initial user mode network support

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@733 c046a42c-6fe2-441c-8c8c-71466251a162

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);
+    }
+}