/* * llc_conn.c - Driver routines for connection component. * * Copyright (c) 1997 by Procom Technology, Inc. * 2001-2003 by Arnaldo Carvalho de Melo * * 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 #include #include #include #include #include #include #include #include #include #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; 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; 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 && 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)) 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; }