/**
 * \file lib/fko_message.c
 *
 * \brief Set/Get the spa message (access req/command/etc) based on the current spa data.
 */

/*  Fwknop is developed primarily by the people listed in the file 'AUTHORS'.
 *  Copyright (C) 2009-2015 fwknop developers and contributors. For a full
 *  list of contributors, see the file 'CREDITS'.
 *
 *  License (GNU General Public License):
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version 2
 *  of the License, or (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 *  USA
 *
 *****************************************************************************
*/
#include "fko_common.h"
#include "fko_message.h"
#include "fko.h"

static int
have_allow_ip(const char *msg)
{
    const char         *ndx     = msg;
    char                ip_str[MAX_IPV4_STR_LEN];
    int                 dot_ctr = 0, char_ctr = 0;
    int                 res     = FKO_SUCCESS;

    while(*ndx != ',' && *ndx != '\0')
    {
        ip_str[char_ctr] = *ndx;
        char_ctr++;
        if(char_ctr >= MAX_IPV4_STR_LEN)
        {
            res = FKO_ERROR_INVALID_ALLOW_IP;
            break;
        }
        if(*ndx == '.')
            dot_ctr++;
        else if(isdigit((int)(unsigned char)*ndx) == 0)
        {
            res = FKO_ERROR_INVALID_ALLOW_IP;
            break;
        }
        ndx++;
    }

    if(char_ctr < MAX_IPV4_STR_LEN)
        ip_str[char_ctr] = '\0';
    else
        res = FKO_ERROR_INVALID_ALLOW_IP;

    if(res == FKO_SUCCESS)
        if (! is_valid_ipv4_addr(ip_str, strlen(ip_str)))
            res = FKO_ERROR_INVALID_ALLOW_IP;

    return(res);
}

static int
have_port(const char *msg)
{
    const char  *ndx = msg;
    char        port_str[MAX_PORT_STR_LEN+1] = {0};
    int         startlen = strnlen(msg, MAX_SPA_MESSAGE_SIZE);
    int         port_str_len=0, i=0, is_err;

    if(startlen == MAX_SPA_MESSAGE_SIZE)
        return(FKO_ERROR_INVALID_DATA_MESSAGE_PORT_MISSING);

    /* Must have at least one digit for the port number
    */
    if(isdigit((int)(unsigned char)*ndx) == 0)
        return(FKO_ERROR_INVALID_SPA_ACCESS_MSG);

    while(*ndx != '\0' && *ndx != ',')
    {
        port_str_len++;
        if((isdigit((int)(unsigned char)*ndx) == 0) || (port_str_len > MAX_PORT_STR_LEN))
            return(FKO_ERROR_INVALID_SPA_ACCESS_MSG);
        port_str[i] = *ndx;
        ndx++;
        i++;
    }
    port_str[i] = '\0';

    strtol_wrapper(port_str, 1, MAX_PORT, NO_EXIT_UPON_ERR, &is_err);
    if(is_err != FKO_SUCCESS)
        return(FKO_ERROR_INVALID_SPA_ACCESS_MSG);

    return FKO_SUCCESS;
}

/* Set the SPA message type.
*/
int
fko_set_spa_message_type(fko_ctx_t ctx, const short msg_type)
{
#if HAVE_LIBFIU
    fiu_return_on("fko_set_spa_message_type_init",
            FKO_ERROR_CTX_NOT_INITIALIZED);
#endif
    /* Must be initialized
    */
    if(!CTX_INITIALIZED(ctx))
        return FKO_ERROR_CTX_NOT_INITIALIZED;

#if HAVE_LIBFIU
    fiu_return_on("fko_set_spa_message_type_val",
            FKO_ERROR_INVALID_DATA_MESSAGE_TYPE_VALIDFAIL);
#endif
    if(msg_type < 0 || msg_type >= FKO_LAST_MSG_TYPE)
        return(FKO_ERROR_INVALID_DATA_MESSAGE_TYPE_VALIDFAIL);

    ctx->message_type = msg_type;

    ctx->state |= FKO_SPA_MSG_TYPE_MODIFIED;

    return(FKO_SUCCESS);
}

/* Return the SPA message type.
*/
int
fko_get_spa_message_type(fko_ctx_t ctx, short *msg_type)
{

