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-rw-r--r--net/dccp/dccp.h2
-rw-r--r--net/dccp/ipv4.c9
-rw-r--r--net/dccp/ipv6.c16
-rw-r--r--net/dccp/output.c53
-rw-r--r--net/dccp/timer.c20
5 files changed, 56 insertions, 44 deletions
diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h
index 743d85fcd651..1c2e3ec2eb57 100644
--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -226,7 +226,7 @@ static inline void dccp_csum_outgoing(struct sk_buff *skb)
extern void dccp_v4_send_check(struct sock *sk, int len, struct sk_buff *skb);
-extern int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb);
+extern int dccp_retransmit_skb(struct sock *sk);
extern void dccp_send_ack(struct sock *sk);
extern void dccp_reqsk_send_ack(struct sk_buff *sk, struct request_sock *rsk);
diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c
index a835b88237cb..882c5c4de69e 100644
--- a/net/dccp/ipv4.c
+++ b/net/dccp/ipv4.c
@@ -196,8 +196,8 @@ static inline void dccp_do_pmtu_discovery(struct sock *sk,
static void dccp_v4_err(struct sk_buff *skb, u32 info)
{
const struct iphdr *iph = (struct iphdr *)skb->data;
- const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data +
- (iph->ihl << 2));
+ const u8 offset = iph->ihl << 2;
+ const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data + offset);
struct dccp_sock *dp;
struct inet_sock *inet;
const int type = icmp_hdr(skb)->type;
@@ -207,7 +207,8 @@ static void dccp_v4_err(struct sk_buff *skb, u32 info)
int err;
struct net *net = dev_net(skb->dev);
- if (skb->len < (iph->ihl << 2) + 8) {
+ if (skb->len < offset + sizeof(*dh) ||
+ skb->len < offset + __dccp_basic_hdr_len(dh)) {
ICMP_INC_STATS_BH(net, ICMP_MIB_INERRORS);
return;
}
@@ -238,7 +239,7 @@ static void dccp_v4_err(struct sk_buff *skb, u32 info)
dp = dccp_sk(sk);
seq = dccp_hdr_seq(dh);
if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) &&
- !between48(seq, dp->dccps_swl, dp->dccps_swh)) {
+ !between48(seq, dp->dccps_awl, dp->dccps_awh)) {
NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
goto out;
}
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index da509127e00c..5e1ee0da2c40 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -89,12 +89,19 @@ static void dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
{
struct ipv6hdr *hdr = (struct ipv6hdr *)skb->data;
const struct dccp_hdr *dh = (struct dccp_hdr *)(skb->data + offset);
+ struct dccp_sock *dp;
struct ipv6_pinfo *np;
struct sock *sk;
int err;
__u64 seq;
struct net *net = dev_net(skb->dev);
+ if (skb->len < offset + sizeof(*dh) ||
+ skb->len < offset + __dccp_basic_hdr_len(dh)) {
+ ICMP6_INC_STATS_BH(__in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
+ return;
+ }
+
sk = inet6_lookup(net, &dccp_hashinfo,
&hdr->daddr, dh->dccph_dport,
&hdr->saddr, dh->dccph_sport, inet6_iif(skb));
@@ -116,6 +123,14 @@ static void dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
if (sk->sk_state == DCCP_CLOSED)
goto out;
+ dp = dccp_sk(sk);
+ seq = dccp_hdr_seq(dh);
+ if ((1 << sk->sk_state) & ~(DCCPF_REQUESTING | DCCPF_LISTEN) &&
+ !between48(seq, dp->dccps_awl, dp->dccps_awh)) {
+ NET_INC_STATS_BH(net, LINUX_MIB_OUTOFWINDOWICMPS);
+ goto out;
+ }
+
np = inet6_sk(sk);
if (type == ICMPV6_PKT_TOOBIG) {
@@ -168,7 +183,6 @@ static void dccp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
icmpv6_err_convert(type, code, &err);
- seq = dccp_hdr_seq(dh);
/* Might be for an request_sock */
switch (sk->sk_state) {
struct request_sock *req, **prev;
diff --git a/net/dccp/output.c b/net/dccp/output.c
index fe20068c5d8e..d06945c7d3df 100644
--- a/net/dccp/output.c
+++ b/net/dccp/output.c
@@ -53,8 +53,11 @@ static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
dccp_packet_hdr_len(dcb->dccpd_type);
int err, set_ack = 1;
u64 ackno = dp->dccps_gsr;
-
- dccp_inc_seqno(&dp->dccps_gss);
+ /*
+ * Increment GSS here already in case the option code needs it.
+ * Update GSS for real only if option processing below succeeds.
+ */
+ dcb->dccpd_seq = ADD48(dp->dccps_gss, 1);
switch (dcb->dccpd_type) {
case DCCP_PKT_DATA:
@@ -66,6 +69,9 @@ static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
case DCCP_PKT_REQUEST:
set_ack = 0;
+ /* Use ISS on the first (non-retransmitted) Request. */
+ if (icsk->icsk_retransmits == 0)
+ dcb->dccpd_seq = dp->dccps_iss;
/* fall through */
case DCCP_PKT_SYNC:
@@ -84,8 +90,6 @@ static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
break;
}
- dcb->dccpd_seq = dp->dccps_gss;
-
if (dccp_insert_options(sk, skb)) {
kfree_skb(skb);
return -EPROTO;
@@ -103,7 +107,7 @@ static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
/* XXX For now we're using only 48 bits sequence numbers */
dh->dccph_x = 1;
- dp->dccps_awh = dp->dccps_gss;
+ dccp_update_gss(sk, dcb->dccpd_seq);
dccp_hdr_set_seq(dh, dp->dccps_gss);
if (set_ack)
dccp_hdr_set_ack(dccp_hdr_ack_bits(skb), ackno);
@@ -112,6 +116,11 @@ static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb)
case DCCP_PKT_REQUEST:
dccp_hdr_request(skb)->dccph_req_service =
dp->dccps_service;
+ /*
+ * Limit Ack window to ISS <= P.ackno <= GSS, so that
+ * only Responses to Requests we sent are considered.
