17c478bd9Sstevel@tonic-gate /* 27c478bd9Sstevel@tonic-gate * CDDL HEADER START 37c478bd9Sstevel@tonic-gate * 47c478bd9Sstevel@tonic-gate * The contents of this file are subject to the terms of the 5*d04ccbb3Scarlsonj * Common Development and Distribution License (the "License"). 6*d04ccbb3Scarlsonj * You may not use this file except in compliance with the License. 77c478bd9Sstevel@tonic-gate * 87c478bd9Sstevel@tonic-gate * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 97c478bd9Sstevel@tonic-gate * or http://www.opensolaris.org/os/licensing. 107c478bd9Sstevel@tonic-gate * See the License for the specific language governing permissions 117c478bd9Sstevel@tonic-gate * and limitations under the License. 127c478bd9Sstevel@tonic-gate * 137c478bd9Sstevel@tonic-gate * When distributing Covered Code, include this CDDL HEADER in each 147c478bd9Sstevel@tonic-gate * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 157c478bd9Sstevel@tonic-gate * If applicable, add the following below this CDDL HEADER, with the 167c478bd9Sstevel@tonic-gate * fields enclosed by brackets "[]" replaced with your own identifying 177c478bd9Sstevel@tonic-gate * information: Portions Copyright [yyyy] [name of copyright owner] 187c478bd9Sstevel@tonic-gate * 197c478bd9Sstevel@tonic-gate * CDDL HEADER END 207c478bd9Sstevel@tonic-gate */ 217c478bd9Sstevel@tonic-gate /* 22*d04ccbb3Scarlsonj * Copyright 2007 Sun Microsystems, Inc. All rights reserved. 237c478bd9Sstevel@tonic-gate * Use is subject to license terms. 247c478bd9Sstevel@tonic-gate * 257c478bd9Sstevel@tonic-gate * Routines used to extract/insert DHCP options. Must be kept MT SAFE, 267c478bd9Sstevel@tonic-gate * as they are called from different threads. 277c478bd9Sstevel@tonic-gate */ 287c478bd9Sstevel@tonic-gate 297c478bd9Sstevel@tonic-gate #pragma ident "%Z%%M% %I% %E% SMI" 307c478bd9Sstevel@tonic-gate 317c478bd9Sstevel@tonic-gate #include <sys/types.h> 327c478bd9Sstevel@tonic-gate #include "dhcp_impl.h" 337c478bd9Sstevel@tonic-gate #if defined(_KERNEL) && !defined(_BOOT) 347c478bd9Sstevel@tonic-gate #include <sys/sunddi.h> 357c478bd9Sstevel@tonic-gate #else 367c478bd9Sstevel@tonic-gate #include <strings.h> 377c478bd9Sstevel@tonic-gate #endif /* _KERNEL && !_BOOT */ 387c478bd9Sstevel@tonic-gate 397c478bd9Sstevel@tonic-gate static uint8_t bootmagic[] = BOOTMAGIC; 407c478bd9Sstevel@tonic-gate 417c478bd9Sstevel@tonic-gate /* 427c478bd9Sstevel@tonic-gate * Scan field for options. 437c478bd9Sstevel@tonic-gate */ 447c478bd9Sstevel@tonic-gate static void 457c478bd9Sstevel@tonic-gate field_scan(uint8_t *start, uint8_t *end, DHCP_OPT **options, 467c478bd9Sstevel@tonic-gate uint8_t last_option) 477c478bd9Sstevel@tonic-gate { 487c478bd9Sstevel@tonic-gate uint8_t *current; 497c478bd9Sstevel@tonic-gate 507c478bd9Sstevel@tonic-gate while (start < end) { 517c478bd9Sstevel@tonic-gate if (*start == CD_PAD) { 527c478bd9Sstevel@tonic-gate start++; 537c478bd9Sstevel@tonic-gate continue; 547c478bd9Sstevel@tonic-gate } 557c478bd9Sstevel@tonic-gate if (*start == CD_END) 567c478bd9Sstevel@tonic-gate break; /* done */ 577c478bd9Sstevel@tonic-gate if (*start > last_option) { 