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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/resolve.c
Denis Kenzior b96bbb35e0 resolve: Add "none" method
There may be situations where DNS information should not be set (for
example in auto-tests where the resolver daemon is not running) or if a
user wishes to ignore DNS information obtained.
2022-05-20 10:03:42 -05:00

652 lines
15 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 <sys/stat.h>
#include <stdio.h>
#include <unistd.h>
#include <ell/ell.h>
#include "src/iwd.h"
#include "src/module.h"
#include "src/dbus.h"
#include "src/netconfig.h"
#include "src/resolve.h"
struct resolve_ops {
void (*set_dns)(struct resolve *resolve, char **dns_list);
void (*set_domains)(struct resolve *resolve, char **domain_list);
void (*set_mdns)(struct resolve *resolve, const char *mdns);
void (*revert)(struct resolve *resolve);
void (*destroy)(struct resolve *resolve);
};
struct resolve {
const struct resolve_ops *ops;
uint32_t ifindex;
};
static inline void _resolve_init(struct resolve *resolve, uint32_t ifindex,
const struct resolve_ops *ops)
{
resolve->ifindex = ifindex;
resolve->ops = ops;
}
void resolve_set_dns(struct resolve *resolve, char **dns_list)
{
if (!dns_list || !*dns_list)
return;
if (!resolve->ops->set_dns)
return;
resolve->ops->set_dns(resolve, dns_list);
}
void resolve_set_domains(struct resolve *resolve, char **domain_list)
{
if (!domain_list)
return;
if (!resolve->ops->set_domains)
return;
resolve->ops->set_domains(resolve, domain_list);
}
void resolve_set_mdns(struct resolve *resolve, const char *mdns)
{
if (!mdns)
return;
if (!resolve->ops->set_mdns)
return;
resolve->ops->set_mdns(resolve, mdns);
}
void resolve_revert(struct resolve *resolve)
{
if (!resolve->ops->revert)
return;
resolve->ops->revert(resolve);
}
void resolve_free(struct resolve *resolve)
{
resolve->ops->destroy(resolve);
}
struct resolve_method_ops {
int (*init)(void);
void (*exit)(void);
struct resolve *(*alloc)(uint32_t ifindex);
};
#define SYSTEMD_RESOLVED_SERVICE "org.freedesktop.resolve1"
#define SYSTEMD_RESOLVED_MANAGER_PATH "/org/freedesktop/resolve1"
#define SYSTEMD_RESOLVED_MANAGER_INTERFACE "org.freedesktop.resolve1.Manager"
struct systemd_method_state {
uint32_t service_watch;
bool is_ready:1;
};
struct systemd_method_state systemd_state;
struct systemd {
struct resolve super;
};
static void systemd_link_generic_reply(struct l_dbus_message *message,
void *user_data)
{
const char *type = user_data;
const char *name;
const char *text;
if (!l_dbus_message_get_error(message, &name, &text))
return;
l_error("resolve-systemd: Failed to modify the %s entries. %s: %s",
type, name, text);
}
static bool systemd_builder_add_dns(struct l_dbus_message_builder *builder,
const char *dns)
{
uint8_t buf[16];
uint8_t buf_size;
uint8_t i;
int t;
l_debug("installing DNS: %s", dns);
if (inet_pton(AF_INET, dns, buf) == 1) {
t = AF_INET;
buf_size = 4;
} else if (inet_pton(AF_INET6, dns, buf) == 1) {
t = AF_INET6;
buf_size = 16;
} else
return false;
l_dbus_message_builder_append_basic(builder, 'i', &t);
l_dbus_message_builder_enter_array(builder, "y");
for (i = 0; i < buf_size; i++)
l_dbus_message_builder_append_basic(builder, 'y', &buf[i]);
l_dbus_message_builder_leave_array(builder);
return true;
}
static void resolve_systemd_set_dns(struct resolve *resolve, char **dns_list)
{
struct l_dbus_message_builder *builder;
struct l_dbus_message *message;
