include/net/ax25.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  *      Declarations of AX.25 type objects.
   4  *
   5  *      Alan Cox (GW4PTS)       10/11/93
   6  */
   7 #ifndef _AX25_H
   8 #define _AX25_H
   9
  10 #include <linux/ax25.h>
  11 #include <linux/spinlock.h>
  12 #include <linux/timer.h>
  13 #include <linux/list.h>
  14 #include <linux/slab.h>
  15 #include <linux/refcount.h>
  16 #include <net/neighbour.h>
  17 #include <net/sock.h>
  18 #include <linux/seq_file.h>
  19
  20 #define AX25_T1CLAMPLO                  1
  21 #define AX25_T1CLAMPHI                  (30 * HZ)
  22
  23 #define AX25_BPQ_HEADER_LEN             16
  24 #define AX25_KISS_HEADER_LEN            1
  25
  26 #define AX25_HEADER_LEN                 17
  27 #define AX25_ADDR_LEN                   7
  28 #define AX25_DIGI_HEADER_LEN            (AX25_MAX_DIGIS * AX25_ADDR_LEN)
  29 #define AX25_MAX_HEADER_LEN             (AX25_HEADER_LEN + AX25_DIGI_HEADER_LEN)
  30
  31 /* AX.25 Protocol IDs */
  32 #define AX25_P_ROSE                     0x01
  33 #define AX25_P_VJCOMP                   0x06    /* Compressed TCP/IP packet   */
  34                                                 /* Van Jacobsen (RFC 1144)    */
  35 #define AX25_P_VJUNCOMP                 0x07    /* Uncompressed TCP/IP packet */
  36                                                 /* Van Jacobsen (RFC 1144)    */
  37 #define AX25_P_SEGMENT                  0x08    /* Segmentation fragment      */
  38 #define AX25_P_TEXNET                   0xc3    /* TEXTNET datagram protocol  */
  39 #define AX25_P_LQ                       0xc4    /* Link Quality Protocol      */
  40 #define AX25_P_ATALK                    0xca    /* Appletalk                  */
  41 #define AX25_P_ATALK_ARP                0xcb    /* Appletalk ARP              */
  42 #define AX25_P_IP                       0xcc    /* ARPA Internet Protocol     */
  43 #define AX25_P_ARP                      0xcd    /* ARPA Address Resolution    */
  44 #define AX25_P_FLEXNET                  0xce    /* FlexNet                    */
  45 #define AX25_P_NETROM                   0xcf    /* NET/ROM                    */
  46 #define AX25_P_TEXT                     0xF0    /* No layer 3 protocol impl.  */
  47
  48 /* AX.25 Segment control values */
  49 #define AX25_SEG_REM                    0x7F
  50 #define AX25_SEG_FIRST                  0x80
  51
  52 #define AX25_CBIT                       0x80    /* Command/Response bit */
  53 #define AX25_EBIT                       0x01    /* HDLC Address Extension bit */
  54 #define AX25_HBIT                       0x80    /* Has been repeated bit */
  55
  56 #define AX25_SSSID_SPARE                0x60    /* Unused bits in SSID for standard AX.25 */
  57 #define AX25_ESSID_SPARE                0x20    /* Unused bits in SSID for extended AX.25 */
  58 #define AX25_DAMA_FLAG                  0x20    /* Well, it is *NOT* unused! (dl1bke 951121 */
  59
  60 #define AX25_COND_ACK_PENDING           0x01
  61 #define AX25_COND_REJECT                0x02
  62 #define AX25_COND_PEER_RX_BUSY          0x04
  63 #define AX25_COND_OWN_RX_BUSY           0x08
  64 #define AX25_COND_DAMA_MODE             0x10
  65
  66 #ifndef _LINUX_NETDEVICE_H
  67 #include <linux/netdevice.h>
  68 #endif
  69
  70 /* Upper sub-layer (LAPB) definitions */
  71
  72 /* Control field templates */
