nl-qdisc-add tool

Adds a cli based tool to add/update/replace qdiscs. This tool requires
each qdisc to be supported via a dynamic loadable module in
pkglibdir/cli/qdisc/$name.so.

So far HTB and blackhole have been implemented.

Syntax:
nl-qdisc-add --dev eth2 --parent root --id 1: htb --r2q=5
nl-qdisc-add --update-only --dev eth2 --id 1: htb --r2q=10

include/netlink/cli/qdisc.h

@@ -13,11 +13,24 @@
 #define __NETLINK_CLI_QDISC_H_
 
 #include <netlink/route/qdisc.h>
+#include <netlink/route/qdisc-modules.h>
 
 #define nl_cli_qdisc_alloc_cache(sk) \
 		nl_cli_alloc_cache((sk), "queueing disciplines", \
 				   rtnl_qdisc_alloc_cache)
 
+struct nl_cli_qdisc_module
+{
+	const char *		qm_name;
+	struct rtnl_qdisc_ops *	qm_ops;
+	void		      (*qm_parse_argv)(struct rtnl_qdisc *, int, char **);
+	struct nl_list_head	qm_list;
+};
+
+extern struct nl_cli_qdisc_module *nl_cli_qdisc_lookup(struct rtnl_qdisc_ops *);
+extern void nl_cli_qdisc_register(struct nl_cli_qdisc_module *);
+extern void nl_cli_qdisc_unregister(struct nl_cli_qdisc_module *);
+
 extern struct rtnl_qdisc *nl_cli_qdisc_alloc(void);
 
 extern void nl_cli_qdisc_parse_dev(struct rtnl_qdisc *, struct nl_cache *, char *);

include/netlink/cli/utils.h

@@ -73,6 +73,8 @@ extern int		nl_cli_confirm(struct nl_object *,
 extern struct nl_cache *nl_cli_alloc_cache(struct nl_sock *, const char *,
 			     int (*ac)(struct nl_sock *, struct nl_cache **));
 
+extern void		nl_cli_load_module(const char *, const char *);
+
 #ifdef __cplusplus
 }
 #endif

lib/Makefile.am

@@ -52,3 +52,13 @@ libnl_route_la_SOURCES = \
 	fib_lookup/lookup.c fib_lookup/request.c \
 	\
 	route/pktloc_syntax.c route/pktloc_grammar.c route/pktloc.c
+
+
+if ENABLE_CLI
+nobase_pkglib_LTLIBRARIES = \
+	cli/qdisc/htb.la \
+	cli/qdisc/blackhole.la
+
+cli_qdisc_htb_la_LDFLAGS = -module -version-info 0:0:0
+cli_qdisc_blackhole_la_LDFLAGS = -module -version-info 0:0:0
+endif

lib/cli/qdisc/blackhole.c

@@ -0,0 +1,63 @@
+/*
+ * src/lib/blackhole.c    Blackhole module for CLI lib
+ *
+ *	This library is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU Lesser General Public
+ *	License as published by the Free Software Foundation version 2.1
+ *	of the License.
+ *
+ * Copyright (c) 2010 Thomas Graf <tgraf@suug.ch>
+ */
+
+#include <netlink/cli/utils.h>
+#include <netlink/cli/qdisc.h>
+
+static void print_usage(void)
+{
+	printf(
+"Usage: nl-qdisc-add [...] blackhole [OPTIONS]...\n"
+"\n"
+"OPTIONS\n"
+"     --help                Show this help text.\n"
+"\n"
+"EXAMPLE"
+"    # Drop all outgoing packets on eth1\n"
+"    nl-qdisc-add --dev=eth1 --parent=root blackhole\n");
+}
+
+static void blackhole_parse_argv(struct rtnl_qdisc *qdisc, int argc, char **argv)
+{
+	for (;;) {
+		int c, optidx = 0;
+		static struct option long_opts[] = {
+			{ "help", 0, 0, 'h' },
+			{ 0, 0, 0, 0 }
+		};
+	
+		c = getopt_long(argc, argv, "h", long_opts, &optidx);
+		if (c == -1)
+			break;
+
+		switch (c) {
+		case 'h':
+			print_usage();
+			return;
+		}
+ 	}
+}
+
+static struct nl_cli_qdisc_module blackhole_module =
+{
+	.qm_name	= "blackhole",
+	.qm_parse_argv	= blackhole_parse_argv,
+};
+
+static void __init blackhole_init(void)
+{
+	nl_cli_qdisc_register(&blackhole_module);
+}
+
+static void __exit blackhole_exit(void)
+{
+	nl_cli_qdisc_unregister(&blackhole_module);
+}

