text: /* vi: set sw=4 ts=4: */
  /*
   * Small implementation of brctl for busybox.
   *
   * Copyright (C) 2008 by Bernhard Reutner-Fischer
   *
   * Some helper functions from bridge-utils are
   * Copyright (C) 2000 Lennert Buytenhek
   *
   * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   */
  /* This applet currently uses only the ioctl interface and no sysfs at all.
   * At the time of this writing this was considered a feature.
   */
  //config:config BRCTL
  //config:	bool "brctl"
  //config:	default y
  //config:	select PLATFORM_LINUX
  //config:	help
  //config:	  Manage ethernet bridges.
  //config:	  Supports addbr/delbr and addif/delif.
  //config:
  //config:config FEATURE_BRCTL_FANCY
  //config:	bool "Fancy options"
  //config:	default y
  //config:	depends on BRCTL
  //config:	help
  //config:	  Add support for extended option like:
  //config:	    setageing, setfd, sethello, setmaxage,
  //config:	    setpathcost, setportprio, setbridgeprio,
  //config:	    stp
  //config:	  This adds about 600 bytes.
  //config:
  //config:config FEATURE_BRCTL_SHOW
  //config:	bool "Support show"
  //config:	default y
  //config:	depends on BRCTL && FEATURE_BRCTL_FANCY
  //config:	help
  //config:	  Add support for option which prints the current config:
  //config:	    show
  
  //applet:IF_BRCTL(APPLET(brctl, BB_DIR_USR_SBIN, BB_SUID_DROP))
  
  //kbuild:lib-$(CONFIG_BRCTL) += brctl.o
  
  //usage:#define brctl_trivial_usage
  //usage:       "COMMAND [BRIDGE [INTERFACE]]"
  //usage:#define brctl_full_usage "\n\n"
  //usage:       "Manage ethernet bridges\n"
  //usage:     "\nCommands:"
  //usage:	IF_FEATURE_BRCTL_SHOW(
  //usage:     "\n	show			Show a list of bridges"
  //usage:	)
  //usage:     "\n	addbr BRIDGE		Create BRIDGE"
  //usage:     "\n	delbr BRIDGE		Delete BRIDGE"
  //usage:     "\n	addif BRIDGE IFACE	Add IFACE to BRIDGE"
  //usage:     "\n	delif BRIDGE IFACE	Delete IFACE from BRIDGE"
  //usage:	IF_FEATURE_BRCTL_FANCY(
  //usage:     "\n	setageing BRIDGE TIME		Set ageing time"
  //usage:     "\n	setfd BRIDGE TIME		Set bridge forward delay"
  //usage:     "\n	sethello BRIDGE TIME		Set hello time"
  //usage:     "\n	setmaxage BRIDGE TIME		Set max message age"
  //usage:     "\n	setpathcost BRIDGE COST		Set path cost"
  //usage:     "\n	setportprio BRIDGE PRIO		Set port priority"
  //usage:     "\n	setbridgeprio BRIDGE PRIO	Set bridge priority"
  //usage:     "\n	stp BRIDGE [1/yes/on|0/no/off]	STP on/off"
  //usage:	)
  
  #include "libbb.h"
  #include <linux/sockios.h>
  #include <net/if.h>
  
  #ifndef SIOCBRADDBR
  # define SIOCBRADDBR BRCTL_ADD_BRIDGE
  #endif
  #ifndef SIOCBRDELBR
  # define SIOCBRDELBR BRCTL_DEL_BRIDGE
  #endif
  #ifndef SIOCBRADDIF
  # define SIOCBRADDIF BRCTL_ADD_IF
  #endif
  #ifndef SIOCBRDELIF
  # define SIOCBRDELIF BRCTL_DEL_IF
  #endif
  
  
  /* Maximum number of ports supported per bridge interface.  */
  #ifndef MAX_PORTS
  # define MAX_PORTS 32
  #endif
  
  /* Use internal number parsing and not the "exact" conversion.  */
  /* #define BRCTL_USE_INTERNAL 0 */ /* use exact conversion */
  #define BRCTL_USE_INTERNAL 1
  
