11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * X.25 Packet Layer release 002 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * This is ALPHA test software. This code may break your machine, 51da177e4SLinus Torvalds * randomly fail to work with new releases, misbehave and/or generally 61da177e4SLinus Torvalds * screw up. It might even work. 71da177e4SLinus Torvalds * 81da177e4SLinus Torvalds * This code REQUIRES 2.1.15 or higher 91da177e4SLinus Torvalds * 101da177e4SLinus Torvalds * This module: 111da177e4SLinus Torvalds * This module is free software; you can redistribute it and/or 121da177e4SLinus Torvalds * modify it under the terms of the GNU General Public License 131da177e4SLinus Torvalds * as published by the Free Software Foundation; either version 141da177e4SLinus Torvalds * 2 of the License, or (at your option) any later version. 151da177e4SLinus Torvalds * 161da177e4SLinus Torvalds * History 171da177e4SLinus Torvalds * X.25 001 Jonathan Naylor Started coding. 181da177e4SLinus Torvalds * X.25 002 Jonathan Naylor Centralised disconnection code. 191da177e4SLinus Torvalds * New timer architecture. 201da177e4SLinus Torvalds * 2000-03-20 Daniela Squassoni Disabling/enabling of facilities 211da177e4SLinus Torvalds * negotiation. 221da177e4SLinus Torvalds * 2000-11-10 Henner Eisen Check and reset for out-of-sequence 231da177e4SLinus Torvalds * i-frames. 241da177e4SLinus Torvalds */ 251da177e4SLinus Torvalds 261da177e4SLinus Torvalds #include <linux/errno.h> 271da177e4SLinus Torvalds #include <linux/kernel.h> 281da177e4SLinus Torvalds #include <linux/string.h> 291da177e4SLinus Torvalds #include <linux/skbuff.h> 301da177e4SLinus Torvalds #include <net/sock.h> 311da177e4SLinus Torvalds #include <net/tcp.h> 321da177e4SLinus Torvalds #include <net/x25.h> 331da177e4SLinus Torvalds 341da177e4SLinus Torvalds static int x25_queue_rx_frame(struct sock *sk, struct sk_buff *skb, int more) 351da177e4SLinus Torvalds { 361da177e4SLinus Torvalds struct sk_buff *skbo, *skbn = skb; 371da177e4SLinus Torvalds struct x25_sock *x25 = x25_sk(sk); 381da177e4SLinus Torvalds 391da177e4SLinus Torvalds if (more) { 401da177e4SLinus Torvalds x25->fraglen += skb->len; 411da177e4SLinus Torvalds skb_queue_tail(&x25->fragment_queue, skb); 421da177e4SLinus Torvalds skb_set_owner_r(skb, sk); 431da177e4SLinus Torvalds return 0; 441da177e4SLinus Torvalds } 451da177e4SLinus Torvalds 461da177e4SLinus Torvalds if (!more && x25->fraglen > 0) { /* End of fragment */ 471da177e4SLinus Torvalds int len = x25->fraglen + skb->len; 481da177e4SLinus Torvalds 491da177e4SLinus Torvalds if ((skbn = alloc_skb(len, GFP_ATOMIC)) == NULL){ 501da177e4SLinus Torvalds kfree_skb(skb); 511da177e4SLinus Torvalds return 1; 521da177e4SLinus Torvalds } 531da177e4SLinus Torvalds 541da177e4SLinus Torvalds skb_queue_tail(&x25->fragment_queue, skb); 551da177e4SLinus Torvalds 561da177e4SLinus Torvalds skbn->h.raw = skbn->data; 571da177e4SLinus Torvalds 581da177e4SLinus Torvalds skbo = skb_dequeue(&x25->fragment_queue); 591da177e4SLinus Torvalds memcpy(skb_put(skbn, skbo->len), skbo->data, skbo->len); 601da177e4SLinus Torvalds kfree_skb(skbo); 611da177e4SLinus Torvalds 621da177e4SLinus Torvalds while ((skbo = 631da177e4SLinus Torvalds skb_dequeue(&x25->fragment_queue)) != NULL) { 641da177e4SLinus Torvalds skb_pull(skbo, (x25->neighbour->extended) ? 