| | 1 | /* -*-c-*- |
| | 2 | * |
| | 3 | * Tunnel interface for Linux-tun-shaped arrangements |
| | 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 it under |
| | 13 | * the terms of the GNU General Public License as published by the Free |
| | 14 | * Software Foundation; either version 3 of the License, or (at your |
| | 15 | * option) any later version. |
| | 16 | * |
| | 17 | * TrIPE is distributed in the hope that it will be useful, but WITHOUT |
| | 18 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| | 19 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| | 20 | * for more details. |
| | 21 | * |
| | 22 | * You should have received a copy of the GNU General Public License |
| | 23 | * along with TrIPE. If not, see <https://www.gnu.org/licenses/>. |
| | 24 | */ |
| | 25 | |
| | 26 | /*----- Header files ------------------------------------------------------*/ |
| | 27 | |
| | 28 | #define TUN_INTERNALS |
| | 29 | |
| | 30 | #include "tripe.h" |
| | 31 | |
| | 32 | /*----- Main code ---------------------------------------------------------*/ |
| | 33 | |
| | 34 | #if defined(TUN_LINUX) || defined(TUN_BSD) || defined(TUN_UNET) |
| | 35 | |
| | 36 | struct tunnel { |
| | 37 | const tunnel_ops *ops; /* Pointer to operations */ |
| | 38 | sel_file f; /* Selector for TUN/TAP device */ |
| | 39 | struct peer *p; /* Pointer to my peer */ |
| | 40 | }; |
| | 41 | |
| | 42 | /* --- @t_read@ --- * |
| | 43 | * |
| | 44 | * Arguments: @int fd@ = file descriptor to read |
| | 45 | * @unsigned mode@ = what's happened |
| | 46 | * @void *v@ = pointer to tunnel block |
| | 47 | * |
| | 48 | * Returns: --- |
| | 49 | * |
| | 50 | * Use: Reads data from the tunnel. |
| | 51 | */ |
| | 52 | |
| | 53 | static void t_read(int fd, unsigned mode, void *v) |
| | 54 | { |
| | 55 | tunnel *t = v; |
| | 56 | ssize_t n; |
| | 57 | buf b; |
| | 58 | |
| | 59 | n = read(fd, buf_i, sizeof(buf_i)); |
| | 60 | if (n < 0) { |
| | 61 | a_warn("TUN", "%s", p_ifname(t->p), "%s", t->ops->name, |
| | 62 | "read-error", "?ERRNO", A_END); |
| | 63 | return; |
| | 64 | } |
| | 65 | IF_TRACING(T_TUNNEL, { |
| | 66 | trace(T_TUNNEL, "tun-%s: packet arrived", t->ops->name); |
| | 67 | trace_block(T_PACKET, "tunnel: packet contents", buf_i, n); |
| | 68 | }) |
| | 69 | buf_init(&b, buf_i, n); |
| | 70 | p_tun(t->p, &b); |
| | 71 | } |
| | 72 | |
| | 73 | /* --- @t_init@ --- * |
| | 74 | * |
| | 75 | * Arguments: --- |
| | 76 | * |
| | 77 | * Returns: Zero on success, @-1@ on failure. |
| | 78 | * |
| | 79 | * Use: Initializes the tunneling system. Maybe this will require |
| | 80 | * opening file descriptors or something. |
| | 81 | */ |
| | 82 | |
| | 83 | static int t_init(void) { return (0); } |
| | 84 | |
| | 85 | /* --- @t_create@ --- * |
| | 86 | * |
| | 87 | * Arguments: @peer *p@ = pointer to peer block |
| | 88 | * @int fd@ = file descriptor of tunnel device |
| | 89 | * @char **ifn@ = where to put the interface name |
| | 90 | * |
| | 91 | * Returns: A tunnel block if it worked, or null on failure. |
| | 92 | * |
| | 93 | * Use: Initializes a new tunnel. |
| | 94 | */ |
| | 95 | |
| | 96 | static tunnel *t_create(peer *p, int fd, char **ifn, const tunnel_ops *ops) |
| | 97 | { |
| | 98 | tunnel *t; |
| | 99 | |
| | 100 | fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC); |
| | 101 | t = CREATE(tunnel); |
| | 102 | t->ops = ops; |
| | 103 | t->p = p; |
| | 104 | sel_initfile(&sel, &t->f, fd, SEL_READ, t_read, t); |
| | 105 | sel_addfile(&t->f); |
| | 106 | return (t); |
| | 107 | } |
| | 108 | |
| | 109 | /* --- @t_inject@ --- * |
| | 110 | * |
| | 111 | * Arguments: @tunnel *t@ = pointer to tunnel block |
| | 112 | * @buf *b@ = buffer to send |
| | 113 | * |
| | 114 | * Returns: --- |
| | 115 | * |
| | 116 | * Use: Injects a packet into the local network stack. |
| | 117 | */ |
| | 118 | |
| | 119 | static void t_inject(tunnel *t, buf *b) |
| | 120 | { |
| | 121 | IF_TRACING(T_TUNNEL, { |
| | 122 | trace(T_TUNNEL, "tun-%s: inject decrypted packet", t->ops->name); |
| | 123 | trace_block(T_PACKET, "tunnel: packet contents", BBASE(b), BLEN(b)); |
| | 124 | }) |
| | 125 | DISCARD(write(t->f.fd, BBASE(b), BLEN(b))); |
| | 126 | } |
| | 127 | |
| | 128 | /* --- @t_destroy@ --- * |
| | 129 | * |
| | 130 | * Arguments: @tunnel *t@ = pointer to tunnel block |
| | 131 | * |
| | 132 | * Returns: --- |
| | 133 | * |
| | 134 | * Use: Destroys a tunnel. |
| | 135 | */ |
| | 136 | |
| | 137 | static void t_destroy(tunnel *t) |
| | 138 | { sel_rmfile(&t->f); close(t->f.fd); DESTROY(t); } |
| | 139 | |
| | 140 | #define DEFOPS(name) \ |
| | 141 | \ |
| | 142 | static tunnel *t_create_##name(peer *p, int fd, char **ifn); \ |
| | 143 | \ |
| | 144 | const tunnel_ops tun_##name = { \ |
| | 145 | #name, TUNF_PRIVOPEN, \ |
| | 146 | t_init, t_create_##name, 0, t_inject, t_destroy \ |
| | 147 | }; \ |
| | 148 | \ |
| | 149 | static tunnel *t_create_##name(peer *p, int fd, char **ifn) \ |
| | 150 | { return t_create(p, fd, ifn, &tun_##name); } |
| | 151 | |
| | 152 | #ifdef TUN_LINUX |
| | 153 | DEFOPS(linux) |
| | 154 | #endif |
| | 155 | |
| | 156 | #ifdef TUN_BSD |
| | 157 | DEFOPS(bsd) |
| | 158 | #endif |
| | 159 | |
| | 160 | #ifdef TUN_UNET |
| | 161 | DEFOPS(unet) |
| | 162 | #endif |
| | 163 | |
| | 164 | #endif |
| | 165 | |
| | 166 | /*----- That's all, folks -------------------------------------------------*/ |
~mdw / tripe / blame_incremental