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
  19 #define AX25_T1CLAMPLO                  1
  20 #define AX25_T1CLAMPHI                  (30 * HZ)
  21
  22 #define AX25_BPQ_HEADER_LEN             16
  23 #define AX25_KISS_HEADER_LEN            1
  24
  25 #define AX25_HEADER_LEN                 17
  26 #define AX25_ADDR_LEN                   7
  27 #define AX25_DIGI_HEADER_LEN            (AX25_MAX_DIGIS * AX25_ADDR_LEN)
  28 #define AX25_MAX_HEADER_LEN             (AX25_HEADER_LEN + AX25_DIGI_HEADER_LEN)
  29
  30 /* AX.25 Protocol IDs */
  31 #define AX25_P_ROSE                     0x01
  32 #define AX25_P_VJCOMP                   0x06    /* Compressed TCP/IP packet   */
  33                                                 /* Van Jacobsen (RFC 1144)    */
  34 #define AX25_P_VJUNCOMP                 0x07    /* Uncompressed TCP/IP packet */
  35                                                 /* Van Jacobsen (RFC 1144)    */
  36 #define AX25_P_SEGMENT                  0x08    /* Segmentation fragment      */
  37 #define AX25_P_TEXNET                   0xc3    /* TEXTNET datagram protocol  */
  38 #define AX25_P_LQ                       0xc4    /* Link Quality Protocol      */
  39 #define AX25_P_ATALK                    0xca    /* Appletalk                  */
  40 #define AX25_P_ATALK_ARP                0xcb    /* Appletalk ARP              */
  41 #define AX25_P_IP                       0xcc    /* ARPA Internet Protocol     */
  42 #define AX25_P_ARP                      0xcd    /* ARPA Address Resolution    */
  43 #define AX25_P_FLEXNET                  0xce    /* FlexNet                    */
  44 #define AX25_P_NETROM                   0xcf    /* NET/ROM                    */
  45 #define AX25_P_TEXT                     0xF0    /* No layer 3 protocol impl.  */
  46
  47 /* AX.25 Segment control values */
  48 #define AX25_SEG_REM                    0x7F
  49 #define AX25_SEG_FIRST                  0x80
  50
  51 #define AX25_CBIT                       0x80    /* Command/Response bit */
  52 #define AX25_EBIT                       0x01    /* HDLC Address Extension bit */
  53 #define AX25_HBIT                       0x80    /* Has been repeated bit */
  54
  55 #define AX25_SSSID_SPARE                0x60    /* Unused bits in SSID for standard AX.25 */
  56 #define AX25_ESSID_SPARE                0x20    /* Unused bits in SSID for extended AX.25 */
  57 #define AX25_DAMA_FLAG                  0x20    /* Well, it is *NOT* unused! (dl1bke 951121 */
  58
  59 #define AX25_COND_ACK_PENDING           0x01
  60 #define AX25_COND_REJECT                0x02
  61 #define AX25_COND_PEER_RX_BUSY          0x04
  62 #define AX25_COND_OWN_RX_BUSY           0x08
  63 #define AX25_COND_DAMA_MODE             0x10
  64
  65 #ifndef _LINUX_NETDEVICE_H
  66 #include <linux/netdevice.h>
  67 #endif
  68
  69 /* Upper sub-layer (LAPB) definitions */
  70
  71 /* Control field templates */
  72 #define AX25_I                  0x00    /* Information frames */
  73 #define AX25_S                  0x01    /* Supervisory frames */
  74 #define AX25_RR                 0x01    /* Receiver ready */
  75 #define AX25_RNR                0x05    /* Receiver not ready */
  76 #define AX25_REJ                0x09    /* Reject */
