From 5a9302bab9c9bb3d1577f04678d074fb7af4115f Mon Sep 17 00:00:00 2001
From: Stefano Brivio <sbrivio@redhat.com>
Date: Wed, 15 May 2024 08:49:56 +0200
Subject: Add fsetxattr(), fremovexattr(), open_by_handle_at(), and "virtiofsd
 demo"

Mostly assorted fixes, a new FDGET operation (get a copy of the
target file descriptor via pidfd_getfd()) and a new "FD" flag that
means we have to do that on direct tag reference.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
---
 cooker/calls/fs.c | 190 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 190 insertions(+)

(limited to 'cooker/calls')

diff --git a/cooker/calls/fs.c b/cooker/calls/fs.c
index 4135be9..29c653a 100644
--- a/cooker/calls/fs.c
+++ b/cooker/calls/fs.c
@@ -60,6 +60,7 @@ swapoff
 
 #define _GNU_SOURCE
 #include <sys/stat.h>
+#include <sys/xattr.h>
 #include <fcntl.h>
 #include <linux/limits.h>
 
@@ -200,10 +201,199 @@ static struct arg chown_args[] = {
 	{ 0 }
 };
 
+static struct num xattr_flags[] = {
+	{ "create",	XATTR_CREATE },
+	{ "replace",	XATTR_REPLACE },
+	{ 0 },
+};
+
+static struct arg fsetxattr_args[] = {
+	{ 0,
+		{
+			"fd",		INT,		FD,	0,	0,
+			{ 0 }
+		}
+	},
+	{ 0,
+		{
+			"path",		FDPATH,		FD,	0,	0,
+			{ 0 }
+		}
+	},
+	{ 1,
+		{
+			"name",		STRING,		0,	0,
+			XATTR_NAME_MAX,
+			{ 0 }
+		}
+	},
+	{ 2,
+		{
+			"value",	STRING,		WBUF,	0,
+			XATTR_SIZE_MAX,
+			{ 0 }
+		}
+	},
+	{ 3,
+		{
+			"size",		LONG,		0,	0,	0,
+			{ 0 }
+		}
+	},
+	{ 4,
+		{
+			"flags",	INT,		FLAGS,	0,	0,
+			{ .d_num = xattr_flags }
+		}
+	},
+	{ 0 },
+};
+
+static struct arg fremovexattr_args[] = {
+	{ 0,
+		{
+			"fd",		INT,		FD,	0,	0,
+			{ 0 }
+		}
+	},
+	{ 0,
+		{
+			"path",		FDPATH,		FD,	0,	0,
+			{ 0 }
+		}
+	},
+	{ 1,
+		{
+			"name",		STRING,		0,	0,
+			XATTR_NAME_MAX,
+			{ 0 }
+		}
+	},
+	{ 0 },
+};
+
+/* enum fid_type copied (without comments) from include/linux/exportfs.h of
+ * Linux 6.9. Just copied and pasted like that? Is that an acceptable practice?
+ * Well then, let's say I _vendored_ it.
+ */
+enum fid_type {
+	FILEID_ROOT = 0,
+	FILEID_INO32_GEN = 1,
+	FILEID_INO32_GEN_PARENT = 2,
+	FILEID_BTRFS_WITHOUT_PARENT = 0x4d,
+	FILEID_BTRFS_WITH_PARENT = 0x4e,
+	FILEID_BTRFS_WITH_PARENT_ROOT = 0x4f,
+	FILEID_UDF_WITHOUT_PARENT = 0x51,
+	FILEID_UDF_WITH_PARENT = 0x52,
+	FILEID_NILFS_WITHOUT_PARENT = 0x61,
+	FILEID_NILFS_WITH_PARENT = 0x62,
+	FILEID_FAT_WITHOUT_PARENT = 0x71,
+	FILEID_FAT_WITH_PARENT = 0x72,
+	FILEID_INO64_GEN = 0x81,
+	FILEID_INO64_GEN_PARENT = 0x82,
