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-rw-r--r--sql/hostname.cc986
1 files changed, 986 insertions, 0 deletions
diff --git a/sql/hostname.cc b/sql/hostname.cc
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index 00000000..d5f342b9
--- /dev/null
+++ b/sql/hostname.cc
@@ -0,0 +1,986 @@
+/* Copyright (c) 2000, 2013, Oracle and/or its affiliates.
+ Copyright (c) 2011, 2014, SkySQL Ab.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; version 2 of the License.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA */
+
+
+/**
+ @file
+
+ @brief
+ Get hostname for an IP address.
+
+ Hostnames are checked with reverse name lookup and checked that they
+ doesn't resemble an IP address.
+*/
+#include "mariadb.h"
+#include "sql_priv.h"
+#include "unireg.h" // SPECIAL_NO_HOST_CACHE
+#include "hostname.h"
+#ifndef _WIN32
+#include <netdb.h> // getservbyname, servent
+#endif
+#include "hash_filo.h"
+#include <m_ctype.h>
+#include "log.h" // sql_print_warning,
+ // sql_print_information
+#include "violite.h" // vio_getnameinfo,
+ // vio_get_normalized_ip_string
+#ifdef __cplusplus
+extern "C" { // Because of SCO 3.2V4.2
+#endif
+#if !defined( _WIN32)
+#ifdef HAVE_SYS_UN_H
+#include <sys/un.h>
+#endif
+#include <sys/utsname.h>
+#endif // _WIN32
+#ifdef __cplusplus
+}
+#endif
+
+Host_errors::Host_errors()
+: m_connect(0),
+ m_host_blocked(0),
+ m_nameinfo_transient(0),
+ m_nameinfo_permanent(0),
+ m_format(0),
+ m_addrinfo_transient(0),
+ m_addrinfo_permanent(0),
+ m_FCrDNS(0),
+ m_host_acl(0),
+ m_no_auth_plugin(0),
+ m_auth_plugin(0),
+ m_handshake(0),
+ m_proxy_user(0),
+ m_proxy_user_acl(0),
+ m_authentication(0),
+ m_ssl(0),
+ m_max_user_connection(0),
+ m_max_user_connection_per_hour(0),
+ m_default_database(0),
+ m_init_connect(0),
+ m_local(0)
+{}
+
+Host_errors::~Host_errors() = default;
+
+void Host_errors::reset()
+{
+ m_connect= 0;
+ m_host_blocked= 0;
+ m_nameinfo_transient= 0;
+ m_nameinfo_permanent= 0;
+ m_format= 0;
+ m_addrinfo_transient= 0;
+ m_addrinfo_permanent= 0;
+ m_FCrDNS= 0;
+ m_host_acl= 0;
+ m_no_auth_plugin= 0;
+ m_auth_plugin= 0;
+ m_handshake= 0;
+ m_proxy_user= 0;
+ m_proxy_user_acl= 0;
+ m_authentication= 0;
+ m_ssl= 0;
+ m_max_user_connection= 0;
+ m_max_user_connection_per_hour= 0;
+ m_default_database= 0;
+ m_init_connect= 0;
+ m_local= 0;
+}
+
+void Host_errors::aggregate(const Host_errors *errors)
+{
+ m_connect+= errors->m_connect;
+ m_host_blocked+= errors->m_host_blocked;
+ m_nameinfo_transient+= errors->m_nameinfo_transient;
+ m_nameinfo_permanent+= errors->m_nameinfo_permanent;
+ m_format+= errors->m_format;
+ m_addrinfo_transient+= errors->m_addrinfo_transient;
+ m_addrinfo_permanent+= errors->m_addrinfo_permanent;
+ m_FCrDNS+= errors->m_FCrDNS;
+ m_host_acl+= errors->m_host_acl;
+ m_no_auth_plugin+= errors->m_no_auth_plugin;
+ m_auth_plugin+= errors->m_auth_plugin;
+ m_handshake+= errors->m_handshake;
+ m_proxy_user+= errors->m_proxy_user;
+ m_proxy_user_acl+= errors->m_proxy_user_acl;
+ m_authentication+= errors->m_authentication;
+ m_ssl+= errors->m_ssl;
+ m_max_user_connection+= errors->m_max_user_connection;