  73 #define AX25_I                  0x00    /* Information frames */
  74 #define AX25_S                  0x01    /* Supervisory frames */
  75 #define AX25_RR                 0x01    /* Receiver ready */
  76 #define AX25_RNR                0x05    /* Receiver not ready */
  77 #define AX25_REJ                0x09    /* Reject */
  78 #define AX25_U                  0x03    /* Unnumbered frames */
  79 #define AX25_SABM               0x2f    /* Set Asynchronous Balanced Mode */
  80 #define AX25_SABME              0x6f    /* Set Asynchronous Balanced Mode Extended */
  81 #define AX25_DISC               0x43    /* Disconnect */
  82 #define AX25_DM                 0x0f    /* Disconnected mode */
  83 #define AX25_UA                 0x63    /* Unnumbered acknowledge */
  84 #define AX25_FRMR               0x87    /* Frame reject */
  85 #define AX25_UI                 0x03    /* Unnumbered information */
  86 #define AX25_XID                0xaf    /* Exchange information */
  87 #define AX25_TEST               0xe3    /* Test */
  88
  89 #define AX25_PF                 0x10    /* Poll/final bit for standard AX.25 */
  90 #define AX25_EPF                0x01    /* Poll/final bit for extended AX.25 */
  91
  92 #define AX25_ILLEGAL            0x100   /* Impossible to be a real frame type */
  93
  94 #define AX25_POLLOFF            0
  95 #define AX25_POLLON             1
  96
  97 /* AX25 L2 C-bit */
  98 #define AX25_COMMAND            1
  99 #define AX25_RESPONSE           2
 100
 101 /* Define Link State constants. */
 102
 103 enum {
 104         AX25_STATE_0,                   /* Listening */
 105         AX25_STATE_1,                   /* SABM sent */
 106         AX25_STATE_2,                   /* DISC sent */
 107         AX25_STATE_3,                   /* Established */
 108         AX25_STATE_4                    /* Recovery */
 109 };
 110
 111 #define AX25_MODULUS            8       /*  Standard AX.25 modulus */
 112 #define AX25_EMODULUS           128     /*  Extended AX.25 modulus */
 113
 114 enum {
 115         AX25_PROTO_STD_SIMPLEX,
 116         AX25_PROTO_STD_DUPLEX,
 117 #ifdef CONFIG_AX25_DAMA_SLAVE
 118         AX25_PROTO_DAMA_SLAVE,
 119 #ifdef CONFIG_AX25_DAMA_MASTER
 120         AX25_PROTO_DAMA_MASTER,
 121 #define AX25_PROTO_MAX AX25_PROTO_DAMA_MASTER
 122 #endif
 123 #endif
 124         __AX25_PROTO_MAX,
 125         AX25_PROTO_MAX = __AX25_PROTO_MAX -1
 126 };
 127
 128 enum {
 129         AX25_VALUES_IPDEFMODE,  /* 0=DG 1=VC */
 130         AX25_VALUES_AXDEFMODE,  /* 0=Normal 1=Extended Seq Nos */
 131         AX25_VALUES_BACKOFF,    /* 0=None 1=Linear 2=Exponential */
 132         AX25_VALUES_CONMODE,    /* Allow connected modes - 0=No 1=no "PID text" 2=all PIDs */
 133         AX25_VALUES_WINDOW,     /* Default window size for standard AX.25 */
 134         AX25_VALUES_EWINDOW,    /* Default window size for extended AX.25 */
 135         AX25_VALUES_T1,         /* Default T1 timeout value */
 136         AX25_VALUES_T2,         /* Default T2 timeout value */
 137         AX25_VALUES_T3,         /* Default T3 timeout value */
 138         AX25_VALUES_IDLE,       /* Connected mode idle timer */
 139         AX25_VALUES_N2,         /* Default N2 value */
 140         AX25_VALUES_PACLEN,     /* AX.25 MTU */
 141         AX25_VALUES_PROTOCOL,   /* Std AX.25, DAMA Slave, DAMA Master */
 142 #ifdef CONFIG_AX25_DAMA_SLAVE
 143         AX25_VALUES_DS_TIMEOUT, /* DAMA Slave timeout */
