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Diffstat (limited to 'Utilities/cmcurl/lib/asyn-ares.c')
| -rw-r--r-- | Utilities/cmcurl/lib/asyn-ares.c | 816 |
1 files changed, 816 insertions, 0 deletions
diff --git a/Utilities/cmcurl/lib/asyn-ares.c b/Utilities/cmcurl/lib/asyn-ares.c new file mode 100644 index 0000000..ba5160b --- /dev/null +++ b/Utilities/cmcurl/lib/asyn-ares.c @@ -0,0 +1,816 @@ +/*************************************************************************** + * _ _ ____ _ + * Project ___| | | | _ \| | + * / __| | | | |_) | | + * | (__| |_| | _ <| |___ + * \___|\___/|_| \_\_____| + * + * Copyright (C) 1998 - 2020, 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.haxx.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. + * + ***************************************************************************/ + +#include "curl_setup.h" + +/*********************************************************************** + * Only for ares-enabled builds + * And only for functions that fulfill the asynch resolver backend API + * as defined in asyn.h, nothing else belongs in this file! + **********************************************************************/ + +#ifdef CURLRES_ARES + +#include <limits.h> +#ifdef HAVE_NETINET_IN_H +#include <netinet/in.h> +#endif +#ifdef HAVE_NETDB_H +#include <netdb.h> +#endif +#ifdef HAVE_ARPA_INET_H +#include <arpa/inet.h> +#endif +#ifdef __VMS +#include <in.h> +#include <inet.h> +#endif + +#ifdef HAVE_PROCESS_H +#include <process.h> +#endif + +#if (defined(NETWARE) && defined(__NOVELL_LIBC__)) +#undef in_addr_t +#define in_addr_t unsigned long +#endif + +#include "urldata.h" +#include "sendf.h" +#include "hostip.h" +#include "hash.h" +#include "share.h" +#include "strerror.h" +#include "url.h" +#include "multiif.h" +#include "inet_pton.h" +#include "connect.h" +#include "select.h" +#include "progress.h" + +# if defined(CURL_STATICLIB) && !defined(CARES_STATICLIB) && \ + (defined(WIN32) || defined(__SYMBIAN32__)) +# define CARES_STATICLIB +# endif +# include <ares.h> +# include <ares_version.h> /* really old c-ares didn't include this by + itself */ + +#if ARES_VERSION >= 0x010500 +/* c-ares 1.5.0 or later, the callback proto is modified */ +#define HAVE_CARES_CALLBACK_TIMEOUTS 1 +#endif + +/* The last 3 #include files should be in this order */ +#include "curl_printf.h" +#include "curl_memory.h" +#include "memdebug.h" + +struct ResolverResults { + int num_pending; /* number of ares_gethostbyname() requests */ + struct Curl_addrinfo *temp_ai; /* intermediary result while fetching c-ares + parts */ + int last_status; + struct curltime happy_eyeballs_dns_time; /* when this timer started, or 0 */ +}; + +/* How long we are willing to wait for additional parallel responses after + obtaining a "definitive" one. + + This is intended to equal the c-ares default timeout. cURL always uses that + default value. Unfortunately, c-ares doesn't expose its default timeout in + its API, but it is officially documented as 5 seconds. + + See query_completed_cb() for an explanation of how this is used. + */ +#define HAPPY_EYEBALLS_DNS_TIMEOUT 5000 + +/* + * Curl_resolver_global_init() - the generic low-level asynchronous name + * resolve API. Called from curl_global_init() to initialize global resolver + * environment. Initializes ares library. + */ +int Curl_resolver_global_init(void) +{ +#ifdef CARES_HAVE_ARES_LIBRARY_INIT + if(ares_library_init(ARES_LIB_INIT_ALL)) { + return CURLE_FAILED_INIT; + } +#endif + return CURLE_OK; +} + +/* + * Curl_resolver_global_cleanup() + * + * Called from curl_global_cleanup() to destroy global resolver environment. + * Deinitializes ares library. + */ +void Curl_resolver_global_cleanup(void) +{ +#ifdef CARES_HAVE_ARES_LIBRARY_CLEANUP + ares_library_cleanup(); +#endif +} + + +static void Curl_ares_sock_state_cb(void *data, ares_socket_t socket_fd, + int readable, int writable) +{ + struct Curl_easy *easy = data; + if(!readable && !writable) { + DEBUGASSERT(easy); + Curl_multi_closed(easy, socket_fd); + } +} + +/* + * Curl_resolver_init() + * + * Called from curl_easy_init() -> Curl_open() to initialize resolver + * URL-state specific environment ('resolver' member of the UrlState + * structure). Fills the passed pointer by the initialized ares_channel. + */ +CURLcode Curl_resolver_init(struct Curl_easy *easy, void **resolver) +{ + int status; + struct ares_options options; + int optmask = ARES_OPT_SOCK_STATE_CB; + options.sock_state_cb = Curl_ares_sock_state_cb; + options.sock_state_cb_data = easy; + status = ares_init_options((ares_channel*)resolver, &options, optmask); + if(status != ARES_SUCCESS) { + if(status == ARES_ENOMEM) + return CURLE_OUT_OF_MEMORY; + else + return CURLE_FAILED_INIT; + } + return CURLE_OK; + /* make sure that all other returns from this function should destroy the + ares channel before returning error! */ +} + +/* + * Curl_resolver_cleanup() + * + * Called from curl_easy_cleanup() -> Curl_close() to cleanup resolver + * URL-state specific environment ('resolver' member of the UrlState + * structure). Destroys the ares channel. + */ +void Curl_resolver_cleanup(void *resolver) +{ + ares_destroy((ares_channel)resolver); +} + +/* + * Curl_resolver_duphandle() + * + * Called from curl_easy_duphandle() to duplicate resolver URL-state specific + * environment ('resolver' member of the UrlState structure). Duplicates the + * 'from' ares channel and passes the resulting channel to the 'to' pointer. + */ +CURLcode Curl_resolver_duphandle(struct Curl_easy *easy, void **to, void *from) +{ + (void)from; + /* + * it would be better to call ares_dup instead, but right now + * it is not possible to set 'sock_state_cb_data' outside of + * ares_init_options + */ + return Curl_resolver_init(easy, to); +} + +static void destroy_async_data(struct Curl_async *async); + +/* + * Cancel all possibly still on-going resolves for this connection. + */ +void Curl_resolver_cancel(struct connectdata *conn) +{ + if(conn->data && conn->data->state.resolver) + ares_cancel((ares_channel)conn->data->state.resolver); + destroy_async_data(&conn->async); +} + +/* + * We're equivalent to Curl_resolver_cancel() for the c-ares resolver. We + * never block. + */ +void Curl_resolver_kill(struct connectdata *conn) +{ + /* We don't need to check the resolver state because we can be called safely + at any time and we always do the same thing. */ + Curl_resolver_cancel(conn); +} + +/* + * destroy_async_data() cleans up async resolver data. + */ +static void destroy_async_data(struct Curl_async *async) +{ + free(async->hostname); + + if(async->os_specific) { + struct ResolverResults *res = (struct ResolverResults *)async->os_specific; + if(res) { + if(res->temp_ai) { + Curl_freeaddrinfo(res->temp_ai); + res->temp_ai = NULL; + } + free(res); + } + async->os_specific = NULL; + } + + async->hostname = NULL; +} + +/* + * Curl_resolver_getsock() is called when someone from the outside world + * (using curl_multi_fdset()) wants to get our fd_set setup and we're talking + * with ares. The caller must make sure that this function is only called when + * we have a working ares channel. + * + * Returns: sockets-in-use-bitmap + */ + +int Curl_resolver_getsock(struct connectdata *conn, + curl_socket_t *socks) +{ + struct timeval maxtime; + struct timeval timebuf; + struct timeval *timeout; + long milli; + int max = ares_getsock((ares_channel)conn->data->state.resolver, + (ares_socket_t *)socks, MAX_SOCKSPEREASYHANDLE); + + maxtime.tv_sec = CURL_TIMEOUT_RESOLVE; + maxtime.tv_usec = 0; + + timeout = ares_timeout((ares_channel)conn->data->state.resolver, &maxtime, + &timebuf); + milli = (timeout->tv_sec * 1000) + (timeout->tv_usec/1000); + if(milli == 0) + milli += 10; + Curl_expire(conn->data, milli, EXPIRE_ASYNC_NAME); + + return max; +} + +/* + * waitperform() + * + * 1) Ask ares what sockets it currently plays with, then + * 2) wait for the timeout period to check for action on ares' sockets. + * 3) tell ares to act on all the sockets marked as "with