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/* Copyright 2001, 2002 Jeff Dike and others
* Licensed under the GPL
*/
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <signal.h>
#include <fcntl.h>
#include <stdint.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/poll.h>
#include <sys/time.h>
#include <unistd.h>
#include "switch.h"
#include "port.h"
#include "hash.h"
#ifdef TUNTAP
#include "tuntap.h"
#endif
#ifdef notdef
#include <stddef.h>
#endif
static int hub = 0;
static int compat_v0 = 0;
enum request_type { REQ_NEW_CONTROL };
struct request_v0 {
enum request_type type;
union {
struct {
unsigned char addr[ETH_ALEN];
struct sockaddr_un name;
} new_control;
} u;
};
#define SWITCH_MAGIC 0xfeedface
struct request_v1 {
uint32_t magic;
enum request_type type;
union {
struct {
unsigned char addr[ETH_ALEN];
struct sockaddr_un name;
} new_control;
} u;
};
struct request_v2 {
uint32_t magic;
uint32_t version;
enum request_type type;
struct sockaddr_un sock;
};
struct reply_v2 {
unsigned char mac[ETH_ALEN];
struct sockaddr_un sock;
};
struct request_v3 {
uint32_t magic;
uint32_t version;
enum request_type type;
struct sockaddr_un sock;
};
union request {
struct request_v0 v0;
struct request_v1 v1;
struct request_v2 v2;
struct request_v3 v3;
};
static char *ctl_socket = "/tmp/uml.ctl";
static char *data_socket = NULL;
static struct sockaddr_un data_sun;
static void cleanup(void)
{
if(unlink(ctl_socket) < 0){
printf("Couldn't remove control socket '%s' : ", ctl_socket);
perror("");
}
if((data_socket != NULL) && (unlink(data_socket) < 0)){
printf("Couldn't remove data socket '%s' : ", data_socket);
perror("");
}
}
static struct pollfd *fds = NULL;
static int maxfds = 0;
static int nfds = 0;
static void add_fd(int fd)
{
struct pollfd *p;
if(nfds == maxfds){
maxfds = maxfds ? 2 * maxfds : 4;
if((fds = realloc(fds, maxfds * sizeof(struct pollfd))) == NULL){
perror("realloc");
cleanup();
exit(1);
}
}
p = &fds[nfds++];
p->fd = fd;
p->events = POLLIN;
}
static void remove_fd(int fd)
{
int i;
for(i = 0; i < nfds; i++){
if(fds[i].fd == fd) break;
}
if(i == nfds){
fprintf(stderr, "remove_fd : Couldn't find descriptor %d\n", fd);
}
memmove(&fds[i], &fds[i + 1], (maxfds - i - 1) * sizeof(struct pollfd));
nfds--;
}
static void sig_handler(int sig)
{
printf("Caught signal %d, cleaning up and exiting\n", sig);
cleanup();
signal(sig, SIG_DFL);
kill(getpid(), sig);
}
static void close_descriptor(int fd)
{
remove_fd(fd);
close(fd);
close_port(fd);
}
static void new_port_v0(int fd, struct request_v0 *req, int data_fd)
{
switch(req->type){
case REQ_NEW_CONTROL:
setup_sock_port(fd, &req->u.new_control.name, data_fd);
break;
default:
printf("Bad request type : %d\n", req->type);
close_descriptor(fd);
}
}
static void new_port_v1_v3(int fd, enum request_type type,
struct sockaddr_un *sock, int data_fd)
{
int n, err;
switch(type){
case REQ_NEW_CONTROL:
err = setup_sock_port(fd, sock, data_fd);
if(err) return;
n = write(fd, &data_sun, sizeof(data_sun));
if(n != sizeof(data_sun)){
perror("Sending data socket name");
close_descriptor(fd);
}
break;
default:
printf("Bad request type : %d\n", type);
close_descriptor(fd);
}
}
static void new_port_v2(int fd)
{
fprintf(stderr, "Version 2 is not supported\n");
close_descriptor(fd);
}
static void new_port(int fd, int data_fd)
{
union request req;
int len;
len = read(fd, &req, sizeof(req));
if(len < 0){
if(errno != EAGAIN){
perror("Reading request");
close_descriptor(fd);
}
return;
}
else if(len == 0){
printf("EOF from new port\n");
close_descriptor(fd);
return;
}
if(req.v1.magic == SWITCH_MAGIC){
if(req.v2.version == 2) new_port_v2(fd);
if(req.v3.version == 3)
new_port_v1_v3(fd, req.v3.type, &req.v3.sock, data_fd);
else if(req.v2.version > 2)
fprintf(stderr, "Request for a version %d port, which this "
"uml_switch doesn't support\n", req.v2.version);