  #if ENABLE_FEATURE_BRCTL_FANCY
  /* #include <linux/if_bridge.h>
   * breaks on musl: we already included netinet/in.h in libbb.h,
   * if we include <linux/if_bridge.h> here, we get this:
   * In file included from /usr/include/linux/if_bridge.h:18,
   *                  from networking/brctl.c:67:
   * /usr/include/linux/in6.h:32: error: redefinition of 'struct in6_addr'
   * /usr/include/linux/in6.h:49: error: redefinition of 'struct sockaddr_in6'
   * /usr/include/linux/in6.h:59: error: redefinition of 'struct ipv6_mreq'
   */
  /* From <linux/if_bridge.h> */
  #define BRCTL_GET_VERSION 0
  #define BRCTL_GET_BRIDGES 1
  #define BRCTL_ADD_BRIDGE 2
  #define BRCTL_DEL_BRIDGE 3
  #define BRCTL_ADD_IF 4
  #define BRCTL_DEL_IF 5
  #define BRCTL_GET_BRIDGE_INFO 6
  #define BRCTL_GET_PORT_LIST 7
  #define BRCTL_SET_BRIDGE_FORWARD_DELAY 8
  #define BRCTL_SET_BRIDGE_HELLO_TIME 9
  #define BRCTL_SET_BRIDGE_MAX_AGE 10
  #define BRCTL_SET_AGEING_TIME 11
  #define BRCTL_SET_GC_INTERVAL 12
  #define BRCTL_GET_PORT_INFO 13
  #define BRCTL_SET_BRIDGE_STP_STATE 14
  #define BRCTL_SET_BRIDGE_PRIORITY 15
  #define BRCTL_SET_PORT_PRIORITY 16
  #define BRCTL_SET_PATH_COST 17
  #define BRCTL_GET_FDB_ENTRIES 18
  struct __bridge_info {
  	uint64_t designated_root;
  	uint64_t bridge_id;
  	uint32_t root_path_cost;
  	uint32_t max_age;
  	uint32_t hello_time;
  	uint32_t forward_delay;
  	uint32_t bridge_max_age;
  	uint32_t bridge_hello_time;
  	uint32_t bridge_forward_delay;
  	uint8_t  topology_change;
  	uint8_t  topology_change_detected;
  	uint8_t  root_port;
  	uint8_t  stp_enabled;
  	uint32_t ageing_time;
  	uint32_t gc_interval;
  	uint32_t hello_timer_value;
  	uint32_t tcn_timer_value;
  	uint32_t topology_change_timer_value;
  	uint32_t gc_timer_value;
  };
  /* end <linux/if_bridge.h> */
  
  /* FIXME: These 4 funcs are not really clean and could be improved */
  static ALWAYS_INLINE void bb_strtotimeval(struct timeval *tv,
  		const char *time_str)
  {
  	double secs;
  # if BRCTL_USE_INTERNAL
  	char *endptr;
  	secs = /*bb_*/strtod(time_str, &endptr);
  	if (endptr == time_str)
  # else
  	if (sscanf(time_str, "%lf", &secs) != 1)
  # endif
  		bb_error_msg_and_die(bb_msg_invalid_arg_to, time_str, "timespec");
  	tv->tv_sec = secs;
  	tv->tv_usec = 1000000 * (secs - tv->tv_sec);
  }
  
  static ALWAYS_INLINE unsigned long tv_to_jiffies(const struct timeval *tv)
  {
  	unsigned long long jif;
  
  	jif = 1000000ULL * tv->tv_sec + tv->tv_usec;
  
  	return jif/10000;
  }
  # if 0
  static void jiffies_to_tv(struct timeval *tv, unsigned long jiffies)
  {
  	unsigned long long tvusec;
  
  	tvusec = 10000ULL*jiffies;
  	tv->tv_sec = tvusec/1000000;
  	tv->tv_usec = tvusec - 1000000 * tv->tv_sec;
  }
  # endif
  static unsigned long str_to_jiffies(const char *time_str)
  {
  	struct timeval tv;
  	bb_strtotimeval(&tv, time_str);
  	return tv_to_jiffies(&tv);
  }
  
  static void arm_ioctl(unsigned long *args,
  		unsigned long arg0, unsigned long arg1, unsigned long arg2)
  {
  	args[0] = arg0;
  	args[1] = arg1;
  	args[2] = arg2;
  	args[3] = 0;
  }
  #endif
  
