/*
* Copyright (C) 1999-2001, 2004-2008, 2012, 2014, 2016 Internet Systems Consortium, Inc. ("ISC")
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* This code is derived from software contributed to ISC by
* Berkeley Software Design, Inc.
*
* 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 AND BERKELEY SOFTWARE DESIGN, INC.
* 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: getaddrinfo.c,v 1.54 2008/11/25 23:47:23 tbox Exp $ */
/*! \file */
/**
* lwres_getaddrinfo() is used to get a list of IP addresses and port
* numbers for host hostname and service servname. The function is the
* lightweight resolver's implementation of getaddrinfo() as defined in
* RFC2133. hostname and servname are pointers to null-terminated strings
* or NULL. hostname is either a host name or a numeric host address
* string: a dotted decimal IPv4 address or an IPv6 address. servname is
* either a decimal port number or a service name as listed in
* /etc/services.
*
* If the operating system does not provide a struct addrinfo, the
* following structure is used:
*
* \code
* struct addrinfo {
* int ai_flags; // AI_PASSIVE, AI_CANONNAME
* int ai_family; // PF_xxx
* int ai_socktype; // SOCK_xxx
* int ai_protocol; // 0 or IPPROTO_xxx for IPv4 and IPv6
* size_t ai_addrlen; // length of ai_addr
* char *ai_canonname; // canonical name for hostname
* struct sockaddr *ai_addr; // binary address
* struct addrinfo *ai_next; // next structure in linked list
* };
* \endcode
*
*
* hints is an optional pointer to a struct addrinfo. This structure can
* be used to provide hints concerning the type of socket that the caller
* supports or wishes to use. The caller can supply the following
* structure elements in *hints:
*
* <ul>
* <li>ai_family:
* The protocol family that should be used. When ai_family is set
* to PF_UNSPEC, it means the caller will accept any protocol
* family supported by the operating system.</li>
*
* <li>ai_socktype:
* denotes the type of socket -- SOCK_STREAM, SOCK_DGRAM or
* SOCK_RAW -- that is wanted. When ai_socktype is zero the caller
* will accept any socket type.</li>
*
* <li>ai_protocol:
* indicates which transport protocol is wanted: IPPROTO_UDP or
* IPPROTO_TCP. If ai_protocol is zero the caller will accept any
* protocol.</li>
*
* <li>ai_flags:
* Flag bits. If the AI_CANONNAME bit is set, a successful call to
* lwres_getaddrinfo() will return a null-terminated string
* containing the canonical name of the specified hostname in
* ai_canonname of the first addrinfo structure returned. Setting
* the AI_PASSIVE bit indicates that the returned socket address
* structure is intended for used in a call to bind(2). In this
* case, if the hostname argument is a NULL pointer, then the IP
* address portion of the socket address structure will be set to
* INADDR_ANY for an IPv4 address or IN6ADDR_ANY_INIT for an IPv6
* address.<br /><br />
*
* When ai_flags does not set the AI_PASSIVE bit, the returned
* socket address structure will be ready for use in a call to
* connect(2) for a connection-oriented protocol or connect(2),
* sendto(2), or sendmsg(2) if a connectionless protocol was
* chosen. The IP address portion of the socket address structure
* will be set to the loopback address if hostname is a NULL
* pointer and AI_PASSIVE is not set in ai_flags.<br /><br />
*
* If ai_flags is set to AI_NUMERICHOST it indicates that hostname
* should be treated as a numeric string defining an IPv4 or IPv6
* address and no name resolution should be attempted.
* </li></ul>
*
* All other elements of the struct addrinfo passed via hints must be
* zero.
*
* A hints of NULL is treated as if the caller provided a struct addrinfo
* initialized to zero with ai_familyset to PF_UNSPEC.
*
* After a successful call to lwres_getaddrinfo(), *res is a pointer to a
* linked list of one or more addrinfo structures. Each struct addrinfo
* in this list cn be processed by following the ai_next pointer, until a
* NULL pointer is encountered. The three members ai_family, ai_socktype,
* and ai_protocol in each returned addrinfo structure contain the
* corresponding arguments for a call to socket(2). For each addrinfo
* structure in the list, the ai_addr member points to a filled-in socket
* address structure of length ai_addrlen.
