src/patches/dnsmasq/004-Add_contrib_lease-tools_dhcp_release6.patch

   1 From 69cbf78bb676e493f0a4cd6dc7ffec0fcafafed5 Mon Sep 17 00:00:00 2001
   2 From: Simon Kelley <simon@thekelleys.org.uk>
   3 Date: Tue, 3 May 2016 21:33:38 +0100
   4 Subject: [PATCH] Add contrib/lease-tools/dhcp_release6
   5
   6 ---
   7  CHANGELOG                           |   6 +
   8  contrib/lease-tools/Makefile        |   4 +-
   9  contrib/lease-tools/dhcp_release6.1 |  38 ++++
  10  contrib/lease-tools/dhcp_release6.c | 416 ++++++++++++++++++++++++++++++++++++
  11  debian/rules                        |   3 +
  12  5 files changed, 465 insertions(+), 2 deletions(-)
  13  create mode 100644 contrib/lease-tools/dhcp_release6.1
  14  create mode 100644 contrib/lease-tools/dhcp_release6.c
  15
  16 diff --git a/CHANGELOG b/CHANGELOG
  17 index aa53fba..7d4a061 100644
  18 --- a/CHANGELOG
  19 +++ b/CHANGELOG
  20 @@ -65,6 +65,12 @@ version 2.76
  21             --servers-file to define upstream DNS servers. Thanks to
  22             Scott Bonar for the bug report.
  23
  24 +           Move the dhcp_release and dhcp_lease_time tools from
  25 +           contrib/wrt to contrib/lease-tools.
  26 +
  27 +           Add dhcp_release6 to contrib/lease-tools. Many thanks
  28 +           to Sergey Nechaev for this code.
  29 +
  30
  31  version 2.75
  32              Fix reversion on 2.74 which caused 100% CPU use when a
  33 diff --git a/contrib/lease-tools/Makefile b/contrib/lease-tools/Makefile
  34 index 68e8d32..f38f2ed 100644
  35 --- a/contrib/lease-tools/Makefile
  36 +++ b/contrib/lease-tools/Makefile
  37 @@ -1,6 +1,6 @@
  38  CFLAGS?= -O2 -Wall -W
  39
  40 -all: dhcp_release dhcp_lease_time
  41 +all: dhcp_release dhcp_release6 dhcp_lease_time
  42
  43  clean:
  44 -       rm -f *~ *.o core dhcp_release dhcp_lease_time
  45 +       rm -f *~ *.o core dhcp_release dhcp_release6 dhcp_lease_time
  46 diff --git a/contrib/lease-tools/dhcp_release6.1 b/contrib/lease-tools/dhcp_release6.1
  47 new file mode 100644
  48 index 0000000..763e01c
  49 --- /dev/null
  50 +++ b/contrib/lease-tools/dhcp_release6.1
  51 @@ -0,0 +1,38 @@
  52 +.TH DHCP_RELEASE 1
  53 +.SH NAME
  54 +dhcp_release6 \- Release a DHCPv6 lease on a the local dnsmasq DHCP server.
  55 +.SH SYNOPSIS
  56 +.B dhcp_release6 --iface <interface> --client-id <client-id> --server-id
  57 +server-id --iaid <iaid>  --ip <IP>  [--dry-run] [--help]
  58 +.SH "DESCRIPTION"
  59 +A utility which forces the DHCP server running on this machine to release a
  60 +DHCPv6 lease.
  61 +.SS OPTIONS
  62 +.IP "-a, --ip"
  63 +IPv6 address to release.
  64 +.IP "-c, --client-id"
  65 +Colon-separated hex string representing DHCPv6 client id. Normally
  66 +it can be found in leases file both on client and server.
  67 +.IP "-d, --dry-run"
  68 +Print hexadecimal representation of generated DHCPv6 release packet to standard
  69 +output and exit.
  70 +.IP "-h, --help"
  71 +print usage information to standard output and exit.
  72 +.IP "-i, --iaid"
  73 +Decimal representation of DHCPv6 IAID. Normally it can be found in leases file
  74 +both on client and server.