  
  int brctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  int brctl_main(int argc UNUSED_PARAM, char **argv)
  {
  	static const char keywords[] ALIGN1 =
  		"addbr\0" "delbr\0" "addif\0" "delif\0"
  	IF_FEATURE_BRCTL_FANCY(
  		"stp\0"
  		"setageing\0" "setfd\0" "sethello\0" "setmaxage\0"
  		"setpathcost\0" "setportprio\0" "setbridgeprio\0"
  	)
  	IF_FEATURE_BRCTL_SHOW("show\0");
  
  	enum { ARG_addbr = 0, ARG_delbr, ARG_addif, ARG_delif
  		IF_FEATURE_BRCTL_FANCY(,
  			ARG_stp,
  			ARG_setageing, ARG_setfd, ARG_sethello, ARG_setmaxage,
  			ARG_setpathcost, ARG_setportprio, ARG_setbridgeprio
  		)
  		IF_FEATURE_BRCTL_SHOW(, ARG_show)
  	};
  
  	int fd;
  	smallint key;
  	struct ifreq ifr;
  	char *br, *brif;
  
  	argv++;
  	while (*argv) {
  #if ENABLE_FEATURE_BRCTL_FANCY
  		int ifidx[MAX_PORTS];
  		unsigned long args[4];
  		ifr.ifr_data = (char *) &args;
  #endif
  
  		key = index_in_strings(keywords, *argv);
  		if (key == -1) /* no match found in keywords array, bail out. */
  			bb_error_msg_and_die(bb_msg_invalid_arg_to, *argv, applet_name);
  		argv++;
  		fd = xsocket(AF_INET, SOCK_STREAM, 0);
  
  #if ENABLE_FEATURE_BRCTL_SHOW
  		if (key == ARG_show) { /* show */
  			char brname[IFNAMSIZ];
  			int bridx[MAX_PORTS];
  			int i, num;
  			arm_ioctl(args, BRCTL_GET_BRIDGES,
  						(unsigned long) bridx, MAX_PORTS);
  			num = xioctl(fd, SIOCGIFBR, args);
  			puts("bridge name\tbridge id\t\tSTP enabled\tinterfaces");
  			for (i = 0; i < num; i++) {
  				char ifname[IFNAMSIZ];
  				int j, tabs;
  				struct __bridge_info bi;
  				unsigned char *x;
  
  				if (!if_indextoname(bridx[i], brname))
  					bb_perror_msg_and_die("can't get bridge name for index %d", i);
  				strncpy_IFNAMSIZ(ifr.ifr_name, brname);
  
  				arm_ioctl(args, BRCTL_GET_BRIDGE_INFO,
  							(unsigned long) &bi, 0);
  				xioctl(fd, SIOCDEVPRIVATE, &ifr);
  				printf("%s\t\t", brname);
  
  				/* print bridge id */
  				x = (unsigned char *) &bi.bridge_id;
  				for (j = 0; j < 8; j++) {
  					printf("%02x", x[j]);
  					if (j == 1)
  						bb_putchar('.');
  				}
  				printf(bi.stp_enabled ? "\tyes" : "\tno");
  
  				/* print interface list */
  				arm_ioctl(args, BRCTL_GET_PORT_LIST,
  							(unsigned long) ifidx, MAX_PORTS);
  				xioctl(fd, SIOCDEVPRIVATE, &ifr);
  				tabs = 0;
  				for (j = 0; j < MAX_PORTS; j++) {
  					if (!ifidx[j])
  						continue;
  					if (!if_indextoname(ifidx[j], ifname))
  						bb_perror_msg_and_die("can't get interface name for index %d", j);
  					if (tabs)
  						printf("\t\t\t\t\t");
  					else
  						tabs = 1;
  					printf("\t\t%s\n", ifname);
  				}
  				if (!tabs)  /* bridge has no interfaces */
  					bb_putchar('\n');
  			}
  			goto done;
  		}
  #endif
  
  		if (!*argv) /* all but 'show' need at least one argument */
  			bb_show_usage();
  
  		br = *argv++;
  