 144 #endif
 145         AX25_MAX_VALUES         /* THIS MUST REMAIN THE LAST ENTRY OF THIS LIST */
 146 };
 147
 148 #define AX25_DEF_IPDEFMODE      0                       /* Datagram */
 149 #define AX25_DEF_AXDEFMODE      0                       /* Normal */
 150 #define AX25_DEF_BACKOFF        1                       /* Linear backoff */
 151 #define AX25_DEF_CONMODE        2                       /* Connected mode allowed */
 152 #define AX25_DEF_WINDOW         2                       /* Window=2 */
 153 #define AX25_DEF_EWINDOW        32                      /* Module-128 Window=32 */
 154 #define AX25_DEF_T1             10000                   /* T1=10s */
 155 #define AX25_DEF_T2             3000                    /* T2=3s  */
 156 #define AX25_DEF_T3             300000                  /* T3=300s */
 157 #define AX25_DEF_N2             10                      /* N2=10 */
 158 #define AX25_DEF_IDLE           0                       /* Idle=None */
 159 #define AX25_DEF_PACLEN         256                     /* Paclen=256 */
 160 #define AX25_DEF_PROTOCOL       AX25_PROTO_STD_SIMPLEX  /* Standard AX.25 */
 161 #define AX25_DEF_DS_TIMEOUT     180000                  /* DAMA timeout 3 minutes */
 162
 163 typedef struct ax25_uid_assoc {
 164         struct hlist_node       uid_node;
 165         refcount_t              refcount;
 166         kuid_t                  uid;
 167         ax25_address            call;
 168 } ax25_uid_assoc;
 169
 170 #define ax25_uid_for_each(__ax25, list) \
 171         hlist_for_each_entry(__ax25, list, uid_node)
 172
 173 #define ax25_uid_hold(ax25) \
 174         refcount_inc(&((ax25)->refcount))
 175
 176 static inline void ax25_uid_put(ax25_uid_assoc *assoc)
 177 {
 178         if (refcount_dec_and_test(&assoc->refcount)) {
 179                 kfree(assoc);
 180         }
 181 }
 182
 183 typedef struct {
 184         ax25_address            calls[AX25_MAX_DIGIS];
 185         unsigned char           repeated[AX25_MAX_DIGIS];
 186         unsigned char           ndigi;
 187         signed char             lastrepeat;
 188 } ax25_digi;
 189
 190 typedef struct ax25_route {
 191         struct ax25_route       *next;
 192         ax25_address            callsign;
 193         struct net_device       *dev;
 194         ax25_digi               *digipeat;
 195         char                    ip_mode;
 196 } ax25_route;
 197
 198 void __ax25_put_route(ax25_route *ax25_rt);
 199
 200 extern rwlock_t ax25_route_lock;
 201
 202 static inline void ax25_route_lock_use(void)
 203 {
 204         read_lock(&ax25_route_lock);
 205 }
 206
 207 static inline void ax25_route_lock_unuse(void)
 208 {
 209         read_unlock(&ax25_route_lock);
 210 }
 211
 212 typedef struct {
 213         char                    slave;                  /* slave_mode?   */
 214         struct timer_list       slave_timer;            /* timeout timer */
 215         unsigned short          slave_timeout;          /* when? */
 216 } ax25_dama_info;
 217
 218 struct ctl_table;
 219
 220 typedef struct ax25_dev {
 221         struct list_head        list;
 222
 223         struct net_device       *dev;
 224         netdevice_tracker       dev_tracker;
 225
 226         struct net_device       *forward;
 227         struct ctl_table_header *sysheader;
 228         int                     values[AX25_MAX_VALUES];
