telnetd/libtelnet/getaddrinfo.c
Stephen Heumann 9bab5c3dec Add an implementation of getaddrinfo and getnameinfo, which are missing in GNO.
These are adapted from a version in netperf.
2015-05-31 16:56:05 -05:00

546 lines
12 KiB
C

/*
* Copyright (c) 2001, 02 Motoyuki Kasahara
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* This program provides getaddrinfo() and getnameinfo() described in
* RFC2133, 2553 and 3493. These functions are mainly used for IPv6
* application to resolve hostname or address.
*
* This program is designed to be working on traditional IPv4 systems
* which don't have those functions. Therefore, this implementation
* supports IPv4 only.
*
* This program is useful for application which should support both IPv6
* and traditional IPv4 systems. Use genuine getaddrinfo() and getnameinfo()
* provided by system if the system supports IPv6. Otherwise, use this
* implementation.
*
* This program is intended to be used in combination with GNU Autoconf.
*
* This program also provides freeaddrinfo() and gai_strerror().
*
* To use this program in your application, insert the following lines to
* C source files after including `sys/types.h', `sys/socket.h' and
* `netdb.h'. `getaddrinfo.h' defines `struct addrinfo' and AI_, NI_,
* EAI_ macros.
*
* #ifndef HAVE_GETADDRINFO
* #include "getaddrinfo.h"
* #endif
*
* Restriction:
* getaddrinfo() and getnameinfo() of this program are NOT thread
* safe, unless the cpp macro ENABLE_PTHREAD is defined.
*/
#ifdef __GNO__
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <sys/types.h>
#include <stdio.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <string.h>
#include <stdlib.h>
#ifdef ENABLE_PTHREAD
#include <pthread.h>
#endif
#ifdef ENABLE_NLS
#include <libintl.h>
#endif
extern int h_errno;
#include "getaddrinfo.h"
#ifdef ENABLE_NLS
#define _(string) gettext(string)
#ifdef gettext_noop
#define N_(string) gettext_noop(string)
#else
#define N_(string) (string)
#endif
#else
#define gettext(string) (string)
#define _(string) (string)
#define N_(string) (string)
#endif
/*
* Error messages for gai_strerror().
*/
static char *eai_errlist[] = {
N_("Success"),
/* EAI_ADDRFAMILY */
N_("Address family for hostname not supported"),
/* EAI_AGAIN */
N_("Temporary failure in name resolution"),
/* EAI_BADFLAGS */
N_("Invalid value for ai_flags"),
/* EAI_FAIL */
N_("Non-recoverable failure in name resolution"),
/* EAI_FAMILY */
N_("ai_family not supported"),
/* EAI_MEMORY */
N_("Memory allocation failure"),
/* EAI_NONAME */
N_("hostname nor servname provided, or not known"),
/* EAI_OVERFLOW */
N_("An argument buffer overflowed"),
/* EAI_SERVICE */
N_("servname not supported for ai_socktype"),
/* EAI_SOCKTYPE */
N_("ai_socktype not supported"),
/* EAI_SYSTEM */
N_("System error returned in errno")
};
/*
* Default hints for getaddrinfo().
*/
static struct addrinfo default_hints = {
0, PF_UNSPEC, 0, 0, 0, NULL, NULL, NULL
};
/*
* Mutex.
*/
#ifdef ENABLE_PTHREAD
static pthread_mutex_t gai_mutex = PTHREAD_MUTEX_INITIALIZER;
#endif
/*
* Declaration of static functions.
*/
static int is_integer(const char *);
static int is_address(const char *);
static int itoa_length(int);
/*
* gai_strerror().
*/
const char *
gai_strerror(int ecode)
{
if (ecode < 0 || ecode > EAI_SYSTEM)
return _("Unknown error");
return gettext(eai_errlist[ecode]);
}
/*
* freeaddrinfo().
*/
void
freeaddrinfo(struct addrinfo *ai)
{
struct addrinfo *next_ai;
while (ai != NULL) {
if (ai->ai_canonname != NULL)
free(ai->ai_canonname);
if (ai->ai_addr != NULL)
free(ai->ai_addr);
next_ai = ai->ai_next;
free(ai);
ai = next_ai;
}
}
/*
* Return 1 if the string `s' represents an integer.
