| /*************************************************************************** |
| * _ _ ____ _ |
| * Project ___| | | | _ \| | |
| * / __| | | | |_) | | |
| * | (__| |_| | _ <| |___ |
| * \___|\___/|_| \_\_____| |
| * |
| * Copyright (C) 1998 - 2020, 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 https://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. |
| * |
| ***************************************************************************/ |
| |
| #include "curl_setup.h" |
| |
| /*********************************************************************** |
| * Only for plain IPv4 builds |
| **********************************************************************/ |
| #ifdef CURLRES_IPV4 /* plain IPv4 code coming up */ |
| |
| #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 __VMS |
| #include <in.h> |
| #include <inet.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" |
| /* The last 3 #include files should be in this order */ |
| #include "curl_printf.h" |
| #include "curl_memory.h" |
| #include "memdebug.h" |
| |
| /* |
| * Curl_ipvalid() checks what CURL_IPRESOLVE_* requirements that might've |
| * been set and returns TRUE if they are OK. |
| */ |
| bool Curl_ipvalid(struct connectdata *conn) |
| { |
| if(conn->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 |
| |
| /* |
| * 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) |
| { |
| Curl_addrinfo *ai = NULL; |
| |
| #ifdef CURL_DISABLE_VERBOSE_STRINGS |
| (void)conn; |
| #endif |
| |
| *waitp = 0; /* synchronous response only */ |
| |
| ai = Curl_ipv4_resolve_r(hostname, port); |
| if(!ai) |
| infof(conn->data, "Curl_ipv4_resolve_r failed for %s\n", hostname); |
| |
| return ai; |
| } |
| #endif /* CURLRES_SYNCH */ |
| #endif /* CURLRES_IPV4 */ |
| |
| #if defined(CURLRES_IPV4) && !defined(CURLRES_ARES) |
| |
| /* |
| * Curl_ipv4_resolve_r() - ipv4 threadsafe resolver function. |
| * |
| * This is used for both synchronous and asynchronous resolver builds, |
| * implying that only threadsafe code and function calls may be used. |
| * |
| */ |
| Curl_addrinfo *Curl_ipv4_resolve_r(const char *hostname, |
| int port) |
| { |
| #if !defined(HAVE_GETADDRINFO_THREADSAFE) && defined(HAVE_GETHOSTBYNAME_R_3) |
| int res; |
| #endif |
| Curl_addrinfo *ai = NULL; |
| struct hostent *h = NULL; |
| struct hostent *buf = NULL; |
| |
| #if defined(HAVE_GETADDRINFO_THREADSAFE) |
| struct addrinfo hints; |
| char sbuf[12]; |
| char *sbufptr = NULL; |
| |
| memset(&hints, 0, sizeof(hints)); |
| hints.ai_family = PF_INET; |
| hints.ai_socktype = SOCK_STREAM; |
| if(port) { |
| msnprintf(sbuf, sizeof(sbuf), "%d", port); |
| sbufptr = sbuf; |
| } |
| |
| (void)Curl_getaddrinfo_ex(hostname, sbufptr, &hints, &ai); |
| |
| #elif 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. |
| */ |
| int h_errnop; |
| |
| buf = calloc(1, CURL_HOSTENT_SIZE); |
| 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. |
| */ |
| |
| #if defined(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 |
| #elif defined(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 */ |
| #elif defined(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_...BYNAME_R_5 || HAVE_...BYNAME_R_6 || HAVE_...BYNAME_R_3 */ |
| { |
| h = NULL; /* set return code to NULL */ |
| free(buf); |
| } |
| #else /* HAVE_GETADDRINFO_THREADSAFE || HAVE_GETHOSTBYNAME_R */ |
| /* |
| * Here is code for platforms that don't have a thread safe |
| * getaddrinfo() nor gethostbyname_r() function or for which |
| * gethostbyname() is the preferred one. |
| */ |
| h = gethostbyname((void *)hostname); |
| #endif /* HAVE_GETADDRINFO_THREADSAFE || HAVE_GETHOSTBYNAME_R */ |
| |
| if(h) { |
| ai = Curl_he2ai(h, port); |
| |
| if(buf) /* used a *_r() function */ |
| free(buf); |
| } |
| |
| return ai; |
| } |
| #endif /* defined(CURLRES_IPV4) && !defined(CURLRES_ARES) */ |
