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         AX25_VALUES_DS_TIMEOUT, /* DAMA Slave timeout */
 143         AX25_MAX_VALUES         /* THIS MUST REMAIN THE LAST ENTRY OF THIS LIST */
 144 };
 145
 146 #define AX25_DEF_IPDEFMODE      0                       /* Datagram */
 147 #define AX25_DEF_AXDEFMODE      0                       /* Normal */
 148 #define AX25_DEF_BACKOFF        1                       /* Linear backoff */
 149 #define AX25_DEF_CONMODE        2                       /* Connected mode allowed */
 150 #define AX25_DEF_WINDOW         2                       /* Window=2 */
 151 #define AX25_DEF_EWINDOW        32                      /* Module-128 Window=32 */
 152 #define AX25_DEF_T1             10000                   /* T1=10s */
 153 #define AX25_DEF_T2             3000                    /* T2=3s  */
 154 #define AX25_DEF_T3             300000                  /* T3=300s */
 155 #define AX25_DEF_N2             10                      /* N2=10 */
 156 #define AX25_DEF_IDLE           0                       /* Idle=None */
 157 #define AX25_DEF_PACLEN         256                     /* Paclen=256 */
 158 #define AX25_DEF_PROTOCOL       AX25_PROTO_STD_SIMPLEX  /* Standard AX.25 */
 159 #define AX25_DEF_DS_TIMEOUT     180000                  /* DAMA timeout 3 minutes */
 160
 161 typedef struct ax25_uid_assoc {
 162         struct hlist_node       uid_node;
 163         refcount_t              refcount;
 164         kuid_t                  uid;
 165         ax25_address            call;
 166 } ax25_uid_assoc;
 167
 168 #define ax25_uid_for_each(__ax25, list) \
 169         hlist_for_each_entry(__ax25, list, uid_node)
 170
 171 #define ax25_uid_hold(ax25) \
 172         refcount_inc(&((ax25)->refcount))
 173
 174 static inline void ax25_uid_put(ax25_uid_assoc *assoc)
 175 {
 176         if (refcount_dec_and_test(&assoc->refcount)) {
 177                 kfree(assoc);
 178         }
 179 }
 180
 181 typedef struct {
 182         ax25_address            calls[AX25_MAX_DIGIS];
 183         unsigned char           repeated[AX25_MAX_DIGIS];
 184         unsigned char           ndigi;
 185         signed char             lastrepeat;
 186 } ax25_digi;
 187
 188 typedef struct ax25_route {
 189         struct ax25_route       *next;
 190         refcount_t              refcount;
 191         ax25_address            callsign;
 192         struct net_device       *dev;
 193         ax25_digi               *digipeat;
 194         char                    ip_mode;
 195 } ax25_route;
 196
 197 static inline void ax25_hold_route(ax25_route *ax25_rt)
 198 {
 199         refcount_inc(&ax25_rt->refcount);
 200 }
 201
 202 void __ax25_put_route(ax25_route *ax25_rt);
 203
 204 extern rwlock_t ax25_route_lock;
 205
 206 static inline void ax25_route_lock_use(void)
 207 {
 208         read_lock(&ax25_route_lock);
 209 }
 210
 211 static inline void ax25_route_lock_unuse(void)
 212 {
 213         read_unlock(&ax25_route_lock);
 214 }
 215
 216 static inline void ax25_put_route(ax25_route *ax25_rt)
 217 {
 218         if (refcount_dec_and_test(&ax25_rt->refcount))
 219                 __ax25_put_route(ax25_rt);
 220 }
 221
 222 typedef struct {
 223         char                    slave;                  /* slave_mode?   */
 224         struct timer_list       slave_timer;            /* timeout timer */
