Filtering a flow requires a classifier to match the packets, and a rule to filter on the matches.
A classifier consists of one or more selectors. There is one selector per header type. A selector must only use fields set in the selector capability. If partial matching is supported, the classifier mask for a particular field can be a subset of the mask for that field in the capability. The rule consists of a priority, an action and a key. The key is a byte array containing headers corresponding to the selectors in the classifier. This patch implements ethtool rules for ethernet headers. Example: $ ethtool -U ens9 flow-type ether dst 08:11:22:33:44:54 action 30 Added rule with ID 1 The rule in the example directs received packets with the specified destination MAC address to rq 30. Signed-off-by: Daniel Jurgens <[email protected]> Reviewed-by: Parav Pandit <[email protected]> Reviewed-by: Shahar Shitrit <[email protected]> Reviewed-by: Xuan Zhuo <[email protected]> --- v4: - Fixed double free bug in error flows - Build bug on for classifier struct ordering. - (u8 *) to (void *) casting. - Documentation in UAPI - Answered questions about overflow with no changes. v6: - Fix sparse warning "array of flexible structures" Jakub K/Simon H v7: - Move for (int i -> for (i hunk from next patch. Paolo Abeni --- drivers/net/virtio_net.c | 462 +++++++++++++++++++++++++++++ include/uapi/linux/virtio_net_ff.h | 50 ++++ 2 files changed, 512 insertions(+) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 804a77e3d3c1..85df425f993e 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -284,6 +284,11 @@ static const struct virtnet_stat_desc virtnet_stats_tx_speed_desc_qstat[] = { VIRTNET_STATS_DESC_TX_QSTAT(speed, ratelimit_packets, hw_drop_ratelimits), }; +struct virtnet_ethtool_ff { + struct xarray rules; + int num_rules; +}; + #define VIRTNET_FF_ETHTOOL_GROUP_PRIORITY 1 #define VIRTNET_FF_MAX_GROUPS 1 @@ -293,8 +298,16 @@ struct virtnet_ff { struct virtio_net_ff_cap_data *ff_caps; struct virtio_net_ff_cap_mask_data *ff_mask; struct virtio_net_ff_actions *ff_actions; + struct xarray classifiers; + int num_classifiers; + struct virtnet_ethtool_ff ethtool; }; +static int virtnet_ethtool_flow_insert(struct virtnet_ff *ff, + struct ethtool_rx_flow_spec *fs, + u16 curr_queue_pairs); +static int virtnet_ethtool_flow_remove(struct virtnet_ff *ff, int location); + #define VIRTNET_Q_TYPE_RX 0 #define VIRTNET_Q_TYPE_TX 1 #define VIRTNET_Q_TYPE_CQ 2 @@ -5637,6 +5650,21 @@ static u32 virtnet_get_rx_ring_count(struct net_device *dev) return vi->curr_queue_pairs; } +static int virtnet_set_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info) +{ + struct virtnet_info *vi = netdev_priv(dev); + + switch (info->cmd) { + case ETHTOOL_SRXCLSRLINS: + return virtnet_ethtool_flow_insert(&vi->ff, &info->fs, + vi->curr_queue_pairs); + case ETHTOOL_SRXCLSRLDEL: + return virtnet_ethtool_flow_remove(&vi->ff, info->fs.location); + } + + return -EOPNOTSUPP; +} + static const struct ethtool_ops virtnet_ethtool_ops = { .supported_coalesce_params = ETHTOOL_COALESCE_MAX_FRAMES | ETHTOOL_COALESCE_USECS | ETHTOOL_COALESCE_USE_ADAPTIVE_RX, @@ -5663,6 +5691,7 @@ static const struct ethtool_ops virtnet_ethtool_ops = { .get_rxfh_fields = virtnet_get_hashflow, .set_rxfh_fields = virtnet_set_hashflow, .get_rx_ring_count = virtnet_get_rx_ring_count, + .set_rxnfc = virtnet_set_rxnfc, }; static void virtnet_get_queue_stats_rx(struct net_device *dev, int i, @@ -6774,6 +6803,428 @@ static const struct xdp_metadata_ops virtnet_xdp_metadata_ops = { .xmo_rx_hash = virtnet_xdp_rx_hash, }; +struct virtnet_ethtool_rule { + struct ethtool_rx_flow_spec flow_spec; + u32 classifier_id; +}; + +/* The classifier struct must be the last field in this struct */ +struct virtnet_classifier { + size_t size; + u32 id; + struct virtio_net_resource_obj_ff_classifier classifier; +}; + +static_assert(sizeof(struct virtnet_classifier) == + ALIGN(offsetofend(struct virtnet_classifier, classifier), + __alignof__(struct virtnet_classifier)), + "virtnet_classifier: classifier must be the last member"); + +static bool check_mask_vs_cap(const void *m, const void *c, + u16 len, bool partial) +{ + const u8 *mask = m; + const u8 *cap = c; + int i; + + for (i = 0; i < len; i++) { + if (partial && ((mask[i] & cap[i]) != mask[i])) + return false; + if (!partial && mask[i] != cap[i]) + return false; + } + + return true; +} + +static +struct virtio_net_ff_selector *get_selector_cap(const struct virtnet_ff *ff, + u8 selector_type) +{ + struct virtio_net_ff_selector *sel; + void *buf; + int i; + + buf = &ff->ff_mask->selectors; + sel = buf; + + for (i = 0; i < ff->ff_mask->count; i++) { + if (sel->type == selector_type) + return sel; + + buf += sizeof(struct virtio_net_ff_selector) + sel->length; + sel = buf; + } + + return NULL; +} + +static bool validate_eth_mask(const struct virtnet_ff *ff, + const struct virtio_net_ff_selector *sel, + const struct virtio_net_ff_selector *sel_cap) +{ + bool partial_mask = !!(sel_cap->flags & VIRTIO_NET_FF_MASK_F_PARTIAL_MASK); + struct ethhdr *cap, *mask; + struct ethhdr zeros = {}; + + cap = (struct ethhdr *)&sel_cap->mask; + mask = (struct ethhdr *)&sel->mask; + + if (memcmp(&zeros.h_dest, mask->h_dest, sizeof(zeros.h_dest)) && + !check_mask_vs_cap(mask->h_dest, cap->h_dest, + sizeof(mask->h_dest), partial_mask)) + return false; + + if (memcmp(&zeros.h_source, mask->h_source, sizeof(zeros.h_source)) && + !check_mask_vs_cap(mask->h_source, cap->h_source, + sizeof(mask->h_source), partial_mask)) + return false; + + if (mask->h_proto && + !check_mask_vs_cap(&mask->h_proto, &cap->h_proto, + sizeof(__be16), partial_mask)) + return false; + + return true; +} + +static bool validate_mask(const struct virtnet_ff *ff, + const struct virtio_net_ff_selector *sel) +{ + struct virtio_net_ff_selector *sel_cap = get_selector_cap(ff, sel->type); + + if (!sel_cap) + return false; + + switch (sel->type) { + case VIRTIO_NET_FF_MASK_TYPE_ETH: + return validate_eth_mask(ff, sel, sel_cap); + } + + return false; +} + +static int setup_classifier(struct virtnet_ff *ff, struct virtnet_classifier *c) +{ + int err; + + err = xa_alloc(&ff->classifiers, &c->id, c, + XA_LIMIT(0, le32_to_cpu(ff->ff_caps->classifiers_limit) - 1), + GFP_KERNEL); + if (err) + return err; + + err = virtio_admin_obj_create(ff->vdev, + VIRTIO_NET_RESOURCE_OBJ_FF_CLASSIFIER, + c->id, + VIRTIO_ADMIN_GROUP_TYPE_SELF, + 0, + &c->classifier, + c->size); + if (err) + goto err_xarray; + + return 0; + +err_xarray: + xa_erase(&ff->classifiers, c->id); + + return err; +} + +static void destroy_classifier(struct virtnet_ff *ff, + u32 classifier_id) +{ + struct virtnet_classifier *c; + + c = xa_load(&ff->classifiers, classifier_id); + if (c) { + virtio_admin_obj_destroy(ff->vdev, + VIRTIO_NET_RESOURCE_OBJ_FF_CLASSIFIER, + c->id, + VIRTIO_ADMIN_GROUP_TYPE_SELF, + 0); + + xa_erase(&ff->classifiers, c->id); + kfree(c); + } +} + +static void destroy_ethtool_rule(struct virtnet_ff *ff, + struct virtnet_ethtool_rule *eth_rule) +{ + ff->ethtool.num_rules--; + + virtio_admin_obj_destroy(ff->vdev, + VIRTIO_NET_RESOURCE_OBJ_FF_RULE, + eth_rule->flow_spec.location, + VIRTIO_ADMIN_GROUP_TYPE_SELF, + 0); + + xa_erase(&ff->ethtool.rules, eth_rule->flow_spec.location); + destroy_classifier(ff, eth_rule->classifier_id); + kfree(eth_rule); +} + +static int insert_rule(struct virtnet_ff *ff, + struct virtnet_ethtool_rule *eth_rule, + u32 classifier_id, + const u8 *key, + size_t key_size) +{ + struct ethtool_rx_flow_spec *fs = ð_rule->flow_spec; + struct virtio_net_resource_obj_ff_rule *ff_rule; + int err; + + ff_rule = kzalloc(sizeof(*ff_rule) + key_size, GFP_KERNEL); + if (!ff_rule) + return -ENOMEM; + + /* Intentionally leave the priority as 0. All rules have the same + * priority. + */ + ff_rule->group_id = cpu_to_le32(VIRTNET_FF_ETHTOOL_GROUP_PRIORITY); + ff_rule->classifier_id = cpu_to_le32(classifier_id); + ff_rule->key_length = (u8)key_size; + ff_rule->action = fs->ring_cookie == RX_CLS_FLOW_DISC ? + VIRTIO_NET_FF_ACTION_DROP : + VIRTIO_NET_FF_ACTION_RX_VQ; + ff_rule->vq_index = fs->ring_cookie != RX_CLS_FLOW_DISC ? + cpu_to_le16(fs->ring_cookie) : 0; + memcpy(&ff_rule->keys, key, key_size); + + err = virtio_admin_obj_create(ff->vdev, + VIRTIO_NET_RESOURCE_OBJ_FF_RULE, + fs->location, + VIRTIO_ADMIN_GROUP_TYPE_SELF, + 0, + ff_rule, + sizeof(*ff_rule) + key_size); + if (err) + goto err_ff_rule; + + eth_rule->classifier_id = classifier_id; + ff->ethtool.num_rules++; + kfree(ff_rule); + + return 0; + +err_ff_rule: + kfree(ff_rule); + + return err; +} + +static u32 flow_type_mask(u32 flow_type) +{ + return flow_type & ~(FLOW_EXT | FLOW_MAC_EXT | FLOW_RSS); +} + +static bool supported_flow_type(const struct ethtool_rx_flow_spec *fs) +{ + switch (fs->flow_type) { + case ETHER_FLOW: + return true; + } + + return false; +} + +static int validate_flow_input(struct virtnet_ff *ff, + const struct ethtool_rx_flow_spec *fs, + u16 curr_queue_pairs) +{ + /* Force users to use RX_CLS_LOC_ANY - don't allow specific locations */ + if (fs->location != RX_CLS_LOC_ANY) + return -EOPNOTSUPP; + + if (fs->ring_cookie != RX_CLS_FLOW_DISC && + fs->ring_cookie >= curr_queue_pairs) + return -EINVAL; + + if (fs->flow_type != flow_type_mask(fs->flow_type)) + return -EOPNOTSUPP; + + if (!supported_flow_type(fs)) + return -EOPNOTSUPP; + + return 0; +} + +static void calculate_flow_sizes(struct ethtool_rx_flow_spec *fs, + size_t *key_size, size_t *classifier_size, + int *num_hdrs) +{ + *num_hdrs = 1; + *key_size = sizeof(struct ethhdr); + /* + * The classifier size is the size of the classifier header, a selector + * header for each type of header in the match criteria, and each header + * providing the mask for matching against. + */ + *classifier_size = *key_size + + sizeof(struct virtio_net_resource_obj_ff_classifier) + + sizeof(struct virtio_net_ff_selector) * (*num_hdrs); +} + +static void setup_eth_hdr_key_mask(struct virtio_net_ff_selector *selector, + u8 *key, + const struct ethtool_rx_flow_spec *fs) +{ + struct ethhdr *eth_m = (struct ethhdr *)&selector->mask; + struct ethhdr *eth_k = (struct ethhdr *)key; + + selector->type = VIRTIO_NET_FF_MASK_TYPE_ETH; + selector->length = sizeof(struct ethhdr); + + memcpy(eth_m, &fs->m_u.ether_spec, sizeof(*eth_m)); + memcpy(eth_k, &fs->h_u.ether_spec, sizeof(*eth_k)); +} + +static int +validate_classifier_selectors(struct virtnet_ff *ff, + struct virtio_net_resource_obj_ff_classifier *classifier, + int num_hdrs) +{ + struct virtio_net_ff_selector *selector = (void *)classifier->selectors; + int i; + + for (i = 0; i < num_hdrs; i++) { + if (!validate_mask(ff, selector)) + return -EINVAL; + + selector = (((void *)selector) + sizeof(*selector) + + selector->length); + } + + return 0; +} + +static int build_and_insert(struct virtnet_ff *ff, + struct virtnet_ethtool_rule *eth_rule) +{ + struct virtio_net_resource_obj_ff_classifier *classifier; + struct ethtool_rx_flow_spec *fs = ð_rule->flow_spec; + struct virtio_net_ff_selector *selector; + struct virtnet_classifier *c; + size_t classifier_size; + size_t key_size; + int num_hdrs; + u8 *key; + int err; + + calculate_flow_sizes(fs, &key_size, &classifier_size, &num_hdrs); + + key = kzalloc(key_size, GFP_KERNEL); + if (!key) + return -ENOMEM; + + /* + * virtio_net_ff_obj_ff_classifier is already included in the + * classifier_size. + */ + c = kzalloc(classifier_size + + sizeof(struct virtnet_classifier) - + sizeof(struct virtio_net_resource_obj_ff_classifier), + GFP_KERNEL); + if (!c) { + kfree(key); + return -ENOMEM; + } + + c->size = classifier_size; + classifier = &c->classifier; + classifier->count = num_hdrs; + selector = (void *)&classifier->selectors[0]; + + setup_eth_hdr_key_mask(selector, key, fs); + + err = validate_classifier_selectors(ff, classifier, num_hdrs); + if (err) + goto err_key; + + err = setup_classifier(ff, c); + if (err) + goto err_classifier; + + err = insert_rule(ff, eth_rule, c->id, key, key_size); + if (err) { + /* destroy_classifier will free the classifier */ + destroy_classifier(ff, c->id); + goto err_key; + } + + return 0; + +err_classifier: + kfree(c); +err_key: + kfree(key); + + return err; +} + +static int virtnet_ethtool_flow_insert(struct virtnet_ff *ff, + struct ethtool_rx_flow_spec *fs, + u16 curr_queue_pairs) +{ + struct virtnet_ethtool_rule *eth_rule; + int err; + + if (!ff->ff_supported) + return -EOPNOTSUPP; + + err = validate_flow_input(ff, fs, curr_queue_pairs); + if (err) + return err; + + eth_rule = kzalloc(sizeof(*eth_rule), GFP_KERNEL); + if (!eth_rule) + return -ENOMEM; + + err = xa_alloc(&ff->ethtool.rules, &fs->location, eth_rule, + XA_LIMIT(0, le32_to_cpu(ff->ff_caps->rules_limit) - 1), + GFP_KERNEL); + if (err) + goto err_rule; + + eth_rule->flow_spec = *fs; + + err = build_and_insert(ff, eth_rule); + if (err) + goto err_xa; + + return err; + +err_xa: + xa_erase(&ff->ethtool.rules, eth_rule->flow_spec.location); + +err_rule: + fs->location = RX_CLS_LOC_ANY; + kfree(eth_rule); + + return err; +} + +static int virtnet_ethtool_flow_remove(struct virtnet_ff *ff, int location) +{ + struct virtnet_ethtool_rule *eth_rule; + int err = 0; + + if (!ff->ff_supported) + return -EOPNOTSUPP; + + eth_rule = xa_load(&ff->ethtool.rules, location); + if (!eth_rule) { + err = -ENOENT; + goto out; + } + + destroy_ethtool_rule(ff, eth_rule); +out: + return err; +} + static size_t get_mask_size(u16 type) { switch (type) { @@ -6923,6 +7374,8 @@ static int virtnet_ff_init(struct virtnet_ff *ff, struct virtio_device *vdev) if (err) goto err_ff_action; + xa_init_flags(&ff->classifiers, XA_FLAGS_ALLOC); + xa_init_flags(&ff->ethtool.rules, XA_FLAGS_ALLOC); ff->vdev = vdev; ff->ff_supported = true; @@ -6947,9 +7400,18 @@ static int virtnet_ff_init(struct virtnet_ff *ff, struct virtio_device *vdev) static void virtnet_ff_cleanup(struct virtnet_ff *ff) { + struct virtnet_ethtool_rule *eth_rule; + unsigned long i; + if (!ff->ff_supported) return; + xa_for_each(&ff->ethtool.rules, i, eth_rule) + destroy_ethtool_rule(ff, eth_rule); + + xa_destroy(&ff->ethtool.rules); + xa_destroy(&ff->classifiers); + virtio_admin_obj_destroy(ff->vdev, VIRTIO_NET_RESOURCE_OBJ_FF_GROUP, VIRTNET_FF_ETHTOOL_GROUP_PRIORITY, diff --git a/include/uapi/linux/virtio_net_ff.h b/include/uapi/linux/virtio_net_ff.h index 6d1f953c2b46..c98aa4942bee 100644 --- a/include/uapi/linux/virtio_net_ff.h +++ b/include/uapi/linux/virtio_net_ff.h @@ -13,6 +13,8 @@ #define VIRTIO_NET_FF_ACTION_CAP 0x802 #define VIRTIO_NET_RESOURCE_OBJ_FF_GROUP 0x0200 +#define VIRTIO_NET_RESOURCE_OBJ_FF_CLASSIFIER 0x0201 +#define VIRTIO_NET_RESOURCE_OBJ_FF_RULE 0x0202 /** * struct virtio_net_ff_cap_data - Flow filter resource capability limits @@ -103,4 +105,52 @@ struct virtio_net_resource_obj_ff_group { __le16 group_priority; }; +/** + * struct virtio_net_resource_obj_ff_classifier - Flow filter classifier object + * @count: number of selector entries in @selectors + * @reserved: must be set to 0 by the driver and ignored by the device + * @selectors: array of selector descriptors that define match masks + * + * Payload for the VIRTIO_NET_RESOURCE_OBJ_FF_CLASSIFIER administrative object. + * Each selector describes a header mask used to match packets + * (see struct virtio_net_ff_selector). Selectors appear in the order they are + * to be applied. + */ +struct virtio_net_resource_obj_ff_classifier { + __u8 count; + __u8 reserved[7]; + __u8 selectors[]; +}; + +/** + * struct virtio_net_resource_obj_ff_rule - Flow filter rule object + * @group_id: identifier of the target flow filter group + * @classifier_id: identifier of the classifier referenced by this rule + * @rule_priority: relative priority of this rule within the group + * @key_length: number of bytes in @keys + * @action: action to perform, one of VIRTIO_NET_FF_ACTION_* + * @reserved: must be set to 0 by the driver and ignored by the device + * @vq_index: RX virtqueue index for VIRTIO_NET_FF_ACTION_RX_VQ, 0 otherwise + * @reserved1: must be set to 0 by the driver and ignored by the device + * @keys: concatenated key bytes matching the classifier's selectors order + * + * Payload for the VIRTIO_NET_RESOURCE_OBJ_FF_RULE administrative object. + * @group_id and @classifier_id refer to previously created objects of types + * VIRTIO_NET_RESOURCE_OBJ_FF_GROUP and VIRTIO_NET_RESOURCE_OBJ_FF_CLASSIFIER + * respectively. The key bytes are compared against packet headers using the + * masks provided by the classifier's selectors. Multi-byte fields are + * little-endian. + */ +struct virtio_net_resource_obj_ff_rule { + __le32 group_id; + __le32 classifier_id; + __u8 rule_priority; + __u8 key_length; /* length of key in bytes */ + __u8 action; + __u8 reserved; + __le16 vq_index; + __u8 reserved1[2]; + __u8 keys[]; +}; + #endif -- 2.50.1
