On Sun, Nov 25, 2012 at 04:54:32PM +0100, Florian Westphal wrote:
> 1. struct nlattr *attr[NFQA_MAX+1] must be initialized.
> Otherwise, attr[FOO] might be non-null after parsing
> even if that attribute isn't present in the message.
>
> 2. mnl_attr_get_payload will never return NULL (if the
> attribute is NULL, it returns MNL_ATTR_HDRLEN.)
Fine with me, just a question:
> Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
> ---
> examples/nf-queue.c | 26 ++++++++++++++------------
> 1 files changed, 14 insertions(+), 12 deletions(-)
>
> diff --git a/examples/nf-queue.c b/examples/nf-queue.c
> index 4d56751..3d64386 100644
> --- a/examples/nf-queue.c
> +++ b/examples/nf-queue.c
> @@ -31,12 +31,11 @@ nfq_hdr_put(char *buf, int type, uint32_t queue_num)
> return nlh;
> }
>
> -static int
> +static void
> nfq_send_verdict(int queue_num, uint32_t id)
> {
> char buf[MNL_SOCKET_BUFFER_SIZE];
> struct nlmsghdr *nlh;
> - int ret;
>
> nlh = nfq_hdr_put(buf, NFQNL_MSG_VERDICT, queue_num);
> nfq_nlmsg_verdict_put(nlh, id, NF_ACCEPT);
> @@ -45,16 +44,15 @@ nfq_send_verdict(int queue_num, uint32_t id)
> perror("mnl_socket_send");
> exit(EXIT_FAILURE);
> }
> -
> - return ret;
> }
>
> static int queue_cb(const struct nlmsghdr *nlh, void *data)
> {
> struct nfqnl_msg_packet_hdr *ph = NULL;
> - struct nlattr *attr[NFQA_MAX+1];
> + struct nlattr *attr[NFQA_MAX+1] = {};
> uint32_t id = 0;
> struct nfgenmsg *nfg;
> + uint16_t plen;
>
> if (nfq_nlmsg_parse(nlh, attr) < 0) {
> perror("problems parsing");
> @@ -63,18 +61,22 @@ static int queue_cb(const struct nlmsghdr *nlh, void *data)
>
> nfg = mnl_nlmsg_get_payload(nlh);
>
> - ph = (struct nfqnl_msg_packet_hdr *)
> - mnl_attr_get_payload(attr[NFQA_PACKET_HDR]);
> - if (ph == NULL) {
> - perror("problems retrieving metaheader");
> + if (attr[NFQA_PACKET_HDR] == NULL) {
> + fputs("metaheader not set\n", stderr);
> return MNL_CB_ERROR;
> }
>
> - id = ntohl(ph->packet_id);
> + ph = mnl_attr_get_payload(attr[NFQA_PACKET_HDR]);
>
> - printf("packet received (id=%u hw=0x%04x hook=%u)\n",
> - id, ntohs(ph->hw_protocol), ph->hook);
> + plen = mnl_attr_get_payload_len(attr[NFQA_PAYLOAD]);
> + /* void *payload = mnl_attr_get_payload(attr[NFQA_PAYLOAD]); */
> +
> + id = ntohl(ph->packet_id);
> + printf("packet received (id=%u hw=0x%04x hook=%u, payload len %u)\n",
> + id, ntohs(ph->hw_protocol), ph->hook, plen);
>
> + puts("sleep 10 seconds");
> + sleep(10);
Why this sleep 10 seconds? :-)
> nfq_send_verdict(ntohs(nfg->res_id), id);
>
> return MNL_CB_OK;
> --
> 1.7.8.6
>
> --
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