From 2cf5be93d1b704f342ad423a49f0e78d73939e66 Mon Sep 17 00:00:00 2001 From: Samuel Jero Date: Thu, 30 Dec 2010 12:15:16 +0100 Subject: [PATCH 1/3] dccp: fix return value for sequence-invalid packets Currently dccp_check_seqno returns 0 (indicating a valid packet) if the acknowledgment number is out of bounds and the sync that RFC 4340 mandates at this point is currently being rate-limited. This function should return -1, indicating an invalid packet. Signed-off-by: Samuel Jero Acked-by: Gerrit Renker --- net/dccp/input.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/dccp/input.c b/net/dccp/input.c index 15af247ea007..8cde009e8b85 100644 --- a/net/dccp/input.c +++ b/net/dccp/input.c @@ -260,7 +260,7 @@ static int dccp_check_seqno(struct sock *sk, struct sk_buff *skb) */ if (time_before(now, (dp->dccps_rate_last + sysctl_dccp_sync_ratelimit))) - return 0; + return -1; DCCP_WARN("Step 6 failed for %s packet, " "(LSWL(%llu) <= P.seqno(%llu) <= S.SWH(%llu)) and " From 763dadd47c884853a22f2f19ea27e58431303ff3 Mon Sep 17 00:00:00 2001 From: Samuel Jero Date: Thu, 30 Dec 2010 12:15:41 +0100 Subject: [PATCH 2/3] dccp: fix bug in updating the GSR Currently dccp_check_seqno allows any valid packet to update the Greatest Sequence Number Received, even if that packet's sequence number is less than the current GSR. This patch adds a check to make sure that the new packet's sequence number is greater than GSR. Signed-off-by: Samuel Jero Signed-off-by: Gerrit Renker --- net/dccp/dccp.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h index 45087052d894..5fdb07229017 100644 --- a/net/dccp/dccp.h +++ b/net/dccp/dccp.h @@ -426,7 +426,8 @@ static inline void dccp_update_gsr(struct sock *sk, u64 seq) { struct dccp_sock *dp = dccp_sk(sk); - dp->dccps_gsr = seq; + if (after48(seq, dp->dccps_gsr)) + dp->dccps_gsr = seq; /* Sequence validity window depends on remote Sequence Window (7.5.1) */ dp->dccps_swl = SUB48(ADD48(dp->dccps_gsr, 1), dp->dccps_r_seq_win / 4); /* From bfbb23466adcbc77facea3046b44f75530079472 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Sun, 2 Jan 2011 18:15:58 +0100 Subject: [PATCH 3/3] dccp: make upper bound for seq_window consistent on 32/64 bit The 'seq_window' sysctl sets the initial value for the DCCP Sequence Window, which may range from 32..2^46-1 (RFC 4340, 7.5.2). The patch sets the upper bound consistently to 2^32-1 on both 32 and 64 bit systems, which should be sufficient - with a RTT of 1sec and 1-byte packets, a seq_window of 2^32-1 corresponds to a link speed of 34 Gbps. Signed-off-by: Gerrit Renker --- Documentation/networking/dccp.txt | 1 + net/dccp/sysctl.c | 4 +++- 2 files changed, 4 insertions(+), 1 deletion(-) diff --git a/Documentation/networking/dccp.txt b/Documentation/networking/dccp.txt index b395ca6a49f2..811872b45bee 100644 --- a/Documentation/networking/dccp.txt +++ b/Documentation/networking/dccp.txt @@ -167,6 +167,7 @@ rx_ccid = 2 seq_window = 100 The initial sequence window (sec. 7.5.2) of the sender. This influences the local ackno validity and the remote seqno validity windows (7.5.1). + Values in the range Wmin = 32 (RFC 4340, 7.5.2) up to 2^32-1 can be set. tx_qlen = 5 The size of the transmit buffer in packets. A value of 0 corresponds diff --git a/net/dccp/sysctl.c b/net/dccp/sysctl.c index 563943822e58..42348824ee31 100644 --- a/net/dccp/sysctl.c +++ b/net/dccp/sysctl.c @@ -21,7 +21,8 @@ /* Boundary values */ static int zero = 0, u8_max = 0xFF; -static unsigned long seqw_min = 32; +static unsigned long seqw_min = DCCPF_SEQ_WMIN, + seqw_max = 0xFFFFFFFF; /* maximum on 32 bit */ static struct ctl_table dccp_default_table[] = { { @@ -31,6 +32,7 @@ static struct ctl_table dccp_default_table[] = { .mode = 0644, .proc_handler = proc_doulongvec_minmax, .extra1 = &seqw_min, /* RFC 4340, 7.5.2 */ + .extra2 = &seqw_max, }, { .procname = "rx_ccid",