| 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 | #include "magic.h" |
| 42 | |
| 43 | #define MIN_BUFFER_SIZE 64 |
| 44 | #define DEFAULT_BUFFER_SIZE 4096 |
| 45 | #define MAX_BUFFER_SIZE 131072 |
| 46 | |
| 47 | static const char *hexdigits="0123456789abcdef"; |
| 48 | |
| 49 | uint32_t current_phase=0; |
| 50 | |
| 51 | struct phase_hook { |
| 52 | hook_fn *fn; |
| 53 | void *state; |
| 54 | struct phase_hook *next; |
| 55 | }; |
| 56 | |
| 57 | static struct phase_hook *hooks[NR_PHASES]={NULL,}; |
| 58 | |
| 59 | char *safe_strdup(const char *s, const char *message) |
| 60 | { |
| 61 | char *d; |
| 62 | d=strdup(s); |
| 63 | if (!d) { |
| 64 | fatal_perror("%s",message); |
| 65 | } |
| 66 | return d; |
| 67 | } |
| 68 | |
| 69 | void *safe_malloc(size_t size, const char *message) |
| 70 | { |
| 71 | void *r; |
| 72 | r=malloc(size); |
| 73 | if (!r) { |
| 74 | fatal_perror("%s",message); |
| 75 | } |
| 76 | return r; |
| 77 | } |
| 78 | void *safe_malloc_ary(size_t size, size_t count, const char *message) { |
| 79 | if (count >= INT_MAX/size) { |
| 80 | fatal("array allocation overflow: %s", message); |
| 81 | } |
| 82 | return safe_malloc(size*count, message); |
| 83 | } |
| 84 | |
| 85 | /* Convert a buffer into its MP_INT representation */ |
| 86 | void read_mpbin(MP_INT *a, uint8_t *bin, int binsize) |
| 87 | { |
| 88 | char *buff; |
| 89 | int i; |
| 90 | |
| 91 | buff=safe_malloc(binsize*2 + 1,"read_mpbin"); |
| 92 | |
| 93 | for (i=0; i<binsize; i++) { |
| 94 | buff[i*2]=hexdigits[(bin[i] & 0xf0) >> 4]; |
| 95 | buff[i*2+1]=hexdigits[(bin[i] & 0xf)]; |
| 96 | } |
| 97 | buff[binsize*2]=0; |
| 98 | |
| 99 | mpz_set_str(a, buff, 16); |
| 100 | free(buff); |
| 101 | } |
| 102 | |
| 103 | /* Convert a MP_INT into a hex string */ |
| 104 | char *write_mpstring(MP_INT *a) |
| 105 | { |
| 106 | char *buff; |
| 107 | |
| 108 | buff=safe_malloc(mpz_sizeinbase(a,16)+2,"write_mpstring"); |
| 109 | mpz_get_str(buff, 16, a); |
| 110 | return buff; |
| 111 | } |
| 112 | |
| 113 | static uint8_t hexval(uint8_t c) |
| 114 | { |
| 115 | switch (c) { |
| 116 | case '0': return 0; |
| 117 | case '1': return 1; |
| 118 | case '2': return 2; |
| 119 | case '3': return 3; |
| 120 | case '4': return 4; |
| 121 | case '5': return 5; |
| 122 | case '6': return 6; |
| 123 | case '7': return 7; |
| 124 | case '8': return 8; |
| 125 | case '9': return 9; |
| 126 | case 'a': return 10; |
| 127 | case 'A': return 10; |
| 128 | case 'b': return 11; |
| 129 | case 'B': return 11; |
| 130 | case 'c': return 12; |
| 131 | case 'C': return 12; |
| 132 | case 'd': return 13; |
| 133 | case 'D': return 13; |
| 134 | case 'e': return 14; |
| 135 | case 'E': return 14; |
| 136 | case 'f': return 15; |
| 137 | case 'F': return 15; |
| 138 | } |
| 139 | return -1; |
| 140 | } |
| 141 | |
| 142 | /* Convert a MP_INT into a buffer; return length; truncate if necessary */ |
| 143 | int32_t write_mpbin(MP_INT *a, uint8_t *buffer, int32_t buflen) |
| 144 | { |
| 145 | char *hb; |
| 146 | int i,j,l; |
| 147 | |
| 148 | if (buflen==0) return 0; |
