--- /dev/null
+/*
+ * llc_conn.c - Driver routines for connection component.
+ *
+ * Copyright (c) 1997 by Procom Technology, Inc.
+ * 2001-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
+ *
+ * This program can be redistributed or modified under the terms of the
+ * GNU General Public License as published by the Free Software Foundation.
+ * This program is distributed without any warranty or implied warranty
+ * of merchantability or fitness for a particular purpose.
+ *
+ * See the GNU General Public License for more details.
+ */
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <net/llc_sap.h>
+#include <net/llc_conn.h>
+#include <net/sock.h>
+#include <net/tcp_states.h>
+#include <net/llc_c_ev.h>
+#include <net/llc_c_ac.h>
+#include <net/llc_c_st.h>
+#include <net/llc_pdu.h>
+
+#if 0
+#define dprintk(args...) printk(KERN_DEBUG args)
+#else
+#define dprintk(args...)
+#endif
+
+static int llc_find_offset(int state, int ev_type);
+static void llc_conn_send_pdus(struct sock *sk);
+static int llc_conn_service(struct sock *sk, struct sk_buff *skb);
+static int llc_exec_conn_trans_actions(struct sock *sk,
+ struct llc_conn_state_trans *trans,
+ struct sk_buff *ev);
+static struct llc_conn_state_trans *llc_qualify_conn_ev(struct sock *sk,
+ struct sk_buff *skb);
+
+/* Offset table on connection states transition diagram */
+static int llc_offset_table[NBR_CONN_STATES][NBR_CONN_EV];
+
+int sysctl_llc2_ack_timeout = LLC2_ACK_TIME * HZ;
+int sysctl_llc2_p_timeout = LLC2_P_TIME * HZ;
+int sysctl_llc2_rej_timeout = LLC2_REJ_TIME * HZ;
+int sysctl_llc2_busy_timeout = LLC2_BUSY_TIME * HZ;
+
+/**
+ * llc_conn_state_process - sends event to connection state machine
+ * @sk: connection
+ * @skb: occurred event
+ *
+ * Sends an event to connection state machine. After processing event
+ * (executing it's actions and changing state), upper layer will be
+ * indicated or confirmed, if needed. Returns 0 for success, 1 for
+ * failure. The socket lock has to be held before calling this function.
+ */
+int llc_conn_state_process(struct sock *sk, struct sk_buff *skb)
+{
+ int rc;
+ struct llc_sock *llc = llc_sk(skb->sk);
+ struct llc_conn_state_ev *ev = llc_conn_ev(skb);
+
+ /*
+ * We have to hold the skb, because llc_conn_service will kfree it in
+ * the sending path and we need to look at the skb->cb, where we encode
+ * llc_conn_state_ev.
+ */
+ skb_get(skb);
+ ev->ind_prim = ev->cfm_prim = 0;
+ /*
+ * Send event to state machine
+ */
+ rc = llc_conn_service(skb->sk, skb);
+ if (unlikely(rc != 0)) {
+ printk(KERN_ERR "%s: llc_conn_service failed\n", __func__);
+ goto out_kfree_skb;
+ }
+
+ if (unlikely(!ev->ind_prim && !ev->cfm_prim)) {
+ /* indicate or confirm not required */
+ if (!skb->next)
+ goto out_kfree_skb;
+ goto out_skb_put;
+ }
+
+ if (unlikely(ev->ind_prim && ev->cfm_prim)) /* Paranoia */
+ skb_get(skb);
+
+ switch (ev->ind_prim) {
+ case LLC_DATA_PRIM:
+ llc_save_primitive(sk, skb, LLC_DATA_PRIM);
+ if (unlikely(sock_queue_rcv_skb(sk, skb))) {
+ /*
+ * shouldn't happen
+ */
+ printk(KERN_ERR "%s: sock_queue_rcv_skb failed!\n",
+ __func__);
+ kfree_skb(skb);
+ }
+ break;
+ case LLC_CONN_PRIM:
+ /*
+ * Can't be sock_queue_rcv_skb, because we have to leave the
+ * skb->sk pointing to the newly created struct sock in
+ * llc_conn_handler. -acme
+ */
+ skb_queue_tail(&sk->sk_receive_queue, skb);
