src/patches/dnsmasq-2.70-Add-support-to-read-ISC-DHCP-lease-file.patch

   1 From b3c0d11d8bcf810b8f50f695ea36c8183fa4791a Mon Sep 17 00:00:00 2001
   2 From: Michael Tremer <michael.tremer@ipfire.org>
   3 Date: Mon, 28 Apr 2014 00:51:13 +0200
   4 Subject: [PATCH] Add support to read ISC DHCP lease file.
   5
   6 ---
   7  Makefile      |   2 +-
   8  src/cache.c   |  13 +++-
   9  src/dnsmasq.c |   5 ++
  10  src/dnsmasq.h |   5 ++
  11  src/isc.c     | 234 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
  12  src/option.c  |   2 +-
  13  6 files changed, 256 insertions(+), 5 deletions(-)
  14  create mode 100644 src/isc.c
  15
  16 diff --git a/Makefile b/Makefile
  17 index 292c8bd..5e0cdbe 100644
  18 --- a/Makefile
  19 +++ b/Makefile
  20 @@ -69,7 +69,7 @@ objs = cache.o rfc1035.o util.o option.o forward.o network.o \
  21         dnsmasq.o dhcp.o lease.o rfc2131.o netlink.o dbus.o bpf.o \
  22         helper.o tftp.o log.o conntrack.o dhcp6.o rfc3315.o \
  23         dhcp-common.o outpacket.o radv.o slaac.o auth.o ipset.o \
  24 -       domain.o dnssec.o blockdata.o
  25 +       domain.o dnssec.o blockdata.o isc.o
  26
  27  hdrs = dnsmasq.h config.h dhcp-protocol.h dhcp6-protocol.h \
  28         dns-protocol.h radv-protocol.h ip6addr.h
  29 diff --git a/src/cache.c b/src/cache.c
  30 index 5cec918..1f5657f 100644
  31 --- a/src/cache.c
  32 +++ b/src/cache.c
  33 @@ -17,7 +17,7 @@
  34  #include "dnsmasq.h"
  35
  36  static struct crec *cache_head = NULL, *cache_tail = NULL, **hash_table = NULL;
  37 -#ifdef HAVE_DHCP
  38 +#if (defined HAVE_DHCP) || (defined HAVE_ISC_READER)
  39  static struct crec *dhcp_spare = NULL;
  40  #endif
  41  static struct crec *new_chain = NULL;
  42 @@ -222,6 +222,9 @@ static void cache_free(struct crec *crecp)
  43        crecp->flags &= ~F_BIGNAME;
  44      }
  45
  46 +  if (crecp->flags & F_DHCP)
  47 +    free(crecp->name.namep);
  48 +
  49  #ifdef HAVE_DNSSEC
  50    cache_blockdata_free(crecp);
  51  #endif
  52 @@ -1110,7 +1113,7 @@ void cache_reload(void)
  53        total_size = read_hostsfile(ah->fname, ah->index, total_size, (struct crec **)daemon->packet, revhashsz);
  54  }
  55
  56 -#ifdef HAVE_DHCP
  57 +#if (defined HAVE_DHCP) || (defined HAVE_ISC_READER)
  58  struct in_addr a_record_from_hosts(char *name, time_t now)
  59  {
  60    struct crec *crecp = NULL;
  61 @@ -1188,7 +1191,7 @@ void cache_add_dhcp_entry(char *host_name, int prot,
  62        addrlen = sizeof(struct in6_addr);
  63      }
  64  #endif
  65 -
  66 +
  67    inet_ntop(prot, host_address, daemon->addrbuff, ADDRSTRLEN);
  68
  69    while ((crec = cache_find_by_name(crec, host_name, 0, flags | F_CNAME)))
  70 @@ -1253,7 +1256,11 @@ void cache_add_dhcp_entry(char *host_name, int prot,
  71        else
  72         crec->ttd = ttd;
  73        crec->addr.addr = *host_address;
  74 +#ifdef HAVE_ISC_READER
  75 +      crec->name.namep = strdup(host_name);
  76 +#else
  77        crec->name.namep = host_name;
  78 +#endif
  79        crec->uid = next_uid();
  80        cache_hash(crec);
  81
  82 diff --git a/src/dnsmasq.c b/src/dnsmasq.c
  83 index 1c96a0e..156ac9a 100644
  84 --- a/src/dnsmasq.c
  85 +++ b/src/dnsmasq.c
  86 @@ -934,6 +934,11 @@ int main (int argc, char **argv)
  87
  88           poll_resolv(0, daemon->last_resolv != 0, now);
  89           daemon->last_resolv = now;
  90 +
  91 +#ifdef HAVE_ISC_READER
  92 +         if (daemon->lease_file && !daemon->dhcp)
  93 +           load_dhcp(now);
  94 +#endif
  95         }
  96
  97        if (FD_ISSET(piperead, &rset))
  98 diff --git a/src/dnsmasq.h b/src/dnsmasq.h
  99 index 3032546..a40b2a9 100644
 100 --- a/src/dnsmasq.h
 101 +++ b/src/dnsmasq.h
 102 @@ -1447,3 +1447,8 @@ void slaac_add_addrs(struct dhcp_lease *lease, time_t now, int force);