587c478bd9Sstevel@tonic-gate if (++start < end) 597c478bd9Sstevel@tonic-gate start += *start + 1; 607c478bd9Sstevel@tonic-gate continue; /* unrecognized option */ 617c478bd9Sstevel@tonic-gate } 627c478bd9Sstevel@tonic-gate 637c478bd9Sstevel@tonic-gate current = start; 647c478bd9Sstevel@tonic-gate if (++start < end) 657c478bd9Sstevel@tonic-gate start += *start + 1; /* advance to next option */ 667c478bd9Sstevel@tonic-gate 677c478bd9Sstevel@tonic-gate /* all options besides CD_END and CD_PAD should have a len */ 687c478bd9Sstevel@tonic-gate if ((current + 1) >= end) 697c478bd9Sstevel@tonic-gate continue; 707c478bd9Sstevel@tonic-gate 717c478bd9Sstevel@tonic-gate /* Ignores duplicate options. */ 727c478bd9Sstevel@tonic-gate if (options[*current] == NULL) { 737c478bd9Sstevel@tonic-gate 747c478bd9Sstevel@tonic-gate options[*current] = (DHCP_OPT *)current; 757c478bd9Sstevel@tonic-gate 767c478bd9Sstevel@tonic-gate /* verify that len won't go beyond end */ 777c478bd9Sstevel@tonic-gate if ((current + options[*current]->len + 1) >= end) { 787c478bd9Sstevel@tonic-gate options[*current] = NULL; 797c478bd9Sstevel@tonic-gate continue; 807c478bd9Sstevel@tonic-gate } 817c478bd9Sstevel@tonic-gate } 827c478bd9Sstevel@tonic-gate } 837c478bd9Sstevel@tonic-gate } 847c478bd9Sstevel@tonic-gate 857c478bd9Sstevel@tonic-gate /* 867c478bd9Sstevel@tonic-gate * Scan Vendor field for options. 877c478bd9Sstevel@tonic-gate */ 887c478bd9Sstevel@tonic-gate static void 897c478bd9Sstevel@tonic-gate vendor_scan(PKT_LIST *pl) 907c478bd9Sstevel@tonic-gate { 917c478bd9Sstevel@tonic-gate uint8_t *start, *end, len; 927c478bd9Sstevel@tonic-gate 937c478bd9Sstevel@tonic-gate if (pl->opts[CD_VENDOR_SPEC] == NULL) 947c478bd9Sstevel@tonic-gate return; 957c478bd9Sstevel@tonic-gate len = pl->opts[CD_VENDOR_SPEC]->len; 967c478bd9Sstevel@tonic-gate start = pl->opts[CD_VENDOR_SPEC]->value; 977c478bd9Sstevel@tonic-gate 987c478bd9Sstevel@tonic-gate /* verify that len won't go beyond the end of the packet */ 997c478bd9Sstevel@tonic-gate if (((start - (uint8_t *)pl->pkt) + len) > pl->len) 1007c478bd9Sstevel@tonic-gate return; 1017c478bd9Sstevel@tonic-gate 1027c478bd9Sstevel@tonic-gate end = start + len; 1037c478bd9Sstevel@tonic-gate field_scan(start, end, pl->vs, VS_OPTION_END); 1047c478bd9Sstevel@tonic-gate } 1057c478bd9Sstevel@tonic-gate 1067c478bd9Sstevel@tonic-gate /* 1077c478bd9Sstevel@tonic-gate * Load opts table in PKT_LIST entry with PKT's options. 1087c478bd9Sstevel@tonic-gate * Returns 0 if no fatal errors occur, otherwise... 1097c478bd9Sstevel@tonic-gate */ 1107c478bd9Sstevel@tonic-gate int 1117c478bd9Sstevel@tonic-gate dhcp_options_scan(PKT_LIST *pl, boolean_t scan_vendor) 1127c478bd9Sstevel@tonic-gate { 1137c478bd9Sstevel@tonic-gate PKT *pkt = pl->pkt; 1147c478bd9Sstevel@tonic-gate uint_t opt_size = pl->len - BASE_PKT_SIZE; 1157c478bd9Sstevel@tonic-gate 1167c478bd9Sstevel@tonic-gate /* 1177c478bd9Sstevel@tonic-gate * bcmp() is used here instead of memcmp() since kernel/standalone 1187c478bd9Sstevel@tonic-gate * doesn't have a memcmp(). 