  77 #define AX25_U                  0x03    /* Unnumbered frames */
  78 #define AX25_SABM               0x2f    /* Set Asynchronous Balanced Mode */
  79 #define AX25_SABME              0x6f    /* Set Asynchronous Balanced Mode Extended */
  80 #define AX25_DISC               0x43    /* Disconnect */
  81 #define AX25_DM                 0x0f    /* Disconnected mode */
  82 #define AX25_UA                 0x63    /* Unnumbered acknowledge */
  83 #define AX25_FRMR               0x87    /* Frame reject */
  84 #define AX25_UI                 0x03    /* Unnumbered information */
  85 #define AX25_XID                0xaf    /* Exchange information */
  86 #define AX25_TEST               0xe3    /* Test */
  87
  88 #define AX25_PF                 0x10    /* Poll/final bit for standard AX.25 */
  89 #define AX25_EPF                0x01    /* Poll/final bit for extended AX.25 */
  90
  91 #define AX25_ILLEGAL            0x100   /* Impossible to be a real frame type */
  92
  93 #define AX25_POLLOFF            0
  94 #define AX25_POLLON             1
  95
  96 /* AX25 L2 C-bit */
  97 #define AX25_COMMAND            1
  98 #define AX25_RESPONSE           2
  99
 100 /* Define Link State constants. */
 101
 102 enum {
 103         AX25_STATE_0,                   /* Listening */
 104         AX25_STATE_1,                   /* SABM sent */
 105         AX25_STATE_2,                   /* DISC sent */
 106         AX25_STATE_3,                   /* Established */
 107         AX25_STATE_4                    /* Recovery */
 108 };
 109
 110 #define AX25_MODULUS            8       /*  Standard AX.25 modulus */
 111 #define AX25_EMODULUS           128     /*  Extended AX.25 modulus */
 112
 113 enum {
 114         AX25_PROTO_STD_SIMPLEX,
 115         AX25_PROTO_STD_DUPLEX,
 116 #ifdef CONFIG_AX25_DAMA_SLAVE
 117         AX25_PROTO_DAMA_SLAVE,
 118 #ifdef CONFIG_AX25_DAMA_MASTER
 119         AX25_PROTO_DAMA_MASTER,
 120 #define AX25_PROTO_MAX AX25_PROTO_DAMA_MASTER
 121 #endif
 122 #endif
 123         __AX25_PROTO_MAX,
 124         AX25_PROTO_MAX = __AX25_PROTO_MAX -1
 125 };
 126
 127 enum {
 128         AX25_VALUES_IPDEFMODE,  /* 0=DG 1=VC */
 129         AX25_VALUES_AXDEFMODE,  /* 0=Normal 1=Extended Seq Nos */
 130         AX25_VALUES_BACKOFF,    /* 0=None 1=Linear 2=Exponential */
 131         AX25_VALUES_CONMODE,    /* Allow connected modes - 0=No 1=no "PID text" 2=all PIDs */
 132         AX25_VALUES_WINDOW,     /* Default window size for standard AX.25 */
 133         AX25_VALUES_EWINDOW,    /* Default window size for extended AX.25 */
 134         AX25_VALUES_T1,         /* Default T1 timeout value */
 135         AX25_VALUES_T2,         /* Default T2 timeout value */
 136         AX25_VALUES_T3,         /* Default T3 timeout value */
 137         AX25_VALUES_IDLE,       /* Connected mode idle timer */
 138         AX25_VALUES_N2,         /* Default N2 value */
 139         AX25_VALUES_PACLEN,     /* AX.25 MTU */
 140         AX25_VALUES_PROTOCOL,   /* Std AX.25, DAMA Slave, DAMA Master */
 141         AX25_VALUES_DS_TIMEOUT, /* DAMA Slave timeout */
 142         AX25_MAX_VALUES         /* THIS MUST REMAIN THE LAST ENTRY OF THIS LIST */
 143 };
 144
 145 #define AX25_DEF_IPDEFMODE      0                       /* Datagram */
