300 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			300 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /***************************************************************************
 | |
|  *                                  _   _ ____  _
 | |
|  *  Project                     ___| | | |  _ \| |
 | |
|  *                             / __| | | | |_) | |
 | |
|  *                            | (__| |_| |  _ <| |___
 | |
|  *                             \___|\___/|_| \_\_____|
 | |
|  *
 | |
|  * Copyright (C) 1998 - 2008, Daniel Stenberg, <daniel@haxx.se>, et al.
 | |
|  *
 | |
|  * This software is licensed as described in the file COPYING, which
 | |
|  * you should have received as part of this distribution. The terms
 | |
|  * are also available at http://curl.haxx.se/docs/copyright.html.
 | |
|  *
 | |
|  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 | |
|  * copies of the Software, and permit persons to whom the Software is
 | |
|  * furnished to do so, under the terms of the COPYING file.
 | |
|  *
 | |
|  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 | |
|  * KIND, either express or implied.
 | |
|  *
 | |
|  * $Id: hostip4.c,v 1.47 2008-11-06 17:19:57 yangtse Exp $
 | |
|  ***************************************************************************/
 | |
| 
 | |
| #include "setup.h"
 | |
| 
 | |
| #include <string.h>
 | |
| #include <errno.h>
 | |
| 
 | |
| #ifdef NEED_MALLOC_H
 | |
| #include <malloc.h>
 | |
| #endif
 | |
| #ifdef HAVE_SYS_SOCKET_H
 | |
| #include <sys/socket.h>
 | |
| #endif
 | |
| #ifdef HAVE_NETINET_IN_H
 | |
| #include <netinet/in.h>
 | |
| #endif
 | |
| #ifdef HAVE_NETDB_H
 | |
| #include <netdb.h>
 | |
| #endif
 | |
| #ifdef HAVE_ARPA_INET_H
 | |
| #include <arpa/inet.h>
 | |
| #endif
 | |
| #ifdef HAVE_STDLIB_H
 | |
| #include <stdlib.h>     /* required for free() prototypes */
 | |
| #endif
 | |
| #ifdef HAVE_UNISTD_H
 | |
| #include <unistd.h>     /* for the close() proto */
 | |
| #endif
 | |
| #ifdef  VMS
 | |
| #include <in.h>
 | |
| #include <inet.h>
 | |
| #include <stdlib.h>
 | |
| #endif
 | |
| 
 | |
| #ifdef HAVE_PROCESS_H
 | |
| #include <process.h>
 | |
| #endif
 | |
| 
 | |
| #include "urldata.h"
 | |
| #include "sendf.h"
 | |
| #include "hostip.h"
 | |
| #include "hash.h"
 | |
| #include "share.h"
 | |
| #include "strerror.h"
 | |
| #include "url.h"
 | |
| #include "inet_pton.h"
 | |
| 
 | |
| #define _MPRINTF_REPLACE /* use our functions only */
 | |
| #include <curl/mprintf.h>
 | |
| 
 | |
| #include "memory.h"
 | |
| /* The last #include file should be: */
 | |
| #include "memdebug.h"
 | |
| 
 | |
| /***********************************************************************
 | |
|  * Only for plain-ipv4 builds
 | |
|  **********************************************************************/
 | |
| #ifdef CURLRES_IPV4 /* plain ipv4 code coming up */
 | |
| /*
 | |
|  * Curl_ipvalid() checks what CURL_IPRESOLVE_* requirements that might've
 | |
|  * been set and returns TRUE if they are OK.
 | |
|  */
 | |
| bool Curl_ipvalid(struct SessionHandle *data)
 | |
| {
 | |
|   if(data->set.ip_version == CURL_IPRESOLVE_V6)
 | |
|     /* an ipv6 address was requested and we can't get/use one */
 | |
|     return FALSE;
 | |
| 
 | |
|   return TRUE; /* OK, proceed */
 | |
| }
 | |
| 
 | |
| #ifdef CURLRES_SYNCH /* the functions below are for synchronous resolves */
 | |
| 
 | |
| /*
 | |
|  * Curl_getaddrinfo() - the ipv4 synchronous version.
 | |
|  *
 | |
|  * The original code to this function was from the Dancer source code, written
 | |
|  * by Bjorn Reese, it has since been patched and modified considerably.
 | |
|  *
 | |
|  * gethostbyname_r() is the thread-safe version of the gethostbyname()
 | |
|  * function. When we build for plain IPv4, we attempt to use this
 | |
|  * function. There are _three_ different gethostbyname_r() versions, and we
 | |
|  * detect which one this platform supports in the configure script and set up
 | |
|  * the HAVE_GETHOSTBYNAME_R_3, HAVE_GETHOSTBYNAME_R_5 or
 | |
|  * HAVE_GETHOSTBYNAME_R_6 defines accordingly. Note that HAVE_GETADDRBYNAME
 | |
|  * has the corresponding rules. This is primarily on *nix. Note that some unix
 | |
|  * flavours have thread-safe versions of the plain gethostbyname() etc.
