From c94a70e0b3ad54f1aab6eb48e70c07a3daba476e Mon Sep 17 00:00:00 2001 From: bg- Date: Wed, 2 Aug 2006 14:40:47 +0000 Subject: [PATCH] Import of userspace SLIP implementation. --- tools/tunslip.c | 923 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 923 insertions(+) create mode 100644 tools/tunslip.c diff --git a/tools/tunslip.c b/tools/tunslip.c new file mode 100644 index 000000000..36aec3ded --- /dev/null +++ b/tools/tunslip.c @@ -0,0 +1,923 @@ +/* + * Copyright (c) 2001, Adam Dunkels. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. The name of the author may not be used to endorse or promote + * products derived from this software without specific prior + * written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS + * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY + * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE + * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, + * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * + * This file is part of the uIP TCP/IP stack. + * + * $Id: tunslip.c,v 1.1 2006/08/02 14:40:47 bg- Exp $ + * + */ + +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +#include +#include +#include + +#include + +int ssystem(const char *fmt, ...) + __attribute__((__format__ (__printf__, 1, 2))); +void write_to_serial(int outfd, void *inbuf, int len); + +//#define PROGRESS(s) fprintf(stderr, s) +#define PROGRESS(s) do { } while (0) + +struct ip { + u_int8_t ip_vhl; /* version and header length */ +#define IP_V4 0x40 +#define IP_V 0xf0 +#define IP_HL 0x0f + u_int8_t ip_tos; /* type of service */ + u_int16_t ip_len; /* total length */ + u_int16_t ip_id; /* identification */ + u_int16_t ip_off; /* fragment offset field */ +#define IP_RF 0x8000 /* reserved fragment flag */ +#define IP_DF 0x4000 /* dont fragment flag */ +#define IP_MF 0x2000 /* more fragments flag */ +#define IP_OFFMASK 0x1fff /* mask for fragmenting bits */ + u_int8_t ip_ttl; /* time to live */ + u_int8_t ip_p; /* protocol */ + u_int16_t ip_sum; /* checksum */ + u_int32_t ip_src, ip_dst; /* source and dest address */ + u_int16_t uh_sport; /* source port */ + u_int16_t uh_dport; /* destination port */ + u_int16_t uh_ulen; /* udp length */ + u_int16_t uh_sum; /* udp checksum */ +}; + +int check_ip(const struct ip *ip, unsigned ip_len); +u_int16_t ip4sum(u_int16_t sum, const void *_p, u_int16_t len); + +struct dhcp_msg { + u_int8_t op, htype, hlen, hops; + u_int8_t xid[4]; + u_int16_t secs, flags; + u_int8_t ciaddr[4]; + u_int8_t yiaddr[4]; + u_int8_t siaddr[4]; + u_int8_t giaddr[4]; + u_int8_t chaddr[16]; +#define DHCP_BASE_LEN (4*7 + 16) + u_int8_t sname[64]; + u_int8_t file[128]; +#define DHCP_HOLE_LEN (64 + 128) +#define DHCP_MSG_LEN (DHCP_BASE_LEN + DHCP_HOLE_LEN) + u_int8_t options[312]; +}; + +struct dhcp_light_msg { + u_int8_t op, htype, hlen, hops; + u_int8_t xid[4]; + u_int16_t secs, flags; + u_int8_t ciaddr[4]; + u_int8_t yiaddr[4]; + u_int8_t siaddr[4]; + u_int8_t giaddr[4]; + u_int8_t chaddr[16]; +#define