4 files changed, 722 insertions, 0 deletions

diff --git a/include/linux/pkt_cls.h b/include/linux/pkt_cls.h
index 30b8571e6b34..1c1dba9ea5fb 100644
--- a/include/linux/pkt_cls.h
+++ b/include/linux/pkt_cls.h
@@ -328,6 +328,56 @@ enum
 
 #define TCA_TCINDEX_MAX     (__TCA_TCINDEX_MAX - 1)
 
+/* Flow filter */
+
+enum
+{
+        FLOW_KEY_SRC,
+        FLOW_KEY_DST,
+        FLOW_KEY_PROTO,
+        FLOW_KEY_PROTO_SRC,
+        FLOW_KEY_PROTO_DST,
+        FLOW_KEY_IIF,
+        FLOW_KEY_PRIORITY,
+        FLOW_KEY_MARK,
+        FLOW_KEY_NFCT,
+        FLOW_KEY_NFCT_SRC,
+        FLOW_KEY_NFCT_DST,
+        FLOW_KEY_NFCT_PROTO_SRC,
+        FLOW_KEY_NFCT_PROTO_DST,
+        FLOW_KEY_RTCLASSID,
+        FLOW_KEY_SKUID,
+        FLOW_KEY_SKGID,
+        __FLOW_KEY_MAX,
+};
+
+#define FLOW_KEY_MAX    (__FLOW_KEY_MAX - 1)
+
+enum
+{
+        FLOW_MODE_MAP,
+        FLOW_MODE_HASH,
+};
+
+enum
+{
+        TCA_FLOW_UNSPEC,
+        TCA_FLOW_KEYS,
+        TCA_FLOW_MODE,
+        TCA_FLOW_BASECLASS,
+        TCA_FLOW_RSHIFT,
+        TCA_FLOW_ADDEND,
+        TCA_FLOW_MASK,
+        TCA_FLOW_XOR,
+        TCA_FLOW_DIVISOR,
+        TCA_FLOW_ACT,
+        TCA_FLOW_POLICE,
+        TCA_FLOW_EMATCHES,
+        __TCA_FLOW_MAX
+};
+
+#define TCA_FLOW_MAX    (__TCA_FLOW_MAX - 1)
+
 /* Basic filter */
 
 enum
diff --git a/net/sched/Kconfig b/net/sched/Kconfig
index 7d4085a4af66..82adfe6447d7 100644
--- a/net/sched/Kconfig
+++ b/net/sched/Kconfig
@@ -307,6 +307,17 @@ config NET_CLS_RSVP6
           To compile this code as a module, choose M here: the
           module will be called cls_rsvp6.
 
+config NET_CLS_FLOW
+        tristate "Flow classifier"
+        select NET_CLS
+        ---help---
+          If you say Y here, you will be able to classify packets based on
+          a configurable combination of packet keys. This is mostly useful
+          in combination with SFQ.
+
+          To compile this code as a module, choose M here: the
+          module will be called cls_flow.
+
 config NET_EMATCH
         bool "Extended Matches"
         select NET_CLS
diff --git a/net/sched/Makefile b/net/sched/Makefile
index 81ecbe8e7dce..1d2b0f7df848 100644
--- a/net/sched/Makefile
+++ b/net/sched/Makefile
@@ -35,6 +35,7 @@ obj-$(CONFIG_NET_CLS_RSVP)	+= cls_rsvp.o
 obj-$(CONFIG_NET_CLS_TCINDEX)   += cls_tcindex.o
 obj-$(CONFIG_NET_CLS_RSVP6)     += cls_rsvp6.o
 obj-$(CONFIG_NET_CLS_BASIC)     += cls_basic.o
+obj-$(CONFIG_NET_CLS_FLOW)      += cls_flow.o
 obj-$(CONFIG_NET_EMATCH)        += ematch.o
 obj-$(CONFIG_NET_EMATCH_CMP)    += em_cmp.o
 obj-$(CONFIG_NET_EMATCH_NBYTE)  += em_nbyte.o
diff --git a/net/sched/cls_flow.c b/net/sched/cls_flow.c
new file mode 100644
index 000000000000..5a7f6a3060fc
--- /dev/null
+++ b/net/sched/cls_flow.c
@@ -0,0 +1,660 @@
+/*
+ * net/sched/cls_flow.c         Generic flow classifier
+ *
+ * Copyright (c) 2007, 2008 Patrick McHardy <kaber@trash.net>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/list.h>
+#include <linux/jhash.h>
+#include <linux/random.h>
+#include <linux/pkt_cls.h>
+#include <linux/skbuff.h>
+#include <linux/in.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+
+#include <net/pkt_cls.h>
+#include <net/ip.h>
+#include <net/route.h>
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+#include <net/netfilter/nf_conntrack.h>
+#endif
+
+struct flow_head {
+        struct list_head        filters;
+};
+
+struct flow_filter {
+        struct list_head        list;
+        struct tcf_exts         exts;
+        struct tcf_ematch_tree  ematches;
+        u32                     handle;
+
+        u32                     nkeys;
+        u32                     keymask;
+        u32                     mode;
+        u32                     mask;
