slirp: Rework internal configuration

The user mode IP stack is currently only minimally configurable /wrt to
its virtual IP addresses. This is unfortunate if some guest has a fixed
idea of which IP addresses to use.

Therefore this patch prepares the stack for fully configurable IP
addresses and masks. The user interface and default addresses remain
untouched in this step, they will be enhanced in the following patch.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

1 files changed, 10 insertions, 16 deletions

diff --git a/slirp/bootp.c b/slirp/bootp.c
index a2fd734cd4..97c2811fbf 100644
--- a/slirp/bootp.c
+++ b/slirp/bootp.c
@@ -27,8 +27,6 @@
 
 #define NB_ADDR 16
 
-#define START_ADDR 15
-
 #define LEASE_TIME (24 * 3600)
 
 typedef struct {
@@ -64,7 +62,7 @@ static BOOTPClient *get_new_addr(struct in_addr *paddr,
  found:
     bc = &bootp_clients[i];
     bc->allocated = 1;
-    paddr->s_addr = htonl(ntohl(special_addr.s_addr) | (i + START_ADDR));
+    paddr->s_addr = vdhcp_startaddr.s_addr + htonl(i);
     return bc;
 }
 
@@ -72,12 +70,12 @@ static BOOTPClient *request_addr(const struct in_addr *paddr,
                                  const uint8_t *macaddr)
 {
     uint32_t req_addr = ntohl(paddr->s_addr);
-    uint32_t spec_addr = ntohl(special_addr.s_addr);
+    uint32_t dhcp_addr = ntohl(vdhcp_startaddr.s_addr);
     BOOTPClient *bc;
 
-    if (req_addr >= (spec_addr | START_ADDR) &&
-        req_addr < (spec_addr | (NB_ADDR + START_ADDR))) {
-        bc = &bootp_clients[(req_addr & 0xff) - START_ADDR];
+    if (req_addr >= dhcp_addr &&
+        req_addr < (dhcp_addr + NB_ADDR)) {
+        bc = &bootp_clients[req_addr - dhcp_addr];
         if (!bc->allocated || !memcmp(macaddr, bc->macaddr, 6)) {
             bc->allocated = 1;
             return bc;
@@ -99,7 +97,7 @@ static BOOTPClient *find_addr(struct in_addr *paddr, const uint8_t *macaddr)
  found:
     bc = &bootp_clients[i];
     bc->allocated = 1;
-    paddr->s_addr = htonl(ntohl(special_addr.s_addr) | (i + START_ADDR));
+    paddr->s_addr = vdhcp_startaddr.s_addr + htonl(i);
     return bc;
 }
 
@@ -156,7 +154,6 @@ static void bootp_reply(const struct bootp_t *bp)
     struct mbuf *m;
     struct bootp_t *rbp;
     struct sockaddr_in saddr, daddr;
-    struct in_addr dns_addr;
     const struct in_addr *preq_addr;
     int dhcp_msg_type, val;
     uint8_t *q;
@@ -218,7 +215,7 @@ static void bootp_reply(const struct bootp_t *bp)
         }
     }
 
-    saddr.sin_addr.s_addr = htonl(ntohl(special_addr.s_addr) | CTL_ALIAS);
+    saddr.sin_addr = vhost_addr;
     saddr.sin_port = htons(BOOTP_SERVER);
 
     daddr.sin_port = htons(BOOTP_CLIENT);
@@ -262,10 +259,8 @@ static void bootp_reply(const struct bootp_t *bp)
 
         *q++ = RFC1533_NETMASK;
         *q++ = 4;
-        *q++ = 0xff;
-        *q++ = 0xff;
-        *q++ = 0xff;
-        *q++ = 0x00;
+        memcpy(q, &vnetwork_mask, 4);
+        q += 4;
 
         if (!slirp_restrict) {
             *q++ = RFC1533_GATEWAY;
@@ -275,8 +270,7 @@ static void bootp_reply(const struct bootp_t *bp)
 
             *q++ = RFC1533_DNS;
             *q++ = 4;
-            dns_addr.s_addr = htonl(ntohl(special_addr.s_addr) | CTL_DNS);
-            memcpy(q, &dns_addr, 4);
+            memcpy(q, &vnameserver_addr, 4);
             q += 4;
         }