DHCP_LIGHT_MSG_LEN (4*7 + 16) + u_int8_t options[312]; +}; + +#define DHCP_OPTION_SUBNET_MASK 1 +#define DHCP_OPTION_ROUTER 3 +#define DHCP_OPTION_DNS_SERVER 6 +#define DHCP_OPTION_REQ_IPADDR 50 +#define DHCP_OPTION_LEASE_TIME 51 +#define DHCP_OPTION_MSG_TYPE 53 +#define DHCP_OPTION_SERVER_ID 54 +#define DHCP_OPTION_REQ_LIST 55 +#define DHCP_OPTION_AGENT 82 +#define DHCP_OPTION_SUBNET_SELECTION 118 +#define DHCP_OPTION_END 255 + +/* DHCP_OPTION_AGENT, Relay Agent Information option subtypes: */ +#define RAI_CIRCUIT_ID 1 +#define RAI_REMOTE_ID 2 +#define RAI_AGENT_ID 3 +#define RAI_SUBNET_SELECTION 5 + +#define DHCPDISCOVER 1 +#define DHCPOFFER 2 +#define DHCPREQUEST 3 +#define DHCPDECLINE 4 +#define DHCPACK 5 +#define DHCPNAK 6 +#define DHCPRELEASE 7 + +#define BOOTP_BROADCAST 0x8000 + +#define BOOTPS 67 +#define BOOTPC 68 + +#define BOOTREQUEST 1 +#define BOOTREPLY 2 + +in_addr_t giaddr; +in_addr_t netaddr; +in_addr_t circuit_addr; + +struct sockaddr_in dhaddr; +int dhsock = -1; + +void +relay_dhcp_to_server(struct ip *ip, int len) +{ + struct dhcp_light_msg *inm; + struct dhcp_msg m; + int n; + u_int8_t *optptr; + + inm = (void*)(((u_int8_t*)ip) + 20 + 8); /* Skip over IP&UDP headers. */ + + if (inm->op != BOOTREQUEST) { + return; + } + + inm->flags = ntohs(BOOTP_BROADCAST); + + memcpy(&m, inm, DHCP_BASE_LEN); + memset(&m.sname, 0x0, DHCP_HOLE_LEN); + memcpy(&m.options, &inm->options, len - 20 - 8 - DHCP_BASE_LEN); + n = (len - 20 - 8) + DHCP_HOLE_LEN; /* +HOLE -IP&UDP headers. */ + + /* + * Ideally we would like to use the Relay Agent information option + * (RFC3046) together with the Link Selection sub-option (RFC3527) + * to ensure that addresses are allocated for this + * subnet. Unfortunately ISC-DHCPD does not currently implement + * RFC3527 and some other mechanism must be used. For this reason + * this implementation in addition uses the DHCP option for subnet + * selection (RFC3011) which is really not intended to be used by + * relays. + * + * Find DHCP_OPTION_END and add the new option here. + */ + optptr = &m.options[n - DHCP_BASE_LEN - DHCP_HOLE_LEN - 1]; + { + *optptr++ = DHCP_OPTION_SUBNET_SELECTION; /* RFC3011 */ + *optptr++ = 4; + memcpy(optptr, &netaddr, 4); optptr += 4; + n += 4 + 2; + } + { + *optptr++ = DHCP_OPTION_AGENT; /* RFC3046 */ + *optptr++ = 18; /* Sum of all suboptions below! */ + + *optptr++ = RAI_SUBNET_SELECTION; /* RFC3527 */ + *optptr++ = 4; + memcpy(optptr, &netaddr, 4); optptr += 4; + *optptr++ = RAI_CIRCUIT_ID; + *optptr++ = 4; + memcpy(optptr, &circuit_addr, 4); optptr += 4; + *optptr++ = RAI_AGENT_ID; + *optptr++ = 4; + memcpy(optptr, &giaddr, 4); optptr += 4; + n += 18 + 2; /* Sum of all suboptions + 2! */ + } + /* And finally put back the END. */ + *optptr++ = DHCP_OPTION_END; + + m.hops++; + memcpy(m.giaddr, &giaddr, sizeof(m.giaddr)); + if (n != sendto(dhsock, &m, n, 0x0/*flags*/, + (struct sockaddr *)&dhaddr, sizeof(dhaddr))) + err(1, "sendto relay failed"); +} + +static