Actually add the new dns-example.c code. :p

svn:r1512

1 files changed, 169 insertions, 0 deletions

diff --git a/sample/dns-example.c b/sample/dns-example.c
new file mode 100644
index 00000000..7757dd48
--- /dev/null
+++ b/sample/dns-example.c
@@ -0,0 +1,169 @@
+
+#include <event-config.h>
+
+#ifdef WIN32
+#include <winsock2.h>
+#include <ws2tcpip.h>
+#else
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#endif
+
+#include <event2/event.h>
+#include <event2/dns.h>
+#include <event2/dns_struct.h>
+#include <event2/util.h>
+
+#ifdef _EVENT_HAVE_NETINET_IN6_H
+#include <netinet/in6.h>
+#endif
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define u32 ev_uint32_t
+#define u8 ev_uint8_t
+
+static const char *
+debug_ntoa(u32 address)
+{
+	static char buf[32];
+	u32 a = ntohl(address);
+	evutil_snprintf(buf, sizeof(buf), "%d.%d.%d.%d",
+					(int)(u8)((a>>24)&0xff),
+					(int)(u8)((a>>16)&0xff),
+					(int)(u8)((a>>8 )&0xff),
+					(int)(u8)((a	)&0xff));
+	return buf;
+}
+
+static void
+main_callback(int result, char type, int count, int ttl,
+			  void *addrs, void *orig) {
+	char *n = (char*)orig;
+	int i;
+	for (i = 0; i < count; ++i) {
+		if (type == DNS_IPv4_A) {
+			printf("%s: %s\n", n, debug_ntoa(((u32*)addrs)[i]));
+		} else if (type == DNS_PTR) {
+			printf("%s: %s\n", n, ((char**)addrs)[i]);
+		}
+	}
+	if (!count) {
+		printf("%s: No answer (%d)\n", n, result);
+	}
+	fflush(stdout);
+}
+
+static void
+evdns_server_callback(struct evdns_server_request *req, void *data)
+{
+	int i, r;
+	(void)data;
+	/* dummy; give 192.168.11.11 as an answer for all A questions,
+	 *	give foo.bar.example.com as an answer for all PTR questions. */
+	for (i = 0; i < req->nquestions; ++i) {
+		u32 ans = htonl(0xc0a80b0bUL);
+		if (req->questions[i]->type == EVDNS_TYPE_A &&
+		    req->questions[i]->dns_question_class == EVDNS_CLASS_INET) {
+			printf(" -- replying for %s (A)\n", req->questions[i]->name);
+			r = evdns_server_request_add_a_reply(req, req->questions[i]->name,
+										  1, &ans, 10);
+			if (r<0)
+				printf("eeep, didn't work.\n");
+		} else if (req->questions[i]->type == EVDNS_TYPE_PTR &&
+		    req->questions[i]->dns_question_class == EVDNS_CLASS_INET) {
+			printf(" -- replying for %s (PTR)\n", req->questions[i]->name);
+			r = evdns_server_request_add_ptr_reply(req, NULL, req->questions[i]->name,
+											"foo.bar.example.com", 10);
+		} else {
+			printf(" -- skipping %s [%d %d]\n", req->questions[i]->name,
+				   req->questions[i]->type, req->questions[i]->dns_question_class);
+		}
+	}
+
+	r = evdns_server_request_respond(req, 0);
+	if (r<0)
+		printf("eeek, couldn't send reply.\n");
+}
+
+static int verbose = 0;
+
+static void
+logfn(int is_warn, const char *msg) {
+	if (!is_warn && !verbose)
+		return;
+	fprintf(stderr, "%s: %s\n", is_warn?"WARN":"INFO", msg);
+}
+
+int
+main(int c, char **v) {
+	int idx;
+	int reverse = 0, servertest = 0;
+	struct event_base *event_base = NULL;
+	struct evdns_base *evdns_base = NULL;
+	if (c<2) {
+		fprintf(stderr, "syntax: %s [-x] [-v] hostname\n", v[0]);
+		fprintf(stderr, "syntax: %s [-servertest]\n", v[0]);
+		return 1;
+	}
+	idx = 1;
+	while (idx < c && v[idx][0] == '-') {
+		if (!strcmp(v[idx], "-x"))
+			reverse = 1;
+		else if (!strcmp(v[idx], "-v"))
+			verbose = 1;
+		else if (!strcmp(v[idx], "-servertest"))
+			servertest = 1;
+		else
+			fprintf(stderr, "Unknown option %s\n", v[idx]);
+		++idx;
+	}
+
+	event_base = event_base_new();
+	evdns_base = evdns_base_new(event_base, 0);
+	evdns_set_log_fn(logfn);
+
+	if (servertest) {
+		int sock;
+		struct sockaddr_in my_addr;
+		sock = socket(PF_INET, SOCK_DGRAM, 0);
+		evutil_make_socket_nonblocking(sock);
+		my_addr.sin_family = AF_INET;
+		my_addr.sin_port = htons(10053);
+		my_addr.sin_addr.s_addr = INADDR_ANY;
+		if (bind(sock, (struct sockaddr*)&my_addr, sizeof(my_addr))<0) {
+			perror("bind");
+			exit(1);
+		}
+		evdns_add_server_port_with_base(event_base, sock, 0, evdns_server_callback, NULL);
+	}
+	if (idx < c) {
+#ifdef WIN32
+		evdns_base_config_windows_nameservers(evdns_base);
+#else
+		evdns_base_resolv_conf_parse(evdns_base, DNS_OPTION_NAMESERVERS,
+		    "/etc/resolv.conf");
+#endif
+	}
+	for (; idx < c; ++idx) {
+		if (reverse) {
+			struct in_addr addr;
+			if (!inet_aton(v[idx], &addr)) {
+				fprintf(stderr, "Skipping non-IP %s\n", v[idx]);
+				continue;
+			}
+			fprintf(stderr, "resolving %s...\n",v[idx]);
+			evdns_base_resolve_reverse(evdns_base, &addr, 0, main_callback, v[idx]);
+		} else {
+			fprintf(stderr, "resolving (fwd) %s...\n",v[idx]);
+			evdns_base_resolve_ipv4(evdns_base, v[idx], 0, main_callback, v[idx]);
+		}
+	}
+	fflush(stdout);
+	event_base_dispatch(event_base);
+	return 0;
+}
+