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Add support for DHCP static route options

Browse source 
This adds support for DHCP options 33 and 121: Static Route and
Classless Static Route. To enable this feature, set UseRoutes=true
in .network file. Returned routes are added to the routing table.
This commit is contained in:
Eugene Yakubovich 2014-06-27 15:00:06 -07:00 committed by Tom Gundersen
parent ed942a9eb2
commit e1ea665eda
12 changed files with 404 additions and 6 deletions
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7
man/systemd.network.xml
View file

@ -388,6 +388,13 @@
will be used as the transient hostname.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>UseRoutes=</varname></term>
<listitem>
<para>When true (the default), the static routes will be requested from the DHCP server
and added to the routing table with metric of 1024.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>CriticalConnection=</varname></term>
<listitem>

9
src/libsystemd-network/dhcp-lease-internal.h
View file

@ -32,6 +32,12 @@
#include "sd-dhcp-client.h"
struct sd_dhcp_route {
struct in_addr dst_addr;
struct in_addr gw_addr;
uint8_t dst_prefixlen;
};
struct sd_dhcp_lease {
RefCount n_ref;
@ -52,8 +58,9 @@ struct sd_dhcp_lease {
size_t ntp_size;
struct in_addr *policy_filter;
size_t policy_filter_size;
struct in_addr *static_route;
struct sd_dhcp_route *static_route;
size_t static_route_size;
size_t static_route_allocated;
uint16_t boot_file_size;
uint16_t mdr;
uint16_t mtu;

1
src/libsystemd-network/dhcp-protocol.h
View file

@ -132,5 +132,6 @@ enum {
DHCP_OPTION_RENEWAL_T1_TIME = 58,
DHCP_OPTION_REBINDING_T2_TIME = 59,
DHCP_OPTION_CLIENT_IDENTIFIER = 61,
DHCP_OPTION_CLASSLESS_STATIC_ROUTE = 121,
DHCP_OPTION_END = 255,
};

86
src/libsystemd-network/network-internal.c
View file

@ -28,6 +28,7 @@
#include "siphash24.h"
#include "libudev-private.h"
#include "network-internal.h"
#include "dhcp-lease-internal.h"
#include "log.h"
#include "utf8.h"
#include "util.h"
@ -432,3 +433,88 @@ int deserialize_in6_addrs(struct in6_addr **ret, size_t *ret_size, const char *s
return 0;
}
void serialize_dhcp_routes(FILE *f, const char *key, struct sd_dhcp_route *routes, size_t size) {
unsigned i;
assert(f);
assert(key);
assert(routes);
assert(size);
fprintf(f, "%s=", key);
for (i = 0; i < size; i++)
fprintf(f, "%s/%" PRIu8 ",%s%s", inet_ntoa(routes[i].dst_addr),
routes[i].dst_prefixlen, inet_ntoa(routes[i].gw_addr),
(i < (size - 1)) ? " ": "");
fputs("\n", f);
}
int deserialize_dhcp_routes(struct sd_dhcp_route **ret, size_t *ret_size, size_t *ret_allocated, const char *string) {
_cleanup_free_ struct sd_dhcp_route *routes = NULL;
size_t size = 0, allocated = 0;
char *word, *state;
size_t len;
assert(ret);
assert(ret_size);
assert(ret_allocated);
assert(string);
FOREACH_WORD(word, len, string, state) {
/* WORD FORMAT: dst_ip/dst_prefixlen,gw_ip */
_cleanup_free_ char* entry;
char *tok, *tok_end;
unsigned n;
int r;
if (!GREEDY_REALLOC(routes, allocated, size + 1))
return -ENOMEM;
entry = strndup(word, len);
tok = entry;
/* get the subnet */
tok_end = strchr(tok, '/');
if (!tok_end)
continue;
*tok_end = '\0';
r = inet_aton(tok, &routes[size].dst_addr);
if (r == 0)
continue;
tok = tok_end + 1;
/* get the prefixlen */
tok_end = strchr(tok, ',');
if (!tok_end)
continue;
*tok_end = '\0';
r = safe_atou(tok, &n);
if (r < 0 || n > 32)
continue;
routes[size].dst_prefixlen = (uint8_t) n;
tok = tok_end + 1;
/* get the gateway */
r = inet_aton(tok, &routes[size].gw_addr);
if (r == 0)
continue;
size++;
}
*ret_size = size;
*ret_allocated = allocated;
*ret = routes;
routes = NULL;
return 0;
}