+ m_max_user_connection_per_hour+= errors->m_max_user_connection_per_hour;
+ m_default_database+= errors->m_default_database;
+ m_init_connect+= errors->m_init_connect;
+ m_local+= errors->m_local;
+}
+
+static Hash_filo<Host_entry> *hostname_cache;
+ulong host_cache_size;
+
+void hostname_cache_refresh()
+{
+ hostname_cache->clear();
+}
+
+uint hostname_cache_size()
+{
+ return hostname_cache->size();
+}
+
+void hostname_cache_resize(uint size)
+{
+ hostname_cache->resize(size);
+}
+
+bool hostname_cache_init()
+{
+ Host_entry tmp;
+ uint key_offset= (uint) ((char*) (&tmp.ip_key) - (char*) &tmp);
+
+ if (!(hostname_cache= new Hash_filo<Host_entry>(key_memory_host_cache_hostname,
+ host_cache_size, key_offset, HOST_ENTRY_KEY_SIZE,
+ NULL, (my_hash_free_key) my_free, &my_charset_bin)))
+ return 1;
+
+ hostname_cache->clear();
+
+ return 0;
+}
+
+void hostname_cache_free()
+{
+ delete hostname_cache;
+ hostname_cache= NULL;
+}
+
+void hostname_cache_lock()
+{
+ mysql_mutex_lock(&hostname_cache->lock);
+}
+
+void hostname_cache_unlock()
+{
+ mysql_mutex_unlock(&hostname_cache->lock);
+}
+
+static void prepare_hostname_cache_key(const char *ip_string,
+ char *ip_key)
+{
+ size_t ip_string_length= strlen(ip_string);
+ DBUG_ASSERT(ip_string_length < HOST_ENTRY_KEY_SIZE);
+
+ memset(ip_key, 0, HOST_ENTRY_KEY_SIZE);
+ memcpy(ip_key, ip_string, ip_string_length);
+}
+
+Host_entry *hostname_cache_first()
+{ return hostname_cache->first(); }
+
+static inline Host_entry *hostname_cache_search(const char *ip_key)
+{
+ return hostname_cache->search((uchar *) ip_key, HOST_ENTRY_KEY_SIZE);
+}
+
+static void add_hostname_impl(const char *ip_key, const char *hostname,
+ bool validated, Host_errors *errors,
+ ulonglong now)
+{
+ Host_entry *entry;
+ bool need_add= false;
+
+ entry= hostname_cache_search(ip_key);
+
+ if (likely(entry == NULL))
+ {
+ entry= (Host_entry *) my_malloc(key_memory_host_cache_hostname,
+ sizeof (Host_entry), 0);
+ if (entry == NULL)
+ return;
+
+ need_add= true;
+ memcpy(&entry->ip_key, ip_key, HOST_ENTRY_KEY_SIZE);
+ entry->m_errors.reset();
+ entry->m_hostname_length= 0;
+ entry->m_host_validated= false;
+ entry->m_first_seen= now;
+ entry->m_last_seen= now;
+ entry->m_first_error_seen= 0;
+ entry->m_last_error_seen= 0;
+ }
+ else
+ {
+ entry->m_last_seen= now;
+ }
+
+ if (validated)
+ {
+ if (hostname != NULL)
+ {
+ size_t len= strlen(hostname);
+ if (len > sizeof(entry->m_hostname) - 1)
+ len= sizeof(entry->m_hostname) - 1;
+ memcpy(entry->m_hostname, hostname, len);
+ entry->m_hostname[len]= '\0';
+ entry->m_hostname_length= (uint)len;
+
+ DBUG_PRINT("info",
+ ("Adding/Updating '%s' -> '%s' (validated) to the hostname cache...'",
+ (const char *) ip_key,
+ (const char *) entry->m_hostname));
+ }
+ else
+ {
+ entry->m_hostname_length= 0;
+ DBUG_PRINT("info",
+ ("Adding/Updating '%s' -> NULL (validated) to the hostname cache...'",
+ (const char *) ip_key));
+ }
+ entry->m_host_validated= true;
+ /*
+ New errors that are considered 'blocking',
+ that will eventually cause the IP to be black listed and blocked.
