vde-2/vde_plug2tap/vde_plug2tap.c

   1 /* Copyright 2006 Renzo Davoli
   2  * from vde_plug Davoli Gardenghi
   3  */
   4
   5 #include <config.h>
   6 #include <stdio.h>
   7 #include <fcntl.h>
   8 #include <stdlib.h>
   9 #include <unistd.h>
  10 #include <signal.h>
  11 #include <poll.h>
  12 #include <syslog.h>
  13 #include <errno.h>
  14 #include <string.h>
  15 #include <sys/ioctl.h>
  16 #include <sys/types.h>
  17 #include <sys/stat.h>
  18 #include <stdarg.h>
  19 #include <syslog.h>
  20 #include <libgen.h>
  21 #include <libvdeplug/libvdeplug.h>
  22 #define _GNU_SOURCE
  23 #include <getopt.h>
  24 #include <vde.h>
  25
  26 #define BUFSIZE 2048
  27
  28 #ifdef VDE_LINUX
  29 #include <net/if.h>
  30 #include <linux/if_tun.h>
  31 #endif
  32
  33 #ifdef VDE_DARWIN
  34 #       define TAP_PREFIX "/dev/"
  35 #       include <limits.h>
  36 #       if defined HAVE_SYSLIMITS_H
  37 #               include <syslimits.h>
  38 #       elif defined HAVE_SYS_SYSLIMITS_H
  39 #               include <sys/syslimits.h>
  40 #       else
  41 #               error "No syslimits.h found"
  42 #       endif
  43 #endif
  44
  45 VDECONN *conn;
  46
  47 char *prog;
  48 int logok;
  49 static char *pidfile = NULL;
  50 static char pidfile_path[PATH_MAX];
  51
  52 void printlog(int priority, const char *format, ...)
  53 {
  54         va_list arg;
  55
  56         va_start (arg, format);
  57
  58         if (logok)
  59                 vsyslog(priority,format,arg);
  60         else {
  61                 fprintf(stderr,"%s: ",prog);
  62                 vfprintf(stderr,format,arg);
  63                 fprintf(stderr,"\n");
  64         }
  65         va_end (arg);
  66 }
  67
  68 static void cleanup(void)
  69 {
  70         if((pidfile != NULL) && unlink(pidfile_path) < 0) {
  71                 printlog(LOG_WARNING,"Couldn't remove pidfile '%s': %s", pidfile, strerror(errno));
  72         }
  73
  74         vde_close(conn);
  75 }
  76
  77 static void sig_handler(int sig)
  78 {
  79         cleanup();
  80         signal(sig, SIG_DFL);
  81         kill(getpid(), sig);
  82 }
  83
  84 static void setsighandlers()
  85 {
  86         /* setting signal handlers.
  87          * sets clean termination for SIGHUP, SIGINT and SIGTERM, and simply
  88          * ignores all the others signals which could cause termination. */
  89         struct { int sig; const char *name; int ignore; } signals[] = {
  90                 { SIGHUP, "SIGHUP", 0 },
  91                 { SIGINT, "SIGINT", 0 },
  92                 { SIGPIPE, "SIGPIPE", 1 },
  93                 { SIGALRM, "SIGALRM", 1 },
  94                 { SIGTERM, "SIGTERM", 0 },
  95                 { SIGUSR1, "SIGUSR1", 1 },
  96                 { SIGUSR2, "SIGUSR2", 1 },
  97                 { SIGPROF, "SIGPROF", 1 },
  98                 { SIGVTALRM, "SIGVTALRM", 1 },
  99 #ifdef VDE_LINUX
 100                 { SIGPOLL, "SIGPOLL", 1 },
 101 #ifdef SIGSTKFLT
 102                 { SIGSTKFLT, "SIGSTKFLT", 1 },
 103 #endif
 104                 { SIGIO, "SIGIO", 1 },
 105                 { SIGPWR, "SIGPWR", 1 },
 106 #ifdef SIGUNUSED
 107                 { SIGUNUSED, "SIGUNUSED", 1 },
 108 #endif
 109 #endif
 110 #ifdef VDE_DARWIN
 111                 { SIGXCPU, "SIGXCPU", 1 },
 112                 { SIGXFSZ, "SIGXFSZ", 1 },
 113 #endif
 114                 { 0, NULL, 0 }
 115         };
 116
 117         int i;
 118         for(i = 0; signals[i].sig != 0; i++)
 119                 if(signal(signals[i].sig,
 120                                         signals[i].ignore ? SIG_IGN : sig_handler) < 0)
 121                         perror("Setting handler");
 122 }
 123
 124 struct pollfd pollv[]={{0,POLLIN|POLLHUP},{0,POLLIN|POLLHUP},{0,POLLIN|POLLHUP}};
 125
 126 static void usage(void) {
 127         fprintf(stderr, "Usage: %s [OPTION]... tap_name\n\n", prog);
 128         fprintf(stderr, "  -p, --port=portnum          Port number in the VDE switch\n"
 129                                 "  -g, --group=group           Group for the socket\n"
 130                                         "  -m, --mode=mode             Octal mode for the socket\n"