 229 #if defined(CONFIG_AX25_DAMA_SLAVE) || defined(CONFIG_AX25_DAMA_MASTER)
 230         ax25_dama_info          dama;
 231 #endif
 232         refcount_t              refcount;
 233         bool device_up;
 234 } ax25_dev;
 235
 236 typedef struct ax25_cb {
 237         struct hlist_node       ax25_node;
 238         ax25_address            source_addr, dest_addr;
 239         ax25_digi               *digipeat;
 240         ax25_dev                *ax25_dev;
 241         netdevice_tracker       dev_tracker;
 242         unsigned char           iamdigi;
 243         unsigned char           state, modulus, pidincl;
 244         unsigned short          vs, vr, va;
 245         unsigned char           condition, backoff;
 246         unsigned char           n2, n2count;
 247         struct timer_list       t1timer, t2timer, t3timer, idletimer;
 248         unsigned long           t1, t2, t3, idle, rtt;
 249         unsigned short          paclen, fragno, fraglen;
 250         struct sk_buff_head     write_queue;
 251         struct sk_buff_head     reseq_queue;
 252         struct sk_buff_head     ack_queue;
 253         struct sk_buff_head     frag_queue;
 254         unsigned char           window;
 255         struct timer_list       timer, dtimer;
 256         struct sock             *sk;            /* Backlink to socket */
 257         refcount_t              refcount;
 258 } ax25_cb;
 259
 260 struct ax25_sock {
 261         struct sock             sk;
 262         struct ax25_cb          *cb;
 263 };
 264
 265 #define ax25_sk(ptr) container_of_const(ptr, struct ax25_sock, sk)
 266
 267 static inline struct ax25_cb *sk_to_ax25(const struct sock *sk)
 268 {
 269         return ax25_sk(sk)->cb;
 270 }
 271
 272 #define ax25_for_each(__ax25, list) \
 273         hlist_for_each_entry(__ax25, list, ax25_node)
 274
 275 #define ax25_cb_hold(__ax25) \
 276         refcount_inc(&((__ax25)->refcount))
 277
 278 static __inline__ void ax25_cb_put(ax25_cb *ax25)
 279 {
 280         if (refcount_dec_and_test(&ax25->refcount)) {
 281                 kfree(ax25->digipeat);
 282                 kfree(ax25);
 283         }
 284 }
 285
 286 static inline void ax25_dev_hold(ax25_dev *ax25_dev)
 287 {
 288         refcount_inc(&ax25_dev->refcount);
 289 }
 290
 291 static inline void ax25_dev_put(ax25_dev *ax25_dev)
 292 {
 293         if (refcount_dec_and_test(&ax25_dev->refcount)) {
 294                 kfree(ax25_dev);
 295         }
 296 }
 297 static inline __be16 ax25_type_trans(struct sk_buff *skb, struct net_device *dev)
 298 {
 299         skb->dev      = dev;
 300         skb_reset_mac_header(skb);
 301         skb->pkt_type = PACKET_HOST;
 302         return htons(ETH_P_AX25);
 303 }
 304
 305 /* af_ax25.c */
 306 extern struct hlist_head ax25_list;
 307 extern spinlock_t ax25_list_lock;
 308 void ax25_cb_add(ax25_cb *);
 309 struct sock *ax25_find_listener(ax25_address *, int, struct net_device *, int);
 310 struct sock *ax25_get_socket(ax25_address *, ax25_address *, int);
 311 ax25_cb *ax25_find_cb(const ax25_address *, ax25_address *, ax25_digi *,
 312                       struct net_device *);
 313 void ax25_send_to_raw(ax25_address *, struct sk_buff *, int);
 314 void ax25_destroy_socket(ax25_cb *);
 315 ax25_cb * __must_check ax25_create_cb(void);
 316 void ax25_fillin_cb(ax25_cb *, ax25_dev *);
 317 struct sock *ax25_make_new(struct sock *, struct ax25_dev *);
 318
