/* * Ouroboros - Copyright (C) 2016 - 2017 * * Policy for flat addresses in a distributed way * * Dimitri Staessens <dimitri.staessens@ugent.be> * Sander Vrijders <sander.vrijders@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_PATH); 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 int flat_init(void) { return 0; } int flat_fini(void) { return 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_PATH); 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; }