651da177e4SLinus Torvalds X25_EXT_MIN_LEN : X25_STD_MIN_LEN); 661da177e4SLinus Torvalds memcpy(skb_put(skbn, skbo->len), skbo->data, skbo->len); 671da177e4SLinus Torvalds kfree_skb(skbo); 681da177e4SLinus Torvalds } 691da177e4SLinus Torvalds 701da177e4SLinus Torvalds x25->fraglen = 0; 711da177e4SLinus Torvalds } 721da177e4SLinus Torvalds 731da177e4SLinus Torvalds skb_set_owner_r(skbn, sk); 741da177e4SLinus Torvalds skb_queue_tail(&sk->sk_receive_queue, skbn); 751da177e4SLinus Torvalds if (!sock_flag(sk, SOCK_DEAD)) 761da177e4SLinus Torvalds sk->sk_data_ready(sk, skbn->len); 771da177e4SLinus Torvalds 781da177e4SLinus Torvalds return 0; 791da177e4SLinus Torvalds } 801da177e4SLinus Torvalds 811da177e4SLinus Torvalds /* 821da177e4SLinus Torvalds * State machine for state 1, Awaiting Call Accepted State. 831da177e4SLinus Torvalds * The handling of the timer(s) is in file x25_timer.c. 841da177e4SLinus Torvalds * Handling of state 0 and connection release is in af_x25.c. 851da177e4SLinus Torvalds */ 861da177e4SLinus Torvalds static int x25_state1_machine(struct sock *sk, struct sk_buff *skb, int frametype) 871da177e4SLinus Torvalds { 881da177e4SLinus Torvalds struct x25_address source_addr, dest_addr; 891da177e4SLinus Torvalds 901da177e4SLinus Torvalds switch (frametype) { 911da177e4SLinus Torvalds case X25_CALL_ACCEPTED: { 921da177e4SLinus Torvalds struct x25_sock *x25 = x25_sk(sk); 931da177e4SLinus Torvalds 941da177e4SLinus Torvalds x25_stop_timer(sk); 951da177e4SLinus Torvalds x25->condition = 0x00; 961da177e4SLinus Torvalds x25->vs = 0; 971da177e4SLinus Torvalds x25->va = 0; 981da177e4SLinus Torvalds x25->vr = 0; 991da177e4SLinus Torvalds x25->vl = 0; 1001da177e4SLinus Torvalds x25->state = X25_STATE_3; 1011da177e4SLinus Torvalds sk->sk_state = TCP_ESTABLISHED; 1021da177e4SLinus Torvalds /* 1031da177e4SLinus Torvalds * Parse the data in the frame. 1041da177e4SLinus Torvalds */ 1051da177e4SLinus Torvalds skb_pull(skb, X25_STD_MIN_LEN); 1061da177e4SLinus Torvalds skb_pull(skb, x25_addr_ntoa(skb->data, &source_addr, &dest_addr)); 1071da177e4SLinus Torvalds skb_pull(skb, 1081da177e4SLinus Torvalds x25_parse_facilities(skb, &x25->facilities, 1091da177e4SLinus Torvalds &x25->vc_facil_mask)); 1101da177e4SLinus Torvalds /* 1111da177e4SLinus Torvalds * Copy any Call User Data. 1121da177e4SLinus Torvalds */ 1131da177e4SLinus Torvalds if (skb->len >= 0) { 1141da177e4SLinus Torvalds memcpy(x25->calluserdata.cuddata, skb->data, 1151da177e4SLinus Torvalds skb->len); 