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dhcpcd/dhcp.c

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/*
* dhcpcd - DHCP client daemon
* Copyright 2006-2008 Roy Marples <roy@marples.name>
* All rights reserved
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <net/if_arp.h>
#include <arpa/inet.h>
#include <errno.h>
#include <limits.h>
#include <math.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include "config.h"
#include "common.h"
#include "dhcpcd.h"
#include "dhcp.h"
#include "interface.h"
#include "logger.h"
#include "socket.h"
typedef struct message {
int value;
const char *name;
} dhcp_message_t;
static dhcp_message_t dhcp_messages[] = {
{ DHCP_DISCOVER, "DHCP_DISCOVER" },
{ DHCP_OFFER, "DHCP_OFFER" },
{ DHCP_REQUEST, "DHCP_REQUEST" },
{ DHCP_DECLINE, "DHCP_DECLINE" },
{ DHCP_ACK, "DHCP_ACK" },
{ DHCP_NAK, "DHCP_NAK" },
{ DHCP_RELEASE, "DHCP_RELEASE" },
{ DHCP_INFORM, "DHCP_INFORM" },
{ -1, NULL }
};
static const char *dhcp_message (int type)
{
dhcp_message_t *d;
for (d = dhcp_messages; d->name; d++)
if (d->value == type)
return (d->name);
return (NULL);
}
ssize_t send_message (const interface_t *iface, const dhcp_t *dhcp,
uint32_t xid, char type, const options_t *options)
{
struct udp_dhcp_packet *packet;
dhcpmessage_t *message;
unsigned char *m;
unsigned char *p;
unsigned char *n_params = NULL;
size_t l;
struct in_addr from;
struct in_addr to;
time_t up = uptime() - iface->start_uptime;
uint32_t ul;
uint16_t sz;
size_t message_length;
ssize_t retval;
if (!iface || !options || !dhcp)
return -1;
memset (&from, 0, sizeof (from));
memset (&to, 0, sizeof (to));
if (type == DHCP_RELEASE)
to.s_addr = dhcp->serveraddress.s_addr;
message = xzalloc (sizeof (*message));
m = (unsigned char *) message;
p = (unsigned char *) &message->options;
if ((type == DHCP_INFORM ||
type == DHCP_RELEASE ||
type == DHCP_REQUEST) &&
! IN_LINKLOCAL (ntohl (iface->previous_address.s_addr)))
{
message->ciaddr = iface->previous_address.s_addr;
from.s_addr = iface->previous_address.s_addr;
/* Just incase we haven't actually configured the address yet */
if (type == DHCP_INFORM && iface->previous_address.s_addr == 0)
message->ciaddr = dhcp->address.s_addr;
/* Zero the address if we're currently on a different subnet */
if (type == DHCP_REQUEST &&
iface->previous_netmask.s_addr != dhcp->netmask.s_addr)
message->ciaddr = from.s_addr = 0;
}
message->op = DHCP_BOOTREQUEST;
message->hwtype = iface->family;
switch (iface->family) {
case ARPHRD_ETHER:
case ARPHRD_IEEE802:
message->hwlen = ETHER_ADDR_LEN;
memcpy (&message->chaddr, &iface->hwaddr,
ETHER_ADDR_LEN);
break;
case ARPHRD_IEEE1394:
case ARPHRD_INFINIBAND:
message->hwlen = 0;
if (message->ciaddr == 0)
message->flags = htons (BROADCAST_FLAG);
break;
default:
logger (LOG_ERR, "dhcp: unknown hardware type %d",
iface->family);
}
if (up < 0 || up > (time_t) UINT16_MAX)
message->secs = htons ((uint16_t) UINT16_MAX);
else
message->secs = htons (up);
message->xid = xid;
message->cookie = htonl (MAGIC_COOKIE);
*p++ = DHCP_MESSAGETYPE;
*p++ = 1;
*p++ = type;
if (type == DHCP_REQUEST) {
*p++ = DHCP_MAXMESSAGESIZE;
*p++ = 2;
sz = get_mtu (iface->name);
if (sz < MTU_MIN) {
if (set_mtu (iface->name, MTU_MIN) == 0)
sz = MTU_MIN;
}
sz = htons (sz);
memcpy (p, &sz, 2);
p += 2;
}
