1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (C) 2018 Universita` di Pisa
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 #ifndef LIBNETMAP_H_
31 #define LIBNETMAP_H_
32 /* if thread-safety is not needed, define LIBNETMAP_NOTHREADSAFE before including
33 * this file.
34 */
35
36 /* NOTE: we include net/netmap_user.h without defining NETMAP_WITH_LIBS, which
37 * is deprecated. If you still need it, please define NETMAP_WITH_LIBS and
38 * include net/netmap_user.h before including this file.
39 */
40 #include <net/netmap_user.h>
41
42 struct nmctx;
43 struct nmport_d;
44 struct nmem_d;
45
46 /*
47 * A port open specification (portspec for brevity) has the following syntax
48 * (square brackets delimit optional parts):
49 *
50 * subsystem:vpname[mode][options]
51 *
52 * The "subsystem" is denoted by a prefix, possibly followed by an identifier.
53 * There can be several kinds of subsystems, each one selected by a unique
54 * prefix. Currently defined subsystems are:
55 *
56 * netmap (no id allowed)
57 * the standard subsystem
58 *
59 * vale (followed by a possibly empty id)
60 * the vpname is connected to a VALE switch identified by
61 * the id (an empty id selects the default switch)
62 *
63 * The "vpname" has the following syntax:
64 *
65 * identifier or
66 * identifier1{identifier2 or
67 * identifier1}identifier2
68 *
69 * Identifiers are sequences of alphanumeric characters. The part that begins
70 * with either '{' or '}', when present, denotes a netmap pipe opened in the
71 * same memory region as the subsystem:indentifier1 port.
72 *
73 * The "mode" can be one of the following:
74 *
75 * ^ bind all host (sw) ring pairs
76 * ^NN bind individual host ring pair
77 * * bind host and NIC ring pairs
78 * -NN bind individual NIC ring pair
79 * @NN open the port in the NN memory region
80 * a suffix starting with / and the following flags,
81 * in any order:
82 * x exclusive access
83 * z zero copy monitor (both tx and rx)
84 * t monitor tx side (copy monitor)
85 * r monitor rx side (copy monitor)
86 * R bind only RX ring(s)
87 * T bind only TX ring(s)
88 *
89 * The "options" start at the first '@' character not followed by a number.
90 * Each option starts with '@' and has the following syntax:
91 *
92 * option (flag option)
93 * option=value (single key option)
94 * option:key1=value1,key2=value2,... (multi-key option)
95 *
96 * For multi-key options, the keys can be assigned in any order, but they
97 * cannot be assigned more than once. It is not necessary to assign all the
98 * option keys: unmentioned keys will receive default values. Some multi-key
99 * options define a default key and also accept the single-key syntax, by
100 * assigning the value to this key.
101 *
102 * NOTE: Options may be silently ignored if the port is already open by some
103 * other process.
104 *
105 * The currently available options are (default keys, when defined, are marked
106 * with '*'):
107 *
108 * share (single-key)
109 * open the port in the same memory region used by the
110 * given port name (the port name must be given in
111 * subsystem:vpname form)
112 *
113 * conf (multi-key)
114 * specify the rings/slots numbers (effective only on
115 * ports that are created by the open operation itself,
116 * and ignored otherwise).
117 *
118 * The keys are:
119 *
120 * *rings number of tx and rx rings
121 * tx-rings number of tx rings
122 * rx-rings number of rx rings
123 * host-rings number of tx and rx host rings
124 * host-tx-rings number of host tx rings
125 * host-rx-rings number of host rx rings
126 * slots number of slots in each tx and rx
127 * ring
128 * tx-slots number of slots in each tx ring
129 * rx-slots number of slots in each rx ring
130 *
131 * (more specific keys override the less specific ones)
132 * All keys default to zero if not assigned, and the
133 * corresponding value will be chosen by netmap.
134 *
135 * extmem (multi-key)
136 * open the port in the memory region obtained by
137 * mmap()ing the given file.
138 *
139 * The keys are:
140 *
141 * *file the file to mmap
142 * if-num number of pre-allocated netmap_if's
143 * if-size size of each netmap_if
144 * ring-num number of pre-allocated netmap_ring's
145 * ring-size size of each netmap_ring
146 * buf-num number of pre-allocated buffers
147 * buf-size size of each buffer
148 *
149 * file must be assigned. The other keys default to zero,
150 * causing netmap to take the corresponding values from
151 * the priv_{if,ring,buf}_{num,size} sysctls.
