1 files changed, 518 insertions, 0 deletions

diff --git a/net/sched/sch_dsmark.c b/net/sched/sch_dsmark.c
new file mode 100644
index 000000000..401ffaf87
--- /dev/null
+++ b/net/sched/sch_dsmark.c
@@ -0,0 +1,518 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* net/sched/sch_dsmark.c - Differentiated Services field marker */
+
+/* Written 1998-2000 by Werner Almesberger, EPFL ICA */
+
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/skbuff.h>
+#include <linux/rtnetlink.h>
+#include <linux/bitops.h>
+#include <net/pkt_sched.h>
+#include <net/pkt_cls.h>
+#include <net/dsfield.h>
+#include <net/inet_ecn.h>
+#include <asm/byteorder.h>
+
+/*
+ * classid	class		marking
+ * -------	-----		-------
+ *   n/a	  0		n/a
+ *   x:0	  1		use entry [0]
+ *   ...	 ...		...
+ *   x:y y>0	 y+1		use entry [y]
+ *   ...	 ...		...
+ * x:indices-1	indices		use entry [indices-1]
+ *   ...	 ...		...
+ *   x:y	 y+1		use entry [y & (indices-1)]
+ *   ...	 ...		...
+ * 0xffff	0x10000		use entry [indices-1]
+ */
+
+
+#define NO_DEFAULT_INDEX	(1 << 16)
+
+struct mask_value {
+	u8			mask;
+	u8			value;
+};
+
+struct dsmark_qdisc_data {
+	struct Qdisc		*q;
+	struct tcf_proto __rcu	*filter_list;
+	struct tcf_block	*block;
+	struct mask_value	*mv;
+	u16			indices;
+	u8			set_tc_index;
+	u32			default_index;	/* index range is 0...0xffff */
+#define DSMARK_EMBEDDED_SZ	16
+	struct mask_value	embedded[DSMARK_EMBEDDED_SZ];
+};
+
+static inline int dsmark_valid_index(struct dsmark_qdisc_data *p, u16 index)
+{
+	return index <= p->indices && index > 0;
+}
+
+/* ------------------------- Class/flow operations ------------------------- */
+
+static int dsmark_graft(struct Qdisc *sch, unsigned long arg,
+			struct Qdisc *new, struct Qdisc **old,
+			struct netlink_ext_ack *extack)
+{
+	struct dsmark_qdisc_data *p = qdisc_priv(sch);
+
+	pr_debug("%s(sch %p,[qdisc %p],new %p,old %p)\n",
+		 __func__, sch, p, new, old);
+
+	if (new == NULL) {
+		new = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops,
+					sch->handle, NULL);
+		if (new == NULL)
+			new = &noop_qdisc;
+	}
+
+	*old = qdisc_replace(sch, new, &p->q);
+	return 0;
+}
+
+static struct Qdisc *dsmark_leaf(struct Qdisc *sch, unsigned long arg)
+{
+	struct dsmark_qdisc_data *p = qdisc_priv(sch);
+	return p->q;
+}
+
+static unsigned long dsmark_find(struct Qdisc *sch, u32 classid)
+{
+	return TC_H_MIN(classid) + 1;
+}
+
+static unsigned long dsmark_bind_filter(struct Qdisc *sch,
+					unsigned long parent, u32 classid)
+{
+	pr_debug("%s(sch %p,[qdisc %p],classid %x)\n",
+		 __func__, sch, qdisc_priv(sch), classid);
+
+	return dsmark_find(sch, classid);
+}
+
+static void dsmark_unbind_filter(struct Qdisc *sch, unsigned long cl)
+{
+}
+
+static const struct nla_policy dsmark_policy[TCA_DSMARK_MAX + 1] = {
+	[TCA_DSMARK_INDICES]		= { .type = NLA_U16 },
+	[TCA_DSMARK_DEFAULT_INDEX]	= { .type = NLA_U16 },
+	[TCA_DSMARK_SET_TC_INDEX]	= { .type = NLA_FLAG },
+	[TCA_DSMARK_MASK]		= { .type = NLA_U8 },
+	[TCA_DSMARK_VALUE]		= { .type = NLA_U8 },
+};
+
+static int dsmark_change(struct Qdisc *sch, u32 classid, u32 parent,
+			 struct nlattr **tca, unsigned long *arg,
+			 struct netlink_ext_ack *extack)
+{
