added parser for netem settings and several functions to apply them

git-svn-id: https://zerberus.eonerc.rwth-aachen.de:8443/svn/s2ss/trunk@79 8ec27952-4edc-4aab-86aa-e87bb2611832

etc/example.conf

@@ -19,7 +19,18 @@ nodes = {
 		id = 2,
 		type = "rtds",
 		local = "127.0.0.1:10202",
-		remote = "127.0.0.1:10203"
+		remote = "127.0.0.1:10203",
+
+		# Network emulation for single nodes
+		netem = {
+			limit = 99999,		# Limit network emulation to a certain amount of packets
+			delay = 100000,		# Additional latency in uS
+			jitter = 30000,		# Jitter in uS
+			distribution = "normal",# Distribution of delay (uniform, normal, pareto, paretonormal)
+			loss = 10		# Loss in percentage
+			duplicate = 10,		# Duplication in percentage
+			corrupt = 10,		# Corruption in percentage
+		}
 	}
 };
 
@@ -29,16 +40,5 @@ paths = (
 		reverse = true,			# Setup a path in the reverse direction too
 		in = "acs",			# Name of the node we listen to (see above)
 		out = "sintef",			# Name of the node we send to
-
-		# TODO: Some 'netem' settings might arrive here in the future...
-		# netem = {
-		#	delay = (10, 10,	# Time, jitter in milliseconds
-		#		 10,		# Correlation in percentage
-		#		 "normal")	# Distribution: uniform, normal, pareto or paretonormal
-		# 	loss = (10, 25),	# Loss in percentage
-		# 	duplicate = (10, 25),	# Duplication in percentage
-		# 	corrupt = (10, 25),	# Corruption in percentage
-		# 	reorder = (10, 25)	# Reorder in percentage
-		# }
 	}
 );

include/cfg.h

@@ -14,6 +14,8 @@ struct node;
 struct path;
 struct interface;
 
+struct netem;
+
 /** Global configuration */
 struct settings {
 	/** Name of this node */
@@ -79,9 +81,15 @@ int config_parse_path(config_setting_t *cfg,
  */
 int config_parse_node(config_setting_t *cfg,
 	struct node **nodes, struct interface **interfaces);
+
+/** Parse network emulator (netem) settings
+ *
+ * @param cfg A libconfig object containing the settings
+ * @param em A pointer to the settings
  * @return
  *  - 0 on success
  *  - otherwise an error occured
  */
+int config_parse_netem(config_setting_t *cfg, struct netem *em);
 
 #endif /* _CFG_H_ */

include/node.h

@@ -18,6 +18,8 @@
 #include <netinet/in.h>
 #include <libconfig.h>
 
+#include "tc.h"
+
 /** The type of a node.
  *
  * This type is used to determine the message format of the remote node
@@ -58,6 +60,9 @@ struct node
 	/** The egress interface */
 	struct interface *interface;
 
+	/** Network emulator settings */
+	struct netem *netem;
+
 	/** Socket mark for netem, routing and filtering */
 	int mark;
 

include/tc.h

@@ -0,0 +1,80 @@
+/**
+ * Setup interface queuing desciplines for network emulation
+ *
+ * @author Steffen Vogel <stvogel@eonerc.rwth-aachen.de>
+ * @copyright 2014, Institute for Automation of Complex Power Systems, EONERC
+ */
+
+#ifndef _TC_H_
+#define _TC_H_
+
+#include <stdint.h>
+
+/* Some helper for TC handles */
+typedef uint32_t tc_hdl_t;
+
+#define TC_HDL(maj, min)	((maj & 0xFFFF) << 16 | (min & 0xFFFF))
+#define TC_HDL_MAJ(h)		((h >> 16) & 0xFFFF)
+#define TC_HDL_MIN(h)		((h >>  0) & 0xFFFF)
+#define TC_HDL_ROOT		(0xFFFFFFFFU)
+
+/* Bitfield for valid fields in struct netem */
+#define TC_NETEM_LIMIT		(1 << 0)
+#define TC_NETEM_DELAY		(1 << 1)
+#define TC_NETEM_JITTER		(1 << 2)
+#define TC_NETEM_DISTR		(1 << 3)
+#define TC_NETEM_LOSS		(1 << 4)
+#define TC_NETEM_CORRUPT	(1 << 5)
+#define TC_NETEM_DUPL		(1 << 6)
+
+struct interface;
+
+struct netem {
+	/** Which fields of this struct contain valid data (TC_NETEM_*). */
+	char valid;
+
+	/** Delay distribution: uniform, normal, pareto, paretonormal */
+	const char *distribution;
+	/** Fifo limit (packets) */
+	int limit;
+	/** Added delay (uS) */
+	int delay;
+	/** Delay jitter (uS) */
+	int jitter;
+	/** Random loss probability (%) */
+	int loss;
+	/** Packet corruption probability (%) */
+	int corrupt;
+	/** Packet duplication probability (%) */
+	int duplicate;
+};
+
+/** Remove all queuing disciplines and filters 
+ *
+ * @param i The interface
+ */
+int tc_reset(struct interface *i);
+
+/** Create a prio queueing discipline
+ *
+ * @param i The interface
+ * @param parent
+ * @param handle
+ * @param bands
+ * @return
+ *  - 0 on success
+ *  - otherwise an error occured
+ */
+int tc_prio(struct interface *i, tc_hdl_t handle, int bands);
+
+/** Add a new network emulator discipline
+ *
+ * @param i The interface
+ * @param parent Make this
+ */
+int tc_netem(struct interface *i, tc_hdl_t parent, struct netem *em);
+
+/** Add a new fwmark filter */
+int tc_mark(struct interface *i, tc_hdl_t flowid, int mark);
+
+#endif /* _TC_H_ */

src/cfg.c

@@ -13,6 +13,7 @@
 #include <pwd.h>
 
 #include "if.h"
+#include "tc.h"
 #include "cfg.h"
 #include "node.h"
 #include "path.h"
@@ -147,7 +148,7 @@ int config_parse_path(config_setting_t *cfg,
 
 			path_rev->in = path->out; /* Swap in/out */
 			path_rev->out = path->in;
-				
+
 			list_add(*paths, path_rev);
 		}
 	}
@@ -202,6 +203,13 @@ int config_parse_node(config_setting_t *cfg,
 	if (resolve_addr(remote_str, &node->remote, 0))
 		cerror(cfg, "Failed to resolve remote address '%s' of node '%s'", remote_str, node->name);
 