7
src/libsystemd-network/network-internal.h
View file

@ -70,3 +70,10 @@ const char *net_get_name(struct udev_device *device);
void serialize_in_addrs(FILE *f, const char *key, struct in_addr *addresses, size_t size);
int deserialize_in_addrs(struct in_addr **addresses, size_t *size, const char *string);
int deserialize_in6_addrs(struct in6_addr **addresses, size_t *size, const char *string);
/* don't include "dhcp-lease-internal.h" as it causes conflicts between netinet/ip.h and linux/ip.h */
struct sd_dhcp_route;
void serialize_dhcp_routes(FILE *f, const char *key, struct sd_dhcp_route *routes, size_t size);
int deserialize_dhcp_routes(struct sd_dhcp_route **ret, size_t *ret_size, size_t *ret_allocated, const char *string);

149
src/libsystemd-network/sd-dhcp-lease.c
View file

@ -171,6 +171,22 @@ int sd_dhcp_lease_get_next_server(sd_dhcp_lease *lease, struct in_addr *addr) {
return 0;
}
int sd_dhcp_lease_get_routes(sd_dhcp_lease *lease, struct sd_dhcp_route **routes,
size_t *routes_size) {
assert_return(lease, -EINVAL);
assert_return(routes, -EINVAL);
assert_return(routes_size, -EINVAL);
if (lease->static_route_size) {
*routes = lease->static_route;
*routes_size = 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);
@ -184,6 +200,7 @@ sd_dhcp_lease *sd_dhcp_lease_unref(sd_dhcp_lease *lease) {
free(lease->domainname);
free(lease->dns);
free(lease->ntp);
free(lease->static_route);
free(lease);
}
@ -301,6 +318,111 @@ static int lease_parse_in_addrs_pairs(const uint8_t *option, size_t len, struct
return lease_parse_in_addrs_aux(option, len, ret, ret_size, 2);
}
static int class_prefixlen(uint8_t msb_octet, uint8_t *ret) {
if (msb_octet < 128)
/* Class A */
*ret = 8;
else if (msb_octet < 192)
/* Class B */
*ret = 16;
else if (msb_octet < 224)
/* Class C */
*ret = 24;
else
/* Class D or E -- no subnet mask */
return -ERANGE;
return 0;
}
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;
if (class_prefixlen(*option, &route->dst_prefixlen) < 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;
@ -367,7 +489,8 @@ int dhcp_lease_parse_options(uint8_t code, uint8_t len, const uint8_t *option,
break;
case DHCP_OPTION_STATIC_ROUTE:
r = lease_parse_in_addrs_pairs(option, len, &lease->static_route, &lease->static_route_size);
r = lease_parse_routes(option, len, &lease->static_route, &lease->static_route_size,
&lease->static_route_allocated);
if (r < 0)
return r;
@ -433,6 +556,14 @@ int dhcp_lease_parse_options(uint8_t code, uint8_t len, const uint8_t *option,
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;
@ -460,6 +591,8 @@ int dhcp_lease_save(sd_dhcp_lease *lease, const char *lease_file) {
size_t addresses_size;
const char *string;
uint16_t mtu;
struct sd_dhcp_route *routes;
size_t routes_size;
int r;
assert(lease);
@ -522,6 +655,10 @@ int dhcp_lease_save(sd_dhcp_lease *lease, const char *lease_file) {
if (r >= 0)
fprintf(f, "ROOT_PATH=%s\n", string);
r = sd_dhcp_lease_get_routes(lease, &routes, &routes_size);
if (r >= 0)
serialize_dhcp_routes(f, "ROUTES", routes, routes_size);
r = 0;
fflush(f);
@ -543,7 +680,7 @@ int dhcp_lease_load(const char *lease_file, sd_dhcp_lease **ret) {
_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;
*dns = NULL, *ntp = NULL, *mtu = NULL, *routes = NULL;
struct in_addr addr;
int r;
@ -566,6 +703,7 @@ int dhcp_lease_load(const char *lease_file, sd_dhcp_lease **ret) {
"DOMAINNAME", &lease->domainname,
"HOSTNAME", &lease->hostname,
"ROOT_PATH", &lease->root_path,
"ROUTES", &routes,
NULL);
if (r < 0) {
if (r == -ENOENT)
@ -629,6 +767,13 @@ int dhcp_lease_load(const char *lease_file, sd_dhcp_lease **ret) {
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;
}
*ret = lease;
lease = NULL;