+	struct dsmark_qdisc_data *p = qdisc_priv(sch);
+	struct nlattr *opt = tca[TCA_OPTIONS];
+	struct nlattr *tb[TCA_DSMARK_MAX + 1];
+	int err = -EINVAL;
+
+	pr_debug("%s(sch %p,[qdisc %p],classid %x,parent %x), arg 0x%lx\n",
+		 __func__, sch, p, classid, parent, *arg);
+
+	if (!dsmark_valid_index(p, *arg)) {
+		err = -ENOENT;
+		goto errout;
+	}
+
+	if (!opt)
+		goto errout;
+
+	err = nla_parse_nested_deprecated(tb, TCA_DSMARK_MAX, opt,
+					  dsmark_policy, NULL);
+	if (err < 0)
+		goto errout;
+
+	if (tb[TCA_DSMARK_VALUE])
+		p->mv[*arg - 1].value = nla_get_u8(tb[TCA_DSMARK_VALUE]);
+
+	if (tb[TCA_DSMARK_MASK])
+		p->mv[*arg - 1].mask = nla_get_u8(tb[TCA_DSMARK_MASK]);
+
+	err = 0;
+
+errout:
+	return err;
+}
+
+static int dsmark_delete(struct Qdisc *sch, unsigned long arg,
+			 struct netlink_ext_ack *extack)
+{
+	struct dsmark_qdisc_data *p = qdisc_priv(sch);
+
+	if (!dsmark_valid_index(p, arg))
+		return -EINVAL;
+
+	p->mv[arg - 1].mask = 0xff;
+	p->mv[arg - 1].value = 0;
+
+	return 0;
+}
+
+static void dsmark_walk(struct Qdisc *sch, struct qdisc_walker *walker)
+{
+	struct dsmark_qdisc_data *p = qdisc_priv(sch);
+	int i;
+
+	pr_debug("%s(sch %p,[qdisc %p],walker %p)\n",
+		 __func__, sch, p, walker);
+
+	if (walker->stop)
+		return;
+
+	for (i = 0; i < p->indices; i++) {
+		if (p->mv[i].mask == 0xff && !p->mv[i].value) {
+			walker->count++;
+			continue;
+		}
+		if (!tc_qdisc_stats_dump(sch, i + 1, walker))
+			break;
+	}
+}
+
+static struct tcf_block *dsmark_tcf_block(struct Qdisc *sch, unsigned long cl,
+					  struct netlink_ext_ack *extack)
+{
+	struct dsmark_qdisc_data *p = qdisc_priv(sch);
+
+	return p->block;
+}
+
+/* --------------------------- Qdisc operations ---------------------------- */
+
+static int dsmark_enqueue(struct sk_buff *skb, struct Qdisc *sch,
+			  struct sk_buff **to_free)
+{
+	unsigned int len = qdisc_pkt_len(skb);
+	struct dsmark_qdisc_data *p = qdisc_priv(sch);
+	int err;
+
+	pr_debug("%s(skb %p,sch %p,[qdisc %p])\n", __func__, skb, sch, p);
+
+	if (p->set_tc_index) {
+		int wlen = skb_network_offset(skb);
+
+		switch (skb_protocol(skb, true)) {
+		case htons(ETH_P_IP):
+			wlen += sizeof(struct iphdr);
+			if (!pskb_may_pull(skb, wlen) ||
+			    skb_try_make_writable(skb, wlen))
+				goto drop;
+
+			skb->tc_index = ipv4_get_dsfield(ip_hdr(skb))
+				& ~INET_ECN_MASK;
+			break;
+
+		case htons(ETH_P_IPV6):
+			wlen += sizeof(struct ipv6hdr);
+			if (!pskb_may_pull(skb, wlen) ||
+			    skb_try_make_writable(skb, wlen))
+				goto drop;
+
+			skb->tc_index = ipv6_get_dsfield(ipv6_hdr(skb))
+				& ~INET_ECN_MASK;
+			break;
+		default:
+			skb->tc_index = 0;
+			break;
+		}
+	}
+
+	if (TC_H_MAJ(skb->priority) == sch->handle)
+		skb->tc_index = TC_H_MIN(skb->priority);
+	else {
+		struct tcf_result res;
+		struct tcf_proto *fl = rcu_dereference_bh(p->filter_list);
+		int result = tcf_classify(skb, NULL, fl, &res, false);
+
+		pr_debug("result %d class 0x%04x\n", result, res.classid);
+
+		switch (result) {
+#ifdef CONFIG_NET_CLS_ACT
+		case TC_ACT_QUEUED:
+		case TC_ACT_STOLEN:
+		case TC_ACT_TRAP:
+			__qdisc_drop(skb, to_free);
+			return NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
+