*
* All of the information returned by lwres_getaddrinfo() is dynamically
* allocated: the addrinfo structures, and the socket address structures
* and canonical host name strings pointed to by the addrinfostructures.
* Memory allocated for the dynamically allocated structures created by a
* successful call to lwres_getaddrinfo() is released by
* lwres_freeaddrinfo(). ai is a pointer to a struct addrinfo created by
* a call to lwres_getaddrinfo().
*
* \section lwresreturn RETURN VALUES
*
* lwres_getaddrinfo() returns zero on success or one of the error codes
* listed in gai_strerror() if an error occurs. If both hostname and
* servname are NULL lwres_getaddrinfo() returns #EAI_NONAME.
*
* \section lwressee SEE ALSO
*
* lwres(3), lwres_getaddrinfo(), lwres_freeaddrinfo(),
* lwres_gai_strerror(), RFC2133, getservbyname(3), connect(2),
* sendto(2), sendmsg(2), socket(2).
*/
#include <config.h>
#include <errno.h>
#include <string.h>
#include <lwres/lwres.h>
#include <lwres/net.h>
#include <lwres/netdb.h>
#include <lwres/stdlib.h>
#include <lwres/string.h>
#define SA(addr) ((struct sockaddr *)(addr))
#define SIN(addr) ((struct sockaddr_in *)(addr))
#define SIN6(addr) ((struct sockaddr_in6 *)(addr))
#define SLOCAL(addr) ((struct sockaddr_un *)(addr))
/*! \struct addrinfo
*/
static struct addrinfo
*ai_reverse(struct addrinfo *oai),
*ai_clone(struct addrinfo *oai, int family),
*ai_alloc(int family, int addrlen);
#ifdef AF_LOCAL
static int get_local(const char *name, int socktype, struct addrinfo **res);
#endif
static int add_ipv4(const char *hostname, int flags, struct addrinfo **aip,
int socktype, int port);
static int add_ipv6(const char *hostname, int flags, struct addrinfo **aip,
int socktype, int port);
static void set_order(int, int (**)(const char *, int, struct addrinfo **,
int, int));
#define FOUND_IPV4 0x1
#define FOUND_IPV6 0x2
#define FOUND_MAX 2
#define ISC_AI_MASK (AI_PASSIVE|AI_CANONNAME|AI_NUMERICHOST)
/*% Get a list of IP addresses and port numbers for host hostname and service servname. */
int
lwres_getaddrinfo(const char *hostname, const char *servname,
const struct addrinfo *hints, struct addrinfo **res)
{
struct servent *sp;
const char *proto;
int family, socktype, flags, protocol;
struct addrinfo *ai, *ai_list;
int port, err, i;
int (*net_order[FOUND_MAX+1])(const char *, int, struct addrinfo **,
int, int);
if (hostname == NULL && servname == NULL)
return (EAI_NONAME);
proto = NULL;
if (hints != NULL) {
if ((hints->ai_flags & ~(ISC_AI_MASK)) != 0)
return (EAI_BADFLAGS);
if (hints->ai_addrlen || hints->ai_canonname ||
hints->ai_addr || hints->ai_next) {
errno = EINVAL;
return (EAI_SYSTEM);
}
family = hints->ai_family;
socktype = hints->ai_socktype;
protocol = hints->ai_protocol;
flags = hints->ai_flags;
switch (family) {
case AF_UNSPEC:
switch (hints->ai_socktype) {
case SOCK_STREAM:
proto = "tcp";
break;
case SOCK_DGRAM:
proto = "udp";
break;
}
break;
case AF_INET:
case AF_INET6:
switch (hints->ai_socktype) {
case 0:
break;
case SOCK_STREAM:
proto = "tcp";
break;
case SOCK_DGRAM:
proto = "udp";
break;
case SOCK_RAW:
break;
default:
return (EAI_SOCKTYPE);
}
break;
#ifdef AF_LOCAL
case AF_LOCAL:
switch (hints->ai_socktype) {
case 0:
break;
case SOCK_STREAM:
break;
case SOCK_DGRAM:
break;
default:
return (EAI_SOCKTYPE);
}
break;
#endif
default:
return (EAI_FAMILY);
}
} else {
protocol = 0;
family = 0;
socktype = 0;
flags = 0;
}
#ifdef AF_LOCAL
/*!
