/*** This file is part of systemd. Copyright (C) 2013 Intel Corporation. All rights reserved. Copyright (C) 2014 Tom Gundersen systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd 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 Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <stdlib.h> #include <errno.h> #include <string.h> #include <stdio.h> #include <arpa/inet.h> #include "fileio.h" #include "unaligned.h" #include "in-addr-util.h" #include "dhcp-protocol.h" #include "dhcp-lease-internal.h" #include "sd-dhcp-lease.h" #include "network-internal.h" int sd_dhcp_lease_get_address(sd_dhcp_lease *lease, struct in_addr *addr) { assert_return(lease, -EINVAL); assert_return(addr, -EINVAL); addr->s_addr = lease->address; return 0; } int sd_dhcp_lease_get_lifetime(sd_dhcp_lease *lease, uint32_t *lifetime) { assert_return(lease, -EINVAL); assert_return(lifetime, -EINVAL); *lifetime = lease->lifetime; return 0; } int sd_dhcp_lease_get_mtu(sd_dhcp_lease *lease, uint16_t *mtu) { assert_return(lease, -EINVAL); assert_return(mtu, -EINVAL); if (lease->mtu) *mtu = lease->mtu; else return -ENOENT; return 0; } int sd_dhcp_lease_get_dns(sd_dhcp_lease *lease, const struct in_addr **addr) { assert_return(lease, -EINVAL); assert_return(addr, -EINVAL); if (lease->dns_size) { *addr = lease->dns; return lease->dns_size; } else return -ENOENT; return 0; } int sd_dhcp_lease_get_ntp(sd_dhcp_lease *lease, const struct in_addr **addr) { assert_return(lease, -EINVAL); assert_return(addr, -EINVAL); if (lease->ntp_size) { *addr = lease->ntp; return lease->ntp_size; } else return -ENOENT; return 0; } int sd_dhcp_lease_get_domainname(sd_dhcp_lease *lease, const char **domainname) { assert_return(lease, -EINVAL); assert_return(domainname, -EINVAL); if (lease->domainname) *domainname = lease->domainname; else return -ENOENT; return 0; } int sd_dhcp_lease_get_hostname(sd_dhcp_lease *lease, const char **hostname) { assert_return(lease, -EINVAL); assert_return(hostname, -EINVAL); if (lease->hostname) *hostname = lease->hostname; else return -ENOENT; return 0; } int sd_dhcp_lease_get_root_path(sd_dhcp_lease *lease, const char **root_path) { assert_return(lease, -EINVAL); assert_return(root_path, -EINVAL); if (lease->root_path) *root_path = lease->root_path; else return -ENOENT; return 0; } int sd_dhcp_lease_get_router(sd_dhcp_lease *lease, struct in_addr *addr) { assert_return(lease, -EINVAL); assert_return(addr, -EINVAL); if (lease->router != INADDR_ANY) addr->s_addr = lease->router; else return -ENOENT; return 0; } int sd_dhcp_lease_get_netmask(sd_dhcp_lease *lease, struct in_addr *addr) { assert_return(lease, -EINVAL); assert_return(addr, -EINVAL); addr->s_addr = lease->subnet_mask; return 0; } int sd_dhcp_lease_get_server_identifier(sd_dhcp_lease *lease, struct in_addr *addr) { assert_return(lease, -EINVAL); assert_return(addr, -EINVAL); addr->s_addr = lease->server_address; return 0; } int sd_dhcp_lease_get_next_server(sd_dhcp_lease *lease, struct in_addr *addr) { assert_return(lease, -EINVAL); assert_return(addr, -EINVAL); addr->s_addr = lease->next_server; return 0; } int sd_dhcp_lease_get_routes(sd_dhcp_lease *lease, struct sd_dhcp_route **routes) { assert_return(lease, -EINVAL); assert_return(routes, -EINVAL); if (lease->static_route_size) { *routes = lease->static_route; return lease->static_route_size; } else return -ENOENT; return 0; } sd_dhcp_lease *sd_dhcp_lease_ref(sd_dhcp_lease *lease) { if (lease) assert_se(REFCNT_INC(lease->n_ref) >= 2); return lease; } sd_dhcp_lease *sd_dhcp_lease_unref(sd_dhcp_lease *lease) { if (lease && REFCNT_DEC(lease->n_ref) == 0) { free(lease->hostname); free(lease->domainname); free(lease->dns); free(lease->ntp); free(lease->static_route); free(lease->client_id); free(lease); } return NULL; } static void lease_parse_u32(const uint8_t *option, size_t len, uint32_t *ret, uint32_t min) { assert(option); assert(ret); if (len == 4) { *ret = unaligned_read_be32((be32_t*) option); if (*ret < min) *ret = min; } } static void lease_parse_s32(const uint8_t *option, size_t len, int32_t *ret) { lease_parse_u32(option, len, (uint32_t *)ret, 0); } static void lease_parse_u16(const uint8_t *option, size_t len, uint16_t *ret, uint16_t min) { assert(option); assert(ret); if (len == 2) { *ret = unaligned_read_be16((be16_t*) option); if (*ret < min) *ret = min; } } static void lease_parse_be32(const uint8_t *option, size_t len, be32_t *ret) { assert(option); assert(ret); if (len == 4) memcpy(ret, option, 4); } static void lease_parse_bool(const uint8_t *option, size_t len, bool *ret) { assert(option); assert(ret); if (len == 1) *ret = !!(*option); } static void lease_parse_u8(const uint8_t *option, size_t len, uint8_t *ret, uint8_t min) { assert(option); assert(ret); if (len == 1) { *ret = *option; if (*ret < min) *ret = min; } } static int lease_parse_string(const uint8_t *option, size_t len, char **ret) { assert(option); assert(ret); if (len >= 1) { char *string; string = strndup((const char *)option, len); if (!string) return -errno; free(*ret); *ret = string; } return 0; } static int lease_parse_in_addrs_aux(const uint8_t *option, size_t len, struct in_addr **ret, size_t *ret_size, size_t mult) { assert(option); assert(ret); assert(ret_size); if (len && !(len % (4 * mult))) { size_t size; struct in_addr *addresses; size = len / 4; addresses = newdup(struct in_addr, option, size); if (!addresses) return -ENOMEM; free(*ret); *ret = addresses; *ret_size = size; } return 0; } static int lease_parse_in_addrs(const uint8_t *option, size_t len, struct in_addr **ret, size_t *ret_size) { return lease_parse_in_addrs_aux(option, len, ret, ret_size, 1); } static int lease_parse_in_addrs_pairs(const uint8_t *option, size_t len, struct in_addr **ret, size_t *ret_size) { return lease_parse_in_addrs_aux(option, len, ret, ret_size, 2); } static int lease_parse_routes(const uint8_t *option, size_t len, struct sd_dhcp_route **routes, size_t *routes_size, size_t *routes_allocated) { struct in_addr addr; assert(option); assert(routes); assert(routes_size); assert(routes_allocated); if (!len) return 0; if (len % 8 != 0) return -EINVAL; if (!GREEDY_REALLOC(*routes, *routes_allocated, *routes_size + (len / 8))) return -ENOMEM; while (len >= 8) { struct sd_dhcp_route *route = *routes + *routes_size; int r; r = in_addr_default_prefixlen((struct in_addr*) option, &route->dst_prefixlen); if (r < 0) { log_error("Failed to determine destination prefix length from class based IP, ignoring"); continue; } lease_parse_be32(option, 4, &addr.s_addr); route->dst_addr = inet_makeaddr(inet_netof(addr), 0); option += 4; lease_parse_be32(option, 4, &route->gw_addr.s_addr); option += 4; len -= 8; (*routes_size)++; } return 0; } /* parses