mdw@git.distorted.org.uk Git - secnet/blob - util.c

   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
  78 /* Convert a buffer into its MP_INT representation */
  79 void read_mpbin(MP_INT *a, uint8_t *bin, int binsize)
  80 {
  81     char *buff;
  82     int i;
  83
  84     buff=safe_malloc(binsize*2 + 1,"read_mpbin");
  85
  86     for (i=0; i<binsize; i++) {
  87         buff[i*2]=hexdigits[(bin[i] & 0xf0) >> 4];
  88         buff[i*2+1]=hexdigits[(bin[i] & 0xf)];
  89     }
  90     buff[binsize*2]=0;
  91
  92     mpz_set_str(a, buff, 16);
  93     free(buff);
  94 }
  95
  96 /* Convert a MP_INT into a hex string */
  97 char *write_mpstring(MP_INT *a)
  98 {
  99     char *buff;
 100
 101     buff=safe_malloc(mpz_sizeinbase(a,16)+2,"write_mpstring");
 102     mpz_get_str(buff, 16, a);
 103     return buff;
 104 }
 105
 106 static uint8_t hexval(uint8_t c)
 107 {
 108     switch (c) {
 109     case '0': return 0;
 110     case '1': return 1;
 111     case '2': return 2;
 112     case '3': return 3;
 113     case '4': return 4;
 114     case '5': return 5;
 115     case '6': return 6;
 116     case '7': return 7;
 117     case '8': return 8;
 118     case '9': return 9;
 119     case 'a': return 10;
 120     case 'A': return 10;
 121     case 'b': return 11;
 122     case 'B': return 11;
 123     case 'c': return 12;
 124     case 'C': return 12;
 125     case 'd': return 13;
 126     case 'D': return 13;
 127     case 'e': return 14;
 128     case 'E': return 14;
 129     case 'f': return 15;
 130     case 'F': return 15;
 131     }
 132     return -1;
 133 }
 134
 135 /* Convert a MP_INT into a buffer; return length; truncate if necessary */
 136 uint32_t write_mpbin(MP_INT *a, uint8_t *buffer, uint32_t buflen)
 137 {
 138     char *hb;
 139     int i,j,l;
 140
 141     if (buflen==0) return 0;
 142     hb=write_mpstring(a);
 143
 144     l=strlen(hb);
 145     i=0; j=0;
 146     if (l&1) {
 147         /* The number starts with a half-byte */
 148         buffer[i++]=hexval(hb[j++]);
 149     }
 150     for (; hb[j] && i<buflen; i++) {
 151         buffer[i]=(hexval(hb[j])<<4)|hexval(hb[j+1]);
 152         j+=2;
 153     }
 154     free(hb);
 155     return i;
 156 }
 157
 158 static const char *phases[NR_PHASES]={
 159     "PHASE_INIT",
 160     "PHASE_GETOPTS",
 161     "PHASE_READCONFIG",
 162     "PHASE_SETUP",
 163     "PHASE_GETRESOURCES",
 164     "PHASE_DROPPRIV",
 165     "PHASE_RUN",
 166     "PHASE_SHUTDOWN"
 167 };
 168
 169 void enter_phase(uint32_t new_phase)
 170 {
 171     struct phase_hook *i;
 172
 173     if (hooks[new_phase])
 174         Message(M_DEBUG_PHASE,"Running hooks for %s...\n", phases[new_phase]);
 175     current_phase=new_phase;
 176
 177     for (i=hooks[new_phase]; i; i=i->next)
 178         i->fn(i->state, new_phase);
 179     Message(M_DEBUG_PHASE,"Now in %s\n",phases[new_phase]);
 180 }
 181
 182 bool_t add_hook(uint32_t phase, hook_fn *fn, void *state)
 183 {
 184     struct phase_hook *h;
 185
 186     h=safe_malloc(sizeof(*h),"add_hook");
 187     h->fn=fn;
 188     h->state=state;
 189     h->next=hooks[phase];
 190     hooks[phase]=h;
 191     return True;
 192 }
 193
 194 bool_t remove_hook(uint32_t phase, hook_fn *fn, void *state)
 195 {
 196     fatal("remove_hook: not implemented");
 197
 198     return False;
 199 }
 200
 201 void log(struct log_if *lf, int priority, const char *message, ...)
