| 1 | /* |
| 2 | * util.c |
| 3 | * - output and logging support |
| 4 | * - program lifetime support |
| 5 | * - IP address and subnet munging routines |
| 6 | * - MPI convenience functions |
| 7 | */ |
| 8 | /* |
| 9 | * This file is |
| 10 | * Copyright (C) 1995--2001 Stephen Early <steve@greenend.org.uk> |
| 11 | * |
| 12 | * It is part of secnet, which is |
| 13 | * Copyright (C) 1995--2001 Stephen Early <steve@greenend.org.uk> |
| 14 | * Copyright (C) 1998 Ross Anderson, Eli Biham, Lars Knudsen |
| 15 | * |
| 16 | * This program is free software; you can redistribute it and/or modify |
| 17 | * it under the terms of the GNU General Public License as published by |
| 18 | * the Free Software Foundation; either version 2, or (at your option) |
| 19 | * any later version. |
| 20 | * |
| 21 | * This program is distributed in the hope that it will be useful, |
| 22 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 23 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 24 | * GNU General Public License for more details. |
| 25 | * |
| 26 | * You should have received a copy of the GNU General Public License |
| 27 | * along with this program; if not, write to the Free Software Foundation, |
| 28 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 29 | */ |
| 30 | |
| 31 | #include "secnet.h" |
| 32 | #include <stdio.h> |
| 33 | #include <string.h> |
| 34 | #include <errno.h> |
| 35 | #include <unistd.h> |
| 36 | #include <limits.h> |
| 37 | #include <assert.h> |
| 38 | #include <sys/wait.h> |
| 39 | #include "util.h" |
| 40 | #include "unaligned.h" |
| 41 | |
| 42 | #define MIN_BUFFER_SIZE 64 |
| 43 | #define DEFAULT_BUFFER_SIZE 4096 |
| 44 | #define MAX_BUFFER_SIZE 131072 |
| 45 | |
| 46 | static const char *hexdigits="0123456789abcdef"; |
| 47 | |
| 48 | uint32_t current_phase=0; |
| 49 | |
| 50 | struct phase_hook { |
| 51 | hook_fn *fn; |
| 52 | void *state; |
| 53 | struct phase_hook *next; |
| 54 | }; |
| 55 | |
| 56 | static struct phase_hook *hooks[NR_PHASES]={NULL,}; |
| 57 | |
| 58 | char *safe_strdup(const char *s, const char *message) |
| 59 | { |
| 60 | char *d; |
| 61 | d=strdup(s); |
| 62 | if (!d) { |
| 63 | fatal_perror(message); |
| 64 | } |
| 65 | return d; |
| 66 | } |
| 67 | |
| 68 | void *safe_malloc(size_t size, const char *message) |
| 69 | { |
| 70 | void *r; |
| 71 | r=malloc(size); |
| 72 | if (!r) { |
| 73 | fatal_perror(message); |
| 74 | } |
| 75 | return r; |
| 76 | } |
| 77 | void *safe_malloc_ary(size_t size, size_t count, const char *message) { |
| 78 | if (count >= INT_MAX/size) { |
| 79 | fatal("array allocation overflow: %s", message); |
| 80 | } |
| 81 | return safe_malloc(size*count, message); |
| 82 | } |
| 83 | |
| 84 | /* Convert a buffer into its MP_INT representation */ |
| 85 | void read_mpbin(MP_INT *a, uint8_t *bin, int binsize) |
| 86 | { |
| 87 | char *buff; |
| 88 | int i; |
| 89 | |
| 90 | buff=safe_malloc(binsize*2 + 1,"read_mpbin"); |
| 91 | |
| 92 | for (i=0; i<binsize; i++) { |
| 93 | buff[i*2]=hexdigits[(bin[i] & 0xf0) >> 4]; |
| 94 | buff[i*2+1]=hexdigits[(bin[i] & 0xf)]; |
| 95 | } |
| 96 | buff[binsize*2]=0; |
| 97 | |
| 98 | mpz_set_str(a, buff, 16); |
| 99 | free(buff); |
| 100 | } |
| 101 | |
| 102 | /* Convert a MP_INT into a hex string */ |
| 103 | char *write_mpstring(MP_INT *a) |
| 104 | { |
| 105 | char *buff; |
| 106 | |
| 107 | buff=safe_malloc(mpz_sizeinbase(a,16)+2,"write_mpstring"); |
| 108 | mpz_get_str(buff, 16, a); |
| 109 | return buff; |
| 110 | } |
| 111 | |
| 112 | static uint8_t hexval(uint8_t c) |
| 113 | { |
| 114 | switch (c) { |
| 115 | case '0': return 0; |