if (type != DHCP_INFORM) {
#define PUTADDR(_type, _val) { \
*p++ = _type; \
*p++ = 4; \
memcpy (p, &_val.s_addr, 4); \
p += 4; \
}
if (IN_LINKLOCAL (ntohl (dhcp->address.s_addr)))
logger (LOG_ERR,
"cannot request a link local address");
else {
if (dhcp->address.s_addr &&
dhcp->address.s_addr !=
iface->previous_address.s_addr &&
type != DHCP_RELEASE)
PUTADDR (DHCP_ADDRESS, dhcp->address);
if (dhcp->serveraddress.s_addr &&
dhcp->address.s_addr &&
(type == DHCP_REQUEST || type == DHCP_RELEASE))
PUTADDR (DHCP_SERVERIDENTIFIER,
dhcp->serveraddress);
}
#undef PUTADDR
}
if (type == DHCP_REQUEST || type == DHCP_DISCOVER) {
if (options->leasetime != 0) {
*p++ = DHCP_LEASETIME;
*p++ = 4;
ul = htonl (options->leasetime);
memcpy (p, &ul, 4);
p += 4;
}
}
if (type == DHCP_DISCOVER ||
type == DHCP_INFORM ||
type == DHCP_REQUEST)
{
*p++ = DHCP_PARAMETERREQUESTLIST;
n_params = p;
*p++ = 0;
/* Only request DNSSERVER in discover to keep the packets small.
* RFC2131 Section 3.5 states that the REQUEST must include the
* list from the DISCOVER message, so I think this is ok. */
if (type == DHCP_DISCOVER && ! options->test)
*p++ = DHCP_DNSSERVER;
else {
if (type != DHCP_INFORM) {
*p++ = DHCP_RENEWALTIME;
*p++ = DHCP_REBINDTIME;
}
*p++ = DHCP_NETMASK;
*p++ = DHCP_BROADCAST;
/* -S means request CSR and MSCSR
* -SS means only request MSCSR incase DHCP message
* is too big */
if (options->domscsr < 2)
*p++ = DHCP_CSR;
if (options->domscsr > 0)
*p++ = DHCP_MSCSR;
/* RFC 3442 states classless static routes should be
* before routers and static routes as classless static
* routes override them both */
*p++ = DHCP_STATICROUTE;
*p++ = DHCP_ROUTERS;
*p++ = DHCP_HOSTNAME;
*p++ = DHCP_DNSSEARCH;
*p++ = DHCP_DNSDOMAIN;
*p++ = DHCP_DNSSERVER;
#ifdef ENABLE_NIS
*p++ = DHCP_NISDOMAIN;
*p++ = DHCP_NISSERVER;
#endif
#ifdef ENABLE_NTP
*p++ = DHCP_NTPSERVER;
#endif
*p++ = DHCP_MTU;
#ifdef ENABLE_INFO
*p++ = DHCP_ROOTPATH;
*p++ = DHCP_SIPSERVER;
#endif
}
*n_params = p - n_params - 1;
if (options->hostname[0]) {
if (options->fqdn == FQDN_DISABLE) {
*p++ = DHCP_HOSTNAME;
*p++ = l = strlen (options->hostname);
memcpy (p, options->hostname, l);
p += l;
} else {
/* Draft IETF DHC-FQDN option (81) */
*p++ = DHCP_FQDN;
*p++ = (l = strlen (options->hostname)) + 3;
/* Flags: 0000NEOS
* S: 1 => Client requests Server to update
* a RR in DNS as well as PTR
* O: 1 => Server indicates to client that
* DNS has been updated
* E: 1 => Name data is DNS format
* N: 1 => Client requests Server to not
* update DNS
*/
*p++ = options->fqdn & 0x9;
*p++ = 0; /* from server for PTR RR */
*p++ = 0; /* from server for A RR if S=1 */
memcpy (p, options->hostname, l);
p += l;
}
}
}
if (type != DHCP_DECLINE && type != DHCP_RELEASE) {
if (options->userclass_len > 0) {
*p++ = DHCP_USERCLASS;
*p++ = options->userclass_len;
memcpy (p, &options->userclass, options->userclass_len);
p += options->userclass_len;
}
if (*options->classid > 0) {
*p++ = DHCP_CLASSID;
*p++ = l = strlen (options->classid);
memcpy (p, options->classid, l);
p += l;
}
}
*p++ = DHCP_CLIENTID;
*p++ = iface->clientid_len;
memcpy (p, iface->clientid, iface->clientid_len);
p+= iface->clientid_len;
*p++ = DHCP_END;
#ifdef BOOTP_MESSAGE_LENTH_MIN
/* Some crappy DHCP servers think they have to obey the BOOTP minimum
* message length.
