自学教程：C++ strncpy_IFNAMSIZ函数代码示例

/* Exits on error */static void do_changename(char *dev, char *newdev){	struct ifreq ifr;	int fd;	strncpy_IFNAMSIZ(ifr.ifr_name, dev);	strncpy_IFNAMSIZ(ifr.ifr_newname, newdev);	fd = get_ctl_fd();	xioctl(fd, SIOCSIFNAME, &ifr);	close(fd);}

static smallint detect_link_wlan(void){	int i;	struct iwreq iwrequest;	uint8_t mac[ETH_ALEN];	memset(&iwrequest, 0, sizeof(iwrequest));	strncpy_IFNAMSIZ(iwrequest.ifr_ifrn.ifrn_name, G.iface);	if (network_ioctl(SIOCGIWAP, &iwrequest, "SIOCGIWAP") < 0) {		return IFSTATUS_ERR;	}	memcpy(mac, &iwrequest.u.ap_addr.sa_data, ETH_ALEN);	if (mac[0] == 0xFF || mac[0] == 0x44 || mac[0] == 0x00) {		for (i = 1; i < ETH_ALEN; ++i) {			if (mac[i] != mac[0])				return IFSTATUS_UP;		}		return IFSTATUS_DOWN;	}	return IFSTATUS_UP;}

/* Exits on error */static int get_address(char *dev, int *htype){	struct ifreq ifr;	struct sockaddr_ll me;	socklen_t alen;	int s;	s = xsocket(PF_PACKET, SOCK_DGRAM, 0);	memset(&ifr, 0, sizeof(ifr));	strncpy_IFNAMSIZ(ifr.ifr_name, dev);	xioctl(s, SIOCGIFINDEX, &ifr);	memset(&me, 0, sizeof(me));	me.sll_family = AF_PACKET;	me.sll_ifindex = ifr.ifr_ifindex;	me.sll_protocol = htons(ETH_P_LOOP);	xbind(s, (struct sockaddr*)&me, sizeof(me));	alen = sizeof(me);	getsockname(s, (struct sockaddr*)&me, &alen);	//never happens:	//if (getsockname(s, (struct sockaddr*)&me, &alen) == -1)	//	bb_perror_msg_and_die("getsockname");	close(s);	*htype = me.sll_hatype;	return me.sll_halen;}

/* Dies on error, otherwise returns 0 */static int do_del_ioctl(const char *basedev, struct ip_tunnel_parm *p){	struct ifreq ifr;	int fd;	if (p->name[0]) {		strncpy_IFNAMSIZ(ifr.ifr_name, p->name);	} else {		strncpy_IFNAMSIZ(ifr.ifr_name, basedev);	}	ifr.ifr_ifru.ifru_data = (void*)p;	fd = xsocket(AF_INET, SOCK_DGRAM, 0);	xioctl(fd, SIOCDELTUNNEL, &ifr);	close(fd);	return 0;}

int tunctl_main(int argc UNUSED_PARAM, char **argv){	struct ifreq ifr;	int fd;	const char *opt_name = "tap%d";	const char *opt_device = "/dev/net/tun";	unsigned opts;	enum {		OPT_f = 1 << 0, // control device name (/dev/net/tun)		OPT_t = 1 << 1, // create named interface		OPT_d = 1 << 2, // delete named interface	};	opt_complementary = "=0:t--d:d--t"; // no arguments; t ^ d	opts = getopt32(argv, "f:t:d:u:g:b", // u, g, b accepted and ignored			&opt_device, &opt_name, &opt_name, NULL, NULL);	// set interface name	memset(&ifr, 0, sizeof(ifr));	ifr.ifr_flags = IFF_TAP | IFF_NO_PI;	strncpy_IFNAMSIZ(ifr.ifr_name, opt_name);	// open device	fd = xopen(opt_device, O_RDWR);	IOCTL(fd, TUNSETIFF, (void *)&ifr);	// create or delete interface	IOCTL(fd, TUNSETPERSIST, (void *)(uintptr_t)(0 == (opts & OPT_d)));	return EXIT_SUCCESS;}