lib/cli/qdisc/htb.c

@@ -0,0 +1,79 @@
+/*
+ * src/lib/htb.c     	HTB module for CLI lib
+ *
+ *	This library is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU Lesser General Public
+ *	License as published by the Free Software Foundation version 2.1
+ *	of the License.
+ *
+ * Copyright (c) 2010 Thomas Graf <tgraf@suug.ch>
+ */
+
+#include <netlink/cli/utils.h>
+#include <netlink/cli/qdisc.h>
+
+static void print_usage(void)
+{
+	printf(
+"Usage: nl-qdisc-add [...] htb [OPTIONS]...\n"
+"\n"
+"OPTIONS\n"
+"     --help                Show this help text.\n"
+"     --r2q=DIV             Rate to quantum divisor (default: 10)\n"
+"     --default=ID          Default class for unclassified traffic.\n"
+"\n"
+"EXAMPLE"
+"    # Create htb root qdisc 1: and direct unclassified traffic to class 1:10\n"
+"    nl-qdisc-add --dev=eth1 --parent=root --handle=1: htb --default=10\n");
+}
+
+static void htb_parse_argv(struct rtnl_qdisc *qdisc, int argc, char **argv)
+{
+	for (;;) {
+		int c, optidx = 0;
+		enum {
+			ARG_R2Q = 257,
+			ARG_DEFAULT = 258,
+		};
+		static struct option long_opts[] = {
+			{ "help", 0, 0, 'h' },
+			{ "r2q", 1, 0, ARG_R2Q },
+			{ "default", 1, 0, ARG_DEFAULT },
+			{ 0, 0, 0, 0 }
+		};
+	
+		c = getopt_long(argc, argv, "hv", long_opts, &optidx);
+		if (c == -1)
+			break;
+
+		switch (c) {
+		case 'h':
+			print_usage();
+			return;
+
+		case ARG_R2Q:
+			rtnl_htb_set_rate2quantum(qdisc, nl_cli_parse_u32(optarg));
+			break;
+
+		case ARG_DEFAULT:
+			rtnl_htb_set_defcls(qdisc, nl_cli_parse_u32(optarg));
+			break;
+		}
+ 	}
+}
+
+static struct nl_cli_qdisc_module htb_module =
+{
+	.qm_name	= "htb",
+	.qm_parse_argv	= htb_parse_argv,
+};
+
+static void __init htb_init(void)
+{
+	nl_cli_qdisc_register(&htb_module);
+}
+
+static void __exit htb_exit(void)
+{
+	nl_cli_qdisc_unregister(&htb_module);
+}

src/Makefile.am

@@ -5,6 +5,9 @@ SUBDIRS = lib
 AM_CPPFLAGS  = -Wall -I${top_srcdir}/include -I${top_builddir}/include -D_GNU_SOURCE
 AM_LDFLAGS = -L${top_builddir}/lib -L${top_builddir}/src/lib -lnl-cli
 
+sbin_PROGRAMS = \
+	nl-qdisc-add
+
 noinst_PROGRAMS = \
 	genl-ctrl-list \
 	nf-ct-list nf-log nf-queue nf-monitor \
@@ -66,6 +69,8 @@ nl_neigh_list_LDADD = -lnl-route
 nl_neightbl_list_SOURCES = nl-neightbl-list.c
 nl_neightbl_list_LDADD = -lnl-route
 
+nl_qdisc_add_SOURCES = nl-qdisc-add.c
+nl_qdisc_add_LDADD = -lnl-route
 nl_qdisc_delete_SOURCES = nl-qdisc-delete.c
 nl_qdisc_delete_LDADD = -lnl-route
 nl_qdisc_list_SOURCES = nl-qdisc-list.c

src/lib/qdisc.c

@@ -6,13 +6,12 @@
  *	License as published by the Free Software Foundation version 2.1
  *	of the License.
  *
- * Copyright (c) 2008-2009 Thomas Graf <tgraf@suug.ch>
+ * Copyright (c) 2008-2010 Thomas Graf <tgraf@suug.ch>
  */
 
 /**
  * @ingroup cli
  * @defgroup cli_qdisc Queueing Disciplines
- *
  * @{
  */
 
@@ -69,4 +68,58 @@ void nl_cli_qdisc_parse_kind(struct rtnl_qdisc *qdisc, char *arg)
 	rtnl_qdisc_set_kind(qdisc, arg);
 }
 
