Publish libshare protocols, use enum-based API

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes openzfs#13165

lib/libshare/libshare.c

@@ -45,77 +45,63 @@
 		.sa_mountpoint = path, \
 		.sa_shareopts = shareopts, \
 	}
-#define	find_proto(pcol) \
-	/* CSTYLED */ \
-	({ \
-		sa_fstype_t prot = { \
-			.protocol = pcol, \
-		}; \
-		avl_find(&fstypes, &prot, NULL); \
-	})
-
-static avl_tree_t fstypes;
-
-static int
-fstypes_compar(const void *lhs, const void *rhs)
-{
-	const sa_fstype_t *l = lhs, *r = rhs;
-	int cmp = strcmp(l->protocol, r->protocol);
-	return ((0 < cmp) - (cmp < 0));
-}
 
-__attribute__((constructor)) static void
-libshare_init(void)
-{
-	avl_create(&fstypes, fstypes_compar,
-	    sizeof (sa_fstype_t), offsetof(sa_fstype_t, node));
-	avl_add(&fstypes, &libshare_nfs_type);
-	avl_add(&fstypes, &libshare_smb_type);
-}
+#define	VALIDATE_PROTOCOL(proto, ...) \
+	if ((proto) < 0 || (proto) >= SA_PROTOCOL_COUNT) \
+		return __VA_ARGS__
+
+const char *const sa_protocol_names[SA_PROTOCOL_COUNT] = {
+	[SA_PROTOCOL_NFS] = "nfs",
+	[SA_PROTOCOL_SMB] = "smb",
+};
+
+static const sa_fstype_t *fstypes[SA_PROTOCOL_COUNT] =
+	{&libshare_nfs_type, &libshare_smb_type};
 
 int
 sa_enable_share(const char *zfsname, const char *mountpoint,
-    const char *shareopts, const char *protocol)
+    const char *shareopts, enum sa_protocol protocol)
 {
-	sa_fstype_t *fstype = find_proto(protocol);
-	if (!fstype)
-		return (SA_INVALID_PROTOCOL);
+	VALIDATE_PROTOCOL(protocol, SA_INVALID_PROTOCOL);
 
 	const struct sa_share_impl args =
 	    init_share(zfsname, mountpoint, shareopts);
-	return (fstype->enable_share(&args));
+	return (fstypes[protocol]->enable_share(&args));
 }
 
 int
-sa_disable_share(const char *mountpoint, const char *protocol)
+sa_disable_share(const char *mountpoint, enum sa_protocol protocol)
 {
-	sa_fstype_t *fstype = find_proto(protocol);
-	if (!fstype)
-		return (SA_INVALID_PROTOCOL);
+	VALIDATE_PROTOCOL(protocol, SA_INVALID_PROTOCOL);
 
 	const struct sa_share_impl args = init_share(NULL, mountpoint, NULL);
-	return (fstype->disable_share(&args));
+	return (fstypes[protocol]->disable_share(&args));
 }
 
 boolean_t
-sa_is_shared(const char *mountpoint, const char *protocol)
+sa_is_shared(const char *mountpoint, enum sa_protocol protocol)
 {
-	sa_fstype_t *fstype = find_proto(protocol);
-	if (!fstype)
-		return (B_FALSE);
+	VALIDATE_PROTOCOL(protocol, B_FALSE);
 
 	const struct sa_share_impl args = init_share(NULL, mountpoint, NULL);
-	return (fstype->is_shared(&args));
+	return (fstypes[protocol]->is_shared(&args));
 }
 
 void
-sa_commit_shares(const char *protocol)
+sa_commit_shares(enum sa_protocol protocol)
+{
+	/* CSTYLED */
+	VALIDATE_PROTOCOL(protocol, );
+
+	fstypes[protocol]->commit_shares();
+}
+
+int
+sa_validate_shareopts(const char *options, enum sa_protocol protocol)
 {
-	sa_fstype_t *fstype = find_proto(protocol);
-	if (!fstype)
-		return;
+	VALIDATE_PROTOCOL(protocol, SA_INVALID_PROTOCOL);
 
-	fstype->commit_shares();
+	return (fstypes[protocol]->validate_shareopts(options));
 }
 
 /*
@@ -205,13 +191,3 @@ sa_errorstr(int err)
 		return (errstr);
 	}
 }
-
-int
-sa_validate_shareopts(const char *options, const char *protocol)
-{
-	sa_fstype_t *fstype = find_proto(protocol);
-	if (!fstype)
-		return (SA_INVALID_PROTOCOL);
-
-	return (fstype->validate_shareopts(options));
-}

lib/libshare/libshare_impl.h

@@ -27,26 +27,20 @@
 #ifndef _LIBSPL_LIBSHARE_IMPL_H
 #define	_LIBSPL_LIBSHARE_IMPL_H
 