+        u32                     xor;
+        u32                     rshift;
+        u32                     addend;
+        u32                     divisor;
+        u32                     baseclass;
+};
+
+static u32 flow_hashrnd __read_mostly;
+static int flow_hashrnd_initted __read_mostly;
+
+static const struct tcf_ext_map flow_ext_map = {
+        .action = TCA_FLOW_ACT,
+        .police = TCA_FLOW_POLICE,
+};
+
+static inline u32 addr_fold(void *addr)
+{
+        unsigned long a = (unsigned long)addr;
+
+        return (a & 0xFFFFFFFF) ^ (BITS_PER_LONG > 32 ? a >> 32 : 0);
+}
+
+static u32 flow_get_src(const struct sk_buff *skb)
+{
+        switch (skb->protocol) {
+        case __constant_htons(ETH_P_IP):
+                return ntohl(ip_hdr(skb)->saddr);
+        case __constant_htons(ETH_P_IPV6):
+                return ntohl(ipv6_hdr(skb)->saddr.s6_addr32[3]);
+        default:
+                return addr_fold(skb->sk);
+        }
+}
+
+static u32 flow_get_dst(const struct sk_buff *skb)
+{
+        switch (skb->protocol) {
+        case __constant_htons(ETH_P_IP):
+                return ntohl(ip_hdr(skb)->daddr);
+        case __constant_htons(ETH_P_IPV6):
+                return ntohl(ipv6_hdr(skb)->daddr.s6_addr32[3]);
+        default:
+                return addr_fold(skb->dst) ^ (__force u16)skb->protocol;
+        }
+}
+
+static u32 flow_get_proto(const struct sk_buff *skb)
+{
+        switch (skb->protocol) {
+        case __constant_htons(ETH_P_IP):
+                return ip_hdr(skb)->protocol;
+        case __constant_htons(ETH_P_IPV6):
+                return ipv6_hdr(skb)->nexthdr;
+        default:
+                return 0;
+        }
+}
+
+static int has_ports(u8 protocol)
+{
+        switch (protocol) {
+        case IPPROTO_TCP:
+        case IPPROTO_UDP:
+        case IPPROTO_UDPLITE:
+        case IPPROTO_SCTP:
+        case IPPROTO_DCCP:
+        case IPPROTO_ESP:
+                return 1;
+        default:
+                return 0;
+        }
+}
+
+static u32 flow_get_proto_src(const struct sk_buff *skb)
+{
+        u32 res = 0;
+
+        switch (skb->protocol) {
+        case __constant_htons(ETH_P_IP): {
+                struct iphdr *iph = ip_hdr(skb);
+
+                if (!(iph->frag_off&htons(IP_MF|IP_OFFSET)) &&
+                    has_ports(iph->protocol))
+                        res = ntohs(*(__be16 *)((void *)iph + iph->ihl * 4));
+                break;
+        }
+        case __constant_htons(ETH_P_IPV6): {
+                struct ipv6hdr *iph = ipv6_hdr(skb);
+
+                if (has_ports(iph->nexthdr))
+                        res = ntohs(*(__be16 *)&iph[1]);
+                break;
+        }
+        default:
+                res = addr_fold(skb->sk);
+        }
+
+        return res;
+}
+
+static u32 flow_get_proto_dst(const struct sk_buff *skb)
+{
+        u32 res = 0;
+
+        switch (skb->protocol) {
+        case __constant_htons(ETH_P_IP): {
+                struct iphdr *iph = ip_hdr(skb);
+
+                if (!(iph->frag_off&htons(IP_MF|IP_OFFSET)) &&
+                    has_ports(iph->protocol))
+                        res = ntohs(*(__be16 *)((void *)iph + iph->ihl * 4 + 2));
+                break;
+        }
+        case __constant_htons(ETH_P_IPV6): {
+                struct ipv6hdr *iph = ipv6_hdr(skb);
+
+                if (has_ports(iph->nexthdr))
+                        res = ntohs(*(__be16 *)((void *)&iph[1] + 2));
+                break;
+        }
+        default:
+                res = addr_fold(skb->dst) ^ (__force u16)skb->protocol;
+        }
+
+        return res;
+}
+
+static u32 flow_get_iif(const struct sk_buff *skb)
+{
+        return skb->iif;
+}
+
+static u32 flow_get_priority(const struct sk_buff *skb)
