Bochs/bochs/iodev/network/slirp/bootp.cc
2017-04-21 15:28:25 +00:00

479 lines
16 KiB
C++

/////////////////////////////////////////////////////////////////////////
// $Id$
/////////////////////////////////////////////////////////////////////////
/*
* BOOTP/DHCP server (ported from Qemu)
* Bochs additions: parameter list and some other options
*
* Copyright (c) 2004 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "slirp.h"
#if BX_NETWORKING && BX_NETMOD_SLIRP
/* XXX: only DHCP is supported */
#define LEASE_TIME (24 * 3600)
typedef struct {
int msg_type;
bx_bool found_srv_id;
struct in_addr req_addr;
uint8_t *params;
uint8_t params_len;
char *hostname;
uint32_t lease_time;
} dhcp_options_t;
static const uint8_t rfc1533_cookie[] = { RFC1533_COOKIE };
#ifdef DEBUG
#define DPRINTF(fmt, ...) \
do if (slirp_debug & DBG_CALL) { fprintf(dfd, fmt, ## __VA_ARGS__); fflush(dfd); } while (0)
#else
#define DPRINTF(fmt, ...) do{}while(0)
#endif
static BOOTPClient *get_new_addr(Slirp *slirp, struct in_addr *paddr,
const uint8_t *macaddr)
{
BOOTPClient *bc;
int i;
for(i = 0; i < NB_BOOTP_CLIENTS; i++) {
bc = &slirp->bootp_clients[i];
if (!bc->allocated || !memcmp(macaddr, bc->macaddr, 6))
goto found;
}
return NULL;
found:
bc = &slirp->bootp_clients[i];
bc->allocated = 1;
paddr->s_addr = slirp->vdhcp_startaddr.s_addr + htonl(i);
return bc;
}
static BOOTPClient *request_addr(Slirp *slirp, const struct in_addr *paddr,
const uint8_t *macaddr)
{
uint32_t req_addr = ntohl(paddr->s_addr);
uint32_t dhcp_addr = ntohl(slirp->vdhcp_startaddr.s_addr);
BOOTPClient *bc;
if (req_addr >= dhcp_addr &&
req_addr < (dhcp_addr + NB_BOOTP_CLIENTS)) {
bc = &slirp->bootp_clients[req_addr - dhcp_addr];
if (!bc->allocated || !memcmp(macaddr, bc->macaddr, 6)) {
bc->allocated = 1;
return bc;
}
}
return NULL;
}
static BOOTPClient *find_addr(Slirp *slirp, struct in_addr *paddr,
const uint8_t *macaddr)
{
BOOTPClient *bc;
int i;
for(i = 0; i < NB_BOOTP_CLIENTS; i++) {
if (!memcmp(macaddr, slirp->bootp_clients[i].macaddr, 6))
goto found;
}
return NULL;
found:
bc = &slirp->bootp_clients[i];
bc->allocated = 1;
paddr->s_addr = slirp->vdhcp_startaddr.s_addr + htonl(i);
return bc;
}
static void dhcp_decode(Slirp *slirp, const struct bootp_t *bp, dhcp_options_t *opts)
{
const uint8_t *p, *p_end;
uint16_t defsize, maxsize;
int len, tag;
char msg[80];
memset(opts, 0, sizeof(dhcp_options_t));
p = bp->bp_vend;
p_end = p + DHCP_OPT_LEN;
if (memcmp(p, rfc1533_cookie, 4) != 0)
return;
p += 4;
while (p < p_end) {
tag = p[0];
if (tag == RFC1533_PAD) {
p++;
} else if (tag == RFC1533_END) {
break;
} else {
p++;
if (p >= p_end)