+ */
+ errors->sum_connect_errors();
+ }
+ else
+ {
+ entry->m_hostname_length= 0;
+ entry->m_host_validated= false;
+ /* Do not count new blocking errors during DNS failures. */
+ errors->clear_connect_errors();
+ DBUG_PRINT("info",
+ ("Adding/Updating '%s' -> NULL (not validated) to the hostname cache...'",
+ (const char *) ip_key));
+ }
+
+ if (errors->has_error())
+ entry->set_error_timestamps(now);
+
+ entry->m_errors.aggregate(errors);
+
+ if (need_add)
+ hostname_cache->add(entry);
+
+ return;
+}
+
+static void add_hostname(const char *ip_key, const char *hostname,
+ bool validated, Host_errors *errors)
+{
+ if (specialflag & SPECIAL_NO_HOST_CACHE)
+ return;
+
+ ulonglong now= my_hrtime().val;
+
+ mysql_mutex_lock(&hostname_cache->lock);
+
+ add_hostname_impl(ip_key, hostname, validated, errors, now);
+
+ mysql_mutex_unlock(&hostname_cache->lock);
+
+ return;
+}
+
+void inc_host_errors(const char *ip_string, Host_errors *errors)
+{
+ if (!ip_string)
+ return;
+
+ ulonglong now= my_hrtime().val;
+ char ip_key[HOST_ENTRY_KEY_SIZE];
+ prepare_hostname_cache_key(ip_string, ip_key);
+
+ mysql_mutex_lock(&hostname_cache->lock);
+
+ Host_entry *entry= hostname_cache_search(ip_key);
+
+ if (entry)
+ {
+ if (entry->m_host_validated)
+ errors->sum_connect_errors();
+ else
+ errors->clear_connect_errors();
+
+ entry->m_errors.aggregate(errors);
+ entry->set_error_timestamps(now);
+ }
+
+ mysql_mutex_unlock(&hostname_cache->lock);
+}
+
+void reset_host_connect_errors(const char *ip_string)
+{
+ if (!ip_string)
+ return;
+
+ char ip_key[HOST_ENTRY_KEY_SIZE];
+ prepare_hostname_cache_key(ip_string, ip_key);
+
+ mysql_mutex_lock(&hostname_cache->lock);
+
+ Host_entry *entry= hostname_cache_search(ip_key);
+
+ if (entry)
+ entry->m_errors.clear_connect_errors();
+
+ mysql_mutex_unlock(&hostname_cache->lock);
+}
+
+static inline bool is_ip_loopback(const struct sockaddr *ip)
+{
+ switch (ip->sa_family) {
+ case AF_INET:
+ {
+ /* Check for IPv4 127.0.0.1. */
+ struct in_addr *ip4= &((struct sockaddr_in *) ip)->sin_addr;
+ return ntohl(ip4->s_addr) == INADDR_LOOPBACK;
+ }
+
+#ifdef HAVE_IPV6
+ case AF_INET6:
+ {
+ /* Check for IPv6 ::1. */
+ struct in6_addr *ip6= &((struct sockaddr_in6 *) ip)->sin6_addr;
+ return IN6_IS_ADDR_LOOPBACK(ip6);
+ }
+#endif /* HAVE_IPV6 */
+
+ default:
+ return FALSE;
+ }
+}
+
+static inline bool is_hostname_valid(const char *hostname)
+{
+ /*
+ A hostname is invalid if it starts with a number followed by a dot
+ (IPv4 address).
+ */
+
+ if (!my_isdigit(&my_charset_latin1, hostname[0]))
+ return TRUE;
+
+ const char *p= hostname + 1;
+
+ while (my_isdigit(&my_charset_latin1, *p))
+ ++p;
+
+ return *p != '.';
+}
+
+/**
+ Resolve IP-address to host name.
+
+ This function does the following things:
+ - resolves IP-address;
+ - employs Forward Confirmed Reverse DNS technique to validate IP-address;
+ - returns host name if IP-address is validated;
+ - set value to out-variable connect_errors -- this variable represents the
+ number of connection errors from the specified IP-address.
+ - update the host_cache statistics
+
+ NOTE: connect_errors are counted (are supported) only for the clients
+ where IP-address can be resolved and FCrDNS check is passed.
+
+ @param [in] ip_storage IP address (sockaddr). Must be set.
+ @param [in] ip_string IP address (string). Must be set.
+ @param [out] hostname
+ @param [out] connect_errors
+
+ @return Error status
+ @retval 0 Success
+ @retval RC_BLOCKED_HOST The host is blocked.
