/* Copyright (c) 2011, 2012, 2013, 2014, 2015, 2016, 2017 Nicira, Inc.

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at:

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

#include <config.h>

#include "bundle.h"

#include <sys/types.h>

#include <netinet/in.h>

#include <arpa/inet.h>

#include <inttypes.h>

#include "colors.h"

#include "multipath.h"

#include "nx-match.h"

#include "openflow/nicira-ext.h"

#include "openvswitch/dynamic-string.h"

#include "openvswitch/meta-flow.h"

#include "openvswitch/ofp-actions.h"

#include "openvswitch/ofp-errors.h"

#include "openvswitch/ofp-port.h"

#include "openvswitch/ofpbuf.h"

#include "openvswitch/vlog.h"

#include "util.h"

VLOG_DEFINE_THIS_MODULE(bundle);

static ofp_port_t

execute_ab(const struct ofpact_bundle *bundle,

           bool (*member_enabled)(ofp_port_t ofp_port, void *aux), void *aux)

{

    size_t i;

    for (i = 0; i < bundle->n_members; i++) {

        ofp_port_t member = bundle->members[i];

        if (member_enabled(member, aux)) {

            return member;

        }

    }

    return OFPP_NONE;

}

static ofp_port_t

execute_hrw(const struct ofpact_bundle *bundle,

            const struct flow *flow, struct flow_wildcards *wc,

            bool (*member_enabled)(ofp_port_t ofp_port, void *aux), void *aux)

{

    uint32_t flow_hash, best_hash;

    int best, i;

    if (bundle->n_members > 1) {

        flow_mask_hash_fields(flow, wc, bundle->fields);

    }

    flow_hash = flow_hash_fields(flow, bundle->fields, bundle->basis);

    best = -1;

    best_hash = 0;

    for (i = 0; i < bundle->n_members; i++) {

        if (member_enabled(bundle->members[i], aux)) {

            uint32_t hash = hash_2words(i, flow_hash);

            if (best < 0 || hash > best_hash) {

                best_hash = hash;

                best = i;

            }

        }

    }

    return best >= 0 ? bundle->members[best] : OFPP_NONE;

}

/* Executes 'bundle' on 'flow'.  Sets fields in 'wc' that were used to

 * calculate the result.  Uses 'member_enabled' to determine if the member

 * designated by 'ofp_port' is up.  Returns the chosen member, or

 * OFPP_NONE if none of the members are acceptable. */

ofp_port_t

bundle_execute(const struct ofpact_bundle *bundle,

               const struct flow *flow, struct flow_wildcards *wc,

               bool (*member_enabled)(ofp_port_t ofp_port, void *aux),

               void *aux)

{

    switch (bundle->algorithm) {

    case NX_BD_ALG_HRW:

        return execute_hrw(bundle, flow, wc, member_enabled, aux);

    case NX_BD_ALG_ACTIVE_BACKUP:

        return execute_ab(bundle, member_enabled, aux);

    default:

        OVS_NOT_REACHED();

    }

}

enum ofperr

bundle_check(const struct ofpact_bundle *bundle, ofp_port_t max_ports,

             const struct match *match)

{

    static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);

    size_t i;

    if (bundle->dst.field) {

        enum ofperr error = mf_check_dst(&bundle->dst, match);

        if (error) {

            return error;

        }

    }

    for (i = 0; i < bundle->n_members; i++) {

        ofp_port_t ofp_port = bundle->members[i];

        if (ofp_port != OFPP_NONE) {

            enum ofperr error = ofpact_check_output_port(ofp_port, max_ports);

            if (error) {

                VLOG_WARN_RL(&rl, "invalid member %"PRIu32, ofp_port);

                return error;

            }

        }

        /* Controller members are unsupported due to the lack of a max_len

         * argument. This may or may not change in the future.  There doesn't

         * seem to be a real-world use-case for supporting it. */

        if (ofp_port == OFPP_CONTROLLER) {

            VLOG_WARN_RL(&rl, "unsupported controller member");

            return OFPERR_OFPBAC_BAD_OUT_PORT;

        }

    }

    return 0;

}

/* Helper for bundle_parse and bundle_parse_load.

