| /* SPDX-License-Identifier: LGPL-2.1-or-later */ |
| |
| #include <netinet/in.h> |
| #include <linux/if_arp.h> |
| #include <linux/if.h> |
| |
| #include "sd-dhcp-server.h" |
| |
| #include "fd-util.h" |
| #include "fileio.h" |
| #include "networkd-address.h" |
| #include "networkd-dhcp-server-bus.h" |
| #include "networkd-dhcp-server-static-lease.h" |
| #include "networkd-dhcp-server.h" |
| #include "networkd-link.h" |
| #include "networkd-manager.h" |
| #include "networkd-network.h" |
| #include "networkd-queue.h" |
| #include "parse-util.h" |
| #include "socket-netlink.h" |
| #include "string-table.h" |
| #include "string-util.h" |
| #include "strv.h" |
| |
| static bool link_dhcp4_server_enabled(Link *link) { |
| assert(link); |
| |
| if (link->flags & IFF_LOOPBACK) |
| return false; |
| |
| if (!link->network) |
| return false; |
| |
| if (link->iftype == ARPHRD_CAN) |
| return false; |
| |
| return link->network->dhcp_server; |
| } |
| |
| void network_adjust_dhcp_server(Network *network) { |
| assert(network); |
| |
| if (!network->dhcp_server) |
| return; |
| |
| if (network->bond) { |
| log_warning("%s: DHCPServer= is enabled for bond slave. Disabling DHCP server.", |
| network->filename); |
| network->dhcp_server = false; |
| return; |
| } |
| |
| if (!in4_addr_is_set(&network->dhcp_server_address)) { |
| Address *address; |
| bool have = false; |
| |
| ORDERED_HASHMAP_FOREACH(address, network->addresses_by_section) { |
| if (section_is_invalid(address->section)) |
| continue; |
| if (address->family == AF_INET && |
| !in4_addr_is_localhost(&address->in_addr.in) && |
| in4_addr_is_null(&address->in_addr_peer.in)) { |
| have = true; |
| break; |
| } |
| } |
| if (!have) { |
| log_warning("%s: DHCPServer= is enabled, but no static address configured. " |
| "Disabling DHCP server.", |
| network->filename); |
| network->dhcp_server = false; |
| return; |
| } |
| } |
| } |
| |
| static int link_find_dhcp_server_address(Link *link, Address **ret) { |
| Address *address; |
| |
| assert(link); |
| assert(link->network); |
| |
| /* If ServerAddress= is specified, then use the address. */ |
| if (in4_addr_is_set(&link->network->dhcp_server_address)) |
| return link_get_ipv4_address(link, &link->network->dhcp_server_address, |
| link->network->dhcp_server_address_prefixlen, ret); |
| |
| /* If not, then select one from static addresses. */ |
| SET_FOREACH(address, link->static_addresses) |
| if (address->family == AF_INET && |
| !in4_addr_is_localhost(&address->in_addr.in) && |
| in4_addr_is_null(&address->in_addr_peer.in)) { |
| *ret = address; |
| return 0; |
| } |
| |
| return -ENOENT; |
| } |
| |
| static int dhcp_server_find_uplink(Link *link, Link **ret) { |
| assert(link); |
| |
| if (link->network->dhcp_server_uplink_name) |
| return link_get_by_name(link->manager, link->network->dhcp_server_uplink_name, ret); |
| |
| if (link->network->dhcp_server_uplink_index > 0) |
| return link_get_by_index(link->manager, link->network->dhcp_server_uplink_index, ret); |
| |
| if (link->network->dhcp_server_uplink_index == 0) { |
| /* It is not necessary to propagate error in automatic selection. */ |
| if (manager_find_uplink(link->manager, AF_INET, link, ret) < 0) |
| *ret = NULL; |
| return 0; |
| } |
| |
| *ret = NULL; |
| return 0; |
| } |
| |
| static int link_push_uplink_to_dhcp_server( |
| Link *link, |
| sd_dhcp_lease_server_type_t what, |
| sd_dhcp_server *s) { |
