diff options
author | Thomas Graf <tgraf@suug.ch> | 2011-03-29 10:41:59 (GMT) |
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committer | Thomas Graf <tgraf@suug.ch> | 2011-03-29 10:41:59 (GMT) |
commit | 7c620500bbca24c3d18b731756c375a45bb0fcba (patch) | |
tree | f5a507f13dc3039bff8e5fabcf054fbbc9a3adde /lib | |
parent | 747b892c91de7a852664f015405d6d37ea2b66b6 (diff) | |
download | libnl-7c620500bbca24c3d18b731756c375a45bb0fcba.zip libnl-7c620500bbca24c3d18b731756c375a45bb0fcba.tar.gz libnl-7c620500bbca24c3d18b731756c375a45bb0fcba.tar.bz2 |
trafic class/classifer API improvements and documentation
- removed dead functions in header files
- deprecated rtnl_class_foreach_*() functions due to their missing
handling possibility of OOM situations
- improved API documentation
Diffstat (limited to 'lib')
-rw-r--r-- | lib/route/class.c | 368 | ||||
-rw-r--r-- | lib/route/cls.c | 186 |
2 files changed, 322 insertions, 232 deletions
diff --git a/lib/route/class.c b/lib/route/class.c index a0f3758..2a9606b 100644 --- a/lib/route/class.c +++ b/lib/route/class.c @@ -1,17 +1,17 @@ /* - * lib/route/class.c Queueing Classes + * lib/route/class.c Traffic Classes * * 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) 2003-2010 Thomas Graf <tgraf@suug.ch> + * Copyright (c) 2003-2011 Thomas Graf <tgraf@suug.ch> */ /** * @ingroup tc - * @defgroup class Queueing Classes + * @defgroup class Traffic Classes * @{ */ @@ -69,52 +69,104 @@ static int class_request_update(struct nl_cache *cache, struct nl_sock *sk) } /** - * @name Addition/Modification + * @name Allocation/Freeing + * @{ + */ + +struct rtnl_class *rtnl_class_alloc(void) +{ + struct rtnl_tc *tc; + + tc = TC_CAST(nl_object_alloc(&class_obj_ops)); + if (tc) + tc->tc_type = RTNL_TC_TYPE_CLASS; + + return (struct rtnl_class *) tc; +} + +void rtnl_class_put(struct rtnl_class *class) +{ + nl_object_put((struct nl_object *) class); +} + +/** @} */ + + +/** + * @name Addition/Modification/Deletion * @{ */ static int class_build(struct rtnl_class *class, int type, int flags, struct nl_msg **result) { + int needed = TCA_ATTR_PARENT | TCA_ATTR_HANDLE; + + if ((class->ce_mask & needed) == needed && + TC_H_MAJ(class->c_parent) && TC_H_MAJ(class->c_handle) && + TC_H_MAJ(class->c_parent) != TC_H_MAJ(class->c_handle)) { + APPBUG("TC_H_MAJ(parent) must match TC_H_MAJ(handle)"); + return -NLE_INVAL; + } + return rtnl_tc_msg_build(TC_CAST(class), type, flags, result); } /** - * Build a netlink message to add a new class - * @arg class class to add - * @arg flags additional netlink message flags - * @arg result Pointer to store resulting message. + * Build a netlink message requesting the addition of a traffic class + * @arg class Traffic class to add + * @arg flags Additional netlink message flags + * @arg result Pointer to store resulting netlink message * - * Builds a new netlink message requesting an addition of a class. - * The netlink message header isn't fully equipped with all relevant - * fields and must be sent out via nl_send_auto_complete() or - * supplemented as needed. + * The behaviour of this function is identical to rtnl_class_add() with + * the exception that it will not send the message but return it int the + * provided return pointer instead. * - * Common message flags - * - NLM_F_REPLACE - replace possibly existing classes + * @see rtnl_class_add() * * @return 0 on success or a negative error code. */ int rtnl_class_build_add_request(struct rtnl_class *class, int flags, struct nl_msg **result) { - return class_build(class, RTM_NEWTCLASS, NLM_F_CREATE | flags, result); + return class_build(class, RTM_NEWTCLASS, flags, result); } /** - * Add a new class - * @arg sk Netlink socket. - * @arg class class to delete - * @arg flags additional netlink message flags + * Add/Update traffic class + * @arg sk Netlink socket + * @arg class Traffic class to add + * @arg flags Additional netlink message flags + * + * Builds a \c RTM_NEWTCLASS netlink message requesting the addition + * of a new