+ sk->sk_state_change(sk);
+ break;
+ case LLC_DISC_PRIM:
+ sock_hold(sk);
+ if (sk->sk_type == SOCK_STREAM &&
+ sk->sk_state == TCP_ESTABLISHED) {
+ sk->sk_shutdown = SHUTDOWN_MASK;
+ sk->sk_socket->state = SS_UNCONNECTED;
+ sk->sk_state = TCP_CLOSE;
+ if (!sock_flag(sk, SOCK_DEAD)) {
+ sock_set_flag(sk, SOCK_DEAD);
+ sk->sk_state_change(sk);
+ }
+ }
+ kfree_skb(skb);
+ sock_put(sk);
+ break;
+ case LLC_RESET_PRIM:
+ /*
+ * FIXME:
+ * RESET is not being notified to upper layers for now
+ */
+ printk(KERN_INFO "%s: received a reset ind!\n", __func__);
+ kfree_skb(skb);
+ break;
+ default:
+ if (ev->ind_prim) {
+ printk(KERN_INFO "%s: received unknown %d prim!\n",
+ __func__, ev->ind_prim);
+ kfree_skb(skb);
+ }
+ /* No indication */
+ break;
+ }
+
+ switch (ev->cfm_prim) {
+ case LLC_DATA_PRIM:
+ if (!llc_data_accept_state(llc->state))
+ sk->sk_write_space(sk);
+ else
+ rc = llc->failed_data_req = 1;
+ break;
+ case LLC_CONN_PRIM:
+ if (sk->sk_type == SOCK_STREAM &&
+ sk->sk_state == TCP_SYN_SENT) {
+ if (ev->status) {
+ sk->sk_socket->state = SS_UNCONNECTED;
+ sk->sk_state = TCP_CLOSE;
+ } else {
+ sk->sk_socket->state = SS_CONNECTED;
+ sk->sk_state = TCP_ESTABLISHED;
+ }
+ sk->sk_state_change(sk);
+ }
+ break;
+ case LLC_DISC_PRIM:
+ sock_hold(sk);
+ if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSING) {
+ sk->sk_socket->state = SS_UNCONNECTED;
+ sk->sk_state = TCP_CLOSE;
+ sk->sk_state_change(sk);
+ }
+ sock_put(sk);
+ break;
+ case LLC_RESET_PRIM:
+ /*
+ * FIXME:
+ * RESET is not being notified to upper layers for now
+ */
+ printk(KERN_INFO "%s: received a reset conf!\n", __func__);
+ break;
+ default:
+ if (ev->cfm_prim) {
+ printk(KERN_INFO "%s: received unknown %d prim!\n",
+ __func__, ev->cfm_prim);
+ break;
+ }
+ goto out_skb_put; /* No confirmation */
+ }
+out_kfree_skb:
+ kfree_skb(skb);
+out_skb_put:
+ kfree_skb(skb);
+ return rc;
+}
+
+void llc_conn_send_pdu(struct sock *sk, struct sk_buff *skb)
+{
+ /* queue PDU to send to MAC layer */
+ skb_queue_tail(&sk->sk_write_queue, skb);
+ llc_conn_send_pdus(sk);
+}
+
+/**
+ * llc_conn_rtn_pdu - sends received data pdu to upper layer
+ * @sk: Active connection
+ * @skb: Received data frame
+ *
+ * Sends received data pdu to upper layer (by using indicate function).
+ * Prepares service parameters (prim and prim_data). calling indication
+ * function will be done in llc_conn_state_process.
+ */
+void llc_conn_rtn_pdu(struct sock *sk, struct sk_buff *skb)
+{
+ struct llc_conn_state_ev *ev = llc_conn_ev(skb);
+
+ ev->ind_prim = LLC_DATA_PRIM;
+}
+
+/**
+ * llc_conn_resend_i_pdu_as_cmd - resend all all unacknowledged I PDUs
+ * @sk: active connection
+ * @nr: NR
+ * @first_p_bit: p_bit value of first pdu
+ *
+ * Resend all unacknowledged I PDUs, starting with the NR; send first as
+ * command PDU with P bit equal first_p_bit; if more than one send
+ * subsequent as command PDUs with P bit equal zero (0).
+ */
+void llc_conn_resend_i_pdu_as_cmd(struct sock *sk, u8 nr, u8 first_p_bit)
+{
+ struct sk_buff *skb;
+ struct llc_pdu_sn *pdu;
+ u16 nbr_unack_pdus;
+ struct llc_sock *llc;
+ u8 howmany_resend = 0;
+
+ llc_conn_remove_acked_pdus(sk, nr, &nbr_unack_pdus);
+ if (!nbr_unack_pdus)
+ goto out;
+ /*
+ * Process unack PDUs only if unack queue is not empty; remove
+ * appropriate PDUs, fix them up, and put them on mac_pdu_q.