* They are wrong, but we should still cater for them. */
while (p - m < BOOTP_MESSAGE_LENTH_MIN)
*p++ = DHCP_PAD;
#endif
message_length = p - m;
packet = xzalloc (sizeof (*packet));
make_dhcp_packet (packet, (unsigned char *) message, message_length,
from, to);
free (message);
logger (LOG_DEBUG, "sending %s with xid 0x%x",
dhcp_message (type), xid);
retval = send_packet (iface, ETHERTYPE_IP, (unsigned char *) packet,
message_length +
sizeof (packet->ip) + sizeof (packet->udp));
free (packet);
return (retval);
}
/* Decode an RFC3397 DNS search order option into a space
* seperated string. Returns length of string (including
* terminating zero) or zero on error. out may be NULL
* to just determine output length. */
static unsigned int decode_search (const unsigned char *p, int len, char *out)
{
const unsigned char *r, *q = p;
unsigned int count = 0, l, hops;
while (q - p < len) {
r = NULL;
hops = 0;
while ((l = *q++)) {
unsigned int label_type = l & 0xc0;
if (label_type == 0x80 || label_type == 0x40)
return 0;
else if (label_type == 0xc0) { /* pointer */
l = (l & 0x3f) << 8;
l |= *q++;
/* save source of first jump. */
if (!r)
r = q;
hops++;
if (hops > 255)
return 0;
q = p + l;
if (q - p >= len)
return 0;
} else {
/* straightforward name segment, add with '.' */
count += l + 1;
if (out) {
memcpy (out, q, l);
out += l;
*out++ = '.';
}
q += l;
}
}
/* change last dot to space */
if (out)
*(out - 1) = ' ';
if (r)
q = r;
}
/* change last space to zero terminator */
if (out)
*(out - 1) = 0;
return count;
}
/* Add our classless static routes to the routes variable
* and return the last route set */
static route_t *decode_CSR(const unsigned char *p, int len)
{
const unsigned char *q = p;
unsigned int cidr;
unsigned int ocets;
route_t *first;
route_t *route;
/* Minimum is 5 -first is CIDR and a router length of 4 */
if (len < 5)
return NULL;
first = xzalloc (sizeof (*first));
route = first;
while (q - p < len) {
memset (route, 0, sizeof (*route));
cidr = *q++;
if (cidr > 32) {
logger (LOG_ERR,
"invalid CIDR of %d in classless static route",
cidr);
free_route (first);
return (NULL);
}
ocets = (cidr + 7) / 8;
if (ocets > 0) {
memcpy (&route->destination.s_addr, q, (size_t) ocets);
q += ocets;
}
/* Now enter the netmask */
if (ocets > 0) {
memset (&route->netmask.s_addr, 255, (size_t) ocets - 1);
memset ((unsigned char *) &route->netmask.s_addr +
(ocets - 1),
(256 - (1 << (32 - cidr) % 8)), 1);
}
/* Finally, snag the router */
memcpy (&route->gateway.s_addr, q, 4);
q += 4;
/* We have another route */
if (q - p < len) {
route->next = xzalloc (sizeof (*route));
route = route->next;
}
}
return first;
}
void free_dhcp (dhcp_t *dhcp)
{
if (! dhcp)
return;
free_route (dhcp->routes);
free (dhcp->hostname);
free_address (dhcp->dnsservers);
free (dhcp->dnsdomain);
free (dhcp->dnssearch);
free_address (dhcp->ntpservers);
free (dhcp->nisdomain);
free_address (dhcp->nisservers);
free (dhcp->rootpath);
free (dhcp->sipservers);
