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![Eric Dumazet](/assets/img/avatar_default.png)
sk_add_backlog() & sk_rcvqueues_full() hard coded sk_rcvbuf as the memory limit. We need to make this limit a parameter for TCP use. No functional change expected in this patch, all callers still using the old sk_rcvbuf limit. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <therbert@google.com> Cc: Maciej Żenczykowski <maze@google.com> Cc: Yuchung Cheng <ycheng@google.com> Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi> Cc: Rick Jones <rick.jones2@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1016 lines
27 KiB
C
1016 lines
27 KiB
C
/*
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* llc_conn.c - Driver routines for connection component.
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*
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* Copyright (c) 1997 by Procom Technology, Inc.
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* 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
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*
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* This program can be redistributed or modified under the terms of the
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* GNU General Public License as published by the Free Software Foundation.
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* This program is distributed without any warranty or implied warranty
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* of merchantability or fitness for a particular purpose.
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*
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* See the GNU General Public License for more details.
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*/
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <net/llc_sap.h>
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#include <net/llc_conn.h>
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#include <net/sock.h>
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#include <net/tcp_states.h>
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#include <net/llc_c_ev.h>
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#include <net/llc_c_ac.h>
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#include <net/llc_c_st.h>
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#include <net/llc_pdu.h>
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#if 0
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#define dprintk(args...) printk(KERN_DEBUG args)
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#else
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#define dprintk(args...)
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#endif
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static int llc_find_offset(int state, int ev_type);
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static void llc_conn_send_pdus(struct sock *sk);
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static int llc_conn_service(struct sock *sk, struct sk_buff *skb);
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static int llc_exec_conn_trans_actions(struct sock *sk,
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struct llc_conn_state_trans *trans,
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struct sk_buff *ev);
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static struct llc_conn_state_trans *llc_qualify_conn_ev(struct sock *sk,
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struct sk_buff *skb);
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/* Offset table on connection states transition diagram */
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static int llc_offset_table[NBR_CONN_STATES][NBR_CONN_EV];
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int sysctl_llc2_ack_timeout = LLC2_ACK_TIME * HZ;
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int sysctl_llc2_p_timeout = LLC2_P_TIME * HZ;
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int sysctl_llc2_rej_timeout = LLC2_REJ_TIME * HZ;
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int sysctl_llc2_busy_timeout = LLC2_BUSY_TIME * HZ;
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/**
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* llc_conn_state_process - sends event to connection state machine
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* @sk: connection
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* @skb: occurred event
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*
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* Sends an event to connection state machine. After processing event
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* (executing it's actions and changing state), upper layer will be
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* indicated or confirmed, if needed. Returns 0 for success, 1 for
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* failure. The socket lock has to be held before calling this function.
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*/
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int llc_conn_state_process(struct sock *sk, struct sk_buff *skb)
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{
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int rc;
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struct llc_sock *llc = llc_sk(skb->sk);
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struct llc_conn_state_ev *ev = llc_conn_ev(skb);
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/*
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* We have to hold the skb, because llc_conn_service will kfree it in
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* the sending path and we need to look at the skb->cb, where we encode
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* llc_conn_state_ev.
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*/
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skb_get(skb);
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ev->ind_prim = ev->cfm_prim = 0;
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/*
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* Send event to state machine
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*/
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rc = llc_conn_service(skb->sk, skb);
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if (unlikely(rc != 0)) {
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printk(KERN_ERR "%s: llc_conn_service failed\n", __func__);
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goto out_kfree_skb;
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}
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if (unlikely(!ev->ind_prim && !ev->cfm_prim)) {
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/* indicate or confirm not required */
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if (!skb->next)
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goto out_kfree_skb;
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goto out_skb_put;
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}
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if (unlikely(ev->ind_prim && ev->cfm_prim)) /* Paranoia */
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skb_get(skb);
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switch (ev->ind_prim) {
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case LLC_DATA_PRIM:
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llc_save_primitive(sk, skb, LLC_DATA_PRIM);
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if (unlikely(sock_queue_rcv_skb(sk, skb))) {
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/*
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* shouldn't happen
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*/
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printk(KERN_ERR "%s: sock_queue_rcv_skb failed!\n",
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__func__);
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kfree_skb(skb);
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}
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break;
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case LLC_CONN_PRIM:
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/*
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* Can't be sock_queue_rcv_skb, because we have to leave the
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* skb->sk pointing to the newly created struct sock in
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* llc_conn_handler. -acme
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*/
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skb_queue_tail(&sk->sk_receive_queue, skb);
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sk->sk_state_change(sk);
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break;
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case LLC_DISC_PRIM:
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sock_hold(sk);
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if (sk->sk_type == SOCK_STREAM &&
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sk->sk_state == TCP_ESTABLISHED) {
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sk->sk_shutdown = SHUTDOWN_MASK;
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sk->sk_socket->state = SS_UNCONNECTED;
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sk->sk_state = TCP_CLOSE;
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if (!sock_flag(sk, SOCK_DEAD)) {
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sock_set_flag(sk, SOCK_DEAD);
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sk->sk_state_change(sk);
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}
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}
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kfree_skb(skb);
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sock_put(sk);
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break;
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case LLC_RESET_PRIM:
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/*
