0f62c4d065
requestip, vendorclass, clientid are client-side variables,
they do not make sense as udhcpd opts
dhcptype is the packet type (not interesting, it's always 5)
userclass needs parser support in order to work
function old new delta
dhcp_options 68 66 -2
read_opt 865 859 -6
dhcp_option_strings 253 203 -50
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-58) Total: -58 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
267 lines
9.1 KiB
C
267 lines
9.1 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* options.c -- DHCP server option packet tools
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* Rewrite by Russ Dill <Russ.Dill@asu.edu> July 2001
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*
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* Licensed under GPLv2, see file LICENSE in this tarball for details.
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*/
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#include "common.h"
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#include "dhcpd.h"
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#include "options.h"
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/* Supported options are easily added here.
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* See RFC2132 for more options.
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*/
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const struct dhcp_option dhcp_options[] = {
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/* flags code */
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{ OPTION_IP | OPTION_REQ, 0x01 }, /* DHCP_SUBNET */
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{ OPTION_S32 , 0x02 }, /* DHCP_TIME_OFFSET */
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{ OPTION_IP | OPTION_LIST | OPTION_REQ, 0x03 }, /* DHCP_ROUTER */
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{ OPTION_IP | OPTION_LIST , 0x04 }, /* DHCP_TIME_SERVER */
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// { OPTION_IP | OPTION_LIST , 0x05 }, /* DHCP_NAME_SERVER */
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{ OPTION_IP | OPTION_LIST | OPTION_REQ, 0x06 }, /* DHCP_DNS_SERVER */
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{ OPTION_IP | OPTION_LIST , 0x07 }, /* DHCP_LOG_SERVER */
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// { OPTION_IP | OPTION_LIST , 0x08 }, /* DHCP_COOKIE_SERVER */
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{ OPTION_IP | OPTION_LIST , 0x09 }, /* DHCP_LPR_SERVER */
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{ OPTION_STRING | OPTION_REQ, 0x0c }, /* DHCP_HOST_NAME */
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{ OPTION_U16 , 0x0d }, /* DHCP_BOOT_SIZE */
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{ OPTION_STRING | OPTION_REQ, 0x0f }, /* DHCP_DOMAIN_NAME */
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{ OPTION_IP , 0x10 }, /* DHCP_SWAP_SERVER */
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{ OPTION_STRING , 0x11 }, /* DHCP_ROOT_PATH */
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{ OPTION_U8 , 0x17 }, /* DHCP_IP_TTL */
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{ OPTION_U16 , 0x1a }, /* DHCP_MTU */
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{ OPTION_IP | OPTION_REQ, 0x1c }, /* DHCP_BROADCAST */
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{ OPTION_STRING , 0x28 }, /* nisdomain */
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{ OPTION_IP | OPTION_LIST , 0x29 }, /* nissrv */
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{ OPTION_IP | OPTION_LIST | OPTION_REQ, 0x2a }, /* DHCP_NTP_SERVER */
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{ OPTION_IP | OPTION_LIST , 0x2c }, /* DHCP_WINS_SERVER */
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{ OPTION_U32 , 0x33 }, /* DHCP_LEASE_TIME */
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{ OPTION_IP , 0x36 }, /* DHCP_SERVER_ID */
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{ OPTION_STRING , 0x38 }, /* DHCP_MESSAGE */
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{ OPTION_STRING , 0x42 }, /* tftp */
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{ OPTION_STRING , 0x43 }, /* bootfile */
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//TODO: not a string, but a set of LASCII strings:
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// { OPTION_STRING , 0x4D }, /* userclass */
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#if ENABLE_FEATURE_UDHCP_RFC3397
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{ OPTION_STR1035 | OPTION_LIST , 0x77 }, /* search */
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#endif
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{ OPTION_STATIC_ROUTES , 0x79 }, /* DHCP_STATIC_ROUTES */
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/* MSIE's "Web Proxy Autodiscovery Protocol" support */
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{ OPTION_STRING , 0xfc }, /* wpad */
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/* Options below have no match in dhcp_option_strings[],
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* are not passed to dhcpc scripts, and cannot be specified
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* with "option XXX YYY" syntax in dhcpd config file.
