Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
---
examples/nf-queue.c | 29 +++++++++++++++++++++++++++--
1 files changed, 27 insertions(+), 2 deletions(-)
diff --git a/examples/nf-queue.c b/examples/nf-queue.c
index 6641a24..1f465ad 100644
--- a/examples/nf-queue.c
+++ b/examples/nf-queue.c
@@ -51,7 +51,7 @@ static int queue_cb(const struct nlmsghdr *nlh, void *data)
{
struct nfqnl_msg_packet_hdr *ph = NULL;
struct nlattr *attr[NFQA_MAX+1] = {};
- uint32_t id = 0;
+ uint32_t id = 0, skbinfo;
struct nfgenmsg *nfg;
uint16_t plen;
@@ -72,10 +72,32 @@ static int queue_cb(const struct nlmsghdr *nlh, void *data)
plen = mnl_attr_get_payload_len(attr[NFQA_PAYLOAD]);
/* void *payload = mnl_attr_get_payload(attr[NFQA_PAYLOAD]); */
+ skbinfo = attr[NFQA_SKB_INFO] ? ntohl(mnl_attr_get_u32(attr[NFQA_SKB_INFO])) : 0;
+
+ if (attr[NFQA_CAP_LEN]) {
+ uint32_t orig_len = ntohl(mnl_attr_get_u32(attr[NFQA_CAP_LEN]));
+ if (orig_len != plen)
+ printf("truncated ");
+ }
+
+ if (skbinfo & NFQA_SKB_GSO)
+ printf("GSO ");
+
id = ntohl(ph->packet_id);
- printf("packet received (id=%u hw=0x%04x hook=%u, payload len %u)\n",
+ printf("packet received (id=%u hw=0x%04x hook=%u, payload len %u",
id, ntohs(ph->hw_protocol), ph->hook, plen);
+ /*
+ * ip/tcp checksums are not yet valid, e.g. due to GRO/GSO.
+ * The application should behave as if the checksums are correct.
+ *
+ * If these packets are later forwarded/sent out, the checksums will
+ * be corrected by kernel/hardware.
+ */
+ if (skbinfo & NFQA_SKB_CSUMNOTREADY)
+ printf(", checksum not ready");
+ puts(")");
+
nfq_send_verdict(ntohs(nfg->res_id), id);
return MNL_CB_OK;
@@ -141,6 +163,9 @@ int main(int argc, char *argv[])
nlh = nfq_hdr_put(buf, NFQNL_MSG_CONFIG, queue_num);
nfq_nlmsg_cfg_put_params(nlh, NFQNL_COPY_PACKET, 0xffff);
+ mnl_attr_put_u32(nlh, NFQA_CFG_FLAGS, htonl(NFQA_CFG_F_GSO));
+ mnl_attr_put_u32(nlh, NFQA_CFG_MASK, htonl(NFQA_CFG_F_GSO));
+
if (mnl_socket_sendto(nl, nlh, nlh->nlmsg_len) < 0) {
perror("mnl_socket_send");
exit(EXIT_FAILURE);
--
1.7.8.6
--
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