Ok. Here's what I tried, but libnet_build_ip() is still crapping. I understand what you said about making all the functions accept the same type at the end of your Re4. Some where accepting the buf itself and others a pointer to it even when my calls were using passing simply $buf each time. This is how I changed the XS file to fix this (I think) for the two functions in question:
int
libnet_init_packet(p_size, buf)
size_t p_size
u_char & buf
CODE:
u_char * buf_temp;
buf_temp = &buf;
RETVAL = libnet_init_packet(p_size, &buf_temp);
OUTPUT:
RETVAL
buf
int
libnet_destroy_packet(buf)
u_char & buf
CODE:
u_char * buf_temp;
buf_temp = &buf;
RETVAL = libnet_destroy_packet(&buf_temp);
OUTPUT:
RETVAL
buf sv_setsv(ST(0),&PL_sv_undef);
The resultant C code appears to hold the proper type for the passed in $buf now...
XS(XS_Net__LibnetRaw_libnet_init_packet)
{
dXSARGS;
if (items != 2)
Perl_croak(aTHX_ "Usage: Net::LibnetRaw::libnet_init_packet(p_
+size, buf)");
{
size_t p_size = (size_t)SvIV(ST(0));
u_char buf = (u_char)SvUV(ST(1));
int RETVAL;
dXSTARG;
#line 39 "LibnetRaw.xs"
u_char * buf_temp;
buf_temp = &buf;
RETVAL = libnet_init_packet(p_size, &buf_temp);
#line 106 "LibnetRaw.c"
sv_setuv(ST(1), (UV)buf);
SvSETMAGIC(ST(1));
XSprePUSH; PUSHi((IV)RETVAL);
}
XSRETURN(1);
}
XS(XS_Net__LibnetRaw_libnet_destroy_packet)
{
dXSARGS;
if (items != 1)
Perl_croak(aTHX_ "Usage: Net::LibnetRaw::libnet_destroy_packet
+(buf)");
{
u_char buf = (u_char)SvUV(ST(0));
int RETVAL;
dXSTARG;
#line 50 "LibnetRaw.xs"
u_char * buf_temp;
buf_temp = &buf;
RETVAL = libnet_destroy_packet(&buf_temp);
#line 127 "LibnetRaw.c"
sv_setsv(ST(0),&PL_sv_undef);
SvSETMAGIC(ST(0));
XSprePUSH; PUSHi((IV)RETVAL);
}
XSRETURN(1);
}
So now, the type for buf passed in is u_char just like the other calls. I just noticed some other value vs. pointer to value mistakes I've made (It seems * and & are not quite as similar as I thought). That aside, I still think the error I am getting does not make sense. | [reply]
[d/l]
[select] |
No, you've made things worse. buf needs to always be u_char * or u_char * &. u_char & is completely different.
Try again and/or reread what I wrote. You want $buf to hold an opaque UV that gets converted to/from a u_char *. Some of your calls should pass a reference to this u_char * rather than passing the u_char * directly (that is what the "&" is for). Those routines are the ones that might change the pointer (by allocating or reallocating the memory) and are also the ones that need buf mentioned in the OUTPUT: section.
-
tye
(but my friends call me "Tye")
| [reply]
[d/l]
[select] |
Ok, I think you are bit confused about the calls. A couple of posts ago, you wrote:
Now for the source of your problem (I think):
XS(XS_Net__LibnetRaw_libnet_init_packet)
[...]
u_char * buf = (u_char *)SvPV(ST(1),PL_
+na);
[...]
RETVAL = libnet_init_packet(p_size, &buf);
sv_setpv((SV*)ST(1), buf);
This function seems to have used a different typemap for buf which is trying to extract the '\0'-terminated string that it is supposed to point to. I
think all you need to do is fix this typemap to be like the other functions.
I'm going to check some other things I noticed and I'll reply separately if I detect any problems.
It seems that you are under the impression that libnet_init_packet() and functions like libnet_do_checksum() have the same prototype for buf. They don't. As per my original post, the prototype for libnet_init_packet() is<
int libnet_init_packet(size_t p_size, u_char **buf);
This function asks for a pointer to a pointer. So the pointed-to pointer (confusing, I know...) is being altered. This is how the function gets the pointer returns from malloc() back to the program. The other functions are prototyped like this:
int libnet_build_ip([...], u_char *buf);
The pointer itself is not being modified so the pointer to a pointer is unnecessasry. But the data being pointed to is. If I understand correctly, you thought that this was the way in wich libnet_init_packet() and libnet_destroy_packet() were also prototyped.
So my feeling is that, like a C program would using this library, the value stored in the top level of the program in $buf should be a pointer. In C, I usually do something like this:
u_char *buf;
libnet_init_packet(IP_H + TCP_H, &buf); /* This calls malloc() and set
+s buf as a pointer to that new memory */
[...]
libnet_build_ip([...], buf); /* The pointer value is the same, but dat
+a pointed to is altered */
So essentially I am attempt to make the perl calls the same. I did try it some others ways, based on your suggestions and my own tinkering. In the past couple of days, I have tried a few things. Not being experience with XS, I am obviously confused on some issues. The unary & was one example.
For now, though, I don't have a lot of time to devote to contemplating this problem. I still have some ideas that I might attempt to bounce off this thread in the future. | [reply]
[d/l]
[select] |