networking/libiproute/iptunnel.c

/* vi: set sw=4 ts=4: */
/*
 * iptunnel.c	       "ip tunnel"
 *
 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
 *
 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 * Changes:
 *
 * Rani Assaf <rani@magic.metawire.com> 980929:	resolve addresses
 * Rani Assaf <rani@magic.metawire.com> 980930:	do not allow key for ipip/sit
 * Phil Karn <karn@ka9q.ampr.org>	990408:	"pmtudisc" flag
 */

#include <netinet/ip.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <asm/types.h>

#ifndef __constant_htons
#define __constant_htons htons
#endif

// FYI: #define SIOCDEVPRIVATE 0x89F0

/* From linux/if_tunnel.h. #including it proved troublesome
 * (redefiniton errors due to name collisions in linux/ and net[inet]/) */
#define SIOCGETTUNNEL   (SIOCDEVPRIVATE + 0)
#define SIOCADDTUNNEL   (SIOCDEVPRIVATE + 1)
#define SIOCDELTUNNEL   (SIOCDEVPRIVATE + 2)
#define SIOCCHGTUNNEL   (SIOCDEVPRIVATE + 3)
//#define SIOCGETPRL      (SIOCDEVPRIVATE + 4)
//#define SIOCADDPRL      (SIOCDEVPRIVATE + 5)
//#define SIOCDELPRL      (SIOCDEVPRIVATE + 6)
//#define SIOCCHGPRL      (SIOCDEVPRIVATE + 7)
#define GRE_CSUM        __constant_htons(0x8000)
//#define GRE_ROUTING     __constant_htons(0x4000)
#define GRE_KEY         __constant_htons(0x2000)
#define GRE_SEQ         __constant_htons(0x1000)
//#define GRE_STRICT      __constant_htons(0x0800)
//#define GRE_REC         __constant_htons(0x0700)
//#define GRE_FLAGS       __constant_htons(0x00F8)
//#define GRE_VERSION     __constant_htons(0x0007)
struct ip_tunnel_parm {
	char            name[IFNAMSIZ];
	int             link;
	uint16_t        i_flags;
	uint16_t        o_flags;
	uint32_t        i_key;
	uint32_t        o_key;
	struct iphdr    iph;
};
/* SIT-mode i_flags */
//#define SIT_ISATAP 0x0001
//struct ip_tunnel_prl {
//	uint32_t          addr;
//	uint16_t          flags;
//	uint16_t          __reserved;
//	uint32_t          datalen;
//	uint32_t          __reserved2;
//	/* data follows */
//};
///* PRL flags */
//#define PRL_DEFAULT 0x0001

#include "ip_common.h"  /* #include "libbb.h" is inside */
#include "rt_names.h"
#include "utils.h"


/* 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;
}

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;
}

static char *do_ioctl_get_ifname(int idx)
{
	struct ifreq ifr;
	int fd;
	int err;

	ifr.ifr_ifindex = idx;
	fd = xsocket(AF_INET, SOCK_DGRAM, 0);
	err = ioctl_or_warn(fd, SIOCGIFNAME, &ifr);
	close(fd);
	return err ? NULL : xstrndup(ifr.ifr_name, sizeof(ifr.ifr_name));
}

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;
}

/* 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;
}

/* 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;
}

/* Dies on error */
static void parse_args(char **argv, int cmd, struct ip_tunnel_parm *p)
{
	static const char keywords[] ALIGN1 =
		"mode\0""ipip\0""ip/ip\0""gre\0""gre/ip\0""sit\0""ipv6/ip\0"
		"key\0""ikey\0""okey\0""seq\0""iseq\0""oseq\0"
		"csum\0""icsum\0""ocsum\0""nopmtudisc\0""pmtudisc\0"
		"remote\0""any\0""local\0""dev\0"
		"ttl\0""inherit\0""tos\0""dsfield\0"
		"name\0";
	enum {
		ARG_mode, ARG_ipip, ARG_ip_ip, ARG_gre, ARG_gre_ip, ARG_sit, ARG_ip6_ip,
		ARG_key, ARG_ikey, ARG_okey, ARG_seq, ARG_iseq, ARG_oseq,
		ARG_csum, ARG_icsum, ARG_ocsum, ARG_nopmtudisc, ARG_pmtudisc,
		ARG_remote, ARG_any, ARG_local, ARG_dev,
		ARG_ttl, ARG_inherit, ARG_tos, ARG_dsfield,
		ARG_name
	};
	int count = 0;
	char medium[IFNAMSIZ];
	int key;

	memset(p, 0, sizeof(*p));
	medium[0] = '\0';

	p->iph.version = 4;
	p->iph.ihl = 5;
#ifndef IP_DF
#define IP_DF 0x4000  /* Flag: "Don't Fragment" */
#endif
	p->iph.frag_off = htons(IP_DF);

