| /* |
| * X.25 Packet Layer release 002 |
| * |
| * This is ALPHA test software. This code may break your machine, |
| * randomly fail to work with new releases, misbehave and/or generally |
| * screw up. It might even work. |
| * |
| * This code REQUIRES 2.1.15 or higher |
| * |
| * This module: |
| * This module is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| * |
| * History |
| * X.25 001 Jonathan Naylor Started coding. |
| * X.25 002 Jonathan Naylor Centralised disconnection processing. |
| * mar/20/00 Daniela Squassoni Disabling/enabling of facilities |
| * negotiation. |
| * jun/24/01 Arnaldo C. Melo use skb_queue_purge, cleanups |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/string.h> |
| #include <linux/skbuff.h> |
| #include <net/sock.h> |
| #include <net/tcp.h> |
| #include <net/x25.h> |
| |
| /* |
| * This routine purges all of the queues of frames. |
| */ |
| void x25_clear_queues(struct sock *sk) |
| { |
| struct x25_sock *x25 = x25_sk(sk); |
| |
| skb_queue_purge(&sk->sk_write_queue); |
| skb_queue_purge(&x25->ack_queue); |
| skb_queue_purge(&x25->interrupt_in_queue); |
| skb_queue_purge(&x25->interrupt_out_queue); |
| skb_queue_purge(&x25->fragment_queue); |
| } |
| |
| |
| /* |
| * This routine purges the input queue of those frames that have been |
| * acknowledged. This replaces the boxes labelled "V(a) <- N(r)" on the |
| * SDL diagram. |
| */ |
| void x25_frames_acked(struct sock *sk, unsigned short nr) |
| { |
| struct sk_buff *skb; |
| struct x25_sock *x25 = x25_sk(sk); |
| int modulus = x25->neighbour->extended ? X25_EMODULUS : X25_SMODULUS; |
| |
| /* |
| * Remove all the ack-ed frames from the ack queue. |
| */ |
| if (x25->va != nr) |
| while (skb_peek(&x25->ack_queue) && x25->va != nr) { |
| skb = skb_dequeue(&x25->ack_queue); |
| kfree_skb(skb); |
| x25->va = (x25->va + 1) % modulus; |
| } |
| } |
| |
| void x25_requeue_frames(struct sock *sk) |
| { |
| struct sk_buff *skb, *skb_prev = NULL; |
| |
| /* |
| * Requeue all the un-ack-ed frames on the output queue to be picked |
| * up by x25_kick. This arrangement handles the possibility of an empty |
| * output queue. |
| */ |
| while ((skb = skb_dequeue(&x25_sk(sk)->ack_queue)) != NULL) { |
| if (!skb_prev) |
| skb_queue_head(&sk->sk_write_queue, skb); |
| else |
| skb_append(skb_prev, skb); |
| skb_prev = skb; |
| } |
| } |
| |
| /* |
| * Validate that the value of nr is between va and vs. Return true or |
| * false for testing. |
| */ |
| int x25_validate_nr(struct sock *sk, unsigned short nr) |
| { |
| struct x25_sock *x25 = x25_sk(sk); |
| unsigned short vc = x25->va; |
| int modulus = x25->neighbour->extended ? X25_EMODULUS : X25_SMODULUS; |
| |
| while (vc != x25->vs) { |
| if (nr == vc) |
| return 1; |
| vc = (vc + 1) % modulus; |
| } |
| |
| return nr == x25->vs ? 1 : 0; |
| } |
| |
| /* |
| * This routine is called when the packet layer internally generates a |
| * control frame. |
| */ |
| void x25_write_internal(struct sock *sk, int frametype) |
| { |
| struct x25_sock *x25 = x25_sk(sk); |
| struct sk_buff *skb; |
| unsigned char *dptr; |
| unsigned char facilities[X25_MAX_FAC_LEN]; |
| unsigned char addresses[1 + X25_ADDR_LEN]; |
| unsigned char lci1, lci2; |
| /* |
| * Default safe frame size. |
