contiki/tools/wpcapslip/wpcapstdio.c

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/*
* Copyright (c) 2012, Thingsquare, www.thingsquare.com.
* 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: Fredrik Osterlind <fredrik@thingsquare.com>
* Based on wpcapslip.c by : Oliver Schmidt <ol.sc@web.de>
*/
/* This is a stripped-down version of wpcapslip: Instead of reading from and writing
* to a serial port, this program just reads and writes to stdin/stdout. To
* achieve the same functionality as wpcapslip, this program can hence be connected
* to serialdump. But, in contrast to wpcapslip, this program can easily be connected
* to networked or simulated serial ports. -- Fredrik, 2012 */
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#ifdef __CYGWIN__
#include <alloca.h>
#else /* __CYGWIN__ */
#include <malloc.h>
#endif /* __CYGWIN__ */
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <time.h>
#include <sys/types.h>
#include <sys/select.h>
#include <unistd.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <termios.h>
#include <sys/ioctl.h>
#include <err.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#define PROGRESS(x)
void wpcap_start(char *ethifaddr, char *netaddr, char *netmask, int logging);
void wpcap_send(void *buf, int len);
void raw_send(void *buf, int len);
uint16_t wpcap_poll(char **buf, int eth);
#include "net/tcpdump.h"
static int should_print = 0;
static int send_eth = 0; /* Sends ethernet frames or IP packets */
#define IP_HLEN 20
/*---------------------------------------------------------------------------*/
uint16_t
uip_htons(uint16_t val)
{
return UIP_HTONS(val);
}
/*---------------------------------------------------------------------------*/
uint32_t
uip_htonl(uint32_t val)
{
return UIP_HTONL(val);
}
/*---------------------------------------------------------------------------*/
static void
print_packet(char* prefix, uint8_t *packet, int len)
{
char buf[2000];
if(should_print) {
tcpdump_format(packet, len, buf, sizeof(buf));
fprintf(stderr, "%s: %s\n", prefix, 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, last_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);
fprintf(stderr, "%s\n", cmd);
fflush(stderr);
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;
}
/*---------------------------------------------------------------------------*/
static uint16_t
chksum(const void *p, uint16_t len)
{
uint16_t sum = ip4sum(0, p, len);
return (sum == 0) ? 0xffff : uip_htons(sum);
}
/*---------------------------------------------------------------------------*/
int
check_ip(const struct ip *ip, unsigned ip_len)
{
u_int16_t sum, ip_hl;
if(send_eth) {
return 0;
}
/* Check IP version and length. */
if((ip->ip_vhl & IP_V) != IP_V4) {
return -1;
}
if(uip_ntohs(ip->ip_len) > ip_len) {
return -2;
}
if(uip_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 a single character from stdin. When we have a full packet, write it to
* the network interface.
*/
void
serial_to_wpcap(void)
{
static union {
unsigned char inbuf[2000];
struct ip iphdr;
} uip;
static int inbufptr = 0;
int ret;
unsigned char c;
if(inbufptr >= sizeof(uip.inbuf)) {
inbufptr = 0;
return;
}
ret = read(STDIN_FILENO, &c, 1);
if(ret <= 0) {
err(1, "serial_to_wpcap: read");
inbufptr = 0;
return;
}
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((const char*)uip.inbuf, "=IPA", 4) == 0) {
static struct in_addr ipa;
inbufptr = 0;
if(memcmp(&ipa, &uip.inbuf[4], sizeof(ipa)) == 0) {
break;
}
memcpy(&ipa, &uip.inbuf[4], sizeof(ipa));
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_wpcap: drop packet len=%d ecode=%d\n",
inbufptr, ecode);
}
inbufptr = 0;
break;
}
PROGRESS("s");
if(send_eth) {
raw_send(uip.inbuf, inbufptr);
} else {
/* printf("Sending to wpcap\n");*/
if(uip.iphdr.ip_id != last_id) {
last_id = uip.iphdr.ip_id;
print_packet("to wpcap: ", uip.inbuf, inbufptr);
wpcap_send(uip.inbuf, inbufptr);
} else {
/*print_packet("IGNORED to wpcap: ", uip.inbuf, inbufptr);*/
}
}
/* printf("After sending to wpcap\n");*/
inbufptr = 0;
}
break;
case SLIP_ESC:
/* TODO We do not actually check that we have another byte incoming, so
* we may block here */
read(STDIN_FILENO, &c, 1);
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;
}
}
/*---------------------------------------------------------------------------*/
unsigned char stdout_buf[2000];
int stdout_buf_cnt;
/*---------------------------------------------------------------------------*/
void
stdout_write(unsigned char c)
{
if(stdout_buf_cnt >= sizeof(stdout_buf)) {
err(1, "stdout_write overflow");
}
stdout_buf[stdout_buf_cnt] = c;
stdout_buf_cnt++;
}
/*---------------------------------------------------------------------------*/
int
stdout_buf_empty(void)
{
return stdout_buf_cnt == 0;
}
/*---------------------------------------------------------------------------*/
void
stdout_flushbuf(void)
{
if(stdout_buf_empty()) {
return;
}
fwrite(stdout_buf, stdout_buf_cnt, 1, stdout);
stdout_buf_cnt = 0;
fflush(stdout);
}
/*---------------------------------------------------------------------------*/
void
write_slip_stdout(void *inbuf, int len)
{
u_int8_t *p = inbuf;
int i, ecode;
struct ip *iphdr = inbuf;
if(!send_eth) {
/*
* Sanity checks.