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* FIXME:
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* RESET is not being notified to upper layers for now
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*/
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printk(KERN_INFO "%s: received a reset ind!\n", __func__);
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kfree_skb(skb);
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break;
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default:
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if (ev->ind_prim) {
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printk(KERN_INFO "%s: received unknown %d prim!\n",
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__func__, ev->ind_prim);
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kfree_skb(skb);
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}
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/* No indication */
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break;
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}
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switch (ev->cfm_prim) {
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case LLC_DATA_PRIM:
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if (!llc_data_accept_state(llc->state))
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sk->sk_write_space(sk);
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else
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rc = llc->failed_data_req = 1;
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break;
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case LLC_CONN_PRIM:
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if (sk->sk_type == SOCK_STREAM &&
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sk->sk_state == TCP_SYN_SENT) {
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if (ev->status) {
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sk->sk_socket->state = SS_UNCONNECTED;
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sk->sk_state = TCP_CLOSE;
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} else {
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sk->sk_socket->state = SS_CONNECTED;
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sk->sk_state = TCP_ESTABLISHED;
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}
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sk->sk_state_change(sk);
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}
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break;
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case LLC_DISC_PRIM:
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sock_hold(sk);
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if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSING) {
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sk->sk_socket->state = SS_UNCONNECTED;
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sk->sk_state = TCP_CLOSE;
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sk->sk_state_change(sk);
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}
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sock_put(sk);
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break;
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case LLC_RESET_PRIM:
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/*
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* FIXME:
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* RESET is not being notified to upper layers for now
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*/
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printk(KERN_INFO "%s: received a reset conf!\n", __func__);
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break;
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default:
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if (ev->cfm_prim) {
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printk(KERN_INFO "%s: received unknown %d prim!\n",
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__func__, ev->cfm_prim);
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break;
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}
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goto out_skb_put; /* No confirmation */
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}
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out_kfree_skb:
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kfree_skb(skb);
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out_skb_put:
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kfree_skb(skb);
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return rc;
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}
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void llc_conn_send_pdu(struct sock *sk, struct sk_buff *skb)
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{
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/* queue PDU to send to MAC layer */
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skb_queue_tail(&sk->sk_write_queue, skb);
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llc_conn_send_pdus(sk);
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}
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/**
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* llc_conn_rtn_pdu - sends received data pdu to upper layer
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* @sk: Active connection
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* @skb: Received data frame
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*
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* Sends received data pdu to upper layer (by using indicate function).
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* Prepares service parameters (prim and prim_data). calling indication
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* function will be done in llc_conn_state_process.
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*/
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void llc_conn_rtn_pdu(struct sock *sk, struct sk_buff *skb)
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{
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struct llc_conn_state_ev *ev = llc_conn_ev(skb);
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ev->ind_prim = LLC_DATA_PRIM;
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}
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/**
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* llc_conn_resend_i_pdu_as_cmd - resend all all unacknowledged I PDUs
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* @sk: active connection
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* @nr: NR
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* @first_p_bit: p_bit value of first pdu
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*
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* Resend all unacknowledged I PDUs, starting with the NR; send first as
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* command PDU with P bit equal first_p_bit; if more than one send
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* subsequent as command PDUs with P bit equal zero (0).
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*/
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void llc_conn_resend_i_pdu_as_cmd(struct sock *sk, u8 nr, u8 first_p_bit)
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{
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struct sk_buff *skb;
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struct llc_pdu_sn *pdu;
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u16 nbr_unack_pdus;
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struct llc_sock *llc;
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u8 howmany_resend = 0;
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llc_conn_remove_acked_pdus(sk, nr, &nbr_unack_pdus);
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if (!nbr_unack_pdus)
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goto out;
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/*
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* Process unack PDUs only if unack queue is not empty; remove
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* appropriate PDUs, fix them up, and put them on mac_pdu_q.
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*/
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llc = llc_sk(sk);
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while ((skb = skb_dequeue(&llc->pdu_unack_q)) != NULL) {
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pdu = llc_pdu_sn_hdr(skb);
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llc_pdu_set_cmd_rsp(skb, LLC_PDU_CMD);
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llc_pdu_set_pf_bit(skb, first_p_bit);
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skb_queue_tail(&sk->sk_write_queue, skb);
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first_p_bit = 0;
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llc->vS = LLC_I_GET_NS(pdu);
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howmany_resend++;
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}
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if (howmany_resend > 0)
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llc->vS = (llc->vS + 1) % LLC_2_SEQ_NBR_MODULO;
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/* any PDUs to re-send are queued up; start sending to MAC */
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llc_conn_send_pdus(sk);
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out:;
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}
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/**
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* llc_conn_resend_i_pdu_as_rsp - Resend all unacknowledged I PDUs
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* @sk: active connection.
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* @nr: NR
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* @first_f_bit: f_bit value of first pdu.
