1085 lines
26 KiB
C
1085 lines
26 KiB
C
/*
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* Copyright (c) 2001, Adam Dunkels.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote
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* products derived from this software without specific prior
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* written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
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* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
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* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
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* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
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* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
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* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
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* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* This file is part of the uIP TCP/IP stack.
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*
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* $Id: tunslip.c,v 1.13 2007/05/02 08:58:00 bg- Exp $
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*
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include <stdarg.h>
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#include <string.h>
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#include <time.h>
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#include <sys/types.h>
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#include <unistd.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <signal.h>
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#include <termios.h>
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#include <sys/ioctl.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#include <err.h>
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int ssystem(const char *fmt, ...)
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__attribute__((__format__ (__printf__, 1, 2)));
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void write_to_serial(int outfd, void *inbuf, int len);
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//#define PROGRESS(s) fprintf(stderr, s)
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#define PROGRESS(s) do { } while (0)
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struct ip {
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u_int8_t ip_vhl; /* version and header length */
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#define IP_V4 0x40
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#define IP_V 0xf0
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#define IP_HL 0x0f
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u_int8_t ip_tos; /* type of service */
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u_int16_t ip_len; /* total length */
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u_int16_t ip_id; /* identification */
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u_int16_t ip_off; /* fragment offset field */
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#define IP_RF 0x8000 /* reserved fragment flag */
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#define IP_DF 0x4000 /* dont fragment flag */
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#define IP_MF 0x2000 /* more fragments flag */
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#define IP_OFFMASK 0x1fff /* mask for fragmenting bits */
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u_int8_t ip_ttl; /* time to live */
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u_int8_t ip_p; /* protocol */
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u_int16_t ip_sum; /* checksum */
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u_int32_t ip_src, ip_dst; /* source and dest address */
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u_int16_t uh_sport; /* source port */
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u_int16_t uh_dport; /* destination port */
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u_int16_t uh_ulen; /* udp length */
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u_int16_t uh_sum; /* udp checksum */
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};
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int check_ip(const struct ip *ip, unsigned ip_len);
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u_int16_t ip4sum(u_int16_t sum, const void *_p, u_int16_t len);
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struct dhcp_msg {
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u_int8_t op, htype, hlen, hops;
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u_int8_t xid[4];
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u_int16_t secs, flags;
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u_int8_t ciaddr[4];
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u_int8_t yiaddr[4];
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u_int8_t siaddr[4];
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u_int8_t giaddr[4];
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u_int8_t chaddr[16];
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#define DHCP_BASE_LEN (4*7 + 16)
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u_int8_t sname[64];
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u_int8_t file[128];
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#define DHCP_HOLE_LEN (64 + 128)
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#define DHCP_MSG_LEN (DHCP_BASE_LEN + DHCP_HOLE_LEN)
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u_int8_t options[312];
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};
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struct dhcp_light_msg {
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u_int8_t op, htype, hlen, hops;
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u_int8_t xid[4];
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u_int16_t secs, flags;
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u_int8_t ciaddr[4];
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u_int8_t yiaddr[4];
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u_int8_t siaddr[4];
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u_int8_t giaddr[4];
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u_int8_t chaddr[16];
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#define DHCP_LIGHT_MSG_LEN (4*7 + 16)
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u_int8_t options[312];
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};
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#define DHCP_OPTION_SUBNET_MASK 1
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#define DHCP_OPTION_ROUTER 3
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#define DHCP_OPTION_DNS_SERVER 6
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#define DHCP_OPTION_REQ_IPADDR 50
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#define DHCP_OPTION_LEASE_TIME 51
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#define DHCP_OPTION_MSG_TYPE 53
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#define DHCP_OPTION_SERVER_ID 54
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#define DHCP_OPTION_REQ_LIST 55
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#define DHCP_OPTION_AGENT 82
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#define DHCP_OPTION_SUBNET_SELECTION 118
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#define DHCP_OPTION_END 255
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/* DHCP_OPTION_AGENT, Relay Agent Information option subtypes: */
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#define RAI_CIRCUIT_ID 1
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#define RAI_REMOTE_ID 2
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#define RAI_AGENT_ID 3
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#define RAI_SUBNET_SELECTION 5
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#define DHCPDISCOVER 1
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#define DHCPOFFER 2
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#define DHCPREQUEST 3
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#define DHCPDECLINE 4
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#define DHCPACK 5
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#define DHCPNAK 6
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#define DHCPRELEASE 7
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#define BOOTP_BROADCAST 0x8000
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#define BOOTPS 67
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#define BOOTPC 68
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#define BOOTREQUEST 1
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#define BOOTREPLY 2
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in_addr_t giaddr;
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in_addr_t netaddr;
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in_addr_t circuit_addr;
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char tundev[32] = { "tun0" };
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struct sockaddr_in dhaddr;
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int dhsock = -1;
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void
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relay_dhcp_to_server(struct ip *ip, int len)
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{
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struct dhcp_light_msg *inm;
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struct dhcp_msg m;
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int n;
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u_int8_t *optptr;
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inm = (void*)(((u_int8_t*)ip) + 20 + 8); /* Skip over IP&UDP headers. */
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if (inm->op != BOOTREQUEST) {
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return;
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}
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inm->flags = ntohs(BOOTP_BROADCAST);
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memcpy(&m, inm, DHCP_BASE_LEN);
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memset(&m.sname, 0x0, DHCP_HOLE_LEN);
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memcpy(&m.options, &inm->options, len - 20 - 8 - DHCP_BASE_LEN);
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n = (len - 20 - 8) + DHCP_HOLE_LEN; /* +HOLE -IP&UDP headers. */
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/*
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* Ideally we would like to use the Relay Agent information option
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* (RFC3046) together with the Link Selection sub-option (RFC3527)
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* to ensure that addresses are allocated for this
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* subnet. Unfortunately ISC-DHCPD does not currently implement
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* RFC3527 and some other mechanism must be used. For this reason
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* this implementation in addition uses the DHCP option for subnet
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* selection (RFC3011) which is really not intended to be used by
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* relays.
