tools/xenstore: add include file for state structure definitions

Add an include file containing all structures and defines needed for
dumping and restoring the internal Xenstore state.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Acked-by: Wei Liu <wl@xen.org>

tools/xenstore/include/xenstore_state.h

@@ -0,0 +1,131 @@
+/*
+ * Xenstore internal state dump definitions.
+ * Copyright (C) Juergen Gross, SUSE Software Solutions Germany GmbH
+ *
+ * Used for live-update and migration, possibly across Xenstore implementations.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef XENSTORE_STATE_H
+#define XENSTORE_STATE_H
+
+#include <endian.h>
+#include <sys/types.h>
+
+#ifndef htobe32
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+#define htobe32(x) __builtin_bswap32(x)
+#else
+#define htobe32(x) (x)
+#endif
+#endif
+
+struct xs_state_preamble {
+    char ident[8];
+#define XS_STATE_IDENT    "xenstore"  /* To be used without the NUL byte. */
+    uint32_t version;                 /* Version in big endian format. */
+#define XS_STATE_VERSION  0x00000001
+    uint32_t flags;                   /* Endianess. */
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+#define XS_STATE_FLAGS    0x00000000  /* Little endian. */
+#else
+#define XS_STATE_FLAGS    0x00000001  /* Big endian. */
+#endif
+};
+
+/*
+ * Each record is starting with xs_state_record_header.
+ * All records have a length of a multiple of 8 bytes.
+ */
+
+/* Common record layout: */
+struct xs_state_record_header {
+    uint32_t type;
+#define XS_STATE_TYPE_END        0x00000000
+#define XS_STATE_TYPE_GLOBAL     0x00000001
+#define XS_STATE_TYPE_CONN       0x00000002
+#define XS_STATE_TYPE_WATCH      0x00000003
+#define XS_STATE_TYPE_TA         0x00000004
+#define XS_STATE_TYPE_NODE       0x00000005
+    uint32_t length;         /* Length of record in bytes. */
+};
+
+/* Global state of Xenstore: */
+struct xs_state_global {
+    int32_t socket_fd;      /* File descriptor for socket connections or -1. */
+    int32_t evtchn_fd;      /* File descriptor for event channel operations. */
+};
+
+/* Connection to Xenstore: */
+struct xs_state_connection {
+    uint32_t conn_id;       /* Used as reference in watch and TA records. */
+    uint16_t conn_type;
+#define XS_STATE_CONN_TYPE_RING   0
+#define XS_STATE_CONN_TYPE_SOCKET 1
+    uint16_t pad;
+    union {
+        struct {
+            uint16_t domid;  /* Domain-Id. */
+            uint16_t tdomid; /* Id of target domain or DOMID_INVALID. */
+            uint32_t evtchn; /* Event channel port. */
+        } ring;
+        int32_t socket_fd;   /* File descriptor for socket connections. */
+    } spec;
+    uint16_t data_in_len;    /* Number of unprocessed bytes read from conn. */
+    uint16_t data_resp_len;  /* Size of partial response pending for conn. */
+    uint32_t data_out_len;   /* Number of bytes not yet written to conn. */
+    uint8_t  data[];         /* Pending data (read, written) + 0-7 pad bytes. */
+};
+
+/* Watch: */
+struct xs_state_watch {
+    uint32_t conn_id;       /* Connection this watch is associated with. */
+    uint16_t path_length;   /* Number of bytes of path watched (incl. 0). */
+    uint16_t token_length;  /* Number of bytes of watch token (incl. 0). */
+    uint8_t data[];         /* Path bytes, token bytes, 0-7 pad bytes. */
+};
+
+/* Transaction: */
+struct xs_state_transaction {
+    uint32_t conn_id;       /* Connection this TA is associated with. */
+    uint32_t ta_id;         /* Transaction Id. */
+};
+
+/* Node (either XS_STATE_TYPE_NODE or XS_STATE_TYPE_TANODE[_MOD]): */
+struct xs_state_node_perm {
+    uint8_t access;         /* Access rights. */
+#define XS_STATE_NODE_PERM_NONE   'n'
+#define XS_STATE_NODE_PERM_READ   'r'
+#define XS_STATE_NODE_PERM_WRITE  'w'
+#define XS_STATE_NODE_PERM_BOTH   'b'
+    uint8_t flags;
+#define XS_STATE_NODE_PERM_IGNORE 0x01 /* Stale permission, ignore for check. */
+    uint16_t domid;         /* Domain-Id. */
+};
+struct xs_state_node {
+    uint32_t conn_id;       /* Connection in case of transaction or 0. */
+    uint32_t ta_id;         /* Transaction Id or 0. */
+    uint16_t path_len;      /* Length of path string including NUL byte. */
+    uint16_t data_len;      /* Length of node data. */
+    uint16_t ta_access;
+#define XS_STATE_NODE_TA_DELETED  0x0000
+#define XS_STATE_NODE_TA_READ     0x0001
+#define XS_STATE_NODE_TA_WRITTEN  0x0002
+    uint16_t perm_n;        /* Number of permissions (0 in TA: node deleted). */
+    /* Permissions (first is owner, has full access). */
+    struct xs_state_node_perm perms[];
+    /* Path and data follows, plus 0-7 pad bytes. */
+};
+#endif /* XENSTORE_STATE_H */