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mirror of https://git.kernel.org/pub/scm/network/wireless/iwd.git synced 2024-11-25 09:39:25 +01:00
iwd/src/netconfig.c
James Prestwood aa0a439856 netconfig: limit DHCPv4 attempts to avoid extended netconfig times
ELL now has a setting to limit the number of DHCP attempts. This
will now be set in IWD and if reached will result in a failure
event, and in turn a disconnect.

IWD will set a maximum of 4 retries which should keep the maximum
DHCP time to ~60 seconds roughly.
2024-01-30 13:59:22 -06:00

791 lines
21 KiB
C

/*
*
* Wireless daemon for Linux
*
* Copyright (C) 2019 Intel Corporation. All rights reserved.
*
* This library 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.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <errno.h>
#include <arpa/inet.h>
#include <net/if_arp.h>
#include <netinet/in.h>
#include <limits.h>
#include <string.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <ell/ell.h>
#include "ell/useful.h"
#include "src/iwd.h"
#include "src/module.h"
#include "src/netdev.h"
#include "src/station.h"
#include "src/common.h"
#include "src/network.h"
#include "src/resolve.h"
#include "src/util.h"
#include "src/ie.h"
#include "src/netconfig.h"
#include "src/sysfs.h"
#define DHCP_ATTEMPTS 4
/*
* Routing priority offset, configurable in main.conf. The route with lower
* priority offset is preferred.
*/
static uint32_t ROUTE_PRIORITY_OFFSET;
static bool ipv6_enabled;
static char *mdns_global;
static void do_debug(const char *str, void *user_data)
{
const char *prefix = user_data;
l_info("%s%s", prefix, str);
}
static void netconfig_free_settings(struct netconfig *netconfig)
{
netconfig->enabled[0] = true;
netconfig->enabled[1] = false;
netconfig->static_config[0] = false;
netconfig->static_config[1] = false;
netconfig->gateway_overridden[0] = false;
netconfig->gateway_overridden[1] = false;
netconfig->dns_overridden[0] = false;
netconfig->dns_overridden[1] = false;
l_netconfig_reset_config(netconfig->nc);
l_free(netconfig->mdns);
netconfig->mdns = NULL;
l_free(l_steal_ptr(netconfig->fils_override));
}
static void netconfig_free(void *data)
{
struct netconfig *netconfig = data;
l_netconfig_destroy(netconfig->nc);
l_free(netconfig);
}
static bool netconfig_addr_to_str(uint8_t af, const void *v4_addr,
const void *v6_addr, char *out_str,
bool *out_is_zero)
{
const void *addr = (af == AF_INET ? v4_addr : v6_addr);
uint8_t bytes = (af == AF_INET ? 4 : 16);
if (l_memeqzero(addr, bytes)) {
*out_is_zero = true;
return true;
}
*out_is_zero = false;
if (L_WARN_ON(!inet_ntop(af, addr, out_str, INET6_ADDRSTRLEN)))
return false;
return true;
}
bool netconfig_use_fils_addr(struct netconfig *netconfig, int af)
{
if (!netconfig->enabled[INDEX_FOR_AF(af)])
return false;
if (netconfig->static_config[INDEX_FOR_AF(af)])
return false;
if (!netconfig->fils_override)
return false;
if (af == AF_INET)
return !!netconfig->fils_override->ipv4_addr;
return !l_memeqzero(netconfig->fils_override->ipv6_addr, 16);
}
static struct l_rtnl_address *netconfig_get_static4_address(
const struct l_settings *active_settings)
{
_auto_(l_rtnl_address_free) struct l_rtnl_address *ifaddr = NULL;
L_AUTO_FREE_VAR(char *, ip) = NULL;
L_AUTO_FREE_VAR(char *, netmask) = NULL;
struct in_addr in_addr;
L_AUTO_FREE_VAR(char *, broadcast) = NULL;
uint32_t prefix_len;
ip = l_settings_get_string(active_settings, "IPv4", "Address");
if (unlikely(!ip)) {
l_error("netconfig: Can't load IPv4.Address");
return NULL;
}
if (l_settings_has_key(active_settings, "IPv4", "Netmask") &&
!(netmask = l_settings_get_string(active_settings,
"IPv4",
"Netmask"))) {
l_error("netconfig: Can't load IPv4.Netmask");
return NULL;
}
if (netmask) {
