classid database

A database to resolve qdisc/class names to classid values and vice versa.
The function rtnl_tc_handle2str() and rtnl_tc_str2handle() will resolve
names automatically.

A CLI based tool nl-classid-lookup is provided to integrate the database
into existing iproute2 scripts.

Makefile.am

@@ -8,12 +8,12 @@ if ENABLE_CLI
 OPT_DIRS += src
 endif
 
-SUBDIRS = include lib doc $(OPT_DIRS)
+SUBDIRS = include lib doc man $(OPT_DIRS)
 
 pkgconfig_DATA = libnl-2.1.pc
 
 sysconfdir = @sysconfdir@/libnl
-sysconf_DATA = etc/pktloc
+sysconf_DATA = etc/pktloc etc/classid
 
 .PHONY: cscope
 cscope:

configure.in

@@ -37,6 +37,6 @@ AM_CONDITIONAL([ENABLE_CLI], [test "$enable_cli" = "yes"])
 AC_CHECK_LIB([m], [pow], [], AC_MSG_ERROR([libm is required]))
 
 AC_CONFIG_FILES([Makefile doc/Doxyfile doc/Makefile lib/Makefile
-	include/Makefile src/Makefile src/lib/Makefile \
+	include/Makefile src/Makefile src/lib/Makefile man/Makefile
 	libnl-2.1.pc include/netlink/version.h])
 AC_OUTPUT

etc/classid

@@ -0,0 +1,36 @@
+###############################################################################
+#
+# ClassID <-> Name Translation Table
+#
+# This file can be used to assign names to classids for easier reference
+# in all libnl tools.
+#
+# Format:
+#   <MAJ:>		<NAME>		# qdisc definition
+#   <MAJ:MIN>		<NAME>		# class deifnition
+#   <NAME:MIN>		<NAME>		# class definition referencing an
+#					  existing qdisc definition.
+#
+# Example:
+#   1:			top		# top -> 1:0
+#   top:1		interactive	# interactive -> 1:1
+#   top:2		www		# www -> 1:2
+#   top:3		bulk		# bulk -> 1:3
+#   2:1			test_class	# test_class -> 2:1
+#
+# Illegal Example:
+#   30:1                classD
+#   classD:2            invalidClass    # classD refers to a class, not a qdisc
+#
+###############################################################################
+
+# <CLASSID>		<NAME>
+
+# Reserved default classids
+0:0			none
+ffff:ffff		root
+ffff:fff1		ingress
+
+#
+# List your classid definitions below:
+#

include/netlink-local.h

@@ -28,6 +28,7 @@
 #include <inttypes.h>
 #include <assert.h>
 #include <limits.h>
+#include <search.h>
 
 #include <arpa/inet.h>
 #include <netdb.h>

include/netlink/route/tc.h

@@ -53,6 +53,7 @@ extern int rtnl_tc_build_rate_table(uint32_t *, uint8_t, uint8_t, int, int);
 
 
 /* TC Handle Translations */
+extern int		rtnl_tc_read_classid_file(void);
 extern char *		rtnl_tc_handle2str(uint32_t, char *, size_t);
 extern int		rtnl_tc_str2handle(const char *, uint32_t *);
 

lib/Makefile.am

@@ -39,7 +39,7 @@ libnl_route_la_SOURCES = \
 	route/cls.c route/cls_api.c route/cls_obj.c route/link.c \
 	route/neigh.c route/neightbl.c route/nexthop.c route/qdisc.c \
 	route/qdisc_api.c route/qdisc_obj.c route/route.c route/route_obj.c \
-	route/route_utils.c route/rtnl.c route/rule.c route/tc.c \
+	route/route_utils.c route/rtnl.c route/rule.c route/tc.c route/classid.c \
 	\
 	route/cls/fw.c route/cls/police.c route/cls/u32.c \
 	\

