/* 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; assert(ret); 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++; }; 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; assert(ret); 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; } } } typesafe_qsort(list, n_list, address_compare); *ret = TAKE_PTR(list); return (int) n_list; }