| |
| _cleanup_free_ struct in_addr *addresses = NULL; |
| bool use_dhcp_lease_data = true; |
| size_t n_addresses = 0; |
| |
| assert(link); |
| |
| if (!link->network) |
| return 0; |
| assert(link->network); |
| |
| log_link_debug(link, "Copying %s from link", dhcp_lease_server_type_to_string(what)); |
| |
| switch (what) { |
| |
| case SD_DHCP_LEASE_DNS: |
| /* For DNS we have a special case. We the data configured explicitly locally along with the |
| * data from the DHCP lease. */ |
| |
| for (unsigned i = 0; i < link->network->n_dns; i++) { |
| struct in_addr ia; |
| |
| /* Only look for IPv4 addresses */ |
| if (link->network->dns[i]->family != AF_INET) |
| continue; |
| |
| ia = link->network->dns[i]->address.in; |
| |
| /* Never propagate obviously borked data */ |
| if (in4_addr_is_null(&ia) || in4_addr_is_localhost(&ia)) |
| continue; |
| |
| if (!GREEDY_REALLOC(addresses, n_addresses + 1)) |
| return log_oom(); |
| |
| addresses[n_addresses++] = ia; |
| } |
| |
| use_dhcp_lease_data = link->network->dhcp_use_dns; |
| break; |
| |
| case SD_DHCP_LEASE_NTP: { |
| char **i; |
| |
| /* For NTP things are similar, but for NTP hostnames can be configured too, which we cannot |
| * propagate via DHCP. Hence let's only propagate those which are IP addresses. */ |
| |
| STRV_FOREACH(i, link->network->ntp) { |
| union in_addr_union ia; |
| |
| if (in_addr_from_string(AF_INET, *i, &ia) < 0) |
| continue; |
| |
| /* Never propagate obviously borked data */ |
| if (in4_addr_is_null(&ia.in) || in4_addr_is_localhost(&ia.in)) |
| continue; |
| |
| if (!GREEDY_REALLOC(addresses, n_addresses + 1)) |
| return log_oom(); |
| |
| addresses[n_addresses++] = ia.in; |
| } |
| |
| use_dhcp_lease_data = link->network->dhcp_use_ntp; |
| break; |
| } |
| |
| case SD_DHCP_LEASE_SIP: |
| |
| /* For SIP we don't allow explicit, local configuration, but there's control whether to use the data */ |
| use_dhcp_lease_data = link->network->dhcp_use_sip; |
| break; |
| |
| case SD_DHCP_LEASE_POP3: |
| case SD_DHCP_LEASE_SMTP: |
| case SD_DHCP_LEASE_LPR: |
| /* For the other server types we currently do not allow local configuration of server data, |
| * since there are typically no local consumers of the data. */ |
| break; |
| |
| default: |
| assert_not_reached("Unexpected server type"); |
| } |
| |
| if (use_dhcp_lease_data && link->dhcp_lease) { |
| const struct in_addr *da; |
| |
| int n = sd_dhcp_lease_get_servers(link->dhcp_lease, what, &da); |
| if (n > 0) { |
| if (!GREEDY_REALLOC(addresses, n_addresses + n)) |
| return log_oom(); |
| |
| for (int j = 0; j < n; j++) |
| if (in4_addr_is_non_local(&da[j])) |
| addresses[n_addresses++] = da[j]; |
| } |
| } |
| |
| if (n_addresses <= 0) |
| return 0; |
| |
| return sd_dhcp_server_set_servers(s, what, addresses, n_addresses); |
| } |
| |
| static int dhcp4_server_parse_dns_server_string_and_warn( |
| const char *string, |
| struct in_addr **addresses, |
| size_t *n_addresses) { |
| |
| for (;;) { |
| _cleanup_free_ char *word = NULL, *server_name = NULL; |
| union in_addr_union address; |
| int family, r, ifindex = 0; |
| |
| r = extract_first_word(&string, &word, NULL, 0); |
| if (r < 0) |
| return r; |
| if (r == 0) |
| break; |
| |
| r = in_addr_ifindex_name_from_string_auto(word, &family, &address, &ifindex, &server_name); |
| if (r < 0) { |
| log_warning_errno(r, "Failed to parse DNS server address '%s', ignoring: %m", word); |