break;
len = *p++;
DPRINTF("dhcp: tag=%d len=%d\n", tag, len);
switch(tag) {
case RFC2132_MSG_TYPE:
if (len >= 1)
opts->msg_type = p[0];
break;
case RFC2132_REQ_ADDR:
if (len >= 4) {
memcpy(&(opts->req_addr.s_addr), p, 4);
}
break;
case RFC2132_SRV_ID:
if (len >= 4) {
if (!memcmp(p, &slirp->vhost_addr, 4)) {
opts->found_srv_id = 1;
}
}
break;
case RFC2132_PARAM_LIST:
if (len >= 1) {
opts->params = (uint8_t*)malloc(len);
memcpy(opts->params, p, len);
opts->params_len = len;
}
break;
case RFC1533_HOSTNAME:
if (len >= 1) {
opts->hostname = (char*)malloc(len + 1);
memcpy(opts->hostname, p, len);
opts->hostname[len] = 0;
}
break;
case RFC2132_LEASE_TIME:
if (len == 4) {
memcpy(&opts->lease_time, p, len);
}
break;
case RFC2132_MAX_SIZE:
if (len == 2) {
memcpy(&maxsize, p, len);
defsize = sizeof(struct bootp_t) - sizeof(struct ip) - sizeof(struct udphdr);
if (ntohs(maxsize) < defsize) {
sprintf(msg, "DHCP server: RFB2132_MAX_SIZE=%u not supported yet", ntohs(maxsize));
slirp_warning(slirp, msg);
}
}
break;
default:
sprintf(msg, "DHCP server: option %d not supported yet", tag);
slirp_warning(slirp, msg);
break;
}
p += len;
}
}
if ((opts->msg_type == DHCPREQUEST) && (opts->req_addr.s_addr == htonl(0L)) &&
bp->bp_ciaddr.s_addr) {
memcpy(&(opts->req_addr.s_addr), &bp->bp_ciaddr, 4);
}
}
static void bootp_reply(Slirp *slirp, const struct bootp_t *bp)
{
BOOTPClient *bc = NULL;
struct mbuf *m;
struct bootp_t *rbp;
struct sockaddr_in saddr, daddr;
struct in_addr bcast_addr;
int val;
uint8_t *q, *pp, plen, dhcp_def_params_len;
uint8_t client_ethaddr[ETH_ALEN];
uint8_t dhcp_def_params[8];
bx_bool dhcp_def_params_valid = 0;
dhcp_options_t dhcp_opts;
size_t spaceleft;
char msg[80];
/* extract exact DHCP msg type */
dhcp_decode(slirp, bp, &dhcp_opts);
DPRINTF("bootp packet op=%d msgtype=%d", bp->bp_op, dhcp_opts.msg_type);
if (dhcp_opts.req_addr.s_addr != htonl(0L))
DPRINTF(" req_addr=%08x\n", ntohl(dhcp_opts.req_addr.s_addr));
else
DPRINTF("\n");
if (dhcp_opts.msg_type == 0)
dhcp_opts.msg_type = DHCPREQUEST; /* Force reply for old BOOTP clients */
if (dhcp_opts.msg_type != DHCPDISCOVER &&
dhcp_opts.msg_type != DHCPREQUEST)
return;
/* Get client's hardware address from bootp request */
memcpy(client_ethaddr, bp->bp_hwaddr, ETH_ALEN);
m = m_get(slirp);
if (!m) {
return;
}
m->m_data += IF_MAXLINKHDR;
rbp = (struct bootp_t *)m->m_data;
m->m_data += sizeof(struct udpiphdr);
memset(rbp, 0, sizeof(struct bootp_t));
dhcp_def_params_len = 0;
if (dhcp_opts.msg_type == DHCPDISCOVER) {
if (dhcp_opts.req_addr.s_addr != htonl(0L)) {
bc = request_addr(slirp, &dhcp_opts.req_addr, client_ethaddr);
if (bc) {
