Error when compiling - unknown field specified in initializer

Question

I have found an old script written in C and when I try to compile it I get the following message

 # gcc libipt_rope.c -o libipt_rope.so
libipt_rope.c:349: error: variable ‘rope’ has initializer but incomplete type
libipt_rope.c:350: error: unknown field ‘next’ specified in initializer
libipt_rope.c:350: warning: excess elements in struct initializer
libipt_rope.c:350: warning: (near initialization for ‘rope’)
libipt_rope.c:351: error: unknown field ‘name’ specified in initializer
libipt_rope.c:351: warning: excess elements in struct initializer
libipt_rope.c:351: warning: (near initialization for ‘rope’)
libipt_rope.c:352: error: unknown field ‘version’ specified in initializer
libipt_rope.c:352: warning: excess elements in struct initializer
libipt_rope.c:352: warning: (near initialization for ‘rope’)
libipt_rope.c:353: error: unknown field ‘size’ specified in initializer
libipt_rope.c:353: warning: excess elements in struct initializer
libipt_rope.c:353: warning: (near initialization for ‘rope’)
libipt_rope.c:354: error: unknown field ‘userspacesize’ specified in initializer
libipt_rope.c:354: warning: excess elements in struct initializer
libipt_rope.c:354: warning: (near initialization for ‘rope’)
libipt_rope.c:355: error: unknown field ‘help’ specified in initializer
libipt_rope.c:355: warning: excess elements in struct initializer
libipt_rope.c:355: warning: (near initialization for ‘rope’)
libipt_rope.c:356: error: unknown field ‘init’ specified in initializer
libipt_rope.c:356: warning: excess elements in struct initializer
libipt_rope.c:356: warning: (near initialization for ‘rope’)
libipt_rope.c:357: error: unknown field ‘parse’ specified in initializer
libipt_rope.c:357: warning: excess elements in struct initializer
libipt_rope.c:357: warning: (near initialization for ‘rope’)
libipt_rope.c:358: error: unknown field ‘final_check’ specified in initializer
libipt_rope.c:358: warning: excess elements in struct initializer
libipt_rope.c:358: warning: (near initialization for ‘rope’)
libipt_rope.c:359: error: unknown field ‘print’ specified in initializer
libipt_rope.c:359: warning: excess elements in struct initializer
libipt_rope.c:359: warning: (near initialization for ‘rope’)
libipt_rope.c:360: error: unknown field ‘save’ specified in initializer
libipt_rope.c:360: warning: excess elements in struct initializer
libipt_rope.c:360: warning: (near initialization for ‘rope’)
libipt_rope.c:361: error: unknown field ‘extra_opts’ specified in initializer
libipt_rope.c:362: warning: excess elements in struct initializer
libipt_rope.c:362: warning: (near initialization for ‘rope’

I'm asking the C gurus, since i'm quite familiar with C, but not that much.

And here's the code

/

/* For detailed documentation about ROPE, visit http://www.lowth.com/rope */

#include <sys/socket.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <netdb.h>
#include <string.h>
#include <stdlib.h>
#include <getopt.h>
#include <ctype.h>
#include <fcntl.h>
#include <unistd.h>
#include <assert.h>

#include "iptables.h"

#define _USERLAND_ 1
#define _ROPE_IPTABLES_ 1
#include "rope.h"
#include "rope-enum.h"

#define WANT_ROPE_LOAD_SCRIPT
#include "rope-util.h"

#define IPT_ROPE_SCRIPT     0x0001
#define IPT_ROPE_PUSH_INT   0x0002
#define IPT_ROPE_PUSH_STR   0x0004
#define IPT_ROPE_PUSH_IP    0x0008

#define OPT_SCRIPT   "rope-script"
#define OPT_PUSH_INT "rope-push-int"
#define OPT_PUSH_STR "rope-push-str"
#define OPT_PUSH_IP  "rope-push-ip"

/* Function which prints out usage message. */
static void help(void)
{
    printf(
"ROPE (version " ROPE_VERSION ") match v%s options:\n"
"[!] --" OPT_SCRIPT "    scriptfile    Name of packet-matching ROPE script\n"
"    --" OPT_PUSH_INT "  integer       Push integer onto stack\n"
"    --" OPT_PUSH_STR "  string        Push string onto stack\n"
"    --" OPT_PUSH_IP "   ip-address    Push IPv4 address onto stack\n",
IPTABLES_VERSION);

    fputc('\n', stdout);
}

static struct option opts[] = {
    { "script",     1, 0, '1' },    // for backwards compatibility
    { OPT_SCRIPT,   1, 0, '1' },
    { OPT_PUSH_INT, 1, 0, '2' },
    { OPT_PUSH_STR, 1, 0, '3' },
    { OPT_PUSH_IP,  1, 0, '4' },
    {0}
};