u_int16_t ip_id; + +void +relay_dhcp_to_client(int slipfd) +{ + struct dhcp_msg inm; + struct { + struct ip ip; + struct dhcp_light_msg m; + } pkt; + int n, optlen, ip_len, udp_len; + u_int8_t *p, *t, *end; + u_int16_t sum; + u_int8_t op, msg_type = 0; + struct in_addr yiaddr; + + memset(&inm.options, 0x0, sizeof(inm.options)); + + n = recv(dhsock, &inm, sizeof(inm), 0x0/*flags*/); + + if (inm.op != BOOTREPLY) { + return; + } + + memcpy(&yiaddr, inm.yiaddr, sizeof(inm.yiaddr)); + memcpy(&pkt.m, &inm, DHCP_BASE_LEN); + pkt.m.hops++; + memset(pkt.m.giaddr, 0x0, sizeof(pkt.m.giaddr)); + + /* + * Copy options we would like to send to client. + */ + memcpy(pkt.m.options, inm.options, 4); /* Magic cookie */ + + end = &inm.op + n; + p = inm.options + 4; /* Magic cookie */ + t = pkt.m.options + 4; /* Magic cookie */ + while (p < end) { + op = p[0]; + switch (op) { + case DHCP_OPTION_END: + goto done; + + case DHCP_OPTION_MSG_TYPE: + msg_type = p[2]; + case DHCP_OPTION_SUBNET_MASK: + case DHCP_OPTION_ROUTER: + case DHCP_OPTION_LEASE_TIME: + case DHCP_OPTION_SERVER_ID: /* Copy these options */ + memcpy(t, p, p[1] + 2); + t += p[1] + 2; + p += p[1] + 2; + break; + + case DHCP_OPTION_DNS_SERVER: /* Only copy first server */ + memcpy(t, p, 4/**/ + 2); + t += 4/**/ + 2; + p += p[1] + 2; + break; + + default: /* Ignore these options */ + /* printf("option type %d len %d\n", op, p[1]); */ + p += p[1] + 2; + continue; + } + } + done: + if (op == DHCP_OPTION_END) { + *t++ = op; *p++; + } + + optlen = t - pkt.m.options; + ip_len = 20 + 8 + DHCP_BASE_LEN + optlen; + udp_len = 8 + DHCP_BASE_LEN + optlen; + + pkt.ip.ip_vhl = 0x45; /* IPv4 and hdrlen=5*4 */ + pkt.ip.ip_tos = 0; + pkt.ip.ip_len = htons(ip_len); + pkt.ip.ip_id = htons(ip_id++); + pkt.ip.ip_off = 0; + pkt.ip.ip_ttl = 64; + pkt.ip.ip_p = 17; /* proto UDP */ + pkt.ip.ip_sum = 0; + pkt.ip.ip_src = giaddr; + if (inm.flags & htons(BOOTP_BROADCAST)) /* check bcast bit */ + pkt.ip.ip_dst = 0xffffffff; /* 255.255.255.255 */ + else + pkt.ip.ip_dst = yiaddr.s_addr; + + pkt.ip.uh_sport = htons(BOOTPS); + pkt.ip.uh_dport = htons(BOOTPC); + pkt.ip.uh_ulen = htons(udp_len); + pkt.ip.uh_sum = 0; + + pkt.ip.ip_sum = ~htons(ip4sum(0, &pkt.ip, 20)); + sum = 17 + udp_len; + sum = ip4sum(sum, &pkt.ip.ip_src, 8); + sum = ip4sum(sum, &pkt.ip.uh_sport, udp_len); + if (sum != 0xffff) + pkt.ip.uh_sum = ~htons(sum); + else + pkt.ip.uh_sum = 0xffff; + + write_to_serial(slipfd, &pkt, ip_len); + if (msg_type == DHCPACK) { + printf("DHCPACK %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x IP %s\n", + pkt.m.chaddr[0], pkt.m.chaddr[1], pkt.m.chaddr[2], pkt.m.chaddr[3], + pkt.m.chaddr[4], pkt.m.chaddr[5], pkt.m.chaddr[6], pkt.m.chaddr[7], + inet_ntoa(yiaddr)); + /* ssystem("arp -s %s auto pub only", inet_ntoa(yiaddr)); */ + } +} + +/* + * Internet checksum in host byte order. + */ +u_int16_t +ip4sum(u_int16_t sum, const void *_p, u_int16_t len) +{ + u_int16_t t; + const u_int8_t *p = _p; + const u_int8_t *end = p + len; + + while(p < (end-1)) { + t = (p[0] << 8) + p[1]; + sum += t; + if (sum < t) sum++; + p += 2; + } + if(p < end) { + t = (p[0] << 8) + 0; + sum += t; + if (sum < t) sum++; + } + return sum; +} + +int +check_ip(const struct ip *ip, unsigned ip_len) +{ + u_int16_t sum, ip_hl; + + /* Check IP version and length. */ + if((ip->ip_vhl & IP_V) != IP_V4) + return -1; + + if(ntohs(ip->ip_len) > ip_len) + return -2; + + if(ntohs(ip->ip_len) < ip_len) + return -3; + + /* Check IP header. */ + ip_hl = 4*(ip->ip_vhl & IP_HL); + sum = ip4sum(0, ip, ip_hl); + if(sum != 0xffff && sum != 0x0) + return -4; + + if(ip->ip_p == 6 || ip->ip_p == 17) { /* Check TCP or UDP header. */ + u_int16_t tcp_len = ip_len - ip_hl; + + /* Sum pseudoheader. */ + sum = ip->ip_p + tcp_len; /* proto and len, no carry */ + sum = ip4sum(sum, &ip->ip_src, 8); /* src and dst */ + + /* Sum TCP/UDP header and data. */ + sum = ip4sum(sum, (u_int8_t*)ip + ip_hl, tcp_len); + + /* Failed checksum test? */ + if (sum != 0xffff && sum != 0x0) { + if (ip->ip_p == 6) { /* TCP == 6 */ + return -5; + } else { /* UDP */ + /* Deal with disabled UDP checksums. */ + if (ip->uh_sum != 0) + return -6; + } + } + } else if (ip->ip_p == 1) { /* ICMP */ + u_int16_t icmp_len = ip_len - ip_hl; + + sum = ip4sum(0, (u_int8_t*)ip + ip_hl, icmp_len); + if(sum != 0xffff && sum != 0x0) + return -7; + } + return 0; +} + +int +is_sensible_string(const unsigned char *s, int len) +{ + int i; + for(i = 1; i < len; i++) + if (s[i] == 0 || s[i] == '\r' || s[i] == '\n' || s[i] == '\t') + continue; + else if (s[i] < ' ' || '~' < s[i]) + return 0; + return 1; +} + +int +ssystem(const char *fmt, ...) __attribute__((__format__ (__printf__, 1, 2))); + +int +ssystem(const char *fmt, ...) +{ + char cmd[128]; + va_list ap; + va_start(ap, fmt); + vsnprintf(cmd, sizeof(cmd), fmt, ap); + va_end(ap); + printf("%s\n", cmd); + return system(cmd); +} + +#define SLIP_END 0300 +#define SLIP_ESC 0333 +#define SLIP_ESC_END 0334 +#define SLIP_ESC_ESC 0335 + +/* + * Read from serial, when we have a packet write it to tun. No output + * buffering, input buffered by stdio. + */ +void +serial_to_tun(FILE *inslip, int outfd) +{ + static union { + unsigned char inbuf[2000]; + struct ip iphdr; + } uip; + static int inbufptr = 0; + + int ret; + unsigned char c; + + read_more: + if(inbufptr >= sizeof(uip.inbuf)) { + inbufptr = 0; + } + ret = fread(&c, 1, 1, inslip); + if(ret == -1) err(1, "serial_to_tun: read"); + if(ret == 0) { + clearerr(inslip); + 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) { + /* + * 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_id = htons(ip_id++); + iphdr->ip_sum = 0; + iphdr->ip_sum = ~htons(ip4sum(0, iphdr, 20)); + 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); +} + +#define BAUDRATE B57600 +//#define BAUDRATE B38400 +//#define BAUDRATE B19200 + +void +stty_telos(int fd) +{ + struct termios tty; + speed_t speed = BAUDRATE; + 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"); +} + +#ifdef