 | |
|  *
 | |
|  */
 | |
| Curl_addrinfo *Curl_getaddrinfo(struct connectdata *conn,
 | |
|                                 const char *hostname,
 | |
|                                 int port,
 | |
|                                 int *waitp)
 | |
| {
 | |
| #if defined(HAVE_GETHOSTBYNAME_R_3)
 | |
|   int res;
 | |
| #endif
 | |
|   Curl_addrinfo *ai = NULL;
 | |
|   struct hostent *h = NULL;
 | |
|   struct in_addr in;
 | |
|   struct hostent *buf = NULL;
 | |
| 
 | |
| #ifdef CURL_DISABLE_VERBOSE_STRINGS
 | |
|   (void)conn;
 | |
| #endif
 | |
| 
 | |
|   *waitp = 0; /* don't wait, we act synchronously */
 | |
| 
 | |
|   if(Curl_inet_pton(AF_INET, hostname, &in) > 0)
 | |
|     /* This is a dotted IP address 123.123.123.123-style */
 | |
|     return Curl_ip2addr(AF_INET, &in, hostname, port);
 | |
| 
 | |
| #if defined(HAVE_GETHOSTBYNAME_R)
 | |
|   /*
 | |
|    * gethostbyname_r() is the preferred resolve function for many platforms.
 | |
|    * Since there are three different versions of it, the following code is
 | |
|    * somewhat #ifdef-ridden.
 | |
|    */
 | |
|   else {
 | |
|     int h_errnop;
 | |
| 
 | |
|     buf = calloc(CURL_HOSTENT_SIZE, 1);
 | |
|     if(!buf)
 | |
|       return NULL; /* major failure */
 | |
|     /*
 | |
|      * The clearing of the buffer is a workaround for a gethostbyname_r bug in
 | |
|      * qnx nto and it is also _required_ for some of these functions on some
 | |
|      * platforms.
 | |
|      */
 | |
| 
 | |
| #ifdef HAVE_GETHOSTBYNAME_R_5
 | |
|     /* Solaris, IRIX and more */
 | |
|     h = gethostbyname_r(hostname,
 | |
|                         (struct hostent *)buf,
 | |
|                         (char *)buf + sizeof(struct hostent),
 | |
|                         CURL_HOSTENT_SIZE - sizeof(struct hostent),
 | |
|                         &h_errnop);
 | |
| 
 | |
|     /* If the buffer is too small, it returns NULL and sets errno to
 | |
|      * ERANGE. The errno is thread safe if this is compiled with
 | |
|      * -D_REENTRANT as then the 'errno' variable is a macro defined to get
 | |
|      * used properly for threads.
 | |
|      */
 | |
| 
 | |
|     if(h) {
 | |
|       ;
 | |
|     }
 | |
|     else
 | |
| #endif /* HAVE_GETHOSTBYNAME_R_5 */
 | |
| #ifdef HAVE_GETHOSTBYNAME_R_6
 | |
|     /* Linux */
 | |
| 
 | |
|     (void)gethostbyname_r(hostname,
 | |
|                         (struct hostent *)buf,
 | |
|                         (char *)buf + sizeof(struct hostent),
 | |
|                         CURL_HOSTENT_SIZE - sizeof(struct hostent),
 | |
|                         &h, /* DIFFERENCE */
 | |
|                         &h_errnop);
 | |
|     /* Redhat 8, using glibc 2.2.93 changed the behavior. Now all of a
 | |
|      * sudden this function returns EAGAIN if the given buffer size is too
 | |
|      * small. Previous versions are known to return ERANGE for the same
 | |
|      * problem.
 | |
|      *
 | |
|      * This wouldn't be such a big problem if older versions wouldn't
 | |
|      * sometimes return EAGAIN on a common failure case. Alas, we can't
 | |
|      * assume that EAGAIN *or* ERANGE means ERANGE for any given version of
 | |
|      * glibc.
 | |
|      *
 | |
|      * For now, we do that and thus we may call the function repeatedly and
 | |
|      * fail for older glibc versions that return EAGAIN, until we run out of
 | |
|      * buffer size (step_size grows beyond CURL_HOSTENT_SIZE).
 | |
|      *
 | |
|      * If anyone has a better fix, please tell us!
 | |
|      *
 | |
|      * -------------------------------------------------------------------
 | |
|      *
 | |
|      * On October 23rd 2003, Dan C dug up more details on the mysteries of
 | |
|      * gethostbyname_r() in glibc:
 | |
|      *
 | |
|      * In glibc 2.2.5 the interface is different (this has also been
 | |
|      * discovered in glibc 2.1.1-6 as shipped by Redhat 6). What I can't
 | |
|      * explain, is that tests performed on glibc 2.2.4-34 and 2.2.4-32
 | |
|      * (shipped/upgraded by Redhat 7.2) don't show this behavior!