152 *
153 */
154
155
156 /* nmport manipulation */
157
158 /* struct nmport_d - describes a netmap port */
159 struct nmport_d {
160 /* see net/netmap.h for the definition of these fields */
161 struct nmreq_header hdr;
162 struct nmreq_register reg;
163
164 /* all the fields below should be considered read-only */
165
166 /* if the same context is used throughout the program, d1->mem ==
167 * d2->mem iff d1 and d2 are using the memory region (i.e., zero
168 * copy is possible between the two ports)
169 */
170 struct nmem_d *mem;
171
172 /* the nmctx used when this nmport_d was created */
173 struct nmctx *ctx;
174
175 int register_done; /* nmport_register() has been called */
176 int mmap_done; /* nmport_mmap() has been called */
177 /* pointer to the extmem option contained in the hdr options, if any */
178 struct nmreq_opt_extmem *extmem;
179
180 /* the fields below are compatible with nm_open() */
181 int fd; /* "/dev/netmap", -1 if not open */
182 struct netmap_if *nifp; /* pointer to the netmap_if */
183 uint16_t first_tx_ring;
184 uint16_t last_tx_ring;
185 uint16_t first_rx_ring;
186 uint16_t last_rx_ring;
187 uint16_t cur_tx_ring; /* used by nmport_inject */
188 uint16_t cur_rx_ring;
189
190 /* LIFO list of cleanup functions (used internally) */
191 struct nmport_cleanup_d *clist;
192 };
193
194 /* nmport_open - opens a port from a portspec
195 * @portspec the port opening specification
196 *
197 * If successful, the function returns a new nmport_d describing a netmap
198 * port, opened according to the port specification, ready to be used for rx
199 * and/or tx.
200 *
201 * The rings available for tx are in the [first_tx_ring, last_tx_ring]
202 * interval, and similarly for rx. One or both intervals may be empty.
203 *
204 * When done using it, the nmport_d descriptor must be closed using
205 * nmport_close().
206 *
207 * In case of error, NULL is returned, errno is set to some error, and an
208 * error message is sent through the error() method of the current context.
209 */
210 struct nmport_d * nmport_open(const char *portspec);
211
212 /* nport_close - close a netmap port
213 * @d the port we want to close
214 *
215 * Undoes the actions performed by the nmport_open that created d, then
216 * frees the descriptor.
217 */
218 void nmport_close(struct nmport_d *d);
219
220 /* nmport_inject - sends a packet
221 * @d the port through which we want to send
222 * @buf base address of the packet
223 * @size its size in bytes
224 *
225 * Sends a packet using the cur_tx_ring and updates the index
226 * to use all available tx rings in turn. Note: the packet is copied.
227 *
228 * Returns 0 on success an -1 on error.
229 */
230 int nmport_inject(struct nmport_d *d, const void *buf, size_t size);
231
232 /*
233 * the functions below can be used to split the functionality of
234 * nmport_open when special features (e.g., extra buffers) are needed
235 *
236 * The relation among the functions is as follows:
237 *
238 * |nmport_new
239 * |nmport_prepare = |
240 * | |nmport_parse
241 * nmport_open =|
242 * | |nmport_register
243 * |nmport_open_desc =|
244 * |nmport_mmap
245 *
246 */
247
248 /* nmport_new - create a new nmport_d
249 *
250 * Creates a new nmport_d using the malloc() method of the current default
251 * context. Returns NULL on error, setting errno to an error value.
252 */
253 struct nmport_d *nmport_new(void);
254
255 /* nmport_parse - fills the nmport_d netmap-register request
256 * @d the nmport to be filled
257 * @portspec the port opening specification
258 *
259 * This function parses the portspec and initizalizes the @d->hdr and @d->reg
260 * fields. It may need to allocate a list of options. If an extmem option is
261 * found, it may also mmap() the corresponding file.
262 *
263 * It returns 0 on success. On failure it returns -1, sets errno to an error
264 * value and sends an error message to the error() method of the context used
265 * when @d was created. Moreover, *@d is left unchanged.
