| File: | src/usr.sbin/dhcpd/bootp.c |
| Warning: | line 259, column 8 Access to field 'group' results in a dereference of a null pointer (loaded from variable 'hp') |
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| 1 | /* $OpenBSD: bootp.c,v 1.18 2017/02/13 22:33:39 krw Exp $ */ | |||
| 2 | ||||
| 3 | /* | |||
| 4 | * BOOTP Protocol support. | |||
| 5 | */ | |||
| 6 | ||||
| 7 | /* | |||
| 8 | * Copyright (c) 1995, 1996, 1998, 1999 The Internet Software Consortium. | |||
| 9 | * All rights reserved. | |||
| 10 | * | |||
| 11 | * Redistribution and use in source and binary forms, with or without | |||
| 12 | * modification, are permitted provided that the following conditions | |||
| 13 | * are met: | |||
| 14 | * | |||
| 15 | * 1. Redistributions of source code must retain the above copyright | |||
| 16 | * notice, this list of conditions and the following disclaimer. | |||
| 17 | * 2. Redistributions in binary form must reproduce the above copyright | |||
| 18 | * notice, this list of conditions and the following disclaimer in the | |||
| 19 | * documentation and/or other materials provided with the distribution. | |||
| 20 | * 3. Neither the name of The Internet Software Consortium nor the names | |||
| 21 | * of its contributors may be used to endorse or promote products derived | |||
| 22 | * from this software without specific prior written permission. | |||
| 23 | * | |||
| 24 | * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND | |||
| 25 | * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, | |||
| 26 | * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF | |||
| 27 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | |||
| 28 | * DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR | |||
| 29 | * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |||
| 30 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT | |||
| 31 | * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF | |||
| 32 | * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND | |||
| 33 | * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, | |||
| 34 | * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT | |||
| 35 | * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |||
| 36 | * SUCH DAMAGE. | |||
| 37 | * | |||
| 38 | * This software has been written for the Internet Software Consortium | |||
| 39 | * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie | |||
| 40 | * Enterprises. To learn more about the Internet Software Consortium, | |||
| 41 | * see ``http://www.vix.com/isc''. To learn more about Vixie | |||
| 42 | * Enterprises, see ``http://www.vix.com''. | |||
| 43 | */ | |||
| 44 | ||||
| 45 | #include <sys/socket.h> | |||
| 46 | ||||
| 47 | #include <arpa/inet.h> | |||
| 48 | ||||
| 49 | #include <net/if.h> | |||
| 50 | ||||
| 51 | #include <netinet/in.h> | |||
| 52 | ||||
| 53 | #include <errno(*__errno()).h> | |||
| 54 | #include <stdio.h> | |||
| 55 | #include <string.h> | |||
| 56 | ||||
| 57 | #include "dhcp.h" | |||
| 58 | #include "tree.h" | |||
| 59 | #include "dhcpd.h" | |||
| 60 | #include "log.h" | |||
| 61 | ||||
| 62 | void | |||