int FAST_FUNC udhcp_read_interface(const char *interface, int *ifindex, uint32_t *nip, uint8_t *mac, uint16_t *mtu){	/* char buffer instead of bona-fide struct avoids aliasing warning */	char ifr_buf[sizeof(struct ifreq)];	struct ifreq *const ifr = (void *)ifr_buf;	int fd;	struct sockaddr_in *our_ip;	memset(ifr, 0, sizeof(*ifr));	fd = xsocket(AF_INET, SOCK_RAW, IPPROTO_RAW);	ifr->ifr_addr.sa_family = AF_INET;	strncpy_IFNAMSIZ(ifr->ifr_name, interface);	if (nip) {		if (ioctl_or_perror(fd, SIOCGIFADDR, ifr,			"is interface %s up and configured?", interface)		) {			close(fd);			return -1;		}		our_ip = (struct sockaddr_in *) &ifr->ifr_addr;		*nip = our_ip->sin_addr.s_addr;		log1("IP %s", inet_ntoa(our_ip->sin_addr));	}	if (ifindex) {		if (ioctl_or_warn(fd, SIOCGIFINDEX, ifr) != 0) {			close(fd);			return -1;		}		log1("Adapter index %d", ifr->ifr_ifindex);		*ifindex = ifr->ifr_ifindex;	}	if (mac) {		if (ioctl_or_warn(fd, SIOCGIFHWADDR, ifr) != 0) {			close(fd);			return -1;		}		memcpy(mac, ifr->ifr_hwaddr.sa_data, 6);		log1("MAC %02x:%02x:%02x:%02x:%02x:%02x",			mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);	}	if (mtu) {		if (ioctl_or_warn(fd, SIOCGIFMTU, ifr) != 0) {			close(fd);			return -1;		}		log1("Adapter mtu %d", ifr->ifr_mtu);		*mtu = ifr->ifr_mtu;	}	close(fd);	return 0;}

/* Dies on error */static int do_ioctl_get_ifindex(char *dev){	struct ifreq ifr;	int fd;	strncpy_IFNAMSIZ(ifr.ifr_name, dev);	fd = xsocket(AF_INET, SOCK_DGRAM, 0);	xioctl(fd, SIOCGIFINDEX, &ifr);	close(fd);	return ifr.ifr_ifindex;}

/* Exits on error */static void set_mtu(char *dev, int mtu){	struct ifreq ifr;	int s;	s = get_ctl_fd();	memset(&ifr, 0, sizeof(ifr));	strncpy_IFNAMSIZ(ifr.ifr_name, dev);	ifr.ifr_mtu = mtu;	xioctl(s, SIOCSIFMTU, &ifr);	close(s);}

/* Exits on error */static void set_qlen(char *dev, int qlen){	struct ifreq ifr;	int s;	s = get_ctl_fd();	memset(&ifr, 0, sizeof(ifr));	strncpy_IFNAMSIZ(ifr.ifr_name, dev);	ifr.ifr_qlen = qlen;	xioctl(s, SIOCSIFTXQLEN, &ifr);	close(s);}

static int do_ioctl_get_iftype(char *dev){	struct ifreq ifr;	int fd;	int err;	strncpy_IFNAMSIZ(ifr.ifr_name, dev);	fd = xsocket(AF_INET, SOCK_DGRAM, 0);	err = ioctl_or_warn(fd, SIOCGIFHWADDR, &ifr);	close(fd);	return err ? -1 : ifr.ifr_addr.sa_family;}

int vconfig_main(int argc, char **argv){	struct vlan_ioctl_args ifr;	const char *p;	int fd;	if (argc < 3) {		bb_show_usage();	}	/* Don't bother closing the filedes.  It will be closed on cleanup. */	/* Will die if 802.1q is not present */	xopen(conf_file_name, O_RDONLY);	memset(&ifr, 0, sizeof(ifr));	++argv;	p = xfind_str(cmds+2, *argv);	ifr.cmd = *p;	if (argc != p[-1]) {		bb_show_usage();	}	if (ifr.cmd == SET_VLAN_NAME_TYPE_CMD) { /* set_name_type */		ifr.u.name_type = *xfind_str(name_types+1, argv[1]);	} else {		strncpy_IFNAMSIZ(ifr.device1, argv[1]);		p = argv[2];		/* I suppose one could try to combine some of the function calls below,		 * since ifr.u.flag, ifr.u.VID, and ifr.u.skb_priority are all same-sized		 * (unsigned) int members of a unions.  But because of the range checking,		 * doing so wouldn't save that much space and would also make maintainence		 * more of a pain. */		if (ifr.cmd == SET_VLAN_FLAG_CMD) { /* set_flag */			ifr.u.flag = xatoul_range(p, 0, 1);			/* DM: in order to set reorder header, qos must be set */			ifr.vlan_qos = xatoul_range(argv[3], 0, 7);		} else if (ifr.cmd == ADD_VLAN_CMD) { /* add */			ifr.u.VID = xatoul_range(p, 0, VLAN_GROUP_ARRAY_LEN-1);		} else if (ifr.cmd != DEL_VLAN_CMD) { /* set_{egress|ingress}_map */			ifr.u.skb_priority = xatou(p);			ifr.vlan_qos = xatoul_range(argv[3], 0, 7);		}	}	fd = xsocket(AF_INET, SOCK_STREAM, 0);	ioctl_or_perror_and_die(fd, SIOCSIFVLAN, &ifr,						"ioctl error for %s", *argv);	return 0;}

