removed priviledge dropping to make code simpler

git-svn-id: https://zerberus.eonerc.rwth-aachen.de:8443/svn/s2ss/trunk@121 8ec27952-4edc-4aab-86aa-e87bb2611832

documentation/Mainpage.md

@@ -35,6 +35,7 @@ Install these via:
 
 	$ sudo yum install iproute2
 or:
+
 	$ sudo apt-get install iproute2
 
 ## Configuration
@@ -45,9 +46,6 @@ See [configuration](Configuration.md) for more information.
 
 The S2SS server (`server`) expects the path to a configuration file as a single argument.
 
-The server requires root privileges during the startup.
-Afterwards privileges can be dropped by using the `user` and `group` settings in the config file.
-
 	Usage: ./server CONFIG
 	  CONFIG is a required path to a configuration file
 
@@ -55,6 +53,12 @@ Afterwards privileges can be dropped by using the `user` and `group` settings in
 	 Copyright 2014, Institute for Automation of Complex Power Systems, EONERC
 	   Steffen Vogel <stvogel@eonerc.rwth-aachen.de>
 
+The server requires root privileges for:
+
+ - Enable the realtime fifo scheduler
+ - Increase the task priority
+ - Configure the network emulator (netem)
+ - Change the SMP affinity of threads and network interrupts
 
 ### Examples
 

server/etc/example.conf

@@ -5,9 +5,6 @@ name = "s2ss";		# The name of this node
 affinity = 0x02;	# Mask of cores the server should run on
 priority = 50;		# Scheduler priority for the server
 
-user = "acs-admin";	# Drop privileges after initialization
-group = "acs-admin";
-
 nodes = {
 	acs = {
 		id = 1, 			# Device ID

server/src/cfg.c

@@ -69,30 +69,6 @@ int config_parse_global(config_setting_t *cfg, struct settings *set)
 	config_setting_lookup_int(cfg, "priority", &set->priority);
 	config_setting_lookup_int(cfg, "protocol", &set->protocol);
 
-	const char *user = NULL;
-	const char *group = NULL;
-
-	config_setting_lookup_string(cfg, "user", &user);
-	config_setting_lookup_string(cfg, "group", &group);
-
-	/* Lookup uid and gid */
-	if (user) {
-		struct passwd *pw = getpwnam(user);
-		if (!pw)
-			error("Unknown username: '%s'", user);
-
-		set->uid = pw->pw_uid;
-		set->gid = pw->pw_gid;
-	}
-
-	if (group) {
-		struct group *gr = getgrnam(group);
-		if (!gr)
-			error("Unknown group: '%s'", group);
-
-		set->gid = gr->gr_gid;
-	}
-
 	set->cfg = cfg;
 
 	return CONFIG_TRUE;

server/src/server.c

@@ -104,9 +104,6 @@ static void stop()
 		node_disconnect(n);
 	}
 
-	if (getuid() != 0)
-		return; /* The following tasks require root privs */
-
 	/* Determine default affinity */
 	FILE * f = fopen("/proc/irq/default_smp_affinity", "r");
 	fscanf(f, "%x", &affinity);
@@ -187,15 +184,6 @@ int main(int argc, char *argv[])
 	/* Connect all nodes and start one thread per path */
 	start();
 
-	/* Process is running as root, drop privileges */
-	if (getuid() == 0) {
-		if (setgid(settings.gid) || setuid(settings.uid))
-			perror("Unable to drop privileges");
-		else
-			debug(3, "Dropped privileges to uid = %u, gid = %u",
-				settings.uid, settings.gid);
-	}
-
 	/* Main thread is sleeping */
 	pause();