Zpool: uses runtime lookup for zpool properties to ensure portability

Fixes #2051

Author: CarterLi

src/detection/zpool/libzfs_simplified.h

@@ -25,65 +25,23 @@
  * CDDL HEADER END
  */
 
-typedef enum {
-    ZPOOL_PROP_INVAL = -1,
-    ZPOOL_PROP_NAME,
-    ZPOOL_PROP_SIZE,
-    ZPOOL_PROP_CAPACITY,
-    ZPOOL_PROP_ALTROOT,
-    ZPOOL_PROP_HEALTH,
-    ZPOOL_PROP_GUID,
-    ZPOOL_PROP_VERSION,
-    ZPOOL_PROP_BOOTFS,
-    ZPOOL_PROP_DELEGATION,
-    ZPOOL_PROP_AUTOREPLACE,
-    ZPOOL_PROP_CACHEFILE,
-    ZPOOL_PROP_FAILUREMODE,
-    ZPOOL_PROP_LISTSNAPS,
-    ZPOOL_PROP_AUTOEXPAND,
-    ZPOOL_PROP_DEDUPDITTO,
-    ZPOOL_PROP_DEDUPRATIO,
-    ZPOOL_PROP_FREE,
-    ZPOOL_PROP_ALLOCATED,
-    ZPOOL_PROP_READONLY,
-    ZPOOL_PROP_ASHIFT,
-    ZPOOL_PROP_COMMENT,
-    ZPOOL_PROP_EXPANDSZ,
-    ZPOOL_PROP_FREEING,
-    ZPOOL_PROP_FRAGMENTATION,
-    ZPOOL_PROP_LEAKED,
-    ZPOOL_PROP_MAXBLOCKSIZE,
-    ZPOOL_PROP_TNAME,
-    ZPOOL_PROP_MAXDNODESIZE,
-    ZPOOL_PROP_MULTIHOST,
-    ZPOOL_PROP_CHECKPOINT,
-    ZPOOL_PROP_LOAD_GUID,
-    ZPOOL_PROP_AUTOTRIM,
-    ZPOOL_PROP_COMPATIBILITY,
-    ZPOOL_PROP_BCLONEUSED,
-    ZPOOL_PROP_BCLONESAVED,
-    ZPOOL_PROP_BCLONERATIO,
-    ZPOOL_NUM_PROPS
-} zpool_prop_t;
-
-typedef enum {
-    ZPROP_SRC_NONE = 0x1,
-    ZPROP_SRC_DEFAULT = 0x2,
-    ZPROP_SRC_TEMPORARY = 0x4,
-    ZPROP_SRC_LOCAL = 0x8,
-    ZPROP_SRC_INHERITED = 0x10,
-    ZPROP_SRC_RECEIVED = 0x20
-} zprop_source_t;
-
+// zpool_prop_t and zprop_source_t were previously enums in upstream OpenZFS.
+// However, the enum values for these types vary greatly between different platforms,
+// making it unsafe to use the enum values directly. To ensure portability,
+// we define them as simple int typedefs and use zpool_name_to_prop to look up
+// the correct value for a property at runtime.
+typedef int zpool_prop_t;
+typedef int zprop_source_t;
 typedef bool boolean_t;
 
 typedef struct libzfs_handle libzfs_handle_t;
 typedef struct zpool_handle zpool_handle_t;
 typedef int (*zpool_iter_f)(zpool_handle_t *, void *);
-extern int zpool_iter(libzfs_handle_t *, zpool_iter_f, void *);
 
 extern libzfs_handle_t *libzfs_init(void);
 extern void libzfs_fini(libzfs_handle_t *);
+extern int zpool_iter(libzfs_handle_t *, zpool_iter_f, void *);
+extern zpool_prop_t zpool_name_to_prop(const char *);
 // https://github.com/openzfs/zfs/blob/06c73cffabc30b61a695988ec8e290f43cb3768d/lib/libzfs/libzfs_pool.c#L300
 extern uint64_t zpool_get_prop_int(zpool_handle_t *zhp, zpool_prop_t prop, zprop_source_t *srctype);
 extern int zpool_get_prop(zpool_handle_t *zhp, zpool_prop_t prop, char *buf, size_t len, zprop_source_t *srctype, boolean_t literal);

src/detection/zpool/zpool_linux.c

@@ -18,6 +18,19 @@ typedef struct FFZfsData
     FF_LIBRARY_SYMBOL(zpool_get_prop)
     FF_LIBRARY_SYMBOL(zpool_close)
 