RFC3442 Classless Static Route Option */ static int lease_parse_classless_routes(const uint8_t *option, size_t len, struct sd_dhcp_route **routes, size_t *routes_size, size_t *routes_allocated) { assert(option); assert(routes); assert(routes_size); assert(routes_allocated); /* option format: (subnet-mask-width significant-subnet-octets gateway-ip)* */ while (len > 0) { uint8_t dst_octets; struct sd_dhcp_route *route; if (!GREEDY_REALLOC(*routes, *routes_allocated, *routes_size + 1)) return -ENOMEM; route = *routes + *routes_size; dst_octets = (*option == 0 ? 0 : ((*option - 1) / 8) + 1); route->dst_prefixlen = *option; option++; len--; /* can't have more than 4 octets in IPv4 */ if (dst_octets > 4 || len < dst_octets) return -EINVAL; route->dst_addr.s_addr = 0; memcpy(&route->dst_addr.s_addr, option, dst_octets); option += dst_octets; len -= dst_octets; if (len < 4) return -EINVAL; lease_parse_be32(option, 4, &route->gw_addr.s_addr); option += 4; len -= 4; (*routes_size)++; } return 0; } int dhcp_lease_parse_options(uint8_t code, uint8_t len, const uint8_t *option, void *user_data) { sd_dhcp_lease *lease = user_data; int r; assert(lease); switch(code) { case DHCP_OPTION_TIME_OFFSET: lease_parse_s32(option, len, &lease->time_offset); break; case DHCP_OPTION_INTERFACE_MTU_AGING_TIMEOUT: lease_parse_u32(option, len, &lease->mtu_aging_timeout, 0); break; case DHCP_OPTION_IP_ADDRESS_LEASE_TIME: lease_parse_u32(option, len, &lease->lifetime, 1); break; case DHCP_OPTION_SERVER_IDENTIFIER: lease_parse_be32(option, len, &lease->server_address); break; case DHCP_OPTION_SUBNET_MASK: lease_parse_be32(option, len, &lease->subnet_mask); break; case DHCP_OPTION_BROADCAST: lease_parse_be32(option, len, &lease->broadcast); break; case DHCP_OPTION_ROUTER: lease_parse_be32(option, len, &lease->router); break; case DHCP_OPTION_DOMAIN_NAME_SERVER: r = lease_parse_in_addrs(option, len, &lease->dns, &lease->dns_size); if (r < 0) return r; break; case DHCP_OPTION_NTP_SERVER: r = lease_parse_in_addrs(option, len, &lease->ntp, &lease->ntp_size); if (r < 0) return r; break; case DHCP_OPTION_POLICY_FILTER: r = lease_parse_in_addrs_pairs(option, len, &lease->policy_filter, &lease->policy_filter_size); if (r < 0) return r; break; case DHCP_OPTION_STATIC_ROUTE: r = lease_parse_routes(option, len, &lease->static_route, &lease->static_route_size, &lease->static_route_allocated); if (r < 0) return r; break; case DHCP_OPTION_INTERFACE_MTU: lease_parse_u16(option, len, &lease->mtu, 68); break; case DHCP_OPTION_INTERFACE_MDR: lease_parse_u16(option, len, &lease->mdr, 576); break; case DHCP_OPTION_INTERFACE_TTL: lease_parse_u8(option, len, &lease->ttl, 1); break; case DHCP_OPTION_BOOT_FILE_SIZE: lease_parse_u16(option, len, &lease->boot_file_size, 0); break; case DHCP_OPTION_DOMAIN_NAME: { _cleanup_free_ char *domainname = NULL; char *e; r = lease_parse_string(option, len, &domainname); if (r < 0) return r; /* Chop off trailing dot of domain name that some DHCP * servers send us back. Internally we want to store * host names without trailing dots and * host_name_is_valid() doesn't accept them. */ e = endswith(domainname, "."); if (e) *e = 0; if (!hostname_is_valid(domainname) || is_localhost(domainname)) break; free(lease->domainname); lease->domainname = domainname; domainname = NULL; break; } case DHCP_OPTION_HOST_NAME: { _cleanup_free_ char *hostname = NULL; char *e; r = lease_parse_string(option, len, &hostname); if (r < 0) return r; e = endswith(hostname, "."); if (e) *e = 0; if (!hostname_is_valid(hostname) || is_localhost(hostname)) break; free(lease->hostname); lease->hostname = hostname; hostname = NULL; break; } case DHCP_OPTION_ROOT_PATH: r = lease_parse_string(option, len, &lease->root_path); if (r < 0) return r; break; case DHCP_OPTION_RENEWAL_T1_TIME: lease_parse_u32(option, len, &lease->t1, 1); break; case DHCP_OPTION_REBINDING_T2_TIME: lease_parse_u32(option, len, &lease->t2, 1); break; case DHCP_OPTION_ENABLE_IP_FORWARDING: lease_parse_bool(option, len, &lease->ip_forward); break; case DHCP_OPTION_ENABLE_IP_FORWARDING_NL: lease_parse_bool(option, len, &lease->ip_forward_non_local); break; case DHCP_OPTION_CLASSLESS_STATIC_ROUTE: r = lease_parse_classless_routes(option, len, &lease->static_route, &lease->static_route_size, &lease->static_route_allocated); if (r < 0) return r; break; } return 0; } int dhcp_lease_new(sd_dhcp_lease **ret) { sd_dhcp_lease *lease; lease = new0(sd_dhcp_lease, 1); if (!lease) return -ENOMEM; lease->router = INADDR_ANY; lease->n_ref = REFCNT_INIT; *ret = lease; return 0; } int sd_dhcp_lease_save(sd_dhcp_lease *lease, const char *lease_file) { _cleanup_free_ char *temp_path = NULL; _cleanup_fclose_ FILE *f = NULL; struct in_addr address; const struct in_addr *addresses; const uint8_t *client_id; size_t client_id_len; const char *string; uint16_t mtu; struct sd_dhcp_route *routes; int r; assert(lease); assert(lease_file); r = fopen_temporary(lease_file, &f, &temp_path); if (r < 0) goto finish; fchmod(fileno(f), 0644); r = sd_dhcp_lease_get_address(lease, &address); if (r < 0) goto finish; fprintf(f, "# This is private data. Do not parse.\n" "ADDRESS=%s\n", inet_ntoa(address)); r = sd_dhcp_lease_get_netmask(lease, &address); if (r < 0) goto finish; fprintf(f, "NETMASK=%s\n", inet_ntoa(address)); r = sd_dhcp_lease_get_router(lease, &address); if (r >= 0) fprintf(f, "ROUTER=%s\n", inet_ntoa(address)); r = sd_dhcp_lease_get_server_identifier(lease, &address); if (r >= 0) fprintf(f, "SERVER_ADDRESS=%s\n", inet_ntoa(address)); r = sd_dhcp_lease_get_next_server(lease, &address); if (r >= 0) fprintf(f, "NEXT_SERVER=%s\n", inet_ntoa(address)); r = sd_dhcp_lease_get_mtu(lease, &mtu); if (r >= 0) fprintf(f, "MTU=%" PRIu16 "\n", mtu); fputs("DNS=", f); r = sd_dhcp_lease_get_dns(lease, &addresses); if (r >= 0) serialize_in_addrs(f, addresses, r); fputs("\n", f); fputs("NTP=", f); r = sd_dhcp_lease_get_ntp(lease, &addresses); if (r >= 0) serialize_in_addrs(f, addresses, r); fputs("\n", f); r = sd_dhcp_lease_get_domainname(lease, &string); if (r >= 0) fprintf(f, "DOMAINNAME=%s\n", string); r = sd_dhcp_lease_get_hostname(lease, &string); if (r >= 0) fprintf(f, "HOSTNAME=%s\n", string); r = sd_dhcp_lease_get_root_path(lease, &string); if (r >= 0) fprintf(f, "ROOT_PATH=%s\n", string); r = sd_dhcp_lease_get_routes(lease, &routes); if (r >= 0) serialize_dhcp_routes(f, "ROUTES", routes, r); r = sd_dhcp_lease_get_client_id(lease, &client_id, &client_id_len); if (r >= 0) { _cleanup_free_ char *client_id_hex; client_id_hex = hexmem (client_id, client_id_len); if (!client_id_hex) { r = -ENOMEM; goto finish; } fprintf(f, "CLIENTID=%s\n", client_id_hex); } r = 0; fflush(f); if (ferror(f) || rename(temp_path, lease_file) < 