if (inet_pton(AF_INET, netmask, &in_addr) != 1) {
l_error("netconfig: Can't parse IPv4.Netmask");
return NULL;
}
prefix_len = __builtin_popcountl(in_addr.s_addr);
if (ntohl(in_addr.s_addr) !=
util_netmask_from_prefix(prefix_len)) {
l_error("netconfig: Invalid IPv4.Netmask");
return NULL;
}
} else
prefix_len = 24;
ifaddr = l_rtnl_address_new(ip, prefix_len);
if (!ifaddr || l_rtnl_address_get_family(ifaddr) != AF_INET) {
l_error("netconfig: Unable to parse IPv4.Address");
return NULL;
}
broadcast = l_settings_get_string(active_settings, "IPv4", "Broadcast");
if (broadcast && !l_rtnl_address_set_broadcast(ifaddr, broadcast)) {
l_error("netconfig: Unable to parse IPv4.Broadcast");
return NULL;
}
return l_steal_ptr(ifaddr);
}
static struct l_rtnl_address *netconfig_get_static6_address(
const struct l_settings *active_settings)
{
L_AUTO_FREE_VAR(char *, ip);
char *p;
char *endp;
_auto_(l_rtnl_address_free) struct l_rtnl_address *ret = NULL;
uint32_t prefix_len = 64;
ip = l_settings_get_string(active_settings, "IPv6", "Address");
if (unlikely(!ip)) {
l_error("netconfig: Can't load IPv6.Address");
return NULL;
}
p = strrchr(ip, '/');
if (!p)
goto no_prefix_len;
*p = '\0';
if (*++p == '\0')
goto no_prefix_len;
errno = 0;
prefix_len = strtoul(p, &endp, 10);
if (unlikely(*endp != '\0' || errno ||
!prefix_len || prefix_len > 128)) {
l_error("netconfig: Invalid prefix '%s' provided in network"
" configuration file", p);
return NULL;
}
no_prefix_len:
ret = l_rtnl_address_new(ip, prefix_len);
if (!ret || l_rtnl_address_get_family(ret) != AF_INET6) {
l_error("netconfig: Invalid IPv6 address %s provided in "
"network configuration file.", ip);
return NULL;
}
return l_steal_ptr(ret);
}
static bool netconfig_load_dns(struct netconfig *netconfig,
const struct l_settings *active_settings,
const char *group_name, uint8_t family)
{
_auto_(l_strv_free) char **dns_str_list = NULL;
if (!l_settings_has_key(active_settings, group_name, "DNS"))
return true;
dns_str_list = l_settings_get_string_list(active_settings,
group_name, "DNS", ' ');
if (unlikely(!dns_str_list)) {
l_error("netconfig: Can't load [%s].DNS", group_name);
return false;
}
if (unlikely(!l_netconfig_set_dns_override(netconfig->nc, family,
dns_str_list))) {
l_error("netconfig: l_netconfig_set_dns_override(%s) failed",
family == AF_INET ? "AF_INET" : "AF_INET6");
return false;
}
netconfig->dns_overridden[INDEX_FOR_AF(family)] = true;
return true;
}
static bool netconfig_load_gateway(struct netconfig *netconfig,
const struct l_settings *active_settings,
const char *group_name, uint8_t family)
{
_auto_(l_free) char *gateway_str = NULL;
if (!l_settings_has_key(active_settings, group_name, "Gateway"))
return true;
gateway_str = l_settings_get_string(active_settings, group_name,
"Gateway");
if (unlikely(!gateway_str)) {
l_error("netconfig: Can't load [%s].Gateway", group_name);
return false;
}
if (unlikely(!l_netconfig_set_gateway_override(netconfig->nc, family,
gateway_str))) {
l_error("netconfig: l_netconfig_set_gateway_override(%s) "
"failed", family == AF_INET ? "AF_INET" : "AF_INET6");
return false;
}
netconfig->gateway_overridden[INDEX_FOR_AF(family)] = true;
return true;
}
bool netconfig_load_settings(struct netconfig *netconfig,
const struct l_settings *active_settings)
{
bool send_hostname = false;
char hostname[HOST_NAME_MAX + 1];
_auto_(l_free) char *mdns = NULL;
bool success = true;
bool static_ipv4 = false;
bool static_ipv6 = false;
bool enable_ipv4 = true;
bool enable_ipv6 = ipv6_enabled;
netconfig_free_settings(netconfig);
/*
* Note we try to print errors and continue validating the
* configuration until we've gone through all the settings so
* as to make fixing the settings more efficient for the user.
