Re: [patch 2.6.12-rc1-mm4] fork_connector: add a fork connector

[Evgeniy Polyakov]

On Thu, 2005-04-07 at 15:47 -0700, Jay Lan wrote:
> BTW, when it happened last time, my program listening to the socket
> complained about duplicate messages received.
> 
>     Unmatched seq. Rcvd=1824062, expected=1824061   <===
>     Unmatched seq. Rcvd=1824062, expected=1824063   <===
>     Unmatched seq. Rcvd=1824348, expected=1824307
> 
> When my program received 1824062 while expecting 1824061
> it adjusted itself to expect the next one being 1824063. But instead
> the message of 1824062 arrived the second time.

Thank you for your report.

Could you reproduce a bug with the attached patch?

>     - jay


* looking for [EMAIL PROTECTED]/connector--main--0--patch-38 to compare with
* comparing to [EMAIL PROTECTED]/connector--main--0--patch-38
M  connector.c

* modified files

--- orig/drivers/connector/connector.c
+++ mod/drivers/connector/connector.c
@@ -121,7 +121,7 @@
        NETLINK_CB(skb).dst_groups = groups;
 
        uskb = skb_clone(skb, GFP_ATOMIC);
-       if (uskb)
+       if (uskb && 0)
                netlink_unicast(dev->nls, uskb, 0, 0);
        
        netlink_broadcast(dev->nls, skb, 0, groups, GFP_ATOMIC);
@@ -158,7 +158,7 @@
        }
        spin_unlock_bh(&dev->cbdev->queue_lock);
 
-       return found;
+       return (found)?0:-ENODEV;
 }
 
 /*
@@ -181,7 +181,6 @@
                                "requested msg->len=%u[%u], nlh->nlmsg_len=%u, 
skb->len=%u.\n",
                                msg->len, NLMSG_SPACE(msg->len + sizeof(*msg)),
                                nlh->nlmsg_len, skb->len);
-               kfree_skb(skb);
                return -EINVAL;
        }
 #if 0
@@ -215,17 +214,18 @@
               skb->len, skb->data_len, skb->truesize, skb->protocol,
               skb_cloned(skb), skb_shared(skb));
 #endif
-       while (skb->len >= NLMSG_SPACE(0)) {
+       if (skb->len >= NLMSG_SPACE(0)) {
                nlh = (struct nlmsghdr *)skb->data;
+
                if (nlh->nlmsg_len < sizeof(struct cn_msg) ||
                    skb->len < nlh->nlmsg_len ||
                    nlh->nlmsg_len > CONNECTOR_MAX_MSG_SIZE) {
-#if 0
+#if 1
                        printk(KERN_INFO "nlmsg_len=%u, sizeof(*nlh)=%u\n",
                               nlh->nlmsg_len, sizeof(*nlh));
 #endif
                        kfree_skb(skb);
-                       break;
+                       goto out;
                }
 
                len = NLMSG_ALIGN(nlh->nlmsg_len);
@@ -233,22 +233,11 @@
                        len = skb->len;
 
                err = __cn_rx_skb(skb, nlh);
-               if (err) {
-#if 0
-                       if (err < 0 && (nlh->nlmsg_flags & NLM_F_ACK))
-                               netlink_ack(skb, nlh, -err);
-#endif
-                       break;
-               } else {
-#if 0
-                       if (nlh->nlmsg_flags & NLM_F_ACK)
-                               netlink_ack(skb, nlh, 0);
-#endif
-                       break;
-               }
-               skb_pull(skb, len);
+               if (err < 0)
+                       kfree_skb(skb);
        }
-                       
+
+out:
        kfree_skb(__skb);
 }
 





-- 
        Evgeniy Polyakov

Crash is better than data corruption -- Arthur Grabowski

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