traffic class and sends the message to the kernel. The + * configuration of the traffic class is derived from the attributes + * of the specified traffic class. * - * Builds a netlink message by calling rtnl_qdisc_build_add_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. + * The following flags may be specified: + * - \c NLM_F_CREATE: Create traffic class if it does not exist, + * otherwise -NLE_OBJ_NOTFOUND is returned. + * - \c NLM_F_EXCL: Return -NLE_EXISTS if a traffic class with + * matching handle exists already. * - * Common message flags - * - NLM_F_REPLACE - replace possibly existing classes + * Existing traffic classes with matching handles will be updated, + * unless the flag \c NLM_F_EXCL is specified. If no matching traffic + * class exists, it will be created if the flag \c NLM_F_CREATE is set, + * otherwise the error -NLE_OBJ_NOTFOUND is returned. * - * @return 0 on success or a negative error code + * 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_class_add(struct nl_sock *sk, struct rtnl_class *class, int flags) { @@ -124,32 +176,44 @@ int rtnl_class_add(struct nl_sock *sk, struct rtnl_class *class, int flags) if ((err = rtnl_class_build_add_request(class, flags, &msg)) < 0) return err; - err = nl_send_auto_complete(sk, msg); - nlmsg_free(msg); - if (err < 0) - return err; - - return wait_for_ack(sk); + return nl_send_sync(sk, msg); } -int rtnl_class_build_delete_request(struct rtnl_class *class, - struct nl_msg **result) +/** + * Build netlink message requesting the deletion of a traffic class + * @arg class Traffic class to delete + * @arg result Pointer to store resulting netlink message + * + * The behaviour of this function is identical to rtnl_class_delete() with + * the exception that it will not send the message but return it in the + * provided return pointer instead. + * + * @see rtnl_class_delete() + * + * @return 0 on success or a negative error code. + */ +int rtnl_class_build_delete_request(struct rtnl_class *class, struct nl_msg **result) { struct nl_msg *msg; struct tcmsg tchdr; - int required = TCA_ATTR_IFINDEX | TCA_ATTR_PARENT; + int required = TCA_ATTR_IFINDEX | TCA_ATTR_HANDLE; - if ((class->ce_mask & required) != required) - BUG(); + if ((class->ce_mask & required) != required) { + APPBUG("ifindex and handle must be specified"); + return -NLE_MISSING_ATTR; + } - msg = nlmsg_alloc_simple(RTM_DELTCLASS, 0); - if (!msg) + if (!(msg = nlmsg_alloc_simple(RTM_DELTCLASS, 0))) return -NLE_NOMEM; + memset(&tchdr, 0, sizeof(tchdr)); tchdr.tcm_family = AF_UNSPEC; - tchdr.tcm_handle = class->c_handle; - tchdr.tcm_parent = class->c_parent; tchdr.tcm_ifindex = class->c_ifindex; + tchdr.tcm_handle = class->c_handle; + + if (class->ce_mask & TCA_ATTR_PARENT) + tchdr.tcm_parent = class->c_parent; + if (nlmsg_append(msg, &tchdr, sizeof(tchdr), NLMSG_ALIGNTO) < 0) { nlmsg_free(msg); return -NLE_MSGSIZE; @@ -160,15 +224,30 @@ int rtnl_class_build_delete_request(struct rtnl_class *class, } /** - * Delete a class - * @arg sk Netlink socket. - * @arg class class to delete + * Delete traffic class + * @arg sk Netlink socket + * @arg class Traffic class to delete + * + * Builds a \c RTM_DELTCLASS netlink message requesting the deletion + * of a traffic class and sends the message to the kernel. + * + * The message is constructed out of the following attributes: + * - \c ifindex and \c handle (required) + * - \c parent (optional, must match if provided) * - * Builds a netlink message by calling rtnl_class_build_delete_request(), - * sends the request to the kernel and waits for the ACK to be - * received and thus blocks until the request has been processed. + * All other class attributes including all class type specific + * attributes are ignored. * - * @return 0 on success or a negative error code + * 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_class_delete(struct nl_sock *sk, struct rtnl_class *class) { @@ -178,35 +257,7 @@ int rtnl_class_delete(struct nl_sock *sk, struct rtnl_class *class) if ((err = rtnl_class_build_delete_request(class, &msg)) < 0) return err; - err = nl_send_auto_complete(sk, msg); - nlmsg_free(msg); - if (err < 0) - return err; - - return wait_for_ack(sk); -} - -/** @} */ - -/** - * @name Allocation/Freeing - * @{ - */ - -struct rtnl_class *rtnl_class_alloc(void) -{ - struct rtnl_tc *tc; - - tc = TC_CAST(nl_object_alloc(&class_obj_ops)); - if (tc) - tc->tc_type = RTNL_TC_TYPE_CLASS; - - return (struct rtnl_class *) tc; -} - -void rtnl_class_put(struct rtnl_class *class) -{ - nl_object_put((struct nl_object *) class); + return nl_send_sync(sk, msg); } /** @} */ @@ -217,11 +268,11 @@ void rtnl_class_put(struct rtnl_class *class) */ /** - * Lookup the leaf qdisc of a class - * @arg class the parent class - * @arg cache a qdisc cache including at laest all qdiscs of the - * interface the specified class is attached to - * @return The qdisc from the cache or NULL if the class has no leaf qdisc + * Lookup the leaf qdisc of a traffic class + * @arg class the parent traffic class + * @arg cache a qdisc cache allocated using rtnl_qdisc_alloc_cache() + * + * @return Matching Qdisc or NULL if the traffic class has no leaf qdisc */ struct rtnl_qdisc *rtnl_class_leaf_qdisc(struct rtnl_class *class, struct nl_cache *cache) @@ -241,78 +292,20 @@ struct rtnl_qdisc *rtnl_class_leaf_qdisc(struct rtnl_class *class, /** @} */ - /** - * @name Iterators + * @name Cache Related Functions * @{ */ /** - * Call a callback for each child of a class - * @arg class the parent class - * @arg cache a class cache including all classes of the interface - * the specified class is attached to - * @arg cb callback function - * @arg arg argument to be passed to callback function - */ -void rtnl_class_foreach_child(struct rtnl_class *class, struct nl_cache *cache, - void (*cb)(struct nl_object *, void *), void *arg) -{ - struct rtnl_class *filter; - - filter = rtnl_class_alloc(); - if (!filter) - return; - - rtnl_tc_set_parent(TC_CAST(filter), class->c_handle); - rtnl_tc_set_ifindex(TC_CAST(filter), class->c_ifindex); - rtnl_tc_set_kind(TC_CAST(filter), class->c_kind); - - nl_cache_foreach_filter(cache, OBJ_CAST(filter), cb, arg); - rtnl_class_put(filter); -} - -/** - * Call a callback for each classifier attached to the class - * @arg class the parent class - * @arg cache a filter cache including at least all the filters - * attached to the specified class - * @arg cb callback function - * @arg arg argument to be passed to callback function - */ -void rtnl_class_foreach_cls(struct rtnl_class *class, struct nl_cache *cache, - void (*cb)(struct nl_object *, void *), void *arg) -{ - struct rtnl_cls *filter; - - filter = rtnl_cls_alloc(); - if (!filter) - return; - - rtnl_tc_set_ifindex((struct rtnl_tc *) filter, class->c_ifindex); - rtnl_tc_set_parent((struct rtnl_tc *) filter, class->c_parent); - - nl_cache_foreach_filter(cache, (struct nl_object *) filter, cb, arg); - rtnl_cls_put(filter); -} - -/** @} */ - - -/** - * @name Cache Management - * @{ - */ - -/** - * Build a class cache including all classes attached to the specified interface - * @arg sk Netlink socket. - * @arg ifindex interface index of the link the classes are - * attached to. - * @arg result Result pointer + * Allocate a cache and fill it with all configured traffic classes + * @arg sk Netlink socket + * @arg ifindex Interface index of the network device + * @arg result Pointer to store the created cache * - * Allocates a new cache, initializes it properly and updates it to - * include all classes attached to the specified interface. + * Allocates a new traffic class cache and fills it with a list of all + * configured traffic classes on a specific network device. Release the + * cache with nl_cache_free(). * * @return 0 on success or a negative error code. */ @@ -321,9 +314,13 @@ int rtnl_class_alloc_cache(struct nl_sock *sk, int ifindex, { struct nl_cache * cache; int err; + + if (!ifindex) { + APPBUG("ifindex must be specified"); + return -NLE_INVAL; + } - cache = nl_cache_alloc(&rtnl_class_ops); - if (!cache) + if (!