1161da177e4SLinus Torvalds x25->calluserdata.cudlength = skb->len; 1171da177e4SLinus Torvalds } 1181da177e4SLinus Torvalds if (!sock_flag(sk, SOCK_DEAD)) 1191da177e4SLinus Torvalds sk->sk_state_change(sk); 1201da177e4SLinus Torvalds break; 1211da177e4SLinus Torvalds } 1221da177e4SLinus Torvalds case X25_CLEAR_REQUEST: 1231da177e4SLinus Torvalds x25_write_internal(sk, X25_CLEAR_CONFIRMATION); 1241da177e4SLinus Torvalds x25_disconnect(sk, ECONNREFUSED, skb->data[3], skb->data[4]); 1251da177e4SLinus Torvalds break; 1261da177e4SLinus Torvalds 1271da177e4SLinus Torvalds default: 1281da177e4SLinus Torvalds break; 1291da177e4SLinus Torvalds } 1301da177e4SLinus Torvalds 1311da177e4SLinus Torvalds return 0; 1321da177e4SLinus Torvalds } 1331da177e4SLinus Torvalds 1341da177e4SLinus Torvalds /* 1351da177e4SLinus Torvalds * State machine for state 2, Awaiting Clear Confirmation State. 1361da177e4SLinus Torvalds * The handling of the timer(s) is in file x25_timer.c 1371da177e4SLinus Torvalds * Handling of state 0 and connection release is in af_x25.c. 1381da177e4SLinus Torvalds */ 1391da177e4SLinus Torvalds static int x25_state2_machine(struct sock *sk, struct sk_buff *skb, int frametype) 1401da177e4SLinus Torvalds { 1411da177e4SLinus Torvalds switch (frametype) { 1421da177e4SLinus Torvalds 1431da177e4SLinus Torvalds case X25_CLEAR_REQUEST: 1441da177e4SLinus Torvalds x25_write_internal(sk, X25_CLEAR_CONFIRMATION); 1451da177e4SLinus Torvalds x25_disconnect(sk, 0, skb->data[3], skb->data[4]); 1461da177e4SLinus Torvalds break; 1471da177e4SLinus Torvalds 1481da177e4SLinus Torvalds case X25_CLEAR_CONFIRMATION: 1491da177e4SLinus Torvalds x25_disconnect(sk, 0, 0, 0); 1501da177e4SLinus Torvalds break; 1511da177e4SLinus Torvalds 1521da177e4SLinus Torvalds default: 1531da177e4SLinus Torvalds break; 1541da177e4SLinus Torvalds } 1551da177e4SLinus Torvalds 1561da177e4SLinus Torvalds return 0; 1571da177e4SLinus Torvalds } 1581da177e4SLinus Torvalds 1591da177e4SLinus Torvalds /* 1601da177e4SLinus Torvalds * State machine for state 3, Connected State. 1611da177e4SLinus Torvalds * The handling of the timer(s) is in file x25_timer.c 1621da177e4SLinus Torvalds * Handling of state 0 and connection release is in af_x25.c. 1631da177e4SLinus Torvalds */ 1641da177e4SLinus Torvalds static int x25_state3_machine(struct sock *sk, struct sk_buff *skb, int frametype, int ns, int nr, int q, int d, int m) 1651da177e4SLinus Torvalds { 1661da177e4SLinus Torvalds int queued = 0; 1671da177e4SLinus Torvalds int modulus; 1681da177e4SLinus Torvalds struct x25_sock *x25 = x25_sk(sk); 1691da177e4SLinus Torvalds 1701da177e4SLinus Torvalds modulus = (x25->neighbour->extended) ? X25_EMODULUS : X25_SMODULUS; 1711da177e4SLinus Torvalds 1721da177e4SLinus Torvalds switch (frametype) { 1731da177e4SLinus Torvalds 1741da177e4SLinus Torvalds case X25_RESET_REQUEST: 1751da177e4SLinus Torvalds x25_write_internal(sk, X25_RESET_CONFIRMATION); 