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/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
* SPDX-License-Identifier: curl
*
***************************************************************************/
#include "curl_setup.h"
#include "fake_addrinfo.h"
#ifdef USE_FAKE_GETADDRINFO
#include <string.h>
#include <stdlib.h>
#include <ares.h>
/* The last 3 #include files should be in this order */
#include "curl_printf.h"
#include "curl_memory.h"
#include "memdebug.h"
void r_freeaddrinfo(struct addrinfo *cahead)
{
struct addrinfo *canext;
struct addrinfo *ca;
for(ca = cahead; ca; ca = canext) {
canext = ca->ai_next;
free(ca);
}
}
struct context {
struct ares_addrinfo *result;
};
static void async_addrinfo_cb(void *userp, int status, int timeouts,
struct ares_addrinfo *result)
{
struct context *ctx = (struct context *)userp;
(void)timeouts;
if(ARES_SUCCESS == status) {
ctx->result = result;
}
}
/* convert the c-ares version into the "native" version */
static struct addrinfo *mk_getaddrinfo(const struct ares_addrinfo *aihead)
{
const struct ares_addrinfo_node *ai;
struct addrinfo *ca;
struct addrinfo *cafirst = NULL;
struct addrinfo *calast = NULL;
const char *name = aihead->name;
/* traverse the addrinfo list */
for(ai = aihead->nodes; ai != NULL; ai = ai->ai_next) {
size_t ss_size;
size_t namelen = name ? strlen(name) + 1 : 0;
/* ignore elements with unsupported address family, */
/* settle family-specific sockaddr structure size. */
if(ai->ai_family == AF_INET)
ss_size = sizeof(struct sockaddr_in);
else if(ai->ai_family == AF_INET6)
ss_size = sizeof(struct sockaddr_in6);
else
continue;
/* ignore elements without required address info */
if(!ai->ai_addr || !(ai->ai_addrlen > 0))
continue;
/* ignore elements with bogus address size */
if((size_t)ai->ai_addrlen < ss_size)
continue;
ca = malloc(sizeof(struct addrinfo) + ss_size + namelen);
if(!ca) {
r_freeaddrinfo(cafirst);
return NULL;
}
/* copy each structure member individually, member ordering, */
/* size, or padding might be different for each platform. */
ca->ai_flags = ai->ai_flags;
ca->ai_family = ai->ai_family;
ca->ai_socktype = ai->ai_socktype;
ca->ai_protocol = ai->ai_protocol;
ca->ai_addrlen = (curl_socklen_t)ss_size;
ca->ai_addr = NULL;
ca->ai_canonname = NULL;
ca->ai_next = NULL;
ca->ai_addr = (void *)((char *)ca + sizeof(struct addrinfo));
memcpy(ca->ai_addr, ai->ai_addr, ss_size);
if(namelen) {
ca->ai_canonname = (void *)((char *)ca->ai_addr + ss_size);
memcpy(ca->ai_canonname, name, namelen);
/* the name is only pointed to by the first entry in the "real"
addrinfo chain, so stop now */
name = NULL;
}
/* if the return list is empty, this becomes the first element */
if(!cafirst)
cafirst = ca;
/* add this element last in the return list */
if(calast)
calast->ai_next = ca;
calast = ca;
}
return cafirst;
}
/*
RETURN VALUE
getaddrinfo() returns 0 if it succeeds, or one of the following nonzero
error codes:
...
*/
int r_getaddrinfo(const char *node,
const char *service,
const struct addrinfo *hints,
struct addrinfo **res)
{
int status;
struct context ctx;
struct ares_options options;
int optmask = 0;
struct ares_addrinfo_hints ahints;
ares_channel channel;
int rc = 0;
memset(&options, 0, sizeof(options));
optmask |= ARES_OPT_EVENT_THREAD;
options.evsys = ARES_EVSYS_DEFAULT;
memset(&ahints, 0, sizeof(ahints));
memset(&ctx, 0, sizeof(ctx));
if(hints) {
ahints.ai_flags = hints->ai_flags;
ahints.ai_family = hints->ai_family;
ahints.ai_socktype = hints->ai_socktype;
ahints.ai_protocol = hints->ai_protocol;
}
status = ares_init_options(&channel, &options, optmask);
if(status)
return EAI_MEMORY; /* major problem */
else {
const char *env = getenv("CURL_DNS_SERVER");
if(env) {
rc = ares_set_servers_ports_csv(channel, env);
if(rc) {
fprintf(stderr, "ares_set_servers_ports_csv failed: %d", rc);
/* Cleanup */
ares_destroy(channel);
return EAI_MEMORY; /* we can't run */
}
}
}
ares_getaddrinfo(channel, node, service, &ahints,
async_addrinfo_cb, &ctx);
/* Wait until no more requests are left to be processed */
ares_queue_wait_empty(channel, -1);
if(ctx.result) {
/* convert the c-ares version */
*res = mk_getaddrinfo(ctx.result);
/* free the old */
ares_freeaddrinfo(ctx.result);
}
else
rc = EAI_NONAME; /* got nothing */
/* Cleanup */
ares_destroy(channel);
return rc;
}
#endif /* USE_FAKE_GETADDRINFO */
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