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/* SPDX-License-Identifier: LGPL-2.1-only */
/*
* lib/route/classifier.c Classifier
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation version 2.1
* of the License.
*
* Copyright (c) 2003-2013 Thomas Graf <tgraf@suug.ch>
*/
/**
* @ingroup tc
* @defgroup cls Classifiers
* @{
*/
#include <netlink-private/netlink.h>
#include <netlink-private/tc.h>
#include <netlink/netlink.h>
#include <netlink/utils.h>
#include <netlink-private/route/tc-api.h>
#include <netlink/route/classifier.h>
#include <netlink/route/link.h>
/** @cond SKIP */
#define CLS_ATTR_PRIO (TCA_ATTR_MAX << 1)
#define CLS_ATTR_PROTOCOL (TCA_ATTR_MAX << 2)
/** @endcond */
static struct nl_object_ops cls_obj_ops;
static struct nl_cache_ops rtnl_cls_ops;
static int cls_build(struct rtnl_cls *cls, int type, int flags,
struct nl_msg **result)
{
int err, prio, proto;
struct tcmsg *tchdr;
uint32_t required = TCA_ATTR_IFINDEX;
if ((cls->ce_mask & required) != required) {
APPBUG("ifindex must be specified");
return -NLE_MISSING_ATTR;
}
err = rtnl_tc_msg_build(TC_CAST(cls), type, flags, result);
if (err < 0)
return err;
tchdr = nlmsg_data(nlmsg_hdr(*result));
prio = rtnl_cls_get_prio(cls);
proto = rtnl_cls_get_protocol(cls);
tchdr->tcm_info = TC_H_MAKE(prio << 16, htons(proto));
return 0;
}
/**
* @name Allocation/Freeing
* @{
*/
struct rtnl_cls *rtnl_cls_alloc(void)
{
struct rtnl_tc *tc;
tc = TC_CAST(nl_object_alloc(&cls_obj_ops));
if (tc)
tc->tc_type = RTNL_TC_TYPE_CLS;
return (struct rtnl_cls *) tc;
}
void rtnl_cls_put(struct rtnl_cls *cls)
{
nl_object_put((struct nl_object *) cls);
}
/** @} */
/**
* @name Attributes
* @{
*/
void rtnl_cls_set_prio(struct rtnl_cls *cls, uint16_t prio)
{
cls->c_prio = prio;
cls->ce_mask |= CLS_ATTR_PRIO;
}
uint16_t rtnl_cls_get_prio(struct rtnl_cls *cls)
{
if (cls->ce_mask & CLS_ATTR_PRIO)
return cls->c_prio;
else
return 0;
}
void rtnl_cls_set_protocol(struct rtnl_cls *cls, uint16_t protocol)
{
cls->c_protocol = protocol;
cls->ce_mask |= CLS_ATTR_PROTOCOL;
}
uint16_t rtnl_cls_get_protocol(struct rtnl_cls *cls)
{
if (cls->ce_mask & CLS_ATTR_PROTOCOL)
return cls->c_protocol;
else
return ETH_P_ALL;
}
/** @} */
/**
* @name Addition/Modification/Deletion
* @{
*/
/**
* Build a netlink message requesting the addition of a classifier
* @arg cls Classifier to add
* @arg flags Additional netlink message flags
* @arg result Pointer to store resulting netlink message
*
* The behaviour of this function is identical to rtnl_cls_add() with
* the exception that it will not send the message but return it int the
* provided return pointer instead.
*
* @see rtnl_cls_add()
*
* @return 0 on success or a negative error code.
*/
int rtnl_cls_build_add_request(struct rtnl_cls *cls, int flags,
struct nl_msg **result)
{
if (!(flags & NLM_F_CREATE) && !(cls->ce_mask & CLS_ATTR_PRIO)) {
APPBUG("prio must be specified if not a new classifier");
return -NLE_MISSING_ATTR;
}
return cls_build(cls, RTM_NEWTFILTER, flags, result);
}
/**
* Add/Update classifier
* @arg sk Netlink socket
* @arg cls Classifier to add/update
* @arg flags Additional netlink message flags
*
* Builds a \c RTM_NEWTFILTER netlink message requesting the addition
* of a new classifier and sends the message to the kernel. The
* configuration of the classifier is derived from the attributes of
* the specified traffic class.
*
* The following flags may be specified:
* - \c NLM_F_CREATE: Create classifier if it does not exist,
* otherwise -NLE_OBJ_NOTFOUND is returned.
* - \c NLM_F_EXCL: Return -NLE_EXISTS if a classifier with
* matching handle exists already.