action" + * + * return number of sockets it worked on + */ + +static int waitperform(struct connectdata *conn, timediff_t timeout_ms) +{ + struct Curl_easy *data = conn->data; + int nfds; + int bitmask; + ares_socket_t socks[ARES_GETSOCK_MAXNUM]; + struct pollfd pfd[ARES_GETSOCK_MAXNUM]; + int i; + int num = 0; + + bitmask = ares_getsock((ares_channel)data->state.resolver, socks, + ARES_GETSOCK_MAXNUM); + + for(i = 0; i < ARES_GETSOCK_MAXNUM; i++) { + pfd[i].events = 0; + pfd[i].revents = 0; + if(ARES_GETSOCK_READABLE(bitmask, i)) { + pfd[i].fd = socks[i]; + pfd[i].events |= POLLRDNORM|POLLIN; + } + if(ARES_GETSOCK_WRITABLE(bitmask, i)) { + pfd[i].fd = socks[i]; + pfd[i].events |= POLLWRNORM|POLLOUT; + } + if(pfd[i].events != 0) + num++; + else + break; + } + + if(num) + nfds = Curl_poll(pfd, num, timeout_ms); + else + nfds = 0; + + if(!nfds) + /* Call ares_process() unconditonally here, even if we simply timed out + above, as otherwise the ares name resolve won't timeout! */ + ares_process_fd((ares_channel)data->state.resolver, ARES_SOCKET_BAD, + ARES_SOCKET_BAD); + else { + /* move through the descriptors and ask for processing on them */ + for(i = 0; i < num; i++) + ares_process_fd((ares_channel)data->state.resolver, + (pfd[i].revents & (POLLRDNORM|POLLIN))? + pfd[i].fd:ARES_SOCKET_BAD, + (pfd[i].revents & (POLLWRNORM|POLLOUT))? + pfd[i].fd:ARES_SOCKET_BAD); + } + return nfds; +} + +/* + * Curl_resolver_is_resolved() is called repeatedly to check if a previous + * name resolve request has completed. It should also make sure to time-out if + * the operation seems to take too long. + * + * Returns normal CURLcode errors. + */ +CURLcode Curl_resolver_is_resolved(struct connectdata *conn, + struct Curl_dns_entry **dns) +{ + struct Curl_easy *data = conn->data; + struct ResolverResults *res = (struct ResolverResults *) + conn->async.os_specific; + CURLcode result = CURLE_OK; + + DEBUGASSERT(dns); + *dns = NULL; + + waitperform(conn, 0); + + /* Now that we've checked for any last minute results above, see if there are + any responses still pending when the EXPIRE_HAPPY_EYEBALLS_DNS timer + expires. */ + if(res + && res->num_pending + /* This is only set to non-zero if the timer was started. */ + && (res->happy_eyeballs_dns_time.tv_sec + || res->happy_eyeballs_dns_time.tv_usec) + && (Curl_timediff(Curl_now(), res->happy_eyeballs_dns_time) + >= HAPPY_EYEBALLS_DNS_TIMEOUT)) { + /* Remember that the EXPIRE_HAPPY_EYEBALLS_DNS timer is no longer + running. */ + memset( + &res->happy_eyeballs_dns_time, 0, sizeof(res->happy_eyeballs_dns_time)); + + /* Cancel the raw c-ares request, which will fire query_completed_cb() with + ARES_ECANCELLED synchronously for all pending responses. This will + leave us with res->num_pending == 0, which is perfect for the next + block. */ + ares_cancel((ares_channel)data->state.resolver); + DEBUGASSERT(res->num_pending == 0); + } + + if(res && !res->num_pending) { + (void)Curl_addrinfo_callback(conn, res->last_status, res->temp_ai); + /* temp_ai ownership is moved to the connection, so we need not free-up + them */ + res->temp_ai = NULL; + + if(!conn->async.dns) { + failf(data, "Could not resolve: %s (%s)", + conn->async.hostname, ares_strerror(conn->async.status)); + result = conn->bits.proxy?CURLE_COULDNT_RESOLVE_PROXY: + CURLE_COULDNT_RESOLVE_HOST; + } + else + *dns = conn->async.dns; + + destroy_async_data(&conn->async); + } + + return result; +} + +/* + * Curl_resolver_wait_resolv() + * + * Waits for a resolve to finish. This function should be avoided since using + * this risk getting the multi interface to "hang". + * + * 'entry' MUST be non-NULL. + * + * Returns CURLE_COULDNT_RESOLVE_HOST if the host was not resolved, + * CURLE_OPERATION_TIMEDOUT if a time-out occurred, or other errors. + */ +CURLcode Curl_resolver_wait_resolv(struct connectdata *conn, + struct Curl_dns_entry **entry) +{ + CURLcode result = CURLE_OK; + struct Curl_easy *data = conn->data; + timediff_t timeout; + struct curltime now = Curl_now(); + + DEBUGASSERT(entry); + *entry = NULL; /* clear on entry */ + + timeout = Curl_timeleft(data, &now, TRUE); + if(timeout < 0) { + /* already expired! */ + connclose(conn, "Timed out before name resolve started"); + return CURLE_OPERATION_TIMEDOUT; + } + if(!timeout) + timeout = CURL_TIMEOUT_RESOLVE * 1000; /* default name resolve timeout */ + + /* Wait for the name resolve query to complete. */ + while(!result) { + struct timeval *tvp, tv, store; + int itimeout; + timediff_t timeout_ms; + +#if TIMEDIFF_T_MAX > INT_MAX + itimeout = (timeout > INT_MAX) ? INT_MAX : (int)timeout; +#else + itimeout = (int)timeout; +#endif + + store.tv_sec = itimeout/1000; + store.tv_usec = (itimeout%1000)*1000; + + tvp = ares_timeout((ares_channel)data->state.resolver, &store, &tv); + + /* use the timeout period ares returned to us above if less than one + second is left, otherwise just use 1000ms to make sure the progress + callback gets called frequent enough */ + if(!tvp->tv_sec) + timeout_ms = (timediff_t)(tvp->tv_usec/1000); + else + timeout_ms = 1000; + + waitperform(conn, timeout_ms); + result = Curl_resolver_is_resolved(conn, entry); + + if(result || conn->async.done) + break; + + if(Curl_pgrsUpdate(conn)) + result = CURLE_ABORTED_BY_CALLBACK; + else { + struct curltime now2 = Curl_now(); + timediff_t timediff = Curl_timediff(now2, now); /* spent time */ + if(timediff <= 0) + timeout -= 1; /* always deduct at least 1 */ + else if(timediff > timeout) + timeout = -1; + else + timeout -= timediff; + now = now2; /* for next loop */ + } + if(timeout < 0) + result = CURLE_OPERATION_TIMEDOUT; + } + if(result) + /* failure, so we cancel the ares operation */ + ares_cancel((ares_channel)data->state.resolver); + + /* Operation complete, if the lookup was successful we now have the entry + in the cache. */ + if(entry) + *entry = conn->async.dns; + + if(result) + /* close the connection, since we can't return failure here without + cleaning up this connection properly. */ + connclose(conn, "c-ares resolve failed"); + + return result; +} + +/* Connects results to the list */ +static void compound_results(struct ResolverResults *res, + struct Curl_addrinfo *ai) +{ + struct Curl_addrinfo *ai_tail; + if(!ai) + return; + ai_tail = ai; + + while(ai_tail->ai_next) + ai_tail = ai_tail->ai_next; + + /* Add the new results to the list of old results. */ + ai_tail->ai_next = res->temp_ai; + res->temp_ai = ai; +} + +/* + * ares_query_completed_cb() is the callback that ares will call when + * the host query initiated by ares_gethostbyname() from Curl_getaddrinfo(), + * when using ares, is completed either successfully or with failure. + */ +static void query_completed_cb(void *arg, /* (struct connectdata *) */ + int status, +#ifdef HAVE_CARES_CALLBACK_TIMEOUTS + int timeouts, +#endif + struct hostent *hostent) +{ + struct connectdata *conn = (struct connectdata *)arg; + struct ResolverResults *res; + +#ifdef HAVE_CARES_CALLBACK_TIMEOUTS + (void)timeouts; /* ignored */ +#endif + + if(ARES_EDESTRUCTION == status) + /* when this ares handle is getting destroyed, the 'arg' pointer may not + be valid so only defer it when we know the 'status' says its fine! */ + return; + + res = (struct ResolverResults *)conn->async.os_specific; + if(res) { + res->num_pending--; + + if(CURL_ASYNC_SUCCESS == status) { + struct Curl_addrinfo *ai = Curl_he2ai(hostent, conn->async.port); + if(ai) { + compound_results(res, ai); + } + } + /* A successful result overwrites any previous error */ + if(res->last_status != ARES_SUCCESS) + res->last_status = status; + + /* If there are responses still pending, we presume they must be the + complementary IPv4 or IPv6 lookups that we started in parallel in + Curl_resolver_getaddrinfo() (for Happy Eyeballs). If we've got a + "definitive" response from one of a set of parallel queries, we need to + think about how long we're willing to wait for more responses. */ + if(res->num_pending + /* Only these c-ares status values count as "definitive" for these + purposes. For