src/patches/dhcp/dhcp-UseMulticast.patch

   1 diff -up dhcp-4.3.1b1/server/dhcpv6.c.UseMulticast dhcp-4.3.1b1/server/dhcpv6.c
   2 --- dhcp-4.3.1b1/server/dhcpv6.c.UseMulticast   2014-07-02 19:58:40.000000000 +0200
   3 +++ dhcp-4.3.1b1/server/dhcpv6.c        2014-07-10 18:20:03.066256219 +0200
   4 @@ -376,6 +376,48 @@ generate_new_server_duid(void) {
   5  }
   6
   7  /*
   8 + * Is the D6O_UNICAST option defined in dhcpd.conf ?
   9 + */
  10 +static isc_boolean_t unicast_option_defined;
  11 +
  12 +/*
  13 + * Did we already search dhcpd.conf for D6O_UNICAST option ?
  14 + * We need to store it here to not parse dhcpd.conf repeatedly.
  15 + */
  16 +static isc_boolean_t unicast_option_parsed = ISC_FALSE;
  17 +
  18 +
  19 +/*
  20 + * Is the D6O_UNICAST option defined in dhcpd.conf ?
  21 + */
  22 +isc_boolean_t
  23 +is_unicast_option_defined(void) {
  24 +       struct option_state *opt_state;
  25 +       struct option_cache *oc;
  26 +
  27 +       /*
  28 +        * If we are looking for the unicast option for the first time
  29 +        */
  30 +       if (unicast_option_parsed == ISC_FALSE) {
  31 +               unicast_option_parsed = ISC_TRUE;
  32 +               opt_state = NULL;
  33 +               if (!option_state_allocate(&opt_state, MDL)) {
  34 +                       log_fatal("No memory for option state.");
  35 +               }
  36 +
  37 +               execute_statements_in_scope(NULL, NULL, NULL, NULL, NULL,
  38 +                            opt_state, &global_scope, root_group, NULL, NULL);
  39 +
  40 +               oc = lookup_option(&dhcpv6_universe, opt_state, D6O_UNICAST);
  41 +               unicast_option_defined = (oc != NULL);
  42 +
  43 +               option_state_dereference(&opt_state, MDL);
  44 +       }
  45 +
  46 +       return (unicast_option_defined);
  47 +}
  48 +
  49 +/*
  50   * Get the client identifier from the packet.
  51   */
  52  isc_result_t
  53 @@ -706,6 +748,12 @@ static const int required_opts[] = {
  54         D6O_PREFERENCE,
  55         0
  56  };
  57 +static const int required_opts_NAA[] = {
  58 +       D6O_CLIENTID,
  59 +       D6O_SERVERID,
  60 +       D6O_STATUS_CODE,
  61 +       0
  62 +};
  63  static const int required_opts_solicit[] = {
  64         D6O_CLIENTID,
  65         D6O_SERVERID,
  66 @@ -1587,6 +1635,56 @@ lease_to_client(struct data_string *repl
  67                                                     reply.shared->group, NULL);
  68         }
  69
  70 +       /* reject unicast message, unless we set unicast option */
  71 +       if ((packet->unicast == ISC_TRUE) && !is_unicast_option_defined())
  72 +       /*
  73 +        * RFC3315 section 18.2.1 (Request):
  74 +        *
  75 +        * When the server receives a Request message via unicast from a client
  76 +        * to which the server has not sent a unicast option, the server
  77 +        * discards the Request message and responds with a Reply message
  78 +        * containing a Status Code option with the value UseMulticast, a Server
  79 +        * Identifier option containing the server's DUID, the Client Identifier
  80 +        * option from the client message, and no other options.
  81 +        *
  82 +        * Section 18.2.3 (Renew):
  83 +        *
  84 +        * When the server receives a Renew message via unicast from a client to
  85 +        * which the server has not sent a unicast option, the server discards
  86 +        * the Renew message and responds with a Reply message containing a
  87 +        * Status Code option with the value UseMulticast, a Server Identifier
  88 +        * option containing the server's DUID, the Client Identifier option
  89 +        * from the client message, and no other options.
  90 +        */
  91 +       {
  92 +               /* Set the UseMulticast status code. */
  93 +               if (!set_status_code(STATUS_UseMulticast,
  94 +                                       "Unicast not allowed by server.",
  95 +                                       reply.opt_state)) {
  96 +                       log_error("lease_to_client: Unable to set "
  97 +                                       "UseMulticast status code.");
  98 +                       goto exit;
  99 +               }
 100 +
 101 +               /* Rewind the cursor to the start. */
 102 +               reply.cursor = REPLY_OPTIONS_INDEX;
 103 +
 104 +               /*
 105 +                * Produce an reply that includes only:
 106 +                *
 107 +                * Status code.
 108 +                * Server DUID.
 109 +                * Client DUID.
 110 +                */
 111 +               reply.cursor += store_options6((char *)reply.buf.data +
 112 +                                       reply.cursor,
 113 +                                       sizeof(reply.buf) -
 114 +                                       reply.cursor,
 115 +                                       reply.opt_state, reply.packet,
 116 +                                       required_opts_NAA,
 117 +                                       NULL);
 118 +       }
 119 +
 120         /*
 121          * RFC3315 section 17.2.2 (Solicit):
 122          *
 123 @@ -1619,6 +1717,7 @@ lease_to_client(struct data_string *repl
 124          * Having stored the client's IA's, store any options that
 125          * will fit in the remaining space.
