| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * $Id$ |
| 4 | * |
| 5 | * Tunnel interface based on Linux Usernet |
| 6 | * |
| 7 | * (c) 2001 Straylight/Edgeware |
| 8 | */ |
| 9 | |
| 10 | /*----- Licensing notice --------------------------------------------------* |
| 11 | * |
| 12 | * This file is part of Trivial IP Encryption (TrIPE). |
| 13 | * |
| 14 | * TrIPE is free software; you can redistribute it and/or modify |
| 15 | * it under the terms of the GNU General Public License as published by |
| 16 | * the Free Software Foundation; either version 2 of the License, or |
| 17 | * (at your option) any later version. |
| 18 | * |
| 19 | * TrIPE is distributed in the hope that it will be useful, |
| 20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 22 | * GNU General Public License for more details. |
| 23 | * |
| 24 | * You should have received a copy of the GNU General Public License |
| 25 | * along with TrIPE; if not, write to the Free Software Foundation, |
| 26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 27 | */ |
| 28 | |
| 29 | /*----- Header files ------------------------------------------------------*/ |
| 30 | |
| 31 | #define TUN_INTERNALS |
| 32 | |
| 33 | #include "tripe.h" |
| 34 | |
| 35 | #ifdef TUN_UNET |
| 36 | # include <sys/ioctl.h> |
| 37 | # include <net/if.h> |
| 38 | # include <unet.h> |
| 39 | #endif |
| 40 | |
| 41 | /*----- Main code ---------------------------------------------------------*/ |
| 42 | |
| 43 | #ifdef TUN_UNET |
| 44 | |
| 45 | struct tunnel { |
| 46 | const tunnel_ops *ops; /* Pointer to operations */ |
| 47 | sel_file f; /* Selector for Usernet device */ |
| 48 | struct peer *p; /* Pointer to my peer */ |
| 49 | }; |
| 50 | |
| 51 | /* --- @t_ifname@ --- * |
| 52 | * |
| 53 | * Arguments: @tunnel *t@ = pointer to tunnel block |
| 54 | * |
| 55 | * Returns: A pointer to the tunnel's interface name. |
| 56 | */ |
| 57 | |
| 58 | static const char *t_ifname(tunnel *t) |
| 59 | { |
| 60 | static char b[UNET_NAMEMAX]; |
| 61 | struct unet_info uni; |
| 62 | if (ioctl(t->f.fd, UNIOCGINFO, &uni)) { |
| 63 | a_warn("TUN - unet getinfo-error -- %s", strerror(errno)); |
| 64 | return ("<error>"); |
| 65 | } |
| 66 | if (strlen(uni.uni_ifname) + 1 > sizeof(b)) { |
| 67 | a_warn("TUN - unet ifname-too-long"); |
| 68 | return ("<error>"); |
| 69 | } |
| 70 | strcpy(b, uni.uni_ifname); |
| 71 | return (b); |
| 72 | } |
| 73 | |
| 74 | /* --- @t_read@ --- * |
| 75 | * |
| 76 | * Arguments: @int fd@ = file descriptor to read |
| 77 | * @unsigned mode@ = what's happened |
| 78 | * @void *v@ = pointer to tunnel block |
| 79 | * |
| 80 | * Returns: --- |
| 81 | * |
| 82 | * Use: Reads data from the tunnel. |
| 83 | */ |
| 84 | |
| 85 | static void t_read(int fd, unsigned mode, void *v) |
| 86 | { |
| 87 | tunnel *t = v; |
| 88 | ssize_t n; |
| 89 | buf b; |
| 90 | |
| 91 | n = read(fd, buf_i, sizeof(buf_i)); |
| 92 | if (n < 0) { |
| 93 | a_warn("TUN %s read-error -- %s", t_ifname(t), strerror(errno)); |
| 94 | return; |
| 95 | } |