266 */
267 int nmport_parse(struct nmport_d *d, const char *portspec);
268
269 /* nmport_register - registers the port with netmap
270 * @d the nmport to be registered
271 *
272 * This function obtains a netmap file descriptor and registers the port with
273 * netmap. The @d->hdr and @d->reg data structures must have been previously
274 * initialized (via nmport_parse() or otherwise).
275 *
276 * It returns 0 on success. On failure it returns -1, sets errno to an error
277 * value and sends an error message to the error() method of the context used
278 * when @d was created. Moreover, *@d is left unchanged.
279 */
280 int nmport_register(struct nmport_d *);
281
282 /* nmport_mmap - maps the port resources into the process memory
283 * @d the nmport to be mapped
284 *
285 * The port must have been previously been registered using nmport_register.
286 *
287 * Note that if extmem is used (either via an option or by calling an
288 * nmport_extmem_* function before nmport_register()), no new mmap() is issued.
289 *
290 * It returns 0 on success. On failure it returns -1, sets errno to an error
291 * value and sends an error message to the error() method of the context used
292 * when @d was created. Moreover, *@d is left unchanged.
293 */
294 int nmport_mmap(struct nmport_d *);
295
296 /* the following functions undo the actions of nmport_new(), nmport_parse(),
297 * nmport_register() and nmport_mmap(), respectively.
298 */
299 void nmport_delete(struct nmport_d *);
300 void nmport_undo_parse(struct nmport_d *);
301 void nmport_undo_register(struct nmport_d *);
302 void nmport_undo_mmap(struct nmport_d *);
303
304 /* nmport_prepare - create a port descriptor, but do not open it
305 * @portspec the port opening specification
306 *
307 * This functions creates a new nmport_d and initializes it according to
308 * @portspec. It is equivalent to nmport_new() followed by nmport_parse().
309 *
310 * It returns 0 on success. On failure it returns -1, sets errno to an error
311 * value and sends an error message to the error() method of the context used
312 * when @d was created. Moreover, *@d is left unchanged.
313 */
314 struct nmport_d *nmport_prepare(const char *portspec);
315
316 /* nmport_open_desc - open an initialized port descriptor
317 * @d the descriptor we want to open
318 *
319 * Registers the port with netmap and maps the rings and buffers into the
320 * process memory. It is equivalent to nmport_register() followed by
321 * nmport_mmap().
322 *
323 * It returns 0 on success. On failure it returns -1, sets errno to an error
324 * value and sends an error message to the error() method of the context used
325 * when @d was created. Moreover, *@d is left unchanged.
326 */
327 int nmport_open_desc(struct nmport_d *d);
328
329 /* the following functions undo the actions of nmport_prepare()
330 * and nmport_open_desc(), respectively.
331 */
332 void nmport_undo_prepare(struct nmport_d *);
333 void nmport_undo_open_desc(struct nmport_d *);
334
335 /* nmport_clone - copy an nmport_d
336 * @d the nmport_d we want to copy
337 *
338 * Copying an nmport_d by hand should be avoided, since adjustments are needed
339 * and some part of the state cannot be easily duplicated. This function
340 * creates a copy of @d in a safe way. The returned nmport_d contains
341 * nmreq_header and nmreq_register structures equivalent to those contained in
342 * @d, except for the option list, which is ignored. The returned nmport_d is
343 * already nmport_prepare()d, but it must still be nmport_open_desc()ed. The
344 * new nmport_d uses the same nmctx as @d.
345 *
346 * If extmem was used for @d, then @d cannot be nmport_clone()d until it has
347 * been nmport_register()ed.
348 *
349 * In case of error, the function returns NULL, sets errno to an error value
350 * and sends an error message to the nmctx error() method.
351 */
352 struct nmport_d *nmport_clone(struct nmport_d *);
353
354 /* nmport_extmem - use extmem for this port
355 * @d the port we want to use the extmem for
356 * @base the base address of the extmem region
357 * @size the size in bytes of the extmem region
358 *
359 * the memory that contains the netmap ifs, rings and buffers is usually
360 * allocated by netmap and later mmap()ed by the applications. It is sometimes
361 * useful to reverse this process, by having the applications allocate some
362 * memory (through mmap() or otherwise) and then let netmap use it. The extmem
363 * option can be used to implement this latter strategy. The option can be
364 * passed through the portspec using the '@extmem:...' syntax, or
365 * programmatically by calling nmport_extmem() or nmport_extmem_from_file()
366 * between nmport_parse() and nmport_register() (or between nmport_prepare()
367 * and nmport_open_desc()).