	while (*argv) {
		key = index_in_strings(keywords, *argv);
		if (key == ARG_mode) {
			NEXT_ARG();
			key = index_in_strings(keywords, *argv);
			if (key == ARG_ipip ||
			    key == ARG_ip_ip
			) {
				if (p->iph.protocol && p->iph.protocol != IPPROTO_IPIP) {
					bb_error_msg_and_die("%s tunnel mode", "you managed to ask for more than one");
				}
				p->iph.protocol = IPPROTO_IPIP;
			} else if (key == ARG_gre ||
				   key == ARG_gre_ip
			) {
				if (p->iph.protocol && p->iph.protocol != IPPROTO_GRE) {
					bb_error_msg_and_die("%s tunnel mode", "you managed to ask for more than one");
				}
				p->iph.protocol = IPPROTO_GRE;
			} else if (key == ARG_sit ||
				   key == ARG_ip6_ip
			) {
				if (p->iph.protocol && p->iph.protocol != IPPROTO_IPV6) {
					bb_error_msg_and_die("%s tunnel mode", "you managed to ask for more than one");
				}
				p->iph.protocol = IPPROTO_IPV6;
			} else {
				bb_error_msg_and_die("%s tunnel mode", "can't guess");
			}
		} else if (key == ARG_key) {
			unsigned uval;
			NEXT_ARG();
			p->i_flags |= GRE_KEY;
			p->o_flags |= GRE_KEY;
			if (strchr(*argv, '.'))
				p->i_key = p->o_key = get_addr32(*argv);
			else {
				uval = get_unsigned(*argv, "key");
				p->i_key = p->o_key = htonl(uval);
			}
		} else if (key == ARG_ikey) {
			unsigned uval;
			NEXT_ARG();
			p->i_flags |= GRE_KEY;
			if (strchr(*argv, '.'))
				p->o_key = get_addr32(*argv);
			else {
				uval = get_unsigned(*argv, "ikey");
				p->i_key = htonl(uval);
			}
		} else if (key == ARG_okey) {
			unsigned uval;
			NEXT_ARG();
			p->o_flags |= GRE_KEY;
			if (strchr(*argv, '.'))
				p->o_key = get_addr32(*argv);
			else {
				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));
				if (do_get_ioctl(*argv, &old_p))
					exit(EXIT_FAILURE);
				*p = old_p;
			}
		}
		count++;
		argv++;
	}

	if (p->iph.protocol == 0) {
		if (memcmp(p->name, "gre", 3) == 0)
			p->iph.protocol = IPPROTO_GRE;
		else if (memcmp(p->name, "ipip", 4) == 0)
			p->iph.protocol = IPPROTO_IPIP;
		else if (memcmp(p->name, "sit", 3) == 0)
			p->iph.protocol = IPPROTO_IPV6;
	}

	if (p->iph.protocol == IPPROTO_IPIP || p->iph.protocol == IPPROTO_IPV6) {
		if ((p->i_flags & GRE_KEY) || (p->o_flags & GRE_KEY)) {
			bb_error_msg_and_die("keys are not allowed with ipip and sit");
		}
	}

	if (medium[0]) {
		p->link = do_ioctl_get_ifindex(medium);
	}

	if (p->i_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
		p->i_key = p->iph.daddr;
		p->i_flags |= GRE_KEY;
	}
	if (p->o_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
		p->o_key = p->iph.daddr;
		p->o_flags |= GRE_KEY;
	}
	if (IN_MULTICAST(ntohl(p->iph.daddr)) && !p->iph.saddr) {
		bb_error_msg_and_die("broadcast tunnel requires a source address");
	}
}

/* Return value becomes exitcode. It's okay to not return at all */
static int do_add(int cmd, char **argv)
{
	struct ip_tunnel_parm p;

	parse_args(argv, cmd, &p);

	if (p.iph.ttl && p.iph.frag_off == 0) {
		bb_error_msg_and_die("ttl != 0 and noptmudisc are incompatible");
	}

	switch (p.iph.protocol) {
	case IPPROTO_IPIP:
		return do_add_ioctl(cmd, "tunl0", &p);
	case IPPROTO_GRE:
		return do_add_ioctl(cmd, "gre0", &p);
	case IPPROTO_IPV6:
		return do_add_ioctl(cmd, "sit0", &p);
	default:
		bb_error_msg_and_die("can't determine tunnel mode (ipip, gre or sit)");
	}
}

/* Return value becomes exitcode. It's okay to not return at all */
static int do_del(char **argv)
{
	struct ip_tunnel_parm p;

	parse_args(argv, SIOCDELTUNNEL, &p);

	switch (p.iph.protocol) {
	case IPPROTO_IPIP:
		return do_del_ioctl("tunl0", &p);
	case IPPROTO_GRE:
		return do_del_ioctl("gre0", &p);
	case IPPROTO_IPV6:
		return do_del_ioctl("sit0", &p);
	default:
		return do_del_ioctl(p.name, &p);
	}
}

static void print_tunnel(struct ip_tunnel_parm *p)
{
	char s1[256];
	char s2[256];
	char s3[64];
	char s4[64];

