git.maemo.org Git - udhcp/blob - files.c

   1 /*
   2  * files.c -- DHCP server file manipulation *
   3  * Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
   4  */
   5
   6 #include <sys/socket.h>
   7 #include <arpa/inet.h>
   8 #include <string.h>
   9 #include <stdlib.h>
  10 #include <time.h>
  11 #include <ctype.h>
  12 #include <netdb.h>
  13
  14 #include <netinet/ether.h>
  15 #include "static_leases.h"
  16
  17 #include "dhcpd.h"
  18 #include "files.h"
  19 #include "options.h"
  20 #include "common.h"
  21
  22 /*
  23  * Domain names may have 254 chars, and string options can be 254
  24  * chars long. However, 80 bytes will be enough for most, and won't
  25  * hog up memory. If you have a special application, change it
  26  */
  27 #define READ_CONFIG_BUF_SIZE 80
  28
  29 /* on these functions, make sure you datatype matches */
  30 static int read_ip(const char *line, void *arg)
  31 {
  32         struct in_addr *addr = arg;
  33         struct hostent *host;
  34         int retval = 1;
  35
  36         if (!inet_aton(line, addr)) {
  37                 if ((host = gethostbyname(line)))
  38                         addr->s_addr = *((unsigned long *) host->h_addr_list[0]);
  39                 else retval = 0;
  40         }
  41         return retval;
  42 }
  43
  44 static int read_mac(const char *line, void *arg)
  45 {
  46         uint8_t *mac_bytes = arg;
  47         struct ether_addr *temp_ether_addr;
  48         int retval = 1;
  49
  50         temp_ether_addr = ether_aton(line);
  51
  52         if(temp_ether_addr == NULL)
  53                 retval = 0;
  54         else
  55                 memcpy(mac_bytes, temp_ether_addr, 6);
  56
  57         return retval;
  58 }
  59
  60
  61 static int read_str(const char *line, void *arg)
  62 {
  63         char **dest = arg;
  64
  65         if (*dest) free(*dest);
  66         *dest = strdup(line);
  67
  68         return 1;
  69 }
  70
  71
  72 static int read_u32(const char *line, void *arg)
  73 {
  74         uint32_t *dest = arg;
  75         char *endptr;
  76         *dest = strtoul(line, &endptr, 0);
  77         return endptr[0] == '\0';
  78 }
  79
  80
  81 static int read_yn(const char *line, void *arg)
  82 {
  83         char *dest = arg;
  84         int retval = 1;
  85
  86         if (!strcasecmp("yes", line))
  87                 *dest = 1;
  88         else if (!strcasecmp("no", line))
  89                 *dest = 0;
  90         else retval = 0;
  91
  92         return retval;
  93 }
  94
  95
  96 /* read a dhcp option and add it to opt_list */
  97 static int read_opt(const char *const_line, void *arg)
  98 {
  99         struct option_set **opt_list = arg;
 100         char *opt, *val, *endptr;
 101         struct dhcp_option *option;
 102         int retval = 0, length;
 103         char buffer[8];
 104         char *line;
 105         uint16_t *result_u16 = (uint16_t *) buffer;
 106         uint32_t *result_u32 = (uint32_t *) buffer;
 107
 108         /* Cheat, the only const line we'll actually get is "" */
 109         line = (char *) const_line;
 110         if (!(opt = strtok(line, " \t="))) return 0;
 111
 112         for (option = dhcp_options; option->code; option++)
 113                 if (!strcasecmp(option->name, opt))
 114                         break;
 115
 116         if (!option->code) return 0;
 117
 118         do {
 119                 if (!(val = strtok(NULL, ", \t"))) break;
 120                 length = option_lengths[option->flags & TYPE_MASK];
 121                 retval = 0;
 122                 opt = buffer; /* new meaning for variable opt */
 123                 switch (option->flags & TYPE_MASK) {
 124                 case OPTION_IP:
 125                         retval = read_ip(val, buffer);
 126                         break;
 127                 case OPTION_IP_PAIR:
 128                         retval = read_ip(val, buffer);
 129                         if (!(val = strtok(NULL, ", \t/-"))) retval = 0;
 130                         if (retval) retval = read_ip(val, buffer + 4);
 131                         break;
 132                 case OPTION_STRING:
 133                         length = strlen(val);
 134                         if (length > 0) {
 135                                 if (length > 254) length = 254;
 136                                 opt = val;
 137                                 retval = 1;
 138                         }
