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gethostbyname() will not attempt a DNS lookup if so enabled

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This commit is contained in:
Gregory Nutt 2015-07-10 13:30:09 -06:00
parent 4102470bdd
commit 7dec298ef3
10 changed files with 226 additions and 71 deletions
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4
include/nuttx/net/dnsclient.h
View File

@ -206,7 +206,11 @@ int dns_whois(FAR const char *name, FAR struct sockaddr_in *addr);
*
****************************************************************************/
#ifdef CONFIG_NETDB_DNSCLIENT_IPv6
int dns_gethostip(FAR const char *hostname, FAR struct in6_addr *ipaddr);
#else
int dns_gethostip(FAR const char *hostname, FAR in_addr_t *ipaddr);
#endif
#undef EXTERN
#if defined(__cplusplus)

6
libc/Kconfig
View File

@ -513,6 +513,9 @@ menuconfig NETDB_HOSTFILE
default n
depends on FS_READABLE
select LIBC_NETDB
---help---
Enable network host table look ups via gethostbyname() and
gethostbyaddr().
if NETDB_HOSTFILE
@ -536,7 +539,8 @@ config NETDB_DNSCLIENT
depends on NET && NET_UDP
select LIBC_NETDB
---help---
Enable support for the name resolution.
Enable support for the name resolution; Enable network host
resolution via gethostbyname().
if NETDB_DNSCLIENT

1
libc/lib_internal.h
View File

@ -219,6 +219,7 @@ float lib_sqrtapprox(float x);
/* Defined in lib_parsehostfile.c */
#ifdef CONFIG_NETDB_HOSTFILE
struct hostent;
ssize_t lib_parse_hostfile(FAR FILE *stream, FAR struct hostent *host,
FAR char *buf, size_t buflen);
#endif

7
libc/net/Make.defs
View File

@ -44,13 +44,6 @@ ifeq ($(CONFIG_NET_ROUTE),y)
CSRCS += lib_addroute.c lib_delroute.c
endif
# netdb support
ifeq ($(CONFIG_NETDB_HOSTFILE),y)
CSRCS += lib_netdb.c lib_gethostbyname.c lib_gethostbynamer.c
CSRCS += lib_gethostbyaddr.c lib_gethostbyaddrr.c lib_parsehostfile.c
endif
# Add the net directory to the build
DEPPATH += --dep-path net

13
libc/netdb/Make.defs
View File

@ -37,17 +37,22 @@ ifeq ($(CONFIG_LIBC_NETDB),y)
# Add the netdb C files to the build
CSRCS += lib_netdb.c
# Add host file support
ifeq ($(CONFIG_NETDB_HOSTFILE),y)
CSRCS += lib_netdb.c lib_gethostbyname.c lib_gethostbynamer.c
CSRCS += lib_gethostbyaddr.c lib_gethostbyaddrr.c lib_parsehostfile.c
CSRCS += lib_gethostbyname.c lib_gethostbynamer.c lib_gethostbyaddr.c
CSRCS += lib_gethostbyaddrr.c lib_parsehostfile.c
endif
# Add DNS support
# Add DNS lookup support
ifeq ($(CONFIG_NETDB_DNSCLIENT),y)
CSRCS = dns_resolver.c dns_socket.c dns_gethostip.c
ifneq ($(CONFIG_NETDB_HOSTFILE),y)
CSRCS += lib_gethostbyname.c lib_gethostbynamer.c
endif
CSRCS += dns_resolver.c dns_socket.c dns_gethostip.c
endif
# Add the net directory to the build

4
libc/netdb/dns_gethostip.c
View File

@ -75,7 +75,11 @@
*
****************************************************************************/
#ifdef CONFIG_NETDB_DNSCLIENT_IPv6
int dns_gethostip(FAR const char *hostname, FAR struct in6_addr *ipaddr)
#else
int dns_gethostip(FAR const char *hostname, FAR in_addr_t *ipaddr)
#endif
{
int sockfd = -1;
int ret=ERROR;

4
libc/netdb/lib_gethostbyname.c
View File

@ -45,7 +45,7 @@
#include "lib_internal.h"
#include "netdb/lib_netdb.h"
#ifdef CONFIG_NETDB_HOSTFILE
#ifdef CONFIG_LIBC_NETDB
/****************************************************************************
* Public Functions
@ -89,4 +89,4 @@ FAR struct hostent *gethostbyname(FAR const char *name)
return ret == 0 ? &g_hostent : NULL;
}
#endif /* CONFIG_NETDB_HOSTFILE */
#endif /* CONFIG_LIBC_NETDB */