| 149 | hb=write_mpstring(a); |
| 150 | |
| 151 | l=strlen(hb); |
| 152 | i=0; j=0; |
| 153 | if (l&1) { |
| 154 | /* The number starts with a half-byte */ |
| 155 | buffer[i++]=hexval(hb[j++]); |
| 156 | } |
| 157 | for (; hb[j] && i<buflen; i++) { |
| 158 | buffer[i]=(hexval(hb[j])<<4)|hexval(hb[j+1]); |
| 159 | j+=2; |
| 160 | } |
| 161 | free(hb); |
| 162 | return i; |
| 163 | } |
| 164 | |
| 165 | static const char *phases[NR_PHASES]={ |
| 166 | "PHASE_INIT", |
| 167 | "PHASE_GETOPTS", |
| 168 | "PHASE_READCONFIG", |
| 169 | "PHASE_SETUP", |
| 170 | "PHASE_DAEMONIZE", |
| 171 | "PHASE_GETRESOURCES", |
| 172 | "PHASE_DROPPRIV", |
| 173 | "PHASE_RUN", |
| 174 | "PHASE_SHUTDOWN" |
| 175 | }; |
| 176 | |
| 177 | void enter_phase(uint32_t new_phase) |
| 178 | { |
| 179 | struct phase_hook *i; |
| 180 | |
| 181 | if (hooks[new_phase]) |
| 182 | Message(M_DEBUG_PHASE,"Running hooks for %s...\n", phases[new_phase]); |
| 183 | current_phase=new_phase; |
| 184 | |
| 185 | for (i=hooks[new_phase]; i; i=i->next) |
| 186 | i->fn(i->state, new_phase); |
| 187 | Message(M_DEBUG_PHASE,"Now in %s\n",phases[new_phase]); |
| 188 | } |
| 189 | |
| 190 | bool_t add_hook(uint32_t phase, hook_fn *fn, void *state) |
| 191 | { |
| 192 | struct phase_hook *h; |
| 193 | |
| 194 | h=safe_malloc(sizeof(*h),"add_hook"); |
| 195 | h->fn=fn; |
| 196 | h->state=state; |
| 197 | h->next=hooks[phase]; |
| 198 | hooks[phase]=h; |
| 199 | return True; |
| 200 | } |
| 201 | |
| 202 | bool_t remove_hook(uint32_t phase, hook_fn *fn, void *state) |
| 203 | { |
| 204 | fatal("remove_hook: not implemented"); |
| 205 | |
| 206 | return False; |
| 207 | } |
| 208 | |
| 209 | void vslilog(struct log_if *lf, int priority, const char *message, va_list ap) |
| 210 | { |
| 211 | lf->vlogfn(lf->st,priority,message,ap); |
| 212 | } |
| 213 | |
| 214 | void slilog(struct log_if *lf, int priority, const char *message, ...) |
| 215 | { |
| 216 | va_list ap; |
| 217 | |
| 218 | va_start(ap,message); |
| 219 | vslilog(lf,priority,message,ap); |
| 220 | va_end(ap); |
| 221 | } |
| 222 | |
| 223 | struct buffer { |
| 224 | closure_t cl; |
| 225 | struct buffer_if ops; |
| 226 | }; |
| 227 | |
| 228 | void buffer_assert_free(struct buffer_if *buffer, cstring_t file, |
| 229 | int line) |
| 230 | { |
| 231 | if (!buffer->free) { |
| 232 | fprintf(stderr,"secnet: BUF_ASSERT_FREE, %s line %d, owned by %s", |
| 233 | file,line,buffer->owner); |
| 234 | assert(!"buffer_assert_free failure"); |
| 235 | } |
| 236 | } |
| 237 | |
| 238 | void buffer_assert_used(struct buffer_if *buffer, cstring_t file, |
| 239 | int line) |
| 240 | { |
| 241 | if (buffer->free) { |
| 242 | fprintf(stderr,"secnet: BUF_ASSERT_USED, %s line %d, last owned by %s", |
| 243 | file,line,buffer->owner); |
| 244 | assert(!"buffer_assert_used failure"); |
| 245 | } |
| 246 | } |
| 247 | |
| 248 | void buffer_init(struct buffer_if *buffer, int32_t max_start_pad) |
| 249 | { |
| 250 | assert(max_start_pad<=buffer->len); |
| 251 | buffer->start=buffer->base+max_start_pad; |
| 252 | buffer->size=0; |
| 253 | } |
| 254 | |
