/*
 * This file is part of the Chelsio T4 Ethernet driver for Linux.
 *
 * Copyright (c) 2016 Chelsio Communications, Inc. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * 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.
 */

#include <net/tc_act/tc_gact.h>
#include <net/tc_act/tc_mirred.h>

#include "cxgb4.h"
#include "cxgb4_tc_u32_parse.h"
#include "cxgb4_tc_u32.h"

/* Fill ch_filter_specification with parsed match value/mask pair. */
static int fill_match_fields(struct adapter *adap,
                             struct ch_filter_specification *fs,
                             struct tc_cls_u32_offload *cls,
                             const struct cxgb4_match_field *entry,
                             bool next_header)
{
        unsigned int i, j;
        u32 val, mask;
        int off, err;
        bool found;

        for (i = 0; i < cls->knode.sel->nkeys; i++) {
                off = cls->knode.sel->keys[i].off;
                val = cls->knode.sel->keys[i].val;
                mask = cls->knode.sel->keys[i].mask;

                if (next_header) {
                        /* For next headers, parse only keys with offmask */
                        if (!cls->knode.sel->keys[i].offmask)
                                continue;
                } else {
                        /* For the remaining, parse only keys without offmask */
                        if (cls->knode.sel->keys[i].offmask)
                                continue;
                }

                found = false;

                for (j = 0; entry[j].val; j++) {
                        if (off == entry[j].off) {
                                found = true;
                                err = entry[j].val(fs, val, mask);
                                if (err)
                                        return err;
                                break;
                        }
                }

                if (!found)
                        return -EINVAL;
        }

        return 0;
}

/* Fill ch_filter_specification with parsed action. */
static int fill_action_fields(struct adapter *adap,
                              struct ch_filter_specification *fs,
                              struct tc_cls_u32_offload *cls)
{
        unsigned int num_actions = 0;
        const struct tc_action *a;
        struct tcf_exts *exts;
        LIST_HEAD(actions);

        exts = cls->knode.exts;
        if (!tcf_exts_has_actions(exts))
                return -EINVAL;

        tcf_exts_to_list(exts, &actions);
        list_for_each_entry(a, &actions, list) {
                /* Don't allow more than one action per rule. */
                if (num_actions)
                        return -EINVAL;

                /* Drop in hardware. */
                if (is_tcf_gact_shot(a)) {
                        fs->action = FILTER_DROP;
                        num_actions++;
                        continue;
                }

                /* Re-direct to specified port in hardware. */
                if (is_tcf_mirred_egress_redirect(a)) {
                        struct net_device *n_dev;
                        unsigned int i, index;
                        bool found = false;

                        index = tcf_mirred_ifindex(a);
                        for_each_port(adap, i) {
                                n_dev = adap->port[i];
                                if (index == n_dev->ifindex) {
                                        fs->action = FILTER_SWITCH;
                                        fs->eport = i;
                                        found = true;
                                        break;
                                }
                        }

                        /* Interface doesn't belong to any port of
                         * the underlying hardware.
                         */
                        if (!found)
                                return -EINVAL;

                        num_actions++;
                        continue;
                }

                /* Un-supported action. */
                return -EINVAL;
        }

        return 0;
}

int cxgb4_config_knode(struct net_device *dev, struct tc_cls_u32_offload *cls)
{
        const struct cxgb4_match_field *start, *link_start = NULL;
        struct adapter *adapter = netdev2adap(dev);
        __be16 protocol = cls->common.protocol;
        struct ch_filter_specification fs;
        struct cxgb4_tc_u32_table *t;
        struct cxgb4_link *link;
        unsigned int filter_id;
        u32 uhtid, link_uhtid;
        bool is_ipv6 = false;
        int ret;

        if (!can_tc_u32_offload(dev))
                return -EOPNOTSUPP;

        if (protocol != htons(ETH_P_IP) && protocol != htons(ETH_P_IPV6))
                return -EOPNOTSUPP;

        /* Fetch the location to insert the filter. */
        filter_id = cls->knode.handle & 0xFFFFF;

        if (filter_id > adapter->tids.nftids) {
                dev_err(adapter->pdev_dev,
                        "Location %d out of range for insertion. Max: %d\n",
                        filter_id, adapter->tids.nftids);
                return -ERANGE;
        }

        t = adapter->tc_u32;
        uhtid = TC_U32_USERHTID(cls->knode.handle);
        link_uhtid = TC_U32_USERHTID(cls->knode.link_handle);