| 96 | IF_TRACING(T_TUNNEL, { |
| 97 | trace(T_TUNNEL, "tun-unet: packet arrived"); |
| 98 | trace_block(T_PACKET, "tun-unet: packet contents", buf_i, n); |
| 99 | }) |
| 100 | buf_init(&b, buf_i, n); |
| 101 | p_tun(t->p, &b); |
| 102 | } |
| 103 | |
| 104 | /* --- @t_init@ --- * |
| 105 | * |
| 106 | * Arguments: --- |
| 107 | * |
| 108 | * Returns: --- |
| 109 | * |
| 110 | * Use: Initializes the tunneling system. Maybe this will require |
| 111 | * opening file descriptors or something. |
| 112 | */ |
| 113 | |
| 114 | static void t_init(void) { return; } |
| 115 | |
| 116 | /* --- @t_create@ --- * |
| 117 | * |
| 118 | * Arguments: @tunnel *t@ = pointer to tunnel block |
| 119 | * @peer *p@ = pointer to peer block |
| 120 | * |
| 121 | * Returns: A tunnel block if it worked, or null on failure. |
| 122 | * |
| 123 | * Use: Initializes a new tunnel. |
| 124 | */ |
| 125 | |
| 126 | static tunnel *t_create(peer *p) |
| 127 | { |
| 128 | int fd; |
| 129 | tunnel *t; |
| 130 | int f; |
| 131 | |
| 132 | if ((fd = open("/dev/unet", O_RDWR)) < 0) { |
| 133 | a_warn("TUN - open-error /dev/unet -- %s", strerror(errno)); |
| 134 | return (0); |
| 135 | } |
| 136 | fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC); |
| 137 | if ((f = ioctl(fd, UNIOCGIFFLAGS)) < 0 || |
| 138 | ioctl(fd, UNIOCSIFFLAGS, f | IFF_POINTOPOINT)) { |
| 139 | a_warn("TUN - unet config-error -- %s", strerror(errno)); |
| 140 | close(fd); |
| 141 | return (0); |
| 142 | } |
| 143 | t = CREATE(tunnel); |
| 144 | t->ops = &tun_unet; |
| 145 | t->p = p; |
| 146 | sel_initfile(&sel, &t->f, fd, SEL_READ, t_read, t); |
| 147 | sel_addfile(&t->f); |
| 148 | T( trace(T_TUNNEL, "tun-unet: attached interface %s to peer `%s'", |
| 149 | t_ifname(t), p_name(p)); ) |
| 150 | return (t); |
| 151 | } |
| 152 | |
| 153 | /* --- @t_inject@ --- * |
| 154 | * |
| 155 | * Arguments: @tunnel *t@ = pointer to tunnel block |
| 156 | * @buf *b@ = buffer to send |
| 157 | * |
| 158 | * Returns: --- |
| 159 | * |
| 160 | * Use: Injects a packet into the local network stack. |
| 161 | */ |
| 162 | |
| 163 | static void t_inject(tunnel *t, buf *b) |
| 164 | { |
| 165 | IF_TRACING(T_TUNNEL, { |
| 166 | trace(T_TUNNEL, "tun-unet: inject decrypted packet"); |
| 167 | trace_block(T_PACKET, "tun-unet: packet contents", BBASE(b), BLEN(b)); |
| 168 | }) |
| 169 | write(t->f.fd, BBASE(b), BLEN(b)); |
| 170 | } |
| 171 | |
| 172 | /* --- @t_destroy@ --- * |
| 173 | * |
| 174 | * Arguments: @tunnel *t@ = pointer to tunnel block |
| 175 | * |
| 176 | * Returns: --- |
| 177 | * |
| 178 | * Use: Destroys a tunnel. |
| 179 | */ |
| 180 | |
| 181 | static void t_destroy(tunnel *t) |
| 182 | { |
| 183 | sel_rmfile(&t->f); |
| 184 | close(t->f.fd); |
| 185 | DESTROY(t); |
| 186 | } |
| 187 | |
| 188 | const tunnel_ops tun_unet = { |
| 189 | "unet", |
| 190 | t_init, |
| 191 | t_create, |
| 192 | t_ifname, |
| 193 | t_inject, |
| 194 | t_destroy |
| 195 | }; |
| 196 | |
| 197 | #endif |
| 198 | |
| 199 | /*----- That's all, folks -------------------------------------------------*/ |