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trylink: explain how to modify link and drastically decrease amount of padding (unfortunately, needs hand editing ATM). *: add ALIGN1 / ALIGN2 to global strings and arrays of bytes and shorts size saving: 0.5k
542 lines
14 KiB
C
542 lines
14 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* iptunnel.c "ip tunnel"
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*
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* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
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*
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* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
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*
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*
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* Changes:
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*
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* Rani Assaf <rani@magic.metawire.com> 980929: resolve addresses
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* Rani Assaf <rani@magic.metawire.com> 980930: do not allow key for ipip/sit
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* Phil Karn <karn@ka9q.ampr.org> 990408: "pmtudisc" flag
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*/
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#include <netinet/ip.h>
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#include <net/if.h>
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#include <net/if_arp.h>
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#include <asm/types.h>
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#ifndef __constant_htons
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#define __constant_htons htons
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#endif
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#include <linux/if_tunnel.h>
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#include "ip_common.h" /* #include "libbb.h" is inside */
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#include "rt_names.h"
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#include "utils.h"
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/* Dies on error */
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static int do_ioctl_get_ifindex(char *dev)
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{
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struct ifreq ifr;
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int fd;
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strncpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name));
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fd = xsocket(AF_INET, SOCK_DGRAM, 0);
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xioctl(fd, SIOCGIFINDEX, &ifr);
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close(fd);
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return ifr.ifr_ifindex;
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}
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static int do_ioctl_get_iftype(char *dev)
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{
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struct ifreq ifr;
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int fd;
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int err;
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strncpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name));
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fd = xsocket(AF_INET, SOCK_DGRAM, 0);
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err = ioctl_or_warn(fd, SIOCGIFHWADDR, &ifr);
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close(fd);
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return err ? -1 : ifr.ifr_addr.sa_family;
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}
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static char *do_ioctl_get_ifname(int idx)
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{
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struct ifreq ifr;
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int fd;
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int err;
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ifr.ifr_ifindex = idx;
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fd = xsocket(AF_INET, SOCK_DGRAM, 0);
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err = ioctl_or_warn(fd, SIOCGIFNAME, &ifr);
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close(fd);
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return err ? NULL : xstrndup(ifr.ifr_name, sizeof(ifr.ifr_name));
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}
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static int do_get_ioctl(const char *basedev, struct ip_tunnel_parm *p)
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{
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struct ifreq ifr;
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int fd;
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int err;
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strncpy(ifr.ifr_name, basedev, sizeof(ifr.ifr_name));
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ifr.ifr_ifru.ifru_data = (void*)p;
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fd = xsocket(AF_INET, SOCK_DGRAM, 0);
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err = ioctl_or_warn(fd, SIOCGETTUNNEL, &ifr);
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close(fd);
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return err;
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}
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/* Dies on error, otherwise returns 0 */
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static int do_add_ioctl(int cmd, const char *basedev, struct ip_tunnel_parm *p)
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{
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struct ifreq ifr;
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int fd;
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if (cmd == SIOCCHGTUNNEL && p->name[0]) {
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strncpy(ifr.ifr_name, p->name, sizeof(ifr.ifr_name));
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} else {
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strncpy(ifr.ifr_name, basedev, sizeof(ifr.ifr_name));
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}
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ifr.ifr_ifru.ifru_data = (void*)p;
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fd = xsocket(AF_INET, SOCK_DGRAM, 0);
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#if ENABLE_IOCTL_HEX2STR_ERROR
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/* #define magic will turn ioctl# into string */
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if (cmd == SIOCCHGTUNNEL)
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xioctl(fd, SIOCCHGTUNNEL, &ifr);
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else
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xioctl(fd, SIOCADDTUNNEL, &ifr);
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#else
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xioctl(fd, cmd, &ifr);
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#endif
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close(fd);
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return 0;
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}
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/* Dies on error, otherwise returns 0 */
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static int do_del_ioctl(const char *basedev, struct ip_tunnel_parm *p)
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{
