Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*

 *  net/dccp/minisocks.c

 *

 *  An implementation of the DCCP protocol

 *  Arnaldo Carvalho de Melo <acme@conectiva.com.br>

 *

 *      This program is free software; you can redistribute it and/or

 *      modify it under the terms of the GNU General Public License

 *      as published by the Free Software Foundation; either version

 *      2 of the License, or (at your option) any later version.

 */

#include <linux/dccp.h>

#include <linux/kernel.h>

#include <linux/skbuff.h>

#include <linux/timer.h>

#include <net/sock.h>

#include <net/xfrm.h>

#include <net/inet_timewait_sock.h>

#include "ackvec.h"

#include "ccid.h"

#include "dccp.h"

#include "feat.h"

struct inet_timewait_death_row dccp_death_row = {

        .sysctl_max_tw_buckets = NR_FILE * 2,

        .period         = DCCP_TIMEWAIT_LEN / INET_TWDR_TWKILL_SLOTS,

        .death_lock     = __SPIN_LOCK_UNLOCKED(dccp_death_row.death_lock),

        .hashinfo       = &dccp_hashinfo,

        .tw_timer       = TIMER_INITIALIZER(inet_twdr_hangman, 0,

                                            (unsigned long)&dccp_death_row),

        .twkill_work    = __WORK_INITIALIZER(dccp_death_row.twkill_work,

                                             inet_twdr_twkill_work),

/* Short-time timewait calendar */

        .twcal_hand     = -1,

        .twcal_timer    = TIMER_INITIALIZER(inet_twdr_twcal_tick, 0,

                                            (unsigned long)&dccp_death_row),

};

EXPORT_SYMBOL_GPL(dccp_death_row);

void dccp_minisock_init(struct dccp_minisock *dmsk)

{

        dmsk->dccpms_sequence_window = sysctl_dccp_feat_sequence_window;

        dmsk->dccpms_rx_ccid         = sysctl_dccp_feat_rx_ccid;

        dmsk->dccpms_tx_ccid         = sysctl_dccp_feat_tx_ccid;

        dmsk->dccpms_ack_ratio       = sysctl_dccp_feat_ack_ratio;

        dmsk->dccpms_send_ack_vector = sysctl_dccp_feat_send_ack_vector;

        dmsk->dccpms_send_ndp_count  = sysctl_dccp_feat_send_ndp_count;

}

void dccp_time_wait(struct sock *sk, int state, int timeo)

{

        struct inet_timewait_sock *tw = NULL;

        if (dccp_death_row.tw_count < dccp_death_row.sysctl_max_tw_buckets)

                tw = inet_twsk_alloc(sk, state);

        if (tw != NULL) {

                const struct inet_connection_sock *icsk = inet_csk(sk);

                const int rto = (icsk->icsk_rto << 2) - (icsk->icsk_rto >> 1);

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)

                if (tw->tw_family == PF_INET6) {

                        const struct ipv6_pinfo *np = inet6_sk(sk);

                        struct inet6_timewait_sock *tw6;

                        tw->tw_ipv6_offset = inet6_tw_offset(sk->sk_prot);

                        tw6 = inet6_twsk((struct sock *)tw);

                        ipv6_addr_copy(&tw6->tw_v6_daddr, &np->daddr);

                        ipv6_addr_copy(&tw6->tw_v6_rcv_saddr, &np->rcv_saddr);

                        tw->tw_ipv6only = np->ipv6only;

                }

#endif

                /* Linkage updates. */

                __inet_twsk_hashdance(tw, sk, &dccp_hashinfo);

                /* Get the TIME_WAIT timeout firing. */

                if (timeo < rto)

                        timeo = rto;

                tw->tw_timeout = DCCP_TIMEWAIT_LEN;

                if (state == DCCP_TIME_WAIT)

                        timeo = DCCP_TIMEWAIT_LEN;

                inet_twsk_schedule(tw, &dccp_death_row, timeo,

                                   DCCP_TIMEWAIT_LEN);

                inet_twsk_put(tw);

        } else {

                /* Sorry, if we're out of memory, just CLOSE this

                 * socket up.  We've got bigger problems than

                 * non-graceful socket closings.