| 63 | bootp(struct packet *packet) | |||
| 64 | { | |||
| 65 | struct host_decl *hp, *host = NULL((void *)0); | |||
| 66 | struct packet outgoing; | |||
| 67 | struct dhcp_packet raw; | |||
| 68 | struct sockaddr_in to; | |||
| 69 | struct in_addr from; | |||
| 70 | struct tree_cache *options[256]; | |||
| 71 | struct shared_network *s; | |||
| 72 | struct subnet *subnet = NULL((void *)0); | |||
| 73 | struct lease *lease; | |||
| 74 | struct iaddr ip_address; | |||
| 75 | int i; | |||
| 76 | ||||
| 77 | if (packet->raw->op != BOOTREQUEST1) | |||
| ||||
| 78 | return; | |||
| 79 | ||||
| 80 | log_info("BOOTREQUEST from %s via %s%s", | |||
| 81 | print_hw_addr(packet->raw->htype, packet->raw->hlen, | |||
| 82 | packet->raw->chaddr), packet->raw->giaddr.s_addr ? | |||
| 83 | inet_ntoa(packet->raw->giaddr) : packet->interface->name, | |||
| 84 | packet->options_valid ? "" : " (non-rfc1048)"); | |||
| 85 | ||||
| 86 | if (!locate_network(packet)) | |||
| 87 | return; | |||
| 88 | ||||
| 89 | hp = find_hosts_by_haddr(packet->raw->htype, packet->raw->chaddr, | |||
| 90 | packet->raw->hlen); | |||
| 91 | ||||
| 92 | s = packet->shared_network; | |||
| 93 | lease = find_lease(packet, s, 0); | |||
| 94 | ||||
| 95 | /* | |||
| 96 | * Find an IP address in the host_decl that matches the specified | |||
| 97 | * network. | |||
| 98 | */ | |||
| 99 | if (hp) | |||
| 100 | subnet = find_host_for_network(&hp, &ip_address, s); | |||
| 101 | ||||
| 102 | if (!subnet) { | |||
| 103 | /* | |||
| 104 | * We didn't find an applicable host declaration. Just in case | |||
| 105 | * we may be able to dynamically assign an address, see if | |||
| 106 | * there's a host declaration that doesn't have an ip address | |||
| 107 | * associated with it. | |||
| 108 | */ | |||
| 109 | if (hp) | |||
| 110 | for (; hp; hp = hp->n_ipaddr) | |||
| 111 | if (!hp->fixed_addr) { | |||
| 112 | host = hp; | |||
| 113 | break; | |||
| 114 | } | |||
| 115 | ||||
| 116 | if (host && (!host->group->allow_booting)) { | |||
| 117 | log_info("Ignoring excluded BOOTP client %s", | |||
| 118 | host->name ? host->name : | |||
| 119 | print_hw_addr (packet->raw->htype, | |||
| 120 | packet->raw->hlen, packet->raw->chaddr)); | |||
| 121 | return; | |||
| 122 | } | |||
| 123 | ||||
| 124 | if (host && (!host->group->allow_bootp)) { | |||
| 125 | log_info("Ignoring BOOTP request from client %s", | |||
| 126 | host->name ? host->name : | |||
| 127 | print_hw_addr(packet->raw->htype, | |||
| 128 | packet->raw->hlen, packet->raw->chaddr)); | |||
| 129 | return; | |||
| 130 | } | |||
| 131 | ||||
| 132 | /* | |||
| 133 | * If we've been told not to boot unknown clients, and we | |||
| 134 | * didn't find any host record for this client, ignore it. | |||
| 135 | */ | |||
| 136 | if (!host && !(s->group->boot_unknown_clients)) { | |||
| 137 | log_info("Ignoring unknown BOOTP client %s via %s", | |||
| 138 | print_hw_addr(packet->raw->htype, | |||
| 139 | packet->raw->hlen, packet->raw->chaddr), | |||
| 140 | packet->raw->giaddr.s_addr ? | |||
| 141 | inet_ntoa(packet->raw->giaddr) : | |||
| 142 | packet->interface->name); | |||
| 143 | return; | |||
