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-rw-r--r--src/shared/local-addresses.c315
1 files changed, 315 insertions, 0 deletions
diff --git a/src/shared/local-addresses.c b/src/shared/local-addresses.c
new file mode 100644
index 0000000..2c860f7
--- /dev/null
+++ b/src/shared/local-addresses.c
@@ -0,0 +1,315 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "sd-netlink.h"
+
+#include "alloc-util.h"
+#include "local-addresses.h"
+#include "macro.h"
+#include "netlink-util.h"
+#include "sort-util.h"
+
+static int address_compare(const struct local_address *a, const struct local_address *b) {
+ int r;
+
+ /* Order lowest scope first, IPv4 before IPv6, lowest interface index first */
+
+ if (a->family == AF_INET && b->family == AF_INET6)
+ return -1;
+ if (a->family == AF_INET6 && b->family == AF_INET)
+ return 1;
+
+ r = CMP(a->scope, b->scope);
+ if (r != 0)
+ return r;
+
+ r = CMP(a->metric, b->metric);
+ if (r != 0)
+ return r;
+
+ r = CMP(a->ifindex, b->ifindex);
+ if (r != 0)
+ return r;
+
+ return memcmp(&a->address, &b->address, FAMILY_ADDRESS_SIZE(a->family));
+}
+
+int local_addresses(sd_netlink *context, int ifindex, int af, struct local_address **ret) {
+ _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL, *reply = NULL;
+ _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+ _cleanup_free_ struct local_address *list = NULL;
+ size_t n_list = 0, n_allocated = 0;
+ sd_netlink_message *m;
+ int r;
+
+ if (context)
+ rtnl = sd_netlink_ref(context);
+ else {
+ r = sd_netlink_open(&rtnl);
+ if (r < 0)
+ return r;
+ }
+
+ r = sd_rtnl_message_new_addr(rtnl, &req, RTM_GETADDR, 0, af);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_call(rtnl, req, 0, &reply);
+ if (r < 0)
+ return r;
+
+ for (m = reply; m; m = sd_netlink_message_next(m)) {
+ struct local_address *a;
+ unsigned char flags;
+ uint16_t type;
+ int ifi, family;
+
+ r = sd_netlink_message_get_errno(m);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_get_type(m, &type);
+ if (r < 0)
+ return r;
+ if (type != RTM_NEWADDR)
+ continue;
+
+ r = sd_rtnl_message_addr_get_ifindex(m, &ifi);
+ if (r < 0)
+ return r;
+ if (ifindex > 0 && ifi != ifindex)
+ continue;
+
+ r = sd_rtnl_message_addr_get_family(m, &family);
+ if (r < 0)
+ return r;
+ if (af != AF_UNSPEC && af != family)
+ continue;
+
+ r = sd_rtnl_message_addr_get_flags(m, &flags);
+ if (r < 0)
+ return r;
+ if (flags & IFA_F_DEPRECATED)
+ continue;
+
+ if (!GREEDY_REALLOC0(list, n_allocated, n_list+1))
+ return -ENOMEM;
+
+ a = list + n_list;
+
+ r = sd_rtnl_message_addr_get_scope(m, &a->scope);
+ if (r < 0)
+ return r;
+
+ if (ifindex == 0 && IN_SET(a->scope, RT_SCOPE_HOST, RT_SCOPE_NOWHERE))
+ continue;
+
+ switch (family) {
+
+ case AF_INET:
+ r = sd_netlink_message_read_in_addr(m, IFA_LOCAL, &a->address.in);
+ if (r < 0) {
+ r = sd_netlink_message_read_in_addr(m, IFA_ADDRESS, &a->address.in);
+ if (r < 0)
+ continue;
+ }
+ break;
+
+ case AF_INET6:
+ r = sd_netlink_message_read_in6_addr(m, IFA_LOCAL, &a->address.in6);
+ if (r < 0) {
+ r = sd_netlink_message_read_in6_addr(m, IFA_ADDRESS, &a->address.in6);
+ if (r < 0)
+ continue;
+ }
+ break;
+
+ default:
+ continue;
+ }
+
+ a->ifindex = ifi;
+ a->family = family;
+
+ n_list++;
+ };
+
+ if (ret) {
+ typesafe_qsort(list, n_list, address_compare);
+ *ret = TAKE_PTR(list);
+ }
+
+ return (int) n_list;
+}
+
+static int add_local_gateway(
+ struct local_address **list,
+ size_t *n_list,
+ size_t *n_allocated,
+ int af,
+ int ifindex,
+ uint32_t metric,
+ const RouteVia *via) {
+
+ assert(list);
+ assert(n_list);
+ assert(n_allocated);
+ assert(via);
+
