src/vpn/gnunet-helper-vpn.c

   1 /*
   2      This file is part of GNUnet.
   3      (C) 2010 Christian Grothoff
   4
   5      GNUnet is free software; you can redistribute it and/or modify
   6      it under the terms of the GNU General Public License as published
   7      by the Free Software Foundation; either version 3, or (at your
   8      option) any later version.
   9
  10      GNUnet is distributed in the hope that it will be useful, but
  11      WITHOUT ANY WARRANTY; without even the implied warranty of
  12      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13      General Public License for more details.
  14
  15      You should have received a copy of the GNU General Public License
  16      along with GNUnet; see the file COPYING.  If not, write to the
  17      Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18      Boston, MA 02111-1307, USA.
  19 */
  20
  21 /**
  22  * @file vpn/gnunet-daemon-vpn.c
  23  * @brief
  24  * @author Philipp Tölke
  25  */
  26 #include <platform.h>
  27
  28 #include "gnunet-vpn-tun.h"
  29 #include "gnunet_common.h"
  30 #include "gnunet_protocols.h"
  31 #include "gnunet-vpn-helper-p.h"
  32
  33 #ifndef _LINUX_IN6_H
  34 // This is in linux/include/net/ipv6.h.
  35
  36 #define MAX_SIZE (65535 - sizeof(struct GNUNET_MessageHeader))
  37
  38 struct in6_ifreq {
  39     struct in6_addr ifr6_addr;
  40     uint32_t ifr6_prefixlen;
  41     unsigned int ifr6_ifindex;
  42 };
  43
  44 #endif
  45
  46 int running = 1;
  47
  48 void term(int sig) {
  49         fprintf(stderr, "Got SIGTERM...\n");
  50         if (sig == SIGTERM)
  51                 running = 0;
  52 }
  53
  54 static void set_address6(char* dev, char* address, unsigned long prefix_len) { /* {{{ */
  55         int fd = socket(AF_INET6, SOCK_DGRAM, 0);
  56
  57         struct ifreq ifr;
  58         struct in6_ifreq ifr6;
  59
  60         struct sockaddr_in6 sa6;
  61         memset(&sa6, 0, sizeof(struct sockaddr_in6));
  62
  63         sa6.sin6_family = AF_INET6;
  64
  65         /* FIXME */ inet_pton(AF_INET6, address, sa6.sin6_addr.s6_addr);
  66
  67         memcpy((char *) &ifr6.ifr6_addr, (char *) &sa6.sin6_addr, sizeof(struct in6_addr));
  68
  69         strncpy(ifr.ifr_name, dev, IFNAMSIZ);
  70
  71         if (ioctl(fd, SIOGIFINDEX, &ifr) < 0) {
  72                 perror("SIOGIFINDEX");
  73         }
  74
  75         ifr6.ifr6_ifindex = ifr.ifr_ifindex;
  76         ifr6.ifr6_prefixlen = prefix_len;
  77
  78         if (ioctl(fd, SIOCSIFADDR, &ifr6) < 0) {
  79                 perror("SIOCSIFADDR");
  80         }
  81
  82         /* FIXME */ ioctl(fd, SIOCGIFFLAGS, &ifr);
  83         ifr.ifr_flags |= IFF_UP | IFF_RUNNING;
  84         /* FIXME */ ioctl(fd, SIOCSIFFLAGS, &ifr);
  85 } /* }}} */
  86
  87 static void set_address4(char* dev, char* address, char* mask) { /* {{{ */
  88         int fd=0;
  89         struct sockaddr_in* addr;
  90         struct ifreq ifr;
  91
  92         memset(&ifr, 0, sizeof(struct ifreq));
  93         addr = (struct sockaddr_in *)&(ifr.ifr_addr);
  94         memset(addr, 0, sizeof(struct sockaddr_in));
  95         addr->sin_family = AF_INET;
  96         addr->sin_addr.s_addr = inet_addr(address);
  97
  98         /* FIXME */ inet_pton(AF_INET, address, &addr->sin_addr.s_addr);
  99
 100         fd = socket(PF_INET, SOCK_DGRAM, 0);
 101         if(fd < 0) {
 102                 perror("socket()");
 103                 return;
 104         }
 105
 106         strncpy(ifr.ifr_name, dev, IFNAMSIZ);
 107
 108         if(ioctl(fd, SIOCSIFADDR, &ifr) != 0 ) {
 109                 perror("SIOCSIFADDR");
 110                 close(fd);
 111                 return;
 112         }
 113
 114         addr = (struct sockaddr_in*)&(ifr.ifr_netmask);
 115         /* FIXME */ inet_pton(AF_INET, mask, &addr->sin_addr.s_addr);
 116
 117         if(ioctl(fd, SIOCSIFNETMASK, &ifr) != 0 ) {
