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random-seed: configure logging before use and define main through macro

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This commit is contained in:
Zbigniew Jędrzejewski-Szmek 2018-11-16 15:06:40 +01:00
parent 2ab2a55bd6
commit 72d0d7a628
1 changed files with 27 additions and 46 deletions
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73
src/random-seed/random-seed.c
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@ -19,7 +19,7 @@
#define POOL_SIZE_MIN 512 #define POOL_SIZE_MIN 512
#define POOL_SIZE_MAX (10*1024*1024) #define POOL_SIZE_MAX (10*1024*1024)
int main(int argc, char *argv[]) { static int run(int argc, char *argv[]) {
_cleanup_close_ int seed_fd = -1, random_fd = -1; _cleanup_close_ int seed_fd = -1, random_fd = -1;
bool read_seed_file, write_seed_file; bool read_seed_file, write_seed_file;
_cleanup_free_ void* buf = NULL; _cleanup_free_ void* buf = NULL;
@ -29,15 +29,15 @@ int main(int argc, char *argv[]) {
FILE *f; FILE *f;
int r; int r;
if (argc != 2) {
log_error("This program requires one argument.");
return EXIT_FAILURE;
}
log_set_target(LOG_TARGET_AUTO); log_set_target(LOG_TARGET_AUTO);
log_parse_environment(); log_parse_environment();
log_open(); log_open();
if (argc != 2) {
log_error("This program requires one argument.");
return -EINVAL;
}
umask(0022); umask(0022);
/* Read pool size, if possible */ /* Read pool size, if possible */
@ -54,10 +54,8 @@ int main(int argc, char *argv[]) {
buf_size = POOL_SIZE_MIN; buf_size = POOL_SIZE_MIN;
r = mkdir_parents_label(RANDOM_SEED, 0755); r = mkdir_parents_label(RANDOM_SEED, 0755);
if (r < 0) { if (r < 0)
log_error_errno(r, "Failed to create directory " RANDOM_SEED_DIR ": %m"); return log_error_errno(r, "Failed to create directory " RANDOM_SEED_DIR ": %m");
goto finish;
}
/* When we load the seed we read it and write it to the device and then immediately update the saved seed with /* When we load the seed we read it and write it to the device and then immediately update the saved seed with
* new data, to make sure the next boot gets seeded differently. */ * new data, to make sure the next boot gets seeded differently. */
@ -78,10 +76,7 @@ int main(int argc, char *argv[]) {
open_rw_error, "Failed to open " RANDOM_SEED " for writing: %m"); open_rw_error, "Failed to open " RANDOM_SEED " for writing: %m");
r = log_full_errno(missing ? LOG_DEBUG : LOG_ERR, r = log_full_errno(missing ? LOG_DEBUG : LOG_ERR,
errno, "Failed to open " RANDOM_SEED " for reading: %m"); errno, "Failed to open " RANDOM_SEED " for reading: %m");
if (missing) return missing ? 0 : r;
r = 0;
goto finish;
} }
} else } else
write_seed_file = true; write_seed_file = true;
@ -91,10 +86,8 @@ int main(int argc, char *argv[]) {
write_seed_file = false; write_seed_file = false;
random_fd = open("/dev/urandom", O_WRONLY|O_CLOEXEC|O_NOCTTY, 0600); random_fd = open("/dev/urandom", O_WRONLY|O_CLOEXEC|O_NOCTTY, 0600);
if (random_fd < 0) { if (random_fd < 0)
r = log_error_errno(errno, "Failed to open /dev/urandom: %m"); return log_error_errno(errno, "Failed to open /dev/urandom: %m");
goto finish;
}
} }
read_seed_file = true; read_seed_file = true;
@ -102,40 +95,31 @@ int main(int argc, char *argv[]) {
} else if (streq(argv[1], "save")) { } else if (streq(argv[1], "save")) {
random_fd = open("/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOCTTY); random_fd = open("/dev/urandom", O_RDONLY|O_CLOEXEC|O_NOCTTY);
if (random_fd < 0) { if (random_fd < 0)
r = log_error_errno(errno, "Failed to open /dev/urandom: %m"); return log_error_errno(errno, "Failed to open /dev/urandom: %m");
goto finish;
}
seed_fd = open(RANDOM_SEED, O_WRONLY|O_CLOEXEC|O_NOCTTY|O_CREAT, 0600); seed_fd = open(RANDOM_SEED, O_WRONLY|O_CLOEXEC|O_NOCTTY|O_CREAT, 0600);
if (seed_fd < 0) { if (seed_fd < 0)
r = log_error_errno(errno, "Failed to open " RANDOM_SEED ": %m"); return log_error_errno(errno, "Failed to open " RANDOM_SEED ": %m");
goto finish;
}
read_seed_file = false; read_seed_file = false;
write_seed_file = true; write_seed_file = true;
} else { } else {
log_error("Unknown verb '%s'.", argv[1]); log_error("Unknown verb '%s'.", argv[1]);
r = -EINVAL; return -EINVAL;
goto finish;
} }
if (fstat(seed_fd, &st) < 0) { if (fstat(seed_fd, &st) < 0)
r = log_error_errno(errno, "Failed to stat() seed file " RANDOM_SEED ": %m"); return log_error_errno(errno, "Failed to stat() seed file " RANDOM_SEED ": %m");
goto finish;
}
/* If the seed file is larger than what we expect, then honour the existing size and save/restore as much as it says */ /* If the seed file is larger than what we expect, then honour the existing size and save/restore as much as it says */
if ((uint64_t) st.st_size > buf_size) if ((uint64_t) st.st_size > buf_size)
buf_size = MIN(st.st_size, POOL_SIZE_MAX); buf_size = MIN(st.st_size, POOL_SIZE_MAX);
buf = malloc(buf_size); buf = malloc(buf_size);
if (!buf) { if (!buf)
r = log_oom(); return log_oom();
goto finish;
}
if (read_seed_file) { if (read_seed_file) {
sd_id128_t mid; sd_id128_t mid;
@ -172,7 +156,6 @@ int main(int argc, char *argv[]) {
} }
if (write_seed_file) { if (write_seed_file) {
/* This is just a safety measure. Given that we are root and /* This is just a safety measure. Given that we are root and
* most likely created the file ourselves the mode and owner * most likely created the file ourselves the mode and owner
* should be correct anyway. */ * should be correct anyway. */
@ -180,21 +163,19 @@ int main(int argc, char *argv[]) {
(void) fchown(seed_fd, 0, 0); (void) fchown(seed_fd, 0, 0);
k = loop_read(random_fd, buf, buf_size, false); k = loop_read(random_fd, buf, buf_size, false);
if (k < 0) { if (k < 0)
r = log_error_errno(k, "Failed to read new seed from /dev/urandom: %m"); return log_error_errno(k, "Failed to read new seed from /dev/urandom: %m");
goto finish;
}
if (k == 0) { if (k == 0) {
log_error("Got EOF while reading from /dev/urandom."); log_error("Got EOF while reading from /dev/urandom.");
r = -EIO; return -EIO;
goto finish;
} }
r = loop_write(seed_fd, buf, (size_t) k, false); r = loop_write(seed_fd, buf, (size_t) k, false);
if (r < 0) if (r < 0)
log_error_errno(r, "Failed to write new random seed file: %m"); return log_error_errno(r, "Failed to write new random seed file: %m");
} }
finish: return r;
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
} }
DEFINE_MAIN_FUNCTION(run);