/*
* Curl_fetch_addr() fetches a 'Curl_dns_entry' already in the DNS cache.
*
* Curl_resolv() checks initially and multi_runsingle() checks each time
* it discovers the handle in the state WAITRESOLVE whether the hostname
* has already been resolved and the address has already been stored in
* the DNS cache. This short circuits waiting for a lot of pending
* lookups for the same hostname requested by different handles.
*
* Returns the Curl_dns_entry entry pointer or NULL if not in the cache.
*/
struct Curl_dns_entry *
Curl_fetch_addr(struct connectdata *conn,
const char *hostname,
int port, int *stale)
{
char *entry_id = NULL;
struct Curl_dns_entry *dns = NULL;
size_t entry_len;
struct SessionHandle *data = conn->data;
/* Create an entry id, based upon the hostname and port */
entry_id = create_hostcache_id(hostname, port);
/* If we can't create the entry id, fail */
if(!entry_id)
return dns;
entry_len = strlen(entry_id);
/* See if its already in our dns cache */
dns = Curl_hash_pick(data->dns.hostcache, entry_id, entry_len+1);
/* free the allocated entry_id again */
free(entry_id);
/* See whether the returned entry is stale. Done before we release lock */
*stale = remove_entry_if_stale(data, dns);
if(*stale)
dns = NULL; /* the memory deallocation is being handled by the hash */
return dns;
}
/*
* Curl_cache_addr() stores a 'Curl_addrinfo' struct in the DNS cache.
*
* When calling Curl_resolv() has resulted in a response with a returned
* address, we call this function to store the information in the dns
* cache etc
*
* Returns the Curl_dns_entry entry pointer or NULL if the storage failed.
*/
struct Curl_dns_entry *
Curl_cache_addr(struct SessionHandle *data,
Curl_addrinfo *addr,
const char *hostname,
int port)
{
char *entry_id;
size_t entry_len;
struct Curl_dns_entry *dns;
struct Curl_dns_entry *dns2;
time_t now;
/* Create an entry id, based upon the hostname and port */
entry_id = create_hostcache_id(hostname, port);
/* If we can't create the entry id, fail */
if (!entry_id)
return NULL;
entry_len = strlen(entry_id);
/* Create a new cache entry */
dns = calloc(sizeof(struct Curl_dns_entry), 1);
if (!dns)
{
free(entry_id);
return NULL;
}
dns->inuse = 0; /* init to not used */
dns->addr = addr; /* this is the address(es) */
/* Store the resolved data in our DNS cache. This function may return a
pointer to an existing struct already present in the hash, and it may
return the same argument we pass in. Make no assumptions. */
dns2 = Curl_hash_add(data->dns.hostcache, entry_id, entry_len + 1,
(void *)dns);
if (!dns2)
{
/* Major badness, run away. */
free(dns);
free(entry_id);
return NULL;
}
time(&now);
dns = dns2;
dns->timestamp = now; /* used now */
dns->inuse++; /* mark entry as in-use */
/* free the allocated entry_id again */
free(entry_id);
return dns;
}
static struct Curl_dns_entry *
cache_resolv_response(struct SessionHandle *data,
Curl_addrinfo *addr,
char *hostname,
int port)
{
char *entry_id;
size_t entry_len;
struct Curl_dns_entry *dns;
time_t now;
/* Create an entry id, based upon the hostname and port */
entry_id = create_hostcache_id(hostname, port, &entry_len);
/* If we can't create the entry id, fail */
if (!entry_id)
return NULL;
/* Create a new cache entry */
dns = (struct Curl_dns_entry *) malloc(sizeof(struct Curl_dns_entry));
if (!dns) {
Curl_freeaddrinfo(addr);
free(entry_id);
return NULL;
}
dns->inuse = 0; /* init to not used */
dns->addr = addr; /* this is the address(es) */
/* Store the resolved data in our DNS cache. This function may return a
pointer to an existing struct already present in the hash, and it may
return the same argument we pass in. Make no assumptions. */
dns = Curl_hash_add(data->hostcache, entry_id, entry_len+1, (void *)dns);
if(!dns) {
/* Major badness, run away. When this happens, the 'dns' data has
already been cleared up by Curl_hash_add(). */
free(entry_id);
return NULL;
}
time(&now);
dns->timestamp = now; /* used now */
dns->inuse++; /* mark entry as in-use */
/* free the allocated entry_id again */
free(entry_id);
return dns;
}
/*
* Curl_cache_addr() stores a 'Curl_addrinfo' struct in the DNS cache.
