| 1 | /* |
| 2 | * Copyright (c) 2008-2017 Apple Computer, Inc. All rights reserved. |
| 3 | * |
| 4 | * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ |
| 5 | * |
| 6 | * This file contains Original Code and/or Modifications of Original Code |
| 7 | * as defined in and that are subject to the Apple Public Source License |
| 8 | * Version 2.0 (the 'License'). You may not use this file except in |
| 9 | * compliance with the License. The rights granted to you under the License |
| 10 | * may not be used to create, or enable the creation or redistribution of, |
| 11 | * unlawful or unlicensed copies of an Apple operating system, or to |
| 12 | * circumvent, violate, or enable the circumvention or violation of, any |
| 13 | * terms of an Apple operating system software license agreement. |
| 14 | * |
| 15 | * Please obtain a copy of the License at |
| 16 | * http://www.opensource.apple.com/apsl/ and read it before using this file. |
| 17 | * |
| 18 | * The Original Code and all software distributed under the License are |
| 19 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER |
| 20 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, |
| 21 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, |
| 22 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. |
| 23 | * Please see the License for the specific language governing rights and |
| 24 | * limitations under the License. |
| 25 | * |
| 26 | * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ |
| 27 | */ |
| 28 | /*! |
| 29 | @header kpi_socketfilter.h |
| 30 | This header defines an API for intercepting communications at the |
| 31 | socket layer. |
| 32 | |
| 33 | For the most part, socket filters want to do three things: Filter |
| 34 | data in and out, watch for state changes, and intercept a few calls |
| 35 | for security. The number of function pointers supplied by a socket |
| 36 | filter has been significantly reduced. The filter no longer has any |
| 37 | knowledge of socket buffers. The filter no longer intercepts nearly |
| 38 | every internal socket call. There are two data filters, an in |
| 39 | filter, and an out filter. The in filter occurs before data is |
| 40 | placed in the receive socket buffer. This is done to avoid waking |
| 41 | the process unnecessarily. The out filter occurs before the data is |
| 42 | appended to the send socket buffer. This should cover inbound and |
| 43 | outbound data. For monitoring state changes, we've added a notify |
| 44 | function that will be called when various events that the filter can |
| 45 | not intercept occur. In addition, we've added a few functions that a |
| 46 | filter may use to intercept common operations. These functions are: |
| 47 | connect (inbound), connect (outbound), bind, set socket option, |
| 48 | get socket option, and listen. Bind, listen, connect in, and connect |
| 49 | out could be used together to build a fairly comprehensive firewall |
| 50 | without having to do much with individual packets. |
| 51 | */ |
| 52 | #ifndef __KPI_SOCKETFILTER__ |
| 53 | #define __KPI_SOCKETFILTER__ |
| 54 | |
| 55 | #include <sys/kernel_types.h> |
| 56 | #include <sys/kpi_socket.h> |
| 57 | |
| 58 | struct sockaddr; |
| 59 | |
| 60 | /*! |
| 61 | @enum sflt_flags |
| 62 | @abstract Constants defining mbuf flags. Only the flags listed below |
| 63 | can be set or retrieved. |
| 64 | @constant SFLT_GLOBAL Indicates this socket filter should be |
| 65 | attached to all new sockets when they're created. |
| 66 | @constant SFLT_PROG Indicates this socket filter should be attached |
| 67 | only when request by the application using the SO_NKE socket |
| 68 | option. |
| 69 | @constant SFLT_EXTENDED Indicates that this socket filter utilizes |
| 70 | the extended fields within the sflt_filter structure. |
| 71 | @constant SFLT_EXTENDED_REGISTRY Indicates that this socket filter |
| 72 | wants to attach to all the sockets already present on the |
| 73 | system. It will also receive notifications for these sockets. |
| 74 | */ |
| 75 | enum { |
| 76 | SFLT_GLOBAL = 0x01, |
| 77 | SFLT_PROG = 0x02, |
| 78 | SFLT_EXTENDED = 0x04, |
| 79 | SFLT_EXTENDED_REGISTRY = 0x08 |
| 80 | }; |
| 81 | typedef u_int32_t sflt_flags; |