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*
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* Find DHCP_OPTION_END and add the new option here.
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*/
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optptr = &m.options[n - DHCP_BASE_LEN - DHCP_HOLE_LEN - 1];
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{
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*optptr++ = DHCP_OPTION_SUBNET_SELECTION; /* RFC3011 */
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*optptr++ = 4;
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memcpy(optptr, &netaddr, 4); optptr += 4;
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n += 4 + 2;
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}
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{
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*optptr++ = DHCP_OPTION_AGENT; /* RFC3046 */
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*optptr++ = 18; /* Sum of all suboptions below! */
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*optptr++ = RAI_SUBNET_SELECTION; /* RFC3527 */
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*optptr++ = 4;
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memcpy(optptr, &netaddr, 4); optptr += 4;
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*optptr++ = RAI_CIRCUIT_ID;
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*optptr++ = 4;
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memcpy(optptr, &circuit_addr, 4); optptr += 4;
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*optptr++ = RAI_AGENT_ID;
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*optptr++ = 4;
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memcpy(optptr, &giaddr, 4); optptr += 4;
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n += 18 + 2; /* Sum of all suboptions + 2! */
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}
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/* And finally put back the END. */
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*optptr++ = DHCP_OPTION_END;
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m.hops++;
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memcpy(m.giaddr, &giaddr, sizeof(m.giaddr));
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if (n != sendto(dhsock, &m, n, 0x0/*flags*/,
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(struct sockaddr *)&dhaddr, sizeof(dhaddr)))
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err(1, "sendto relay failed");
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}
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static u_int16_t ip_id;
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void
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relay_dhcp_to_client(int slipfd)
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{
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struct dhcp_msg inm;
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struct {
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struct ip ip;
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struct dhcp_light_msg m;
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} pkt;
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int n, optlen, ip_len, udp_len;
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u_int8_t *p, *t, *end;
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u_int16_t sum;
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u_int8_t op, msg_type = 0;
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struct in_addr yiaddr;
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memset(&inm.options, 0x0, sizeof(inm.options));
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n = recv(dhsock, &inm, sizeof(inm), 0x0/*flags*/);
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if (inm.op != BOOTREPLY) {
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return;
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}
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memcpy(&yiaddr, inm.yiaddr, sizeof(inm.yiaddr));
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memcpy(&pkt.m, &inm, DHCP_BASE_LEN);
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pkt.m.hops++;
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memset(pkt.m.giaddr, 0x0, sizeof(pkt.m.giaddr));
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/*
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* Copy options we would like to send to client.