        /* Ensure that uhtid is either root u32 (i.e. 0x800)
         * or a a valid linked bucket.
         */
        if (uhtid != 0x800 && uhtid >= t->size)
                return -EINVAL;

        /* Ensure link handle uhtid is sane, if specified. */
        if (link_uhtid >= t->size)
                return -EINVAL;

        memset(&fs, 0, sizeof(fs));

        if (protocol == htons(ETH_P_IPV6)) {
                start = cxgb4_ipv6_fields;
                is_ipv6 = true;
        } else {
                start = cxgb4_ipv4_fields;
                is_ipv6 = false;
        }

        if (uhtid != 0x800) {
                /* Link must exist from root node before insertion. */
                if (!t->table[uhtid - 1].link_handle)
                        return -EINVAL;

                /* Link must have a valid supported next header. */
                link_start = t->table[uhtid - 1].match_field;
                if (!link_start)
                        return -EINVAL;
        }

        /* Parse links and record them for subsequent jumps to valid
         * next headers.
         */
        if (link_uhtid) {
                const struct cxgb4_next_header *next;
                bool found = false;
                unsigned int i, j;
                u32 val, mask;
                int off;

                if (t->table[link_uhtid - 1].link_handle) {
                        dev_err(adapter->pdev_dev,
                                "Link handle exists for: 0x%x\n",
                                link_uhtid);
                        return -EINVAL;
                }

                next = is_ipv6 ? cxgb4_ipv6_jumps : cxgb4_ipv4_jumps;

                /* Try to find matches that allow jumps to next header. */
                for (i = 0; next[i].jump; i++) {
                        if (next[i].offoff != cls->knode.sel->offoff ||
                            next[i].shift != cls->knode.sel->offshift ||
                            next[i].mask != cls->knode.sel->offmask ||
                            next[i].offset != cls->knode.sel->off)
                                continue;

                        /* Found a possible candidate.  Find a key that
                         * matches the corresponding offset, value, and
                         * mask to jump to next header.
                         */
                        for (j = 0; j < cls->knode.sel->nkeys; j++) {
                                off = cls->knode.sel->keys[j].off;
                                val = cls->knode.sel->keys[j].val;
                                mask = cls->knode.sel->keys[j].mask;

                                if (next[i].match_off == off &&
                                    next[i].match_val == val &&
                                    next[i].match_mask == mask) {
                                        found = true;
                                        break;
                                }
                        }

                        if (!found)
                                continue; /* Try next candidate. */

                        /* Candidate to jump to next header found.
                         * Translate all keys to internal specification
                         * and store them in jump table. This spec is copied
                         * later to set the actual filters.
                         */
                        ret = fill_match_fields(adapter, &fs, cls,
                                                start, false);
                        if (ret)
                                goto out;

                        link = &t->table[link_uhtid - 1];
                        link->match_field = next[i].jump;
                        link->link_handle = cls->knode.handle;
                        memcpy(&link->fs, &fs, sizeof(fs));
                        break;
                }

                /* No candidate found to jump to next header. */
                if (!found)
                        return -EINVAL;

                return 0;
        }

        /* Fill ch_filter_specification match fields to be shipped to hardware.
         * Copy the linked spec (if any) first.  And then update the spec as
         * needed.
         */
        if (uhtid != 0x800 && t->table[uhtid - 1].link_handle) {
                /* Copy linked ch_filter_specification */
                memcpy(&fs, &t->table[uhtid - 1].fs, sizeof(fs));
                ret = fill_match_fields(adapter, &fs, cls,
                                        link_start, true);
                if (ret)
                        goto out;
        }

        ret = fill_match_fields(adapter, &fs, cls, start, false);
        if (ret)
                goto out;

        /* Fill ch_filter_specification action fields to be shipped to
         * hardware.
         */
        ret = fill_action_fields(adapter, &fs, cls);
        if (ret)
                goto out;

        /* The filter spec has been completely built from the info
         * provided from u32.  We now set some default fields in the
         * spec for sanity.
         */

        /* Match only packets coming from the ingress port where this
         * filter will be created.
         */
        fs.val.iport = netdev2pinfo(dev)->port_id;
        fs.mask.iport = ~0;

        /* Enable filter hit counts. */
        fs.hitcnts = 1;

        /* Set type of filter - IPv6 or IPv4 */
        fs.type = is_ipv6 ? 1 : 0;

