dereferencing pointer to incomplete type2

[shridharpandey]

Hello all of u .. well i was trying to compile the iscsi module over ma system whn i was faced with this error .. the code segment is as under

int
cnv_inet_to_string(struct sockaddr *ip_address, char *ip_string,
           char *port_string)
{
    __u8 *ptr;
    __u32 k;
    int i, c;
 
    if (ip_address == NULL) {
        i = -EINVAL;
    } else if (ip_address->sa_family == AF_INET) 
    {
        ptr = (__u8 *)&((struct sockaddr_in *)ip_address)->sin_addr.s_addr;  //Dereferencing Pointer to incompete type
        for (i = 0; i < 3; i++) {
            ip_string += sprintf(ip_string, "%u.", *ptr++);
        }
        sprintf(ip_string, "%u", *ptr);
        sprintf(port_string, "%u",
            ntohs(((struct sockaddr_in *)ip_address)->sin_port));
        i = AF_INET;
    } else if (ip_address->sa_family == AF_INET6) {
        ptr = (__u8 *)((struct sockaddr_in6 *)ip_address)
            ->sin6_addr.s6_addr;
        c = '[';
        for (i = 0; i < 8; i++ ) {
            k = *ptr++ << 8;
            k += *ptr++;
            ip_string += sprintf(ip_string, "%c%x", c, k);
            c = ':';
        }
        sprintf(ip_string, "]");
        sprintf(port_string, "%u",
            ntohs(((struct sockaddr_in6 *)ip_address)->sin6_port));
        i = AF_INET6;
    } else {
        strcpy(ip_string, "Unknown protocol family");
        i = -EPFNOSUPPORT;
    }
    return i;
}
 

So some1 plzz suggest me wat shd i do to get rid of this **** ....

[shridharpandey]

_u8 *ptr;
ptr = (__u8 *)&((struct sockaddr_in *)ip_address)->sin_addr.s_addr;

Why is this showing dereferencing pointer to incomplete type????

[JosAH]

@shridharpandey: I split your posts from the old thread you posted your questions
in; don't hijack other threads for your question, no matter how old they are and
no matter how similar your question is to another question. Also add code tags
around your code for readability reasons. And please use proper spelling if you
want to be taken seriously.

kind regards,

Jos

ps. I added those code tags for you this time.

[Banfa]

Also note that we don't allow swearing on this site, please read our posting guidelines.


Dereference to an incomplete type usually means that the compiler is aware that a structure of a given name exists but has no visibility of that structure of that structure. This most often happens when a structure name is forward declared and then the header the structure is defined in is accidentally not included.

For example suppose the file Example.h contains the following

#ifndef EXAMPLE_H_INCLUDED
#define EXAMPLE_H_INCLUDED
 
struct Example {
    int someData;
};
 
#endif
 

Then suppose a file main.c contained the following

struct Example; // Forward declaration of struct Example
 
extern Example *GetExample();
extern void ReleaseExample(Example *ex);
 
int main(int argc, char *argp[])
{
    Example *ex = GetExample();
 
    ex->someData = 6;
 
    ReleaseExample(ex);
 
    return 0;
}
 

Supposing that GetExample and ReleaseExample are defined in another file somewhere you would get a 'dereferencing pointer to incomplete' type error on line 10. This would be solved by including the file with the declaration of struct Example rather than forward declaring it.