1761da177e4SLinus Torvalds x25_stop_timer(sk); 1771da177e4SLinus Torvalds x25->condition = 0x00; 1781da177e4SLinus Torvalds x25->vs = 0; 1791da177e4SLinus Torvalds x25->vr = 0; 1801da177e4SLinus Torvalds x25->va = 0; 1811da177e4SLinus Torvalds x25->vl = 0; 1821da177e4SLinus Torvalds x25_requeue_frames(sk); 1831da177e4SLinus Torvalds break; 1841da177e4SLinus Torvalds 1851da177e4SLinus Torvalds case X25_CLEAR_REQUEST: 1861da177e4SLinus Torvalds x25_write_internal(sk, X25_CLEAR_CONFIRMATION); 1871da177e4SLinus Torvalds x25_disconnect(sk, 0, skb->data[3], skb->data[4]); 1881da177e4SLinus Torvalds break; 1891da177e4SLinus Torvalds 1901da177e4SLinus Torvalds case X25_RR: 1911da177e4SLinus Torvalds case X25_RNR: 1921da177e4SLinus Torvalds if (!x25_validate_nr(sk, nr)) { 1931da177e4SLinus Torvalds x25_clear_queues(sk); 1941da177e4SLinus Torvalds x25_write_internal(sk, X25_RESET_REQUEST); 1951da177e4SLinus Torvalds x25_start_t22timer(sk); 1961da177e4SLinus Torvalds x25->condition = 0x00; 1971da177e4SLinus Torvalds x25->vs = 0; 1981da177e4SLinus Torvalds x25->vr = 0; 1991da177e4SLinus Torvalds x25->va = 0; 2001da177e4SLinus Torvalds x25->vl = 0; 2011da177e4SLinus Torvalds x25->state = X25_STATE_4; 2021da177e4SLinus Torvalds } else { 2031da177e4SLinus Torvalds x25_frames_acked(sk, nr); 2041da177e4SLinus Torvalds if (frametype == X25_RNR) { 2051da177e4SLinus Torvalds x25->condition |= X25_COND_PEER_RX_BUSY; 2061da177e4SLinus Torvalds } else { 2071da177e4SLinus Torvalds x25->condition &= ~X25_COND_PEER_RX_BUSY; 2081da177e4SLinus Torvalds } 2091da177e4SLinus Torvalds } 2101da177e4SLinus Torvalds break; 2111da177e4SLinus Torvalds 2121da177e4SLinus Torvalds case X25_DATA: /* XXX */ 2131da177e4SLinus Torvalds x25->condition &= ~X25_COND_PEER_RX_BUSY; 2141da177e4SLinus Torvalds if ((ns != x25->vr) || !x25_validate_nr(sk, nr)) { 2151da177e4SLinus Torvalds x25_clear_queues(sk); 2161da177e4SLinus Torvalds x25_write_internal(sk, X25_RESET_REQUEST); 2171da177e4SLinus Torvalds x25_start_t22timer(sk); 2181da177e4SLinus Torvalds x25->condition = 0x00; 2191da177e4SLinus Torvalds x25->vs = 0; 2201da177e4SLinus Torvalds x25->vr = 0; 2211da177e4SLinus Torvalds x25->va = 0; 2221da177e4SLinus Torvalds x25->vl = 0; 2231da177e4SLinus Torvalds x25->state = X25_STATE_4; 2241da177e4SLinus Torvalds break; 2251da177e4SLinus Torvalds } 2261da177e4SLinus Torvalds x25_frames_acked(sk, nr); 2271da177e4SLinus Torvalds if (ns == x25->vr) { 2281da177e4SLinus Torvalds if (x25_queue_rx_frame(sk, skb, m) == 0) { 2291da177e4SLinus Torvalds x25->vr = (x25->vr + 1) % modulus; 2301da177e4SLinus Torvalds queued = 1; 2311da177e4SLinus Torvalds } else { 2321da177e4SLinus Torvalds /* Should never happen */ 2331da177e4SLinus Torvalds x25_clear_queues(sk); 2341da177e4SLinus Torvalds x25_write_internal(sk, X25_RESET_REQUEST); 2351da177e4SLinus Torvalds x25_start_t22timer(sk); 2361da177e4SLinus Torvalds x25->condition = 0x00; 