 319 /* ax25_addr.c */
 320 extern const ax25_address ax25_bcast;
 321 extern const ax25_address ax25_defaddr;
 322 extern const ax25_address null_ax25_address;
 323 char *ax2asc(char *buf, const ax25_address *);
 324 void asc2ax(ax25_address *addr, const char *callsign);
 325 int ax25cmp(const ax25_address *, const ax25_address *);
 326 int ax25digicmp(const ax25_digi *, const ax25_digi *);
 327 const unsigned char *ax25_addr_parse(const unsigned char *, int,
 328         ax25_address *, ax25_address *, ax25_digi *, int *, int *);
 329 int ax25_addr_build(unsigned char *, const ax25_address *,
 330                     const ax25_address *, const ax25_digi *, int, int);
 331 int ax25_addr_size(const ax25_digi *);
 332 void ax25_digi_invert(const ax25_digi *, ax25_digi *);
 333
 334 /* ax25_dev.c */
 335 extern spinlock_t ax25_dev_lock;
 336
 337 #if IS_ENABLED(CONFIG_AX25)
 338 static inline ax25_dev *ax25_dev_ax25dev(struct net_device *dev)
 339 {
 340         return dev->ax25_ptr;
 341 }
 342 #endif
 343
 344 ax25_dev *ax25_addr_ax25dev(ax25_address *);
 345 void ax25_dev_device_up(struct net_device *);
 346 void ax25_dev_device_down(struct net_device *);
 347 int ax25_fwd_ioctl(unsigned int, struct ax25_fwd_struct *);
 348 struct net_device *ax25_fwd_dev(struct net_device *);
 349 void ax25_dev_free(void);
 350
 351 /* ax25_ds_in.c */
 352 int ax25_ds_frame_in(ax25_cb *, struct sk_buff *, int);
 353
 354 /* ax25_ds_subr.c */
 355 void ax25_ds_nr_error_recovery(ax25_cb *);
 356 void ax25_ds_enquiry_response(ax25_cb *);
 357 void ax25_ds_establish_data_link(ax25_cb *);
 358 void ax25_dev_dama_off(ax25_dev *);
 359 void ax25_dama_on(ax25_cb *);
 360 void ax25_dama_off(ax25_cb *);
 361
 362 /* ax25_ds_timer.c */
 363 void ax25_ds_setup_timer(ax25_dev *);
 364 void ax25_ds_set_timer(ax25_dev *);
 365 void ax25_ds_del_timer(ax25_dev *);
 366 void ax25_ds_timer(ax25_cb *);
 367 void ax25_ds_t1_timeout(ax25_cb *);
 368 void ax25_ds_heartbeat_expiry(ax25_cb *);
 369 void ax25_ds_t3timer_expiry(ax25_cb *);
 370 void ax25_ds_idletimer_expiry(ax25_cb *);
 371
 372 /* ax25_iface.c */
 373
 374 struct ax25_protocol {
 375         struct ax25_protocol *next;
 376         unsigned int pid;
 377         int (*func)(struct sk_buff *, ax25_cb *);
 378 };
 379
 380 void ax25_register_pid(struct ax25_protocol *ap);
 381 void ax25_protocol_release(unsigned int);
 382
 383 struct ax25_linkfail {
 384         struct hlist_node lf_node;
 385         void (*func)(ax25_cb *, int);
 386 };
 387
 388 void ax25_linkfail_register(struct ax25_linkfail *lf);
 389 void ax25_linkfail_release(struct ax25_linkfail *lf);
 390 int __must_check ax25_listen_register(const ax25_address *,
 391                                       struct net_device *);
 392 void ax25_listen_release(const ax25_address *, struct net_device *);
 393 int(*ax25_protocol_function(unsigned int))(struct sk_buff *, ax25_cb *);
 394 int ax25_listen_mine(const ax25_address *, struct net_device *);
 395 void ax25_link_failed(ax25_cb *, int);
 396 int ax25_protocol_is_registered(unsigned int);
 397
 398 /* ax25_in.c */
 399 int ax25_rx_iframe(ax25_cb *, struct sk_buff *);
 400 int ax25_kiss_rcv(struct sk_buff *, struct net_device *, struct packet_type *,
 401                   struct net_device *);
 402
 403 /* ax25_ip.c */
 404 netdev_tx_t ax25_ip_xmit(struct sk_buff *skb);
 405 extern const struct header_ops ax25_header_ops;
