1 /* SPDX-License-Identifier: MIT */ 2 /* 3 * Details of the "wire" protocol between Xen Store Daemon and client 4 * library or guest kernel. 5 * 6 * Copyright (C) 2005 Rusty Russell IBM Corporation 7 */ 8 9 #ifndef _XS_WIRE_H 10 #define _XS_WIRE_H 11 12 enum xsd_sockmsg_type 13 { 14 XS_CONTROL, 15 #define XS_DEBUG XS_CONTROL 16 XS_DIRECTORY, 17 XS_READ, 18 XS_GET_PERMS, 19 XS_WATCH, 20 XS_UNWATCH, 21 XS_TRANSACTION_START, 22 XS_TRANSACTION_END, 23 XS_INTRODUCE, 24 XS_RELEASE, 25 XS_GET_DOMAIN_PATH, 26 XS_WRITE, 27 XS_MKDIR, 28 XS_RM, 29 XS_SET_PERMS, 30 XS_WATCH_EVENT, 31 XS_ERROR, 32 XS_IS_DOMAIN_INTRODUCED, 33 XS_RESUME, 34 XS_SET_TARGET, 35 /* XS_RESTRICT has been removed */ 36 XS_RESET_WATCHES = XS_SET_TARGET + 2, 37 XS_DIRECTORY_PART, 38 39 XS_TYPE_COUNT, /* Number of valid types. */ 40 41 XS_INVALID = 0xffff /* Guaranteed to remain an invalid type */ 42 }; 43 44 #define XS_WRITE_NONE "NONE" 45 #define XS_WRITE_CREATE "CREATE" 46 #define XS_WRITE_CREATE_EXCL "CREATE|EXCL" 47 48 /* We hand errors as strings, for portability. */ 49 struct xsd_errors 50 { 51 int errnum; 52 const char *errstring; 53 }; 54 #ifdef EINVAL 55 #define XSD_ERROR(x) { x, #x } 56 /* LINTED: static unused */ 57 static const struct xsd_errors xsd_errors[] 58 #if defined(__GNUC__) 59 __attribute__((unused)) 60 #endif 61 = { 62 /* /!\ New errors should be added at the end of the array. */ 63 XSD_ERROR(EINVAL), 64 XSD_ERROR(EACCES), 65 XSD_ERROR(EEXIST), 66 XSD_ERROR(EISDIR), 67 XSD_ERROR(ENOENT), 68 XSD_ERROR(ENOMEM), 69 XSD_ERROR(ENOSPC), 70 XSD_ERROR(EIO), 71 XSD_ERROR(ENOTEMPTY), 72 XSD_ERROR(ENOSYS), 73 XSD_ERROR(EROFS), 74 XSD_ERROR(EBUSY), 75 XSD_ERROR(EAGAIN), 76 XSD_ERROR(EISCONN), 77 XSD_ERROR(E2BIG), 78 XSD_ERROR(EPERM), 79 }; 80 #endif 81 82 struct xsd_sockmsg 83 { 84 uint32_t type; /* XS_??? */ 85 uint32_t req_id;/* Request identifier, echoed in daemon's response. */ 86 uint32_t tx_id; /* Transaction id (0 if not related to a transaction). */ 87 uint32_t len; /* Length of data following this. */ 88 89 /* Generally followed by nul-terminated string(s). */ 90 }; 91 92 enum xs_watch_type 93 { 94 XS_WATCH_PATH = 0, 95 XS_WATCH_TOKEN 96 }; 97 98 /* 99 * `incontents 150 xenstore_struct XenStore wire protocol. 100 * 101 * Inter-domain shared memory communications. */ 102 #define XENSTORE_RING_SIZE 1024 103 typedef uint32_t XENSTORE_RING_IDX; 104 #define MASK_XENSTORE_IDX(idx) ((idx) & (XENSTORE_RING_SIZE-1)) 105 struct xenstore_domain_interface { 106 char req[XENSTORE_RING_SIZE]; /* Requests to xenstore daemon. */ 107 char rsp[XENSTORE_RING_SIZE]; /* Replies and async watch events. */ 108 XENSTORE_RING_IDX req_cons, req_prod; 109 XENSTORE_RING_IDX rsp_cons, rsp_prod; 110 uint32_t server_features; /* Bitmap of features supported by the server */ 111 uint32_t connection; 112 uint32_t error; 113 }; 114 115 /* Violating this is very bad. See docs/misc/xenstore.txt. */ 116 #define XENSTORE_PAYLOAD_MAX 4096 117 118 /* Violating these just gets you an error back */ 119 #define XENSTORE_ABS_PATH_MAX 3072 120 #define XENSTORE_REL_PATH_MAX 2048 121 122 /* The ability to reconnect a ring */ 123 #define XENSTORE_SERVER_FEATURE_RECONNECTION 1 124 /* The presence of the "error" field in the ring page */ 125 #define XENSTORE_SERVER_FEATURE_ERROR 2 126 127 /* Valid values for the connection field */ 128 #define XENSTORE_CONNECTED 0 /* the steady-state */ 129 #define XENSTORE_RECONNECT 1 /* reconnect in progress */ 130 131 /* Valid values for the error field */ 132 #define XENSTORE_ERROR_NONE 0 /* No error */ 133 #define XENSTORE_ERROR_COMM 1 /* Communication problem */ 134 #define XENSTORE_ERROR_RINGIDX 2 /* Invalid ring index */ 135 #define XENSTORE_ERROR_PROTO 3 /* Protocol violation (payload too long) */ 136 137 #endif /* _XS_WIRE_H */ 138 139 /* 140 * Local variables: 141 * mode: C 142 * c-file-style: "BSD" 143 * c-basic-offset: 4 144 * tab-width: 4 145 * indent-tabs-mode: nil 146 * End: 147 */ 148