+		case TC_ACT_SHOT:
+			goto drop;
+#endif
+		case TC_ACT_OK:
+			skb->tc_index = TC_H_MIN(res.classid);
+			break;
+
+		default:
+			if (p->default_index != NO_DEFAULT_INDEX)
+				skb->tc_index = p->default_index;
+			break;
+		}
+	}
+
+	err = qdisc_enqueue(skb, p->q, to_free);
+	if (err != NET_XMIT_SUCCESS) {
+		if (net_xmit_drop_count(err))
+			qdisc_qstats_drop(sch);
+		return err;
+	}
+
+	sch->qstats.backlog += len;
+	sch->q.qlen++;
+
+	return NET_XMIT_SUCCESS;
+
+drop:
+	qdisc_drop(skb, sch, to_free);
+	return NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
+}
+
+static struct sk_buff *dsmark_dequeue(struct Qdisc *sch)
+{
+	struct dsmark_qdisc_data *p = qdisc_priv(sch);
+	struct sk_buff *skb;
+	u32 index;
+
+	pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
+
+	skb = qdisc_dequeue_peeked(p->q);
+	if (skb == NULL)
+		return NULL;
+
+	qdisc_bstats_update(sch, skb);
+	qdisc_qstats_backlog_dec(sch, skb);
+	sch->q.qlen--;
+
+	index = skb->tc_index & (p->indices - 1);
+	pr_debug("index %d->%d\n", skb->tc_index, index);
+
+	switch (skb_protocol(skb, true)) {
+	case htons(ETH_P_IP):
+		ipv4_change_dsfield(ip_hdr(skb), p->mv[index].mask,
+				    p->mv[index].value);
+			break;
+	case htons(ETH_P_IPV6):
+		ipv6_change_dsfield(ipv6_hdr(skb), p->mv[index].mask,
+				    p->mv[index].value);
+			break;
+	default:
+		/*
+		 * Only complain if a change was actually attempted.
+		 * This way, we can send non-IP traffic through dsmark
+		 * and don't need yet another qdisc as a bypass.
+		 */
+		if (p->mv[index].mask != 0xff || p->mv[index].value)
+			pr_warn("%s: unsupported protocol %d\n",
+				__func__, ntohs(skb_protocol(skb, true)));
+		break;
+	}
+
+	return skb;
+}
+
+static struct sk_buff *dsmark_peek(struct Qdisc *sch)
+{
+	struct dsmark_qdisc_data *p = qdisc_priv(sch);
+
+	pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
+
+	return p->q->ops->peek(p->q);
+}
+
+static int dsmark_init(struct Qdisc *sch, struct nlattr *opt,
+		       struct netlink_ext_ack *extack)
+{
+	struct dsmark_qdisc_data *p = qdisc_priv(sch);
+	struct nlattr *tb[TCA_DSMARK_MAX + 1];
+	int err = -EINVAL;
+	u32 default_index = NO_DEFAULT_INDEX;
+	u16 indices;
+	int i;
+
+	pr_debug("%s(sch %p,[qdisc %p],opt %p)\n", __func__, sch, p, opt);
+
+	if (!opt)
+		goto errout;
+
+	err = tcf_block_get(&p->block, &p->filter_list, sch, extack);
+	if (err)
+		return err;
+
+	err = nla_parse_nested_deprecated(tb, TCA_DSMARK_MAX, opt,
+					  dsmark_policy, NULL);
+	if (err < 0)
+		goto errout;
+
+	err = -EINVAL;
+	if (!tb[TCA_DSMARK_INDICES])
+		goto errout;
+	indices = nla_get_u16(tb[TCA_DSMARK_INDICES]);
+
+	if (hweight32(indices) != 1)
+		goto errout;
+
+	if (tb[TCA_DSMARK_DEFAULT_INDEX])
+		default_index = nla_get_u16(tb[TCA_DSMARK_DEFAULT_INDEX]);
+
+	if (indices <= DSMARK_EMBEDDED_SZ)
+		p->mv = p->embedded;
+	else
+		p->mv = kmalloc_array(indices, sizeof(*p->mv), GFP_KERNEL);
+	if (!p->mv) {
+		err = -ENOMEM;
+		goto errout;
+	}
+	for (i = 0; i < indices; i++) {
+		p->mv[i].mask = 0xff;
+		p->mv[i].value = 0;
+	}
+	p->indices = indices;
+	p->default_index = default_index;
+	p->set_tc_index = nla_get_flag(tb[TCA_DSMARK_SET_TC_INDEX]);
+