/* Initialize the match. */
static void init(struct ipt_entry_match *m, unsigned int *nfcache)
{
    struct ipt_rope_info *ropeinfo = (struct ipt_rope_info *)(m)->data;
    *nfcache |= NFC_UNKNOWN;
    memset(ropeinfo, 0, sizeof(*ropeinfo));
    ropeinfo->version = ROPE_SCRIPT_VERSION;
    ropeinfo->info_size = (u_int16_t)sizeof(struct ipt_rope_info);
}

static void read_scriptfile(struct ipt_rope_info *info, char *filename)
{
    int i;
    int len = strlen(filename);
    char *scriptdir = "/etc/rope.d/scripts";
    char path[ROPE_MAX_FILENAME + strlen(scriptdir)+8];
    struct stat stat_info;
    int ok, script_offset, script_len, ipsets_offset, ipsets_len, used_buff;

    if (len < 1) exit_error(PARAMETER_PROBLEM, "Script file name cannot be empty" );
    if (len >= ROPE_MAX_FILENAME) exit_error(PARAMETER_PROBLEM, "Script file name too long" );
    for (i=0; i<len; i++) {
        char c = filename[i];
        if ( !isalnum(c) && c != '-' && c != '_' )
            exit_error(
                PARAMETER_PROBLEM,
                "Script file name can only contain letters, digits or hyphens"
            );
    }
    strcpy(path, scriptdir);
    strcat(path, "/");
    strcat(path, filename);
    strcat(path, ".rp");

    /* Verify that it is safe to load scripts from the directory */
    if (lstat(scriptdir, &stat_info) != 0)
        exit_error( PARAMETER_PROBLEM, "Cant stat '%s'", scriptdir );
    if (!S_ISDIR(stat_info.st_mode))
        exit_error( PARAMETER_PROBLEM, "'%s' is not a directory (it should be)", scriptdir);
    if (stat_info.st_uid != 0)
        exit_error( PARAMETER_PROBLEM, "Directory '%s' is not owned by 'root' (it should be)", scriptdir);
    if (stat_info.st_mode & (S_IWGRP | S_IWOTH))
        exit_error( PARAMETER_PROBLEM, "Directory '%s' may be writeable by non-root users (it should not be)", scriptdir);

    /* Verify that only root can modify it */
    if (lstat(path, &stat_info) != 0)
        exit_error( PARAMETER_PROBLEM, "Cant stat '%s'", path);
    if (!S_ISREG(stat_info.st_mode))
        exit_error( PARAMETER_PROBLEM, "'%s' is not a regular file (it should be)", path);
    if (stat_info.st_uid != 0)
        exit_error( PARAMETER_PROBLEM, "File '%s' is not owned by 'root' (it should be)", path);
    if (stat_info.st_mode & (S_IWGRP | S_IWOTH))
        exit_error( PARAMETER_PROBLEM, "File '%s' may be writeable by non-root users (it should not be)", path);

    strcpy(info->scriptfile, filename);

    ok = rope_load_script(
        path,
        info->scriptbuff+info->arguments_len, ROPE_MAX_COMPILED_SIZE - info->arguments_len, &used_buff,
        &script_offset, &script_len,
        &ipsets_offset, &ipsets_len
    );

    if ( !ok )
        exit_error( PARAMETER_PROBLEM, "Cant load file '%s'", path );

    info->script_offset = 0;
    info->script_len = info->arguments_len + script_len;
    info->ipsets_offset = ipsets_offset + info->arguments_len;
    info->ipsets_len = ipsets_len;
    info->scriptbuff_len = used_buff;
}

