1 files changed, 264 insertions, 0 deletions

diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
new file mode 100644
index 000000000000..ce5dff4ac22e
--- /dev/null
+++ b/net/dccp/minisocks.c
@@ -0,0 +1,264 @@
+/*
+ *  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/config.h>
+#include <linux/dccp.h>
+#include <linux/skbuff.h>
+#include <linux/timer.h>
+
+#include <net/sock.h>
+#include <net/xfrm.h>
+#include <net/inet_timewait_sock.h>
+
+#include "ccid.h"
+#include "dccp.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,
+        .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,
+                                             &dccp_death_row),
+/* Short-time timewait calendar */
+
+        .twcal_hand     = -1,
+        .twcal_timer    = TIMER_INITIALIZER(inet_twdr_twcal_tick, 0,
+                                            (unsigned long)&dccp_death_row),
+};
+
+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);
+
+                /* 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.
+                 */
+                LIMIT_NETDEBUG(KERN_INFO "DCCP: 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(sk);
+                struct dccp_sock *newdp = dccp_sk(newsk);
+
+                newdp->dccps_hc_rx_ackpkts = NULL;
+                newdp->dccps_role = DCCP_ROLE_SERVER;
+                newicsk->icsk_rto = DCCP_TIMEOUT_INIT;
+
+                if (newdp->dccps_options.dccpo_send_ack_vector) {
+                        newdp->dccps_hc_rx_ackpkts =
+                                dccp_ackpkts_alloc(DCCP_MAX_ACK_VECTOR_LEN,
+                                                   GFP_ATOMIC);
+                        /*
+                         * XXX: We're using the same CCIDs set on the parent,
+                         * i.e. sk_clone copied the master sock and left the
+                         * CCID pointers for this child, that is why we do the
+                         * __ccid_get calls.
+                         */
+                        if (unlikely(newdp->dccps_hc_rx_ackpkts == NULL))
+                                goto out_free;
+                }
+
+                if (unlikely(ccid_hc_rx_init(newdp->dccps_hc_rx_ccid,
+                                             newsk) != 0 ||
+                             ccid_hc_tx_init(newdp->dccps_hc_tx_ccid,
+                                             newsk) != 0)) {
+                        dccp_ackpkts_free(newdp->dccps_hc_rx_ackpkts);
+                        ccid_hc_rx_exit(newdp->dccps_hc_rx_ccid, newsk);
+                        ccid_hc_tx_exit(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;
+                }
+
+                __ccid_get(newdp->dccps_hc_rx_ccid);
+                __ccid_get(newdp->dccps_hc_tx_ccid);
+
+                /*
+                 * Step 3: Process LISTEN state
+                 *
+                 *      Choose S.ISS (initial seqno) or set from Init Cookie
+                 *      Set S.ISR, S.GSR, S.SWL, S.SWH from packet or Init
+                 *      Cookie
+                 */
+
+                /* See dccp_v4_conn_request */
+                newdp->dccps_options.dccpo_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;
+}
+
+/* 
+ * 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) {
+                if (after48(DCCP_SKB_CB(skb)->dccpd_seq,
+                            dccp_rsk(req)->dreq_isr)) {
+                        struct dccp_request_sock *dreq = dccp_rsk(req);
+
+                        dccp_pr_debug("Retransmitted REQUEST\n");
+                        /* Send another RESPONSE packet */
+                        dccp_set_seqno(&dreq->dreq_iss, dreq->dreq_iss + 1);
+                        dccp_set_seqno(&dreq->dreq_isr,
+                                       DCCP_SKB_CB(skb)->dccpd_seq);
+                        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 = dccp_v4_request_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(skb);
+
+        inet_csk_reqsk_queue_drop(sk, req, prev);
+        goto out;
+}
+
+/*
+ *  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;
+}