lib/route/classid.c

@@ -0,0 +1,357 @@
+/*
+ * lib/route/classid.c       ClassID Management
+ *
+ *	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>
+ */
+
+/**
+ * @ingroup tc
+ * @defgroup classid ClassID Management
+ * @{
+ */
+
+#include <netlink-local.h>
+#include <netlink-tc.h>
+#include <netlink/netlink.h>
+#include <netlink/utils.h>
+#include <netlink/route/tc.h>
+
+struct classid_map
+{
+	uint32_t		classid;
+	char *			name;
+	struct nl_list_head	name_list;
+};
+
+#define CLASSID_NAME_HT_SIZ 256
+
+static struct nl_list_head tbl_name[CLASSID_NAME_HT_SIZ];
+
+static void *id_root = NULL;
+
+static int compare_id(const void *pa, const void *pb)
+{
+	const struct classid_map *ma = pa;
+	const struct classid_map *mb = pb;
+
+	if (ma->classid < mb->classid)
+		return -1;
+	
+	if (ma->classid > mb->classid)
+		return 1;
+
+	return 0;
+}
+
+/* djb2 */
+static unsigned int classid_tbl_hash(const char *str)
+{
+	unsigned long hash = 5381;
+	int c;
+
+	while ((c = *str++))
+		hash = ((hash << 5) + hash) + c; /* hash * 33 + c */
+
+	return hash % CLASSID_NAME_HT_SIZ;
+}
+
+static int classid_lookup(const char *name, uint32_t *result)
+{
+	struct classid_map *map;
+	int n = classid_tbl_hash(name);
+
+	nl_list_for_each_entry(map, &tbl_name[n], name_list) {
+		if (!strcasecmp(map->name, name)) {
+			*result = map->classid;
+			return 0;
+		}
+	}
+
+	return -NLE_OBJ_NOTFOUND;
+}
+
+/**
+ * @name Traffic Control Handle Translations
+ * @{
+ */
+
+/**
+ * Convert a traffic control handle to a character string (Reentrant).
+ * @arg handle		traffic control handle
+ * @arg buf		destination buffer
+ * @arg len		buffer length
+ *
+ * Converts a tarffic control handle to a character string in the
+ * form of \c MAJ:MIN and stores it in the specified destination buffer.
+ *
+ * @return The destination buffer or the type encoded in hexidecimal
+ *         form if no match was found.
+ */
+char * rtnl_tc_handle2str(uint32_t handle, char *buf, size_t len)
+{
+	if (TC_H_ROOT == handle)
+		snprintf(buf, len, "root");
+	else if (TC_H_UNSPEC == handle)
+		snprintf(buf, len, "none");
+	else if (TC_H_INGRESS == handle)
+		snprintf(buf, len, "ingress");
+	else {
+		void *res;
+		struct classid_map cm = {
+			.classid = handle,
+			.name = "search entry",
+		};
+
+		if ((res = tfind(&cm, &id_root, &compare_id)))
+			snprintf(buf, len, "%s", (*(struct classid_map **) res)->name);
+		else if (0 == TC_H_MAJ(handle))
+			snprintf(buf, len, ":%02x", TC_H_MIN(handle));
+		else if (0 == TC_H_MIN(handle))
+			snprintf(buf, len, "%02x:", TC_H_MAJ(handle) >> 16);
+		else
+			snprintf(buf, len, "%02x:%02x",
+				TC_H_MAJ(handle) >> 16, TC_H_MIN(handle));
+	}
+
+	return buf;
+}
+
+/**
+ * Convert a charactering strint to a traffic control handle
+ * @arg str		traffic control handle as character string
+ * @arg res		destination buffer
+ *
+ * Converts the provided character string specifying a traffic
+ * control handle to the corresponding numeric value.
+ *
+ * The handle must be provided in one of the following formats:
+ *  - NAME
+ *  - root
+ *  - none
+ *  - MAJ:
+ *  - :MIN
+ *  - NAME:MIN
+ *  - MAJ:MIN
+ *  - MAJMIN
+ *
+ * @return 0 on success or a negative error code
+ */
+int rtnl_tc_str2handle(const char *str, uint32_t *res)
+{
+	char *colon, *end;
+	uint32_t h, err;
+
+	if (!strcasecmp(str, "root")) {
+		*res = TC_H_ROOT;
+		return 0;
+	}
+
+	if (!strcasecmp(str, "none")) {
+		*res = TC_H_UNSPEC;
+		return 0;
+	}
+
+	h = strtoul(str, &colon, 16);
+
+	/* MAJ is not a number */
+	if (colon == str) {
+		if (*colon == ':') {
+			/* :YYYY */
