From fd1cbaa0907b30f639497c38953fe605bfc68ad0 Mon Sep 17 00:00:00 2001

From: "Richard W.M. Jones" <rjones@redhat.com>

Date: Tue, 28 Jul 2020 13:20:10 +0100

Subject: [PATCH] v2v: Check that --mac :ip: parameters are sensible

 (RHBZ#1858775).

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This is not a complete check since IP addresses come in many forms,

but this at least stops nonsense being written through to the Windows

firstboot script.

$ virt-v2v --mac 11:22:33:44:55:66:ip:hello,world,999,invalid -i disk test1.img -o null

virt-v2v: error: cannot parse --mac ip ipaddr: doesn’t look like

“hello” is an IP address

$ virt-v2v --mac 11:22:33:44:55:66:ip:192.168.0.10,192.168.0.1,999,192.168.2.1,192.168.2.2 -i disk test1.img -o null

virt-v2v: error: --mac ip prefix length field is out of range

Thanks: Zi Liu

(cherry picked from commit e8bcf9615490447e1b53a8b0d3e9d202ab178cf0)

---

 v2v/cmdline.ml | 55 ++++++++++++++++++++++++++++++++------------------

 1 file changed, 35 insertions(+), 20 deletions(-)

diff --git a/v2v/cmdline.ml b/v2v/cmdline.ml

index 249137ab..3b74f307 100644

--- a/v2v/cmdline.ml

+++ b/v2v/cmdline.ml

@@ -47,6 +47,7 @@ type cmdline = {

 (* Matches --mac command line parameters. *)

 let mac_re = PCRE.compile ~anchored:true "([[:xdigit:]]{2}:[[:xdigit:]]{2}:[[:xdigit:]]{2}:[[:xdigit:]]{2}:[[:xdigit:]]{2}:[[:xdigit:]]{2}):(network|bridge|ip):(.*)"

+let mac_ip_re = PCRE.compile ~anchored:true "([[:xdigit:]]|:|\\.)+"

 let parse_cmdline () =

   let bandwidth = ref None in

@@ -102,7 +103,7 @@ let parse_cmdline () =

   let network_map = Networks.create () in

   let static_ips = ref [] in

-  let add_network str =

+  let rec add_network str =

     match String.split ":" str with

     | "", "" ->

        error (f_"invalid -n/--network parameter")

@@ -110,8 +111,7 @@ let parse_cmdline () =

        Networks.add_default_network network_map out

     | in_, out ->

        Networks.add_network network_map in_ out

-  in

-  let add_bridge str =

+  and add_bridge str =

     match String.split ":" str with

     | "", "" ->

        error (f_"invalid -b/--bridge parameter")

@@ -119,8 +119,7 @@ let parse_cmdline () =

        Networks.add_default_bridge network_map out

     | in_, out ->

        Networks.add_bridge network_map in_ out

-  in

-  let add_mac str =

+  and add_mac str =

     if not (PCRE.matches mac_re str) then

       error (f_"cannot parse --mac \"%s\" parameter") str;

     let mac = PCRE.sub 1 and out = PCRE.sub 3 in

@@ -130,24 +129,40 @@ let parse_cmdline () =

     | "bridge" ->

        Networks.add_mac network_map mac Bridge out

     | "ip" ->

-       let add if_mac_addr if_ip_address if_default_gateway

-               if_prefix_length if_nameservers =

-         List.push_back static_ips

-                        { if_mac_addr; if_ip_address; if_default_gateway;

-                          if_prefix_length; if_nameservers }

-       in

        (match String.nsplit "," out with

-        | [] ->

-           error (f_"invalid --mac ip option")

-        | [ip] -> add mac ip None None []

-        | [ip; gw] -> add mac ip (Some gw) None []

+        | [] -> error (f_"invalid --mac ip option")

+        | [ip] -> add_static_ip mac ip None None []

+        | [ip; gw] -> add_static_ip mac ip (Some gw) None []

         | ip :: gw :: len :: nameservers ->

-           let len =

-             try int_of_string len with

-             | Failure _ -> error (f_"cannot parse --mac ip prefix length field as an integer: %s") len in

-           add mac ip (Some gw) (Some len) nameservers

-       );

+           add_static_ip mac ip (Some gw) (Some len) nameservers

+       )

     | _ -> assert false

+  and add_static_ip if_mac_addr if_ip_address if_default_gateway

+                    if_prefix_length_str if_nameservers =

+    (* Check the IP addresses and prefix length are sensible.  This

+     * is only a very simple test that they are sane, since IP addresses

+     * come in too many valid forms to check thoroughly.

+     *)

+    let rec error_unless_ip_addr what addr =

+      if not (PCRE.matches mac_ip_re addr) then

+        error (f_"cannot parse --mac ip %s: doesn’t look like “%s” is an IP address") what addr

+    in

+    error_unless_ip_addr "ipaddr" if_ip_address;

+    Option.may (error_unless_ip_addr "gw") if_default_gateway;

+    List.iter (error_unless_ip_addr "nameserver") if_nameservers;

+    let if_prefix_length =

+      match if_prefix_length_str with

+      | None -> None

+      | Some len ->

+         let len =

+           try int_of_string len with

+           | Failure _ -> error (f_"cannot parse --mac ip prefix length field as an integer: %s") len in

+         if len < 0 || len > 128 then

+           error (f_"--mac ip prefix length field is out of range");

+         Some len in

+    List.push_back static_ips

+      { if_mac_addr; if_ip_address; if_default_gateway;

+        if_prefix_length; if_nameservers }

   in

   let no_trim_warning _ =

-- 

2.31.1