/*
 * Copyright (c) 2010 Nicira Networks.
 *
 * 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 "ofp-parse.h"

#include <errno.h>
#include <stdlib.h>

#include "byte-order.h"
#include "dynamic-string.h"
#include "netdev.h"
#include "ofp-util.h"
#include "ofpbuf.h"
#include "openflow/openflow.h"
#include "packets.h"
#include "socket-util.h"
#include "vconn.h"
#include "vlog.h"

VLOG_DEFINE_THIS_MODULE(ofp_parse);

static uint32_t
str_to_u32(const char *str)
{
    char *tail;
    uint32_t value;

    if (!str) {
        ovs_fatal(0, "missing required numeric argument");
    }

    errno = 0;
    value = strtoul(str, &tail, 0);
    if (errno == EINVAL || errno == ERANGE || *tail) {
        ovs_fatal(0, "invalid numeric format %s", str);
    }
    return value;
}

static uint64_t
str_to_u64(const char *str)
{
    char *tail;
    uint64_t value;

    errno = 0;
    value = strtoull(str, &tail, 0);
    if (errno == EINVAL || errno == ERANGE || *tail) {
        ovs_fatal(0, "invalid numeric format %s", str);
    }
    return value;
}

static void
str_to_mac(const char *str, uint8_t mac[6])
{
    if (sscanf(str, ETH_ADDR_SCAN_FMT, ETH_ADDR_SCAN_ARGS(mac))
        != ETH_ADDR_SCAN_COUNT) {
        ovs_fatal(0, "invalid mac address %s", str);
    }
}

static void
str_to_ip(const char *str_, ovs_be32 *ip, ovs_be32 *maskp)
{
    char *str = xstrdup(str_);
    char *save_ptr = NULL;
    const char *name, *netmask;
    struct in_addr in_addr;
    ovs_be32 mask;
    int retval;

    name = strtok_r(str, "/", &save_ptr);
    retval = name ? lookup_ip(name, &in_addr) : EINVAL;
    if (retval) {
        ovs_fatal(0, "%s: could not convert to IP address", str);
    }
    *ip = in_addr.s_addr;

    netmask = strtok_r(NULL, "/", &save_ptr);
    if (netmask) {
        uint8_t o[4];
        if (sscanf(netmask, "%"SCNu8".%"SCNu8".%"SCNu8".%"SCNu8,
                   &o[0], &o[1], &o[2], &o[3]) == 4) {
            mask = htonl((o[0] << 24) | (o[1] << 16) | (o[2] << 8) | o[3]);
        } else {
            int prefix = atoi(netmask);
            if (prefix <= 0 || prefix > 32) {
                ovs_fatal(0, "%s: network prefix bits not between 1 and 32",
                          str);
            } else if (prefix == 32) {
                mask = htonl(UINT32_MAX);
            } else {
                mask = htonl(((1u << prefix) - 1) << (32 - prefix));
            }
        }
    } else {
        mask = htonl(UINT32_MAX);
    }
    *ip &= mask;

    if (maskp) {
        *maskp = mask;
    } else {
        if (mask != htonl(UINT32_MAX)) {
            ovs_fatal(0, "%s: netmask not allowed here", str_);
        }
    }

    free(str);
}

static void *
put_action(struct ofpbuf *b, size_t size, uint16_t type)
{
    struct ofp_action_header *ah = ofpbuf_put_zeros(b, size);
    ah->type = htons(type);
    ah->len = htons(size);
    return ah;
}

static struct ofp_action_output *
put_output_action(struct ofpbuf *b, uint16_t port)
{
    struct ofp_action_output *oao = put_action(b, sizeof *oao, OFPAT_OUTPUT);
    oao->port = htons(port);
    return oao;
}

static void
put_enqueue_action(struct ofpbuf *b, uint16_t port, uint32_t queue)
{
    struct ofp_action_enqueue *oae = put_action(b, sizeof *oae, OFPAT_ENQUEUE);
    oae->port = htons(port);
    oae->queue_id = htonl(queue);
}

static void
put_dl_addr_action(struct ofpbuf *b, uint16_t type, const char *addr)
{
    struct ofp_action_dl_addr *oada = put_action(b, sizeof *oada, type);
    str_to_mac(addr, oada->dl_addr);
}