| 82 | |
| 83 | /*! |
| 84 | @typedef sflt_handle |
| 85 | @abstract A 4 byte identifier used with the SO_NKE socket option to |
| 86 | identify the socket filter to be attached. |
| 87 | */ |
| 88 | typedef u_int32_t sflt_handle; |
| 89 | |
| 90 | /*! |
| 91 | @enum sflt_event_t |
| 92 | @abstract Events notify a filter of state changes and other various |
| 93 | events related to the socket. These events cannot be prevented |
| 94 | or intercepted, only observed. |
| 95 | @constant sock_evt_connected Indicates this socket has moved to the |
| 96 | connected state. |
| 97 | @constant sock_evt_disconnected Indicates this socket has moved to |
| 98 | the disconnected state. |
| 99 | @constant sock_evt_flush_read The read socket buffer has been |
| 100 | flushed. |
| 101 | @constant sock_evt_shutdown The read and or write side(s) of the |
| 102 | connection have been shutdown. The param will point to an |
| 103 | integer that indicates the direction that has been shutdown. See |
| 104 | 'man 2 shutdown' for more information. |
| 105 | @constant sock_evt_cantrecvmore Indicates the socket cannot receive |
| 106 | more data. |
| 107 | @constant sock_evt_cantsendmore Indicates the socket cannot send |
| 108 | more data. |
| 109 | @constant sock_evt_closing Indicates the socket is closing. |
| 110 | @constant sock_evt_bound Indicates this socket has moved to the |
| 111 | bound state (only for PF_INET/PF_INET6 domain). |
| 112 | */ |
| 113 | enum { |
| 114 | sock_evt_connecting = 1, |
| 115 | sock_evt_connected = 2, |
| 116 | sock_evt_disconnecting = 3, |
| 117 | sock_evt_disconnected = 4, |
| 118 | sock_evt_flush_read = 5, |
| 119 | sock_evt_shutdown = 6, /* param points to an integer specifying how (read, write, or both) see man 2 shutdown */ |
| 120 | sock_evt_cantrecvmore = 7, |
| 121 | sock_evt_cantsendmore = 8, |
| 122 | sock_evt_closing = 9, |
| 123 | sock_evt_bound = 10 |
| 124 | }; |
| 125 | typedef u_int32_t sflt_event_t; |
| 126 | |
| 127 | /*! |
| 128 | @enum sflt_data_flag_t |
| 129 | @abstract Inbound and outbound data filters may handle many |
| 130 | different types of incoming and outgoing data. These flags help |
| 131 | distinguish between normal data, out-of-band data, and records. |
| 132 | @constant sock_data_filt_flag_oob Indicates this data is out-of-band |
| 133 | data. |
| 134 | @constant sock_data_filt_flag_record Indicates this data is a |
| 135 | record. This flag is only ever seen on inbound data. |
| 136 | */ |
| 137 | enum { |
| 138 | sock_data_filt_flag_oob = 1, |
| 139 | sock_data_filt_flag_record = 2 |
| 140 | }; |
| 141 | typedef u_int32_t sflt_data_flag_t; |
| 142 | |
| 143 | __BEGIN_DECLS |
| 144 | |
| 145 | /*! |
| 146 | @typedef sf_unregistered_func |
| 147 | |
| 148 | @discussion sf_unregistered_func is called to notify the filter it |
| 149 | has been unregistered. This is the last function the stack will |
| 150 | call and this function will only be called once all other |
| 151 | function calls in to your filter have completed. Once this |
| 152 | function has been called, your kext may safely unload. |
| 153 | @param handle The socket filter handle used to identify this filter. |
| 154 | */ |
| 155 | typedef void (*sf_unregistered_func)(sflt_handle handle); |
| 156 | |
| 157 | /*! |
| 158 | @typedef sf_attach_func |
| 159 | |
| 160 | @discussion sf_attach_func is called to notify the filter it has |
| 161 | been attached to a socket. The filter may allocate memory for |
| 162 | this attachment and use the cookie to track it. This filter is |
| 163 | called in one of two cases: |
| 164 | 1) You've installed a global filter and a new socket was created. |
| 165 | 2) Your non-global socket filter is being attached using the SO_NKE |
| 166 | socket option. |
| 167 | @param cookie Used to allow the socket filter to set the cookie for |
| 168 | this attachment. |
| 169 | @param so The socket the filter is being attached to. |
| 170 | @result If you return a non-zero value, your filter will not be |
| 171 | attached to this socket. |
| 172 | */ |
| 173 | typedef errno_t (*sf_attach_func)(void **cookie, socket_t so); |
| 174 | |
| 175 | /*! |
| 176 | @typedef sf_detach_func |
| 177 | |
