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Diffstat (limited to 'Semestr 4/sieci/pracownia1/icmp_checksum.c')
-rw-r--r--Semestr 4/sieci/pracownia1/icmp_checksum.c10
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)));
+}