 406
 407 /* ax25_out.c */
 408 ax25_cb *ax25_send_frame(struct sk_buff *, int, const ax25_address *,
 409                          ax25_address *, ax25_digi *, struct net_device *);
 410 void ax25_output(ax25_cb *, int, struct sk_buff *);
 411 void ax25_kick(ax25_cb *);
 412 void ax25_transmit_buffer(ax25_cb *, struct sk_buff *, int);
 413 void ax25_queue_xmit(struct sk_buff *skb, struct net_device *dev);
 414 int ax25_check_iframes_acked(ax25_cb *, unsigned short);
 415
 416 /* ax25_route.c */
 417 void ax25_rt_device_down(struct net_device *);
 418 int ax25_rt_ioctl(unsigned int, void __user *);
 419 extern const struct seq_operations ax25_rt_seqops;
 420 ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev);
 421 int ax25_rt_autobind(ax25_cb *, ax25_address *);
 422 struct sk_buff *ax25_rt_build_path(struct sk_buff *, ax25_address *,
 423                                    ax25_address *, ax25_digi *);
 424 void ax25_rt_free(void);
 425
 426 /* ax25_std_in.c */
 427 int ax25_std_frame_in(ax25_cb *, struct sk_buff *, int);
 428
 429 /* ax25_std_subr.c */
 430 void ax25_std_nr_error_recovery(ax25_cb *);
 431 void ax25_std_establish_data_link(ax25_cb *);
 432 void ax25_std_transmit_enquiry(ax25_cb *);
 433 void ax25_std_enquiry_response(ax25_cb *);
 434 void ax25_std_timeout_response(ax25_cb *);
 435
 436 /* ax25_std_timer.c */
 437 void ax25_std_heartbeat_expiry(ax25_cb *);
 438 void ax25_std_t1timer_expiry(ax25_cb *);
 439 void ax25_std_t2timer_expiry(ax25_cb *);
 440 void ax25_std_t3timer_expiry(ax25_cb *);
 441 void ax25_std_idletimer_expiry(ax25_cb *);
 442
 443 /* ax25_subr.c */
 444 void ax25_clear_queues(ax25_cb *);
 445 void ax25_frames_acked(ax25_cb *, unsigned short);
 446 void ax25_requeue_frames(ax25_cb *);
 447 int ax25_validate_nr(ax25_cb *, unsigned short);
 448 int ax25_decode(ax25_cb *, struct sk_buff *, int *, int *, int *);
 449 void ax25_send_control(ax25_cb *, int, int, int);
 450 void ax25_return_dm(struct net_device *, ax25_address *, ax25_address *,
 451                     ax25_digi *);
 452 void ax25_calculate_t1(ax25_cb *);
 453 void ax25_calculate_rtt(ax25_cb *);
 454 void ax25_disconnect(ax25_cb *, int);
 455
 456 /* ax25_timer.c */
 457 void ax25_setup_timers(ax25_cb *);
 458 void ax25_start_heartbeat(ax25_cb *);
 459 void ax25_start_t1timer(ax25_cb *);
 460 void ax25_start_t2timer(ax25_cb *);
 461 void ax25_start_t3timer(ax25_cb *);
 462 void ax25_start_idletimer(ax25_cb *);
 463 void ax25_stop_heartbeat(ax25_cb *);
 464 void ax25_stop_t1timer(ax25_cb *);
 465 void ax25_stop_t2timer(ax25_cb *);
 466 void ax25_stop_t3timer(ax25_cb *);
 467 void ax25_stop_idletimer(ax25_cb *);
 468 int ax25_t1timer_running(ax25_cb *);
 469 unsigned long ax25_display_timer(struct timer_list *);
 470
 471 /* ax25_uid.c */
 472 extern int  ax25_uid_policy;
 473 ax25_uid_assoc *ax25_findbyuid(kuid_t);
 474 int __must_check ax25_uid_ioctl(int, struct sockaddr_ax25 *);
 475 extern const struct seq_operations ax25_uid_seqops;
 476 void ax25_uid_free(void);
 477
 478 /* sysctl_net_ax25.c */
 479 #ifdef CONFIG_SYSCTL
 480 int ax25_register_dev_sysctl(ax25_dev *ax25_dev);
 481 void ax25_unregister_dev_sysctl(ax25_dev *ax25_dev);
 482 #else
 483 static inline int ax25_register_dev_sysctl(ax25_dev *ax25_dev) { return 0; }
 484 static inline void ax25_unregister_dev_sysctl(ax25_dev *ax25_dev) {}
 485 #endif /* CONFIG_SYSCTL */
 486
 487 #endif