/* Function which parses command options; returns true if it
   ate an option */

static int parse(int c, char **argv, int invert, unsigned int *flags,
      const struct ipt_entry *entry,
      unsigned int *nfcache,
      struct ipt_entry_match **match)
{
    struct ipt_rope_info *ropeinfo = (struct ipt_rope_info *)(*match)->data;
    int n, len, i;
    struct hostent *he;
    char push_buff[ROPE_MAX_COMPILED_SIZE];
    int push_len = 0;

    switch (c)
    {
        case '1':   // --rope-script
            ropeinfo->invert = invert;
            if (*flags & IPT_ROPE_SCRIPT)
                exit_error( PARAMETER_PROBLEM, "--"OPT_SCRIPT": cant specify more than one script");
            read_scriptfile( ropeinfo, optarg );
            *flags |= IPT_ROPE_SCRIPT;
            break;

        case '2':   // --rope-push-int
            if (invert)
                exit_error( PARAMETER_PROBLEM, "--"OPT_PUSH_INT": cant specify '!'");
            n = atoi(optarg);
            if (n >= 0 && n <= 127) {
                push_buff[push_len++] = ROPE_ELEMENT_TYPE_INTEGER8;
                push_buff[push_len++] = n;
            } else if (n >= 0 && n <= 32767) {
                push_buff[push_len++] = ROPE_ELEMENT_TYPE_INTEGER16;
                push_buff[push_len++] = ((unsigned int)n & 0xff00) >> 8;
                push_buff[push_len++] = ((unsigned int)n & 0x00ff);
            } else {
                push_buff[push_len++] = ROPE_ELEMENT_TYPE_INTEGER;
                push_buff[push_len++] = ((unsigned int)n & 0xff000000) >> 24;
                push_buff[push_len++] = ((unsigned int)n & 0x00ff0000) >> 16;
                push_buff[push_len++] = ((unsigned int)n & 0x0000ff00) >> 8;
                push_buff[push_len++] = ((unsigned int)n & 0x000000ff);
            }
            *flags |= IPT_ROPE_PUSH_INT;
            break;

        case '3':   // --rope-push-str
            if (invert)
                exit_error( PARAMETER_PROBLEM, "--"OPT_PUSH_STR": cant specify '!'");
            len = strlen(optarg);
            if ((len + 3) > sizeof(push_buff))
                exit_error( PARAMETER_PROBLEM, "--"OPT_PUSH_STR": string too long" );
            if (len < 128) {
                push_buff[push_len++] = ROPE_ELEMENT_TYPE_STRING8;
                push_buff[push_len++] = len;
            } else {
                push_buff[push_len++] = ROPE_ELEMENT_TYPE_STRING;
                push_buff[push_len++] = (len & 0xff00) >> 8;
                push_buff[push_len++] = (len & 0x00ff);
            }

            /*
             * We have to check that the string we provide will work with iptables-save and
             * iptables-restore - which are rather crude in their parsing of the config
             * file they use. Non printable characters, control characters and quotes will
             * all cause us problems.
             */

            for (i=0; i<len; i++) {
                if (iscntrl(optarg[i]) || !isprint(optarg[i]))
                    exit_error( PARAMETER_PROBLEM, "--"OPT_PUSH_STR": string includes non-printable character(s)");
                if (optarg[i] == '"')
                    exit_error( PARAMETER_PROBLEM, "--"OPT_PUSH_STR": string includes double-quote character(s)");
            }

            memcpy(push_buff+push_len, optarg, len);
            push_len += len;
            *flags |= IPT_ROPE_PUSH_STR;
            break;

        case '4':   // --rope-push-ip
            if (invert)
                exit_error( PARAMETER_PROBLEM, "--"OPT_PUSH_IP": cant specify '!'");
            he = gethostbyname( optarg );
            if (he == NULL)
                exit_error( PARAMETER_PROBLEM, "--"OPT_PUSH_IP": cant resolve host name");
            if (he->h_length != 4)
                exit_error( PARAMETER_PROBLEM, "--"OPT_PUSH_IP": IPv4 address expected");
            if ( he->h_addr_list == NULL || he->h_addr_list[0] == NULL || he->h_addr_list[1] != NULL)
                exit_error( PARAMETER_PROBLEM, "--"OPT_PUSH_IP": name resolved to multiple IPv4 addresses");
            push_buff[push_len++] = ROPE_ELEMENT_TYPE_DOTTED_STRING8;
            push_buff[push_len++] = 4;
            memcpy(push_buff + push_len, he->h_addr_list[0], 4);
            push_len += 4;
            *flags |= IPT_ROPE_PUSH_IP;
            break;

        default:
            return 0;
    }

    memmove(
        ropeinfo->scriptbuff + ropeinfo->arguments_len + push_len,
        ropeinfo->scriptbuff + ropeinfo->arguments_len,
        ropeinfo->scriptbuff_len - ropeinfo->arguments_len
    );
    memcpy(ropeinfo->scriptbuff + ropeinfo->arguments_len, push_buff, push_len);
    ropeinfo->script_len += push_len;
    ropeinfo->ipsets_offset += push_len;
    ropeinfo->arguments_len += push_len;
    ropeinfo->scriptbuff_len += push_len;
    return 1;
}

