pkt_action: add new action skbedit

This new action will have the ability to change the priority and/or
queue_mapping fields on an sk_buff.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 215 insertions, 0 deletions

diff --git a/net/sched/Kconfig b/net/sched/Kconfig
index efaa7a75e7f3..6767e54155db 100644
--- a/net/sched/Kconfig
+++ b/net/sched/Kconfig
@@ -485,6 +485,17 @@ config NET_ACT_SIMP
           To compile this code as a module, choose M here: the
           module will be called simple.
 
+config NET_ACT_SKBEDIT
+        tristate "SKB Editing"
+        depends on NET_CLS_ACT
+        ---help---
+          Say Y here to change skb priority or queue_mapping settings.
+
+          If unsure, say N.
+
+          To compile this code as a module, choose M here: the
+          module will be called skbedit.
+
 config NET_CLS_IND
         bool "Incoming device classification"
         depends on NET_CLS_U32 || NET_CLS_FW
diff --git a/net/sched/Makefile b/net/sched/Makefile
index 3d9b953f7f62..e60c9925b269 100644
--- a/net/sched/Makefile
+++ b/net/sched/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_NET_ACT_IPT)	+= act_ipt.o
 obj-$(CONFIG_NET_ACT_NAT)       += act_nat.o
 obj-$(CONFIG_NET_ACT_PEDIT)     += act_pedit.o
 obj-$(CONFIG_NET_ACT_SIMP)      += act_simple.o
+obj-$(CONFIG_NET_ACT_SKBEDIT)   += act_skbedit.o
 obj-$(CONFIG_NET_SCH_FIFO)      += sch_fifo.o
 obj-$(CONFIG_NET_SCH_CBQ)       += sch_cbq.o
 obj-$(CONFIG_NET_SCH_HTB)       += sch_htb.o
diff --git a/net/sched/act_skbedit.c b/net/sched/act_skbedit.c
new file mode 100644
index 000000000000..fe9777e77f35
--- /dev/null
+++ b/net/sched/act_skbedit.c
@@ -0,0 +1,203 @@
+/*
+ * Copyright (c) 2008, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * Author: Alexander Duyck <alexander.h.duyck@intel.com>
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/rtnetlink.h>
+#include <net/netlink.h>
+#include <net/pkt_sched.h>
+
+#include <linux/tc_act/tc_skbedit.h>
+#include <net/tc_act/tc_skbedit.h>
+
+#define SKBEDIT_TAB_MASK     15
+static struct tcf_common *tcf_skbedit_ht[SKBEDIT_TAB_MASK + 1];
+static u32 skbedit_idx_gen;
+static DEFINE_RWLOCK(skbedit_lock);
+
+static struct tcf_hashinfo skbedit_hash_info = {
+        .htab   =       tcf_skbedit_ht,
+        .hmask  =       SKBEDIT_TAB_MASK,
+        .lock   =       &skbedit_lock,
+};
+
+static int tcf_skbedit(struct sk_buff *skb, struct tc_action *a,
+                       struct tcf_result *res)
+{
+        struct tcf_skbedit *d = a->priv;
+
+        spin_lock(&d->tcf_lock);
+        d->tcf_tm.lastuse = jiffies;
+        d->tcf_bstats.bytes += qdisc_pkt_len(skb);
+        d->tcf_bstats.packets++;
+
+        if (d->flags & SKBEDIT_F_PRIORITY)
+                skb->priority = d->priority;
+        if (d->flags & SKBEDIT_F_QUEUE_MAPPING &&
+            skb->dev->real_num_tx_queues > d->queue_mapping)
+                skb_set_queue_mapping(skb, d->queue_mapping);
+
+        spin_unlock(&d->tcf_lock);
+        return d->tcf_action;
+}
+
+static const struct nla_policy skbedit_policy[TCA_SKBEDIT_MAX + 1] = {
+        [TCA_SKBEDIT_PARMS]             = { .len = sizeof(struct tc_skbedit) },
+        [TCA_SKBEDIT_PRIORITY]          = { .len = sizeof(u32) },
+        [TCA_SKBEDIT_QUEUE_MAPPING]     = { .len = sizeof(u16) },
+};
+
+static int tcf_skbedit_init(struct nlattr *nla, struct nlattr *est,
+                         struct tc_action *a, int ovr, int bind)
+{
+        struct nlattr *tb[TCA_SKBEDIT_MAX + 1];
+        struct tc_skbedit *parm;
+        struct tcf_skbedit *d;
+        struct tcf_common *pc;
+        u32 flags = 0, *priority = NULL;
+        u16 *queue_mapping = NULL;
+        int ret = 0, err;
+
+        if (nla == NULL)
+                return -EINVAL;
+
+        err = nla_parse_nested(tb, TCA_SKBEDIT_MAX, nla, skbedit_policy);
+        if (err < 0)
+                return err;
+
+        if (tb[TCA_SKBEDIT_PARMS] == NULL)
+                return -EINVAL;