| */ |
| int len = X25_MAX_L2_LEN + X25_EXT_MIN_LEN; |
| |
| /* |
| * Adjust frame size. |
| */ |
| switch (frametype) { |
| case X25_CALL_REQUEST: |
| len += 1 + X25_ADDR_LEN + X25_MAX_FAC_LEN + |
| X25_MAX_CUD_LEN; |
| break; |
| case X25_CALL_ACCEPTED: |
| len += 1 + X25_MAX_FAC_LEN + X25_MAX_CUD_LEN; |
| break; |
| case X25_CLEAR_REQUEST: |
| case X25_RESET_REQUEST: |
| len += 2; |
| break; |
| case X25_RR: |
| case X25_RNR: |
| case X25_REJ: |
| case X25_CLEAR_CONFIRMATION: |
| case X25_INTERRUPT_CONFIRMATION: |
| case X25_RESET_CONFIRMATION: |
| break; |
| default: |
| printk(KERN_ERR "X.25: invalid frame type %02X\n", |
| frametype); |
| return; |
| } |
| |
| if ((skb = alloc_skb(len, GFP_ATOMIC)) == NULL) |
| return; |
| |
| /* |
| * Space for Ethernet and 802.2 LLC headers. |
| */ |
| skb_reserve(skb, X25_MAX_L2_LEN); |
| |
| /* |
| * Make space for the GFI and LCI, and fill them in. |
| */ |
| dptr = skb_put(skb, 2); |
| |
| lci1 = (x25->lci >> 8) & 0x0F; |
| lci2 = (x25->lci >> 0) & 0xFF; |
| |
| if (x25->neighbour->extended) { |
| *dptr++ = lci1 | X25_GFI_EXTSEQ; |
| *dptr++ = lci2; |
| } else { |
| *dptr++ = lci1 | X25_GFI_STDSEQ; |
| *dptr++ = lci2; |
| } |
| |
| /* |
| * Now fill in the frame type specific information. |
| */ |
| switch (frametype) { |
| |
| case X25_CALL_REQUEST: |
| dptr = skb_put(skb, 1); |
| *dptr++ = X25_CALL_REQUEST; |
| len = x25_addr_aton(addresses, &x25->dest_addr, |
| &x25->source_addr); |
| dptr = skb_put(skb, len); |
| memcpy(dptr, addresses, len); |
| len = x25_create_facilities(facilities, |
| &x25->facilities, |
| x25->neighbour->global_facil_mask); |
| dptr = skb_put(skb, len); |
| memcpy(dptr, facilities, len); |
| dptr = skb_put(skb, x25->calluserdata.cudlength); |
| memcpy(dptr, x25->calluserdata.cuddata, |
| x25->calluserdata.cudlength); |
| x25->calluserdata.cudlength = 0; |
| break; |
| |
| case X25_CALL_ACCEPTED: |
| dptr = skb_put(skb, 2); |
| *dptr++ = X25_CALL_ACCEPTED; |
| *dptr++ = 0x00; /* Address lengths */ |
| len = x25_create_facilities(facilities, |
| &x25->facilities, |
| x25->vc_facil_mask); |
| dptr = skb_put(skb, len); |
| memcpy(dptr, facilities, len); |
| dptr = skb_put(skb, x25->calluserdata.cudlength); |
| memcpy(dptr, x25->calluserdata.cuddata, |
| x25->calluserdata.cudlength); |
| x25->calluserdata.cudlength = 0; |
| break; |
| |
| case X25_CLEAR_REQUEST: |
| case X25_RESET_REQUEST: |
| dptr = skb_put(skb, 3); |
| *dptr++ = frametype; |
| *dptr++ = 0x00; /* XXX */ |
| *dptr++ = 0x00; /* XXX */ |
| break; |
| |
| case X25_RR: |
| case X25_RNR: |
| case X25_REJ: |
| if (x25->neighbour->extended) { |
| dptr = skb_put(skb, 2); |
| *dptr++ = frametype; |
| *dptr++ = (x25->vr << 1) & 0xFE; |
| } else { |
| dptr = skb_put(skb, 1); |
| *dptr = frametype; |
| *dptr++ |= (x25->vr << 5) & 0xE0; |
| } |
| break; |
| |
| case X25_CLEAR_CONFIRMATION: |
| case X25_INTERRUPT_CONFIRMATION: |
| case X25_RESET_CONFIRMATION: |
| dptr = skb_put(skb, 1); |
| *dptr = frametype; |
| break; |
| } |
| |
| x25_transmit_link(skb, x25->neighbour); |
| } |
| |
| /* |
| * Unpick the contents of the passed X.25 Packet Layer frame. |
| */ |
| int x25_decode(struct sock *sk, struct sk_buff *skb, int *ns, int *nr, int *q, |
| int *d, int *m) |
| { |