+    // The fields in this struct store property IDs returned by `zpool_name_to_prop`,
+    // not the property values themselves.
+    struct {
+        int name;
+        int health;
+        int guid;
+        int size;
+        int free;
+        int allocated;
+        int fragmentation;
+        int readonly;
+    } props;
+
     libzfs_handle_t* handle;
     FFlist* result;
 } FFZfsData;
@@ -37,21 +50,21 @@ static int enumZpoolCallback(zpool_handle_t* zpool, void* param)
     zprop_source_t source;
     FFZpoolResult* item = ffListAdd(data->result);
     char buf[1024];
-    if (data->ffzpool_get_prop(zpool, ZPOOL_PROP_NAME, buf, ARRAY_SIZE(buf), &source, false) == 0)
+    if (data->ffzpool_get_prop(zpool, data->props.name, buf, ARRAY_SIZE(buf), &source, false) == 0)
         ffStrbufInitS(&item->name, buf);
     else
         ffStrbufInitStatic(&item->name, "unknown");
-    if (data->ffzpool_get_prop(zpool, ZPOOL_PROP_HEALTH, buf, ARRAY_SIZE(buf), &source, false) == 0)
+    if (data->ffzpool_get_prop(zpool, data->props.health, buf, ARRAY_SIZE(buf), &source, false) == 0)
         ffStrbufInitS(&item->state, buf);
     else
         ffStrbufInitStatic(&item->state, "unknown");
-    item->guid = data->ffzpool_get_prop_int(zpool, ZPOOL_PROP_GUID, &source);
-    item->total = data->ffzpool_get_prop_int(zpool, ZPOOL_PROP_SIZE, &source);
-    item->used = item->total - data->ffzpool_get_prop_int(zpool, ZPOOL_PROP_FREE, &source);
-    item->allocated = data->ffzpool_get_prop_int(zpool, ZPOOL_PROP_ALLOCATED, &source);
-    uint64_t fragmentation = data->ffzpool_get_prop_int(zpool, ZPOOL_PROP_FRAGMENTATION, &source);
+    item->guid = data->ffzpool_get_prop_int(zpool, data->props.guid, &source);
+    item->total = data->ffzpool_get_prop_int(zpool, data->props.size, &source);
+    item->used = item->total - data->ffzpool_get_prop_int(zpool, data->props.free, &source);
+    item->allocated = data->ffzpool_get_prop_int(zpool, data->props.allocated, &source);
+    uint64_t fragmentation = data->ffzpool_get_prop_int(zpool, data->props.fragmentation, &source);
     item->fragmentation = fragmentation == UINT64_MAX ? -DBL_MAX : (double) fragmentation;
-    item->readOnly = (bool) data->ffzpool_get_prop_int(zpool, ZPOOL_PROP_READONLY, &source);
+    item->readOnly = (bool) data->ffzpool_get_prop_int(zpool, data->props.readonly, &source);
     data->ffzpool_close(zpool);
     return 0;
 }
@@ -73,6 +86,23 @@ const char* ffDetectZpool(FFlist* result /* list of FFZpoolResult */)
         .result = result,
     };
 
+    FF_LIBRARY_LOAD_SYMBOL_MESSAGE(libzfs, zpool_name_to_prop);
+
+    #define FF_QUERY_ZPOOL_PROP_FROM_NAME(prop_name) do { \
+        data.props.prop_name = ffzpool_name_to_prop(#prop_name); \
+        if (data.props.prop_name < 0) \
+            return "Failed to query prop: " #prop_name; \
+    } while (false)
+    FF_QUERY_ZPOOL_PROP_FROM_NAME(name);
+    FF_QUERY_ZPOOL_PROP_FROM_NAME(health);
+    FF_QUERY_ZPOOL_PROP_FROM_NAME(guid);
+    FF_QUERY_ZPOOL_PROP_FROM_NAME(size);
+    FF_QUERY_ZPOOL_PROP_FROM_NAME(free);
+    FF_QUERY_ZPOOL_PROP_FROM_NAME(allocated);
+    FF_QUERY_ZPOOL_PROP_FROM_NAME(fragmentation);
+    FF_QUERY_ZPOOL_PROP_FROM_NAME(readonly);
+    #undef FF_QUERY_ZPOOL_PROP_FROM_NAME
+
     FF_LIBRARY_LOAD_SYMBOL_MESSAGE(libzfs, zpool_iter);
     FF_LIBRARY_LOAD_SYMBOL_VAR_MESSAGE(libzfs, data, libzfs_fini);
     FF_LIBRARY_LOAD_SYMBOL_VAR_MESSAGE(libzfs, data, zpool_get_prop_int);