+
+        if (tb[TCA_SKBEDIT_PRIORITY] != NULL) {
+                flags |= SKBEDIT_F_PRIORITY;
+                priority = nla_data(tb[TCA_SKBEDIT_PRIORITY]);
+        }
+
+        if (tb[TCA_SKBEDIT_QUEUE_MAPPING] != NULL) {
+                flags |= SKBEDIT_F_QUEUE_MAPPING;
+                queue_mapping = nla_data(tb[TCA_SKBEDIT_QUEUE_MAPPING]);
+        }
+        if (!flags)
+                return -EINVAL;
+
+        parm = nla_data(tb[TCA_SKBEDIT_PARMS]);
+
+        pc = tcf_hash_check(parm->index, a, bind, &skbedit_hash_info);
+        if (!pc) {
+                pc = tcf_hash_create(parm->index, est, a, sizeof(*d), bind,
+                                     &skbedit_idx_gen, &skbedit_hash_info);
+                if (unlikely(!pc))
+                        return -ENOMEM;
+
+                d = to_skbedit(pc);
+                ret = ACT_P_CREATED;
+        } else {
+                d = to_skbedit(pc);
+                if (!ovr) {
+                        tcf_hash_release(pc, bind, &skbedit_hash_info);
+                        return -EEXIST;
+                }
+        }
+
+        spin_lock_bh(&d->tcf_lock);
+
+        d->flags = flags;
+        if (flags & SKBEDIT_F_PRIORITY)
+                d->priority = *priority;
+        if (flags & SKBEDIT_F_QUEUE_MAPPING)
+                d->queue_mapping = *queue_mapping;
+        d->tcf_action = parm->action;
+
+        spin_unlock_bh(&d->tcf_lock);
+
+        if (ret == ACT_P_CREATED)
+                tcf_hash_insert(pc, &skbedit_hash_info);
+        return ret;
+}
+
+static inline int tcf_skbedit_cleanup(struct tc_action *a, int bind)
+{
+        struct tcf_skbedit *d = a->priv;
+
+        if (d)
+                return tcf_hash_release(&d->common, bind, &skbedit_hash_info);
+        return 0;
+}
+
+static inline int tcf_skbedit_dump(struct sk_buff *skb, struct tc_action *a,
+                                int bind, int ref)
+{
+        unsigned char *b = skb_tail_pointer(skb);
+        struct tcf_skbedit *d = a->priv;
+        struct tc_skbedit opt;
+        struct tcf_t t;
+
+        opt.index = d->tcf_index;
+        opt.refcnt = d->tcf_refcnt - ref;
+        opt.bindcnt = d->tcf_bindcnt - bind;
+        opt.action = d->tcf_action;
+        NLA_PUT(skb, TCA_SKBEDIT_PARMS, sizeof(opt), &opt);
+        if (d->flags & SKBEDIT_F_PRIORITY)
+                NLA_PUT(skb, TCA_SKBEDIT_PRIORITY, sizeof(d->priority),
+                        &d->priority);
+        if (d->flags & SKBEDIT_F_QUEUE_MAPPING)
+                NLA_PUT(skb, TCA_SKBEDIT_QUEUE_MAPPING,
+                        sizeof(d->queue_mapping), &d->queue_mapping);
+        t.install = jiffies_to_clock_t(jiffies - d->tcf_tm.install);
+        t.lastuse = jiffies_to_clock_t(jiffies - d->tcf_tm.lastuse);
+        t.expires = jiffies_to_clock_t(d->tcf_tm.expires);
+        NLA_PUT(skb, TCA_SKBEDIT_TM, sizeof(t), &t);
+        return skb->len;
+
+nla_put_failure:
+        nlmsg_trim(skb, b);
+        return -1;
+}
+
+static struct tc_action_ops act_skbedit_ops = {
+        .kind           =       "skbedit",
+        .hinfo          =       &skbedit_hash_info,
+        .type           =       TCA_ACT_SKBEDIT,
+        .capab          =       TCA_CAP_NONE,
+        .owner          =       THIS_MODULE,
+        .act            =       tcf_skbedit,
+        .dump           =       tcf_skbedit_dump,
+        .cleanup        =       tcf_skbedit_cleanup,
+        .init           =       tcf_skbedit_init,
+        .walk           =       tcf_generic_walker,
+};
+
+MODULE_AUTHOR("Alexander Duyck, <alexander.h.duyck@intel.com>");
+MODULE_DESCRIPTION("SKB Editing");
+MODULE_LICENSE("GPL");
+
+static int __init skbedit_init_module(void)
+{
+        return tcf_register_action(&act_skbedit_ops);
+}
+
+static void __exit skbedit_cleanup_module(void)
+{
+        tcf_unregister_action(&act_skbedit_ops);
+}
+
+module_init(skbedit_init_module);
+module_exit(skbedit_cleanup_module);