 146 #define AX25_DEF_AXDEFMODE      0                       /* Normal */
 147 #define AX25_DEF_BACKOFF        1                       /* Linear backoff */
 148 #define AX25_DEF_CONMODE        2                       /* Connected mode allowed */
 149 #define AX25_DEF_WINDOW         2                       /* Window=2 */
 150 #define AX25_DEF_EWINDOW        32                      /* Module-128 Window=32 */
 151 #define AX25_DEF_T1             10000                   /* T1=10s */
 152 #define AX25_DEF_T2             3000                    /* T2=3s  */
 153 #define AX25_DEF_T3             300000                  /* T3=300s */
 154 #define AX25_DEF_N2             10                      /* N2=10 */
 155 #define AX25_DEF_IDLE           0                       /* Idle=None */
 156 #define AX25_DEF_PACLEN         256                     /* Paclen=256 */
 157 #define AX25_DEF_PROTOCOL       AX25_PROTO_STD_SIMPLEX  /* Standard AX.25 */
 158 #define AX25_DEF_DS_TIMEOUT     180000                  /* DAMA timeout 3 minutes */
 159
 160 typedef struct ax25_uid_assoc {
 161         struct hlist_node       uid_node;
 162         refcount_t              refcount;
 163         kuid_t                  uid;
 164         ax25_address            call;
 165 } ax25_uid_assoc;
 166
 167 #define ax25_uid_for_each(__ax25, list) \
 168         hlist_for_each_entry(__ax25, list, uid_node)
 169
 170 #define ax25_uid_hold(ax25) \
 171         refcount_inc(&((ax25)->refcount))
 172
 173 static inline void ax25_uid_put(ax25_uid_assoc *assoc)
 174 {
 175         if (refcount_dec_and_test(&assoc->refcount)) {
 176                 kfree(assoc);
 177         }
 178 }
 179
 180 typedef struct {
 181         ax25_address            calls[AX25_MAX_DIGIS];
 182         unsigned char           repeated[AX25_MAX_DIGIS];
 183         unsigned char           ndigi;
 184         signed char             lastrepeat;
 185 } ax25_digi;
 186
 187 typedef struct ax25_route {
 188         struct ax25_route       *next;
 189         refcount_t              refcount;
 190         ax25_address            callsign;
 191         struct net_device       *dev;
 192         ax25_digi               *digipeat;
 193         char                    ip_mode;
 194 } ax25_route;
 195
 196 static inline void ax25_hold_route(ax25_route *ax25_rt)
 197 {
 198         refcount_inc(&ax25_rt->refcount);
 199 }
 200
 201 void __ax25_put_route(ax25_route *ax25_rt);
 202
 203 static inline void ax25_put_route(ax25_route *ax25_rt)
 204 {
 205         if (refcount_dec_and_test(&ax25_rt->refcount))
 206                 __ax25_put_route(ax25_rt);
 207 }
 208
 209 typedef struct {
 210         char                    slave;                  /* slave_mode?   */
 211         struct timer_list       slave_timer;            /* timeout timer */
 212         unsigned short          slave_timeout;          /* when? */
 213 } ax25_dama_info;
 214
 215 struct ctl_table;
 216
 217 typedef struct ax25_dev {
 218         struct ax25_dev         *next;
 219         struct net_device       *dev;
 220         struct net_device       *forward;
 221         struct ctl_table_header *sysheader;
 222         int                     values[AX25_MAX_VALUES];
 223 #if defined(CONFIG_AX25_DAMA_SLAVE) || defined(CONFIG_AX25_DAMA_MASTER)