+ */
+ dp->dccps_awl = dp->dccps_iss;
break;
case DCCP_PKT_RESET:
dccp_hdr_reset(skb)->dccph_reset_code =
@@ -284,14 +293,26 @@ void dccp_write_xmit(struct sock *sk, int block)
}
}
-int dccp_retransmit_skb(struct sock *sk, struct sk_buff *skb)
+/**
+ * dccp_retransmit_skb - Retransmit Request, Close, or CloseReq packets
+ * There are only four retransmittable packet types in DCCP:
+ * - Request in client-REQUEST state (sec. 8.1.1),
+ * - CloseReq in server-CLOSEREQ state (sec. 8.3),
+ * - Close in node-CLOSING state (sec. 8.3),
+ * - Acks in client-PARTOPEN state (sec. 8.1.5, handled by dccp_delack_timer()).
+ * This function expects sk->sk_send_head to contain the original skb.
+ */
+int dccp_retransmit_skb(struct sock *sk)
{
+ WARN_ON(sk->sk_send_head == NULL);
+
if (inet_csk(sk)->icsk_af_ops->rebuild_header(sk) != 0)
return -EHOSTUNREACH; /* Routing failure or similar. */
- return dccp_transmit_skb(sk, (skb_cloned(skb) ?
- pskb_copy(skb, GFP_ATOMIC):
- skb_clone(skb, GFP_ATOMIC)));
+ /* this count is used to distinguish original and retransmitted skb */
+ inet_csk(sk)->icsk_retransmits++;
+
+ return dccp_transmit_skb(sk, skb_clone(sk->sk_send_head, GFP_ATOMIC));
}
struct sk_buff *dccp_make_response(struct sock *sk, struct dst_entry *dst,
@@ -437,19 +458,7 @@ static inline void dccp_connect_init(struct sock *sk)
dccp_sync_mss(sk, dst_mtu(dst));
- /*
- * 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_update_gss(sk, dp->dccps_iss);
- dccp_set_seqno(&dp->dccps_awl, max48(dp->dccps_awl, dp->dccps_iss));
-
- /* S.GAR - greatest valid acknowledgement number received on a non-Sync;
- * initialized to S.ISS (sec. 8.5) */
+ /* Initialise GAR as per 8.5; AWL/AWH are set in dccp_transmit_skb() */
dp->dccps_gar = dp->dccps_iss;
icsk->icsk_retransmits = 0;
diff --git a/net/dccp/timer.c b/net/dccp/timer.c
index 6a5b961b6f5c..54b3c7e9e016 100644
--- a/net/dccp/timer.c
+++ b/net/dccp/timer.c
@@ -99,21 +99,11 @@ static void dccp_retransmit_timer(struct sock *sk)
}
/*
- * sk->sk_send_head has to have one skb with
- * DCCP_SKB_CB(skb)->dccpd_type set to one of the retransmittable DCCP
- * packet types. The only packets eligible for retransmission are:
- * -- Requests in client-REQUEST state (sec. 8.1.1)
- * -- Acks in client-PARTOPEN state (sec. 8.1.5)
- * -- CloseReq in server-CLOSEREQ state (sec. 8.3)
- * -- Close in node-CLOSING state (sec. 8.3) */
- WARN_ON(sk->sk_send_head == NULL);
-
- /*
* More than than 4MSL (8 minutes) has passed, a RESET(aborted) was
* sent, no need to retransmit, this sock is dead.
*/
if (dccp_write_timeout(sk))
- goto out;
+ return;
/*
* We want to know the number of packets retransmitted, not the
@@ -122,30 +112,28 @@ static void dccp_retransmit_timer(struct sock *sk)
if (icsk->icsk_retransmits == 0)
DCCP_INC_STATS_BH(DCCP_MIB_TIMEOUTS);
- if (dccp_retransmit_skb(sk, sk->sk_send_head) < 0) {
+ if (dccp_retransmit_skb(sk) != 0) {
/*
* Retransmission failed because of local congestion,
* do not backoff.
*/
- if (icsk->icsk_retransmits == 0)
+ if (--icsk->icsk_retransmits == 0)
icsk->icsk_retransmits = 1;
inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS,
min(icsk->icsk_rto,
TCP_RESOURCE_PROBE_INTERVAL),
DCCP_RTO_MAX);
- goto out;
+ return;
}
backoff:
icsk->icsk_backoff++;
- icsk->icsk_retransmits++;
icsk->icsk_rto = min(icsk->icsk_rto << 1, DCCP_RTO_MAX);
inet_csk_reset_xmit_timer(sk, ICSK_TIME_RETRANS, icsk->icsk_rto,
DCCP_RTO_MAX);
if (icsk->icsk_retransmits > sysctl_dccp_retries1)
__sk_dst_reset(sk);
-out:;
}
static void dccp_write_timer(unsigned long data)
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-20 16:12:24 +0000