From 29c5d4afba51c71cfeadd3f74f3c42e064483fb0 Mon Sep 17 00:00:00 2001 From: Eric Leblond Date: Tue, 18 Sep 2007 13:07:15 -0700 Subject: [PATCH] [NETFILTER]: nfnetlink_log: fix sending of multipart messages The following patch fixes the handling of netlink packets containing multiple messages. As exposed during netfilter workshop, nfnetlink_log was overwritten the message type of the last message (setting it to MSG_DONE) in a multipart packet. The consequence was libnfnetlink to ignore the last message in the packet. The following patch adds a supplementary message (with type MSG_DONE) af the end of the netlink skb. Signed-off-by: Eric Leblond Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- net/netfilter/nfnetlink_log.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c index e185a5b559..2351533a85 100644 --- a/net/netfilter/nfnetlink_log.c +++ b/net/netfilter/nfnetlink_log.c @@ -58,7 +58,6 @@ struct nfulnl_instance { unsigned int qlen; /* number of nlmsgs in skb */ struct sk_buff *skb; /* pre-allocatd skb */ - struct nlmsghdr *lastnlh; /* netlink header of last msg in skb */ struct timer_list timer; int peer_pid; /* PID of the peer process */ @@ -345,10 +344,12 @@ static struct sk_buff *nfulnl_alloc_skb(unsigned int inst_size, static int __nfulnl_send(struct nfulnl_instance *inst) { - int status; + int status = -1; if (inst->qlen > 1) - inst->lastnlh->nlmsg_type = NLMSG_DONE; + NLMSG_PUT(inst->skb, 0, 0, + NLMSG_DONE, + sizeof(struct nfgenmsg)); status = nfnetlink_unicast(inst->skb, inst->peer_pid, MSG_DONTWAIT); if (status < 0) { @@ -358,8 +359,8 @@ __nfulnl_send(struct nfulnl_instance *inst) inst->qlen = 0; inst->skb = NULL; - inst->lastnlh = NULL; +nlmsg_failure: return status; } @@ -538,7 +539,6 @@ __build_packet_message(struct nfulnl_instance *inst, } nlh->nlmsg_len = inst->skb->tail - old_tail; - inst->lastnlh = nlh; return 0; nlmsg_failure: @@ -644,7 +644,8 @@ nfulnl_log_packet(unsigned int pf, } if (inst->qlen >= qthreshold || - (inst->skb && size > skb_tailroom(inst->skb))) { + (inst->skb && size > + skb_tailroom(inst->skb) - sizeof(struct nfgenmsg))) { /* either the queue len is too high or we don't have * enough room in the skb left. flush to userspace. */ UDEBUG("flushing old skb\n"); -- 2.39.5