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*/
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memcpy(pkt.m.options, inm.options, 4); /* Magic cookie */
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end = &inm.op + n;
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p = inm.options + 4; /* Magic cookie */
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t = pkt.m.options + 4; /* Magic cookie */
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while (p < end) {
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op = p[0];
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switch (op) {
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case DHCP_OPTION_END:
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goto done;
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case DHCP_OPTION_MSG_TYPE:
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msg_type = p[2];
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case DHCP_OPTION_SUBNET_MASK:
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case DHCP_OPTION_ROUTER:
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case DHCP_OPTION_LEASE_TIME:
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case DHCP_OPTION_SERVER_ID: /* Copy these options */
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memcpy(t, p, p[1] + 2);
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t += p[1] + 2;
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p += p[1] + 2;
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break;
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case DHCP_OPTION_DNS_SERVER: /* Only copy first server */
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*t++ = p[0];
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*t++ = 4;
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memcpy(t, p + 2, 4); t += 4;
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p += p[1] + 2;
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break;
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default: /* Ignore these options */
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/* printf("option type %d len %d\n", op, p[1]); */
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p += p[1] + 2;
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continue;
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}
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}
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done:
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if (op == DHCP_OPTION_END) {
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*t++ = op; *p++;
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}
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optlen = t - pkt.m.options;
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ip_len = 20 + 8 + DHCP_BASE_LEN + optlen;
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udp_len = 8 + DHCP_BASE_LEN + optlen;
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pkt.ip.ip_vhl = 0x45; /* IPv4 and hdrlen=5*4 */
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pkt.ip.ip_tos = 0;
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pkt.ip.ip_len = htons(ip_len);
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pkt.ip.ip_id = htons(ip_id++);
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pkt.ip.ip_off = 0;
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pkt.ip.ip_ttl = 64;
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pkt.ip.ip_p = 17; /* proto UDP */
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pkt.ip.ip_sum = 0;
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pkt.ip.ip_src = giaddr;
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if (inm.flags & htons(BOOTP_BROADCAST)) /* check bcast bit */
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pkt.ip.ip_dst = 0xffffffff; /* 255.255.255.255 */
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else
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pkt.ip.ip_dst = yiaddr.s_addr;
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pkt.ip.uh_sport = htons(BOOTPS);
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pkt.ip.uh_dport = htons(BOOTPC);
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pkt.ip.uh_ulen = htons(udp_len);
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pkt.ip.uh_sum = 0;
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pkt.ip.ip_sum = ~htons(ip4sum(0, &pkt.ip, 20));
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sum = 17 + udp_len;
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sum = ip4sum(sum, &pkt.ip.ip_src, 8);
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sum = ip4sum(sum, &pkt.ip.uh_sport, udp_len);
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if (sum != 0xffff)
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pkt.ip.uh_sum = ~htons(sum);
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else
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pkt.ip.uh_sum = 0xffff;
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write_to_serial(slipfd, &pkt, ip_len);
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if (msg_type == DHCPACK) {
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printf("DHCPACK %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x IP %s\n",
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pkt.m.chaddr[0], pkt.m.chaddr[1], pkt.m.chaddr[2], pkt.m.chaddr[3],
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pkt.m.chaddr[4], pkt.m.chaddr[5], pkt.m.chaddr[6], pkt.m.chaddr[7],
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inet_ntoa(yiaddr));
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/* ssystem("arp -s %s auto pub only", inet_ntoa(yiaddr)); */
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}
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}
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/*
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* Internet checksum in host byte order.
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*/
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u_int16_t
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ip4sum(u_int16_t sum, const void *_p, u_int16_t len)
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{
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u_int16_t t;
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const u_int8_t *p = _p;
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const u_int8_t *end = p + len;
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while(p < (end-1)) {
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t = (p[0] << 8) + p[1];
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sum += t;
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if (sum < t) sum++;
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p += 2;
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}
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if(p < end) {
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t = (p[0] << 8) + 0;
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sum += t;
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if (sum < t) sum++;
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}
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return sum;
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}
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int
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check_ip(const struct ip *ip, unsigned ip_len)
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{
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u_int16_t sum, ip_hl;
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/* Check IP version and length. */
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if((ip->ip_vhl & IP_V) != IP_V4)
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return -1;
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if(ntohs(ip->ip_len) > ip_len)
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return -2;
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if(ntohs(ip->ip_len) < ip_len)
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return -3;
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/* Check IP header. */
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ip_hl = 4*(ip->ip_vhl & IP_HL);
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sum = ip4sum(0, ip, ip_hl);
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if(sum != 0xffff && sum != 0x0)
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return -4;
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if(ip->ip_p == 6 || ip->ip_p == 17) { /* Check TCP or UDP header. */
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u_int16_t tcp_len = ip_len - ip_hl;
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/* Sum pseudoheader. */
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sum = ip->ip_p + tcp_len; /* proto and len, no carry */
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sum = ip4sum(sum, &ip->ip_src, 8); /* src and dst */
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/* Sum TCP/UDP header and data. */
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sum = ip4sum(sum, (u_int8_t*)ip + ip_hl, tcp_len);
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/* Failed checksum test? */
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if (sum != 0xffff && sum != 0x0) {
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if (ip->ip_p == 6) { /* TCP == 6 */
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return -5;
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} else { /* UDP */
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/* Deal with disabled UDP checksums. */
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if (ip->uh_sum != 0)
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return -6;
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}
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}
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} else if (ip->ip_p == 1) { /* ICMP */
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u_int16_t icmp_len = ip_len - ip_hl;
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sum = ip4sum(0, (u_int8_t*)ip + ip_hl, icmp_len);
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if(sum != 0xffff && sum != 0x0)
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return -7;
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}
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return 0;
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}
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|
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int
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is_sensible_string(const unsigned char *s, int len)
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{
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int i;
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for(i = 1; i < len; i++)
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if (s[i] == 0 || s[i] == '\r' || s[i] == '\n' || s[i] == '\t')
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continue;
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else if (s[i] < ' ' || '~' < s[i])
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return 0;
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return 1;
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}
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|
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int
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ssystem(const char *fmt, ...) __attribute__((__format__ (__printf__, 1, 2)));
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|
|
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int
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ssystem(const char *fmt, ...)
