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network: assign new DHCP address before removing old lease address 

Closes #12676.
This commit is contained in:
Yu Watanabe 2019-06-07 15:31:07 +09:00
parent 3ab7ed3f12
commit d03073ddcd
3 changed files with 126 additions and 24 deletions
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145
src/network/networkd-dhcp4.c
View File

@ -13,6 +13,34 @@
#include "string-util.h"
#include "sysctl-util.h"
static int dhcp_remove_routes(Link *link, sd_dhcp_lease *lease, sd_dhcp_lease *new_lease, struct in_addr *address);
static int dhcp_remove_router(Link *link, sd_dhcp_lease *lease, struct in_addr *address);
static int dhcp_remove_address(Link *link, sd_dhcp_lease *lease, struct in_addr *address);
void dhcp4_release_old_lease(Link *link) {
union in_addr_union address = IN_ADDR_NULL, address_old = IN_ADDR_NULL;
assert(link);
if (!link->dhcp_lease_old)
return;
assert(link->dhcp_lease);
(void) sd_dhcp_lease_get_address(link->dhcp_lease_old, &address_old.in);
(void) sd_dhcp_lease_get_address(link->dhcp_lease, &address.in);
(void) dhcp_remove_routes(link, link->dhcp_lease_old, link->dhcp_lease, &address_old.in);
if (!in_addr_equal(AF_INET, &address_old, &address)) {
(void) dhcp_remove_router(link, link->dhcp_lease_old, &address_old.in);
(void) dhcp_remove_address(link, link->dhcp_lease_old, &address_old.in);
}
link->dhcp_lease_old = sd_dhcp_lease_unref(link->dhcp_lease_old);
link_dirty(link);
}
static int dhcp4_route_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *link) {
int r;
@ -33,6 +61,8 @@ static int dhcp4_route_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *li
if (link->dhcp4_messages == 0) {
link->dhcp4_configured = true;
/* New address and routes are configured now. Let's release old lease. */
dhcp4_release_old_lease(link);
link_check_ready(link);
}
@ -182,10 +212,32 @@ static int link_set_dhcp_routes(Link *link) {
return 0;
}
static int dhcp_remove_routes(Link *link, struct in_addr *address) {
_cleanup_free_ sd_dhcp_route **routes = NULL;
static bool route_present_in_routes(const Route *route, sd_dhcp_route **routes, unsigned n_routes) {
assert(n_routes == 0 || routes);
for (unsigned j = 0; j < n_routes; j++) {
union in_addr_union a;
unsigned char l;
assert_se(sd_dhcp_route_get_gateway(routes[j], &a.in) >= 0);
if (!in_addr_equal(AF_INET, &a, &route->gw))
continue;
assert_se(sd_dhcp_route_get_destination(routes[j], &a.in) >= 0);
if (!in_addr_equal(AF_INET, &a, &route->dst))
continue;
assert_se(sd_dhcp_route_get_destination_prefix_length(routes[j], &l) >= 0);
if (l != route->dst_prefixlen)
continue;
return true;
}
return false;
}
static int dhcp_remove_routes(Link *link, sd_dhcp_lease *lease, sd_dhcp_lease *new_lease, struct in_addr *address) {
_cleanup_free_ sd_dhcp_route **routes = NULL, **new_routes = NULL;
uint32_t table;
int n, i, r;
int m = 0, n, i, r;
assert(link);
assert(address);
@ -193,12 +245,19 @@ static int dhcp_remove_routes(Link *link, struct in_addr *address) {
if (!link->network->dhcp_use_routes)
return 0;
n = sd_dhcp_lease_get_routes(link->dhcp_lease, &routes);
if (IN_SET(n, 0, -ENODATA)) {
log_link_debug(link, "DHCP: No routes received from DHCP server: %m");
n = sd_dhcp_lease_get_routes(lease, &routes);
if (IN_SET(n, 0, -ENODATA))
return 0;
} else if (n < 0)
return log_link_error_errno(link, n, "DHCP error: could not get routes: %m");
else if (n < 0)
return log_link_error_errno(link, n, "DHCP error: Failed to get routes: %m");
if (new_lease) {
m = sd_dhcp_lease_get_routes(new_lease, &new_routes);
if (m == -ENODATA)
m = 0;
else if (m < 0)
return log_link_error_errno(link, m, "DHCP error: Failed to get routes: %m");
}
table = link_get_dhcp_route_table(link);
@ -217,13 +276,16 @@ static int dhcp_remove_routes(Link *link, struct in_addr *address) {
route->table = table;
route->scope = route_scope_from_address(route, address);
if (route_present_in_routes(route, new_routes, m))
continue;
(void) route_remove(route, link, NULL);
}
return n;
}
static int dhcp_remove_router(Link *link, struct in_addr *address) {
static int dhcp_remove_router(Link *link, sd_dhcp_lease *lease, struct in_addr *address) {
_cleanup_(route_freep) Route *route_gw = NULL, *route = NULL;
const struct in_addr *router;
uint32_t table;
@ -235,7 +297,7 @@ static int dhcp_remove_router(Link *link, struct in_addr *address) {
if (!link->network->dhcp_use_routes)
return 0;
r = sd_dhcp_lease_get_router(link->dhcp_lease, &router);
r = sd_dhcp_lease_get_router(lease, &router);
if (IN_SET(r, 0, -ENODATA)) {
log_link_debug(link, "DHCP: No gateway received from DHCP server.");
return 0;
@ -279,7 +341,7 @@ static int dhcp_remove_router(Link *link, struct in_addr *address) {
return 0;
}
static int dhcp_remove_address(Link *link, struct in_addr *address) {
static int dhcp_remove_address(Link *link, sd_dhcp_lease *lease, struct in_addr *address) {
_cleanup_(address_freep) Address *a = NULL;
struct in_addr netmask;
int r;
@ -297,7 +359,7 @@ static int dhcp_remove_address(Link *link, struct in_addr *address) {
a->family = AF_INET;
a->in_addr.in = *address;
if (sd_dhcp_lease_get_netmask(link->dhcp_lease, &netmask) >= 0)
if (sd_dhcp_lease_get_netmask(lease, &netmask) >= 0)
a->prefixlen = in4_addr_netmask_to_prefixlen(&netmask);
(void) address_remove(a, link, NULL);
@ -366,9 +428,9 @@ static int dhcp_lease_lost(Link *link) {
link->dhcp4_configured = false;
(void) sd_dhcp_lease_get_address(link->dhcp_lease, &address);
(void) dhcp_remove_routes(link, &address);
(void) dhcp_remove_router(link, &address);
(void) dhcp_remove_address(link, &address);
(void) dhcp_remove_routes(link, link->dhcp_lease, NULL, &address);
(void) dhcp_remove_router(link, link->dhcp_lease, &address);
(void) dhcp_remove_address(link, link->dhcp_lease, &address);
(void) dhcp_reset_mtu(link);
(void) dhcp_reset_hostname(link);
@ -406,6 +468,9 @@ static int dhcp4_address_handler(sd_netlink *rtnl, sd_netlink_message *m, Link *
if (link->dhcp4_messages == 0) {
link->dhcp4_configured = true;
/* The new address is configured, and no route is requested.
* Let's drop the old lease. */
dhcp4_release_old_lease(link);
link_check_ready(link);
}
@ -601,6 +666,37 @@ static int dhcp_lease_acquired(sd_dhcp_client *client, Link *link) {
return 0;
}
static int dhcp_lease_ip_change(sd_dhcp_client *client, Link *link) {
int r;
link->dhcp_lease_old = TAKE_PTR(link->dhcp_lease);
/* On ip address change, to keep the connectability, we would like to assign new address and
* routes, and then release old lease. There are two possible success paths:
*
* 1. new address and routes are configured.
* -> handled by dhcp_release_old_lease() in dhcp4_route_handler().
* 2. new address is configured and no route is requested.
* -> handled by dhcp_release_old_lease() in dhcp4_address_handler().
*
* On error in assigning new address and routes, then the link always enters to the failed
* state. And link_enter_failed() leads to the DHCP client to be stopped. So,
* dhcp_release_old_lease() will be also called by link_stop_clients().
*/
r = dhcp_lease_acquired(client, link);
if (r < 0) {
/* If it fails, then the new address is not configured yet.
* So, let's simply drop the old lease. */
sd_dhcp_lease_unref(link->dhcp_lease);
link->dhcp_lease = TAKE_PTR(link->dhcp_lease_old);
(void) dhcp_lease_lost(link);
return r;
}
return 0;
}
static int dhcp_server_is_black_listed(Link *link, sd_dhcp_client *client) {
sd_dhcp_lease *lease;
struct in_addr addr;
@ -671,8 +767,6 @@ static int dhcp4_handler(sd_dhcp_client *client, int event, void *userdata) {
break;
case SD_DHCP_CLIENT_EVENT_EXPIRED:
case SD_DHCP_CLIENT_EVENT_IP_CHANGE:
if (FLAGS_SET(link->network->keep_configuration, KEEP_CONFIGURATION_DHCP)) {
log_link_notice(link, "DHCPv4 connection considered critical, ignoring request to reconfigure it.");
return 0;
@ -686,12 +780,17 @@ static int dhcp4_handler(sd_dhcp_client *client, int event, void *userdata) {
}
}
if (event == SD_DHCP_CLIENT_EVENT_IP_CHANGE) {
r = dhcp_lease_acquired(client, link);
if (r < 0) {
link_enter_failed(link);
return r;
}
break;
case SD_DHCP_CLIENT_EVENT_IP_CHANGE:
if (FLAGS_SET(link->network->keep_configuration, KEEP_CONFIGURATION_DHCP)) {
log_link_notice(link, "DHCPv4 connection considered critical, ignoring request to reconfigure it.");
return 0;
}
r = dhcp_lease_ip_change(client, link);
if (r < 0) {
link_enter_failed(link);
return r;
}
break;