/* Final check; must have specified --string. */
static void final_check(unsigned int flags)
{
    if (! (flags & IPT_ROPE_SCRIPT) )
        exit_error(
            PARAMETER_PROBLEM,
            "ROPE match: You must specify `--" OPT_SCRIPT "'"
        );
}

static void print_string(int len, unsigned char *str)
{
    putchar( '\"' );
    while (len) {
        putchar(*str);
        /*if (ch == '\n') printf( "\\n" );
        else if (ch == '\r') printf( "\\r" );
        else if (ch == '\t') printf( "\\t" );
        else if (ch == '"') printf( "\\\"" );
        else if (ch == '\\') printf( "\\\\" );
        else if (isprint( ch )) printf( "%c", ch );
        else printf( "\\%03o", ch );*/
        str ++;
        len --;
    }
    putchar( '\"' );
}

static void print_pushes(struct ipt_rope_info *info, char *prefix, char *delim)
{
    int opcode, len;
    unsigned char *buff = info->scriptbuff;
    unsigned char *end = info->scriptbuff + info->arguments_len;

    while (buff < end) {
        opcode = (*buff++);
        if (opcode == ROPE_ELEMENT_TYPE_INTEGER8) {
            printf( "%spush-int%s%d", prefix, delim, (*buff++) );
        } else if (opcode == ROPE_ELEMENT_TYPE_INTEGER16) {
            printf( "%spush-int%s%d", prefix, delim, buff[0] << 8 | buff[1]);
            buff += 2;
        } else if (opcode == ROPE_ELEMENT_TYPE_INTEGER) {
            printf( "%spush-int%s%d", prefix, delim, buff[0] << 24 | buff[1] << 16 | buff[2] << 8 | buff[3]);
            buff += 4;
        } else if (opcode == ROPE_ELEMENT_TYPE_DOTTED_STRING8 && *buff == 4) {
            printf( "%spush-ip%s%d.%d.%d.%d", prefix, delim, buff[1], buff[2], buff[3], buff[4] );
            buff += 5;
        } else if (opcode == ROPE_ELEMENT_TYPE_STRING8) {
            len = buff[0];
            printf( "%spush-str%s", prefix, delim );
            print_string(len, buff+1);
            buff += len + 1;
        } else if (opcode == ROPE_ELEMENT_TYPE_STRING) {
            len = buff[0] << 8 | buff[1];
            printf( "%spush-str%s", prefix, delim );
            print_string(len, buff+2);
            buff += len + 2;
        } else {
            return;
        }
        printf( " " );
    }
}

/* Prints out the matchinfo. */
static void print(const struct ipt_ip *ip, const struct ipt_entry_match *match, int numeric)
{
    printf( "ROPE script: %s%s ",
        ((struct ipt_rope_info *)match->data)->invert ? "!" : "",
        ((struct ipt_rope_info *)match->data)->scriptfile
    );
    print_pushes((struct ipt_rope_info *)match->data, "", ":");
}

/* Saves the union ipt_matchinfo in parsable form to stdout. */
static void save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
{
    printf( "%s--" OPT_SCRIPT " %s ",
        ((struct ipt_rope_info *)match->data)->invert ? "! " : "",
        ((struct ipt_rope_info *)match->data)->scriptfile
    );
    print_pushes((struct ipt_rope_info *)match->data, "--rope-", " ");
}

static struct iptables_match rope = {
        .next           = NULL,
        .name           = "rope",
        .version        = IPTABLES_VERSION,
        .size           = IPT_ALIGN(sizeof(struct ipt_rope_info)),
        .userspacesize  = IPT_ALIGN(sizeof(struct ipt_rope_info)),
        .help           = &help,
        .init           = &init,
        .parse          = &parse,
        .final_check    = &final_check,
        .print          = &print,
        .save           = &save,
        .extra_opts     = opts
};

void _init(void)
{
    register_match(&rope);
}

Thanks for reading :)

score 2 · Answer 1 · answered Mar 14 '11 at 13:40

2

that sounds like your iptables_match structure doesn't have the expected help, print, save ... fields to me. Since it's an old program (we don't use 'script' for C) that relies on a kernel header (iptables) that is likely to have evolved, have you checked the new structure of iptables_match ?

answered Mar 14 '11 at 13:40

PypeBros

2,607
24
37

The program includes a patch for iptables so I thought that it would support those fields. – Sakis Tourloumpoukis Mar 14 '11 at 14:03

score 1 · Accepted Answer · edited May 23 '17 at 11:44

1

I'm not familiar with ROPE, but from the docs it looks like it is meant to be build as a kernel module so there may be more to building it than a straighforward gcc call.

