X-Git-Url: http://git.annexia.org/?p=virt-mem.git;a=blobdiff_plain;f=lib%2Fvirt_mem_net_devices.ml;h=a7078af0ea545d450811b927096a90093b2fd894;hp=d792d0de327e42850261b2f5b11c3d27dd7e8efe;hb=f6bb3caa719a564615e7fd2f21a3ad5bca010a88;hpb=a5fb949b73a604972a9b339fd6ec2786ea59f23c

diff --git a/lib/virt_mem_net_devices.ml b/lib/virt_mem_net_devices.ml
index d792d0d..a7078af 100644
--- a/lib/virt_mem_net_devices.ml
+++ b/lib/virt_mem_net_devices.ml
@@ -24,8 +24,9 @@ open Virt_mem_utils
 open Virt_mem_types
 
 open Kernel_net_device
+open Kernel_net
 
-type linkage = Next | DevList of int
+let max_net_devices = 10000
 
 let rec find_net_devices debug image ksymmap kernel_version =
   if not (net_device_known kernel_version) then (
@@ -38,75 +39,87 @@ supported Linux distribution, see this page about adding support:
   ) else (
     let size = net_device_size kernel_version in
 
-    (* In kernels < around 2.6.22, this is a simple linked list:
+    (* In kernels < ~ 2.6.22, this is a simple linked list:
      *   dev_base -> next -> next
      * In kernels >= 2.6.23, this is a list_head:
      *   dev_base_head -> list_head dev_list -> ...
      *)
-    let linkage =
+    let map =
       let { field_available = available } =
 	field_signature_of_net_device_next kernel_version in
       if available then
-	Some Next
+	Some map_next
       else (
 	let { field_available = available; field_offset = offset } =
 	  field_signature_of_net_device_dev_list'next kernel_version in
 	if available then
-	  Some (DevList offset)
+	  Some (map_dev_list offset)
 	else (
 	  eprintf (f_"%s: kernel net_device table is not linked through either next pointer or dev_list list_head.  Cannot read net devices.\n") image.domname;
 	  None
 	)
       ) in
-    match linkage with
-    | None -> image, None
 
-    | Some Next ->
-	printf "linkage = Next\n%!";
+    match map with
+    | None -> image, None
 
-	(* Linkage through old-style chain of next pointers. *)
-	let dev_base =
+    | Some map ->
+	(* What is the starting point for iteration?  In older kernels
+	 * it was the symbol 'dev_base'.  Then briefly (2.6.22-2.6.24)
+	 * it became 'sruct list_head dev_base_head'.  Then when net
+	 * namespaces were introduced (>= 2.6.25) it became 'struct
+	 * list_head init_net.dev_base_head'.
+	 *)
+	let addr =
 	  try Some (Ksymmap.find "dev_base" ksymmap)
 	  with Not_found ->
-	    eprintf (f_"%s: could not find dev_base symbol in kernel image\n") image.domname;
-	    None in
-	(match dev_base with
-	 | None -> image, None
-	 | Some dev_base ->
-	     do_next image kernel_version dev_base size
-	);
-
-    | Some (DevList offset) ->
-	printf "linkage = DevList %d\n%!" offset;
-
-	(* Linkage through new-style list_head dev_list. *)
-	let dev_base_head =
-	  try Some (Ksymmap.find "dev_base_head" ksymmap)
-	  with Not_found ->
-	    eprintf (f_"%s: could not find dev_base_head symbol in kernel image\n") image.domname;
-	    None in
-	(match dev_base_head with
-	 | None -> image, None
-	 | Some dev_base_head ->
-	     let dev_base_head =
-	       Virt_mem_mmap.follow_pointer image.mem dev_base_head in
-
-	     do_dev_list image kernel_version dev_base_head offset size
-	);
+	    try
+	      let addr = Ksymmap.find "dev_base_head" ksymmap in
+	      let addr = Virt_mem_mmap.follow_pointer image.mem addr in
+	      Some addr
+	    with Not_found ->
+	      try
+		let addr = Ksymmap.find "init_net" ksymmap in
+		if not (net_known kernel_version) then (
+		  eprintf (f_"%s: struct net not available in this kernel version.\n") image.domname;
+		  raise Not_found
+		);
+		let init_net = get_net kernel_version image.mem addr in
+		let addr = init_net.net_dev_base_head'next in
+		Some addr
+	      with Not_found ->
+		eprintf (f_"%s: cannot find dev_base, dev_base_head or init_net symbols in kernel image.\n") image.domname;
+		None in
+
+	match addr with
+	| None -> image, None
+
+	| Some addr ->
+	    (* Map over the structure using previously defined map function. *)
+	    let image, netdevs =
+	      map image kernel_version addr size (
+		fun netdev ->
+		  { netdev_name = truncate_c_string netdev.net_device_name;
+		    netdev_dev_addr = netdev.net_device_dev_addr }
+	      ) in
+
+	    image, Some netdevs
   )
 