  75 +.IP "-n, --iface"
  76 +Network interface to send a DHCPv6 release packet from.
  77 +.IP "-s, --server-id"
  78 +Colon-separated hex string representing DHCPv6 server id. Normally
  79 +it can be found in leases file both on client and server.
  80 +.SH NOTES
  81 +MUST be run as root - will fail otherwise.
  82 +.SH LIMITATIONS
  83 +Only usable on IPv6 DHCP leases.
  84 +.SH SEE ALSO
  85 +.BR dnsmasq (8)
  86 +.SH AUTHOR
  87 +This manual page was written by Simon Kelley <simon@thekelleys.org.uk>.
  88 +
  89 +
  90 diff --git a/contrib/lease-tools/dhcp_release6.c b/contrib/lease-tools/dhcp_release6.c
  91 new file mode 100644
  92 index 0000000..74fb26a
  93 --- /dev/null
  94 +++ b/contrib/lease-tools/dhcp_release6.c
  95 @@ -0,0 +1,416 @@
  96 +/*
  97 + dhcp_release6 --iface <interface> --client-id <client-id> --server-id
  98 + server-id --iaid <iaid>  --ip <IP>  [--dry-run] [--help]
  99 + MUST be run as root - will fail othewise
 100 + */
 101 +
 102 +/* Send a DHCPRELEASE message  to IPv6 multicast address  via the specified interface
 103 + to tell the local DHCP server to delete a particular lease.
 104 +
 105 + The interface argument is the interface in which a DHCP
 106 + request _would_ be received if it was coming from the client,
 107 + rather than being faked up here.
 108 +
 109 + The client-id argument is colon-separated hex string and mandatory. Normally
 110 + it can be found in leases file both on client and server
 111 +
 112 + The server-id argument is colon-separated hex string and mandatory. Normally
 113 + it can be found in leases file both on client and server.
 114 +
 115 + The iaid argument is numeric string and mandatory. Normally
 116 + it can be found in leases file both on client and server.
 117 +
 118 + IP is an IPv6 adress to release
 119 +
 120 + If --dry-run is specified, dhcp_release6 just prints hexadecimal represantation of
 121 + packet to send to stdout and exits.
 122 +
 123 + If --help is specified, dhcp_release6 print usage information to stdout and exits
 124 +
 125 +
 126 +
 127 + */
 128 +#include <stdio.h>
 129 +#include <stdlib.h>
 130 +#include <string.h>
 131 +#include <strings.h>
 132 +#include <sys/types.h>
 133 +#include <sys/socket.h>
 134 +#include <arpa/inet.h>
 135 +#include <getopt.h>
 136 +#include <errno.h>
 137 +#include <unistd.h>
 138 +
 139 +#define NOT_REPLY_CODE 115
 140 +typedef unsigned char u8;
 141 +typedef unsigned short u16;
 142 +typedef unsigned int u32;
 143 +
 144 +enum DHCP6_TYPES{
 145 +    SOLICIT = 1,
 146 +    ADVERTISE = 2,
 147 +    REQUEST = 3,
 148 +    CONFIRM = 4,
 149 +    RENEW = 5,
 150 +    REBIND = 6,
 151 +    REPLY = 7,
 152 +    RELEASE = 8,
 153 +    DECLINE = 9,
 154 +    RECONFIGURE = 10,
 155 +    INFORMATION_REQUEST = 11,
 156 +    RELAY_FORW = 12,
 157 +    RELAY_REPL = 13
 158 +
 159 +};
 160 +enum DHCP6_OPTIONS{
 161 +    CLIENTID = 1,
 162 +    SERVERID = 2,
 163 +    IA_NA = 3,
 164 +    IA_TA = 4,
 165 +    IAADDR = 5,
 166 +    ORO = 6,
 167 +    PREFERENCE = 7,
 168 +    ELAPSED_TIME = 8,
 169 +    RELAY_MSG = 9,
 170 +    AUTH = 11,
 171 +    UNICAST = 12,
 172 +    STATUS_CODE = 13,
 173 +    RAPID_COMMIT = 14,
 174 +    USER_CLASS = 15,
 175 +    VENDOR_CLASS = 16,
 176 +    VENDOR_OPTS = 17,
 177 +    INTERFACE_ID = 18,
