| | 1 | /* -*-c-*- |
| | 2 | * |
| | 3 | * Tunnel interface based on Linux TUN/TAP driver |
| | 4 | * |
| | 5 | * (c) 2003 Straylight/Edgeware |
| | 6 | */ |
| | 7 | |
| | 8 | /*----- Licensing notice --------------------------------------------------* |
| | 9 | * |
| | 10 | * This file is part of Trivial IP Encryption (TrIPE). |
| | 11 | * |
| | 12 | * TrIPE is free software; you can redistribute it and/or modify |
| | 13 | * it under the terms of the GNU General Public License as published by |
| | 14 | * the Free Software Foundation; either version 2 of the License, or |
| | 15 | * (at your option) any later version. |
| | 16 | * |
| | 17 | * TrIPE is distributed in the hope that it will be useful, |
| | 18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| | 19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| | 20 | * GNU General Public License for more details. |
| | 21 | * |
| | 22 | * You should have received a copy of the GNU General Public License |
| | 23 | * along with TrIPE; if not, write to the Free Software Foundation, |
| | 24 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| | 25 | */ |
| | 26 | |
| | 27 | /*----- Header files ------------------------------------------------------*/ |
| | 28 | |
| | 29 | #define TUN_INTERNALS |
| | 30 | |
| | 31 | #include "tripe.h" |
| | 32 | |
| | 33 | #ifdef TUN_LINUX |
| | 34 | # include <sys/ioctl.h> |
| | 35 | # include <linux/if.h> |
| | 36 | # include <linux/if_tun.h> |
| | 37 | #endif |
| | 38 | |
| | 39 | /*----- Main code ---------------------------------------------------------*/ |
| | 40 | |
| | 41 | #ifdef TUN_LINUX |
| | 42 | |
| | 43 | struct tunnel { |
| | 44 | const tunnel_ops *ops; /* Pointer to operations */ |
| | 45 | sel_file f; /* Selector for TUN/TAP device */ |
| | 46 | struct peer *p; /* Pointer to my peer */ |
| | 47 | }; |
| | 48 | |
| | 49 | /* --- @t_read@ --- * |
| | 50 | * |
| | 51 | * Arguments: @int fd@ = file descriptor to read |
| | 52 | * @unsigned mode@ = what's happened |
| | 53 | * @void *v@ = pointer to tunnel block |
| | 54 | * |
| | 55 | * Returns: --- |
| | 56 | * |
| | 57 | * Use: Reads data from the tunnel. |
| | 58 | */ |
| | 59 | |
| | 60 | static void t_read(int fd, unsigned mode, void *v) |
| | 61 | { |
| | 62 | tunnel *t = v; |
| | 63 | ssize_t n; |
| | 64 | buf b; |
| | 65 | |
| | 66 | n = read(fd, buf_i, sizeof(buf_i)); |
| | 67 | if (n < 0) { |
| | 68 | a_warn("TUN", "%s", p_ifname(t->p), "read-error", "?ERRNO", A_END); |
| | 69 | return; |
| | 70 | } |
| | 71 | IF_TRACING(T_TUNNEL, { |
| | 72 | trace(T_TUNNEL, "tun-linux: packet arrived"); |
| | 73 | trace_block(T_PACKET, "tun-linux: packet contents", buf_i, n); |
| | 74 | }) |
| | 75 | buf_init(&b, buf_i, n); |
| | 76 | p_tun(t->p, &b); |
| | 77 | } |
| | 78 | |
| | 79 | /* --- @t_init@ --- * |
| | 80 | * |
| | 81 | * Arguments: --- |
| | 82 | * |
| | 83 | * Returns: --- |
| | 84 | * |
| | 85 | * Use: Initializes the tunneling system. Maybe this will require |
