1 files changed, 661 insertions, 0 deletions

diff --git a/net/sched/em_meta.c b/net/sched/em_meta.c
new file mode 100644
index 000000000000..f1eeaf65cee5
--- /dev/null
+++ b/net/sched/em_meta.c
@@ -0,0 +1,661 @@
+/*
+ * net/sched/em_meta.c  Metadata ematch
+ *
+ *              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.
+ *
+ * Authors:     Thomas Graf <tgraf@suug.ch>
+ *
+ * ==========================================================================
+ * 
+ *      The metadata ematch compares two meta objects where each object
+ *      represents either a meta value stored in the kernel or a static
+ *      value provided by userspace. The objects are not provided by
+ *      userspace itself but rather a definition providing the information
+ *      to build them. Every object is of a certain type which must be
+ *      equal to the object it is being compared to.
+ *
+ *      The definition of a objects conists of the type (meta type), a
+ *      identifier (meta id) and additional type specific information.
+ *      The meta id is either TCF_META_TYPE_VALUE for values provided by
+ *      userspace or a index to the meta operations table consisting of
+ *      function pointers to type specific meta data collectors returning
+ *      the value of the requested meta value.
+ *
+ *               lvalue                                   rvalue
+ *            +-----------+                           +-----------+
+ *            | type: INT |                           | type: INT |
+ *       def  | id: INDEV |                           | id: VALUE |
+ *            | data:     |                           | data: 3   |
+ *            +-----------+                           +-----------+
+ *                  |                                       |
+ *                  ---> meta_ops[INT][INDEV](...)          |
+ *                            |                            |
+ *                  -----------                             |
+ *                  V                                       V
+ *            +-----------+                           +-----------+
+ *            | type: INT |                           | type: INT |
+ *       obj  | id: INDEV |                           | id: VALUE |
+ *            | data: 2   |<--data got filled out     | data: 3   |
+ *            +-----------+                           +-----------+
+ *                  |                                         |
+ *                  --------------> 2  equals 3 <--------------
+ *
+ *      This is a simplified schema, the complexity varies depending
+ *      on the meta type. Obviously, the length of the data must also
+ *      be provided for non-numeric types.
+ *
+ *      Additionaly, type dependant modifiers such as shift operators
+ *      or mask may be applied to extend the functionaliy. As of now,
+ *      the variable length type supports shifting the byte string to
+ *      the right, eating up any number of octets and thus supporting
+ *      wildcard interface name comparisons such as "ppp%" matching
+ *      ppp0..9.
+ *
+ *      NOTE: Certain meta values depend on other subsystems and are
+ *            only available if that subsytem is enabled in the kernel.
+ */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/string.h>
+#include <linux/skbuff.h>
+#include <linux/random.h>
+#include <linux/tc_ematch/tc_em_meta.h>
+#include <net/dst.h>
+#include <net/route.h>
+#include <net/pkt_cls.h>
+
+struct meta_obj
+{
+        unsigned long           value;
+        unsigned int            len;
+};
+
+struct meta_value
+{
+        struct tcf_meta_val     hdr;
+        unsigned long           val;
+        unsigned int            len;
+};
+
+struct meta_match
+{
+        struct meta_value       lvalue;
+        struct meta_value       rvalue;
+};
+
+static inline int meta_id(struct meta_value *v)
+{
+        return TCF_META_ID(v->hdr.kind);
+}
+
+static inline int meta_type(struct meta_value *v)
+{
+        return TCF_META_TYPE(v->hdr.kind);
+}
+
+#define META_COLLECTOR(FUNC) static void meta_##FUNC(struct sk_buff *skb, \