l_debug("ifindex: %u", resolve->ifindex);
if (L_WARN_ON(!systemd_state.is_ready))
return;
message = l_dbus_message_new_method_call(dbus_get_bus(),
SYSTEMD_RESOLVED_SERVICE,
SYSTEMD_RESOLVED_MANAGER_PATH,
SYSTEMD_RESOLVED_MANAGER_INTERFACE,
"SetLinkDNS");
if (!message)
return;
builder = l_dbus_message_builder_new(message);
if (!builder) {
l_dbus_message_unref(message);
return;
}
l_dbus_message_builder_append_basic(builder, 'i', &resolve->ifindex);
l_dbus_message_builder_enter_array(builder, "(iay)");
for (; *dns_list; dns_list++) {
l_dbus_message_builder_enter_struct(builder, "iay");
if (systemd_builder_add_dns(builder, *dns_list)) {
l_dbus_message_builder_leave_struct(builder);
continue;
}
l_dbus_message_builder_destroy(builder);
l_dbus_message_unref(message);
return;
}
l_dbus_message_builder_leave_array(builder);
l_dbus_message_builder_finalize(builder);
l_dbus_message_builder_destroy(builder);
l_dbus_send_with_reply(dbus_get_bus(), message,
systemd_link_generic_reply, "DNS", NULL);
}
static void resolve_systemd_set_domains(struct resolve *resolve,
char **domain_list)
{
struct l_dbus_message *message;
struct l_dbus_message_builder *builder;
bool f = false;
l_debug("ifindex: %u", resolve->ifindex);
if (L_WARN_ON(!systemd_state.is_ready))
return;
message = l_dbus_message_new_method_call(dbus_get_bus(),
SYSTEMD_RESOLVED_SERVICE,
SYSTEMD_RESOLVED_MANAGER_PATH,
SYSTEMD_RESOLVED_MANAGER_INTERFACE,
"SetLinkDomains");
if (!message)
return;
builder = l_dbus_message_builder_new(message);
if (!builder) {
l_dbus_message_unref(message);
return;
}
l_dbus_message_builder_append_basic(builder, 'i', &resolve->ifindex);
l_dbus_message_builder_enter_array(builder, "(sb)");
for (; *domain_list; domain_list++) {
l_dbus_message_builder_enter_struct(builder, "sb");
l_dbus_message_builder_append_basic(builder, 's', *domain_list);
l_dbus_message_builder_append_basic(builder, 'b', &f);
l_dbus_message_builder_leave_struct(builder);
}
l_dbus_message_builder_leave_array(builder);
l_dbus_message_builder_finalize(builder);
l_dbus_message_builder_destroy(builder);
l_dbus_send_with_reply(dbus_get_bus(), message,
systemd_link_generic_reply, "domains", NULL);
}
static void resolve_systemd_set_mdns(struct resolve *resolve, const char *mdns)
{
struct l_dbus_message *message;
l_debug("ifindex: %u", resolve->ifindex);
if (L_WARN_ON(!systemd_state.is_ready))
return;
message = l_dbus_message_new_method_call(dbus_get_bus(),
SYSTEMD_RESOLVED_SERVICE,
SYSTEMD_RESOLVED_MANAGER_PATH,
SYSTEMD_RESOLVED_MANAGER_INTERFACE,
"SetLinkMulticastDNS");
if (!message)
return;
l_dbus_message_set_arguments(message, "is", resolve->ifindex, mdns);
l_dbus_send_with_reply(dbus_get_bus(), message,
systemd_link_generic_reply,
"MulticastDNS", NULL);
}
static void resolve_systemd_revert(struct resolve *resolve)
{
struct l_dbus_message *message;
l_debug("ifindex: %u", resolve->ifindex);
if (L_WARN_ON(!systemd_state.is_ready))
return;
message = l_dbus_message_new_method_call(dbus_get_bus(),
SYSTEMD_RESOLVED_SERVICE,
SYSTEMD_RESOLVED_MANAGER_PATH,
SYSTEMD_RESOLVED_MANAGER_INTERFACE,
"RevertLink");
if (!message)
return;
l_dbus_message_set_arguments(message, "i", resolve->ifindex);
l_dbus_send_with_reply(dbus_get_bus(), message,
systemd_link_generic_reply, "DNS", NULL);
}
static void resolve_systemd_destroy(struct resolve *resolve)
{
struct systemd *sd = l_container_of(resolve, struct systemd, super);
l_free(sd);
}
static const struct resolve_ops systemd_ops = {