* First, deal with AF_LOCAL. If the family was not set,
* then assume AF_LOCAL if the first character of the
* hostname/servname is '/'.
*/
if (hostname != NULL &&
(family == AF_LOCAL || (family == 0 && *hostname == '/')))
return (get_local(hostname, socktype, res));
if (servname != NULL &&
(family == AF_LOCAL || (family == 0 && *servname == '/')))
return (get_local(servname, socktype, res));
#endif
/*
* Ok, only AF_INET and AF_INET6 left.
*/
ai_list = NULL;
/*
* First, look up the service name (port) if it was
* requested. If the socket type wasn't specified, then
* try and figure it out.
*/
if (servname != NULL) {
char *e;
port = strtol(servname, &e, 10);
if (*e == '\0') {
if (socktype == 0)
return (EAI_SOCKTYPE);
if (port < 0 || port > 65535)
return (EAI_SERVICE);
port = htons((unsigned short) port);
} else {
sp = getservbyname(servname, proto);
if (sp == NULL)
return (EAI_SERVICE);
port = sp->s_port;
if (socktype == 0) {
if (strcmp(sp->s_proto, "tcp") == 0)
socktype = SOCK_STREAM;
else if (strcmp(sp->s_proto, "udp") == 0)
socktype = SOCK_DGRAM;
}
}
} else
port = 0;
/*
* Next, deal with just a service name, and no hostname.
* (we verified that one of them was non-null up above).
*/
if (hostname == NULL && (flags & AI_PASSIVE) != 0) {
if (family == AF_INET || family == 0) {
ai = ai_alloc(AF_INET, sizeof(struct sockaddr_in));
if (ai == NULL)
return (EAI_MEMORY);
ai->ai_socktype = socktype;
ai->ai_protocol = protocol;
SIN(ai->ai_addr)->sin_port = port;
ai->ai_next = ai_list;
ai_list = ai;
}
if (family == AF_INET6 || family == 0) {
ai = ai_alloc(AF_INET6, sizeof(struct sockaddr_in6));
if (ai == NULL) {
lwres_freeaddrinfo(ai_list);
return (EAI_MEMORY);
}
ai->ai_socktype = socktype;
ai->ai_protocol = protocol;
SIN6(ai->ai_addr)->sin6_port = port;
ai->ai_next = ai_list;
ai_list = ai;
}
*res = ai_list;
return (0);
}
/*
* If the family isn't specified or AI_NUMERICHOST specified,
* check first to see if it is a numeric address.
* Though the gethostbyname2() routine
* will recognize numeric addresses, it will only recognize
* the format that it is being called for. Thus, a numeric
* AF_INET address will be treated by the AF_INET6 call as
* a domain name, and vice versa. Checking for both numerics
* here avoids that.
*/
if (hostname != NULL &&
(family == 0 || (flags & AI_NUMERICHOST) != 0)) {
char abuf[sizeof(struct in6_addr)];
char nbuf[NI_MAXHOST];
int addrsize, addroff;
#ifdef LWRES_HAVE_SIN6_SCOPE_ID
char *p, *ep;
char ntmp[NI_MAXHOST];
lwres_uint32_t scopeid;
#endif
#ifdef LWRES_HAVE_SIN6_SCOPE_ID
/*
* Scope identifier portion.
*/
ntmp[0] = '\0';
if (strchr(hostname, '%') != NULL) {
strncpy(ntmp, hostname, sizeof(ntmp) - 1);
ntmp[sizeof(ntmp) - 1] = '\0';
p = strchr(ntmp, '%');
ep = NULL;
/*
* Vendors may want to support non-numeric
* scopeid around here.
*/
if (p != NULL)
scopeid = (lwres_uint32_t)strtoul(p + 1,
&ep, 10);
if (p != NULL && ep != NULL && ep[0] == '\0')
*p = '\0';
else {
ntmp[0] = '\0';
scopeid = 0;
}
} else
scopeid = 0;
#endif
if (lwres_net_pton(AF_INET, hostname, (struct in_addr *)abuf)
== 1)
{
if (family == AF_INET6) {
/*
* Convert to a V4 mapped address.
