diff options
| author | NeilBrown <neilb@suse.de> | 2009-03-10 16:28:18 +1100 |
|---|---|---|
| committer | NeilBrown <neilb@suse.de> | 2009-03-10 16:28:18 +1100 |
| commit | bfb7ea78e49bd851ee9fb73cac813123cb78b1de (patch) | |
| tree | 617e54cda3b12d8eca51d958d0915459be52721e /super-ddf.c | |
| parent | bceedeec55eeb5fc37065fed39159a04cffc1307 (diff) | |
| download | mdadm-bfb7ea78e49bd851ee9fb73cac813123cb78b1de.tar.gz mdadm-bfb7ea78e49bd851ee9fb73cac813123cb78b1de.tar.xz mdadm-bfb7ea78e49bd851ee9fb73cac813123cb78b1de.zip | |
ddf: use better random number generation.
use /dev/urandom rather than calls to 'random()' if possible.
Signed-off-by: NeilBrown <neilb@suse.de>
Diffstat (limited to 'super-ddf.c')
| -rw-r--r-- | super-ddf.c | 23 |
1 files changed, 15 insertions, 8 deletions
diff --git a/super-ddf.c b/super-ddf.c index 8725eab..009fbfb 100644 --- a/super-ddf.c +++ b/super-ddf.c @@ -1493,10 +1493,20 @@ static int update_super_ddf(struct supertype *st, struct mdinfo *info, return rv; } +__u32 random32(void) +{ + __u32 rv; + int rfd = open("/dev/urandom", O_RDONLY); + if (rfd < 0 || read(rfd, &rv, 4) != 4) + rv = random(); + if (rfd >= 0) + close(rfd); + return rv; +} + static void make_header_guid(char *guid) { __u32 stamp; - int rfd; /* Create a DDF Header of Virtual Disk GUID */ /* 24 bytes of fiction required. @@ -1511,11 +1521,8 @@ static void make_header_guid(char *guid) memcpy(guid+12, &stamp, 4); stamp = __cpu_to_be32(time(0) - DECADE); memcpy(guid+16, &stamp, 4); - rfd = open("/dev/urandom", O_RDONLY); - if (rfd < 0 || read(rfd, &stamp, 4) != 4) - stamp = random(); + stamp = random32(); memcpy(guid+20, &stamp, 4); - if (rfd >= 0) close(rfd); } static int init_super_ddf_bvd(struct supertype *st, @@ -2148,12 +2155,12 @@ static int add_to_super_ddf(struct supertype *st, tm = localtime(&now); sprintf(dd->disk.guid, "%8s%04d%02d%02d", T10, tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday); - *(__u32*)(dd->disk.guid + 16) = random(); - *(__u32*)(dd->disk.guid + 20) = random(); + *(__u32*)(dd->disk.guid + 16) = random32(); + *(__u32*)(dd->disk.guid + 20) = random32(); do { /* Cannot be bothered finding a CRC of some irrelevant details*/ - dd->disk.refnum = random(); + dd->disk.refnum = random32(); for (i = __be16_to_cpu(ddf->active->max_pd_entries) - 1; i >= 0; i--) if (ddf->phys->entries[i].refnum == dd->disk.refnum) |