	format_host(AF_INET, 4, &p->iph.daddr, s1, sizeof(s1));
	format_host(AF_INET, 4, &p->iph.saddr, s2, sizeof(s2));
	inet_ntop(AF_INET, &p->i_key, s3, sizeof(s3));
	inet_ntop(AF_INET, &p->o_key, s4, sizeof(s4));

	printf("%s: %s/ip  remote %s  local %s ",
	       p->name,
	       p->iph.protocol == IPPROTO_IPIP ? "ip" :
	       (p->iph.protocol == IPPROTO_GRE ? "gre" :
		(p->iph.protocol == IPPROTO_IPV6 ? "ipv6" : "unknown")),
	       p->iph.daddr ? s1 : "any", p->iph.saddr ? s2 : "any");
	if (p->link) {
		char *n = do_ioctl_get_ifname(p->link);
		if (n) {
			printf(" dev %s ", n);
			free(n);
		}
	}
	if (p->iph.ttl)
		printf(" ttl %d ", p->iph.ttl);
	else
		printf(" ttl inherit ");
	if (p->iph.tos) {
		SPRINT_BUF(b1);
		printf(" tos");
		if (p->iph.tos & 1)
			printf(" inherit");
		if (p->iph.tos & ~1)
			printf("%c%s ", p->iph.tos & 1 ? '/' : ' ',
			       rtnl_dsfield_n2a(p->iph.tos & ~1, b1));
	}
	if (!(p->iph.frag_off & htons(IP_DF)))
		printf(" nopmtudisc");

	if ((p->i_flags & GRE_KEY) && (p->o_flags & GRE_KEY) && p->o_key == p->i_key)
		printf(" key %s", s3);
	else if ((p->i_flags | p->o_flags) & GRE_KEY) {
		if (p->i_flags & GRE_KEY)
			printf(" ikey %s ", s3);
		if (p->o_flags & GRE_KEY)
			printf(" okey %s ", s4);
	}

	if (p->i_flags & GRE_SEQ)
		printf("%c  Drop packets out of sequence.\n", _SL_);
	if (p->i_flags & GRE_CSUM)
		printf("%c  Checksum in received packet is required.", _SL_);
	if (p->o_flags & GRE_SEQ)
		printf("%c  Sequence packets on output.", _SL_);
	if (p->o_flags & GRE_CSUM)
		printf("%c  Checksum output packets.", _SL_);
}

static void do_tunnels_list(struct ip_tunnel_parm *p)
{
	char name[IFNAMSIZ];
	unsigned long rx_bytes, rx_packets, rx_errs, rx_drops,
		rx_fifo, rx_frame,
		tx_bytes, tx_packets, tx_errs, tx_drops,
		tx_fifo, tx_colls, tx_carrier, rx_multi;
	int type;
	struct ip_tunnel_parm p1;
	char buf[512];
	FILE *fp = fopen_or_warn("/proc/net/dev", "r");

	if (fp == NULL) {
		return;
	}
	/* skip headers */
	fgets(buf, sizeof(buf), fp);
	fgets(buf, sizeof(buf), fp);

	while (fgets(buf, sizeof(buf), fp) != NULL) {
		char *ptr;

		/*buf[sizeof(buf) - 1] = 0; - fgets is safe anyway */
		ptr = strchr(buf, ':');
		if (ptr == NULL ||
		    (*ptr++ = 0, sscanf(buf, "%s", name) != 1)
		) {
			bb_error_msg("wrong format of /proc/net/dev");
			return;
		}
		if (sscanf(ptr, "%lu%lu%lu%lu%lu%lu%lu%*d%lu%lu%lu%lu%lu%lu%lu",
			   &rx_bytes, &rx_packets, &rx_errs, &rx_drops,
			   &rx_fifo, &rx_frame, &rx_multi,
			   &tx_bytes, &tx_packets, &tx_errs, &tx_drops,
			   &tx_fifo, &tx_colls, &tx_carrier) != 14)
			continue;
		if (p->name[0] && strcmp(p->name, name))
			continue;
		type = do_ioctl_get_iftype(name);
		if (type == -1) {
			bb_error_msg("can't get type of [%s]", name);
			continue;
		}
		if (type != ARPHRD_TUNNEL && type != ARPHRD_IPGRE && type != ARPHRD_SIT)
			continue;
		memset(&p1, 0, sizeof(p1));
		if (do_get_ioctl(name, &p1))
			continue;
		if ((p->link && p1.link != p->link) ||
		    (p->name[0] && strcmp(p1.name, p->name)) ||
		    (p->iph.daddr && p1.iph.daddr != p->iph.daddr) ||
		    (p->iph.saddr && p1.iph.saddr != p->iph.saddr) ||
		    (p->i_key && p1.i_key != p->i_key)
		) {
			continue;
		}
		print_tunnel(&p1);
		bb_putchar('\n');
	}
}