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*
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* Resend all unacknowledged I PDUs, starting with the NR; send first as
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* response PDU with F bit equal first_f_bit; if more than one send
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* subsequent as response PDUs with F bit equal zero (0).
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*/
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void llc_conn_resend_i_pdu_as_rsp(struct sock *sk, u8 nr, u8 first_f_bit)
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{
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struct sk_buff *skb;
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u16 nbr_unack_pdus;
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struct llc_sock *llc = llc_sk(sk);
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u8 howmany_resend = 0;
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llc_conn_remove_acked_pdus(sk, nr, &nbr_unack_pdus);
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if (!nbr_unack_pdus)
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goto out;
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/*
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* Process unack PDUs only if unack queue is not empty; remove
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* appropriate PDUs, fix them up, and put them on mac_pdu_q
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*/
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while ((skb = skb_dequeue(&llc->pdu_unack_q)) != NULL) {
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struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
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llc_pdu_set_cmd_rsp(skb, LLC_PDU_RSP);
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llc_pdu_set_pf_bit(skb, first_f_bit);
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skb_queue_tail(&sk->sk_write_queue, skb);
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first_f_bit = 0;
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llc->vS = LLC_I_GET_NS(pdu);
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howmany_resend++;
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}
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if (howmany_resend > 0)
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llc->vS = (llc->vS + 1) % LLC_2_SEQ_NBR_MODULO;
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/* any PDUs to re-send are queued up; start sending to MAC */
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llc_conn_send_pdus(sk);
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out:;
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}
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/**
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* llc_conn_remove_acked_pdus - Removes acknowledged pdus from tx queue
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* @sk: active connection
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* nr: NR
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* how_many_unacked: size of pdu_unack_q after removing acked pdus
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*
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* Removes acknowledged pdus from transmit queue (pdu_unack_q). Returns
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* the number of pdus that removed from queue.
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*/
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int llc_conn_remove_acked_pdus(struct sock *sk, u8 nr, u16 *how_many_unacked)
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{
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int pdu_pos, i;
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struct sk_buff *skb;
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struct llc_pdu_sn *pdu;
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int nbr_acked = 0;
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struct llc_sock *llc = llc_sk(sk);
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int q_len = skb_queue_len(&llc->pdu_unack_q);
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if (!q_len)
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goto out;
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skb = skb_peek(&llc->pdu_unack_q);
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pdu = llc_pdu_sn_hdr(skb);
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/* finding position of last acked pdu in queue */
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pdu_pos = ((int)LLC_2_SEQ_NBR_MODULO + (int)nr -
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(int)LLC_I_GET_NS(pdu)) % LLC_2_SEQ_NBR_MODULO;
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for (i = 0; i < pdu_pos && i < q_len; i++) {
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skb = skb_dequeue(&llc->pdu_unack_q);
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kfree_skb(skb);
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nbr_acked++;
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}
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out:
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*how_many_unacked = skb_queue_len(&llc->pdu_unack_q);
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return nbr_acked;
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}
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/**
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* llc_conn_send_pdus - Sends queued PDUs
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* @sk: active connection
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*
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* Sends queued pdus to MAC layer for transmission.
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*/
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static void llc_conn_send_pdus(struct sock *sk)
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{
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struct sk_buff *skb;
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while ((skb = skb_dequeue(&sk->sk_write_queue)) != NULL) {
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struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
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if (LLC_PDU_TYPE_IS_I(pdu) &&
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!(skb->dev->flags & IFF_LOOPBACK)) {
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struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
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skb_queue_tail(&llc_sk(sk)->pdu_unack_q, skb);
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if (!skb2)
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break;
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skb = skb2;
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}
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dev_queue_xmit(skb);
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}
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}
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/**
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* llc_conn_service - finds transition and changes state of connection
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* @sk: connection
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* @skb: happened event
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*
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* This function finds transition that matches with happened event, then
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* executes related actions and finally changes state of connection.
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* Returns 0 for success, 1 for failure.
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*/
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static int llc_conn_service(struct sock *sk, struct sk_buff *skb)
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{
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int rc = 1;
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struct llc_sock *llc = llc_sk(sk);
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struct llc_conn_state_trans *trans;
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if (llc->state > NBR_CONN_STATES)
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goto out;
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rc = 0;
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trans = llc_qualify_conn_ev(sk, skb);
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if (trans) {
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rc = llc_exec_conn_trans_actions(sk, trans, skb);
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if (!rc && trans->next_state != NO_STATE_CHANGE) {
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llc->state = trans->next_state;
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if (!llc_data_accept_state(llc->state))
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sk->sk_state_change(sk);
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}
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}
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out:
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return rc;
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}
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/**
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* llc_qualify_conn_ev - finds transition for event
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* @sk: connection
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* @skb: happened event
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*
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* This function finds transition that matches with happened event.
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* Returns pointer to found transition on success, %NULL otherwise.