+{
+        return skb->priority;
+}
+
+static u32 flow_get_mark(const struct sk_buff *skb)
+{
+        return skb->mark;
+}
+
+static u32 flow_get_nfct(const struct sk_buff *skb)
+{
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+        return addr_fold(skb->nfct);
+#else
+        return 0;
+#endif
+}
+
+#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
+#define CTTUPLE(skb, member)                                            \
+({                                                                      \
+        enum ip_conntrack_info ctinfo;                                  \
+        struct nf_conn *ct = nf_ct_get(skb, &ctinfo);                   \
+        if (ct == NULL)                                                 \
+                goto fallback;                                          \
+        ct->tuplehash[CTINFO2DIR(ctinfo)].tuple.member;                 \
+})
+#else
+#define CTTUPLE(skb, member)                                            \
+({                                                                      \
+        goto fallback;                                                  \
+        0;                                                              \
+})
+#endif
+
+static u32 flow_get_nfct_src(const struct sk_buff *skb)
+{
+        switch (skb->protocol) {
+        case __constant_htons(ETH_P_IP):
+                return ntohl(CTTUPLE(skb, src.u3.ip));
+        case __constant_htons(ETH_P_IPV6):
+                return ntohl(CTTUPLE(skb, src.u3.ip6[3]));
+        }
+fallback:
+        return flow_get_src(skb);
+}
+
+static u32 flow_get_nfct_dst(const struct sk_buff *skb)
+{
+        switch (skb->protocol) {
+        case __constant_htons(ETH_P_IP):
+                return ntohl(CTTUPLE(skb, dst.u3.ip));
+        case __constant_htons(ETH_P_IPV6):
+                return ntohl(CTTUPLE(skb, dst.u3.ip6[3]));
+        }
+fallback:
+        return flow_get_dst(skb);
+}
+
+static u32 flow_get_nfct_proto_src(const struct sk_buff *skb)
+{
+        return ntohs(CTTUPLE(skb, src.u.all));
+fallback:
+        return flow_get_proto_src(skb);
+}
+
+static u32 flow_get_nfct_proto_dst(const struct sk_buff *skb)
+{
+        return ntohs(CTTUPLE(skb, dst.u.all));
+fallback:
+        return flow_get_proto_dst(skb);
+}
+
+static u32 flow_get_rtclassid(const struct sk_buff *skb)
+{
+#ifdef CONFIG_NET_CLS_ROUTE
+        if (skb->dst)
+                return skb->dst->tclassid;
+#endif
+        return 0;
+}
+
+static u32 flow_get_skuid(const struct sk_buff *skb)
+{
+        if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file)
+                return skb->sk->sk_socket->file->f_uid;
+        return 0;
+}
+
+static u32 flow_get_skgid(const struct sk_buff *skb)
+{
+        if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file)
+                return skb->sk->sk_socket->file->f_gid;
+        return 0;
+}
+
+static u32 flow_key_get(const struct sk_buff *skb, int key)
+{
+        switch (key) {
+        case FLOW_KEY_SRC:
+                return flow_get_src(skb);
+        case FLOW_KEY_DST:
+                return flow_get_dst(skb);
+        case FLOW_KEY_PROTO:
+                return flow_get_proto(skb);
+        case FLOW_KEY_PROTO_SRC:
+                return flow_get_proto_src(skb);
+        case FLOW_KEY_PROTO_DST:
+                return flow_get_proto_dst(skb);
+        case FLOW_KEY_IIF:
+                return flow_get_iif(skb);
+        case FLOW_KEY_PRIORITY:
+                return flow_get_priority(skb);
+        case FLOW_KEY_MARK:
+                return flow_get_mark(skb);
+        case FLOW_KEY_NFCT:
+                return flow_get_nfct(skb);
+        case FLOW_KEY_NFCT_SRC:
+                return flow_get_nfct_src(skb);