+			h = 0;
+		} else {
+			size_t len;
+			char name[64] = { 0 };
+
+			if (!(colon = strpbrk(str, ":"))) {
+				/* NAME */
+				return classid_lookup(str, res);
+			} else {
+				/* NAME:YYYY */
+				len = colon - str;
+				if (len >= sizeof(name))
+					return -NLE_INVAL;
+
+				memcpy(name, str, len);
+
+				if ((err = classid_lookup(name, &h)) < 0)
+					return err;
+
+				/* Name must point to a qdisc alias */
+				if (TC_H_MIN(h))
+					return -NLE_INVAL;
+
+				/* NAME: is not allowed */
+				if (colon[1] == '\0')
+					return -NLE_INVAL;
+
+				goto update;
+			}
+		}
+	}
+
+	if (':' == *colon) {
+		/* check if we would lose bits */
+		if (TC_H_MAJ(h))
+			return -NLE_RANGE;
+		h <<= 16;
+
+		if ('\0' == colon[1]) {
+			/* XXXX: */
+			*res = h;
+		} else {
+			/* XXXX:YYYY */
+			uint32_t l;
+			
+update:
+			l = strtoul(colon+1, &end, 16);
+
+			/* check if we overlap with major part */
+			if (TC_H_MAJ(l))
+				return -NLE_RANGE;
+
+			if ('\0' != *end)
+				return -NLE_INVAL;
+
+			*res = (h | l);
+		}
+	} else if ('\0' == *colon) {
+		/* XXXXYYYY */
+		*res = h;
+	} else
+		return -NLE_INVAL;
+
+	return 0;
+}
+
+static void free_nothing(void *arg)
+{
+}
+
+static void clear_hashtable(void)
+{
+	int i;
+
+	for (i = 0; i < CLASSID_NAME_HT_SIZ; i++) {
+		struct classid_map *map, *n;
+
+		nl_list_for_each_entry_safe(map, n, &tbl_name[i], name_list) {
+			free(map->name);
+			free(map);
+		}
+
+		nl_init_list_head(&tbl_name[i]);
+
+	}
+
+	if (id_root) {
+		tdestroy(&id_root, &free_nothing);
+		id_root = NULL;
+	}
+}
+
+/**
+ * (Re-)read classid file
+ * 
+ * Rereads the contents of the classid file (typically found at the location
+ * /etc/libnl/classid) and refreshes the classid maps.
+ *
+ * @return 0 on success or a negative error code.
+ */
+int rtnl_tc_read_classid_file(void)
+{
+	static time_t last_read;
+	struct stat st = {0};
+	char buf[256], *path;
+	FILE *fd;
+	int err;
+
+	asprintf(&path, "%s/classid", SYSCONFDIR);
+
+	/* if stat fails, just (re-)read the file */
+	if (stat(path, &st) == 0) {
+		/* Don't re-read file if file is unchanged */
+		if (last_read == st.st_mtime) {
+			err = 0;
+			goto errout;
+		}
+	}
+
+	if (!(fd = fopen(path, "r"))) {
+		err = -nl_syserr2nlerr(errno);
+		goto errout;
+	}
+
+	clear_hashtable();
+
+	while (fgets(buf, sizeof(buf), fd)) {
+		struct classid_map *map;
+		uint32_t classid;
+		char *ptr, *tok;
+		int n;
+
+		/* ignore comments and empty lines */
+		if (*buf == '#' || *buf == '\n' || *buf == '\r')
+			continue;
+
+		/* token 1 */
+		if (!(tok = strtok_r(buf, " \t", &ptr))) {
+			err = -NLE_INVAL;
+			goto errout_close;
+		}
+
+		if ((err = rtnl_tc_str2handle(tok, &classid)) < 0)
+			goto errout_close;
+
+		if (!(tok = strtok_r(NULL, " \t\n\r#", &ptr))) {
+			err = -NLE_INVAL;
+			goto errout_close;
+		}
+
+		if (!(map = calloc(1, sizeof(*map)))) {
+			err = -NLE_NOMEM;
+			goto errout_close;
+		}
+
+		map->classid = classid;
+		map->name = strdup(tok);
+
+		n = classid_tbl_hash(map->name);
+		nl_list_add_tail(&map->name_list, &tbl_name[n]);
+
+		if (!tsearch((void *) map, &id_root, &compare_id)) {
+			err = -NLE_NOMEM;
+			goto errout_close;
+		}
+	}
+
+	err = 0;
+	last_read = st.st_mtime;
+
+errout_close:
+	fclose(fd);
+errout:
+	free(path);
+
+	return err;
+
+}
+
+/** @} */
+
+static void __init classid_init(void)
+{
+	int err, i;
+
+	for (i = 0; i < CLASSID_NAME_HT_SIZ; i++)
+		nl_init_list_head(&tbl_name[i]);
+
+	if ((err = rtnl_tc_read_classid_file()) < 0)
+		fprintf(stderr, "Failed to read classid file: %s\n", nl_geterror(err));
+}
+
+/** @} */