/* Return value becomes exitcode. It's okay to not return at all */
static int do_show(char **argv)
{
	int err;
	struct ip_tunnel_parm p;

	parse_args(argv, SIOCGETTUNNEL, &p);

	switch (p.iph.protocol) {
	case IPPROTO_IPIP:
		err = do_get_ioctl(p.name[0] ? p.name : "tunl0", &p);
		break;
	case IPPROTO_GRE:
		err = do_get_ioctl(p.name[0] ? p.name : "gre0", &p);
		break;
	case IPPROTO_IPV6:
		err = do_get_ioctl(p.name[0] ? p.name : "sit0", &p);
		break;
	default:
		do_tunnels_list(&p);
		return 0;
	}
	if (err)
		return -1;

	print_tunnel(&p);
	bb_putchar('\n');
	return 0;
}

/* Return value becomes exitcode. It's okay to not return at all */
int do_iptunnel(char **argv)
{
	static const char keywords[] ALIGN1 =
		"add\0""change\0""delete\0""show\0""list\0""lst\0";
	enum { ARG_add = 0, ARG_change, ARG_del, ARG_show, ARG_list, ARG_lst };

	if (*argv) {
		smalluint key = index_in_substrings(keywords, *argv);
		if (key > 5)
			bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name);
		argv++;
		if (key == ARG_add)
			return do_add(SIOCADDTUNNEL, argv);
		if (key == ARG_change)
			return do_add(SIOCCHGTUNNEL, argv);
		if (key == ARG_del)
			return do_del(argv);
	}
	return do_show(argv);
}
1	/* vi: set sw=4 ts=4: */
2	/*
3	* iptunnel.c "ip tunnel"
4	*
5	* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
6	*
7	* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
8	*
9	* Changes:
10	*
11	* Rani Assaf <rani@magic.metawire.com> 980929: resolve addresses
12	* Rani Assaf <rani@magic.metawire.com> 980930: do not allow key for ipip/sit
13	* Phil Karn <karn@ka9q.ampr.org> 990408: "pmtudisc" flag
14	*/
15
16	#include <netinet/ip.h>
17	#include <net/if.h>
18	#include <net/if_arp.h>
19	#include <asm/types.h>
20
21	#ifndef __constant_htons
22	#define __constant_htons htons
23	#endif
24
25	// FYI: #define SIOCDEVPRIVATE 0x89F0
26
27	/* From linux/if_tunnel.h. #including it proved troublesome
28	* (redefiniton errors due to name collisions in linux/ and net[inet]/) */
29	#define SIOCGETTUNNEL (SIOCDEVPRIVATE + 0)
30	#define SIOCADDTUNNEL (SIOCDEVPRIVATE + 1)
31	#define SIOCDELTUNNEL (SIOCDEVPRIVATE + 2)
32	#define SIOCCHGTUNNEL (SIOCDEVPRIVATE + 3)
33	//#define SIOCGETPRL (SIOCDEVPRIVATE + 4)
34	//#define SIOCADDPRL (SIOCDEVPRIVATE + 5)
35	//#define SIOCDELPRL (SIOCDEVPRIVATE + 6)
36	//#define SIOCCHGPRL (SIOCDEVPRIVATE + 7)
37	#define GRE_CSUM __constant_htons(0x8000)
38	//#define GRE_ROUTING __constant_htons(0x4000)
39	#define GRE_KEY __constant_htons(0x2000)
40	#define GRE_SEQ __constant_htons(0x1000)
41	//#define GRE_STRICT __constant_htons(0x0800)
42	//#define GRE_REC __constant_htons(0x0700)
43	//#define GRE_FLAGS __constant_htons(0x00F8)
44	//#define GRE_VERSION __constant_htons(0x0007)
45	struct ip_tunnel_parm {
46	char name[IFNAMSIZ];
47	int link;
48	uint16_t i_flags;
49	uint16_t o_flags;
50	uint32_t i_key;
51	uint32_t o_key;
52	struct iphdr iph;
53	};
54	/* SIT-mode i_flags */
55	//#define SIT_ISATAP 0x0001
56	//struct ip_tunnel_prl {
57	// uint32_t addr;
58	// uint16_t flags;
59	// uint16_t __reserved;
60	// uint32_t datalen;
61	// uint32_t __reserved2;
62	// /* data follows */
63	//};
64	///* PRL flags */
65	//#define PRL_DEFAULT 0x0001
66
67	#include "ip_common.h" /* #include "libbb.h" is inside */
68	#include "rt_names.h"
69	#include "utils.h"
70
71
72	/* Dies on error */
73	static int do_ioctl_get_ifindex(char *dev)
74	{
75	struct ifreq ifr;
76	int fd;
77
78	strncpy_IFNAMSIZ(ifr.ifr_name, dev);
79	fd = xsocket(AF_INET, SOCK_DGRAM, 0);