368 *
369 * It returns 0 on success. On failure it returns -1, sets errno to an error
370 * value and sends an error message to the error() method of the context used
371 * when @d was created. Moreover, *@d is left unchanged.
372 */
373 int nmport_extmem(struct nmport_d *d, void *base, size_t size);
374
375 /* nmport_extmem_from_file - use the extmem obtained by mapping a file
376 * @d the port we want to use the extmem for
377 * @fname path of the file we want to map
378 *
379 * This works like nmport_extmem, but the extmem memory is obtained by
380 * mmap()ping @fname. nmport_close() will also automatically munmap() the file.
381 *
382 * It returns 0 on success. On failure it returns -1, sets errno to an error
383 * value and sends an error message to the error() method of the context used
384 * when @d was created. Moreover, *@d is left unchanged.
385 */
386 int nmport_extmem_from_file(struct nmport_d *d, const char *fname);
387
388 /* nmport_extmem_getinfo - opbtai a pointer to the extmem configuration
389 * @d the port we want to obtain the pointer from
390 *
391 * Returns a pointer to the nmreq_pools_info structure containing the
392 * configuration of the extmem attached to port @d, or NULL if no extmem
393 * is attached. This can be used to set the desired configuration before
394 * registering the port, or to read the actual configuration after
395 * registration.
396 */
397 struct nmreq_pools_info* nmport_extmem_getinfo(struct nmport_d *d);
398
399
400 /* enable/disable options
401 *
402 * These functions can be used to disable options that the application cannot
403 * or doesn't want to handle, or to enable options that require special support
404 * from the application and are, therefore, disabled by default. Disabled
405 * options will cause an error if encountered during option parsing.
406 *
407 * If the option is unknown, nmport_disable_option is a NOP, while
408 * nmport_enable_option returns -1 and sets errno to EOPNOTSUPP.
409 *
410 * These functions are not threadsafe and are meant to be used at the beginning
411 * of the program.
412 */
413 void nmport_disable_option(const char *opt);
414 int nmport_enable_option(const char *opt);
415
416 /* nmreq manipulation
417 *
418 * nmreq_header_init - initialize an nmreq_header
419 * @hdr the nmreq_header to initialize
420 * @reqtype the kind of netmap request
421 * @body the body of the request
422 *
423 * Initialize the nr_version, nr_reqtype and nr_body fields of *@hdr.
424 * The other fields are set to zero.
425 */
426 void nmreq_header_init(struct nmreq_header *hdr, uint16_t reqtype, void *body);
427
428 /*
429 * These functions allow for finer grained parsing of portspecs. They are used
430 * internally by nmport_parse().
431 */
432
433 /* nmreq_header_decode - initialize an nmreq_header
434 * @ppspec: (in/out) pointer to a pointer to the portspec
435 * @hdr: pointer to the nmreq_header to be initialized
436 * @ctx: pointer to the nmctx to use (for errors)
437 *
438 * This function fills the @hdr the nr_name field with the port name extracted
439 * from *@pifname. The other fields of *@hdr are unchanged. The @pifname is
440 * updated to point at the first char past the port name.
441 *
442 * Returns 0 on success. In case of error, -1 is returned with errno set to
443 * EINVAL, @pifname is unchanged, *@hdr is also unchanged, and an error message
444 * is sent through @ctx->error().
445 */
446 int nmreq_header_decode(const char **ppspec, struct nmreq_header *hdr,
447 struct nmctx *ctx);
448
449 /* nmreq_regiter_decode - initialize an nmreq_register
450 * @pmode: (in/out) pointer to a pointer to an opening mode
451 * @reg: pointer to the nmreq_register to be initialized
452 * @ctx: pointer to the nmctx to use (for errors)
453 *
454 * This function fills the nr_mode, nr_ringid, nr_flags and nr_mem_id fields of
455 * the structure pointed by @reg, according to the opening mode specified by
456 * *@pmode. The other fields of *@reg are unchanged. The @pmode is updated to
457 * point at the first char past the opening mode.
458 *
459 * If a '@' is encountered followed by something which is not a number, parsing
460 * stops (without error) and @pmode is left pointing at the '@' char. The
461 * nr_mode, nr_ringid and nr_flags fields are still updated, but nr_mem_id is
462 * not touched and the interpretation of the '@' field is left to the caller.
