From 71be9f3894761549a73df8dfc76fd92d680364ed Mon Sep 17 00:00:00 2001
From: Akshay Narayan <akshayn@mit.edu>
Date: Thu, 4 Mar 2021 17:30:29 +0000
Subject: [PATCH] Cleanup netlink socket on post-nl failure

---
 ccp_nl.c  | 8 ++++----
 tcp_ccp.c | 6 ++++++
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/ccp_nl.c b/ccp_nl.c
index fa84bf2..6b7ecbc 100644
--- a/ccp_nl.c
+++ b/ccp_nl.c
@@ -14,7 +14,7 @@ void nl_recv(struct sk_buff *skb) {
     int ok;
     struct nlmsghdr *nlh = nlmsg_hdr(skb);
     if (ccp_msg_reader == NULL) {
-        pr_info("ccp_msg_reader not ready\n");
+        pr_info("[ccp] [nl] ccp_msg_reader not ready\n");
         return;
     }
     
@@ -26,7 +26,7 @@ void nl_recv(struct sk_buff *skb) {
 
     ok = ccp_msg_reader(kernel_datapath, (char*)nlmsg_data(nlh), nlh->nlmsg_len);
     if (ok < 0) {
-        pr_info("message read failed: %d.\n", ok);
+        pr_info("[ccp] [nl] message read failed: %d.\n", ok);
     }
 }
 
@@ -38,7 +38,7 @@ int ccp_nl_sk(ccp_nl_recv_handler msg) {
     ccp_msg_reader = msg;
     nl_sk = netlink_kernel_create(&init_net, NETLINK_USERSOCK, &cfg);
     if (!nl_sk) {
-        printk(KERN_ALERT "Error creating netlink socket.\n");
+        printk(KERN_ALERT "[ccp] [nl] Error creating netlink socket.\n");
         return -1;
     }
 
@@ -66,7 +66,7 @@ int nl_sendmsg(
         GFP_NOWAIT // @flags: the type of memory to allocate.
     );
     if (!skb_out) {
-        printk(KERN_ERR "Failed to allocate new skb\n");
+        printk(KERN_ERR "[ccp] [nl] Failed to allocate new skb\n");
         return -1;
     }
 
diff --git a/tcp_ccp.c b/tcp_ccp.c
index 3c4048b..3d35d34 100644
--- a/tcp_ccp.c
+++ b/tcp_ccp.c
@@ -452,6 +452,12 @@ static int __init tcp_ccp_register(void) {
 	
     ok = ccp_init(kernel_datapath);
     if (ok < 0) {
+        pr_info("[ccp] ccp_init failed: %d\n", ok);
+#if __IPC__ == IPC_NETLINK
+        free_ccp_nl_sk();
+#elif __IPC__ == IPC_CHARDEV
+        ccpkp_cleanup();
+#endif
         return -6;
     }