1197c478bd9Sstevel@tonic-gate */ 1207c478bd9Sstevel@tonic-gate if (pl->len < BASE_PKT_SIZE || 1217c478bd9Sstevel@tonic-gate bcmp(pl->pkt->cookie, bootmagic, sizeof (pl->pkt->cookie)) != 0) { 1227c478bd9Sstevel@tonic-gate pl->rfc1048 = 0; 1237c478bd9Sstevel@tonic-gate return (0); 1247c478bd9Sstevel@tonic-gate } 1257c478bd9Sstevel@tonic-gate 1267c478bd9Sstevel@tonic-gate pl->rfc1048 = 1; 1277c478bd9Sstevel@tonic-gate 1287c478bd9Sstevel@tonic-gate /* check the options field */ 1297c478bd9Sstevel@tonic-gate field_scan(pkt->options, &pkt->options[opt_size], pl->opts, 1307c478bd9Sstevel@tonic-gate DHCP_LAST_OPT); 1317c478bd9Sstevel@tonic-gate 1327c478bd9Sstevel@tonic-gate /* 1337c478bd9Sstevel@tonic-gate * process vendor specific options. We look at the vendor options 1347c478bd9Sstevel@tonic-gate * here, simply because a BOOTP server could fake DHCP vendor 1357c478bd9Sstevel@tonic-gate * options. This increases our interoperability with BOOTP. 1367c478bd9Sstevel@tonic-gate */ 1377c478bd9Sstevel@tonic-gate if (scan_vendor && (pl->opts[CD_VENDOR_SPEC] != NULL)) 1387c478bd9Sstevel@tonic-gate vendor_scan(pl); 1397c478bd9Sstevel@tonic-gate 1407c478bd9Sstevel@tonic-gate if (pl->opts[CD_DHCP_TYPE] == NULL) 1417c478bd9Sstevel@tonic-gate return (0); 1427c478bd9Sstevel@tonic-gate 1437c478bd9Sstevel@tonic-gate if (pl->opts[CD_DHCP_TYPE]->len != 1) 1447c478bd9Sstevel@tonic-gate return (DHCP_GARBLED_MSG_TYPE); 1457c478bd9Sstevel@tonic-gate 1467c478bd9Sstevel@tonic-gate if (*pl->opts[CD_DHCP_TYPE]->value < DISCOVER || 1477c478bd9Sstevel@tonic-gate *pl->opts[CD_DHCP_TYPE]->value > INFORM) 1487c478bd9Sstevel@tonic-gate return (DHCP_WRONG_MSG_TYPE); 1497c478bd9Sstevel@tonic-gate 1507c478bd9Sstevel@tonic-gate if (pl->opts[CD_OPTION_OVERLOAD]) { 1517c478bd9Sstevel@tonic-gate if (pl->opts[CD_OPTION_OVERLOAD]->len != 1) { 1527c478bd9Sstevel@tonic-gate pl->opts[CD_OPTION_OVERLOAD] = NULL; 1537c478bd9Sstevel@tonic-gate return (DHCP_BAD_OPT_OVLD); 1547c478bd9Sstevel@tonic-gate } 1557c478bd9Sstevel@tonic-gate switch (*pl->opts[CD_OPTION_OVERLOAD]->value) { 1567c478bd9Sstevel@tonic-gate case 1: 1577c478bd9Sstevel@tonic-gate field_scan(pkt->file, &pkt->cookie[0], pl->opts, 1587c478bd9Sstevel@tonic-gate DHCP_LAST_OPT); 1597c478bd9Sstevel@tonic-gate break; 1607c478bd9Sstevel@tonic-gate case 2: 1617c478bd9Sstevel@tonic-gate field_scan(pkt->sname, &pkt->file[0], pl->opts, 1627c478bd9Sstevel@tonic-gate DHCP_LAST_OPT); 1637c478bd9Sstevel@tonic-gate break; 1647c478bd9Sstevel@tonic-gate case 3: 1657c478bd9Sstevel@tonic-gate field_scan(pkt->file, &pkt->cookie[0], pl->opts, 1667c478bd9Sstevel@tonic-gate DHCP_LAST_OPT); 1677c478bd9Sstevel@tonic-gate field_scan(pkt->sname, &pkt->file[0], pl->opts, 1687c478bd9Sstevel@tonic-gate DHCP_LAST_OPT); 1697c478bd9Sstevel@tonic-gate break; 1707c478bd9Sstevel@tonic-gate default: 1717c478bd9Sstevel@tonic-gate pl->opts[CD_OPTION_OVERLOAD] = NULL; 1727c478bd9Sstevel@tonic-gate return (DHCP_BAD_OPT_OVLD); 1737c478bd9Sstevel@tonic-gate } 1747c478bd9Sstevel@tonic-gate } 1757c478bd9Sstevel@tonic-gate return (0); 1767c478bd9Sstevel@tonic-gate } 177*d04ccbb3Scarlsonj 178*d04ccbb3Scarlsonj /* 179*d04ccbb3Scarlsonj * Locate a DHCPv6 option or suboption within a buffer. DHCPv6 uses nested 180*d04ccbb3Scarlsonj * options within options, and this function is designed to work with both 181*d04ccbb3Scarlsonj * primary options and the suboptions contained within. 