+static NL_LIST_HEAD(qdisc_modules);
+
+struct nl_cli_qdisc_module *__nl_cli_qdisc_lookup(struct rtnl_qdisc_ops *ops)
+{
+	struct nl_cli_qdisc_module *qm;
+
+	nl_list_for_each_entry(qm, &qdisc_modules, qm_list)
+		if (qm->qm_ops == ops)
+			return qm;
+
+	return NULL;
+}
+
+struct nl_cli_qdisc_module *nl_cli_qdisc_lookup(struct rtnl_qdisc_ops *ops)
+{
+	struct nl_cli_qdisc_module *qm;
+
+	if ((qm = __nl_cli_qdisc_lookup(ops)))
+		return qm;
+
+	nl_cli_load_module("cli/qdisc", ops->qo_kind);
+
+	if (!(qm = __nl_cli_qdisc_lookup(ops)))  {
+		nl_cli_fatal(EINVAL, "Application bug: The shared library for "
+			"the qdisc \"%s\" was successfully loaded but it "
+			"seems that module did not register itself");
+	}
+
+	return qm;
+}
+
+void nl_cli_qdisc_register(struct nl_cli_qdisc_module *qm)
+{
+	struct rtnl_qdisc_ops *ops;
+
+	if (!(ops = __rtnl_qdisc_lookup_ops(qm->qm_name))) {
+		nl_cli_fatal(ENOENT, "Unable to register CLI qdisc module "
+		"\"%s\": No matching libnl qdisc module found.", qm->qm_name);
+	}
+
+	if (__nl_cli_qdisc_lookup(ops)) {
+		nl_cli_fatal(EEXIST, "Unable to register CLI qdisc module "
+		"\"%s\": Module already registered.", qm->qm_name);
+	}
+
+	qm->qm_ops = ops;
+	nl_list_add_tail(&qm->qm_list, &qdisc_modules);
+}
+
+void nl_cli_qdisc_unregister(struct nl_cli_qdisc_module *qm)
+{
+	nl_list_del(&qm->qm_list);
+}
+
 /** @} */

src/lib/utils.c

@@ -13,10 +13,25 @@
  * @defgroup cli Command Line Interface API
  *
  * @{
+ *
+ * These modules provide an interface for text based applications. The
+ * functions provided are wrappers for their libnl equivalent with
+ * added error handling. The functions check for allocation failures,
+ * invalid input, and unknown types and will print error messages
+ * accordingly via nl_cli_fatal().
  */
 
 #include <netlink/cli/utils.h>
 
+/**
+ * Parse a text based 32 bit unsigned integer argument
+ * @arg arg		Integer in text form.
+ *
+ * Tries to convert the number provided in arg to a uint32_t. Will call
+ * nl_cli_fatal() if the conversion fails.
+ *
+ * @return 32bit unsigned integer.
+ */
 uint32_t nl_cli_parse_u32(const char *arg)
 {
 	unsigned long lval;
@@ -34,7 +49,7 @@ void nl_cli_print_version(void)
 {
 	printf("libnl tools version %s\n", LIBNL_VERSION);
 	printf(
-	"Copyright (C) 2003-2009 Thomas Graf <tgraf@redhat.com>\n"
+	"Copyright (C) 2003-2010 Thomas Graf <tgraf@redhat.com>\n"
 	"\n"
 	"This program comes with ABSOLUTELY NO WARRANTY. This is free \n"
 	"software, and you are welcome to redistribute it under certain\n"
@@ -44,6 +59,14 @@ void nl_cli_print_version(void)
 	exit(0);
 }
 
+/**
+ * Print error message and quit application
+ * @arg err		Error code.
+ * @arg fmt		Error message.
+ *
+ * Prints the formatted error message to stderr and quits the application
+ * using the provided error code.
+ */
 void nl_cli_fatal(int err, const char *fmt, ...)
 {
 	va_list ap;
@@ -144,4 +167,17 @@ struct nl_cache *nl_cli_alloc_cache(struct nl_sock *sock, const char *name,
 	return cache;
 }
 
+void nl_cli_load_module(const char *prefix, const char *name)
+{
+	char path[FILENAME_MAX+1];
+	void *handle;
+
+	snprintf(path, sizeof(path), "%s/%s/%s.so",
+		 PKGLIBDIR, prefix, name);
+
+	if (!(handle = dlopen(path, RTLD_NOW)))
+		nl_cli_fatal(ENOENT, "Unable to load module \"%s\": %s\n",
+			path, dlerror());
+}
+
 /** @} */

