--- /dev/null
+/*
+ * QEMU BOOTP/DHCP server
+ *
+ * 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>
+
+/* XXX: only DHCP is supported */
+
+#define LEASE_TIME (24 * 3600)
+
+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(const struct bootp_t *bp, int *pmsg_type,
+ struct in_addr *preq_addr)
+{
+ const uint8_t *p, *p_end;
+ int len, tag;
+
+ *pmsg_type = 0;
+ preq_addr->s_addr = htonl(0L);
+
+ 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)
+ *pmsg_type = p[0];
+ break;
+ case RFC2132_REQ_ADDR:
+ if (len >= 4) {
+ memcpy(&(preq_addr->s_addr), p, 4);
+ }
+ break;
+ default:
+ break;
+ }
+ p += len;
+ }
+ }
+ if (*pmsg_type == DHCPREQUEST && preq_addr->s_addr == htonl(0L) &&
+ bp->bp_ciaddr.s_addr) {
+ memcpy(&(preq_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 preq_addr;
+ int dhcp_msg_type, val;
+ uint8_t *q;
+ uint8_t client_ethaddr[ETH_ALEN];
+
+ /* extract exact DHCP msg type */
+ dhcp_decode(bp, &dhcp_msg_type, &preq_addr);
+ DPRINTF("bootp packet op=%d msgtype=%d", bp->bp_op, dhcp_msg_type);
+ if (preq_addr.s_addr != htonl(0L))
+ DPRINTF(" req_addr=%08x\n", ntohl(preq_addr.s_addr));
+ else
+ DPRINTF("\n");
+
+ if (dhcp_msg_type == 0)
+ dhcp_msg_type = DHCPREQUEST; /* Force reply for old BOOTP clients */
+
+ if (dhcp_msg_type != DHCPDISCOVER &&
+ dhcp_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));
+
+ if (dhcp_msg_type == DHCPDISCOVER) {
+ if (preq_addr.s_addr != htonl(0L)) {
+ bc = request_addr(slirp, &preq_addr, client_ethaddr);
+ if (bc) {
+ daddr.sin_addr = preq_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);
+ } else if (preq_addr.s_addr != htonl(0L)) {
+ bc = request_addr(slirp, &preq_addr, client_ethaddr);
+ if (bc) {
+ daddr.sin_addr = preq_addr;
+ memcpy(bc->macaddr, client_ethaddr, ETH_ALEN);
+ } 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_msg_type == DHCPDISCOVER) ? "offered" : "ack'ed",
+ ntohl(daddr.sin_addr.s_addr));
+
+ if (dhcp_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);
+
+ *q++ = RFC2132_SRV_ID;
+ *q++ = 4;
+ memcpy(q, &saddr.sin_addr, 4);
+ q += 4;
+
+ *q++ = RFC1533_NETMASK;
+ *q++ = 4;
+ memcpy(q, &slirp->vnetwork_mask, 4);
+ q += 4;
+
+ if (!slirp->restricted) {
+ *q++ = RFC1533_GATEWAY;
+ *q++ = 4;
+ memcpy(q, &saddr.sin_addr, 4);
+ q += 4;
+
+ *q++ = RFC1533_DNS;
+ *q++ = 4;
+ memcpy(q, &slirp->vnameserver_addr, 4);
+ q += 4;
+ }
+
+ *q++ = RFC2132_LEASE_TIME;
+ *q++ = 4;
+ val = htonl(LEASE_TIME);
+ memcpy(q, &val, 4);
+ q += 4;
+
+ if (*slirp->client_hostname) {
+ val = strlen(slirp->client_hostname);
+ *q++ = RFC1533_HOSTNAME;
+ *q++ = val;
+ memcpy(q, slirp->client_hostname, val);
+ q += val;
+ }
+
+ if (slirp->vdnssearch) {
+ size_t spaceleft = sizeof(rbp->bp_vend) - (q - rbp->bp_vend);
+ val = slirp->vdnssearch_len;
+ if (val + 1 > spaceleft) {
+ g_warning("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(preq_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;
+
+ 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);
+ }
+}
Code Review / kvmfornfv.git / blobdiff