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Diffstat (limited to 'lib/hostip4.c')
| -rw-r--r-- | lib/hostip4.c | 310 |
1 files changed, 310 insertions, 0 deletions
diff --git a/lib/hostip4.c b/lib/hostip4.c new file mode 100644 index 000000000..3babe7269 --- /dev/null +++ b/lib/hostip4.c @@ -0,0 +1,310 @@ +/*************************************************************************** + * _ _ ____ _ + * Project ___| | | | _ \| | + * / __| | | | |_) | | + * | (__| |_| | _ <| |___ + * \___|\___/|_| \_\_____| + * + * Copyright (C) 1998 - 2012, 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. + * + ***************************************************************************/ + +#include "setup.h" + +#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" +#include "inet_pton.h" + +#define _MPRINTF_REPLACE /* use our functions only */ +#include <curl/mprintf.h> + +#include "curl_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 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 in_addr in; + struct hostent *buf = NULL; + + 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_GETADDRINFO_THREADSAFE) + else { + struct addrinfo hints; + char sbuf[NI_MAXSERV]; + char *sbufptr = NULL; + + memset(&hints, 0, sizeof(hints)); + hints.ai_family = PF_INET; + hints.ai_socktype = SOCK_STREAM; + if(port) { + snprintf(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. + */ + else { + 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. + */ + else { + 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) */ |