 178 +    RECONF_MSG = 19,
 179 +    RECONF_ACCEPT = 20,
 180 +};
 181 +
 182 +enum DHCP6_STATUSES{
 183 +    SUCCESS = 0,
 184 +    UNSPEC_FAIL = 1,
 185 +    NOADDR_AVAIL=2,
 186 +    NO_BINDING  = 3,
 187 +    NOT_ON_LINK = 4,
 188 +    USE_MULTICAST =5
 189 +};
 190 +static struct option longopts[] = {
 191 +    {"ip", required_argument, 0, 'a'},
 192 +    {"server-id", required_argument, 0, 's'},
 193 +    {"client-id", required_argument, 0, 'c'},
 194 +    {"iface", required_argument, 0, 'n'},
 195 +    {"iaid", required_argument, 0, 'i'},
 196 +    {"dry-run", no_argument, 0, 'd'},
 197 +    {"help", no_argument, 0, 'h'},
 198 +    {0,     0,           0,   0}
 199 +};
 200 +
 201 +const short DHCP6_CLIENT_PORT = 546;
 202 +const short DHCP6_SERVER_PORT = 547;
 203 +
 204 +const char*  DHCP6_MULTICAST_ADDRESS = "ff02::1:2";
 205 +
 206 +struct dhcp6_option{
 207 +    uint16_t type;
 208 +    uint16_t len;
 209 +    char  value[1024];
 210 +};
 211 +
 212 +struct dhcp6_iaaddr_option{
 213 +    uint16_t type;
 214 +    uint16_t len;
 215 +    struct in6_addr ip;
 216 +    uint32_t preferred_lifetime;
 217 +    uint32_t valid_lifetime;
 218 +
 219 +
 220 +};
 221 +
 222 +struct dhcp6_iana_option{
 223 +    uint16_t type;
 224 +    uint16_t len;
 225 +    uint32_t iaid;
 226 +    uint32_t t1;
 227 +    uint32_t t2;
 228 +    char options[1024];
 229 +};
 230 +
 231 +
 232 +struct dhcp6_packet{
 233 +    size_t len;
 234 +    char buf[2048];
 235 +
 236 +} ;
 237 +
 238 +size_t pack_duid(const char* str, char* dst){
 239 +
 240 +    char* tmp = strdup(str);
 241 +    char* tmp_to_free = tmp;
 242 +    char *ptr;
 243 +    uint8_t write_pos = 0;
 244 +    while ((ptr = strtok (tmp, ":"))) {
 245 +        dst[write_pos] = (uint8_t) strtol(ptr, NULL, 16);
 246 +        write_pos += 1;
 247 +        tmp = NULL;
 248 +
 249 +    }
 250 +    free(tmp_to_free);
 251 +    return write_pos;
 252 +}
 253 +
 254 +struct dhcp6_option create_client_id_option(const char* duid){
 255 +    struct dhcp6_option option;
 256 +    option.type = htons(CLIENTID);
 257 +    bzero(option.value, sizeof(option.value));
 258 +    option.len  = htons(pack_duid(duid, option.value));
 259 +    return option;
 260 +}
 261 +
 262 +struct dhcp6_option create_server_id_option(const char* duid){
 263 +    struct dhcp6_option   option;
 264 +    option.type = htons(SERVERID);
 265 +    bzero(option.value, sizeof(option.value));
 266 +    option.len  = htons(pack_duid(duid, option.value));
 267 +    return option;
 268 +}
 269 +
 270 +struct dhcp6_iaaddr_option create_iaadr_option(const char* ip){
 271 +    struct dhcp6_iaaddr_option result;
 272 +    result.type =htons(IAADDR);
 273 +    /* no suboptions needed here, so length is 24  */
 274 +    result.len = htons(24);
 275 +    result.preferred_lifetime = 0;
 276 +    result.valid_lifetime = 0;
 277 +    int s = inet_pton(AF_INET6, ip, &(result.ip));
 278 +    if (s <= 0) {
 279 +        if (s == 0)
 280 +            fprintf(stderr, "Not in presentation format");
 281 +        else
 282 +            perror("inet_pton");
 283 +        exit(EXIT_FAILURE);
 284 +    }
 285 +    return result;
 286 +}
 287 +struct dhcp6_iana_option  create_iana_option(const char * iaid, struct dhcp6_iaaddr_option  ia_addr){
 288 +    struct dhcp6_iana_option  result;