*
* Existing classifiers with matching handles will be updated, unless
* the flag \c NLM_F_EXCL is specified. If no matching classifier
* exists, it will be created if the flag \c NLM_F_CREATE is set,
* otherwise the error -NLE_OBJ_NOTFOUND is returned.
*
* If the parent qdisc does not support classes, the error
* \c NLE_OPNOTSUPP is returned.
*
* After sending, the function will wait for the ACK or an eventual
* error message to be received and will therefore block until the
* operation has been completed.
*
* @note Disabling auto-ack (nl_socket_disable_auto_ack()) will cause
* this function to return immediately after sending. In this case,
* it is the responsibility of the caller to handle any error
* messages returned.
*
* @return 0 on success or a negative error code.
*/
int rtnl_cls_add(struct nl_sock *sk, struct rtnl_cls *cls, int flags)
{
struct nl_msg *msg;
int err;
if ((err = rtnl_cls_build_add_request(cls, flags, &msg)) < 0)
return err;
return nl_send_sync(sk, msg);
}
/**
* Build a netlink message to change classifier attributes
* @arg cls classifier to change
* @arg flags additional netlink message flags
* @arg result Pointer to store resulting message.
*
* Builds a new netlink message requesting a change of a neigh
* attributes. The netlink message header isn't fully equipped with
* all relevant fields and must thus be sent out via nl_send_auto_complete()
* or supplemented as needed.
*
* @return 0 on success or a negative error code.
*/
int rtnl_cls_build_change_request(struct rtnl_cls *cls, int flags,
struct nl_msg **result)
{
return cls_build(cls, RTM_NEWTFILTER, NLM_F_REPLACE | flags, result);
}
/**
* Change a classifier
* @arg sk Netlink socket.
* @arg cls classifier to change
* @arg flags additional netlink message flags
*
* Builds a netlink message by calling rtnl_cls_build_change_request(),
* sends the request to the kernel and waits for the next ACK to be
* received and thus blocks until the request has been processed.
*
* @return 0 on sucess or a negative error if an error occured.
*/
int rtnl_cls_change(struct nl_sock *sk, struct rtnl_cls *cls, int flags)
{
struct nl_msg *msg;
int err;
if ((err = rtnl_cls_build_change_request(cls, flags, &msg)) < 0)
return err;
return nl_send_sync(sk, msg);
}
/**
* Build netlink message requesting the deletion of a classifier
* @arg cls Classifier to delete
* @arg flags Additional netlink message flags
* @arg result Pointer to store resulting netlink message
*
* The behaviour of this function is identical to rtnl_cls_delete() with
* the exception that it will not send the message but return it in the
* provided return pointer instead.
*
* @see rtnl_cls_delete()
*
* @return 0 on success or a negative error code.
*/
int rtnl_cls_build_delete_request(struct rtnl_cls *cls, int flags,
struct nl_msg **result)
{
uint32_t required = CLS_ATTR_PRIO;
if ((cls->ce_mask & required) != required) {
APPBUG("prio must be specified");
return -NLE_MISSING_ATTR;
}
return cls_build(cls, RTM_DELTFILTER, flags, result);
}
/**
* Delete classifier
* @arg sk Netlink socket
* @arg cls Classifier to delete
* @arg flags Additional netlink message flags
*
* Builds a \c RTM_DELTFILTER netlink message requesting the deletion
* of a classifier and sends the message to the kernel.
*
* The message is constructed out of the following attributes:
* - \c ifindex (required)
* - \c prio (required)
* - \c protocol (required)
* - \c handle (required)
* - \c parent (optional, if not specified parent equals root-qdisc)
* - \c kind (optional, must match if provided)
*
* All other classifier attributes including all class type specific
* attributes are ignored.
*
* After sending, the function will wait for the ACK or an eventual
* error message to be received and will therefore block until the
* operation has been completed.
*
* @note Disabling auto-ack (nl_socket_disable_auto_ack()) will cause
* this function to return immediately after sending. In this case,
* it is the responsibility of the caller to handle any error
* messages returned.
*
* @return 0 on success or a negative error code.
*/
int rtnl_cls_delete(struct nl_sock *sk, struct rtnl_cls *cls, int flags)
{
struct nl_msg *msg;
int err;
if ((err = rtnl_cls_build_delete_request(cls, flags, &msg)) < 0)
return err;
return nl_send_sync(sk, msg);
}
/** @} */
/**
* @name Cache Related Functions
* @{
*/
/**
* Allocate a cache and fill it with all configured classifiers
* @arg sk Netlink socket
* @arg ifindex Interface index of the network device
* @arg parent Parent qdisc/traffic class class
* @arg result Pointer to store the created cache
*
* Allocates a new classifier cache and fills it with a list of all
* configured classifier attached to the specified parent qdisc/traffic
* class on the specified network device. Release the cache with
* nl_cache_free().