85
src/network/networkd-link.c
View file

@ -402,6 +402,51 @@ static int route_handler(sd_rtnl *rtnl, sd_rtnl_message *m, void *userdata) {
return 1;
}
static int link_set_dhcp_routes(Link *link) {
struct sd_dhcp_route *static_routes;
size_t static_routes_size;
int r;
unsigned i;
assert(link);
r = sd_dhcp_lease_get_routes(link->dhcp_lease, &static_routes, &static_routes_size);
if (r < 0) {
if (r != -ENOENT)
log_warning_link(link, "DHCP error: %s", strerror(-r));
return r;
}
for (i = 0; i < static_routes_size; i++) {
_cleanup_route_free_ Route *route = NULL;
r = route_new_dynamic(&route);
if (r < 0) {
log_error_link(link, "Could not allocate route: %s",
strerror(-r));
return r;
}
route->family = AF_INET;
route->in_addr.in = static_routes[i].gw_addr;
route->dst_addr.in = static_routes[i].dst_addr;
route->dst_prefixlen = static_routes[i].dst_prefixlen;
route->metrics = DHCP_STATIC_ROUTE_METRIC;
r = route_configure(route, link, &route_handler);
if (r < 0) {
log_warning_link(link,
"could not set host route: %s", strerror(-r));
return r;
}
link_ref(link);
link->route_messages ++;
}
return 0;
}
static int link_enter_set_routes(Link *link) {
Route *rt;
int r;
@ -525,6 +570,9 @@ static int link_enter_set_routes(Link *link) {
link_ref(link);
link->route_messages ++;
}
if (link->network->dhcp_routes)
link_set_dhcp_routes(link);
}
if (link->route_messages == 0) {
@ -901,12 +949,11 @@ static int link_set_mtu(Link *link, uint32_t mtu) {
static int dhcp_lease_lost(Link *link) {
_cleanup_address_free_ Address *address = NULL;
_cleanup_route_free_ Route *route_gw = NULL;
_cleanup_route_free_ Route *route = NULL;
struct in_addr addr;
struct in_addr netmask;
struct in_addr gateway;
unsigned prefixlen;
unsigned i;
int r;
assert(link);
@ -914,10 +961,36 @@ static int dhcp_lease_lost(Link *link) {
log_warning_link(link, "DHCP lease lost");
if (link->network->dhcp_routes) {
struct sd_dhcp_route *routes;
size_t routes_size;
r = sd_dhcp_lease_get_routes(link->dhcp_lease, &routes, &routes_size);
if (r >= 0) {
for (i = 0; i < routes_size; i++) {
_cleanup_route_free_ Route *route = NULL;
r = route_new_dynamic(&route);
if (r >= 0) {
route->family = AF_INET;
route->in_addr.in = routes[i].gw_addr;
route->dst_addr.in = routes[i].dst_addr;
route->dst_prefixlen = routes[i].dst_prefixlen;
route_drop(route, link, &route_drop_handler);
link_ref(link);
}
}
}
}
r = address_new_dynamic(&address);
if (r >= 0) {
r = sd_dhcp_lease_get_router(link->dhcp_lease, &gateway);
if (r >= 0) {
_cleanup_route_free_ Route *route_gw = NULL;
_cleanup_route_free_ Route *route = NULL;
r = route_new_dynamic(&route_gw);
if (r >= 0) {
route_gw->family = AF_INET;
@ -1952,6 +2025,14 @@ static int link_configure(Link *link) {
if (r < 0)
return r;
}
if (link->network->dhcp_routes) {
r = sd_dhcp_client_set_request_option(link->dhcp_client, DHCP_OPTION_STATIC_ROUTE);
if (r < 0)
return r;
r = sd_dhcp_client_set_request_option(link->dhcp_client, DHCP_OPTION_CLASSLESS_STATIC_ROUTE);
if (r < 0)
return r;
}
}
if (link->network->dhcp_server) {

1
src/network/networkd-network-gperf.gperf
View file

@ -53,4 +53,5 @@ DHCPv4.UseDNS, config_parse_bool, 0,
DHCPv4.UseMTU, config_parse_bool, 0, offsetof(Network, dhcp_mtu)
DHCPv4.UseHostname, config_parse_bool, 0, offsetof(Network, dhcp_hostname)
DHCPv4.UseDomainName, config_parse_bool, 0, offsetof(Network, dhcp_domainname)
DHCPv4.UseRoutes, config_parse_bool, 0, offsetof(Network, dhcp_routes)
DHCPv4.CriticalConnection, config_parse_bool, 0, offsetof(Network, dhcp_critical)

1
src/network/networkd-network.c
View file

@ -89,6 +89,7 @@ static int network_load_one(Manager *manager, const char *filename) {
network->dhcp_dns = true;
network->dhcp_hostname = true;
network->dhcp_domainname = true;
network->dhcp_routes = true;
r = config_parse(NULL, filename, file, "Match\0Network\0Address\0Route\0DHCPv4\0", config_item_perf_lookup,
(void*) network_network_gperf_lookup, false, false, network);

2
src/network/networkd.h
View file

@ -42,6 +42,7 @@
#define CACHE_INFO_INFINITY_LIFE_TIME 0xFFFFFFFFU
#define VXLAN_VID_MAX (1u << 24) - 1
#define DHCP_STATIC_ROUTE_METRIC 1024
typedef struct NetDev NetDev;
typedef struct Network Network;
@ -169,6 +170,7 @@ struct Network {
bool dhcp_hostname;
bool dhcp_domainname;
bool dhcp_critical;
bool dhcp_routes;
bool ipv4ll;
bool dhcp_server;