static bool
parse_port_name(const char *name, uint16_t *port)
{
    struct pair {
        const char *name;
        uint16_t value;
    };
    static const struct pair pairs[] = {
#define DEF_PAIR(NAME) {#NAME, OFPP_##NAME}
        DEF_PAIR(IN_PORT),
        DEF_PAIR(TABLE),
        DEF_PAIR(NORMAL),
        DEF_PAIR(FLOOD),
        DEF_PAIR(ALL),
        DEF_PAIR(CONTROLLER),
        DEF_PAIR(LOCAL),
        DEF_PAIR(NONE),
#undef DEF_PAIR
    };
    static const int n_pairs = ARRAY_SIZE(pairs);
    size_t i;

    for (i = 0; i < n_pairs; i++) {
        if (!strcasecmp(name, pairs[i].name)) {
            *port = pairs[i].value;
            return true;
        }
    }
    return false;
}

static void
str_to_action(char *str, struct ofpbuf *b)
{
    char *act, *arg;
    char *saveptr = NULL;
    bool drop = false;
    int n_actions;

    for (act = strtok_r(str, ", \t\r\n", &saveptr), n_actions = 0; act;
         act = strtok_r(NULL, ", \t\r\n", &saveptr), n_actions++)
    {
        uint16_t port;

        if (drop) {
            ovs_fatal(0, "Drop actions must not be followed by other actions");
        }

        /* Arguments are separated by colons */
        arg = strchr(act, ':');
        if (arg) {
            *arg = '\0';
            arg++;
        }

        if (!strcasecmp(act, "mod_vlan_vid")) {
            struct ofp_action_vlan_vid *va;
            va = put_action(b, sizeof *va, OFPAT_SET_VLAN_VID);
            va->vlan_vid = htons(str_to_u32(arg));
        } else if (!strcasecmp(act, "mod_vlan_pcp")) {
            struct ofp_action_vlan_pcp *va;
            va = put_action(b, sizeof *va, OFPAT_SET_VLAN_PCP);
            va->vlan_pcp = str_to_u32(arg);
        } else if (!strcasecmp(act, "strip_vlan")) {
            struct ofp_action_header *ah;
            ah = put_action(b, sizeof *ah, OFPAT_STRIP_VLAN);
            ah->type = htons(OFPAT_STRIP_VLAN);
        } else if (!strcasecmp(act, "mod_dl_src")) {
            put_dl_addr_action(b, OFPAT_SET_DL_SRC, arg);
        } else if (!strcasecmp(act, "mod_dl_dst")) {
            put_dl_addr_action(b, OFPAT_SET_DL_DST, arg);
        } else if (!strcasecmp(act, "mod_nw_src")) {
            struct ofp_action_nw_addr *na;
            na = put_action(b, sizeof *na, OFPAT_SET_NW_SRC);
            str_to_ip(arg, &na->nw_addr, NULL);
        } else if (!strcasecmp(act, "mod_nw_dst")) {
            struct ofp_action_nw_addr *na;
            na = put_action(b, sizeof *na, OFPAT_SET_NW_DST);
            str_to_ip(arg, &na->nw_addr, NULL);
        } else if (!strcasecmp(act, "mod_tp_src")) {
            struct ofp_action_tp_port *ta;
            ta = put_action(b, sizeof *ta, OFPAT_SET_TP_SRC);
            ta->tp_port = htons(str_to_u32(arg));
        } else if (!strcasecmp(act, "mod_tp_dst")) {
            struct ofp_action_tp_port *ta;
            ta = put_action(b, sizeof *ta, OFPAT_SET_TP_DST);
            ta->tp_port = htons(str_to_u32(arg));
        } else if (!strcasecmp(act, "mod_nw_tos")) {
            struct ofp_action_nw_tos *nt;
            nt = put_action(b, sizeof *nt, OFPAT_SET_NW_TOS);
            nt->nw_tos = str_to_u32(arg);
        } else if (!strcasecmp(act, "resubmit")) {
            struct nx_action_resubmit *nar;
            nar = put_action(b, sizeof *nar, OFPAT_VENDOR);
            nar->vendor = htonl(NX_VENDOR_ID);
            nar->subtype = htons(NXAST_RESUBMIT);
            nar->in_port = htons(str_to_u32(arg));
        } else if (!strcasecmp(act, "set_tunnel")) {
            struct nx_action_set_tunnel *nast;
            nast = put_action(b, sizeof *nast, OFPAT_VENDOR);
            nast->vendor = htonl(NX_VENDOR_ID);
            nast->subtype = htons(NXAST_SET_TUNNEL);
            nast->tun_id = htonl(str_to_u32(arg));
        } else if (!strcasecmp(act, "drop_spoofed_arp")) {
            struct nx_action_header *nah;
            nah = put_action(b, sizeof *nah, OFPAT_VENDOR);
            nah->vendor = htonl(NX_VENDOR_ID);
            nah->subtype = htons(NXAST_DROP_SPOOFED_ARP);
        } else if (!strcasecmp(act, "set_queue")) {
            struct nx_action_set_queue *nasq;
            nasq = put_action(b, sizeof *nasq, OFPAT_VENDOR);
            nasq->vendor = htonl(NX_VENDOR_ID);
            nasq->subtype = htons(NXAST_SET_QUEUE);
            nasq->queue_id = htonl(str_to_u32(arg));
        } else if (!strcasecmp(act, "pop_queue")) {
            struct nx_action_header *nah;
            nah = put_action(b, sizeof *nah, OFPAT_VENDOR);
            nah->vendor = htonl(NX_VENDOR_ID);
            nah->subtype = htons(NXAST_POP_QUEUE);
        } else if (!strcasecmp(act, "note")) {
            size_t start_ofs = b->size;
            struct nx_action_note *nan;
            int remainder;
            size_t len;