| 178 | @discussion sf_detach_func is called to notify the filter it has |
| 179 | been detached from a socket. If the filter allocated any memory |
| 180 | for this attachment, it should be freed. This function will |
| 181 | be called when the socket is disposed of. |
| 182 | @param cookie Cookie value specified when the filter attach was |
| 183 | called. |
| 184 | @param so The socket the filter is attached to. |
| 185 | @discussion If you return a non-zero value, your filter will not be |
| 186 | attached to this socket. |
| 187 | */ |
| 188 | typedef void (*sf_detach_func)(void *cookie, socket_t so); |
| 189 | |
| 190 | /*! |
| 191 | @typedef sf_notify_func |
| 192 | |
| 193 | @discussion sf_notify_func is called to notify the filter of various |
| 194 | state changes and other events occuring on the socket. |
| 195 | @param cookie Cookie value specified when the filter attach was |
| 196 | called. |
| 197 | @param so The socket the filter is attached to. |
| 198 | @param event The type of event that has occurred. |
| 199 | @param param Additional information about the event. |
| 200 | */ |
| 201 | typedef void (*sf_notify_func)(void *cookie, socket_t so, sflt_event_t event, |
| 202 | void *param); |
| 203 | |
| 204 | /*! |
| 205 | @typedef sf_getpeername_func |
| 206 | |
| 207 | @discussion sf_getpeername_func is called to allow a filter to |
| 208 | to intercept the getpeername function. When called, sa will |
| 209 | point to a pointer to a socket address that was malloced |
| 210 | in zone M_SONAME. If you want to replace this address, either |
| 211 | modify the currenty copy or allocate a new one and free the |
| 212 | old one. |
| 213 | @param cookie Cookie value specified when the filter attach was |
| 214 | called. |
| 215 | @param so The socket the filter is attached to. |
| 216 | @param sa A pointer to a socket address pointer. |
| 217 | @result If you return a non-zero value, processing will stop. If |
| 218 | you return EJUSTRETURN, no further filters will be called |
| 219 | but a result of zero will be returned to the caller of |
| 220 | getpeername. |
| 221 | */ |
| 222 | typedef int (*sf_getpeername_func)(void *cookie, socket_t so, |
| 223 | struct sockaddr **sa); |
| 224 | |
| 225 | /*! |
| 226 | @typedef sf_getsockname_func |
| 227 | |
| 228 | @discussion sf_getsockname_func is called to allow a filter to |
| 229 | to intercept the getsockname function. When called, sa will |
| 230 | point to a pointer to a socket address that was malloced |
| 231 | in zone M_SONAME. If you want to replace this address, either |
| 232 | modify the currenty copy or allocate a new one and free the |
| 233 | old one. |
| 234 | @param cookie Cookie value specified when the filter attach was |
| 235 | called. |
| 236 | @param so The socket the filter is attached to. |
| 237 | @param sa A pointer to a socket address pointer. |
| 238 | @result If you return a non-zero value, processing will stop. If |
| 239 | you return EJUSTRETURN, no further filters will be called |
| 240 | but a result of zero will be returned to the caller of |
| 241 | getsockname. |
| 242 | */ |
| 243 | typedef int (*sf_getsockname_func)(void *cookie, socket_t so, |
| 244 | struct sockaddr **sa); |
| 245 | |
| 246 | /*! |
| 247 | @typedef sf_data_in_func |
| 248 | |
| 249 | @discussion sf_data_in_func is called to filter incoming data. If your |
| 250 | filter intercepts data for later reinjection, it must queue |
| 251 | all incoming data to preserve the order of the data. Use |
| 252 | sock_inject_data_in to later reinject this data if you return |
| 253 | EJUSTRETURN. Warning: This filter is on the data path. Do not |
| 254 | spend excesive time. Do not wait for data on another socket. |
| 255 | @param cookie Cookie value specified when the filter attach was |
| 256 | called. |
| 257 | @param so The socket the filter is attached to. |
| 258 | @param from The addres the data is from, may be NULL if the socket |
| 259 | is connected. |
| 260 | @param data The data being received. Control data may appear in the |
| 261 | mbuf chain, be sure to check the mbuf types to find control |
| 262 | data. |
| 263 | @param control Control data being passed separately from the data. |
