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authorDuncan Roe <duncan_roe@optusnet.com.au>2019-12-20 16:53:48 +1100
committerPablo Neira Ayuso <pablo@netfilter.org>2019-12-30 12:32:04 +0100
commit535a79f002c95b9d37ebded4f34c3b225c4c738d (patch)
treef4adb21b5883a73467d9d8fe0032f54692cb9a79 /src/extra/tcp.c
parentc432a84f1b6a5fb4435f74408d11ed8f7672ec4b (diff)
src: add mangle functions for IPv6, IPv6/TCP and IPv6/UDP
Signed-off-by: Duncan Roe <duncan_roe@optusnet.com.au> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'src/extra/tcp.c')
-rw-r--r--src/extra/tcp.c40
1 files changed, 40 insertions, 0 deletions
diff --git a/src/extra/tcp.c b/src/extra/tcp.c
index 136d7ea..8119843 100644
--- a/src/extra/tcp.c
+++ b/src/extra/tcp.c
@@ -21,6 +21,7 @@
#include <libnetfilter_queue/libnetfilter_queue.h>
#include <libnetfilter_queue/libnetfilter_queue_tcp.h>
#include <libnetfilter_queue/libnetfilter_queue_ipv4.h>
+#include <libnetfilter_queue/libnetfilter_queue_ipv6.h>
#include <libnetfilter_queue/pktbuff.h>
#include "internal.h"
@@ -207,5 +208,44 @@ int nfq_tcp_mangle_ipv4(struct pkt_buff *pkt,
}
/**
+ * nfq_tcp_mangle_ipv6 - Mangle TCP/IPv6 packet buffer
+ * \param pktb: Pointer to network packet buffer
+ * \param match_offset: Offset from start of TCP data of content that you want
+ * to mangle
+ * \param match_len: Length of the existing content you want to mangle
+ * \param rep_buffer: Pointer to data you want to use to replace current content
+ * \param rep_len: Length of data you want to use to replace current content
+ * \returns 1 for success and 0 for failure. See pktb_mangle() for failure case
+ * \note This function updates the IPv6 length and recalculates the TCP
+ * checksum for you.
+ * \warning After changing the length of a TCP message, the application will
+ * need to mangle sequence numbers in both directions until another change
+ * puts them in sync again
+ */
+EXPORT_SYMBOL
+int nfq_tcp_mangle_ipv6(struct pkt_buff *pktb,
+ unsigned int match_offset, unsigned int match_len,
+ const char *rep_buffer, unsigned int rep_len)
+{
+ struct ip6_hdr *ip6h;
+ struct tcphdr *tcph;
+
+ ip6h = (struct ip6_hdr *)pktb->network_header;
+ tcph = (struct tcphdr *)(pktb->transport_header);
+ if (!tcph)
+ return 0;
+
+ if (!nfq_ip6_mangle(pktb,
+ pktb->transport_header - pktb->network_header +
+ tcph->doff * 4,
+ match_offset, match_len, rep_buffer, rep_len))
+ return 0;
+
+ nfq_tcp_compute_checksum_ipv6(tcph, ip6h);
+
+ return 1;
+}
+
+/**
* @}
*/