static int do_get_ioctl(const char *basedev, struct ip_tunnel_parm *p){	struct ifreq ifr;	int fd;	int err;	strncpy_IFNAMSIZ(ifr.ifr_name, basedev);	ifr.ifr_ifru.ifru_data = (void*)p;	fd = xsocket(AF_INET, SOCK_DGRAM, 0);	err = ioctl_or_warn(fd, SIOCGETTUNNEL, &ifr);	close(fd);	return err;}

int FAST_FUNC setsockopt_bindtodevice(int fd, const char *iface){	int r;	struct ifreq ifr;	strncpy_IFNAMSIZ(ifr.ifr_name, iface);	/* NB: passing (iface, strlen(iface) + 1) does not work!	 * (maybe it works on _some_ kernels, but not on 2.6.26)	 * Actually, ifr_name is at offset 0, and in practice	 * just giving char[IFNAMSIZ] instead of struct ifreq works too.	 * But just in case it's not true on some obscure arch... */	r = setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr));	if (r)		bb_perror_msg("can't bind to interface %s", iface);	return r;}

/* Exits on error */static void do_chflags(char *dev, uint32_t flags, uint32_t mask){	struct ifreq ifr;	int fd;	strncpy_IFNAMSIZ(ifr.ifr_name, dev);	fd = get_ctl_fd();	xioctl(fd, SIOCGIFFLAGS, &ifr);	if ((ifr.ifr_flags ^ flags) & mask) {		ifr.ifr_flags &= ~mask;		ifr.ifr_flags |= mask & flags;		xioctl(fd, SIOCSIFFLAGS, &ifr);	}	close(fd);}

/* Dies on error, otherwise returns 0 */static int do_add_ioctl(int cmd, const char *basedev, struct ip_tunnel_parm *p){	struct ifreq ifr;	int fd;	if (cmd == SIOCCHGTUNNEL && p->name[0]) {		strncpy_IFNAMSIZ(ifr.ifr_name, p->name);	} else {		strncpy_IFNAMSIZ(ifr.ifr_name, basedev);	}	ifr.ifr_ifru.ifru_data = (void*)p;	fd = xsocket(AF_INET, SOCK_DGRAM, 0);#if ENABLE_IOCTL_HEX2STR_ERROR	/* #define magic will turn ioctl# into string */	if (cmd == SIOCCHGTUNNEL)		xioctl(fd, SIOCCHGTUNNEL, &ifr);	else		xioctl(fd, SIOCADDTUNNEL, &ifr);#else	xioctl(fd, cmd, &ifr);#endif	close(fd);	return 0;}

/* Exits on error */static void parse_address(char *dev, int hatype, int halen, char *lla, struct ifreq *ifr){	int alen;	memset(ifr, 0, sizeof(*ifr));	strncpy_IFNAMSIZ(ifr->ifr_name, dev);	ifr->ifr_hwaddr.sa_family = hatype;	alen = hatype == 1/*ARPHRD_ETHER*/ ? 14/*ETH_HLEN*/ : 19/*INFINIBAND_HLEN*/;	alen = ll_addr_a2n((unsigned char *)(ifr->ifr_hwaddr.sa_data), alen, lla);	if (alen < 0)		exit(EXIT_FAILURE);	if (alen != halen) {		bb_error_msg_and_die("wrong address (%s) length: expected %d bytes", lla, halen);	}}