| 144 | } | |||
| 145 | ||||
| 146 | /* | |||
| 147 | * If we've been told not to boot with bootp on this network, | |||
| 148 | * ignore it. | |||
| 149 | */ | |||
| 150 | if (!host && !(s->group->allow_bootp)) { | |||
| 151 | log_info("Ignoring BOOTP request from client %s via " | |||
| 152 | "%s", print_hw_addr(packet->raw->htype, | |||
| 153 | packet->raw->hlen, packet->raw->chaddr), | |||
| 154 | packet->raw->giaddr.s_addr ? | |||
| 155 | inet_ntoa(packet->raw->giaddr) : | |||
| 156 | packet->interface->name); | |||
| 157 | return; | |||
| 158 | } | |||
| 159 | ||||
| 160 | /* | |||
| 161 | * If the packet is from a host we don't know and there are no | |||
| 162 | * dynamic bootp addresses on the network it came in on, drop | |||
| 163 | * it on the floor. | |||
| 164 | */ | |||
| 165 | if (!(s->group->dynamic_bootp)) { | |||
| 166 | lose: | |||
| 167 | log_info("No applicable record for BOOTP host %s via " | |||
| 168 | "%s", print_hw_addr(packet->raw->htype, | |||
| 169 | packet->raw->hlen, packet->raw->chaddr), | |||
| 170 | packet->raw->giaddr.s_addr ? | |||
| 171 | inet_ntoa(packet->raw->giaddr) : | |||
| 172 | packet->interface->name); | |||
| 173 | return; | |||
| 174 | } | |||
| 175 | ||||
| 176 | /* | |||
| 177 | * If a lease has already been assigned to this client and it's | |||
| 178 | * still okay to use dynamic bootp on that lease, reassign it. | |||
| 179 | */ | |||
| 180 | if (lease) { | |||
| 181 | /* | |||
| 182 | * If this lease can be used for dynamic bootp, do so. | |||
| 183 | */ | |||
| 184 | if ((lease->flags & DYNAMIC_BOOTP_OK4)) { | |||
| 185 | /* | |||
| 186 | * If it's not a DYNAMIC_BOOTP lease, release | |||
| 187 | * it before reassigning it so that we don't | |||
| 188 | * get a lease conflict. | |||
| 189 | */ | |||
| 190 | if (!(lease->flags & BOOTP_LEASE2)) | |||
| 191 | release_lease(lease); | |||
| 192 | ||||
| 193 | lease->host = host; | |||
| 194 | ack_lease(packet, lease, 0, 0); | |||
| 195 | return; | |||
| 196 | } | |||
| 197 | ||||
| 198 | /* | |||
| 199 | * If dynamic BOOTP is no longer allowed for this | |||
| 200 | * lease, set it free. | |||
| 201 | */ | |||
| 202 | release_lease(lease); | |||
| 203 | } | |||
| 204 | ||||
| 205 | /* | |||
| 206 | * If there are dynamic bootp addresses that might be | |||
| 207 | * available, try to snag one. | |||
| 208 | */ | |||
| 209 | for (lease = s->last_lease; | |||
| 210 | lease && lease->ends <= cur_time; | |||
| 211 | lease = lease->prev) { | |||
| 212 | if ((lease->flags & DYNAMIC_BOOTP_OK4)) { | |||
| 213 | lease->host = host; | |||
| 214 | ack_lease(packet, lease, 0, 0); | |||
| 215 | return; | |||
| 216 | } | |||
| 217 | } | |||
| 218 | goto lose; | |||
| 219 | } | |||
| 220 | ||||
| 221 | /* Make sure we're allowed to boot this client. */ | |||
| 222 | if (hp && (!hp->group->allow_booting)) { | |||
| 223 | log_info("Ignoring excluded BOOTP client %s", hp->name); | |||
| 224 | return; | |||
| 225 | } | |||
| 226 | ||||
| 227 | /* Make sure we're allowed to boot this client with bootp. */ | |||
| 228 | if (hp
| |||
| 229 | log_info("Ignoring BOOTP request from client %s", hp->name); | |||