 225         unsigned short          slave_timeout;          /* when? */
 226 } ax25_dama_info;
 227
 228 struct ctl_table;
 229
 230 typedef struct ax25_dev {
 231         struct ax25_dev         *next;
 232         struct net_device       *dev;
 233         struct net_device       *forward;
 234         struct ctl_table_header *sysheader;
 235         int                     values[AX25_MAX_VALUES];
 236 #if defined(CONFIG_AX25_DAMA_SLAVE) || defined(CONFIG_AX25_DAMA_MASTER)
 237         ax25_dama_info          dama;
 238 #endif
 239 } ax25_dev;
 240
 241 typedef struct ax25_cb {
 242         struct hlist_node       ax25_node;
 243         ax25_address            source_addr, dest_addr;
 244         ax25_digi               *digipeat;
 245         ax25_dev                *ax25_dev;
 246         unsigned char           iamdigi;
 247         unsigned char           state, modulus, pidincl;
 248         unsigned short          vs, vr, va;
 249         unsigned char           condition, backoff;
 250         unsigned char           n2, n2count;
 251         struct timer_list       t1timer, t2timer, t3timer, idletimer;
 252         unsigned long           t1, t2, t3, idle, rtt;
 253         unsigned short          paclen, fragno, fraglen;
 254         struct sk_buff_head     write_queue;
 255         struct sk_buff_head     reseq_queue;
 256         struct sk_buff_head     ack_queue;
 257         struct sk_buff_head     frag_queue;
 258         unsigned char           window;
 259         struct timer_list       timer, dtimer;
 260         struct sock             *sk;            /* Backlink to socket */
 261         refcount_t              refcount;
 262 } ax25_cb;
 263
 264 struct ax25_sock {
 265         struct sock             sk;
 266         struct ax25_cb          *cb;
 267 };
 268
 269 static inline struct ax25_sock *ax25_sk(const struct sock *sk)
 270 {
 271         return (struct ax25_sock *) sk;
 272 }
 273
 274 static inline struct ax25_cb *sk_to_ax25(const struct sock *sk)
 275 {
 276         return ax25_sk(sk)->cb;
 277 }
 278
 279 #define ax25_for_each(__ax25, list) \
 280         hlist_for_each_entry(__ax25, list, ax25_node)
 281
 282 #define ax25_cb_hold(__ax25) \
 283         refcount_inc(&((__ax25)->refcount))
 284
 285 static __inline__ void ax25_cb_put(ax25_cb *ax25)
 286 {
 287         if (refcount_dec_and_test(&ax25->refcount)) {
 288                 kfree(ax25->digipeat);
 289                 kfree(ax25);
 290         }
 291 }
 292
 293 static inline __be16 ax25_type_trans(struct sk_buff *skb, struct net_device *dev)
 294 {
 295         skb->dev      = dev;
 296         skb_reset_mac_header(skb);
 297         skb->pkt_type = PACKET_HOST;
 298         return htons(ETH_P_AX25);
 299 }
 300
 301 /* af_ax25.c */
 302 extern struct hlist_head ax25_list;
 303 extern spinlock_t ax25_list_lock;
 304 void ax25_cb_add(ax25_cb *);
 305 struct sock *ax25_find_listener(ax25_address *, int, struct net_device *, int);
 306 struct sock *ax25_get_socket(ax25_address *, ax25_address *, int);
 307 ax25_cb *ax25_find_cb(ax25_address *, ax25_address *, ax25_digi *,
 308                       struct net_device *);
 309 void ax25_send_to_raw(ax25_address *, struct sk_buff *, int);
 310 void ax25_destroy_socket(ax25_cb *);
 311 ax25_cb * __must_check ax25_create_cb(void);
 312 void ax25_fillin_cb(ax25_cb *, ax25_dev *);
 313 struct sock *ax25_make_new(struct sock *, struct ax25_dev *);