80	xioctl(fd, SIOCGIFINDEX, &ifr);
81	close(fd);
82	return ifr.ifr_ifindex;
83	}
84
85	static int do_ioctl_get_iftype(char *dev)
86	{
87	struct ifreq ifr;
88	int fd;
89	int err;
90
91	strncpy_IFNAMSIZ(ifr.ifr_name, dev);
92	fd = xsocket(AF_INET, SOCK_DGRAM, 0);
93	err = ioctl_or_warn(fd, SIOCGIFHWADDR, &ifr);
94	close(fd);
95	return err ? -1 : ifr.ifr_addr.sa_family;
96	}
97
98	static char *do_ioctl_get_ifname(int idx)
99	{
100	struct ifreq ifr;
101	int fd;
102	int err;
103
104	ifr.ifr_ifindex = idx;
105	fd = xsocket(AF_INET, SOCK_DGRAM, 0);
106	err = ioctl_or_warn(fd, SIOCGIFNAME, &ifr);
107	close(fd);
108	return err ? NULL : xstrndup(ifr.ifr_name, sizeof(ifr.ifr_name));
109	}
110
111	static int do_get_ioctl(const char basedev, struct ip_tunnel_parm p)
112	{
113	struct ifreq ifr;
114	int fd;
115	int err;
116
117	strncpy_IFNAMSIZ(ifr.ifr_name, basedev);
118	ifr.ifr_ifru.ifru_data = (void*)p;
119	fd = xsocket(AF_INET, SOCK_DGRAM, 0);
120	err = ioctl_or_warn(fd, SIOCGETTUNNEL, &ifr);
121	close(fd);
122	return err;
123	}
124
125	/* Dies on error, otherwise returns 0 */
126	static int do_add_ioctl(int cmd, const char basedev, struct ip_tunnel_parm p)
127	{
128	struct ifreq ifr;
129	int fd;
130
131	if (cmd == SIOCCHGTUNNEL && p->name[0]) {
132	strncpy_IFNAMSIZ(ifr.ifr_name, p->name);
133	} else {
134	strncpy_IFNAMSIZ(ifr.ifr_name, basedev);
135	}
136	ifr.ifr_ifru.ifru_data = (void*)p;
137	fd = xsocket(AF_INET, SOCK_DGRAM, 0);
138	#if ENABLE_IOCTL_HEX2STR_ERROR
139	/* #define magic will turn ioctl# into string */
140	if (cmd == SIOCCHGTUNNEL)
141	xioctl(fd, SIOCCHGTUNNEL, &ifr);
142	else
143	xioctl(fd, SIOCADDTUNNEL, &ifr);
144	#else
145	xioctl(fd, cmd, &ifr);
146	#endif
147	close(fd);
148	return 0;
149	}
150
151	/* Dies on error, otherwise returns 0 */
152	static int do_del_ioctl(const char basedev, struct ip_tunnel_parm p)
153	{
154	struct ifreq ifr;
155	int fd;
156
157	if (p->name[0]) {
158	strncpy_IFNAMSIZ(ifr.ifr_name, p->name);
159	} else {
160	strncpy_IFNAMSIZ(ifr.ifr_name, basedev);
161	}
162	ifr.ifr_ifru.ifru_data = (void*)p;
163	fd = xsocket(AF_INET, SOCK_DGRAM, 0);
164	xioctl(fd, SIOCDELTUNNEL, &ifr);
165	close(fd);
166	return 0;
167	}
168
169	/* Dies on error */
170	static void parse_args(char *argv, int cmd, struct ip_tunnel_parm p)
171	{
172	static const char keywords[] ALIGN1 =
173	"mode\0""ipip\0""ip/ip\0""gre\0""gre/ip\0""sit\0""ipv6/ip\0"
174	"key\0""ikey\0""okey\0""seq\0""iseq\0""oseq\0"
175	"csum\0""icsum\0""ocsum\0""nopmtudisc\0""pmtudisc\0"
176	"remote\0""any\0""local\0""dev\0"
177	"ttl\0""inherit\0""tos\0""dsfield\0"
178	"name\0";
179	enum {
180	ARG_mode, ARG_ipip, ARG_ip_ip, ARG_gre, ARG_gre_ip, ARG_sit, ARG_ip6_ip,
181	ARG_key, ARG_ikey, ARG_okey, ARG_seq, ARG_iseq, ARG_oseq,
182	ARG_csum, ARG_icsum, ARG_ocsum, ARG_nopmtudisc, ARG_pmtudisc,
183	ARG_remote, ARG_any, ARG_local, ARG_dev,
184	ARG_ttl, ARG_inherit, ARG_tos, ARG_dsfield,
185	ARG_name
186	};
187	int count = 0;
188	char medium[IFNAMSIZ];
189	int key;
190
191	memset(p, 0, sizeof(*p));
192	medium[0] = '\0';
193
194	p->iph.version = 4;
195	p->iph.ihl = 5;
196	#ifndef IP_DF
197	#define IP_DF 0x4000 /* Flag: "Don't Fragment" */
198	#endif
199	p->iph.frag_off = htons(IP_DF);
200
201	while (*argv) {
202	key = index_in_strings(keywords, *argv);
203	if (key == ARG_mode) {
204	NEXT_ARG();
205	key = index_in_strings(keywords, *argv);
206	if (key == ARG_ipip \|\|
207	key == ARG_ip_ip
208	) {
209	if (p->iph.protocol && p->iph.protocol != IPPROTO_IPIP) {