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*/
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static struct llc_conn_state_trans *llc_qualify_conn_ev(struct sock *sk,
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struct sk_buff *skb)
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{
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struct llc_conn_state_trans **next_trans;
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llc_conn_ev_qfyr_t *next_qualifier;
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struct llc_conn_state_ev *ev = llc_conn_ev(skb);
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struct llc_sock *llc = llc_sk(sk);
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struct llc_conn_state *curr_state =
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&llc_conn_state_table[llc->state - 1];
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/* search thru events for this state until
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* list exhausted or until no more
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*/
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for (next_trans = curr_state->transitions +
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llc_find_offset(llc->state - 1, ev->type);
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(*next_trans)->ev; next_trans++) {
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if (!((*next_trans)->ev)(sk, skb)) {
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/* got POSSIBLE event match; the event may require
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* qualification based on the values of a number of
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* state flags; if all qualifications are met (i.e.,
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* if all qualifying functions return success, or 0,
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* then this is THE event we're looking for
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*/
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for (next_qualifier = (*next_trans)->ev_qualifiers;
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next_qualifier && *next_qualifier &&
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!(*next_qualifier)(sk, skb); next_qualifier++)
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/* nothing */;
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if (!next_qualifier || !*next_qualifier)
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/* all qualifiers executed successfully; this is
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* our transition; return it so we can perform
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* the associated actions & change the state
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*/
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return *next_trans;
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}
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}
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return NULL;
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}
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/**
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* llc_exec_conn_trans_actions - executes related actions
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* @sk: connection
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* @trans: transition that it's actions must be performed
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* @skb: event
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*
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* Executes actions that is related to happened event. Returns 0 for
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* success, 1 to indicate failure of at least one action.
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*/
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static int llc_exec_conn_trans_actions(struct sock *sk,
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struct llc_conn_state_trans *trans,
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struct sk_buff *skb)
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{
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int rc = 0;
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llc_conn_action_t *next_action;
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|
for (next_action = trans->ev_actions;
|
|
next_action && *next_action; next_action++) {
|
|
int rc2 = (*next_action)(sk, skb);
|
|
|
|
if (rc2 == 2) {
|
|
rc = rc2;
|
|
break;
|
|
} else if (rc2)
|
|
rc = 1;
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
static inline bool llc_estab_match(const struct llc_sap *sap,
|
|
const struct llc_addr *daddr,
|
|
const struct llc_addr *laddr,
|
|
const struct sock *sk)
|
|
{
|
|
struct llc_sock *llc = llc_sk(sk);
|
|
|
|
return llc->laddr.lsap == laddr->lsap &&
|
|
llc->daddr.lsap == daddr->lsap &&
|
|
llc_mac_match(llc->laddr.mac, laddr->mac) &&
|
|
llc_mac_match(llc->daddr.mac, daddr->mac);
|
|
}
|
|
|
|
/**
|
|
* __llc_lookup_established - Finds connection for the remote/local sap/mac
|
|
* @sap: SAP
|
|
* @daddr: address of remote LLC (MAC + SAP)
|
|
* @laddr: address of local LLC (MAC + SAP)
|
|
*
|
|
* Search connection list of the SAP and finds connection using the remote
|
|
* mac, remote sap, local mac, and local sap. Returns pointer for
|
|
* connection found, %NULL otherwise.
|
|
* Caller has to make sure local_bh is disabled.
|
|
*/
|
|
static struct sock *__llc_lookup_established(struct llc_sap *sap,
|
|
struct llc_addr *daddr,
|
|
struct llc_addr *laddr)
|
|
{
|
|
struct sock *rc;
|
|
struct hlist_nulls_node *node;
|
|
int slot = llc_sk_laddr_hashfn(sap, laddr);
|
|
struct hlist_nulls_head *laddr_hb = &sap->sk_laddr_hash[slot];
|
|
|
|
rcu_read_lock();
|
|
again:
|
|
sk_nulls_for_each_rcu(rc, node, laddr_hb) {
|
|
if (llc_estab_match(sap, daddr, laddr, rc)) {
|
|
/* Extra checks required by SLAB_DESTROY_BY_RCU */
|
|
if (unlikely(!atomic_inc_not_zero(&rc->sk_refcnt)))
|
|
goto again;
|
|
if (unlikely(llc_sk(rc)->sap != sap ||
|
|
!llc_estab_match(sap, daddr, laddr, rc))) {
|
|
sock_put(rc);
|
|
continue;
|
|
}
|
|
goto found;
|
|
}
|
|
}
|
|
rc = NULL;
|
|
/*
|
|
* if the nulls value we got at the end of this lookup is
|
|
* not the expected one, we must restart lookup.
|
|
* We probably met an item that was moved to another chain.
