/*

 * Copyright (c) 2010, 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 "openvswitch/ofp-parse.h"

#include <errno.h>

#include "byte-order.h"

#include "openvswitch/match.h"

#include "openvswitch/meta-flow.h"

#include "openvswitch/ofp-actions.h"

#include "openvswitch/ofp-flow.h"

#include "openvswitch/ofp-match.h"

#include "openvswitch/ofp-table.h"

#include "packets.h"

#include "socket-util.h"

#include "util.h"

/* Parses 'str' as an 8-bit unsigned integer into '*valuep'.

 *

 * 'name' describes the value parsed in an error message, if any.

 *

 * 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

str_to_u8(const char *str, const char *name, uint8_t *valuep)

{

    int value;

    if (!str_to_int(str, 0, &value) || value < 0 || value > 255) {

        return xasprintf("invalid %s \"%s\"", name, str);

    }

    *valuep = value;

    return NULL;

}

/* Parses 'str' as a 16-bit unsigned integer into '*valuep'.

 *

 * 'name' describes the value parsed in an error message, if any.

 *

 * 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

str_to_u16(const char *str, const char *name, uint16_t *valuep)

{

    int value;

    if (!str_to_int(str, 0, &value) || value < 0 || value > 65535) {

        return xasprintf("invalid %s \"%s\"", name, str);

    }

    *valuep = value;

    return NULL;

}

/* Parses 'str' as a 32-bit unsigned integer into '*valuep'.

 *

 * 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

str_to_u32(const char *str, uint32_t *valuep)

{

    char *tail;

    uint32_t value;

    if (!str[0]) {

        return xstrdup("missing required numeric argument");

    }

    errno = 0;

    value = strtoul(str, &tail, 0);

    if (errno == EINVAL || errno == ERANGE || *tail) {

        return xasprintf("invalid numeric format %s", str);

    }

    *valuep = value;

    return NULL;

}

/* Parses 'str' as an 64-bit unsigned integer into '*valuep'.

 *

 * 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

str_to_u64(const char *str, uint64_t *valuep)

{

    char *tail;

    uint64_t value;

    if (!str[0]) {

        return xstrdup("missing required numeric argument");

    }

    errno = 0;

    value = strtoull(str, &tail, 0);

    if (errno == EINVAL || errno == ERANGE || *tail) {

        return xasprintf("invalid numeric format %s", str);

    }

    *valuep = value;

    return NULL;

}

/* Parses 'str' as an 64-bit unsigned integer in network byte order into

 * '*valuep'.

 *

 * 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

str_to_be64(const char *str, ovs_be64 *valuep)

{

    uint64_t value = 0;

    char *error;

    error = str_to_u64(str, &value);

    if (!error) {

        *valuep = htonll(value);

    }

    return error;

}

/* Parses 'str' as an Ethernet address into 'mac'.

 *

 * 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

str_to_mac(const char *str, struct eth_addr *mac)

{

    if (!ovs_scan(str, ETH_ADDR_SCAN_FMT, ETH_ADDR_SCAN_ARGS(*mac))) {

        return xasprintf("invalid mac address %s", str);

    }

    return NULL;

}

/* Parses 'str' as an IP address into '*ip'.

 *

 * 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

str_to_ip(const char *str, ovs_be32 *ip)

{

    struct in_addr in_addr;

    if (lookup_ip(str, &in_addr)) {

        return xasprintf("%s: could not convert to IP address", str);

    }

    *ip = in_addr.s_addr;

    return NULL;

}

/* Parses 'str' as a conntrack helper into 'alg'.

 *

 * 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

str_to_connhelper(const char *str, uint16_t *alg)

{

    if (!strcmp(str, "ftp")) {

        *alg = IPPORT_FTP;

        return NULL;

    }

    if (!strcmp(str, "tftp")) {

        *alg = IPPORT_TFTP;

        return NULL;

    }

    return xasprintf("invalid conntrack helper \"%s\"", str);

}

bool

ofp_parse_protocol(const char *name, const struct ofp_protocol **p_out)

{

    static const struct ofp_protocol protocols[] = {

        { "ip", ETH_TYPE_IP, 0 },

        { "ipv4", ETH_TYPE_IP, 0 },

        { "ip4", ETH_TYPE_IP, 0 },

        { "arp", ETH_TYPE_ARP, 0 },

        { "icmp", ETH_TYPE_IP, IPPROTO_ICMP },

        { "tcp", ETH_TYPE_IP, IPPROTO_TCP },

        { "udp", ETH_TYPE_IP, IPPROTO_UDP },

        { "sctp", ETH_TYPE_IP, IPPROTO_SCTP },

        { "ipv6", ETH_TYPE_IPV6, 0 },

        { "ip6", ETH_TYPE_IPV6, 0 },

        { "icmp6", ETH_TYPE_IPV6, IPPROTO_ICMPV6 },

        { "tcp6", ETH_TYPE_IPV6, IPPROTO_TCP },

        { "udp6", ETH_TYPE_IPV6, IPPROTO_UDP },

        { "sctp6", ETH_TYPE_IPV6, IPPROTO_SCTP },

        { "rarp", ETH_TYPE_RARP, 0},

        { "mpls", ETH_TYPE_MPLS, 0 },

        { "mplsm", ETH_TYPE_MPLS_MCAST, 0 },

    };

    const struct ofp_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;