463 *
464 * Returns 0 on success. In case of error, -1 is returned with errno set to
465 * EINVAL, @pmode is unchanged, *@reg is also unchanged, and an error message
466 * is sent through @ctx->error().
467 */
468 int nmreq_register_decode(const char **pmode, struct nmreq_register *reg,
469 struct nmctx *ctx);
470
471 /* nmreq_options_decode - parse the "options" part of the portspec
472 * @opt: pointer to the option list
473 * @parsers: list of option parsers
474 * @token: token to pass to each parser
475 * @ctx: pointer to the nmctx to use (for errors and malloc/free)
476 *
477 * This function parses each option in @opt. Each option is matched (based on
478 * the "option" prefix) to a corresponding parser in @parsers. The function
479 * checks that the syntax is appropriate for the parser and it assigns all the
480 * keys mentioned in the option. It then passes control to the parser, to
481 * interpret the keys values.
482 *
483 * Returns 0 on success. In case of error, -1 is returned, errno is set to an
484 * error value and a message is sent to @ctx->error(). The effects of partially
485 * interpreted options may not be undone.
486 */
487 struct nmreq_opt_parser;
488 int nmreq_options_decode(const char *opt, struct nmreq_opt_parser *parsers,
489 void *token, struct nmctx *ctx);
490
491 struct nmreq_parse_ctx;
492 /* type of the option-parsers callbacks */
493 typedef int (*nmreq_opt_parser_cb)(struct nmreq_parse_ctx *);
494
495 #define NMREQ_OPT_MAXKEYS 16 /* max nr of recognized keys per option */
496
497 /* struct nmreq_opt_key - describes an option key */
498 struct nmreq_opt_key {
499 const char *key; /* the key name */
500 int id; /* its position in the parse context */
501 unsigned int flags;
502 #define NMREQ_OPTK_ALLOWEMPTY (1U << 0) /* =value may be omitted */
503 #define NMREQ_OPTK_MUSTSET (1U << 1) /* the key is mandatory */
504 #define NMREQ_OPTK_DEFAULT (1U << 2) /* this is the default key */
505 };
506
507 /* struct nmreq_opt_parser - describes an option parser */
508 struct nmreq_opt_parser {
509 const char *prefix; /* matches one option prefix */
510 nmreq_opt_parser_cb parse; /* the parse callback */
511 int default_key; /* which option is the default if the
512 parser is multi-key (-1 if none) */
513 int nr_keys;
514 unsigned int flags;
515 #define NMREQ_OPTF_DISABLED (1U << 0)
516 #define NMREQ_OPTF_ALLOWEMPTY (1U << 1) /* =value can be omitted */
517
518 struct nmreq_opt_parser *next; /* list of options */
519
520 /* recognized keys */
521 struct nmreq_opt_key keys[NMREQ_OPT_MAXKEYS];
522 } __attribute__((aligned(16)));
523
524 /* struct nmreq_parse_ctx - the parse context received by the parse callback */
525 struct nmreq_parse_ctx {
526 struct nmctx *ctx; /* the nmctx for errors and malloc/free */
527 void *token; /* the token passed to nmreq_options_parse */
528
529 /* the value (i.e., the part after the = sign) of each recognized key
530 * is assigned to the corresponding entry in this array, based on the
531 * key id. Unassigned keys are left at NULL.
532 */
533 const char *keys[NMREQ_OPT_MAXKEYS];
534 };
535
536 /* nmreq_get_mem_id - get the mem_id of the given port
537 * @portname pointer to a pointer to the portname
538 * @ctx pointer to the nmctx to use (for errors)
539 *
540 * *@portname must point to a substem:vpname porname, possibly followed by
541 * something else.
542 *
543 * If successful, returns the mem_id of *@portname and moves @portname past the
544 * subsystem:vpname part of the input. In case of error it returns -1, sets
545 * errno to an error value and sends an error message to ctx->error().