lib/route/tc.c

@@ -465,113 +465,5 @@ int rtnl_tc_build_rate_table(uint32_t *dst, uint8_t mpu, uint8_t overhead,
 
 /** @} */
 
-/**
- * @name Traffic Control Handle Translations
- * @{
- */
-
-/**
- * Convert a traffic control handle to a character string (Reentrant).
- * @arg handle		traffic control handle
- * @arg buf		destination buffer
- * @arg len		buffer length
- *
- * Converts a tarffic control handle to a character string in the
- * form of \c MAJ:MIN and stores it in the specified destination buffer.
- *
- * @return The destination buffer or the type encoded in hexidecimal
- *         form if no match was found.
- */
-char * rtnl_tc_handle2str(uint32_t handle, char *buf, size_t len)
-{
-	if (TC_H_ROOT == handle)
-		snprintf(buf, len, "root");
-	else if (TC_H_UNSPEC == handle)
-		snprintf(buf, len, "none");
-	else if (0 == TC_H_MAJ(handle))
-		snprintf(buf, len, ":%02x", TC_H_MIN(handle));
-	else if (0 == TC_H_MIN(handle))
-		snprintf(buf, len, "%02x:", TC_H_MAJ(handle) >> 16);
-	else
-		snprintf(buf, len, "%02x:%02x",
-			TC_H_MAJ(handle) >> 16, TC_H_MIN(handle));
-
-	return buf;
-}
-
-/**
- * Convert a charactering strint to a traffic control handle
- * @arg name		traffic control handle as character string
- * @arg res		destination buffer
- *
- * Converts the provided character string specifying a traffic
- * control handle to the corresponding numeric value.
- *
- * The handle must be provided in one of the following formats:
- *  - root
- *  - none
- *  - XXXX:
- *  - :YYYY
- *  - XXXX:YYYY
- *  - XXXXYYYY
- *
- * @return 0 on success or a negative error code
- */
-int rtnl_tc_str2handle(const char *name, uint32_t *res)
-{
-	char *colon, *end;
-	uint32_t h;
-
-	if (!strcasecmp(name, "root")) {
-		*res = TC_H_ROOT;
-		return 0;
-	}
-
-	if (!strcasecmp(name, "none")) {
-		*res = TC_H_UNSPEC;
-		return 0;
-	}
-
-	h = strtoul(name, &colon, 16);
-
-	if (colon == name) {
-		/* :YYYY */
-		h = 0;
-		if (':' != *colon)
-			return -NLE_INVAL;
-	}
-
-	if (':' == *colon) {
-		/* check if we would lose bits */
-		if (TC_H_MAJ(h))
-			return -NLE_RANGE;
-		h <<= 16;
-
-		if ('\0' == colon[1]) {
-			/* XXXX: */
-			*res = h;
-		} else {
-			/* XXXX:YYYY */
-			uint32_t l = strtoul(colon+1, &end, 16);
-
-			/* check if we overlap with major part */
-			if (TC_H_MAJ(l))
-				return -NLE_RANGE;
-
-			if ('\0' != *end)
-				return -NLE_INVAL;
-
-			*res = (h | l);
-		}
-	} else if ('\0' == *colon) {
-		/* XXXXYYYY */
-		*res = h;
-	} else
-		return -NLE_INVAL;
-
-	return 0;
-}
-
-/** @} */
 