        /* Set the filter */
        ret = cxgb4_set_filter(dev, filter_id, &fs);
        if (ret)
                goto out;

        /* If this is a linked bucket, then set the corresponding
         * entry in the bitmap to mark it as belonging to this linked
         * bucket.
         */
        if (uhtid != 0x800 && t->table[uhtid - 1].link_handle)
                set_bit(filter_id, t->table[uhtid - 1].tid_map);

out:
        return ret;
}

int cxgb4_delete_knode(struct net_device *dev, struct tc_cls_u32_offload *cls)
{
        struct adapter *adapter = netdev2adap(dev);
        unsigned int filter_id, max_tids, i, j;
        struct cxgb4_link *link = NULL;
        struct cxgb4_tc_u32_table *t;
        u32 handle, uhtid;
        int ret;

        if (!can_tc_u32_offload(dev))
                return -EOPNOTSUPP;

        /* Fetch the location to delete the filter. */
        filter_id = cls->knode.handle & 0xFFFFF;

        if (filter_id > adapter->tids.nftids) {
                dev_err(adapter->pdev_dev,
                        "Location %d out of range for deletion. Max: %d\n",
                        filter_id, adapter->tids.nftids);
                return -ERANGE;
        }

        t = adapter->tc_u32;
        handle = cls->knode.handle;
        uhtid = TC_U32_USERHTID(cls->knode.handle);

        /* Ensure that uhtid is either root u32 (i.e. 0x800)
         * or a a valid linked bucket.
         */
        if (uhtid != 0x800 && uhtid >= t->size)
                return -EINVAL;

        /* Delete the specified filter */
        if (uhtid != 0x800) {
                link = &t->table[uhtid - 1];
                if (!link->link_handle)
                        return -EINVAL;

                if (!test_bit(filter_id, link->tid_map))
                        return -EINVAL;
        }

        ret = cxgb4_del_filter(dev, filter_id);
        if (ret)
                goto out;

        if (link)
                clear_bit(filter_id, link->tid_map);

        /* If a link is being deleted, then delete all filters
         * associated with the link.
         */
        max_tids = adapter->tids.nftids;
        for (i = 0; i < t->size; i++) {
                link = &t->table[i];

                if (link->link_handle == handle) {
                        for (j = 0; j < max_tids; j++) {
                                if (!test_bit(j, link->tid_map))
                                        continue;

                                ret = __cxgb4_del_filter(dev, j, NULL);
                                if (ret)
                                        goto out;

                                clear_bit(j, link->tid_map);
                        }

                        /* Clear the link state */
                        link->match_field = NULL;
                        link->link_handle = 0;
                        memset(&link->fs, 0, sizeof(link->fs));
                        break;
                }
        }

out:
        return ret;
}

void cxgb4_cleanup_tc_u32(struct adapter *adap)
{
        struct cxgb4_tc_u32_table *t;
        unsigned int i;

        if (!adap->tc_u32)
                return;

        /* Free up all allocated memory. */
        t = adap->tc_u32;
        for (i = 0; i < t->size; i++) {
                struct cxgb4_link *link = &t->table[i];

                kvfree(link->tid_map);
        }
        kvfree(adap->tc_u32);
}

struct cxgb4_tc_u32_table *cxgb4_init_tc_u32(struct adapter *adap)
{
        unsigned int max_tids = adap->tids.nftids;
        struct cxgb4_tc_u32_table *t;
        unsigned int i;

        if (!max_tids)
                return NULL;

        t = kvzalloc(sizeof(*t) +
                         (max_tids * sizeof(struct cxgb4_link)), GFP_KERNEL);
        if (!t)
                return NULL;

        t->size = max_tids;

        for (i = 0; i < t->size; i++) {
                struct cxgb4_link *link = &t->table[i];
                unsigned int bmap_size;

                bmap_size = BITS_TO_LONGS(max_tids);
                link->tid_map = kvzalloc(sizeof(unsigned long) * bmap_size, GFP_KERNEL);
                if (!link->tid_map)
                        goto out_no_mem;
                bitmap_zero(link->tid_map, max_tids);
        }

        return t;

out_no_mem:
        for (i = 0; i < t->size; i++) {
                struct cxgb4_link *link = &t->table[i];

                if (link->tid_map)
                        kvfree(link->tid_map);
        }

        if (t)
                kvfree(t);

        return NULL;
}