Home | History | Annotate | Line # | Download | only in io 
      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_CONTROL,
     32 #define XS_DEBUG XS_CONTROL
     33     XS_DIRECTORY,
     34     XS_READ,
     35     XS_GET_PERMS,
     36     XS_WATCH,
     37     XS_UNWATCH,
     38     XS_TRANSACTION_START,
     39     XS_TRANSACTION_END,
     40     XS_INTRODUCE,
     41     XS_RELEASE,
     42     XS_GET_DOMAIN_PATH,
     43     XS_WRITE,
     44     XS_MKDIR,
     45     XS_RM,
     46     XS_SET_PERMS,
     47     XS_WATCH_EVENT,
     48     XS_ERROR,
     49     XS_IS_DOMAIN_INTRODUCED,
     50     XS_RESUME,
     51     XS_SET_TARGET,
     52     /* XS_RESTRICT has been removed */
     53     XS_RESET_WATCHES = XS_SET_TARGET + 2,
     54     XS_DIRECTORY_PART,
     55 
     56     XS_TYPE_COUNT,      /* Number of valid types. */
     57 
     58     XS_INVALID = 0xffff /* Guaranteed to remain an invalid type */
     59 };
     60 
     61 #define XS_WRITE_NONE "NONE"
     62 #define XS_WRITE_CREATE "CREATE"
     63 #define XS_WRITE_CREATE_EXCL "CREATE|EXCL"
     64 
     65 /* We hand errors as strings, for portability. */
     66 struct xsd_errors
     67 {
     68     int errnum;
     69     const char *errstring;
     70 };
     71 #ifdef EINVAL
     72 #define XSD_ERROR(x) { x, #x }
     73 /* LINTED: static unused */
     74 static struct xsd_errors xsd_errors[]
     75 #if defined(__GNUC__)
     76 __attribute__((unused))
     77 #endif
     78     = {
     79     XSD_ERROR(EINVAL),
     80     XSD_ERROR(EACCES),
     81     XSD_ERROR(EEXIST),
     82     XSD_ERROR(EISDIR),
     83     XSD_ERROR(ENOENT),
     84     XSD_ERROR(ENOMEM),
     85     XSD_ERROR(ENOSPC),
     86     XSD_ERROR(EIO),
     87     XSD_ERROR(ENOTEMPTY),
     88     XSD_ERROR(ENOSYS),
     89     XSD_ERROR(EROFS),
     90     XSD_ERROR(EBUSY),
     91     XSD_ERROR(EAGAIN),
     92     XSD_ERROR(EISCONN),
     93     XSD_ERROR(E2BIG)
     94 };
     95 #endif
     96 
     97 struct xsd_sockmsg
     98 {
     99     uint32_t type;  /* XS_??? */
    100     uint32_t req_id;/* Request identifier, echoed in daemon's response.  */
    101     uint32_t tx_id; /* Transaction id (0 if not related to a transaction). */
    102     uint32_t len;   /* Length of data following this. */
    103 
    104     /* Generally followed by nul-terminated string(s). */
    105 };
    106 
    107 enum xs_watch_type
    108 {
    109     XS_WATCH_PATH = 0,
    110     XS_WATCH_TOKEN
    111 };
    112 
    113 /*
    114  * `incontents 150 xenstore_struct XenStore wire protocol.
    115  *
    116  * Inter-domain shared memory communications. */
    117 #define XENSTORE_RING_SIZE 1024
    118 typedef uint32_t XENSTORE_RING_IDX;
    119 #define MASK_XENSTORE_IDX(idx) ((idx) & (XENSTORE_RING_SIZE-1))
    120 struct xenstore_domain_interface {
    121     char req[XENSTORE_RING_SIZE]; /* Requests to xenstore daemon. */
    122     char rsp[XENSTORE_RING_SIZE]; /* Replies and async watch events. */
    123     XENSTORE_RING_IDX req_cons, req_prod;
    124     XENSTORE_RING_IDX rsp_cons, rsp_prod;
    125     uint32_t server_features; /* Bitmap of features supported by the server */
    126     uint32_t connection;
    127 };
    128 
    129 /* Violating this is very bad.  See docs/misc/xenstore.txt. */
    130 #define XENSTORE_PAYLOAD_MAX 4096
    131 
    132 /* Violating these just gets you an error back */
    133 #define XENSTORE_ABS_PATH_MAX 3072
    134 #define XENSTORE_REL_PATH_MAX 2048
    135 
    136 /* The ability to reconnect a ring */
    137 #define XENSTORE_SERVER_FEATURE_RECONNECTION 1
    138 
    139 /* Valid values for the connection field */
    140 #define XENSTORE_CONNECTED 0 /* the steady-state */
    141 #define XENSTORE_RECONNECT 1 /* guest has initiated a reconnect */
    142 
    143 #endif /* _XS_WIRE_H */
    144 
    145 /*
    146  * Local variables:
    147  * mode: C
    148  * c-file-style: "BSD"
    149  * c-basic-offset: 4
    150  * tab-width: 4
    151  * indent-tabs-mode: nil
    152  * End:
    153  */
    154