            nan = put_action(b, sizeof *nan, OFPAT_VENDOR);
            nan->vendor = htonl(NX_VENDOR_ID);
            nan->subtype = htons(NXAST_NOTE);

            b->size -= sizeof nan->note;
            while (arg && *arg != '\0') {
                uint8_t byte;
                bool ok;

                if (*arg == '.') {
                    arg++;
                }
                if (*arg == '\0') {
                    break;
                }

                byte = hexits_value(arg, 2, &ok);
                if (!ok) {
                    ovs_fatal(0, "bad hex digit in `note' argument");
                }
                ofpbuf_put(b, &byte, 1);

                arg += 2;
            }

            len = b->size - start_ofs;
            remainder = len % OFP_ACTION_ALIGN;
            if (remainder) {
                ofpbuf_put_zeros(b, OFP_ACTION_ALIGN - remainder);
            }
            nan->len = htons(b->size - start_ofs);
        } else if (!strcasecmp(act, "output")) {
            put_output_action(b, str_to_u32(arg));
        } else if (!strcasecmp(act, "enqueue")) {
            char *sp = NULL;
            char *port_s = strtok_r(arg, ":q", &sp);
            char *queue = strtok_r(NULL, "", &sp);
            if (port_s == NULL || queue == NULL) {
                ovs_fatal(0, "\"enqueue\" syntax is \"enqueue:PORT:QUEUE\"");
            }
            put_enqueue_action(b, str_to_u32(port_s), str_to_u32(queue));
        } else if (!strcasecmp(act, "drop")) {
            /* A drop action in OpenFlow occurs by just not setting
             * an action. */
            drop = true;
            if (n_actions) {
                ovs_fatal(0, "Drop actions must not be preceded by other "
                          "actions");
            }
        } else if (!strcasecmp(act, "CONTROLLER")) {
            struct ofp_action_output *oao;
            oao = put_output_action(b, OFPP_CONTROLLER);

            /* Unless a numeric argument is specified, we send the whole
             * packet to the controller. */
            if (arg && (strspn(arg, "0123456789") == strlen(arg))) {
               oao->max_len = htons(str_to_u32(arg));
            } else {
                oao->max_len = htons(UINT16_MAX);
            }
        } else if (parse_port_name(act, &port)) {
            put_output_action(b, port);
        } else if (strspn(act, "0123456789") == strlen(act)) {
            put_output_action(b, str_to_u32(act));
        } else {
            ovs_fatal(0, "Unknown action: %s", act);
        }
    }
}

struct protocol {
    const char *name;
    uint16_t dl_type;
    uint8_t nw_proto;
};

static bool
parse_protocol(const char *name, const struct protocol **p_out)
{
    static const struct protocol protocols[] = {
        { "ip", ETH_TYPE_IP, 0 },
        { "arp", ETH_TYPE_ARP, 0 },
        { "icmp", ETH_TYPE_IP, IP_TYPE_ICMP },
        { "tcp", ETH_TYPE_IP, IP_TYPE_TCP },
        { "udp", ETH_TYPE_IP, IP_TYPE_UDP },
    };
    const struct protocol *p;

    for (p = protocols; p < &protocols[ARRAY_SIZE(protocols)]; p++) {
        if (!strcmp(p->name, name)) {
            *p_out = p;
            return true;
        }
    }
    *p_out = NULL;
    return false;
}

