From 5c974d1f80d6bbbcbbe7138fec974a79379702b2 Mon Sep 17 00:00:00 2001 From: Franciszek Malinka Date: Tue, 16 Mar 2021 19:31:22 +0100 Subject: pracownia 1 z sieci --- Semestr 4/sieci/pracownia1/icmp_checksum.c | 10 ++++++++++ 1 file changed, 10 insertions(+) create mode 100644 Semestr 4/sieci/pracownia1/icmp_checksum.c (limited to 'Semestr 4/sieci/pracownia1/icmp_checksum.c') 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))); +} -- cgit v1.2.3