+        case FLOW_KEY_NFCT_DST:
+                return flow_get_nfct_dst(skb);
+        case FLOW_KEY_NFCT_PROTO_SRC:
+                return flow_get_nfct_proto_src(skb);
+        case FLOW_KEY_NFCT_PROTO_DST:
+                return flow_get_nfct_proto_dst(skb);
+        case FLOW_KEY_RTCLASSID:
+                return flow_get_rtclassid(skb);
+        case FLOW_KEY_SKUID:
+                return flow_get_skuid(skb);
+        case FLOW_KEY_SKGID:
+                return flow_get_skgid(skb);
+        default:
+                WARN_ON(1);
+                return 0;
+        }
+}
+
+static int flow_classify(struct sk_buff *skb, struct tcf_proto *tp,
+                         struct tcf_result *res)
+{
+        struct flow_head *head = tp->root;
+        struct flow_filter *f;
+        u32 keymask;
+        u32 classid;
+        unsigned int n, key;
+        int r;
+
+        list_for_each_entry(f, &head->filters, list) {
+                u32 keys[f->nkeys];
+
+                if (!tcf_em_tree_match(skb, &f->ematches, NULL))
+                        continue;
+
+                keymask = f->keymask;
+
+                for (n = 0; n < f->nkeys; n++) {
+                        key = ffs(keymask) - 1;
+                        keymask &= ~(1 << key);
+                        keys[n] = flow_key_get(skb, key);
+                }
+
+                if (f->mode == FLOW_MODE_HASH)
+                        classid = jhash2(keys, f->nkeys, flow_hashrnd);
+                else {
+                        classid = keys[0];
+                        classid = (classid & f->mask) ^ f->xor;
+                        classid = (classid >> f->rshift) + f->addend;
+                }
+
+                if (f->divisor)
+                        classid %= f->divisor;
+
+                res->class   = 0;
+                res->classid = TC_H_MAKE(f->baseclass, f->baseclass + classid);
+
+                r = tcf_exts_exec(skb, &f->exts, res);
+                if (r < 0)
+                        continue;
+                return r;
+        }
+        return -1;
+}
+
+static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
+        [TCA_FLOW_KEYS]         = { .type = NLA_U32 },
+        [TCA_FLOW_MODE]         = { .type = NLA_U32 },
+        [TCA_FLOW_BASECLASS]    = { .type = NLA_U32 },
+        [TCA_FLOW_RSHIFT]       = { .type = NLA_U32 },
+        [TCA_FLOW_ADDEND]       = { .type = NLA_U32 },
+        [TCA_FLOW_MASK]         = { .type = NLA_U32 },
+        [TCA_FLOW_XOR]          = { .type = NLA_U32 },
+        [TCA_FLOW_DIVISOR]      = { .type = NLA_U32 },
+        [TCA_FLOW_ACT]          = { .type = NLA_NESTED },
+        [TCA_FLOW_POLICE]       = { .type = NLA_NESTED },
+        [TCA_FLOW_EMATCHES]     = { .type = NLA_NESTED },
+};
+
+static int flow_change(struct tcf_proto *tp, unsigned long base,
+                       u32 handle, struct nlattr **tca,
+                       unsigned long *arg)
+{
+        struct flow_head *head = tp->root;
+        struct flow_filter *f;
+        struct nlattr *opt = tca[TCA_OPTIONS];
+        struct nlattr *tb[TCA_FLOW_MAX + 1];
+        struct tcf_exts e;
+        struct tcf_ematch_tree t;
+        unsigned int nkeys = 0;
+        u32 baseclass = 0;
+        u32 keymask = 0;
+        u32 mode;
+        int err;
+
+        if (opt == NULL)
+                return -EINVAL;
+
+        err = nla_parse_nested(tb, TCA_FLOW_MAX, opt, flow_policy);
+        if (err < 0)
+                return err;
+
+        if (tb[TCA_FLOW_BASECLASS]) {
+                baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]);
+                if (TC_H_MIN(baseclass) == 0)
+                        return -EINVAL;
+        }
+
+        if (tb[TCA_FLOW_KEYS]) {
+                keymask = nla_get_u32(tb[TCA_FLOW_KEYS]);