*/
struct in6_addr *a6 = (struct in6_addr *)abuf;
memmove(&a6->s6_addr[12], &a6->s6_addr[0], 4);
memset(&a6->s6_addr[10], 0xff, 2);
memset(&a6->s6_addr[0], 0, 10);
goto inet6_addr;
}
addrsize = sizeof(struct in_addr);
addroff = offsetof(struct sockaddr_in, sin_addr);
family = AF_INET;
goto common;
#ifdef LWRES_HAVE_SIN6_SCOPE_ID
} else if (ntmp[0] != '\0' &&
lwres_net_pton(AF_INET6, ntmp, abuf) == 1)
{
if (family && family != AF_INET6)
return (EAI_NONAME);
addrsize = sizeof(struct in6_addr);
addroff = offsetof(struct sockaddr_in6, sin6_addr);
family = AF_INET6;
goto common;
#endif
} else if (lwres_net_pton(AF_INET6, hostname, abuf) == 1) {
if (family != 0 && family != AF_INET6)
return (EAI_NONAME);
inet6_addr:
addrsize = sizeof(struct in6_addr);
addroff = offsetof(struct sockaddr_in6, sin6_addr);
family = AF_INET6;
common:
ai = ai_clone(ai_list, family);
if (ai == NULL)
return (EAI_MEMORY);
ai_list = ai;
ai->ai_socktype = socktype;
SIN(ai->ai_addr)->sin_port = port;
memmove((char *)ai->ai_addr + addroff, abuf, addrsize);
if (flags & AI_CANONNAME) {
#if defined(LWRES_HAVE_SIN6_SCOPE_ID)
if (ai->ai_family == AF_INET6)
SIN6(ai->ai_addr)->sin6_scope_id =
scopeid;
#endif
if (lwres_getnameinfo(ai->ai_addr,
ai->ai_addrlen, nbuf, sizeof(nbuf),
NULL, 0,
NI_NUMERICHOST) == 0) {
ai->ai_canonname = strdup(nbuf);
if (ai->ai_canonname == NULL) {
lwres_freeaddrinfo(ai_list);
return (EAI_MEMORY);
}
} else {
/* XXX raise error? */
ai->ai_canonname = NULL;
}
}
goto done;
} else if ((flags & AI_NUMERICHOST) != 0) {
return (EAI_NONAME);
}
}
set_order(family, net_order);
for (i = 0; i < FOUND_MAX; i++) {
if (net_order[i] == NULL)
break;
err = (net_order[i])(hostname, flags, &ai_list,
socktype, port);
if (err != 0)
return (err);
}
if (ai_list == NULL)
return (EAI_NODATA);
done:
ai_list = ai_reverse(ai_list);
*res = ai_list;
return (0);
}
static char *
lwres_strsep(char **stringp, const char *delim) {
char *string = *stringp;
char *s;
const char *d;
char sc, dc;
if (string == NULL)
return (NULL);
for (s = string; *s != '\0'; s++) {
sc = *s;
for (d = delim; (dc = *d) != '\0'; d++)
if (sc == dc) {
*s++ = '\0';
*stringp = s;
return (string);
}
}
*stringp = NULL;
return (string);
}
static void
set_order(int family, int (**net_order)(const char *, int, struct addrinfo **,
int, int))
{
char *order, *tok;
int found;
if (family) {
switch (family) {
case AF_INET:
*net_order++ = add_ipv4;
break;
case AF_INET6:
*net_order++ = add_ipv6;
break;
}
} else {
order = getenv("NET_ORDER");
found = 0;
while (order != NULL) {
/*
* We ignore any unknown names.
*/
tok = lwres_strsep(&order, ":");
if (strcasecmp(tok, "inet6") == 0) {
if ((found & FOUND_IPV6) == 0)
*net_order++ = add_ipv6;
found |= FOUND_IPV6;
} else if (strcasecmp(tok, "inet") == 0 ||
strcasecmp(tok, "inet4") == 0) {
if ((found & FOUND_IPV4) == 0)
*net_order++ = add_ipv4;
found |= FOUND_IPV4;
}
}
/*
* Add in anything that we didn't find.