 *

 * Returns NULL if successful, otherwise a malloc()'d string describing the

 * error.  The caller is responsible for freeing the returned string.*/

static char * OVS_WARN_UNUSED_RESULT

bundle_parse__(const char *s, const struct ofputil_port_map *port_map,

               char **save_ptr,

               const char *fields, const char *basis, const char *algorithm,

               const char *member_type, const char *dst,

               const char *member_delim, struct ofpbuf *ofpacts)

{

    struct ofpact_bundle *bundle;

    if (!member_delim) {

        return xasprintf("%s: not enough arguments to bundle action", s);

    }

    if (strcasecmp(member_delim, "members")

        && strcasecmp(member_delim, "slaves")) {

        return xasprintf("%s: missing member delimiter, expected `members', "

                         "got `%s'", s, member_delim);

    }

    bundle = ofpact_put_BUNDLE(ofpacts);

    for (;;) {

        ofp_port_t member_port;

        char *member;

        member = strtok_r(NULL, ", []", save_ptr);

        if (!member || bundle->n_members >= BUNDLE_MAX_MEMBERS) {

            break;

        }

        if (!ofputil_port_from_string(member, port_map, &member_port)) {

            return xasprintf("%s: bad port number", member);

        }

        ofpbuf_put(ofpacts, &member_port, sizeof member_port);

        bundle = ofpacts->header;

        bundle->n_members++;

    }

    if (ofpbuf_oversized(ofpacts)) {

        return xasprintf("input too big");

    }

    ofpact_finish_BUNDLE(ofpacts, &bundle);

    bundle->basis = atoi(basis);

    if (!strcasecmp(fields, "eth_src")) {

        bundle->fields = NX_HASH_FIELDS_ETH_SRC;

    } else if (!strcasecmp(fields, "symmetric_l4")) {

        bundle->fields = NX_HASH_FIELDS_SYMMETRIC_L4;

    } else if (!strcasecmp(fields, "symmetric_l3l4")) {

        bundle->fields = NX_HASH_FIELDS_SYMMETRIC_L3L4;

    } else if (!strcasecmp(fields, "symmetric_l3l4+udp")) {

        bundle->fields = NX_HASH_FIELDS_SYMMETRIC_L3L4_UDP;

    } else if (!strcasecmp(fields, "nw_src")) {

        bundle->fields = NX_HASH_FIELDS_NW_SRC;

    } else if (!strcasecmp(fields, "nw_dst")) {

        bundle->fields = NX_HASH_FIELDS_NW_DST;

    } else if (!strcasecmp(fields, "symmetric_l3")) {

        bundle->fields = NX_HASH_FIELDS_SYMMETRIC_L3;

    } else {

        return xasprintf("%s: unknown fields `%s'", s, fields);

    }

    if (!strcasecmp(algorithm, "active_backup")) {

        bundle->algorithm = NX_BD_ALG_ACTIVE_BACKUP;

    } else if (!strcasecmp(algorithm, "hrw")) {

        bundle->algorithm = NX_BD_ALG_HRW;

    } else {

        return xasprintf("%s: unknown algorithm `%s'", s, algorithm);

    }

    if (strcasecmp(member_type, "ofport")) {

        return xasprintf("%s: unknown member_type `%s'", s, member_type);

    }

    if (dst) {

        char *error = mf_parse_subfield(&bundle->dst, dst);

        if (error) {

            return error;

        }

        if (!mf_nxm_header(bundle->dst.field->id)) {

            return xasprintf("%s: experimenter OXM field '%s' not supported",

                             s, dst);

        }

    }

    return NULL;

}

/* Converts a bundle action string contained in 's' to an nx_action_bundle and

 * stores it in 'b'.  Sets 'b''s l2 pointer to NULL.