daddr.sin_addr = dhcp_opts.req_addr;
}
}
if (!bc) {
new_addr:
bc = get_new_addr(slirp, &daddr.sin_addr, client_ethaddr);
if (!bc) {
DPRINTF("no address left\n");
return;
}
}
memcpy(bc->macaddr, client_ethaddr, ETH_ALEN);
dhcp_def_params[0] = RFC2132_LEASE_TIME;
dhcp_def_params[1] = RFC2132_SRV_ID;
dhcp_def_params_len = 2;
if (*slirp->client_hostname || (dhcp_opts.hostname != NULL)) {
dhcp_def_params[dhcp_def_params_len++] = RFC1533_HOSTNAME;
}
dhcp_def_params_valid = 1;
} else if (dhcp_opts.req_addr.s_addr != htonl(0L)) {
bc = request_addr(slirp, &dhcp_opts.req_addr, client_ethaddr);
if (bc) {
daddr.sin_addr = dhcp_opts.req_addr;
memcpy(bc->macaddr, client_ethaddr, ETH_ALEN);
dhcp_def_params[0] = RFC2132_LEASE_TIME;
dhcp_def_params_len = 1;
if (!dhcp_opts.found_srv_id) {
dhcp_def_params[dhcp_def_params_len++] = RFC2132_SRV_ID;
}
dhcp_def_params_valid = 1;
} else {
/* DHCPNAKs should be sent to broadcast */
daddr.sin_addr.s_addr = 0xffffffff;
}
} else {
bc = find_addr(slirp, &daddr.sin_addr, bp->bp_hwaddr);
if (!bc) {
/* if never assigned, behaves as if it was already
assigned (windows fix because it remembers its address) */
goto new_addr;
}
}
/* Update ARP table for this IP address */
arp_table_add(slirp, daddr.sin_addr.s_addr, client_ethaddr);
saddr.sin_addr = slirp->vhost_addr;
saddr.sin_port = htons(BOOTP_SERVER);
daddr.sin_port = htons(BOOTP_CLIENT);
rbp->bp_op = BOOTP_REPLY;
rbp->bp_xid = bp->bp_xid;
rbp->bp_htype = 1;
rbp->bp_hlen = 6;
memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, ETH_ALEN);
rbp->bp_yiaddr = daddr.sin_addr; /* Client IP address */
rbp->bp_siaddr = saddr.sin_addr; /* Server IP address */
q = rbp->bp_vend;
memcpy(q, rfc1533_cookie, 4);
q += 4;
if (bc) {
DPRINTF("%s addr=%08x\n",
(dhcp_opts.msg_type == DHCPDISCOVER) ? "offered" : "ack'ed",
ntohl(daddr.sin_addr.s_addr));
if (dhcp_opts.msg_type == DHCPDISCOVER) {
*q++ = RFC2132_MSG_TYPE;
*q++ = 1;
*q++ = DHCPOFFER;
} else /* DHCPREQUEST */ {
*q++ = RFC2132_MSG_TYPE;
*q++ = 1;
*q++ = DHCPACK;
}
if (slirp->bootp_filename)
snprintf((char *)rbp->bp_file, sizeof(rbp->bp_file), "%s",
slirp->bootp_filename);
strcpy((char *)rbp->bp_sname, "slirp");
pp = dhcp_opts.params;
plen = dhcp_opts.params_len;
while (1) {
while (plen-- > 0) {
spaceleft = sizeof(rbp->bp_vend) - (q - rbp->bp_vend);
if (spaceleft < 6) break;
switch (*pp++) {
case RFC1533_NETMASK:
*q++ = RFC1533_NETMASK;
*q++ = 4;
memcpy(q, &slirp->vnetwork_mask, 4);
q += 4;
break;
case RFC1533_GATEWAY:
if (!slirp->restricted) {
*q++ = RFC1533_GATEWAY;
*q++ = 4;
memcpy(q, &saddr.sin_addr, 4);
q += 4;
}
break;
case RFC1533_DNS:
if (!slirp->restricted) {
