all: import netsniff-ng 0.5.8-rc0 source

We decided to get rid of the old Git history and start a new one for
several reasons:

 *) Allow / enforce only high-quality commits (which was not the case
    for many commits in the history), have a policy that is more close
    to the one from the Linux kernel. With high quality commits, we
    mean code that is logically split into commits and commit messages
    that are signed-off and have a proper subject and message body.
    We do not allow automatic Github merges anymore, since they are
    total bullshit. However, we will either cherry-pick your patches
    or pull them manually.

 *) The old archive was about ~27MB for no particular good reason.
    This basically derived from the bad decision that also some PDF
    files where stored there. From this moment onwards, no binary
    objects are allowed to be stored in this repository anymore.

The old archive is not wiped away from the Internet. You will still
be able to find it, e.g. on git.cryptoism.org etc.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>

1 files changed, 179 insertions, 0 deletions

diff --git a/csum.h b/csum.h
new file mode 100644
index 0000000..212faae
--- /dev/null
+++ b/csum.h
@@ -0,0 +1,179 @@
+/*
+ * netsniff-ng - the packet sniffing beast
+ * Copyright 2010 Emmanuel Roullit.
+ * Subject to the GPL, version 2.
+ */
+
+#ifndef CSUM_H
+#define	CSUM_H
+
+#include <netinet/in.h>
+#include <netinet/ip.h>
+
+#include "built_in.h"
+
+static inline unsigned short csum(unsigned short *buf, int nwords)
+{
+	unsigned long sum;
+
+	for (sum = 0; nwords > 0; nwords--)
+		sum += *buf++;
+	sum = (sum >> 16) + (sum & 0xffff);
+	sum += (sum >> 16);
+
+	return ~sum;
+}
+
+static inline uint16_t calc_csum(void *addr, size_t len, int ccsum)
+{
+	return csum(addr, len >> 1);
+}
+
+static inline uint16_t csum_expected(uint16_t sum, uint16_t computed_sum)
+{
+	uint32_t shouldbe;
+
+	shouldbe = sum;
+	shouldbe += ntohs(computed_sum);
+	shouldbe = (shouldbe & 0xFFFF) + (shouldbe >> 16);
+	shouldbe = (shouldbe & 0xFFFF) + (shouldbe >> 16);
+
+	return shouldbe;
+}
+
+/* Taken and modified from tcpdump, Copyright belongs to them! */
+
+struct cksum_vec {
+	const u8 *ptr;
+	int len;
+};
+
+#define ADDCARRY(x)		\
+	do { if ((x) > 65535)	\
+		(x) -= 65535;	\
+	} while (0)
+
+#define REDUCE						\
+	do {						\
+		l_util.l = sum;				\
+		sum = l_util.s[0] + l_util.s[1];	\
+		ADDCARRY(sum);				\
+	} while (0)
+
+static inline u16 __in_cksum(const struct cksum_vec *vec, int veclen)
+{
+	const u16 *w;
+	int sum = 0, mlen = 0;
+	int byte_swapped = 0;
+	union {
+		u8 c[2];
+		u16 s;
+	} s_util;
+	union {
+		u16 s[2];
+		u32 l;
+	} l_util;
+
+	for (; veclen != 0; vec++, veclen--) {
+		if (vec->len == 0)
+			continue;
+
+		w = (const u16 *) (void *) vec->ptr;
+
+		if (mlen == -1) {
+			s_util.c[1] = *(const u8 *) w;
+			sum += s_util.s;
+			w = (const u16 *) (void *) ((const u8 *) w + 1);
+			mlen = vec->len - 1;
+		} else
+			mlen = vec->len;
+
+		if ((1 & (unsigned long) w) && (mlen > 0)) {
+			REDUCE;
+			sum <<= 8;
+			s_util.c[0] = *(const u8 *) w;
+			w = (const u16 *) (void *) ((const u8 *) w + 1);
+			mlen--;
+			byte_swapped = 1;
+		}
+
+		while ((mlen -= 32) >= 0) {
+			sum +=  w[0]; sum +=  w[1]; sum +=  w[2]; sum +=  w[3];
+			sum +=  w[4]; sum +=  w[5]; sum +=  w[6]; sum +=  w[7];
+			sum +=  w[8]; sum +=  w[9]; sum += w[10]; sum += w[11];
+			sum += w[12]; sum += w[13]; sum += w[14]; sum += w[15];
+			w += 16;
+		}
+
+		mlen += 32;
+
+		while ((mlen -= 8) >= 0) {
+			sum += w[0]; sum += w[1]; sum += w[2]; sum += w[3];
+			w += 4;
+		}
+
+		mlen += 8;
+
+		if (mlen == 0 && byte_swapped == 0)
+			continue;
+
+		REDUCE;
+
+		while ((mlen -= 2) >= 0) {
+			sum += *w++;
+		}
+
+		if (byte_swapped) {
+			REDUCE;
+			sum <<= 8;
+			byte_swapped = 0;
+
+			if (mlen == -1) {
+				s_util.c[1] = *(const u8 *) w;
+				sum += s_util.s;
+				mlen = 0;
+			} else
+				mlen = -1;
+		} else if (mlen == -1)
+			s_util.c[0] = *(const u8 *) w;
+	}
+
+	if (mlen == -1) {
+		s_util.c[1] = 0;
+		sum += s_util.s;
+	}
+
+	REDUCE;
+
+	return (~sum & 0xffff);
+}
+
+static inline u16 p4_csum(const struct ip *ip, const u8 *data, u16 len,
+			  u8 next_proto)
+{
+	struct cksum_vec vec[2];
+	struct pseudo_hdr {
+		u32 src;
+		u32 dst;
+		u8 mbz;
+		u8 proto;
+		u16 len;
+	} ph;
+
+	memset(&ph, 0, sizeof(ph));
+	ph.len = htons(len);
+	ph.mbz = 0;
+	ph.proto = next_proto;
+	ph.src = ip->ip_src.s_addr;
+	ph.dst = ip->ip_dst.s_addr;
+
+	vec[0].ptr = (const u8 *) (void *) &ph;
+	vec[0].len = sizeof(ph);
+
+	vec[1].ptr = data;
+	vec[1].len = len;
+
+	return __in_cksum(vec, 2);
+}
+
+#endif /* CSUM_H */