 103  time_t periodic_slaac(time_t now, struct dhcp_lease *leases);
 104  void slaac_ping_reply(struct in6_addr *sender, unsigned char *packet, char *interface, struct dhcp_lease *leases);
 105  #endif
 106 +
 107 +/* isc.c */
 108 +#ifdef HAVE_ISC_READER
 109 +void load_dhcp(time_t now);
 110 +#endif
 111 diff --git a/src/isc.c b/src/isc.c
 112 new file mode 100644
 113 index 0000000..565e4e2
 114 --- /dev/null
 115 +++ b/src/isc.c
 116 @@ -0,0 +1,234 @@
 117 +/* dnsmasq is Copyright (c) 2014 John Volpe, Simon Kelley and
 118 +     Michael Tremer
 119 +
 120 +  This program is free software; you can redistribute it and/or modify
 121 +  it under the terms of the GNU General Public License as published by
 122 +  the Free Software Foundation; version 2 dated June, 1991, or
 123 +  (at your option) version 3 dated 29 June, 2007.
 124 +
 125 +  This program is distributed in the hope that it will be useful,
 126 +  but WITHOUT ANY WARRANTY; without even the implied warranty of
 127 +  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 128 +  GNU General Public License for more details.
 129 +
 130 +  You should have received a copy of the GNU General Public License
 131 +  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 132 +
 133 +  Code in this file is based on contributions by John Volpe and
 134 +  Simon Kelley. Updated for recent versions of dnsmasq by
 135 +  Michael Tremer.
 136 +*/
 137 +
 138 +#include "dnsmasq.h"
 139 +
 140 +#ifdef HAVE_ISC_READER
 141 +#define MAXTOK 50
 142 +
 143 +struct isc_dhcp_lease {
 144 +       char* name;
 145 +       char* fqdn;
 146 +       time_t expires;
 147 +       struct in_addr addr;
 148 +       struct isc_dhcp_lease* next;
 149 +};
 150 +
 151 +static struct isc_dhcp_lease* dhcp_lease_new() {
 152 +       struct isc_dhcp_lease* lease = whine_malloc(sizeof(*lease));
 153 +
 154 +       lease->name = NULL;
 155 +       lease->fqdn = NULL;
 156 +       lease->next = NULL;
 157 +
 158 +       return lease;
 159 +}
 160 +
 161 +static void dhcp_lease_free(struct isc_dhcp_lease* lease) {
 162 +       if (!lease)
 163 +               return;
 164 +
 165 +       if (lease->name)
 166 +               free(lease->name);
 167 +       if (lease->fqdn)
 168 +               free(lease->fqdn);
 169 +       free(lease);
 170 +}
 171 +
 172 +static int next_token(char* token, int buffsize, FILE* fp) {
 173 +       int c, count = 0;
 174 +       char* cp = token;
 175 +
 176 +       while ((c = getc(fp)) != EOF) {
 177 +               if (c == '#') {
 178 +                       do {
 179 +                               c = getc(fp);
 180 +                       } while (c != '\n' && c != EOF);
 181 +               }
 182 +
 183 +               if (c == ' ' || c == '\t' || c == '\n' || c == ';') {
 184 +                       if (count)
 185 +                               break;
 186 +               } else if ((c != '"') && (count < buffsize - 1)) {
 187 +                       *cp++ = c;
 188 +                       count++;
 189 +               }
 190 +       }
 191 +
 192 +       *cp = 0;
 193 +       return count ? 1 : 0;
 194 +}
 195 +
 196 +static time_t parse_lease_time(const char* token_date, const char* token_time) {
 197 +       time_t time = (time_t)(-1);
 198 +       struct tm lease_time;
 199 +
 200 +       static const int months[11] = {31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334};
 201 +
 202 +       if (sscanf(token_date, "%d/%d/%d", &lease_time.tm_year, &lease_time.tm_mon, &lease_time.tm_mday) == 3) {
 203 +               if (sscanf(token_time, "%d:%d:%d", &lease_time.tm_hour, &lease_time.tm_min, &lease_time.tm_sec) == 3) {
 204 +                       /* There doesn't seem to be a universally available library function
 205 +                          which converts broken-down _GMT_ time to seconds-in-epoch.
