ICMP checksum function not returning correct
I am studying a program that my instructor gave me for my Networking class. It is suppose to Ping a server using ICMP. However the program isn't working. I've run it with WireShark and it says that the checksum byte is not returning correctly. Apparently this works for my other classmates but not for me. And for those who might says "ask your professor" I have been trying to ask him about it for a while now but I haven't been able to meet with him yet. Here is the function that implements the checksum.
def checksum(string):
csum = 0
countTo = (len(string) // 2) *2
count = 0
while count < countTo:
thisVal = ord(strin[count+1]) *256 + ord(string[count])
csum = csum + this Val
csum = csum & 0xffffffff
count = count +2
if coutnTo < len(string):
csum = csum = ord(string[len(string) -1])
csum = csum & 0xffffffff
csum = (csumm >> 16) + (csum & 0xffff)
csum = csum + (csum >>16)
answer = ~csum
answer = answer & 0xffff
answer = answer >> 8 | (answer << 8 & 0xff00)
return answer
I should also mention that to create the string argument he uses struct.pack like so:
header = struct.pack("bbHHh", ICMP_ECHO_REQUEST,0,0, ID,1)
data = struct.pack("d",time.time())
checksum(str(header+data))
I am also running this in a Kali Vm if it matters.
python-3.x networking icmp
asked Nov 12 at 6:45
Blake Padrones
11
add a comment |
I am studying a program that my instructor gave me for my Networking class. It is suppose to Ping a server using ICMP. However the program isn't working. I've run it with WireShark and it says that the checksum byte is not returning correctly. Apparently this works for my other classmates but not for me. And for those who might says "ask your professor" I have been trying to ask him about it for a while now but I haven't been able to meet with him yet. Here is the function that implements the checksum.
def checksum(string):
csum = 0
countTo = (len(string) // 2) *2
count = 0
while count < countTo:
thisVal = ord(strin[count+1]) *256 + ord(string[count])
csum = csum + this Val
csum = csum & 0xffffffff
count = count +2
if coutnTo < len(string):
csum = csum = ord(string[len(string) -1])
csum = csum & 0xffffffff
csum = (csumm >> 16) + (csum & 0xffff)
csum = csum + (csum >>16)
answer = ~csum
answer = answer & 0xffff
answer = answer >> 8 | (answer << 8 & 0xff00)
return answer
I should also mention that to create the string argument he uses struct.pack like so:
header = struct.pack("bbHHh", ICMP_ECHO_REQUEST,0,0, ID,1)
data = struct.pack("d",time.time())
checksum(str(header+data))
I am also running this in a Kali Vm if it matters.
python-3.x networking icmp
asked Nov 12 at 6:45
Blake Padrones
11
add a comment |
I am studying a program that my instructor gave me for my Networking class. It is suppose to Ping a server using ICMP. However the program isn't working. I've run it with WireShark and it says that the checksum byte is not returning correctly. Apparently this works for my other classmates but not for me. And for those who might says "ask your professor" I have been trying to ask him about it for a while now but I haven't been able to meet with him yet. Here is the function that implements the checksum.
def checksum(string):
csum = 0
countTo = (len(string) // 2) *2
count = 0
while count < countTo:
thisVal = ord(strin[count+1]) *256 + ord(string[count])
csum = csum + this Val
csum = csum & 0xffffffff
count = count +2
if coutnTo < len(string):
csum = csum = ord(string[len(string) -1])
csum = csum & 0xffffffff
csum = (csumm >> 16) + (csum & 0xffff)
csum = csum + (csum >>16)
answer = ~csum
answer = answer & 0xffff
answer = answer >> 8 | (answer << 8 & 0xff00)
return answer
I should also mention that to create the string argument he uses struct.pack like so:
header = struct.pack("bbHHh", ICMP_ECHO_REQUEST,0,0, ID,1)
data = struct.pack("d",time.time())
checksum(str(header+data))
I am also running this in a Kali Vm if it matters.
python-3.x networking icmp
asked Nov 12 at 6:45
Blake Padrones
11
I am studying a program that my instructor gave me for my Networking class. It is suppose to Ping a server using ICMP. However the program isn't working. I've run it with WireShark and it says that the checksum byte is not returning correctly. Apparently this works for my other classmates but not for me. And for those who might says "ask your professor" I have been trying to ask him about it for a while now but I haven't been able to meet with him yet. Here is the function that implements the checksum.
def checksum(string):
csum = 0
countTo = (len(string) // 2) *2
count = 0
while count < countTo:
thisVal = ord(strin[count+1]) *256 + ord(string[count])
csum = csum + this Val
csum = csum & 0xffffffff
count = count +2
if coutnTo < len(string):
csum = csum = ord(string[len(string) -1])
csum = csum & 0xffffffff
csum = (csumm >> 16) + (csum & 0xffff)
csum = csum + (csum >>16)
answer = ~csum
answer = answer & 0xffff
answer = answer >> 8 | (answer << 8 & 0xff00)
return answer
I should also mention that to create the string argument he uses struct.pack like so:
header = struct.pack("bbHHh", ICMP_ECHO_REQUEST,0,0, ID,1)
data = struct.pack("d",time.time())
checksum(str(header+data))
I am also running this in a Kali Vm if it matters.
python-3.x networking icmp
python-3.x networking icmp
asked Nov 12 at 6:45
Blake Padrones
11
asked Nov 12 at 6:45
Blake Padrones
11
asked Nov 12 at 6:45
Blake Padrones
11
asked Nov 12 at 6:45
Blake Padrones
11
asked Nov 12 at 6:45
Blake Padrones
11
11
add a comment |
add a comment |
active
oldest
votes
Your Answer
StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53257084%2ficmp-checksum-function-not-returning-correct%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
active
oldest
votes
active
oldest
votes
active
oldest
votes
active
oldest
votes
Thanks for contributing an answer to Stack Overflow!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Some of your past answers have not been well-received, and you're in danger of being blocked from answering.
Please pay close attention to the following guidance:
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53257084%2ficmp-checksum-function-not-returning-correct%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