242
libc/netdb/lib_gethostbynamer.c
View File

@ -47,9 +47,11 @@
#include <arpa/inet.h>
#include <nuttx/net/dnsclient.h>
#include "lib_internal.h"
#ifdef CONFIG_NETDB_HOSTFILE
#ifdef CONFIG_LIBC_NETDB
/****************************************************************************
* Pre-processor Definitions
@ -189,71 +191,120 @@ static int lib_numeric_address(FAR const char *name, FAR struct hostent *host,
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: gethostname_r
* Name: lib_dns_lookup
*
* Description:
* The gethostbyname_r() function returns a structure of type hostent for
* the given host name. Here name is either a hostname, or an IPv4 address
* in standard dot notation (as for inet_addr(3)), or an IPv6 address in
* colon (and possibly dot) notation.
* Try to look-up the host name from the DNS server
*
* If name is an IPv4 or IPv6 address, no lookup is performed and
* gethostbyname_r() simply copies name into the h_name field
* and its struct in_addr equivalent into the h_addr_list[0] field of the
* returned hostent structure.
*
* gethostname_r() is *not* POSIX but is similar to a Glibc extension and is
* used internally by NuttX to implement the POSIX gethostname().
*
* Input Parameters:
* Input paramters:
* name - The name of the host to find.
* host - Caller provided location to return the host data.
* buf - Caller provided buffer to hold string data associated with the
* host data.
* buflen - The size of the caller-provided buffer
* h_errnop - There h_errno value returned in the event of a failure.
*
* Returned Value:
* Zero (OK) is returned on success, -1 (ERROR) is returned on a failure
* with the returned h_errno value provided the reason for the failure.
* Zero (0) is returned if the DNS lookup was successful.
*
****************************************************************************/
int gethostbyname_r(FAR const char *name, FAR struct hostent *host,
FAR char *buf, size_t buflen, int *h_errnop)
#ifdef CONFIG_NETDB_DNSCLIENT
static int lib_dns_lookup(FAR const char *name, FAR struct hostent *host,
FAR char *buf, size_t buflen)
{
FAR struct hostent_info_s *info;
FAR char *ptr;
size_t addrlen;
int addrtype;
int namelen;
int ret;
/* Verify that we have a buffer big enough to get started (it still may not
* be big enough).
*/
if (buflen <= sizeof(struct hostent_info_s))
{
return -ERANGE;
}
/* Initialize buffers */
info = (FAR struct hostent_info_s *)buf;
ptr = info->hi_data;
buflen -= (sizeof(struct hostent_info_s) - 1);
memset(host, 0, sizeof(struct hostent));
memset(info, 0, sizeof(struct hostent_info_s));
/* Try to get the host address using the DNS name server */
#ifdef CONFIG_NETDB_DNSCLIENT_IPv6
addrlen = sizeof(struct in6_addr);
addrtype = AF_INET6;
ret = dns_gethostip(name, (FAR struct in6_addr *)ptr);
#else
addrlen = sizeof(struct in6_addr);
addrtype = AF_INET;
ret = dns_gethostip(name, (FAR in_addr_t *)ptr);
#endif
/* Was the DNS lookup successful? */
if (ret >= 0)
{
/* Yes.. Return the address that we obtained from the DNS name server. */
info->hi_addrlist[0] = ptr;
host->h_addr_list = info->hi_addrlist;
host->h_addrtype = addrtype;
host->h_length = addrlen;
ptr += addrlen;
buflen -= addrlen;
/* And copy name */
namelen = strlen(name);
if (addrlen + namelen + 1 > buflen)
{
return -ERANGE;
}
strncpy(ptr, name, buflen);
return OK;
}
return ret;
}
#endif /* CONFIG_NETDB_DNSCLIENT */
/****************************************************************************
* Name: lib_hostfile_lookup
*
* Description:
* Try to look-up the host name from the network host file
*
* Input paramters:
* name - The name of the host to find.
* host - Caller provided location to return the host data.
* buf - Caller provided buffer to hold string data associated with the
* host data.
* buflen - The size of the caller-provided buffer
*
* Returned Value:
* Zero (0) is returned if the DNS lookup was successful.
*
****************************************************************************/
#ifdef CONFIG_NETDB_HOSTFILE
static int lib_hostfile_lookup(FAR const char *name, FAR struct hostent *host,
FAR char *buf, size_t buflen, int *h_errnop)
{
FAR FILE *stream;
int herrnocode;
int nread;
DEBUGASSERT(name != NULL && host != NULL && buf != NULL);
/* Make sure that the h_errno has a non-error code */
if (h_errnop)
{
*h_errnop = 0;
}
/* Check for a numeric hostname */
if (lib_numeric_address(name, host, buf, buflen) == 0)
{
/* Yes.. we are done */
return OK;
}
/* Try to find the name in the HOSTALIASES environment variable */
/* REVISIT: Not implemented */
/* Try to get the host address using the DNS name server */
/* REVISIT: Not implemented */
/* Search the hosts file for a match */
stream = fopen(CONFIG_NETDB_HOSTCONF_PATH, "r");
@ -352,5 +403,98 @@ errorout_with_herrnocode:
return ERROR;
}
#endif /* CONFIG_NETDB_HOSTFILE */
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: gethostname_r
*
* Description:
* The gethostbyname_r() function returns a structure of type hostent for
* the given host name. Here name is either a hostname, or an IPv4 address
* in standard dot notation (as for inet_addr(3)), or an IPv6 address in
* colon (and possibly dot) notation.
*
* If name is an IPv4 or IPv6 address, no lookup is performed and
* gethostbyname_r() simply copies name into the h_name field
* and its struct in_addr equivalent into the h_addr_list[0] field of the
* returned hostent structure.
*
* gethostname_r() is *not* POSIX but is similar to a Glibc extension and is
* used internally by NuttX to implement the POSIX gethostname().
*
* Input Parameters:
* name - The name of the host to find.
* host - Caller provided location to return the host data.
* buf - Caller provided buffer to hold string data associated with the
* host data.
* buflen - The size of the caller-provided buffer
* h_errnop - There h_errno value returned in the event of a failure.
*
* Returned Value:
* Zero (OK) is returned on success, -1 (ERROR) is returned on a failure
* with the returned h_errno value provided the reason for the failure.
*
****************************************************************************/
int gethostbyname_r(FAR const char *name, FAR struct hostent *host,
FAR char *buf, size_t buflen, int *h_errnop)
{
int ret;
DEBUGASSERT(name != NULL && host != NULL && buf != NULL);
/* Make sure that the h_errno has a non-error code */
if (h_errnop)
{
*h_errnop = 0;
}
/* Check for a numeric hostname */
if (lib_numeric_address(name, host, buf, buflen) == 0)
{
/* Yes.. we are done */
return OK;
}
/* Try to find the name in the HOSTALIASES environment variable */
/* REVISIT: Not implemented */
#ifdef CONFIG_NETDB_DNSCLIENT
/* Try to get the host address using the DNS name server */
ret = lib_dns_lookup(name, host, buf, buflen);
if (ret >= 0)
{
/* Successful DNS lookup! */
return OK;
}
#endif /* CONFIG_NETDB_DNSCLIENT */
#ifdef CONFIG_NETDB_HOSTFILE
/* Search the hosts file for a match */
return lib_hostfile_lookup(name, host, buf, buflen, h_errnop);
#else
/* The host file file is not supported. The host name mapping was not
* found from any lookup heuristic
*/
if (h_errnop)
{
*h_errnop = HOST_NOT_FOUND;
}
return ERROR;
#endif
}
#endif /* CONFIG_LIBC_NETDB */