int zcip_main(int argc UNUSED_PARAM, char **argv){	char *r_opt;	const char *l_opt = "169.254.0.0";	int state;	int nsent;	unsigned opts;	// Ugly trick, but I want these zeroed in one go	struct {		const struct ether_addr null_ethaddr;		struct ifreq ifr;		uint32_t chosen_nip;		int conflicts;		int timeout_ms; // must be signed		int verbose;	} L;#define null_ethaddr (L.null_ethaddr)#define ifr          (L.ifr         )#define chosen_nip   (L.chosen_nip  )#define conflicts    (L.conflicts   )#define timeout_ms   (L.timeout_ms  )#define verbose      (L.verbose     )	memset(&L, 0, sizeof(L));	INIT_G();#define FOREGROUND (opts & 1)#define QUIT       (opts & 2)	// Parse commandline: prog [options] ifname script	// exactly 2 args; -v accumulates and implies -f	opt_complementary = "=2:vv:vf";	opts = getopt32(argv, "fqr:l:v", &r_opt, &l_opt, &verbose);#if !BB_MMU	// on NOMMU reexec early (or else we will rerun things twice)	if (!FOREGROUND)		bb_daemonize_or_rexec(0 /*was: DAEMON_CHDIR_ROOT*/, argv);#endif	// Open an ARP socket	// (need to do it before openlog to prevent openlog from taking	// fd 3 (sock_fd==3))	xmove_fd(xsocket(AF_PACKET, SOCK_PACKET, htons(ETH_P_ARP)), sock_fd);	if (!FOREGROUND) {		// do it before all bb_xx_msg calls		openlog(applet_name, 0, LOG_DAEMON);		logmode |= LOGMODE_SYSLOG;	}	bb_logenv_override();	{ // -l n.n.n.n		struct in_addr net;		if (inet_aton(l_opt, &net) == 0		 || (net.s_addr & htonl(IN_CLASSB_NET)) != net.s_addr		) {			bb_error_msg_and_die("invalid network address");		}		G.localnet_ip = ntohl(net.s_addr);	}	if (opts & 4) { // -r n.n.n.n		struct in_addr ip;		if (inet_aton(r_opt, &ip) == 0		 || (ntohl(ip.s_addr) & IN_CLASSB_NET) != G.localnet_ip		) {			bb_error_msg_and_die("invalid link address");		}		chosen_nip = ip.s_addr;	}	argv += optind - 1;	/* Now: argv[0]:junk argv[1]:intf argv[2]:script argv[3]:NULL */	/* We need to make space for script argument: */	argv[0] = argv[1];	argv[1] = argv[2];	/* Now: argv[0]:intf argv[1]:script argv[2]:junk argv[3]:NULL */#define argv_intf (argv[0])	xsetenv("interface", argv_intf);	// Initialize the interface (modprobe, ifup, etc)	if (run(argv, "init", 0))		return EXIT_FAILURE;	// Initialize G.iface_sockaddr	// G.iface_sockaddr is: { u16 sa_family; u8 sa_data[14]; }	//memset(&G.iface_sockaddr, 0, sizeof(G.iface_sockaddr));	//TODO: are we leaving sa_family == 0 (AF_UNSPEC)?!	safe_strncpy(G.iface_sockaddr.sa_data, argv_intf, sizeof(G.iface_sockaddr.sa_data));	// Bind to the interface's ARP socket	xbind(sock_fd, &G.iface_sockaddr, sizeof(G.iface_sockaddr));	// Get the interface's ethernet address	//memset(&ifr, 0, sizeof(ifr));	strncpy_IFNAMSIZ(ifr.ifr_name, argv_intf);	xioctl(sock_fd, SIOCGIFHWADDR, &ifr);	memcpy(&G.our_ethaddr, &ifr.ifr_hwaddr.sa_data, ETH_ALEN);	// Start with some stable ip address, either a function of	// the hardware address or else the last address we used.	// we are taking low-order four bytes, as top-order ones//.........这里部分代码省略.........

