User networking: Show active connections

In case you're wondering what connections exactly you have open
or maybe redir'ed in the past, you can't really find out from qemu
right now.

This patch enables you to see all current connections the host
only networking holds open, so you can kill them using the previous
patch.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

4 files changed, 74 insertions, 1 deletions

diff --git a/monitor.c b/monitor.c
index dbab3de827..443f6d47c2 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1761,7 +1761,8 @@ static const mon_cmd_t mon_cmds[] = {
 #ifdef CONFIG_SLIRP
     { "host_net_redir", "ss?", net_slirp_redir,
       "[tcp|udp]:host-port:[guest-host]:guest-port", "redirect TCP or UDP connections from host to guest (requires -net user)\n"
-      "host_net_redir remove [tcp:|udp:]host-port -- remove redirection" },
+      "host_net_redir remove [tcp:|udp:]host-port -- remove redirection\n"
+      "host_net_redir list -- show all redirections" },
 #endif
     { "balloon", "i", do_balloon,
       "target", "request VM to change it's memory allocation (in MB)" },
diff --git a/net.c b/net.c
index 9f5b79bc49..2d24a7ce5f 100644
--- a/net.c
+++ b/net.c
@@ -568,6 +568,45 @@ static int net_slirp_init(VLANState *vlan, const char *model, const char *name)
     return 0;
 }
 
+static void net_slirp_redir_print(void *opaque, int is_udp,
+                                  struct in_addr *laddr, u_int lport,
+                                  struct in_addr *faddr, u_int fport)
+{
+    Monitor *mon = (Monitor *)opaque;
+    uint32_t h_addr;
+    uint32_t g_addr;
+    char buf[16];
+
+    h_addr = ntohl(faddr->s_addr);
+    g_addr = ntohl(laddr->s_addr);
+
+    monitor_printf(mon, "  %s |", is_udp ? "udp" : "tcp" );
+    snprintf(buf, 15, "%d.%d.%d.%d", (h_addr >> 24) & 0xff,
+                                     (h_addr >> 16) & 0xff,
+                                     (h_addr >> 8) & 0xff,
+                                     (h_addr) & 0xff);
+    monitor_printf(mon, " %15s |", buf);
+    monitor_printf(mon, " %5d |", fport);
+
+    snprintf(buf, 15, "%d.%d.%d.%d", (g_addr >> 24) & 0xff,
+                                     (g_addr >> 16) & 0xff,
+                                     (g_addr >> 8) & 0xff,
+                                     (g_addr) & 0xff);
+    monitor_printf(mon, " %15s |", buf);
+    monitor_printf(mon, " %5d\n", lport);
+
+}
+
+static void net_slirp_redir_list(Monitor *mon)
+{
+    if (!mon)
+        return;
+
+    monitor_printf(mon, " Prot |    Host Addr    | HPort |    Guest Addr   | GPort\n");
+    monitor_printf(mon, "      |                 |       |                 |      \n");
+    slirp_redir_loop(net_slirp_redir_print, mon);
+}
+
 static void net_slirp_redir_rm(Monitor *mon, const char *port_str)
 {
     int host_port;
@@ -622,6 +661,11 @@ void net_slirp_redir(Monitor *mon, const char *redir_str, const char *redir_opt2
         return;
     }
 
+    if (!strcmp(redir_str, "list")) {
+        net_slirp_redir_list(mon);
+        return;
+    }
+
     p = redir_str;
     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0)
         goto fail_syntax;
diff --git a/slirp/libslirp.h b/slirp/libslirp.h
index 6fc2c329ad..b2313b43c6 100644
--- a/slirp/libslirp.h
+++ b/slirp/libslirp.h
@@ -18,6 +18,10 @@ 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);
 
+void slirp_redir_loop(void (*func)(void *opaque, int is_udp,
+                                  struct in_addr *laddr, u_int lport,              
+                                  struct in_addr *faddr, u_int fport),
+                     void *opaque);
 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);
diff --git a/slirp/slirp.c b/slirp/slirp.c
index 33397c07dc..9cab73124e 100644
--- a/slirp/slirp.c
+++ b/slirp/slirp.c
@@ -734,6 +734,30 @@ void if_encap(const uint8_t *ip_data, int ip_data_len)
     }
 }
 
+static void _slirp_redir_loop(void (*func)(void *opaque, int is_udp,
+                                           struct in_addr *laddr, u_int lport,
+                                           struct in_addr *faddr, u_int fport),
+                              void *opaque, int is_udp)
+{
+    struct socket *head = (is_udp ? &udb : &tcb);
+    struct socket *so;
+
+    for (so = head->so_next; so != head; so = so->so_next) {
+        func(opaque, is_udp,
+             &so->so_laddr, ntohs(so->so_lport),
+             &so->so_faddr, ntohs(so->so_fport));
+    }
+}
+
+void slirp_redir_loop(void (*func)(void *opaque, int is_udp,
+                                  struct in_addr *laddr, u_int lport,
+                                  struct in_addr *faddr, u_int fport),
+                     void *opaque)
+{
+    _slirp_redir_loop(func, opaque, 0);
+    _slirp_redir_loop(func, opaque, 1);
+}
+
 /* Unlistens a redirection
  *
  * Return value: number of redirs removed */