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-rw-r--r--net/dccp/minisocks.c282
1 files changed, 282 insertions, 0 deletions
diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c
new file mode 100644
index 00000000..ea850ce3
--- /dev/null
+++ b/net/dccp/minisocks.c
@@ -0,0 +1,282 @@
+/*
+ * 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/gfp.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_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 IS_ENABLED(CONFIG_IPV6)
+ 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);
+ tw6->tw_v6_daddr = np->daddr;
+ 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_lock(sk, req, GFP_ATOMIC);
+
+ if (newsk != NULL) {
+ struct dccp_request_sock *dreq = dccp_rsk(req);
+ struct inet_connection_sock *newicsk = inet_csk(newsk);
+ struct dccp_sock *newdp = dccp_sk(newsk);
+
+ newdp->dccps_role = DCCP_ROLE_SERVER;
+ newdp->dccps_hc_rx_ackvec = NULL;
+ newdp->dccps_service_list = NULL;
+ newdp->dccps_service = dreq->dreq_service;
+ newdp->dccps_timestamp_echo = dreq->dreq_timestamp_echo;
+ newdp->dccps_timestamp_time = dreq->dreq_timestamp_time;
+ newicsk->icsk_rto = DCCP_TIMEOUT_INIT;
+
+ INIT_LIST_HEAD(&newdp->dccps_featneg);
+ /*
+ * 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 from packet (or Init Cookies)
+ *
+ * Setting AWL/AWH and SWL/SWH happens as part of the feature
+ * activation below, as these windows all depend on the local
+ * and remote Sequence Window feature values (7.5.2).
+ */
+ newdp->dccps_iss = dreq->dreq_iss;
+ newdp->dccps_gss = dreq->dreq_gss;
+ newdp->dccps_gar = newdp->dccps_iss;
+ newdp->dccps_isr = dreq->dreq_isr;
+ newdp->dccps_gsr = dreq->dreq_gsr;
+
+ /*
+ * Activate features: initialise CCIDs, sequence windows etc.
+ */
+ if (dccp_feat_activate_values(newsk, &dreq->dreq_featneg)) {
+ /* It is still raw copy of parent, so invalidate
+ * destructor and make plain sk_free() */
+ newsk->sk_destruct = NULL;
+ sk_free(newsk);
+ return NULL;
+ }
+ 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;
+ struct dccp_request_sock *dreq = dccp_rsk(req);
+
+ /* Check for retransmitted REQUEST */
+ if (dccp_hdr(skb)->dccph_type == DCCP_PKT_REQUEST) {
+
+ if (after48(DCCP_SKB_CB(skb)->dccpd_seq, dreq->dreq_gsr)) {
+ dccp_pr_debug("Retransmitted REQUEST\n");
+ dreq->dreq_gsr = 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 (!between48(DCCP_SKB_CB(skb)->dccpd_ack_seq,
+ dreq->dreq_iss, dreq->dreq_gss)) {
+ dccp_pr_debug("Invalid ACK number: ack_seq=%llu, "
+ "dreq_iss=%llu, dreq_gss=%llu\n",
+ (unsigned long long)
+ DCCP_SKB_CB(skb)->dccpd_ack_seq,
+ (unsigned long long) dreq->dreq_iss,
+ (unsigned long long) dreq->dreq_gss);
+ goto drop;
+ }
+
+ if (dccp_parse_options(sk, dreq, skb))
+ goto drop;
+
+ child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL);
+ if (child == NULL)
+ goto listen_overflow;
+
+ 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 sock *sk, 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);
+
+int dccp_reqsk_init(struct request_sock *req,
+ struct dccp_sock const *dp, struct sk_buff const *skb)
+{
+ struct dccp_request_sock *dreq = dccp_rsk(req);
+
+ inet_rsk(req)->rmt_port = dccp_hdr(skb)->dccph_sport;
+ inet_rsk(req)->loc_port = dccp_hdr(skb)->dccph_dport;
+ inet_rsk(req)->acked = 0;
+ dreq->dreq_timestamp_echo = 0;
+
+ /* inherit feature negotiation options from listening socket */
+ return dccp_feat_clone_list(&dp->dccps_featneg, &dreq->dreq_featneg);
+}
+
+EXPORT_SYMBOL_GPL(dccp_reqsk_init);
generated by cgit (git 2.34.1) at 2024-12-20 11:46:33 +0000