+
+ The function does not set/report MySQL server error in case of failure.
+ It's caller's responsibility to handle failures of this function
+ properly.
+*/
+
+int ip_to_hostname(struct sockaddr_storage *ip_storage,
+ const char *ip_string,
+ const char **hostname,
+ uint *connect_errors)
+{
+ const struct sockaddr *ip= (const sockaddr *) ip_storage;
+ int err_code;
+ bool err_status __attribute__((unused));
+ Host_errors errors;
+
+ DBUG_ENTER("ip_to_hostname");
+ DBUG_PRINT("info", ("IP address: '%s'; family: %d.",
+ (const char *) ip_string,
+ (int) ip->sa_family));
+
+ /* Default output values, for most cases. */
+ *hostname= NULL;
+ *connect_errors= 0;
+
+ /* Check if we have loopback address (127.0.0.1 or ::1). */
+
+ if (is_ip_loopback(ip))
+ {
+ DBUG_PRINT("info", ("Loopback address detected."));
+
+ /* Do not count connect errors from localhost. */
+ *hostname= my_localhost;
+
+ DBUG_RETURN(0);
+ }
+
+ /* Prepare host name cache key. */
+
+ char ip_key[HOST_ENTRY_KEY_SIZE];
+ prepare_hostname_cache_key(ip_string, ip_key);
+
+ /* Check first if we have host name in the cache. */
+
+ if (!(specialflag & SPECIAL_NO_HOST_CACHE))
+ {
+ ulonglong now= my_hrtime().val;
+
+ mysql_mutex_lock(&hostname_cache->lock);
+
+ Host_entry *entry= hostname_cache_search(ip_key);
+
+ if (entry)
+ {
+ entry->m_last_seen= now;
+ *connect_errors= entry->m_errors.m_connect;
+
+ if (unlikely(entry->m_errors.m_connect >= max_connect_errors))
+ {
+ entry->m_errors.m_host_blocked++;
+ entry->set_error_timestamps(now);
+ mysql_mutex_unlock(&hostname_cache->lock);
+ DBUG_RETURN(RC_BLOCKED_HOST);
+ }
+
+ /*
+ If there is an IP -> HOSTNAME association in the cache,
+ but for a hostname that was not validated,
+ do not return that hostname: perform the network validation again.
+ */
+ if (entry->m_host_validated)
+ {
+ if (entry->m_hostname_length)
+ *hostname= my_strdup(key_memory_host_cache_hostname,
+ entry->m_hostname, MYF(0));
+
+ DBUG_PRINT("info",("IP (%s) has been found in the cache. "
+ "Hostname: '%s'",
+ (const char *) ip_key,
+ (const char *) (*hostname? *hostname : "null")
+ ));
+
+ mysql_mutex_unlock(&hostname_cache->lock);
+
+ DBUG_RETURN(0);
+ }
+ }
+
+ mysql_mutex_unlock(&hostname_cache->lock);
+ }
+
+ /*
+ Resolve host name. Return an error if a host name can not be resolved
+ (instead of returning the numeric form of the host name).
+ */
+
+ char hostname_buffer[NI_MAXHOST];
+
+ DBUG_PRINT("info", ("Resolving '%s'...", (const char *) ip_key));
+
+ err_code= vio_getnameinfo(ip, hostname_buffer, NI_MAXHOST, NULL, 0,
+ NI_NAMEREQD);
+
+ /*
+ ===========================================================================
+ DEBUG code only (begin)
+ Simulate various output from vio_getnameinfo().
