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Actually add the new dns-example.c code. :p
svn:r1512
This commit is contained in:
Nick Mathewson
parent
d2e7e65d21
commit
ae5fbf492f
169
sample/dns-example.c
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169
sample/dns-example.c
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#include <event-config.h>
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#ifdef WIN32
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#include <winsock2.h>
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#include <ws2tcpip.h>
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#else
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <arpa/inet.h>
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#endif
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#include <event2/event.h>
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#include <event2/dns.h>
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#include <event2/dns_struct.h>
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#include <event2/util.h>
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#ifdef _EVENT_HAVE_NETINET_IN6_H
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#include <netinet/in6.h>
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#endif
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#define u32 ev_uint32_t
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#define u8 ev_uint8_t
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static const char *
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debug_ntoa(u32 address)
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{
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static char buf[32];
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u32 a = ntohl(address);
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evutil_snprintf(buf, sizeof(buf), "%d.%d.%d.%d",
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(int)(u8)((a>>24)&0xff),
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(int)(u8)((a>>16)&0xff),
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(int)(u8)((a>>8 )&0xff),
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(int)(u8)((a )&0xff));
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return buf;
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}
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static void
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main_callback(int result, char type, int count, int ttl,
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void *addrs, void *orig) {
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char *n = (char*)orig;
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int i;
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for (i = 0; i < count; ++i) {
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if (type == DNS_IPv4_A) {
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printf("%s: %s\n", n, debug_ntoa(((u32*)addrs)[i]));
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} else if (type == DNS_PTR) {
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printf("%s: %s\n", n, ((char**)addrs)[i]);
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}
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}
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if (!count) {
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printf("%s: No answer (%d)\n", n, result);
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}
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fflush(stdout);
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}
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static void
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evdns_server_callback(struct evdns_server_request *req, void *data)
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{
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int i, r;
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(void)data;
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/* dummy; give 192.168.11.11 as an answer for all A questions,
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* give foo.bar.example.com as an answer for all PTR questions. */
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for (i = 0; i < req->nquestions; ++i) {
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u32 ans = htonl(0xc0a80b0bUL);
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if (req->questions[i]->type == EVDNS_TYPE_A &&
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req->questions[i]->dns_question_class == EVDNS_CLASS_INET) {
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printf(" -- replying for %s (A)\n", req->questions[i]->name);
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r = evdns_server_request_add_a_reply(req, req->questions[i]->name,
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1, &ans, 10);
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if (r<0)
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printf("eeep, didn't work.\n");
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} else if (req->questions[i]->type == EVDNS_TYPE_PTR &&
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req->questions[i]->dns_question_class == EVDNS_CLASS_INET) {
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printf(" -- replying for %s (PTR)\n", req->questions[i]->name);
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r = evdns_server_request_add_ptr_reply(req, NULL, req->questions[i]->name,
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"foo.bar.example.com", 10);
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} else {
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printf(" -- skipping %s [%d %d]\n", req->questions[i]->name,
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req->questions[i]->type, req->questions[i]->dns_question_class);
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}
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}
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r = evdns_server_request_respond(req, 0);
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if (r<0)
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printf("eeek, couldn't send reply.\n");
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}
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static int verbose = 0;
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static void
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logfn(int is_warn, const char *msg) {
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if (!is_warn && !verbose)
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return;
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fprintf(stderr, "%s: %s\n", is_warn?"WARN":"INFO", msg);
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}
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int
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main(int c, char **v) {
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int idx;
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int reverse = 0, servertest = 0;
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struct event_base *event_base = NULL;
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struct evdns_base *evdns_base = NULL;
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if (c<2) {
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fprintf(stderr, "syntax: %s [-x] [-v] hostname\n", v[0]);
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fprintf(stderr, "syntax: %s [-servertest]\n", v[0]);
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return 1;
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}
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idx = 1;
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while (idx < c && v[idx][0] == '-') {
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if (!strcmp(v[idx], "-x"))
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reverse = 1;
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else if (!strcmp(v[idx], "-v"))
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verbose = 1;
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else if (!strcmp(v[idx], "-servertest"))
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servertest = 1;
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else
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fprintf(stderr, "Unknown option %s\n", v[idx]);
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++idx;
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}
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event_base = event_base_new();
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evdns_base = evdns_base_new(event_base, 0);
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evdns_set_log_fn(logfn);
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if (servertest) {
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int sock;
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struct sockaddr_in my_addr;
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sock = socket(PF_INET, SOCK_DGRAM, 0);
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evutil_make_socket_nonblocking(sock);
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my_addr.sin_family = AF_INET;
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my_addr.sin_port = htons(10053);
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my_addr.sin_addr.s_addr = INADDR_ANY;
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if (bind(sock, (struct sockaddr*)&my_addr, sizeof(my_addr))<0) {
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perror("bind");
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exit(1);
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}
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evdns_add_server_port_with_base(event_base, sock, 0, evdns_server_callback, NULL);
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}
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if (idx < c) {
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#ifdef WIN32
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evdns_base_config_windows_nameservers(evdns_base);
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#else
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evdns_base_resolv_conf_parse(evdns_base, DNS_OPTION_NAMESERVERS,
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"/etc/resolv.conf");
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#endif
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}
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for (; idx < c; ++idx) {
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if (reverse) {
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struct in_addr addr;
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if (!inet_aton(v[idx], &addr)) {
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fprintf(stderr, "Skipping non-IP %s\n", v[idx]);
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continue;
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}
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fprintf(stderr, "resolving %s...\n",v[idx]);
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evdns_base_resolve_reverse(evdns_base, &addr, 0, main_callback, v[idx]);
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} else {
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fprintf(stderr, "resolving (fwd) %s...\n",v[idx]);
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evdns_base_resolve_ipv4(evdns_base, v[idx], 0, main_callback, v[idx]);
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}
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}
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fflush(stdout);
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event_base_dispatch(event_base);
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return 0;
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}
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