 131                                         "  -s, --sock=socket           VDE switch control socket or dir\n"
 132                                         "  -d, --daemon                Launch in background\n"
 133                                         "  -P, --pidfile=pidfile       Create pidfile with our PID\n"
 134                                         "  -h, --help                  This help\n");
 135         exit(-1);
 136 }
 137
 138 #ifdef VDE_LINUX
 139 int open_tap(char *dev)
 140 {
 141         struct ifreq ifr;
 142         int fd;
 143
 144         if((fd = open("/dev/net/tun", O_RDWR)) < 0){
 145                 printlog(LOG_ERR,"Failed to open /dev/net/tun %s",strerror(errno));
 146                 return(-1);
 147         }
 148         memset(&ifr, 0, sizeof(ifr));
 149         ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
 150         strncpy(ifr.ifr_name, dev, sizeof(ifr.ifr_name) - 1);
 151         /*printf("dev=\"%s\", ifr.ifr_name=\"%s\"\n", ifr.ifr_name, dev);*/
 152         if(ioctl(fd, TUNSETIFF, (void *) &ifr) < 0){
 153                 printlog(LOG_ERR,"TUNSETIFF failed %s",strerror(errno));
 154                 close(fd);
 155                 return(-1);
 156         }
 157         return(fd);
 158 }
 159 #endif
 160
 161 #ifdef VDE_DARWIN
 162 int open_tap(char *dev)
 163 {
 164         int fd;
 165         int prefixlen = strlen(TAP_PREFIX);
 166         char *path = NULL;
 167         if (*dev == '/')
 168                 fd=open(dev, O_RDWR);
 169         else
 170         {
 171                 path = malloc(strlen(dev) + prefixlen + 1);
 172                 if (path != NULL)
 173                 {
 174                         snprintf(path, strlen(dev) + prefixlen + 1, "%s%s", TAP_PREFIX, dev);
 175                         fd=open(path, O_RDWR);
 176                         free(path);
 177                 }
 178                 else
 179                         fd = -1;
 180         }
 181
 182         if (fd < 0)
 183         {
 184                 printlog(LOG_ERR,"Failed to open tap device %s: %s", (*dev == '/') ? dev : path, strerror(errno));
 185                 return(-1);
 186         }
 187         return fd;
 188 }
 189 #endif
 190
 191 unsigned char bufin[BUFSIZE];
 192
 193 static void save_pidfile()
 194 {
 195         if(pidfile[0] != '/')
 196                 strncat(pidfile_path, pidfile, PATH_MAX - strlen(pidfile_path));
 197         else
 198                 strcpy(pidfile_path, pidfile);
 199
 200         int fd = open(pidfile_path,
 201                         O_WRONLY | O_CREAT | O_EXCL,
 202                         S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH);
 203         FILE *f;
 204
 205         if(fd == -1) {
 206                 printlog(LOG_ERR, "Error in pidfile creation: %s", strerror(errno));
 207                 exit(1);
 208         }
 209
 210         if((f = fdopen(fd, "w")) == NULL) {
 211                 printlog(LOG_ERR, "Error in FILE* construction: %s", strerror(errno));
 212                 exit(1);
 213         }
 214
 215         if(fprintf(f, "%ld\n", (long int)getpid()) <= 0) {
 216                 printlog(LOG_ERR, "Error in writing pidfile");
 217                 exit(1);
 218         }
 219
 220         fclose(f);
 221 }
 222
 223 int main(int argc, char **argv)
 224 {
 225         static char *sockname=NULL;
 226         static char *tapname=NULL;
 227         int daemonize=0;
 228         int result;
 229         int tapfd;
 230         register ssize_t nx;
 231         struct vde_open_args open_args={.port=0,.group=NULL,.mode=0700};
 232         int c;
 233         prog=argv[0];
 234         while (1) {
 235                 int option_index = 0;
 236
 237                 static struct option long_options[] = {
 238                         {"sock", 1, 0, 's'},
 239                         {"port", 1, 0, 'p'},
 240                         {"help",0,0,'h'},
 241                         {"mod",1,0,'m'},
 242                         {"group",1,0,'g'},
 243                         {"daemon",0,0,'d'},
 244                         {"pidfile", 1, 0, 'P'},
 245                         {0, 0, 0, 0}
 246                 };
