Left bit shift result in UB

[semihalf-berestovskyy-andriy]

Note: the issue was created automatically with bugzilla2github tool

Bugzilla Bug ID: 119

Date: 2017-01-08 12:46:03 +0100
From: Dapeng Liu <[email protected]>
To: Dapeng Liu <[email protected]>
CC: [email protected]

Depends on: #118, #114
Blocker for: #115, #116
Last updated: 2017-01-08 12:46:15 +0100

Bugzilla Comment ID: 225

Date: 2017-01-08 12:46:03 +0100
From: Dapeng Liu <[email protected]>

For E1 << E2, according to C programming language, the result is undefined if the right operand is negative, or greater than or equal to the number of bits in the left expression’s type. On my testbed 0xFFFFFFFF << (32 - masklen) in to_network_prefix result in 0xFFFFFFFF when masklen is 0, which is clearly wrong. Will check all bit shift operation and provide fix soon.