                 */

                DCCP_WARN("time wait bucket table overflow\n");

        }

        dccp_done(sk);

}

struct sock *dccp_create_openreq_child(struct sock *sk,

                                       const struct request_sock *req,

                                       const struct sk_buff *skb)

{

        /*

         * Step 3: Process LISTEN state

         *

         *   (* Generate a new socket and switch to that socket *)

         *   Set S := new socket for this port pair

         */

        struct sock *newsk = inet_csk_clone(sk, req, GFP_ATOMIC);

        if (newsk != NULL) {

                const struct dccp_request_sock *dreq = dccp_rsk(req);

                struct inet_connection_sock *newicsk = inet_csk(newsk);

                struct dccp_sock *newdp = dccp_sk(newsk);

                struct dccp_minisock *newdmsk = dccp_msk(newsk);

                newdp->dccps_role          = DCCP_ROLE_SERVER;

                newdp->dccps_hc_rx_ackvec  = NULL;

                newdp->dccps_service_list  = NULL;

                newdp->dccps_service       = dreq->dreq_service;

                newicsk->icsk_rto          = DCCP_TIMEOUT_INIT;

                if (dccp_feat_clone(sk, newsk))

                        goto out_free;

                if (newdmsk->dccpms_send_ack_vector) {

                        newdp->dccps_hc_rx_ackvec =

                                                dccp_ackvec_alloc(GFP_ATOMIC);

                        if (unlikely(newdp->dccps_hc_rx_ackvec == NULL))

                                goto out_free;

                }

                newdp->dccps_hc_rx_ccid =

                            ccid_hc_rx_new(newdmsk->dccpms_rx_ccid,

                                           newsk, GFP_ATOMIC);

                newdp->dccps_hc_tx_ccid =

                            ccid_hc_tx_new(newdmsk->dccpms_tx_ccid,

                                           newsk, GFP_ATOMIC);

                if (unlikely(newdp->dccps_hc_rx_ccid == NULL ||

                             newdp->dccps_hc_tx_ccid == NULL)) {

                        dccp_ackvec_free(newdp->dccps_hc_rx_ackvec);

                        ccid_hc_rx_delete(newdp->dccps_hc_rx_ccid, newsk);

                        ccid_hc_tx_delete(newdp->dccps_hc_tx_ccid, newsk);

out_free:

                        /* It is still raw copy of parent, so invalidate

                         * destructor and make plain sk_free() */

                        newsk->sk_destruct = NULL;

                        sk_free(newsk);

                        return NULL;

                }

                /*

                 * Step 3: Process LISTEN state

                 *

                 *    Choose S.ISS (initial seqno) or set from Init Cookies

                 *    Initialize S.GAR := S.ISS

                 *    Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init Cookies

                 */

                /* See dccp_v4_conn_request */

                newdmsk->dccpms_sequence_window = req->rcv_wnd;

                newdp->dccps_gar = newdp->dccps_isr = dreq->dreq_isr;

                dccp_update_gsr(newsk, dreq->dreq_isr);

                newdp->dccps_iss = dreq->dreq_iss;

                dccp_update_gss(newsk, dreq->dreq_iss);

                /*

                 * SWL and AWL are initially adjusted so that they are not less than

                 * the initial Sequence Numbers received and sent, respectively:

                 *      SWL := max(GSR + 1 - floor(W/4), ISR),

                 *      AWL := max(GSS - W' + 1, ISS).

                 * These adjustments MUST be applied only at the beginning of the

                 * connection.

                 */

                dccp_set_seqno(&newdp->dccps_swl,

                               max48(newdp->dccps_swl, newdp->dccps_isr));

                dccp_set_seqno(&newdp->dccps_awl,

                               max48(newdp->dccps_awl, newdp->dccps_iss));

                dccp_init_xmit_timers(newsk);

                DCCP_INC_STATS_BH(DCCP_MIB_PASSIVEOPENS);

        }

        return newsk;

}

EXPORT_SYMBOL_GPL(dccp_create_openreq_child);

/*

 * Process an incoming packet for RESPOND sockets represented

 * as an request_sock.