| 264 | @param flags Flags to indicate if this is out of band data or a |
| 265 | record. |
| 266 | @result Return: |
| 267 | 0 - The caller will continue with normal processing of the data. |
| 268 | EJUSTRETURN - The caller will stop processing the data, the |
| 269 | data will not be freed. |
| 270 | Anything Else - The caller will free the data and stop |
| 271 | processing. |
| 272 | */ |
| 273 | typedef errno_t (*sf_data_in_func)(void *cookie, socket_t so, |
| 274 | const struct sockaddr *from, mbuf_t *data, mbuf_t *control, |
| 275 | sflt_data_flag_t flags); |
| 276 | |
| 277 | /*! |
| 278 | @typedef sf_data_out_func |
| 279 | |
| 280 | @discussion sf_data_out_func is called to filter outbound data. If |
| 281 | your filter intercepts data for later reinjection, it must queue |
| 282 | all outbound data to preserve the order of the data when |
| 283 | reinjecting. Use sock_inject_data_out to later reinject this |
| 284 | data. |
| 285 | @param cookie Cookie value specified when the filter attach was |
| 286 | called. |
| 287 | @param so The socket the filter is attached to. |
| 288 | @param to The address the data is to, may be NULL if the socket |
| 289 | is connected. |
| 290 | @param data The data being received. Control data may appear in the |
| 291 | mbuf chain, be sure to check the mbuf types to find control |
| 292 | data. |
| 293 | @param control Control data being passed separately from the data. |
| 294 | @param flags Flags to indicate if this is out of band data or a |
| 295 | record. |
| 296 | @result Return: |
| 297 | 0 - The caller will continue with normal processing of the data. |
| 298 | EJUSTRETURN - The caller will stop processing the data, |
| 299 | the data will not be freed. |
| 300 | Anything Else - The caller will free the data and stop |
| 301 | processing. |
| 302 | */ |
| 303 | typedef errno_t (*sf_data_out_func)(void *cookie, socket_t so, |
| 304 | const struct sockaddr *to, mbuf_t *data, mbuf_t *control, |
| 305 | sflt_data_flag_t flags); |
| 306 | |
| 307 | /*! |
| 308 | @typedef sf_connect_in_func |
| 309 | |
| 310 | @discussion sf_connect_in_func is called to filter inbound connections. |
| 311 | A protocol will call this before accepting an incoming |
| 312 | connection and placing it on the queue of completed connections. |
| 313 | Warning: This filter is on the data path. Do not spend excesive |
| 314 | time. Do not wait for data on another socket. |
| 315 | @param cookie Cookie value specified when the filter attach was |
| 316 | called. |
| 317 | @param so The socket the filter is attached to. |
| 318 | @param from The address the incoming connection is from. |
| 319 | @result Return: |
| 320 | 0 - The caller will continue with normal processing of the |
| 321 | connection. |
| 322 | Anything Else - The caller will rejecting the incoming |
| 323 | connection. |
| 324 | */ |
| 325 | typedef errno_t (*sf_connect_in_func)(void *cookie, socket_t so, |
| 326 | const struct sockaddr *from); |
| 327 | |
| 328 | /*! |
| 329 | @typedef sf_connect_out_func |
| 330 | |
| 331 | @discussion sf_connect_out_func is called to filter outbound |
| 332 | connections. A protocol will call this before initiating an |
| 333 | outbound connection. |
| 334 | @param cookie Cookie value specified when the filter attach was |
| 335 | called. |
| 336 | @param so The socket the filter is attached to. |
| 337 | @param to The remote address of the outbound connection. |
| 338 | @result Return: |
| 339 | 0 - The caller will continue with normal processing of the |
| 340 | connection. |
| 341 | EJUSTRETURN - The caller will return with a value of 0 (no error) |
| 342 | from that point without further processing the connect command. The |
| 343 | protocol layer will not see the call. |
| 344 | Anything Else - The caller will rejecting the outbound |
| 345 | connection. |
| 346 | */ |
| 347 | typedef errno_t (*sf_connect_out_func)(void *cookie, socket_t so, |
| 348 | const struct sockaddr *to); |
| 349 | |
| 350 | /*! |
| 351 | @typedef sf_bind_func |
| 352 | |
| 353 | @discussion sf_bind_func is called before performing a bind |
| 354 | operation on a socket. |
| 355 | @param cookie Cookie value specified when the filter attach was |
| 356 | called. |
