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authorEugene Yakubovich <eyakubovich@gmail.com>2014-06-27 15:00:06 -0700
committerTom Gundersen <teg@jklm.no>2014-06-29 15:18:21 +0200
commite1ea665edac17d75fce01b72dadfa3211b60df2c (patch)
tree9f1d4c8ae93862cf5ebae973cd48d053ef34c0dd /src/libsystemd-network/sd-dhcp-lease.c
parented942a9eb22d50f667909ad6184b45015d28d054 (diff)
Add support for DHCP static route options
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.
Diffstat (limited to 'src/libsystemd-network/sd-dhcp-lease.c')
-rw-r--r--src/libsystemd-network/sd-dhcp-lease.c149
1 files changed, 147 insertions, 2 deletions
diff --git a/src/libsystemd-network/sd-dhcp-lease.c b/src/libsystemd-network/sd-dhcp-lease.c
index 94ba283cf0..20a95f6de6 100644
--- a/src/libsystemd-network/sd-dhcp-lease.c
+++ b/src/libsystemd-network/sd-dhcp-lease.c
@@ -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;