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