2
src/network/networkd-link.c
View File

@ -687,6 +687,8 @@ int link_stop_clients(Link *link, bool may_keep_dhcp) {
assert(link->manager);
assert(link->manager->event);
dhcp4_release_old_lease(link);
if (link->dhcp_client && (!may_keep_dhcp || !link->network ||
!FLAGS_SET(link->network->keep_configuration, KEEP_CONFIGURATION_DHCP_ON_STOP))) {
k = sd_dhcp_client_stop(link->dhcp_client);

3
src/network/networkd-link.h
View File

@ -78,7 +78,7 @@ typedef struct Link {
bool addresses_ready;
sd_dhcp_client *dhcp_client;
sd_dhcp_lease *dhcp_lease;
sd_dhcp_lease *dhcp_lease, *dhcp_lease_old;
char *lease_file;
uint32_t original_mtu;
unsigned dhcp4_messages;
@ -167,6 +167,7 @@ int link_set_mtu(Link *link, uint32_t mtu);
int ipv4ll_configure(Link *link);
bool link_ipv4ll_enabled(Link *link, AddressFamilyBoolean mask);
void dhcp4_release_old_lease(Link *link);
int dhcp4_configure(Link *link);
int dhcp4_set_client_identifier(Link *link);
int dhcp4_set_promote_secondaries(Link *link);