From 7ad07e7cf343181002c10c39d3f57a88e4903d4f Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Tue, 23 Aug 2005 21:50:06 -0700 Subject: [PATCH] [DCCP]: Implement the CLOSING timer So that we retransmit CLOSE/CLOSEREQ packets till they elicit an answer or we hit a timeout. Most of the machinery uses TCP approaches, this code has to be polished & audited, but this is better than we had before. Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller --- net/dccp/dccp.h | 2 +- net/dccp/input.c | 26 +++++++++++--------------- net/dccp/output.c | 23 ++++++++++++----------- net/dccp/proto.c | 26 ++++++++++++++++++++++---- 4 files changed, 46 insertions(+), 31 deletions(-) diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h index 33968a9..53994f1 100644 --- a/net/dccp/dccp.h +++ b/net/dccp/dccp.h @@ -255,7 +255,7 @@ extern int dccp_v4_checksum(const struct sk_buff *skb, extern int dccp_v4_send_reset(struct sock *sk, enum dccp_reset_codes code); -extern void dccp_send_close(struct sock *sk); +extern void dccp_send_close(struct sock *sk, const int active); struct dccp_skb_cb { __u8 dccpd_type; diff --git a/net/dccp/input.c b/net/dccp/input.c index 8540253..02af05e 100644 --- a/net/dccp/input.c +++ b/net/dccp/input.c @@ -31,14 +31,9 @@ static void dccp_fin(struct sock *sk, struct sk_buff *skb) static void dccp_rcv_close(struct sock *sk, struct sk_buff *skb) { - switch (sk->sk_state) { - case DCCP_PARTOPEN: - case DCCP_OPEN: - dccp_v4_send_reset(sk, DCCP_RESET_CODE_CLOSED); - dccp_fin(sk, skb); - dccp_set_state(sk, DCCP_CLOSED); - break; - } + dccp_v4_send_reset(sk, DCCP_RESET_CODE_CLOSED); + dccp_fin(sk, skb); + dccp_set_state(sk, DCCP_CLOSED); } static void dccp_rcv_closereq(struct sock *sk, struct sk_buff *skb) @@ -54,13 +49,8 @@ static void dccp_rcv_closereq(struct sock *sk, struct sk_buff *skb) return; } - switch (sk->sk_state) { - case DCCP_PARTOPEN: - case DCCP_OPEN: - dccp_set_state(sk, DCCP_CLOSING); - dccp_send_close(sk); - break; - } + dccp_set_state(sk, DCCP_CLOSING); + dccp_send_close(sk, 0); } static inline void dccp_event_ack_recv(struct sock *sk, struct sk_buff *skb) @@ -562,6 +552,12 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_PKT_SYNC); goto discard; + } else if (dh->dccph_type == DCCP_PKT_CLOSEREQ) { + dccp_rcv_closereq(sk, skb); + goto discard; + } else if (dh->dccph_type == DCCP_PKT_CLOSE) { + dccp_rcv_close(sk, skb); + return 0; } switch (sk->sk_state) { diff --git a/net/dccp/output.c b/net/dccp/output.c index 708fc3c..630ca77 100644 --- a/net/dccp/output.c +++ b/net/dccp/output.c @@ -96,8 +96,7 @@ int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb) dh->dccph_checksum = dccp_v4_checksum(skb, inet->saddr, inet->daddr); - if (dcb->dccpd_type == DCCP_PKT_ACK || - dcb->dccpd_type == DCCP_PKT_DATAACK) + if (set_ack) dccp_event_ack_sent(sk); DCCP_INC_STATS(DCCP_MIB_OUTSEGS); @@ -429,18 +428,15 @@ void dccp_send_sync(struct sock *sk, const u64 seq, * cannot be allowed to fail queueing a DCCP_PKT_CLOSE/CLOSEREQ frame under * any circumstances. */ -void dccp_send_close(struct sock *sk) +void dccp_send_close(struct sock *sk, const int active) { struct dccp_sock *dp = dccp_sk(sk); struct sk_buff *skb; + const unsigned int prio = active ? GFP_KERNEL : GFP_ATOMIC; - /* Socket is locked, keep trying until memory is available. */ - for (;;) { - skb = alloc_skb(sk->sk_prot->max_header, GFP_KERNEL); - if (skb != NULL) - break; - yield(); - } + skb = alloc_skb(sk->sk_prot->max_header, prio); + if (skb == NULL) + return; /* Reserve space for headers and prepare control bits. */ skb_reserve(skb, sk->sk_prot->max_header); @@ -449,7 +445,12 @@ void dccp_send_close(struct sock *sk) DCCP_PKT_CLOSE : DCCP_PKT_CLOSEREQ; skb_set_owner_w(skb, sk); - dccp_transmit_skb(sk, skb); + if (active) { + BUG_TRAP(sk->sk_send_head == NULL); + sk->sk_send_head = skb; + dccp_transmit_skb(sk, skb_clone(skb, prio)); + } else + dccp_transmit_skb(sk, skb); ccid_hc_rx_exit(dp->dccps_hc_rx_ccid, sk); ccid_hc_tx_exit(dp->dccps_hc_tx_ccid, sk); diff --git a/net/dccp/proto.c b/net/dccp/proto.c index 8b613c3..a3f8a80 100644 --- a/net/dccp/proto.c +++ b/net/dccp/proto.c @@ -402,12 +402,15 @@ void dccp_close(struct sock *sk, long timeout) /* Check zero linger _after_ checking for unread data. */ sk->sk_prot->disconnect(sk, 0); } else if (dccp_close_state(sk)) { - dccp_send_close(sk); + dccp_send_close(sk, 1); } sk_stream_wait_close(sk, timeout); adjudge_to_death: + /* + * It is the last release_sock in its life. It will remove backlog. + */ release_sock(sk); /* * Now socket is owned by kernel and we acquire BH lock @@ -419,11 +422,26 @@ adjudge_to_death: sock_hold(sk); sock_orphan(sk); - - if (sk->sk_state != DCCP_CLOSED) + + /* + * The last release_sock may have processed the CLOSE or RESET + * packet moving sock to CLOSED state, if not we have to fire + * the CLOSE/CLOSEREQ retransmission timer, see "8.3. Termination" + * in draft-ietf-dccp-spec-11. -acme + */ + if (sk->sk_state == DCCP_CLOSING) { + /* FIXME: should start at 2 * RTT */ + /* Timer for repeating the CLOSE/CLOSEREQ until an answer. */ + inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, + inet_csk(sk)->icsk_rto, + DCCP_RTO_MAX); +#if 0 + /* Yeah, we should use sk->sk_prot->orphan_count, etc */ dccp_set_state(sk, DCCP_CLOSED); +#endif + } - atomic_inc(&dccp_orphan_count); + atomic_inc(sk->sk_prot->orphan_count); if (sk->sk_state == DCCP_CLOSED) inet_csk_destroy_sock(sk); -- 2.7.4