From ea7ae60bfe39aeedfb29571c47280bf0067ee5f3 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Thu, 11 Jun 2009 14:31:35 -0400 Subject: [PATCH] Audit: clean up audit_receive_skb audit_receive_skb is hard to clearly parse what it is doing to the netlink message. Clean the function up so it is easy and clear to see what is going on. Signed-off-by: Eric Paris --- kernel/audit.c | 35 ++++++++++++++++++----------------- 1 file changed, 18 insertions(+), 17 deletions(-) diff --git a/kernel/audit.c b/kernel/audit.c index 01082a1d2bc5..ce77e81a0e71 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -937,28 +937,29 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) } /* - * Get message from skb (based on rtnetlink_rcv_skb). Each message is - * processed by audit_receive_msg. Malformed skbs with wrong length are - * discarded silently. + * Get message from skb. Each message is processed by audit_receive_msg. + * Malformed skbs with wrong length are discarded silently. */ static void audit_receive_skb(struct sk_buff *skb) { - int err; - struct nlmsghdr *nlh; - u32 rlen; + struct nlmsghdr *nlh; + /* + * len MUST be signed for NLMSG_NEXT to be able to dec it below 0 + * if the nlmsg_len was not aligned + */ + int len; + int err; - while (skb->len >= NLMSG_SPACE(0)) { - nlh = nlmsg_hdr(skb); - if (nlh->nlmsg_len < sizeof(*nlh) || skb->len < nlh->nlmsg_len) - return; - rlen = NLMSG_ALIGN(nlh->nlmsg_len); - if (rlen > skb->len) - rlen = skb->len; - if ((err = audit_receive_msg(skb, nlh))) { + nlh = nlmsg_hdr(skb); + len = skb->len; + + while (NLMSG_OK(nlh, len)) { + err = audit_receive_msg(skb, nlh); + /* if err or if this message says it wants a response */ + if (err || (nlh->nlmsg_flags & NLM_F_ACK)) netlink_ack(skb, nlh, err); - } else if (nlh->nlmsg_flags & NLM_F_ACK) - netlink_ack(skb, nlh, 0); - skb_pull(skb, rlen); + + nlh = NLMSG_NEXT(nlh, len); } } -- 2.30.2