|
|
*/
|
|
if (unlikely(get_nulls_value(node) != slot))
|
|
goto again;
|
|
found:
|
|
rcu_read_unlock();
|
|
return rc;
|
|
}
|
|
|
|
struct sock *llc_lookup_established(struct llc_sap *sap,
|
|
struct llc_addr *daddr,
|
|
struct llc_addr *laddr)
|
|
{
|
|
struct sock *sk;
|
|
|
|
local_bh_disable();
|
|
sk = __llc_lookup_established(sap, daddr, laddr);
|
|
local_bh_enable();
|
|
return sk;
|
|
}
|
|
|
|
static inline bool llc_listener_match(const struct llc_sap *sap,
|
|
const struct llc_addr *laddr,
|
|
const struct sock *sk)
|
|
{
|
|
struct llc_sock *llc = llc_sk(sk);
|
|
|
|
return sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN &&
|
|
llc->laddr.lsap == laddr->lsap &&
|
|
llc_mac_match(llc->laddr.mac, laddr->mac);
|
|
}
|
|
|
|
static struct sock *__llc_lookup_listener(struct llc_sap *sap,
|
|
struct llc_addr *laddr)
|
|
{
|
|
struct sock *rc;
|
|
struct hlist_nulls_node *node;
|
|
int slot = llc_sk_laddr_hashfn(sap, laddr);
|
|
struct hlist_nulls_head *laddr_hb = &sap->sk_laddr_hash[slot];
|
|
|
|
rcu_read_lock();
|
|
again:
|
|
sk_nulls_for_each_rcu(rc, node, laddr_hb) {
|
|
if (llc_listener_match(sap, laddr, rc)) {
|
|
/* Extra checks required by SLAB_DESTROY_BY_RCU */
|
|
if (unlikely(!atomic_inc_not_zero(&rc->sk_refcnt)))
|
|
goto again;
|
|
if (unlikely(llc_sk(rc)->sap != sap ||
|
|
!llc_listener_match(sap, laddr, rc))) {
|
|
sock_put(rc);
|
|
continue;
|
|
}
|
|
goto found;
|
|
}
|
|
}
|
|
rc = NULL;
|
|
/*
|
|
* if the nulls value we got at the end of this lookup is
|
|
* not the expected one, we must restart lookup.
|
|
* We probably met an item that was moved to another chain.
|
|
*/
|
|
if (unlikely(get_nulls_value(node) != slot))
|
|
goto again;
|
|
found:
|
|
rcu_read_unlock();
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* llc_lookup_listener - Finds listener for local MAC + SAP
|
|
* @sap: SAP
|
|
* @laddr: address of local LLC (MAC + SAP)
|
|
*
|
|
* Search connection list of the SAP and finds connection listening on
|
|
* local mac, and local sap. Returns pointer for parent socket found,
|
|
* %NULL otherwise.
|
|
* Caller has to make sure local_bh is disabled.
|
|
*/
|
|
static struct sock *llc_lookup_listener(struct llc_sap *sap,
|
|
struct llc_addr *laddr)
|
|
{
|
|
static struct llc_addr null_addr;
|
|
struct sock *rc = __llc_lookup_listener(sap, laddr);
|
|
|
|
if (!rc)
|
|
rc = __llc_lookup_listener(sap, &null_addr);
|
|
|
|
return rc;
|
|
}
|
|
|
|
static struct sock *__llc_lookup(struct llc_sap *sap,
|
|
struct llc_addr *daddr,
|
|
struct llc_addr *laddr)
|
|
{
|
|
struct sock *sk = __llc_lookup_established(sap, daddr, laddr);
|
|
|
|
return sk ? : llc_lookup_listener(sap, laddr);
|
|
}
|
|
|
|
/**
|
|
* llc_data_accept_state - designates if in this state data can be sent.
|
|
* @state: state of connection.
|
|
*
|
|
* Returns 0 if data can be sent, 1 otherwise.
|
|
*/
|
|
u8 llc_data_accept_state(u8 state)
|
|
{
|
|
return state != LLC_CONN_STATE_NORMAL && state != LLC_CONN_STATE_BUSY &&
|
|
state != LLC_CONN_STATE_REJ;
|
|
}
|
|
|
|
/**
|
|
* llc_find_next_offset - finds offset for next category of transitions
|
|
* @state: state table.
|
|
* @offset: start offset.
|
|
*
|
|
* Finds offset of next category of transitions in transition table.
|
|
* Returns the start index of next category.
|
|
*/
|
|
static u16 __init llc_find_next_offset(struct llc_conn_state *state, u16 offset)
|
|
{
|
|
u16 cnt = 0;
|
|
struct llc_conn_state_trans **next_trans;
|
|
|
|
for (next_trans = state->transitions + offset;
|
|
(*next_trans)->ev; next_trans++)
|
|
++cnt;
|
|
return cnt;
|
|
}
|
|
|
|
/**
|
|
* llc_build_offset_table - builds offset table of connection
|
|
*
|
|
* Fills offset table of connection state transition table
|
|
* (llc_offset_table).
|
|
*/
|
|
void __init llc_build_offset_table(void)
|
|
{
|
|
struct llc_conn_state *curr_state;
|
|
int state, ev_type, next_offset;
|
|
|
|
for (state = 0; state < NBR_CONN_STATES; state++) {
|
|
curr_state = &llc_conn_state_table[state];
|
|
next_offset = 0;
|
|
for (ev_type = 0; ev_type < NBR_CONN_EV; ev_type++) {
|
|
llc_offset_table[state][ev_type] = next_offset;
|
|
next_offset += llc_find_next_offset(curr_state,
|
|
next_offset) + 1;
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* llc_find_offset - finds start offset of category of transitions
|
|
* @state: state of connection
|
|
* @ev_type: type of happened event
|
|
*
|
|
* Finds start offset of desired category of transitions. Returns the
|
|
* desired start offset.
