Buffer overflow? Won't join channel sometimes -- IRC Bot in C

This is a discussion on Buffer overflow? Won't join channel sometimes -- IRC Bot in C within the Networking/Device Communication forums, part of the General Programming Boards category; http://uranther.pastebin.com/510905 The code is above. It will connect to that server but it won't join the channel. With the same ...

  1. #1
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    Buffer overflow? Won't join channel sometimes -- IRC Bot in C

    http://uranther.pastebin.com/510905

    The code is above. It will connect to that server but it won't join the channel. With the same code it does connect and join the channel. What am I missing? irc.neverside.com is UnrealIRCd if you're wondering.

    I was wondering if the weird characters (SĘ(p) I get from the message printed from the server are a buffer overflow somewhere but I can't find where. Is that attributing to the flakiness of the connecting etc? Or is there something fundamentally wrong with my code?

  2. #2
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    Code:
    n = read(sockfd, buffer, BUFFER - 1);
    printf("%s\n", buffer);
    You never null terminate the buffer before you print it out. Do this:
    Code:
    n = read(sockfd, buffer, BUFFER - 1);
    buffer[n] = 0;
    printf("%s\n", buffer);

  3. #3
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    Also, you are calling strlen() way too many times. Save the string lengths into an integer so you don't have to keep calculating the length of the same string over and over again.

  4. #4
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    Oh, and you will run into problems with the following code:
    Code:
    if (strstr(buffer, "PING :"))
    What happens if a user sends a chat message with "PING :" somewhere in it?

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