210	bb_error_msg_and_die("%s tunnel mode", "you managed to ask for more than one");
211	}
212	p->iph.protocol = IPPROTO_IPIP;
213	} else if (key == ARG_gre \|\|
214	key == ARG_gre_ip
215	) {
216	if (p->iph.protocol && p->iph.protocol != IPPROTO_GRE) {
217	bb_error_msg_and_die("%s tunnel mode", "you managed to ask for more than one");
218	}
219	p->iph.protocol = IPPROTO_GRE;
220	} else if (key == ARG_sit \|\|
221	key == ARG_ip6_ip
222	) {
223	if (p->iph.protocol && p->iph.protocol != IPPROTO_IPV6) {
224	bb_error_msg_and_die("%s tunnel mode", "you managed to ask for more than one");
225	}
226	p->iph.protocol = IPPROTO_IPV6;
227	} else {
228	bb_error_msg_and_die("%s tunnel mode", "can't guess");
229	}
230	} else if (key == ARG_key) {
231	unsigned uval;
232	NEXT_ARG();
233	p->i_flags \|= GRE_KEY;
234	p->o_flags \|= GRE_KEY;
235	if (strchr(*argv, '.'))
236	p->i_key = p->o_key = get_addr32(*argv);
237	else {
238	uval = get_unsigned(*argv, "key");
239	p->i_key = p->o_key = htonl(uval);
240	}
241	} else if (key == ARG_ikey) {
242	unsigned uval;
243	NEXT_ARG();
244	p->i_flags \|= GRE_KEY;
245	if (strchr(*argv, '.'))
246	p->o_key = get_addr32(*argv);
247	else {
248	uval = get_unsigned(*argv, "ikey");
249	p->i_key = htonl(uval);
250	}
251	} else if (key == ARG_okey) {
252	unsigned uval;
253	NEXT_ARG();
254	p->o_flags \|= GRE_KEY;
255	if (strchr(*argv, '.'))
256	p->o_key = get_addr32(*argv);
257	else {
258	uval = get_unsigned(*argv, "okey");
259	p->o_key = htonl(uval);
260	}
261	} else if (key == ARG_seq) {
262	p->i_flags \|= GRE_SEQ;
263	p->o_flags \|= GRE_SEQ;
264	} else if (key == ARG_iseq) {
265	p->i_flags \|= GRE_SEQ;
266	} else if (key == ARG_oseq) {
267	p->o_flags \|= GRE_SEQ;
268	} else if (key == ARG_csum) {
269	p->i_flags \|= GRE_CSUM;
270	p->o_flags \|= GRE_CSUM;
271	} else if (key == ARG_icsum) {
272	p->i_flags \|= GRE_CSUM;
273	} else if (key == ARG_ocsum) {
274	p->o_flags \|= GRE_CSUM;
275	} else if (key == ARG_nopmtudisc) {
276	p->iph.frag_off = 0;
277	} else if (key == ARG_pmtudisc) {
278	p->iph.frag_off = htons(IP_DF);
279	} else if (key == ARG_remote) {
280	NEXT_ARG();
281	key = index_in_strings(keywords, *argv);
282	if (key != ARG_any)
283	p->iph.daddr = get_addr32(*argv);
284	} else if (key == ARG_local) {
285	NEXT_ARG();
286	key = index_in_strings(keywords, *argv);
287	if (key != ARG_any)
288	p->iph.saddr = get_addr32(*argv);
289	} else if (key == ARG_dev) {
290	NEXT_ARG();
291	strncpy_IFNAMSIZ(medium, *argv);
292	} else if (key == ARG_ttl) {
293	unsigned uval;
294	NEXT_ARG();
295	key = index_in_strings(keywords, *argv);
296	if (key != ARG_inherit) {
297	uval = get_unsigned(*argv, "TTL");
298	if (uval > 255)
299	invarg(*argv, "TTL must be <=255");
300	p->iph.ttl = uval;
301	}
302	} else if (key == ARG_tos \|\|
303	key == ARG_dsfield
304	) {
305	uint32_t uval;
306	NEXT_ARG();
307	key = index_in_strings(keywords, *argv);
308	if (key != ARG_inherit) {
309	if (rtnl_dsfield_a2n(&uval, *argv))
310	invarg(*argv, "TOS");
311	p->iph.tos = uval;
312	} else
313	p->iph.tos = 1;
314	} else {
315	if (key == ARG_name) {
316	NEXT_ARG();
317	}
318	if (p->name[0])
319	duparg2("name", *argv);
320	strncpy_IFNAMSIZ(p->name, *argv);
321	if (cmd == SIOCCHGTUNNEL && count == 0) {
322	struct ip_tunnel_parm old_p;
323	memset(&old_p, 0, sizeof(old_p));
324	if (do_get_ioctl(*argv, &old_p))
325	exit(EXIT_FAILURE);
326	*p = old_p;
327	}
328	}
329	count++;
330	argv++;
331	}
332
333	if (p->iph.protocol == 0) {