*
* When calling Curl_resolv() has resulted in a response with a returned
* address, we call this function to store the information in the dns
* cache etc
*
* Returns the Curl_dns_entry entry pointer or NULL if the storage failed.
*/
struct Curl_dns_entry *
Curl_cache_addr(struct SessionHandle *data,
Curl_addrinfo *addr,
const char *hostname,
int port)
{
char *entry_id;
size_t entry_len;
struct Curl_dns_entry *dns;
struct Curl_dns_entry *dns2;
/* Create an entry id, based upon the hostname and port */
entry_id = create_hostcache_id(hostname, port);
/* If we can't create the entry id, fail */
if(!entry_id)
return NULL;
entry_len = strlen(entry_id);
/* Create a new cache entry */
dns = calloc(1, sizeof(struct Curl_dns_entry));
if(!dns) {
free(entry_id);
return NULL;
}
dns->inuse = 0; /* init to not used */
dns->addr = addr; /* this is the address(es) */
time(&dns->timestamp);
if(dns->timestamp == 0)
dns->timestamp = 1; /* zero indicates that entry isn't in hash table */
/* Store the resolved data in our DNS cache. */
dns2 = Curl_hash_add(data->dns.hostcache, entry_id, entry_len+1,
(void *)dns);
if(!dns2) {
free(dns);
free(entry_id);
return NULL;
}
dns = dns2;
dns->inuse++; /* mark entry as in-use */
/* free the allocated entry_id */
free(entry_id);
return dns;
}
/* lookup address, returns entry if found and not stale */
static struct Curl_dns_entry *
fetch_addr(struct connectdata *conn,
const char *hostname,
int port)
{
char *entry_id = NULL;
struct Curl_dns_entry *dns = NULL;
size_t entry_len;
struct SessionHandle *data = conn->data;
/* Create an entry id, based upon the hostname and port */
entry_id = create_hostcache_id(hostname, port);
/* If we can't create the entry id, fail */
if(!entry_id)
return dns;
entry_len = strlen(entry_id);
/* See if its already in our dns cache */
dns = Curl_hash_pick(data->dns.hostcache, entry_id, entry_len+1);
if(dns && (data->set.dns_cache_timeout != -1)) {
/* See whether the returned entry is stale. Done before we release lock */
struct hostcache_prune_data user;
time(&user.now);
user.cache_timeout = data->set.dns_cache_timeout;
if(hostcache_timestamp_remove(&user, dns)) {
infof(data, "Hostname in DNS cache was stale, zapped\n");
dns = NULL; /* the memory deallocation is being handled by the hash */
Curl_hash_delete(data->dns.hostcache, entry_id, entry_len+1);
}
}
/* free the allocated entry_id again */
free(entry_id);
return dns;
}
/* Resolve a name and return a pointer in the 'entry' argument if one
is available.
