From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- net/netrom/nr_out.c | 274 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 274 insertions(+) create mode 100644 net/netrom/nr_out.c (limited to 'net/netrom/nr_out.c') diff --git a/net/netrom/nr_out.c b/net/netrom/nr_out.c new file mode 100644 index 000000000000..7939ded9c98c --- /dev/null +++ b/net/netrom/nr_out.c @@ -0,0 +1,274 @@ +/* + * This program 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. + * + * Copyright Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk) + * Copyright Darryl Miles G7LED (dlm@g7led.demon.co.uk) + */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * This is where all NET/ROM frames pass, except for IP-over-NET/ROM which + * cannot be fragmented in this manner. + */ +void nr_output(struct sock *sk, struct sk_buff *skb) +{ + struct sk_buff *skbn; + unsigned char transport[NR_TRANSPORT_LEN]; + int err, frontlen, len; + + if (skb->len - NR_TRANSPORT_LEN > NR_MAX_PACKET_SIZE) { + /* Save a copy of the Transport Header */ + memcpy(transport, skb->data, NR_TRANSPORT_LEN); + skb_pull(skb, NR_TRANSPORT_LEN); + + frontlen = skb_headroom(skb); + + while (skb->len > 0) { + if ((skbn = sock_alloc_send_skb(sk, frontlen + NR_MAX_PACKET_SIZE, 0, &err)) == NULL) + return; + + skb_reserve(skbn, frontlen); + + len = (NR_MAX_PACKET_SIZE > skb->len) ? skb->len : NR_MAX_PACKET_SIZE; + + /* Copy the user data */ + memcpy(skb_put(skbn, len), skb->data, len); + skb_pull(skb, len); + + /* Duplicate the Transport Header */ + skb_push(skbn, NR_TRANSPORT_LEN); + memcpy(skbn->data, transport, NR_TRANSPORT_LEN); + + if (skb->len > 0) + skbn->data[4] |= NR_MORE_FLAG; + + skb_queue_tail(&sk->sk_write_queue, skbn); /* Throw it on the queue */ + } + + kfree_skb(skb); + } else { + skb_queue_tail(&sk->sk_write_queue, skb); /* Throw it on the queue */ + } + + nr_kick(sk); +} + +/* + * This procedure is passed a buffer descriptor for an iframe. It builds + * the rest of the control part of the frame and then writes it out. + */ +static void nr_send_iframe(struct sock *sk, struct sk_buff *skb) +{ + struct nr_sock *nr = nr_sk(sk); + + if (skb == NULL) + return; + + skb->data[2] = nr->vs; + skb->data[3] = nr->vr; + + if (nr->condition & NR_COND_OWN_RX_BUSY) + skb->data[4] |= NR_CHOKE_FLAG; + + nr_start_idletimer(sk); + + nr_transmit_buffer(sk, skb); +} + +void nr_send_nak_frame(struct sock *sk) +{ + struct sk_buff *skb, *skbn; + struct nr_sock *nr = nr_sk(sk); + + if ((skb = skb_peek(&nr->ack_queue)) == NULL) + return; + + if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) + return; + + skbn->data[2] = nr->va; + skbn->data[3] = nr->vr; + + if (nr->condition & NR_COND_OWN_RX_BUSY) + skbn->data[4] |= NR_CHOKE_FLAG; + + nr_transmit_buffer(sk, skbn); + + nr->condition &= ~NR_COND_ACK_PENDING; + nr->vl = nr->vr; + + nr_stop_t1timer(sk); +} + +void nr_kick(struct sock *sk) +{ + struct nr_sock *nr = nr_sk(sk); + struct sk_buff *skb, *skbn; + unsigned short start, end; + + if (nr->state != NR_STATE_3) + return; + + if (nr->condition & NR_COND_PEER_RX_BUSY) + return; + + if (!skb_peek(&sk->sk_write_queue)) + return; + + start = (skb_peek(&nr->ack_queue) == NULL) ? nr->va : nr->vs; + end = (nr->va + nr->window) % NR_MODULUS; + + if (start == end) + return; + + nr->vs = start; + + /* + * Transmit data until either we're out of data to send or + * the window is full. + */ + + /* + * Dequeue the frame and copy it. + */ + skb = skb_dequeue(&sk->sk_write_queue); + + do { + if ((skbn = skb_clone(skb, GFP_ATOMIC)) == NULL) { + skb_queue_head(&sk->sk_write_queue, skb); + break; + } + + skb_set_owner_w(skbn, sk); + + /* + * Transmit the frame copy. + */ + nr_send_iframe(sk, skbn); + + nr->vs = (nr->vs + 1) % NR_MODULUS; + + /* + * Requeue the original data frame. + */ + skb_queue_tail(&nr->ack_queue, skb); + + } while (nr->vs != end && + (skb = skb_dequeue(&sk->sk_write_queue)) != NULL); + + nr->vl = nr->vr; + nr->condition &= ~NR_COND_ACK_PENDING; + + if (!nr_t1timer_running(sk)) + nr_start_t1timer(sk); +} + +void nr_transmit_buffer(struct sock *sk, struct sk_buff *skb) +{ + struct nr_sock *nr = nr_sk(sk); + unsigned char *dptr; + + /* + * Add the protocol byte and network header. + */ + dptr = skb_push(skb, NR_NETWORK_LEN); + + memcpy(dptr, &nr->source_addr, AX25_ADDR_LEN); + dptr[6] &= ~AX25_CBIT; + dptr[6] &= ~AX25_EBIT; + dptr[6] |= AX25_SSSID_SPARE; + dptr += AX25_ADDR_LEN; + + memcpy(dptr, &nr->dest_addr, AX25_ADDR_LEN); + dptr[6] &= ~AX25_CBIT; + dptr[6] |= AX25_EBIT; + dptr[6] |= AX25_SSSID_SPARE; + dptr += AX25_ADDR_LEN; + + *dptr++ = sysctl_netrom_network_ttl_initialiser; + + if (!nr_route_frame(skb, NULL)) { + kfree_skb(skb); + nr_disconnect(sk, ENETUNREACH); + } +} + +/* + * The following routines are taken from page 170 of the 7th ARRL Computer + * Networking Conference paper, as is the whole state machine. + */ + +void nr_establish_data_link(struct sock *sk) +{ + struct nr_sock *nr = nr_sk(sk); + + nr->condition = 0x00; + nr->n2count = 0; + + nr_write_internal(sk, NR_CONNREQ); + + nr_stop_t2timer(sk); + nr_stop_t4timer(sk); + nr_stop_idletimer(sk); + nr_start_t1timer(sk); +} + +/* + * Never send a NAK when we are CHOKEd. + */ +void nr_enquiry_response(struct sock *sk) +{ + struct nr_sock *nr = nr_sk(sk); + int frametype = NR_INFOACK; + + if (nr->condition & NR_COND_OWN_RX_BUSY) { + frametype |= NR_CHOKE_FLAG; + } else { + if (skb_peek(&nr->reseq_queue) != NULL) + frametype |= NR_NAK_FLAG; + } + + nr_write_internal(sk, frametype); + + nr->vl = nr->vr; + nr->condition &= ~NR_COND_ACK_PENDING; +} + +void nr_check_iframes_acked(struct sock *sk, unsigned short nr) +{ + struct nr_sock *nrom = nr_sk(sk); + + if (nrom->vs == nr) { + nr_frames_acked(sk, nr); + nr_stop_t1timer(sk); + nrom->n2count = 0; + } else { + if (nrom->va != nr) { + nr_frames_acked(sk, nr); + nr_start_t1timer(sk); + } + } +} -- cgit v1.2.2