334	if (memcmp(p->name, "gre", 3) == 0)
335	p->iph.protocol = IPPROTO_GRE;
336	else if (memcmp(p->name, "ipip", 4) == 0)
337	p->iph.protocol = IPPROTO_IPIP;
338	else if (memcmp(p->name, "sit", 3) == 0)
339	p->iph.protocol = IPPROTO_IPV6;
340	}
341
342	if (p->iph.protocol == IPPROTO_IPIP \|\| p->iph.protocol == IPPROTO_IPV6) {
343	if ((p->i_flags & GRE_KEY) \|\| (p->o_flags & GRE_KEY)) {
344	bb_error_msg_and_die("keys are not allowed with ipip and sit");
345	}
346	}
347
348	if (medium[0]) {
349	p->link = do_ioctl_get_ifindex(medium);
350	}
351
352	if (p->i_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
353	p->i_key = p->iph.daddr;
354	p->i_flags \|= GRE_KEY;
355	}
356	if (p->o_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
357	p->o_key = p->iph.daddr;
358	p->o_flags \|= GRE_KEY;
359	}
360	if (IN_MULTICAST(ntohl(p->iph.daddr)) && !p->iph.saddr) {
361	bb_error_msg_and_die("broadcast tunnel requires a source address");
362	}
363	}
364
365	/* Return value becomes exitcode. It's okay to not return at all */
366	static int do_add(int cmd, char **argv)
367	{
368	struct ip_tunnel_parm p;
369
370	parse_args(argv, cmd, &p);
371
372	if (p.iph.ttl && p.iph.frag_off == 0) {
373	bb_error_msg_and_die("ttl != 0 and noptmudisc are incompatible");
374	}
375
376	switch (p.iph.protocol) {
377	case IPPROTO_IPIP:
378	return do_add_ioctl(cmd, "tunl0", &p);
379	case IPPROTO_GRE:
380	return do_add_ioctl(cmd, "gre0", &p);
381	case IPPROTO_IPV6:
382	return do_add_ioctl(cmd, "sit0", &p);
383	default:
384	bb_error_msg_and_die("can't determine tunnel mode (ipip, gre or sit)");
385	}
386	}
387
388	/* Return value becomes exitcode. It's okay to not return at all */
389	static int do_del(char **argv)
390	{
391	struct ip_tunnel_parm p;
392
393	parse_args(argv, SIOCDELTUNNEL, &p);
394
395	switch (p.iph.protocol) {
396	case IPPROTO_IPIP:
397	return do_del_ioctl("tunl0", &p);
398	case IPPROTO_GRE:
399	return do_del_ioctl("gre0", &p);
400	case IPPROTO_IPV6:
401	return do_del_ioctl("sit0", &p);
402	default:
403	return do_del_ioctl(p.name, &p);
404	}
405	}
406
407	static void print_tunnel(struct ip_tunnel_parm *p)
408	{
409	char s1[256];
410	char s2[256];
411	char s3[64];
412	char s4[64];
413
414	format_host(AF_INET, 4, &p->iph.daddr, s1, sizeof(s1));
415	format_host(AF_INET, 4, &p->iph.saddr, s2, sizeof(s2));
416	inet_ntop(AF_INET, &p->i_key, s3, sizeof(s3));
417	inet_ntop(AF_INET, &p->o_key, s4, sizeof(s4));
418
419	printf("%s: %s/ip remote %s local %s ",
420	p->name,
421	p->iph.protocol == IPPROTO_IPIP ? "ip" :
422	(p->iph.protocol == IPPROTO_GRE ? "gre" :
423	(p->iph.protocol == IPPROTO_IPV6 ? "ipv6" : "unknown")),
424	p->iph.daddr ? s1 : "any", p->iph.saddr ? s2 : "any");
425	if (p->link) {
426	char *n = do_ioctl_get_ifname(p->link);
427	if (n) {
428	printf(" dev %s ", n);
429	free(n);
430	}
431	}
432	if (p->iph.ttl)
433	printf(" ttl %d ", p->iph.ttl);
434	else
435	printf(" ttl inherit ");
436	if (p->iph.tos) {
437	SPRINT_BUF(b1);
438	printf(" tos");
439	if (p->iph.tos & 1)
440	printf(" inherit");
441	if (p->iph.tos & ~1)
442	printf("%c%s ", p->iph.tos & 1 ? '/' : ' ',
443	rtnl_dsfield_n2a(p->iph.tos & ~1, b1));
444	}
445	if (!(p->iph.frag_off & htons(IP_DF)))
446	printf(" nopmtudisc");
447
448	if ((p->i_flags & GRE_KEY) && (p->o_flags & GRE_KEY) && p->o_key == p->i_key)
449	printf(" key %s", s3);
450	else if ((p->i_flags \| p->o_flags) & GRE_KEY) {
451	if (p->i_flags & GRE_KEY)
452	printf(" ikey %s ", s3);
453	if (p->o_flags & GRE_KEY)
454	printf(" okey %s ", s4);
