Brad House added ares_save_options() and ares_destroy_options() that can be (79d59ec9) · Commits · CYBER - Cyber Security / TS 103 523 MSP / TLMSP / TLMSP curl

ares/CHANGES

+19 −0

Original line number	Diff line number	Diff line
		@@ -2,6 +2,25 @@

		* May 30 2007

		- Brad House added ares_save_options() and ares_destroy_options() that can be
		used to keep options for later re-usal when ares_init_options() is used.

		Problem: Calling ares_init() for each lookup can be unnecessarily resource
		intensive. On windows, it must LoadLibrary() or search the registry
		on each call to ares_init(). On unix, it must read and parse
		multiple files to obtain the necessary configuration information. In
		a single-threaded environment, it would make sense to only
		ares_init() once, but in a heavily multi-threaded environment, it is
		undesirable to ares_init() and ares_destroy() for each thread created
		and track that.

		Solution: Create ares_save_options() and ares_destroy_options() functions to
		retrieve and free options obtained from an initialized channel. The
		options populated can be used to pass back into ares_init_options(),
		it should populate all needed fields and not retrieve any information
		from the system. Probably wise to destroy the cache every minute or
		so to prevent the data from becoming stale.

		- Daniel S added ares_process_fd() to allow applications to ask for processing
		on specific sockets and thus avoiding select() and associated
		functions/macros. This function will be used by upcoming libcurl releases

ares/ares.h

+7 −0

Original line number	Diff line number	Diff line
		@@ -94,6 +94,7 @@ extern "C" {
		#define ARES_OPT_DOMAINS (1 << 7)
		#define ARES_OPT_LOOKUPS (1 << 8)
		#define ARES_OPT_SOCK_STATE_CB (1 << 9)
		#define ARES_OPT_SORTLIST (1 << 10)

		/* Nameinfo flag values */
		#define ARES_NI_NOFQDN (1 << 0)
		@@ -164,6 +165,8 @@ typedef void (ares_sock_state_cb)(void data,
		int writable);
		#endif

		struct apattern;

		struct ares_options {
		int flags;
		int timeout;
		@@ -178,6 +181,8 @@ struct ares_options {
		char *lookups;
		ares_sock_state_cb sock_state_cb;
		void *sock_state_cb_data;
		struct apattern *sortlist;
		int nsort;
		};

		struct hostent;
		@@ -195,6 +200,8 @@ typedef void (ares_nameinfo_callback)(void arg, int status,
		int ares_init(ares_channel *channelptr);
		int ares_init_options(ares_channel channelptr, struct ares_options options,
		int optmask);
		int ares_save_options(ares_channel channel, struct ares_options options, int optmask);
		void ares_destroy_options(struct ares_options *options);
		void ares_destroy(ares_channel channel);
		void ares_cancel(ares_channel channel);
		void ares_send(ares_channel channel, const unsigned char *qbuf, int qlen,

ares/ares_destroy.c

+13 −0

Original line number	Diff line number	Diff line
		@@ -20,6 +20,19 @@
		#include "ares.h"
		#include "ares_private.h"

		void ares_destroy_options(struct ares_options *options)
		{
		int i;

		free(options->servers);
		for (i = 0; i < options->ndomains; i++)
		free(options->domains[i]);
		free(options->domains);
		if(options->sortlist)
		free(options->sortlist);
		free(options->lookups);
		}

		void ares_destroy(ares_channel channel)
		{
		int i;

ares/ares_init.c

+94 −2

Original line number	Diff line number	Diff line
		@@ -61,7 +61,7 @@
		#undef WIN32 /* Redefined in MingW/MSVC headers */
		#endif

		static int init_by_options(ares_channel channel, struct ares_options *options,
		static int init_by_options(ares_channel channel, const struct ares_options *options,
		int optmask);
		static int init_by_environment(ares_channel channel);
		static int init_by_resolv_conf(ares_channel channel);
		@@ -84,6 +84,12 @@ static int config_sortlist(struct apattern *sortlist, int nsort,
		static char try_config(char s, const char *opt);
		#endif

