Add support for DNS cache timeouts via the CURLOPT_DNS_CACHE_TIMEOUT option. (22ac08e0) · Commits · CYBER - Cyber Security / TS 103 523 MSP / TLMSP / TLMSP curl

include/curl/curl.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -491,6 +491,9 @@ typedef enum {
		/* Non-zero value means to use the global dns cache */
		CINIT(DNS_USE_GLOBAL_CACHE, LONG, 91),

		/* DNS cache timeout */
		CINIT(DNS_CACHE_TIMEOUT, LONG, 92),

		CURLOPT_LASTENTRY /* the last unusued */
		} CURLoption;

lib/hostip.c

+50 −11

Original line number	Diff line number	Diff line
		@@ -93,24 +93,59 @@ void Curl_global_host_cache_dtor(void)
		}
		}

		struct curl_dns_cache_entry {
		Curl_addrinfo *addr;
		int timestamp;
		};

		Curl_addrinfo Curl_resolv(struct SessionHandle data,
		char *hostname,
		int port,
		char **bufp)
		{
		Curl_addrinfo *addr = NULL;
		size_t hostname_len = strlen(hostname)+1;
		struct curl_dns_cache_entry *p = NULL;
		size_t hostname_len;
		time_t now;

		/* If the host cache timeout is 0, we don't do DNS cach'ing
		so fall through */
		if (data->set.dns_cache_timeout == 0) {
		return Curl_getaddrinfo(data, hostname, port, bufp);
		}

		hostname_len = strlen(hostname)+1;

		time(&now);
		/* See if its already in our dns cache */
		if (curl_hash_find(data->hostcache, hostname, hostname_len, (void **) &p)) {
		/* Do we need to check for a cache timeout? */
		if (data->set.dns_cache_timeout != -1) {
		/* Return if the entry has not timed out */
		if ((now - p->timestamp) < data->set.dns_cache_timeout) {
		return p->addr;
		}
		}
		else {
		return p->addr;
		}
		}

		if (curl_hash_find(data->hostcache, hostname, hostname_len, (void **) &addr)) {
		return addr;
		/* Create a new cache entry */
		p = (struct curl_dns_cache_entry *) malloc(sizeof(struct curl_dns_cache_entry));
		if (!p) {
		return NULL;
		}

		addr = Curl_getaddrinfo(data, hostname, port, bufp);
		if (!addr)
		p->addr = Curl_getaddrinfo(data, hostname, port, bufp);
		if (!p->addr) {
		return NULL;
		}
		p->timestamp = now;

		curl_hash_add(data->hostcache, hostname, hostname_len, (const void *) addr);
		return addr;
		/* Save it in our host cache */
		curl_hash_update(data->hostcache, hostname, hostname_len, (const void *) p);

		return p->addr;
		}

		/*
		@@ -120,11 +155,15 @@ Curl_addrinfo Curl_resolv(struct SessionHandle data,
		*/
		void Curl_freeaddrinfo(void *freethis)
		{
		struct curl_dns_cache_entry p = (struct curl_dns_cache_entry ) freethis;

		#ifdef ENABLE_IPV6
		freeaddrinfo(freethis);
		freeaddrinfo(p->addr);
		#else
		free(freethis);
		free(p->addr);
		#endif

		free(p);
		}

		/* --- resolve name or IP-number --- */

lib/url.c

+8 −2

Original line number	Diff line number	Diff line
		@@ -251,6 +251,8 @@ CURLcode Curl_open(struct SessionHandle **curl)
		data->set.httpreq = HTTPREQ_GET; /* Default HTTP request */
		data->set.ftp_use_epsv = TRUE; /* FTP defaults to EPSV operations */

		data->set.dns_cache_timeout = 60; /* Timeout every 60 seconds by default */

		/* make libcurl quiet by default: */
		data->set.hide_progress = TRUE; /* CURLOPT_NOPROGRESS changes these */
		data->progress.flags \|= PGRS_HIDE;
		@@ -284,7 +286,11 @@ CURLcode Curl_setopt(struct SessionHandle *data, CURLoption option, ...)
		va_start(param, option);

		switch(option) {
		case CURLOPT_DNS_USE_GLOBAL_CACHE: {
		case CURLOPT_DNS_CACHE_TIMEOUT:
		data->set.dns_cache_timeout = va_arg(param, int);
		break;
		case CURLOPT_DNS_USE_GLOBAL_CACHE:
		{
		int use_cache = va_arg(param, int);
		if (use_cache) {
		Curl_global_host_cache_init();

lib/urldata.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -647,6 +647,7 @@ struct UserDefined {
		bool ftp_use_epsv; /* if EPSV is to be attempted or not */

		bool global_dns_cache;
		bool dns_cache_timeout;
		};

		/*