Return codes:
-1 = error, no pointer
0 = OK, pointer provided
1 = waiting for response, no pointer
*/
int Curl_resolv(struct connectdata *conn,
char *hostname,
int port,
struct Curl_dns_entry **entry)
{
char *entry_id = NULL;
struct Curl_dns_entry *dns = NULL;
size_t entry_len;
int wait;
struct SessionHandle *data = conn->data;
CURLcode result;
/* default to failure */
int rc = -1;
*entry = NULL;
#ifdef HAVE_SIGSETJMP
/* this allows us to time-out from the name resolver, as the timeout
will generate a signal and we will siglongjmp() from that here */
if(!data->set.no_signal && sigsetjmp(curl_jmpenv, 1)) {
/* this is coming from a siglongjmp() */
failf(data, "name lookup timed out");
return -1;
}
#endif
/* Create an entry id, based upon the hostname and port */
entry_id = create_hostcache_id(hostname, port, &entry_len);
/* If we can't create the entry id, fail */
if (!entry_id)
return -1;
if(data->share)
Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
/* See if its already in our dns cache */
dns = Curl_hash_pick(data->hostcache, entry_id, entry_len+1);
if(data->share)
Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
/* free the allocated entry_id again */
free(entry_id);
if (!dns) {
/* The entry was not in the cache. Resolve it to IP address */
/* If my_getaddrinfo() returns NULL, 'wait' might be set to a non-zero
value indicating that we need to wait for the response to the resolve
call */
Curl_addrinfo *addr = my_getaddrinfo(conn, hostname, port, &wait);
if (!addr) {
if(wait) {
/* the response to our resolve call will come asynchronously at
a later time, good or bad */
/* First, check that we haven't received the info by now */
result = Curl_is_resolved(conn, &dns);
if(result) /* error detected */
return -1;
if(dns)
rc = 0; /* pointer provided */
else
rc = 1; /* no info yet */
}
}
else {
if(data->share)
Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
/* we got a response, store it in the cache */
dns = cache_resolv_response(data, addr, hostname, port);
if(data->share)
Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
if(!dns)
/* returned failure, bail out nicely */
Curl_freeaddrinfo(addr);
else
rc = 0;
}
}
else {
dns->inuse++; /* we use it! */
rc = 0;
}
*entry = dns;
return rc;
}
int Curl_resolv(struct connectdata *conn,
const char *hostname,
int port,
struct Curl_dns_entry **entry)
{
char *entry_id = NULL;
struct Curl_dns_entry *dns = NULL;
size_t entry_len;
struct SessionHandle *data = conn->data;
CURLcode result;
int rc = CURLRESOLV_ERROR; /* default to failure */
*entry = NULL;
/* Create an entry id, based upon the hostname and port */
entry_id = create_hostcache_id(hostname, port);
/* If we can't create the entry id, fail */
if(!entry_id)
return rc;
entry_len = strlen(entry_id);
if(data->share)
Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
/* See if its already in our dns cache */
dns = Curl_hash_pick(data->dns.hostcache, entry_id, entry_len+1);
/* free the allocated entry_id again */
free(entry_id);
/* See whether the returned entry is stale. Done before we release lock */
if( remove_entry_if_stale(data, dns) )
dns = NULL; /* the memory deallocation is being handled by the hash */
if(dns) {
dns->inuse++; /* we use it! */
rc = CURLRESOLV_RESOLVED;
}
if(data->share)
Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
if(!dns) {
/* The entry was not in the cache. Resolve it to IP address */
Curl_addrinfo *addr;
int respwait;
/* Check what IP specifics the app has requested and if we can provide it.