#define FIELDS                                              \
    FIELD(F_IN_PORT,     "in_port",     FWW_IN_PORT)        \
    FIELD(F_DL_VLAN,     "dl_vlan",     FWW_DL_VLAN)        \
    FIELD(F_DL_VLAN_PCP, "dl_vlan_pcp", FWW_DL_VLAN_PCP)    \
    FIELD(F_DL_SRC,      "dl_src",      FWW_DL_SRC)         \
    FIELD(F_DL_DST,      "dl_dst",      FWW_DL_DST)         \
    FIELD(F_DL_TYPE,     "dl_type",     FWW_DL_TYPE)        \
    FIELD(F_NW_SRC,      "nw_src",      0)                  \
    FIELD(F_NW_DST,      "nw_dst",      0)                  \
    FIELD(F_NW_PROTO,    "nw_proto",    FWW_NW_PROTO)       \
    FIELD(F_NW_TOS,      "nw_tos",      FWW_NW_TOS)         \
    FIELD(F_TP_SRC,      "tp_src",      FWW_TP_SRC)         \
    FIELD(F_TP_DST,      "tp_dst",      FWW_TP_DST)         \
    FIELD(F_ICMP_TYPE,   "icmp_type",   FWW_TP_SRC)         \
    FIELD(F_ICMP_CODE,   "icmp_code",   FWW_TP_DST)

enum field_index {
#define FIELD(ENUM, NAME, WILDCARD) ENUM,
    FIELDS
#undef FIELD
    N_FIELDS
};

struct field {
    enum field_index index;
    const char *name;
    flow_wildcards_t wildcard;  /* FWW_* bit. */
};

static bool
parse_field_name(const char *name, const struct field **f_out)
{
    static const struct field fields[N_FIELDS] = {
#define FIELD(ENUM, NAME, WILDCARD) { ENUM, NAME, WILDCARD },
        FIELDS
#undef FIELD
    };
    const struct field *f;

    for (f = fields; f < &fields[ARRAY_SIZE(fields)]; f++) {
        if (!strcmp(f->name, name)) {
            *f_out = f;
            return true;
        }
    }
    *f_out = NULL;
    return false;
}

static void
parse_field_value(struct cls_rule *rule, enum field_index index,
                  const char *value)
{
    uint8_t mac[ETH_ADDR_LEN];
    ovs_be32 ip, mask;
    uint16_t port_no;

    switch (index) {
    case F_IN_PORT:
        if (!parse_port_name(value, &port_no)) {
            port_no = atoi(value);
        }
        if (port_no == OFPP_LOCAL) {
            port_no = ODPP_LOCAL;
        }
        cls_rule_set_in_port(rule, port_no);
        break;

    case F_DL_VLAN:
        cls_rule_set_dl_vlan(rule, htons(str_to_u32(value)));
        break;

    case F_DL_VLAN_PCP:
        cls_rule_set_dl_vlan_pcp(rule, str_to_u32(value));
        break;

    case F_DL_SRC:
        str_to_mac(value, mac);
        cls_rule_set_dl_src(rule, mac);
        break;

    case F_DL_DST:
        str_to_mac(value, mac);
        cls_rule_set_dl_dst(rule, mac);
        break;

    case F_DL_TYPE:
        cls_rule_set_dl_type(rule, htons(str_to_u32(value)));
        break;

    case F_NW_SRC:
        str_to_ip(value, &ip, &mask);
        cls_rule_set_nw_src_masked(rule, ip, mask);
        break;

    case F_NW_DST:
        str_to_ip(value, &ip, &mask);
        cls_rule_set_nw_dst_masked(rule, ip, mask);
        break;

    case F_NW_PROTO:
        cls_rule_set_nw_proto(rule, str_to_u32(value));
        break;

    case F_NW_TOS:
        cls_rule_set_nw_tos(rule, str_to_u32(value));
        break;

    case F_TP_SRC:
        cls_rule_set_tp_src(rule, htons(str_to_u32(value)));
        break;

    case F_TP_DST:
        cls_rule_set_tp_dst(rule, htons(str_to_u32(value)));
        break;

    case F_ICMP_TYPE:
        cls_rule_set_icmp_type(rule, str_to_u32(value));
        break;

    case F_ICMP_CODE:
        cls_rule_set_icmp_code(rule, str_to_u32(value));
        break;

    case N_FIELDS:
        NOT_REACHED();
    }
}

/* Convert 'string' (as described in the Flow Syntax section of the ovs-ofctl
 * man page) into 'pf'.  If 'actions' is specified, an action must be in
 * 'string' and may be expanded or reallocated. */
void
parse_ofp_str(struct parsed_flow *pf, struct ofpbuf *actions, char *string)
{
    char *save_ptr = NULL;
    char *name;

