/* * Copyright (c) 2007, Swedish Institute of Computer Science. * 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. Neither the name of the Institute nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``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 INSTITUTE OR CONTRIBUTORS 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 Contiki operating system. * * Author: Oliver Schmidt * * $Id: wpcapslip.c,v 1.1 2008/02/07 09:39:35 adamdunkels Exp $ */ #include #include #include #ifdef __CYGWIN__ #include #else /* __CYGWIN__ */ #include #endif /* __CYGWIN__ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define PROGRESS(x) void wpcap_start(char *ethifaddr, char *netaddr, char *netmask); void wpcap_send(void *buf, int len); uint16_t wpcap_poll(char **buf); /*---------------------------------------------------------------------------*/ void cleanup(void); /*---------------------------------------------------------------------------*/ void sigcleanup(int signo) { fprintf(stderr, "signal %d\n", signo); exit(0); /* exit(0) will call cleanup() */ } /*---------------------------------------------------------------------------*/ #define SLIP_END 0300 #define SLIP_ESC 0333 #define SLIP_ESC_END 0334 #define SLIP_ESC_ESC 0335 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 */ }; static int ip_id; 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); fflush(stdout); return system(cmd); } 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; } 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; } /* * Read from serial, when we have a packet write it to tun. No output * buffering, input buffered by stdio. */ void serial_to_wpcap(FILE *inslip) { static union { unsigned char inbuf[2000]; struct ip iphdr; } uip; static int inbufptr = 0; int ret; unsigned char c; #ifdef linux ret = fread(&c, 1, 1, inslip); if(ret == -1 || ret == 0) err(1, "serial_to_tun: read"); goto after_fread; #endif read_more: if(inbufptr >= sizeof(uip.inbuf)) { inbufptr = 0; } ret = fread(&c, 1, 1, inslip); #ifdef linux after_fread: #endif 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 && 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) { #if 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 #endif /* 0 */ } memcpy(&ipa, &uip.inbuf[4], sizeof(ipa)); if(ipa.s_addr != 0) { #if 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 #endif /* 0 */ } break; } else if(ecode < 0) { /* * If sensible ASCII string, print it as debug info! */ /* printf("----------------------------------\n");*/ 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 0 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; } } #endif /* 0 */ /* if(write(outfd, uip.inbuf, inbufptr) != inbufptr) { err(1, "serial_to_tun: write"); }*/ /* printf("Sending to wpcap\n");*/ wpcap_send(uip.inbuf, inbufptr); /* printf("After sending to wpcap\n");*/ 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, "write_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. */ #if 0 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); } #endif /* 0 */ /*---------------------------------------------------------------------------*/ #ifndef BAUDRATE #define BAUDRATE B115200 #endif speed_t b_rate = BAUDRATE; void cfmakeraw(t) struct termios *t; { t->c_iflag &= ~(IMAXBEL|IXOFF|INPCK|BRKINT|PARMRK|ISTRIP|INLCR|IGNCR|ICRNL|IXON|IGNPAR); t->c_iflag |= IGNBRK; t->c_oflag &= ~OPOST; t->c_lflag &= ~(ECHO|ECHOE|ECHOK|ECHONL|ICANON|ISIG|IEXTEN|NOFLSH|TOSTOP); t->c_cflag &= ~(CSIZE|PARENB); t->c_cflag |= CS8|CREAD; t->c_cc[VMIN] = 1; t->c_cc[VTIME] = 0; } void stty_telos(int fd) { struct termios options; speed_t speed = b_rate; /* if(fcntl(fd, F_SETFL, 0) < 0) { perror("could not set fcntl"); exit(-1); }*/ if(tcgetattr(fd, &options) < 0) { perror("could not get options"); exit(-1); } cfsetispeed(&options, speed); cfsetospeed(&options, speed); /* Enable the receiver and set local mode */ options.c_cflag |= (CLOCAL | CREAD); /* Mask the character size bits and turn off (odd) parity */ options.c_cflag &= ~(CSIZE|PARENB|PARODD); /* Select 8 data bits */ options.c_cflag |= CS8; /* Raw input */ options.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG); /* Raw output */ options.c_oflag &= ~OPOST; if (tcsetattr(fd, TCSANOW, &options) < 0) { perror("could not set options"); exit(-1); } #if 0 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"); #endif /* 0 */ } /*---------------------------------------------------------------------------*/ int devopen(const char *dev, int flags) { char t[32]; strcpy(t, "/dev/"); strcat(t, dev); return open(t, flags); } /*---------------------------------------------------------------------------*/ /*const char *ipaddr;*/ /*const char *netmask;*/ 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; } /*---------------------------------------------------------------------------*/ int main(int argc, char **argv) { int c; int 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; char buf[4000]; ip_id = getpid() * time(NULL); setvbuf(stdout, NULL, _IOLBF, 0); /* Line buffered output. */ 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; #if 0 case 't': if(strncmp("/dev/", optarg, 5) == 0) { strcpy(tundev, optarg + 5); } else { strcpy(tundev, optarg); } break; #endif /* 0 */ case '?': case 'h': default: err(1, "usage: wpcapslip [-B baudrate] [-s siodev] [-D dhcp-server] ipaddress netmask [dhcp-server]"); break; } } argc -= (optind - 1); argv += (optind - 1); if(argc != 4) { err(1, "usage: wpcapslip [-s siodev] [-D dhcp-server] "); } /* ipaddr = argv[1]; netmask = argv[2];*/ wpcap_start(argv[1], argv[2], argv[3]); /* 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 0 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); } #endif /* 0 */ if(siodev != NULL) { slipfd = devopen(siodev, O_RDWR | O_NONBLOCK | O_NOCTTY | O_NDELAY | O_DIRECT | O_SYNC ); 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; }*/ } if(slip_empty()) { char *pbuf = buf; ret = wpcap_poll(&pbuf); if(ret > 0) { /* printf("wpcap_poll ret %d", ret); printf("IP packet\n");*/ write_to_serial(slipfd, pbuf, ret); slip_flushbuf(slipfd); sigalarm_reset(); } /* } else { printf("!slip_empty\n");*/ } { struct timeval tv; tv.tv_sec = 0; tv.tv_usec = 10; ret = select(maxfd + 1, &rset, &wset, NULL, &tv); } if(ret == -1 && errno != EINTR) { err(1, "select"); } else if(ret > 0) { if(FD_ISSET(slipfd, &rset)) { /* printf("serial_to_wpcap\n");*/ /*serial_to_tun(inslip, tunfd);*/ serial_to_wpcap(inslip); /* printf("End of serial_to_wpcap\n");*/ } if(FD_ISSET(slipfd, &wset)) { /* printf("slip_flushbuf\n");*/ slip_flushbuf(slipfd); sigalarm_reset(); } /* if(slip_empty() && FD_ISSET(tunfd, &rset)) { tun_to_serial(tunfd, slipfd); slip_flushbuf(slipfd); sigalarm_reset(); }*/ #if 0 if(dhsock != -1 && slip_empty() && FD_ISSET(dhsock, &rset)) { relay_dhcp_to_client(slipfd); slip_flushbuf(slipfd); } #endif /* 0 */ } } } /*---------------------------------------------------------------------------*/