/*

Copyright (c) 2007-2010 by Juliusz Chroboczek

Permission is hereby granted, free of charge, to any person obtaining a copy

of this software and associated documentation files (the "Software"), to deal

in the Software without restriction, including without limitation the rights

to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

copies of the Software, and to permit persons to whom the Software is

furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in

all copies or substantial portions of the Software.

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 <stdlib.h>

#include <string.h>

#include <stdio.h>

#include <arpa/inet.h>

#include "prefix.h"

#include "config.h"

int client_config = 1;

struct server_config *server_config = NULL;

/* get_next_char callback */

typedef int (*gnc_t)(void*);

static int

skip_whitespace(int c, gnc_t gnc, void *closure)

{

while(c == ' ' || c == '\t')

c = gnc(closure);

return c;

}

static int

skip_to_eol(int c, gnc_t gnc, void *closure)

{

while(c != '\n' && c >= 0)

c = gnc(closure);

if(c == '\n')

c = gnc(closure);

return c;

}

static int

skip_eol(int c, gnc_t gnc, void *closure)

{

c = skip_whitespace(c, gnc, closure);

if(c == '\n' || c == '#') {

c = skip_to_eol(c, gnc, closure);

return c;

} else if(c == -1) {

return -1;

} else {

return -2;

}

}

static int

getword(int c, char **token_r, gnc_t gnc, void *closure)

{

char buf[256];

int i = 0;

c = skip_whitespace(c, gnc, closure);

if(c < 0)

return -2;

if(c == '"' || c == '\n')

return -2;

do {

if(i >= 255) return -2;

buf[i++] = c;

c = gnc(closure);

} while(c != ' ' && c != '\t' && c != '\n' && c >= 0);

buf[i] = '\0';

*token_r = strdup(buf);

return c;

}

static int

getstring(int c, char **token_r, gnc_t gnc, void *closure)

{

char buf[256];

int i = 0;

c = skip_whitespace(c, gnc, closure);

if(c < 0)

return c;

if(c == '\n')

return -2;

/* Unquoted strings have the same syntax as words. */

if(c != '"')

return getword(c, token_r, gnc, closure);

c = gnc(closure);

while(1) {

if(i >= 255 || c == '\n') return -2;

if(c == '"') {

c = gnc(closure);

break;

}

if(c == '\\')

c = gnc(closure);

buf[i++] = c;

c = gnc(closure);

}

buf[i] = '\0';

*token_r = strdup(buf);

return c;

}

static int

parse_config(gnc_t gnc, void *closure)

{

int c;

char *token;

c = gnc(closure);

if(c < 2)

return -1;

while(c >= 0) {

c = skip_whitespace(c, gnc, closure);

if(c == '\n' || c == '#') {

c = skip_to_eol(c, gnc, closure);

continue;

}

if(c < 0)

break;

c = getword(c, &token, gnc, closure);

if(c < -1)

return -1;

if(strcmp(token, "mode") == 0) {

char *mtoken;

c = getword(c, &mtoken, gnc, closure);

if(c < -1)

return -1;

if(strcmp(mtoken, "server") == 0) {

#ifndef NO_SERVER

client_config = 0;

if(!server_config)

server_config = calloc(1, sizeof(struct server_config));

if(!server_config)

return -1;

#else

return -1;

#endif

} else if(strcmp(mtoken, "client") == 0) {

if(server_config)

return -1;

client_config = 1;

} else if(strcmp(mtoken, "forwarder") == 0) {

if(server_config)

return -1;

client_config = 0;

} else {

return -1;

}

free(mtoken);

c = skip_eol(c, gnc, closure);

if(c < -1)

return -1;

} else if(strcmp(token, "lease-dir") == 0) {

char *dir;

if(!server_config)

return -1;

c = getstring(c, &dir, gnc, closure);

if(c < -1)

return -1;

if(dir[0] != '/')

return -1;

server_config->lease_dir = dir;

c = skip_eol(c, gnc, closure);

if(c < -1)

return -1;

} else if(strcmp(token, "prefix") == 0) {

char *ptoken;

struct prefix_list *prefix;

if(!server_config)

return -1;

c = getword(c, &ptoken, gnc, closure);

if(c < -1)

return -1;

prefix = parse_prefix(ptoken, PREFIX);

if(prefix == NULL || prefix->n != 1)

return -1;

if(prefix_list_v4(prefix)) {

unsigned const char zeroes[4] = {0};

unsigned mask, first, last;

if(memcmp(server_config->lease_first, zeroes, 4) != 0)

return -1;

mask = 0xFFFFFFFF << (128 - prefix->l[0].plen);

first =

(prefix->l[0].p[12] << 24 |

prefix->l[0].p[13] << 16 |

prefix->l[0].p[14] << 8 |

prefix->l[0].p[15] ) & mask;

last = first | (~ mask);

first = htonl(first + 1);

last = htonl(last - 1);

memcpy(server_config->lease_first, &first, 4);

memcpy(server_config->lease_last, &last, 4);

free(prefix);

} else {

server_config->ipv6_prefix =

cat_prefix_list(server_config->ipv6_prefix,

prefix);

}

free(ptoken);

c = skip_eol(c, gnc, closure);

if(c < -1)

return -1;

} else if(strcmp(token, "name-server") == 0 ||

strcmp(token, "ntp-server") == 0) {

char *ptoken;

struct prefix_list *prefix;

if(!server_config)

return -1;

c = getword(c, &ptoken, gnc, closure);

if(c < -1)

return -1;

prefix = parse_prefix(ptoken, ADDRESS);

if(prefix == NULL)

return -1;

if(strcmp(token, "name-server") == 0)

server_config->name_server =

cat_prefix_list(server_config->name_server,

prefix);

else

server_config->ntp_server =

cat_prefix_list(server_config->ntp_server,

prefix);

free(ptoken);

} else {

return -1;

}

free(token);

}

return 1;

}

int

parse_config_from_file(char *filename)

{

FILE *f;

int rc;

f = fopen(filename, "r");

if(f == NULL)

return -1;

rc = parse_config((gnc_t)fgetc, f);

fclose(f);

return rc;

}

struct string_state {

char *string;

int n;

};

static int

gnc_string(struct string_state *s)

{

if(s->string[s->n] == '\0')

return -1;

else

return s->string[s->n++];

}

int

parse_config_from_string(char *string)

{

struct string_state s = { string, 0 };

return parse_config((gnc_t)gnc_string, &s);

}