pracownia 1 z sieci

1 files changed, 10 insertions, 0 deletions

diff --git a/Semestr 4/sieci/pracownia1/icmp_checksum.c b/Semestr 4/sieci/pracownia1/icmp_checksum.c
new file mode 100644
index 0000000..c9dc96b
--- /dev/null
+++ b/Semestr 4/sieci/pracownia1/icmp_checksum.c
@@ -0,0 +1,10 @@
+u_int16_t compute_icmp_checksum (const void *buff, int length)
+{
+	u_int32_t sum;
+	const u_int16_t* ptr = buff;
+	assert (length % 2 == 0);
+	for (sum = 0; length > 0; length -= 2)
+		sum += *ptr++;
+	sum = (sum >> 16) + (sum & 0xffff);
+	return (u_int16_t)(~(sum + (sum >> 16)));
+}