*/
if ((found & FOUND_IPV4) == 0)
*net_order++ = add_ipv4;
if ((found & FOUND_IPV6) == 0)
*net_order++ = add_ipv6;
}
*net_order = NULL;
return;
}
static char v4_loop[4] = { 127, 0, 0, 1 };
/*
* The test against 0 is there to keep the Solaris compiler
* from complaining about "end-of-loop code not reached".
*/
#define SETERROR(code) \
do { result = (code); \
if (result != 0) goto cleanup; \
} while (0)
static int
add_ipv4(const char *hostname, int flags, struct addrinfo **aip,
int socktype, int port)
{
struct addrinfo *ai;
lwres_context_t *lwrctx = NULL;
lwres_gabnresponse_t *by = NULL;
lwres_addr_t *addr;
lwres_result_t lwres;
int result = 0;
lwres = lwres_context_create(&lwrctx, NULL, NULL, NULL, 0);
if (lwres != LWRES_R_SUCCESS)
SETERROR(EAI_FAIL);
(void) lwres_conf_parse(lwrctx, lwres_resolv_conf);
if (hostname == NULL && (flags & AI_PASSIVE) == 0) {
ai = ai_clone(*aip, AF_INET);
if (ai == NULL)
SETERROR(EAI_MEMORY);
*aip = ai;
ai->ai_socktype = socktype;
SIN(ai->ai_addr)->sin_port = port;
memmove(&SIN(ai->ai_addr)->sin_addr, v4_loop, 4);
} else {
lwres = lwres_getaddrsbyname(lwrctx, hostname,
LWRES_ADDRTYPE_V4, &by);
if (lwres != LWRES_R_SUCCESS) {
if (lwres == LWRES_R_NOTFOUND)
goto cleanup;
else
SETERROR(EAI_FAIL);
}
addr = LWRES_LIST_HEAD(by->addrs);
while (addr != NULL) {
ai = ai_clone(*aip, AF_INET);
if (ai == NULL)
SETERROR(EAI_MEMORY);
*aip = ai;
ai->ai_socktype = socktype;
SIN(ai->ai_addr)->sin_port = port;
memmove(&SIN(ai->ai_addr)->sin_addr,
addr->address, 4);
if (flags & AI_CANONNAME) {
ai->ai_canonname = strdup(by->realname);
if (ai->ai_canonname == NULL)
SETERROR(EAI_MEMORY);
}
addr = LWRES_LIST_NEXT(addr, link);
}
}
cleanup:
if (by != NULL)
lwres_gabnresponse_free(lwrctx, &by);
if (lwrctx != NULL) {
lwres_conf_clear(lwrctx);
lwres_context_destroy(&lwrctx);
}
return (result);
}
static char v6_loop[16] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1 };
static int
add_ipv6(const char *hostname, int flags, struct addrinfo **aip,
int socktype, int port)
{
struct addrinfo *ai;
lwres_context_t *lwrctx = NULL;
lwres_gabnresponse_t *by = NULL;
lwres_addr_t *addr;
lwres_result_t lwres;
int result = 0;
lwres = lwres_context_create(&lwrctx, NULL, NULL, NULL, 0);
if (lwres != LWRES_R_SUCCESS)
SETERROR(EAI_FAIL);
(void) lwres_conf_parse(lwrctx, lwres_resolv_conf);
if (hostname == NULL && (flags & AI_PASSIVE) == 0) {
ai = ai_clone(*aip, AF_INET6);
if (ai == NULL)
SETERROR(EAI_MEMORY);
*aip = ai;
ai->ai_socktype = socktype;
SIN6(ai->ai_addr)->sin6_port = port;
memmove(&SIN6(ai->ai_addr)->sin6_addr, v6_loop, 16);
} else {
lwres = lwres_getaddrsbyname(lwrctx, hostname,
LWRES_ADDRTYPE_V6, &by);
if (lwres != LWRES_R_SUCCESS) {
if (lwres == LWRES_R_NOTFOUND)
goto cleanup;
else
SETERROR(EAI_FAIL);
}
addr = LWRES_LIST_HEAD(by->addrs);
while (addr != NULL) {