0) { r = -errno; unlink(lease_file); unlink(temp_path); } finish: if (r < 0) log_error_errno(r, "Failed to save lease data %s: %m", lease_file); return r; } int sd_dhcp_lease_load(sd_dhcp_lease **ret, const char *lease_file) { _cleanup_dhcp_lease_unref_ sd_dhcp_lease *lease = NULL; _cleanup_free_ char *address = NULL, *router = NULL, *netmask = NULL, *server_address = NULL, *next_server = NULL, *dns = NULL, *ntp = NULL, *mtu = NULL, *routes = NULL, *client_id_hex = NULL; struct in_addr addr; int r; assert(lease_file); assert(ret); r = dhcp_lease_new(&lease); if (r < 0) return r; r = parse_env_file(lease_file, NEWLINE, "ADDRESS", &address, "ROUTER", &router, "NETMASK", &netmask, "SERVER_IDENTIFIER", &server_address, "NEXT_SERVER", &next_server, "DNS", &dns, "NTP", &ntp, "MTU", &mtu, "DOMAINNAME", &lease->domainname, "HOSTNAME", &lease->hostname, "ROOT_PATH", &lease->root_path, "ROUTES", &routes, "CLIENTID", &client_id_hex, NULL); if (r < 0) { if (r == -ENOENT) return 0; return log_error_errno(r, "Failed to read %s: %m", lease_file); } r = inet_pton(AF_INET, address, &addr); if (r < 0) return r; lease->address = addr.s_addr; if (router) { r = inet_pton(AF_INET, router, &addr); if (r < 0) return r; lease->router = addr.s_addr; } r = inet_pton(AF_INET, netmask, &addr); if (r < 0) return r; lease->subnet_mask = addr.s_addr; if (server_address) { r = inet_pton(AF_INET, server_address, &addr); if (r < 0) return r; lease->server_address = addr.s_addr; } if (next_server) { r = inet_pton(AF_INET, next_server, &addr); if (r < 0) return r; lease->next_server = addr.s_addr; } if (dns) { r = deserialize_in_addrs(&lease->dns, dns); if (r < 0) return r; lease->dns_size = r; } if (ntp) { r = deserialize_in_addrs(&lease->ntp, ntp); if (r < 0) return r; lease->ntp_size = r; } if (mtu) { uint16_t u; if (sscanf(mtu, "%" SCNu16, &u) > 0) lease->mtu = u; } if (routes) { r = deserialize_dhcp_routes(&lease->static_route, &lease->static_route_size, &lease->static_route_allocated, routes); if (r < 0) return r; } if (client_id_hex) { if (strlen (client_id_hex) % 2) return -EINVAL; lease->client_id = unhexmem (client_id_hex, strlen (client_id_hex)); if (!lease->client_id) return -ENOMEM; lease->client_id_len = strlen (client_id_hex) / 2; } *ret = lease; lease = NULL; return 0; } int dhcp_lease_set_default_subnet_mask(sd_dhcp_lease *lease) { struct in_addr address; struct in_addr mask; int r; assert(lease); address.s_addr = lease->address; /* fall back to the default subnet masks based on address class */ r = in_addr_default_subnet_mask(&address, &mask); if (r < 0) return r; lease->subnet_mask = mask.s_addr; return 0; } int sd_dhcp_lease_get_client_id(sd_dhcp_lease *lease, const uint8_t **client_id, size_t *client_id_len) { assert_return(lease, -EINVAL); assert_return(client_id, -EINVAL); assert_return(client_id_len, -EINVAL); *client_id = lease->client_id; *client_id_len = lease->client_id_len; return 0; } int dhcp_lease_set_client_id(sd_dhcp_lease *lease, const uint8_t *client_id, size_t client_id_len) { assert_return(lease, -EINVAL); assert_return((!client_id && !client_id_len) || (client_id && client_id_len), -EINVAL); free (lease->client_id); lease->client_id = NULL; lease->client_id_len = 0; if (client_id) { lease->client_id = memdup (client_id, client_id_len); lease->client_id_len = client_id_len; } return 0; }