| 230 | return; | |||
| 231 | } | |||
| 232 | ||||
| 233 | /* Set up the outgoing packet... */ | |||
| 234 | memset(&outgoing, 0, sizeof outgoing); | |||
| 235 | memset(&raw, 0, sizeof raw); | |||
| 236 | outgoing.raw = &raw; | |||
| 237 | ||||
| 238 | /* | |||
| 239 | * If we didn't get a known vendor magic number on the way in, just | |||
| 240 | * copy the input options to the output. | |||
| 241 | */ | |||
| 242 | if (!packet->options_valid && !subnet->group->always_reply_rfc1048 && | |||
| 243 | (!hp || !hp->group->always_reply_rfc1048)) { | |||
| 244 | memcpy(outgoing.raw->options, packet->raw->options, | |||
| 245 | DHCP_OPTION_LEN(1500 - (236 + (20 + 8)))); | |||
| 246 | outgoing.packet_length = BOOTP_MIN_LEN300; | |||
| 247 | } else { | |||
| 248 | struct tree_cache netmask_tree; /* -- RBF */ | |||
| 249 | ||||
| 250 | /* | |||
| 251 | * Come up with a list of options that we want to send to this | |||
| 252 | * client. Start with the per-subnet options, and then override | |||
| 253 | * those with client-specific options. | |||
| 254 | */ | |||
| 255 | ||||
| 256 | memcpy(options, subnet->group->options, sizeof(options)); | |||
| 257 | ||||
| 258 | for (i = 0; i < 256; i++) | |||
| 259 | if (hp->group->options[i]) | |||
| ||||
| 260 | options[i] = hp->group->options[i]; | |||
| 261 | ||||
| 262 | /* | |||
| 263 | * Use the subnet mask from the subnet declaration if no other | |||
| 264 | * mask has been provided. | |||
| 265 | */ | |||
| 266 | if (!options[DHO_SUBNET_MASK1]) { | |||
| 267 | options[DHO_SUBNET_MASK1] = &netmask_tree; | |||
| 268 | netmask_tree.flags = TC_TEMPORARY2; | |||
| 269 | netmask_tree.value = lease->subnet->netmask.iabuf; | |||
| 270 | netmask_tree.len = lease->subnet->netmask.len; | |||
| 271 | netmask_tree.buf_size = lease->subnet->netmask.len; | |||
| 272 | netmask_tree.timeout = -1; | |||
| 273 | netmask_tree.tree = NULL((void *)0); | |||
| 274 | } | |||
| 275 | ||||
| 276 | /* | |||
| 277 | * Pack the options into the buffer. Unlike DHCP, we can't pack | |||
| 278 | * options into the filename and server name buffers. | |||
| 279 | */ | |||
| 280 | ||||
| 281 | outgoing.packet_length = cons_options(packet, outgoing.raw, | |||
| 282 | 0, options, 0, 0, 1, NULL((void *)0), 0); | |||
| 283 | ||||
| 284 | if (outgoing.packet_length < BOOTP_MIN_LEN300) | |||
| 285 | outgoing.packet_length = BOOTP_MIN_LEN300; | |||
| 286 | } | |||
| 287 | ||||
| 288 | /* Take the fields that we care about... */ | |||
| 289 | raw.op = BOOTREPLY2; | |||
| 290 | raw.htype = packet->raw->htype; | |||
| 291 | raw.hlen = packet->raw->hlen; | |||
| 292 | memcpy(raw.chaddr, packet->raw->chaddr, sizeof(raw.chaddr)); | |||
| 293 | raw.hops = packet->raw->hops; | |||
| 294 | raw.xid = packet->raw->xid; | |||
| 295 | raw.secs = packet->raw->secs; | |||
| 296 | raw.flags = packet->raw->flags; | |||
| 297 | raw.ciaddr = packet->raw->ciaddr; | |||
| 298 | memcpy(&raw.yiaddr, ip_address.iabuf, sizeof(raw.yiaddr)); | |||
| 299 | ||||
| 300 | /* Figure out the address of the next server. */ | |||
| 301 | if (hp && hp->group->next_server.len) | |||
| 302 | memcpy(&raw.siaddr, hp->group->next_server.iabuf, 4); | |||