int nameif_main(int argc UNUSED_PARAM, char **argv){	ethtable_t *clist = NULL;	const char *fname = "/etc/mactab";	int ctl_sk;	ethtable_t *ch;	parser_t *parser;	char *token[2];	if (1 & getopt32(argv, "sc:", &fname)) {		openlog(applet_name, 0, LOG_LOCAL0);		/* Why not just "="? I assume logging to stderr		 * can't hurt. 2>/dev/null if you don't like it: */		logmode |= LOGMODE_SYSLOG;	}	argv += optind;	if (argv[0]) {		do {			if (!argv[1])				bb_show_usage();			prepend_new_eth_table(&clist, argv[0], argv[1]);			argv += 2;		} while (*argv);	} else {		parser = config_open(fname);		while (config_read(parser, token, 2, 2, "# /t", PARSE_NORMAL))			prepend_new_eth_table(&clist, token[0], token[1]);		config_close(parser);	}	ctl_sk = xsocket(PF_INET, SOCK_DGRAM, 0);	parser = config_open2("/proc/net/dev", xfopen_for_read);	while (clist && config_read(parser, token, 2, 2, "/0: /t", PARSE_NORMAL)) {		struct ifreq ifr;#if  ENABLE_FEATURE_NAMEIF_EXTENDED		struct ethtool_drvinfo drvinfo;		struct ethtool_cmd eth_settings;#endif		if (parser->lineno <= 2)			continue; /* Skip the first two lines */		/* Find the current interface name and copy it to ifr.ifr_name */		memset(&ifr, 0, sizeof(struct ifreq));		strncpy_IFNAMSIZ(ifr.ifr_name, token[0]);#if ENABLE_FEATURE_NAMEIF_EXTENDED		/* Check for phy address */		memset(&eth_settings, 0, sizeof(eth_settings));		eth_settings.cmd = ETHTOOL_GSET;		ifr.ifr_data = (caddr_t) &eth_settings;		ioctl(ctl_sk, SIOCETHTOOL, &ifr);		/* Check for driver etc. */		memset(&drvinfo, 0, sizeof(drvinfo));		drvinfo.cmd = ETHTOOL_GDRVINFO;		ifr.ifr_data = (caddr_t) &drvinfo;		/* Get driver and businfo first, so we have it in drvinfo */		ioctl(ctl_sk, SIOCETHTOOL, &ifr);#endif		ioctl(ctl_sk, SIOCGIFHWADDR, &ifr);		/* Search the list for a matching device */		for (ch = clist; ch; ch = ch->next) {#if ENABLE_FEATURE_NAMEIF_EXTENDED			if (ch->bus_info && strcmp(ch->bus_info, drvinfo.bus_info) != 0)				continue;			if (ch->driver && strcmp(ch->driver, drvinfo.driver) != 0)				continue;			if (ch->phy_address != -1 && ch->phy_address != eth_settings.phy_address)				continue;#endif			if (ch->mac && memcmp(ch->mac, ifr.ifr_hwaddr.sa_data, ETH_ALEN) != 0)				continue;			/* if we came here, all selectors have matched */			break;		}		/* Nothing found for current interface */		if (!ch)			continue;		if (strcmp(ifr.ifr_name, ch->ifname) != 0) {			strcpy(ifr.ifr_newname, ch->ifname);			ioctl_or_perror_and_die(ctl_sk, SIOCSIFNAME, &ifr,					"can't change ifname %s to %s",					ifr.ifr_name, ch->ifname);		}		/* Remove list entry of renamed interface */		if (ch->prev != NULL)			ch->prev->next = ch->next;		else			clist = ch->next;		if (ch->next != NULL)			ch->next->prev = ch->prev;		if (ENABLE_FEATURE_CLEAN_UP)			delete_eth_table(ch);	}	if (ENABLE_FEATURE_CLEAN_UP) {		for (ch = clist; ch; ch = ch->next)//.........这里部分代码省略.........