* If not, bail out. */
if(!Curl_ipvalid(conn))
return CURLRESOLV_ERROR;
/* If Curl_getaddrinfo() returns NULL, 'respwait' might be set to a
non-zero value indicating that we need to wait for the response to the
resolve call */
addr = Curl_getaddrinfo(conn,
#ifdef DEBUGBUILD
(data->set.str[STRING_DEVICE]
&& !strcmp(data->set.str[STRING_DEVICE],
"LocalHost"))?"localhost":
#endif
hostname, port, &respwait);
if(!addr) {
if(respwait) {
/* the response to our resolve call will come asynchronously at
a later time, good or bad */
/* First, check that we haven't received the info by now */
result = Curl_is_resolved(conn, &dns);
if(result) /* error detected */
return CURLRESOLV_ERROR;
if(dns)
rc = CURLRESOLV_RESOLVED; /* pointer provided */
else
rc = CURLRESOLV_PENDING; /* no info yet */
}
}
else {
if(data->share)
Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
/* we got a response, store it in the cache */
dns = Curl_cache_addr(data, addr, hostname, port);
if(data->share)
Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
if(!dns)
/* returned failure, bail out nicely */
Curl_freeaddrinfo(addr);
else
rc = CURLRESOLV_RESOLVED;
}
}
*entry = dns;
return rc;
}
CURLcode Curl_loadhostpairs(struct SessionHandle *data)
{
struct curl_slist *hostp;
char hostname[256];
char address[256];
int port;
for(hostp = data->change.resolve; hostp; hostp = hostp->next) {
if(!hostp->data)
continue;
if(hostp->data[0] == '-') {
char *entry_id;
size_t entry_len;
if(2 != sscanf(hostp->data + 1, "%255[^:]:%d", hostname, &port)) {
infof(data, "Couldn't parse CURLOPT_RESOLVE removal entry '%s'!\n",
hostp->data);
continue;
}
/* Create an entry id, based upon the hostname and port */
entry_id = create_hostcache_id(hostname, port);
/* If we can't create the entry id, fail */
if(!entry_id) {
return CURLE_OUT_OF_MEMORY;
}
entry_len = strlen(entry_id);
if(data->share)
Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
/* delete entry, ignore if it didn't exist */
Curl_hash_delete(data->dns.hostcache, entry_id, entry_len+1);
if(data->share)
Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
/* free the allocated entry_id again */
free(entry_id);
}
else {
struct Curl_dns_entry *dns;
Curl_addrinfo *addr;
char *entry_id;
size_t entry_len;
if(3 != sscanf(hostp->data, "%255[^:]:%d:%255s", hostname, &port,
address)) {
infof(data, "Couldn't parse CURLOPT_RESOLVE entry '%s'!\n",
hostp->data);
continue;
}
addr = Curl_str2addr(address, port);
if(!addr) {
infof(data, "Address in '%s' found illegal!\n", hostp->data);
continue;
}
/* Create an entry id, based upon the hostname and port */
entry_id = create_hostcache_id(hostname, port);
/* If we can't create the entry id, fail */
if(!entry_id) {
Curl_freeaddrinfo(addr);
return CURLE_OUT_OF_MEMORY;
}
entry_len = strlen(entry_id);
if(data->share)
Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
/* See if its already in our dns cache */
dns = Curl_hash_pick(data->dns.hostcache, entry_id, entry_len+1);
/* free the allocated entry_id again */
free(entry_id);
if(!dns) {
/* if not in the cache already, put this host in the cache */
dns = Curl_cache_addr(data, addr, hostname, port);
if(dns) {
dns->timestamp = 0; /* mark as added by CURLOPT_RESOLVE */
/* release the returned reference; the cache itself will keep the
* entry alive: */
dns->inuse--;
}
}
else
/* this is a duplicate, free it again */
Curl_freeaddrinfo(addr);
if(data->share)
Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
if(!dns) {
Curl_freeaddrinfo(addr);
return CURLE_OUT_OF_MEMORY;
}
infof(data, "Added %s:%d:%s to DNS cache\n",
hostname, port, address);
}
}
data->change.resolve = NULL; /* dealt with now */
return CURLE_OK;
}
CURLcode Curl_loadhostpairs(struct SessionHandle *data)
{
struct curl_slist *hostp;
char hostname[256];
char address[256];
int port;
for(hostp = data->change.resolve; hostp; hostp = hostp->next ) {
if(!hostp->data)
continue;
if(hostp->data[0] == '-') {
/* TODO: mark an entry for removal */
}
else if(3 == sscanf(hostp->data, "%255[^:]:%d:%255s", hostname, &port,
