AlliedModders - WRBot Segmentation fault (Server crash on map load)

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WRBot Segmentation fault (Server crash on map load)

Hello,

I'm using "WRBot Auto" from kraster (https://xtreme-jumps.eu/e107_plugins...c.php?364070.0) for my KZ Server

Unfortunately nearly 50% of available KZ Maps are getting crashed by this plugin due to a segmentation fault. Crash Log:
Aside from that plugin's really impressive so it would be a waste to not fix this. Hope someone has the knowledge to help me.

Code:

L 06/20/2018 - 08:55:03: [AmxxArch] Processing addons/amxmodx/data/hm_timeattack_LeblE_0004.71.rar addons/amxmodx/data/demo0.dem

! rar.c:214: RAR 5 format isn't supported

! _7z.c:191: 7z support requires 7z SDK (define HAVE_7Z)

Segmentation fault (core dumped)

BFD: Warning: /opt/sell/srv311220/core is truncated: expected core file size >= 185425920, found: 1069056.

Cannot access memory at address 0xf77af908

Cannot access memory at address 0xf77af904

Failed to read a valid object file image from memory.

Cannot access memory at address 0xf77af908

Cannot access memory at address 0xf77af904

debug.cmds:4: Error in sourced command file:

Cannot access memory at address 0xec7fbaf0

email debug.log to [email protected]

Wed Jun 20 08:55:03 CEST 2018: Server restart in 10 seconds

Got 3 other maps as an example, 1st one is working, 2nd/3rd crashing server.

https://i.imgur.com/SblELgG.jpg

Re: WRBot Segmentation fault (Server crash on map load)

It seems like the module used for extracting .RAR archives only supports some types of them. When it fails to extract, the failure never gets passed to the plugin which continues trying to handle the newly extracted files (that don't exist).

To prevent this from happening, you'd need to add a check to make sure the files actually exist after extraction.

Changing this:

PHP Code:


		
			
public bool:is_valid_demo_file( file )
{
    fseek( file, 0, SEEK_END );
    new header_size = ftell( file );


    if ( header_size < 544 )
    {
        return(false);
    }

    fseek( file, 0, SEEK_SET );
    new signature[6];

    fread_blocks( file, signature, sizeof(signature), BLOCK_CHAR );

    if ( !contain( "HLDEMO", signature ) )
    {
        return(false);
    }

    return(true);
}

... to this:

PHP Code:


		
			
public bool:is_valid_demo_file( file )
{
    if ( !file )
    {
        return(false);
    }
    
    fseek( file, 0, SEEK_END );
    new header_size = ftell( file );


    if ( header_size < 544 )
    {
        return(false);
    }

    fseek( file, 0, SEEK_SET );
    new signature[6];

    fread_blocks( file, signature, sizeof(signature), BLOCK_CHAR );

    if ( !contain( "HLDEMO", signature ) )
    {
        return(false);
    }

    return(true);
}

should do the job.

If your goal is to make the bot work for all maps though, I'm afraid it's much more complicated than that, since AFAIK there are no other modules for extracting archives, so you'd need to develop one that works for all RAR types yourself. Either that, or repackage all the bad demos into the default RAR format.

Re: WRBot Segmentation fault (Server crash on map load)

Thanks for your code, unluckily server is still crashing on mapchange. Anyway gotta wait for someone to be able to fix unsupported rar format.

Re: WRBot Segmentation fault (Server crash on map load)

Quote:

Originally Posted by wAyz (Post 2598581)

Thanks for your code, unluckily server is still crashing on mapchange. Anyway gotta wait for someone to be able to fix unsupported rar format.

Ah bummer, I guess something is wrong with the AmxxArch module itself as well then, making the server crash when it runs into an unsupported file format. Unfortunately I won't be able to help too much with that, since I don't have any C++ knowledge, but after having a quick look, I'd guess the problem lies here:

PHP Code:


		
			
// File: AmxxZip.cpp
// Line: 234
void extract(const char *filename, const char *dest)
{
    ar_stream *stream = NULL;
    ar_archive *ar = NULL;
    int entry_count = 1;
    int entry_skips = 0;
    int error_step = 1;
    stream = ar_open_file(filename);
    ar = ar_open_any_archive(stream, strrchr(filename, '.'));
    FILE* destfile = fopen(dest, "wb");;
    while (ar_parse_entry(ar)) {
        size_t size = ar_entry_get_size(ar);
        while (size > 0) {
            unsigned char buffer[1024];
            size_t count = size < sizeof(buffer) ? size : sizeof(buffer);
            if (!ar_entry_uncompress(ar, buffer, count))
                break;

            fwrite(buffer, sizeof(char), count, destfile);
            size -= count;
        }
        if (size > 0) {
            fprintf(stderr, "Warning: Failed to uncompress... skipping\n");
            entry_skips++;
        }
    }
    error_step = entry_skips > 0 ? 1000 + entry_skips : 0;
    fclose(destfile);
    ar_close_archive(ar);
    ar_close(stream);
    return;
}

----->

PHP Code:


		
			
// File: AmxxZip.cpp
// Line: 234
void extract(const char *filename, const char *dest)
{
    ar_stream *stream = NULL;
    ar_archive *ar = NULL;
    stream = ar_open_file(filename);
    ar = ar_open_any_archive(stream, strrchr(filename, '.'));
    if (!ar)
    {
        MF_Log("Warning: Unable to extract %s - unsupported format", filename);
    }
    else
    {
        FILE* destfile = fopen(dest, "wb");;
        int entry_count = 1;
        int entry_skips = 0;
        int error_step = 1;
        while (ar_parse_entry(ar)) {
            size_t size = ar_entry_get_size(ar);
            while (size > 0) {
                unsigned char buffer[1024];
                size_t count = size < sizeof(buffer) ? size : sizeof(buffer);
                if (!ar_entry_uncompress(ar, buffer, count))
                    break;

                fwrite(buffer, sizeof(char), count, destfile);
                size -= count;
            }
            if (size > 0) {
                fprintf(stderr, "Warning: Failed to uncompress... skipping\n");
                entry_skips++;
            }
        }
        error_step = entry_skips > 0 ? 1000 + entry_skips : 0;
        fclose(destfile);
        ar_close_archive(ar);
    }
    ar_close(stream);
    return;
}

Hope this fixes the crash at least. Good luck! :)