*/
if (l_settings_has_key(active_settings, "IPv4", "Address")) {
_auto_(l_rtnl_address_free) struct l_rtnl_address *addr =
netconfig_get_static4_address(active_settings);
if (unlikely(!addr)) {
success = false;
goto ipv6_addr;
}
if (!l_netconfig_set_static_addr(netconfig->nc, AF_INET,
addr)) {
l_error("netconfig: l_netconfig_set_static_addr("
"AF_INET) failed");
success = false;
goto ipv6_addr;
}
static_ipv4 = true;
}
ipv6_addr:
if (l_settings_has_key(active_settings, "IPv6", "Address")) {
_auto_(l_rtnl_address_free) struct l_rtnl_address *addr =
netconfig_get_static6_address(active_settings);
if (unlikely(!addr)) {
success = false;
goto gateway;
}
if (!l_netconfig_set_static_addr(netconfig->nc, AF_INET6,
addr)) {
l_error("netconfig: l_netconfig_set_static_addr("
"AF_INET6) failed");
success = false;
goto gateway;
}
static_ipv6 = true;
}
gateway:
if (!netconfig_load_gateway(netconfig, active_settings,
"IPv4", AF_INET))
success = false;
if (!netconfig_load_gateway(netconfig, active_settings,
"IPv6", AF_INET6))
success = false;
if (!netconfig_load_dns(netconfig, active_settings, "IPv4", AF_INET))
success = false;
if (!netconfig_load_dns(netconfig, active_settings, "IPv6", AF_INET6))
success = false;
if (l_settings_has_key(active_settings, "IPv6", "Enabled") &&
!l_settings_get_bool(active_settings, "IPv6", "Enabled",
&enable_ipv6)) {
l_error("netconfig: Can't load IPv6.Enabled");
success = false;
goto send_hostname;
}
if (!l_netconfig_set_family_enabled(netconfig->nc, AF_INET,
enable_ipv4) ||
!l_netconfig_set_family_enabled(netconfig->nc, AF_INET6,
enable_ipv6)) {
l_error("netconfig: l_netconfig_set_family_enabled() failed");
success = false;
}
send_hostname:
if (l_settings_has_key(active_settings, "IPv4", "SendHostname") &&
!l_settings_get_bool(active_settings, "IPv4",
"SendHostname",
&send_hostname)) {
l_error("netconfig: Can't load [IPv4].SendHostname");
success = false;
goto mdns;
}
if (send_hostname && gethostname(hostname, sizeof(hostname)) != 0) {
/* Warning only */
l_warn("netconfig: Unable to get hostname. "
"Error %d: %s", errno, strerror(errno));
goto mdns;
}
if (send_hostname &&
!l_netconfig_set_hostname(netconfig->nc, hostname)) {
l_error("netconfig: l_netconfig_set_hostname() failed");
success = false;
goto mdns;
}
mdns:
/* If the networks has this set take that over the global */
if (l_settings_has_key(active_settings, "Network", "MulticastDNS")) {
mdns = l_settings_get_string(active_settings, "Network",
"MulticastDNS");
if (!mdns) {
l_error("netconfig: Can't load Network.MulticastDNS");
success = false;
}
if (mdns && !L_IN_STRSET(mdns, "true", "false", "resolve")) {