*q++ = RFC1533_DNS;
*q++ = 4;
memcpy(q, &slirp->vnameserver_addr, 4);
q += 4;
}
break;
case RFC1533_HOSTNAME:
val = 0;
if (*slirp->client_hostname) {
val = strlen(slirp->client_hostname);
} else if (dhcp_opts.hostname != NULL) {
val = strlen(dhcp_opts.hostname);
}
if ((val > 0) && (spaceleft >= (size_t)(val + 2))) {
*q++ = RFC1533_HOSTNAME;
*q++ = val;
if (*slirp->client_hostname) {
memcpy(q, slirp->client_hostname, val);
} else {
memcpy(q, dhcp_opts.hostname, val);
}
q += val;
}
if (dhcp_opts.hostname != NULL) {
free(dhcp_opts.hostname);
dhcp_opts.hostname = NULL;
}
break;
case RFC1533_INTBROADCAST:
*q++ = RFC1533_INTBROADCAST;
*q++ = 4;
bcast_addr.s_addr = slirp->vhost_addr.s_addr | ~slirp->vnetwork_mask.s_addr;
memcpy(q, &bcast_addr, 4);
q += 4;
break;
case RFC2132_LEASE_TIME:
*q++ = RFC2132_LEASE_TIME;
*q++ = 4;
if ((dhcp_opts.lease_time != 0) &&
(ntohl(dhcp_opts.lease_time) < LEASE_TIME)) {
memcpy(q, &dhcp_opts.lease_time, 4);
} else {
val = htonl(LEASE_TIME);
memcpy(q, &val, 4);
}
q += 4;
dhcp_opts.lease_time = 0;
break;
case RFC2132_SRV_ID:
*q++ = RFC2132_SRV_ID;
*q++ = 4;
memcpy(q, &saddr.sin_addr, 4);
q += 4;
break;
case RFC2132_RENEWAL_TIME:
*q++ = RFC2132_RENEWAL_TIME;
*q++ = 4;
val = htonl(600);
memcpy(q, &val, 4);
q += 4;
break;
case RFC2132_REBIND_TIME:
*q++ = RFC2132_REBIND_TIME;
*q++ = 4;
val = htonl(1800);
memcpy(q, &val, 4);
q += 4;
break;
default:
sprintf(msg, "DHCP server: requested parameter %u not supported yet",
*(pp-1));
slirp_warning(slirp, msg);
}
}
if (!dhcp_def_params_valid) break;
pp = dhcp_def_params;
plen = dhcp_def_params_len;
dhcp_def_params_valid = 0;
}
if (slirp->vdnssearch) {
spaceleft = sizeof(rbp->bp_vend) - (q - rbp->bp_vend);
val = slirp->vdnssearch_len;
if (val + 1 > (int)spaceleft) {
slirp_warning(slirp, "DHCP packet size exceeded, omitting domain-search option.");
} else {
memcpy(q, slirp->vdnssearch, val);
q += val;
}
}
} else {
static const char nak_msg[] = "requested address not available";
DPRINTF("nak'ed addr=%08x\n", ntohl(dhcp_opts.req_addr.s_addr));
*q++ = RFC2132_MSG_TYPE;
*q++ = 1;
*q++ = DHCPNAK;
*q++ = RFC2132_MESSAGE;
*q++ = sizeof(nak_msg) - 1;
memcpy(q, nak_msg, sizeof(nak_msg) - 1);
q += sizeof(nak_msg) - 1;
}
*q = RFC1533_END;
daddr.sin_addr.s_addr = 0xffffffffu;
if (dhcp_opts.params != NULL) free(dhcp_opts.params);
m->m_len = sizeof(struct bootp_t) -
sizeof(struct ip) - sizeof(struct udphdr);
udp_output2(NULL, m, &saddr, &daddr, IPTOS_LOWDELAY);
}
void bootp_input(struct mbuf *m)
{
struct bootp_t *bp = mtod(m, struct bootp_t *);
if (bp->bp_op == BOOTP_REQUEST) {
bootp_reply(m->slirp, bp);
}
}
#endif