int zcip_main(int argc UNUSED_PARAM, char **argv){	int state;	char *r_opt;	unsigned opts;	// ugly trick, but I want these zeroed in one go	struct {		const struct in_addr null_ip;		const struct ether_addr null_addr;		struct in_addr ip;		struct ifreq ifr;		int timeout_ms; /* must be signed */		unsigned conflicts;		unsigned nprobes;		unsigned nclaims;		int ready;	} L;#define null_ip    (L.null_ip   )#define null_addr  (L.null_addr )#define ip         (L.ip        )#define ifr        (L.ifr       )#define timeout_ms (L.timeout_ms)#define conflicts  (L.conflicts )#define nprobes    (L.nprobes   )#define nclaims    (L.nclaims   )#define ready      (L.ready     )	memset(&L, 0, sizeof(L));	INIT_G();#define FOREGROUND (opts & 1)#define QUIT       (opts & 2)	// parse commandline: prog [options] ifname script	// exactly 2 args; -v accumulates and implies -f	opt_complementary = "=2:vv:vf";	opts = getopt32(argv, "fqr:p:v", &r_opt, &pidfile, &verbose);#if !BB_MMU	// on NOMMU reexec early (or else we will rerun things twice)	if (!FOREGROUND)		bb_daemonize_or_rexec(0 /*was: DAEMON_CHDIR_ROOT*/, argv);#endif	// open an ARP socket	// (need to do it before openlog to prevent openlog from taking	// fd 3 (sock_fd==3))	xmove_fd(xsocket(AF_PACKET, SOCK_PACKET, htons(ETH_P_ARP)), sock_fd);	if (!FOREGROUND) {		// do it before all bb_xx_msg calls		openlog(applet_name, 0, LOG_DAEMON);		logmode |= LOGMODE_SYSLOG;	}	if (opts & 4) { // -r n.n.n.n		if (inet_aton(r_opt, &ip) == 0		 || (ntohl(ip.s_addr) & IN_CLASSB_NET) != LINKLOCAL_ADDR		) {			bb_error_msg_and_die("invalid link address");		}	}	argv += optind - 1;	/* Now: argv[0]:junk argv[1]:intf argv[2]:script argv[3]:NULL */	/* We need to make space for script argument: */	argv[0] = argv[1];	argv[1] = argv[2];	/* Now: argv[0]:intf argv[1]:script argv[2]:junk argv[3]:NULL */#define argv_intf (argv[0])	xsetenv("interface", argv_intf);	// initialize the interface (modprobe, ifup, etc)	if (run(argv, "init", NULL))		return EXIT_FAILURE;	// initialize saddr	// saddr is: { u16 sa_family; u8 sa_data[14]; }	//memset(&saddr, 0, sizeof(saddr));	//TODO: are we leaving sa_family == 0 (AF_UNSPEC)?!	safe_strncpy(saddr.sa_data, argv_intf, sizeof(saddr.sa_data));	// bind to the interface's ARP socket	xbind(sock_fd, &saddr, sizeof(saddr));	// get the interface's ethernet address	//memset(&ifr, 0, sizeof(ifr));	strncpy_IFNAMSIZ(ifr.ifr_name, argv_intf);	xioctl(sock_fd, SIOCGIFHWADDR, &ifr);	memcpy(&eth_addr, &ifr.ifr_hwaddr.sa_data, ETH_ALEN);	// start with some stable ip address, either a function of	// the hardware address or else the last address we used.	// we are taking low-order four bytes, as top-order ones	// aren't random enough.	// NOTE: the sequence of addresses we try changes only	// depending on when we detect conflicts.	{		uint32_t t;		move_from_unaligned32(t, ((char *)&eth_addr + 2));		srand(t);	}	if (ip.s_addr == 0)//.........这里部分代码省略.........