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{
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char cmd[128];
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va_list ap;
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va_start(ap, fmt);
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vsnprintf(cmd, sizeof(cmd), fmt, ap);
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va_end(ap);
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printf("%s\n", cmd);
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fflush(stdout);
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return system(cmd);
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}
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|
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#define SLIP_END 0300
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#define SLIP_ESC 0333
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#define SLIP_ESC_END 0334
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#define SLIP_ESC_ESC 0335
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|
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/*
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* Read from serial, when we have a packet write it to tun. No output
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* buffering, input buffered by stdio.
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*/
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void
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serial_to_tun(FILE *inslip, int outfd)
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{
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static union {
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unsigned char inbuf[2000];
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struct ip iphdr;
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} uip;
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static int inbufptr = 0;
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int ret;
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unsigned char c;
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#ifdef linux
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ret = fread(&c, 1, 1, inslip);
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if(ret == -1 || ret == 0) err(1, "serial_to_tun: read");
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goto after_fread;
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#endif
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read_more:
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if(inbufptr >= sizeof(uip.inbuf)) {
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inbufptr = 0;
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}
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ret = fread(&c, 1, 1, inslip);
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#ifdef linux
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after_fread:
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#endif
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if(ret == -1) err(1, "serial_to_tun: read");
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if(ret == 0) {
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clearerr(inslip);
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return;
|
|
fprintf(stderr, "serial_to_tun: EOF\n");
|
|
exit(1);
|
|
}
|
|
/* fprintf(stderr, ".");*/
|
|
switch(c) {
|
|
case SLIP_END:
|
|
if(inbufptr > 0) {
|
|
/*
|
|
* Sanity checks.
|
|
*/
|
|
#define DEBUG_LINE_MARKER '\r'
|
|
int ecode;
|
|
ecode = check_ip(&uip.iphdr, inbufptr);
|
|
if(ecode < 0 && inbufptr == 8 && strncmp(uip.inbuf, "=IPA", 4) == 0) {
|
|
static struct in_addr ipa;
|
|
|
|
inbufptr = 0;
|
|
if(memcmp(&ipa, &uip.inbuf[4], sizeof(ipa)) == 0)
|
|
break;
|
|
|
|
/* New address. */
|
|
if(ipa.s_addr != 0) {
|