+        struct tcf_pkt_info *info, struct meta_value *v, \
+        struct meta_obj *dst, int *err)
+
+/**************************************************************************
+ * System status & misc
+ **************************************************************************/
+
+META_COLLECTOR(int_random)
+{
+        get_random_bytes(&dst->value, sizeof(dst->value));
+}
+
+static inline unsigned long fixed_loadavg(int load)
+{
+        int rnd_load = load + (FIXED_1/200);
+        int rnd_frac = ((rnd_load & (FIXED_1-1)) * 100) >> FSHIFT;
+
+        return ((rnd_load >> FSHIFT) * 100) + rnd_frac;
+}
+
+META_COLLECTOR(int_loadavg_0)
+{
+        dst->value = fixed_loadavg(avenrun[0]);
+}
+
+META_COLLECTOR(int_loadavg_1)
+{
+        dst->value = fixed_loadavg(avenrun[1]);
+}
+
+META_COLLECTOR(int_loadavg_2)
+{
+        dst->value = fixed_loadavg(avenrun[2]);
+}
+
+/**************************************************************************
+ * Device names & indices
+ **************************************************************************/
+
+static inline int int_dev(struct net_device *dev, struct meta_obj *dst)
+{
+        if (unlikely(dev == NULL))
+                return -1;
+
+        dst->value = dev->ifindex;
+        return 0;
+}
+
+static inline int var_dev(struct net_device *dev, struct meta_obj *dst)
+{
+        if (unlikely(dev == NULL))
+                return -1;
+
+        dst->value = (unsigned long) dev->name;
+        dst->len = strlen(dev->name);
+        return 0;
+}
+
+META_COLLECTOR(int_dev)
+{
+        *err = int_dev(skb->dev, dst);
+}
+
+META_COLLECTOR(var_dev)
+{
+        *err = var_dev(skb->dev, dst);
+}
+
+META_COLLECTOR(int_indev)
+{
+        *err = int_dev(skb->input_dev, dst);
+}
+
+META_COLLECTOR(var_indev)
+{
+        *err = var_dev(skb->input_dev, dst);
+}
+
+META_COLLECTOR(int_realdev)
+{
+        *err = int_dev(skb->real_dev, dst);
+}
+
+META_COLLECTOR(var_realdev)
+{
+        *err = var_dev(skb->real_dev, dst);
+}
+
+/**************************************************************************
+ * skb attributes
+ **************************************************************************/
+
+META_COLLECTOR(int_priority)
+{
+        dst->value = skb->priority;
+}
+
+META_COLLECTOR(int_protocol)
+{
+        /* Let userspace take care of the byte ordering */
+        dst->value = skb->protocol;
+}
+
+META_COLLECTOR(int_security)
+{
+        dst->value = skb->security;
+}
+
+META_COLLECTOR(int_pkttype)
+{
+        dst->value = skb->pkt_type;
+}
+
+META_COLLECTOR(int_pktlen)
+{
+        dst->value = skb->len;
+}
+
+META_COLLECTOR(int_datalen)
+{
+        dst->value = skb->data_len;
+}
+
+META_COLLECTOR(int_maclen)
+{
+        dst->value = skb->mac_len;
+}
+
+/**************************************************************************
+ * Netfilter
+ **************************************************************************/
+
+#ifdef CONFIG_NETFILTER
+META_COLLECTOR(int_nfmark)
+{
+        dst->value = skb->nfmark;
+}
+#endif
+
+/**************************************************************************
+ * Traffic Control
+ **************************************************************************/
+
+META_COLLECTOR(int_tcindex)
+{
+        dst->value = skb->tc_index;
+}
+
+#ifdef CONFIG_NET_CLS_ACT
+META_COLLECTOR(int_tcverd)
+{
+        dst->value = skb->tc_verd;
+}
+
+META_COLLECTOR(int_tcclassid)
+{
+        dst->value = skb->tc_classid;
+}
+#endif
+
+/**************************************************************************
+ * Routing
+ **************************************************************************/
+
+#ifdef CONFIG_NET_CLS_ROUTE
+META_COLLECTOR(int_rtclassid)
+{
+        if (unlikely(skb->dst == NULL))
+                *err = -1;
+        else
+                dst->value = skb->dst->tclassid;
+}
+#endif
+
+META_COLLECTOR(int_rtiif)
+{
+        if (unlikely(skb->dst == NULL))
+                *err = -1;
+        else
+                dst->value = ((struct rtable*) skb->dst)->fl.iif;
+}
+
+/**************************************************************************
