IP applet by Bastian Blank <waldi@debian.org>
diff --git a/networking/libiproute/iptunnel.c b/networking/libiproute/iptunnel.c
new file mode 100644
index 0000000..beb8bb6
--- /dev/null
+++ b/networking/libiproute/iptunnel.c
@@ -0,0 +1,548 @@
+/*
+ * iptunnel.c	       "ip tunnel"
+ *
+ *		This program is free software; you can redistribute it and/or
+ *		modify it under the terms of the GNU General Public License
+ *		as published by the Free Software Foundation; either version
+ *		2 of the License, or (at your option) any later version.
+ *
+ * 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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <syslog.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+#include <sys/ioctl.h>
+#include <netinet/in.h>
+#include <netinet/ip.h>
+#include <arpa/inet.h>
+
+#include <linux/if.h>
+#include <linux/if_arp.h>
+#include <linux/if_tunnel.h>
+
+#include "rt_names.h"
+#include "utils.h"
+
+#include "busybox.h"
+
+static int do_ioctl_get_ifindex(char *dev)
+{
+	struct ifreq ifr;
+	int fd;
+	int err;
+
+	strcpy(ifr.ifr_name, dev);
+	fd = socket(AF_INET, SOCK_DGRAM, 0);
+	err = ioctl(fd, SIOCGIFINDEX, &ifr);
+	if (err) {
+		perror("ioctl");
+		return 0;
+	}
+	close(fd);
+	return ifr.ifr_ifindex;
+}
+
+static int do_ioctl_get_iftype(char *dev)
+{
+	struct ifreq ifr;
+	int fd;
+	int err;
+
+	strcpy(ifr.ifr_name, dev);
+	fd = socket(AF_INET, SOCK_DGRAM, 0);
+	err = ioctl(fd, SIOCGIFHWADDR, &ifr);
+	if (err) {
+		perror("ioctl");
+		return -1;
+	}
+	close(fd);
+	return ifr.ifr_addr.sa_family;
+}
+
+
+static char * do_ioctl_get_ifname(int idx)
+{
+	static struct ifreq ifr;
+	int fd;
+	int err;
+
+	ifr.ifr_ifindex = idx;
+	fd = socket(AF_INET, SOCK_DGRAM, 0);
+	err = ioctl(fd, SIOCGIFNAME, &ifr);
+	if (err) {
+		perror("ioctl");
+		return NULL;
+	}
+	close(fd);
+	return ifr.ifr_name;
+}
+
+
+
+static int do_get_ioctl(char *basedev, struct ip_tunnel_parm *p)
+{
+	struct ifreq ifr;
+	int fd;
+	int err;
+
+	strcpy(ifr.ifr_name, basedev);
+	ifr.ifr_ifru.ifru_data = (void*)p;
+	fd = socket(AF_INET, SOCK_DGRAM, 0);
+	err = ioctl(fd, SIOCGETTUNNEL, &ifr);
+	if (err)
+		perror("ioctl");
+	close(fd);
+	return err;
+}
+
+static int do_add_ioctl(int cmd, char *basedev, struct ip_tunnel_parm *p)
+{
+	struct ifreq ifr;
+	int fd;
+	int err;
+
+	if (cmd == SIOCCHGTUNNEL && p->name[0])
+		strcpy(ifr.ifr_name, p->name);
+	else
+		strcpy(ifr.ifr_name, basedev);
+	ifr.ifr_ifru.ifru_data = (void*)p;
+	fd = socket(AF_INET, SOCK_DGRAM, 0);
+	err = ioctl(fd, cmd, &ifr);
+	if (err)
+		perror("ioctl");
+	close(fd);
+	return err;
+}
+
+static int do_del_ioctl(char *basedev, struct ip_tunnel_parm *p)
+{
+	struct ifreq ifr;
+	int fd;
+	int err;
+
+	if (p->name[0])
+		strcpy(ifr.ifr_name, p->name);
+	else
+		strcpy(ifr.ifr_name, basedev);
+	ifr.ifr_ifru.ifru_data = (void*)p;
+	fd = socket(AF_INET, SOCK_DGRAM, 0);
+	err = ioctl(fd, SIOCDELTUNNEL, &ifr);
+	if (err)
+		perror("ioctl");
+	close(fd);
+	return err;
+}
+
+static int parse_args(int argc, char **argv, int cmd, struct ip_tunnel_parm *p)
+{
+	int count = 0;
+	char medium[IFNAMSIZ];
+
+	memset(p, 0, sizeof(*p));
+	memset(&medium, 0, sizeof(medium));
+
+	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 (argc > 0) {
+		if (strcmp(*argv, "mode") == 0) {
+			NEXT_ARG();
+			if (strcmp(*argv, "ipip") == 0 ||
+			    strcmp(*argv, "ip/ip") == 0) {