(cache = nl_cache_alloc(&rtnl_class_ops))) return -NLE_NOMEM; cache->c_iarg1 = ifindex; @@ -338,14 +335,23 @@ int rtnl_class_alloc_cache(struct nl_sock *sk, int ifindex, } /** - * Look up class by its handle in the provided cache - * @arg cache class cache - * @arg ifindex interface the class is attached to - * @arg handle class handle - * @return pointer to class inside the cache or NULL if no match was found. + * Search traffic class by interface index and handle + * @arg cache Traffic class cache + * @arg ifindex Interface index + * @arg handle ID of traffic class + * + * Searches a traffic class cache previously allocated with + * rtnl_class_alloc_cache() and searches for a traffi class matching + * the interface index and handle. + * + * The reference counter is incremented before returning the traffic + * class, therefore the reference must be given back with rtnl_class_put() + * after usage. + * + * @return Traffic class or NULL if no match was found. */ struct rtnl_class *rtnl_class_get(struct nl_cache *cache, int ifindex, - uint32_t handle) + uint32_t handle) { struct rtnl_class *class; @@ -363,6 +369,58 @@ struct rtnl_class *rtnl_class_get(struct nl_cache *cache, int ifindex, /** @} */ +/** + * @name Deprecated Functions + * @{ + */ + +/** + * Call a callback for each child of a class + * + * @deprecated Use of this function is deprecated, it does not allow + * to handle the out of memory situation that can occur. + */ +void rtnl_class_foreach_child(struct rtnl_class *class, struct nl_cache *cache, + void (*cb)(struct nl_object *, void *), void *arg) +{ + struct rtnl_class *filter; + + filter = rtnl_class_alloc(); + if (!filter) + return; + + rtnl_tc_set_parent(TC_CAST(filter), class->c_handle); + rtnl_tc_set_ifindex(TC_CAST(filter), class->c_ifindex); + rtnl_tc_set_kind(TC_CAST(filter), class->c_kind); + + nl_cache_foreach_filter(cache, OBJ_CAST(filter), cb, arg); + rtnl_class_put(filter); +} + +/** + * Call a callback for each classifier attached to the class + * + * @deprecated Use of this function is deprecated, it does not allow + * to handle the out of memory situation that can occur. + */ +void rtnl_class_foreach_cls(struct rtnl_class *class, struct nl_cache *cache, + void (*cb)(struct nl_object *, void *), void *arg) +{ + struct rtnl_cls *filter; + + filter = rtnl_cls_alloc(); + if (!filter) + return; + + rtnl_tc_set_ifindex((struct rtnl_tc *) filter, class->c_ifindex); + rtnl_tc_set_parent((struct rtnl_tc *) filter, class->c_parent); + + nl_cache_foreach_filter(cache, (struct nl_object *) filter, cb, arg); + rtnl_cls_put(filter); +} + +/** @} */ + static struct rtnl_tc_type_ops class_ops = { .tt_type = RTNL_TC_TYPE_CLASS, .tt_dump_prefix = "class", diff --git a/lib/route/cls.c b/lib/route/cls.c index a041baa..aa79b09 100644 --- a/lib/route/cls.c +++ b/lib/route/cls.c @@ -6,21 +6,12 @@ * License as published by the Free Software Foundation version 2.1 * of the License. * - * Copyright (c) 2003-2009 Thomas Graf <tgraf@suug.ch> + * Copyright (c) 2003-2011 Thomas Graf <tgraf@suug.ch> */ /** * @ingroup tc * @defgroup cls Classifiers - * - * @par Classifier Identification - * - protocol - * - priority - * - parent - * - interface - * - kind - * - handle - * * @{ */ @@ -46,6 +37,12 @@ static int cls_build(struct rtnl_cls *cls, int type, int flags, { int err, prio, proto; struct tcmsg *tchdr; + int 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) @@ -119,42 +116,70 @@ uint16_t rtnl_cls_get_protocol(struct rtnl_cls *cls) /** - * @name Classifier Addition/Modification/Deletion + * @name Addition/Modification/Deletion * @{ */ /** - * Build a netlink message to add a new classifier - * @arg cls classifier to add - * @arg flags additional netlink message flags - * @arg result Pointer to store resulting message. + * 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. * - * Builds a new netlink message requesting an addition of a classifier - * The netlink