*/
static int
is_integer(const char *s)
{
if (*s == '-' || *s == '+')
s++;
if (*s < '0' || '9' < *s)
return 0;
s++;
while ('0' <= *s && *s <= '9')
s++;
return (*s == '\0');
}
/*
* Return 1 if the string `s' represents an IPv4 address.
* Unlike inet_addr(), it doesn't permit malformed nortation such
* as "192.168".
*/
static int
is_address(const char *s)
{
const static char delimiters[] = {'.', '.', '.', '\0'};
int i, j;
int octet;
for (i = 0; i < 4; i++) {
if (*s == '0' && *(s + 1) != delimiters[i])
return 0;
for (j = 0, octet = 0; '0' <= *s && *s <= '9' && j < 3; s++, j++)
octet = octet * 10 + (*s - '0');
if (j == 0 || octet > 255 || *s != delimiters[i])
return 0;
s++;
}
return 1;
}
/*
* Calcurate length of the string `s', where `s' is set by
* sprintf(s, "%d", n).
*/
static int
itoa_length(int n)
{
int result = 1;
if (n < 0) {
n = -n;
result++;
}
while (n >= 10) {
result++;
n /= 10;
}
return result;
}
/*
* getaddrinfo().
*/
int
getaddrinfo(
const char *nodename,
const char *servname,
const struct addrinfo *hints,
struct addrinfo **res
)
{
struct addrinfo *head_res = NULL;
struct addrinfo *tail_res = NULL;
struct addrinfo *new_res;
struct sockaddr_in *sa_in;
struct in_addr **addr_list;
struct in_addr *addr_list_buf[2];
struct in_addr addr_buf;
struct in_addr **ap;
struct servent *servent;
struct hostent *hostent;
const char *canonname = NULL;
in_port_t port;
int saved_h_errno;
int result = 0;
#ifdef ENABLE_PTHREAD
pthread_mutex_lock(&gai_mutex);
#endif
saved_h_errno = h_errno;
if (nodename == NULL && servname == NULL) {
result = EAI_NONAME;
goto end;
}
if (hints != NULL) {
if (hints->ai_family != PF_INET && hints->ai_family != PF_UNSPEC) {
result = EAI_FAMILY;
goto end;
}
if (hints->ai_socktype != SOCK_DGRAM
&& hints->ai_socktype != SOCK_STREAM
&& hints->ai_socktype != 0) {
result = EAI_SOCKTYPE;
goto end;
}
} else {
hints = &default_hints;
}
if (servname != NULL) {
if (is_integer(servname))
port = htons(atoi(servname));
else {
if (hints->ai_flags & AI_NUMERICSERV) {
result = EAI_NONAME;
goto end;
}
if (hints->ai_socktype == SOCK_DGRAM)
servent = getservbyname(servname, "udp");
else if (hints->ai_socktype == SOCK_STREAM)
servent = getservbyname(servname, "tcp");
else if (hints->ai_socktype == 0)
servent = getservbyname(servname, "tcp");
else {
result = EAI_SOCKTYPE;
goto end;
}
if (servent == NULL) {
result = EAI_SERVICE;
goto end;
}
port = servent->s_port;
}
} else {
port = htons(0);
}
if (nodename != NULL) {
if (is_address(nodename)) {
addr_buf.s_addr = inet_addr(nodename);
addr_list_buf[0] = &addr_buf;
addr_list_buf[1] = NULL;
addr_list = addr_list_buf;
if (hints->ai_flags & AI_CANONNAME
&& !(hints->ai_flags & AI_NUMERICHOST)) {
hostent = gethostbyaddr((char *)&addr_buf,
sizeof(struct in_addr), AF_INET);
if (hostent != NULL)
canonname = hostent->h_name;
else
canonname = nodename;
}
} else {
if (hints->ai_flags & AI_NUMERICHOST) {
result = EAI_NONAME;
goto end;
}
hostent = gethostbyname(nodename);
if (hostent == NULL) {
switch (h_errno) {
case HOST_NOT_FOUND:
case NO_DATA:
result = EAI_NONAME;
goto end;
case TRY_AGAIN:
result = EAI_AGAIN;
goto end;
default:
result = EAI_FAIL;
goto end;
}
}
addr_list = (struct in_addr **)hostent->h_addr_list;