src/nl-qdisc-add.c

@@ -0,0 +1,136 @@
+/*
+ * src/nl-qdisc-add.c     Add Queueing Discipline
+ *
+ *	This library is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU Lesser General Public
+ *	License as published by the Free Software Foundation version 2.1
+ *	of the License.
+ *
+ * Copyright (c) 2010 Thomas Graf <tgraf@suug.ch>
+ */
+
+#include <netlink/cli/utils.h>
+#include <netlink/cli/qdisc.h>
+#include <netlink/cli/link.h>
+
+static int quiet = 0;
+
+static void print_usage(void)
+{
+	printf(
+"Usage: nl-qdisc-add [OPTIONS]... QDISC [CONFIGURATION]...\n"
+"\n"
+"OPTIONS\n"
+" -q, --quiet               Do not print informal notifications.\n"
+" -h, --help                Show this help text.\n"
+" -v, --version             Show versioning information.\n"
+"     --update              Update qdisc if it exists.\n"
+"     --replace             Replace or update qdisc if it exists.\n"
+"     --update-only         Only update qdisc, never create it.\n"
+"     --replace-only        Only replace or update qdisc, never create it.\n"
+" -d, --dev=DEV             Network device the qdisc should be attached to.\n"
+" -i, --id=ID               ID of new qdisc (default: auto-generated)r\n"
+" -p, --parent=ID           ID of parent { root | ingress | QDISC-ID }\n"
+"\n"
+"CONFIGURATION\n"
+" -h, --help                Show help text of qdisc specific options.\n"
+"\n"
+"EXAMPLE\n"
+"   $ nl-qdisc-add --dev=eth1 --parent=root htb --rate=100mbit\n"
+"\n"
+	);
+	exit(0);
+}
+
+int main(int argc, char *argv[])
+{
+	struct nl_sock *sock;
+	struct rtnl_qdisc *qdisc;
+	struct nl_cache *link_cache;
+	struct nl_dump_params dp = {
+		.dp_type = NL_DUMP_DETAILS,
+		.dp_fd = stdout,
+	};
+	struct nl_cli_qdisc_module *qm;
+	struct rtnl_qdisc_ops *ops;
+	int err, flags = NLM_F_CREATE | NLM_F_EXCL;
+	char *kind;
+ 
+	sock = nl_cli_alloc_socket();
+	nl_cli_connect(sock, NETLINK_ROUTE);
+
+	link_cache = nl_cli_link_alloc_cache(sock);
+
+ 	qdisc = nl_cli_qdisc_alloc();
+ 
+	for (;;) {
+		int c, optidx = 0;
+		enum {
+			ARG_REPLACE = 257,
+			ARG_UPDATE = 258,
+			ARG_REPLACE_ONLY,
+			ARG_UPDATE_ONLY,
+		};
+		static struct option long_opts[] = {
+			{ "quiet", 0, 0, 'q' },
+			{ "help", 0, 0, 'h' },
+			{ "version", 0, 0, 'v' },
+			{ "dev", 1, 0, 'd' },
+			{ "parent", 1, 0, 'p' },
+			{ "id", 1, 0, 'i' },
+			{ "replace", 0, 0, ARG_REPLACE },
+			{ "update", 0, 0, ARG_UPDATE },
+			{ "replace-only", 0, 0, ARG_REPLACE_ONLY },
+			{ "update-only", 0, 0, ARG_UPDATE_ONLY },
+			{ 0, 0, 0, 0 }
+		};
+	
+		c = getopt_long(argc, argv, "+qhvd:p:i:",
+				long_opts, &optidx);
+		if (c == -1)
+			break;
+
+		switch (c) {
+		case 'q': quiet = 1; break;
+		case 'h': print_usage(); break;
+		case 'v': nl_cli_print_version(); break;
+		case 'd': nl_cli_qdisc_parse_dev(qdisc, link_cache, optarg); break;
+		case 'p': nl_cli_qdisc_parse_parent(qdisc, optarg); break;
+		case 'i': nl_cli_qdisc_parse_handle(qdisc, optarg); break;
+		case ARG_UPDATE: flags = NLM_F_CREATE; break;
+		case ARG_REPLACE: flags = NLM_F_CREATE | NLM_F_REPLACE; break;
+		case ARG_UPDATE_ONLY: flags = 0; break;
+		case ARG_REPLACE_ONLY: flags = NLM_F_REPLACE; break;
+		}
+ 	}
+
+	if (optind >= argc)
+		print_usage();
+
+	if (!rtnl_qdisc_get_ifindex(qdisc))
+		nl_cli_fatal(EINVAL, "You must specify a network device (--dev=XXX)");
+
+	if (!rtnl_qdisc_get_parent(qdisc))
+		nl_cli_fatal(EINVAL, "You must specify a parent");
+
+	kind = argv[optind++];
+	rtnl_qdisc_set_kind(qdisc, kind);
+
+	if (!(ops = rtnl_qdisc_lookup_ops(qdisc)))
+		nl_cli_fatal(ENOENT, "Unknown qdisc \"%s\"", kind);
+
+	if (!(qm = nl_cli_qdisc_lookup(ops)))
+		nl_cli_fatal(ENOTSUP, "Qdisc type \"%s\" not supported.", kind);
+
+	qm->qm_parse_argv(qdisc, argc, argv);
+
+	if (!quiet) {
+		printf("Adding ");
+		nl_object_dump(OBJ_CAST(qdisc), &dp);
+ 	}
+
+	if ((err = rtnl_qdisc_add(sock, qdisc, flags)) < 0)
+		nl_cli_fatal(EINVAL, "Unable to add qdisc: %s", nl_geterror(err));
+
+	return 0;
+}