| 357 | @param so The socket the filter is attached to. |
| 358 | @param to The local address of the socket will be bound to. |
| 359 | @result Return: |
| 360 | 0 - The caller will continue with normal processing of the bind. |
| 361 | EJUSTRETURN - The caller will return with a value of 0 (no error) |
| 362 | from that point without further processing the bind command. The |
| 363 | protocol layer will not see the call. |
| 364 | Anything Else - The caller will rejecting the bind. |
| 365 | */ |
| 366 | typedef errno_t (*sf_bind_func)(void *cookie, socket_t so, |
| 367 | const struct sockaddr *to); |
| 368 | |
| 369 | /*! |
| 370 | @typedef sf_setoption_func |
| 371 | |
| 372 | @discussion sf_setoption_func is called before performing setsockopt |
| 373 | on a socket. |
| 374 | @param cookie Cookie value specified when the filter attach was |
| 375 | called. |
| 376 | @param so The socket the filter is attached to. |
| 377 | @param opt The socket option to set. |
| 378 | @result Return: |
| 379 | 0 - The caller will continue with normal processing of the |
| 380 | setsockopt. |
| 381 | EJUSTRETURN - The caller will return with a value of 0 (no error) |
| 382 | from that point without further propagating the set option |
| 383 | command. The socket and protocol layers will not see the call. |
| 384 | Anything Else - The caller will stop processing and return |
| 385 | this error. |
| 386 | */ |
| 387 | typedef errno_t (*sf_setoption_func)(void *cookie, socket_t so, sockopt_t opt); |
| 388 | |
| 389 | /*! |
| 390 | @typedef sf_getoption_func |
| 391 | |
| 392 | @discussion sf_getoption_func is called before performing getsockopt |
| 393 | on a socket. |
| 394 | @param cookie Cookie value specified when the filter attach was |
| 395 | called. |
| 396 | @param so The socket the filter is attached to. |
| 397 | @param opt The socket option to get. |
| 398 | @result Return: |
| 399 | 0 - The caller will continue with normal processing of the |
| 400 | getsockopt. |
| 401 | EJUSTRETURN - The caller will return with a value of 0 (no error) |
| 402 | from that point without further propagating the get option |
| 403 | command. The socket and protocol layers will not see the call. |
| 404 | Anything Else - The caller will stop processing and return |
| 405 | this error. |
| 406 | */ |
| 407 | typedef errno_t (*sf_getoption_func)(void *cookie, socket_t so, sockopt_t opt); |
| 408 | |
| 409 | /*! |
| 410 | @typedef sf_listen_func |
| 411 | |
| 412 | @discussion sf_listen_func is called before performing listen |
| 413 | on a socket. |
| 414 | @param cookie Cookie value specified when the filter attach was |
| 415 | called. |
| 416 | @param so The socket the filter is attached to. |
| 417 | @result Return: |
| 418 | 0 - The caller will continue with normal processing of listen. |
| 419 | EJUSTRETURN - The caller will return with a value of 0 (no error) |
| 420 | from that point without further processing the listen command. The |
| 421 | protocol will not see the call. |
| 422 | Anything Else - The caller will stop processing and return |
| 423 | this error. |
| 424 | */ |
| 425 | typedef errno_t (*sf_listen_func)(void *cookie, socket_t so); |
| 426 | |
| 427 | /*! |
| 428 | @typedef sf_ioctl_func |
| 429 | |
| 430 | @discussion sf_ioctl_func is called before performing an ioctl |
| 431 | on a socket. |
| 432 | |
| 433 | All undefined ioctls are reserved for future use by Apple. If |
| 434 | you need to communicate with your kext using an ioctl, please |
| 435 | use SIOCSIFKPI and SIOCGIFKPI. |
| 436 | @param cookie Cookie value specified when the filter attach was |
| 437 | called. |
| 438 | @param so The socket the filter is attached to. |
| 439 | @param request The ioctl name. |
| 440 | @param argp A pointer to the ioctl parameter. |
| 441 | @result Return: |
| 442 | 0 - The caller will continue with normal processing of |
| 443 | this ioctl. |
| 444 | EJUSTRETURN - The caller will return with a value of 0 (no error) |
| 445 | from that point without further processing or propogating |
| 446 | the ioctl. |
| 447 | Anything Else - The caller will stop processing and return |
| 448 | this error. |
| 449 | */ |
| 450 | typedef errno_t (*sf_ioctl_func)(void *cookie, socket_t so, |
