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      1 /*
      2  * Details of the "wire" protocol between Xen Store Daemon and client
      3  * library or guest kernel.
      4  *
      5  * Permission is hereby granted, free of charge, to any person obtaining a copy
      6  * of this software and associated documentation files (the "Software"), to
      7  * deal in the Software without restriction, including without limitation the
      8  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
      9  * sell copies of the Software, and to permit persons to whom the Software is
     10  * furnished to do so, subject to the following conditions:
     11  *
     12  * The above copyright notice and this permission notice shall be included in
     13  * all copies or substantial portions of the Software.
     14  *
     15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
     18  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
     19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
     20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
     21  * DEALINGS IN THE SOFTWARE.
     22  *
     23  * Copyright (C) 2005 Rusty Russell IBM Corporation
     24  */
     25 
     26 #ifndef _XS_WIRE_H
     27 #define _XS_WIRE_H
     28 
     29 enum xsd_sockmsg_type
     30 {
     31     XS_DEBUG,
     32     XS_DIRECTORY,
     33     XS_READ,
     34     XS_GET_PERMS,
     35     XS_WATCH,
     36     XS_UNWATCH,
     37     XS_TRANSACTION_START,
     38     XS_TRANSACTION_END,
     39     XS_INTRODUCE,
     40     XS_RELEASE,
     41     XS_GET_DOMAIN_PATH,
     42     XS_WRITE,
     43     XS_MKDIR,
     44     XS_RM,
     45     XS_SET_PERMS,
     46     XS_WATCH_EVENT,
     47     XS_ERROR,
     48     XS_IS_DOMAIN_INTRODUCED,
     49     XS_RESUME,
     50     XS_SET_TARGET,
     51     XS_RESTRICT,
     52     XS_RESET_WATCHES,
     53 
     54     XS_INVALID = 0xffff /* Guaranteed to remain an invalid type */
     55 };
     56 
     57 #define XS_WRITE_NONE "NONE"
     58 #define XS_WRITE_CREATE "CREATE"
     59 #define XS_WRITE_CREATE_EXCL "CREATE|EXCL"
     60 
     61 /* We hand errors as strings, for portability. */
     62 struct xsd_errors
     63 {
     64     INT32 errnum;
     65     const CHAR8 *errstring;
     66 };
     67 #ifdef EINVAL
     68 #define XSD_ERROR(x) { x, #x }
     69 /* LINTED: static unused */
     70 static struct xsd_errors xsd_errors[]
     71 #if defined(__GNUC__)
     72 __attribute__((unused))
     73 #endif
     74     = {
     75     XSD_ERROR(EINVAL),
     76     XSD_ERROR(EACCES),
     77     XSD_ERROR(EEXIST),
     78     XSD_ERROR(EISDIR),
     79     XSD_ERROR(ENOENT),
     80     XSD_ERROR(ENOMEM),
     81     XSD_ERROR(ENOSPC),
     82     XSD_ERROR(EIO),
     83     XSD_ERROR(ENOTEMPTY),
     84     XSD_ERROR(ENOSYS),
     85     XSD_ERROR(EROFS),
     86     XSD_ERROR(EBUSY),
     87     XSD_ERROR(EAGAIN),
     88     XSD_ERROR(EISCONN),
     89     XSD_ERROR(E2BIG)
     90 };
     91 #endif
     92 
     93 struct xsd_sockmsg
     94 {
     95     UINT32 type;  /* XS_??? */
     96     UINT32 req_id;/* Request identifier, echoed in daemon's response.  */
     97     UINT32 tx_id; /* Transaction id (0 if not related to a transaction). */
     98     UINT32 len;   /* Length of data following this. */
     99 
    100     /* Generally followed by nul-terminated string(s). */
    101 };
    102 
    103 enum xs_watch_type
    104 {
    105     XS_WATCH_PATH = 0,
    106     XS_WATCH_TOKEN
    107 };
    108 
    109 /*
    110  * `incontents 150 xenstore_struct XenStore wire protocol.
    111  *
    112  * Inter-domain shared memory communications. */
    113 #define XENSTORE_RING_SIZE 1024
    114 typedef UINT32 XENSTORE_RING_IDX;
    115 #define MASK_XENSTORE_IDX(idx) ((idx) & (XENSTORE_RING_SIZE-1))
    116 struct xenstore_domain_interface {
    117     CHAR8 req[XENSTORE_RING_SIZE]; /* Requests to xenstore daemon. */
    118     CHAR8 rsp[XENSTORE_RING_SIZE]; /* Replies and async watch events. */
    119     XENSTORE_RING_IDX req_cons, req_prod;
    120     XENSTORE_RING_IDX rsp_cons, rsp_prod;
    121     UINT32 server_features; /* Bitmap of features supported by the server */
    122     UINT32 connection;
    123 };
    124 
    125 /* Violating this is very bad.  See docs/misc/xenstore.txt. */
    126 #define XENSTORE_PAYLOAD_MAX 4096
    127 
    128 /* Violating these just gets you an error back */
    129 #define XENSTORE_ABS_PATH_MAX 3072
    130 #define XENSTORE_REL_PATH_MAX 2048
    131 
    132 /* The ability to reconnect a ring */
    133 #define XENSTORE_SERVER_FEATURE_RECONNECTION 1
    134 
    135 /* Valid values for the connection field */
    136 #define XENSTORE_CONNECTED 0 /* the steady-state */
    137 #define XENSTORE_RECONNECT 1 /* guest has initiated a reconnect */
    138 
    139 #endif /* _XS_WIRE_H */
    140 
    141 /*
    142  * Local variables:
    143  * mode: C
    144  * c-file-style: "BSD"
    145  * c-basic-offset: 4
    146  * tab-width: 4
    147  * indent-tabs-mode: nil
    148  * End:
    149  */
    150