| continue; |
| } |
| |
| /* Only look for IPv4 addresses */ |
| if (family != AF_INET) |
| continue; |
| |
| /* Never propagate obviously borked data */ |
| if (in4_addr_is_null(&address.in) || in4_addr_is_localhost(&address.in)) |
| continue; |
| |
| if (!GREEDY_REALLOC(*addresses, *n_addresses + 1)) |
| return log_oom(); |
| |
| (*addresses)[(*n_addresses)++] = address.in; |
| } |
| |
| return 0; |
| } |
| |
| static int dhcp4_server_set_dns_from_resolve_conf(Link *link) { |
| _cleanup_free_ struct in_addr *addresses = NULL; |
| _cleanup_fclose_ FILE *f = NULL; |
| size_t n_addresses = 0; |
| int n = 0, r; |
| |
| f = fopen(PRIVATE_UPLINK_RESOLV_CONF, "re"); |
| if (!f) { |
| if (errno == ENOENT) |
| return 0; |
| |
| return log_warning_errno(errno, "Failed to open " PRIVATE_UPLINK_RESOLV_CONF ": %m"); |
| } |
| |
| for (;;) { |
| _cleanup_free_ char *line = NULL; |
| const char *a; |
| char *l; |
| |
| r = read_line(f, LONG_LINE_MAX, &line); |
| if (r < 0) |
| return log_error_errno(r, "Failed to read " PRIVATE_UPLINK_RESOLV_CONF ": %m"); |
| if (r == 0) |
| break; |
| |
| n++; |
| |
| l = strstrip(line); |
| if (IN_SET(*l, '#', ';', 0)) |
| continue; |
| |
| a = first_word(l, "nameserver"); |
| if (!a) |
| continue; |
| |
| r = dhcp4_server_parse_dns_server_string_and_warn(a, &addresses, &n_addresses); |
| if (r < 0) |
| log_warning_errno(r, "Failed to parse DNS server address '%s', ignoring.", a); |
| } |
| |
| if (n_addresses <= 0) |
| return 0; |
| |
| return sd_dhcp_server_set_dns(link->dhcp_server, addresses, n_addresses); |
| } |
| |
| static int dhcp4_server_configure(Link *link) { |
| bool acquired_uplink = false; |
| sd_dhcp_option *p; |
| DHCPStaticLease *static_lease; |
| Link *uplink = NULL; |
| Address *address; |
| bool bind_to_interface; |
| int r; |
| |
| assert(link); |
| |
| log_link_debug(link, "Configuring DHCP Server."); |
| |
| if (link->dhcp_server) |
| return -EBUSY; |
| |
| r = sd_dhcp_server_new(&link->dhcp_server, link->ifindex); |
| if (r < 0) |
| return r; |
| |
| r = sd_dhcp_server_attach_event(link->dhcp_server, link->manager->event, 0); |
| if (r < 0) |
| return r; |
| |
| r = sd_dhcp_server_set_callback(link->dhcp_server, dhcp_server_callback, link); |
| if (r < 0) |
| return log_link_warning_errno(link, r, "Failed to set callback for DHCPv4 server instance: %m"); |
| |
| r = link_find_dhcp_server_address(link, &address); |
| if (r < 0) |
| return log_link_error_errno(link, r, "Failed to find suitable address for DHCPv4 server instance: %m"); |
| |
| /* use the server address' subnet as the pool */ |
| r = sd_dhcp_server_configure_pool(link->dhcp_server, &address->in_addr.in, address->prefixlen, |
| link->network->dhcp_server_pool_offset, link->network->dhcp_server_pool_size); |
| if (r < 0) |
| return log_link_error_errno(link, r, "Failed to configure address pool for DHCPv4 server instance: %m"); |
| |
| /* TODO: |
| r = sd_dhcp_server_set_router(link->dhcp_server, &main_address->in_addr.in); |
| if (r < 0) |
| return r; |
| */ |
| |
| if (link->network->dhcp_server_max_lease_time_usec > 0) { |
| r = sd_dhcp_server_set_max_lease_time(link->dhcp_server, |
| DIV_ROUND_UP(link->network->dhcp_server_max_lease_time_usec, USEC_PER_SEC)); |
| if (r < 0) |
| return log_link_error_errno(link, r, "Failed to set maximum lease time for DHCPv4 server instance: %m"); |
| } |
| |
| if (link->network->dhcp_server_default_lease_time_usec > 0) { |