 224         ax25_dama_info          dama;
 225 #endif
 226 } ax25_dev;
 227
 228 typedef struct ax25_cb {
 229         struct hlist_node       ax25_node;
 230         ax25_address            source_addr, dest_addr;
 231         ax25_digi               *digipeat;
 232         ax25_dev                *ax25_dev;
 233         unsigned char           iamdigi;
 234         unsigned char           state, modulus, pidincl;
 235         unsigned short          vs, vr, va;
 236         unsigned char           condition, backoff;
 237         unsigned char           n2, n2count;
 238         struct timer_list       t1timer, t2timer, t3timer, idletimer;
 239         unsigned long           t1, t2, t3, idle, rtt;
 240         unsigned short          paclen, fragno, fraglen;
 241         struct sk_buff_head     write_queue;
 242         struct sk_buff_head     reseq_queue;
 243         struct sk_buff_head     ack_queue;
 244         struct sk_buff_head     frag_queue;
 245         unsigned char           window;
 246         struct timer_list       timer, dtimer;
 247         struct sock             *sk;            /* Backlink to socket */
 248         refcount_t              refcount;
 249 } ax25_cb;
 250
 251 struct ax25_sock {
 252         struct sock             sk;
 253         struct ax25_cb          *cb;
 254 };
 255
 256 static inline struct ax25_sock *ax25_sk(const struct sock *sk)
 257 {
 258         return (struct ax25_sock *) sk;
 259 }
 260
 261 static inline struct ax25_cb *sk_to_ax25(const struct sock *sk)
 262 {
 263         return ax25_sk(sk)->cb;
 264 }
 265
 266 #define ax25_for_each(__ax25, list) \
 267         hlist_for_each_entry(__ax25, list, ax25_node)
 268
 269 #define ax25_cb_hold(__ax25) \
 270         refcount_inc(&((__ax25)->refcount))
 271
 272 static __inline__ void ax25_cb_put(ax25_cb *ax25)
 273 {
 274         if (refcount_dec_and_test(&ax25->refcount)) {
 275                 kfree(ax25->digipeat);
 276                 kfree(ax25);
 277         }
 278 }
 279
 280 static inline __be16 ax25_type_trans(struct sk_buff *skb, struct net_device *dev)
 281 {
 282         skb->dev      = dev;
 283         skb_reset_mac_header(skb);
 284         skb->pkt_type = PACKET_HOST;
 285         return htons(ETH_P_AX25);
 286 }
 287
 288 /* af_ax25.c */
 289 extern struct hlist_head ax25_list;
 290 extern spinlock_t ax25_list_lock;
 291 void ax25_cb_add(ax25_cb *);
 292 struct sock *ax25_find_listener(ax25_address *, int, struct net_device *, int);
 293 struct sock *ax25_get_socket(ax25_address *, ax25_address *, int);
 294 ax25_cb *ax25_find_cb(ax25_address *, ax25_address *, ax25_digi *,
 295                       struct net_device *);
 296 void ax25_send_to_raw(ax25_address *, struct sk_buff *, int);
 297 void ax25_destroy_socket(ax25_cb *);
 298 ax25_cb * __must_check ax25_create_cb(void);
 299 void ax25_fillin_cb(ax25_cb *, ax25_dev *);
 300 struct sock *ax25_make_new(struct sock *, struct ax25_dev *);
 301
 302 /* ax25_addr.c */
 303 extern const ax25_address ax25_bcast;
 304 extern const ax25_address ax25_defaddr;
 305 extern const ax25_address null_ax25_address;
 306 char *ax2asc(char *buf, const ax25_address *);
 307 void asc2ax(ax25_address *addr, const char *callsign);
