From 71ed8fff9069326543d63c3623468be038610656 Mon Sep 17 00:00:00 2001
From: grossmj <grossmj@gns3.net>
Date: Tue, 17 Sep 2024 19:24:17 +0700
Subject: [PATCH] Support to set a MAC address on an interface (Linux only)

---
 README.md               | 10 +++++++++-
 src/hypervisor_docker.c | 42 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 51 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index 473983c..32a3438 100644
--- a/README.md
+++ b/README.md
@@ -76,7 +76,7 @@ The modules that are currently defined are given below:
 - hypervisor : General hypervisor management 
 - bridge : bridges management 
 - iol_bridge : IOL (IOS on Linux) bridges management 
-- docker : Docker veth management 
+- docker : Docker management 
 - brctl : Linux bridge management
 
 ### Hypervisor module ("hypervisor")
@@ -414,6 +414,14 @@ docker move_to_ns guestif 6367 eth0
 100-guestif moved to namespace 6367
 ```
 
+- **docker set_mac_addr** *\<interface\>* *\<mac_addr\>*
+    *\<mac_addr\>*: Set a MAC address on an interface.
+
+``` {.bash}
+docker set_mac_addr tap-gns3-e0 12:34:56:78:12:42
+100-MAC address 12:34:56:78:12:42" has been successfully set on interface tap-gns3-e0
+```
+
 - **docker delete_veth** *\<interface_name\>*: Delete virtual
     Ethernet interface.
 
diff --git a/src/hypervisor_docker.c b/src/hypervisor_docker.c
index 16d3dc1..79065ff 100644
--- a/src/hypervisor_docker.c
+++ b/src/hypervisor_docker.c
@@ -308,11 +308,53 @@ static int cmd_move_ns(hypervisor_conn_t *conn, int argc, char *argv[])
 	return err;
 }
 
+static int cmd_set_mac_addr(hypervisor_conn_t *conn, int argc, char *argv[])
+{
+    int fd;
+    struct ifreq ifr;
+	char *interface = argv[0];
+	char mac_char[17];
+
+    if (strlen(argv[1]) != 17) {
+        hypervisor_send_reply(conn, HSC_ERR_CREATE, 1, "invalid MAC address format");
+        return (-1);
+    }
+
+    strncpy(mac_char, argv[1], 17);
+    sscanf(mac_char, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx",
+        &ifr.ifr_hwaddr.sa_data[0],
+        &ifr.ifr_hwaddr.sa_data[1],
+        &ifr.ifr_hwaddr.sa_data[2],
+        &ifr.ifr_hwaddr.sa_data[3],
+        &ifr.ifr_hwaddr.sa_data[4],
+        &ifr.ifr_hwaddr.sa_data[5]
+        );
+
+    if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
+      hypervisor_send_reply(conn, HSC_ERR_CREATE, 1, "could not create socket: %s", strerror(errno));
+      return (-1);
+    }
+
+    strncpy(ifr.ifr_name, interface, strlen(interface));
+    ifr.ifr_hwaddr.sa_family = ARPHRD_ETHER;
+
+    if (ioctl(fd, SIOCSIFHWADDR, &ifr) < 0) {
+      hypervisor_send_reply(conn, HSC_ERR_CREATE, 1, "could not set a MAC address on interface %s", interface);
+      close(fd);
+      return (-1);
+    }
+
+    hypervisor_send_reply(conn, HSC_INFO_OK, 1, "MAC address %s has been successfully set on interface %s", mac_char, interface);
+    close(fd);
+    return (0);
+}
+
 /* Docker commands */
 static hypervisor_cmd_t docker_cmd_array[] = {
    { "create_veth", 2, 2, cmd_create_veth_pair, NULL },
    { "delete_veth", 1, 1, cmd_delete_veth, NULL },
    { "move_to_ns", 3, 3, cmd_move_ns, NULL },
+   { "set_mac_addr", 2, 2, cmd_set_mac_addr, NULL },
    { NULL, -1, -1, NULL, NULL },
 };