|
#ifdef linux
|
|
ssystem("route delete -net %s netmask %s dev %s",
|
|
inet_ntoa(ipa), "255.255.255.255", tundev);
|
|
#else
|
|
ssystem("route delete -net %s -netmask %s -interface %s",
|
|
inet_ntoa(ipa), "255.255.255.255", tundev);
|
|
#endif
|
|
}
|
|
|
|
memcpy(&ipa, &uip.inbuf[4], sizeof(ipa));
|
|
if(ipa.s_addr != 0) {
|
|
#ifdef linux
|
|
ssystem("route add -net %s netmask %s dev %s",
|
|
inet_ntoa(ipa), "255.255.255.255", tundev);
|
|
#else
|
|
ssystem("route add -net %s -netmask %s -interface %s",
|
|
inet_ntoa(ipa), "255.255.255.255", tundev);
|
|
#endif
|
|
}
|
|
break;
|
|
} else if(ecode < 0) {
|
|
/*
|
|
* If sensible ASCII string, print it as debug info!
|
|
*/
|
|
if (uip.inbuf[0] == DEBUG_LINE_MARKER)
|
|
fwrite(uip.inbuf + 1, inbufptr - 1, 1, stderr);
|
|
else if (is_sensible_string(uip.inbuf, inbufptr))
|
|
fwrite(uip.inbuf, inbufptr, 1, stderr);
|
|
else
|
|
fprintf(stderr,
|
|
"serial_to_tun: drop packet len=%d ecode=%d\n",
|
|
inbufptr, ecode);
|
|
inbufptr = 0;
|
|
break;
|
|
}
|
|
PROGRESS("s");
|
|
|
|
if (dhsock != -1) {
|
|
struct ip *ip = (void *)uip.inbuf;
|
|
if (ip->ip_p == 17 && ip->ip_dst == 0xffffffff /* UDP and broadcast */
|
|
&& ip->uh_sport == ntohs(BOOTPC) && ip->uh_dport == ntohs(BOOTPS)){
|
|
relay_dhcp_to_server(ip, inbufptr);
|
|
inbufptr = 0;
|
|
}
|
|
}
|
|
if(write(outfd, uip.inbuf, inbufptr) != inbufptr) err(1, "serial_to_tun: write");
|
|
inbufptr = 0;
|
|
}
|
|
break;
|
|
|
|
case SLIP_ESC:
|
|
if(fread(&c, 1, 1, inslip) != 1) {
|
|
clearerr(inslip);
|
|
/* Put ESC back and give up! */
|
|
ungetc(SLIP_ESC, inslip);
|
|
return;
|
|
}
|
|
|
|
switch(c) {
|
|
case SLIP_ESC_END:
|
|
c = SLIP_END;
|
|
break;
|
|
case SLIP_ESC_ESC:
|
|
c = SLIP_ESC;
|
|
break;
|
|
}
|
|
/* FALLTHROUGH */
|
|
default:
|
|
uip.inbuf[inbufptr++] = c;
|
|
break;
|
|
}
|
|
|
|
goto read_more;
|
|
}
|
|
|
|
unsigned char slip_buf[2000];
|
|
int slip_end, slip_begin;
|
|
|
|
void
|
|
slip_send(int fd, unsigned char c)
|
|
{
|
|
if (slip_end >= sizeof(slip_buf))
|
|
err(1, "slip_send overflow");
|
|
slip_buf[slip_end] = c;
|
|
slip_end++;
|
|
}
|
|
|
|
int
|
|
slip_empty()
|
|
{
|
|
return slip_end == 0;
|
|
}
|
|
|
|
void
|
|
slip_flushbuf(int fd)
|
|
{
|
|
int n;
|
|
|
|
if (slip_empty())
|
|
return;
|
|
|
|
n = write(fd, slip_buf + slip_begin, (slip_end - slip_begin));
|
|
|
|
if (n == -1 && errno != EAGAIN)
|
|
err(1, "slip_flushbuf write failed");
|
|
else if (n == -1)
|
|
PROGRESS("Q"); /* Outqueueis full! */
|
|
else {
|
|
slip_begin += n;
|
|
if (slip_begin == slip_end)
|
|
slip_begin = slip_end = 0;
|
|
}
|
|
}
|
|
|
|
void
|
|
write_to_serial(int outfd, void *inbuf, int len)
|
|
{
|
|
u_int8_t *p = inbuf;
|
|
int i, ecode;
|
|
struct ip *iphdr = inbuf;
|
|
|
|
/*
|
|
* Sanity checks.
|
|
*/
|
|
ecode = check_ip(inbuf, len);
|
|
if(ecode < 0) {
|
|
fprintf(stderr, "tun_to_serial: drop packet %d\n", ecode);
|
|
return;
|
|
}
|
|
|
|
if (iphdr->ip_id == 0 && iphdr->ip_off & IP_DF) {
|
|
uint16_t nid = htons(ip_id++);
|
|
iphdr->ip_id = nid;
|
|
nid = ~nid; /* negate */
|
|
iphdr->ip_sum += nid; /* add */
|
|
if (iphdr->ip_sum < nid) /* 1-complement overflow? */
|
|
iphdr->ip_sum++;
|
|
ecode = check_ip(inbuf, len);
|
|
if(ecode < 0) {
|
|
fprintf(stderr, "tun_to_serial: drop packet %d\n", ecode);
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* It would be ``nice'' to send a SLIP_END here but it's not
|
|
* really necessary.
|
|
*/
|
|
/* slip_send(outfd, SLIP_END); */
|
|
|
|
for(i = 0; i < len; i++) {
|
|
switch(p[i]) {
|
|
case SLIP_END:
|
|
slip_send(outfd, SLIP_ESC);
|
|
slip_send(outfd, SLIP_ESC_END);
|
|
break;
|
|
case SLIP_ESC:
|
|
slip_send(outfd, SLIP_ESC);
|
|
slip_send(outfd, SLIP_ESC_ESC);
|
|
break;
|
|
default:
|
|
slip_send(outfd, p[i]);
|
|
break;
|
|
}
|
|
|
|
}
|
|
slip_send(outfd, SLIP_END);
|
|
PROGRESS("t");
|
|
}
|
|
|
|
|
|
/*
|
|
* Read from tun, write to slip.