 */

struct sock *dccp_check_req(struct sock *sk, struct sk_buff *skb,

                            struct request_sock *req,

                            struct request_sock **prev)

{

        struct sock *child = NULL;

        /* Check for retransmitted REQUEST */

        if (dccp_hdr(skb)->dccph_type == DCCP_PKT_REQUEST) {

                struct dccp_request_sock *dreq = dccp_rsk(req);

                if (after48(DCCP_SKB_CB(skb)->dccpd_seq, dreq->dreq_isr)) {

                        dccp_pr_debug("Retransmitted REQUEST\n");

                        dreq->dreq_isr = DCCP_SKB_CB(skb)->dccpd_seq;

                        /*

                         * Send another RESPONSE packet

                         * To protect against Request floods, increment retrans

                         * counter (backoff, monitored by dccp_response_timer).

                         */

                        req->retrans++;

                        req->rsk_ops->rtx_syn_ack(sk, req, NULL);

                }

                /* Network Duplicate, discard packet */

                return NULL;

        }

        DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_PACKET_ERROR;

        if (dccp_hdr(skb)->dccph_type != DCCP_PKT_ACK &&

            dccp_hdr(skb)->dccph_type != DCCP_PKT_DATAACK)

                goto drop;

        /* Invalid ACK */

        if (DCCP_SKB_CB(skb)->dccpd_ack_seq != dccp_rsk(req)->dreq_iss) {

                dccp_pr_debug("Invalid ACK number: ack_seq=%llu, "

                              "dreq_iss=%llu\n",

                              (unsigned long long)

                              DCCP_SKB_CB(skb)->dccpd_ack_seq,

                              (unsigned long long)

                              dccp_rsk(req)->dreq_iss);

                goto drop;

        }

        child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL);

        if (child == NULL)

                goto listen_overflow;

        /* FIXME: deal with options */

        inet_csk_reqsk_queue_unlink(sk, req, prev);

        inet_csk_reqsk_queue_removed(sk, req);

        inet_csk_reqsk_queue_add(sk, req, child);

out:

        return child;

listen_overflow:

        dccp_pr_debug("listen_overflow!\n");

        DCCP_SKB_CB(skb)->dccpd_reset_code = DCCP_RESET_CODE_TOO_BUSY;

drop:

        if (dccp_hdr(skb)->dccph_type != DCCP_PKT_RESET)

                req->rsk_ops->send_reset(sk, skb);

        inet_csk_reqsk_queue_drop(sk, req, prev);

        goto out;

}

EXPORT_SYMBOL_GPL(dccp_check_req);

/*

 *  Queue segment on the new socket if the new socket is active,

 *  otherwise we just shortcircuit this and continue with

 *  the new socket.

 */

int dccp_child_process(struct sock *parent, struct sock *child,

                       struct sk_buff *skb)

{

        int ret = 0;

        const int state = child->sk_state;

        if (!sock_owned_by_user(child)) {

                ret = dccp_rcv_state_process(child, skb, dccp_hdr(skb),

                                             skb->len);

                /* Wakeup parent, send SIGIO */

                if (state == DCCP_RESPOND && child->sk_state != state)

                        parent->sk_data_ready(parent, 0);

        } else {

                /* Alas, it is possible again, because we do lookup

                 * in main socket hash table and lock on listening

                 * socket does not protect us more.

                 */

                sk_add_backlog(child, skb);

        }

        bh_unlock_sock(child);

        sock_put(child);

        return ret;

}

EXPORT_SYMBOL_GPL(dccp_child_process);

void dccp_reqsk_send_ack(struct sk_buff *skb, struct request_sock *rsk)

{

        DCCP_BUG("DCCP-ACK packets are never sent in LISTEN/RESPOND state");

}

EXPORT_SYMBOL_GPL(dccp_reqsk_send_ack);

void dccp_reqsk_init(struct request_sock *req, struct sk_buff *skb)

{

        inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;

        inet_rsk(req)->acked    = 0;

        req->rcv_wnd            = sysctl_dccp_feat_sequence_window;

}

EXPORT_SYMBOL_GPL(dccp_reqsk_init);