| r = sd_dhcp_server_set_default_lease_time(link->dhcp_server, |
| DIV_ROUND_UP(link->network->dhcp_server_default_lease_time_usec, USEC_PER_SEC)); |
| if (r < 0) |
| return log_link_error_errno(link, r, "Failed to set default lease time for DHCPv4 server instance: %m"); |
| } |
| |
| for (sd_dhcp_lease_server_type_t type = 0; type < _SD_DHCP_LEASE_SERVER_TYPE_MAX; type ++) { |
| |
| if (!link->network->dhcp_server_emit[type].emit) |
| continue; |
| |
| if (link->network->dhcp_server_emit[type].n_addresses > 0) |
| /* Explicitly specified servers to emit */ |
| r = sd_dhcp_server_set_servers( |
| link->dhcp_server, |
| type, |
| link->network->dhcp_server_emit[type].addresses, |
| link->network->dhcp_server_emit[type].n_addresses); |
| else { |
| /* Emission is requested, but nothing explicitly configured. Let's find a suitable upling */ |
| if (!acquired_uplink) { |
| (void) dhcp_server_find_uplink(link, &uplink); |
| acquired_uplink = true; |
| } |
| |
| if (uplink && uplink->network) |
| r = link_push_uplink_to_dhcp_server(uplink, type, link->dhcp_server); |
| else if (type == SD_DHCP_LEASE_DNS) |
| r = dhcp4_server_set_dns_from_resolve_conf(link); |
| else { |
| log_link_debug(link, |
| "Not emitting %s on link, couldn't find suitable uplink.", |
| dhcp_lease_server_type_to_string(type)); |
| continue; |
| } |
| } |
| |
| if (r < 0) |
| log_link_warning_errno(link, r, |
| "Failed to set %s for DHCP server, ignoring: %m", |
| dhcp_lease_server_type_to_string(type)); |
| } |
| |
| r = sd_dhcp_server_set_emit_router(link->dhcp_server, link->network->dhcp_server_emit_router); |
| if (r < 0) |
| return log_link_error_errno(link, r, "Failed to set router emission for DHCP server: %m"); |
| |
| r = sd_dhcp_server_set_relay_target(link->dhcp_server, &link->network->dhcp_server_relay_target); |
| if (r < 0) |
| return log_link_error_errno(link, r, "Failed to set relay target for DHCP server: %m"); |
| |
| bind_to_interface = sd_dhcp_server_is_in_relay_mode(link->dhcp_server) ? false : link->network->dhcp_server_bind_to_interface; |
| r = sd_dhcp_server_set_bind_to_interface(link->dhcp_server, bind_to_interface); |
| if (r < 0) |
| return log_link_error_errno(link, r, "Failed to set interface binding for DHCP server: %m"); |
| |
| r = sd_dhcp_server_set_relay_agent_information(link->dhcp_server, link->network->dhcp_server_relay_agent_circuit_id, link->network->dhcp_server_relay_agent_remote_id); |
| if (r < 0) |
| return log_link_error_errno(link, r, "Failed to set agent circuit/remote id for DHCP server: %m"); |
| |
| if (link->network->dhcp_server_emit_timezone) { |
| _cleanup_free_ char *buffer = NULL; |
| const char *tz = NULL; |
| |
| if (link->network->dhcp_server_timezone) |
| tz = link->network->dhcp_server_timezone; |
| else { |
| r = get_timezone(&buffer); |
| if (r < 0) |
| log_link_warning_errno(link, r, "Failed to determine timezone, not sending timezone: %m"); |
| else |
| tz = buffer; |
| } |
| |
| if (tz) { |
| r = sd_dhcp_server_set_timezone(link->dhcp_server, tz); |
| if (r < 0) |
| return log_link_error_errno(link, r, "Failed to set timezone for DHCP server: %m"); |
| } |
| } |
| |
| ORDERED_HASHMAP_FOREACH(p, link->network->dhcp_server_send_options) { |
| r = sd_dhcp_server_add_option(link->dhcp_server, p); |
| if (r == -EEXIST) |
| continue; |
| if (r < 0) |
| return log_link_error_errno(link, r, "Failed to set DHCPv4 option: %m"); |
| } |
| |