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* These entries are only used internally by udhcp[cd]
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* to correctly encode options into packets.
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*/
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{ OPTION_IP , 0x32 }, /* DHCP_REQUESTED_IP */
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{ OPTION_U8 , 0x35 }, /* DHCP_MESSAGE_TYPE */
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{ OPTION_U16 , 0x39 }, /* DHCP_MAX_SIZE */
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{ OPTION_STRING , 0x3C }, /* DHCP_VENDOR */
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{ OPTION_STRING , 0x3D }, /* DHCP_CLIENT_ID */
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{ 0, 0 } /* zeroed terminating entry */
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};
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/* Used for converting options from incoming packets to env variables
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* for udhcpc stript, and for setting options for udhcpd via
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* "opt OPTION_NAME OPTION_VALUE" directives in udhcpd.conf file.
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*/
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/* Must match dhcp_options[] order */
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const char dhcp_option_strings[] ALIGN1 =
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"subnet" "\0" /* DHCP_SUBNET */
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"timezone" "\0" /* DHCP_TIME_OFFSET */
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"router" "\0" /* DHCP_ROUTER */
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"timesrv" "\0" /* DHCP_TIME_SERVER */
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// "namesrv" "\0" /* DHCP_NAME_SERVER */
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"dns" "\0" /* DHCP_DNS_SERVER */
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"logsrv" "\0" /* DHCP_LOG_SERVER */
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// "cookiesrv" "\0" /* DHCP_COOKIE_SERVER */
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"lprsrv" "\0" /* DHCP_LPR_SERVER */
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"hostname" "\0" /* DHCP_HOST_NAME */
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"bootsize" "\0" /* DHCP_BOOT_SIZE */
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"domain" "\0" /* DHCP_DOMAIN_NAME */
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"swapsrv" "\0" /* DHCP_SWAP_SERVER */
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"rootpath" "\0" /* DHCP_ROOT_PATH */
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"ipttl" "\0" /* DHCP_IP_TTL */
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"mtu" "\0" /* DHCP_MTU */
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"broadcast" "\0" /* DHCP_BROADCAST */
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"nisdomain" "\0" /* */
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"nissrv" "\0" /* */
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"ntpsrv" "\0" /* DHCP_NTP_SERVER */
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"wins" "\0" /* DHCP_WINS_SERVER */
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"lease" "\0" /* DHCP_LEASE_TIME */
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"serverid" "\0" /* DHCP_SERVER_ID */
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"message" "\0" /* DHCP_MESSAGE */
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"tftp" "\0"
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"bootfile" "\0"
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// "userclass" "\0"
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#if ENABLE_FEATURE_UDHCP_RFC3397
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"search" "\0"
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#endif
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// "staticroutes" is only used to set udhcpc environment, it doesn't work
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// in udhcpd.conf since OPTION_STATIC_ROUTES is not handled yet:
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"staticroutes" "\0" /* DHCP_STATIC_ROUTES */
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/* MSIE's "Web Proxy Autodiscovery Protocol" support */
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"wpad" "\0"
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;
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/* Lengths of the different option types */
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const uint8_t dhcp_option_lengths[] ALIGN1 = {
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[OPTION_IP] = 4,
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[OPTION_IP_PAIR] = 8,
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[OPTION_BOOLEAN] = 1,
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[OPTION_STRING] = 1,
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#if ENABLE_FEATURE_UDHCP_RFC3397
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[OPTION_STR1035] = 1,
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#endif
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[OPTION_U8] = 1,
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[OPTION_U16] = 2,
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[OPTION_S16] = 2,
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[OPTION_U32] = 4,
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[OPTION_S32] = 4,
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/* Just like OPTION_STRING, we use minimum length here */
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[OPTION_STATIC_ROUTES] = 5,
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};
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#if defined CONFIG_UDHCP_DEBUG && CONFIG_UDHCP_DEBUG >= 2
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static void log_option(const char *pfx, const uint8_t *opt)
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{
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if (dhcp_verbose >= 2) {
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char buf[256 * 2 + 2];
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*bin2hex(buf, (void*) (opt + OPT_DATA), opt[OPT_LEN]) = '\0';
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bb_info_msg("%s: 0x%02x %s", pfx, opt[OPT_CODE], buf);
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}
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}
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#else
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# define log_option(pfx, opt) ((void)0)
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#endif
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/* get an option with bounds checking (warning, result is not aligned). */
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uint8_t* FAST_FUNC get_option(struct dhcp_packet *packet, int code)
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{
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uint8_t *optionptr;
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int len;
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int rem;
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int overload = 0;
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enum {
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FILE_FIELD101 = FILE_FIELD * 0x101,
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SNAME_FIELD101 = SNAME_FIELD * 0x101,
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};