To install it for use in userland (not part of kernel), look at this section in the docs: http://www.lowth.com/rope/UserLand

Also, it looks like the last available version of ROPE was developed against the 2.4 kernel so as the @sylvainulg mentioned there might be some incompatibility issues with current kernels headers.

updates

Looks like ROPE works fine on kernel 2.6 but not with the latest iptables. Website states:

So far, ROPE has been developed and tested against the 2.4.x and 2.6.x linux kernels (for single Intel CPU platforms) and IpTables from 1.2.x to 1.3.x.

Compiling it against several version of iptables shows that the error is reproducable when compiled agains the lates (1.4.10) but does not occur for 1.3.0.

update2

Here's a last ditch attempt at trying to make it work. Try adding the following to the top of your source:

#ifdef _XTABLES_H
    #define iptables_rule_match        xtables_rule_match
    #define iptables_match             xtables_match
    #define iptables_target            xtables_target
    #define ipt_tryload                xt_tryload

    #if (!defined(IPTABLES_VERSION) && defined(XTABLES_VERSION))
        #define IPTABLES_VERSION   XTABLES_VERSION
    #endif

#endif

As of iptables 1.4.0, iptables_match seems to be defined as xtables_match (see includes/xtables.h). Assuming none of the other changes updates break ROPE, that should compile (no guarantees that it will work as stated thought. Do test it out thoroughly).

edited May 23 '17 at 11:44

Community

1
1

answered Mar 14 '11 at 13:52

Shawn Chin

84,080
19
162
191

Yes, I have all the needed headers in the same directory. It's indeed part of a kernel module but I need to compile it first, and that's where I have the problem. :) – Sakis Tourloumpoukis Mar 14 '11 at 14:01
Just checking. No condescension meant, honest. :) – Shawn Chin Mar 14 '11 at 14:04
It was developed both for 2.4 and 2.6 kernel ( at least that's what the site says :) ). So, no other way than using the old headers ? :) – Sakis Tourloumpoukis Mar 14 '11 at 14:09
I looks like ROPE requires you to patch the iptables headers. See step 5 here: http://www.lowth.com/rope/Building#2. Out of curiosity, I tried the patch command on a fresh iptables source, and it works for iptables 1.3.0 but fails for the latest (1.4.10). – Shawn Chin Mar 14 '11 at 14:43
also, `register_match()` used at the end of the file is defined in `ipt_rope.c` so at the very least, you'll need to get that compile first. – Shawn Chin Mar 14 '11 at 14:44
What message did you get on 1.4.10 iptables patch? I got the patch working for the lastest iptables version. Weird :S – Sakis Tourloumpoukis Mar 14 '11 at 14:52
From the looks of it, compiling `ipt_rope.c` may require you to patch the kernel source, as described in step 3 of the previously mentioned doc section. Ouch. – Shawn Chin Mar 14 '11 at 14:52
re: 1.4.10 patch error -- it couldn't find `extensions/.rope-test`. Works if I touch the file ;) – Shawn Chin Mar 14 '11 at 14:54
`ipt_rope.c` compiles fine. The only file that doesn't is this and when I install rope and try to use it I get something like this : `# iptables -m rope /usr/local/libexec/xtables/libipt_rope.so: /usr/local/libexec/xtables/libipt_rope.so: undefined symbol: __guard iptables v1.4.10: Couldn't load match `rope':(null) ` – Sakis Tourloumpoukis Mar 14 '11 at 14:54
And when I mean install, I took the `libiptc_rope.so` from the compiled binaries of the program and placed it in the folder. That's why I believe that if I compile it correctly, it will work. – Sakis Tourloumpoukis Mar 14 '11 at 14:55
I get the same error (as shown in Q) when compiled against iptables 1.4.10. Almost successful when compiled against 1.3.0 (failed when it couldn't find `register_match()`), but I had to manually define `IPTABLES_VERSIONS`. i.e. `gcc -I../iptables-1.3.0/include/ -DIPTABLES_VERSION='"1.3.0"' libipt_rope.c` – Shawn Chin Mar 14 '11 at 14:58
Website states that _"ROPE has been developed and tested ... ipTables from **1.2.x to 1.3.x**"_ – Shawn Chin Mar 14 '11 at 15:01
the `.rope-test` file isn't supposed to be in the iptables dir so if it IS found, that means it's already patched and then stops :) – Sakis Tourloumpoukis Mar 14 '11 at 15:01
Of course... I must have tried it once too many. Silly me. Anyway, I've updated my answer with conclusion that ROPE isn't compatible with latest iptables source. Hopefully someone can help with patching ROPE? downgrading iptables for the sake of using ROPE is certainly not a good idea. – Shawn Chin Mar 14 '11 at 15:14
I hope so but I don't think so. ROPE has stopped development some time now. I just want to use it because it can help me drop packets depending on their payload. – Sakis Tourloumpoukis Mar 14 '11 at 15:20
I tried installing with 1.3.0 iptables version, but again I get an error :( Anyways, thanks a lot @Shawn-Chin for your help :) – Sakis Tourloumpoukis Mar 14 '11 at 15:21
1