 | |
|      *
 | |
|      * In this "buggy" version, the return code is -1 on error and 'errno'
 | |
|      * is set to the ERANGE or EAGAIN code. Note that 'errno' is not a
 | |
|      * thread-safe variable.
 | |
|      */
 | |
| 
 | |
|     if(!h) /* failure */
 | |
| #endif/* HAVE_GETHOSTBYNAME_R_6 */
 | |
| #ifdef HAVE_GETHOSTBYNAME_R_3
 | |
|     /* AIX, Digital Unix/Tru64, HPUX 10, more? */
 | |
| 
 | |
|     /* For AIX 4.3 or later, we don't use gethostbyname_r() at all, because of
 | |
|      * the plain fact that it does not return unique full buffers on each
 | |
|      * call, but instead several of the pointers in the hostent structs will
 | |
|      * point to the same actual data! This have the unfortunate down-side that
 | |
|      * our caching system breaks down horribly. Luckily for us though, AIX 4.3
 | |
|      * and more recent versions have a "completely thread-safe"[*] libc where
 | |
|      * all the data is stored in thread-specific memory areas making calls to
 | |
|      * the plain old gethostbyname() work fine even for multi-threaded
 | |
|      * programs.
 | |
|      *
 | |
|      * This AIX 4.3 or later detection is all made in the configure script.
 | |
|      *
 | |
|      * Troels Walsted Hansen helped us work this out on March 3rd, 2003.
 | |
|      *
 | |
|      * [*] = much later we've found out that it isn't at all "completely
 | |
|      * thread-safe", but at least the gethostbyname() function is.
 | |
|      */
 | |
| 
 | |
|     if(CURL_HOSTENT_SIZE >=
 | |
|        (sizeof(struct hostent)+sizeof(struct hostent_data))) {
 | |
| 
 | |
|       /* August 22nd, 2000: Albert Chin-A-Young brought an updated version
 | |
|        * that should work! September 20: Richard Prescott worked on the buffer
 | |
|        * size dilemma.
 | |
|        */
 | |
| 
 | |
|       res = gethostbyname_r(hostname,
 | |
|                             (struct hostent *)buf,
 | |
|                             (struct hostent_data *)((char *)buf +
 | |
|                                                     sizeof(struct hostent)));
 | |
|       h_errnop = SOCKERRNO; /* we don't deal with this, but set it anyway */
 | |
|     }
 | |
|     else
 | |
|       res = -1; /* failure, too smallish buffer size */
 | |
| 
 | |
|     if(!res) { /* success */
 | |
| 
 | |
|       h = buf; /* result expected in h */
 | |
| 
 | |
|       /* This is the worst kind of the different gethostbyname_r() interfaces.
 | |
|        * Since we don't know how big buffer this particular lookup required,
 | |
|        * we can't realloc down the huge alloc without doing closer analysis of
 | |
|        * the returned data. Thus, we always use CURL_HOSTENT_SIZE for every
 | |
|        * name lookup. Fixing this would require an extra malloc() and then
 | |
|        * calling Curl_addrinfo_copy() that subsequent realloc()s down the new
 | |
|        * memory area to the actually used amount.
 | |
|        */
 | |
|     }
 | |
|     else
 | |
| #endif /* HAVE_GETHOSTBYNAME_R_3 */
 | |
|       {
 | |
|       infof(conn->data, "gethostbyname_r(2) failed for %s\n", hostname);
 | |
|       h = NULL; /* set return code to NULL */
 | |
|       free(buf);
 | |
|     }
 | |
| #else /* HAVE_GETHOSTBYNAME_R */
 | |
|     /*
 | |
|      * Here is code for platforms that don't have gethostbyname_r() or for
 | |
|      * which the gethostbyname() is the preferred() function.
 | |
|      */
 | |
|   else {
 | |
| #if (defined(NETWARE) && !defined(__NOVELL_LIBC__))
 | |
|     h = gethostbyname((char*)hostname);
 | |
| #else
 | |
|     h = gethostbyname(hostname);
 | |
| #endif
 | |
|     if(!h)
 | |
|       infof(conn->data, "gethostbyname(2) failed for %s\n", hostname);
 | |
| #endif /*HAVE_GETHOSTBYNAME_R */
 | |
|   }
 | |
| 
 | |
|   if(h) {
 | |
|     ai = Curl_he2ai(h, port);
 | |
| 
 | |
|     if(buf) /* used a *_r() function */
 | |
|       free(buf);
 | |
|   }
 | |
| 
 | |
|   return ai;
 | |
| }
 | |
| 
 | |
| #endif /* CURLRES_SYNCH */
 | |
| #endif /* CURLRES_IPV4 */
 | |
| 
 |