|
|
*/
|
|
void
|
|
tun_to_serial(int infd, int outfd)
|
|
{
|
|
static union {
|
|
unsigned char inbuf[2000];
|
|
struct ip iphdr;
|
|
} uip;
|
|
int size;
|
|
|
|
if((size = read(infd, uip.inbuf, 2000)) == -1) err(1, "tun_to_serial: read");
|
|
|
|
write_to_serial(outfd, uip.inbuf, size);
|
|
}
|
|
|
|
#ifndef BAUDRATE
|
|
#define BAUDRATE B115200
|
|
#endif
|
|
speed_t b_rate = BAUDRATE;
|
|
|
|
void
|
|
stty_telos(int fd)
|
|
{
|
|
struct termios tty;
|
|
speed_t speed = b_rate;
|
|
int i;
|
|
|
|
if(tcflush(fd, TCIOFLUSH) == -1) err(1, "tcflush");
|
|
|
|
if(tcgetattr(fd, &tty) == -1) err(1, "tcgetattr");
|
|
|
|
cfmakeraw(&tty);
|
|
|
|
/* Nonblocking read. */
|
|
tty.c_cc[VTIME] = 0;
|
|
tty.c_cc[VMIN] = 0;
|
|
tty.c_cflag &= ~CRTSCTS;
|
|
tty.c_cflag &= ~HUPCL;
|
|
tty.c_cflag &= ~CLOCAL;
|
|
|
|
cfsetispeed(&tty, speed);
|
|
cfsetospeed(&tty, speed);
|
|
|
|
if(tcsetattr(fd, TCSAFLUSH, &tty) == -1) err(1, "tcsetattr");
|
|
|
|
#if 1
|
|
/* Nonblocking read and write. */
|
|
/* if(fcntl(fd, F_SETFL, O_NONBLOCK) == -1) err(1, "fcntl"); */
|
|
|
|
tty.c_cflag |= CLOCAL;
|
|
if(tcsetattr(fd, TCSAFLUSH, &tty) == -1) err(1, "tcsetattr");
|
|
|
|
i = TIOCM_DTR;
|
|
if(ioctl(fd, TIOCMBIS, &i) == -1) err(1, "ioctl");
|
|
#endif
|
|
|
|
usleep(10*1000); /* Wait for hardware 10ms. */
|
|
|
|
/* Flush input and output buffers. */
|
|
if(tcflush(fd, TCIOFLUSH) == -1) err(1, "tcflush");
|
|
}
|
|
|
|
int
|
|
devopen(const char *dev, int flags)
|
|
{
|
|
char t[32];
|
|
strcpy(t, "/dev/");
|
|
strcat(t, dev);
|
|
return open(t, flags);
|
|
}
|
|
|
|
#ifdef linux
|
|
#include <linux/if.h>
|
|
#include <linux/if_tun.h>
|
|
|
|
int
|
|
tun_alloc(char *dev)
|
|
{
|
|
struct ifreq ifr;
|
|
int fd, err;
|
|
|
|
if( (fd = open("/dev/net/tun", O_RDWR)) < 0 )
|
|
return -1;
|
|
|
|
memset(&ifr, 0, sizeof(ifr));
|
|
|
|
/* Flags: IFF_TUN - TUN device (no Ethernet headers)
|
|
* IFF_TAP - TAP device
|
|
*
|
|
* IFF_NO_PI - Do not provide packet information
|
|
*/
|
|
ifr.ifr_flags = IFF_TUN | IFF_NO_PI;
|
|
if(*dev != 0)
|
|
strncpy(ifr.ifr_name, dev, IFNAMSIZ);
|
|
|
|
if((err = ioctl(fd, TUNSETIFF, (void *) &ifr)) < 0 ){
|
|
close(fd);
|
|
return err;
|
|
}
|
|
strcpy(dev, ifr.ifr_name);
|
|
return fd;
|
|
}
|
|
#else
|
|
int
|
|
tun_alloc(char *dev)
|
|
{
|
|
return devopen(dev, O_RDWR);
|
|
}
|
|
#endif
|
|
|
|
const char *ipaddr;
|
|
const char *netmask;
|
|
|
|
void
|
|
cleanup(void)
|
|
{
|
|
ssystem("ifconfig %s down", tundev);
|
|
#ifndef linux
|
|
ssystem("sysctl -w net.inet.ip.forwarding=0");
|
|
#endif
|
|
/* ssystem("arp -d %s", ipaddr); */
|
|
ssystem("netstat -nr"
|
|
" | awk '{ if ($2 == \"%s\") print \"route delete -net \"$1; }'"
|
|
" | sh",
|
|
tundev);
|
|
}
|
|
|
|
void
|
|
sigcleanup(int signo)
|
|
{
|
|
fprintf(stderr, "signal %d\n", signo);
|
|
exit(0); /* exit(0) will call cleanup() */
|
|
}
|
|
|
|
static int got_sigalarm;
|
|
|
|
void
|
|
sigalarm(int signo)
|
|
{
|
|
got_sigalarm = 1;
|
|
return;
|
|
}
|
|
|
|
void
|
|
sigalarm_reset()
|
|
{
|
|
#ifdef linux
|
|
#define TIMEOUT (997*1000)
|
|
#else
|
|
#define TIMEOUT (2451*1000)
|
|
#endif
|
|
ualarm(TIMEOUT, TIMEOUT);
|
|
got_sigalarm = 0;
|
|
}
|
|
|
|
void
|
|
ifconf(const char *tundev, const char *ipaddr, const char *netmask)
|
|
{
|
|
struct in_addr netname;
|
|
netname.s_addr = inet_addr(ipaddr) & inet_addr(netmask);
|
|
|
|
#ifdef linux
|
|
ssystem("ifconfig %s inet `hostname` up", tundev);
|
|
if (strcmp(ipaddr, "0.0.0.0") != 0)
|
|
ssystem("route add -net %s netmask %s dev %s",