+ ===========================================================================
+ */
+
+ DBUG_EXECUTE_IF("getnameinfo_error_noname",
+ {
+ strcpy(hostname_buffer, "<garbage>");
+ err_code= EAI_NONAME;
+ }
+ );
+
+ DBUG_EXECUTE_IF("getnameinfo_error_again",
+ {
+ strcpy(hostname_buffer, "<garbage>");
+ err_code= EAI_AGAIN;
+ }
+ );
+
+ DBUG_EXECUTE_IF("getnameinfo_fake_ipv4",
+ {
+ strcpy(hostname_buffer, "santa.claus.ipv4.example.com");
+ err_code= 0;
+ }
+ );
+
+ DBUG_EXECUTE_IF("getnameinfo_fake_ipv6",
+ {
+ strcpy(hostname_buffer, "santa.claus.ipv6.example.com");
+ err_code= 0;
+ }
+ );
+
+ DBUG_EXECUTE_IF("getnameinfo_format_ipv4",
+ {
+ strcpy(hostname_buffer, "12.12.12.12");
+ err_code= 0;
+ }
+ );
+
+ DBUG_EXECUTE_IF("getnameinfo_format_ipv6",
+ {
+ strcpy(hostname_buffer, "12:DEAD:BEEF:0");
+ err_code= 0;
+ }
+ );
+
+ DBUG_EXECUTE_IF("getnameinfo_fake_long_host",
+ {
+ strcpy(hostname_buffer, "host5678901_345678902_345678903_345678904_345678905_345678906_345678907_345678908_345678909_345678910_345678911_345678912_345678913_345678914_345678915_345678916_345678917_345678918_345678919_345678920_345678921_345678922_345678923_345678924_345678925_345");
+ err_code= 0;
+ }
+ );
+
+ /*
+ ===========================================================================
+ DEBUG code only (end)
+ ===========================================================================
+ */
+
+ if (err_code)
+ {
+ // NOTE: gai_strerror() returns a string ending by a dot.
+
+ DBUG_PRINT("error", ("IP address '%s' could not be resolved: %s",
+ (const char *) ip_key,
+ (const char *) gai_strerror(err_code)));
+
+ sql_print_warning("IP address '%s' could not be resolved: %s",
+ (const char *) ip_key,
+ (const char *) gai_strerror(err_code));
+
+ bool validated;
+ if (vio_is_no_name_error(err_code))
+ {
+ /*
+ The no-name error means that there is no reverse address mapping
+ for the IP address. A host name can not be resolved.
+ */
+ errors.m_nameinfo_permanent= 1;
+ validated= true;
+ }
+ else
+ {
+ /*
+ If it is not the no-name error, we should not cache the hostname
+ (or rather its absence), because the failure might be transient.
+ Only the ip error statistics are cached.
+ */
+ errors.m_nameinfo_transient= 1;
+ validated= false;
+ }
+ add_hostname(ip_key, NULL, validated, &errors);
+
+ DBUG_RETURN(0);
+ }
+
+ DBUG_PRINT("info", ("IP '%s' resolved to '%s'.",
+ (const char *) ip_key,
+ (const char *) hostname_buffer));
+
+ /*
+ Validate hostname: the server does not accept host names, which
+ resemble IP addresses.
+
+ The thing is that theoretically, a host name can be in a form of IPv4
+ address (123.example.org, or 1.2 or even 1.2.3.4). We have to deny such
+ host names because ACL-systems is not designed to work with them.
+
+ For example, it is possible to specify a host name mask (like
+ 192.168.1.%) for an ACL rule. Then, if IPv4-like hostnames are allowed,
+ there is a security hole: instead of allowing access for
+ 192.168.1.0/255 network (which was assumed by the user), the access
+ will be allowed for host names like 192.168.1.example.org.
+ */
+
+ if (!is_hostname_valid(hostname_buffer))
+ {
+ DBUG_PRINT("error", ("IP address '%s' has been resolved "
+ "to the host name '%s', which resembles "
+ "IPv4-address itself.",
+ (const char *) ip_key,
+ (const char *) hostname_buffer));
+
+ sql_print_warning("IP address '%s' has been resolved "
+ "to the host name '%s', which resembles "
+ "IPv4-address itself.",
+ (const char *) ip_key,
+ (const char *) hostname_buffer);
+
+ errors.m_format= 1;
+ add_hostname(ip_key, hostname_buffer, false, &errors);
+
+ DBUG_RETURN(false);
+ }
+
+ /* Get IP-addresses for the resolved host name (FCrDNS technique). */
+
+ struct addrinfo hints;
+ struct addrinfo *addr_info_list;
+ /*
+ Makes fault injection with DBUG_EXECUTE_IF easier.
+ Invoking free_addr_info(NULL) crashes on some platforms.
+ */
+ bool free_addr_info_list= false;
+
+ memset(&hints, 0, sizeof (struct addrinfo));
+ hints.ai_flags= AI_PASSIVE;
+ hints.ai_socktype= SOCK_STREAM;
+ hints.ai_family= AF_UNSPEC;
+
+ DBUG_PRINT("info", ("Getting IP addresses for hostname '%s'...",
+ (const char *) hostname_buffer));
+
+ err_code= getaddrinfo(hostname_buffer, NULL, &hints, &addr_info_list);
+ if (err_code == 0)
+ free_addr_info_list= true;
+
+ /*
+ ===========================================================================
+ DEBUG code only (begin)
+ Simulate various output from getaddrinfo().
