Add support for variable length optional metadata in softraid(4). This

will allow new optional metadata types to be added without needing to
change the softraid metadata version.

Note that this commit changes the softraid metadata version, however
an upgrade from older metadata is handled automatically. A full backup
prior to upgrading is still strongly recommended.

With feedback from stsp@ and marco.

1 files changed, 40 insertions, 23 deletions

diff --git a/sys/dev/softraid_crypto.c b/sys/dev/softraid_crypto.c
index 73ae5efc3da..80a1983ddeb 100644
--- a/sys/dev/softraid_crypto.c
+++ b/sys/dev/softraid_crypto.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: softraid_crypto.c,v 1.72 2011/09/18 13:11:08 jsing Exp $ */
+/* $OpenBSD: softraid_crypto.c,v 1.73 2011/09/18 19:40:49 jsing Exp $ */
 /*
  * Copyright (c) 2007 Marco Peereboom <marco@peereboom.us>
  * Copyright (c) 2008 Hans-Joerg Hoexer <hshoexer@openbsd.org>
@@ -92,7 +92,7 @@ int		sr_crypto_free_resources(struct sr_discipline *);
 int		sr_crypto_ioctl(struct sr_discipline *,
 		    struct bioc_discipline *);
 int		sr_crypto_meta_opt_handler(struct sr_discipline *,
-		    struct sr_meta_opt *);
+		    struct sr_meta_opt_hdr *);
 int		sr_crypto_write(struct cryptop *);
 int		sr_crypto_rw(struct sr_workunit *);
 int		sr_crypto_rw2(struct sr_workunit *, struct sr_crypto_wu *);
@@ -154,9 +154,12 @@ sr_crypto_create(struct sr_discipline *sd, struct bioc_createraid *bc,
 	/* Create crypto optional metadata. */
 	omi = malloc(sizeof(struct sr_meta_opt_item), M_DEVBUF,
 	    M_WAITOK | M_ZERO);
-	omi->omi_om.somi.som_type = SR_OPT_CRYPTO;
+	omi->omi_som = malloc(sizeof(struct sr_meta_crypto), M_DEVBUF,
+	    M_WAITOK | M_ZERO);
+	omi->omi_som->som_type = SR_OPT_CRYPTO;
+	omi->omi_som->som_length = sizeof(struct sr_meta_crypto);
 	SLIST_INSERT_HEAD(&sd->sd_meta_opt, omi, omi_link);
-	sd->mds.mdd_crypto.scr_meta = &omi->omi_om.somi.som_meta.smm_crypto;
+	sd->mds.mdd_crypto.scr_meta = (struct sr_meta_crypto *)omi->omi_som;
 	sd->sd_meta->ssdi.ssd_opt_no++;
 
 	sd->mds.mdd_crypto.key_disk = NULL;
@@ -676,6 +679,7 @@ sr_crypto_create_key_disk(struct sr_discipline *sd, dev_t dev)
 	struct sr_metadata	*sm = NULL;
 	struct sr_meta_chunk    *km;
 	struct sr_meta_opt_item *omi = NULL;
+	struct sr_meta_keydisk	*skm;
 	struct sr_chunk		*key_disk = NULL;
 	struct disklabel	label;
 	struct vnode		*vn;
@@ -793,14 +797,17 @@ sr_crypto_create_key_disk(struct sr_discipline *sd, dev_t dev)
 	    sizeof(sd->mds.mdd_crypto.scr_maskkey));
 
 	/* Copy mask key to optional metadata area. */
-	sm->ssdi.ssd_opt_no = 1;
 	omi = malloc(sizeof(struct sr_meta_opt_item), M_DEVBUF,
 	    M_WAITOK | M_ZERO);
-	omi->omi_om.somi.som_type = SR_OPT_KEYDISK;
-	bcopy(sd->mds.mdd_crypto.scr_maskkey,
-	    omi->omi_om.somi.som_meta.smm_keydisk.skm_maskkey,
-	    sizeof(omi->omi_om.somi.som_meta.smm_keydisk.skm_maskkey));
+	omi->omi_som = malloc(sizeof(struct sr_meta_keydisk), M_DEVBUF,
+	    M_WAITOK | M_ZERO);
+	omi->omi_som->som_type = SR_OPT_KEYDISK;
+	omi->omi_som->som_length = sizeof(struct sr_meta_keydisk);
+	skm = (struct sr_meta_keydisk *)omi->omi_som;
+	bcopy(sd->mds.mdd_crypto.scr_maskkey, &skm->skm_maskkey,
+	    sizeof(skm->skm_maskkey));
 	SLIST_INSERT_HEAD(&fakesd->sd_meta_opt, omi, omi_link);
+	fakesd->sd_meta->ssdi.ssd_opt_no++;
 
