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-rw-r--r--slirp/bootp.c212
1 files changed, 212 insertions, 0 deletions
diff --git a/slirp/bootp.c b/slirp/bootp.c
new file mode 100644
index 0000000..7e4b5ba
--- /dev/null
+++ b/slirp/bootp.c
@@ -0,0 +1,212 @@
+/*
+ * 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 NB_ADDR 16
+
+#define START_ADDR 15
+
+#define LEASE_TIME (24 * 3600)
+
+typedef struct {
+ uint8_t allocated;
+} BOOTPClient;
+
+BOOTPClient bootp_clients[NB_ADDR];
+
+static const uint8_t rfc1533_cookie[] = { RFC1533_COOKIE };
+
+#ifdef DEBUG
+#define dprintf(fmt, args...) \
+if (slirp_debug & DBG_CALL) { fprintf(dfd, fmt, ## args); fflush(dfd); }
+#else
+#define dprintf(fmt, args...)
+#endif
+
+static BOOTPClient *get_new_addr(struct in_addr *paddr)
+{
+ BOOTPClient *bc;
+ int i;
+
+ for(i = 0; i < NB_ADDR; i++) {
+ if (!bootp_clients[i].allocated)
+ goto found;
+ }
+ return NULL;
+ found:
+ bc = &bootp_clients[i];
+ bc->allocated = 1;
+ paddr->s_addr = htonl(ntohl(special_addr.s_addr) | (i + START_ADDR));
+ return bc;
+}
+
+static void dhcp_decode(const uint8_t *buf, int size,
+ int *pmsg_type)
+{
+ const uint8_t *p, *p_end;
+ int len, tag;
+
+ *pmsg_type = 0;
+
+ p = buf;
+ p_end = buf + size;
+ if (size < 5)
+ return;
+ 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=0x%02x len=%d\n", tag, len);
+
+ switch(tag) {
+ case RFC2132_MSG_TYPE:
+ if (len >= 1)
+ *pmsg_type = p[0];
+ break;
+ default:
+ break;
+ }
+ p += len;
+ }
+ }
+}
+
+static void bootp_reply(struct bootp_t *bp)
+{
+ BOOTPClient *bc;
+ struct mbuf *m;
+ struct bootp_t *rbp;
+ struct sockaddr_in saddr, daddr;
+ struct in_addr dns_addr;
+ int dhcp_msg_type, val;
+ uint8_t *q;
+
+ /* extract exact DHCP msg type */
+ dhcp_decode(bp->bp_vend, DHCP_OPT_LEN, &dhcp_msg_type);
+ dprintf("bootp packet op=%d msgtype=%d\n", bp->bp_op, dhcp_msg_type);
+
+ if (dhcp_msg_type != DHCPDISCOVER &&
+ dhcp_msg_type != DHCPREQUEST)
+ return;
+ /* XXX: this is a hack to get the client mac address */
+ memcpy(client_ethaddr, bp->bp_hwaddr, 6);
+
+ if ((m = m_get()) == NULL)
+ 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));
+
+ bc = get_new_addr(&daddr.sin_addr);
+ if (!bc) {
+ dprintf("no address left\n");
+ return;
+ }
+ dprintf("offered addr=%08x\n", ntohl(daddr.sin_addr.s_addr));
+
+ saddr.sin_addr.s_addr = htonl(ntohl(special_addr.s_addr) | CTL_ALIAS);
+ 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, 6);
+
+ rbp->bp_yiaddr = daddr.sin_addr; /* IP address */
+
+ q = rbp->bp_vend;
+ memcpy(q, rfc1533_cookie, 4);
+ q += 4;
+
+ if (dhcp_msg_type == DHCPDISCOVER) {
+ *q++ = RFC2132_MSG_TYPE;
+ *q++ = 1;
+ *q++ = DHCPOFFER;
+ } else if (dhcp_msg_type == DHCPREQUEST) {
+ *q++ = RFC2132_MSG_TYPE;
+ *q++ = 1;
+ *q++ = DHCPACK;
+ }
+
+ if (dhcp_msg_type == DHCPDISCOVER ||
+ dhcp_msg_type == DHCPREQUEST) {
+ *q++ = RFC2132_SRV_ID;
+ *q++ = 4;
+ memcpy(q, &saddr.sin_addr, 4);
+ q += 4;
+
+ *q++ = RFC1533_NETMASK;
+ *q++ = 4;
+ *q++ = 0xff;
+ *q++ = 0xff;
+ *q++ = 0xff;
+ *q++ = 0x00;
+
+ *q++ = RFC1533_GATEWAY;
+ *q++ = 4;
+ memcpy(q, &saddr.sin_addr, 4);
+ q += 4;
+
+ *q++ = RFC1533_DNS;
+ *q++ = 4;
+ dns_addr.s_addr = htonl(ntohl(special_addr.s_addr) | CTL_DNS);
+ memcpy(q, &dns_addr, 4);
+ q += 4;
+
+ *q++ = RFC2132_LEASE_TIME;
+ *q++ = 4;
+ val = htonl(LEASE_TIME);
+ memcpy(q, &val, 4);
+ q += 4;
+ }
+ *q++ = RFC1533_END;
+
+ m->m_len = sizeof(struct bootp_t);
+ udp_output2(NULL, m, &saddr, &daddr, IPTOS_LOWDELAY);
+}
+
+void bootp_input(struct mbuf *m)
+{
+ struct bootp_t *bp = (struct bootp_t *)m->m_data;
+
+ if (bp->bp_op == BOOTP_REQUEST) {
+ bootp_reply(bp);
+ }
+}