 289 +    result.type = htons(IA_NA);
 290 +    result.iaid = htonl(atoi(iaid));
 291 +    result.t1 = 0;
 292 +    result.t2 = 0;
 293 +    result.len = htons(12 + ntohs(ia_addr.len) + 2 * sizeof(uint16_t));
 294 +    memcpy(result.options, &ia_addr, ntohs(ia_addr.len) + 2 * sizeof(uint16_t));
 295 +    return result;
 296 +}
 297 +
 298 +struct dhcp6_packet create_release_packet(const char* iaid, const char* ip, const char* client_id, const char* server_id){
 299 +    struct dhcp6_packet result;
 300 +    bzero(result.buf, sizeof(result.buf));
 301 +    /* message_type */
 302 +    result.buf[0] = RELEASE;
 303 +    /* tx_id */
 304 +    bzero(result.buf+1, 3);
 305 +
 306 +    struct dhcp6_option client_option = create_client_id_option(client_id);
 307 +    struct dhcp6_option server_option = create_server_id_option(server_id);
 308 +    struct dhcp6_iaaddr_option iaaddr_option = create_iaadr_option(ip);
 309 +    struct dhcp6_iana_option iana_option = create_iana_option(iaid, iaaddr_option);
 310 +    int offset = 4;
 311 +    memcpy(result.buf + offset, &client_option, ntohs(client_option.len) + 2*sizeof(uint16_t));
 312 +    offset += (ntohs(client_option.len)+ 2 *sizeof(uint16_t) );
 313 +    memcpy(result.buf + offset, &server_option, ntohs(server_option.len) + 2*sizeof(uint16_t) );
 314 +    offset += (ntohs(server_option.len)+ 2* sizeof(uint16_t));
 315 +    memcpy(result.buf + offset, &iana_option, ntohs(iana_option.len) + 2*sizeof(uint16_t) );
 316 +    offset += (ntohs(iana_option.len)+ 2* sizeof(uint16_t));
 317 +    result.len = offset;
 318 +    return result;
 319 +}
 320 +
 321 +uint16_t parse_iana_suboption(char* buf, size_t len){
 322 +    size_t current_pos = 0;
 323 +    char option_value[1024];
 324 +    while (current_pos < len) {
 325 +        uint16_t option_type, option_len;
 326 +        memcpy(&option_type,buf + current_pos, sizeof(uint16_t));
 327 +        memcpy(&option_len,buf + current_pos + sizeof(uint16_t), sizeof(uint16_t));
 328 +        option_type = ntohs(option_type);
 329 +        option_len = ntohs(option_len);
 330 +        current_pos += 2 * sizeof(uint16_t);
 331 +        if (option_type == STATUS_CODE){
 332 +            uint16_t status;
 333 +            memcpy(&status, buf + current_pos, sizeof(uint16_t));
 334 +            status = ntohs(status);
 335 +            if (status != SUCCESS){
 336 +                memcpy(option_value, buf + current_pos + sizeof(uint16_t) , option_len - sizeof(uint16_t));
 337 +                option_value[option_len-sizeof(uint16_t)] ='\0';
 338 +                fprintf(stderr, "Error: %s\n", option_value);
 339 +            }
 340 +            return status;
 341 +        }
 342 +    }
 343 +    return -2;
 344 +}
 345 +
 346 +int16_t parse_packet(char* buf, size_t len){
 347 +    uint8_t type  = buf[0];
 348 +    /*skipping tx id. you need it, uncomment following line
 349 +        uint16_t tx_id = ntohs((buf[1] <<16) + (buf[2] <<8) + buf[3]);
 350 +     */
 351 +    size_t current_pos = 4;
 352 +    if (type != REPLY ){
 353 +        return NOT_REPLY_CODE;
 354 +    }
 355 +    char option_value[1024];
 356 +    while (current_pos < len) {
 357 +        uint16_t option_type, option_len;
 358 +        memcpy(&option_type,buf + current_pos, sizeof(uint16_t));