455	}
456
457	if (p->i_flags & GRE_SEQ)
458	printf("%c Drop packets out of sequence.\n", _SL_);
459	if (p->i_flags & GRE_CSUM)
460	printf("%c Checksum in received packet is required.", _SL_);
461	if (p->o_flags & GRE_SEQ)
462	printf("%c Sequence packets on output.", _SL_);
463	if (p->o_flags & GRE_CSUM)
464	printf("%c Checksum output packets.", _SL_);
465	}
466
467	static void do_tunnels_list(struct ip_tunnel_parm *p)
468	{
469	char name[IFNAMSIZ];
470	unsigned long rx_bytes, rx_packets, rx_errs, rx_drops,
471	rx_fifo, rx_frame,
472	tx_bytes, tx_packets, tx_errs, tx_drops,
473	tx_fifo, tx_colls, tx_carrier, rx_multi;
474	int type;
475	struct ip_tunnel_parm p1;
476	char buf[512];
477	FILE *fp = fopen_or_warn("/proc/net/dev", "r");
478
479	if (fp == NULL) {
480	return;
481	}
482	/* skip headers */
483	fgets(buf, sizeof(buf), fp);
484	fgets(buf, sizeof(buf), fp);
485
486	while (fgets(buf, sizeof(buf), fp) != NULL) {
487	char *ptr;
488
489	/buf[sizeof(buf) - 1] = 0; - fgets is safe anyway /
490	ptr = strchr(buf, ':');
491	if (ptr == NULL \|\|
492	(*ptr++ = 0, sscanf(buf, "%s", name) != 1)
493	) {
494	bb_error_msg("wrong format of /proc/net/dev");
495	return;
496	}
497	if (sscanf(ptr, "%lu%lu%lu%lu%lu%lu%lu%*d%lu%lu%lu%lu%lu%lu%lu",
498	&rx_bytes, &rx_packets, &rx_errs, &rx_drops,
499	&rx_fifo, &rx_frame, &rx_multi,
500	&tx_bytes, &tx_packets, &tx_errs, &tx_drops,
501	&tx_fifo, &tx_colls, &tx_carrier) != 14)
502	continue;
503	if (p->name[0] && strcmp(p->name, name))
504	continue;
505	type = do_ioctl_get_iftype(name);
506	if (type == -1) {
507	bb_error_msg("can't get type of [%s]", name);
508	continue;
509	}
510	if (type != ARPHRD_TUNNEL && type != ARPHRD_IPGRE && type != ARPHRD_SIT)
511	continue;
512	memset(&p1, 0, sizeof(p1));
513	if (do_get_ioctl(name, &p1))
514	continue;
515	if ((p->link && p1.link != p->link) \|\|
516	(p->name[0] && strcmp(p1.name, p->name)) \|\|
517	(p->iph.daddr && p1.iph.daddr != p->iph.daddr) \|\|
518	(p->iph.saddr && p1.iph.saddr != p->iph.saddr) \|\|
519	(p->i_key && p1.i_key != p->i_key)
520	) {
521	continue;
522	}
523	print_tunnel(&p1);
524	bb_putchar('\n');
525	}
526	}
527
528	/* Return value becomes exitcode. It's okay to not return at all */
529	static int do_show(char **argv)
530	{
531	int err;
532	struct ip_tunnel_parm p;
533
534	parse_args(argv, SIOCGETTUNNEL, &p);
535
536	switch (p.iph.protocol) {
537	case IPPROTO_IPIP:
538	err = do_get_ioctl(p.name[0] ? p.name : "tunl0", &p);
539	break;
540	case IPPROTO_GRE:
541	err = do_get_ioctl(p.name[0] ? p.name : "gre0", &p);
542	break;
543	case IPPROTO_IPV6:
544	err = do_get_ioctl(p.name[0] ? p.name : "sit0", &p);
545	break;
546	default:
547	do_tunnels_list(&p);
548	return 0;
549	}
550	if (err)
551	return -1;
552
553	print_tunnel(&p);
554	bb_putchar('\n');
555	return 0;
556	}
557
558	/* Return value becomes exitcode. It's okay to not return at all */
559	int do_iptunnel(char **argv)
560	{
561	static const char keywords[] ALIGN1 =
562	"add\0""change\0""delete\0""show\0""list\0""lst\0";
563	enum { ARG_add = 0, ARG_change, ARG_del, ARG_show, ARG_list, ARG_lst };
564
565	if (*argv) {
566	smalluint key = index_in_substrings(keywords, *argv);
567	if (key > 5)
568	bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name);
569	argv++;
570	if (key == ARG_add)
571	return do_add(SIOCADDTUNNEL, argv);
572	if (key == ARG_change)
573	return do_add(SIOCCHGTUNNEL, argv);
574	if (key == ARG_del)
575	return do_del(argv);
576	}
577	return do_show(argv);
578	}