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1020 lines
27 KiB
1020 lines
27 KiB
/* |
|
* llc_conn.c - Driver routines for connection component. |
|
* |
|
* Copyright (c) 1997 by Procom Technology, Inc. |
|
* 2001-2003 by Arnaldo Carvalho de Melo <[email protected]> |
|
* |
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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. |
|
* This program is distributed without any warranty or implied warranty |
|
* 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> |
|
#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> |
|
#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> |
|
|
|
#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); |
|
static void llc_conn_send_pdus(struct sock *sk); |
|
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 */ |
|
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; |
|
|
|
/** |
|
* 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 |
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* (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. |
|
* |
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* This function always consumes a reference to the skb. |
|
*/ |
|
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); |
|
|
|
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_skb_put; |
|
} |
|
|
|
switch (ev->ind_prim) { |
|
case LLC_DATA_PRIM: |
|
skb_get(skb); |
|
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 |
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* llc_conn_handler. -acme |
|
*/ |
|
skb_get(skb); |
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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; |
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sk->sk_state = TCP_CLOSE; |
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if (!sock_flag(sk, SOCK_DEAD)) { |
|
sock_set_flag(sk, SOCK_DEAD); |
|
sk->sk_state_change(sk); |
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} |
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} |
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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__); |
|
break; |
|
default: |
|
if (ev->ind_prim) |
|
printk(KERN_INFO "%s: received unknown %d prim!\n", |
|
__func__, ev->ind_prim); |
|
/* No indication */ |
|
break; |
|
} |
|
|
|
switch (ev->cfm_prim) { |
|
case LLC_DATA_PRIM: |
|
if (!llc_data_accept_state(llc->state)) |
|
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; |
|
case LLC_CONN_PRIM: |
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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; |
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} else { |
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sk->sk_socket->state = SS_CONNECTED; |
|
sk->sk_state = TCP_ESTABLISHED; |
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} |
|
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); |
|
/* No confirmation */ |
|
break; |
|
} |
|
out_skb_put: |
|
kfree_skb(skb); |
|
return rc; |
|
} |
|
|
|
void llc_conn_send_pdu(struct sock *sk, struct sk_buff *skb) |
|
{ |
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/* queue PDU to send to MAC layer */ |
|
skb_queue_tail(&sk->sk_write_queue, skb); |
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llc_conn_send_pdus(sk); |
|
} |
|
|
|
/** |
|
* llc_conn_rtn_pdu - sends received data pdu to upper layer |
|
* @sk: Active connection |
|
* @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. |
|
*/ |
|
void llc_conn_rtn_pdu(struct sock *sk, struct sk_buff *skb) |
|
{ |
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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 |
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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; |
|
struct llc_sock *llc; |
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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); |
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llc_pdu_set_pf_bit(skb, first_p_bit); |
|
skb_queue_tail(&sk->sk_write_queue, skb); |
|
first_p_bit = 0; |
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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 */ |
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llc_conn_send_pdus(sk); |
|
out:; |
|
} |
|
|
|
/** |
|
* llc_conn_resend_i_pdu_as_rsp - Resend all unacknowledged I PDUs |
|
* @sk: active connection. |
|
* @nr: NR |
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* @first_f_bit: f_bit value of first pdu. |
|
* |
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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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void llc_conn_resend_i_pdu_as_rsp(struct sock *sk, u8 nr, u8 first_f_bit) |
|
{ |
|
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; |
|
|
|
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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* Process unack PDUs only if unack queue is not empty; remove |
|
* appropriate PDUs, fix them up, and put them on mac_pdu_q |
|
*/ |
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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; |
|
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 |
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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) |
|
{ |
|
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_TYPESAFE_BY_RCU */ |
|
if (unlikely(!refcount_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_TYPESAFE_BY_RCU */ |
|
if (unlikely(!refcount_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); |
|
sock_set_flag(sk, SOCK_RCU_FREE); |
|
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, 0); |
|
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_orphan(skb); |
|
sock_hold(sk); |
|
skb->sk = sk; |
|
skb->destructor = sock_efree; |
|
} |
|
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, READ_ONCE(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; |
|
|
|
timer_setup(&llc->ack_timer.timer, llc_conn_ack_tmr_cb, 0); |
|
llc->ack_timer.expire = sysctl_llc2_ack_timeout; |
|
|
|
timer_setup(&llc->pf_cycle_timer.timer, llc_conn_pf_cycle_tmr_cb, 0); |
|
llc->pf_cycle_timer.expire = sysctl_llc2_p_timeout; |
|
|
|
timer_setup(&llc->rej_sent_timer.timer, llc_conn_rej_tmr_cb, 0); |
|
llc->rej_sent_timer.expire = sysctl_llc2_rej_timeout; |
|
|
|
timer_setup(&llc->busy_state_timer.timer, llc_conn_busy_tmr_cb, 0); |
|
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 |
|
* @net: network namespace |
|
* @family: upper layer protocol family |
|
* @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc) |
|
* @prot: struct proto associated with this new sock instance |
|
* @kern: is this to be a kernel socket? |
|
* |
|
* 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, int kern) |
|
{ |
|
struct sock *sk = sk_alloc(net, family, priority, prot, kern); |
|
|
|
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; |
|
} |
|
|
|
void llc_sk_stop_all_timers(struct sock *sk, bool sync) |
|
{ |
|
struct llc_sock *llc = llc_sk(sk); |
|
|
|
if (sync) { |
|
del_timer_sync(&llc->pf_cycle_timer.timer); |
|
del_timer_sync(&llc->ack_timer.timer); |
|
del_timer_sync(&llc->rej_sent_timer.timer); |
|
del_timer_sync(&llc->busy_state_timer.timer); |
|
} else { |
|
del_timer(&llc->pf_cycle_timer.timer); |
|
del_timer(&llc->ack_timer.timer); |
|
del_timer(&llc->rej_sent_timer.timer); |
|
del_timer(&llc->busy_state_timer.timer); |
|
} |
|
|
|
llc->ack_must_be_send = 0; |
|
llc->ack_pf = 0; |
|
} |
|
|
|
/** |
|
* 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_sk_stop_all_timers(sk, true); |
|
#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 (refcount_read(&sk->sk_refcnt) != 1) { |
|
printk(KERN_DEBUG "Destruction of LLC sock %p delayed in %s, cnt=%d\n", |
|
sk, __func__, refcount_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; |
|
}
|
|
|