 *

 * Returns NULL if successful, otherwise a malloc()'d string describing the

 * error.  The caller is responsible for freeing the returned string. */

char * OVS_WARN_UNUSED_RESULT

bundle_parse(const char *s, const struct ofputil_port_map *port_map,

             struct ofpbuf *ofpacts)

{

    char *fields, *basis, *algorithm, *member_type, *member_delim;

    char *tokstr, *save_ptr;

    char *error;

    save_ptr = NULL;

    tokstr = xstrdup(s);

    fields = strtok_r(tokstr, ", ", &save_ptr);

    basis = strtok_r(NULL, ", ", &save_ptr);

    algorithm = strtok_r(NULL, ", ", &save_ptr);

    member_type = strtok_r(NULL, ", ", &save_ptr);

    member_delim = strtok_r(NULL, ": ", &save_ptr);

    error = bundle_parse__(s, port_map,

                           &save_ptr, fields, basis, algorithm, member_type,

                           NULL, member_delim, ofpacts);

    free(tokstr);

    return error;

}

/* Converts a bundle_load action string contained in 's' to an nx_action_bundle

 * and stores it in 'b'.  Sets 'b''s l2 pointer to NULL.

 *

 * Returns NULL if successful, otherwise a malloc()'d string describing the

 * error.  The caller is responsible for freeing the returned string.*/

char * OVS_WARN_UNUSED_RESULT

bundle_parse_load(const char *s, const struct ofputil_port_map *port_map,

                  struct ofpbuf *ofpacts)

{

    char *fields, *basis, *algorithm, *member_type, *dst, *member_delim;

    char *tokstr, *save_ptr;

    char *error;

    save_ptr = NULL;

    tokstr = xstrdup(s);

    fields = strtok_r(tokstr, ", ", &save_ptr);

    basis = strtok_r(NULL, ", ", &save_ptr);

    algorithm = strtok_r(NULL, ", ", &save_ptr);

    member_type = strtok_r(NULL, ", ", &save_ptr);

    dst = strtok_r(NULL, ", ", &save_ptr);

    member_delim = strtok_r(NULL, ": ", &save_ptr);

    error = bundle_parse__(s, port_map,

                           &save_ptr, fields, basis, algorithm, member_type,

                           dst, member_delim, ofpacts);

    free(tokstr);

    return error;

}

/* Appends a human-readable representation of 'nab' to 's'.  If 'port_map' is

 * nonnull, uses it to translate port numbers to names in output. */

void

bundle_format(const struct ofpact_bundle *bundle,

              const struct ofputil_port_map *port_map, struct ds *s)

{

    const char *action, *fields, *algorithm;

    size_t i;

    fields = flow_hash_fields_to_str(bundle->fields);

    switch (bundle->algorithm) {

    case NX_BD_ALG_HRW:

        algorithm = "hrw";

        break;

    case NX_BD_ALG_ACTIVE_BACKUP:

        algorithm = "active_backup";

        break;

    default:

        algorithm = "<unknown>";

    }

    action = bundle->dst.field ? "bundle_load" : "bundle";

    ds_put_format(s, "%s%s(%s%s,%"PRIu16",%s,%s,", colors.paren, action,

                  colors.end, fields, bundle->basis, algorithm, "ofport");

    if (bundle->dst.field) {

        mf_format_subfield(&bundle->dst, s);

        ds_put_char(s, ',');

    }

    ds_put_format(s, "%smembers:%s", colors.param, colors.end);

    for (i = 0; i < bundle->n_members; i++) {

        if (i) {

            ds_put_char(s, ',');

        }

        ofputil_format_port(bundle->members[i], port_map, s);

    }

    ds_put_format(s, "%s)%s", colors.paren, colors.end);

}