message header isn't fully equipped with all relevant - * fields and must be sent out via nl_send_auto_complete() or - * supplemented as needed. \a classifier must contain the attributes of - * the new classifier set via \c rtnl_cls_set_* functions. \a opts - * may point to the clsasifier specific options. + * @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) { - return cls_build(cls, RTM_NEWTFILTER, NLM_F_CREATE | flags, 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 a new classifier - * @arg sk Netlink socket. - * @arg cls classifier to add - * @arg flags additional netlink message flags + * Add/Update classifier + * @arg sk Netlink socket + * @arg cls Classifier to add/update + * @arg flags Additional netlink message flags * - * Builds a netlink message by calling rtnl_cls_build_add_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. + * 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. * - * @return 0 on sucess or a negative error if an error occured. + * 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) { @@ -163,13 +188,8 @@ int rtnl_cls_add(struct nl_sock *sk, struct rtnl_cls *cls, int flags) if ((err = rtnl_cls_build_add_request(cls, flags, &msg)) < 0) return err; - - err = nl_send_auto_complete(sk, msg); - nlmsg_free(msg); - if (err < 0) - return err; - return nl_wait_for_ack(sk); + return nl_send_sync(sk, msg); } /** @@ -211,45 +231,64 @@ int rtnl_cls_change(struct nl_sock *sk, struct rtnl_cls *cls, int flags) if ((err = rtnl_cls_build_change_request(cls, flags, &msg)) < 0) return err; - err = nl_send_auto_complete(sk, msg); - nlmsg_free(msg); - if (err < 0) - return err; - - return nl_wait_for_ack(sk); + return nl_send_sync(sk, msg); } /** - * Build a netlink request message to delete a classifier - * @arg cls classifier to delete - * @arg flags additional netlink message flags - * @arg result Pointer to store resulting message. + * Build netlink message requesting the deletion of a classifier + * @arg cls Classifier to delete + * @arg result Pointer to store resulting netlink message * - * Builds a new netlink message requesting a deletion of a classifier. - * 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. + * 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) { + int 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 a classifier - * @arg sk Netlink socket. - * @arg cls classifier to delete - * @arg flags additional netlink message flags + * Delete classifier + * @arg sk Netlink socket + * @arg cls Classifier to delete * - * Builds a netlink message by calling rtnl_cls_build_delete_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. + * Builds a \c RTM_DELTFILTER netlink message requesting the deletion + * of a classifier and sends the message to the kernel. * - * @return 0 on sucess or a negative error if an error occured. + * 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) { @@ -259,35 +298,28 @@ int rtnl_cls_delete(struct nl_sock *sk, struct rtnl_cls *cls, int flags) if ((err = rtnl_cls_build_delete_request(cls, flags, &msg)) < 0) return err; - err = nl_send_auto_complete(sk, msg); - nlmsg_free(msg); - if (err < 0) - return err; - - return nl_wait_for_ack(sk); + return nl_send_sync(sk, msg); } /** @} */ /** - * @name Cache Management + * @name Cache Related Functions * @{ */ /** - * Build a classifier cache including all classifiers attached to the - * specified class/qdisc on eht specified interface. - * @arg sk Netlink socket. - * @arg ifindex interface index of the link the classes are - * attached to. - * @arg parent parent qdisc/class - * @arg result Pointer to store resulting cache. + * 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 cache, initializes it properly and updates it to - * include all classes attached to the specified interface. + * 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(). * - * @note The caller is responsible for destroying and freeing the - * cache after using it. * @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) |