+                if (fls(keymask) - 1 > FLOW_KEY_MAX)
+                        return -EOPNOTSUPP;
+
+                nkeys = hweight32(keymask);
+                if (nkeys == 0)
+                        return -EINVAL;
+        }
+
+        err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &flow_ext_map);
+        if (err < 0)
+                return err;
+
+        err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &t);
+        if (err < 0)
+                goto err1;
+
+        f = (struct flow_filter *)*arg;
+        if (f != NULL) {
+                err = -EINVAL;
+                if (f->handle != handle && handle)
+                        goto err2;
+
+                mode = f->mode;
+                if (tb[TCA_FLOW_MODE])
+                        mode = nla_get_u32(tb[TCA_FLOW_MODE]);
+                if (mode != FLOW_MODE_HASH && nkeys > 1)
+                        goto err2;
+        } else {
+                err = -EINVAL;
+                if (!handle)
+                        goto err2;
+                if (!tb[TCA_FLOW_KEYS])
+                        goto err2;
+
+                mode = FLOW_MODE_MAP;
+                if (tb[TCA_FLOW_MODE])
+                        mode = nla_get_u32(tb[TCA_FLOW_MODE]);
+                if (mode != FLOW_MODE_HASH && nkeys > 1)
+                        goto err2;
+
+                if (TC_H_MAJ(baseclass) == 0)
+                        baseclass = TC_H_MAKE(tp->q->handle, baseclass);
+                if (TC_H_MIN(baseclass) == 0)
+                        baseclass = TC_H_MAKE(baseclass, 1);
+
+                err = -ENOBUFS;
+                f = kzalloc(sizeof(*f), GFP_KERNEL);
+                if (f == NULL)
+                        goto err2;
+
+                f->handle = handle;
+                f->mask   = ~0U;
+        }
+
+        tcf_exts_change(tp, &f->exts, &e);
+        tcf_em_tree_change(tp, &f->ematches, &t);
+
+        tcf_tree_lock(tp);
+
+        if (tb[TCA_FLOW_KEYS]) {
+                f->keymask = keymask;
+                f->nkeys   = nkeys;
+        }
+
+        f->mode = mode;
+
+        if (tb[TCA_FLOW_MASK])
+                f->mask = nla_get_u32(tb[TCA_FLOW_MASK]);
+        if (tb[TCA_FLOW_XOR])
+                f->xor = nla_get_u32(tb[TCA_FLOW_XOR]);
+        if (tb[TCA_FLOW_RSHIFT])
+                f->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]);
+        if (tb[TCA_FLOW_ADDEND])
+                f->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]);
+
+        if (tb[TCA_FLOW_DIVISOR])
+                f->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]);
+        if (baseclass)
+                f->baseclass = baseclass;
+
+        if (*arg == 0)
+                list_add_tail(&f->list, &head->filters);
+
+        tcf_tree_unlock(tp);
+
+        *arg = (unsigned long)f;
+        return 0;
+
+err2:
+        tcf_em_tree_destroy(tp, &t);
+err1:
+        tcf_exts_destroy(tp, &e);
+        return err;
+}
+
+static void flow_destroy_filter(struct tcf_proto *tp, struct flow_filter *f)
+{
+        tcf_exts_destroy(tp, &f->exts);
+        tcf_em_tree_destroy(tp, &f->ematches);
+        kfree(f);
+}
+
+static int flow_delete(struct tcf_proto *tp, unsigned long arg)
+{
+        struct flow_filter *f = (struct flow_filter *)arg;
+
+        tcf_tree_lock(tp);
+        list_del(&f->list);
+        tcf_tree_unlock(tp);
+        flow_destroy_filter(tp, f);
+        return 0;
+}
+
+static int flow_init(struct tcf_proto *tp)
+{
+        struct flow_head *head;
+
+        if (!flow_hashrnd_initted) {
+                get_random_bytes(&flow_hashrnd, 4);
+                flow_hashrnd_initted = 1;
+        }
+
+        head = kzalloc(sizeof(*head), GFP_KERNEL);
+        if (head == NULL)
