slirp: Rework external configuration interface

With the internal IP configuration made more flexible, we can now
enhance the user interface. This patch adds a number of new options to
"-net user": net (address and mask), host, dhcpstart, dns and smbserver.
It also renames "redir" to "hostfwd" and "channel" to "guestfwd" in
order to (hopefully) clarify their meanings. The format of guestfwd is
extended so that the user can define not only the port but also the
virtual server's IP address the forwarding starts from.

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

3 files changed, 38 insertions, 39 deletions

diff --git a/slirp/libslirp.h b/slirp/libslirp.h
index 7dee34b369..e4c9c99c3b 100644
--- a/slirp/libslirp.h
+++ b/slirp/libslirp.h
@@ -5,8 +5,11 @@
 extern "C" {
 #endif
 
-void slirp_init(int restricted, const char *special_ip, const char *tftp_path,
-                const char *bootfile);
+void slirp_init(int restricted, struct in_addr vnetwork,
+                struct in_addr vnetmask, struct in_addr vhost,
+                const char *vhostname, const char *tftp_path,
+                const char *bootfile, struct in_addr vdhcp_start,
+                struct in_addr vnameserver);
 
 void slirp_select_fill(int *pnfds,
                        fd_set *readfds, fd_set *writefds, fd_set *xfds);
@@ -19,18 +22,17 @@ void slirp_input(const uint8_t *pkt, int pkt_len);
 int slirp_can_output(void);
 void slirp_output(const uint8_t *pkt, int pkt_len);
 
-int slirp_redir_rm(int is_udp, int host_port);
-int slirp_redir(int is_udp, int host_port,
-                struct in_addr guest_addr, int guest_port);
-int slirp_add_exec(int do_pty, const void *args, int addr_low_byte,
-                   int guest_port);
+int slirp_add_hostfwd(int is_udp, int host_port,
+                      struct in_addr guest_addr, int guest_port);
+int slirp_remove_hostfwd(int is_udp, int host_port);
 
-extern char slirp_hostname[33];
+int slirp_add_exec(int do_pty, const void *args, struct in_addr guest_addr,
+                   int guest_port);
 
 void slirp_stats(void);
-void slirp_socket_recv(int addr_low_byte, int guest_port, const uint8_t *buf,
-		int size);
-size_t slirp_socket_can_recv(int addr_low_byte, int guest_port);
+void slirp_socket_recv(struct in_addr guest_addr, int guest_port,
+                       const uint8_t *buf, int size);
+size_t slirp_socket_can_recv(struct in_addr guest_addr, int guest_port);
 
 #ifdef __cplusplus
 }
diff --git a/slirp/main.h b/slirp/main.h
index edbb9cb39a..891220ae91 100644
--- a/slirp/main.h
+++ b/slirp/main.h
@@ -47,6 +47,7 @@ extern int ppp_exit;
 extern int tcp_keepintvl;
 extern uint8_t client_ethaddr[6];
 extern int slirp_restrict;
+extern char slirp_hostname[33];
 extern char *tftp_prefix;
 extern char *bootp_filename;
 
diff --git a/slirp/slirp.c b/slirp/slirp.c
index 8affd46c7c..a918232034 100644
--- a/slirp/slirp.c
+++ b/slirp/slirp.c
@@ -173,12 +173,14 @@ static void slirp_cleanup(void)
 static void slirp_state_save(QEMUFile *f, void *opaque);
 static int slirp_state_load(QEMUFile *f, void *opaque, int version_id);
 
-void slirp_init(int restricted, const char *special_ip, const char *tftp_path,
-                const char *bootfile)
+void slirp_init(int restricted, struct in_addr vnetwork,
+                struct in_addr vnetmask, struct in_addr vhost,
+                const char *vhostname, const char *tftp_path,
+                const char *bootfile, struct in_addr vdhcp_start,
+                struct in_addr vnameserver)
 {
     //    debug_init("/tmp/slirp.log", DEBUG_DEFAULT);
 
-    struct in_addr special_addr = { .s_addr = htonl(0x0a000200) };
 #ifdef _WIN32
     WSADATA Data;
 
@@ -203,8 +205,11 @@ void slirp_init(int restricted, const char *special_ip, const char *tftp_path,
         fprintf (stderr, "Warning: No DNS servers found\n");
     }
 