| ORDERED_HASHMAP_FOREACH(p, link->network->dhcp_server_send_vendor_options) { |
| r = sd_dhcp_server_add_vendor_option(link->dhcp_server, p); |
| if (r == -EEXIST) |
| continue; |
| if (r < 0) |
| return log_link_error_errno(link, r, "Failed to set DHCPv4 option: %m"); |
| } |
| |
| HASHMAP_FOREACH(static_lease, link->network->dhcp_static_leases_by_section) { |
| r = sd_dhcp_server_set_static_lease(link->dhcp_server, &static_lease->address, static_lease->client_id, static_lease->client_id_size); |
| if (r < 0) |
| return log_link_error_errno(link, r, "Failed to set DHCPv4 static lease for DHCP server: %m"); |
| } |
| |
| r = sd_dhcp_server_start(link->dhcp_server); |
| if (r < 0) |
| return log_link_error_errno(link, r, "Could not start DHCPv4 server instance: %m"); |
| |
| log_link_debug(link, "Offering DHCPv4 leases"); |
| |
| return 1; |
| } |
| |
| int link_request_dhcp_server(Link *link) { |
| assert(link); |
| |
| if (!link_dhcp4_server_enabled(link)) |
| return 0; |
| |
| if (link->dhcp_server) |
| return 0; |
| |
| log_link_debug(link, "Requesting DHCP server."); |
| return link_queue_request(link, REQUEST_TYPE_DHCP_SERVER, NULL, false, NULL, NULL, NULL); |
| } |
| |
| static bool dhcp_server_is_ready_to_configure(Link *link) { |
| Link *uplink = NULL; |
| Address *a; |
| |
| assert(link); |
| |
| if (!link->network) |
| return false; |
| |
| if (!IN_SET(link->state, LINK_STATE_CONFIGURING, LINK_STATE_CONFIGURED)) |
| return false; |
| |
| if (link->set_flags_messages > 0) |
| return false; |
| |
| if (!link_has_carrier(link)) |
| return false; |
| |
| if (link->address_remove_messages > 0) |
| return false; |
| |
| if (!link->static_addresses_configured) |
| return false; |
| |
| if (link_find_dhcp_server_address(link, &a) < 0) |
| return false; |
| |
| if (!address_is_ready(a)) |
| return false; |
| |
| if (dhcp_server_find_uplink(link, &uplink) < 0) |
| return false; |
| |
| if (uplink && !uplink->network) |
| return false; |
| |
| return true; |
| } |
| |
| int request_process_dhcp_server(Request *req) { |
| assert(req); |
| assert(req->link); |
| assert(req->type == REQUEST_TYPE_DHCP_SERVER); |
| |
| if (!dhcp_server_is_ready_to_configure(req->link)) |
| return 0; |
| |
| return dhcp4_server_configure(req->link); |
| } |
| |
| int config_parse_dhcp_server_relay_agent_suboption( |
| const char *unit, |
| const char *filename, |
| unsigned line, |
| const char *section, |
| unsigned section_line, |
| const char *lvalue, |
| int ltype, |
| const char *rvalue, |
| void *data, |
| void *userdata) { |
| |
| char **suboption_value = data; |
| char* p; |
| |
| assert(filename); |
| assert(lvalue); |
| assert(rvalue); |
| |
| if (isempty(rvalue)) { |
| *suboption_value = mfree(*suboption_value); |
| return 0; |
| } |
| |
| p = startswith(rvalue, "string:"); |
| if (!p) { |
| log_syntax(unit, LOG_WARNING, filename, line, 0, |
| "Failed to parse %s=%s'. Invalid format, ignoring.", lvalue, rvalue); |
| return 0; |
| } |
| return free_and_strdup(suboption_value, empty_to_null(p)); |
| } |
| |
| int config_parse_dhcp_server_emit( |
| const char *unit, |
| const char *filename, |
| unsigned line, |
| const char *section, |
| unsigned section_line, |
| const char *lvalue, |
| int ltype, |
| const char *rvalue, |
| void *data, |
| void *userdata) { |
| |
| NetworkDHCPServerEmitAddress *emit = data; |
| |
| assert(emit); |
| assert(rvalue); |
| |
| for (const char *p = rvalue;;) { |