int ether_wake_main(int argc UNUSED_PARAM, char **argv){	const char *ifname = "eth0";	char *pass;	unsigned flags;	unsigned char wol_passwd[6];	int wol_passwd_sz = 0;	int s;  /* Raw socket */	int pktsize;	unsigned char outpack[1000];	struct ether_addr eaddr;	struct whereto_t whereto;  /* who to wake up */	/* handle misc user options */	opt_complementary = "=1";	flags = getopt32(argv, "bi:p:", &ifname, &pass);	if (flags & 4) /* -p */		wol_passwd_sz = get_wol_pw(pass, wol_passwd);	flags &= 1; /* we further interested only in -b [bcast] flag */	/* create the raw socket */	s = make_socket();	/* now that we have a raw socket we can drop root */	/* xsetuid(getuid()); - but save on code size... */	/* look up the dest mac address */	get_dest_addr(argv[optind], &eaddr);	/* fill out the header of the packet */	pktsize = get_fill(outpack, &eaddr, flags /* & 1 OPT_BROADCAST */);	bb_debug_dump_packet(outpack, pktsize);	/* Fill in the source address, if possible. */#ifdef __linux__	{		struct ifreq if_hwaddr;		strncpy_IFNAMSIZ(if_hwaddr.ifr_name, ifname);		ioctl_or_perror_and_die(s, SIOCGIFHWADDR, &if_hwaddr, "SIOCGIFHWADDR on %s failed", ifname);		memcpy(outpack+6, if_hwaddr.ifr_hwaddr.sa_data, 6);# ifdef DEBUG		{			unsigned char *hwaddr = if_hwaddr.ifr_hwaddr.sa_data;			printf("The hardware address (SIOCGIFHWADDR) of %s is type %d  "				"%2.2x:%2.2x:%2.2x:%2.2x:%2.2x:%2.2x/n/n", ifname,				if_hwaddr.ifr_hwaddr.sa_family, hwaddr[0], hwaddr[1],				hwaddr[2], hwaddr[3], hwaddr[4], hwaddr[5]);		}# endif	}#endif /* __linux__ */	bb_debug_dump_packet(outpack, pktsize);	/* append the password if specified */	if (wol_passwd_sz > 0) {		memcpy(outpack+pktsize, wol_passwd, wol_passwd_sz);		pktsize += wol_passwd_sz;	}	bb_debug_dump_packet(outpack, pktsize);	/* This is necessary for broadcasts to work */	if (flags /* & 1 OPT_BROADCAST */) {		if (setsockopt_broadcast(s) != 0)			bb_perror_msg("SO_BROADCAST");	}#if defined(PF_PACKET)	{		struct ifreq ifr;		strncpy_IFNAMSIZ(ifr.ifr_name, ifname);		xioctl(s, SIOCGIFINDEX, &ifr);		memset(&whereto, 0, sizeof(whereto));		whereto.sll_family = AF_PACKET;		whereto.sll_ifindex = ifr.ifr_ifindex;		/* The manual page incorrectly claims the address must be filled.		   We do so because the code may change to match the docs. */		whereto.sll_halen = ETH_ALEN;		memcpy(whereto.sll_addr, outpack, ETH_ALEN);	}#else	whereto.sa_family = 0;	strcpy(whereto.sa_data, ifname);#endif	xsendto(s, outpack, pktsize, (struct sockaddr *)&whereto, sizeof(whereto));	if (ENABLE_FEATURE_CLEAN_UP)		close(s);	return EXIT_SUCCESS;}

static void set_ifreq_to_ifname(struct ifreq *ifreq){	memset(ifreq, 0, sizeof(struct ifreq));	strncpy_IFNAMSIZ(ifreq->ifr_name, G.iface);}

int arping_main(int argc UNUSED_PARAM, char **argv){	const char *device = "eth0";	char *source = NULL;	char *target;	unsigned char *packet;	char *err_str;	INIT_G();	sock_fd = xsocket(AF_PACKET, SOCK_DGRAM, 0);	// Drop suid root privileges	// Need to remove SUID_NEVER from applets.h for this to work	//xsetuid(getuid());	err_str = xasprintf("interface %s %%s", device);	{		unsigned opt;		char *str_timeout;		/* Dad also sets quit_on_reply.		 * Advert also sets unsolicited.		 */		opt_complementary = "=1:Df:AU:c+";		opt = getopt32(argv, "DUAqfbc:w:I:s:",				&count, &str_timeout, &device, &source);		if (opt & 0x80) /* -w: timeout */			timeout_us = xatou_range(str_timeout, 0, INT_MAX/2000000) * 1000000 + 500000;		//if (opt & 0x200) /* -s: source */		option_mask32 &= 0x3f; /* set respective flags */	}	target = argv[optind];	xfunc_error_retval = 2;	{		struct ifreq ifr;		memset(&ifr, 0, sizeof(ifr));		strncpy_IFNAMSIZ(ifr.ifr_name, device);		/* We use ifr.ifr_name in error msg so that problem		 * with truncated name will be visible */		ioctl_or_perror_and_die(sock_fd, SIOCGIFINDEX, &ifr, err_str, "not found");		me.sll_ifindex = ifr.ifr_ifindex;		xioctl(sock_fd, SIOCGIFFLAGS, (char *) &ifr);		if (!(ifr.ifr_flags & IFF_UP)) {			bb_error_msg_and_die(err_str, "is down");		}		if (ifr.ifr_flags & (IFF_NOARP | IFF_LOOPBACK)) {			bb_error_msg(err_str, "is not ARPable");			return (option_mask32 & DAD ? 0 : 2);		}	}	/* if (!inet_aton(target, &dst)) - not needed */ {		len_and_sockaddr *lsa;		lsa = xhost_and_af2sockaddr(target, 0, AF_INET);		dst = lsa->u.sin.sin_addr;		if (ENABLE_FEATURE_CLEAN_UP)			free(lsa);	}	if (source && !inet_aton(source, &src)) {		bb_error_msg_and_die("invalid source address %s", source);	}	if ((option_mask32 & (DAD|UNSOLICITED)) == UNSOLICITED && src.s_addr == 0)		src = dst;	if (!(option_mask32 & DAD) || src.s_addr) {		struct sockaddr_in saddr;		int probe_fd = xsocket(AF_INET, SOCK_DGRAM, 0);		setsockopt_bindtodevice(probe_fd, device);		memset(&saddr, 0, sizeof(saddr));		saddr.sin_family = AF_INET;		if (src.s_addr) {			/* Check that this is indeed our IP */			saddr.sin_addr = src;			xbind(probe_fd, (struct sockaddr *) &saddr, sizeof(saddr));		} else { /* !(option_mask32 & DAD) case */			/* Find IP address on this iface */			socklen_t alen = sizeof(saddr);			saddr.sin_port = htons(1025);			saddr.sin_addr = dst;			if (setsockopt(probe_fd, SOL_SOCKET, SO_DONTROUTE, &const_int_1, sizeof(const_int_1)) == -1)				bb_perror_msg("setsockopt(SO_DONTROUTE)");			xconnect(probe_fd, (struct sockaddr *) &saddr, sizeof(saddr));			if (getsockname(probe_fd, (struct sockaddr *) &saddr, &alen) == -1) {				bb_perror_msg_and_die("getsockname");			}			if (saddr.sin_family != AF_INET)				bb_error_msg_and_die("no IP address configured");			src = saddr.sin_addr;//.........这里部分代码省略.........