 308 int ax25cmp(const ax25_address *, const ax25_address *);
 309 int ax25digicmp(const ax25_digi *, const ax25_digi *);
 310 const unsigned char *ax25_addr_parse(const unsigned char *, int,
 311         ax25_address *, ax25_address *, ax25_digi *, int *, int *);
 312 int ax25_addr_build(unsigned char *, const ax25_address *,
 313                     const ax25_address *, const ax25_digi *, int, int);
 314 int ax25_addr_size(const ax25_digi *);
 315 void ax25_digi_invert(const ax25_digi *, ax25_digi *);
 316
 317 /* ax25_dev.c */
 318 extern ax25_dev *ax25_dev_list;
 319 extern spinlock_t ax25_dev_lock;
 320
 321 #if IS_ENABLED(CONFIG_AX25)
 322 static inline ax25_dev *ax25_dev_ax25dev(struct net_device *dev)
 323 {
 324         return dev->ax25_ptr;
 325 }
 326 #endif
 327
 328 ax25_dev *ax25_addr_ax25dev(ax25_address *);
 329 void ax25_dev_device_up(struct net_device *);
 330 void ax25_dev_device_down(struct net_device *);
 331 int ax25_fwd_ioctl(unsigned int, struct ax25_fwd_struct *);
 332 struct net_device *ax25_fwd_dev(struct net_device *);
 333 void ax25_dev_free(void);
 334
 335 /* ax25_ds_in.c */
 336 int ax25_ds_frame_in(ax25_cb *, struct sk_buff *, int);
 337
 338 /* ax25_ds_subr.c */
 339 void ax25_ds_nr_error_recovery(ax25_cb *);
 340 void ax25_ds_enquiry_response(ax25_cb *);
 341 void ax25_ds_establish_data_link(ax25_cb *);
 342 void ax25_dev_dama_off(ax25_dev *);
 343 void ax25_dama_on(ax25_cb *);
 344 void ax25_dama_off(ax25_cb *);
 345
 346 /* ax25_ds_timer.c */
 347 void ax25_ds_setup_timer(ax25_dev *);
 348 void ax25_ds_set_timer(ax25_dev *);
 349 void ax25_ds_del_timer(ax25_dev *);
 350 void ax25_ds_timer(ax25_cb *);
 351 void ax25_ds_t1_timeout(ax25_cb *);
 352 void ax25_ds_heartbeat_expiry(ax25_cb *);
 353 void ax25_ds_t3timer_expiry(ax25_cb *);
 354 void ax25_ds_idletimer_expiry(ax25_cb *);
 355
 356 /* ax25_iface.c */
 357
 358 struct ax25_protocol {
 359         struct ax25_protocol *next;
 360         unsigned int pid;
 361         int (*func)(struct sk_buff *, ax25_cb *);
 362 };
 363
 364 void ax25_register_pid(struct ax25_protocol *ap);
 365 void ax25_protocol_release(unsigned int);
 366
 367 struct ax25_linkfail {
 368         struct hlist_node lf_node;
 369         void (*func)(ax25_cb *, int);
 370 };
 371
 372 void ax25_linkfail_register(struct ax25_linkfail *lf);
 373 void ax25_linkfail_release(struct ax25_linkfail *lf);
 374 int __must_check ax25_listen_register(ax25_address *, struct net_device *);
 375 void ax25_listen_release(ax25_address *, struct net_device *);
 376 int(*ax25_protocol_function(unsigned int))(struct sk_buff *, ax25_cb *);
 377 int ax25_listen_mine(ax25_address *, struct net_device *);
 378 void ax25_link_failed(ax25_cb *, int);
 379 int ax25_protocol_is_registered(unsigned int);
 380
 381 /* ax25_in.c */
 382 int ax25_rx_iframe(ax25_cb *, struct sk_buff *);
 383 int ax25_kiss_rcv(struct sk_buff *, struct net_device *, struct packet_type *,
 384                   struct net_device *);
 385
 386 /* ax25_ip.c */
 387 netdev_tx_t ax25_ip_xmit(struct sk_buff *skb);
 388 extern const struct header_ops ax25_header_ops;
 389
 390 /* ax25_out.c */
 391 ax25_cb *ax25_send_frame(struct sk_buff *, int, ax25_address *, ax25_address *,
 392                          ax25_digi *, struct net_device *);