| | 86 | * opening file descriptors or something. |
| | 87 | */ |
| | 88 | |
| | 89 | static void t_init(void) { return; } |
| | 90 | |
| | 91 | /* --- @t_create@ --- * |
| | 92 | * |
| | 93 | * Arguments: @peer *p@ = pointer to peer block |
| | 94 | * @char **ifn@ = where to put the interface name |
| | 95 | * |
| | 96 | * Returns: A tunnel block if it worked, or null on failure. |
| | 97 | * |
| | 98 | * Use: Initializes a new tunnel. |
| | 99 | */ |
| | 100 | |
| | 101 | static tunnel *t_create(peer *p, char **ifn) |
| | 102 | { |
| | 103 | int fd; |
| | 104 | int f; |
| | 105 | struct ifreq iff; |
| | 106 | tunnel *t; |
| | 107 | |
| | 108 | if ((fd = open("/dev/net/tun", O_RDWR)) < 0) { |
| | 109 | a_warn("TUN", "-", "linux", |
| | 110 | "open-error", "/dev/net/tun", "?ERRNO", |
| | 111 | A_END); |
| | 112 | return (0); |
| | 113 | } |
| | 114 | fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC); |
| | 115 | memset(&iff, 0, sizeof(iff)); |
| | 116 | iff.ifr_name[0] = 0; |
| | 117 | iff.ifr_flags = IFF_TUN | IFF_NO_PI; |
| | 118 | if ((f = ioctl(fd, TUNSETIFF, &iff)) < 0) { |
| | 119 | a_warn("TUN", "-", "linux", "config-error", "?ERRNO", A_END); |
| | 120 | close(fd); |
| | 121 | return (0); |
| | 122 | } |
| | 123 | t = CREATE(tunnel); |
| | 124 | t->ops = &tun_linux; |
| | 125 | t->p = p; |
| | 126 | sel_initfile(&sel, &t->f, fd, SEL_READ, t_read, t); |
| | 127 | sel_addfile(&t->f); |
| | 128 | iff.ifr_name[IFNAMSIZ - 1] = 0; |
| | 129 | *ifn = xstrdup(iff.ifr_name); |
| | 130 | T( trace(T_TUNNEL, "tun-linux: attached interface %s to peer `%s'", |
| | 131 | *ifn, p_name(p)); ) |
| | 132 | return (t); |
| | 133 | } |
| | 134 | |
| | 135 | /* --- @t_inject@ --- * |
| | 136 | * |
| | 137 | * Arguments: @tunnel *t@ = pointer to tunnel block |
| | 138 | * @buf *b@ = buffer to send |
| | 139 | * |
| | 140 | * Returns: --- |
| | 141 | * |
| | 142 | * Use: Injects a packet into the local network stack. |
| | 143 | */ |
| | 144 | |
| | 145 | static void t_inject(tunnel *t, buf *b) |
| | 146 | { |
| | 147 | IF_TRACING(T_TUNNEL, { |
| | 148 | trace(T_TUNNEL, "tun-linux: inject decrypted packet"); |
| | 149 | trace_block(T_PACKET, "tunnel: packet contents", BBASE(b), BLEN(b)); |
| | 150 | }) |
| | 151 | write(t->f.fd, BBASE(b), BLEN(b)); |
| | 152 | } |
| | 153 | |
| | 154 | /* --- @t_destroy@ --- * |
| | 155 | * |
| | 156 | * Arguments: @tunnel *t@ = pointer to tunnel block |
| | 157 | * |
| | 158 | * Returns: --- |
| | 159 | * |
| | 160 | * Use: Destroys a tunnel. |
| | 161 | */ |
| | 162 | |
| | 163 | static void t_destroy(tunnel *t) |
| | 164 | { sel_rmfile(&t->f); close(t->f.fd); DESTROY(t); } |
| | 165 | |
| | 166 | const tunnel_ops tun_linux = { |
| | 167 | "linux", |
| | 168 | t_init, |
| | 169 | t_create, |
| | 170 | 0, |
| | 171 | t_inject, |
| | 172 | t_destroy |
| | 173 | }; |
| | 174 | |
| | 175 | #endif |
| | 176 | |
| | 177 | /*----- That's all, folks -------------------------------------------------*/ |
~mdw / tripe / blame_incremental