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-rw-r--r--net/dccp/Makefile2
-rw-r--r--net/dccp/dccp.h12
-rw-r--r--net/dccp/output.c7
-rw-r--r--net/dccp/proto.c67
-rw-r--r--net/dccp/qpolicy.c126
5 files changed, 206 insertions, 8 deletions
diff --git a/net/dccp/Makefile b/net/dccp/Makefile
index b68440bd7fa..0c1c9af2bf7 100644
--- a/net/dccp/Makefile
+++ b/net/dccp/Makefile
@@ -1,7 +1,7 @@
obj-$(CONFIG_IP_DCCP) += dccp.o dccp_ipv4.o
dccp-y := ccid.o feat.o input.o minisocks.o options.o \
- output.o proto.o timer.o ackvec.o
+ qpolicy.o output.o proto.o timer.o ackvec.o
dccp_ipv4-y := ipv4.o
diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h
index 74c90cd2767..ce2dd6f6f34 100644
--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -234,6 +234,18 @@ extern void dccp_reqsk_send_ack(struct sock *sk, struct sk_buff *skb,
extern void dccp_send_sync(struct sock *sk, const u64 seq,
const enum dccp_pkt_type pkt_type);
+/*
+ * TX Packet Dequeueing Interface
+ */
+extern void dccp_qpolicy_push(struct sock *sk, struct sk_buff *skb);
+extern bool dccp_qpolicy_full(struct sock *sk);
+extern void dccp_qpolicy_drop(struct sock *sk, struct sk_buff *skb);
+extern struct sk_buff *dccp_qpolicy_top(struct sock *sk);
+extern struct sk_buff *dccp_qpolicy_pop(struct sock *sk);
+
+/*
+ * TX Packet Output and TX Timers
+ */
extern void dccp_write_xmit(struct sock *sk);
extern void dccp_write_space(struct sock *sk);
extern void dccp_flush_write_queue(struct sock *sk, long *time_budget);
diff --git a/net/dccp/output.c b/net/dccp/output.c
index b1eaf7bcfb1..2532797a800 100644
--- a/net/dccp/output.c
+++ b/net/dccp/output.c
@@ -241,7 +241,7 @@ static void dccp_xmit_packet(struct sock *sk)
{
int err, len;
struct dccp_sock *dp = dccp_sk(sk);
- struct sk_buff *skb = skb_dequeue(&sk->sk_write_queue);
+ struct sk_buff *skb = dccp_qpolicy_pop(sk);
if (unlikely(skb == NULL))
return;
@@ -344,7 +344,7 @@ void dccp_write_xmit(struct sock *sk)
struct dccp_sock *dp = dccp_sk(sk);
struct sk_buff *skb;
- while ((skb = skb_peek(&sk->sk_write_queue))) {
+ while ((skb = dccp_qpolicy_top(sk))) {
int rc = ccid_hc_tx_send_packet(dp->dccps_hc_tx_ccid, sk, skb);
switch (ccid_packet_dequeue_eval(rc)) {
@@ -358,8 +358,7 @@ void dccp_write_xmit(struct sock *sk)
dccp_xmit_packet(sk);
break;
case CCID_PACKET_ERR:
- skb_dequeue(&sk->sk_write_queue);
- kfree_skb(skb);
+ dccp_qpolicy_drop(sk, skb);
dccp_pr_debug("packet discarded due to err=%d\n", rc);
}
}
diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 8c125ffab1c..b56efdd2a42 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -189,6 +189,7 @@ int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized)
dp->dccps_rate_last = jiffies;
dp->dccps_role = DCCP_ROLE_UNDEFINED;
dp->dccps_service = DCCP_SERVICE_CODE_IS_ABSENT;
+ dp->dccps_tx_qlen = sysctl_dccp_tx_qlen;
dccp_init_xmit_timers(sk);
@@ -541,6 +542,20 @@ static int do_dccp_setsockopt(struct sock *sk, int level, int optname,
case DCCP_SOCKOPT_RECV_CSCOV:
err = dccp_setsockopt_cscov(sk, val, true);