ai = ai_clone(*aip, AF_INET6);
if (ai == NULL)
SETERROR(EAI_MEMORY);
*aip = ai;
ai->ai_socktype = socktype;
SIN6(ai->ai_addr)->sin6_port = port;
memmove(&SIN6(ai->ai_addr)->sin6_addr,
addr->address, 16);
if (flags & AI_CANONNAME) {
ai->ai_canonname = strdup(by->realname);
if (ai->ai_canonname == NULL)
SETERROR(EAI_MEMORY);
}
addr = LWRES_LIST_NEXT(addr, link);
}
}
cleanup:
if (by != NULL)
lwres_gabnresponse_free(lwrctx, &by);
if (lwrctx != NULL) {
lwres_conf_clear(lwrctx);
lwres_context_destroy(&lwrctx);
}
return (result);
}
/*% Free address info. */
void
lwres_freeaddrinfo(struct addrinfo *ai) {
struct addrinfo *ai_next;
while (ai != NULL) {
ai_next = ai->ai_next;
if (ai->ai_addr != NULL)
free(ai->ai_addr);
if (ai->ai_canonname)
free(ai->ai_canonname);
free(ai);
ai = ai_next;
}
}
#ifdef AF_LOCAL
static int
get_local(const char *name, int socktype, struct addrinfo **res) {
struct addrinfo *ai;
struct sockaddr_un *slocal;
if (socktype == 0)
return (EAI_SOCKTYPE);
if (strlen(name) >= sizeof(slocal->sun_path))
return (EAI_OVERFLOW);
ai = ai_alloc(AF_LOCAL, sizeof(*slocal));
if (ai == NULL)
return (EAI_MEMORY);
slocal = SLOCAL(ai->ai_addr);
strncpy(slocal->sun_path, name, sizeof(slocal->sun_path));
slocal->sun_path[sizeof(slocal->sun_path) - 1] = '\0';
ai->ai_socktype = socktype;
/*
* ai->ai_flags, ai->ai_protocol, ai->ai_canonname,
* and ai->ai_next were initialized to zero.
*/
*res = ai;
return (0);
}
#endif
/*!
* Allocate an addrinfo structure, and a sockaddr structure
* of the specificed length. We initialize:
* ai_addrlen
* ai_family
* ai_addr
* ai_addr->sa_family
* ai_addr->sa_len (LWRES_PLATFORM_HAVESALEN)
* and everything else is initialized to zero.
*/
static struct addrinfo *
ai_alloc(int family, int addrlen) {
struct addrinfo *ai;
ai = (struct addrinfo *)calloc(1, sizeof(*ai));
if (ai == NULL)
return (NULL);
ai->ai_addr = SA(calloc(1, addrlen));
if (ai->ai_addr == NULL) {
free(ai);
return (NULL);
}
ai->ai_addrlen = addrlen;
ai->ai_family = family;
ai->ai_addr->sa_family = family;
#ifdef LWRES_PLATFORM_HAVESALEN
ai->ai_addr->sa_len = addrlen;
#endif
return (ai);
}
static struct addrinfo *
ai_clone(struct addrinfo *oai, int family) {
struct addrinfo *ai;
ai = ai_alloc(family, ((family == AF_INET6) ?
sizeof(struct sockaddr_in6) : sizeof(struct sockaddr_in)));
if (ai == NULL) {
lwres_freeaddrinfo(oai);
return (NULL);
}
if (oai == NULL)
return (ai);
ai->ai_flags = oai->ai_flags;
ai->ai_socktype = oai->ai_socktype;
ai->ai_protocol = oai->ai_protocol;
ai->ai_canonname = NULL;
ai->ai_next = oai;
return (ai);
}
static struct addrinfo *
ai_reverse(struct addrinfo *oai) {
struct addrinfo *nai, *tai;
nai = NULL;
while (oai != NULL) {
/*
* Grab one off the old list.
*/
tai = oai;
oai = oai->ai_next;
/*
* Put it on the front of the new list.
*/
tai->ai_next = nai;
nai = tai;
}
return (nai);
}