if (dhcp->fqdn) {
free (dhcp->fqdn->name);
free (dhcp->fqdn);
}
}
static bool dhcp_add_address (address_t **address,
const unsigned char *data, int length)
{
int i;
address_t *p = *address;
for (i = 0; i < length; i += 4) {
if (*address == NULL) {
p = *address = xzalloc (sizeof (*p));
} else {
p->next = xzalloc (sizeof (*p));
p = p->next;
}
/* Sanity check */
if (i + 4 > length) {
logger (LOG_ERR, "invalid address length");
return (false);
}
memcpy (&p->address.s_addr, data + i, 4);
}
return (true);
}
#ifdef ENABLE_INFO
static char *decode_sipservers (const unsigned char *data, int length)
{
char *sip = NULL;
char *p;
const char encoding = *data++;
struct in_addr addr;
size_t len;
length--;
switch (encoding) {
case 0:
if ((len = decode_search (data, length, NULL)) > 0) {
sip = xmalloc (len);
decode_search (data, length, sip);
}
break;
case 1:
if (length == 0 || length % 4 != 0) {
logger (LOG_ERR,
"invalid length %d for option 120",
length + 1);
break;
}
len = ((length / 4) * (4 * 4)) + 1;
sip = p = xmalloc (len);
while (length != 0) {
memcpy (&addr.s_addr, data, 4);
data += 4;
p += snprintf (p, len - (p - sip),
"%s ", inet_ntoa (addr));
length -= 4;
}
*--p = '\0';
break;
default:
logger (LOG_ERR, "unknown sip encoding %d", encoding);
break;
}
return (sip);
}
#endif
/* This calculates the netmask that we should use for static routes.
* This IS different from the calculation used to calculate the netmask
* for an interface address. */
static uint32_t route_netmask (uint32_t ip_in)
{
/* used to be unsigned long - check if error */
uint32_t p = ntohl (ip_in);
uint32_t t;
if (IN_CLASSA (p))
t = ~IN_CLASSA_NET;
else {
if (IN_CLASSB (p))
t = ~IN_CLASSB_NET;
else {
if (IN_CLASSC (p))
t = ~IN_CLASSC_NET;
else
t = 0;
}
}
while (t & p)
t >>= 1;
return (htonl (~t));
}
static route_t *decode_routes (const unsigned char *data, int length)
{
int i;
route_t *head = NULL;
route_t *routes = NULL;
for (i = 0; i < length; i += 8) {
if (routes) {
routes->next = xzalloc (sizeof (*routes));
routes = routes->next;
} else
head = routes = xzalloc (sizeof (*head));
memcpy (&routes->destination.s_addr, data + i, 4);
memcpy (&routes->gateway.s_addr, data + i + 4, 4);
routes->netmask.s_addr =
route_netmask (routes->destination.s_addr);
}
return (head);
}
static route_t *decode_routers (const unsigned char *data, int length)
{
int i;
route_t *head = NULL;
route_t *routes = NULL;
for (i = 0; i < length; i += 4) {
if (routes) {
routes->next = xzalloc (sizeof (*routes));
routes = routes->next;
} else
head = routes = xzalloc (sizeof (*head));
memcpy (&routes->gateway.s_addr, data + i, 4);
}
return (head);
}
int parse_dhcpmessage (dhcp_t *dhcp, const dhcpmessage_t *message)
{
const unsigned char *p = message->options;
const unsigned char *end = p; /* Add size later for gcc-3 issue */
unsigned char option;
unsigned char length;
unsigned int len = 0;
int retval = -1;
struct timeval tv;
route_t *routers = NULL;