 202 {
 203     va_list ap;
 204
 205     va_start(ap,message);
 206     lf->vlog(lf->st,priority,message,ap);
 207     va_end(ap);
 208 }
 209
 210 struct buffer {
 211     closure_t cl;
 212     struct buffer_if ops;
 213 };
 214
 215 void buffer_assert_free(struct buffer_if *buffer, cstring_t file,
 216                         uint32_t line)
 217 {
 218     if (!buffer->free) {
 219         fatal("BUF_ASSERT_FREE, %s line %d, owned by %s",
 220               file,line,buffer->owner);
 221     }
 222 }
 223
 224 void buffer_assert_used(struct buffer_if *buffer, cstring_t file,
 225                         uint32_t line)
 226 {
 227     if (buffer->free) {
 228         fatal("BUF_ASSERT_USED, %s line %d, last owned by %s",
 229               file,line,buffer->owner);
 230     }
 231 }
 232
 233 void buffer_init(struct buffer_if *buffer, uint32_t max_start_pad)
 234 {
 235     buffer->start=buffer->base+max_start_pad;
 236     buffer->size=0;
 237 }
 238
 239 void *buf_append(struct buffer_if *buf, uint32_t amount) {
 240     void *p;
 241     p=buf->start + buf->size;
 242     buf->size+=amount;
 243     return p;
 244 }
 245
 246 void *buf_prepend(struct buffer_if *buf, uint32_t amount) {
 247     buf->size+=amount;
 248     return buf->start-=amount;
 249 }
 250
 251 void *buf_unappend(struct buffer_if *buf, uint32_t amount) {
 252     if (buf->size < amount) return 0;
 253     return buf->start+(buf->size-=amount);
 254 }
 255
 256 void *buf_unprepend(struct buffer_if *buf, uint32_t amount) {
 257     void *p;
 258     p=buf->start;
 259     buf->start+=amount;
 260     buf->size-=amount;
 261     return p;
 262 }
 263
 264 /* Append a two-byte length and the string to the buffer. Length is in
 265    network byte order. */
 266 void buf_append_string(struct buffer_if *buf, cstring_t s)
 267 {
 268     uint16_t len;
 269
 270     len=strlen(s);
 271     buf_append_uint16(buf,len);
 272     memcpy(buf_append(buf,len),s,len);
 273 }
 274
 275 void buffer_new(struct buffer_if *buf, uint32_t len)
 276 {
 277     buf->free=True;
 278     buf->owner=NULL;
 279     buf->flags=0;
 280     buf->loc.file=NULL;
 281     buf->loc.line=0;
 282     buf->size=0;
 283     buf->len=len;
 284     buf->start=NULL;
 285     buf->base=safe_malloc(len,"buffer_new");
 286 }
 287
 288 static list_t *buffer_apply(closure_t *self, struct cloc loc, dict_t *context,
 289                             list_t *args)
 290 {
 291     struct buffer *st;
 292     item_t *item;
 293     dict_t *dict;
 294     bool_t lockdown=False;
 295     uint32_t len=DEFAULT_BUFFER_SIZE;
 296
 297     st=safe_malloc(sizeof(*st),"buffer_apply");
 298     st->cl.description="buffer";
 299     st->cl.type=CL_BUFFER;
 300     st->cl.apply=NULL;
 301     st->cl.interface=&st->ops;
 302
 303     /* First argument, if present, is buffer length */
 304     item=list_elem(args,0);
 305     if (item) {
 306         if (item->type!=t_number) {
 307             cfgfatal(st->ops.loc,"buffer","first parameter must be a "
 308                      "number (buffer size)\n");
 309         }
 310         len=item->data.number;
 311         if (len<MIN_BUFFER_SIZE) {
 312             cfgfatal(st->ops.loc,"buffer","ludicrously small buffer size\n");
 313         }
 314         if (len>MAX_BUFFER_SIZE) {
 315             cfgfatal(st->ops.loc,"buffer","ludicrously large buffer size\n");
 316         }
 317     }
 318     /* Second argument, if present, is a dictionary */
 319     item=list_elem(args,1);
 320     if (item) {
 321         if (item->type!=t_dict) {
 322             cfgfatal(st->ops.loc,"buffer","second parameter must be a "
 323                      "dictionary\n");
 324         }
 325         dict=item->data.dict;
 326         lockdown=dict_read_bool(dict,"lockdown",False,"buffer",st->ops.loc,
 327                                 False);
 328     }
 329
 330     buffer_new(&st->ops,len);
 331     if (lockdown) {
 332         /* XXX mlock the buffer if possible */
 333     }
 334
 335     return new_closure(&st->cl);
 336 }
 337
 338 init_module util_module;
 339 void util_module(dict_t *dict)
 340 {
 341     add_closure(dict,"sysbuffer",buffer_apply);
 342 }