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 <[email protected]> Signed-off-by: Anthony Liguori <[email protected]>
0x3h · Jun 29, 2009 · a13a412 · a13a412
1 parent ad196a9
commit a13a412
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Showing 13 changed files with 149 additions and 142 deletions.
diff --git 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 {
@@ -64,20 +62,20 @@ 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;
 }
 
 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;
         }
 

diff --git a/slirp/ctl.h b/slirp/ctl.h
diff --git a/slirp/ip_icmp.c b/slirp/ip_icmp.c
@@ -110,7 +110,7 @@ icmp_input(struct mbuf *m, int hlen)
   case ICMP_ECHO:
     icp->icmp_type = ICMP_ECHOREPLY;
     ip->ip_len += hlen;	             /* since ip_input subtracts this */
-    if (ip->ip_dst.s_addr == alias_addr.s_addr) {
+    if (ip->ip_dst.s_addr == vhost_addr.s_addr) {
       icmp_reflect(m);
     } else {
       struct socket *so;
@@ -134,16 +134,13 @@ icmp_input(struct mbuf *m, int hlen)
 
       /* Send the packet */
       addr.sin_family = AF_INET;
-      if ((so->so_faddr.s_addr & htonl(0xffffff00)) == special_addr.s_addr) {
+      if ((so->so_faddr.s_addr & vnetwork_mask.s_addr) ==
+          vnetwork_addr.s_addr) {
 	/* It's an alias */
-	switch(ntohl(so->so_faddr.s_addr) & 0xff) {
-	case CTL_DNS:
+	if (so->so_faddr.s_addr == vnameserver_addr.s_addr) {
 	  addr.sin_addr = dns_addr;
-	  break;
-	case CTL_ALIAS:
-	default:
+	} else {
 	  addr.sin_addr = loopback_addr;
-	  break;
 	}
       } else {
 	addr.sin_addr = so->so_faddr;
@@ -302,7 +299,7 @@ icmp_error(struct mbuf *msrc, u_char type, u_char code, int minsize,
   ip->ip_ttl = MAXTTL;
   ip->ip_p = IPPROTO_ICMP;
   ip->ip_dst = ip->ip_src;    /* ip adresses */
-  ip->ip_src = alias_addr;
+  ip->ip_src = vhost_addr;
 
   (void ) ip_output((struct socket *)NULL, m);
 

diff --git a/slirp/ip_input.c b/slirp/ip_input.c
@@ -134,18 +134,19 @@ ip_input(struct mbuf *m)
 	}
 
     if (slirp_restrict) {
-        if (memcmp(&ip->ip_dst.s_addr, &special_addr, 3)) {
+        if ((ip->ip_dst.s_addr & vnetwork_mask.s_addr) ==
+            vnetwork_addr.s_addr) {
             if (ip->ip_dst.s_addr == 0xffffffff && ip->ip_p != IPPROTO_UDP)
                 goto bad;
         } else {
-            int host = ntohl(ip->ip_dst.s_addr) & 0xff;
             struct ex_list *ex_ptr;
 
-            if (host == 0xff)
+            if ((ip->ip_dst.s_addr & ~vnetwork_mask.s_addr) ==
+                ~vnetwork_mask.s_addr)
                 goto bad;
 
             for (ex_ptr = exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next)
-                if (ex_ptr->ex_addr == host)
+                if (ex_ptr->ex_addr.s_addr == ip->ip_dst.s_addr)
                     break;
 
             if (!ex_ptr)

diff --git a/slirp/main.h b/slirp/main.h
@@ -32,9 +32,11 @@ extern char *slirp_tty;
 extern char *exec_shell;
 extern u_int curtime;
 extern fd_set *global_readfds, *global_writefds, *global_xfds;
-extern struct in_addr ctl_addr;
-extern struct in_addr special_addr;
-extern struct in_addr alias_addr;
+extern struct in_addr vnetwork_addr;
+extern struct in_addr vnetwork_mask;
+extern struct in_addr vhost_addr;
+extern struct in_addr vdhcp_startaddr;
+extern struct in_addr vnameserver_addr;
 extern struct in_addr our_addr;
 extern struct in_addr loopback_addr;
 extern struct in_addr dns_addr;
@@ -44,7 +46,6 @@ extern int towrite_max;
 extern int ppp_exit;
 extern int tcp_keepintvl;
 extern uint8_t client_ethaddr[6];
-extern const char *slirp_special_ip;
 extern int slirp_restrict;
 extern char *tftp_prefix;
 extern char *bootp_filename;

diff --git a/slirp/misc.c b/slirp/misc.c
@@ -112,15 +112,16 @@ remque(void *a)
 /* #endif */
 
 
-int
-add_exec(struct ex_list **ex_ptr, int do_pty, char *exec, int addr, int port)
+int add_exec(struct ex_list **ex_ptr, int do_pty, char *exec,
+             struct in_addr addr, int port)
 {
 	struct ex_list *tmp_ptr;
 
 	/* First, check if the port is "bound" */
 	for (tmp_ptr = *ex_ptr; tmp_ptr; tmp_ptr = tmp_ptr->ex_next) {
-		if (port == tmp_ptr->ex_fport && addr == tmp_ptr->ex_addr)
-		   return -1;
+		if (port == tmp_ptr->ex_fport &&
+		    addr.s_addr == tmp_ptr->ex_addr.s_addr)
+			return -1;
 	}
 
 	tmp_ptr = *ex_ptr;

diff --git a/slirp/misc.h b/slirp/misc.h
@@ -10,7 +10,7 @@
 
 struct ex_list {
 	int ex_pty;			/* Do we want a pty? */
-	int ex_addr;			/* The last byte of the address */
+	struct in_addr ex_addr;		/* Server address */
 	int ex_fport;                   /* Port to telnet to */
 	const char *ex_exec;            /* Command line of what to exec */
 	struct ex_list *ex_next;
@@ -74,7 +74,7 @@ void redir_x _P((u_int32_t, int, int, int));
 void getouraddr _P((void));
 void slirp_insque _P((void *, void *));
 void slirp_remque _P((void *));
-int add_exec _P((struct ex_list **, int, char *, int, int));
+int add_exec _P((struct ex_list **, int, char *, struct in_addr, int));
 int slirp_openpty _P((int *, int *));
 int fork_exec(struct socket *so, const char *ex, int do_pty);
 void snooze_hup _P((int));