+ */
+ llc = llc_sk(sk);
+
+ while ((skb = skb_dequeue(&llc->pdu_unack_q)) != NULL) {
+ pdu = llc_pdu_sn_hdr(skb);
+ llc_pdu_set_cmd_rsp(skb, LLC_PDU_CMD);
+ llc_pdu_set_pf_bit(skb, first_p_bit);
+ skb_queue_tail(&sk->sk_write_queue, skb);
+ first_p_bit = 0;
+ llc->vS = LLC_I_GET_NS(pdu);
+ howmany_resend++;
+ }
+ if (howmany_resend > 0)
+ llc->vS = (llc->vS + 1) % LLC_2_SEQ_NBR_MODULO;
+ /* any PDUs to re-send are queued up; start sending to MAC */
+ llc_conn_send_pdus(sk);
+out:;
+}
+
+/**
+ * llc_conn_resend_i_pdu_as_rsp - Resend all unacknowledged I PDUs
+ * @sk: active connection.
+ * @nr: NR
+ * @first_f_bit: f_bit value of first pdu.
+ *
+ * Resend all unacknowledged I PDUs, starting with the NR; send first as
+ * response PDU with F bit equal first_f_bit; if more than one send
+ * subsequent as response PDUs with F bit equal zero (0).
+ */
+void llc_conn_resend_i_pdu_as_rsp(struct sock *sk, u8 nr, u8 first_f_bit)
+{
+ struct sk_buff *skb;
+ u16 nbr_unack_pdus;
+ struct llc_sock *llc = llc_sk(sk);
+ u8 howmany_resend = 0;
+
+ llc_conn_remove_acked_pdus(sk, nr, &nbr_unack_pdus);
+ if (!nbr_unack_pdus)
+ goto out;
+ /*
+ * Process unack PDUs only if unack queue is not empty; remove
+ * appropriate PDUs, fix them up, and put them on mac_pdu_q
+ */
+ while ((skb = skb_dequeue(&llc->pdu_unack_q)) != NULL) {
+ struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
+
+ llc_pdu_set_cmd_rsp(skb, LLC_PDU_RSP);
+ llc_pdu_set_pf_bit(skb, first_f_bit);
+ skb_queue_tail(&sk->sk_write_queue, skb);
+ first_f_bit = 0;
+ llc->vS = LLC_I_GET_NS(pdu);
+ howmany_resend++;
+ }
+ if (howmany_resend > 0)
+ llc->vS = (llc->vS + 1) % LLC_2_SEQ_NBR_MODULO;
+ /* any PDUs to re-send are queued up; start sending to MAC */
+ llc_conn_send_pdus(sk);
+out:;
+}
+
+/**
+ * llc_conn_remove_acked_pdus - Removes acknowledged pdus from tx queue
+ * @sk: active connection
+ * nr: NR
+ * how_many_unacked: size of pdu_unack_q after removing acked pdus
+ *
+ * Removes acknowledged pdus from transmit queue (pdu_unack_q). Returns
+ * the number of pdus that removed from queue.
+ */
+int llc_conn_remove_acked_pdus(struct sock *sk, u8 nr, u16 *how_many_unacked)
+{
+ int pdu_pos, i;
+ struct sk_buff *skb;
+ struct llc_pdu_sn *pdu;
+ int nbr_acked = 0;
+ struct llc_sock *llc = llc_sk(sk);
+ int q_len = skb_queue_len(&llc->pdu_unack_q);
+
+ if (!q_len)
+ goto out;
+ skb = skb_peek(&llc->pdu_unack_q);
+ pdu = llc_pdu_sn_hdr(skb);
+
+ /* finding position of last acked pdu in queue */
+ pdu_pos = ((int)LLC_2_SEQ_NBR_MODULO + (int)nr -
+ (int)LLC_I_GET_NS(pdu)) % LLC_2_SEQ_NBR_MODULO;
+
+ for (i = 0; i < pdu_pos && i < q_len; i++) {
+ skb = skb_dequeue(&llc->pdu_unack_q);
+ kfree_skb(skb);
+ nbr_acked++;
+ }
+out:
+ *how_many_unacked = skb_queue_len(&llc->pdu_unack_q);
+ return nbr_acked;
+}
+
+/**
+ * llc_conn_send_pdus - Sends queued PDUs
+ * @sk: active connection
+ *
+ * Sends queued pdus to MAC layer for transmission.