+ ===========================================================================
+ */
+ DBUG_EXECUTE_IF("getaddrinfo_error_noname",
+ {
+ if (free_addr_info_list)
+ freeaddrinfo(addr_info_list);
+
+ addr_info_list= NULL;
+ err_code= EAI_NONAME;
+ free_addr_info_list= false;
+ }
+ );
+
+ DBUG_EXECUTE_IF("getaddrinfo_error_again",
+ {
+ if (free_addr_info_list)
+ freeaddrinfo(addr_info_list);
+
+ addr_info_list= NULL;
+ err_code= EAI_AGAIN;
+ free_addr_info_list= false;
+ }
+ );
+
+ DBUG_EXECUTE_IF("getaddrinfo_fake_bad_ipv4",
+ {
+ if (free_addr_info_list)
+ freeaddrinfo(addr_info_list);
+
+ struct sockaddr_in *debug_addr;
+ /*
+ Not thread safe, which is ok.
+ Only one connection at a time is tested with
+ fault injection.
+ */
+ static struct sockaddr_in debug_sock_addr[2];
+ static struct addrinfo debug_addr_info[2];
+ /* Simulating ipv4 192.0.2.126 */
+ debug_addr= & debug_sock_addr[0];
+ debug_addr->sin_family= AF_INET;
+ inet_pton(AF_INET,"192.0.2.126", &debug_addr->sin_addr);
+
+ /* Simulating ipv4 192.0.2.127 */
+ debug_addr= & debug_sock_addr[1];
+ debug_addr->sin_family= AF_INET;
+ inet_pton(AF_INET,"192.0.2.127", &debug_addr->sin_addr);
+
+ debug_addr_info[0].ai_addr= (struct sockaddr*) & debug_sock_addr[0];
+ debug_addr_info[0].ai_addrlen= sizeof (struct sockaddr_in);
+ debug_addr_info[0].ai_next= & debug_addr_info[1];
+
+ debug_addr_info[1].ai_addr= (struct sockaddr*) & debug_sock_addr[1];
+ debug_addr_info[1].ai_addrlen= sizeof (struct sockaddr_in);
+ debug_addr_info[1].ai_next= NULL;
+
+ addr_info_list= & debug_addr_info[0];
+ err_code= 0;
+ free_addr_info_list= false;
+ }
+ );
+
+ DBUG_EXECUTE_IF("getaddrinfo_fake_good_ipv4",
+ {
+ if (free_addr_info_list)
+ freeaddrinfo(addr_info_list);
+
+ struct sockaddr_in *debug_addr;
+ static struct sockaddr_in debug_sock_addr[2];
+ static struct addrinfo debug_addr_info[2];
+ /* Simulating ipv4 192.0.2.5 */
+ debug_addr= & debug_sock_addr[0];
+ debug_addr->sin_family= AF_INET;
+ inet_pton(AF_INET,"192.0.2.5", &debug_addr->sin_addr);
+
+ /* Simulating ipv4 192.0.2.4 */
+ debug_addr= & debug_sock_addr[1];
+ debug_addr->sin_family= AF_INET;
+ inet_pton(AF_INET,"192.0.2.4", &debug_addr->sin_addr);
+
+ debug_addr_info[0].ai_addr= (struct sockaddr*) & debug_sock_addr[0];
+ debug_addr_info[0].ai_addrlen= sizeof (struct sockaddr_in);
+ debug_addr_info[0].ai_next= & debug_addr_info[1];
+
+ debug_addr_info[1].ai_addr= (struct sockaddr*) & debug_sock_addr[1];
+ debug_addr_info[1].ai_addrlen= sizeof (struct sockaddr_in);
+ debug_addr_info[1].ai_next= NULL;
+
+ addr_info_list= & debug_addr_info[0];
+ err_code= 0;
+ free_addr_info_list= false;
+ }
+ );
+
+#ifdef HAVE_IPV6
+ DBUG_EXECUTE_IF("getaddrinfo_fake_bad_ipv6",
+ {
+ if (free_addr_info_list)
+ freeaddrinfo(addr_info_list);
+
+ struct sockaddr_in6 *debug_addr;
+ struct in6_addr *ip6;
+ /*
+ Not thread safe, which is ok.
