1door_getparam(3C) Standard C Library Functions door_getparam(3C)
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6 door_getparam, door_setparam - retrieve and set door parameters
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9 cc -mt [ flag... ] file... [ library... ]
10 #include <door.h>
11 int door_getparam(int d, int param, size_t *out);
13 int door_setparam(int d, int param, size_t val);
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19 The door_getparam() function retrieves the value of param for the door
20 descriptor d and writes it through the pointer out. The door_setparam()
21 function sets the value of param for the door descriptor d to val. The
22 param argument names the parameter to view or change and can be one of
23 the following values:
24 DOOR_PARAM_DATA_MAX This parameter represents the maximum amount of
26 data that can be passed to the door routine. Any
27 attempt to call door_call(3C) on a door with a
28 data_size value larger than the door's
29 DOOR_PARAM_DATA_MAX parameter will fail with
30 ENOBUFS. At door creation time, this parameter
31 is initialized to SIZE_MAX and can be set to any
32 value from 0 to SIZE_MAX, inclusive. This param‐
33 eter must be greater than or equal to the
34 DOOR_PARAM_DATA_MIN parameter.
35 DOOR_PARAM_DATA_MIN This parameter represents the the minimum amount
38 of data that can be passed to the door routine.
39 Any attempt to call door_call(3C) on a door with
40 a data_size value smaller than the door's
41 DOOR_PARAM_DATA_MIN parameter will fail with
42 ENOBUFS. At door creation time, this parameter
43 is initialized to 0, and can be set to any value
44 from 0 to SIZE_MAX, inclusive. This parameter
45 must be less than or equal to the
46 DOOR_PARAM_DATA_MAX parameter.
47 DOOR_PARAM_DESC_MAX This parameter represents the the maximum number
50 of argument descriptors that can be passed to
51 the door routine. Any attempt to call
52 door_call(3C) on a door with a desc_num value
53 larger than the door's DOOR_PARAM_DESC_MAX
54 parameter will fail with ENFILE. If the door was
55 created with the DOOR_REFUSE_DESC flag, this
56 parameter is initialized to 0 and cannot be
57 changed to any other value. Otherwise, it is
58 initialized to INT_MAX and can be set to any
59 value from 0 to INT_MAX, inclusive.
60 The door_setparam() function can only affect doors that were created by
64 the current process.
65
67 Upon successful completion, 0 is returned. Otherwise, -1 is returned
68 and errno is set to indicate the error.
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71 The door_getparam() function will fail if:
72 EBADF The d argument is not a door descriptor.
74 EFAULT The out argument is not a valid address.
77 EINVAL The param argument is not a recognized parameter.
80 EOVERFLOW The value of the parameter is larger than the SIZE_MAX.
83 This condition can occur only if the calling process is
84 32-bit and the door targets a 64-bit process or the ker‐
85 nel.
86 The door_setparam() function will fail if:
90 EBADF The d argument is not a door descriptor or has been revoked.
92 EINVAL The param argument is not a recognized parameter, or the
95 requested change would make DOOR_PARAM_DATA_MIN greater than
96 DOOR_PARAM_DATA_MAX.
97 ENOTSUP The param argument is DOOR_PARAM_DESC_MAX, d was created
100 with the DOOR_REFUSE_DESC flag, and val is not zero.
101 EPERM The d argument was not created by this process.
104 ERANGE The val argument is not in supported range of param.
107
110 Example 1 Set up a door with a fixed request size.
111 typedef struct my_request {
113 int request;
114 ar buffer[4096];
115 } my_request_t;
116 fd = door_create(my_handler, DOOR_REFUSE_DESC);
118 if (fd < 0)
119 /* handle error */
120 if (door_setparam(fd, DOOR_PARAM_DATA_MIN,
122 sizeof (my_request_t)) < 0 ||
123 door_setparam(fd, DOOR_PARAM_DATA_MAX,
124 sizeof (my_request_t)) < 0)
125 /* handle error */
126 /*
128 * the door will only accept door_call(3DOOR)s with a
129 * data_size which is exactly sizeof (my_request_t).
130 */
131
134 See attributes(5) for descriptions of the following attributes:
135 ┌─────────────────────────────┬─────────────────────────────┐
140 │ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
141 ├─────────────────────────────┼─────────────────────────────┤
142 │Interface Stability │Stable │
143 ├─────────────────────────────┼─────────────────────────────┤
144 │MT-Level │MT-Safe │
145 └─────────────────────────────┴─────────────────────────────┘
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148 door_call(3C), door_create(3C), attributes(5)
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151 The parameters that can be manipulated by door_setparam() are not the
152 only limitation on the size of requests. If the door server thread's
153 stack size is not large enough to hold all of the data requested plus
154 room for processing the request, the door call will fail with E2BIG.
155 The DOOR_PARAM_DATA_MIN parameter will not prevent DOOR_UNREF_DATA
158 notifications from being sent to the door.
159SunOS 5.11 22 Mar 2005 door_getparam(3C)