| 255 | void *buf_append(struct buffer_if *buf, int32_t amount) { |
| 256 | void *p; |
| 257 | assert(buf->size <= buf->len - amount); |
| 258 | p=buf->start + buf->size; |
| 259 | buf->size+=amount; |
| 260 | return p; |
| 261 | } |
| 262 | |
| 263 | void *buf_prepend(struct buffer_if *buf, int32_t amount) { |
| 264 | assert(amount <= buf->start - buf->base); |
| 265 | buf->size+=amount; |
| 266 | return buf->start-=amount; |
| 267 | } |
| 268 | |
| 269 | void *buf_unappend(struct buffer_if *buf, int32_t amount) { |
| 270 | if (buf->size < amount) return 0; |
| 271 | return buf->start+(buf->size-=amount); |
| 272 | } |
| 273 | |
| 274 | void *buf_unprepend(struct buffer_if *buf, int32_t amount) { |
| 275 | void *p; |
| 276 | if (buf->size < amount) return 0; |
| 277 | p=buf->start; |
| 278 | buf->start+=amount; |
| 279 | buf->size-=amount; |
| 280 | return p; |
| 281 | } |
| 282 | |
| 283 | /* Append a two-byte length and the string to the buffer. Length is in |
| 284 | network byte order. */ |
| 285 | void buf_append_string(struct buffer_if *buf, cstring_t s) |
| 286 | { |
| 287 | size_t len; |
| 288 | |
| 289 | len=strlen(s); |
| 290 | /* fixme: if string is longer than 65535, result is a corrupted packet */ |
| 291 | buf_append_uint16(buf,len); |
| 292 | memcpy(buf_append(buf,len),s,len); |
| 293 | } |
| 294 | |
| 295 | void buffer_new(struct buffer_if *buf, int32_t len) |
| 296 | { |
| 297 | buf->free=True; |
| 298 | buf->owner=NULL; |
| 299 | buf->flags=0; |
| 300 | buf->loc.file=NULL; |
| 301 | buf->loc.line=0; |
| 302 | buf->size=0; |
| 303 | buf->len=len; |
| 304 | buf->start=NULL; |
| 305 | buf->base=safe_malloc(len,"buffer_new"); |
| 306 | } |
| 307 | |
| 308 | void buffer_readonly_view(struct buffer_if *buf, const void *data, int32_t len) |
| 309 | { |
| 310 | buf->free=False; |
| 311 | buf->owner="READONLY"; |
| 312 | buf->flags=0; |
| 313 | buf->loc.file=NULL; |
| 314 | buf->loc.line=0; |
| 315 | buf->size=buf->len=len; |
| 316 | buf->base=buf->start=(uint8_t*)data; |
| 317 | } |
| 318 | |
| 319 | void buffer_readonly_clone(struct buffer_if *out, const struct buffer_if *in) |
| 320 | { |
| 321 | buffer_readonly_view(out,in->start,in->size); |
| 322 | } |
| 323 | |
| 324 | void buffer_copy(struct buffer_if *dst, const struct buffer_if *src) |
| 325 | { |
| 326 | if (dst->len < src->len) { |
| 327 | dst->base=realloc(dst->base,src->len); |
| 328 | if (!dst->base) fatal_perror("buffer_copy"); |
| 329 | dst->len = src->len; |
| 330 | } |
| 331 | dst->start = dst->base + (src->start - src->base); |
| 332 | dst->size = src->size; |
| 333 | memcpy(dst->start, src->start, dst->size); |
| 334 | } |
| 335 | |
| 336 | static list_t *buffer_apply(closure_t *self, struct cloc loc, dict_t *context, |
| 337 | list_t *args) |
| 338 | { |
| 339 | struct buffer *st; |
| 340 | item_t *item; |
| 341 | dict_t *dict; |
| 342 | bool_t lockdown=False; |
| 343 | uint32_t len=DEFAULT_BUFFER_SIZE; |
| 344 | |
| 345 | st=safe_malloc(sizeof(*st),"buffer_apply"); |
| 346 | st->cl.description="buffer"; |
| 347 | st->cl.type=CL_BUFFER; |
| 348 | st->cl.apply=NULL; |