 247                 c = GETOPT_LONG (argc, argv, "hdP:p:s:m:g:",
 248                                 long_options, &option_index);
 249                 if (c == -1)
 250                         break;
 251
 252                 switch (c) {
 253                         case 'p':
 254                                 open_args.port=atoi(optarg);
 255                                 if (open_args.port <= 0 || open_args.port > 255 )
 256                                         usage(); //implies exit
 257                                 break;
 258
 259                         case 'h':
 260                                 usage(); //implies exit
 261                                 break;
 262
 263                         case 's':
 264                                 sockname=strdup(optarg);
 265                                 break;
 266
 267                         case 'm':
 268                                 sscanf(optarg,"%o",&(open_args.mode));
 269                                 break;
 270
 271                         case 'g':
 272                                 open_args.group=strdup(optarg);
 273                                 break;
 274
 275                         case 'd':
 276                                 daemonize=1;
 277                                 break;
 278
 279                         case 'P':
 280                                 pidfile=strdup(optarg);
 281                                 break;
 282
 283                         default:
 284                                 usage(); //implies exit
 285                 }
 286         }
 287
 288         if (daemonize) {
 289                 openlog(basename(prog), LOG_PID, 0);
 290                 logok=1;
 291                 syslog(LOG_INFO,"VDE_PLUG2TAP started");
 292         }
 293         /* saves current path in pidfile_path, because otherwise with daemonize() we
 294          * forget it */
 295         if(getcwd(pidfile_path, PATH_MAX-1) == NULL) {
 296                 printlog(LOG_ERR, "getcwd: %s", strerror(errno));
 297                 exit(1);
 298         }
 299         strcat(pidfile_path, "/");
 300         if (daemonize && daemon(0, 0)) {
 301                 printlog(LOG_ERR,"daemon: %s",strerror(errno));
 302                 exit(1);
 303         }
 304
 305         /* once here, we're sure we're the true process which will continue as a
 306          * server: save PID file if needed */
 307         if(pidfile) save_pidfile();
 308
 309         if (optind < argc)
 310                 tapname=argv[optind];
 311         atexit(cleanup);
 312         setsighandlers();
 313
 314         tapfd=open_tap(tapname);
 315         if(tapfd<0)
 316                 exit(1);
 317         conn=vde_open(sockname,"vde_plug:",&open_args);
 318         if (conn == NULL)
 319                 exit(1);
 320
 321         pollv[0].fd=tapfd;
 322         pollv[1].fd=vde_datafd(conn);
 323         pollv[2].fd=vde_ctlfd(conn);
 324
 325         for(;;) {
 326                 result=poll(pollv,3,-1);
 327                 if ((pollv[0].revents | pollv[1].revents | pollv[2].revents) & POLLHUP ||
 328                                 pollv[2].revents & POLLIN)
 329                         break;
 330                 if (pollv[0].revents & POLLIN) {
 331                         nx=read(tapfd,bufin,sizeof(bufin));
 332                         /* if POLLIN but not data it means that the stream has been
 333                          * closed at the other end */
 334                         //fprintf(stderr,"%s: RECV %d %x %x \n",prog,nx,bufin[0],bufin[1]);
 335                         if (nx<=0)
 336                                 break;
 337                         vde_send(conn,bufin,nx,0);
 338                 }
 339                 if (pollv[1].revents & POLLIN) {
 340                         nx=vde_recv(conn,bufin,sizeof(bufin),0);
 341                         if (nx<=0)
 342                                 break;
 343                         write(tapfd,bufin,nx);
 344                         //fprintf(stderr,"%s: SENT %d %x %x \n",prog,nx,bufin[0],bufin[1]);
 345                 }
 346
 347         }
 348         return(0);
 349 }