4
libc/netdb/lib_netdb.c
View File

@ -43,7 +43,7 @@
#include "netdb/lib_netdb.h"
#ifdef CONFIG_NETDB_HOSTFILE
#ifdef CONFIG_LIBC_NETDB
/****************************************************************************
* Public Data
@ -56,4 +56,4 @@ char g_hostbuffer[CONFIG_NETDB_BUFSIZE];
* Public Functions
****************************************************************************/
#endif /* CONFIG_NETDB_HOSTFILE */
#endif /* CONFIG_LIBC_NETDB */

12
libc/netdb/lib_netdb.h
View File

@ -1,5 +1,5 @@
/****************************************************************************
* libc/netdb/lib_netdb.h
* libc/net/lib_netdb.h
*
* Copyright (C) 2015 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
@ -33,8 +33,8 @@
*
****************************************************************************/
#ifndef __LIBC_NET_LIB_NETDB_H
#define __LIBC_NET_LIB_NETDB_H
#ifndef __LIBC_NETDB_LIB_NETDB_H
#define __LIBC_NETDB_LIB_NETDB_H
/****************************************************************************
* Included Files
@ -44,7 +44,7 @@
#include <netdb.h>
#ifdef CONFIG_NETDB_HOSTFILE
#ifdef CONFIG_LIBC_NETDB
/****************************************************************************
* Pre-processor Definitions
@ -94,5 +94,5 @@ EXTERN char g_hostbuffer[CONFIG_NETDB_BUFSIZE];
}
#endif
#endif /* __INCLUDE_NETDB_H */
#endif /* __LIBC_NET_LIB_NETDB_H */
#endif /* CONFIG_LIBC_NETDB */
#endif /* __LIBC_NETDB_LIB_NETDB_H */