.set_dns = resolve_systemd_set_dns,
.set_domains = resolve_systemd_set_domains,
.set_mdns = resolve_systemd_set_mdns,
.revert = resolve_systemd_revert,
.destroy = resolve_systemd_destroy,
};
static void systemd_appeared(struct l_dbus *dbus, void *user_data)
{
systemd_state.is_ready = true;
}
static void systemd_disappeared(struct l_dbus *dbus, void *user_data)
{
systemd_state.is_ready = false;
}
static int resolve_systemd_init(void)
{
systemd_state.service_watch =
l_dbus_add_service_watch(dbus_get_bus(),
SYSTEMD_RESOLVED_SERVICE,
systemd_appeared,
systemd_disappeared,
NULL, NULL);
return 0;
}
static void resolve_systemd_exit(void)
{
l_dbus_remove_watch(dbus_get_bus(), systemd_state.service_watch);
memset(&systemd_state, 0, sizeof(systemd_state));
}
static struct resolve *resolve_systemd_alloc(uint32_t ifindex)
{
struct systemd *sd = l_new(struct systemd, 1);
_resolve_init(&sd->super, ifindex, &systemd_ops);
return &sd->super;
}
static const struct resolve_method_ops resolve_method_systemd_ops = {
.init = resolve_systemd_init,
.exit = resolve_systemd_exit,
.alloc = resolve_systemd_alloc,
};
char *resolvconf_path;
static bool resolvconf_invoke(const char *ifname, const char *type,
const char *content)
{
FILE *resolvconf;
L_AUTO_FREE_VAR(char *, cmd) = NULL;
int error;
if (content) {
cmd = l_strdup_printf("%s -a %s.%s", resolvconf_path,
ifname, type);
resolvconf = popen(cmd, "w");
} else {
cmd = l_strdup_printf("%s -d %s.%s", resolvconf_path,
ifname, type);
resolvconf = popen(cmd, "r");
}
if (!resolvconf) {
l_error("resolve: Failed to start %s (%s).", resolvconf_path,
strerror(errno));
return false;
}
if (content && fprintf(resolvconf, "%s", content) < 0)
l_error("resolve: Failed to print into %s stdin.",
resolvconf_path);
error = pclose(resolvconf);
if (error < 0)
l_error("resolve: Failed to close pipe to %s (%s).",
resolvconf_path, strerror(errno));
else if (error > 0)
l_info("resolve: %s exited with status (%d).", resolvconf_path,
error);
return !error;
}
struct resolvconf {
struct resolve super;
bool have_domain : 1;
bool have_dns : 1;
char *ifname;
};
static void resolve_resolvconf_set_dns(struct resolve *resolve, char **dns_list)
{
struct resolvconf *rc =
l_container_of(resolve, struct resolvconf, super);
struct l_string *content;
L_AUTO_FREE_VAR(char *, str) = NULL;
if (L_WARN_ON(!resolvconf_path))
return;
if (!dns_list || !dns_list[0]) {
if (rc->have_dns)
resolvconf_invoke(rc->ifname, "dns", NULL);
rc->have_dns = false;
return;
}
content = l_string_new(0);
for (; *dns_list; dns_list++)
l_string_append_printf(content, "nameserver %s\n", *dns_list);
str = l_string_unwrap(content);
if (resolvconf_invoke(rc->ifname, "dns", str))
rc->have_dns = true;
}
static void resolve_resolvconf_set_domains(struct resolve *resolve,
char **domain_list)
{
struct resolvconf *rc =
l_container_of(resolve, struct resolvconf, super);
struct l_string *content;
L_AUTO_FREE_VAR(char *, str) = NULL;
if (L_WARN_ON(!resolvconf_path))
return;
if (!domain_list || !domain_list[0]) {
if (rc->have_domain)
resolvconf_invoke(rc->ifname, "domain", NULL);
rc->have_domain = false;
return;
}
content = l_string_new(0);
for (; *domain_list; domain_list++)
l_string_append_printf(content, "search %s\n", *domain_list);
str = l_string_unwrap(content);
if (resolvconf_invoke(rc->ifname, "domain", str))
rc->have_domain = true;
}
static void resolve_resolvconf_revert(struct resolve *resolve)
{
struct resolvconf *rc =