 393 void ax25_output(ax25_cb *, int, struct sk_buff *);
 394 void ax25_kick(ax25_cb *);
 395 void ax25_transmit_buffer(ax25_cb *, struct sk_buff *, int);
 396 void ax25_queue_xmit(struct sk_buff *skb, struct net_device *dev);
 397 int ax25_check_iframes_acked(ax25_cb *, unsigned short);
 398
 399 /* ax25_route.c */
 400 void ax25_rt_device_down(struct net_device *);
 401 int ax25_rt_ioctl(unsigned int, void __user *);
 402 extern const struct file_operations ax25_route_fops;
 403 ax25_route *ax25_get_route(ax25_address *addr, struct net_device *dev);
 404 int ax25_rt_autobind(ax25_cb *, ax25_address *);
 405 struct sk_buff *ax25_rt_build_path(struct sk_buff *, ax25_address *,
 406                                    ax25_address *, ax25_digi *);
 407 void ax25_rt_free(void);
 408
 409 /* ax25_std_in.c */
 410 int ax25_std_frame_in(ax25_cb *, struct sk_buff *, int);
 411
 412 /* ax25_std_subr.c */
 413 void ax25_std_nr_error_recovery(ax25_cb *);
 414 void ax25_std_establish_data_link(ax25_cb *);
 415 void ax25_std_transmit_enquiry(ax25_cb *);
 416 void ax25_std_enquiry_response(ax25_cb *);
 417 void ax25_std_timeout_response(ax25_cb *);
 418
 419 /* ax25_std_timer.c */
 420 void ax25_std_heartbeat_expiry(ax25_cb *);
 421 void ax25_std_t1timer_expiry(ax25_cb *);
 422 void ax25_std_t2timer_expiry(ax25_cb *);
 423 void ax25_std_t3timer_expiry(ax25_cb *);
 424 void ax25_std_idletimer_expiry(ax25_cb *);
 425
 426 /* ax25_subr.c */
 427 void ax25_clear_queues(ax25_cb *);
 428 void ax25_frames_acked(ax25_cb *, unsigned short);
 429 void ax25_requeue_frames(ax25_cb *);
 430 int ax25_validate_nr(ax25_cb *, unsigned short);
 431 int ax25_decode(ax25_cb *, struct sk_buff *, int *, int *, int *);
 432 void ax25_send_control(ax25_cb *, int, int, int);
 433 void ax25_return_dm(struct net_device *, ax25_address *, ax25_address *,
 434                     ax25_digi *);
 435 void ax25_calculate_t1(ax25_cb *);
 436 void ax25_calculate_rtt(ax25_cb *);
 437 void ax25_disconnect(ax25_cb *, int);
 438
 439 /* ax25_timer.c */
 440 void ax25_setup_timers(ax25_cb *);
 441 void ax25_start_heartbeat(ax25_cb *);
 442 void ax25_start_t1timer(ax25_cb *);
 443 void ax25_start_t2timer(ax25_cb *);
 444 void ax25_start_t3timer(ax25_cb *);
 445 void ax25_start_idletimer(ax25_cb *);
 446 void ax25_stop_heartbeat(ax25_cb *);
 447 void ax25_stop_t1timer(ax25_cb *);
 448 void ax25_stop_t2timer(ax25_cb *);
 449 void ax25_stop_t3timer(ax25_cb *);
 450 void ax25_stop_idletimer(ax25_cb *);
 451 int ax25_t1timer_running(ax25_cb *);
 452 unsigned long ax25_display_timer(struct timer_list *);
 453
 454 /* ax25_uid.c */
 455 extern int  ax25_uid_policy;
 456 ax25_uid_assoc *ax25_findbyuid(kuid_t);
 457 int __must_check ax25_uid_ioctl(int, struct sockaddr_ax25 *);
 458 extern const struct file_operations ax25_uid_fops;
 459 void ax25_uid_free(void);
 460
 461 /* sysctl_net_ax25.c */
 462 #ifdef CONFIG_SYSCTL
 463 int ax25_register_dev_sysctl(ax25_dev *ax25_dev);
 464 void ax25_unregister_dev_sysctl(ax25_dev *ax25_dev);
 465 #else
 466 static inline int ax25_register_dev_sysctl(ax25_dev *ax25_dev) { return 0; }
 467 static inline void ax25_unregister_dev_sysctl(ax25_dev *ax25_dev) {}
 468 #endif /* CONFIG_SYSCTL */
 469
 470 #endif