-#include <sys/avl.h>
-
 typedef const struct sa_share_impl {
 	const char *sa_zfsname;
 	const char *sa_mountpoint;
 	const char *sa_shareopts;
 } *sa_share_impl_t;
 
 typedef struct {
-	const char *protocol;
-
 	int (*const enable_share)(sa_share_impl_t share);
 	int (*const disable_share)(sa_share_impl_t share);
 	boolean_t (*const is_shared)(sa_share_impl_t share);
 	int (*const validate_shareopts)(const char *shareopts);
 	int (*const commit_shares)(void);
-
-	avl_node_t node;
 } sa_fstype_t;
 
-extern sa_fstype_t libshare_nfs_type, libshare_smb_type;
+extern const sa_fstype_t libshare_nfs_type, libshare_smb_type;
 
 #endif /* _LIBSPL_LIBSHARE_IMPL_H */

lib/libshare/os/freebsd/nfs.c

@@ -186,9 +186,7 @@ nfs_commit_shares(void)
 	return (SA_OK);
 }
 
-sa_fstype_t libshare_nfs_type = {
-	.protocol = "nfs",
-
+const sa_fstype_t libshare_nfs_type = {
 	.enable_share = nfs_enable_share,
 	.disable_share = nfs_disable_share,
 	.is_shared = nfs_is_shared,

lib/libshare/os/freebsd/smb.c

@@ -76,9 +76,7 @@ smb_update_shares(void)
 	return (0);
 }
 
-sa_fstype_t libshare_smb_type = {
-	.protocol = "smb",
-
+const sa_fstype_t libshare_smb_type = {
 	.enable_share = smb_enable_share,
 	.disable_share = smb_disable_share,
 	.is_shared = smb_is_share_active,

lib/libshare/os/linux/nfs.c

@@ -481,9 +481,7 @@ nfs_commit_shares(void)
 	return (libzfs_run_process(argv[0], argv, 0));
 }
 
-sa_fstype_t libshare_nfs_type = {
-	.protocol = "nfs",
-
+const sa_fstype_t libshare_nfs_type = {
 	.enable_share = nfs_enable_share,
 	.disable_share = nfs_disable_share,
 	.is_shared = nfs_is_shared,

lib/libshare/os/linux/smb.c

@@ -363,9 +363,7 @@ smb_update_shares(void)
 	return (0);
 }
 
-sa_fstype_t libshare_smb_type = {
-	.protocol = "smb",
-
+const sa_fstype_t libshare_smb_type = {
 	.enable_share = smb_enable_share,
 	.disable_share = smb_disable_share,
 	.is_shared = smb_is_share_active,

lib/libspl/include/libshare.h

@@ -72,14 +72,24 @@
 /* initialization */
 _LIBSPL_LIBSHARE_H const char *sa_errorstr(int);
 
+/* available protocols */
+enum sa_protocol {
+	SA_PROTOCOL_NFS,
+	SA_PROTOCOL_SMB, /* ABI: add before _COUNT */
+	SA_PROTOCOL_COUNT,
+};
+
+/* lower-case */
+_LIBSPL_LIBSHARE_H const char *const sa_protocol_names[SA_PROTOCOL_COUNT];
+
 /* share control */
 _LIBSPL_LIBSHARE_H int sa_enable_share(const char *, const char *, const char *,
-    const char *);
-_LIBSPL_LIBSHARE_H int sa_disable_share(const char *, const char *);
-_LIBSPL_LIBSHARE_H boolean_t sa_is_shared(const char *, const char *);
-_LIBSPL_LIBSHARE_H void sa_commit_shares(const char *);
+    enum sa_protocol);
+_LIBSPL_LIBSHARE_H int sa_disable_share(const char *, enum sa_protocol);
+_LIBSPL_LIBSHARE_H boolean_t sa_is_shared(const char *, enum sa_protocol);
+_LIBSPL_LIBSHARE_H void sa_commit_shares(enum sa_protocol);
 
 /* protocol specific interfaces */
-_LIBSPL_LIBSHARE_H int sa_validate_shareopts(const char *, const char *);
+_LIBSPL_LIBSHARE_H int sa_validate_shareopts(const char *, enum sa_protocol);
 
 #endif /* _LIBSPL_LIBSHARE_H */

lib/libzfs/libzfs_changelist.c

@@ -345,7 +345,7 @@ changelist_rename(prop_changelist_t *clp, const char *src, const char *dst)
  * unshare all the datasets in the list.
  */
 int
-changelist_unshare(prop_changelist_t *clp, const zfs_share_proto_t *proto)
+changelist_unshare(prop_changelist_t *clp, const enum sa_protocol *proto)
 {
 	prop_changenode_t *cn;
 	uu_avl_walk_t *walk;
@@ -363,7 +363,8 @@ changelist_unshare(prop_changelist_t *clp, const zfs_share_proto_t *proto)
 			ret = -1;
 	}
 