 206 +                          The following was borrowed from ISC dhcpd sources, where
 207 +                          it is noted that it might not be entirely accurate for odd seconds.
 208 +                          Since we're trying to get the same answer as dhcpd, that's just
 209 +                          fine here. */
 210 +                       time = ((((((365 * (lease_time.tm_year - 1970) +
 211 +                               (lease_time.tm_year - 1969) / 4 +
 212 +                               (lease_time.tm_mon > 1 ? months[lease_time.tm_mon - 2] : 0) +
 213 +                               (lease_time.tm_mon > 2 && !((lease_time.tm_year - 1972) & 3 )) +
 214 +                               (lease_time.tm_mday - 1)) * 24) +
 215 +                                lease_time.tm_hour) * 60) +
 216 +                                lease_time.tm_mon) * 60) +
 217 +                                lease_time.tm_sec;
 218 +               }
 219 +       }
 220 +
 221 +       return time;
 222 +}
 223 +
 224 +static off_t lease_file_size = (off_t)0;
 225 +static ino_t lease_file_inode = (ino_t)0;
 226 +
 227 +void load_dhcp(time_t now) {
 228 +       struct isc_dhcp_lease* leases = NULL;
 229 +
 230 +       struct stat statbuf;
 231 +       if (stat(daemon->lease_file, &statbuf) == -1) {
 232 +               return;
 233 +       }
 234 +
 235 +       /* Do nothing if the lease file has not changed. */
 236 +       if ((statbuf.st_size <= lease_file_size) && (statbuf.st_ino == lease_file_inode))
 237 +               return;
 238 +
 239 +       lease_file_size = statbuf.st_size;
 240 +       lease_file_inode = statbuf.st_ino;
 241 +
 242 +       FILE* fp = fopen(daemon->lease_file, "r");
 243 +       if (!fp) {
 244 +               my_syslog(LOG_ERR, _("failed to load %s:%s"), daemon->lease_file, strerror(errno));
 245 +               return;
 246 +       }
 247 +
 248 +       my_syslog(LOG_INFO, _("reading %s"), daemon->lease_file);
 249 +
 250 +       char* hostname = daemon->namebuff;
 251 +       struct in_addr host_address;
 252 +       time_t time_starts = -1;
 253 +       time_t time_ends = -1;
 254 +       int nomem;
 255 +
 256 +       char token[MAXTOK];
 257 +       while ((next_token(token, MAXTOK, fp))) {
 258 +               if (strcmp(token, "lease") == 0) {
 259 +                       hostname[0] = '\0';
 260 +
 261 +                       if (next_token(token, MAXTOK, fp) && ((host_address.s_addr = inet_addr(token)) != (in_addr_t)-1)) {
 262 +                               if (next_token(token, MAXTOK, fp) && *token == '{') {
 263 +                                       while (next_token(token, MAXTOK, fp) && *token != '}') {
 264 +                                               if ((strcmp(token, "client-hostname") == 0) || (strcmp(token, "hostname") == 0)) {
 265 +                                                       if (next_token(hostname, MAXDNAME, fp)) {
 266 +                                                               if (!canonicalise(hostname, &nomem)) {
 267 +                                                                       *hostname = 0;
 268 +                                                                       my_syslog(LOG_ERR, _("bad name in %s"), daemon->lease_file);
 269 +                                                               }
 270 +                                                       }
 271 +                                               } else if ((strcmp(token, "starts") == 0) || (strcmp(token, "ends") == 0)) {
 272 +                                                       char token_date[MAXTOK];
 273 +                                                       char token_time[MAXTOK];
 274 +
 275 +                                                       int is_starts = strcmp(token, "starts") == 0;
 276 +
 277 +                                                       // Throw away the weekday and parse the date.