| 451 | unsigned long request, const char* argp); |
| 452 | |
| 453 | /*! |
| 454 | @typedef sf_accept_func |
| 455 | |
| 456 | @discussion sf_accept_func is called after a socket is dequeued |
| 457 | off the completed (incoming) connection list and before |
| 458 | the file descriptor is associated with it. A filter can |
| 459 | utilize this callback to intercept the accepted socket |
| 460 | in order to examine it, prior to returning the socket to |
| 461 | the caller of accept. Such a filter may also choose to |
| 462 | discard the accepted socket if it wishes to do so. |
| 463 | @param cookie Cookie value specified when the filter attach was called. |
| 464 | @param so_listen The listening socket. |
| 465 | @param so The socket that is about to be accepted. |
| 466 | @param local The local address of the about to be accepted socket. |
| 467 | @param remote The remote address of the about to be accepted socket. |
| 468 | @result Return: |
| 469 | 0 - The caller will continue with normal processing of accept. |
| 470 | EJUSTRETURN - The to be accepted socket will be disconnected |
| 471 | prior to being returned to the caller of accept. No further |
| 472 | control or data operations on the socket will be allowed. |
| 473 | This is the recommended return value as it has the least |
| 474 | amount of impact, especially to applications which don't |
| 475 | check the error value returned by accept. |
| 476 | Anything Else - The to be accepted socket will be closed and |
| 477 | the error will be returned to the caller of accept. |
| 478 | Note that socket filter developers are advised to exercise |
| 479 | caution when returning non-zero values to the caller, |
| 480 | since some applications don't check the error value |
| 481 | returned by accept and therefore risk breakage. |
| 482 | */ |
| 483 | typedef errno_t (*sf_accept_func)(void *cookie, socket_t so_listen, socket_t so, |
| 484 | const struct sockaddr *local, const struct sockaddr *remote); |
| 485 | |
| 486 | /*! |
| 487 | @struct sflt_filter |
| 488 | @discussion This structure is used to define a socket filter. |
| 489 | @field sf_handle A value used to find socket filters by |
| 490 | applications. An application can use this value to specify that |
| 491 | this filter should be attached when using the SO_NKE socket |
| 492 | option. |
| 493 | @field sf_flags Indicate whether this filter should be attached to |
| 494 | all new sockets or just those that request the filter be |
| 495 | attached using the SO_NKE socket option. If this filter |
| 496 | utilizes the socket filter extension fields, it must also |
| 497 | set SFLT_EXTENDED. |
| 498 | @field sf_name A name used for debug purposes. |
| 499 | @field sf_unregistered Your function for being notified when your |
| 500 | filter has been unregistered. |
| 501 | @field sf_attach Your function for handling attaches to sockets. |
| 502 | @field sf_detach Your function for handling detaches from sockets. |
| 503 | @field sf_notify Your function for handling events. May be null. |
| 504 | @field sf_data_in Your function for handling incoming data. May be |
| 505 | null. |
| 506 | @field sf_data_out Your function for handling outgoing data. May be |
| 507 | null. |
| 508 | @field sf_connect_in Your function for handling inbound |
| 509 | connections. May be null. |
| 510 | @field sf_connect_out Your function for handling outbound |
| 511 | connections. May be null. |
| 512 | @field sf_bind Your function for handling binds. May be null. |
| 513 | @field sf_setoption Your function for handling setsockopt. May be null. |
| 514 | @field sf_getoption Your function for handling getsockopt. May be null. |
| 515 | @field sf_listen Your function for handling listen. May be null. |
| 516 | @field sf_ioctl Your function for handling ioctls. May be null. |
| 517 | @field sf_len Length of socket filter extension structure; developers |
| 518 | must initialize this to sizeof sflt_filter_ext structure. |
| 519 | This field and all fields following it will only be valid |
| 520 | if SFLT_EXTENDED flag is set in sf_flags field. |
| 521 | @field sf_ext_accept Your function for handling inbound connections |
| 522 | at accept time. May be null. |