 	/* Save metadata. */
 	if (sr_meta_save(fakesd, SR_META_DIRTY)) {
@@ -838,7 +845,10 @@ sr_crypto_read_key_disk(struct sr_discipline *sd, dev_t dev)
 {
 	struct sr_softc		*sc = sd->sd_sc;
 	struct sr_metadata	*sm = NULL;
-	struct sr_meta_opt      *om;
+	struct sr_meta_opt_item *omi, *omi_next;
+	struct sr_meta_opt_hdr	*omh;
+	struct sr_meta_keydisk	*skm;
+	struct sr_meta_opt_head som;
 	struct sr_chunk		*key_disk = NULL;
 	struct disklabel	label;
 	struct vnode		*vn = NULL;
@@ -920,26 +930,33 @@ sr_crypto_read_key_disk(struct sr_discipline *sd, dev_t dev)
 	    sizeof(key_disk->src_meta));
 
 	/* Read mask key from optional metadata. */
-	om = (struct sr_meta_opt *)((u_int8_t *)(sm + 1) +
-	    sizeof(struct sr_meta_chunk) * sm->ssdi.ssd_chunk_no);
-	for (c = 0; c < sm->ssdi.ssd_opt_no; c++) {
-		if (om->somi.som_type == SR_OPT_KEYDISK) {
-			bcopy(&om->somi.som_meta.smm_keydisk.skm_maskkey,
+	SLIST_INIT(&som);
+	sr_meta_opt_load(sc, sm, &som);
+	SLIST_FOREACH(omi, &som, omi_link) {
+		omh = omi->omi_som;
+		if (omh->som_type == SR_OPT_KEYDISK) {
+			skm = (struct sr_meta_keydisk *)omh;
+			bcopy(&skm->skm_maskkey,
 			    sd->mds.mdd_crypto.scr_maskkey,
 			    sizeof(sd->mds.mdd_crypto.scr_maskkey));
-			break;
-		} else if (om->somi.som_type == SR_OPT_CRYPTO) {
-			bcopy(&om->somi.som_meta.smm_crypto,
+		} else if (omh->som_type == SR_OPT_CRYPTO) {
+			/* Original keydisk format with key in crypto area. */
+			bcopy(omh + sizeof(struct sr_meta_opt_hdr),
 			    sd->mds.mdd_crypto.scr_maskkey,
 			    sizeof(sd->mds.mdd_crypto.scr_maskkey));
-			break;
 		}
-		om++;
 	}
 
 	open = 0;
 
 done:
+	for (omi = SLIST_FIRST(&som); omi != SLIST_END(&som); omi = omi_next) {
+		omi_next = SLIST_NEXT(omi, omi_link);
+		if (omi->omi_som)
+			free(omi->omi_som, M_DEVBUF);
+		free(omi, M_DEVBUF);
+	}
+
 	if (sm)
 		free(sm, M_DEVBUF);
 
@@ -1150,12 +1167,12 @@ bad:
 }
 
 int
-sr_crypto_meta_opt_handler(struct sr_discipline *sd, struct sr_meta_opt *om)
+sr_crypto_meta_opt_handler(struct sr_discipline *sd, struct sr_meta_opt_hdr *om)
 {
 	int rv = EINVAL;
 
-	if (om->somi.som_type == SR_OPT_CRYPTO) {
-		sd->mds.mdd_crypto.scr_meta =  &om->somi.som_meta.smm_crypto;
+	if (om->som_type == SR_OPT_CRYPTO) {
+		sd->mds.mdd_crypto.scr_meta = (struct sr_meta_crypto *)om;
 		rv = 0;
 	}