 118                 perror("SIOCSIFNETMASK");
 119                 close(fd);
 120                 return;
 121         }
 122
 123         /* FIXME */ ioctl(fd, SIOCGIFFLAGS, &ifr);
 124         ifr.ifr_flags |= IFF_UP | IFF_RUNNING;
 125         /* FIXME */ ioctl(fd, SIOCSIFFLAGS, &ifr);
 126 } /* }}} */
 127
 128 void setnonblocking(int fd) {/*{{{*/
 129         int opts;
 130
 131         opts = fcntl(fd,F_GETFL);
 132         if (opts < 0) {
 133                         perror("fcntl(F_GETFL)");
 134         }
 135         opts = (opts | O_NONBLOCK);
 136         if (fcntl(fd,F_SETFL,opts) < 0) {
 137                         perror("fcntl(F_SETFL)");
 138         }
 139         return;
 140 }/*}}}*/
 141
 142 int main(int argc, char** argv) {
 143         unsigned char buf[MAX_SIZE];
 144
 145         char dev[IFNAMSIZ];
 146         memset(dev, 0, IFNAMSIZ);
 147
 148         signal(SIGTERM, &term);
 149
 150         int fd_tun = init_tun(dev);
 151
 152         if (fd_tun < 0) {
 153                 fprintf(stderr, "Could not initialize tun-interface: %m\n");
 154                 exit(1);
 155         }
 156
 157         fprintf(stderr, "Initialized the interface %s as %d.\n", dev, fd_tun);
 158
 159         {
 160         // TODO: get this out of argv
 161         char address[] = "1234::1";
 162         unsigned long prefix_len = 16;
 163
 164         set_address6(dev, address, prefix_len);
 165         }
 166
 167         {
 168         char address[] = "10.10.10.1";
 169         char mask[] = "255.255.255.252";
 170
 171         set_address4(dev, address, mask);
 172         }
 173
 174         uid_t uid = getuid ();
 175         if (setresuid (uid, uid, uid) != 0 )
 176                 fprintf (stderr, "Failed to setresuid: %m\n");
 177
 178         setnonblocking(0);
 179         setnonblocking(1);
 180         setnonblocking(fd_tun);
 181
 182         fd_set fds_w;
 183         fd_set fds_r;
 184
 185         int rea = 1;
 186         int wri = 1;
 187
 188         int write_fd_possible = 0;
 189         int write_stdout_possible = 0;
 190 outer:
 191         while((rea == 1 || wri == 1) && running == 1) {
 192                 FD_ZERO(&fds_w);
 193                 FD_ZERO(&fds_r);
 194
 195                 if (rea) {
 196                         FD_SET(fd_tun, &fds_r);
 197                         if (!write_stdout_possible)
 198                                 FD_SET(1, &fds_w);
 199                 }
 200
 201                 if (wri) {
 202                         FD_SET(0, &fds_r);
 203                         if (!write_fd_possible)
 204                                 FD_SET(fd_tun, &fds_w);
 205                 }
 206
 207                 int r = select(fd_tun+1, &fds_r, &fds_w, (fd_set*)0, 0);
 208
 209                 if(r > 0) {
 210                         if (FD_ISSET(fd_tun, &fds_w)) write_fd_possible = 1;
 211                         if (FD_ISSET(1, &fds_w)) write_stdout_possible = 1;
 212
 213                         if (FD_ISSET(0, &fds_r) && write_fd_possible) {
 214                                 write_fd_possible = 0;
 215                                 struct suid_packet *pkt = (struct suid_packet*) buf;
 216                                 r = read(0, buf, sizeof(struct GNUNET_MessageHeader));
 217                                 if (r <= 0) {
 218                                         fprintf(stderr, "read-error: %m\n");
 219                                         shutdown(fd_tun, SHUT_WR);
 220                                         shutdown(0, SHUT_RD);
 221                                         wri=0;
 222                                         goto outer;
 223                                 }
 224                                 while (r < ntohs(pkt->hdr.size)) {
 225                                         int t = read(0, buf + r, ntohs(pkt->hdr.size) - r);
 226                                         if (r < 0) {