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struct ifreq ifr;
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int fd;
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if (p->name[0]) {
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strncpy(ifr.ifr_name, p->name, sizeof(ifr.ifr_name));
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} else {
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strncpy(ifr.ifr_name, basedev, sizeof(ifr.ifr_name));
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}
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ifr.ifr_ifru.ifru_data = (void*)p;
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fd = xsocket(AF_INET, SOCK_DGRAM, 0);
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xioctl(fd, SIOCDELTUNNEL, &ifr);
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close(fd);
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return 0;
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}
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/* Dies on error */
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static void parse_args(int argc, char **argv, int cmd, struct ip_tunnel_parm *p)
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{
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static const char keywords[] ALIGN1 =
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"mode\0""ipip\0""ip/ip\0""gre\0""gre/ip\0""sit\0""ipv6/ip\0"
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"key\0""ikey\0""okey\0""seq\0""iseq\0""oseq\0"
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"csum\0""icsum\0""ocsum\0""nopmtudisc\0""pmtudisc\0"
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"remote\0""any\0""local\0""dev\0"
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"ttl\0""inherit\0""tos\0""dsfield\0"
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"name\0";
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enum {
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ARG_mode, ARG_ipip, ARG_ip_ip, ARG_gre, ARG_gre_ip, ARG_sit, ARG_ip6_ip,
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ARG_key, ARG_ikey, ARG_okey, ARG_seq, ARG_iseq, ARG_oseq,
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ARG_csum, ARG_icsum, ARG_ocsum, ARG_nopmtudisc, ARG_pmtudisc,
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ARG_remote, ARG_any, ARG_local, ARG_dev,
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ARG_ttl, ARG_inherit, ARG_tos, ARG_dsfield,
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ARG_name
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};
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int count = 0;
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char medium[IFNAMSIZ];
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int key;
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memset(p, 0, sizeof(*p));
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memset(&medium, 0, sizeof(medium));
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p->iph.version = 4;
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p->iph.ihl = 5;
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#ifndef IP_DF
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#define IP_DF 0x4000 /* Flag: "Don't Fragment" */
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#endif
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p->iph.frag_off = htons(IP_DF);
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while (argc > 0) {
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key = index_in_strings(keywords, *argv);
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if (key == ARG_mode) {
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NEXT_ARG();
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key = index_in_strings(keywords, *argv);
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if (key == ARG_ipip ||
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key == ARG_ip_ip) {
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if (p->iph.protocol && p->iph.protocol != IPPROTO_IPIP) {
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bb_error_msg_and_die("you managed to ask for more than one tunnel mode");
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}
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p->iph.protocol = IPPROTO_IPIP;
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} else if (key == ARG_gre ||
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key == ARG_gre_ip) {
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if (p->iph.protocol && p->iph.protocol != IPPROTO_GRE) {
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bb_error_msg_and_die("you managed to ask for more than one tunnel mode");
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}
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p->iph.protocol = IPPROTO_GRE;
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} else if (key == ARG_sit ||
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key == ARG_ip6_ip) {
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if (p->iph.protocol && p->iph.protocol != IPPROTO_IPV6) {
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bb_error_msg_and_die("you managed to ask for more than one tunnel mode");
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}
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p->iph.protocol = IPPROTO_IPV6;
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} else {
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bb_error_msg_and_die("cannot guess tunnel mode");
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}
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} else if (key == ARG_key) {
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unsigned uval;
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NEXT_ARG();
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p->i_flags |= GRE_KEY;
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p->o_flags |= GRE_KEY;
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if (strchr(*argv, '.'))
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p->i_key = p->o_key = get_addr32(*argv);
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else {
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if (get_unsigned(&uval, *argv, 0)<0) {
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bb_error_msg_and_die("invalid value of \"key\"");
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}
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p->i_key = p->o_key = htonl(uval);
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}
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} else if (key == ARG_ikey) {
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unsigned uval;
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NEXT_ARG();
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p->i_flags |= GRE_KEY;
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if (strchr(*argv, '.'))
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p->o_key = get_addr32(*argv);
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else {
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if (get_unsigned(&uval, *argv, 0)<0) {
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bb_error_msg_and_die("invalid value of \"ikey\"");
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}
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p->i_key = htonl(uval);
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}
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} else if (key == ARG_okey) {
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unsigned uval;
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NEXT_ARG();
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p->o_flags |= GRE_KEY;
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if (strchr(*argv, '.'))