|
|
*/
|
|
static int llc_find_offset(int state, int ev_type)
|
|
{
|
|
int rc = 0;
|
|
/* at this stage, llc_offset_table[..][2] is not important. it is for
|
|
* init_pf_cycle and I don't know what is it.
|
|
*/
|
|
switch (ev_type) {
|
|
case LLC_CONN_EV_TYPE_PRIM:
|
|
rc = llc_offset_table[state][0]; break;
|
|
case LLC_CONN_EV_TYPE_PDU:
|
|
rc = llc_offset_table[state][4]; break;
|
|
case LLC_CONN_EV_TYPE_SIMPLE:
|
|
rc = llc_offset_table[state][1]; break;
|
|
case LLC_CONN_EV_TYPE_P_TMR:
|
|
case LLC_CONN_EV_TYPE_ACK_TMR:
|
|
case LLC_CONN_EV_TYPE_REJ_TMR:
|
|
case LLC_CONN_EV_TYPE_BUSY_TMR:
|
|
rc = llc_offset_table[state][3]; break;
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* llc_sap_add_socket - adds a socket to a SAP
|
|
* @sap: SAP
|
|
* @sk: socket
|
|
*
|
|
* This function adds a socket to the hash tables of a SAP.
|
|
*/
|
|
void llc_sap_add_socket(struct llc_sap *sap, struct sock *sk)
|
|
{
|
|
struct llc_sock *llc = llc_sk(sk);
|
|
struct hlist_head *dev_hb = llc_sk_dev_hash(sap, llc->dev->ifindex);
|
|
struct hlist_nulls_head *laddr_hb = llc_sk_laddr_hash(sap, &llc->laddr);
|
|
|
|
llc_sap_hold(sap);
|
|
llc_sk(sk)->sap = sap;
|
|
|
|
spin_lock_bh(&sap->sk_lock);
|
|
sap->sk_count++;
|
|
sk_nulls_add_node_rcu(sk, laddr_hb);
|
|
hlist_add_head(&llc->dev_hash_node, dev_hb);
|
|
spin_unlock_bh(&sap->sk_lock);
|
|
}
|
|
|
|
/**
|
|
* llc_sap_remove_socket - removes a socket from SAP
|
|
* @sap: SAP
|
|
* @sk: socket
|
|
*
|
|
* This function removes a connection from the hash tables of a SAP if
|
|
* the connection was in this list.
|
|
*/
|
|
void llc_sap_remove_socket(struct llc_sap *sap, struct sock *sk)
|
|
{
|
|
struct llc_sock *llc = llc_sk(sk);
|
|
|
|
spin_lock_bh(&sap->sk_lock);
|
|
sk_nulls_del_node_init_rcu(sk);
|
|
hlist_del(&llc->dev_hash_node);
|
|
sap->sk_count--;
|
|
spin_unlock_bh(&sap->sk_lock);
|
|
llc_sap_put(sap);
|
|
}
|
|
|
|
/**
|
|
* llc_conn_rcv - sends received pdus to the connection state machine
|
|
* @sk: current connection structure.
|
|
* @skb: received frame.
|
|
*
|
|
* Sends received pdus to the connection state machine.
|
|
*/
|
|
static int llc_conn_rcv(struct sock* sk, struct sk_buff *skb)
|
|
{
|
|
struct llc_conn_state_ev *ev = llc_conn_ev(skb);
|
|
|
|
ev->type = LLC_CONN_EV_TYPE_PDU;
|
|
ev->reason = 0;
|
|
return llc_conn_state_process(sk, skb);
|
|
}
|
|
|
|
static struct sock *llc_create_incoming_sock(struct sock *sk,
|
|
struct net_device *dev,
|
|
struct llc_addr *saddr,
|
|
struct llc_addr *daddr)
|
|
{
|
|
struct sock *newsk = llc_sk_alloc(sock_net(sk), sk->sk_family, GFP_ATOMIC,
|
|
sk->sk_prot);
|
|
struct llc_sock *newllc, *llc = llc_sk(sk);
|
|
|
|
if (!newsk)
|
|
goto out;
|
|
newllc = llc_sk(newsk);
|
|
memcpy(&newllc->laddr, daddr, sizeof(newllc->laddr));
|
|
memcpy(&newllc->daddr, saddr, sizeof(newllc->daddr));
|
|
newllc->dev = dev;
|
|
dev_hold(dev);
|
|
llc_sap_add_socket(llc->sap, newsk);
|
|
llc_sap_hold(llc->sap);
|
|
out:
|
|
return newsk;
|
|
}
|
|
|
|
void llc_conn_handler(struct llc_sap *sap, struct sk_buff *skb)
|
|
{
|