| 523 | @field sf_ext_rsvd Reserved for future use; you must initialize |
| 524 | the reserved fields with zeroes. |
| 525 | */ |
| 526 | struct sflt_filter { |
| 527 | sflt_handle sf_handle; |
| 528 | int sf_flags; |
| 529 | char *sf_name; |
| 530 | |
| 531 | sf_unregistered_func sf_unregistered; |
| 532 | sf_attach_func sf_attach; |
| 533 | sf_detach_func sf_detach; |
| 534 | |
| 535 | sf_notify_func sf_notify; |
| 536 | sf_getpeername_func sf_getpeername; |
| 537 | sf_getsockname_func sf_getsockname; |
| 538 | sf_data_in_func sf_data_in; |
| 539 | sf_data_out_func sf_data_out; |
| 540 | sf_connect_in_func sf_connect_in; |
| 541 | sf_connect_out_func sf_connect_out; |
| 542 | sf_bind_func sf_bind; |
| 543 | sf_setoption_func sf_setoption; |
| 544 | sf_getoption_func sf_getoption; |
| 545 | sf_listen_func sf_listen; |
| 546 | sf_ioctl_func sf_ioctl; |
| 547 | /* |
| 548 | * The following are valid only if SFLT_EXTENDED flag is set. |
| 549 | * Initialize sf_ext_len to sizeof sflt_filter_ext structure. |
| 550 | * Filters must also initialize reserved fields with zeroes. |
| 551 | */ |
| 552 | struct sflt_filter_ext { |
| 553 | unsigned int sf_ext_len; |
| 554 | sf_accept_func sf_ext_accept; |
| 555 | void *sf_ext_rsvd[5]; /* Reserved */ |
| 556 | } sf_ext; |
| 557 | #define sf_len sf_ext.sf_ext_len |
| 558 | #define sf_accept sf_ext.sf_ext_accept |
| 559 | }; |
| 560 | |
| 561 | /*! |
| 562 | @function sflt_register |
| 563 | @discussion Registers a socket filter. See 'man 2 socket' for a |
| 564 | desciption of domain, type, and protocol. |
| 565 | @param filter A structure describing the filter. |
| 566 | @param domain The protocol domain these filters will be attached to. |
| 567 | Only PF_INET & PF_INET6 domains are supported. |
| 568 | @param type The socket type these filters will be attached to. |
| 569 | @param protocol The protocol these filters will be attached to. |
| 570 | @result 0 on success otherwise the errno error. |
| 571 | */ |
| 572 | #ifdef KERNEL_PRIVATE |
| 573 | extern errno_t sflt_register_internal(const struct sflt_filter *filter, |
| 574 | int domain, int type, int protocol); |
| 575 | |
| 576 | #define sflt_register(filter, domain, type, protocol) \ |
| 577 | sflt_register_internal((filter), (domain), (type), (protocol)) |
| 578 | #else |
| 579 | extern errno_t sflt_register(const struct sflt_filter *filter, int domain, |
| 580 | int type, int protocol); |
| 581 | #endif /* KERNEL_PRIVATE */ |
| 582 | |
| 583 | /*! |
| 584 | @function sflt_unregister |
| 585 | @discussion Unregisters a socket filter. This will not detach the |
| 586 | socket filter from all sockets it may be attached to at the |
| 587 | time, it will just prevent the socket filter from being attached |
| 588 | to any new sockets. |
| 589 | @param handle The sf_handle of the socket filter to unregister. |
| 590 | @result 0 on success otherwise the errno error. |
| 591 | */ |
| 592 | extern errno_t sflt_unregister(sflt_handle handle); |
| 593 | |
| 594 | /*! |
| 595 | @function sflt_attach |
| 596 | @discussion Attaches a socket filter to the specified socket. A |
| 597 | filter must be registered before it can be attached. |
| 598 | @param socket The socket the filter should be attached to. |
| 599 | @param handle The handle of the registered filter to be attached. |
| 600 | @result 0 on success otherwise the errno error. |
| 601 | */ |
| 602 | extern errno_t sflt_attach(socket_t socket, sflt_handle handle); |
| 603 | |
| 604 | /*! |
| 605 | @function sflt_detach |
| 606 | @discussion Detaches a socket filter from a specified socket. |
| 607 | @param socket The socket the filter should be detached from. |
| 608 | @param handle The handle of the registered filter to be detached. |
| 609 | @result 0 on success otherwise the errno error. |
| 610 | */ |
| 611 | extern errno_t sflt_detach(socket_t socket, sflt_handle handle); |
| 612 | |
| 613 | /* Functions for manipulating sockets */ |
| 614 | /* |
| 615 | * Inject data in to the receive buffer of the socket as if it |
| 616 | * had come from the network. |
| 617 | * |
| 618 | * flags should match sflt_data_flag_t |
| 619 | */ |
| 620 | |
| 621 | /*! |
| 622 | @function sock_inject_data_in |