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p->o_key = get_addr32(*argv);
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else {
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if (get_unsigned(&uval, *argv, 0)<0) {
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bb_error_msg_and_die("invalid value of \"okey\"");
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}
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p->o_key = htonl(uval);
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}
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} else if (key == ARG_seq) {
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p->i_flags |= GRE_SEQ;
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p->o_flags |= GRE_SEQ;
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} else if (key == ARG_iseq) {
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p->i_flags |= GRE_SEQ;
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} else if (key == ARG_oseq) {
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p->o_flags |= GRE_SEQ;
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} else if (key == ARG_csum) {
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p->i_flags |= GRE_CSUM;
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p->o_flags |= GRE_CSUM;
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} else if (key == ARG_icsum) {
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p->i_flags |= GRE_CSUM;
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} else if (key == ARG_ocsum) {
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p->o_flags |= GRE_CSUM;
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} else if (key == ARG_nopmtudisc) {
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p->iph.frag_off = 0;
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} else if (key == ARG_pmtudisc) {
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p->iph.frag_off = htons(IP_DF);
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} else if (key == ARG_remote) {
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NEXT_ARG();
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key = index_in_strings(keywords, *argv);
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if (key == ARG_any)
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p->iph.daddr = get_addr32(*argv);
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} else if (key == ARG_local) {
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NEXT_ARG();
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key = index_in_strings(keywords, *argv);
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if (key == ARG_any)
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p->iph.saddr = get_addr32(*argv);
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} else if (key == ARG_dev) {
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NEXT_ARG();
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strncpy(medium, *argv, IFNAMSIZ-1);
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} else if (key == ARG_ttl) {
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unsigned uval;
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NEXT_ARG();
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key = index_in_strings(keywords, *argv);
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if (key != ARG_inherit) {
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if (get_unsigned(&uval, *argv, 0))
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invarg(*argv, "TTL");
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if (uval > 255)
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invarg(*argv, "TTL must be <=255");
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p->iph.ttl = uval;
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}
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} else if (key == ARG_tos ||
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key == ARG_dsfield) {
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uint32_t uval;
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NEXT_ARG();
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key = index_in_strings(keywords, *argv);
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if (key != ARG_inherit) {
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if (rtnl_dsfield_a2n(&uval, *argv))
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invarg(*argv, "TOS");
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p->iph.tos = uval;
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} else
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p->iph.tos = 1;
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} else {
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if (key == ARG_name) {
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NEXT_ARG();
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}
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if (p->name[0])
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duparg2("name", *argv);
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strncpy(p->name, *argv, IFNAMSIZ);
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if (cmd == SIOCCHGTUNNEL && count == 0) {
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struct ip_tunnel_parm old_p;
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memset(&old_p, 0, sizeof(old_p));
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if (do_get_ioctl(*argv, &old_p))
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exit(1);
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*p = old_p;
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}
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}
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count++;
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argc--;
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argv++;
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}
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if (p->iph.protocol == 0) {
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if (memcmp(p->name, "gre", 3) == 0)
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p->iph.protocol = IPPROTO_GRE;
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else if (memcmp(p->name, "ipip", 4) == 0)
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p->iph.protocol = IPPROTO_IPIP;
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else if (memcmp(p->name, "sit", 3) == 0)
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p->iph.protocol = IPPROTO_IPV6;
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}
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if (p->iph.protocol == IPPROTO_IPIP || p->iph.protocol == IPPROTO_IPV6) {
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if ((p->i_flags & GRE_KEY) || (p->o_flags & GRE_KEY)) {
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bb_error_msg_and_die("keys are not allowed with ipip and sit");
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}
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}
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if (medium[0]) {
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p->link = do_ioctl_get_ifindex(medium);
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}
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if (p->i_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
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p->i_key = p->iph.daddr;
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p->i_flags |= GRE_KEY;
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}
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if (p->o_key == 0 && IN_MULTICAST(ntohl(p->iph.daddr))) {
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p->o_key = p->iph.daddr;
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p->o_flags |= GRE_KEY;
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}
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if (IN_MULTICAST(ntohl(p->iph.daddr)) && !p->iph.saddr) {
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bb_error_msg_and_die("broadcast tunnel requires a source address");
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}
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}
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/* Return value becomes exitcode. It's okay to not return at all */
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static int do_add(int cmd, int argc, char **argv)
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{
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struct ip_tunnel_parm p;
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parse_args(argc, argv, cmd, &p);
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if (p.iph.ttl && p.iph.frag_off == 0) {
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bb_error_msg_and_die("ttl != 0 and noptmudisc are incompatible");
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}
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switch (p.iph.protocol) {
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case IPPROTO_IPIP:
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return do_add_ioctl(cmd, "tunl0", &p);
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case IPPROTO_GRE:
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return do_add_ioctl(cmd, "gre0", &p);
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case IPPROTO_IPV6:
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return do_add_ioctl(cmd, "sit0", &p);
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default:
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bb_error_msg_and_die("cannot determine tunnel mode (ipip, gre or sit)");
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}
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}
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/* Return value becomes exitcode. It's okay to not return at all */
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static int do_del(int argc, char **argv)
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{
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struct ip_tunnel_parm p;
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parse_args(argc, argv, SIOCDELTUNNEL, &p);
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switch (p.iph.protocol) {
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case IPPROTO_IPIP:
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return do_del_ioctl("tunl0", &p);
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case IPPROTO_GRE:
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return do_del_ioctl("gre0", &p);
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case IPPROTO_IPV6:
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return do_del_ioctl("sit0", &p);
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default:
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return do_del_ioctl(p.name, &p);
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}
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}
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static void print_tunnel(struct ip_tunnel_parm *p)
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{
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char s1[256];
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char s2[256];
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char s3[64];
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char s4[64];
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format_host(AF_INET, 4, &p->iph.daddr, s1, sizeof(s1));
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format_host(AF_INET, 4, &p->iph.saddr, s2, sizeof(s2));
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inet_ntop(AF_INET, &p->i_key, s3, sizeof(s3));
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inet_ntop(AF_INET, &p->o_key, s4, sizeof(s4));
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printf("%s: %s/ip remote %s local %s ",
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p->name,
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p->iph.protocol == IPPROTO_IPIP ? "ip" :
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(p->iph.protocol == IPPROTO_GRE ? "gre" :
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(p->iph.protocol == IPPROTO_IPV6 ? "ipv6" : "unknown")),
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p->iph.daddr ? s1 : "any", p->iph.saddr ? s2 : "any");
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if (p->link) {
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char *n = do_ioctl_get_ifname(p->link);
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if (n) {
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printf(" dev %s ", n);
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free(n);
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}
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}
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if (p->iph.ttl)
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printf(" ttl %d ", p->iph.ttl);
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else
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printf(" ttl inherit ");
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if (p->iph.tos) {
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SPRINT_BUF(b1);
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printf(" tos");
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if (p->iph.tos & 1)
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printf(" inherit");
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if (p->iph.tos & ~1)
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printf("%c%s ", p->iph.tos & 1 ? '/' : ' ',
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rtnl_dsfield_n2a(p->iph.tos & ~1, b1, sizeof(b1)));
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}
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if (!(p->iph.frag_off & htons(IP_DF)))
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printf(" nopmtudisc");
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if ((p->i_flags & GRE_KEY) && (p->o_flags & GRE_KEY) && p->o_key == p->i_key)
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printf(" key %s", s3);
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else if ((p->i_flags | p->o_flags) & GRE_KEY) {
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if (p->i_flags & GRE_KEY)
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printf(" ikey %s ", s3);
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if (p->o_flags & GRE_KEY)
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printf(" okey %s ", s4);
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}
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if (p->i_flags & GRE_SEQ)
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printf("%c Drop packets out of sequence.\n", _SL_);
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if (p->i_flags & GRE_CSUM)
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printf("%c Checksum in received packet is required.", _SL_);
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if (p->o_flags & GRE_SEQ)
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printf("%c Sequence packets on output.", _SL_);
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if (p->o_flags & GRE_CSUM)
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printf("%c Checksum output packets.", _SL_);
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}
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static void do_tunnels_list(struct ip_tunnel_parm *p)
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{
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char name[IFNAMSIZ];
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unsigned long rx_bytes, rx_packets, rx_errs, rx_drops,
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rx_fifo, rx_frame,
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tx_bytes, tx_packets, tx_errs, tx_drops,
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tx_fifo, tx_colls, tx_carrier, rx_multi;
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int type;
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struct ip_tunnel_parm p1;
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char buf[512];
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FILE *fp = fopen_or_warn("/proc/net/dev", "r");
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if (fp == NULL) {
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return;
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}
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fgets(buf, sizeof(buf), fp);
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fgets(buf, sizeof(buf), fp);
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while (fgets(buf, sizeof(buf), fp) != NULL) {
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char *ptr;
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/*buf[sizeof(buf) - 1] = 0; - fgets is safe anyway */
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ptr = strchr(buf, ':');
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if (ptr == NULL ||
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(*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("cannot 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);
|
|
puts("");
|
|
}
|
|
}
|
|
|
|
/* Return value becomes exitcode. It's okay to not return at all */
|
|
static int do_show(int argc, char **argv)
|
|
{
|
|
int err;
|
|
struct ip_tunnel_parm p;
|
|
|
|
parse_args(argc, 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);
|
|
puts("");
|
|
return 0;
|
|
}
|
|
|
|
/* Return value becomes exitcode. It's okay to not return at all */
|
|
int do_iptunnel(int argc, 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 };
|
|
int key;
|
|
|
|
if (argc) {
|
|
key = index_in_substrings(keywords, *argv);
|
|
if (key < 0)
|
|
bb_error_msg_and_die(bb_msg_invalid_arg, *argv, applet_name);
|
|
--argc;
|
|
++argv;
|
|
if (key == ARG_add)
|
|
return do_add(SIOCADDTUNNEL, argc, argv);
|
|
if (key == ARG_change)
|
|
return do_add(SIOCCHGTUNNEL, argc, argv);
|
|
if (key == ARG_del)
|
|
return do_del(argc, argv);
|
|
}
|
|
return do_show(argc, argv);
|
|
}
|