| 116 | case '1': return 1; |
| 117 | case '2': return 2; |
| 118 | case '3': return 3; |
| 119 | case '4': return 4; |
| 120 | case '5': return 5; |
| 121 | case '6': return 6; |
| 122 | case '7': return 7; |
| 123 | case '8': return 8; |
| 124 | case '9': return 9; |
| 125 | case 'a': return 10; |
| 126 | case 'A': return 10; |
| 127 | case 'b': return 11; |
| 128 | case 'B': return 11; |
| 129 | case 'c': return 12; |
| 130 | case 'C': return 12; |
| 131 | case 'd': return 13; |
| 132 | case 'D': return 13; |
| 133 | case 'e': return 14; |
| 134 | case 'E': return 14; |
| 135 | case 'f': return 15; |
| 136 | case 'F': return 15; |
| 137 | } |
| 138 | return -1; |
| 139 | } |
| 140 | |
| 141 | /* Convert a MP_INT into a buffer; return length; truncate if necessary */ |
| 142 | int32_t write_mpbin(MP_INT *a, uint8_t *buffer, int32_t buflen) |
| 143 | { |
| 144 | char *hb; |
| 145 | int i,j,l; |
| 146 | |
| 147 | if (buflen==0) return 0; |
| 148 | hb=write_mpstring(a); |
| 149 | |
| 150 | l=strlen(hb); |
| 151 | i=0; j=0; |
| 152 | if (l&1) { |
| 153 | /* The number starts with a half-byte */ |
| 154 | buffer[i++]=hexval(hb[j++]); |
| 155 | } |
| 156 | for (; hb[j] && i<buflen; i++) { |
| 157 | buffer[i]=(hexval(hb[j])<<4)|hexval(hb[j+1]); |
| 158 | j+=2; |
| 159 | } |
| 160 | free(hb); |
| 161 | return i; |
| 162 | } |
| 163 | |
| 164 | static const char *phases[NR_PHASES]={ |
| 165 | "PHASE_INIT", |
| 166 | "PHASE_GETOPTS", |
| 167 | "PHASE_READCONFIG", |
| 168 | "PHASE_SETUP", |
| 169 | "PHASE_GETRESOURCES", |
| 170 | "PHASE_DROPPRIV", |
| 171 | "PHASE_RUN", |
| 172 | "PHASE_SHUTDOWN" |
| 173 | }; |
| 174 | |
| 175 | void enter_phase(uint32_t new_phase) |
| 176 | { |
| 177 | struct phase_hook *i; |
| 178 | |
| 179 | if (hooks[new_phase]) |
| 180 | Message(M_DEBUG_PHASE,"Running hooks for %s...\n", phases[new_phase]); |
| 181 | current_phase=new_phase; |
| 182 | |
| 183 | for (i=hooks[new_phase]; i; i=i->next) |
| 184 | i->fn(i->state, new_phase); |
| 185 | Message(M_DEBUG_PHASE,"Now in %s\n",phases[new_phase]); |
| 186 | } |
| 187 | |
| 188 | bool_t add_hook(uint32_t phase, hook_fn *fn, void *state) |
| 189 | { |
| 190 | struct phase_hook *h; |
| 191 | |
| 192 | h=safe_malloc(sizeof(*h),"add_hook"); |
| 193 | h->fn=fn; |
| 194 | h->state=state; |
| 195 | h->next=hooks[phase]; |
| 196 | hooks[phase]=h; |
| 197 | return True; |
| 198 | } |
| 199 | |
| 200 | bool_t remove_hook(uint32_t phase, hook_fn *fn, void *state) |
| 201 | { |
| 202 | fatal("remove_hook: not implemented"); |
| 203 | |
| 204 | return False; |
| 205 | } |
| 206 | |
| 207 | void vslilog(struct log_if *lf, int priority, const char *message, va_list ap) |
| 208 | { |
| 209 | lf->vlog(lf->st,priority,message,ap); |
| 210 | } |
| 211 | |
| 212 | void slilog(struct log_if *lf, int priority, const char *message, ...) |
| 213 | { |
| 214 | va_list ap; |
| 215 | |
| 216 | va_start(ap,message); |
| 217 | vslilog(lf,priority,message,ap); |
| 218 | va_end(ap); |
| 219 | } |
| 220 | |
| 221 | struct buffer { |
| 222 | closure_t cl; |
| 223 | struct buffer_if ops; |
| 224 | }; |
| 225 | |
| 226 | void buffer_assert_free(struct buffer_if *buffer, cstring_t file, |
| 227 | int line) |
| 228 | { |
| 229 | if (!buffer->free) { |
| 230 | fatal("BUF_ASSERT_FREE, %s line %d, owned by %s", |
| 231 | file,line,buffer->owner); |
| 232 | } |
| 233 | } |
| 234 | |
| 235 | void buffer_assert_used(struct buffer_if *buffer, cstring_t file, |
| 236 | int line) |
| 237 | { |
| 238 | if (buffer->free) { |
| 239 | fatal("BUF_ASSERT_USED, %s line %d, last owned by %s", |
| 240 | file,line,buffer->owner); |
| 241 | } |
| 242 | } |