2371da177e4SLinus Torvalds x25->vs = 0; 2381da177e4SLinus Torvalds x25->vr = 0; 2391da177e4SLinus Torvalds x25->va = 0; 2401da177e4SLinus Torvalds x25->vl = 0; 2411da177e4SLinus Torvalds x25->state = X25_STATE_4; 2421da177e4SLinus Torvalds break; 2431da177e4SLinus Torvalds } 2441da177e4SLinus Torvalds if (atomic_read(&sk->sk_rmem_alloc) > 2451da177e4SLinus Torvalds (sk->sk_rcvbuf / 2)) 2461da177e4SLinus Torvalds x25->condition |= X25_COND_OWN_RX_BUSY; 2471da177e4SLinus Torvalds } 2481da177e4SLinus Torvalds /* 2491da177e4SLinus Torvalds * If the window is full Ack it immediately, else 2501da177e4SLinus Torvalds * start the holdback timer. 2511da177e4SLinus Torvalds */ 2521da177e4SLinus Torvalds if (((x25->vl + x25->facilities.winsize_in) % modulus) == x25->vr) { 2531da177e4SLinus Torvalds x25->condition &= ~X25_COND_ACK_PENDING; 2541da177e4SLinus Torvalds x25_stop_timer(sk); 2551da177e4SLinus Torvalds x25_enquiry_response(sk); 2561da177e4SLinus Torvalds } else { 2571da177e4SLinus Torvalds x25->condition |= X25_COND_ACK_PENDING; 2581da177e4SLinus Torvalds x25_start_t2timer(sk); 2591da177e4SLinus Torvalds } 2601da177e4SLinus Torvalds break; 2611da177e4SLinus Torvalds 2621da177e4SLinus Torvalds case X25_INTERRUPT_CONFIRMATION: 2631da177e4SLinus Torvalds x25->intflag = 0; 2641da177e4SLinus Torvalds break; 2651da177e4SLinus Torvalds 2661da177e4SLinus Torvalds case X25_INTERRUPT: 2671da177e4SLinus Torvalds if (sock_flag(sk, SOCK_URGINLINE)) 2681da177e4SLinus Torvalds queued = !sock_queue_rcv_skb(sk, skb); 2691da177e4SLinus Torvalds else { 2701da177e4SLinus Torvalds skb_set_owner_r(skb, sk); 2711da177e4SLinus Torvalds skb_queue_tail(&x25->interrupt_in_queue, skb); 2721da177e4SLinus Torvalds queued = 1; 2731da177e4SLinus Torvalds } 2741da177e4SLinus Torvalds sk_send_sigurg(sk); 2751da177e4SLinus Torvalds x25_write_internal(sk, X25_INTERRUPT_CONFIRMATION); 2761da177e4SLinus Torvalds break; 2771da177e4SLinus Torvalds 2781da177e4SLinus Torvalds default: 2791da177e4SLinus Torvalds printk(KERN_WARNING "x25: unknown %02X in state 3\n", frametype); 2801da177e4SLinus Torvalds break; 2811da177e4SLinus Torvalds } 2821da177e4SLinus Torvalds 2831da177e4SLinus Torvalds return queued; 2841da177e4SLinus Torvalds } 2851da177e4SLinus Torvalds 2861da177e4SLinus Torvalds /* 2871da177e4SLinus Torvalds * State machine for state 4, Awaiting Reset Confirmation State. 2881da177e4SLinus Torvalds * The handling of the timer(s) is in file x25_timer.c 2891da177e4SLinus Torvalds * Handling of state 0 and connection release is in af_x25.c. 2901da177e4SLinus Torvalds */ 2911da177e4SLinus Torvalds static int x25_state4_machine(struct sock *sk, struct sk_buff *skb, int frametype) 2921da177e4SLinus Torvalds { 2931da177e4SLinus Torvalds switch (frametype) { 2941da177e4SLinus Torvalds 2951da177e4SLinus Torvalds case X25_RESET_REQUEST: 2961da177e4SLinus Torvalds x25_write_internal(sk, X25_RESET_CONFIRMATION); 2971da177e4SLinus