else new_port_v1_v3(fd, req.v1.type, &req.v1.u.new_control.name, data_fd);
}
else new_port_v0(fd, &req.v0, data_fd);
}
void accept_connection(int fd)
{
struct sockaddr addr;
int len, new;
len = sizeof(addr);
new = accept(fd, &addr, &len);
if(new < 0){
perror("accept");
return;
}
if(fcntl(new, F_SETFL, O_NONBLOCK) < 0){
perror("fcntl - setting O_NONBLOCK");
close(new);
return;
}
add_fd(new);
}
int still_used(struct sockaddr_un *sun)
{
int test_fd, ret = 1;
if((test_fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0){
perror("socket");
exit(1);
}
if(connect(test_fd, (struct sockaddr *) sun, sizeof(*sun)) < 0){
if(errno == ECONNREFUSED){
if(unlink(sun->sun_path) < 0){
fprintf(stderr, "Failed to removed unused socket '%s': ",
sun->sun_path);
perror("");
}
ret = 0;
}
else perror("connect");
}
close(test_fd);
return(ret);
}
int bind_socket(int fd, const char *name, struct sockaddr_un *sock_out)
{
struct sockaddr_un sun;
sun.sun_family = AF_UNIX;
strncpy(sun.sun_path, name, sizeof(sun.sun_path));
if(bind(fd, (struct sockaddr *) &sun, sizeof(sun)) < 0){
if((errno == EADDRINUSE) && still_used(&sun)) return(EADDRINUSE);
else if(bind(fd, (struct sockaddr *) &sun, sizeof(sun)) < 0){
perror("bind");
return(EPERM);
}
}
if(sock_out != NULL) *sock_out = sun;
return(0);
}
static char *prog;
void bind_sockets_v0(int ctl_fd, const char *ctl_name,
int data_fd, const char *data_name)
{
int ctl_err, ctl_present = 0, ctl_used = 0;
int data_err, data_present = 0, data_used = 0;
int try_remove_ctl, try_remove_data;
ctl_err = bind_socket(ctl_fd, ctl_name, NULL);
if(ctl_err != 0) ctl_present = 1;
if(ctl_err == EADDRINUSE) ctl_used = 1;
data_err = bind_socket(data_fd, data_name, &data_sun);
if(data_err != 0) data_present = 1;
if(data_err == EADDRINUSE) data_used = 1;
if(!ctl_err && !data_err){
return;
}
try_remove_ctl = ctl_present;
try_remove_data = data_present;
if(ctl_present && ctl_used){
fprintf(stderr, "The control socket '%s' has another server "
"attached to it\n", ctl_name);
try_remove_ctl = 0;
}
else if(ctl_present && !ctl_used)
fprintf(stderr, "The control socket '%s' exists, isn't used, but couldn't "
"be removed\n", ctl_name);
if(data_present && data_used){
fprintf(stderr, "The data socket '%s' has another server "
"attached to it\n", data_name);
try_remove_data = 0;
}
else if(data_present && !data_used)
fprintf(stderr, "The data socket '%s' exists, isn't used, but couldn't "
"be removed\n", data_name);
if(try_remove_ctl || try_remove_data){
fprintf(stderr, "You can either\n");
if(try_remove_ctl && !try_remove_data)
fprintf(stderr, "\tremove '%s'\n", ctl_socket);
else if(!try_remove_ctl && try_remove_data)
fprintf(stderr, "\tremove '%s'\n", data_socket);
else fprintf(stderr, "\tremove '%s' and '%s'\n", ctl_socket, data_socket);
fprintf(stderr, "\tor rerun with different, unused filenames for "
"sockets:\n");
fprintf(stderr, "\t\t%s -unix <control> <data>\n", prog);
fprintf(stderr, "\t\tand run the UMLs with "
"'eth0=daemon,,unix,<control>,<data>\n");
exit(1);
}
else {
fprintf(stderr, "You should rerun with different, unused filenames for "
"sockets:\n");
fprintf(stderr, "\t%s -unix <control> <data>\n", prog);
fprintf(stderr, "\tand run the UMLs with "
"'eth0=daemon,,unix,<control>,<data>'\n");
exit(1);
}
}
void bind_data_socket(int fd, struct sockaddr_un *sun)
{
struct {
char zero;
int pid;
int usecs;
} name;
struct timeval tv;
name.zero = 0;
name.pid = getpid();
gettimeofday(&tv, NULL);
name.usecs = tv.tv_usec;
sun->sun_family = AF_UNIX;
memcpy(sun->sun_path, &name, sizeof(name));
if(bind(fd, (struct sockaddr *) sun, sizeof(*sun)) < 0){
perror("Binding to data socket");
exit(1);
}
}
void bind_sockets(int ctl_fd, const char *ctl_name, int data_fd)
{
int err, used = 0;
err = bind_socket(ctl_fd, ctl_name, NULL);
if(err == 0){
bind_data_socket(data_fd, &data_sun);
return;
}