linux +#include +#include + +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) +{ + char t[32]; + strcpy(t, "/dev/"); + strcat(t, dev); + return open(t, O_RDWR); +} +#endif + +char tundev[32] = { "tun0" }; +const char *ipaddr; +const char *netmask; + +void +cleanup(int signo) +{ + fprintf(stderr, "signal %d\n", signo); +#ifdef linux +#else + ssystem("sysctl net.inet.ip.forwarding=0"); + /* ssystem("arp -d %s", ipaddr); */ + ssystem("ifconfig %s delete", tundev); +#endif + exit(0); +} + +void +ifconf(const char *tundev, const char *ipaddr, const char *netmask) +{ +#ifdef linux + struct in_addr netname; + netname.s_addr = inet_addr(ipaddr) & inet_addr(netmask); + ssystem("ifconfig %s inet `hostname` up", tundev); + ssystem("route add -net %s netmask %s dev %s", + inet_ntoa(netname), netmask, tundev); +#else + ssystem("ifconfig %s inet `hostname` %s netmask %s up", + tundev, ipaddr, netmask); + ssystem("route add -net %s -netmask %s -interface %s", + ipaddr, netmask, tundev); + /* ssystem("arp -s %s auto pub only", ipaddr); */ + ssystem("sysctl net.inet.ip.forwarding=1"); +#endif /* !linux */ + + ssystem("ifconfig %s\n", tundev); +} + +int +main(int argc, char **argv) +{ + int tunfd, slipfd, maxfd; + int ret; + fd_set rset, wset; + FILE *inslip; + const char *siodev; + u_int16_t myport = BOOTPS, dhport = BOOTPS; + + ip_id = getpid() * time(NULL); + + if (argc != 3 && argc != 4) + err(1, "usage: tunslip ipaddress netmask [dhcp-server]"); + ipaddr = argv[1]; + netmask = argv[2]; + circuit_addr = inet_addr(ipaddr); + netaddr = inet_addr(ipaddr) & inet_addr(netmask); + + /* + * Set up DHCP relay agent socket and find the address of this relay + * agent. + */ + if (argc == 4) { + struct sockaddr_in myaddr; + socklen_t len; + in_addr_t a; + + if (strchr(argv[3], ':') != NULL) { + dhport = atoi(strchr(argv[3], ':') + 1); + myport = dhport + 1; + *strchr(argv[3], ':') = '\0'; + } + a = inet_addr(argv[3]); + 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", argv[3], dhport); + } + + { + static const char *siodevs[] = { + "/dev/ttyUSB0", "/dev/ucom0", "/dev/cuaU0" + }; + int i; + for(i = 0; i < 3; i++) { + siodev = siodevs[i]; + slipfd = open(siodev, O_RDWR | O_NONBLOCK); + if (slipfd != -1) + break; + } + if (slipfd == -1) err(1, "can't open slipdev"); + } + fprintf(stderr, "slip started on ``%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); + + signal(SIGHUP, cleanup); + signal(SIGTERM, cleanup); + signal(SIGINT, cleanup); + ifconf(tundev, ipaddr, netmask); + + while(1) { + maxfd = 0; + FD_ZERO(&rset); + FD_ZERO(&wset); + + 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) + 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); + + if(slip_empty() && FD_ISSET(tunfd, &rset)) { + tun_to_serial(tunfd, slipfd); + slip_flushbuf(slipfd); + } + + if(dhsock != -1 && slip_empty() && FD_ISSET(dhsock, &rset)) { + relay_dhcp_to_client(slipfd); + slip_flushbuf(slipfd); + } + } else + err(1, "select"); + } +}