+	FILEID_LUSTRE = 0x97,
+	FILEID_BCACHEFS_WITHOUT_PARENT = 0xb1,
+	FILEID_BCACHEFS_WITH_PARENT = 0xb2,
+	FILEID_KERNFS = 0xfe,
+	FILEID_INVALID = 0xff,
+};
+
+static struct num handle_types[] = {
+	{ "root",			FILEID_ROOT },
+	{ "ino32_gen",			FILEID_INO32_GEN },
+	{ "ino32_gen_parent",		FILEID_INO32_GEN_PARENT },
+	{ "btrfs_with_parent",		FILEID_BTRFS_WITH_PARENT },
+	{ "btrfs_without_parent",	FILEID_BTRFS_WITHOUT_PARENT },
+	{ "udf_with_parent",		FILEID_UDF_WITH_PARENT },
+	{ "udf_without_parent",		FILEID_UDF_WITHOUT_PARENT },
+	{ "fat_with_parent",		FILEID_FAT_WITH_PARENT },
+	{ "fat_without_parent",		FILEID_FAT_WITHOUT_PARENT },
+	{ "ino64_gen",			FILEID_INO64_GEN },
+	{ "ino64_gen_parent",		FILEID_INO64_GEN_PARENT },
+	{ "lustre",			FILEID_LUSTRE },
+	{ "bcachefs_with_parent",	FILEID_BCACHEFS_WITH_PARENT },
+	{ "bcachefs_without_parent",	FILEID_BCACHEFS_WITHOUT_PARENT },
+	{ "kernfs",			FILEID_KERNFS },
+	{ "invalid",			FILEID_INVALID },
+	{ 0 },
+};
+
+static struct field file_handle[] = {
+	{
+		"handle_bytes",	LONG,		SIZE,
+		offsetof(struct file_handle, handle_bytes),
+		0,
+		{ .d_size = (intptr_t)&file_handle[2] },
+	},
+	{
+		"handle_type",	INT,		FLAGS,
+		offsetof(struct file_handle, handle_type),
+		0,
+		{ .d_num = handle_types },
+	},
+
+	{
+		"f_handle",	STRING,		0,
+		offsetof(struct file_handle, f_handle),
+		MAX_HANDLE_SZ,
+		{ 0 },
+	},
+	{ 0 }
+};
+
+static struct num open_flags[] = {
+	{ "rdonly",	O_RDONLY },
+	{ "wronly",	O_WRONLY },
+	{ "rdwr",	O_RDWR },
+	{ 0 },
+};
+
+static struct arg open_by_handle_at_args[] = {
+	{ 0,
+		{
+			"mount",	FDMOUNT,	0,		0,
+			0,
+			{ 0 }
+		}
+	},
+	{ 0,
+		{
+			"mount_fd",	INT,		0,		0,
+			0,
+			{ 0 }
+		}
+	},
+	{ 1,
+		{
+			"handle",	STRUCT,		0,		0,
+			sizeof(struct file_handle) + MAX_HANDLE_SZ,
+			{ .d_struct = file_handle }
+		}
+	},
+	{ 2,
+		{
+			"flags",	INT,		MASK | FLAGS,	0,
+			0,
+			{ .d_num = open_flags }
+		}
+	},
+	{ 0 },
+};
+
 struct call syscalls_fs[] = {
 	{ __NR_mknod, "mknod", mknod_args },
 	{ __NR_mknodat, "mknodat", mknodat_args },
+
 	{ __NR_chown, "chown", chown_args },
 	{ __NR_lchown, "lchown", chown_args },
+
+	{ __NR_fsetxattr, "fsetxattr", fsetxattr_args },
+	/* fd,  name, value, size, flags */
+
+	{ __NR_fremovexattr, "fremovexattr", fremovexattr_args },
+	/* fd, name */
+
+	{ __NR_open_by_handle_at, "open_by_handle_at", open_by_handle_at_args },
+
 	{ 0 },
 };
-- 
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