diff options
Diffstat (limited to 'drivers/net/xen-netback/hash.c')
| -rw-r--r-- | drivers/net/xen-netback/hash.c | 384 |
1 files changed, 384 insertions, 0 deletions
diff --git a/drivers/net/xen-netback/hash.c b/drivers/net/xen-netback/hash.c new file mode 100644 index 000000000..fb87cb39a --- /dev/null +++ b/drivers/net/xen-netback/hash.c @@ -0,0 +1,384 @@ +/* + * Copyright (c) 2016 Citrix Systems Inc. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version 2 + * as published by the Free Softare Foundation; or, when distributed + * separately from the Linux kernel or incorporated into other + * software packages, subject to the following license: + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this source file (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, modify, + * merge, publish, distribute, sublicense, and/or sell copies of the Software, + * and to permit persons to whom the Software is furnished to do so, subject to + * the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +#define XEN_NETIF_DEFINE_TOEPLITZ + +#include "common.h" +#include <linux/vmalloc.h> +#include <linux/rculist.h> + +static void xenvif_del_hash(struct rcu_head *rcu) +{ + struct xenvif_hash_cache_entry *entry; + + entry = container_of(rcu, struct xenvif_hash_cache_entry, rcu); + + kfree(entry); +} + +static void xenvif_add_hash(struct xenvif *vif, const u8 *tag, + unsigned int len, u32 val) +{ + struct xenvif_hash_cache_entry *new, *entry, *oldest; + unsigned long flags; + bool found; + + new = kmalloc(sizeof(*entry), GFP_KERNEL); + if (!new) + return; + + memcpy(new->tag, tag, len); + new->len = len; + new->val = val; + + spin_lock_irqsave(&vif->hash.cache.lock, flags); + + found = false; + oldest = NULL; + list_for_each_entry_rcu(entry, &vif->hash.cache.list, link) { + /* Make sure we don't add duplicate entries */ + if (entry->len == len && + memcmp(entry->tag, tag, len) == 0) + found = true; + if (!oldest || entry->seq < oldest->seq) + oldest = entry; + } + + if (!found) { + new->seq = atomic_inc_return(&vif->hash.cache.seq); + list_add_rcu(&new->link, &vif->hash.cache.list); + + if (++vif->hash.cache.count > xenvif_hash_cache_size) { + list_del_rcu(&oldest->link); + vif->hash.cache.count--; + call_rcu(&oldest->rcu, xenvif_del_hash); + } + } + + spin_unlock_irqrestore(&vif->hash.cache.lock, flags); + + if (found) + kfree(new); +} + +static u32 xenvif_new_hash(struct xenvif *vif, const u8 *data, + unsigned int len) +{ + u32 val; + + val = xen_netif_toeplitz_hash(vif->hash.key, + sizeof(vif->hash.key), + data, len); + + if (xenvif_hash_cache_size != 0) + xenvif_add_hash(vif, data, len, val); + + return val; +} + +static void xenvif_flush_hash(struct xenvif *vif) +{ + struct xenvif_hash_cache_entry *entry; + unsigned long flags; + + if (xenvif_hash_cache_size == 0) + return; + + spin_lock_irqsave(&vif->hash.cache.lock, flags); + + list_for_each_entry_rcu(entry, &vif->hash.cache.list, link) { + list_del_rcu(&entry->link); + vif->hash.cache.count--; + call_rcu(&entry->rcu, xenvif_del_hash); + } + + spin_unlock_irqrestore(&vif->hash.cache.lock, flags); +} + +static u32 xenvif_find_hash(struct xenvif *vif, const u8 *data, + unsigned int len) +{ + struct xenvif_hash_cache_entry *entry; + u32 val; + bool found; + + if (len >= XEN_NETBK_HASH_TAG_SIZE) + return 0; + + if (xenvif_hash_cache_size == 0) + return xenvif_new_hash(vif, data, len); + + rcu_read_lock(); + + found = false; + + list_for_each_entry_rcu(entry, &vif->hash.cache.list, link) { + if (entry->len == len && + memcmp(entry->tag, data, len) == 0) { + val = entry->val; + entry->seq = atomic_inc_return(&vif->hash.cache.seq); + found = true; + break; + } + } + + rcu_read_unlock(); + + if (!found) + val = xenvif_new_hash(vif, data, len); + + return val; +} + +void xenvif_set_skb_hash(struct xenvif *vif, struct sk_buff *skb) +{ + struct flow_keys flow; + u32 hash = 0; + enum pkt_hash_types type = PKT_HASH_TYPE_NONE; + u32 flags = vif->hash.flags; + bool has_tcp_hdr; + + /* Quick rejection test: If the network protocol doesn't + * correspond to any enabled hash type then there's no point + * in parsing the packet header. + */ + switch (skb->protocol) { + case htons(ETH_P_IP): + if (flags & (XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP | + XEN_NETIF_CTRL_HASH_TYPE_IPV4)) + break; + + goto done; + + case htons(ETH_P_IPV6): + if (flags & (XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP | + XEN_NETIF_CTRL_HASH_TYPE_IPV6)) + break; + + goto done; + + default: + goto done; + } + + memset(&flow, 0, sizeof(flow)); + if (!skb_flow_dissect_flow_keys(skb, &flow, 0)) + goto done; + + has_tcp_hdr = (flow.basic.ip_proto == IPPROTO_TCP) && + !(flow.control.flags & FLOW_DIS_IS_FRAGMENT); + + switch (skb->protocol) { + case htons(ETH_P_IP): + if (has_tcp_hdr && + (flags & XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP)) { + u8 data[12]; + + memcpy(&data[0], &flow.addrs.v4addrs.src, 4); + memcpy(&data[4], &flow.addrs.v4addrs.dst, 4); + memcpy(&data[8], &flow.ports.src, 2); + memcpy(&data[10], &flow.ports.dst, 2); + + hash = xenvif_find_hash(vif, data, sizeof(data)); + type = PKT_HASH_TYPE_L4; + } else if (flags & XEN_NETIF_CTRL_HASH_TYPE_IPV4) { + u8 data[8]; + + memcpy(&data[0], &flow.addrs.v4addrs.src, 4); + memcpy(&data[4], &flow.addrs.v4addrs.dst, 4); + + hash = xenvif_find_hash(vif, data, sizeof(data)); + type = PKT_HASH_TYPE_L3; + } + + break; + + case htons(ETH_P_IPV6): + if (has_tcp_hdr && + (flags & XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP)) { + u8 data[36]; + + memcpy(&data[0], &flow.addrs.v6addrs.src, 16); + memcpy(&data[16], &flow.addrs.v6addrs.dst, 16); + memcpy(&data[32], &flow.ports.src, 2); + memcpy(&data[34], &flow.ports.dst, 2); + + hash = xenvif_find_hash(vif, data, sizeof(data)); + type = PKT_HASH_TYPE_L4; + } else if (flags & XEN_NETIF_CTRL_HASH_TYPE_IPV6) { + u8 data[32]; + + memcpy(&data[0], &flow.addrs.v6addrs.src, 16); + memcpy(&data[16], &flow.addrs.v6addrs.dst, 16); + + hash = xenvif_find_hash(vif, data, sizeof(data)); + type = PKT_HASH_TYPE_L3; + } + + break; + } + +done: + if (type == PKT_HASH_TYPE_NONE) + skb_clear_hash(skb); + else + __skb_set_sw_hash(skb, hash, type == PKT_HASH_TYPE_L4); +} + +u32 xenvif_set_hash_alg(struct xenvif *vif, u32 alg) +{ + switch (alg) { + case XEN_NETIF_CTRL_HASH_ALGORITHM_NONE: + case XEN_NETIF_CTRL_HASH_ALGORITHM_TOEPLITZ: + break; + + default: + return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER; + } + + vif->hash.alg = alg; + + return XEN_NETIF_CTRL_STATUS_SUCCESS; +} + +u32 xenvif_get_hash_flags(struct xenvif *vif, u32 *flags) +{ + if (vif->hash.alg == XEN_NETIF_CTRL_HASH_ALGORITHM_NONE) + return XEN_NETIF_CTRL_STATUS_NOT_SUPPORTED; + + *flags = XEN_NETIF_CTRL_HASH_TYPE_IPV4 | + XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP | + XEN_NETIF_CTRL_HASH_TYPE_IPV6 | + XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP; + + return XEN_NETIF_CTRL_STATUS_SUCCESS; +} + +u32 xenvif_set_hash_flags(struct xenvif *vif, u32 flags) +{ + if (flags & ~(XEN_NETIF_CTRL_HASH_TYPE_IPV4 | + XEN_NETIF_CTRL_HASH_TYPE_IPV4_TCP | + XEN_NETIF_CTRL_HASH_TYPE_IPV6 | + XEN_NETIF_CTRL_HASH_TYPE_IPV6_TCP)) + return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER; + + if (vif->hash.alg == XEN_NETIF_CTRL_HASH_ALGORITHM_NONE) + return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER; + + vif->hash.flags = flags; + + return XEN_NETIF_CTRL_STATUS_SUCCESS; +} + +u32 xenvif_set_hash_key(struct xenvif *vif, u32 gref, u32 len) +{ + u8 *key = vif->hash.key; + struct gnttab_copy copy_op = { + .source.u.ref = gref, + .source.domid = vif->domid, + .dest.u.gmfn = virt_to_gfn(key), + .dest.domid = DOMID_SELF, + .dest.offset = xen_offset_in_page(key), + .len = len, + .flags = GNTCOPY_source_gref + }; + + if (len > XEN_NETBK_MAX_HASH_KEY_SIZE) + return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER; + + if (copy_op.len != 0) { + gnttab_batch_copy(©_op, 1); + + if (copy_op.status != GNTST_okay) + return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER; + } + + /* Clear any remaining key octets */ + if (len < XEN_NETBK_MAX_HASH_KEY_SIZE) + memset(key + len, 0, XEN_NETBK_MAX_HASH_KEY_SIZE - len); + + xenvif_flush_hash(vif); + + return XEN_NETIF_CTRL_STATUS_SUCCESS; +} + +u32 xenvif_set_hash_mapping_size(struct xenvif *vif, u32 size) +{ + if (size > XEN_NETBK_MAX_HASH_MAPPING_SIZE) + return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER; + + vif->hash.size = size; + memset(vif->hash.mapping, 0, sizeof(u32) * size); + + return XEN_NETIF_CTRL_STATUS_SUCCESS; +} + +u32 xenvif_set_hash_mapping(struct xenvif *vif, u32 gref, u32 len, + u32 off) +{ + u32 *mapping = &vif->hash.mapping[off]; + struct gnttab_copy copy_op = { + .source.u.ref = gref, + .source.domid = vif->domid, + .dest.u.gmfn = virt_to_gfn(mapping), + .dest.domid = DOMID_SELF, + .dest.offset = xen_offset_in_page(mapping), + .len = len * sizeof(u32), + .flags = GNTCOPY_source_gref + }; + + if ((off + len > vif->hash.size) || copy_op.len > XEN_PAGE_SIZE) + return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER; + + while (len-- != 0) + if (mapping[off++] >= vif->num_queues) + return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER; + + if (copy_op.len != 0) { + gnttab_batch_copy(©_op, 1); + + if (copy_op.status != GNTST_okay) + return XEN_NETIF_CTRL_STATUS_INVALID_PARAMETER; + } + + return XEN_NETIF_CTRL_STATUS_SUCCESS; +} + +void xenvif_init_hash(struct xenvif *vif) +{ + if (xenvif_hash_cache_size == 0) + return; + + spin_lock_init(&vif->hash.cache.lock); + INIT_LIST_HEAD(&vif->hash.cache.list); +} + +void xenvif_deinit_hash(struct xenvif *vif) +{ + xenvif_flush_hash(vif); +} |