route_t *routes = NULL;
route_t *csr = NULL;
route_t *mscsr = NULL;
bool in_overload = false;
bool parse_sname = false;
bool parse_file = false;
end += sizeof (message->options);
if (gettimeofday (&tv, NULL) == -1) {
logger (LOG_ERR, "gettimeofday: %s", strerror (errno));
return (-1);
}
dhcp->address.s_addr = message->yiaddr;
dhcp->leasedfrom = tv.tv_sec;
dhcp->frominfo = false;
dhcp->address.s_addr = message->yiaddr;
strlcpy (dhcp->servername, (char *) message->servername,
sizeof (dhcp->servername));
#define LEN_ERR \
{ \
logger (LOG_ERR, "invalid length %d for option %d", \
length, option); \
p += length; \
continue; \
}
parse_start:
while (p < end) {
option = *p++;
if (! option)
continue;
if (option == DHCP_END)
goto eexit;
length = *p++;
if (option != DHCP_PAD && length == 0) {
logger (LOG_ERR, "option %d has zero length", option);
retval = -1;
goto eexit;
}
if (p + length >= end) {
logger (LOG_ERR, "dhcp option exceeds message length");
retval = -1;
goto eexit;
}
switch (option) {
case DHCP_MESSAGETYPE:
retval = (int) *p;
p += length;
continue;
default:
if (length == 0) {
logger (LOG_DEBUG,
"option %d has zero length, skipping",
option);
continue;
}
}
#define LENGTH(_length) \
if (length != _length) \
LEN_ERR;
#define MIN_LENGTH(_length) \
if (length < _length) \
LEN_ERR;
#define MULT_LENGTH(_mult) \
if (length % _mult != 0) \
LEN_ERR;
#define GET_UINT8(_val) \
LENGTH (sizeof (uint8_t)); \
memcpy (&_val, p, sizeof (uint8_t));
#define GET_UINT16(_val) \
LENGTH (sizeof (uint16_t)); \
memcpy (&_val, p, sizeof (uint16_t));
#define GET_UINT32(_val) \
LENGTH (sizeof (uint32_t)); \
memcpy (&_val, p, sizeof (uint32_t));
#define GET_UINT16_H(_val) \
GET_UINT16 (_val); \
_val = ntohs (_val);
#define GET_UINT32_H(_val) \
GET_UINT32 (_val); \
_val = ntohl (_val);
switch (option) {
case DHCP_ADDRESS:
GET_UINT32 (dhcp->address.s_addr);
break;
case DHCP_NETMASK:
GET_UINT32 (dhcp->netmask.s_addr);
break;
case DHCP_BROADCAST:
GET_UINT32 (dhcp->broadcast.s_addr);
break;
case DHCP_SERVERIDENTIFIER:
GET_UINT32 (dhcp->serveraddress.s_addr);
break;
case DHCP_LEASETIME:
GET_UINT32_H (dhcp->leasetime);
break;
case DHCP_RENEWALTIME:
GET_UINT32_H (dhcp->renewaltime);
break;
case DHCP_REBINDTIME:
GET_UINT32_H (dhcp->rebindtime);
break;
case DHCP_MTU:
GET_UINT16_H (dhcp->mtu);
/* Minimum legal mtu is 68 accoridng to
* RFC 2132. In practise it's 576 which is the
* minimum maximum message size. */
if (dhcp->mtu < MTU_MIN) {
logger (LOG_DEBUG,
"MTU %d is too low, minimum is %d; ignoring",
dhcp->mtu, MTU_MIN);
dhcp->mtu = 0;
}
break;
#undef GET_UINT32_H
#undef GET_UINT32
#undef GET_UINT16_H
#undef GET_UINT16
#undef GET_UINT8
#define GETSTR(_var) { \
MIN_LENGTH (sizeof (char)); \
if (_var) free (_var); \
_var = xmalloc ((size_t) length + 1); \
memcpy (_var, p, (size_t) length); \
memset (_var + length, 0, 1); \
}
case DHCP_HOSTNAME:
GETSTR (dhcp->hostname);
break;
case DHCP_DNSDOMAIN:
GETSTR (dhcp->dnsdomain);
break;