546 */
547 int32_t nmreq_get_mem_id(const char **portname, struct nmctx *ctx);
548
549 /* option list manipulation */
550 void nmreq_push_option(struct nmreq_header *, struct nmreq_option *);
551 void nmreq_remove_option(struct nmreq_header *, struct nmreq_option *);
552 struct nmreq_option *nmreq_find_option(struct nmreq_header *, uint32_t);
553 void nmreq_free_options(struct nmreq_header *);
554 const char* nmreq_option_name(uint32_t);
555 #define nmreq_foreach_option(h_, o_) \
556 for ((o_) = (struct nmreq_option *)((uintptr_t)((h_)->nr_options));\
557 (o_) != NULL;\
558 (o_) = (struct nmreq_option *)((uintptr_t)((o_)->nro_next)))
559
560 /* nmctx manipulation */
561
562 /* the nmctx serves a few purposes:
563 *
564 * - maintain a list of all memory regions open by the program, so that two
565 * ports that are using the same region (as identified by the mem_id) will
566 * point to the same nmem_d instance.
567 *
568 * - allow the user to specify how to lock accesses to the above list, if
569 * needed (lock() callback)
570 *
571 * - allow the user to specify how error messages should be delivered (error()
572 * callback)
573 *
574 * - select the verbosity of the library (verbose field); if verbose==0, no
575 * errors are sent to the error() callback
576 *
577 * - allow the user to override the malloc/free functions used by the library
578 * (malloc() and free() callbacks)
579 *
580 */
581 typedef void (*nmctx_error_cb)(struct nmctx *, const char *);
582 typedef void *(*nmctx_malloc_cb)(struct nmctx *,size_t);
583 typedef void (*nmctx_free_cb)(struct nmctx *,void *);
584 typedef void (*nmctx_lock_cb)(struct nmctx *, int);
585
586 struct nmctx {
587 int verbose;
588 nmctx_error_cb error;
589 nmctx_malloc_cb malloc;
590 nmctx_free_cb free;
591 nmctx_lock_cb lock;
592
593 struct nmem_d *mem_descs;
594 };
595
596 /* nmctx_get - obtain a pointer to the current default context */
597 struct nmctx *nmctx_get(void);
598
599 /* nmctx_set_default - change the default context
600 * @ctx pointer to the new context
601 *
602 * Returns a pointer to the previous default context.
603 */
604 struct nmctx *nmctx_set_default(struct nmctx *ctx);
605
606 /* internal functions and data structures */
607
608 /* struct nmem_d - describes a memory region currently used */
609 struct nmem_d {
610 uint16_t mem_id; /* the region netmap identifier */
611 int refcount; /* how many nmport_d's point here */
612 void *mem; /* memory region base address */
613 size_t size; /* memory region size */
614 int is_extmem; /* was it obtained via extmem? */
615
616 /* pointers for the circular list implementation.
617 * The list head is the mem_descs filed in the nmctx
618 */
619 struct nmem_d *next;
620 struct nmem_d *prev;
621 };
622
623 /* a trick to force the inclusion of libpthread only if requested. If
624 * LIBNETMAP_NOTHREADSAFE is defined, no pthread symbol is imported.
625 *
626 * There is no need to actually call this function: the ((used)) attribute is
627 * sufficient to include it in the image.
628 */
libnetmap_init(void)629 static __attribute__((used)) void libnetmap_init(void)
630 {
631 #ifndef LIBNETMAP_NOTHREADSAFE
632 extern int nmctx_threadsafe;
633 /* dummy assignment to link-in the nmctx-pthread.o object. The proper
634 * inizialization is performed only once in the library constructor
635 * defined there.
636 */
637 nmctx_threadsafe = 1;
638 #endif /* LIBNETMAP_NOTHREADSAFE */
639 }
640
641 /* nmctx_set_threadsafe - install a threadsafe default context
642 *
643 * called by the constructor in nmctx-pthread.o to initialize a lock and install
644 * the lock() callback in the default context.
645 */
646 void nmctx_set_threadsafe(void);
647
648 /* nmctx_ferror - format and send an error message */
649 void nmctx_ferror(struct nmctx *, const char *, ...);
650 /* nmctx_malloc - allocate memory */
651 void *nmctx_malloc(struct nmctx *, size_t);
652 /* nmctx_free - free memory allocated via nmctx_malloc */
653 void nmctx_free(struct nmctx *, void *);
654 /* nmctx_lock - lock the list of nmem_d */
655 void nmctx_lock(struct nmctx *);
656 /* nmctx_unlock - unlock the list of nmem_d */
657 void nmctx_unlock(struct nmctx *);
658
659 #endif /* LIBNETMAP_H_ */
660