Lines Matching defs:sum4
109 __wsum sum4 = 0;
112 sum4 += ((__u16 *)&ip)[i];
114 // Note that sum4 is guaranteed to be non-zero by virtue of ip.version == 4
115 sum4 = (sum4 & 0xFFFF) + (sum4 >> 16); // collapse u32 into range 1 .. 0x1FFFE
116 sum4 = (sum4 & 0xFFFF) + (sum4 >> 16); // collapse any potential carry into u16
117 ip.check = (__u16)~sum4; // sum4 cannot be zero, so this is never 0xFFFF
183 __wsum sum4 = 0;
186 sum4 += ((__u16 *)ip4)[i];
188 // Note that sum4 is guaranteed to be non-zero by virtue of ip4->version == 4
189 sum4 = (sum4 & 0xFFFF) + (sum4 >> 16); // collapse u32 into range 1 .. 0x1FFFE
190 sum4 = (sum4 & 0xFFFF) + (sum4 >> 16); // collapse any potential carry into u16
191 // for a correct checksum we should get *a* zero, but sum4 must be positive, ie 0xFFFF
192 if (sum4 != 0xFFFF)