| 303 | else if (subnet->group->next_server.len) | |||
| 304 | memcpy(&raw.siaddr, subnet->group->next_server.iabuf, 4); | |||
| 305 | else if (subnet->interface_address.len) | |||
| 306 | memcpy(&raw.siaddr, subnet->interface_address.iabuf, 4); | |||
| 307 | else | |||
| 308 | raw.siaddr = packet->interface->primary_address; | |||
| 309 | ||||
| 310 | raw.giaddr = packet->raw->giaddr; | |||
| 311 | if (hp->group->server_name) | |||
| 312 | strncpy(raw.sname, hp->group->server_name, sizeof(raw.sname)); | |||
| 313 | else if (subnet->group->server_name) | |||
| 314 | strncpy(raw.sname, subnet->group->server_name, | |||
| 315 | sizeof(raw.sname)); | |||
| 316 | ||||
| 317 | if (hp->group->filename) | |||
| 318 | strncpy(raw.file, hp->group->filename, sizeof(raw.file)); | |||
| 319 | else if (subnet->group->filename) | |||
| 320 | strncpy(raw.file, subnet->group->filename, sizeof(raw.file)); | |||
| 321 | else | |||
| 322 | memcpy(raw.file, packet->raw->file, sizeof(raw.file)); | |||
| 323 | ||||
| 324 | from = packet->interface->primary_address; | |||
| 325 | ||||
| 326 | /* Report what we're doing... */ | |||
| 327 | log_info("BOOTREPLY for %s to %s (%s) via %s", piaddr(ip_address), | |||
| 328 | hp->name, print_hw_addr(packet->raw->htype, packet->raw->hlen, | |||
| 329 | packet->raw->chaddr), packet->raw->giaddr.s_addr ? | |||
| 330 | inet_ntoa(packet->raw->giaddr) : packet->interface->name); | |||
| 331 | ||||
| 332 | /* Set up the parts of the address that are in common. */ | |||
| 333 | memset(&to, 0, sizeof(to)); | |||
| 334 | to.sin_family = AF_INET2; | |||
| 335 | #ifdef HAVE_SA_LEN | |||
| 336 | to.sin_len = sizeof(to); | |||
| 337 | #endif | |||
| 338 | ||||
| 339 | /* If this was gatewayed, send it back to the gateway... */ | |||
| 340 | if (raw.giaddr.s_addr) { | |||
| 341 | to.sin_addr = raw.giaddr; | |||
| 342 | to.sin_port = server_port; | |||
| 343 | ||||
| 344 | (void) packet->interface->send_packet(packet->interface, &raw, | |||
| 345 | outgoing.packet_length, from, &to, packet->haddr); | |||
| 346 | return; | |||
| 347 | } | |||
| 348 | ||||
| 349 | /* | |||
| 350 | * If it comes from a client that already knows its address and is not | |||
| 351 | * requesting a broadcast response, and we can unicast to a client | |||
| 352 | * without using the ARP protocol, sent it directly to that client. | |||
| 353 | */ | |||
| 354 | else if (!(raw.flags & htons(BOOTP_BROADCAST)(__uint16_t)(__builtin_constant_p(32768L) ? (__uint16_t)(((__uint16_t )(32768L) & 0xffU) << 8 | ((__uint16_t)(32768L) & 0xff00U) >> 8) : __swap16md(32768L)))) { | |||
| 355 | to.sin_addr = raw.yiaddr; | |||
| 356 | to.sin_port = client_port; | |||
| 357 | } else { | |||
| 358 | /* Otherwise, broadcast it on the local network. */ | |||
| 359 | to.sin_addr.s_addr = INADDR_BROADCAST((u_int32_t)(0xffffffff)); | |||
| 360 | to.sin_port = client_port; /* XXX */ | |||
| 361 | } | |||
| 362 | ||||
| 363 | errno(*__errno()) = 0; | |||
| 364 | (void) packet->interface->send_packet(packet->interface, &raw, | |||
| 365 | outgoing.packet_length, from, &to, packet->haddr); | |||
| 366 | } |