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/* option bytes: [code][len][data1][data2]..[dataLEN] */
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optionptr = packet->options;
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rem = sizeof(packet->options);
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while (1) {
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if (rem <= 0) {
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bb_error_msg("bogus packet, malformed option field");
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return NULL;
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}
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if (optionptr[OPT_CODE] == DHCP_PADDING) {
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rem--;
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optionptr++;
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continue;
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}
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if (optionptr[OPT_CODE] == DHCP_END) {
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if ((overload & FILE_FIELD101) == FILE_FIELD) {
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/* can use packet->file, and didn't look at it yet */
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overload |= FILE_FIELD101; /* "we looked at it" */
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optionptr = packet->file;
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rem = sizeof(packet->file);
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continue;
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}
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if ((overload & SNAME_FIELD101) == SNAME_FIELD) {
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/* can use packet->sname, and didn't look at it yet */
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overload |= SNAME_FIELD101; /* "we looked at it" */
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optionptr = packet->sname;
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rem = sizeof(packet->sname);
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continue;
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}
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break;
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}
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len = 2 + optionptr[OPT_LEN];
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rem -= len;
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if (rem < 0)
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continue; /* complain and return NULL */
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if (optionptr[OPT_CODE] == code) {
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log_option("Option found", optionptr);
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return optionptr + OPT_DATA;
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}
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if (optionptr[OPT_CODE] == DHCP_OPTION_OVERLOAD) {
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overload |= optionptr[OPT_DATA];
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/* fall through */
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}
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optionptr += len;
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}
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/* log3 because udhcpc uses it a lot - very noisy */
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log3("Option 0x%02x not found", code);
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return NULL;
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}
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/* return the position of the 'end' option (no bounds checking) */
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int FAST_FUNC end_option(uint8_t *optionptr)
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{
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int i = 0;
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while (optionptr[i] != DHCP_END) {
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if (optionptr[i] != DHCP_PADDING)
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i += optionptr[i + OPT_LEN] + 1;
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i++;
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}
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return i;
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}
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/* add an option string to the options */
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/* option bytes: [code][len][data1][data2]..[dataLEN] */
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int FAST_FUNC add_option_string(uint8_t *optionptr, uint8_t *string)
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{
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int end = end_option(optionptr);
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/* end position + string length + option code/length + end option */
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if (end + string[OPT_LEN] + 2 + 1 >= DHCP_OPTIONS_BUFSIZE) {
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bb_error_msg("option 0x%02x did not fit into the packet",
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string[OPT_CODE]);
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return 0;
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}
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log_option("Adding option", string);
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memcpy(optionptr + end, string, string[OPT_LEN] + 2);
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optionptr[end + string[OPT_LEN] + 2] = DHCP_END;
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return string[OPT_LEN] + 2;
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}
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/* add a one to four byte option to a packet */
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int FAST_FUNC add_simple_option(uint8_t *optionptr, uint8_t code, uint32_t data)
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{
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const struct dhcp_option *dh;
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for (dh = dhcp_options; dh->code; dh++) {
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if (dh->code == code) {
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uint8_t option[6], len;
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option[OPT_CODE] = code;
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len = dhcp_option_lengths[dh->flags & TYPE_MASK];
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option[OPT_LEN] = len;
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if (BB_BIG_ENDIAN)
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data <<= 8 * (4 - len);
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/* Assignment is unaligned! */
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move_to_unaligned32(&option[OPT_DATA], data);
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return add_option_string(optionptr, option);
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}
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}
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bb_error_msg("can't add option 0x%02x", code);
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return 0;
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}
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