else if(err == EADDRINUSE) used = 1;
if(used){
fprintf(stderr, "The control socket '%s' has another server "
"attached to it\n", ctl_name);
fprintf(stderr, "You can either\n");
fprintf(stderr, "\tremove '%s'\n", ctl_name);
fprintf(stderr, "\tor rerun with a different, unused filename for a "
"socket\n");
}
else
fprintf(stderr, "The control socket '%s' exists, isn't used, but couldn't "
"be removed\n", ctl_name);
exit(1);
}
static void Usage(void)
{
char *tap_str = "";
#ifdef TUNTAP
tap_str = "[ -tap tap-device ]";
#endif
fprintf(stderr, "Usage : %s [ -unix control-socket ] [ -hub ] %s\n"
"or : %s -compat-v0 [ -unix control-socket data-socket ] "
"[ -hub ] %s\n", prog, tap_str, prog, tap_str);
exit(1);
}
int main(int argc, char **argv)
{
int connect_fd, data_fd, n, i, new, one = 1, daemonize = 0;
char *tap_dev = NULL;
#ifdef TUNTAP
int tap_fd = -1;
#endif
prog = argv[0];
argv++;
argc--;
while(argc > 0){
if(!strcmp(argv[0], "-unix")){
if(argc < 2)
Usage();
ctl_socket = argv[1];
argc -= 2;
argv += 2;
if(!compat_v0)
continue;
if(argc < 1)
Usage();
data_socket = argv[0];
argc--;
argv++;
}
else if(!strcmp(argv[0], "-tap")){
#ifdef TUNTAP
if(argc < 2)
Usage();
tap_dev = argv[1];
argv += 2;
argc -= 2;
#else
fprintf(stderr, "-tap isn't supported since TUNTAP isn't enabled\n");
Usage();
#endif
}
else if(!strcmp(argv[0], "-hub")){
printf("%s will be a hub instead of a switch\n", prog);
hub = 1;
argc--;
argv++;
}
else if(!strcmp(argv[0], "-compat-v0")){
printf("Control protocol 0 compatibility\n");
compat_v0 = 1;
data_socket = "/tmp/uml.data";
argc--;
argv++;
}
else if(!strcmp(argv[0], "-daemon")){
daemonize = 1;
argc--;
argv++;
}
else Usage();
}
if((connect_fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0){
perror("socket");
exit(1);
}
if(setsockopt(connect_fd, SOL_SOCKET, SO_REUSEADDR, (char *) &one,
sizeof(one)) < 0){
perror("setsockopt");
exit(1);
}
if(fcntl(connect_fd, F_SETFL, O_NONBLOCK) < 0){
perror("Setting O_NONBLOCK on connection fd");
exit(1);
}
if((data_fd = socket(PF_UNIX, SOCK_DGRAM, 0)) < 0){
perror("socket");
exit(1);
}
if(fcntl(data_fd, F_SETFL, O_NONBLOCK) < 0){
perror("Setting O_NONBLOCK on data fd");
exit(1);
}
if(compat_v0) bind_sockets_v0(connect_fd, ctl_socket, data_fd, data_socket);
else bind_sockets(connect_fd, ctl_socket, data_fd);
if(listen(connect_fd, 15) < 0){
perror("listen");
exit(1);
}
if(signal(SIGINT, sig_handler) == SIG_ERR)
perror("Setting handler for SIGINT");
hash_init();
if(compat_v0)
printf("%s attached to unix sockets '%s' and '%s'", prog, ctl_socket,
data_socket);
else printf("%s attached to unix socket '%s'", prog, ctl_socket);
#ifdef TUNTAP
if(tap_dev != NULL)
printf(" tap device '%s'", tap_dev);
#endif
printf("\n");
if(isatty(0))
add_fd(0);
add_fd(connect_fd);
add_fd(data_fd);
#ifdef TUNTAP
if(tap_dev != NULL) tap_fd = open_tap(tap_dev);
if(tap_fd > -1) add_fd(tap_fd);
#endif
if (daemonize && daemon(0, 1)) {
perror("daemon");
exit(1);
}
while(1){
char buf[128];
n = poll(fds, nfds, -1);
if(n < 0){
if(errno == EINTR) continue;
perror("poll");
break;
}
for(i = 0; i < nfds; i++){
if(fds[i].revents == 0) continue;
if(fds[i].fd == 0){
if(fds[i].revents & POLLHUP){
printf("EOF on stdin, cleaning up and exiting\n");
goto out;
}
n = read(0, buf, sizeof(buf));
if(n < 0){
perror("Reading from stdin");
break;
}
else if(n == 0){
printf("EOF on stdin, cleaning up and exiting\n");
goto out;
}
}
else if(fds[i].fd == connect_fd){
if(fds[i].revents & POLLHUP){
printf("Error on connection fd\n");
continue;
}
accept_connection(connect_fd);
}
else if(fds[i].fd == data_fd) handle_sock_data(data_fd, hub);
#ifdef TUNTAP
else if(fds[i].fd == tap_fd) handle_tap_data(tap_fd, hub);
#endif
else {
new = handle_port(fds[i].fd);
if(new) new_port(fds[i].fd, data_fd);
else close_descriptor(fds[i].fd);
}
}
}
out:
cleanup();
return 0;
}
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