		#define ARES_CONFIG_CHECK(x) (x->lookups && x->nsort > -1 && \
		x->nservers > -1 && \
		x->ndomains > -1 && \
		x->ndots > -1 && x->timeout > -1 && \
		x->tries > -1)

		int ares_init(ares_channel *channelptr)
		{
		return ares_init_options(channelptr, NULL, 0);
		@@ -212,7 +218,76 @@ int ares_init_options(ares_channel channelptr, struct ares_options options,
		return ARES_SUCCESS;
		}

		static int init_by_options(ares_channel channel, struct ares_options *options,
		/* Save options from initialized channel */
		int ares_save_options(ares_channel channel, struct ares_options *options,
		int *optmask)
		{
		int i;

		/* Zero everything out */
		memset(options, 0, sizeof(struct ares_options));

		if (!ARES_CONFIG_CHECK(channel))
		return ARES_ENODATA;

		(*optmask) = (ARES_OPT_FLAGS\|ARES_OPT_TIMEOUT\|ARES_OPT_TRIES\|ARES_OPT_NDOTS\|
		ARES_OPT_UDP_PORT\|ARES_OPT_TCP_PORT\|ARES_OPT_SOCK_STATE_CB\|
		ARES_OPT_SERVERS\|ARES_OPT_DOMAINS\|ARES_OPT_LOOKUPS\|
		ARES_OPT_SORTLIST);

		/* Copy easy stuff */
		options->flags = channel->flags;
		options->timeout = channel->timeout;
		options->tries = channel->tries;
		options->ndots = channel->ndots;
		options->udp_port = channel->udp_port;
		options->tcp_port = channel->tcp_port;
		options->sock_state_cb = channel->sock_state_cb;
		options->sock_state_cb_data = channel->sock_state_cb_data;

		/* Copy servers */
		options->servers =
		malloc(channel->nservers * sizeof(struct server_state));
		if (!options->servers && channel->nservers != 0)
		return ARES_ENOMEM;
		for (i = 0; i < channel->nservers; i++)
		options->servers[i] = channel->servers[i].addr;
		options->nservers = channel->nservers;

		/* copy domains */
		options->domains = malloc(channel->ndomains * sizeof(char *));
		if (!options->domains)
		return ARES_ENOMEM;
		for (i = 0; i < channel->ndomains; i++)
		{
		options->ndomains = i;
		options->domains[i] = strdup(channel->domains[i]);
		if (!options->domains[i])
		return ARES_ENOMEM;
		}
		options->ndomains = channel->ndomains;

		/* copy lookups */
		options->lookups = strdup(channel->lookups);
		if (!options->lookups)
		return ARES_ENOMEM;

		/* copy sortlist */
		options->sortlist = malloc(channel->nsort * sizeof(struct apattern));
		if (!options->sortlist)
		return ARES_ENOMEM;
		for (i = 0; i < channel->nsort; i++)
		{
		memcpy(&(options->sortlist[i]), &(channel->sortlist[i]),
		sizeof(struct apattern));
		}
		options->nsort = channel->nsort;

		return ARES_SUCCESS;
		}

		static int init_by_options(ares_channel channel,
		const struct ares_options *options,
		int optmask)
		{
		int i;
		@@ -282,6 +357,19 @@ static int init_by_options(ares_channel channel, struct ares_options *options,
		return ARES_ENOMEM;
		}

		/* copy sortlist */
		if ((optmask & ARES_OPT_SORTLIST) && channel->nsort == -1)
		{
		channel->sortlist = malloc(options->nsort * sizeof(struct apattern));
		if (!channel->sortlist)
		return ARES_ENOMEM;
		for (i = 0; i < options->nsort; i++)
		{
		memcpy(&(channel->sortlist[i]), &(options->sortlist[i]), sizeof(struct apattern));
		}
		channel->nsort = options->nsort;
		}

		return ARES_SUCCESS;
		}

		@@ -615,6 +703,10 @@ DhcpNameServer
		int linesize;
		int error;

		/* Don't read resolv.conf and friends if we don't have to */
		if (ARES_CONFIG_CHECK(channel))
		return ARES_SUCCESS;

		fp = fopen(PATH_RESOLV_CONF, "r");
		if (fp) {
		while ((status = ares__read_line(fp, &line, &linesize)) == ARES_SUCCESS)