|
struct llc_addr saddr, daddr;
|
|
struct sock *sk;
|
|
|
|
llc_pdu_decode_sa(skb, saddr.mac);
|
|
llc_pdu_decode_ssap(skb, &saddr.lsap);
|
|
llc_pdu_decode_da(skb, daddr.mac);
|
|
llc_pdu_decode_dsap(skb, &daddr.lsap);
|
|
|
|
sk = __llc_lookup(sap, &saddr, &daddr);
|
|
if (!sk)
|
|
goto drop;
|
|
|
|
bh_lock_sock(sk);
|
|
/*
|
|
* This has to be done here and not at the upper layer ->accept
|
|
* method because of the way the PROCOM state machine works:
|
|
* it needs to set several state variables (see, for instance,
|
|
* llc_adm_actions_2 in net/llc/llc_c_st.c) and send a packet to
|
|
* the originator of the new connection, and this state has to be
|
|
* in the newly created struct sock private area. -acme
|
|
*/
|
|
if (unlikely(sk->sk_state == TCP_LISTEN)) {
|
|
struct sock *newsk = llc_create_incoming_sock(sk, skb->dev,
|
|
&saddr, &daddr);
|
|
if (!newsk)
|
|
goto drop_unlock;
|
|
skb_set_owner_r(skb, newsk);
|
|
} else {
|
|
/*
|
|
* Can't be skb_set_owner_r, this will be done at the
|
|
* llc_conn_state_process function, later on, when we will use
|
|
* skb_queue_rcv_skb to send it to upper layers, this is
|
|
* another trick required to cope with how the PROCOM state
|
|
* machine works. -acme
|
|
*/
|
|
skb->sk = sk;
|
|
}
|
|
if (!sock_owned_by_user(sk))
|
|
llc_conn_rcv(sk, skb);
|
|
else {
|
|
dprintk("%s: adding to backlog...\n", __func__);
|
|
llc_set_backlog_type(skb, LLC_PACKET);
|
|
if (sk_add_backlog(sk, skb, sk->sk_rcvbuf))
|
|
goto drop_unlock;
|
|
}
|
|
out:
|
|
bh_unlock_sock(sk);
|
|
sock_put(sk);
|
|
return;
|
|
drop:
|
|
kfree_skb(skb);
|
|
return;
|
|
drop_unlock:
|
|
kfree_skb(skb);
|
|
goto out;
|
|
}
|
|
|
|
#undef LLC_REFCNT_DEBUG
|
|
#ifdef LLC_REFCNT_DEBUG
|
|
static atomic_t llc_sock_nr;
|
|
#endif
|
|
|
|
/**
|
|
* llc_backlog_rcv - Processes rx frames and expired timers.
|
|
* @sk: LLC sock (p8022 connection)
|
|
* @skb: queued rx frame or event
|
|
*
|
|
* This function processes frames that has received and timers that has
|
|
* expired during sending an I pdu (refer to data_req_handler). frames
|
|
* queue by llc_rcv function (llc_mac.c) and timers queue by timer
|
|
* callback functions(llc_c_ac.c).
|
|
*/
|
|
static int llc_backlog_rcv(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
int rc = 0;
|
|
struct llc_sock *llc = llc_sk(sk);
|
|
|
|
if (likely(llc_backlog_type(skb) == LLC_PACKET)) {
|
|
if (likely(llc->state > 1)) /* not closed */
|
|
rc = llc_conn_rcv(sk, skb);
|
|
else
|
|
goto out_kfree_skb;
|
|
} else if (llc_backlog_type(skb) == LLC_EVENT) {
|
|
/* timer expiration event */
|
|
if (likely(llc->state > 1)) /* not closed */
|
|
rc = llc_conn_state_process(sk, skb);
|
|
else
|
|
goto out_kfree_skb;
|
|
} else {
|
|
printk(KERN_ERR "%s: invalid skb in backlog\n", __func__);
|
|
goto out_kfree_skb;
|
|
}
|
|
out:
|
|
return rc;
|
|
out_kfree_skb:
|
|
kfree_skb(skb);
|
|
goto out;
|
|
}
|
|
|
|
/**
|
|
* llc_sk_init - Initializes a socket with default llc values.
|
|
* @sk: socket to initialize.
|
|
*
|
|
* Initializes a socket with default llc values.