Torvalds case X25_RESET_CONFIRMATION: { 2981da177e4SLinus Torvalds struct x25_sock *x25 = x25_sk(sk); 2991da177e4SLinus Torvalds 3001da177e4SLinus Torvalds x25_stop_timer(sk); 3011da177e4SLinus Torvalds x25->condition = 0x00; 3021da177e4SLinus Torvalds x25->va = 0; 3031da177e4SLinus Torvalds x25->vr = 0; 3041da177e4SLinus Torvalds x25->vs = 0; 3051da177e4SLinus Torvalds x25->vl = 0; 3061da177e4SLinus Torvalds x25->state = X25_STATE_3; 3071da177e4SLinus Torvalds x25_requeue_frames(sk); 3081da177e4SLinus Torvalds break; 3091da177e4SLinus Torvalds } 3101da177e4SLinus Torvalds case X25_CLEAR_REQUEST: 3111da177e4SLinus Torvalds x25_write_internal(sk, X25_CLEAR_CONFIRMATION); 3121da177e4SLinus Torvalds x25_disconnect(sk, 0, skb->data[3], skb->data[4]); 3131da177e4SLinus Torvalds break; 3141da177e4SLinus Torvalds 3151da177e4SLinus Torvalds default: 3161da177e4SLinus Torvalds break; 3171da177e4SLinus Torvalds } 3181da177e4SLinus Torvalds 3191da177e4SLinus Torvalds return 0; 3201da177e4SLinus Torvalds } 3211da177e4SLinus Torvalds 3221da177e4SLinus Torvalds /* Higher level upcall for a LAPB frame */ 3231da177e4SLinus Torvalds int x25_process_rx_frame(struct sock *sk, struct sk_buff *skb) 3241da177e4SLinus Torvalds { 3251da177e4SLinus Torvalds struct x25_sock *x25 = x25_sk(sk); 3261da177e4SLinus Torvalds int queued = 0, frametype, ns, nr, q, d, m; 3271da177e4SLinus Torvalds 3281da177e4SLinus Torvalds if (x25->state == X25_STATE_0) 3291da177e4SLinus Torvalds return 0; 3301da177e4SLinus Torvalds 3311da177e4SLinus Torvalds frametype = x25_decode(sk, skb, &ns, &nr, &q, &d, &m); 3321da177e4SLinus Torvalds 3331da177e4SLinus Torvalds switch (x25->state) { 3341da177e4SLinus Torvalds case X25_STATE_1: 3351da177e4SLinus Torvalds queued = x25_state1_machine(sk, skb, frametype); 3361da177e4SLinus Torvalds break; 3371da177e4SLinus Torvalds case X25_STATE_2: 3381da177e4SLinus Torvalds queued = x25_state2_machine(sk, skb, frametype); 3391da177e4SLinus Torvalds break; 3401da177e4SLinus Torvalds case X25_STATE_3: 3411da177e4SLinus Torvalds queued = x25_state3_machine(sk, skb, frametype, ns, nr, q, d, m); 3421da177e4SLinus Torvalds break; 3431da177e4SLinus Torvalds case X25_STATE_4: 3441da177e4SLinus Torvalds queued = x25_state4_machine(sk, skb, frametype); 3451da177e4SLinus Torvalds break; 3461da177e4SLinus Torvalds } 3471da177e4SLinus Torvalds 3481da177e4SLinus Torvalds x25_kick(sk); 3491da177e4SLinus Torvalds 3501da177e4SLinus Torvalds return queued; 3511da177e4SLinus Torvalds } 3521da177e4SLinus Torvalds 3531da177e4SLinus Torvalds int x25_backlog_rcv(struct sock *sk, struct sk_buff *skb) 3541da177e4SLinus Torvalds { 3551da177e4SLinus Torvalds int queued = x25_process_rx_frame(sk, skb); 3561da177e4SLinus Torvalds 3571da177e4SLinus Torvalds if (!queued) 3581da177e4SLinus Torvalds kfree_skb(skb); 3591da177e4SLinus Torvalds 3601da177e4SLinus Torvalds return 0; 3611da177e4SLinus Torvalds } 362