| _cleanup_free_ char *w = NULL; |
| union in_addr_union a; |
| int r; |
| |
| r = extract_first_word(&p, &w, NULL, 0); |
| if (r == -ENOMEM) |
| return log_oom(); |
| if (r < 0) { |
| log_syntax(unit, LOG_WARNING, filename, line, r, |
| "Failed to extract word, ignoring: %s", rvalue); |
| return 0; |
| } |
| if (r == 0) |
| return 0; |
| |
| r = in_addr_from_string(AF_INET, w, &a); |
| if (r < 0) { |
| log_syntax(unit, LOG_WARNING, filename, line, r, |
| "Failed to parse %s= address '%s', ignoring: %m", lvalue, w); |
| continue; |
| } |
| |
| struct in_addr *m = reallocarray(emit->addresses, emit->n_addresses + 1, sizeof(struct in_addr)); |
| if (!m) |
| return log_oom(); |
| |
| emit->addresses = m; |
| emit->addresses[emit->n_addresses++] = a.in; |
| } |
| } |
| |
| int config_parse_dhcp_server_address( |
| const char *unit, |
| const char *filename, |
| unsigned line, |
| const char *section, |
| unsigned section_line, |
| const char *lvalue, |
| int ltype, |
| const char *rvalue, |
| void *data, |
| void *userdata) { |
| |
| Network *network = userdata; |
| union in_addr_union a; |
| unsigned char prefixlen; |
| int r; |
| |
| assert(filename); |
| assert(lvalue); |
| assert(rvalue); |
| |
| if (isempty(rvalue)) { |
| network->dhcp_server_address = (struct in_addr) {}; |
| network->dhcp_server_address_prefixlen = 0; |
| return 0; |
| } |
| |
| r = in_addr_prefix_from_string(rvalue, AF_INET, &a, &prefixlen); |
| if (r < 0) { |
| log_syntax(unit, LOG_WARNING, filename, line, r, |
| "Failed to parse %s=, ignoring assignment: %s", lvalue, rvalue); |
| return 0; |
| } |
| if (in4_addr_is_null(&a.in) || in4_addr_is_localhost(&a.in)) { |
| log_syntax(unit, LOG_WARNING, filename, line, 0, |
| "DHCP server address cannot be the ANY address or a localhost address, " |
| "ignoring assignment: %s", rvalue); |
| return 0; |
| } |
| |
| network->dhcp_server_address = a.in; |
| network->dhcp_server_address_prefixlen = prefixlen; |
| return 0; |
| } |
| |
| int config_parse_dhcp_server_uplink( |
| const char *unit, |
| const char *filename, |
| unsigned line, |
| const char *section, |
| unsigned section_line, |
| const char *lvalue, |
| int ltype, |
| const char *rvalue, |
| void *data, |
| void *userdata) { |
| |
| Network *network = userdata; |
| int r; |
| |
| assert(filename); |
| assert(lvalue); |
| assert(rvalue); |
| |
| if (isempty(rvalue) || streq(rvalue, ":auto")) { |
| network->dhcp_server_uplink_index = 0; /* uplink will be selected automatically */ |
| network->dhcp_server_uplink_name = mfree(network->dhcp_server_uplink_name); |
| return 0; |
| } |
| |
| if (streq(rvalue, ":none")) { |
| network->dhcp_server_uplink_index = -1; /* uplink will not be selected automatically */ |
| network->dhcp_server_uplink_name = mfree(network->dhcp_server_uplink_name); |
| return 0; |
| } |
| |
| r = parse_ifindex(rvalue); |
| if (r > 0) { |
| network->dhcp_server_uplink_index = r; |
| network->dhcp_server_uplink_name = mfree(network->dhcp_server_uplink_name); |
| return 0; |
| } |
| |
| if (!ifname_valid_full(rvalue, IFNAME_VALID_ALTERNATIVE)) { |
| log_syntax(unit, LOG_WARNING, filename, line, 0, |
| "Invalid interface name in %s=, ignoring assignment: %s", lvalue, rvalue); |
| return 0; |
| } |
| |
| r = free_and_strdup_warn(&network->dhcp_server_uplink_name, rvalue); |
| if (r < 0) |
| return r; |
| |
| network->dhcp_server_uplink_index = 0; |
| return 0; |
| } |