-(* Iterate dev_base_head -> list_head dev_list -> ... *)
-and do_dev_list image kernel_version dev_base_head offset size =
+(* Map dev_base_head -> list_head dev_list -> ... *)
+and map_dev_list offset image kernel_version first_addr size f =
+  eprintf "map_dev_list: first_addr is %Lx\n" first_addr;
+
   (* The list_head points into the middle of the structure.
    * Adjust this address to point to the start of the
    * structure.
    *)
-  let addr = Int64.sub dev_base_head (Int64.of_int offset) in
-
-  printf "do_dev_list, size = %d\n" size;
+  let addr = Int64.sub first_addr (Int64.of_int offset) in
+  eprintf "map_dev_list: after subtracting, addr is %Lx\n" addr;
 
-  let image =
-    let rec loop image addr =
+  let rec loop i image acc addr =
+    if i <= max_net_devices then (
+      eprintf "map_dev_list: called at %Lx\n" addr;
       let mapped = Virt_mem_mmap.is_mapped_range image.mem addr size in
       let image =
 	if not mapped then
@@ -114,22 +127,22 @@ and do_dev_list image kernel_version dev_base_head offset size =
 	else
 	  image in
       let dev = get_net_device kernel_version image.mem addr in
-      printf "net_device_name = %S\n" dev.net_device_name;
+      eprintf "map_dev_list: %Lx %S\n" addr dev.net_device_name;
+      let acc = f dev :: acc in
       let addr = Option.get dev.net_device_dev_list'next in
-      if addr <> dev_base_head then
-	loop image addr
+      if addr <> first_addr then
+	loop (i+1) image acc addr
       else
-	image
-    in
-    loop image addr in
-  image, Some dev_base_head
+	image, acc
+    ) else
+      failwith (sprintf (f_"%s: too many network devices") image.domname);
+  in
+  loop 0 image [] addr
 
 (* Iterate dev_base -> next -> next ... *)
-and do_next image kernel_version addr size =
-  printf "do_next, size = %d\n" size;
-
-  let image =
-    let rec loop image addr =
+and map_next image kernel_version addr size f =
+  let rec loop i image acc addr =
+    if i <= max_net_devices then (
       if addr <> 0L then (
 	let mapped = Virt_mem_mmap.is_mapped_range image.mem addr size in
 	let image =
@@ -138,13 +151,15 @@ and do_next image kernel_version addr size =
 	  else
 	    image in
 	let dev = get_net_device kernel_version image.mem addr in
-      printf "net_device_name = %S\n" dev.net_device_name;
+	eprintf "map_next: %S\n" dev.net_device_name;
+	let acc = f dev :: acc in
 	let addr =
 	  match dev.net_device_next with
 	  | None -> assert false | Some addr -> addr in
-	loop image addr
+	loop (i+1) image acc addr
       ) else
-	image
-    in
-    loop image addr in
-  image, Some addr
+	image, acc
+    ) else
+      failwith (sprintf (f_"%s: too many network devices") image.domname);
+  in
+  loop 0 image [] addr