example, ARES_ENODATA is what we expect when there is + no IPv6 entry for a domain name, and that's not a reason to get more + aggressive in our timeouts for the other response. Other errors are + either a result of bad input (which should affect all parallel + requests), local or network conditions, non-definitive server + responses, or us cancelling the request. */ + && (status == ARES_SUCCESS || status == ARES_ENOTFOUND)) { + /* Right now, there can only be up to two parallel queries, so don't + bother handling any other cases. */ + DEBUGASSERT(res->num_pending == 1); + + /* It's possible that one of these parallel queries could succeed + quickly, but the other could always fail or timeout (when we're + talking to a pool of DNS servers that can only successfully resolve + IPv4 address, for example). + + It's also possible that the other request could always just take + longer because it needs more time or only the second DNS server can + fulfill it successfully. But, to align with the philosophy of Happy + Eyeballs, we don't want to wait _too_ long or users will think + requests are slow when IPv6 lookups don't actually work (but IPv4 ones + do). + + So, now that we have a usable answer (some IPv4 addresses, some IPv6 + addresses, or "no such domain"), we start a timeout for the remaining + pending responses. Even though it is typical that this resolved + request came back quickly, that needn't be the case. It might be that + this completing request didn't get a result from the first DNS server + or even the first round of the whole DNS server pool. So it could + already be quite some time after we issued the DNS queries in the + first place. Without modifying c-ares, we can't know exactly where in + its retry cycle we are. We could guess based on how much time has + gone by, but it doesn't really matter. Happy Eyeballs tells us that, + given usable information in hand, we simply don't want to wait "too + much longer" after we get a result. + + We simply wait an additional amount of time equal to the default + c-ares query timeout. That is enough time for a typical parallel + response to arrive without being "too long". Even on a network + where one of the two types of queries is failing or timing out + constantly, this will usually mean we wait a total of the default + c-ares timeout (5 seconds) plus the round trip time for the successful + request, which seems bearable. The downside is that c-ares might race + with us to issue one more retry just before we give up, but it seems + better to "waste" that request instead of trying to guess the perfect + timeout to prevent it. After all, we don't even know where in the + c-ares retry cycle each request is. + */ + res->happy_eyeballs_dns_time = Curl_now(); + Curl_expire( + conn->data, HAPPY_EYEBALLS_DNS_TIMEOUT, EXPIRE_HAPPY_EYEBALLS_DNS); + } + } +} + +/* + * Curl_resolver_getaddrinfo() - when using ares + * + * Returns name information about the given hostname and port number. If + * successful, the 'hostent' is returned and the forth argument will point to + * memory we need to free after use. That memory *MUST* be freed with + * Curl_freeaddrinfo(), nothing else. + */ +struct Curl_addrinfo *Curl_resolver_getaddrinfo(struct connectdata *conn, + const char *hostname, + int port, + int *waitp) +{ + char *bufp; + struct Curl_easy *data = conn->data; + int family = PF_INET; + + *waitp = 0; /* default to synchronous response */ + +#ifdef ENABLE_IPV6 /* CURLRES_IPV6 */ + switch(conn->ip_version) { + default: +#if ARES_VERSION >= 0x010601 + family = PF_UNSPEC; /* supported by c-ares since 1.6.1, so for older + c-ares versions this just falls through and defaults + to PF_INET */ + break; +#endif + case CURL_IPRESOLVE_V4: + family = PF_INET; + break; + case CURL_IPRESOLVE_V6: + family = PF_INET6; + break; + } +#endif /* CURLRES_IPV6 */ + + bufp = strdup(hostname); + if(bufp) { + struct ResolverResults *res = NULL; + free(conn->async.hostname); + conn->async.hostname = bufp; + conn->async.port = port; + conn->async.done = FALSE; /* not done */ + conn->async.status = 0; /* clear */ + conn->async.dns = NULL; /* clear */ + res = calloc(sizeof(struct ResolverResults), 1); + if(!res) { + free(conn->async.hostname); + conn->async.hostname = NULL; + return NULL; + } + conn->async.os_specific = res; + + /* initial status - failed */ + res->last_status = ARES_ENOTFOUND; +#ifdef ENABLE_IPV6 /* CURLRES_IPV6 */ + if(family == PF_UNSPEC) { + if(Curl_ipv6works(conn)) { + res->num_pending = 2; + + /* areschannel is already setup in the Curl_open() function */ + ares_gethostbyname((ares_channel)data->state.resolver, hostname, + PF_INET, query_completed_cb, conn); + ares_gethostbyname((ares_channel)data->state.resolver, hostname, + PF_INET6, query_completed_cb, conn); + } + else { + res->num_pending = 1; + + /* areschannel is already setup in the Curl_open() function */ + ares_gethostbyname((ares_channel)data->state.resolver, hostname, + PF_INET, query_completed_cb, conn); + } + } + else +#endif /* CURLRES_IPV6 */ + { + res->num_pending = 1; + + /* areschannel is already setup in the Curl_open() function */ + ares_gethostbyname((ares_channel)data->state.resolver, hostname, family, + query_completed_cb, conn); + } + + *waitp = 1; /* expect asynchronous response */ + } + return NULL; /* no struct yet */ +} + +CURLcode Curl_set_dns_servers(struct Curl_easy *data, + char *servers) +{ + CURLcode result = CURLE_NOT_BUILT_IN; + int ares_result; + + /* If server is NULL or empty, this would purge all DNS servers + * from ares library, which will cause any and all queries to fail. + * So, just return OK if none are configured and don't actually make + * any changes to c-ares. This lets c-ares use it's defaults, which + * it gets from the OS (for instance from /etc/resolv.conf on Linux). + */ + if(!(servers && servers[0])) + return CURLE_OK; + +#if (ARES_VERSION >= 0x010704) +#if (ARES_VERSION >= 0x010b00) + ares_result = ares_set_servers_ports_csv(data->state.resolver, servers); +#else + ares_result = ares_set_servers_csv(data->state.resolver, servers); +#endif + switch(ares_result) { + case ARES_SUCCESS: + result = CURLE_OK; + break; + case ARES_ENOMEM: + result = CURLE_OUT_OF_MEMORY; + break; + case ARES_ENOTINITIALIZED: + case ARES_ENODATA: + case ARES_EBADSTR: + default: + result = CURLE_BAD_FUNCTION_ARGUMENT; + break; + } +#else /* too old c-ares version! */ + (void)data; + (void)(ares_result); +#endif + return result; +} + +CURLcode Curl_set_dns_interface(struct Curl_easy *data, + const char *interf) +{ +#if (ARES_VERSION >= 0x010704) + if(!interf) + interf = ""; + + ares_set_local_dev((ares_channel)data->state.resolver, interf); + + return CURLE_OK; +#else /* c-ares version too old! */ + (void)data; + (void)interf; + return CURLE_NOT_BUILT_IN; +#endif +} + +CURLcode Curl_set_dns_local_ip4(struct Curl_easy *data, + const char *local_ip4) +{ +#if (ARES_VERSION >= 0x010704) + struct in_addr a4; + + if((!local_ip4) || (local_ip4[0] == 0)) { + a4.s_addr = 0; /* disabled: do not bind to a specific address */ + } + else { + if(Curl_inet_pton(AF_INET, local_ip4, &a4) != 1) { + return CURLE_BAD_FUNCTION_ARGUMENT; + } + } + + ares_set_local_ip4((ares_channel)data->state.resolver, ntohl(a4.s_addr)); + + return CURLE_OK; +#else /* c-ares version too old! */ + (void)data; + (void)local_ip4; + return CURLE_NOT_BUILT_IN; +#endif +} + +CURLcode Curl_set_dns_local_ip6(struct Curl_easy *data, + const char *local_ip6) +{ +#if (ARES_VERSION >= 0x010704) && defined(ENABLE_IPV6) + unsigned char a6[INET6_ADDRSTRLEN]; + + if((!local_ip6) || (local_ip6[0] == 0)) { + /* disabled: do not bind to a specific address */ + memset(a6, 0, sizeof(a6)); + } + else { + if(Curl_inet_pton(AF_INET6, local_ip6, a6) != 1) { + return CURLE_BAD_FUNCTION_ARGUMENT; + } + } + + ares_set_local_ip6((ares_channel)data->state.resolver, a6); + + return CURLE_OK; +#else /* c-ares version too old! */ + (void)data; + (void)local_ip6; + return CURLE_NOT_BUILT_IN; +#endif +} +#endif /* CURLRES_ARES */ |