 126          */
 127 +       else
 128         reply.cursor += store_options6((char *)reply.buf.data + reply.cursor,
 129                                        sizeof(reply.buf) - reply.cursor,
 130                                        reply.opt_state, reply.packet,
 131 @@ -4748,7 +4847,6 @@ dhcpv6_solicit(struct data_string *reply
 132   * Very similar to Solicit handling, except the server DUID is required.
 133   */
 134
 135 -/* TODO: reject unicast messages, unless we set unicast option */
 136  static void
 137  dhcpv6_request(struct data_string *reply_ret, struct packet *packet) {
 138         struct data_string client_id;
 139 @@ -5078,7 +5176,6 @@ exit:
 140   * except for the error code of when addresses don't match.
 141   */
 142
 143 -/* TODO: reject unicast messages, unless we set unicast option */
 144  static void
 145  dhcpv6_renew(struct data_string *reply, struct packet *packet) {
 146         struct data_string client_id;
 147 @@ -5322,18 +5419,60 @@ iterate_over_ia_na(struct data_string *r
 148                 goto exit;
 149         }
 150
 151 -       snprintf(status_msg, sizeof(status_msg), "%s received.", packet_type);
 152 -       if (!set_status_code(STATUS_Success, status_msg, opt_state)) {
 153 -               goto exit;
 154 -       }
 155 +       /* reject unicast message, unless we set unicast option */
 156 +       if ((packet->unicast == ISC_TRUE) && !is_unicast_option_defined()) {
 157 +               /*
 158 +                * RFC3315 section 18.2.6 (Release):
 159 +                *
 160 +                * When the server receives a Release message via unicast from a client
 161 +                * to which the server has not sent a unicast option, the server
 162 +                * discards the Release message and responds with a Reply message
 163 +                * containing a Status Code option with value UseMulticast, a Server
 164 +                * Identifier option containing the server's DUID, the Client Identifier
 165 +                * option from the client message, and no other options.
 166 +                *
 167 +                * Section 18.2.7 (Decline):
 168 +                *
 169 +                * When the server receives a Decline message via unicast from a client
 170 +                * to which the server has not sent a unicast option, the server
 171 +                * discards the Decline message and responds with a Reply message
 172 +                * containing a Status Code option with the value UseMulticast, a Server
 173 +                * Identifier option containing the server's DUID, the Client Identifier
 174 +                * option from the client message, and no other options.
 175 +                */
 176 +               snprintf(status_msg, sizeof(status_msg),
 177 +                                "%s received unicast.", packet_type);
 178 +               if (!set_status_code(STATUS_UseMulticast, status_msg, opt_state)) {
 179 +                       goto exit;
 180 +               }
 181
 182 -       /*
 183 -        * Add our options that are not associated with any IA_NA or IA_TA.
 184 -        */
 185 -       reply_ofs += store_options6(reply_data+reply_ofs,
 186 -                                   sizeof(reply_data)-reply_ofs,
 187 +               /*
 188 +                * Produce an reply that includes only:
 189 +                *
 190 +                * Status code.
 191 +                * Server DUID.
 192 +                * Client DUID.
 193 +                */
 194 +               reply_ofs += store_options6(reply_data+reply_ofs,
 195 +                                   sizeof(reply_data)-reply_ofs,
 196                                     opt_state, packet,
 197 -                                   required_opts, NULL);
 198 +                                   required_opts_NAA, NULL);
 199 +
 200 +               goto return_reply;
 201 +       } else {
 202 +               snprintf(status_msg, sizeof(status_msg), "%s received.", packet_type);
 203 +               if (!set_status_code(STATUS_Success, status_msg, opt_state)) {
 204 +                       goto exit;
 205 +               }
 206 +
 207 +               /*
 208 +                * Add our options that are not associated with any IA_NA or IA_TA.
 209 +                */
 210 +               reply_ofs += store_options6(reply_data+reply_ofs,
 211 +                                           sizeof(reply_data)-reply_ofs,
 212 +                                           opt_state, packet,
 213 +                                           required_opts, NULL);
 214 +       }
 215
 216         /*
 217          * Loop through the IA_NA reported by the client, and deal with
 218 @@ -5471,6 +5610,7 @@ iterate_over_ia_na(struct data_string *r
 219         /*
 220          * Return our reply to the caller.
 221          */
 222 +return_reply:
 223         reply_ret->len = reply_ofs;
 224         reply_ret->buffer = NULL;
 225         if (!buffer_allocate(&reply_ret->buffer, reply_ofs, MDL)) {
 226 @@ -5516,7 +5656,6 @@ exit:
 227   * we still need to be aware of this possibility.
 228   */
 229
 230 -/* TODO: reject unicast messages, unless we set unicast option */
 231  /* TODO: IA_TA */
 232  static void
 233  dhcpv6_decline(struct data_string *reply, struct packet *packet) {
 234 @@ -5986,7 +6125,6 @@ exit:
 235   * Release means a client is done with the leases.
 236   */
 237
 238 -/* TODO: reject unicast messages, unless we set unicast option */
 239  static void
 240  dhcpv6_release(struct data_string *reply, struct packet *packet) {
 241         struct data_string client_id;