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Diffstat (limited to 'usr.sbin/bind/lib/lwres/gethost.c')
| -rw-r--r-- | usr.sbin/bind/lib/lwres/gethost.c | 364 |
1 files changed, 0 insertions, 364 deletions
diff --git a/usr.sbin/bind/lib/lwres/gethost.c b/usr.sbin/bind/lib/lwres/gethost.c deleted file mode 100644 index 2e2d6a7803f..00000000000 --- a/usr.sbin/bind/lib/lwres/gethost.c +++ /dev/null @@ -1,364 +0,0 @@ -/* - * Copyright (C) Internet Systems Consortium, Inc. ("ISC") - * - * Permission to use, copy, modify, and/or distribute this software for any - * purpose with or without fee is hereby granted, provided that the above - * copyright notice and this permission notice appear in all copies. - * - * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH - * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY - * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, - * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM - * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE - * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR - * PERFORMANCE OF THIS SOFTWARE. - */ - -/* $Id: gethost.c,v 1.6 2019/12/17 01:46:38 sthen Exp $ */ - -/*! \file */ - -/** - * These functions provide hostname-to-address and address-to-hostname - * lookups by means of the lightweight resolver. They are similar to the - * standard gethostent(3) functions provided by most operating systems. - * They use a struct hostent which is usually defined in <namedb.h>. - * - * \code - * struct hostent { - * char *h_name; // official name of host - * char **h_aliases; // alias list - * int h_addrtype; // host address type - * int h_length; // length of address - * char **h_addr_list; // list of addresses from name server - * }; - * #define h_addr h_addr_list[0] // address, for backward compatibility - * \endcode - * - * The members of this structure are: - * - * \li h_name: - * The official (canonical) name of the host. - * - * \li h_aliases: - * A NULL-terminated array of alternate names (nicknames) for the - * host. - * - * \li h_addrtype: - * The type of address being returned -- PF_INET or PF_INET6. - * - * \li h_length: - * The length of the address in bytes. - * - * \li h_addr_list: - * A NULL terminated array of network addresses for the host. Host - * addresses are returned in network byte order. - * - * For backward compatibility with very old software, h_addr is the first - * address in h_addr_list. - * - * lwres_gethostent(), lwres_sethostent(), lwres_endhostent(), - * lwres_gethostent_r(), lwres_sethostent_r() and lwres_endhostent_r() - * provide iteration over the known host entries on systems that provide - * such functionality through facilities like /etc/hosts or NIS. The - * lightweight resolver does not currently implement these functions; it - * only provides them as stub functions that always return failure. - * - * lwres_gethostbyname() and lwres_gethostbyname2() look up the hostname - * name. lwres_gethostbyname() always looks for an IPv4 address while - * lwres_gethostbyname2() looks for an address of protocol family af: - * either PF_INET or PF_INET6 -- IPv4 or IPV6 addresses respectively. - * Successful calls of the functions return a struct hostent for the name - * that was looked up. NULL is returned if the lookups by - * lwres_gethostbyname() or lwres_gethostbyname2() fail. - * - * Reverse lookups of addresses are performed by lwres_gethostbyaddr(). - * addr is an address of length len bytes and protocol family type -- - * PF_INET or PF_INET6. lwres_gethostbyname_r() is a thread-safe function - * for forward lookups. If an error occurs, an error code is returned in - * *error. resbuf is a pointer to a struct hostent which is initialised - * by a successful call to lwres_gethostbyname_r() . buf