-    if (special_ip) {
-        inet_aton(special_ip, &special_addr);
+    vnetwork_addr = vnetwork;
+    vnetwork_mask = vnetmask;
+    vhost_addr = vhost;
+    if (vhostname) {
+        pstrcpy(slirp_hostname, sizeof(slirp_hostname), vhostname);
     }
     qemu_free(tftp_prefix);
     tftp_prefix = NULL;
@@ -216,12 +221,9 @@ void slirp_init(int restricted, const char *special_ip, const char *tftp_path,
     if (bootfile) {
         bootp_filename = qemu_strdup(bootfile);
     }
+    vdhcp_startaddr = vdhcp_start;
+    vnameserver_addr = vnameserver;
 
-    vnetwork_addr = special_addr;
-    vnetwork_mask.s_addr = htonl(0xffffff00);
-    vhost_addr.s_addr = special_addr.s_addr | htonl(2);
-    vdhcp_startaddr.s_addr = special_addr.s_addr | htonl(15);
-    vnameserver_addr.s_addr = special_addr.s_addr | htonl(3);
     getouraddr();
     register_savevm("slirp", 0, 1, slirp_state_save, slirp_state_load, NULL);
 }
@@ -755,7 +757,7 @@ void if_encap(const uint8_t *ip_data, int ip_data_len)
 /* Unlistens a redirection
  *
  * Return value: number of redirs removed */
-int slirp_redir_rm(int is_udp, int host_port)
+int slirp_remove_hostfwd(int is_udp, int host_port)
 {
     struct socket *so;
     struct socket *head = (is_udp ? &udb : &tcb);
@@ -775,8 +777,8 @@ int slirp_redir_rm(int is_udp, int host_port)
     return n;
 }
 
-int slirp_redir(int is_udp, int host_port,
-                struct in_addr guest_addr, int guest_port)
+int slirp_add_hostfwd(int is_udp, int host_port,
+                      struct in_addr guest_addr, int guest_port)
 {
     if (!guest_addr.s_addr) {
         guest_addr = vdhcp_startaddr;
@@ -793,13 +795,13 @@ int slirp_redir(int is_udp, int host_port,
     return 0;
 }
 
-int slirp_add_exec(int do_pty, const void *args, int addr_low_byte,
-                  int guest_port)
+int slirp_add_exec(int do_pty, const void *args, struct in_addr guest_addr,
+                   int guest_port)
 {
-    struct in_addr guest_addr = {
-        .s_addr = vnetwork_addr.s_addr | htonl(addr_low_byte)
-    };
-
+    if (!guest_addr.s_addr) {
+        guest_addr.s_addr =
+            vnetwork_addr.s_addr | (htonl(0x0204) & ~vnetwork_mask.s_addr);
+    }
     if ((guest_addr.s_addr & vnetwork_mask.s_addr) != vnetwork_addr.s_addr ||
         guest_addr.s_addr == vhost_addr.s_addr ||
         guest_addr.s_addr == vnameserver_addr.s_addr) {
@@ -833,11 +835,8 @@ slirp_find_ctl_socket(struct in_addr guest_addr, int guest_port)
     return NULL;
 }
 
-size_t slirp_socket_can_recv(int addr_low_byte, int guest_port)
+size_t slirp_socket_can_recv(struct in_addr guest_addr, int guest_port)
 {
-    struct in_addr guest_addr = {
-        .s_addr = vnetwork_addr.s_addr | htonl(addr_low_byte)
-    };
 	struct iovec iov[2];
 	struct socket *so;
 
@@ -855,13 +854,10 @@ size_t slirp_socket_can_recv(int addr_low_byte, int guest_port)
 	return sopreprbuf(so, iov, NULL);
 }
 
-void slirp_socket_recv(int addr_low_byte, int guest_port, const uint8_t *buf,
-        int size)
+void slirp_socket_recv(struct in_addr guest_addr, int guest_port,
+                       const uint8_t *buf, int size)
 {
     int ret;
-    struct in_addr guest_addr = {
-        .s_addr = vnetwork_addr.s_addr | htonl(addr_low_byte)
-    };
     struct socket *so = slirp_find_ctl_socket(guest_addr, guest_port);
 
     if (!so)