From 4d46861be6196d0f1614724590968d8da26af82a Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Tue, 6 Mar 2007 14:24:18 -0800 Subject: [DCCP]: Correctly split CCID half connections This fixes a bug caused by a previous patch, which causes DCCP servers in LISTEN state to not receive packets. This patch changes the logic so that * servers in either LISTEN or OPEN state get the RX half connection packets * clients in OPEN state get the TX half connection packets Signed-off-by: Gerrit Renker Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller --- net/dccp/input.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'net/dccp/input.c') diff --git a/net/dccp/input.c b/net/dccp/input.c index 4dee462f00db..287099f7f042 100644 --- a/net/dccp/input.c +++ b/net/dccp/input.c @@ -256,10 +256,10 @@ int dccp_rcv_established(struct sock *sk, struct sk_buff *skb, * (only one is active at a time); when moving to bidirectional * service, this needs to be revised. */ - if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER) - ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb); - else + if (dccp_sk(sk)->dccps_role == DCCP_ROLE_CLIENT) ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb); + else /* listening or connected server */ + ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb); return __dccp_rcv_established(sk, skb, dh, len); discard: @@ -495,10 +495,10 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, goto discard; /* XXX see the comments in dccp_rcv_established about this */ - if (dccp_sk(sk)->dccps_role == DCCP_ROLE_SERVER) - ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb); - else + if (dccp_sk(sk)->dccps_role == DCCP_ROLE_CLIENT) ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb); + else + ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb); } /* -- cgit v1.2.3 From 151a99317ee9efcfd3e642da62e1edf4f47fcb3e Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Wed, 7 Mar 2007 12:53:48 -0800 Subject: [DCCP]: Revert patch which disables bidirectional mode This reverts an earlier patch which disabled bidirectional mode, meaning that a listening (passive) socket was not allowed to write to the other (active) end of the connection. This mode had been disabled when there were problems with CCID3, but it imposes a constraint on socket programming and thus hinders deployment. A change is included to ignore RX feedback received by the TX CCID3 module. Many thanks to Andre Noll for pointing out this issue. Signed-off-by: Gerrit Renker Signed-off-by: David S. Miller --- net/dccp/ccids/ccid3.c | 7 +------ net/dccp/input.c | 21 ++++----------------- 2 files changed, 5 insertions(+), 23 deletions(-) (limited to 'net/dccp/input.c') diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c index 5361a4d8e13b..746f79d104b3 100644 --- a/net/dccp/ccids/ccid3.c +++ b/net/dccp/ccids/ccid3.c @@ -545,12 +545,7 @@ static void ccid3_hc_tx_packet_recv(struct sock *sk, struct sk_buff *skb) /* set idle flag */ hctx->ccid3hctx_idle = 1; break; - case TFRC_SSTATE_NO_SENT: - /* - * XXX when implementing bidirectional rx/tx check this again - */ - DCCP_WARN("Illegal ACK received - no packet sent\n"); - /* fall through */ + case TFRC_SSTATE_NO_SENT: /* fall through */ case TFRC_SSTATE_TERM: /* ignore feedback when closing */ break; } diff --git a/net/dccp/input.c b/net/dccp/input.c index 287099f7f042..78b043c458bf 100644 --- a/net/dccp/input.c +++ b/net/dccp/input.c @@ -248,18 +248,8 @@ int dccp_rcv_established(struct sock *sk, struct sk_buff *skb, DCCP_ACKVEC_STATE_RECEIVED)) goto discard; - /* - * Deliver to the CCID module in charge. - * FIXME: Currently DCCP operates one-directional only, i.e. a listening - * server is not at the same time a connecting client. There is - * not much sense in delivering to both rx/tx sides at the moment - * (only one is active at a time); when moving to bidirectional - * service, this needs to be revised. - */ - if (dccp_sk(sk)->dccps_role == DCCP_ROLE_CLIENT) - ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb); - else /* listening or connected server */ - ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb); + ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb); + ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb); return __dccp_rcv_established(sk, skb, dh, len); discard: @@ -494,11 +484,8 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, DCCP_ACKVEC_STATE_RECEIVED)) goto discard; - /* XXX see the comments in dccp_rcv_established about this */ - if (dccp_sk(sk)->dccps_role == DCCP_ROLE_CLIENT) - ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb); - else - ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb); + ccid_hc_rx_packet_recv(dp->dccps_hc_rx_ccid, sk, skb); + ccid_hc_tx_packet_recv(dp->dccps_hc_tx_ccid, sk, skb); } /* -- cgit v1.2.3 From 8d13bf9a0bd4984756e234ce54299b92acefab99 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Tue, 20 Mar 2007 13:08:19 -0300 Subject: [DCCP]: Remove ambiguity in the way before48 is used This removes two ambiguities in employing the new definition of before48, following the analysis on http://www.mail-archive.com/dccp@vger.kernel.org/msg01295.html (1) Updating GSR when P.seqno >= S.SWL With the old definition we did not update when P.seqno and S.SWL are 2^47 apart. To ensure the same behaviour as with the old definition, this is replaced with the equivalent condition dccp_delta_seqno(S.SWL, P.seqno) >= 0 (2) Sending SYNC when P.seqno >= S.OSR Here it is debatable whether the new definition causes an ambiguity: the case is similar to (1); and to have consistency with the case (1), we use the equivalent condition dccp_delta_seqno(S.OSR, P.seqno) >= 0 Detailed Justification --- net/dccp/input.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'net/dccp/input.c') diff --git a/net/dccp/input.c b/net/dccp/input.c index 78b043c458bf..a1900157e2d7 100644 --- a/net/dccp/input.c +++ b/net/dccp/input.c @@ -86,7 +86,8 @@ static int dccp_check_seqno(struct sock *sk, struct sk_buff *skb) dh->dccph_type == DCCP_PKT_SYNCACK) { if (between48(DCCP_SKB_CB(skb)->dccpd_ack_seq, dp->dccps_awl, dp->dccps_awh) && - !before48(DCCP_SKB_CB(skb)->dccpd_seq, dp->dccps_swl)) + dccp_delta_seqno(dp->dccps_swl, + DCCP_SKB_CB(skb)->dccpd_seq) >= 0) dccp_update_gsr(sk, DCCP_SKB_CB(skb)->dccpd_seq); else return -1; @@ -203,7 +204,8 @@ static int __dccp_rcv_established(struct sock *sk, struct sk_buff *skb, if (dp->dccps_role != DCCP_ROLE_CLIENT) goto send_sync; check_seq: - if (!before48(DCCP_SKB_CB(skb)->dccpd_seq, dp->dccps_osr)) { + if (dccp_delta_seqno(dp->dccps_osr, + DCCP_SKB_CB(skb)->dccpd_seq) >= 0) { send_sync: dccp_send_sync(sk, DCCP_SKB_CB(skb)->dccpd_seq, DCCP_PKT_SYNC); -- cgit v1.2.3 From 4712a792ee661921374c163eb6a4d06e33fd305f Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Tue, 20 Mar 2007 15:23:18 -0300 Subject: [DCCP]: Provide function for RTT sampling A recurring problem, in particular in the CCID code, is that RTT samples from packets with timestamp echo and elapsed time options need to be taken. This service is provided via a new function dccp_sample_rtt in this patch. Furthermore, to protect against `insane' RTT samples, the sampled value is bounded between 100 microseconds and 4 seconds - for which u32 is sufficient. Signed-off-by: Gerrit Renker Signed-off-by: Ian McDonald Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller --- net/dccp/dccp.h | 10 ++++++++-- net/dccp/input.c | 40 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 48 insertions(+), 2 deletions(-) (limited to 'net/dccp/input.c') diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h index 292f18ef4f61..d8ad27bfe01a 100644 --- a/net/dccp/dccp.h +++ b/net/dccp/dccp.h @@ -71,11 +71,15 @@ extern void dccp_time_wait(struct sock *sk, int state, int timeo); /* RFC 1122, 4.2.3.1 initial RTO value */ #define DCCP_TIMEOUT_INIT ((unsigned)(3 * HZ)) +#define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */ + +/* bounds for sampled RTT values from packet exchanges (in usec) */ +#define DCCP_SANE_RTT_MIN 100 +#define DCCP_SANE_RTT_MAX (4 * USEC_PER_SEC) + /* Maximal interval between probes for local resources. */ #define DCCP_RESOURCE_PROBE_INTERVAL ((unsigned)(HZ / 2U)) -#define DCCP_RTO_MAX ((unsigned)(120 * HZ)) /* FIXME: using TCP value */ - /* sysctl