-	zfs_commit_proto(proto);
+	for (const enum sa_protocol *p = proto; *p != SA_NO_PROTOCOL; ++p)
+		sa_commit_shares(*p);
 	uu_avl_walk_end(walk);
 
 	return (ret);

lib/libzfs/libzfs_dataset.c

@@ -1418,14 +1418,15 @@ zfs_valid_proplist(libzfs_handle_t *hdl, zfs_type_t type, nvlist_t *nvl,
 			    prop == ZFS_PROP_SHARESMB) &&
 			    strcmp(strval, "on") != 0 &&
 			    strcmp(strval, "off") != 0) {
-				zfs_share_proto_t proto;
+				enum sa_protocol proto;
 
 				if (prop == ZFS_PROP_SHARESMB)
-					proto = PROTO_SMB;
+					proto = SA_PROTOCOL_SMB;
 				else
-					proto = PROTO_NFS;
+					proto = SA_PROTOCOL_NFS;
 
-				if (zfs_parse_options(strval, proto) != SA_OK) {
+				if (sa_validate_shareopts(strval, proto) !=
+				    SA_OK) {
 					zfs_error_aux(hdl, dgettext(TEXT_DOMAIN,
 					    "'%s' cannot be set to invalid "
 					    "options"), propname);

lib/libzfs/libzfs_impl.h

@@ -105,21 +105,14 @@ struct zpool_handle {
 	diskaddr_t zpool_start_block;
 };
 
-typedef enum {
-	PROTO_NFS = 0,
-	PROTO_SMB = 1,
-	PROTO_END = 2
-} zfs_share_proto_t;
-
 /*
- * The following can be used as a bitmask and any new values
- * added must preserve that capability.
+ * Bitmask of shared types:
+ * 0 means none, otherwise | (1 << (enum sa_protocol + 1)).
  */
-typedef enum {
-	SHARED_NOT_SHARED = 0x0,
-	SHARED_NFS = 0x2,
-	SHARED_SMB = 0x4
-} zfs_share_type_t;
+typedef unsigned zfs_share_type_t;
+#define	SHARED_NOT_SHARED 0
+
+#define	SA_NO_PROTOCOL -1
 
 typedef int (*zfs_uri_handler_fn_t)(struct libzfs_handle *, const char *,
     const char *, zfs_keyformat_t, boolean_t, uint8_t **, size_t *);
@@ -189,7 +182,7 @@ extern void changelist_remove(prop_changelist_t *, const char *);
 extern void changelist_free(prop_changelist_t *);
 extern prop_changelist_t *changelist_gather(zfs_handle_t *, zfs_prop_t, int,
     int);
-extern int changelist_unshare(prop_changelist_t *, const zfs_share_proto_t *);
+extern int changelist_unshare(prop_changelist_t *, const enum sa_protocol *);
 extern int changelist_haszonedchild(prop_changelist_t *);
 
 extern void remove_mountpoint(zfs_handle_t *);
@@ -209,11 +202,8 @@ extern int zfs_validate_name(libzfs_handle_t *hdl, const char *path, int type,
 
 extern void namespace_clear(libzfs_handle_t *);
 
-extern int zfs_parse_options(char *, zfs_share_proto_t);
-
 typedef struct {
 	zfs_prop_t p_prop;
-	char *p_name;
 	int p_share_err;
 	int p_unshare_err;
 } proto_table_t;
@@ -244,20 +234,19 @@ extern int do_mount(zfs_handle_t *zhp, const char *mntpt, char *opts,
     int flags);
 extern int do_unmount(zfs_handle_t *zhp, const char *mntpt, int flags);
 extern int zfs_mount_delegation_check(void);
-extern int zfs_share_proto(zfs_handle_t *zhp, const zfs_share_proto_t *proto);
+extern int zfs_share_proto(zfs_handle_t *zhp, const enum sa_protocol *proto);
 extern int zfs_unshare_proto(zfs_handle_t *, const char *,
-    const zfs_share_proto_t *);
+    const enum sa_protocol *);
 extern int unshare_one(libzfs_handle_t *hdl, const char *name,
-    const char *mountpoint, zfs_share_proto_t proto);
+    const char *mountpoint, enum sa_protocol proto);
 extern boolean_t zfs_is_mountable(zfs_handle_t *zhp, char *buf, size_t buflen,
     zprop_source_t *source, int flags);
 extern zfs_share_type_t is_shared(const char *mountpoint,
-    zfs_share_proto_t proto);
+    enum sa_protocol proto);
 extern int libzfs_load_module(void);
 extern int zpool_relabel_disk(libzfs_handle_t *hdl, const char *path,
     const char *msg);
 extern int find_shares_object(differ_info_t *di);
-extern void zfs_commit_proto(const zfs_share_proto_t *);
 
 #ifdef	__cplusplus
 }