| 1 | /* -*-c-*- |
| 2 | * |
| 3 | * Privilege separation definitions |
| 4 | * |
| 5 | * (c) 2008 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 | #ifndef PRIV_H |
| 28 | #define PRIV_H |
| 29 | |
| 30 | #ifdef __cplusplus |
| 31 | extern "C" { |
| 32 | #endif |
| 33 | |
| 34 | /*----- Header files ------------------------------------------------------*/ |
| 35 | |
| 36 | #include "config.h" |
| 37 | |
| 38 | #include <errno.h> |
| 39 | #include <stdio.h> |
| 40 | #include <stdlib.h> |
| 41 | #include <string.h> |
| 42 | |
| 43 | #include <sys/types.h> |
| 44 | #include <unistd.h> |
| 45 | #include <fcntl.h> |
| 46 | |
| 47 | #include <sys/socket.h> |
| 48 | #include <sys/un.h> |
| 49 | |
| 50 | #include <mLib/dstr.h> |
| 51 | #include <mLib/fdpass.h> |
| 52 | #include <mLib/quis.h> |
| 53 | #include <mLib/report.h> |
| 54 | #include <mLib/trace.h> |
| 55 | |
| 56 | #include "util.h" |
| 57 | |
| 58 | #undef sun |
| 59 | |
| 60 | /*----- Protocol ----------------------------------------------------------*/ |
| 61 | |
| 62 | /* --- Notes --- * |
| 63 | * |
| 64 | * The protocol is synchronous. The socket is not marked as nonblocking; |
| 65 | * instead we just trust the helper to respond in good time; this is |
| 66 | * reasonable since it's not doing anything complicated. The helper is |
| 67 | * completely trusted. |
| 68 | * |
| 69 | * The protocol works like this. Messages begin with a request code which is |
| 70 | * a single @unsigned int@. The server sends a request @PS_TUNRQ@ to the |
| 71 | * helper, followed by a strin naming the tunnel driver of interest. The |
| 72 | * server responds with a sequence of @PS_TRACE@ and/or @PS_WARN@ messages, |
| 73 | * followed by either a @PS_TUNFD@ carrying a file descriptor, or a |
| 74 | * @PS_TUNERR@ followed by an integer @errno@ code. |
| 75 | * |
| 76 | * Simple data items are sent as native representations. A string is sent as |
| 77 | * a @size_t@ giving the string's length in bytes followed by that many |
| 78 | * characters. There is no padding for alignment. |
| 79 | * |
| 80 | * If all else fails, the helper process will just quit. |
| 81 | */ |
| 82 | |
| 83 | enum { |
| 84 | PS_TUNRQ, /* Request (string) */ |
| 85 | PS_TUNFD, /* Tunnel descriptor (nothing) */ |
| 86 | PS_TUNERR, /* Error (@int errno@) */ |
| 87 | #ifndef NTRACE |
| 88 | PS_TRACE, /* Trace (@unsigned mask@, string) */ |
| 89 | #endif |
| 90 | PS_WARN, /* Warning (string) */ |
| 91 | }; |
| 92 | |
| 93 | /*----- Tracing definitions -----------------------------------------------*/ |
| 94 | |
| 95 | #define T_PRIVSEP 512u |
| 96 | |
| 97 | /*----- Global variables --------------------------------------------------*/ |
| 98 | |
| 99 | extern int pc_fd; /* File descriptor for comms */ |
| 100 | |
| 101 | /*----- Functions provided ------------------------------------------------*/ |
| 102 | |
| 103 | #define COMM_TYPES(_) \ |
| 104 | _(err, int) \ |
| 105 | _(uint, unsigned int) \ |
| 106 | _(sz, size_t) |
| 107 | |
| 108 | /* --- @pc_put@ --- * |
| 109 | * |
| 110 | * Arguments: @const void *p@ = pointer to buffer |
| 111 | * @size_t sz@ = size of the buffer |
| 112 | * |
| 113 | * Returns: Zero on success, @-1@ on error (and @errno@ set). |
| 114 | * |
| 115 | * Use: Writes a buffer, handling short writes and other bogosity. |
| 116 | */ |
| 117 | |
| 118 | extern int pc_put(const void */*p*/, size_t /*sz*/); |
| 119 | |
| 120 | /* --- @pc_puterr@, @pc_putuint@, @pc_putsz@ --- * |
| 121 | * |
| 122 | * Arguments: @int err@ = error number to write |
| 123 | * @uint u@ = unsigned integer to write |
| 124 | * @size_t sz@ = size to write |
| 125 | * |
| 126 | * Returns: Zero on success, @-1@ on error (and @errno@ set). |
| 127 | * |
| 128 | * Use: Sends an error/integer/size. |
| 129 | */ |
| 130 | |
| 131 | #define DECL(abbr, type) extern int pc_put##abbr(type /*x*/); |
| 132 | COMM_TYPES(DECL) |
| 133 | #undef DECL |
| 134 | |
| 135 | /* --- @pc_putstring@ --- * |
| 136 | * |
| 137 | * Arguments: @const char *s@ = pointer to string to write |
| 138 | * |
| 139 | * Returns: Zero on success, @-1@ on error (and @errno@ set). |
| 140 | * |
| 141 | * Use: Sends a string. |
| 142 | */ |
| 143 | |
| 144 | extern int pc_putstring(const char */*s*/); |
| 145 | |
| 146 | /* --- @pc_get@ --- * |
| 147 | * |
| 148 | * Arguments: @void *p@ = pointer to buffer |
| 149 | * @size_t sz@ = size of the buffer |
| 150 | * |
| 151 | * Returns: Zero on success, @-1@ on error (and @errno@ set). |
| 152 | * |
| 153 | * Use: Receives a buffer, handling short reads and other bogosity. |
| 154 | */ |
| 155 | |
| 156 | extern int pc_get(void */*p*/, size_t /*sz*/); |
| 157 | |
| 158 | /* --- @pc_geterr@, @pc_getuint@, @pc_getsz@ --- * |
| 159 | * |
| 160 | * Arguments: @int *err@ = where to put the error number |
| 161 | * @uint *u@ = where to put the unsigned integer |
| 162 | * @size_t *sz@ = where to put the size |
| 163 | * |
| 164 | * Returns: Zero on success, @-1@ on error (and @errno@ set). |
| 165 | * |
| 166 | * Use: Receives an error/integer/size. |
| 167 | */ |
| 168 | |
| 169 | #define DECL(abbr, type) extern int pc_get##abbr(type */*x*/); |
| 170 | COMM_TYPES(DECL) |
| 171 | #undef DECL |
| 172 | |
| 173 | /* --- @pc_getstring@ --- * |
| 174 | * |
| 175 | * Arguments: @dstr *d@ = where to put the string |
| 176 | * |
| 177 | * Returns: Zero on success, @-1@ on error (and @errno@ set). |
| 178 | * |
| 179 | * Use: Receives a string. |
| 180 | */ |
| 181 | |
| 182 | extern int pc_getstring(dstr */*d*/); |
| 183 | |
| 184 | /*----- That's all, folks -------------------------------------------------*/ |
| 185 | |
| 186 | #ifdef __cplusplus |
| 187 | } |
| 188 | #endif |
| 189 | |
| 190 | #endif |