variables for DCCP */ extern int sysctl_dccp_request_retries; extern int sysctl_dccp_retries1; @@ -292,6 +296,8 @@ extern int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, extern int dccp_send_reset(struct sock *sk, enum dccp_reset_codes code); extern void dccp_send_close(struct sock *sk, const int active); extern int dccp_invalid_packet(struct sk_buff *skb); +extern u32 dccp_sample_rtt(struct sock *sk, struct timeval *t_recv, + struct timeval *t_history); static inline int dccp_bad_service_code(const struct sock *sk, const __be32 service) diff --git a/net/dccp/input.c b/net/dccp/input.c index a1900157e2d7..bd578c87b2e7 100644 --- a/net/dccp/input.c +++ b/net/dccp/input.c @@ -577,3 +577,43 @@ discard: } EXPORT_SYMBOL_GPL(dccp_rcv_state_process); + +/** + * dccp_sample_rtt - Sample RTT from packet exchange + * + * @sk: connected dccp_sock + * @t_recv: receive timestamp of packet with timestamp echo + * @t_hist: packet history timestamp or NULL + */ +u32 dccp_sample_rtt(struct sock *sk, struct timeval *t_recv, + struct timeval *t_hist) +{ + struct dccp_sock *dp = dccp_sk(sk); + struct dccp_options_received *or = &dp->dccps_options_received; + suseconds_t delta; + + if (t_hist == NULL) { + if (!or->dccpor_timestamp_echo) { + DCCP_WARN("packet without timestamp echo\n"); + return DCCP_SANE_RTT_MAX; + } + timeval_sub_usecs(t_recv, or->dccpor_timestamp_echo * 10); + delta = timeval_usecs(t_recv); + } else + delta = timeval_delta(t_recv, t_hist); + + delta -= or->dccpor_elapsed_time * 10; /* either set or 0 */ + + if (unlikely(delta <= 0)) { + DCCP_WARN("unusable RTT sample %ld, using min\n", (long)delta); + return DCCP_SANE_RTT_MIN; + } + if (unlikely(delta - (suseconds_t)DCCP_SANE_RTT_MAX > 0)) { + DCCP_WARN("RTT sample %ld too large, using max\n", (long)delta); + return DCCP_SANE_RTT_MAX; + } + + return delta; +} + +EXPORT_SYMBOL_GPL(dccp_sample_rtt); -- cgit v1.2.3 From 89560b53b92a07c529e13a462aa7fd87a844f1f5 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Tue, 20 Mar 2007 15:27:17 -0300 Subject: [DCCP]: Sample RTT from SYN exchange Function: --- include/linux/dccp.h | 2 ++ net/dccp/input.c | 8 ++++++++ net/dccp/options.c | 8 ++++++++ 3 files changed, 18 insertions(+) (limited to 'net/dccp/input.c') diff --git a/include/linux/dccp.h b/include/linux/dccp.h index fdd4217f1047..e668cf531bab 100644 --- a/include/linux/dccp.h +++ b/include/linux/dccp.h @@ -481,10 +481,12 @@ struct dccp_ackvec; * @dccps_hc_rx_insert_options - * @dccps_hc_tx_insert_options - * @dccps_xmit_timer - timer for when CCID is not ready to send + * @dccps_syn_rtt - RTT sample from Request/Response exchange (in usecs) */ struct dccp_sock { /* inet_connection_sock has to be the first member of dccp_sock */ struct inet_connection_sock dccps_inet_connection; +#define dccps_syn_rtt dccps_inet_connection.icsk_ack.lrcvtime __u64 dccps_swl; __u64 dccps_swh; __u64 dccps_awl; diff --git a/net/dccp/input.c b/net/dccp/input.c index bd578c87b2e7..da6ec185ed5b 100644 --- a/net/dccp/input.c +++ b/net/dccp/input.c @@ -300,6 +300,14 @@ static int dccp_rcv_request_sent_state_process(struct sock *sk, if (dccp_parse_options(sk, skb)) goto out_invalid_packet; + /* Obtain RTT sample from SYN exchange (used by CCID 3) */ + if (dp->dccps_options_received.dccpor_timestamp_echo) { + struct timeval now; + + dccp_timestamp(sk, &now); + dp->dccps_syn_rtt = dccp_sample_rtt(sk, &now, NULL); + } + if (dccp_msk(sk)->dccpms_send_ack_vector && dccp_ackvec_add(dp->dccps_hc_rx_ackvec, sk, DCCP_SKB_CB(skb)->dccpd_seq, diff --git a/net/dccp/options.c b/net/dccp/options.c index 9074ca7977b2..14b621227323 100644 --- a/net/dccp/options.c +++ b/net/dccp/options.c @@ -563,6 +563,14 @@ int dccp_insert_options(struct sock *sk, struct sk_buff *skb) dccp_insert_options_feat(sk, skb)) return -1; + /* + * Obtain RTT sample from Request/Response exchange. + * This is currently used in CCID 3 initialisation. + */ + if (DCCP_SKB_CB(skb)->dccpd_type == DCCP_PKT_REQUEST && + dccp_insert_option_timestamp(sk, skb)) + return -1; + /* XXX: insert other options when appropriate */ if (DCCP_SKB_CB(skb)->dccpd_opt_len != 0) { -- cgit v1.2.3