break;
+ case DCCP_SOCKOPT_QPOLICY_ID:
+ if (sk->sk_state != DCCP_CLOSED)
+ err = -EISCONN;
+ else if (val < 0 || val >= DCCPQ_POLICY_MAX)
+ err = -EINVAL;
+ else
+ dp->dccps_qpolicy = val;
+ break;
+ case DCCP_SOCKOPT_QPOLICY_TXQLEN:
+ if (val < 0)
+ err = -EINVAL;
+ else
+ dp->dccps_tx_qlen = val;
+ break;
default:
err = -ENOPROTOOPT;
break;
@@ -648,6 +663,12 @@ static int do_dccp_getsockopt(struct sock *sk, int level, int optname,
case DCCP_SOCKOPT_RECV_CSCOV:
val = dp->dccps_pcrlen;
break;
+ case DCCP_SOCKOPT_QPOLICY_ID:
+ val = dp->dccps_qpolicy;
+ break;
+ case DCCP_SOCKOPT_QPOLICY_TXQLEN:
+ val = dp->dccps_tx_qlen;
+ break;
case 128 ... 191:
return ccid_hc_rx_getsockopt(dp->dccps_hc_rx_ccid, sk, optname,
len, (u32 __user *)optval, optlen);
@@ -690,6 +711,43 @@ int compat_dccp_getsockopt(struct sock *sk, int level, int optname,
EXPORT_SYMBOL_GPL(compat_dccp_getsockopt);
#endif
+static int dccp_msghdr_parse(struct msghdr *msg, struct sk_buff *skb)
+{
+ struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg);
+
+ /*
+ * Assign an (opaque) qpolicy priority value to skb->priority.
+ *
+ * We are overloading this skb field for use with the qpolicy subystem.
+ * The skb->priority is normally used for the SO_PRIORITY option, which
+ * is initialised from sk_priority. Since the assignment of sk_priority
+ * to skb->priority happens later (on layer 3), we overload this field
+ * for use with queueing priorities as long as the skb is on layer 4.
+ * The default priority value (if nothing is set) is 0.
+ */
+ skb->priority = 0;
+
+ for (; cmsg != NULL; cmsg = CMSG_NXTHDR(msg, cmsg)) {
+
+ if (!CMSG_OK(msg, cmsg))
+ return -EINVAL;
+
+ if (cmsg->cmsg_level != SOL_DCCP)
+ continue;
+
+ switch (cmsg->cmsg_type) {
+ case DCCP_SCM_PRIORITY:
+ if (cmsg->cmsg_len != CMSG_LEN(sizeof(__u32)))
+ return -EINVAL;
+ skb->priority = *(__u32 *)CMSG_DATA(cmsg);
+ break;
+ default:
+ return -EINVAL;
+ }
+ }
+ return 0;
+}
+
int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
size_t len)
{
@@ -705,8 +763,7 @@ int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
lock_sock(sk);
- if (sysctl_dccp_tx_qlen &&
- (sk->sk_write_queue.qlen >= sysctl_dccp_tx_qlen)) {
+ if (dccp_qpolicy_full(sk)) {
rc = -EAGAIN;
goto out_release;
}
@@ -734,7 +791,11 @@ int dccp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
if (rc != 0)
goto out_discard;
- skb_queue_tail(&sk->sk_write_queue, skb);
+ rc = dccp_msghdr_parse(msg, skb);
+ if (rc != 0)
+ goto out_discard;
+
+ dccp_qpolicy_push(sk, skb);
dccp_write_xmit(sk);
out_release:
release_sock(sk);
diff --git a/net/dccp/qpolicy.c b/net/dccp/qpolicy.c
new file mode 100644
index 00000000000..414696b0d83
--- /dev/null
+++ b/net/dccp/qpolicy.c
@@ -0,0 +1,126 @@
+/*
+ * net/dccp/qpolicy.c
+ *
+ * Policy-based packet dequeueing interface for DCCP.
+ *
+ * Copyright (c) 2008 Tomasz Grobelny <tomasz@grobelny.oswiecenia.net>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License v2
+ * as published by the Free Software Foundation.