//.........这里部分代码省略.........				uval = get_unsigned(*argv, "okey");				p->o_key = htonl(uval);			}		} else if (key == ARG_seq) {			p->i_flags |= GRE_SEQ;			p->o_flags |= GRE_SEQ;		} else if (key == ARG_iseq) {			p->i_flags |= GRE_SEQ;		} else if (key == ARG_oseq) {			p->o_flags |= GRE_SEQ;		} else if (key == ARG_csum) {			p->i_flags |= GRE_CSUM;			p->o_flags |= GRE_CSUM;		} else if (key == ARG_icsum) {			p->i_flags |= GRE_CSUM;		} else if (key == ARG_ocsum) {			p->o_flags |= GRE_CSUM;		} else if (key == ARG_nopmtudisc) {			p->iph.frag_off = 0;		} else if (key == ARG_pmtudisc) {			p->iph.frag_off = htons(IP_DF);		} else if (key == ARG_remote) {			NEXT_ARG();			key = index_in_strings(keywords, *argv);			if (key != ARG_any)				p->iph.daddr = get_addr32(*argv);		} else if (key == ARG_local) {			NEXT_ARG();			key = index_in_strings(keywords, *argv);			if (key != ARG_any)				p->iph.saddr = get_addr32(*argv);		} else if (key == ARG_dev) {			NEXT_ARG();			strncpy_IFNAMSIZ(medium, *argv);		} else if (key == ARG_ttl) {			unsigned uval;			NEXT_ARG();			key = index_in_strings(keywords, *argv);			if (key != ARG_inherit) {				uval = get_unsigned(*argv, "TTL");				if (uval > 255)					invarg(*argv, "TTL must be <=255");				p->iph.ttl = uval;			}		} else if (key == ARG_tos ||			   key == ARG_dsfield		) {			uint32_t uval;			NEXT_ARG();			key = index_in_strings(keywords, *argv);			if (key != ARG_inherit) {				if (rtnl_dsfield_a2n(&uval, *argv))					invarg(*argv, "TOS");				p->iph.tos = uval;			} else				p->iph.tos = 1;		} else {			if (key == ARG_name) {				NEXT_ARG();			}			if (p->name[0])				duparg2("name", *argv);			strncpy_IFNAMSIZ(p->name, *argv);			if (cmd == SIOCCHGTUNNEL && count == 0) {				struct ip_tunnel_parm old_p;				memset(&old_p, 0, sizeof(old_p));

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++;//.........这里部分代码省略.........