Refactor large parts of the program.

The new design assures revDNS/WHOIS queries will be done exactly once, no matter how many requests the Schachtmeister gets.
This commit also adds cache timeouts.

1 files changed, 78 insertions, 7 deletions

diff --git a/src/main.c b/src/main.c
index 69653c7..fc377e3 100644
--- a/src/main.c
+++ b/src/main.c
@@ -17,9 +17,21 @@ Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
 */
 
 #include "shared.h"
+#include <time.h>
 
 int server_sockfd;
 
+static struct timespec time_ref;
+
+uint64_t get_time(void)
+{
+	static struct timespec now;
+
+	clock_gettime(CLOCK_MONOTONIC, &now);
+	return (uint64_t)(now.tv_sec - time_ref.tv_sec) * TIME_SECOND +
+	       now.tv_nsec + 1;
+}
+
 static int parse_req_addr(char *begin, char *end, uint32_t *out)
 {
 	char *p;
@@ -48,6 +60,68 @@ static int parse_req_addr(char *begin, char *end, uint32_t *out)
 	return 0;
 }
 
+void handle_request(struct sockaddr_in *ret_addr, uint32_t query)
+{
+	db_entry *entry;
+	job_t *reply_job;
+	uint64_t now = get_time();
+
+	DEBUG("query %08X\n", query);
+
+	entry = db_find(query);
+	if (!entry) {
+		eprintf("handle_request: out of memory\n");
+		return;
+	}
+
+	reply_job = job_create(JOB_REPLY, entry);
+	reply_job->ipv4 = query;
+	memcpy(&reply_job->ret_addr, ret_addr, sizeof(struct sockaddr_in));
+
+	if (entry->revdns.state == DB_VALID
+	    && entry->revdns.exp_time <= now) {
+		entry->revdns.state = DB_INVALID;
+		DEBUG("revDNS for %08X expired\n", query);
+	}
+
+	if (entry->whois.state == DB_VALID
+	    && entry->whois.exp_time <= now) {
+		entry->whois.state = DB_INVALID;
+		DEBUG("WHOIS for %08X expired\n", query);
+	}
+
+	if (entry->revdns.state == DB_VALID &&
+	    entry->whois.state == DB_VALID) {
+		job_enqueue(reply_job);
+		goto out;
+	}
+
+	if (entry->revdns.state == DB_INVALID) {
+		job_t *job;
+
+		DEBUG("revDNS cache miss for %08X\n", query);
+		job = job_create(JOB_REVDNS, entry);
+		job->ipv4 = query;
+		job_enqueue(job);
+		entry->revdns.state = DB_IN_PROGRESS;
+	}
+
+	if (entry->whois.state == DB_INVALID) {
+		job_t *job;
+
+		DEBUG("WHOIS cache miss for %08X\n", query);
+		job = job_create(JOB_WHOIS, entry);
+		job->ipv4 = query;
+		job_enqueue(job);
+		entry->whois.state = DB_IN_PROGRESS;
+	}
+
+	eli_append(&entry->waiting_jobs, reply_job, waiting_list);
+
+out:
+	pthread_mutex_unlock(&entry->mutex);
+}
+
 #define NUM_WORKERS 8 // FIXME: shouldn't be hardcoded
 
 int main(void)
@@ -57,6 +131,8 @@ int main(void)
 	pthread_t workers[NUM_WORKERS];
 	size_t i;
 
+	clock_gettime(CLOCK_MONOTONIC_RAW, &time_ref);
+
 	if (lists_load("schachts.list", 0)) {
 		eprintf("fatal error: couldn't load the lists\n");
 		goto error_lists;
@@ -88,7 +164,6 @@ int main(void)
 		socklen_t addrlen = sizeof(addr);
 		ssize_t size;
 		uint32_t query;
-		job_t *job;
 
 		size = recvfrom(server_sockfd, buffer, sizeof(buffer), 0,
 		                (void*)&addr, &addrlen);
@@ -111,11 +186,7 @@ int main(void)
 		                   &query))
 			continue;
 
-		job = job_create();
-		job->type = JOB_TEST;
-		job->query = query;
-		memcpy(&job->reply_to, &addr, sizeof(addr));
-		job_enqueue(job);
+		handle_request(&addr, query);
 	}
 
 	job_quit();
@@ -123,7 +194,7 @@ int main(void)
 	for (i = 0; i < NUM_WORKERS; i++)
 		pthread_join(workers[i], NULL);
 
-	cache_destroy();
+	db_destroy();
 	// todo: clear all jobs
 
 error_recvfrom: