Commit 9d066935 authored by Daniel Stenberg's avatar Daniel Stenberg
Browse files

Keith McGuigan's excellent fix that makes a cloned copy of the hostent struct 

for when gethostbyname() is used so that we have the memory of the struct
allocated. This turns out to be needed if the curl handled is passed between
threads on Windows and possibly other operating systems where we use that
function.
parent bc40063e

lib/hostip.c

+74 −0
Original line number Diff line number Diff line
@@ -94,6 +94,75 @@ Curl_addrinfo *Curl_getaddrinfo(struct SessionHandle *data, 
}

#else /* following code is IPv4-only */



/**

 * Performs a "deep" copy of a hostent into a buffer 

 * (returns a pointer to the copy).

 *

 * Keith McGuigan 

 * 10/3/2001

 */

static struct hostent* pack_hostent(char* buf, struct hostent* orig)

{

  char* bufptr;

  struct hostent* copy;



  int i;

  char* str;

  int len;



  bufptr = buf;

  copy = (struct hostent*)bufptr;



  bufptr += sizeof(struct hostent);

  copy->h_name = bufptr;

  len = strlen(orig->h_name) + 1;

  strncpy(bufptr, orig->h_name, len);

  bufptr += len;



  copy->h_aliases = (char**)bufptr;



  /* Figure out how many aliases there are */

  for (i = 0; orig->h_aliases[i] != NULL; ++i);



  /* Reserve room for the array */

  bufptr += (i + 1) * sizeof(char*);



  i = 0;

  str = orig->h_aliases[i];

  while (str != NULL) {

    len = strlen(str) + 1;

    strncpy(bufptr, str, len);

    copy->h_aliases[i] = bufptr;

    bufptr += len;

    str = orig->h_aliases[++i];

  }

  copy->h_aliases[i] = NULL;



  copy->h_addrtype = orig->h_addrtype;

  copy->h_length = orig->h_length;

    

  copy->h_addr_list = (char**)bufptr;



  /* Figure out how many addresses there are */

  for (i = 0; orig->h_addr_list[i] != NULL; ++i);



  /* Reserve room for the array */

  bufptr += (i + 1) * sizeof(char*);



  i = 0;

  len = orig->h_length;

  str = orig->h_addr_list[i];

  while (str != NULL) {

    memcpy(bufptr, str, len);

    copy->h_addr_list[i] = bufptr;

    bufptr += len;

    str = orig->h_addr_list[++i];

  }

  copy->h_addr_list[i] = NULL;



  return copy;

}



static char *MakeIP(unsigned long num,char *addr, int addr_len)

{

#if defined(HAVE_INET_NTOA) || defined(HAVE_INET_NTOA_R)
@@ -217,6 +286,11 @@ Curl_addrinfo *Curl_getaddrinfo(struct SessionHandle *data, 
      free(buf);

      *bufp=NULL;

    }

    else 

      /* we make a copy of the hostent right now, right here, as the

         static one we got a pointer to might get removed when we don't

         want/expect that */

      h = pack_hostent(buf, h);

#endif

  }

  return (h);