+	p->q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, sch->handle,
+				 NULL);
+	if (p->q == NULL)
+		p->q = &noop_qdisc;
+	else
+		qdisc_hash_add(p->q, true);
+
+	pr_debug("%s: qdisc %p\n", __func__, p->q);
+
+	err = 0;
+errout:
+	return err;
+}
+
+static void dsmark_reset(struct Qdisc *sch)
+{
+	struct dsmark_qdisc_data *p = qdisc_priv(sch);
+
+	pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
+	if (p->q)
+		qdisc_reset(p->q);
+}
+
+static void dsmark_destroy(struct Qdisc *sch)
+{
+	struct dsmark_qdisc_data *p = qdisc_priv(sch);
+
+	pr_debug("%s(sch %p,[qdisc %p])\n", __func__, sch, p);
+
+	tcf_block_put(p->block);
+	qdisc_put(p->q);
+	if (p->mv != p->embedded)
+		kfree(p->mv);
+}
+
+static int dsmark_dump_class(struct Qdisc *sch, unsigned long cl,
+			     struct sk_buff *skb, struct tcmsg *tcm)
+{
+	struct dsmark_qdisc_data *p = qdisc_priv(sch);
+	struct nlattr *opts = NULL;
+
+	pr_debug("%s(sch %p,[qdisc %p],class %ld\n", __func__, sch, p, cl);
+
+	if (!dsmark_valid_index(p, cl))
+		return -EINVAL;
+
+	tcm->tcm_handle = TC_H_MAKE(TC_H_MAJ(sch->handle), cl - 1);
+	tcm->tcm_info = p->q->handle;
+
+	opts = nla_nest_start_noflag(skb, TCA_OPTIONS);
+	if (opts == NULL)
+		goto nla_put_failure;
+	if (nla_put_u8(skb, TCA_DSMARK_MASK, p->mv[cl - 1].mask) ||
+	    nla_put_u8(skb, TCA_DSMARK_VALUE, p->mv[cl - 1].value))
+		goto nla_put_failure;
+
+	return nla_nest_end(skb, opts);
+
+nla_put_failure:
+	nla_nest_cancel(skb, opts);
+	return -EMSGSIZE;
+}
+
+static int dsmark_dump(struct Qdisc *sch, struct sk_buff *skb)
+{
+	struct dsmark_qdisc_data *p = qdisc_priv(sch);
+	struct nlattr *opts = NULL;
+
+	opts = nla_nest_start_noflag(skb, TCA_OPTIONS);
+	if (opts == NULL)
+		goto nla_put_failure;
+	if (nla_put_u16(skb, TCA_DSMARK_INDICES, p->indices))
+		goto nla_put_failure;
+
+	if (p->default_index != NO_DEFAULT_INDEX &&
+	    nla_put_u16(skb, TCA_DSMARK_DEFAULT_INDEX, p->default_index))
+		goto nla_put_failure;
+
+	if (p->set_tc_index &&
+	    nla_put_flag(skb, TCA_DSMARK_SET_TC_INDEX))
+		goto nla_put_failure;
+
+	return nla_nest_end(skb, opts);
+
+nla_put_failure:
+	nla_nest_cancel(skb, opts);
+	return -EMSGSIZE;
+}
+
+static const struct Qdisc_class_ops dsmark_class_ops = {
+	.graft		=	dsmark_graft,
+	.leaf		=	dsmark_leaf,
+	.find		=	dsmark_find,
+	.change		=	dsmark_change,
+	.delete		=	dsmark_delete,
+	.walk		=	dsmark_walk,
+	.tcf_block	=	dsmark_tcf_block,
+	.bind_tcf	=	dsmark_bind_filter,
+	.unbind_tcf	=	dsmark_unbind_filter,
+	.dump		=	dsmark_dump_class,
+};
+
+static struct Qdisc_ops dsmark_qdisc_ops __read_mostly = {
+	.next		=	NULL,
+	.cl_ops		=	&dsmark_class_ops,
+	.id		=	"dsmark",
+	.priv_size	=	sizeof(struct dsmark_qdisc_data),
+	.enqueue	=	dsmark_enqueue,
+	.dequeue	=	dsmark_dequeue,
+	.peek		=	dsmark_peek,
+	.init		=	dsmark_init,
+	.reset		=	dsmark_reset,
+	.destroy	=	dsmark_destroy,
+	.change		=	NULL,
+	.dump		=	dsmark_dump,
+	.owner		=	THIS_MODULE,
+};
+
+static int __init dsmark_module_init(void)
+{
+	return register_qdisc(&dsmark_qdisc_ops);
+}
+
+static void __exit dsmark_module_exit(void)
+{
+	unregister_qdisc(&dsmark_qdisc_ops);
+}
+
+module_init(dsmark_module_init)
+module_exit(dsmark_module_exit)
+
+MODULE_LICENSE("GPL");