kernel-netlink: Add --list option to XFRM interfaces utility

src/libcharon/plugins/kernel_netlink/xfrmi.c

@@ -103,6 +103,148 @@ static int add_xfrm_interface(char *name, uint32_t xfrm_id, uint32_t ifindex)
 	return status;
 }
 
+/**
+ * Parse attributes nested in IFLA_INFO_DATA
+ */
+static void parse_info_data(struct rtattr *rta, size_t rtasize, char *phys,
+							uint32_t *if_id)
+{
+	uint32_t ifindex;
+
+	while (RTA_OK(rta, rtasize))
+	{
+		switch (rta->rta_type)
+		{
+			case IFLA_XFRM_IF_ID:
+				if (RTA_PAYLOAD(rta) == sizeof(*if_id))
+				{
+					*if_id = *(uint32_t*)RTA_DATA(rta);
+				}
+				break;
+			case IFLA_XFRM_LINK:
+				if (RTA_PAYLOAD(rta) == sizeof(ifindex))
+				{
+					ifindex = *(uint32_t*)RTA_DATA(rta);
+					if_indextoname(ifindex, phys);
+				}
+				break;
+			default:
+				break;
+		}
+		rta = RTA_NEXT(rta, rtasize);
+	}
+}
+
+/**
+ * Parse attributes nested in IFLA_LINKINFO
+ */
+static void parse_linkinfo(struct rtattr *rta, size_t rtasize, char *phys,
+						   uint32_t *if_id)
+{
+	while (RTA_OK(rta, rtasize))
+	{
+		switch (rta->rta_type)
+		{
+			case IFLA_INFO_DATA:
+				parse_info_data(RTA_DATA(rta), RTA_PAYLOAD(rta), phys, if_id);
+				break;
+			default:
+				break;
+		}
+		rta = RTA_NEXT(rta, rtasize);
+	}
+}
+
+/**
+ * List all installed XFRM interfaces
+ */
+static int list_xfrm_interfaces()
+{
+	netlink_buf_t request;
+	struct nlmsghdr *hdr, *out, *current;
+	struct ifinfomsg *msg;
+	struct rtattr *linkinfo;
+	netlink_socket_t *socket;
+	size_t len;
+	int status = 0;
+
+	socket = netlink_socket_create(NETLINK_ROUTE, NULL, FALSE);
+	if (!socket)
+	{
+		return 1;
+	}
+
+	memset(&request, 0, sizeof(request));
+
+	hdr = &request.hdr;
+	hdr->nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
+	hdr->nlmsg_type = RTM_GETLINK;
+	hdr->nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg));
+
+	msg = NLMSG_DATA(hdr);
+	msg->ifi_family = AF_UNSPEC;
+
+	/* the following attributes are nested under this one */
+	linkinfo = netlink_reserve(hdr, sizeof(request), IFLA_LINKINFO, 0);
+	linkinfo = (void*)linkinfo - RTA_LENGTH(0);
+
+	netlink_add_attribute(hdr, IFLA_INFO_KIND, chunk_from_str("xfrm"),
+						  sizeof(request));
+
+	linkinfo->rta_len = NLMSG_TAIL(hdr) - (void*)linkinfo;
+
+	if (socket->send(socket, hdr, &out, &len) != SUCCESS)
+	{
+		return FAILED;
+	}
+	current = out;
+	while (NLMSG_OK(current, len))
+	{
+		switch (current->nlmsg_type)
+		{
+			case NLMSG_DONE:
+				break;
+			case RTM_NEWLINK:
+				msg = NLMSG_DATA(current);
+				struct rtattr *rta = IFLA_RTA(msg);
+				size_t rtasize = IFLA_PAYLOAD(current);
+				char *name = NULL, phys[IF_NAMESIZE] = {};
+				uint32_t if_id = 0;
+
+				while (RTA_OK(rta, rtasize))
+				{
+					switch (rta->rta_type)
+					{
+						case IFLA_IFNAME:
+							name = RTA_DATA(rta);
+							break;
+						case IFLA_LINKINFO:
+							parse_linkinfo(RTA_DATA(rta), RTA_PAYLOAD(rta),
+										   phys, &if_id);
+							break;
+						default:
+							break;
+					}
+					rta = RTA_NEXT(rta, rtasize);
+				}
+				if (name)
+				{
+					printf("%2u: %-16s dev %-8s if_id 0x%.8x [%u]\n",
+						   msg->ifi_index, name, phys, if_id, if_id);
+				}
+				/* fall through */
+			default:
+				current = NLMSG_NEXT(current, len);
+				continue;
+		}
+		break;
+	}
+	free(out);
+
+	socket->destroy(socket);
+	return status;
+}
+
 static void usage(FILE *out, char *name)
 {
 	fprintf(out, "Create XFRM interfaces\n\n");
@@ -110,6 +252,7 @@ static void usage(FILE *out, char *name)
 	fprintf(out, "Options:\n");
 	fprintf(out, "  -h, --help          print this help.\n");
 	fprintf(out, "  -v, --debug         set debug level, default: 1.\n");
+	fprintf(out, "  -l, --list          list XFRM interfaces.\n");
 	fprintf(out, "  -n, --name=NAME     name of the XFRM interface.\n");
 	fprintf(out, "  -i, --id=ID         optional numeric XFRM ID.\n");
 	fprintf(out, "  -d, --dev=DEVICE    underlying physical interface.\n");
@@ -122,23 +265,30 @@ int main(int argc, char *argv[])
 	uint32_t xfrm_id = 0;
 	u_int ifindex;
 
+	library_init(NULL, "xfrmi");
+	atexit(library_deinit);
+
 	while (true)
 	{
 		struct option long_opts[] = {
 			{"help",		no_argument,		NULL,	'h' },
 			{"debug",		no_argument,		NULL,	'v' },
+			{"list",		no_argument,		NULL,	'l' },
 			{"name",		required_argument,	NULL,	'n' },
 			{"id",			required_argument,	NULL,	'i' },
 			{"dev",			required_argument,	NULL,	'd' },
 			{0,0,0,0 },
 		};
-		switch (getopt_long(argc, argv, "hvn:i:d:", long_opts, NULL))
+		switch (getopt_long(argc, argv, "hvln:i:d:", long_opts, NULL))
 		{
 			case EOF:
 				break;
 			case 'h':
 				usage(stdout, argv[0]);
 				return 0;
+			case 'l':
+				list_xfrm_interfaces();
+				return 0;
 			case 'v':
 				dbg_default_set_level(atoi(optarg));
 				continue;
@@ -177,8 +327,5 @@ int main(int argc, char *argv[])
 		return 1;
 	}
 
-	library_init(NULL, "xfrmi");
-	atexit(library_deinit);
-
 	return add_xfrm_interface(name, xfrm_id, ifindex);
 }