}
}
if ((random_fd = open("/dev/urandom", O_RDWR|O_CLOEXEC|O_NOCTTY, 0600)) < 0) {
if ((random_fd = open("/dev/urandom", O_WRONLY|O_CLOEXEC|O_NOCTTY, 0600)) < 0) {
random_fd = open("/dev/urandom", O_RDWR|O_CLOEXEC|O_NOCTTY, 0600);
if (random_fd < 0) {
random_fd = open("/dev/urandom", O_WRONLY|O_CLOEXEC|O_NOCTTY, 0600);
if (random_fd < 0) {
log_error("Failed to open /dev/urandom: %m");
r = -errno;
goto finish;
}
}
if ((r = loop_read(seed_fd, buf, buf_size, false)) <= 0) {
k = loop_read(seed_fd, buf, buf_size, false);
if (k <= 0) {
if (r != 0)
log_error("Failed to read seed file: %m");
r = k == 0 ? -EIO : (int) k;
} else {
lseek(seed_fd, 0, SEEK_SET);
if ((r = loop_write(random_fd, buf, (size_t) r, false)) <= 0)
log_error("Failed to write seed to /dev/urandom: %s",
r < 0 ? strerror(errno) : "short write");
k = loop_write(random_fd, buf, (size_t) k, false);
if (k <= 0) {
log_error("Failed to write seed to /dev/urandom: %s", r < 0 ? strerror(-r) : "short write");
r = k == 0 ? -EIO : (int) k;
}
}
} else if (streq(argv[1], "save")) {
if ((seed_fd = open(RANDOM_SEED, O_WRONLY|O_CLOEXEC|O_NOCTTY|O_CREAT, 0600)) < 0) {
seed_fd = open(RANDOM_SEED, O_WRONLY|O_CLOEXEC|O_NOCTTY|O_CREAT, 0600);
if (seed_fd < 0) {
log_error("Failed to open random seed: %m");
r = -errno;
goto finish;
}
if ((random_fd = open("/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOCTTY)) < 0) {
random_fd = open("/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOCTTY);
if (random_fd < 0) {
log_error("Failed to open /dev/urandom: %m");
r = -errno;
goto finish;
}
} else {
log_error("Unknown verb %s.", argv[1]);
r = -EINVAL;
goto finish;
}
@ -127,23 +149,18 @@ int main(int argc, char *argv[]) {
fchmod(seed_fd, 0600);
fchown(seed_fd, 0, 0);
if ((r = loop_read(random_fd, buf, buf_size, false)) <= 0)
log_error("Failed to read new seed from /dev/urandom: %s", r < 0 ? strerror(errno) : "EOF");
else {
if ((r = loop_write(seed_fd, buf, (size_t) r, false)) <= 0)
log_error("Failed to write new random seed file: %s", r < 0 ? strerror(errno) : "short write");
k = loop_read(random_fd, buf, buf_size, false);
if (k <= 0) {
log_error("Failed to read new seed from /dev/urandom: %s", r < 0 ? strerror(-r) : "EOF");
r = k == 0 ? -EIO : (int) k;
} else {
r = loop_write(seed_fd, buf, (size_t) k, false);
if (r <= 0) {
log_error("Failed to write new random seed file: %s", r < 0 ? strerror(-r) : "short write");
r = k == 0 ? -EIO : (int) k;
}
}
ret = EXIT_SUCCESS;
finish:
if (random_fd >= 0)
close_nointr_nofail(random_fd);
if (seed_fd >= 0)
close_nointr_nofail(seed_fd);
free(buf);
return ret;
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}