l_error("netconfig: Bad profile Network.MulticastDNS "
"value '%s'", mdns);
success = false;
}
if (!success)
goto route_priority;
}
if (!mdns && mdns_global) {
mdns = l_strdup(mdns_global);
if (!L_IN_STRSET(mdns, "true", "false", "resolve")) {
l_error("netconfig: Bad global Network.MulticastDNS "
"value '%s'", mdns);
success = false;
}
}
route_priority:
l_netconfig_set_route_priority(netconfig->nc, ROUTE_PRIORITY_OFFSET);
l_netconfig_set_optimistic_dad_enabled(netconfig->nc, true);
if (!l_netconfig_check_config(netconfig->nc)) {
l_error("netconfig: Invalid configuration");
success = false;
}
if (success) {
netconfig->active_settings = active_settings;
netconfig->static_config[INDEX_FOR_AF(AF_INET)] = static_ipv4;
netconfig->static_config[INDEX_FOR_AF(AF_INET6)] = static_ipv6;
netconfig->enabled[INDEX_FOR_AF(AF_INET)] = enable_ipv4;
netconfig->enabled[INDEX_FOR_AF(AF_INET6)] = enable_ipv6;
netconfig->mdns = l_steal_ptr(mdns);
return true;
}
l_netconfig_reset_config(netconfig->nc);
return false;
}
static bool netconfig_load_fils_settings(struct netconfig *netconfig,
uint8_t af)
{
struct ie_fils_ip_addr_response_info *fils = netconfig->fils_override;
char addr_str[INET6_ADDRSTRLEN];
char gw_addr_str[INET6_ADDRSTRLEN];
char dns_addr_str[INET6_ADDRSTRLEN];
_auto_(l_rtnl_address_free) struct l_rtnl_address *rtnl_addr = NULL;
bool is_zero = false;
uint8_t prefix_len;
if (!netconfig_addr_to_str(af, &fils->ipv4_addr, &fils->ipv6_addr,
addr_str, &is_zero) || is_zero)
return is_zero;
prefix_len = (af == AF_INET ? fils->ipv4_prefix_len :
fils->ipv6_prefix_len);
if (L_WARN_ON(!(rtnl_addr = l_rtnl_address_new(addr_str, prefix_len))))
return false;
if (L_WARN_ON(!l_netconfig_set_static_addr(netconfig->nc, af,
rtnl_addr)))
return false;
if (af == AF_INET &&
L_WARN_ON(!l_netconfig_set_acd_enabled(netconfig->nc,
false)))
return false;
/*
* Done with local address, move on to gateway and DNS.
*
* Since load_settings is called early, generally before the actual
* connection setup starts, and load_fils_settings is called after
* 802.11 Authentication & Association, we need to check if either
* the gateway or DNS settings were overridden in load_settings so
* as not to overwrite the user-provided values. Values received
* with FILS are expected to have the same weight as those from
* DHCP/SLAAC.
*
* TODO: If netconfig->fils_override->ipv{4,6}_lifetime is set,
* start a timeout to renew the address using FILS IP Address
* Assignment or perhaps just start the DHCP client after that
* time.
*
* TODO: validate gateway and/or DNS on local subnet, link-local,
* etc.?