#if HAVE_LIBFIU
    fiu_return_on("fko_get_spa_message_type_init",
            FKO_ERROR_CTX_NOT_INITIALIZED);
#endif

    /* Must be initialized
    */
    if(!CTX_INITIALIZED(ctx))
        return FKO_ERROR_CTX_NOT_INITIALIZED;

    if(msg_type == NULL)
        return(FKO_ERROR_INVALID_DATA);

#if HAVE_LIBFIU
    fiu_return_on("fko_get_spa_message_type_val", FKO_ERROR_INVALID_DATA);
#endif

    *msg_type = ctx->message_type;

    return(FKO_SUCCESS);
}

/* Set the SPA MESSAGE data
*/
int
fko_set_spa_message(fko_ctx_t ctx, const char * const msg)
{
    int res = FKO_ERROR_UNKNOWN;

    /* Context must be initialized.
    */
    if(!CTX_INITIALIZED(ctx))
        return FKO_ERROR_CTX_NOT_INITIALIZED;

    /* Gotta have a valid string.
    */
    if(msg == NULL || strnlen(msg, MAX_SPA_MESSAGE_SIZE) == 0)
        return(FKO_ERROR_INVALID_DATA_MESSAGE_EMPTY);

    /* --DSS XXX: Bail out for now.  But consider just
     *            truncating in the future...
    */
    if(strnlen(msg, MAX_SPA_MESSAGE_SIZE) == MAX_SPA_MESSAGE_SIZE)
        return(FKO_ERROR_DATA_TOO_LARGE);

    /* Basic message type and format checking...
    */
    if(ctx->message_type == FKO_COMMAND_MSG)
        res = validate_cmd_msg(msg);
    else
        res = validate_access_msg(msg);

    if(res != FKO_SUCCESS)
        return(res);

    /* Just in case this is a subsequent call to this function.  We
     * do not want to be leaking memory.
    */
    if(ctx->message != NULL)
        free(ctx->message);

    ctx->message = strdup(msg);

    ctx->state |= FKO_DATA_MODIFIED;

    if(ctx->message == NULL)
        return(FKO_ERROR_MEMORY_ALLOCATION);

    return(FKO_SUCCESS);
}

/* Return the SPA message data.
*/
int
fko_get_spa_message(fko_ctx_t ctx, char **msg)
{

#if HAVE_LIBFIU
    fiu_return_on("fko_get_spa_message_init", FKO_ERROR_CTX_NOT_INITIALIZED);
#endif

    /* Must be initialized
    */
    if(!CTX_INITIALIZED(ctx))
        return(FKO_ERROR_CTX_NOT_INITIALIZED);

    if(msg == NULL)
        return(FKO_ERROR_INVALID_DATA);

#if HAVE_LIBFIU
    fiu_return_on("fko_get_spa_message_val", FKO_ERROR_INVALID_DATA);
#endif

    *msg = ctx->message;

    return(FKO_SUCCESS);
}

/* Validate a command message format.
*/
int
validate_cmd_msg(const char *msg)
{
    const char   *ndx;
    int     res         = FKO_SUCCESS;
    int     startlen    = strnlen(msg, MAX_SPA_CMD_LEN);

    if(startlen == MAX_SPA_CMD_LEN)
        return(FKO_ERROR_INVALID_DATA_MESSAGE_CMD_MISSING);

    /* Should always have a valid allow IP regardless of message type
    */
    if((res = have_allow_ip(msg)) != FKO_SUCCESS)
        return(FKO_ERROR_INVALID_SPA_COMMAND_MSG);