 139                         break;
 140                 case OPTION_BOOLEAN:
 141                         retval = read_yn(val, buffer);
 142                         break;
 143                 case OPTION_U8:
 144                         buffer[0] = strtoul(val, &endptr, 0);
 145                         retval = (endptr[0] == '\0');
 146                         break;
 147                 case OPTION_U16:
 148                         *result_u16 = htons(strtoul(val, &endptr, 0));
 149                         retval = (endptr[0] == '\0');
 150                         break;
 151                 case OPTION_S16:
 152                         *result_u16 = htons(strtol(val, &endptr, 0));
 153                         retval = (endptr[0] == '\0');
 154                         break;
 155                 case OPTION_U32:
 156                         *result_u32 = htonl(strtoul(val, &endptr, 0));
 157                         retval = (endptr[0] == '\0');
 158                         break;
 159                 case OPTION_S32:
 160                         *result_u32 = htonl(strtol(val, &endptr, 0));
 161                         retval = (endptr[0] == '\0');
 162                         break;
 163                 default:
 164                         break;
 165                 }
 166                 if (retval)
 167                         attach_option(opt_list, option, opt, length);
 168         } while (retval && option->flags & OPTION_LIST);
 169         return retval;
 170 }
 171
 172 static int read_staticlease(const char *const_line, void *arg)
 173 {
 174
 175         char *line;
 176         char *mac_string;
 177         char *ip_string;
 178         uint8_t *mac_bytes;
 179         uint32_t *ip;
 180
 181
 182         /* Allocate memory for addresses */
 183         mac_bytes = xmalloc(sizeof(unsigned char) * 8);
 184         ip = xmalloc(sizeof(uint32_t));
 185
 186         /* Read mac */
 187         line = (char *) const_line;
 188         mac_string = strtok(line, " \t");
 189         read_mac(mac_string, mac_bytes);
 190
 191         /* Read ip */
 192         ip_string = strtok(NULL, " \t");
 193         read_ip(ip_string, ip);
 194
 195         addStaticLease(arg, mac_bytes, ip);
 196
 197 #ifdef UDHCP_DEBUG
 198         printStaticLeases(arg);
 199 #endif
 200
 201         return 1;
 202
 203 }
 204
 205
 206 static const struct config_keyword keywords[] = {
 207         /* keyword      handler   variable address              default */
 208         {"start",       read_ip,  &(server_config.start),       "192.168.0.20"},
 209         {"end",         read_ip,  &(server_config.end),         "192.168.0.254"},
 210         {"interface",   read_str, &(server_config.interface),   "eth0"},
 211         {"option",      read_opt, &(server_config.options),     ""},
 212         {"opt",         read_opt, &(server_config.options),     ""},
 213         {"max_leases",  read_u32, &(server_config.max_leases),  "254"},
 214         {"remaining",   read_yn,  &(server_config.remaining),   "yes"},
 215         {"auto_time",   read_u32, &(server_config.auto_time),   "7200"},
 216         {"decline_time",read_u32, &(server_config.decline_time),"3600"},
 217         {"conflict_time",read_u32,&(server_config.conflict_time),"3600"},
 218         {"offer_time",  read_u32, &(server_config.offer_time),  "60"},
 219         {"min_lease",   read_u32, &(server_config.min_lease),   "60"},
 220         {"lease_file",  read_str, &(server_config.lease_file),  LEASES_FILE},
 221         {"pidfile",     read_str, &(server_config.pidfile),     "/var/run/udhcpd.pid"},
 222         {"notify_file", read_str, &(server_config.notify_file), ""},
 223         {"siaddr",      read_ip,  &(server_config.siaddr),      "0.0.0.0"},
 224         {"sname",       read_str, &(server_config.sname),       ""},
 225         {"boot_file",   read_str, &(server_config.boot_file),   ""},
 226         {"static_lease",read_staticlease, &(server_config.static_leases),       ""},
 227         /*ADDME: static lease */
 228         {"",            NULL,     NULL,                         ""}
 229 };
 230
 231
 232 int read_config(const char *file)
 233 {
 234         FILE *in;
 235         char buffer[READ_CONFIG_BUF_SIZE], *token, *line;
 236 #ifdef UDHCP_DEBUG
 237         char orig[READ_CONFIG_BUF_SIZE];
 238 #endif
 239         int i, lm = 0;
 240
 241         for (i = 0; keywords[i].keyword[0]; i++)
 242                 if (keywords[i].def[0])
