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authorKim Alvefur <zash@zash.se>2015-10-06 18:03:04 +0200
committerKim Alvefur <zash@zash.se>2015-10-06 18:03:04 +0200
commit2efcb9f82f22b826e3903bb1e014e64570bbb3e5 (patch)
treebdb51b87d13bdc653daa67c03a116279bf764adc
parent5d941b553acfce45e531ac56fa15cda472e728fe (diff)
downloadprosody-2efcb9f82f22b826e3903bb1e014e64570bbb3e5.tar.gz
prosody-2efcb9f82f22b826e3903bb1e014e64570bbb3e5.zip
net.websocket.frames: Pack and unpack 64bit ints without overflows (lua-bitop/bit32 are 32bit)
-rw-r--r--net/websocket/frames.lua10
1 files changed, 6 insertions, 4 deletions
diff --git a/net/websocket/frames.lua b/net/websocket/frames.lua
index e8faab2b..8528ab99 100644
--- a/net/websocket/frames.lua
+++ b/net/websocket/frames.lua
@@ -30,8 +30,9 @@ end
-- FIXME: this may lose precision
local function read_uint64be(str, pos)
local l1, l2, l3, l4, l5, l6, l7, l8 = s_byte(str, pos, pos+7);
- return lshift(l1, 56) + lshift(l2, 48) + lshift(l3, 40) + lshift(l4, 32)
- + lshift(l5, 24) + lshift(l6, 16) + lshift(l7, 8) + l8;
+ local h = lshift(l1, 24) + lshift(l2, 16) + lshift(l3, 8) + l4;
+ local l = lshift(l5, 24) + lshift(l6, 16) + lshift(l7, 8) + l8;
+ return h * 2^32 + l;
end
local function pack_uint16be(x)
return s_char(rshift(x, 8), band(x, 0xFF));
@@ -40,8 +41,9 @@ local function get_byte(x, n)
return band(rshift(x, n), 0xFF);
end
local function pack_uint64be(x)
- return s_char(rshift(x, 56), get_byte(x, 48), get_byte(x, 40), get_byte(x, 32),
- get_byte(x, 24), get_byte(x, 16), get_byte(x, 8), band(x, 0xFF));
+ local h = band(x / 2^32, 2^32-1);
+ return s_char(get_byte(h, 24), get_byte(h, 16), get_byte(h, 8), band(h, 0xFF));
+ get_byte(x, 24), get_byte(x, 16), get_byte(x, 8), band(x, 0xFF);
end
local function parse_frame_header(frame)