l_container_of(resolve, struct resolvconf, super);
if (rc->have_dns)
resolvconf_invoke(rc->ifname, "dns", NULL);
if (rc->have_domain)
resolvconf_invoke(rc->ifname, "domain", NULL);
rc->have_dns = false;
rc->have_domain = false;
}
static void resolve_resolvconf_destroy(struct resolve *resolve)
{
struct resolvconf *rc =
l_container_of(resolve, struct resolvconf, super);
l_free(rc->ifname);
l_free(rc);
}
static struct resolve_ops resolvconf_ops = {
.set_dns = resolve_resolvconf_set_dns,
.set_domains = resolve_resolvconf_set_domains,
.revert = resolve_resolvconf_revert,
.destroy = resolve_resolvconf_destroy,
};
static int resolve_resolvconf_init(void)
{
static const char *default_path = "/sbin:/usr/sbin";
const char *path;
l_debug("Trying to find resolvconf in $PATH");
path = getenv("PATH");
if (path)
resolvconf_path = l_path_find("resolvconf", path, X_OK);
if (!resolvconf_path) {
l_debug("Trying to find resolvconf in default paths");
resolvconf_path = l_path_find("resolvconf", default_path, X_OK);
}
if (!resolvconf_path) {
l_error("No usable resolvconf found on system");
return -ENOENT;
}
l_debug("resolvconf found as: %s", resolvconf_path);
return 0;
}
static void resolve_resolvconf_exit(void)
{
l_free(resolvconf_path);
resolvconf_path = NULL;
}
static struct resolve *resolve_resolvconf_alloc(uint32_t ifindex)
{
struct resolvconf *rc = l_new(struct resolvconf, 1);
_resolve_init(&rc->super, ifindex, &resolvconf_ops);
rc->ifname = l_net_get_name(ifindex);
if (!rc->ifname)
rc->ifname = l_strdup_printf("%u", ifindex);
return &rc->super;
}
static const struct resolve_method_ops resolve_method_resolvconf_ops = {
.init = resolve_resolvconf_init,
.exit = resolve_resolvconf_exit,
.alloc = resolve_resolvconf_alloc,
};
static void resolve_none_destroy(struct resolve *resolve)
{
l_free(resolve);
}
static struct resolve_ops none_ops = {
.destroy = resolve_none_destroy,
};
static int resolve_none_init(void)
{
return 0;
}
static void resolve_none_exit(void)
{
}
static struct resolve *resolve_none_alloc(uint32_t ifindex)
{
struct resolve *r = l_new(struct resolve, 1);
_resolve_init(r, ifindex, &none_ops);
return r;
}
static const struct resolve_method_ops resolve_method_none_ops = {
.init = resolve_none_init,
.exit = resolve_none_exit,
.alloc = resolve_none_alloc,
};
static const struct resolve_method_ops *configured_method;
struct resolve *resolve_new(uint32_t ifindex)
{
if (L_WARN_ON(!configured_method))
return NULL;
return configured_method->alloc(ifindex);
}
static const struct {
const char *name;
const struct resolve_method_ops *method_ops;
} resolve_method_ops_list[] = {
{ "systemd", &resolve_method_systemd_ops },
{ "resolvconf", &resolve_method_resolvconf_ops },
{ "none", &resolve_method_none_ops },
{ }
};
static int resolve_init(void)
{
const char *method_name;
uint8_t i;
if (!netconfig_enabled())
return 0;
method_name = l_settings_get_value(iwd_get_config(), "Network",
"NameResolvingService");
if (!method_name)
method_name = "systemd";
for (i = 0; resolve_method_ops_list[i].name; i++) {
if (strcmp(resolve_method_ops_list[i].name, method_name))
continue;
configured_method = resolve_method_ops_list[i].method_ops;
break;
}
if (!configured_method) {
l_error("Unknown resolution method: %s", method_name);
return -EINVAL;
}
return configured_method->init();
}
static void resolve_exit(void)
{
if (!configured_method)
return;
configured_method->exit();
configured_method = NULL;
}
IWD_MODULE(resolve, resolve_init, resolve_exit)