  		if (key == ARG_addbr || key == ARG_delbr) { /* addbr or delbr */
  			ioctl_or_perror_and_die(fd,
  					key == ARG_addbr ? SIOCBRADDBR : SIOCBRDELBR,
  					br, "bridge %s", br);
  			goto done;
  		}
  
  		if (!*argv) /* all but 'addbr/delbr' need at least two arguments */
  			bb_show_usage();
  
  		strncpy_IFNAMSIZ(ifr.ifr_name, br);
  		if (key == ARG_addif || key == ARG_delif) { /* addif or delif */
  			brif = *argv;
  			ifr.ifr_ifindex = if_nametoindex(brif);
  			if (!ifr.ifr_ifindex) {
  				bb_perror_msg_and_die("iface %s", brif);
  			}
  			ioctl_or_perror_and_die(fd,
  					key == ARG_addif ? SIOCBRADDIF : SIOCBRDELIF,
  					&ifr, "bridge %s", br);
  			goto done_next_argv;
  		}
  #if ENABLE_FEATURE_BRCTL_FANCY
  		if (key == ARG_stp) { /* stp */
  			static const char no_yes[] ALIGN1 =
  				"0\0" "off\0" "n\0" "no\0"   /* 0 .. 3 */
  				"1\0" "on\0"  "y\0" "yes\0"; /* 4 .. 7 */
  			int onoff = index_in_strings(no_yes, *argv);
  			if (onoff < 0)
  				bb_error_msg_and_die(bb_msg_invalid_arg_to, *argv, applet_name);
  			onoff = (unsigned)onoff / 4;
  			arm_ioctl(args, BRCTL_SET_BRIDGE_STP_STATE, onoff, 0);
  			goto fire;
  		}
  		if ((unsigned)(key - ARG_setageing) < 4) { /* time related ops */
  			static const uint8_t ops[] ALIGN1 = {
  				BRCTL_SET_AGEING_TIME,          /* ARG_setageing */
  				BRCTL_SET_BRIDGE_FORWARD_DELAY, /* ARG_setfd     */
  				BRCTL_SET_BRIDGE_HELLO_TIME,    /* ARG_sethello  */
  				BRCTL_SET_BRIDGE_MAX_AGE        /* ARG_setmaxage */
  			};
  			arm_ioctl(args, ops[key - ARG_setageing], str_to_jiffies(*argv), 0);
  			goto fire;
  		}
  		if (key == ARG_setpathcost
  		 || key == ARG_setportprio
  		 || key == ARG_setbridgeprio
  		) {
  			static const uint8_t ops[] ALIGN1 = {
  				BRCTL_SET_PATH_COST,      /* ARG_setpathcost   */
  				BRCTL_SET_PORT_PRIORITY,  /* ARG_setportprio   */
  				BRCTL_SET_BRIDGE_PRIORITY /* ARG_setbridgeprio */
  			};
  			int port = -1;
  			unsigned arg1, arg2;
  
  			if (key != ARG_setbridgeprio) {
  				/* get portnum */
  				unsigned i;
  
  				port = if_nametoindex(*argv++);
  				if (!port)
  					bb_error_msg_and_die(bb_msg_invalid_arg_to, *argv, "port");
  				memset(ifidx, 0, sizeof ifidx);
  				arm_ioctl(args, BRCTL_GET_PORT_LIST, (unsigned long)ifidx,
  						MAX_PORTS);
  				xioctl(fd, SIOCDEVPRIVATE, &ifr);
  				for (i = 0; i < MAX_PORTS; i++) {
  					if (ifidx[i] == port) {
  						port = i;
  						break;
  					}
  				}
  			}
  			arg1 = port;
  			arg2 = xatoi_positive(*argv);
  			if (key == ARG_setbridgeprio) {
  				arg1 = arg2;
  				arg2 = 0;
  			}
  			arm_ioctl(args, ops[key - ARG_setpathcost], arg1, arg2);
  		}
   fire:
  		/* Execute the previously set command */
  		xioctl(fd, SIOCDEVPRIVATE, &ifr);
  #endif
   done_next_argv:
  		argv++;
   done:
  		close(fd);
  	}
  
  	return EXIT_SUCCESS;
  }
  