*
* @return 0 on success or a negative error code.
*/
int rtnl_cls_alloc_cache(struct nl_sock *sk, int ifindex, uint32_t parent,
struct nl_cache **result)
{
struct nl_cache * cache;
int err;
if (!(cache = nl_cache_alloc(&rtnl_cls_ops)))
return -NLE_NOMEM;
cache->c_iarg1 = ifindex;
cache->c_iarg2 = parent;
if (sk && (err = nl_cache_refill(sk, cache)) < 0) {
nl_cache_free(cache);
return err;
}
*result = cache;
return 0;
}
/**
* Set interface index and parent handle for classifier cache.
* @arg cache Pointer to cache
* @arg parent Parent qdisc/traffic class class
*
* Set the interface index and parent handle of a classifier cache.
* This is useful for reusing some existed classifier cache to reduce
* the overhead introduced by memory allocation.
*
* @return void.
*/
void rtnl_cls_cache_set_tc_params(struct nl_cache *cache,
int ifindex, uint32_t parent)
{
cache->c_iarg1 = ifindex;
cache->c_iarg2 = parent;
}
/** @} */
static void cls_dump_line(struct rtnl_tc *tc, struct nl_dump_params *p)
{
struct rtnl_cls *cls = (struct rtnl_cls *) tc;
char buf[32];
nl_dump(p, " prio %u protocol %s", cls->c_prio,
nl_ether_proto2str(cls->c_protocol, buf, sizeof(buf)));
}
static int cls_msg_parser(struct nl_cache_ops *ops, struct sockaddr_nl *who,
struct nlmsghdr *nlh, struct nl_parser_param *pp)
{
struct rtnl_cls *cls;
int err;
if (!(cls = rtnl_cls_alloc()))
return -NLE_NOMEM;
if ((err = rtnl_tc_msg_parse(nlh, TC_CAST(cls))) < 0)
goto errout;
cls->c_prio = TC_H_MAJ(cls->c_info) >> 16;
if (cls->c_prio)
cls->ce_mask |= CLS_ATTR_PRIO;
cls->c_protocol = ntohs(TC_H_MIN(cls->c_info));
if (cls->c_protocol)
cls->ce_mask |= CLS_ATTR_PROTOCOL;
err = pp->pp_cb(OBJ_CAST(cls), pp);
errout:
rtnl_cls_put(cls);
return err;
}
static int cls_request_update(struct nl_cache *cache, struct nl_sock *sk)
{
struct tcmsg tchdr = {
.tcm_family = AF_UNSPEC,
.tcm_ifindex = cache->c_iarg1,
.tcm_parent = cache->c_iarg2,
};
return nl_send_simple(sk, RTM_GETTFILTER, NLM_F_DUMP, &tchdr,
sizeof(tchdr));
}
static struct rtnl_tc_type_ops cls_ops = {
.tt_type = RTNL_TC_TYPE_CLS,
.tt_dump_prefix = "cls",
.tt_dump = {
[NL_DUMP_LINE] = cls_dump_line,
},
};
static struct nl_cache_ops rtnl_cls_ops = {
.co_name = "route/cls",
.co_hdrsize = sizeof(struct tcmsg),
.co_msgtypes = {
{ RTM_NEWTFILTER, NL_ACT_NEW, "new" },
{ RTM_DELTFILTER, NL_ACT_DEL, "del" },
{ RTM_GETTFILTER, NL_ACT_GET, "get" },
END_OF_MSGTYPES_LIST,
},
.co_protocol = NETLINK_ROUTE,
.co_groups = tc_groups,
.co_request_update = cls_request_update,
.co_msg_parser = cls_msg_parser,
.co_obj_ops = &cls_obj_ops,
};
static struct nl_object_ops cls_obj_ops = {
.oo_name = "route/cls",
.oo_size = sizeof(struct rtnl_cls),
.oo_free_data = rtnl_tc_free_data,
.oo_clone = rtnl_tc_clone,
.oo_dump = {
[NL_DUMP_LINE] = rtnl_tc_dump_line,
[NL_DUMP_DETAILS] = rtnl_tc_dump_details,
[NL_DUMP_STATS] = rtnl_tc_dump_stats,
},
.oo_compare = rtnl_tc_compare,
.oo_id_attrs = (TCA_ATTR_IFINDEX | TCA_ATTR_HANDLE),
};
static void __init cls_init(void)
{
rtnl_tc_type_register(&cls_ops);
nl_cache_mngt_register(&rtnl_cls_ops);
}
static void __exit cls_exit(void)
{
nl_cache_mngt_unregister(&rtnl_cls_ops);
rtnl_tc_type_unregister(&cls_ops);
}
/** @} */