1 /* SPDX-License-Identifier: MIT */ 2 /* 3 * Details of the "wire" protocol between Xen Store Daemon and client 4 * library or guest kernel. 5 * Copyright (C) 2005 Rusty Russell IBM Corporation 6 */ 7 8 #ifndef _XS_WIRE_H 9 #define _XS_WIRE_H 10 11 enum xsd_sockmsg_type 12 { 13 XS_CONTROL, 14 #define XS_DEBUG XS_CONTROL 15 XS_DIRECTORY, 16 XS_READ, 17 XS_GET_PERMS, 18 XS_WATCH, 19 XS_UNWATCH, 20 XS_TRANSACTION_START, 21 XS_TRANSACTION_END, 22 XS_INTRODUCE, 23 XS_RELEASE, 24 XS_GET_DOMAIN_PATH, 25 XS_WRITE, 26 XS_MKDIR, 27 XS_RM, 28 XS_SET_PERMS, 29 XS_WATCH_EVENT, 30 XS_ERROR, 31 XS_IS_DOMAIN_INTRODUCED, 32 XS_RESUME, 33 XS_SET_TARGET, 34 /* XS_RESTRICT has been removed */ 35 XS_RESET_WATCHES = XS_SET_TARGET + 2, 36 XS_DIRECTORY_PART, 37 38 XS_TYPE_COUNT, /* Number of valid types. */ 39 40 XS_INVALID = 0xffff /* Guaranteed to remain an invalid type */ 41 }; 42 43 #define XS_WRITE_NONE "NONE" 44 #define XS_WRITE_CREATE "CREATE" 45 #define XS_WRITE_CREATE_EXCL "CREATE|EXCL" 46 47 /* We hand errors as strings, for portability. */ 48 struct xsd_errors 49 { 50 int errnum; 51 const char *errstring; 52 }; 53 #define XSD_ERROR(x) { x, #x } 54 static struct xsd_errors xsd_errors[] __attribute__((unused)) = { 55 XSD_ERROR(EINVAL), 56 XSD_ERROR(EACCES), 57 XSD_ERROR(EEXIST), 58 XSD_ERROR(EISDIR), 59 XSD_ERROR(ENOENT), 60 XSD_ERROR(ENOMEM), 61 XSD_ERROR(ENOSPC), 62 XSD_ERROR(EIO), 63 XSD_ERROR(ENOTEMPTY), 64 XSD_ERROR(ENOSYS), 65 XSD_ERROR(EROFS), 66 XSD_ERROR(EBUSY), 67 XSD_ERROR(EAGAIN), 68 XSD_ERROR(EISCONN), 69 XSD_ERROR(E2BIG) 70 }; 71 72 struct xsd_sockmsg 73 { 74 uint32_t type; /* XS_??? */ 75 uint32_t req_id;/* Request identifier, echoed in daemon's response. */ 76 uint32_t tx_id; /* Transaction id (0 if not related to a transaction). */ 77 uint32_t len; /* Length of data following this. */ 78 79 /* Generally followed by nul-terminated string(s). */ 80 }; 81 82 enum xs_watch_type 83 { 84 XS_WATCH_PATH = 0, 85 XS_WATCH_TOKEN 86 }; 87 88 /* Inter-domain shared memory communications. */ 89 #define XENSTORE_RING_SIZE 1024 90 typedef uint32_t XENSTORE_RING_IDX; 91 #define MASK_XENSTORE_IDX(idx) ((idx) & (XENSTORE_RING_SIZE-1)) 92 struct xenstore_domain_interface { 93 char req[XENSTORE_RING_SIZE]; /* Requests to xenstore daemon. */ 94 char rsp[XENSTORE_RING_SIZE]; /* Replies and async watch events. */ 95 XENSTORE_RING_IDX req_cons, req_prod; 96 XENSTORE_RING_IDX rsp_cons, rsp_prod; 97 uint32_t server_features; /* Bitmap of features supported by the server */ 98 uint32_t connection; 99 uint32_t error; 100 }; 101 102 /* Violating this is very bad. See docs/misc/xenstore.txt. */ 103 #define XENSTORE_PAYLOAD_MAX 4096 104 105 /* Violating these just gets you an error back */ 106 #define XENSTORE_ABS_PATH_MAX 3072 107 #define XENSTORE_REL_PATH_MAX 2048 108 109 /* The ability to reconnect a ring */ 110 #define XENSTORE_SERVER_FEATURE_RECONNECTION 1 111 /* The presence of the "error" field in the ring page */ 112 #define XENSTORE_SERVER_FEATURE_ERROR 2 113 114 /* Valid values for the connection field */ 115 #define XENSTORE_CONNECTED 0 /* the steady-state */ 116 #define XENSTORE_RECONNECT 1 /* guest has initiated a reconnect */ 117 118 /* Valid values for the error field */ 119 #define XENSTORE_ERROR_NONE 0 /* No error */ 120 #define XENSTORE_ERROR_COMM 1 /* Communication problem */ 121 #define XENSTORE_ERROR_RINGIDX 2 /* Invalid ring index */ 122 #define XENSTORE_ERROR_PROTO 3 /* Protocol violation (payload too long) */ 123 124 #endif /* _XS_WIRE_H */ 125