+ * Meta value collectors assignment table
+ **************************************************************************/
+
+struct meta_ops
+{
+        void            (*get)(struct sk_buff *, struct tcf_pkt_info *,
+                               struct meta_value *, struct meta_obj *, int *);
+};
+
+/* Meta value operations table listing all meta value collectors and
+ * assigns them to a type and meta id. */
+static struct meta_ops __meta_ops[TCF_META_TYPE_MAX+1][TCF_META_ID_MAX+1] = {
+        [TCF_META_TYPE_VAR] = {
+                [TCF_META_ID_DEV]       = { .get = meta_var_dev },
+                [TCF_META_ID_INDEV]     = { .get = meta_var_indev },
+                [TCF_META_ID_REALDEV]   = { .get = meta_var_realdev }
+        },
+        [TCF_META_TYPE_INT] = {
+                [TCF_META_ID_RANDOM]    = { .get = meta_int_random },
+                [TCF_META_ID_LOADAVG_0] = { .get = meta_int_loadavg_0 },
+                [TCF_META_ID_LOADAVG_1] = { .get = meta_int_loadavg_1 },
+                [TCF_META_ID_LOADAVG_2] = { .get = meta_int_loadavg_2 },
+                [TCF_META_ID_DEV]       = { .get = meta_int_dev },
+                [TCF_META_ID_INDEV]     = { .get = meta_int_indev },
+                [TCF_META_ID_REALDEV]   = { .get = meta_int_realdev },
+                [TCF_META_ID_PRIORITY]  = { .get = meta_int_priority },
+                [TCF_META_ID_PROTOCOL]  = { .get = meta_int_protocol },
+                [TCF_META_ID_SECURITY]  = { .get = meta_int_security },
+                [TCF_META_ID_PKTTYPE]   = { .get = meta_int_pkttype },
+                [TCF_META_ID_PKTLEN]    = { .get = meta_int_pktlen },
+                [TCF_META_ID_DATALEN]   = { .get = meta_int_datalen },
+                [TCF_META_ID_MACLEN]    = { .get = meta_int_maclen },
+#ifdef CONFIG_NETFILTER
+                [TCF_META_ID_NFMARK]    = { .get = meta_int_nfmark },
+#endif
+                [TCF_META_ID_TCINDEX]   = { .get = meta_int_tcindex },
+#ifdef CONFIG_NET_CLS_ACT
+                [TCF_META_ID_TCVERDICT] = { .get = meta_int_tcverd },
+                [TCF_META_ID_TCCLASSID] = { .get = meta_int_tcclassid },
+#endif
+#ifdef CONFIG_NET_CLS_ROUTE
+                [TCF_META_ID_RTCLASSID] = { .get = meta_int_rtclassid },
+#endif
+                [TCF_META_ID_RTIIF]     = { .get = meta_int_rtiif }
+        }
+};
+
+static inline struct meta_ops * meta_ops(struct meta_value *val)
+{
+        return &__meta_ops[meta_type(val)][meta_id(val)];
+}
+
+/**************************************************************************
+ * Type specific operations for TCF_META_TYPE_VAR
+ **************************************************************************/
+
+static int meta_var_compare(struct meta_obj *a, struct meta_obj *b)
+{
+        int r = a->len - b->len;
+
+        if (r == 0)
+                r = memcmp((void *) a->value, (void *) b->value, a->len);
+
+        return r;
+}
+
+static int meta_var_change(struct meta_value *dst, struct rtattr *rta)
+{
+        int len = RTA_PAYLOAD(rta);
+
+        dst->val = (unsigned long) kmalloc(len, GFP_KERNEL);
+        if (dst->val == 0UL)
+                return -ENOMEM;
+        memcpy((void *) dst->val, RTA_DATA(rta), len);
+        dst->len = len;
+        return 0;
+}
+
+static void meta_var_destroy(struct meta_value *v)
+{
+        if (v->val)
+                kfree((void *) v->val);
+}
+
+static void meta_var_apply_extras(struct meta_value *v,
+                                  struct meta_obj *dst)
+{
+        int shift = v->hdr.shift;
+
+        if (shift && shift < dst->len)
+                dst->len -= shift;
+}
+
+static int meta_var_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
+{
+        if (v->val && v->len)
+                RTA_PUT(skb, tlv, v->len, (void *) v->val);
+        return 0;
+
+rtattr_failure:
+        return -1;
+}
+
+/**************************************************************************
+ * Type specific operations for TCF_META_TYPE_INT
+ **************************************************************************/
+
