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author | obrien <obrien@FreeBSD.org> | 2013-07-29 20:26:27 +0000 |
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committer | obrien <obrien@FreeBSD.org> | 2013-07-29 20:26:27 +0000 |
commit | 721ce839c7c49ecca90b66a4523be0e6e29c057e (patch) | |
tree | 7321ee5c53e41f64a4e3a37d1e501321672bb5af /sys/dev/random/randomdev.c | |
parent | f6b004c36a12554e599bc79d3f4efc2047574d1b (diff) | |
download | FreeBSD-src-721ce839c7c49ecca90b66a4523be0e6e29c057e.zip FreeBSD-src-721ce839c7c49ecca90b66a4523be0e6e29c057e.tar.gz |
Decouple yarrow from random(4) device.
* Make Yarrow an optional kernel component -- enabled by "YARROW_RNG" option.
The files sha2.c, hash.c, randomdev_soft.c and yarrow.c comprise yarrow.
* random(4) device doesn't really depend on rijndael-*. Yarrow, however, does.
* Add random_adaptors.[ch] which is basically a store of random_adaptor's.
random_adaptor is basically an adapter that plugs in to random(4).
random_adaptor can only be plugged in to random(4) very early in bootup.
Unplugging random_adaptor from random(4) is not supported, and is probably a
bad idea anyway, due to potential loss of entropy pools.
We currently have 3 random_adaptors:
+ yarrow
+ rdrand (ivy.c)
+ nehemeiah
* Remove platform dependent logic from probe.c, and move it into
corresponding registration routines of each random_adaptor provider.
probe.c doesn't do anything other than picking a specific random_adaptor
from a list of registered ones.
* If the kernel doesn't have any random_adaptor adapters present then the
creation of /dev/random is postponed until next random_adaptor is kldload'ed.
* Fix randomdev_soft.c to refer to its own random_adaptor, instead of a
system wide one.
Submitted by: arthurmesh@gmail.com, obrien
Obtained from: Juniper Networks
Reviewed by: obrien
Diffstat (limited to 'sys/dev/random/randomdev.c')
-rw-r--r-- | sys/dev/random/randomdev.c | 78 |
1 files changed, 55 insertions, 23 deletions
diff --git a/sys/dev/random/randomdev.c b/sys/dev/random/randomdev.c index 18b17d8..eeef425 100644 --- a/sys/dev/random/randomdev.c +++ b/sys/dev/random/randomdev.c @@ -70,12 +70,15 @@ static struct cdevsw random_cdevsw = { .d_name = "random", }; -struct random_systat *random_systat; +static struct random_adaptor *random_adaptor; +static eventhandler_tag attach_tag; +static int random_inited; + /* For use with make_dev(9)/destroy_dev(9). */ static struct cdev *random_dev; -/* Used to fake out unused random calls in random_systat */ +/* Used to fake out unused random calls in random_adaptor */ void random_null_func(void) { @@ -88,8 +91,8 @@ random_close(struct cdev *dev __unused, int flags, int fmt __unused, { if ((flags & FWRITE) && (priv_check(td, PRIV_RANDOM_RESEED) == 0) && (securelevel_gt(td->td_ucred, 0) == 0)) { - (*random_systat->reseed)(); - random_systat->seeded = 1; + (*random_adaptor->reseed)(); + random_adaptor->seeded = 1; arc4rand(NULL, 0, 1); /* Reseed arc4random as well. */ } @@ -104,8 +107,8 @@ random_read(struct cdev *dev __unused, struct uio *uio, int flag) void *random_buf; /* Blocking logic */ - if (!random_systat->seeded) - error = (*random_systat->block)(flag); + if (!random_adaptor->seeded) + error = (*random_adaptor->block)(flag); /* The actual read */ if (!error) { @@ -114,7 +117,7 @@ random_read(struct cdev *dev __unused, struct uio *uio, int flag) while (uio->uio_resid > 0 && !error) { c = MIN(uio->uio_resid, PAGE_SIZE); - c = (*random_systat->read)(random_buf, c); + c = (*random_adaptor->read)(random_buf, c); error = uiomove(random_buf, c, uio); } @@ -139,7 +142,7 @@ random_write(struct cdev *dev __unused, struct uio *uio, int flag __unused) error = uiomove(random_buf, c, uio); if (error) break; - (*random_systat->write)(random_buf, c); + (*random_adaptor->write)(random_buf, c); } free(random_buf, M_TEMP); @@ -172,14 +175,37 @@ random_poll(struct cdev *dev __unused, int events, struct thread *td) int revents = 0; if (events & (POLLIN | POLLRDNORM)) { - if (random_systat->seeded) + if (random_adaptor->seeded) revents = events & (POLLIN | POLLRDNORM); else - revents = (*random_systat->poll) (events,td); + revents = (*random_adaptor->poll) (events,td); } return (revents); } +static void +random_initialize(void *p, struct random_adaptor *s) +{ + if (random_inited) { + printf("random: <%s> already initialized\n", + random_adaptor->ident); + return; + } + + random_adaptor = s; + + (s->init)(); + + printf("random: <%s> initialized\n", s->ident); + + random_dev = make_dev_credf(MAKEDEV_ETERNAL_KLD, &random_cdevsw, + RANDOM_MINOR, NULL, UID_ROOT, GID_WHEEL, 0666, "random"); + make_dev_alias(random_dev, "urandom"); /* XXX Deprecated */ + + /* mark random(4) as initialized, to avoid being called again */ + random_inited = 1; +} + /* ARGSUSED */ static int random_modevent(module_t mod __unused, int type, void *data __unused) @@ -188,23 +214,29 @@ random_modevent(module_t mod __unused, int type, void *data __unused) switch (type) { case MOD_LOAD: - random_ident_hardware(&random_systat); - (*random_systat->init)(); - - if (bootverbose) - printf("random: <entropy source, %s>\n", - random_systat->ident); - - random_dev = make_dev_credf(MAKEDEV_ETERNAL_KLD, &random_cdevsw, - RANDOM_MINOR, NULL, UID_ROOT, GID_WHEEL, 0666, "random"); - make_dev_alias(random_dev, "urandom"); /* XXX Deprecated */ + random_ident_hardware(&random_adaptor); + + if (random_adaptor == NULL) { + printf( + "random: No random adaptor attached, postponing initialization\n"); + attach_tag = EVENTHANDLER_REGISTER(random_adaptor_attach, + random_initialize, NULL, EVENTHANDLER_PRI_ANY); + } else { + random_initialize(NULL, random_adaptor); + } break; case MOD_UNLOAD: - (*random_systat->deinit)(); - - destroy_dev(random_dev); + if (random_adaptor != NULL) { + (*random_adaptor->deinit)(); + destroy_dev(random_dev); + } + /* Unregister the event handler */ + if (attach_tag != NULL) { + EVENTHANDLER_DEREGISTER(random_adaptor_attach, + attach_tag); + } break; |