address)) {
struct Curl_dns_entry *dns;
Curl_addrinfo *addr;
char *entry_id;
size_t entry_len;
addr = Curl_str2addr(address, port);
if(!addr) {
infof(data, "Resolve %s found illegal!\n", hostp->data);
continue;
}
/* Create an entry id, based upon the hostname and port */
entry_id = create_hostcache_id(hostname, port);
/* If we can't create the entry id, fail */
if(!entry_id) {
Curl_freeaddrinfo(addr);
return CURLE_OUT_OF_MEMORY;
}
entry_len = strlen(entry_id);
if(data->share)
Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
/* See if its already in our dns cache */
dns = Curl_hash_pick(data->dns.hostcache, entry_id, entry_len+1);
/* free the allocated entry_id again */
free(entry_id);
if(!dns)
/* if not in the cache already, put this host in the cache */
dns = Curl_cache_addr(data, addr, hostname, port);
else
/* this is a duplicate, free it again */
Curl_freeaddrinfo(addr);
if(data->share)
Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
if(!dns) {
Curl_freeaddrinfo(addr);
return CURLE_OUT_OF_MEMORY;
}
infof(data, "Added %s:%d:%s to DNS cache\n",
hostname, port, address);
}
}
data->change.resolve = NULL; /* dealt with now */
return CURLE_OK;
}
int Curl_resolv(struct connectdata *conn,
const char *hostname,
int port,
struct Curl_dns_entry **entry)
{
char *entry_id = NULL;
struct Curl_dns_entry *dns = NULL;
size_t entry_len;
int wait;
struct SessionHandle *data = conn->data;
CURLcode result;
int rc;
*entry = NULL;
#ifdef HAVE_SIGSETJMP
/* this allows us to time-out from the name resolver, as the timeout
will generate a signal and we will siglongjmp() from that here */
if(!data->set.no_signal) {
if (sigsetjmp(curl_jmpenv, 1)) {
/* this is coming from a siglongjmp() */
failf(data, "name lookup timed out");
return CURLRESOLV_ERROR;
}
}
#endif
/* Create an entry id, based upon the hostname and port */
entry_id = create_hostcache_id(hostname, port);
/* If we can't create the entry id, fail */
if (!entry_id)
return CURLRESOLV_ERROR;
entry_len = strlen(entry_id);
if(data->share)
Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
/* See if its already in our dns cache */
dns = Curl_hash_pick(data->dns.hostcache, entry_id, entry_len+1);
if(data->share)
Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
/* free the allocated entry_id again */
free(entry_id);
/* See whether the returned entry is stale. Deliberately done after the
locked block */
if ( remove_entry_if_stale(data,dns) )
dns = NULL; /* the memory deallocation is being handled by the hash */
rc = CURLRESOLV_ERROR; /* default to failure */
if (!dns) {
/* The entry was not in the cache. Resolve it to IP address */
Curl_addrinfo *addr;
/* Check what IP specifics the app has requested and if we can provide it.
* If not, bail out. */
if(!Curl_ipvalid(data))
return CURLRESOLV_ERROR;
/* If Curl_getaddrinfo() returns NULL, 'wait' might be set to a non-zero
value indicating that we need to wait for the response to the resolve
call */
addr = Curl_getaddrinfo(conn, hostname, port, &wait);
if (!addr) {
if(wait) {
/* the response to our resolve call will come asynchronously at
a later time, good or bad */
/* First, check that we haven't received the info by now */
result = Curl_is_resolved(conn, &dns);
if(result) /* error detected */
return CURLRESOLV_ERROR;
if(dns)
rc = CURLRESOLV_RESOLVED; /* pointer provided */
else
rc = CURLRESOLV_PENDING; /* no info yet */
}
}
else {
if(data->share)
Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
/* we got a response, store it in the cache */
dns = Curl_cache_addr(data, addr, hostname, port);
if(data->share)
Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
if(!dns)
/* returned failure, bail out nicely */
Curl_freeaddrinfo(addr);
else
rc = CURLRESOLV_RESOLVED;
}
}
else {
if(data->share)
Curl_share_lock(data, CURL_LOCK_DATA_DNS, CURL_LOCK_ACCESS_SINGLE);
dns->inuse++; /* we use it! */
if(data->share)
Curl_share_unlock(data, CURL_LOCK_DATA_DNS);
rc = CURLRESOLV_RESOLVED;
}
*entry = dns;
return rc;
}