|
|
*/
|
|
static void llc_sk_init(struct sock* sk)
|
|
{
|
|
struct llc_sock *llc = llc_sk(sk);
|
|
|
|
llc->state = LLC_CONN_STATE_ADM;
|
|
llc->inc_cntr = llc->dec_cntr = 2;
|
|
llc->dec_step = llc->connect_step = 1;
|
|
|
|
setup_timer(&llc->ack_timer.timer, llc_conn_ack_tmr_cb,
|
|
(unsigned long)sk);
|
|
llc->ack_timer.expire = sysctl_llc2_ack_timeout;
|
|
|
|
setup_timer(&llc->pf_cycle_timer.timer, llc_conn_pf_cycle_tmr_cb,
|
|
(unsigned long)sk);
|
|
llc->pf_cycle_timer.expire = sysctl_llc2_p_timeout;
|
|
|
|
setup_timer(&llc->rej_sent_timer.timer, llc_conn_rej_tmr_cb,
|
|
(unsigned long)sk);
|
|
llc->rej_sent_timer.expire = sysctl_llc2_rej_timeout;
|
|
|
|
setup_timer(&llc->busy_state_timer.timer, llc_conn_busy_tmr_cb,
|
|
(unsigned long)sk);
|
|
llc->busy_state_timer.expire = sysctl_llc2_busy_timeout;
|
|
|
|
llc->n2 = 2; /* max retransmit */
|
|
llc->k = 2; /* tx win size, will adjust dynam */
|
|
llc->rw = 128; /* rx win size (opt and equal to
|
|
* tx_win of remote LLC) */
|
|
skb_queue_head_init(&llc->pdu_unack_q);
|
|
sk->sk_backlog_rcv = llc_backlog_rcv;
|
|
}
|
|
|
|
/**
|
|
* llc_sk_alloc - Allocates LLC sock
|
|
* @family: upper layer protocol family
|
|
* @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc)
|
|
*
|
|
* Allocates a LLC sock and initializes it. Returns the new LLC sock
|
|
* or %NULL if there's no memory available for one
|
|
*/
|
|
struct sock *llc_sk_alloc(struct net *net, int family, gfp_t priority, struct proto *prot)
|
|
{
|
|
struct sock *sk = sk_alloc(net, family, priority, prot);
|
|
|
|
if (!sk)
|
|
goto out;
|
|
llc_sk_init(sk);
|
|
sock_init_data(NULL, sk);
|
|
#ifdef LLC_REFCNT_DEBUG
|
|
atomic_inc(&llc_sock_nr);
|
|
printk(KERN_DEBUG "LLC socket %p created in %s, now we have %d alive\n", sk,
|
|
__func__, atomic_read(&llc_sock_nr));
|
|
#endif
|
|
out:
|
|
return sk;
|
|
}
|
|
|
|
/**
|
|
* llc_sk_free - Frees a LLC socket
|
|
* @sk - socket to free
|
|
*
|
|
* Frees a LLC socket
|
|
*/
|
|
void llc_sk_free(struct sock *sk)
|
|
{
|
|
struct llc_sock *llc = llc_sk(sk);
|
|
|
|
llc->state = LLC_CONN_OUT_OF_SVC;
|
|
/* Stop all (possibly) running timers */
|
|
llc_conn_ac_stop_all_timers(sk, NULL);
|
|
#ifdef DEBUG_LLC_CONN_ALLOC
|
|
printk(KERN_INFO "%s: unackq=%d, txq=%d\n", __func__,
|
|
skb_queue_len(&llc->pdu_unack_q),
|
|
skb_queue_len(&sk->sk_write_queue));
|
|
#endif
|
|
skb_queue_purge(&sk->sk_receive_queue);
|
|
skb_queue_purge(&sk->sk_write_queue);
|
|
skb_queue_purge(&llc->pdu_unack_q);
|
|
#ifdef LLC_REFCNT_DEBUG
|
|
if (atomic_read(&sk->sk_refcnt) != 1) {
|
|
printk(KERN_DEBUG "Destruction of LLC sock %p delayed in %s, cnt=%d\n",
|
|
sk, __func__, atomic_read(&sk->sk_refcnt));
|
|
printk(KERN_DEBUG "%d LLC sockets are still alive\n",
|
|
atomic_read(&llc_sock_nr));
|
|
} else {
|
|
atomic_dec(&llc_sock_nr);
|
|
printk(KERN_DEBUG "LLC socket %p released in %s, %d are still alive\n", sk,
|
|
__func__, atomic_read(&llc_sock_nr));
|
|
}
|
|
#endif
|
|
sock_put(sk);
|
|
}
|
|
|
|
/**
|
|
* llc_sk_reset - resets a connection
|
|
* @sk: LLC socket to reset
|
|
*
|
|
* Resets a connection to the out of service state. Stops its timers
|
|
* and frees any frames in the queues of the connection.
|
|
*/
|
|
void llc_sk_reset(struct sock *sk)
|
|
{
|
|
struct llc_sock *llc = llc_sk(sk);
|
|
|
|
llc_conn_ac_stop_all_timers(sk, NULL);
|
|
skb_queue_purge(&sk->sk_write_queue);
|
|
skb_queue_purge(&llc->pdu_unack_q);
|
|
llc->remote_busy_flag = 0;
|
|
llc->cause_flag = 0;
|
|
llc->retry_count = 0;
|
|
llc_conn_set_p_flag(sk, 0);
|
|
llc->f_flag = 0;
|
|
llc->s_flag = 0;
|
|
llc->ack_pf = 0;
|
|
llc->first_pdu_Ns = 0;
|
|
llc->ack_must_be_send = 0;
|
|
llc->dec_step = 1;
|
|
llc->inc_cntr = 2;
|
|
llc->dec_cntr = 2;
|
|
llc->X = 0;
|
|
llc->failed_data_req = 0 ;
|
|
llc->last_nr = 0;
|
|
}
|