Does it help if you add `#define iptables_match xtables_match` to the top of the file? (compiled against 1.4.10). – Shawn Chin Mar 14 '11 at 15:33
With your help and your code it managed to compile. I was wrong, however. ROPE still doesn't work. When I try `iptables -m rope` it returns with `# iptables -m rope /usr/local/libexec/xtables/libipt_rope.so: /usr/local/libexec/xtables/libipt_rope.so: undefined symbol: register_match iptables v1.4.10: Couldn't load match `rope':(null) Try `iptables -h' or 'iptables --help' for more information. ` again :( – Sakis Tourloumpoukis Mar 14 '11 at 15:49
At least it compiles now! that's a step forward. `register_match` is defined in `ipt_match.c` so it looks like the compiled binary (ipt_match.o) isn't linked in. – Shawn Chin Mar 14 '11 at 15:59
Well, it DID compile, so I can mark this as my answer - Thanks a lot Shawn :) – Sakis Tourloumpoukis Mar 14 '11 at 16:00
One thing you might want to consider is to find out other ways to achieve your goals. Can it be done using just one of the official iptables modules or with combination of other commands (iproute2). I personally would feel uncomfortable relying on a tool that is no longer maintained. The good folks at serverfault.com can help with related queries. – Shawn Chin Mar 14 '11 at 16:07
Back to your original problem, are you still compiling `libipt_rope.so` manually? You mentioned `ipt_rope.c` compiled successfully, so i'm assuming you have `ipt_rope.o` lying around? Try linking it with your compile: `gcc libipt_rope.c ipt_rope.o -o libipt_rope.so`. – Shawn Chin Mar 14 '11 at 16:11
Well, the `string` mod might be helpful, but it would drop other packets too and I can't allow that – Sakis Tourloumpoukis Mar 14 '11 at 16:30
No, `libipt_rope.so` in now compiled by the make file, so it's fine. I'm sorry but I don't get it - why do I have to link those files? :) – Sakis Tourloumpoukis Mar 14 '11 at 16:48
That was in response to the error you posted stating `undefined symbol: register_match`. That routine is defined in `ipt_rope.c` hence my suspicion that its binary is not linked in. Apologies for adding more confusion. It's rather difficult debugging via exchange of comments :D – Shawn Chin Mar 14 '11 at 16:52
No apologies needed. I can't thank you enough for helping me out with this one. Seems I made a mistake. I do not have a compiled version of `ipt_rope.c` and when I try compiling it I get a library missing. Maybe this is causing all of my problems :) – Sakis Tourloumpoukis Mar 14 '11 at 17:06
`linux/config.h` to be precise – Sakis Tourloumpoukis Mar 14 '11 at 17:09
Pleasure was mine. I learnt something too. Anyway, good luck with it. (would love to dig further, but I'm going offline soon) – Shawn Chin Mar 14 '11 at 17:22
AFAIK, `linux/config.h` has been deprecated in newer kernels. Try replacing it with `linux/autoconf.h`. If that doesn't help, post the issue and someone might be able to help you. – Shawn Chin Mar 14 '11 at 17:23

score 0 · Answer 3 · answered Jun 09 '20 at 15:07

Which compiler options do you use to compile that code?

It seems that you're trying to compile with std=c99 and your source code uses some anonymous structs, which are first introduced in c11. So probably you should compile with that option.

If that's the case, you can read more about this topic here: Anonymous union within struct not in c99?

Error when compiling - unknown field specified in initializer

3 Answers3

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