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-rw-r--r--util/tap/tap.cc415
1 files changed, 415 insertions, 0 deletions
diff --git a/util/tap/tap.cc b/util/tap/tap.cc
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--- /dev/null
+++ b/util/tap/tap.cc
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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 "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!");
+
+ if (reuse) {
+ int i = 1;
+ if (::setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (char *)&i,
+ sizeof(i)) < 0)
+ panic("setsockopt() SO_REUSEADDR failed!");
+ }
+
+ 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!");
+
+ if (::listen(fd, 1) == -1)
+ panic("listen() failed!");
+}
+
+// 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!");
+
+ 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", 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 = "";
+ 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];
+ pcap_t *pcap = pcap_open_live(device, 1500, 1, -1, errbuf);
+ if (pcap == NULL)
+ panic("pcap_open_live failed: %s\n", errbuf);
+
+ bpf_program program;
+ bpf_u_int32 localnet, netmask;
+ if (!pcap_lookupnet(device, &localnet, &netmask, errbuf))
+ panic("pcap_lookupnet failed: %s\n", errbuf);
+
+ 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);
+
+ 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;
+
+ 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
+ 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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