+	/* Optional settings */
+	config_setting_t *cfg_netem = config_setting_get_member(cfg, "netem");
+	if (cfg_netem) {
+		node->netem = (struct netem *) malloc(sizeof(struct netem));
+		config_parse_netem(cfg_netem, node->netem);
+	}
+
 	/* Determine outgoing interface */
 	int index = if_getegress(&node->remote);
 	struct interface *i = if_lookup_index(index, *interfaces);
@@ -225,3 +233,27 @@ int config_parse_node(config_setting_t *cfg,
 
 	return 0;
 }
+
+int config_parse_netem(config_setting_t *cfg, struct netem *em)
+{
+	em->valid = 0;
+
+	if (config_setting_lookup_string(cfg, "distribution", &em->distribution))
+		em->valid |= TC_NETEM_DISTR;
+	if (config_setting_lookup_int(cfg, "limit", &em->limit))
+		em->valid |= TC_NETEM_LIMIT;
+	if (config_setting_lookup_int(cfg, "delay", &em->delay))
+		em->valid |= TC_NETEM_DELAY;
+	if (config_setting_lookup_int(cfg, "jitter", &em->jitter))
+		em->valid |= TC_NETEM_JITTER;
+	if (config_setting_lookup_int(cfg, "loss", &em->loss))
+		em->valid |= TC_NETEM_LOSS;
+	if (config_setting_lookup_int(cfg, "duplicate", &em->duplicate))
+		em->valid |= TC_NETEM_DUPL;
+	if (config_setting_lookup_int(cfg, "corrupt", &em->corrupt))
+		em->valid |= TC_NETEM_CORRUPT;
+
+	// TODO: check values
+
+	return 0;
+}

src/tc.c

@@ -0,0 +1,81 @@
+/**
+ * Traffic control: setup interface queuing desciplines
+ *
+ * @author Steffen Vogel <stvogel@eonerc.rwth-aachen.de>
+ * @copyright 2014, Institute for Automation of Complex Power Systems, EONERC
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdarg.h>
+
+#include "utils.h"
+#include "if.h"
+#include "tc.h"
+
+int tc_reset(struct interface *i)
+{
+	char cmd[128];
+	snprintf(cmd, sizeof(cmd), "tc qdisc del dev %s root", i->name);
+
+	debug(6, "system: %s", cmd);
+	return system(cmd);
+}
+
+int tc_prio(struct interface *i, tc_hdl_t handle, int bands)
+{
+	char cmd[128];
+	int len = 0;
+
+	len += snprintf(cmd+len, sizeof(cmd)-len,
+		"tc qdisc add dev %s root handle %u prio bands %u priomap",
+		i->name, TC_HDL_MAJ(handle), bands);
+
+	for (int i = 0; i < bands; i++)
+		len += snprintf(cmd+len, sizeof(cmd)-len, " 0");
+
+	debug(6, "system: %s", cmd);
+	return system(cmd);
+}
+
+int tc_netem(struct interface *i, tc_hdl_t parent, struct netem *em)
+{
+	int len = 0;
+	char cmd[256];
+	len += snprintf(cmd+len, sizeof(cmd)-len,
+		"tc qdisc add dev %s parent %u:%u netem",
+		i->name, TC_HDL_MAJ(parent), TC_HDL_MIN(parent));
+
+	if (em->valid & TC_NETEM_LIMIT)
+		len += snprintf(cmd+len, sizeof(cmd)-len, " limit %u", em->limit);
+	if (em->valid & TC_NETEM_DELAY) {
+		len += snprintf(cmd+len, sizeof(cmd)-len, " delay %u", em->delay);
+
+		if (em->valid & TC_NETEM_JITTER)
+			len += snprintf(cmd+len, sizeof(cmd)-len, " %u", em->jitter);
+		if (em->valid & TC_NETEM_DISTR)
+			len += snprintf(cmd+len, sizeof(cmd)-len, " distribution %s", em->distribution);
+	}
+
+	if (em->valid & TC_NETEM_LOSS)
+		len += snprintf(cmd+len, sizeof(cmd)-len, " loss random %u", em->loss);
+	if (em->valid & TC_NETEM_DUPL)
+		len += snprintf(cmd+len, sizeof(cmd)-len, " duplicate %u", em->duplicate);
+	if (em->valid & TC_NETEM_CORRUPT)
+		len += snprintf(cmd+len, sizeof(cmd)-len, " corrupt %u", em->corrupt);
+
+	debug(6, "system: %s", cmd);
+	return system(cmd);
+}
+
+int tc_mark(struct interface *i, tc_hdl_t flowid, int mark)
+{
+	char cmd[128];
+	snprintf(cmd, sizeof(cmd),
+		"tc filter add dev %s protocol ip handle %u fw flowid %u:%u",
+		i->name, mark, TC_HDL_MAJ(flowid), TC_HDL_MIN(flowid));
+
+	debug(6, "system: %s", cmd);
+	return system(cmd);
+
+}