 359 +        memcpy(&option_len,buf + current_pos + sizeof(uint16_t), sizeof(uint16_t));
 360 +        option_type = ntohs(option_type);
 361 +        option_len = ntohs(option_len);
 362 +        current_pos += 2 * sizeof(uint16_t);
 363 +        if (option_type == STATUS_CODE){
 364 +            uint16_t status;
 365 +            memcpy(&status, buf + current_pos, sizeof(uint16_t));
 366 +            status = ntohs(status);
 367 +            if (status != SUCCESS){
 368 +                memcpy(option_value, buf + current_pos +sizeof(uint16_t) , option_len -sizeof(uint16_t));
 369 +                fprintf(stderr, "Error: %d %s\n", status, option_value);
 370 +                return status;
 371 +            }
 372 +
 373 +        }
 374 +        if (option_type == IA_NA ){
 375 +            uint16_t result = parse_iana_suboption(buf + current_pos +24, option_len -24);
 376 +            if (result){
 377 +                return result;
 378 +            }
 379 +        }
 380 +        current_pos += option_len;
 381 +
 382 +    }
 383 +    return -1;
 384 +}
 385 +
 386 +void usage(const char* arg, FILE* stream){
 387 +    const char* usage_string ="--ip IPv6 --iface IFACE --server-id SERVER_ID --client-id CLIENT_ID --iaid IAID [--dry-run] | --help";
 388 +    fprintf (stream, "Usage: %s %s\n", arg, usage_string);
 389 +
 390 +}
 391 +
 392 +int send_release_packet(const char* iface, struct dhcp6_packet* packet){
 393 +
 394 +    struct sockaddr_in6 server_addr, client_addr;
 395 +    char response[1400];
 396 +    int sock = socket(PF_INET6, SOCK_DGRAM, 0);
 397 +    int i = 0;
 398 +    if (sock < 0) {
 399 +        perror("creating socket");
 400 +        return -1;
 401 +    }
 402 +    if (setsockopt(sock, SOL_SOCKET, 25, iface, strlen(iface)) == -1)  {
 403 +        perror("SO_BINDTODEVICE");
 404 +        close(sock);
 405 +        return -1;
 406 +    }
 407 +    memset(&server_addr, 0, sizeof(server_addr));
 408 +    server_addr.sin6_family = AF_INET6;
 409 +    client_addr.sin6_family = AF_INET6;
 410 +    client_addr.sin6_port = htons(DHCP6_CLIENT_PORT);
 411 +    client_addr.sin6_flowinfo = 0;
 412 +    client_addr.sin6_scope_id =0;
 413 +    inet_pton(AF_INET6, "::", &client_addr.sin6_addr);
 414 +    bind(sock, (struct sockaddr*)&client_addr, sizeof(struct sockaddr_in6));
 415 +    inet_pton(AF_INET6, DHCP6_MULTICAST_ADDRESS, &server_addr.sin6_addr);
 416 +    server_addr.sin6_port = htons(DHCP6_SERVER_PORT);
 417 +    int16_t recv_size = 0;
 418 +    for (i = 0; i < 5; i++) {
 419 +        if (sendto(sock, packet->buf, packet->len, 0,
 420 +               (struct sockaddr *)&server_addr,
 421 +               sizeof(server_addr)) < 0) {
 422 +            perror("sendto failed");
 423 +            exit(4);
 424 +        }
 425 +        recv_size = recvfrom(sock, response, sizeof(response), MSG_DONTWAIT, NULL, 0);
 426 +        if (recv_size == -1){
 427 +            if (errno == EAGAIN){
 428 +                sleep(1);
 429 +                continue;
 430 +            }else {
 431 +                perror("recvfrom");
 432 +            }
 433 +        }
 434 +        int16_t result = parse_packet(response, recv_size);
 435 +        if (result == NOT_REPLY_CODE){
 436 +            sleep(1);
 437 +            continue;
 438 +        }
 439 +        return result;