    cls_rule_init_catchall(&pf->rule, OFP_DEFAULT_PRIORITY);
    pf->table_idx = 0xff;
    pf->out_port = OFPP_NONE;
    pf->idle_timeout = OFP_FLOW_PERMANENT;
    pf->hard_timeout = OFP_FLOW_PERMANENT;
    pf->cookie = 0;
    if (actions) {
        char *act_str = strstr(string, "action");
        if (!act_str) {
            ovs_fatal(0, "must specify an action");
        }
        *act_str = '\0';

        act_str = strchr(act_str + 1, '=');
        if (!act_str) {
            ovs_fatal(0, "must specify an action");
        }

        act_str++;

        str_to_action(act_str, actions);
    }
    for (name = strtok_r(string, "=, \t\r\n", &save_ptr); name;
         name = strtok_r(NULL, "=, \t\r\n", &save_ptr)) {
        const struct protocol *p;

        if (parse_protocol(name, &p)) {
            cls_rule_set_dl_type(&pf->rule, htons(p->dl_type));
            if (p->nw_proto) {
                cls_rule_set_nw_proto(&pf->rule, p->nw_proto);
            }
        } else {
            const struct field *f;
            char *value;

            value = strtok_r(NULL, ", \t\r\n", &save_ptr);
            if (!value) {
                ovs_fatal(0, "field %s missing value", name);
            }

            if (!strcmp(name, "table")) {
                pf->table_idx = atoi(value);
            } else if (!strcmp(name, "out_port")) {
                pf->out_port = atoi(value);
            } else if (!strcmp(name, "priority")) {
                pf->rule.priority = atoi(value);
            } else if (!strcmp(name, "idle_timeout")) {
                pf->idle_timeout = atoi(value);
            } else if (!strcmp(name, "hard_timeout")) {
                pf->hard_timeout = atoi(value);
            } else if (!strcmp(name, "cookie")) {
                pf->cookie = str_to_u64(value);
            } else if (parse_field_name(name, &f)) {
                if (!strcmp(value, "*") || !strcmp(value, "ANY")) {
                    if (f->wildcard) {
                        pf->rule.wc.wildcards |= f->wildcard;
                        cls_rule_zero_wildcarded_fields(&pf->rule);
                    } else if (f->index == F_NW_SRC) {
                        cls_rule_set_nw_src_masked(&pf->rule, 0, 0);
                    } else if (f->index == F_NW_DST) {
                        cls_rule_set_nw_dst_masked(&pf->rule, 0, 0);
                    } else {
                        NOT_REACHED();
                    }
                } else {
                    parse_field_value(&pf->rule, f->index, value);
                }
            } else {
                ovs_fatal(0, "unknown keyword %s", name);
            }
        }
    }
}

/* Parses 'string' as an OFPT_FLOW_MOD with command 'command' (one of OFPFC_*)
 * and returns an ofpbuf that contains it. */
struct ofpbuf *
parse_ofp_flow_mod_str(char *string, uint16_t command)
{
    struct parsed_flow pf;
    struct ofpbuf *buffer;
    struct ofp_flow_mod *ofm;

    /* parse_ofp_str() will expand and reallocate the data in 'buffer', so we
     * can't keep pointers to across the parse_ofp_str() call. */
    make_openflow(sizeof *ofm, OFPT_FLOW_MOD, &buffer);
    parse_ofp_str(&pf, buffer, string);

    ofm = buffer->data;
    ofputil_cls_rule_to_match(&pf.rule, NXFF_OPENFLOW10, &ofm->match);
    ofm->command = htons(command);
    ofm->cookie = htonll(pf.cookie);
    ofm->idle_timeout = htons(pf.idle_timeout);
    ofm->hard_timeout = htons(pf.hard_timeout);
    ofm->buffer_id = htonl(UINT32_MAX);
    ofm->out_port = htons(pf.out_port);
    ofm->priority = htons(pf.rule.priority);
    update_openflow_length(buffer);

    return buffer;
}

/* Parses an OFPT_FLOW_MOD with subtype OFPFC_ADD from 'stream' and returns an
 * ofpbuf that contains it.  Returns a null pointer if end-of-file is reached
 * before reading a flow. */
struct ofpbuf *
parse_ofp_add_flow_file(FILE *stream)
{
    struct ofpbuf *b = NULL;
    struct ds s = DS_EMPTY_INITIALIZER;

    while (!ds_get_line(&s, stream)) {
        char *line = ds_cstr(&s);
        char *comment;

        /* Delete comments. */
        comment = strchr(line, '#');
        if (comment) {
            *comment = '\0';
        }

        /* Drop empty lines. */
        if (line[strspn(line, " \t\n")] == '\0') {
            continue;
        }

        b = parse_ofp_flow_mod_str(line, OFPFC_ADD);
        break;
    }
    ds_destroy(&s);

    return b;
}