+ Only one connection at a time is tested with
+ fault injection.
+ */
+ static struct sockaddr_in6 debug_sock_addr[2];
+ static struct addrinfo debug_addr_info[2];
+ /* Simulating ipv6 2001:DB8::6:7E */
+ debug_addr= & debug_sock_addr[0];
+ debug_addr->sin6_family= AF_INET6;
+ ip6= & debug_addr->sin6_addr;
+ inet_pton(AF_INET6,"2001:DB8::6:7E",ip6);
+
+ /* Simulating ipv6 2001:DB8::6:7F */
+ debug_addr= & debug_sock_addr[1];
+ debug_addr->sin6_family= AF_INET6;
+ ip6= & debug_addr->sin6_addr;
+ inet_pton(AF_INET6,"2001:DB8::6:7F",ip6);
+
+ debug_addr_info[0].ai_addr= (struct sockaddr*) & debug_sock_addr[0];
+ debug_addr_info[0].ai_addrlen= sizeof (struct sockaddr_in6);
+ debug_addr_info[0].ai_next= & debug_addr_info[1];
+
+ debug_addr_info[1].ai_addr= (struct sockaddr*) & debug_sock_addr[1];
+ debug_addr_info[1].ai_addrlen= sizeof (struct sockaddr_in6);
+ debug_addr_info[1].ai_next= NULL;
+
+ addr_info_list= & debug_addr_info[0];
+ err_code= 0;
+ free_addr_info_list= false;
+ }
+ );
+
+ DBUG_EXECUTE_IF("getaddrinfo_fake_good_ipv6",
+ {
+ if (free_addr_info_list)
+ freeaddrinfo(addr_info_list);
+
+ struct sockaddr_in6 *debug_addr;
+ struct in6_addr *ip6;
+ /*
+ Not thread safe, which is ok.
+ Only one connection at a time is tested with
+ fault injection.
+ */
+ static struct sockaddr_in6 debug_sock_addr[2];
+ static struct addrinfo debug_addr_info[2];
+ /* Simulating ipv6 2001:DB8::6:7 */
+ debug_addr= & debug_sock_addr[0];
+ debug_addr->sin6_family= AF_INET6;
+ ip6= & debug_addr->sin6_addr;
+ ip6->s6_addr[ 0] = 0x20;
+ ip6->s6_addr[ 1] = 0x01;
+ ip6->s6_addr[ 2] = 0x0d;
+ ip6->s6_addr[ 3] = 0xb8;
+ ip6->s6_addr[ 4] = 0x00;
+ ip6->s6_addr[ 5] = 0x00;
+ ip6->s6_addr[ 6] = 0x00;
+ ip6->s6_addr[ 7] = 0x00;
+ ip6->s6_addr[ 8] = 0x00;
+ ip6->s6_addr[ 9] = 0x00;
+ ip6->s6_addr[10] = 0x00;
+ ip6->s6_addr[11] = 0x00;
+ ip6->s6_addr[12] = 0x00;
+ ip6->s6_addr[13] = 0x06;
+ ip6->s6_addr[14] = 0x00;
+ ip6->s6_addr[15] = 0x07;
+
+ /* Simulating ipv6 2001:DB8::6:6 */
+ debug_addr= & debug_sock_addr[1];
+ debug_addr->sin6_family= AF_INET6;
+ ip6= & debug_addr->sin6_addr;
+ ip6->s6_addr[ 0] = 0x20;
+ ip6->s6_addr[ 1] = 0x01;
+ ip6->s6_addr[ 2] = 0x0d;
+ ip6->s6_addr[ 3] = 0xb8;
+ ip6->s6_addr[ 4] = 0x00;
+ ip6->s6_addr[ 5] = 0x00;
+ ip6->s6_addr[ 6] = 0x00;
+ ip6->s6_addr[ 7] = 0x00;
+ ip6->s6_addr[ 8] = 0x00;
+ ip6->s6_addr[ 9] = 0x00;
+ ip6->s6_addr[10] = 0x00;
+ ip6->s6_addr[11] = 0x00;
+ ip6->s6_addr[12] = 0x00;
+ ip6->s6_addr[13] = 0x06;
+ ip6->s6_addr[14] = 0x00;
+ ip6->s6_addr[15] = 0x06;
+
+ debug_addr_info[0].ai_addr= (struct sockaddr*) & debug_sock_addr[0];
+ debug_addr_info[0].ai_addrlen= sizeof (struct sockaddr_in6);
+ debug_addr_info[0].ai_next= & debug_addr_info[1];
+
+ debug_addr_info[1].ai_addr= (struct sockaddr*) & debug_sock_addr[1];
+ debug_addr_info[1].ai_addrlen= sizeof (struct sockaddr_in6);