+                return -ENOBUFS;
+        INIT_LIST_HEAD(&head->filters);
+        tp->root = head;
+        return 0;
+}
+
+static void flow_destroy(struct tcf_proto *tp)
+{
+        struct flow_head *head = tp->root;
+        struct flow_filter *f, *next;
+
+        list_for_each_entry_safe(f, next, &head->filters, list) {
+                list_del(&f->list);
+                flow_destroy_filter(tp, f);
+        }
+        kfree(head);
+}
+
+static unsigned long flow_get(struct tcf_proto *tp, u32 handle)
+{
+        struct flow_head *head = tp->root;
+        struct flow_filter *f;
+
+        list_for_each_entry(f, &head->filters, list)
+                if (f->handle == handle)
+                        return (unsigned long)f;
+        return 0;
+}
+
+static void flow_put(struct tcf_proto *tp, unsigned long f)
+{
+        return;
+}
+
+static int flow_dump(struct tcf_proto *tp, unsigned long fh,
+                     struct sk_buff *skb, struct tcmsg *t)
+{
+        struct flow_filter *f = (struct flow_filter *)fh;
+        struct nlattr *nest;
+
+        if (f == NULL)
+                return skb->len;
+
+        t->tcm_handle = f->handle;
+
+        nest = nla_nest_start(skb, TCA_OPTIONS);
+        if (nest == NULL)
+                goto nla_put_failure;
+
+        NLA_PUT_U32(skb, TCA_FLOW_KEYS, f->keymask);
+        NLA_PUT_U32(skb, TCA_FLOW_MODE, f->mode);
+
+        if (f->mask != ~0 || f->xor != 0) {
+                NLA_PUT_U32(skb, TCA_FLOW_MASK, f->mask);
+                NLA_PUT_U32(skb, TCA_FLOW_XOR, f->xor);
+        }
+        if (f->rshift)
+                NLA_PUT_U32(skb, TCA_FLOW_RSHIFT, f->rshift);
+        if (f->addend)
+                NLA_PUT_U32(skb, TCA_FLOW_ADDEND, f->addend);
+
+        if (f->divisor)
+                NLA_PUT_U32(skb, TCA_FLOW_DIVISOR, f->divisor);
+        if (f->baseclass)
+                NLA_PUT_U32(skb, TCA_FLOW_BASECLASS, f->baseclass);
+
+        if (tcf_exts_dump(skb, &f->exts, &flow_ext_map) < 0)
+                goto nla_put_failure;
+
+        if (f->ematches.hdr.nmatches &&
+            tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0)
+                goto nla_put_failure;
+
+        nla_nest_end(skb, nest);
+
+        if (tcf_exts_dump_stats(skb, &f->exts, &flow_ext_map) < 0)
+                goto nla_put_failure;
+
+        return skb->len;
+
+nla_put_failure:
+        nlmsg_trim(skb, nest);
+        return -1;
+}
+
+static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg)
+{
+        struct flow_head *head = tp->root;
+        struct flow_filter *f;
+
+        list_for_each_entry(f, &head->filters, list) {
+                if (arg->count < arg->skip)
+                        goto skip;
+                if (arg->fn(tp, (unsigned long)f, arg) < 0) {
+                        arg->stop = 1;
+                        break;
+                }
+skip:
+                arg->count++;
+        }
+}
+
+static struct tcf_proto_ops cls_flow_ops __read_mostly = {
+        .kind           = "flow",
+        .classify       = flow_classify,
+        .init           = flow_init,
+        .destroy        = flow_destroy,
+        .change         = flow_change,
+        .delete         = flow_delete,
+        .get            = flow_get,
+        .put            = flow_put,
+        .dump           = flow_dump,
+        .walk           = flow_walk,
+        .owner          = THIS_MODULE,
+};
+
+static int __init cls_flow_init(void)
+{
+        return register_tcf_proto_ops(&cls_flow_ops);
+}
+
+static void __exit cls_flow_exit(void)
+{
+        unregister_tcf_proto_ops(&cls_flow_ops);
+}
+
+module_init(cls_flow_init);
+module_exit(cls_flow_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
+MODULE_DESCRIPTION("TC flow classifier");