| struct x25_sock *x25 = x25_sk(sk); |
| unsigned char *frame = skb->data; |
| |
| *ns = *nr = *q = *d = *m = 0; |
| |
| switch (frame[2]) { |
| case X25_CALL_REQUEST: |
| case X25_CALL_ACCEPTED: |
| case X25_CLEAR_REQUEST: |
| case X25_CLEAR_CONFIRMATION: |
| case X25_INTERRUPT: |
| case X25_INTERRUPT_CONFIRMATION: |
| case X25_RESET_REQUEST: |
| case X25_RESET_CONFIRMATION: |
| case X25_RESTART_REQUEST: |
| case X25_RESTART_CONFIRMATION: |
| case X25_REGISTRATION_REQUEST: |
| case X25_REGISTRATION_CONFIRMATION: |
| case X25_DIAGNOSTIC: |
| return frame[2]; |
| } |
| |
| if (x25->neighbour->extended) { |
| if (frame[2] == X25_RR || |
| frame[2] == X25_RNR || |
| frame[2] == X25_REJ) { |
| *nr = (frame[3] >> 1) & 0x7F; |
| return frame[2]; |
| } |
| } else { |
| if ((frame[2] & 0x1F) == X25_RR || |
| (frame[2] & 0x1F) == X25_RNR || |
| (frame[2] & 0x1F) == X25_REJ) { |
| *nr = (frame[2] >> 5) & 0x07; |
| return frame[2] & 0x1F; |
| } |
| } |
| |
| if (x25->neighbour->extended) { |
| if ((frame[2] & 0x01) == X25_DATA) { |
| *q = (frame[0] & X25_Q_BIT) == X25_Q_BIT; |
| *d = (frame[0] & X25_D_BIT) == X25_D_BIT; |
| *m = (frame[3] & X25_EXT_M_BIT) == X25_EXT_M_BIT; |
| *nr = (frame[3] >> 1) & 0x7F; |
| *ns = (frame[2] >> 1) & 0x7F; |
| return X25_DATA; |
| } |
| } else { |
| if ((frame[2] & 0x01) == X25_DATA) { |
| *q = (frame[0] & X25_Q_BIT) == X25_Q_BIT; |
| *d = (frame[0] & X25_D_BIT) == X25_D_BIT; |
| *m = (frame[2] & X25_STD_M_BIT) == X25_STD_M_BIT; |
| *nr = (frame[2] >> 5) & 0x07; |
| *ns = (frame[2] >> 1) & 0x07; |
| return X25_DATA; |
| } |
| } |
| |
| printk(KERN_DEBUG "X.25: invalid PLP frame %02X %02X %02X\n", |
| frame[0], frame[1], frame[2]); |
| |
| return X25_ILLEGAL; |
| } |
| |
| void x25_disconnect(struct sock *sk, int reason, unsigned char cause, |
| unsigned char diagnostic) |
| { |
| struct x25_sock *x25 = x25_sk(sk); |
| |
| x25_clear_queues(sk); |
| x25_stop_timer(sk); |
| |
| x25->lci = 0; |
| x25->state = X25_STATE_0; |
| |
| x25->causediag.cause = cause; |
| x25->causediag.diagnostic = diagnostic; |
| |
| sk->sk_state = TCP_CLOSE; |
| sk->sk_err = reason; |
| sk->sk_shutdown |= SEND_SHUTDOWN; |
| |
| if (!sock_flag(sk, SOCK_DEAD)) { |
| sk->sk_state_change(sk); |
| sock_set_flag(sk, SOCK_DEAD); |
| } |
| } |
| |
| /* |
| * Clear an own-rx-busy condition and tell the peer about this, provided |
| * that there is a significant amount of free receive buffer space available. |
| */ |
| void x25_check_rbuf(struct sock *sk) |
| { |
| struct x25_sock *x25 = x25_sk(sk); |
| |
| if (atomic_read(&sk->sk_rmem_alloc) < (sk->sk_rcvbuf / 2) && |
| (x25->condition & X25_COND_OWN_RX_BUSY)) { |
| x25->condition &= ~X25_COND_OWN_RX_BUSY; |
| x25->condition &= ~X25_COND_ACK_PENDING; |
| x25->vl = x25->vr; |
| x25_write_internal(sk, X25_RR); |
| x25_stop_timer(sk); |
| } |
| } |
| |
| /* |
| * Compare 2 calluserdata structures, used to find correct listening sockets |
| * when call user data is used. |
| */ |
| int x25_check_calluserdata(struct x25_calluserdata *ours, struct x25_calluserdata *theirs) |
| { |
| int i; |
| if (ours->cudlength != theirs->cudlength) |
| return 0; |
| |
| for (i=0;i<ours->cudlength;i++) { |
| if (ours->cuddata[i] != theirs->cuddata[i]) { |
| return 0; |
| } |
| } |
| return 1; |
| } |
| |