*/
if (!netconfig_addr_to_str(af, &fils->ipv4_gateway, &fils->ipv6_gateway,
gw_addr_str, &is_zero))
return false;
if (!netconfig->gateway_overridden[INDEX_FOR_AF(af)] && !is_zero &&
L_WARN_ON(!l_netconfig_set_gateway_override(
netconfig->nc,
af,
gw_addr_str)))
return false;
if (!netconfig_addr_to_str(af, &fils->ipv4_dns, &fils->ipv6_dns,
dns_addr_str, &is_zero))
return is_zero;
if (!netconfig->dns_overridden[INDEX_FOR_AF(af)] && !is_zero) {
char *dns_list[2] = { dns_addr_str, NULL };
if (L_WARN_ON(!l_netconfig_set_dns_override(netconfig->nc,
af, dns_list)))
return false;
}
return true;
}
bool netconfig_configure(struct netconfig *netconfig,
netconfig_notify_func_t notify, void *user_data)
{
if (netconfig->started)
return false;
netconfig->notify = notify;
netconfig->user_data = user_data;
if (netconfig_use_fils_addr(netconfig, AF_INET) &&
!netconfig_load_fils_settings(netconfig, AF_INET))
return false;
if (netconfig_use_fils_addr(netconfig, AF_INET6) &&
!netconfig_load_fils_settings(netconfig, AF_INET6))
return false;
if (unlikely(!l_netconfig_start(netconfig->nc)))
return false;
netconfig->started = true;
return true;
}
bool netconfig_reconfigure(struct netconfig *netconfig, bool set_arp_gw)
{
if (!netconfig->started)
return false;
/*
* Starting with kernel 4.20, ARP cache is flushed when the netdev
* detects NO CARRIER. This can result in unnecessarily long delays
* (about 1 second on some networks) due to ARP query response being
* lost or delayed. Try to force the gateway into the ARP cache
* to alleviate this
*/
if (set_arp_gw) {
netconfig_dhcp_gateway_to_arp(netconfig);
if (netconfig->connected[INDEX_FOR_AF(AF_INET)] &&
netconfig_use_fils_addr(netconfig, AF_INET))
netconfig_commit_fils_macs(netconfig, AF_INET);
if (netconfig->connected[INDEX_FOR_AF(AF_INET6)] &&
netconfig_use_fils_addr(netconfig, AF_INET6))
netconfig_commit_fils_macs(netconfig, AF_INET6);
}
if (!netconfig->static_config[INDEX_FOR_AF(AF_INET)]) {
/* TODO l_dhcp_client sending a DHCP inform request */
}
if (!netconfig->static_config[INDEX_FOR_AF(AF_INET6)]) {
/* TODO l_dhcp_v6_client sending a DHCP inform request */
}
return true;
}
bool netconfig_reset(struct netconfig *netconfig)
{
if (!netconfig->started)
return false;
netconfig->started = false;
l_netconfig_unconfigure(netconfig->nc);
l_netconfig_stop(netconfig->nc);
netconfig->connected[0] = false;
netconfig->connected[1] = false;
netconfig_free_settings(netconfig);
return true;
}
char *netconfig_get_dhcp_server_ipv4(struct netconfig *netconfig)
{
struct l_dhcp_client *client =
l_netconfig_get_dhcp_client(netconfig->nc);
const struct l_dhcp_lease *lease;
if (!client)
return NULL;
lease = l_dhcp_client_get_lease(client);
if (!lease)
return NULL;
return l_dhcp_lease_get_server_id(lease);
}
bool netconfig_get_fils_ip_req(struct netconfig *netconfig,
struct ie_fils_ip_addr_request_info *info)
{
/*
* Fill in the fields used for building the FILS IP Address Assigment
* IE during connection if we're configured to do automatic network
* configuration (usually DHCP). If we're configured with static
* values return false to mean the IE should not be sent.
*/
if (netconfig->static_config[0] && netconfig->static_config[1])
return false;
memset(info, 0, sizeof(*info));
info->ipv4 = !netconfig->static_config[INDEX_FOR_AF(AF_INET)];
info->ipv6 = !netconfig->static_config[INDEX_FOR_AF(AF_INET6)];
info->dns = (info->ipv4 &&
!netconfig->dns_overridden[INDEX_FOR_AF(AF_INET)]) ||
(info->ipv6 &&
!netconfig->dns_overridden[INDEX_FOR_AF(AF_INET)]);
return true;
}
void netconfig_handle_fils_ip_resp(struct netconfig *netconfig,
const struct ie_fils_ip_addr_response_info *info)
{
l_free(netconfig->fils_override);
netconfig->fils_override = l_memdup(info, sizeof(*info));
}
static void netconfig_event_handler(struct l_netconfig *nc, uint8_t family,
enum l_netconfig_event event,
void *user_data)
{
struct netconfig *netconfig = user_data;
/* Once stopped, only commit a final L_NETCONFIG_EVENT_UNCONFIGURE */
if (!netconfig->started && event != L_NETCONFIG_EVENT_UNCONFIGURE)
return;
l_debug("l_netconfig event %d", event);
netconfig_commit(netconfig, family, event);
switch (event) {
case L_NETCONFIG_EVENT_CONFIGURE:
case L_NETCONFIG_EVENT_UPDATE:
break;
case L_NETCONFIG_EVENT_UNCONFIGURE:
break;
case L_NETCONFIG_EVENT_FAILED:
netconfig->connected[INDEX_FOR_AF(family)] = false;
/*
* l_netconfig might have emitted an UNCONFIGURE before this
* but now it tells us it's given up on (re)establishing the
* IP setup.