+static int meta_int_compare(struct meta_obj *a, struct meta_obj *b)
+{
+        /* Let gcc optimize it, the unlikely is not really based on
+         * some numbers but jump free code for mismatches seems
+         * more logical. */
+        if (unlikely(a == b))
+                return 0;
+        else if (a < b)
+                return -1;
+        else
+                return 1;
+}
+
+static int meta_int_change(struct meta_value *dst, struct rtattr *rta)
+{
+        if (RTA_PAYLOAD(rta) >= sizeof(unsigned long)) {
+                dst->val = *(unsigned long *) RTA_DATA(rta);
+                dst->len = sizeof(unsigned long);
+        } else if (RTA_PAYLOAD(rta) == sizeof(u32)) {
+                dst->val = *(u32 *) RTA_DATA(rta);
+                dst->len = sizeof(u32);
+        } else
+                return -EINVAL;
+
+        return 0;
+}
+
+static void meta_int_apply_extras(struct meta_value *v,
+                                  struct meta_obj *dst)
+{
+        if (v->hdr.shift)
+                dst->value >>= v->hdr.shift;
+
+        if (v->val)
+                dst->value &= v->val;
+}
+
+static int meta_int_dump(struct sk_buff *skb, struct meta_value *v, int tlv)
+{
+        if (v->len == sizeof(unsigned long))
+                RTA_PUT(skb, tlv, sizeof(unsigned long), &v->val);
+        else if (v->len == sizeof(u32)) {
+                u32 d = v->val;
+                RTA_PUT(skb, tlv, sizeof(d), &d);
+        }
+
+        return 0;
+
+rtattr_failure:
+        return -1;
+}
+
+/**************************************************************************
+ * Type specific operations table
+ **************************************************************************/
+
+struct meta_type_ops
+{
+        void    (*destroy)(struct meta_value *);
+        int     (*compare)(struct meta_obj *, struct meta_obj *);
+        int     (*change)(struct meta_value *, struct rtattr *);
+        void    (*apply_extras)(struct meta_value *, struct meta_obj *);
+        int     (*dump)(struct sk_buff *, struct meta_value *, int);
+};
+
+static struct meta_type_ops __meta_type_ops[TCF_META_TYPE_MAX+1] = {
+        [TCF_META_TYPE_VAR] = {
+                .destroy = meta_var_destroy,
+                .compare = meta_var_compare,
+                .change = meta_var_change,
+                .apply_extras = meta_var_apply_extras,
+                .dump = meta_var_dump
+        },
+        [TCF_META_TYPE_INT] = {
+                .compare = meta_int_compare,
+                .change = meta_int_change,
+                .apply_extras = meta_int_apply_extras,
+                .dump = meta_int_dump
+        }
+};
+
+static inline struct meta_type_ops * meta_type_ops(struct meta_value *v)
+{
+        return &__meta_type_ops[meta_type(v)];
+}
+
+/**************************************************************************
+ * Core
+ **************************************************************************/
+
+static inline int meta_get(struct sk_buff *skb, struct tcf_pkt_info *info, 
+                           struct meta_value *v, struct meta_obj *dst)
+{
+        int err = 0;
+
+        if (meta_id(v) == TCF_META_ID_VALUE) {
+                dst->value = v->val;
+                dst->len = v->len;
+                return 0;
+        }
+
+        meta_ops(v)->get(skb, info, v, dst, &err);
+        if (err < 0)
+                return err;
+
+        if (meta_type_ops(v)->apply_extras)
+            meta_type_ops(v)->apply_extras(v, dst);
+
+        return 0;
+}
+
+static int em_meta_match(struct sk_buff *skb, struct tcf_ematch *m,
+                         struct tcf_pkt_info *info)
+{
+        int r;
+        struct meta_match *meta = (struct meta_match *) m->data;
+        struct meta_obj l_value, r_value;
+
+        if (meta_get(skb, info, &meta->lvalue, &l_value) < 0 ||
+            meta_get(skb, info, &meta->rvalue, &r_value) < 0)
+                return 0;
+
+        r = meta_type_ops(&meta->lvalue)->compare(&l_value, &r_value);
+
+        switch (meta->lvalue.hdr.op) {
+                case TCF_EM_OPND_EQ:
+                        return !r;