+ debug_addr_info[1].ai_next= NULL;
+
+ addr_info_list= & debug_addr_info[0];
+ err_code= 0;
+ free_addr_info_list= false;
+ }
+ );
+#endif /* HAVE_IPV6 */
+
+ /*
+ ===========================================================================
+ DEBUG code only (end)
+ ===========================================================================
+ */
+
+ if (err_code != 0)
+ {
+ sql_print_warning("Host name '%s' could not be resolved: %s",
+ (const char *) hostname_buffer,
+ (const char *) gai_strerror(err_code));
+
+ bool validated;
+
+ if (err_code == EAI_NONAME)
+ {
+ errors.m_addrinfo_permanent= 1;
+ validated= true;
+ }
+ else
+ {
+ /*
+ Don't cache responses when the DNS server is down, as otherwise
+ transient DNS failure may leave any number of clients (those
+ that attempted to connect during the outage) unable to connect
+ indefinitely.
+ Only cache error statistics.
+ */
+ errors.m_addrinfo_transient= 1;
+ validated= false;
+ }
+ add_hostname(ip_key, NULL, validated, &errors);
+
+ DBUG_RETURN(false);
+ }
+
+ /* Check that getaddrinfo() returned the used IP (FCrDNS technique). */
+
+ DBUG_PRINT("info", ("The following IP addresses found for '%s':",
+ (const char *) hostname_buffer));
+
+ for (struct addrinfo *addr_info= addr_info_list;
+ addr_info; addr_info= addr_info->ai_next)
+ {
+ char ip_buffer[HOST_ENTRY_KEY_SIZE];
+
+ {
+ err_status=
+ vio_get_normalized_ip_string(addr_info->ai_addr, (int)addr_info->ai_addrlen,
+ ip_buffer, sizeof (ip_buffer));
+ DBUG_ASSERT(!err_status);
+ }
+
+ DBUG_PRINT("info", (" - '%s'", (const char *) ip_buffer));
+
+ if (strcasecmp(ip_key, ip_buffer) == 0)
+ {
+ /* Copy host name string to be stored in the cache. */
+
+ *hostname= my_strdup(key_memory_host_cache_hostname,
+ hostname_buffer, MYF(0));
+
+ if (!*hostname)
+ {
+ DBUG_PRINT("error", ("Out of memory."));
+
+ if (free_addr_info_list)
+ freeaddrinfo(addr_info_list);
+ DBUG_RETURN(true);
+ }
+
+ break;
+ }
+ }
+
+ /* Log resolved IP-addresses if no match was found. */
+
+ if (!*hostname)
+ {
+ errors.m_FCrDNS= 1;
+
+ sql_print_warning("Hostname '%s' does not resolve to '%s'.",
+ (const char *) hostname_buffer,
+ (const char *) ip_key);
+ sql_print_information("Hostname '%s' has the following IP addresses:",
+ (const char *) hostname_buffer);
+
+ for (struct addrinfo *addr_info= addr_info_list;
+ addr_info; addr_info= addr_info->ai_next)
+ {
+ char ip_buffer[HOST_ENTRY_KEY_SIZE];
+
+ err_status=
+ vio_get_normalized_ip_string(addr_info->ai_addr, (int)addr_info->ai_addrlen,
+ ip_buffer, sizeof (ip_buffer));
+ DBUG_ASSERT(!err_status);
+
+ sql_print_information(" - %s", (const char *) ip_buffer);
+ }
+ }
+
+ /* Add an entry for the IP to the cache. */
+ add_hostname(ip_key, *hostname, true, &errors);
+
+ /* Free the result of getaddrinfo(). */
+ if (free_addr_info_list)
+ freeaddrinfo(addr_info_list);
+
+ DBUG_RETURN(false);
+}