 314
 315 /* ax25_addr.c */
 316 extern const ax25_address ax25_bcast;
 317 extern const ax25_address ax25_defaddr;
 318 extern const ax25_address null_ax25_address;
 319 char *ax2asc(char *buf, const ax25_address *);
 320 void asc2ax(ax25_address *addr, const char *callsign);
 321 int ax25cmp(const ax25_address *, const ax25_address *);
 322 int ax25digicmp(const ax25_digi *, const ax25_digi *);
 323 const unsigned char *ax25_addr_parse(const unsigned char *, int,
 324         ax25_address *, ax25_address *, ax25_digi *, int *, int *);
 325 int ax25_addr_build(unsigned char *, const ax25_address *,
 326                     const ax25_address *, const ax25_digi *, int, int);
 327 int ax25_addr_size(const ax25_digi *);
 328 void ax25_digi_invert(const ax25_digi *, ax25_digi *);
 329
 330 /* ax25_dev.c */
 331 extern ax25_dev *ax25_dev_list;
 332 extern spinlock_t ax25_dev_lock;
 333
 334 #if IS_ENABLED(CONFIG_AX25)
 335 static inline ax25_dev *ax25_dev_ax25dev(struct net_device *dev)
 336 {
 337         return dev->ax25_ptr;
 338 }
 339 #endif
 340
 341 ax25_dev *ax25_addr_ax25dev(ax25_address *);
 342 void ax25_dev_device_up(struct net_device *);
 343 void ax25_dev_device_down(struct net_device *);
 344 int ax25_fwd_ioctl(unsigned int, struct ax25_fwd_struct *);
 345 struct net_device *ax25_fwd_dev(struct net_device *);
 346 void ax25_dev_free(void);
 347
 348 /* ax25_ds_in.c */
 349 int ax25_ds_frame_in(ax25_cb *, struct sk_buff *, int);
 350
 351 /* ax25_ds_subr.c */
 352 void ax25_ds_nr_error_recovery(ax25_cb *);
 353 void ax25_ds_enquiry_response(ax25_cb *);
 354 void ax25_ds_establish_data_link(ax25_cb *);
 355 void ax25_dev_dama_off(ax25_dev *);
 356 void ax25_dama_on(ax25_cb *);
 357 void ax25_dama_off(ax25_cb *);
 358
 359 /* ax25_ds_timer.c */
 360 void ax25_ds_setup_timer(ax25_dev *);
 361 void ax25_ds_set_timer(ax25_dev *);
 362 void ax25_ds_del_timer(ax25_dev *);
 363 void ax25_ds_timer(ax25_cb *);
 364 void ax25_ds_t1_timeout(ax25_cb *);
 365 void ax25_ds_heartbeat_expiry(ax25_cb *);
 366 void ax25_ds_t3timer_expiry(ax25_cb *);
 367 void ax25_ds_idletimer_expiry(ax25_cb *);
 368
 369 /* ax25_iface.c */
 370
 371 struct ax25_protocol {
 372         struct ax25_protocol *next;
 373         unsigned int pid;
 374         int (*func)(struct sk_buff *, ax25_cb *);
 375 };
 376
 377 void ax25_register_pid(struct ax25_protocol *ap);
 378 void ax25_protocol_release(unsigned int);
 379
 380 struct ax25_linkfail {
 381         struct hlist_node lf_node;
 382         void (*func)(ax25_cb *, int);
 383 };
 384
 385 void ax25_linkfail_register(struct ax25_linkfail *lf);
 386 void ax25_linkfail_release(struct ax25_linkfail *lf);
 387 int __must_check ax25_listen_register(ax25_address *, struct net_device *);
 388 void ax25_listen_release(ax25_address *, struct net_device *);
 389 int(*ax25_protocol_function(unsigned int))(struct sk_buff *, ax25_cb *);
 390 int ax25_listen_mine(ax25_address *, struct net_device *);
 391 void ax25_link_failed(ax25_cb *, int);
 392 int ax25_protocol_is_registered(unsigned int);
 393
 394 /* ax25_in.c */
 395 int ax25_rx_iframe(ax25_cb *, struct sk_buff *);
 396 int ax25_kiss_rcv(struct sk_buff *, struct net_device *, struct packet_type *,
 397                   struct net_device *);
 398
 399 /* ax25_ip.c */
 400 netdev_tx_t ax25_ip_xmit(struct sk_buff *skb);
 401 extern const struct header_ops ax25_header_ops;