 227                                                 fprintf(stderr, "read-error: %m\n");
 228                                                 shutdown(fd_tun, SHUT_WR);
 229                                                 shutdown(0, SHUT_RD);
 230                                                 wri=0;
 231                                                 goto outer;
 232                                         }
 233                                         r += t;
 234                                 }
 235                                 r = 0;
 236                                 while (r < ntohs(pkt->hdr.size) - sizeof(struct GNUNET_MessageHeader)) {
 237                                         int t = write(fd_tun, pkt->data, ntohs(pkt->hdr.size) - sizeof(struct GNUNET_MessageHeader) - r);
 238                                         if (t < 0) {
 239                                                 fprintf(stderr, "write-error 3: %m\n");
 240                                                 shutdown(fd_tun, SHUT_WR);
 241                                                 shutdown(0, SHUT_RD);
 242                                                 wri = 0;
 243                                                 goto outer;
 244                                         }
 245                                         r += t;
 246                                 }
 247                         } else if (write_stdout_possible && FD_ISSET(fd_tun, &fds_r)) {
 248                                 write_stdout_possible = 0;
 249                                 r = read(fd_tun, buf, MAX_SIZE);
 250                                 if (r <= 0) {
 251                                         fprintf(stderr, "read-error: %m\n");
 252                                         shutdown(fd_tun, SHUT_RD);
 253                                         shutdown(1, SHUT_WR);
 254                                         rea = 0;
 255                                         goto outer;
 256                                 }
 257                                 struct GNUNET_MessageHeader hdr = { .size = htons(r + sizeof(struct GNUNET_MessageHeader)), .type = htons(GNUNET_MESSAGE_TYPE_VPN_HELPER) };
 258                                 r = 0;
 259                                 while(r < sizeof(struct GNUNET_MessageHeader)) {
 260                                         int t = write(1, &hdr, sizeof(struct GNUNET_MessageHeader) - r);
 261                                         if (t < 0) {
 262                                                 fprintf(stderr, "write-error 2: %m\n");
 263                                                 shutdown(fd_tun, SHUT_RD);
 264                                                 shutdown(1, SHUT_WR);
 265                                                 rea = 0;
 266                                                 goto outer;
 267                                         }
 268                                         r += t;
 269                                 }
 270                                 while(r < ntohs(hdr.size)) {
 271                                         int t = write(1, buf, ntohs(hdr.size) - r);
 272                                         if (t < 0) {
 273                                                 fprintf(stderr, "write-error 1: %m, written %d/%d\n", r, ntohs(hdr.size));
 274                                                 shutdown(fd_tun, SHUT_RD);
 275                                                 shutdown(1, SHUT_WR);
 276                                                 rea = 0;
 277                                                 goto outer;
 278                                         }
 279                                         r += t;
 280                                 }
 281                         }
 282                 }
 283         }
 284         fprintf(stderr, "Quitting!\n");
 285
 286         return 0;
 287 }