Changeset 0ac2158 in mainline for uspace/srv/net/tl/tcp/pdu.c

Timestamp:

2011-12-08T23:29:06Z (12 years ago)

Author:

Jiri Svoboda <jiri@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

d9e14fa4

Parents:

5f9ecd3

Message:

Determine local IP address, fill it in pseudo header.

File:

• uspace/srv/net/tl/tcp/pdu.c (modified) (3 diffs)

uspace/srv/net/tl/tcp/pdu.c

@@ -48 +48 @@
 #define TCP_CHECKSUM_INIT 0xffff
 
+/** One's complement addition.
+ *
+ * Result is a + b + carry.
+ */
+static uint16_t tcp_ocadd16(uint16_t a, uint16_t b)
+{
+        uint32_t s;
+
+        s = (uint32_t)a + (uint32_t)b;
+        return (s & 0xffff) + (s >> 16);
+}
+
 static uint16_t tcp_checksum_calc(uint16_t ivalue, void *data, size_t size)
 {
         uint16_t sum;
+        uint16_t w;
         size_t words, i;
         uint8_t *bdata;
@@ -59 +72 @@
 
         for (i = 0; i < words; i++) {
-                sum += ~(((uint16_t)bdata[2*i] << 8) + bdata[2*i + 1]);
+                w = ((uint16_t)bdata[2*i] << 8) | bdata[2*i + 1];
+                sum = tcp_ocadd16(sum, w);
         }
 
         if (size % 2 != 0) {
-                sum += ~((uint16_t)bdata[2*words] << 8);
+                w = ((uint16_t)bdata[2*words] << 8);
+                sum = tcp_ocadd16(sum, w);
         }
 
@@ -237 +252 @@
 
         hdr = (tcp_header_t *)pdu->header;
-        hdr->checksum = host2uint16_t_le(checksum);
+        hdr->checksum = host2uint16_t_be(checksum);
 }