59
src/network/test-network.c
View file

@ -21,6 +21,7 @@
#include "networkd.h"
#include "network-internal.h"
#include "dhcp-lease-internal.h"
static void test_deserialize_in_addr(void) {
_cleanup_free_ struct in_addr *addresses = NULL;
@ -53,6 +54,63 @@ static void test_deserialize_in_addr(void) {
assert_se(!memcmp(&f, &addresses6[2], sizeof(struct in6_addr)));
}
static void test_deserialize_dhcp_routes(void) {
size_t size, allocated;
{
_cleanup_free_ struct sd_dhcp_route *routes = NULL;
assert_se(deserialize_dhcp_routes(&routes, &size, &allocated, "") >= 0);
assert_se(size == 0);
}
{
/* no errors */
_cleanup_free_ struct sd_dhcp_route *routes = NULL;
const char *routes_string = "192.168.0.0/16,192.168.0.1 10.1.2.0/24,10.1.2.1 0.0.0.0/0,10.0.1.1";
assert_se(deserialize_dhcp_routes(&routes, &size, &allocated, routes_string) >= 0);
assert_se(size == 3);
assert_se(routes[0].dst_addr.s_addr == inet_addr("192.168.0.0"));
assert_se(routes[0].gw_addr.s_addr == inet_addr("192.168.0.1"));
assert_se(routes[0].dst_prefixlen == 16);
assert_se(routes[1].dst_addr.s_addr == inet_addr("10.1.2.0"));
assert_se(routes[1].gw_addr.s_addr == inet_addr("10.1.2.1"));
assert_se(routes[1].dst_prefixlen == 24);
assert_se(routes[2].dst_addr.s_addr == inet_addr("0.0.0.0"));
assert_se(routes[2].gw_addr.s_addr == inet_addr("10.0.1.1"));
assert_se(routes[2].dst_prefixlen == 0);
}
{
/* error in second word */
_cleanup_free_ struct sd_dhcp_route *routes = NULL;
const char *routes_string = "192.168.0.0/16,192.168.0.1 10.1.2.0#24,10.1.2.1 0.0.0.0/0,10.0.1.1";
assert_se(deserialize_dhcp_routes(&routes, &size, &allocated, routes_string) >= 0);
assert_se(size == 2);
assert_se(routes[0].dst_addr.s_addr == inet_addr("192.168.0.0"));
assert_se(routes[0].gw_addr.s_addr == inet_addr("192.168.0.1"));
assert_se(routes[0].dst_prefixlen == 16);
assert_se(routes[2].dst_addr.s_addr == inet_addr("0.0.0.0"));
assert_se(routes[2].gw_addr.s_addr == inet_addr("10.0.1.1"));
assert_se(routes[2].dst_prefixlen == 0);
}
{
/* error in every word */
_cleanup_free_ struct sd_dhcp_route *routes = NULL;
const char *routes_string = "192.168.0.0/55,192.168.0.1 10.1.2.0#24,10.1.2.1 0.0.0.0/0,10.0.1.X";
assert_se(deserialize_dhcp_routes(&routes, &size, &allocated, routes_string) >= 0);
assert_se(size == 0);
}
}
static void test_load_config(Manager *manager) {
/* TODO: should_reload, is false if the config dirs do not exist, so
* so we can't do this test here, move it to a test for paths_check_timestamps
@ -125,6 +183,7 @@ int main(void) {
struct udev_device *loopback;
test_deserialize_in_addr();
test_deserialize_dhcp_routes();
test_address_equality();
assert_se(manager_new(&manager) >= 0);

3
src/systemd/sd-dhcp-lease.h
View file

@ -27,6 +27,7 @@
#include <net/ethernet.h>
typedef struct sd_dhcp_lease sd_dhcp_lease;
struct sd_dhcp_route;
sd_dhcp_lease *sd_dhcp_lease_ref(sd_dhcp_lease *lease);
sd_dhcp_lease *sd_dhcp_lease_unref(sd_dhcp_lease *lease);
@ -42,5 +43,5 @@ int sd_dhcp_lease_get_mtu(sd_dhcp_lease *lease, uint16_t *mtu);
int sd_dhcp_lease_get_domainname(sd_dhcp_lease *lease, const char **domainname);
int sd_dhcp_lease_get_hostname(sd_dhcp_lease *lease, const char **hostname);
int sd_dhcp_lease_get_root_path(sd_dhcp_lease *lease, const char **root_path);
int sd_dhcp_lease_get_routes(sd_dhcp_lease *lease, struct sd_dhcp_route **routes, size_t *routes_size);
#endif