+				if (p->iph.protocol && p->iph.protocol != IPPROTO_IPIP) {
+					fprintf(stderr,"You managed to ask for more than one tunnel mode.\n");
+					exit(-1);
+				}
+				p->iph.protocol = IPPROTO_IPIP;
+			} else if (strcmp(*argv, "gre") == 0 ||
+				   strcmp(*argv, "gre/ip") == 0) {
+				if (p->iph.protocol && p->iph.protocol != IPPROTO_GRE) {
+					fprintf(stderr,"You managed to ask for more than one tunnel mode.\n");
+					exit(-1);
+				}
+				p->iph.protocol = IPPROTO_GRE;
+			} else if (strcmp(*argv, "sit") == 0 ||
+				   strcmp(*argv, "ipv6/ip") == 0) {
+				if (p->iph.protocol && p->iph.protocol != IPPROTO_IPV6) {
+					fprintf(stderr,"You managed to ask for more than one tunnel mode.\n");
+					exit(-1);
+				}
+				p->iph.protocol = IPPROTO_IPV6;
+			} else {
+				fprintf(stderr,"Cannot guess tunnel mode.\n");
+				exit(-1);
+			}
+		} else if (strcmp(*argv, "key") == 0) {
+			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 {
+				if (get_unsigned(&uval, *argv, 0)<0) {
+					fprintf(stderr, "invalid value of \"key\"\n");
+					exit(-1);
+				}
+				p->i_key = p->o_key = htonl(uval);
+			}
+		} else if (strcmp(*argv, "ikey") == 0) {
+			unsigned uval;
+			NEXT_ARG();
+			p->i_flags |= GRE_KEY;
+			if (strchr(*argv, '.'))
+				p->o_key = get_addr32(*argv);
+			else {
+				if (get_unsigned(&uval, *argv, 0)<0) {
+					fprintf(stderr, "invalid value of \"ikey\"\n");
+					exit(-1);
+				}
+				p->i_key = htonl(uval);
+			}
+		} else if (strcmp(*argv, "okey") == 0) {
+			unsigned uval;
+			NEXT_ARG();
+			p->o_flags |= GRE_KEY;
+			if (strchr(*argv, '.'))
+				p->o_key = get_addr32(*argv);
+			else {
+				if (get_unsigned(&uval, *argv, 0)<0) {
+					fprintf(stderr, "invalid value of \"okey\"\n");
+					exit(-1);
+				}
+				p->o_key = htonl(uval);
+			}
+		} else if (strcmp(*argv, "seq") == 0) {
+			p->i_flags |= GRE_SEQ;
+			p->o_flags |= GRE_SEQ;
+		} else if (strcmp(*argv, "iseq") == 0) {
+			p->i_flags |= GRE_SEQ;
+		} else if (strcmp(*argv, "oseq") == 0) {
+			p->o_flags |= GRE_SEQ;
+		} else if (strcmp(*argv, "csum") == 0) {
+			p->i_flags |= GRE_CSUM;
+			p->o_flags |= GRE_CSUM;
+		} else if (strcmp(*argv, "icsum") == 0) {
+			p->i_flags |= GRE_CSUM;
+		} else if (strcmp(*argv, "ocsum") == 0) {
+			p->o_flags |= GRE_CSUM;
+		} else if (strcmp(*argv, "nopmtudisc") == 0) {
+			p->iph.frag_off = 0;
+		} else if (strcmp(*argv, "pmtudisc") == 0) {
+			p->iph.frag_off = htons(IP_DF);
+		} else if (strcmp(*argv, "remote") == 0) {
+			NEXT_ARG();
+			if (strcmp(*argv, "any"))
+				p->iph.daddr = get_addr32(*argv);
+		} else if (strcmp(*argv, "local") == 0) {
+			NEXT_ARG();
+			if (strcmp(*argv, "any"))
+				p->iph.saddr = get_addr32(*argv);
+		} else if (strcmp(*argv, "dev") == 0) {
+			NEXT_ARG();
+			strncpy(medium, *argv, IFNAMSIZ-1);
+		} else if (strcmp(*argv, "ttl") == 0) {
+			unsigned uval;
+			NEXT_ARG();
+			if (strcmp(*argv, "inherit") != 0) {
+				if (get_unsigned(&uval, *argv, 0))
+					invarg("invalid TTL\n", *argv);
+				if (uval > 255)
+					invarg("TTL must be <=255\n", *argv);
+				p->iph.ttl = uval;
+			}
+		} else if (strcmp(*argv, "tos") == 0 ||
+			   matches(*argv, "dsfield") == 0) {
+			__u32 uval;
+			NEXT_ARG();
+			if (strcmp(*argv, "inherit") != 0) {
+				if (rtnl_dsfield_a2n(&uval, *argv))
+					invarg("bad TOS value", *argv);
+				p->iph.tos = uval;
+			} else
+				p->iph.tos = 1;
+		} else {
+			if (strcmp(*argv, "name") == 0) {