    /* Commands are fairly free-form so all we can really verify is
     * there is something at all. Get past the IP and comma, and make
     * sure we have some string leftover...
    */
    ndx = strchr(msg, ',');
    if(ndx == NULL || (1+(ndx - msg)) >= startlen)
        return(FKO_ERROR_INVALID_SPA_COMMAND_MSG);

    return(FKO_SUCCESS);
}

int
validate_access_msg(const char *msg)
{
    const char   *ndx;
    int     res         = FKO_SUCCESS;
    int     startlen    = strnlen(msg, MAX_SPA_MESSAGE_SIZE);

    if(startlen == MAX_SPA_MESSAGE_SIZE)
        return(FKO_ERROR_INVALID_DATA_MESSAGE_ACCESS_MISSING);

    /* Should always have a valid allow IP regardless of message type
    */
    if((res = have_allow_ip(msg)) != FKO_SUCCESS)
        return(res);

    /* Position ourselves beyond the allow IP and make sure we are
     * still good.
    */
    ndx = strchr(msg, ',');
    if(ndx == NULL || (1+(ndx - msg)) >= startlen)
        return(FKO_ERROR_INVALID_SPA_ACCESS_MSG);

    /* Look for a comma to see if this is a multi-part access request.
    */
    do {
        ndx++;
        res = validate_proto_port_spec(ndx);
        if(res != FKO_SUCCESS)
            break;
    } while((ndx = strchr(ndx, ',')));

    return(res);
}

int
validate_nat_access_msg(const char *msg)
{
    const char   *ndx;
    int     host_len;
    int     res         = FKO_SUCCESS;
    int     startlen    = strnlen(msg, MAX_SPA_MESSAGE_SIZE);

    if(startlen == MAX_SPA_MESSAGE_SIZE)
        return(FKO_ERROR_INVALID_DATA_MESSAGE_NAT_MISSING);

    /* must have exactly one comma here
    */
    if(count_characters(msg, ',', startlen) != 1)
        return(FKO_ERROR_INVALID_SPA_NAT_ACCESS_MSG);

    /* Must not be longer than the max hostname length
    */
    host_len = strcspn(msg, ",");
    if(host_len > MAX_HOSTNAME_LEN)
        return(FKO_ERROR_INVALID_SPA_NAT_ACCESS_MSG);

    /* Check for some invalid characters
    */
    if(strcspn(msg, " /?\"\'\\") < host_len)
        return(FKO_ERROR_INVALID_SPA_NAT_ACCESS_MSG);

    /* Position ourselves beyond the allow IP and make sure we have
     * a single port value
    */
    ndx = strchr(msg, ',');
    if(ndx == NULL || (1+(ndx - msg)) >= startlen)
        return(FKO_ERROR_INVALID_SPA_NAT_ACCESS_MSG);

    ndx++;

    if((res = have_port(ndx)) != FKO_SUCCESS)
        return(FKO_ERROR_INVALID_SPA_NAT_ACCESS_MSG);

    if(msg[startlen-1] == ',')
        return(FKO_ERROR_INVALID_SPA_NAT_ACCESS_MSG);

    return(res);
}

int
validate_proto_port_spec(const char *msg)
{
    int     startlen    = strnlen(msg, MAX_SPA_MESSAGE_SIZE);
    const char   *ndx   = msg;

    if(startlen == MAX_SPA_MESSAGE_SIZE)
        return(FKO_ERROR_INVALID_DATA_MESSAGE_PORTPROTO_MISSING);

    /* Now check for proto/port string.
    */
    if(strncmp(ndx, "tcp", 3)
      && strncmp(ndx, "udp", 3)
      && strncmp(ndx, "icmp", 4)
      && strncmp(ndx, "none", 4))
        return(FKO_ERROR_INVALID_SPA_ACCESS_MSG);

    ndx = strchr(ndx, '/');
    if(ndx == NULL || ((1+(ndx - msg)) > MAX_PROTO_STR_LEN))
        return(FKO_ERROR_INVALID_SPA_ACCESS_MSG);

    /* Skip over the '/' and make sure we only have digits.
    */
    ndx++;

    return have_port(ndx);
}

/***EOF***/