+                case TCF_EM_OPND_LT:
+                        return r < 0;
+                case TCF_EM_OPND_GT:
+                        return r > 0;
+        }
+
+        return 0;
+}
+
+static inline void meta_delete(struct meta_match *meta)
+{
+        struct meta_type_ops *ops = meta_type_ops(&meta->lvalue);
+
+        if (ops && ops->destroy) {
+                ops->destroy(&meta->lvalue);
+                ops->destroy(&meta->rvalue);
+        }
+
+        kfree(meta);
+}
+
+static inline int meta_change_data(struct meta_value *dst, struct rtattr *rta)
+{
+        if (rta) {
+                if (RTA_PAYLOAD(rta) == 0)
+                        return -EINVAL;
+
+                return meta_type_ops(dst)->change(dst, rta);
+        }
+
+        return 0;
+}
+
+static inline int meta_is_supported(struct meta_value *val)
+{
+        return (!meta_id(val) || meta_ops(val)->get);
+}
+
+static int em_meta_change(struct tcf_proto *tp, void *data, int len,
+                          struct tcf_ematch *m)
+{
+        int err = -EINVAL;
+        struct rtattr *tb[TCA_EM_META_MAX];
+        struct tcf_meta_hdr *hdr;
+        struct meta_match *meta = NULL;
+        
+        if (rtattr_parse(tb, TCA_EM_META_MAX, data, len) < 0)
+                goto errout;
+
+        if (tb[TCA_EM_META_HDR-1] == NULL ||
+            RTA_PAYLOAD(tb[TCA_EM_META_HDR-1]) < sizeof(*hdr))
+                goto errout;
+        hdr = RTA_DATA(tb[TCA_EM_META_HDR-1]);
+
+        if (TCF_META_TYPE(hdr->left.kind) != TCF_META_TYPE(hdr->right.kind) ||
+            TCF_META_TYPE(hdr->left.kind) > TCF_META_TYPE_MAX ||
+            TCF_META_ID(hdr->left.kind) > TCF_META_ID_MAX ||
+            TCF_META_ID(hdr->right.kind) > TCF_META_ID_MAX)
+                goto errout;
+
+        meta = kmalloc(sizeof(*meta), GFP_KERNEL);
+        if (meta == NULL)
+                goto errout;
+        memset(meta, 0, sizeof(*meta));
+
+        memcpy(&meta->lvalue.hdr, &hdr->left, sizeof(hdr->left));
+        memcpy(&meta->rvalue.hdr, &hdr->right, sizeof(hdr->right));
+
+        if (!meta_is_supported(&meta->lvalue) ||
+            !meta_is_supported(&meta->rvalue)) {
+                err = -EOPNOTSUPP;
+                goto errout;
+        }
+
+        if (meta_change_data(&meta->lvalue, tb[TCA_EM_META_LVALUE-1]) < 0 ||
+            meta_change_data(&meta->rvalue, tb[TCA_EM_META_RVALUE-1]) < 0)
+                goto errout;
+
+        m->datalen = sizeof(*meta);
+        m->data = (unsigned long) meta;
+
+        err = 0;
+errout:
+        if (err && meta)
+                meta_delete(meta);
+        return err;
+}
+
+static void em_meta_destroy(struct tcf_proto *tp, struct tcf_ematch *m)
+{
+        if (m)
+                meta_delete((struct meta_match *) m->data);
+}
+
+static int em_meta_dump(struct sk_buff *skb, struct tcf_ematch *em)
+{
+        struct meta_match *meta = (struct meta_match *) em->data;
+        struct tcf_meta_hdr hdr;
+        struct meta_type_ops *ops;
+
+        memset(&hdr, 0, sizeof(hdr));
+        memcpy(&hdr.left, &meta->lvalue.hdr, sizeof(hdr.left));
+        memcpy(&hdr.right, &meta->rvalue.hdr, sizeof(hdr.right));
+
+        RTA_PUT(skb, TCA_EM_META_HDR, sizeof(hdr), &hdr);
+
+        ops = meta_type_ops(&meta->lvalue);
+        if (ops->dump(skb, &meta->lvalue, TCA_EM_META_LVALUE) < 0 ||
+            ops->dump(skb, &meta->rvalue, TCA_EM_META_RVALUE) < 0)
+                goto rtattr_failure;
+
+        return 0;
+
+rtattr_failure:
+        return -1;
+}               
+
+static struct tcf_ematch_ops em_meta_ops = {
+        .kind     = TCF_EM_META,
+        .change   = em_meta_change,
+        .match    = em_meta_match,
+        .destroy  = em_meta_destroy,
+        .dump     = em_meta_dump,
+        .owner    = THIS_MODULE,
+        .link     = LIST_HEAD_INIT(em_meta_ops.link)
+};
+
+static int __init init_em_meta(void)
+{
+        return tcf_em_register(&em_meta_ops);
+}
+
+static void __exit exit_em_meta(void) 
+{
+        tcf_em_unregister(&em_meta_ops);
+}
+
+MODULE_LICENSE("GPL");
+
+module_init(init_em_meta);
+module_exit(exit_em_meta);