+ */
+static void llc_conn_send_pdus(struct sock *sk)
+{
+ struct sk_buff *skb;
+
+ while ((skb = skb_dequeue(&sk->sk_write_queue)) != NULL) {
+ struct llc_pdu_sn *pdu = llc_pdu_sn_hdr(skb);
+
+ if (LLC_PDU_TYPE_IS_I(pdu) &&
+ !(skb->dev->flags & IFF_LOOPBACK)) {
+ struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
+
+ skb_queue_tail(&llc_sk(sk)->pdu_unack_q, skb);
+ if (!skb2)
+ break;
+ skb = skb2;
+ }
+ dev_queue_xmit(skb);
+ }
+}
+
+/**
+ * llc_conn_service - finds transition and changes state of connection
+ * @sk: connection
+ * @skb: happened event
+ *
+ * This function finds transition that matches with happened event, then
+ * executes related actions and finally changes state of connection.
+ * Returns 0 for success, 1 for failure.
+ */
+static int llc_conn_service(struct sock *sk, struct sk_buff *skb)
+{
+ int rc = 1;
+ struct llc_sock *llc = llc_sk(sk);
+ struct llc_conn_state_trans *trans;
+
+ if (llc->state > NBR_CONN_STATES)
+ goto out;
+ rc = 0;
+ trans = llc_qualify_conn_ev(sk, skb);
+ if (trans) {
+ rc = llc_exec_conn_trans_actions(sk, trans, skb);
+ if (!rc && trans->next_state != NO_STATE_CHANGE) {
+ llc->state = trans->next_state;
+ if (!llc_data_accept_state(llc->state))
+ sk->sk_state_change(sk);
+ }
+ }
+out:
+ return rc;
+}
+
+/**
+ * llc_qualify_conn_ev - finds transition for event
+ * @sk: connection
+ * @skb: happened event
+ *
+ * This function finds transition that matches with happened event.
+ * Returns pointer to found transition on success, %NULL otherwise.
+ */
+static struct llc_conn_state_trans *llc_qualify_conn_ev(struct sock *sk,
+ struct sk_buff *skb)
+{
+ struct llc_conn_state_trans **next_trans;
+ const llc_conn_ev_qfyr_t *next_qualifier;
+ struct llc_conn_state_ev *ev = llc_conn_ev(skb);
+ struct llc_sock *llc = llc_sk(sk);
+ struct llc_conn_state *curr_state =
+ &llc_conn_state_table[llc->state - 1];
+
+ /* search thru events for this state until
+ * list exhausted or until no more
+ */
+ for (next_trans = curr_state->transitions +
+ llc_find_offset(llc->state - 1, ev->type);
+ (*next_trans)->ev; next_trans++) {
+ if (!((*next_trans)->ev)(sk, skb)) {
+ /* got POSSIBLE event match; the event may require
+ * qualification based on the values of a number of
+ * state flags; if all qualifications are met (i.e.,
+ * if all qualifying functions return success, or 0,
+ * then this is THE event we're looking for
+ */
+ for (next_qualifier = (*next_trans)->ev_qualifiers;
+ next_qualifier && *next_qualifier &&
+ !(*next_qualifier)(sk, skb); next_qualifier++)
+ /* nothing */;
+ if (!next_qualifier || !*next_qualifier)
+ /* all qualifiers executed successfully; this is
+ * our transition; return it so we can perform
+ * the associated actions & change the state
+ */
+ return *next_trans;
+ }
+ }
+ return NULL;
+}
+
+/**
+ * llc_exec_conn_trans_actions - executes related actions
+ * @sk: connection
+ * @trans: transition that it's actions must be performed
+ * @skb: event
+ *
+ * Executes actions that is related to happened event. Returns 0 for
+ * success, 1 to indicate failure of at least one action.
+ */
+static int llc_exec_conn_trans_actions(struct sock *sk,
+ struct llc_conn_state_trans *trans,
+ struct sk_buff *skb)
+{
+ int rc = 0;
+ const llc_conn_action_t *next_action;
+
+ 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 &&
+ ether_addr_equal(llc->laddr.mac, laddr->mac) &&
+ ether_addr_equal(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 &&
+ ether_addr_equal(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;
+}
Code Review / kvmfornfv.git / blobdiff