From 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 27 Apr 2024 12:05:51 +0200 Subject: Adding upstream version 5.10.209. Signed-off-by: Daniel Baumann --- net/x25/x25_subr.c | 384 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 384 insertions(+) create mode 100644 net/x25/x25_subr.c (limited to 'net/x25/x25_subr.c') diff --git a/net/x25/x25_subr.c b/net/x25/x25_subr.c new file mode 100644 index 000000000..0285aaa1e --- /dev/null +++ b/net/x25/x25_subr.c @@ -0,0 +1,384 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * 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 + * + * 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 + * apr/04/15 Shaun Pereira Fast select with no + * restriction on response. + */ + +#define pr_fmt(fmt) "X25: " fmt + +#include +#include +#include +#include +#include +#include +#include + +/* + * 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, &sk->sk_write_queue); + 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: /* fast sel with no restr on resp */ + if (x25->facilities.reverse & 0x80) { + len += 1 + X25_MAX_FAC_LEN + X25_MAX_CUD_LEN; + } else { + len += 1 + X25_MAX_FAC_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: + pr_err("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); + skb_put_data(skb, addresses, len); + len = x25_create_facilities(facilities, + &x25->facilities, + &x25->dte_facilities, + x25->neighbour->global_facil_mask); + skb_put_data(skb, facilities, len); + skb_put_data(skb, 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->dte_facilities, + x25->vc_facil_mask); + skb_put_data(skb, facilities, len); + + /* fast select with no restriction on response + allows call user data. Userland must + ensure it is ours and not theirs */ + if(x25->facilities.reverse & 0x80) { + skb_put_data(skb, + x25->calluserdata.cuddata, + x25->calluserdata.cudlength); + } + x25->calluserdata.cudlength = 0; + break; + + case X25_CLEAR_REQUEST: + dptr = skb_put(skb, 3); + *dptr++ = frametype; + *dptr++ = x25->causediag.cause; + *dptr++ = x25->causediag.diagnostic; + break; + + 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; + + if (!pskb_may_pull(skb, X25_STD_MIN_LEN)) + return X25_ILLEGAL; + 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) { + if (!pskb_may_pull(skb, X25_EXT_MIN_LEN)) + return X25_ILLEGAL; + frame = skb->data; + + *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) { + if (!pskb_may_pull(skb, X25_EXT_MIN_LEN)) + return X25_ILLEGAL; + frame = skb->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; + } + } + + pr_debug("invalid PLP frame %3ph\n", frame); + + 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); + } + if (x25->neighbour) { + read_lock_bh(&x25_list_lock); + x25_neigh_put(x25->neighbour); + x25->neighbour = NULL; + read_unlock_bh(&x25_list_lock); + } +} + +/* + * 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 >> 1) && + (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); + } +} -- cgit v1.2.3