 /** @} */

man/Makefile.am

@@ -0,0 +1,3 @@
+# -*- Makefile -*-
+
+dist_man8_MANS = nl-classid-lookup.8

man/nl-classid-lookup.8

@@ -0,0 +1,48 @@
+.TH nl\-classid\-lookup 8 "19 October 2010" "libnl"
+.LO 1
+.SH NAME
+nl\-classid\-lookup - Lookup classid definitions
+.SH SYNOPSIS
+.B nl\-classid\-lookup
+.RB [ \-hv ]
+.RB [ \-r ]
+.I name
+
+.SH DESCRIPTION
+.PP
+nl\-classid\-lookup searches the classid database for a matching entry. It is used
+to resolve qdisc/class names to classid values and vice versa.
+
+.SH OPTIONS
+.TP
+.BR \-\^h " or " \-\-help
+Print help text to console and exit.
+.TP
+.BR \-\^v " or " \-\-version
+Print versioning information to console and exit.
+.TP
+.BR \-\^r " or " \-\-reverse
+Do a reverse lookup. Lookup a classid and print its name.
+
+.SH USAGE
+.PP
+Resolve the qdisc/class name "interactive":
+.PP
+.RS
+# nl\-classid\-lookup interactive
+.RE
+.PP
+Lookup the name of classid 1:2:
+.PP
+.RS
+# nl\-classid\-lookup -r 1:2
+.RE
+
+.SH FILES
+.PP
+/etc/libnl/classid
+
+.SH AUTHOR
+.PP
+Thomas Graf is the original author and current maintainer of libnl and
+libnl tools. Many people have contributed to it since.

src/.gitignore

@@ -29,3 +29,4 @@ nl-rule-list
 nl-tctree-list
 nl-util-addr
 nf-queue
+nl-classid-lookup

src/Makefile.am

@@ -6,7 +6,8 @@ AM_CPPFLAGS  = -Wall -I${top_srcdir}/include -I${top_builddir}/include -D_GNU_SO
 AM_LDFLAGS = -L${top_builddir}/lib -L${top_builddir}/src/lib -lnl-cli
 
 sbin_PROGRAMS = \
-	nl-qdisc-add
+	nl-qdisc-add \
+	nl-classid-lookup
 
 noinst_PROGRAMS = \
 	genl-ctrl-list \
@@ -104,3 +105,6 @@ nl_util_addr_LDADD = -lnl-route
 
 nl_pktloc_lookup_SOURCES = nl-pktloc-lookup.c
 nl_pktloc_lookup_LDADD = -lnl-route
+
+nl_classid_lookup_SOURCES = nl-classid-lookup.c
+nl_classid_lookup_LDADD = -lnl-route

src/nl-classid-lookup.c

@@ -0,0 +1,79 @@
+/*
+ * src/nl-classid-lookup.c     Lookup classid
+ *
+ *	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>
+
+static void print_usage(void)
+{
+	printf(
+"Usage: nl-classid-lookup [OPTIONS]... NAME\n"
+"\n"
+"OPTIONS\n"
+" -h, --help                Show this help text.\n"
+" -v, --version             Show versioning information.\n"
+" -r, --reverse             Do a reverse lookup, i.e. classid to name.\n"
+"\n"
+"EXAMPLE\n"
+"   $ nl-classid-lookup low_latency\n"
+"   $ nl-classid-lookup -r 1:12\n"
+"\n"
+	);
+	exit(0);
+}
+
+int main(int argc, char *argv[])
+{
+	uint32_t classid;
+	char *name;
+	int err, reverse = 0;
+
+	for (;;) {
+		int c, optidx = 0;
+		static struct option long_opts[] = {
+			{ "help", 0, 0, 'h' },
+			{ "version", 0, 0, 'v' },
+			{ "reverse", 0, 0, 'r' },
+			{ 0, 0, 0, 0 }
+		};
+	
+		c = getopt_long(argc, argv, "hvr", long_opts, &optidx);
+		if (c == -1)
+			break;
+
+		switch (c) {
+		case 'h': print_usage(); break;
+		case 'v': nl_cli_print_version(); break;
+		case 'r': reverse = 1; break;
+		}
+ 	}
+
+	if (optind >= argc)
+		print_usage();
+
+	name = argv[optind++];
+
+	/*
+	 * We use rtnl_tc_str2handle() even while doing a reverse lookup. This
+	 * allows for name -> name lookups. This is intentional, it does not
+	 * do any harm and avoids duplicating a lot of code.
+	 */
+	if ((err = rtnl_tc_str2handle(name, &classid)) < 0)
+		nl_cli_fatal(err, "Unable to lookup classid \"%s\": %s",
+			     name, nl_geterror(err));
+
+	if (reverse) {
+		char buf[64];
+		printf("%s\n", rtnl_tc_handle2str(classid, buf, sizeof(buf)));
+	} else
+		printf("%x:%x\n", TC_H_MAJ(classid) >> 16, TC_H_MIN(classid));
+
+	return 0;
+}