*/
/*fprintf(stderr, "write_slip_stdout: %d\n", len);*/
ecode = check_ip(inbuf, len);
if(ecode < 0) {
fprintf(stderr, "write_slip_stdout: drop packet %d\n", ecode);
return;
}
if(iphdr->ip_id == 0 && iphdr->ip_off & IP_DF) {
uint16_t nid = uip_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, "write_slip_stdout: drop packet %d\n", ecode);
return;
}
}
iphdr->ip_ttl = uip_htons(uip_htons(iphdr->ip_ttl) + 1);
if(iphdr->ip_ttl == 0) {
fprintf(stderr, "Packet with ttl %d dropped\n", iphdr->ip_ttl);
return;
}
iphdr->ip_sum = 0;
iphdr->ip_sum = ~chksum(iphdr, 4 * (iphdr->ip_vhl & IP_HL));
ecode = check_ip(inbuf, len);
if(ecode < 0) {
fprintf(stderr, "write_slip_stdout: drop packet %d\n", ecode);
return;
}
}
for(i = 0; i < len; i++) {
switch (p[i]) {
case SLIP_END:
stdout_write(SLIP_ESC);
stdout_write(SLIP_ESC_END);
break;
case SLIP_ESC:
stdout_write(SLIP_ESC);
stdout_write(SLIP_ESC_ESC);
break;
default:
stdout_write(p[i]);
break;
}
}
stdout_write(SLIP_END);
/* printf("slip end\n");*/
PROGRESS("t");
}
/*---------------------------------------------------------------------------*/
/*const char *ipaddr;*/
/*const char *netmask;*/
static int got_sigalarm;
void
sigalarm(int signo)
{
got_sigalarm = 1;
return;
}
/*---------------------------------------------------------------------------*/
void
sigalarm_reset(void)
{
#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 ret;
char buf[4000];
int logging = 0;
ip_id = getpid() * time(NULL);
while((c = getopt(argc, argv, "E:D:hl:t:T")) != -1) {
switch (c) {
case 'E':
send_eth = 1;
break;
case 'T':
should_print = 1;
break;
case 'l':
logging = 1;
break;
case '?':
case 'h':
default:
err(1,
"usage: wpcapstdio [-E] [-l] [-T] <IP address of local Ethernet card> <IP address of SLIP network> <netmask of SLIP network>");
break;
}
}
argc -= (optind - 1);
argv += (optind - 1);
if(argc != 4) {
err(1, "usage: wpcapstdio [-E] [-T] <IP address of local Ethernet card> <IP address of SLIP network> <netmask of SLIP network>");
}
wpcap_start(argv[1], argv[2], argv[3], logging);
stdout_write(SLIP_END);
atexit(cleanup);
signal(SIGHUP, sigcleanup);
signal(SIGTERM, sigcleanup);
signal(SIGINT, sigcleanup);
signal(SIGALRM, sigalarm);
while(1) {
if(got_sigalarm) {
/* Send "?IPA". */
stdout_write('?');
stdout_write('I');
stdout_write('P');
stdout_write('A');
stdout_write(SLIP_END);
got_sigalarm = 0;
}
if(stdout_buf_empty()) {
char *pbuf = buf;
ret = wpcap_poll(&pbuf, send_eth);
if(ret > 0) {
if(send_eth) {
write_slip_stdout(pbuf, ret);
stdout_flushbuf();
} else {
struct ip *iphdr = (struct ip *)pbuf;
if(iphdr->ip_id != last_id) {
/*last_id = iphdr->ip_id;*/
print_packet("to stdout: ", (uint8_t*)pbuf, ret);
write_slip_stdout(pbuf, ret);
stdout_flushbuf();
} else {
/*print_packet("IGNORED to stdout: ", (uint8_t*)pbuf, ret);*/
}
}
}
}
if(!stdout_buf_empty()) {
stdout_flushbuf();
}
{
fd_set s_rd;
struct timeval tv;
tv.tv_sec = 0;
tv.tv_usec = 100;
do {
FD_ZERO(&s_rd);
FD_SET(fileno(stdin), &s_rd);
select(fileno(stdin) + 1, &s_rd, NULL, NULL, &tv);
if(FD_ISSET(fileno(stdin), &s_rd)) {
serial_to_wpcap();
}
} while(FD_ISSET(fileno(stdin), &s_rd));
}
}
}
/*---------------------------------------------------------------------------*/