diff options
author | Florian Westphal <fw@strlen.de> | 2013-04-26 10:21:16 +0200 |
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committer | Florian Westphal <fw@strlen.de> | 2013-04-30 16:57:22 +0200 |
commit | 6c7b3366eae8a912c56d1940ba221a1d7f8eb680 (patch) | |
tree | 4596d6ed89513d98797ce2cdb0e0daf7fab700f9 /src/libnetfilter_queue.c | |
parent | 0052078cf4cb03b23c49ef1cd65f69df746890b4 (diff) |
src: add new GSO handling capabilities
allows userspace to ask for large gso packets via nfqueue.
Signed-off-by: Florian Westphal <fw@strlen.de>
Diffstat (limited to 'src/libnetfilter_queue.c')
-rw-r--r-- | src/libnetfilter_queue.c | 17 |
1 files changed, 17 insertions, 0 deletions
diff --git a/src/libnetfilter_queue.c b/src/libnetfilter_queue.c index 2894ccd..c59bc63 100644 --- a/src/libnetfilter_queue.c +++ b/src/libnetfilter_queue.c @@ -639,6 +639,23 @@ int nfq_set_mode(struct nfq_q_handle *qh, * - NFQA_CFG_F_CONNTRACK (requires Linux kernel >= 3.6): the kernel will * include the Connection Tracking system information. * + * - NFQA_CFG_F_GSO (requires Linux kernel >= 3.10): the kernel will + * not normalize offload packets, i.e. your application will need to + * be able to handle packets larger than the mtu (up to 64k). + * + * If your application validates checksums (e.g., tcp checksum), + * then you must also check if the NFQA_SKB_INFO attribute is present. + * If it is, you need to test the NFQA_SKB_CSUMNOTREADY bit: + * \verbatim + if (attr[NFQA_SKB_INFO]) { + uint32_t info = ntohl(mnl_attr_get_u32(attr[NFQA_SKB_INFO])); + if (info & NFQA_SKB_CSUMNOTREADY) + validate_checksums = false; + } +\endverbatim + * if this bit is set, the layer 3/4 checksums of the packet appear incorrect, + * but are not (because they will be corrected later by the kernel). + * * Here's a little code snippet to show how to use this API: * \verbatim uint32_t flags = NFQA_CFG_F_FAIL_OPEN; |