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/*
* Ouroboros - Copyright (C) 2016 - 2017
*
* Policy for flat addresses in a distributed way
*
* Sander Vrijders <sander.vrijders@intec.ugent.be>
* Dimitri Staessens <dimitri.staessens@intec.ugent.be>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#define OUROBOROS_PREFIX "flat-addr-auth"
#include <ouroboros/config.h>
#include <ouroboros/logs.h>
#include <ouroboros/errno.h>
#include <ouroboros/time_utils.h>
#include <ouroboros/rib.h>
#include <ouroboros/utils.h>
#include "ipcp.h"
#include "ribconfig.h"
#include <time.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include <assert.h>
#define NAME_LEN 8
#define REC_DIF_SIZE 10000
/* convert 32 bit addr to a hex string */
static void addr_name(char * name,
uint32_t addr)
{
sprintf(name, "%8x", (uint32_t) (addr));
}
static int addr_taken(char * name,
char ** members,
size_t len)
{
size_t i;
char path[RIB_MAX_PATH_LEN + 1];
size_t reset;
strcpy(path, "/" MEMBERS_NAME);
reset = strlen(path);
for (i = 0; i < len; ++i) {
ssize_t j;
ssize_t c;
char ** addrs;
rib_path_append(path, members[i]);
c = rib_children(path, &addrs);
for (j = 0; j < c; ++j)
if (strcmp(addrs[j], name) == 0) {
freepp(char, addrs, c);
return 1;
}
freepp(char, addrs, c);
path[reset] = '\0';
}
return 0;
}
#define INVALID_ADDRESS 0
uint64_t flat_address(void)
{
struct timespec t;
char path[RIB_MAX_PATH_LEN];
char name[NAME_LEN + 1];
uint32_t addr;
uint8_t addr_size;
char ** members;
ssize_t n_members;
strcpy(path, "/" MEMBERS_NAME);
if (!rib_has(path)) {
log_err("Could not read members from RIB.");
return INVALID_ADDRESS;
}
if (rib_read("/" BOOT_NAME "/dt/const/addr_size",
&addr_size, sizeof(addr_size)) != sizeof(addr_size)) {
log_err("Failed to read address size.");
return INVALID_ADDRESS;
}
if (addr_size != 4) {
log_err("Flat address policy mandates 4 byte addresses.");
return INVALID_ADDRESS;
}
n_members = rib_children(path, &members);
if (n_members > REC_DIF_SIZE)
log_warn("DIF exceeding recommended size for flat addresses.");
rib_path_append(path, ipcpi.name);
if (!rib_has(path)) {
log_err("This ipcp is not a member.");
freepp(char, members, n_members);
return INVALID_ADDRESS;
}
clock_gettime(CLOCK_REALTIME, &t);
srand(t.tv_nsec);
assert(n_members > 0);
do {
addr = (rand() % (RAND_MAX - 1) + 1) & 0xFFFFFFFF;
addr_name(name, addr);
} while (addr_taken(name, members, n_members));
freepp(char, members, n_members);
if (rib_add(path, name)) {
log_err("Failed to add address to RIB.");
return INVALID_ADDRESS;
}
if (rib_write(path, &addr, sizeof(addr))) {
log_err("Failed to write address in RIB.");
return INVALID_ADDRESS;
}
return addr;
}
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