if (hints->ai_flags & AI_CANONNAME)
canonname = hostent->h_name;
}
} else {
if (hints->ai_flags & AI_PASSIVE)
addr_buf.s_addr = htonl(INADDR_ANY);
else
addr_buf.s_addr = htonl(0x7F000001);
addr_list_buf[0] = &addr_buf;
addr_list_buf[1] = NULL;
addr_list = addr_list_buf;
}
for (ap = addr_list; *ap != NULL; ap++) {
new_res = (struct addrinfo *)malloc(sizeof(struct addrinfo));
if (new_res == NULL) {
if (head_res != NULL)
freeaddrinfo(head_res);
result = EAI_MEMORY;
goto end;
}
new_res->ai_family = PF_INET;
new_res->ai_socktype = hints->ai_socktype;
new_res->ai_protocol = hints->ai_protocol;
new_res->ai_addr = NULL;
new_res->ai_addrlen = sizeof(struct sockaddr_in);
new_res->ai_canonname = NULL;
new_res->ai_next = NULL;
new_res->ai_addr = (struct sockaddr *)
malloc(sizeof(struct sockaddr_in));
if (new_res->ai_addr == NULL) {
free(new_res);
if (head_res != NULL)
freeaddrinfo(head_res);
result = EAI_MEMORY;
goto end;
}
sa_in = (struct sockaddr_in *)new_res->ai_addr;
memset(sa_in, 0, sizeof(struct sockaddr_in));
sa_in->sin_family = PF_INET;
sa_in->sin_port = port;
memcpy(&sa_in->sin_addr, *ap, sizeof(struct in_addr));
if (head_res == NULL)
head_res = new_res;
else
tail_res->ai_next = new_res;
tail_res = new_res;
}
if (canonname != NULL && head_res != NULL) {
head_res->ai_canonname = (char *)malloc(strlen(canonname) + 1);
if (head_res->ai_canonname != NULL)
strcpy(head_res->ai_canonname, canonname);
}
*res = head_res;
end:
h_errno = saved_h_errno;
#ifdef ENABLE_PTHREAD
pthread_mutex_unlock(&gai_mutex);
#endif
return result;
}
/*
* getnameinfo().
*/
int
getnameinfo(
const struct sockaddr *sa,
socklen_t salen,
char *node,
socklen_t nodelen,
char *serv,
socklen_t servlen,
int flags
)
{
const struct sockaddr_in *sa_in = (const struct sockaddr_in *)sa;
struct hostent *hostent;
struct servent *servent;
char *ntoa_address;
int saved_h_errno;
int result = 0;
#ifdef ENABLE_PTHREAD
pthread_mutex_lock(&gai_mutex);
#endif
saved_h_errno = h_errno;
if (sa_in->sin_family != PF_INET) {
result = EAI_FAMILY;
goto end;
} else if (node == NULL && serv == NULL) {
result = EAI_NONAME;
goto end;
}
if (serv != NULL && servlen > 0) {
if (flags & NI_NUMERICSERV)
servent = NULL;
else if (flags & NI_DGRAM)
servent = getservbyport(sa_in->sin_port, "udp");
else
servent = getservbyport(sa_in->sin_port, "tcp");
if (servent != NULL) {
if (servlen <= strlen(servent->s_name)) {
result = EAI_OVERFLOW;
goto end;
}
strcpy(serv, servent->s_name);
} else {
if (servlen <= itoa_length(ntohs(sa_in->sin_port))) {
result = EAI_OVERFLOW;
goto end;
}
sprintf(serv, "%d", ntohs(sa_in->sin_port));
}
}
if (node != NULL && nodelen > 0) {
if (flags & NI_NUMERICHOST)
hostent = NULL;
else {
hostent = gethostbyaddr((char *)&sa_in->sin_addr,
sizeof(struct in_addr), AF_INET);
}
if (hostent != NULL) {
if (nodelen <= strlen(hostent->h_name)) {
result = EAI_OVERFLOW;
goto end;
}
strcpy(node, hostent->h_name);
} else {
if (flags & NI_NAMEREQD) {
result = EAI_NONAME;
goto end;
}
ntoa_address = inet_ntoa(sa_in->sin_addr);
if (nodelen <= strlen(ntoa_address)) {
result = EAI_OVERFLOW;
goto end;
}
strcpy(node, ntoa_address);
}
}
end:
h_errno = saved_h_errno;
#ifdef ENABLE_PTHREAD
pthread_mutex_unlock(&gai_mutex);
#endif
return result;
}
#endif