 402
 403 /* ax25_out.c */
 404 ax25_cb *ax25_send_frame(struct sk_buff *, int, ax25_address *, ax25_address *,
 405                          ax25_digi *, struct net_device *);
 406 void ax25_output(ax25_cb *, int, struct sk_buff *);
 407 void ax25_kick(ax25_cb *);
 408 void ax25_transmit_buffer(ax25_cb *, struct sk_buff *, int);
 409 void ax25_queue_xmit(struct sk_buff *skb, struct net_device *dev);
 410 int ax25_check_iframes_acked(ax25_cb *, unsigned short);
 411
 412 /* ax25_route.c */
 413 void ax25_rt_device_down(struct net_device *);
 414 int ax25_rt_ioctl(unsigned int, void __user *);
 415 extern const struct seq_operations ax25_rt_seqops;
 416 ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev);
 417 int ax25_rt_autobind(ax25_cb *, ax25_address *);
 418 struct sk_buff *ax25_rt_build_path(struct sk_buff *, ax25_address *,
 419                                    ax25_address *, ax25_digi *);
 420 void ax25_rt_free(void);
 421
 422 /* ax25_std_in.c */
 423 int ax25_std_frame_in(ax25_cb *, struct sk_buff *, int);
 424
 425 /* ax25_std_subr.c */
 426 void ax25_std_nr_error_recovery(ax25_cb *);
 427 void ax25_std_establish_data_link(ax25_cb *);
 428 void ax25_std_transmit_enquiry(ax25_cb *);
 429 void ax25_std_enquiry_response(ax25_cb *);
 430 void ax25_std_timeout_response(ax25_cb *);
 431
 432 /* ax25_std_timer.c */
 433 void ax25_std_heartbeat_expiry(ax25_cb *);
 434 void ax25_std_t1timer_expiry(ax25_cb *);
 435 void ax25_std_t2timer_expiry(ax25_cb *);
 436 void ax25_std_t3timer_expiry(ax25_cb *);
 437 void ax25_std_idletimer_expiry(ax25_cb *);
 438
 439 /* ax25_subr.c */
 440 void ax25_clear_queues(ax25_cb *);
 441 void ax25_frames_acked(ax25_cb *, unsigned short);
 442 void ax25_requeue_frames(ax25_cb *);
 443 int ax25_validate_nr(ax25_cb *, unsigned short);
 444 int ax25_decode(ax25_cb *, struct sk_buff *, int *, int *, int *);
 445 void ax25_send_control(ax25_cb *, int, int, int);
 446 void ax25_return_dm(struct net_device *, ax25_address *, ax25_address *,
 447                     ax25_digi *);
 448 void ax25_calculate_t1(ax25_cb *);
 449 void ax25_calculate_rtt(ax25_cb *);
 450 void ax25_disconnect(ax25_cb *, int);
 451
 452 /* ax25_timer.c */
 453 void ax25_setup_timers(ax25_cb *);
 454 void ax25_start_heartbeat(ax25_cb *);
 455 void ax25_start_t1timer(ax25_cb *);
 456 void ax25_start_t2timer(ax25_cb *);
 457 void ax25_start_t3timer(ax25_cb *);
 458 void ax25_start_idletimer(ax25_cb *);
 459 void ax25_stop_heartbeat(ax25_cb *);
 460 void ax25_stop_t1timer(ax25_cb *);
 461 void ax25_stop_t2timer(ax25_cb *);
 462 void ax25_stop_t3timer(ax25_cb *);
 463 void ax25_stop_idletimer(ax25_cb *);
 464 int ax25_t1timer_running(ax25_cb *);
 465 unsigned long ax25_display_timer(struct timer_list *);
 466
 467 /* ax25_uid.c */
 468 extern int  ax25_uid_policy;
 469 ax25_uid_assoc *ax25_findbyuid(kuid_t);
 470 int __must_check ax25_uid_ioctl(int, struct sockaddr_ax25 *);
 471 extern const struct seq_operations ax25_uid_seqops;
 472 void ax25_uid_free(void);
 473
 474 /* sysctl_net_ax25.c */
 475 #ifdef CONFIG_SYSCTL
 476 int ax25_register_dev_sysctl(ax25_dev *ax25_dev);
 477 void ax25_unregister_dev_sysctl(ax25_dev *ax25_dev);
 478 #else
 479 static inline int ax25_register_dev_sysctl(ax25_dev *ax25_dev) { return 0; }
 480 static inline void ax25_unregister_dev_sysctl(ax25_dev *ax25_dev) {}
 481 #endif /* CONFIG_SYSCTL */
 482
 483 #endif