Flexible guestfs_vmchannel parameter for future appliances.

[libguestfs.git] / src / guestfs.c

diff --git a/src/guestfs.c b/src/guestfs.c
index bc4fe4e..ec7473e 100644 (file)
--- a/src/guestfs.c
+++ b/src/guestfs.c
@@ -85,8 +85,8 @@ static void close_handles (void);
 #define UNIX_PATH_MAX 108
 
 /* Also in guestfsd.c */
-#define GUESTFWD_PORT 6666
 #define GUESTFWD_ADDR "10.0.2.4"
+#define GUESTFWD_PORT "6666"
 
 /* GuestFS handle and connection. */
 enum state { CONFIG, LAUNCHING, READY, BUSY, NO_HANDLE };
@@ -984,18 +984,17 @@ guestfs__launch (guestfs_h *g)
 
   if (r == 0) {                        /* Child (qemu). */
     char buf[256];
-    char append[256];
-    char memsize_str[256];
+    const char *vmchannel = NULL;
 
     /* Set up the full command line.  Do this in the subprocess so we
      * don't need to worry about cleaning up.
      */
     g->cmdline[0] = g->qemu;
 
-    snprintf (memsize_str, sizeof memsize_str, "%d", g->memsize);
-
+    snprintf (buf, sizeof buf, "%d", g->memsize);
     add_cmdline (g, "-m");
-    add_cmdline (g, memsize_str);
+    add_cmdline (g, buf);
+
     add_cmdline (g, "-no-reboot"); /* Force exit instead of reboot on panic */
     add_cmdline (g, "-nographic");
     add_cmdline (g, "-serial");
@@ -1028,8 +1027,8 @@ guestfs__launch (guestfs_h *g)
 
       snprintf (buf, sizeof buf,
                 "user,vlan=0,net=10.0.2.0/8,"
-                "guestfwd=tcp:%s:%d-chardev:guestfsvmc",
-                GUESTFWD_ADDR, GUESTFWD_PORT);
+                "guestfwd=tcp:" GUESTFWD_ADDR ":" GUESTFWD_PORT
+                "-chardev:guestfsvmc");
 
       add_cmdline (g, "-net");
       add_cmdline (g, buf);
@@ -1038,7 +1037,7 @@ guestfs__launch (guestfs_h *g)
        * syntax, or if not then we'll get a quick failure.
        */
       snprintf (buf, sizeof buf,
-                "channel,%d:unix:%s,server,nowait", GUESTFWD_PORT, unixsock);
+                "channel," GUESTFWD_PORT ":unix:%s,server,nowait", unixsock);
 
       add_cmdline (g, "-net");
       add_cmdline (g, buf);
@@ -1047,6 +1046,7 @@ guestfs__launch (guestfs_h *g)
     }
     add_cmdline (g, "-net");
     add_cmdline (g, "nic,model=" NET_IF ",vlan=0");
+    vmchannel = "guestfs_vmchannel=tcp:" GUESTFWD_ADDR ":" GUESTFWD_PORT " ";
 
 #define LINUX_CMDLINE                                                  \
     "panic=1 "         /* force kernel to panic if daemon exits */     \
@@ -1057,13 +1057,15 @@ guestfs__launch (guestfs_h *g)
     "cgroup_disable=memory " /* saves us about 5 MB of RAM */
 
     /* Linux kernel command line. */
-    snprintf (append, sizeof append,
+    snprintf (buf, sizeof buf,
               LINUX_CMDLINE
               "%s"              /* (selinux) */
+              "%s"              /* (vmchannel) */
               "%s"              /* (verbose) */
               "%s",             /* (append) */
               g->selinux ? "selinux=1 enforcing=0 " : "selinux=0 ",
-              g->verbose ? "guestfs_verbose=1 " : " ",
+              vmchannel ? vmchannel : "",
+              g->verbose ? "guestfs_verbose=1 " : "",
               g->append ? g->append : "");
 
     add_cmdline (g, "-kernel");
@@ -1071,7 +1073,7 @@ guestfs__launch (guestfs_h *g)
     add_cmdline (g, "-initrd");
     add_cmdline (g, (char *) initrd);
     add_cmdline (g, "-append");
-    add_cmdline (g, append);
+    add_cmdline (g, buf);
 
     /* Finish off the command line. */
     incr_cmdline_size (g);
@@ -1210,6 +1212,32 @@ guestfs__launch (guestfs_h *g)
 
  connected:
   g->state = LAUNCHING;
+
+  /* Wait for qemu to start and to connect back to us via vmchannel and
+   * send the GUESTFS_LAUNCH_FLAG message.
+   */
+  uint32_t size;
+  void *buf = NULL;
+  r = recv_from_daemon (g, &size, &buf);
+  free (buf);
+
+  if (r == -1) return -1;
+
+  if (size != GUESTFS_LAUNCH_FLAG) {
+    error (g, _("guestfs_launch failed, see earlier error messages"));
+    goto cleanup2;
+  }
+
+  /* This is possible in some really strange situations, such as
+   * guestfsd starts up OK but then qemu immediately exits.  Check for
+   * it because the caller is probably expecting to be able to send
+   * commands after this function returns.
+   */
+  if (g->state != READY) {
+    error (g, _("qemu launched and contacted daemon, but state != READY"));
+    goto cleanup2;
+  }
+
   return 0;
 
  cleanup2:
@@ -1383,45 +1411,17 @@ qemu_supports (guestfs_h *g, const char *option)
   return g->qemu_help && strstr (g->qemu_help, option) != NULL;
 }
 
+/* You had to call this function after launch in versions <= 1.0.70,
+ * but it is now a no-op.
+ */
 int
 guestfs__wait_ready (guestfs_h *g)
 {
-  int r;
-  uint32_t size;
-  void *buf = NULL;
-
-  if (g->state == READY) return 0;
-
-  if (g->state == BUSY) {
-    error (g, _("qemu has finished launching already"));
-    return -1;
-  }
-
-  if (g->state != LAUNCHING) {
+  if (g->state != READY)  {
     error (g, _("qemu has not been launched yet"));
     return -1;
   }
 
-  r = recv_from_daemon (g, &size, &buf);
-  free (buf);
-
-  if (r == -1) return -1;
-
-  if (size != GUESTFS_LAUNCH_FLAG) {
-    error (g, _("guestfs_wait_ready failed, see earlier error messages"));
-    return -1;
-  }
-
-  /* This is possible in some really strange situations, such as
-   * guestfsd starts up OK but then qemu immediately exits.  Check for
-   * it because the caller is probably expecting to be able to send
-   * commands after this function returns.
-   */
-  if (g->state != READY) {
-    error (g, _("qemu launched and contacted daemon, but state != READY"));
-    return -1;
-  }
-
   return 0;
 }