Re: Problem with FD_SET on mips

[Till Elsner <till dot elsner at uni-duesseldorf dot de>]

Hi Andrew,

thanks for your reply. Since I think the whole file is quite too long  
to post it here, I've cutted out the relevant pieces (or at least I  
hope I did). If you need more code please tell me.

--- BEGIN CODE ---

# 1 "/usr/include/bits/select.h" 1
# 26 "/usr/include/bits/select.h"
#define __FD_ZERO(fdsp) do { int __d0, __d1; __asm__ __volatile__  
("cld; rep; stosl" : "=c" (__d0), "=D" (__d1) : "a" (0), "0" (sizeof  
(fd_set) / sizeof (__fd_mask)), "1" (&__FDS_BITS (fdsp)[0]) :  
"memory"); } while (0)
# 37 "/usr/include/bits/select.h"
#define __FD_SET(fd,fdsp) __asm__ __volatile__ ("btsl %1,%0" :  
"=m" (__FDS_BITS (fdsp)[__FDELT (fd)]) : "r" (((int) (fd)) %  
__NFDBITS) : "cc","memory")

...

#define FD_SET(fd,fdsetp) __FD_SET (fd, fdsetp)
#define FD_CLR(fd,fdsetp) __FD_CLR (fd, fdsetp)
#define FD_ISSET(fd,fdsetp) __FD_ISSET (fd, fdsetp)
#define FD_ZERO(fdsetp) __FD_ZERO (fdsetp)

...

int client_challenge(int sock, char * cert_file) {






 X509 *x509 = X509_new();
 RSA *rsa_pk = RSA_new();
 EVP_PKEY *evp_public;
 int bytes, encsize, s_res, validate;
 unsigned char *rnd, *challenge, *response, a_response[1];
 fd_set sockset;
 struct timeval timeout;
 FILE *fp;

 rnd = malloc(512);
 challenge = malloc(1024);
 response = malloc(1024);


 fp = fopen(cert_file, "r");
 if (fp == ((void *)0)) {
  fprintf(LOG, "%i: ERR: Error opening cerificate file: %s. Exiting. 
\n", getpid(), strerror((*__errno_location ())));
  exit(20);
 }

 if (rsa_pk == ((void *)0)) {
  fprintf(LOG, "%i: ERR: Error creating RSA object: %s. Exiting.\n",  
getpid(), ERR_error_string(ERR_get_error(), ((void *)0)));
  exit(200);
 }
 x509 = PEM_read_X509(fp, ((void *)0), ((void *)0), ((void *)0));
 if (x509 == ((void *)0)) {
  fprintf(LOG, "%i: ERR: Error loading certificate from PEM encoded  
file: %s. Exiting.\n", getpid(), ERR_error_string(ERR_get_error(),  
((void *)0)));
  exit(100);
 }
 fclose(fp);

 evp_public = X509_get_pubkey(x509);
 if (evp_public == ((void *)0)) {
  fprintf(LOG, "%i: ERR: Error loading public key from certificate:  
%s. Exiting.\n", getpid(), ERR_error_string(ERR_get_error(), ((void  
*)0)));
  exit(105);
 }

 rsa_pk = EVP_PKEY_get1_RSA(evp_public);
 if (rsa_pk == ((void *)0)) {
  fprintf(LOG, "%i: ERR: Error extracting public key from EVP object:  
%s. Exiting.\n", getpid(), ERR_error_string(ERR_get_error(), ((void  
*)0)));
  exit(105);
 }

 if (RAND_bytes(rnd, 512) < 1) {
  fprintf(LOG, "%i: ERR: Error generating random number as challenge:  
%s. Exiting.\n", getpid(), ERR_error_string(ERR_get_error(), ((void  
*)0)));
  exit(210);
 }

 encsize = RSA_public_encrypt(sizeof(int), rnd, challenge, rsa_pk, 4);
 if (encsize < 0) {
  fprintf(LOG, "%i: ERR: Error encrypting challenge: %s. Exiting.\n",  
getpid(), ERR_error_string(ERR_get_error(), ((void *)0)));
  exit(201);
 }