| 623 | @discussion Inject data in to the receive buffer of the socket as if |
| 624 | it had come from the network. |
| 625 | @param so The socket to inject the data on. |
| 626 | @param from The address the data is from, only necessary on |
| 627 | un-connected sockets. A copy of the address will be made, caller |
| 628 | is responsible for freeing the address after calling this |
| 629 | function. |
| 630 | @param data The data and possibly control mbufs. |
| 631 | @param control The separate control mbufs. |
| 632 | @param flags Flags indicating the type of data. |
| 633 | @result 0 on success otherwise the errno error. If the function |
| 634 | returns an error, the caller is responsible for freeing the |
| 635 | mbuf. |
| 636 | */ |
| 637 | extern errno_t sock_inject_data_in(socket_t so, const struct sockaddr *from, |
| 638 | mbuf_t data, mbuf_t control, sflt_data_flag_t flags); |
| 639 | |
| 640 | /*! |
| 641 | @function sock_inject_data_out |
| 642 | @discussion Inject data in to the send buffer of the socket as if it |
| 643 | had come from the client. |
| 644 | @param so The socket to inject the data on. |
| 645 | @param to The address the data should be sent to, only necessary on |
| 646 | un-connected sockets. The caller is responsible for freeing the |
| 647 | to address after sock_inject_data_out returns. |
| 648 | @param data The data and possibly control mbufs. |
| 649 | @param control The separate control mbufs. |
| 650 | @param flags Flags indicating the type of data. |
| 651 | @result 0 on success otherwise the errno error. The data and control |
| 652 | values are always freed regardless of return value. |
| 653 | */ |
| 654 | extern errno_t sock_inject_data_out(socket_t so, const struct sockaddr *to, |
| 655 | mbuf_t data, mbuf_t control, sflt_data_flag_t flags); |
| 656 | |
| 657 | |
| 658 | /* |
| 659 | * sockopt_t accessors |
| 660 | */ |
| 661 | |
| 662 | enum { |
| 663 | sockopt_get = 1, |
| 664 | sockopt_set = 2 |
| 665 | }; |
| 666 | typedef u_int8_t sockopt_dir; |
| 667 | |
| 668 | /*! |
| 669 | @function sockopt_direction |
| 670 | @discussion Retrieves the direction of the socket option (Get or |
| 671 | Set). |
| 672 | @param sopt The socket option. |
| 673 | @result sock_opt_get or sock_opt_set. |
| 674 | */ |
| 675 | extern sockopt_dir sockopt_direction(sockopt_t sopt); |
| 676 | |
| 677 | /*! |
| 678 | @function sockopt_level |
| 679 | @discussion Retrieves the socket option level. (SOL_SOCKET, etc). |
| 680 | @param sopt The socket option. |
| 681 | @result The socket option level. See man 2 setsockopt |
| 682 | */ |
| 683 | extern int sockopt_level(sockopt_t sopt); |
| 684 | |
| 685 | /*! |
| 686 | @function sockopt_name |
| 687 | @discussion Retrieves the socket option name. (SO_SNDBUF, etc). |
| 688 | @param sopt The socket option. |
| 689 | @result The socket option name. See man 2 setsockopt |
| 690 | */ |
| 691 | extern int sockopt_name(sockopt_t sopt); |
| 692 | |
| 693 | /*! |
| 694 | @function sockopt_valsize |
| 695 | @discussion Retrieves the size of the socket option data. |
| 696 | @param sopt The socket option. |
| 697 | @result The length, in bytes, of the data. |
| 698 | */ |
| 699 | extern size_t sockopt_valsize(sockopt_t sopt); |
| 700 | |
| 701 | /*! |
| 702 | @function sockopt_copyin |
| 703 | @discussion Copies the data from the socket option to a buffer. |
| 704 | @param sopt The socket option. |
| 705 | @param data A pointer to the buffer to copy the data in to. |
| 706 | @param length The number of bytes to copy. |
| 707 | @result An errno error or zero upon success. |
| 708 | */ |
| 709 | extern errno_t sockopt_copyin(sockopt_t sopt, void *data, size_t length); |
| 710 | |
| 711 | /*! |
| 712 | @function sockopt_copyout |
| 713 | @discussion Copies the data from a buffer to a socket option. |
| 714 | @param sopt The socket option. |
| 715 | @param data A pointer to the buffer to copy the data out of. |
| 716 | @param length The number of bytes to copy. |
| 717 | @result An errno error or zero upon success. |
| 718 | */ |
| 719 | extern errno_t sockopt_copyout(sockopt_t sopt, void *data, size_t length); |
| 720 | |
| 721 | __END_DECLS |
| 722 | #endif /* __KPI_SOCKETFILTER__ */ |
| 723 | |