+ if (af != AF_UNSPEC && af != via->family)
+ return 0;
+
+ if (!GREEDY_REALLOC(*list, *n_allocated, *n_list + 1))
+ return -ENOMEM;
+
+ (*list)[(*n_list)++] = (struct local_address) {
+ .ifindex = ifindex,
+ .metric = metric,
+ .family = via->family,
+ .address = via->address,
+ };
+
+ return 0;
+}
+
+int local_gateways(sd_netlink *context, int ifindex, int af, struct local_address **ret) {
+ _cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL, *reply = NULL;
+ _cleanup_(sd_netlink_unrefp) sd_netlink *rtnl = NULL;
+ _cleanup_free_ struct local_address *list = NULL;
+ size_t n_list = 0, n_allocated = 0;
+ int r;
+
+ if (context)
+ rtnl = sd_netlink_ref(context);
+ else {
+ r = sd_netlink_open(&rtnl);
+ if (r < 0)
+ return r;
+ }
+
+ r = sd_rtnl_message_new_route(rtnl, &req, RTM_GETROUTE, af, RTPROT_UNSPEC);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_request_dump(req, true);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_call(rtnl, req, 0, &reply);
+ if (r < 0)
+ return r;
+
+ for (sd_netlink_message *m = reply; m; m = sd_netlink_message_next(m)) {
+ _cleanup_ordered_set_free_free_ OrderedSet *multipath_routes = NULL;
+ _cleanup_free_ void *rta_multipath = NULL;
+ union in_addr_union gateway;
+ uint16_t type;
+ unsigned char dst_len, src_len, table;
+ uint32_t ifi, metric = 0;
+ size_t rta_len;
+ int family;
+ RouteVia via;
+
+ r = sd_netlink_message_get_errno(m);
+ if (r < 0)
+ return r;
+
+ r = sd_netlink_message_get_type(m, &type);
+ if (r < 0)
+ return r;
+ if (type != RTM_NEWROUTE)
+ continue;
+
+ /* We only care for default routes */
+ r = sd_rtnl_message_route_get_dst_prefixlen(m, &dst_len);
+ if (r < 0)
+ return r;
+ if (dst_len != 0)
+ continue;
+
+ r = sd_rtnl_message_route_get_src_prefixlen(m, &src_len);
+ if (r < 0)
+ return r;
+ if (src_len != 0)
+ continue;
+
+ r = sd_rtnl_message_route_get_table(m, &table);
+ if (r < 0)
+ return r;
+ if (table != RT_TABLE_MAIN)
+ continue;
+
+ r = sd_netlink_message_read_u32(m, RTA_PRIORITY, &metric);
+ if (r < 0 && r != -ENODATA)
+ return r;
+
+ r = sd_rtnl_message_route_get_family(m, &family);
+ if (r < 0)
+ return r;
+ if (!IN_SET(family, AF_INET, AF_INET6))
+ continue;
+
+ r = sd_netlink_message_read_u32(m, RTA_OIF, &ifi);
+ if (r < 0 && r != -ENODATA)
+ return r;
+ if (r >= 0) {
+ if (ifi <= 0)
+ return -EINVAL;
+ if (ifindex > 0 && (int) ifi != ifindex)
+ continue;
+
+ r = netlink_message_read_in_addr_union(m, RTA_GATEWAY, family, &gateway);
+ if (r < 0 && r != -ENODATA)
+ return r;
+ if (r >= 0) {
+ via.family = family;
+ via.address = gateway;
+ r = add_local_gateway(&list, &n_list, &n_allocated, af, ifi, metric, &via);
+ if (r < 0)
+ return r;
+
+ continue;
+ }
+
+ if (family != AF_INET)
+ continue;
+
+ r = sd_netlink_message_read(m, RTA_VIA, sizeof(via), &via);
+ if (r < 0 && r != -ENODATA)
+ return r;
+ if (r >= 0) {
+ r = add_local_gateway(&list, &n_list, &n_allocated, af, ifi, metric, &via);
+ if (r < 0)
+ return r;
+
+ continue;
+ }
+ }
+
+ r = sd_netlink_message_read_data(m, RTA_MULTIPATH, &rta_len, &rta_multipath);
+ if (r < 0 && r != -ENODATA)
+ return r;
+ if (r >= 0) {
+ MultipathRoute *mr;
+
+ r = rtattr_read_nexthop(rta_multipath, rta_len, family, &multipath_routes);
+ if (r < 0)
+ return r;
+
+ ORDERED_SET_FOREACH(mr, multipath_routes) {
+ if (ifindex > 0 && mr->ifindex != ifindex)
+ continue;
+
+ r = add_local_gateway(&list, &n_list, &n_allocated, af, ifi, metric, &mr->gateway);
+ if (r < 0)
+ return r;
+ }
+ }
+ }
+
+ if (ret) {
+ typesafe_qsort(list, n_list, address_compare);
+ *ret = TAKE_PTR(list);
+ }
+
+ return (int) n_list;
+}
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