182*d04ccbb3Scarlsonj * 183*d04ccbb3Scarlsonj * The 'oldopt' is a previous option pointer, and is typically used to iterate 184*d04ccbb3Scarlsonj * over options of the same code number. The 'codenum' is in host byte order 185*d04ccbb3Scarlsonj * for simplicity. 'retlenp' may be NULL, and if present gets the _entire_ 186*d04ccbb3Scarlsonj * option length (including header). 187*d04ccbb3Scarlsonj * 188*d04ccbb3Scarlsonj * Warning: the returned pointer has no particular alignment because DHCPv6 189*d04ccbb3Scarlsonj * defines options without alignment. The caller must deal with unaligned 190*d04ccbb3Scarlsonj * pointers carefully. 191*d04ccbb3Scarlsonj */ 192*d04ccbb3Scarlsonj dhcpv6_option_t * 193*d04ccbb3Scarlsonj dhcpv6_find_option(const void *buffer, size_t buflen, 194*d04ccbb3Scarlsonj const dhcpv6_option_t *oldopt, uint16_t codenum, uint_t *retlenp) 195*d04ccbb3Scarlsonj { 196*d04ccbb3Scarlsonj const uchar_t *bp; 197*d04ccbb3Scarlsonj dhcpv6_option_t d6o; 198*d04ccbb3Scarlsonj uint_t olen; 199*d04ccbb3Scarlsonj 200*d04ccbb3Scarlsonj codenum = htons(codenum); 201*d04ccbb3Scarlsonj bp = buffer; 202*d04ccbb3Scarlsonj while (buflen >= sizeof (dhcpv6_option_t)) { 203*d04ccbb3Scarlsonj (void) memcpy(&d6o, bp, sizeof (d6o)); 204*d04ccbb3Scarlsonj olen = ntohs(d6o.d6o_len) + sizeof (d6o); 205*d04ccbb3Scarlsonj if (olen > buflen) 206*d04ccbb3Scarlsonj break; 207*d04ccbb3Scarlsonj if (d6o.d6o_code != codenum || 208*d04ccbb3Scarlsonj (oldopt != NULL && bp <= (const uchar_t *)oldopt)) { 209*d04ccbb3Scarlsonj bp += olen; 210*d04ccbb3Scarlsonj buflen -= olen; 211*d04ccbb3Scarlsonj continue; 212*d04ccbb3Scarlsonj } 213*d04ccbb3Scarlsonj if (retlenp != NULL) 214*d04ccbb3Scarlsonj *retlenp = olen; 215*d04ccbb3Scarlsonj /* LINTED: alignment */ 216*d04ccbb3Scarlsonj return ((dhcpv6_option_t *)bp); 217*d04ccbb3Scarlsonj } 218*d04ccbb3Scarlsonj return (NULL); 219*d04ccbb3Scarlsonj } 220*d04ccbb3Scarlsonj 221*d04ccbb3Scarlsonj /* 222*d04ccbb3Scarlsonj * Locate a DHCPv6 option within the top level of a PKT_LIST entry. DHCPv6 223*d04ccbb3Scarlsonj * uses nested options within options, and this function returns only the 224*d04ccbb3Scarlsonj * primary options. Use dhcpv6_find_option to traverse suboptions. 225*d04ccbb3Scarlsonj * 226*d04ccbb3Scarlsonj * See dhcpv6_find_option for usage details and warnings. 227*d04ccbb3Scarlsonj */ 228*d04ccbb3Scarlsonj dhcpv6_option_t * 229*d04ccbb3Scarlsonj dhcpv6_pkt_option(const PKT_LIST *plp, const dhcpv6_option_t *oldopt, 230*d04ccbb3Scarlsonj uint16_t codenum, uint_t *retlenp) 231*d04ccbb3Scarlsonj { 232*d04ccbb3Scarlsonj const dhcpv6_message_t *d6m; 233*d04ccbb3Scarlsonj 234*d04ccbb3Scarlsonj if (plp == NULL || plp->pkt == NULL || plp->len < sizeof (*d6m)) 235*d04ccbb3Scarlsonj return (NULL); 236*d04ccbb3Scarlsonj d6m = (const dhcpv6_message_t *)plp->pkt; 237*d04ccbb3Scarlsonj return (dhcpv6_find_option(d6m + 1, plp->len - sizeof (*d6m), oldopt, 238*d04ccbb3Scarlsonj codenum, retlenp)); 239*d04ccbb3Scarlsonj } 240