 440 +    }
 441 +    fprintf(stderr, "Response timed out\n");
 442 +    return -1;
 443 +
 444 +}
 445 +
 446 +
 447 +int main(int argc, char *  const argv[]) {
 448 +    const char* iface = "";
 449 +    const char* ip = "";
 450 +    const char* client_id = "";
 451 +    const char* server_id = "";
 452 +    const char* iaid = "";
 453 +    int dry_run = 0;
 454 +    while (1) {
 455 +        int option_index = 0;
 456 +        int c = getopt_long(argc, argv, "a:s:c:n:i:hd", longopts, &option_index);
 457 +        if (c == -1){
 458 +            break;
 459 +        }
 460 +        switch(c){
 461 +            case 0:
 462 +                if (longopts[option_index].flag !=0){
 463 +                    break;
 464 +                }
 465 +                printf ("option %s", longopts[option_index].name);
 466 +                if (optarg)
 467 +                    printf (" with arg %s", optarg);
 468 +                printf ("\n");
 469 +                break;
 470 +            case 'i':
 471 +                iaid = optarg;
 472 +                break;
 473 +            case 'n':
 474 +                iface = optarg;
 475 +                break;
 476 +            case 'a':
 477 +                ip = optarg;
 478 +                break;
 479 +            case 'c':
 480 +                client_id = optarg;
 481 +                break;
 482 +            case 'd':
 483 +                dry_run = 1;
 484 +                break;
 485 +            case 's':
 486 +                server_id = optarg;
 487 +                break;
 488 +            case 'h':
 489 +                usage(argv[0], stdout);
 490 +                break;
 491 +            case '?':
 492 +                usage(argv[0], stderr);
 493 +                return -1;
 494 +             default:
 495 +                abort();
 496 +
 497 +        }
 498 +
 499 +    }
 500 +    struct dhcp6_packet packet = create_release_packet(iaid, ip, client_id, server_id);
 501 +    if (dry_run){
 502 +        uint16_t i;
 503 +        for(i=0;i<packet.len;i++){
 504 +            printf("%hhx", packet.buf[i]);
 505 +        }
 506 +        printf("\n");
 507 +        return 0;
 508 +    }
 509 +    return send_release_packet(iface, &packet);
 510 +
 511 +}
 512 diff --git a/debian/rules b/debian/rules
 513 index 193b30c..d748829 100755
 514 --- a/debian/rules
 515 +++ b/debian/rules
 516 @@ -188,6 +188,9 @@ ifeq ($(DEB_HOST_ARCH_OS),linux)
 517         install -m 755 contrib/lease-tools/dhcp_release debian/utils/usr/bin/dhcp_release
 518         install -m 644 contrib/lease-tools/dhcp_release.1 debian/utils/usr/share/man/man1/dhcp_release.1
 519         gzip -9n debian/utils/usr/share/man/man1/dhcp_release.1
 520 +       install -m 755 contrib/lease-tools/dhcp_release6 debian/utils/usr/bin/dhcp_release6
 521 +       install -m 644 contrib/lease-tools/dhcp_release6.1 debian/utils/usr/share/man/man1/dhcp_release6.1
 522 +       gzip -9n debian/utils/usr/share/man/man1/dhcp_release6.1
 523         install -m 755 contrib/lease-tools/dhcp_lease_time debian/utils/usr/bin/dhcp_lease_time
 524         install -m 644 contrib/lease-tools/dhcp_lease_time.1 debian/utils/usr/share/man/man1/dhcp_lease_time.1
 525         install -m 644 debian/copyright debian/utils/usr/share/doc/dnsmasq-utils/copyright
 526 --
 527 2.5.5
 528