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gem5/util/tap/tap.cc
Nathan Binkert 03ef1a0c09 If a filter isn't specified, don't try to do any filtering 
If pcap_lookupnet fails, just assume the netmask is 0xffffff00
that's all we really wanted from it anyway.

--HG--
extra : convert_revision : ac0a390ddb7a6b0a4e4c6d2885bfa7bd059faf36
2003-11-02 02:13:04 -05:00

424 lines
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C++
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/*
* Copyright (c) 2003 The Regents of The University of Michigan
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* 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;
* neither the name of the copyright holders 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 COPYRIGHT HOLDERS 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 COPYRIGHT
* OWNER 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.
*/
extern "C" {
#include <pcap.h>
}
#include <dnet.h>
#include <arpa/inet.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <errno.h>
#include <fcntl.h>
#include <libgen.h>
#include <netdb.h>
#include <poll.h>
#include <signal.h>
#include <unistd.h>
#include <list>
#include <string>
#include "base/cprintf.hh"
#define panic(arg...) \
do { cprintf("Panic: " arg); exit(1); } while (0)
char *program = "ethertap";
void
usage()
{
cprintf(
"usage: \n"
"\t%s [-b bufsize] [-d] [-f filter] [-p port] [-v] <device> <host>\n"
"\t%s [-b bufsize] [-d] [-f filter] [-l] [-p port] [-v] <device>\n",
program, program);
exit(2);
}
int verbose = 0;
#define DPRINTF(args...) do { \
if (verbose >= 1) \
cprintf(args); \
} while (0)
#define DDUMP(args...) do { \
if (verbose >= 2) \
dump((const u_char *)args); \
} while (0)
void
dump(const u_char *data, int len)
{
int c, i, j;
for (i = 0; i < len; i += 16) {
cprintf("%08x ", i);
c = len - i;
if (c > 16) c = 16;
for (j = 0; j < c; j++) {
cprintf("%02x ", data[i + j] & 0xff);
if ((j & 0xf) == 7 && j > 0)
cprintf(" ");
}
for (; j < 16; j++)
cprintf(" ");
cprintf(" ");
for (j = 0; j < c; j++) {
int ch = data[i + j] & 0x7f;
cprintf("%c", (char)(isprint(ch) ? ch : ' '));
}
cprintf("\n");
if (c < 16)
break;
}
}
bool quit = false;
void
quit_now(int sigtype)
{
DPRINTF("User requested exit\n");
quit = true;
}
int
Socket(int reuse)
{
int fd = ::socket(PF_INET, SOCK_STREAM, 0);
if (fd < 0)
panic("Can't create socket!\n");
if (reuse) {
int i = 1;
if (::setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char *)&i,
sizeof(i)) < 0)
panic("setsockopt() SO_REUSEADDR failed!\n");
}
return fd;
}
void
Listen(int fd, int port)
{
struct sockaddr_in sockaddr;
sockaddr.sin_family = PF_INET;
sockaddr.sin_addr.s_addr = INADDR_ANY;
sockaddr.sin_port = htons(port);
int ret = ::bind(fd, (struct sockaddr *)&sockaddr, sizeof (sockaddr));
if (ret == -1)
panic("bind() failed!\n");
if (::listen(fd, 1) == -1)
panic("listen() failed!\n");
}
// Open a connection. Accept will block, so if you don't want it to,
// make sure a connection is ready before you call accept.
int
Accept(int fd, bool nodelay)
{
struct sockaddr_in sockaddr;
socklen_t slen = sizeof (sockaddr);
int sfd = ::accept(fd, (struct sockaddr *)&sockaddr, &slen);
if (sfd == -1)
panic("accept() failed!\n");
if (nodelay) {
int i = 1;
::setsockopt(sfd, IPPROTO_TCP, TCP_NODELAY, (char *)&i, sizeof(i));
}
return sfd;
}
void
Connect(int fd, const string &host, int port)
{
struct sockaddr_in sockaddr;
if (::inet_aton(host.c_str(), &sockaddr.sin_addr) == 0) {
struct hostent *hp;
hp = ::gethostbyname(host.c_str());
if (!hp)
panic("Host %s not found\n", host);
sockaddr.sin_family = hp->h_addrtype;
memcpy(&sockaddr.sin_addr, hp->h_addr, hp->h_length);
}
sockaddr.sin_port = htons(port);
if (::connect(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr)) != 0)
panic("could not connect to %s on port %d\n", host, port);
DPRINTF("connected to %s on port %d\n", host, port);
}
int
main(int argc, char *argv[])
{
int port = 3500;
int bufsize = 2000;
bool listening = false;
char *device = NULL;
char *filter = NULL;
char c;
int daemon = false;
string host;