 243                         keywords[i].handler(keywords[i].def, keywords[i].var);
 244
 245         if (!(in = fopen(file, "r"))) {
 246                 LOG(LOG_ERR, "unable to open config file: %s", file);
 247                 return 0;
 248         }
 249
 250         while (fgets(buffer, READ_CONFIG_BUF_SIZE, in)) {
 251                 lm++;
 252                 if (strchr(buffer, '\n')) *(strchr(buffer, '\n')) = '\0';
 253 #ifdef UDHCP_DEBUG
 254                 strcpy(orig, buffer);
 255 #endif
 256                 if (strchr(buffer, '#')) *(strchr(buffer, '#')) = '\0';
 257
 258                 if (!(token = strtok(buffer, " \t"))) continue;
 259                 if (!(line = strtok(NULL, ""))) continue;
 260
 261                 /* eat leading whitespace */
 262                 line = line + strspn(line, " \t=");
 263                 /* eat trailing whitespace */
 264                 for (i = strlen(line); i > 0 && isspace(line[i - 1]); i--);
 265                 line[i] = '\0';
 266
 267                 for (i = 0; keywords[i].keyword[0]; i++)
 268                         if (!strcasecmp(token, keywords[i].keyword))
 269                                 if (!keywords[i].handler(line, keywords[i].var)) {
 270                                         LOG(LOG_ERR, "Failure parsing line %d of %s", lm, file);
 271                                         DEBUG(LOG_ERR, "unable to parse '%s'", orig);
 272                                         /* reset back to the default value */
 273                                         keywords[i].handler(keywords[i].def, keywords[i].var);
 274                                 }
 275         }
 276         fclose(in);
 277         return 1;
 278 }
 279
 280
 281 void write_leases(void)
 282 {
 283         FILE *fp;
 284         unsigned int i;
 285         char buf[255];
 286         time_t curr = time(0);
 287         unsigned long tmp_time;
 288
 289         if (!(fp = fopen(server_config.lease_file, "w"))) {
 290                 LOG(LOG_ERR, "Unable to open %s for writing", server_config.lease_file);
 291                 return;
 292         }
 293
 294         for (i = 0; i < server_config.max_leases; i++) {
 295                 if (leases[i].yiaddr != 0) {
 296
 297                         /* screw with the time in the struct, for easier writing */
 298                         tmp_time = leases[i].expires;
 299
 300                         if (server_config.remaining) {
 301                                 if (lease_expired(&(leases[i])))
 302                                         leases[i].expires = 0;
 303                                 else leases[i].expires -= curr;
 304                         } /* else stick with the time we got */
 305                         leases[i].expires = htonl(leases[i].expires);
 306                         fwrite(&leases[i], sizeof(struct dhcpOfferedAddr), 1, fp);
 307
 308                         /* Then restore it when done. */
 309                         leases[i].expires = tmp_time;
 310                 }
 311         }
 312         fclose(fp);
 313
 314         if (server_config.notify_file) {
 315                 sprintf(buf, "%s %s", server_config.notify_file, server_config.lease_file);
 316                 system(buf);
 317         }
 318 }
 319
 320
 321 void read_leases(const char *file)
 322 {
 323         FILE *fp;
 324         unsigned int i = 0;
 325         struct dhcpOfferedAddr lease;
 326
 327         if (!(fp = fopen(file, "r"))) {
 328                 LOG(LOG_ERR, "Unable to open %s for reading", file);
 329                 return;
 330         }
 331
 332         while (i < server_config.max_leases && (fread(&lease, sizeof lease, 1, fp) == 1)) {
 333                 /* ADDME: is it a static lease */
 334                 if (lease.yiaddr >= server_config.start && lease.yiaddr <= server_config.end) {
 335                         lease.expires = ntohl(lease.expires);
 336                         if (!server_config.remaining) lease.expires -= time(0);
 337                         if (!(add_lease(lease.chaddr, lease.yiaddr, lease.expires))) {
 338                                 LOG(LOG_WARNING, "Too many leases while loading %s\n", file);
 339                                 break;
 340                         }
 341                         i++;
 342                 }
 343         }
 344         DEBUG(LOG_INFO, "Read %d leases", i);
 345         fclose(fp);
 346 }