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38 .Nd symmetric cryptographic request buffers
40 .In opencrypto/cryptodev.h
43 .Fa "struct cryptop *crp"
46 .Fa "int (*f)(void *, void *, u_int)"
51 .Fa "struct crypto_buffer *cb"
54 .Fa "int (*f)(void *, void *, u_int)"
58 .Fo crypto_buffer_contiguous_subsegment
59 .Fa "struct crypto_buffer *cb"
64 .Fn crypto_buffer_len "struct crypto_buffer *cb"
66 .Fo crypto_contiguous_subsegment
67 .Fa "struct cryptop *crp"
72 .Fo crypto_cursor_init
73 .Fa "struct crypto_buffer_cursor *cc"
74 .Fa "const struct crypto_buffer *cb"
77 .Fn crypto_cursor_advance "struct crypto_buffer_cursor *cc" "size_t amount"
79 .Fo crypto_cursor_copyback
80 .Fa "struct crypto_buffer_cursor *cc"
85 .Fo crypto_cursor_copydata
86 .Fa "struct crypto_buffer_cursor *cc"
91 .Fo crypto_cursor_copydata_noadv
92 .Fa "struct crypto_buffer_cursor *cc"
97 .Fn crypto_cursor_segment "struct crypto_buffer_cursor *cc" "size_t *len"
99 .Fn CRYPTO_HAS_OUTPUT_BUFFER "struct cryptop *crp"
101 Symmetric cryptographic requests use data buffers to describe the data to
103 Requests can either specify a single data buffer whose contents are modified
105 or requests may specify separate data buffers for input and output.
106 .Vt struct crypto_buffer
107 provides an abstraction that permits cryptographic requests to operate on
108 different types of buffers.
109 .Vt struct crypto_cursor
110 allows cryptographic drivers to iterate over a data buffer.
112 .Fn CRYPTO_HAS_OUTPUT_BUFFER
115 uses separate buffers for input and output and false if
117 uses a single buffer.
119 .Fn crypto_buffer_len
120 returns the length of data buffer
125 invokes a caller-supplied function
126 to a region of the data buffer
130 is called one or more times.
132 the first argument to
137 .Fn crypto_apply_buf .
138 The second and third arguments to
140 are a pointer and length to a segment of the buffer mapped into the kernel.
141 The function is called enough times to cover the
143 bytes of the data buffer which starts at an offset
147 returns a non-zero value,
149 immediately returns that value without invoking
151 on any remaining segments of the region,
154 returns the value from the final call to
159 on a region of the input data buffer for
162 .Fn crypto_buffer_contiguous_subsegment
163 attempts to locate a single, virtually-contiguous segment of the data buffer
167 bytes long and start at an offset of
170 If a segment is found,
171 a pointer to the start of the segment is returned.
175 .Fn crypto_contiguous_subsegment
176 attempts to locate a single, virtually-contiguous segment in the input data
180 Data buffers are described by an instance of
181 .Vt struct crypto buffer .
184 member contains the type of the data buffer.
185 The following types are supported:
186 .Bl -tag -width " CRYPTO_BUF_CONTIG"
187 .It Dv CRYPTO_BUF_NONE
189 Used to mark the output buffer when a crypto request uses a single data buffer.
190 .It Dv CRYPTO_BUF_CONTIG
191 An array of bytes mapped into the kernel's address space.
192 .It Dv CRYPTO_BUF_UIO
193 A scatter/gather list of kernel buffers as described in
195 .It Dv CRYPTO_BUF_MBUF
196 A chain of network memory buffers as described in
198 .It Dv CRYPTO_BUF_SINGLE_MBUF
199 A single network memory buffer as described in
201 .It Dv CRYPTO_BUF_VMPAGE
202 A scatter/gather list of
204 structures describing pages in the kernel's address space.
205 This buffer type is only available if
206 .Dv CRYPTO_HAS_VMPAGE
210 The structure also contains the following type-specific fields:
211 .Bl -tag -width " cb_vm_page_offset"
213 A pointer to the start of a
214 .Dv CRYPTO_BUF_CONTIG
218 .Dv CRYPTO_BUF_CONTIG
226 .Dv CRYPTO_BUF_SINGLE_MBUF .
233 A pointer to an array of
236 .Dv CRYPTO_BUF_VMPAGE .
237 .It Fa cb_vm_page_len
238 The total amount of data included in the
241 .It Fa cb_vm_page_offset
242 Offset in bytes in the first page of
244 where valid data begins.
247 Cursors provide a mechanism for iterating over a data buffer.
248 They are primarily intended for use in software drivers which access data
249 buffers via virtual addresses.
251 .Fn crypto_cursor_init
252 initializes the cursor
254 to reference the start of the data buffer
257 .Fn crypto_cursor_advance
260 bytes forward in the data buffer.
262 .Fn crypto_cursor_copyback
265 bytes from the local buffer pointed to by
267 into the data buffer associated with
269 The bytes are written to the current position of
271 and the cursor is then advanced by
275 .Fn crypto_cursor_copydata
278 bytes out of the data buffer associated with
280 into a local buffer pointed to by
282 The bytes are read from the current position of
284 and the cursor is then advanced by
288 .Fn crypto_cursor_copydata_noadv
290 .Fn crypto_cursor_copydata
291 except that it does not change the current position of
294 .Fn crypto_cursor_segment
295 returns the start of the virtually-contiguous segment at the current position of
297 The length of the segment is stored in
303 return the return value from the caller-supplied callback function.
305 .Fn crypto_buffer_contiguous_subsegment ,
306 .Fn crypto_contiguous_subsegment ,
308 .Fn crypto_cursor_segment
309 return a pointer to a contiguous segment or
312 .Fn crypto_buffer_len
313 returns the length of a buffer in bytes.
315 .Fn crypto_cursor_seglen
316 returns the length in bytes of a contiguous segment.
318 .Fn CRYPTO_HAS_OUTPUT_BUFFER
319 returns true if the request uses a separate output buffer.
325 .Xr crypto_driver 9 ,
326 .Xr crypto_request 9 ,
327 .Xr crypto_session 9 ,
333 functions first appeared in
338 functions and this manual page were written by
339 .An John Baldwin Aq Mt jhb@FreeBSD.org .