case DHCP_MESSAGE:
GETSTR (dhcp->message);
break;
#ifdef ENABLE_INFO
case DHCP_ROOTPATH:
GETSTR (dhcp->rootpath);
break;
#endif
#ifdef ENABLE_NIS
case DHCP_NISDOMAIN:
GETSTR (dhcp->nisdomain);
break;
#endif
#undef GETSTR
#define GETADDR(_var) \
MULT_LENGTH (4); \
if (! dhcp_add_address (&_var, p, length)) \
{ \
retval = -1; \
goto eexit; \
}
case DHCP_DNSSERVER:
GETADDR (dhcp->dnsservers);
break;
#ifdef ENABLE_NTP
case DHCP_NTPSERVER:
GETADDR (dhcp->ntpservers);
break;
#endif
#ifdef ENABLE_NIS
case DHCP_NISSERVER:
GETADDR (dhcp->nisservers);
break;
#endif
#undef GETADDR
case DHCP_DNSSEARCH:
MIN_LENGTH (1);
free (dhcp->dnssearch);
len = decode_search (p, length, NULL);
if (len > 0) {
dhcp->dnssearch = xmalloc (len);
decode_search (p, length,
dhcp->dnssearch);
}
break;
case DHCP_CSR:
MIN_LENGTH (5);
free_route (csr);
csr = decode_CSR (p, length);
break;
case DHCP_MSCSR:
MIN_LENGTH (5);
free_route (mscsr);
mscsr = decode_CSR (p, length);
break;
#ifdef ENABLE_INFO
case DHCP_SIPSERVER:
free (dhcp->sipservers);
dhcp->sipservers = decode_sipservers (p,length);
break;
#endif
case DHCP_STATICROUTE:
MULT_LENGTH (8);
free_route (routes);
routes = decode_routes (p, length);
break;
case DHCP_ROUTERS:
MULT_LENGTH (4);
free_route (routers);
routers = decode_routers (p, length);
break;
case DHCP_OPTIONSOVERLOADED:
LENGTH (1);
/* The overloaded option in an overloaded option
* should be ignored, overwise we may get an
* infinite loop */
if (! in_overload) {
if (*p & 1)
parse_file = true;
if (*p & 2)
parse_sname = true;
}
break;
case DHCP_FQDN:
/* We ignore replies about FQDN */
break;
#undef LENGTH
#undef MIN_LENGTH
#undef MULT_LENGTH
default:
logger (LOG_DEBUG,
"no facility to parse DHCP code %u",
option);
break;
}
p += length;
}
eexit:
/* We may have options overloaded, so go back and grab them */
if (parse_file) {
parse_file = false;
p = message->bootfile;
end = p + sizeof (message->bootfile);
in_overload = true;
goto parse_start;
} else if (parse_sname) {
parse_sname = false;
p = message->servername;
end = p + sizeof (message->servername);
memset (dhcp->servername, 0, sizeof (dhcp->servername));
in_overload = true;
goto parse_start;
}
/* Fill in any missing fields */
if (! dhcp->netmask.s_addr)
dhcp->netmask.s_addr = get_netmask (dhcp->address.s_addr);
if (! dhcp->broadcast.s_addr)
dhcp->broadcast.s_addr = dhcp->address.s_addr |
~dhcp->netmask.s_addr;
/* If we have classess static routes then we discard
* static routes and routers according to RFC 3442 */
if (csr) {
dhcp->routes = csr;
free_route (mscsr);
free_route (routers);
free_route (routes);
} else if (mscsr) {
dhcp->routes = mscsr;
free_route (routers);
free_route (routes);
} else {
/* Ensure that we apply static routes before routers */
if (routes)
{
dhcp->routes = routes;
while (routes->next)
routes = routes->next;
routes->next = routers;
} else
dhcp->routes = routers;
}
return (retval);
}
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