}

/* Parses 's' as the (possibly masked) value of field 'mf', and updates

 * 'match' appropriately.  Restricts the set of usable protocols to ones

 * supporting the parsed field.

 *

 * 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

ofp_parse_field(const struct mf_field *mf, const char *s,

                const struct ofputil_port_map *port_map, struct match *match,

                enum ofputil_protocol *usable_protocols)

{

    union mf_value value, mask;

    char *error;

    if (!*s) {

        /* If there's no string, we're just trying to match on the

         * existence of the field, so use a no-op value. */

        s = "0/0";

    }

    error = mf_parse(mf, s, port_map, &value, &mask);

    if (!error) {

        *usable_protocols &= mf_set(mf, &value, &mask, match, &error);

        match_add_ethernet_prereq(match, mf);

    }

    return error;

}

char *

ofp_extract_actions(char *s)

{

    s = strstr(s, "action");

    if (s) {

        *s = '\0';

        s = strchr(s + 1, '=');

        return s ? s + 1 : NULL;

    } else {

        return NULL;

    }

}

static size_t

parse_value(const char *s, const char *delimiters)

{

    size_t n = 0;

    /* Iterate until we reach a delimiter.

     *

     * strchr(s, '\0') returns s+strlen(s), so this test handles the null

     * terminator at the end of 's'.  */

    while (!strchr(delimiters, s[n])) {

        if (s[n] == '(') {

            int level = 0;

            do {

                switch (s[n]) {

                case '\0':

                    return n;

                case '(':

                    level++;

                    break;

                case ')':

                    level--;

                    break;

                }

                n++;

            } while (level > 0);

        } else {

            n++;

        }

    }

    return n;

}

/* Parses a key or a key-value pair from '*stringp'.

 *

 * On success: Stores the key into '*keyp'.  Stores the value, if present, into

 * '*valuep', otherwise an empty string.  Advances '*stringp' past the end of

 * the key-value pair, preparing it for another call.  '*keyp' and '*valuep'

 * are substrings of '*stringp' created by replacing some of its bytes by null

 * terminators.  Returns true.

 *

 * If '*stringp' is just white space or commas, sets '*keyp' and '*valuep' to

 * NULL and returns false. */

bool

ofputil_parse_key_value(char **stringp, char **keyp, char **valuep)

{

    /* Skip white space and delimiters.  If that brings us to the end of the

     * input string, we are done and there are no more key-value pairs. */

    *stringp += strspn(*stringp, ", \t\r\n");

    if (**stringp == '\0') {

        *keyp = *valuep = NULL;

        return false;

    }

    /* Extract the key and the delimiter that ends the key-value pair or begins

     * the value.  Advance the input position past the key and delimiter. */

    char *key = *stringp;

    size_t key_len = strcspn(key, ":=(, \t\r\n");

    char key_delim = key[key_len];

    key[key_len] = '\0';

    *stringp += key_len + (key_delim != '\0');

    /* Figure out what delimiter ends the value:

     *

     *     - If key_delim is ":" or "=", the value extends until white space

     *       or a comma.

     *

     *     - If key_delim is "(", the value extends until ")".

     *

     * If there is no value, we are done. */

    const char *value_delims;

    if (key_delim == ':' || key_delim == '=') {

        value_delims = ", \t\r\n";

    } else if (key_delim == '(') {

        value_delims = ")";

    } else {

        *keyp = key;

        *valuep = key + key_len; /* Empty string. */

        return true;

    }

    /* Extract the value.  Advance the input position past the value and

     * delimiter. */

    char *value = *stringp;

    size_t value_len = parse_value(value, value_delims);

    char value_delim = value[value_len];

    /* Handle the special case if the value is of the form "(x)->y".

     * After parsing, 'valuep' will be pointing to - "x)->y".

     * */

    if (key_delim == '(' && value[value_len] == ')' &&

        value[value_len + 1] == '-' && value[value_len + 2] == '>') {

        value_delims = ", \t\r\n";

        value_len += parse_value(&value[value_len], value_delims);

        value_delim = value[value_len];

    }

    value[value_len] = '\0';

    *stringp += value_len + (value_delim != '\0');

    *keyp = key;

    *valuep = value;

    return true;

}