Add support for multiple network interfaces

Allow --tap-fd to be given mutliple times, a different virtual network
card will be added each time the flag is given.
Additionally, --tap-fd is no longer mutually exclusive with --host-ip,
etc.

Bug=chromium:931470
Test=booted cuttlefish device with multiple network cards

Change-Id: I4108f97c7f4b19db12fcb3c533088a04a58e56db
Reviewed-on: https://chromium-review.googlesource.com/1469222
Commit-Ready: Jorge Moreira Broche <jemoreira@google.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Jorge Moreira Broche <jemoreira@google.com>
Reviewed-by: Dylan Reid <dgreid@chromium.org>

1 files changed, 6 insertions, 11 deletions

diff --git a/src/plugin/mod.rs b/src/plugin/mod.rs
index 7163d7a..32ea4bb 100644
--- a/src/plugin/mod.rs
+++ b/src/plugin/mod.rs
@@ -506,7 +506,7 @@ pub fn run_config(cfg: Config) -> Result<()> {
         None
     };
 
-    let mut tap_opt: Option<Tap> = None;
+    let mut tap_interfaces: Vec<Tap> = Vec::new();
     if let Some(host_ip) = cfg.host_ip {
         if let Some(netmask) = cfg.netmask {
             if let Some(mac_address) = cfg.mac_address {
@@ -517,17 +517,17 @@ pub fn run_config(cfg: Config) -> Result<()> {
                     .map_err(Error::TapSetMacAddress)?;
 
                 tap.enable().map_err(Error::TapEnable)?;
-                tap_opt = Some(tap);
+                tap_interfaces.push(tap);
             }
         }
     }
-    if let Some(tap_fd) = cfg.tap_fd {
+    for tap_fd in cfg.tap_fd {
         // Safe because we ensure that we get a unique handle to the fd.
         let tap = unsafe {
             Tap::from_raw_fd(validate_raw_fd(tap_fd).map_err(Error::ValidateTapFd)?)
                 .map_err(Error::CreateTapFd)?
         };
-        tap_opt = Some(tap);
+        tap_interfaces.push(tap);
     }
 
     let plugin_args: Vec<&str> = cfg.params.iter().map(|s| &s[..]).collect();
@@ -650,13 +650,8 @@ pub fn run_config(cfg: Config) -> Result<()> {
                     }
                 }
                 Token::Plugin { index } => {
-                    match plugin.handle_socket(
-                        index,
-                        &kvm,
-                        &mut vm,
-                        &vcpu_handles,
-                        tap_opt.as_ref(),
-                    ) {
+                    match plugin.handle_socket(index, &kvm, &mut vm, &vcpu_handles, &tap_interfaces)
+                    {
                         Ok(_) => {}
                         // A HUP is an expected event for a socket, so don't bother warning about
                         // it.