is a buffer of - * length len bytes which is used to store the h_name, h_aliases, and - * h_addr_list elements of the struct hostent returned in resbuf. - * Successful calls to lwres_gethostbyname_r() return resbuf, which is a - * pointer to the struct hostent it created. - * - * lwres_gethostbyaddr_r() is a thread-safe function that performs a - * reverse lookup of address addr which is len bytes long and is of - * protocol family type -- PF_INET or PF_INET6. If an error occurs, the - * error code is returned in *error. The other function parameters are - * identical to those in lwres_gethostbyname_r(). resbuf is a pointer to - * a struct hostent which is initialised by a successful call to - * lwres_gethostbyaddr_r(). buf is a buffer of length len bytes which is - * used to store the h_name, h_aliases, and h_addr_list elements of the - * struct hostent returned in resbuf. Successful calls to - * lwres_gethostbyaddr_r() return resbuf, which is a pointer to the - * struct hostent it created. - * - * \section gethost_return Return Values - * - * The functions lwres_gethostbyname(), lwres_gethostbyname2(), - * lwres_gethostbyaddr(), and lwres_gethostent() return NULL to indicate - * an error. In this case the global variable lwres_h_errno will contain - * one of the following error codes defined in \link netdb.h <lwres/netdb.h>:\endlink - * - * \li #HOST_NOT_FOUND: - * The host or address was not found. - * - * \li #TRY_AGAIN: - * A recoverable error occurred, e.g., a timeout. Retrying the - * lookup may succeed. - * - * \li #NO_RECOVERY: - * A non-recoverable error occurred. - * - * \li #NO_DATA: - * The name exists, but has no address information associated with - * it (or vice versa in the case of a reverse lookup). The code - * NO_ADDRESS is accepted as a synonym for NO_DATA for backwards - * compatibility. - * - * lwres_hstrerror() translates these error codes to suitable error - * messages. - * - * lwres_gethostent() and lwres_gethostent_r() always return NULL. - * - * Successful calls to lwres_gethostbyname_r() and - * lwres_gethostbyaddr_r() return resbuf, a pointer to the struct hostent - * that was initialised by these functions. They return NULL if the - * lookups fail or if buf was too small to hold the list of addresses and - * names referenced by the h_name, h_aliases, and h_addr_list elements of - * the struct hostent. If buf was too small, both lwres_gethostbyname_r() - * and lwres_gethostbyaddr_r() set the global variable errno to ERANGE. - * - * \section gethost_see See Also - * - * gethostent(), \link getipnode.c getipnode\endlink, lwres_hstrerror() - * - * \section gethost_bugs Bugs - * - * lwres_gethostbyname(), lwres_gethostbyname2(), lwres_gethostbyaddr() - * and lwres_endhostent() are not thread safe; they return pointers to - * static data and provide error codes through a global variable. - * Thread-safe versions for name and address lookup are provided by - * lwres_gethostbyname_r(), and lwres_gethostbyaddr_r() respectively. - * - * The resolver daemon does not currently support any non-DNS name - * services such as /etc/hosts or NIS, consequently the above functions - * don't, either. - */ - -#include <config.h> - -#include <errno.h> -#include <string.h> -#ifdef HAVE_INTTYPES_H -#include <inttypes.h> /* uintptr_t */ -#endif - -#include <lwres/net.h> -#include <lwres/netdb.h> - -#include "assert_p.h" - -#define LWRES_ALIGNBYTES (sizeof(char *) - 1) -#define LWRES_ALIGN(p) \ - (((uintptr_t)(p) + LWRES_ALIGNBYTES) &~ LWRES_ALIGNBYTES) - -static struct hostent *he = NULL; -static int copytobuf(struct hostent *, struct hostent *, char *, int); - -/*% Always looks for an IPv4 address. */ -struct hostent * -lwres_gethostbyname(const char *name) { - - if (he != NULL) - lwres_freehostent(he); - - he = lwres_getipnodebyname(name, AF_INET, 0, &lwres_h_errno); - return (he); -} - -/*% Looks for either an IPv4 or IPv6 address. */ -struct hostent * -lwres_gethostbyname2(const char *name, int af) { - if (he != NULL) - lwres_freehostent(he); - - he = lwres_getipnodebyname(name, af, 0, &lwres_h_errno); - return (he); -} - -/*% Reverse lookup of addresses. */ -struct hostent * -lwres_gethostbyaddr(const char *addr, int len, int type) { - - if (he != NULL) - lwres_freehostent(he); - - he = lwres_getipnodebyaddr(addr, len, type, &lwres_h_errno); - return (he); -} - -/*% Stub function. Always returns failure. */ -struct hostent * -lwres_gethostent(void) { - if (he != NULL) - lwres_freehostent(he); - - return (NULL); -} - -/*% Stub function. Always returns failure. */ -void -lwres_sethostent(int stayopen) { - /* - * Empty. - */ - UNUSED(stayopen); -} - -/*% Stub function. Always returns failure. */ -void -lwres_endhostent(void) { - /* - * Empty. - */ -} - -/*% Thread-safe function for forward lookups. */ -struct hostent * -lwres_gethostbyname_r(const char *name, struct hostent *resbuf, - char *buf, int buflen, int *error) -{ - struct hostent *myhe; - int res; - - myhe = lwres_getipnodebyname(name, AF_INET, 0, error); - if (myhe == NULL) - return (NULL); - res = copytobuf(myhe, resbuf, buf, buflen); - lwres_freehostent(myhe); - if (res != 0) { - errno = ERANGE; - return (NULL); - } - return (resbuf); -} - -/*% Thread-safe reverse lookup. */ -struct hostent * -lwres_gethostbyaddr_r(const char *addr, int len, int type, - struct hostent *resbuf, char *buf, int buflen, - int *error) -{ - struct hostent *myhe; - int res; - - myhe = lwres_getipnodebyaddr(addr, len, type, error); - if (myhe == NULL) - return (NULL); - res = copytobuf(myhe, resbuf, buf, buflen); - lwres_freehostent(myhe); - if (res != 0) { - errno = ERANGE; - return (NULL); - } - return (resbuf); -} - -/*% Stub function. Always returns failure. */ -struct hostent * -lwres_gethostent_r(struct hostent *resbuf, char *buf, int buflen, int *error) { - UNUSED(resbuf); - UNUSED(buf); - UNUSED(buflen); - *error = 0; - return (NULL); -} - -/*% Stub function. Always returns failure. */ -void -lwres_sethostent_r(int stayopen) { - /* - * Empty. - */ - UNUSED(stayopen); -} - -/*% Stub function. Always returns failure. */ -void -lwres_endhostent_r(void) { - /* - * Empty. - */ -} - -static int -copytobuf(struct hostent *src, struct hostent *hptr, char *buf, int buflen) { - char *cp; - char **ptr; - int i, n; - int nptr, len; - - /* - * Find out the amount of space required to store the answer. - */ - nptr = 2; /* NULL ptrs */ - len = (int)((char *)LWRES_ALIGN(buf) - buf); - for (i = 0; src->h_addr_list[i]; i++, nptr++) { - len += src->h_length; - } - for (i = 0; src->h_aliases[i]; i++, nptr++) { - len += strlen(src->h_aliases[i]) + 1; - } - len += strlen(src->h_name) + 1; - len += nptr * sizeof(char*); - - if (len > buflen) { - return (-1); - } - - /* - * Copy address size and type. - */ - hptr->h_addrtype = src->h_addrtype; - n = hptr->h_length = src->h_length; - - ptr = (char **)LWRES_ALIGN(buf); - cp = (char *)LWRES_ALIGN(buf) + nptr * sizeof(char *); - - /* - * Copy address list. - */ - hptr->h_addr_list = ptr; - for (i = 0; src->h_addr_list[i]; i++, ptr++) { - memmove(cp, src->h_addr_list[i], n); - hptr->h_addr_list[i] = cp; - cp += n; - } - hptr->h_addr_list[i] = NULL; - ptr++; - - /* - * Copy official name. - */ - n = strlen(src->h_name) + 1; - strcpy(cp, src->h_name); - hptr->h_name = cp; - cp += n; - - /* - * Copy aliases. - */ - hptr->h_aliases = ptr; - for (i = 0; src->h_aliases[i]; i++) { - n = strlen(src->h_aliases[i]) + 1; - strcpy(cp, src->h_aliases[i]); - hptr->h_aliases[i] = cp; - cp += n; - } - hptr->h_aliases[i] = NULL; - - return (0); -} |