program = basename(argv[0]);
while ((c = getopt(argc, argv, "b:df:lp:v")) != -1) {
switch (c) {
case 'b':
bufsize = atoi(optarg);
break;
case 'd':
daemon = true;
break;
case 'f':
filter = optarg;
break;
case 'l':
listening = true;
break;
case 'p':
port = atoi(optarg);
break;
case 'v':
verbose++;
break;
default:
usage();
break;
}
}
signal(SIGINT, quit_now);
signal(SIGTERM, quit_now);
signal(SIGHUP, quit_now);
if (daemon) {
verbose = 0;
switch(fork()) {
case -1:
panic("Fork failed\n");
case 0:
break;
default:
exit(0);
}
}
char *buffer = new char[bufsize];
argc -= optind;
argv += optind;
if (argc-- == 0)
usage();
device = *argv++;
if (listening) {
if (argc)
usage();
} else {
if (argc != 1)
usage();
host = *argv;
}
char errbuf[PCAP_ERRBUF_SIZE];
memset(errbuf, 0, sizeof errbuf);
pcap_t *pcap = pcap_open_live(device, 1500, 1, -1, errbuf);
if (pcap == NULL)
panic("pcap_open_live failed: %s\n", errbuf);
if (filter) {
bpf_program program;
bpf_u_int32 localnet, netmask;
if (pcap_lookupnet(device, &localnet, &netmask, errbuf) == -1) {
DPRINTF("pcap_lookupnet failed: %s\n", errbuf);
netmask = 0xffffff00;
}
if (pcap_compile(pcap, &program, filter, 1, netmask) == -1)
panic("pcap_compile failed, invalid filter:\n%s\n", filter);
if (pcap_setfilter(pcap, &program) == -1)
panic("pcap_setfilter failed\n");
}
eth_t *ethernet = eth_open(device);
if (!ethernet)
panic("cannot open the ethernet device for writing\n");
pollfd pfds[3];
pfds[0].fd = Socket(true);
pfds[0].events = POLLIN;
pfds[0].revents = 0;
if (listening)
Listen(pfds[0].fd, port);
else
Connect(pfds[0].fd, host, port);
pfds[1].fd = pcap_fileno(pcap);
pfds[1].events = POLLIN;
pfds[1].revents = 0;
pfds[2].fd = 0;
pfds[2].events = POLLIN|POLLERR;
pfds[2].revents = 0;
pollfd *listen_pfd = listening ? &pfds[0] : NULL;
pollfd *tap_pfd = &pfds[1];
pollfd *client_pfd = listening ? NULL : &pfds[0];
int npfds = 2;
int32_t buffer_offset = 0;
int32_t data_len = 0;
DPRINTF("Begin poll loop\n");
while (!quit) {
int ret = ::poll(pfds, npfds, INFTIM);
if (ret < 0)
continue;
if (listen_pfd && listen_pfd->revents) {
if (listen_pfd->revents & POLLIN) {
int fd = Accept(listen_pfd->fd, false);
if (client_pfd) {
DPRINTF("Connection rejected\n");
close(fd);
} else {
DPRINTF("Connection accepted\n");
client_pfd = &pfds[2];
client_pfd->fd = fd;
npfds++;
}
}
listen_pfd->revents = 0;
}
if (tap_pfd && tap_pfd->revents) {
if (tap_pfd->revents & POLLIN) {
pcap_pkthdr hdr;
const u_char *data = pcap_next(pcap, &hdr);
if (data && client_pfd) {
DPRINTF("Received packet from ethernet len=%d\n", hdr.len);
DDUMP(data, hdr.len);
u_int32_t len = htonl(hdr.len);
write(client_pfd->fd, &len, sizeof(len));
write(client_pfd->fd, data, hdr.len);
}
}
tap_pfd->revents = 0;
}
if (client_pfd && client_pfd->revents) {
if (client_pfd->revents & POLLIN) {
if (buffer_offset < data_len + sizeof(u_int32_t)) {
int len = read(client_pfd->fd, buffer + buffer_offset,
bufsize - buffer_offset);
if (len <= 0) {
perror("read");
goto error;
}
buffer_offset += len;
if (data_len == 0)
data_len = ntohl(*(u_int32_t *)buffer);
DPRINTF("Received data from peer: len=%d buffer_offset=%d "
"data_len=%d\n", len, buffer_offset, data_len);
}
while (data_len != 0 &&
buffer_offset >= data_len + sizeof(u_int32_t)) {
char *data = buffer + sizeof(u_int32_t);
eth_send(ethernet, data, data_len);
DPRINTF("Sent packet to ethernet len = %d\n", data_len);
DDUMP(data, data_len);
buffer_offset -= data_len + sizeof(u_int32_t);
if (buffer_offset > 0 && data_len > 0) {
memmove(buffer, data + data_len, buffer_offset);
data_len = ntohl(*(u_int32_t *)buffer);
} else
data_len = 0;
}
}
if (client_pfd->revents & POLLERR) {
error:
DPRINTF("Error on client socket\n");
close(client_pfd->fd);
client_pfd = NULL;
if (listening)
npfds--;
else {
DPRINTF("Calling it quits because of poll error\n");
quit = true;
}
}
if (client_pfd)
client_pfd->revents = 0;
}
}
delete [] buffer;
pcap_close(pcap);
eth_close(ethernet);
if (listen_pfd)
close(listen_pfd->fd);
if (client_pfd)
close(client_pfd->fd);
return 0;
}
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