From 0fd2dfdcbb706345ef44797c2e9d92bbfc64b2bf Mon Sep 17 00:00:00 2001
From: Faris Hasim <farishasimsyauqi@gmail.com>
Date: Thu, 25 Nov 2021 11:24:44 +0700
Subject: [PATCH] add segment from/to file
---
halo.txt | 1 +
segment.py | 59 ++++++++++++++++++++++++++++++++++++++++++++----------
2 files changed, 49 insertions(+), 11 deletions(-)
create mode 100644 halo.txt
diff --git a/halo.txt b/halo.txt
new file mode 100644
index 0000000..4bb9374
--- /dev/null
+++ b/halo.txt
@@ -0,0 +1 @@
+ABU ABU CAKUE
\ No newline at end of file
diff --git a/segment.py b/segment.py
index d092bec..a5d966b 100644
--- a/segment.py
+++ b/segment.py
@@ -1,4 +1,5 @@
import struct
+import os
# constant
SEG_SIZE = 32782
@@ -6,8 +7,14 @@ DATA_SIZE = SEG_SIZE - 12
class Segment():
- def __init__(self):
+ def __init__(self, seq_no=0, ack_no=0, data=bytes(), checksum=0):
+ self.DATA_PTR = 12
+
self.bytes = [0 for _ in range(SEG_SIZE)]
+ self.set_seq_no(seq_no)
+ self.set_ack_no(ack_no)
+ self.set_data(data)
+ self.set_checksum(checksum)
def set_seq_no(self, val):
self.bytes[0] = val >> 24 & 0xff
@@ -33,6 +40,20 @@ class Segment():
(self.bytes[6] << 8) + \
self.bytes[7]
+ def set_data(self, data):
+ ptr = self.DATA_PTR
+ for byte in data:
+ self.bytes[ptr] = byte
+ ptr += 1
+
+ def get_data(self):
+ data=[]
+ ptr = self.DATA_PTR # pointer to data in segment
+ while self.bytes[ptr] != 0:
+ data.append(self.bytes[ptr])
+ ptr += 1
+ return bytes(data)
+
def setSYN(self):
# raise SYN flag
self.bytes[8] = self.bytes[8] | 0b01000000
@@ -73,6 +94,7 @@ class Segment():
len_data += 1
data += struct.pack('!B', 0)
+ checksum=0
for i in range (0, len_data, 2):
w = (data[i] << 8) + (data[i + 1])
checksum += w
@@ -91,16 +113,31 @@ class Segment():
self.bytes = list(byte)
return self
-if __name__=="__main__":
- seg = Segment()
+ def from_file(self, filepath):
+ filename = os.path.basename(filepath)
+ with open(filename, 'rb') as f:
+ self.set_data(f.read())
- seg.setFIN()
- seg.set_seq_no()
- seg.set_ack_no()
-
- checksum = seg.count_checksum()
- seg.set_checksum(checksum)
+ def to_file(self, filename):
+ with open(filename, 'wb') as f:
+ data = self.get_data()
+ f.write(data)
- seg = Segment(seqno, ackno, flag, data)
+ def log(self):
+ print(self.bytes[:50])
- print(seg.bytes[:100])
\ No newline at end of file
+if __name__=="__main__":
+ # seg = Segment()
+ # seg.setFIN()
+ # seg.set_seq_no()
+ # seg.set_ack_no()
+ # checksum = seg.count_checksum()
+ # seg.set_checksum(checksum)
+ # seg = Segment(seqno, ackno, flag, data)
+
+ seg = Segment(200, 199)
+ seg.from_file("halo.txt")
+ seg.set_checksum(seg.count_checksum())
+ seg.log()
+
+ seg.to_file("out.txt")
\ No newline at end of file
--
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