From 352cda03027b2a24d503522d48880477b1dcdf48 Mon Sep 17 00:00:00 2001
From: Milan Broz <gmazyland@gmail.com>
Date: Wed, 19 Feb 2025 15:06:47 +0100
Subject: [PATCH] integrity: Detect PI/DIF capable devices in inline mode.

And print better error if not.
---
 lib/internal.h      |  2 ++
 lib/setup.c         | 12 ++++++++++++
 lib/utils_device.c  | 16 ++++++++++++++++
 lib/utils_devpath.c | 23 +++++++++++++++++++++++
 4 files changed, 53 insertions(+)

diff --git a/lib/internal.h b/lib/internal.h
index e7809b32..0202b40c 100644
--- a/lib/internal.h
+++ b/lib/internal.h
@@ -116,6 +116,7 @@ int device_is_identical(struct device *device1, struct device *device2);
 int device_is_rotational(struct device *device);
 int device_is_dax(struct device *device);
 int device_is_zoned(struct device *device);
+int device_is_nop_dif(struct device *device, uint32_t *tag_size);
 size_t device_alignment(struct device *device);
 int device_direct_io(const struct device *device);
 int device_fallocate(struct device *device, uint64_t size);
@@ -167,6 +168,7 @@ char *crypt_lookup_dev(const char *dev_id);
 int crypt_dev_is_rotational(int major, int minor);
 int crypt_dev_is_dax(int major, int minor);
 int crypt_dev_is_zoned(int major, int minor);
+int crypt_dev_is_nop_dif(int major, int minor, uint32_t *tag_size);
 int crypt_dev_is_partition(const char *dev_path);
 char *crypt_get_partition_device(const char *dev_path, uint64_t offset, uint64_t size);
 int crypt_dev_get_partition_number(const char *dev_path);
diff --git a/lib/setup.c b/lib/setup.c
index a605b905..49d76459 100644
--- a/lib/setup.c
+++ b/lib/setup.c
@@ -3068,6 +3068,7 @@ int crypt_format_inline(struct crypt_device *cd,
 	void *params)
 {
 	const struct crypt_params_integrity *iparams;
+	uint32_t device_tag_size;
 	struct device *idevice;
 	size_t sector_size, required_sector_size;
 	int r;
@@ -3113,6 +3114,17 @@ int crypt_format_inline(struct crypt_device *cd,
 		return -EINVAL;
 	}
 
+	if (!device_is_nop_dif(crypt_metadata_device(cd), &device_tag_size)) {
+		log_err(cd, _("Device %s does not provide inline integrity data fields."), mdata_device_path(cd));
+		return -EINVAL;
+	}
+
+	if (device_tag_size < iparams->tag_size) {
+		log_err(cd, _("Inline tag size %" PRIu32 " [bytes] is larger than %" PRIu32 " provided by device %s."),
+			iparams->tag_size, device_tag_size, mdata_device_path(cd));
+		return -EINVAL;
+	}
+
 	if (isINTEGRITY(type))
 		r = _crypt_format_integrity(cd, uuid, params, volume_key, volume_key_size, true);
 	else
diff --git a/lib/utils_device.c b/lib/utils_device.c
index 84acf29b..9bc2fcb4 100644
--- a/lib/utils_device.c
+++ b/lib/utils_device.c
@@ -1017,6 +1017,22 @@ int device_is_zoned(struct device *device)
 	return crypt_dev_is_zoned(major(st.st_rdev), minor(st.st_rdev));
 }
 
+int device_is_nop_dif(struct device *device, uint32_t *tag_size)
+{
+	struct stat st;
+
+	if (!device)
+		return -EINVAL;
+
+	if (stat(device_path(device), &st) < 0)
+		return -EINVAL;
+
+	if (!S_ISBLK(st.st_mode))
+		return 0;
+
+	return crypt_dev_is_nop_dif(major(st.st_rdev), minor(st.st_rdev), tag_size);
+}
+
 size_t device_alignment(struct device *device)
 {
 	int devfd;
diff --git a/lib/utils_devpath.c b/lib/utils_devpath.c
index a7fb582e..28039f0d 100644
--- a/lib/utils_devpath.c
+++ b/lib/utils_devpath.c
@@ -262,6 +262,29 @@ int crypt_dev_is_zoned(int major, int minor)
 	return strncmp(buf, "none", 4) ? 1 : 0;
 }
 
+int crypt_dev_is_nop_dif(int major, int minor, uint32_t *tag_size)
+{
+	char buf[64] = {};
+	uint64_t val = 0;
+
+	if (!_sysfs_get_string(major, minor, buf, sizeof(buf), "integrity/format"))
+		return 0;
+
+	if (strncmp(buf, "nop", 3))
+		return 0;
+
+	/* this field is currently supported only for NVMe */
+	_sysfs_get_uint64(major, minor, &val, "metadata_bytes");
+
+	/* tag_size should be 0, but it is set by dm-integrity, try it as a fallback */
+	if (val == 0)
+		_sysfs_get_uint64(major, minor, &val, "integrity/tag_size");
+
+	/* we can still return 0 and support metadata, caller must handle it */
+	*tag_size = (uint32_t)val;
+	return 1;
+}
+
 int crypt_dev_is_partition(const char *dev_path)
 {
 	uint64_t val;