 RSA_free(rsa_pk);
 X509_free(x509);

 bytes = write(sock, challenge, 1024);
 if (bytes <= 0) {
  fprintf(LOG, "%i: ERR: Error sending challenge: %s. Exiting.\n",  
getpid(), strerror((*__errno_location ())));
  exit(6);
 }

 fprintf(LOG, "%i: INFO: Wait for client response...", getpid());

 do { int __d0, __d1; __asm__ __volatile__ ("cld; rep; stosl" :  
"=c" (__d0), "=D" (__d1) : "a" (0), "0" (sizeof (fd_set) / sizeof  
(__fd_mask)), "1" (&((&sockset)->__fds_bits)[0]) : "memory"); } while  
(0);
 __asm__ __volatile__ ("btsl %1,%0" : "=m" (((&sockset)->__fds_bits) 
[((sock) / (8 * sizeof (__fd_mask)))]) : "r" (((int) (sock)) % (8 *  
sizeof (__fd_mask))) : "cc","memory");
 timeout.tv_sec = 10;
 timeout.tv_usec = 0;
 s_res = select(sock + 1, &sockset, ((void *)0), ((void *)0),  
&timeout);
 if (s_res < 0) {
  fprintf(LOG, "\n%i: ERR: Error setting timeout for socket: %s.  
Exiting.\n", getpid(), strerror((*__errno_location ())));
  exit(5);
 } else if (!(__extension__ ({register char __result; __asm__  
__volatile__ ("btl %1,%2 ; setcb %b0" : "=q" (__result) : "r" (((int)  
(sock)) % (8 * sizeof (__fd_mask))), "m" (((&sockset)->__fds_bits) 
[((sock) / (8 * sizeof (__fd_mask)))]) : "cc"); __result; }))) {
  fprintf(LOG, " [FAILED]\n");
  fprintf(LOG, "%i: ERR: Waiting for client response timed out!\n",  
getpid());
  return 0;
 }
 bytes = read(sock, response, 1024);
 if (bytes < 0) {
  fprintf(LOG, "%i: ERR: Error reading challenge response from  
client: %s. Exiting.\n", getpid(), strerror((*__errno_location ())));
  return 0;
 } else if (bytes == 0) {
  fprintf(LOG, " [FAILED]\n");
  fprintf(LOG, "%i: ERR: Connection closed by client\n", getpid());
  validate = 0;
 } else {
  fprintf(LOG, " [OK]\n");

  if (*rnd == *response) {
   validate = 1;
  } else {
   validate = 0;
  }
  bytes = write(sock, (unsigned char *) &validate, sizeof(int));
  if (bytes <= 0) {
   fprintf(LOG, "%i: ERR: Error contacting client: %s. Exiting.\n",  
getpid(), strerror((*__errno_location ())));
   exit(6);
  }
 }


 free(rnd);
 free(challenge);
 free(response);

 return validate;
}

--- END CODE ---

Am 12.05.2008 um 15:06 schrieb Andrew Haley:

> Andrew Haley wrote:
> > Till Elsner wrote:
> > > Hi,
> > >
> > > while compiling for mips platforms i'm getting the following error:
> > >
> > > main.c: 222: error: impossible constraint in `asm`
> > > main.c: 214: error: can't find a register in class `COP3_REGS` while
> > > loading `asm`
> > > main.c: 214: error: `asm` operand has impossible contraints
> > >
> > > error in line 222 is thrown by FD_ISSET, error in line 214 come from
> > > FD_ZERO
> > >
> > > Compiling and running on i368 platforms works without problems.  
> > > Whats
> > > the problem here with mips platforms?
> >
> > Show us the code.  It's at main.c around line 214.
>
> I should have said: it's the expanded source we need, generated by
> gcc -Wp,-dD -save-temps.  The .i file contains the info.
>
> Andrew.