|
|
inet_ntoa(netname), netmask, tundev);
|
|
#else
|
|
ssystem("ifconfig %s inet `hostname` %s up", tundev, ipaddr);
|
|
if (strcmp(ipaddr, "0.0.0.0") != 0)
|
|
ssystem("route add -net %s -netmask %s -interface %s",
|
|
inet_ntoa(netname), netmask, tundev);
|
|
ssystem("sysctl -w net.inet.ip.forwarding=1");
|
|
#endif /* !linux */
|
|
|
|
ssystem("ifconfig %s\n", tundev);
|
|
}
|
|
|
|
int
|
|
main(int argc, char **argv)
|
|
{
|
|
int c;
|
|
int tunfd, slipfd, maxfd;
|
|
int ret;
|
|
fd_set rset, wset;
|
|
FILE *inslip;
|
|
const char *siodev = NULL;
|
|
const char *dhcp_server = NULL;
|
|
u_int16_t myport = BOOTPS, dhport = BOOTPS;
|
|
int baudrate = -2;
|
|
|
|
ip_id = getpid() * time(NULL);
|
|
|
|
while ((c = getopt(argc, argv, "B:D:hs:t:")) != -1) {
|
|
switch (c) {
|
|
case 'B':
|
|
baudrate = atoi(optarg);
|
|
break;
|
|
|
|
case 'D':
|
|
dhcp_server = optarg;
|
|
break;
|
|
|
|
case 's':
|
|
if (strncmp("/dev/", optarg, 5) == 0)
|
|
siodev = optarg + 5;
|
|
else
|
|
siodev = optarg;
|
|
break;
|
|
|
|
case 't':
|
|
if (strncmp("/dev/", optarg, 5) == 0)
|
|
strcpy(tundev, optarg + 5);
|
|
else
|
|
strcpy(tundev, optarg);
|
|
break;
|
|
|
|
case '?':
|
|
case 'h':
|
|
default:
|
|
err(1, "usage: tunslip [-B baudrate] [-s siodev] [-t tundev] [-D dhcp-server] ipaddress netmask [dhcp-server]");
|
|
break;
|
|
}
|
|
}
|
|
argc -= (optind - 1);
|
|
argv += (optind - 1);
|
|
|
|
if (argc != 3 && argc != 4)
|
|
err(1, "usage: tunslip [-s siodev] [-t tundev] [-D dhcp-server] ipaddress netmask [dhcp-server]");
|
|
ipaddr = argv[1];
|
|
netmask = argv[2];
|
|
circuit_addr = inet_addr(ipaddr);
|
|
netaddr = inet_addr(ipaddr) & inet_addr(netmask);
|
|
|
|
switch (baudrate) {
|
|
case -2:
|
|
break; /* Use default. */
|
|
case 9600:
|
|
b_rate = B9600;
|
|
break;
|
|
case 19200:
|
|
b_rate = B19200;
|
|
break;
|
|
case 38400:
|
|
b_rate = B38400;
|
|
break;
|
|
case 57600:
|
|
b_rate = B57600;
|
|
break;
|
|
case 115200:
|
|
b_rate = B115200;
|
|
break;
|
|
default:
|
|
err(1, "unknown baudrate %d", baudrate);
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Set up DHCP relay agent socket and find the address of this relay
|
|
* agent.
|
|
*/
|
|
if (argc == 4) {
|
|
dhcp_server = argv[3];
|
|
}
|
|
if (dhcp_server != NULL) {
|
|
struct sockaddr_in myaddr;
|
|
socklen_t len;
|
|
in_addr_t a;
|
|
|
|
if (strchr(dhcp_server, ':') != NULL) {
|
|
dhport = atoi(strchr(dhcp_server, ':') + 1);
|
|
myport = dhport + 1;
|
|
*strchr(dhcp_server, ':') = '\0';
|
|
}
|
|
a = inet_addr(dhcp_server);
|
|
if (a == -1)
|
|
err(1, "illegal dhcp-server address");
|
|
#ifndef linux
|
|
dhaddr.sin_len = sizeof(dhaddr);
|
|
#endif
|
|
dhaddr.sin_family = AF_INET;
|
|
dhaddr.sin_port = htons(dhport);
|
|
dhaddr.sin_addr.s_addr = a;
|
|
|
|
dhsock = socket(AF_INET, SOCK_DGRAM, 0);
|
|
if (dhsock < 0)
|
|
err (1, "socket");
|
|
memset(&myaddr, 0x0, sizeof(myaddr));
|
|
#ifndef linux
|
|
myaddr.sin_len = sizeof(myaddr);
|
|
#endif
|
|
myaddr.sin_family = AF_INET;
|
|
myaddr.sin_addr.s_addr = INADDR_ANY;
|
|
myaddr.sin_port = htons(myport);
|
|
if (bind(dhsock, (struct sockaddr *)&myaddr, sizeof(myaddr)) < 0)
|
|
err(1, "bind dhcp-relay");
|
|
|
|
if (connect(dhsock, (struct sockaddr *)&dhaddr, sizeof(dhaddr)) < 0)
|
|
err(1, "connect to dhcp-server");
|
|
|
|
len = sizeof(myaddr);
|
|
if (getsockname(dhsock, (struct sockaddr *)&myaddr, &len) < 0)
|
|
err(1, "getsockname dhsock");
|
|
|
|
giaddr = myaddr.sin_addr.s_addr;
|
|
|
|
/*
|
|
* Don't want connected socket.