| 349 | st->cl.interface=&st->ops; |
| 350 | |
| 351 | /* First argument, if present, is buffer length */ |
| 352 | item=list_elem(args,0); |
| 353 | if (item) { |
| 354 | if (item->type!=t_number) { |
| 355 | cfgfatal(st->ops.loc,"buffer","first parameter must be a " |
| 356 | "number (buffer size)\n"); |
| 357 | } |
| 358 | len=item->data.number; |
| 359 | if (len<MIN_BUFFER_SIZE) { |
| 360 | cfgfatal(st->ops.loc,"buffer","ludicrously small buffer size\n"); |
| 361 | } |
| 362 | if (len>MAX_BUFFER_SIZE) { |
| 363 | cfgfatal(st->ops.loc,"buffer","ludicrously large buffer size\n"); |
| 364 | } |
| 365 | } |
| 366 | /* Second argument, if present, is a dictionary */ |
| 367 | item=list_elem(args,1); |
| 368 | if (item) { |
| 369 | if (item->type!=t_dict) { |
| 370 | cfgfatal(st->ops.loc,"buffer","second parameter must be a " |
| 371 | "dictionary\n"); |
| 372 | } |
| 373 | dict=item->data.dict; |
| 374 | lockdown=dict_read_bool(dict,"lockdown",False,"buffer",st->ops.loc, |
| 375 | False); |
| 376 | } |
| 377 | |
| 378 | buffer_new(&st->ops,len); |
| 379 | if (lockdown) { |
| 380 | /* XXX mlock the buffer if possible */ |
| 381 | } |
| 382 | |
| 383 | return new_closure(&st->cl); |
| 384 | } |
| 385 | |
| 386 | void send_nak(const struct comm_addr *dest, uint32_t our_index, |
| 387 | uint32_t their_index, uint32_t msgtype, |
| 388 | struct buffer_if *buf, const char *logwhy) |
| 389 | { |
| 390 | buffer_init(buf,calculate_max_start_pad()); |
| 391 | buf_append_uint32(buf,their_index); |
| 392 | buf_append_uint32(buf,our_index); |
| 393 | buf_append_uint32(buf,LABEL_NAK); |
| 394 | if (logwhy) |
| 395 | Message(M_INFO,"%s: %08"PRIx32"<-%08"PRIx32": %08"PRIx32":" |
| 396 | " %s; sending NAK\n", |
| 397 | dest->comm->addr_to_string(dest->comm->st,dest), |
| 398 | our_index, their_index, msgtype, logwhy); |
| 399 | dest->comm->sendmsg(dest->comm->st, buf, dest); |
| 400 | } |
| 401 | |
| 402 | int consttime_memeq(const void *s1in, const void *s2in, size_t n) |
| 403 | { |
| 404 | const uint8_t *s1=s1in, *s2=s2in; |
| 405 | register volatile uint8_t accumulator=0; |
| 406 | |
| 407 | while (n-- > 0) { |
| 408 | accumulator |= (*s1++ ^ *s2++); |
| 409 | } |
| 410 | accumulator |= accumulator >> 4; /* constant-time */ |
| 411 | accumulator |= accumulator >> 2; /* boolean canonicalisation */ |
| 412 | accumulator |= accumulator >> 1; |
| 413 | accumulator &= 1; |
| 414 | accumulator ^= 1; |
| 415 | return accumulator; |
| 416 | } |
| 417 | |
| 418 | void util_module(dict_t *dict) |
| 419 | { |
| 420 | add_closure(dict,"sysbuffer",buffer_apply); |
| 421 | } |
| 422 | |
| 423 | void update_max_start_pad(int32_t *our_module_global, int32_t our_instance) |
| 424 | { |
| 425 | if (*our_module_global < our_instance) |
| 426 | *our_module_global=our_instance; |
| 427 | } |
| 428 | |
| 429 | int32_t transform_max_start_pad, comm_max_start_pad; |
| 430 | |
| 431 | int32_t calculate_max_start_pad(void) |
| 432 | { |
| 433 | return |
| 434 | site_max_start_pad + |
| 435 | transform_max_start_pad + |
| 436 | comm_max_start_pad; |
| 437 | } |