+				NEXT_ARG();
+			}
+			if (p->name[0])
+				duparg2("name", *argv);
+			strncpy(p->name, *argv, IFNAMSIZ);
+			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))
+					return -1;
+				*p = old_p;
+			}
+		}
+		count++;
+		argc--; 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)) {
+			fprintf(stderr, "Keys are not allowed with ipip and sit.\n");
+			return -1;
+		}
+	}
+
+	if (medium[0]) {
+		p->link = do_ioctl_get_ifindex(medium);
+		if (p->link == 0)
+			return -1;
+	}
+
+	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) {
+		fprintf(stderr, "Broadcast tunnel requires a source address.\n");
+		return -1;
+	}
+	return 0;
+}
+
+
+static int do_add(int cmd, int argc, char **argv)
+{
+	struct ip_tunnel_parm p;
+
+	if (parse_args(argc, argv, cmd, &p) < 0)
+		return -1;
+
+	if (p.iph.ttl && p.iph.frag_off == 0) {
+		fprintf(stderr, "ttl != 0 and noptmudisc are incompatible\n");
+		return -1;
+	}
+
+	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:	
+		fprintf(stderr, "cannot determine tunnel mode (ipip, gre or sit)\n");
+		return -1;
+	}
+	return -1;
+}
+
+int do_del(int argc, char **argv)
+{
+	struct ip_tunnel_parm p;
+
+	if (parse_args(argc, argv, SIOCDELTUNNEL, &p) < 0)
+		return -1;
+
+	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);
+	}
+	return -1;
+}
+
+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);
+	}
+	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, sizeof(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("%s  Drop packets out of sequence.\n", _SL_);
+	if (p->i_flags&GRE_CSUM)
+		printf("%s  Checksum in received packet is required.", _SL_);
+	if (p->o_flags&GRE_SEQ)
+		printf("%s  Sequence packets on output.", _SL_);
+	if (p->o_flags&GRE_CSUM)
+		printf("%s  Checksum output packets.", _SL_);
+}
+
+static int 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("/proc/net/dev", "r");
+	if (fp == NULL) {
+		perror("fopen");
+		return -1;
+	}
+
+	fgets(buf, sizeof(buf), fp);
+	fgets(buf, sizeof(buf), fp);
+
+	while (fgets(buf, sizeof(buf), fp) != NULL) {
+		char *ptr;
+		buf[sizeof(buf) - 1] = 0;
+		if ((ptr = strchr(buf, ':')) == NULL ||
+		    (*ptr++ = 0, sscanf(buf, "%s", name) != 1)) {
+			fprintf(stderr, "Wrong format of /proc/net/dev. Sorry.\n");
+			return -1;
+		}
+		if (sscanf(ptr, "%ld%ld%ld%ld%ld%ld%ld%*d%ld%ld%ld%ld%ld%ld%ld",
+			   &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) {
+			fprintf(stderr, "Failed to get type of [%s]\n", 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);
+		printf("\n");
+	}
+	return 0;
+}
+
+static int do_show(int argc, char **argv)
+{
+	int err;
+	struct ip_tunnel_parm p;
+
+	if (parse_args(argc, argv, SIOCGETTUNNEL, &p) < 0)
+		return -1;
+
+	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);
+	printf("\n");
+	return 0;
+}
+
+int do_iptunnel(int argc, char **argv)
+{
+	if (argc > 0) {
+		if (matches(*argv, "add") == 0)
+			return do_add(SIOCADDTUNNEL, argc-1, argv+1);
+		if (matches(*argv, "change") == 0)
+			return do_add(SIOCCHGTUNNEL, argc-1, argv+1);
+		if (matches(*argv, "del") == 0)
+			return do_del(argc-1, argv+1);
+		if (matches(*argv, "show") == 0 ||
+		    matches(*argv, "lst") == 0 ||
+		    matches(*argv, "list") == 0)
+			return do_show(argc-1, argv+1);
+	} else
+		return do_show(0, NULL);
+
+	fprintf(stderr, "Command \"%s\" is unknown, try \"ip tunnel help\".\n", *argv);
+	exit(-1);
+}