+ */
+#include "dccp.h"
+
+/*
+ * Simple Dequeueing Policy:
+ * If tx_qlen is different from 0, enqueue up to tx_qlen elements.
+ */
+static void qpolicy_simple_push(struct sock *sk, struct sk_buff *skb)
+{
+ skb_queue_tail(&sk->sk_write_queue, skb);
+}
+
+static bool qpolicy_simple_full(struct sock *sk)
+{
+ return dccp_sk(sk)->dccps_tx_qlen &&
+ sk->sk_write_queue.qlen >= dccp_sk(sk)->dccps_tx_qlen;
+}
+
+static struct sk_buff *qpolicy_simple_top(struct sock *sk)
+{
+ return skb_peek(&sk->sk_write_queue);
+}
+
+/*
+ * Priority-based Dequeueing Policy:
+ * If tx_qlen is different from 0 and the queue has reached its upper bound
+ * of tx_qlen elements, replace older packets lowest-priority-first.
+ */
+static struct sk_buff *qpolicy_prio_best_skb(struct sock *sk)
+{
+ struct sk_buff *skb, *best = NULL;
+
+ skb_queue_walk(&sk->sk_write_queue, skb)
+ if (best == NULL || skb->priority > best->priority)
+ best = skb;
+ return best;
+}
+
+static struct sk_buff *qpolicy_prio_worst_skb(struct sock *sk)
+{
+ struct sk_buff *skb, *worst = NULL;
+
+ skb_queue_walk(&sk->sk_write_queue, skb)
+ if (worst == NULL || skb->priority < worst->priority)
+ worst = skb;
+ return worst;
+}
+
+static bool qpolicy_prio_full(struct sock *sk)
+{
+ if (qpolicy_simple_full(sk))
+ dccp_qpolicy_drop(sk, qpolicy_prio_worst_skb(sk));
+ return false;
+}
+
+/**
+ * struct dccp_qpolicy_operations - TX Packet Dequeueing Interface
+ * @push: add a new @skb to the write queue
+ * @full: indicates that no more packets will be admitted
+ * @top: peeks at whatever the queueing policy defines as its `top'
+ */
+static struct dccp_qpolicy_operations {
+ void (*push) (struct sock *sk, struct sk_buff *skb);
+ bool (*full) (struct sock *sk);
+ struct sk_buff* (*top) (struct sock *sk);
+
+} qpol_table[DCCPQ_POLICY_MAX] = {
+ [DCCPQ_POLICY_SIMPLE] = {
+ .push = qpolicy_simple_push,
+ .full = qpolicy_simple_full,
+ .top = qpolicy_simple_top,
+ },
+ [DCCPQ_POLICY_PRIO] = {
+ .push = qpolicy_simple_push,
+ .full = qpolicy_prio_full,
+ .top = qpolicy_prio_best_skb,
+ },
+};
+
+/*
+ * Externally visible interface
+ */
+void dccp_qpolicy_push(struct sock *sk, struct sk_buff *skb)
+{
+ qpol_table[dccp_sk(sk)->dccps_qpolicy].push(sk, skb);
+}
+
+bool dccp_qpolicy_full(struct sock *sk)
+{
+ return qpol_table[dccp_sk(sk)->dccps_qpolicy].full(sk);
+}
+
+void dccp_qpolicy_drop(struct sock *sk, struct sk_buff *skb)
+{
+ if (skb != NULL) {
+ skb_unlink(skb, &sk->sk_write_queue);
+ kfree_skb(skb);
+ }
+}
+
+struct sk_buff *dccp_qpolicy_top(struct sock *sk)
+{
+ return qpol_table[dccp_sk(sk)->dccps_qpolicy].top(sk);
+}
+
+struct sk_buff *dccp_qpolicy_pop(struct sock *sk)
+{
+ struct sk_buff *skb = dccp_qpolicy_top(sk);
+
+ /* Clear any skb fields that we used internally */
+ skb->priority = 0;
+
+ if (skb)
+ skb_unlink(skb, &sk->sk_write_queue);
+ return skb;
+}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-27 11:39:59 +0000