 278 +                                                       if (next_token(token, MAXTOK, fp) && next_token(token_date, MAXTOK, fp) && next_token(token_time, MAXTOK, fp)) {
 279 +                                                               time_t time = parse_lease_time(token_date, token_time);
 280 +
 281 +                                                               if (is_starts)
 282 +                                                                       time_starts = time;
 283 +                                                               else
 284 +                                                                       time_ends = time;
 285 +                                                       }
 286 +                                               }
 287 +                                       }
 288 +
 289 +                                       if (!*hostname)
 290 +                                               continue;
 291 +
 292 +                                       if ((time_starts == -1) || (time_ends == -1))
 293 +                                               continue;
 294 +
 295 +                                       if (difftime(now, time_ends) > 0)
 296 +                                               continue;
 297 +
 298 +                                       char* dot = strchr(hostname, '.');
 299 +                                       if (dot) {
 300 +                                               if (!daemon->domain_suffix || hostname_isequal(dot + 1, daemon->domain_suffix)) {
 301 +                                                       my_syslog(LOG_WARNING,
 302 +                                                               _("Ignoring DHCP lease for %s because it has an illegal domain part"),
 303 +                                                               hostname);
 304 +                                                       continue;
 305 +                                               }
 306 +                                               *dot = 0;
 307 +                                       }
 308 +
 309 +                                       struct isc_dhcp_lease* lease = dhcp_lease_new();
 310 +                                       lease->name = strdup(hostname);
 311 +                                       lease->addr = host_address;
 312 +                                       lease->expires = time_ends;
 313 +                                       lease->next = NULL;
 314 +
 315 +                                       if (daemon->domain_suffix) {
 316 +                                               asprintf(&lease->fqdn, "%s.%s", hostname, daemon->domain_suffix);
 317 +                                       }
 318 +
 319 +                                       if (!leases)
 320 +                                               leases = lease;
 321 +                                       else
 322 +                                               leases->next = lease;
 323 +                               }
 324 +                       }
 325 +               }
 326 +       }
 327 +
 328 +       fclose(fp);
 329 +
 330 +       // Drop all entries.
 331 +       cache_unhash_dhcp();
 332 +
 333 +       while (leases) {
 334 +               struct isc_dhcp_lease *lease = leases;
 335 +               leases = lease->next;
 336 +
 337 +               if (lease->fqdn) {
 338 +                       cache_add_dhcp_entry(lease->fqdn, AF_INET, (struct all_addr*)&lease->addr.s_addr, lease->expires);
 339 +               }
 340 +
 341 +               if (lease->name) {
 342 +                       cache_add_dhcp_entry(lease->name, AF_INET, (struct all_addr*)&lease->addr.s_addr, lease->expires);
 343 +               }
 344 +
 345 +               // Cleanup
 346 +               dhcp_lease_free(lease);
 347 +       }
 348 +}
 349 +
 350 +#endif
 351 diff --git a/src/option.c b/src/option.c
 352 index daa728f..d16c982 100644
 353 --- a/src/option.c
 354 +++ b/src/option.c
 355 @@ -1642,7 +1642,7 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 356         ret_err(_("bad MX target"));
 357        break;
 358
 359 -#ifdef HAVE_DHCP
 360 +#if (defined HAVE_DHCP) || (defined HAVE_ISC_READER)
 361      case 'l':  /* --dhcp-leasefile */
 362        daemon->lease_file = opt_string_alloc(arg);
 363        break;
 364 --
 365 1.9.0
 366