| 243 | |
| 244 | void buffer_init(struct buffer_if *buffer, int32_t max_start_pad) |
| 245 | { |
| 246 | buffer->start=buffer->base+max_start_pad; |
| 247 | buffer->size=0; |
| 248 | } |
| 249 | |
| 250 | void *buf_append(struct buffer_if *buf, int32_t amount) { |
| 251 | void *p; |
| 252 | assert(buf->size <= buf->len - amount); |
| 253 | p=buf->start + buf->size; |
| 254 | buf->size+=amount; |
| 255 | return p; |
| 256 | } |
| 257 | |
| 258 | void *buf_prepend(struct buffer_if *buf, int32_t amount) { |
| 259 | assert(amount <= buf->start - buf->base); |
| 260 | buf->size+=amount; |
| 261 | return buf->start-=amount; |
| 262 | } |
| 263 | |
| 264 | void *buf_unappend(struct buffer_if *buf, int32_t amount) { |
| 265 | if (buf->size < amount) return 0; |
| 266 | return buf->start+(buf->size-=amount); |
| 267 | } |
| 268 | |
| 269 | void *buf_unprepend(struct buffer_if *buf, int32_t amount) { |
| 270 | void *p; |
| 271 | p=buf->start; |
| 272 | buf->start+=amount; |
| 273 | buf->size-=amount; |
| 274 | return p; |
| 275 | } |
| 276 | |
| 277 | /* Append a two-byte length and the string to the buffer. Length is in |
| 278 | network byte order. */ |
| 279 | void buf_append_string(struct buffer_if *buf, cstring_t s) |
| 280 | { |
| 281 | size_t len; |
| 282 | |
| 283 | len=strlen(s); |
| 284 | /* fixme: if string is longer than 65535, result is a corrupted packet */ |
| 285 | buf_append_uint16(buf,len); |
| 286 | memcpy(buf_append(buf,len),s,len); |
| 287 | } |
| 288 | |
| 289 | void buffer_new(struct buffer_if *buf, int32_t len) |
| 290 | { |
| 291 | buf->free=True; |
| 292 | buf->owner=NULL; |
| 293 | buf->flags=0; |
| 294 | buf->loc.file=NULL; |
| 295 | buf->loc.line=0; |
| 296 | buf->size=0; |
| 297 | buf->len=len; |
| 298 | buf->start=NULL; |
| 299 | buf->base=safe_malloc(len,"buffer_new"); |
| 300 | } |
| 301 | |
| 302 | static list_t *buffer_apply(closure_t *self, struct cloc loc, dict_t *context, |
| 303 | list_t *args) |
| 304 | { |
| 305 | struct buffer *st; |
| 306 | item_t *item; |
| 307 | dict_t *dict; |
| 308 | bool_t lockdown=False; |
| 309 | uint32_t len=DEFAULT_BUFFER_SIZE; |
| 310 | |
| 311 | st=safe_malloc(sizeof(*st),"buffer_apply"); |
| 312 | st->cl.description="buffer"; |
| 313 | st->cl.type=CL_BUFFER; |
| 314 | st->cl.apply=NULL; |
| 315 | st->cl.interface=&st->ops; |
| 316 | |
| 317 | /* First argument, if present, is buffer length */ |
| 318 | item=list_elem(args,0); |
| 319 | if (item) { |
| 320 | if (item->type!=t_number) { |
| 321 | cfgfatal(st->ops.loc,"buffer","first parameter must be a " |
| 322 | "number (buffer size)\n"); |
| 323 | } |
| 324 | len=item->data.number; |
| 325 | if (len<MIN_BUFFER_SIZE) { |
| 326 | cfgfatal(st->ops.loc,"buffer","ludicrously small buffer size\n"); |
| 327 | } |
| 328 | if (len>MAX_BUFFER_SIZE) { |
| 329 | cfgfatal(st->ops.loc,"buffer","ludicrously large buffer size\n"); |
| 330 | } |
| 331 | } |
| 332 | /* Second argument, if present, is a dictionary */ |
| 333 | item=list_elem(args,1); |
| 334 | if (item) { |
| 335 | if (item->type!=t_dict) { |
| 336 | cfgfatal(st->ops.loc,"buffer","second parameter must be a " |
| 337 | "dictionary\n"); |
| 338 | } |
| 339 | dict=item->data.dict; |
| 340 | lockdown=dict_read_bool(dict,"lockdown",False,"buffer",st->ops.loc, |
| 341 | False); |
| 342 | } |
| 343 | |
| 344 | buffer_new(&st->ops,len); |
| 345 | if (lockdown) { |
| 346 | /* XXX mlock the buffer if possible */ |
| 347 | } |
| 348 | |
| 349 | return new_closure(&st->cl); |
| 350 | } |
| 351 | |
| 352 | void util_module(dict_t *dict) |
| 353 | { |
| 354 | add_closure(dict,"sysbuffer",buffer_apply); |
| 355 | } |