*/
if (family == AF_INET && netconfig->notify)
netconfig->notify(NETCONFIG_EVENT_FAILED,
netconfig->user_data);
break;
default:
l_error("netconfig: Received unsupported l_netconfig event: %d",
event);
}
}
struct netconfig *netconfig_new(uint32_t ifindex)
{
struct netdev *netdev = netdev_find(ifindex);
struct netconfig *netconfig;
const char *debug_level = NULL;
int dhcp_priority = L_LOG_INFO;
struct l_dhcp6_client *dhcp6;
struct l_icmp6_client *icmp6;
struct l_dhcp_client *dhcp;
l_debug("Creating netconfig for interface: %d", ifindex);
netconfig = l_new(struct netconfig, 1);
netconfig->nc = l_netconfig_new(ifindex);
netconfig->netdev = netdev;
netconfig->resolve = resolve_new(ifindex);
netconfig_commit_init(netconfig);
debug_level = getenv("IWD_DHCP_DEBUG");
if (debug_level != NULL) {
if (!strcmp("debug", debug_level))
dhcp_priority = L_LOG_DEBUG;
else if (!strcmp("info", debug_level))
dhcp_priority = L_LOG_INFO;
else if (!strcmp("warn", debug_level))
dhcp_priority = L_LOG_WARNING;
else if (!strcmp("error", debug_level))
dhcp_priority = L_LOG_ERR;
else /* Default for backwards compatibility */
dhcp_priority = L_LOG_DEBUG;
}
l_netconfig_set_event_handler(netconfig->nc, netconfig_event_handler,
netconfig, NULL);
dhcp = l_netconfig_get_dhcp_client(netconfig->nc);
l_dhcp_client_set_max_attempts(dhcp, DHCP_ATTEMPTS);
dhcp6 = l_netconfig_get_dhcp6_client(netconfig->nc);
l_dhcp6_client_set_lla_randomized(dhcp6, true);
icmp6 = l_netconfig_get_icmp6_client(netconfig->nc);
l_icmp6_client_set_nodelay(icmp6, true);
if (debug_level) {
l_dhcp6_client_set_debug(dhcp6, do_debug, "[DHCPv6] ", NULL);
l_icmp6_client_set_debug(icmp6, do_debug, "[ICMPv6] ", NULL);
l_dhcp_client_set_debug(dhcp, do_debug, "[DHCPv4] ", NULL,
dhcp_priority);
}
return netconfig;
}
void netconfig_destroy(struct netconfig *netconfig)
{
l_debug("");
netconfig_reset(netconfig);
netconfig_commit_free(netconfig, "aborted");
resolve_free(netconfig->resolve);
netconfig_free(netconfig);
}
bool netconfig_enabled(void)
{
bool enabled;
return l_settings_get_bool(iwd_get_config(), "General",
"EnableNetworkConfiguration",
&enabled) && enabled;
}
static int netconfig_init(void)
{
if (!l_settings_get_uint(iwd_get_config(), "Network",
"RoutePriorityOffset",
&ROUTE_PRIORITY_OFFSET))
ROUTE_PRIORITY_OFFSET = 300;
if (!l_settings_get_bool(iwd_get_config(), "Network",
"EnableIPv6",
&ipv6_enabled))
ipv6_enabled = true;
mdns_global = l_settings_get_string(iwd_get_config(), "Network",
"MulticastDNS");
return 0;
}
static void netconfig_exit(void)
{
l_free(mdns_global);
}
IWD_MODULE(netconfig, netconfig_init, netconfig_exit)