|
|
*/
|
|
close(dhsock);
|
|
dhsock = socket(AF_INET, SOCK_DGRAM, 0);
|
|
if (dhsock < 0)
|
|
err (1, "socket");
|
|
myaddr.sin_family = AF_INET;
|
|
myaddr.sin_addr.s_addr = INADDR_ANY;
|
|
myaddr.sin_port = htons(myport);
|
|
if (bind(dhsock, (struct sockaddr *)&myaddr, sizeof(myaddr)) < 0)
|
|
err(1, "bind dhcp-relay");
|
|
fprintf(stderr, "DHCP server at %s:%d\n", dhcp_server, dhport);
|
|
}
|
|
|
|
if (siodev != NULL) {
|
|
slipfd = devopen(siodev, O_RDWR | O_NONBLOCK);
|
|
if (slipfd == -1) err(1, "can't open siodev ``/dev/%s''", siodev);
|
|
} else {
|
|
static const char *siodevs[] = {
|
|
"ttyUSB0", "cuaU0", "ucom0" /* linux, fbsd6, fbsd5 */
|
|
};
|
|
int i;
|
|
for(i = 0; i < 3; i++) {
|
|
siodev = siodevs[i];
|
|
slipfd = devopen(siodev, O_RDWR | O_NONBLOCK);
|
|
if (slipfd != -1)
|
|
break;
|
|
}
|
|
if (slipfd == -1) err(1, "can't open siodev");
|
|
}
|
|
fprintf(stderr, "slip started on ``/dev/%s''\n", siodev);
|
|
stty_telos(slipfd);
|
|
slip_send(slipfd, SLIP_END);
|
|
inslip = fdopen(slipfd, "r");
|
|
if(inslip == NULL) err(1, "main: fdopen");
|
|
|
|
tunfd = tun_alloc(tundev);
|
|
if(tunfd == -1) err(1, "main: open");
|
|
fprintf(stderr, "opened device ``/dev/%s''\n", tundev);
|
|
|
|
atexit(cleanup);
|
|
signal(SIGHUP, sigcleanup);
|
|
signal(SIGTERM, sigcleanup);
|
|
signal(SIGINT, sigcleanup);
|
|
signal(SIGALRM, sigalarm);
|
|
ifconf(tundev, ipaddr, netmask);
|
|
|
|
while(1) {
|
|
maxfd = 0;
|
|
FD_ZERO(&rset);
|
|
FD_ZERO(&wset);
|
|
|
|
if(got_sigalarm) {
|
|
/* Send "?IPA". */
|
|
slip_send(slipfd, '?');
|
|
slip_send(slipfd, 'I');
|
|
slip_send(slipfd, 'P');
|
|
slip_send(slipfd, 'A');
|
|
slip_send(slipfd, SLIP_END);
|
|
got_sigalarm = 0;
|
|
}
|
|
|
|
if (!slip_empty()) /* Anything to flush? */
|
|
FD_SET(slipfd, &wset);
|
|
|
|
FD_SET(slipfd, &rset); /* Read from slip ASAP! */
|
|
if(slipfd > maxfd) maxfd = slipfd;
|
|
|
|
/* We only have one packet at a time queued for slip output. */
|
|
if(slip_empty()) {
|
|
FD_SET(tunfd, &rset);
|
|
if(tunfd > maxfd) maxfd = tunfd;
|
|
if(dhsock != -1) {
|
|
FD_SET(dhsock, &rset);
|
|
if(dhsock > maxfd) maxfd = dhsock;
|
|
}
|
|
}
|
|
|
|
ret = select(maxfd + 1, &rset, &wset, NULL, NULL);
|
|
if(ret == -1 && errno != EINTR)
|
|
err(1, "select");
|
|
else if(ret > 0) {
|
|
if(FD_ISSET(slipfd, &rset))
|
|
serial_to_tun(inslip, tunfd);
|
|
|
|
if(FD_ISSET(slipfd, &wset)) {
|
|
slip_flushbuf(slipfd);
|
|
sigalarm_reset();
|
|
}
|
|
|
|
if(slip_empty() && FD_ISSET(tunfd, &rset)) {
|
|
tun_to_serial(tunfd, slipfd);
|
|
slip_flushbuf(slipfd);
|
|
sigalarm_reset();
|
|
}
|
|
|
|
if(dhsock != -1 && slip_empty() && FD_ISSET(dhsock, &rset)) {
|
|
relay_dhcp_to_client(slipfd);
|
|
slip_flushbuf(slipfd);
|
|
}
|
|
}
|
|
}
|
|
}
|