int main(int argc, char **argv)
{
ares_channel channel;
int c, i, optmask = ARES_OPT_FLAGS, dnsclass = C_IN, type = T_A;
int status, nfds, count;
struct ares_options options;
struct hostent *hostent;
fd_set read_fds, write_fds;
struct timeval *tvp, tv;
struct ares_addr_node *srvr, *servers = NULL;
#ifdef USE_WINSOCK
WORD wVersionRequested = MAKEWORD(USE_WINSOCK,USE_WINSOCK);
WSADATA wsaData;
WSAStartup(wVersionRequested, &wsaData);
#endif
status = ares_library_init(ARES_LIB_INIT_ALL);
if (status != ARES_SUCCESS)
{
fprintf(stderr, "ares_library_init: %s\n", ares_strerror(status));
return 1;
}
options.flags = ARES_FLAG_NOCHECKRESP;
options.servers = NULL;
options.nservers = 0;
while ((c = ares_getopt(argc, argv, "df:s:c:t:T:U:")) != -1)
{
switch (c)
{
case 'd':
#ifdef WATT32
dbug_init();
#endif
break;
case 'f':
/* Add a flag. */
for (i = 0; i < nflags; i++)
{
if (strcmp(flags[i].name, optarg) == 0)
break;
}
if (i < nflags)
options.flags |= flags[i].value;
else
usage();
break;
case 's':
/* User-specified name servers override default ones. */
srvr = malloc(sizeof(struct ares_addr_node));
if (!srvr)
{
fprintf(stderr, "Out of memory!\n");
destroy_addr_list(servers);
return 1;
}
append_addr_list(&servers, srvr);
if (ares_inet_pton(AF_INET, optarg, &srvr->addr.addr4) > 0)
srvr->family = AF_INET;
else if (ares_inet_pton(AF_INET6, optarg, &srvr->addr.addr6) > 0)
srvr->family = AF_INET6;
else
{
hostent = gethostbyname(optarg);
if (!hostent)
{
fprintf(stderr, "adig: server %s not found.\n", optarg);
destroy_addr_list(servers);
return 1;
}
switch (hostent->h_addrtype)
{
case AF_INET:
srvr->family = AF_INET;
memcpy(&srvr->addr.addr4, hostent->h_addr,
sizeof(srvr->addr.addr4));
break;
case AF_INET6:
srvr->family = AF_INET6;
memcpy(&srvr->addr.addr6, hostent->h_addr,
sizeof(srvr->addr.addr6));
break;
default:
fprintf(stderr,
"adig: server %s unsupported address family.\n", optarg);
destroy_addr_list(servers);
return 1;
}
}
/* Notice that calling ares_init_options() without servers in the
* options struct and with ARES_OPT_SERVERS set simultaneously in
* the options mask, results in an initialization with no servers.
* When alternative name servers have been specified these are set
* later calling ares_set_servers() overriding any existing server
* configuration. To prevent initial configuration with default
* servers that will be discarded later, ARES_OPT_SERVERS is set.
* If this flag is not set here the result shall be the same but
* ares_init_options() will do needless work. */
optmask |= ARES_OPT_SERVERS;
break;
case 'c':
/* Set the query class. */
for (i = 0; i < nclasses; i++)
{
if (strcasecmp(classes[i].name, optarg) == 0)
break;
}
if (i < nclasses)
dnsclass = classes[i].value;
else
usage();
break;
case 't':
/* Set the query type. */
for (i = 0; i < ntypes; i++)
{
if (strcasecmp(types[i].name, optarg) == 0)
break;
}
if (i < ntypes)
type = types[i].value;
else
usage();
break;
case 'T':
/* Set the TCP port number. */
if (!ISDIGIT(*optarg))
usage();
options.tcp_port = (unsigned short)strtol(optarg, NULL, 0);
optmask |= ARES_OPT_TCP_PORT;
break;
case 'U':
/* Set the UDP port number. */
if (!ISDIGIT(*optarg))
usage();
options.udp_port = (unsigned short)strtol(optarg, NULL, 0);
optmask |= ARES_OPT_UDP_PORT;
break;
}
}
argc -= optind;
argv += optind;
if (argc == 0)
usage();
status = ares_init_options(&channel, &options, optmask);
if (status != ARES_SUCCESS)
{
fprintf(stderr, "ares_init_options: %s\n",
ares_strerror(status));
return 1;
}
if(servers)
{
status = ares_set_servers(channel, servers);
destroy_addr_list(servers);
if (status != ARES_SUCCESS)
{
fprintf(stderr, "ares_init_options: %s\n",
ares_strerror(status));
return 1;
}
}
/* Initiate the queries, one per command-line argument. If there is
* only one query to do, supply NULL as the callback argument;
* otherwise, supply the query name as an argument so we can
* distinguish responses for the user when printing them out.
*/
if (argc == 1)
ares_query(channel, *argv, dnsclass, type, callback, (char *) NULL);
else
{
for (; *argv; argv++)
ares_query(channel, *argv, dnsclass, type, callback, *argv);
}
/* Wait for all queries to complete. */
for (;;)
{
FD_ZERO(&read_fds);
FD_ZERO(&write_fds);
nfds = ares_fds(channel, &read_fds, &write_fds);
if (nfds == 0)
break;
tvp = ares_timeout(channel, NULL, &tv);
count = select(nfds, &read_fds, &write_fds, NULL, tvp);
if (count < 0 && SOCKERRNO != EINVAL)
{
perror("select");
return 1;
}
ares_process(channel, &read_fds, &write_fds);
}
ares_destroy(channel);
ares_library_cleanup();
#ifdef USE_WINSOCK
WSACleanup();
#endif
return 0;
}
int dns_start_query(myconn_t *rec, char *targetserver)
{
struct ares_addr_node *srvr, *servers = NULL;
struct ares_options options;
int status, optmask;
char *tdup, *tst;
/* See what IP family we must use to communicate with the target DNS server */
srvr = malloc(sizeof(struct ares_addr_node));
append_addr_list(&servers, srvr);
srvr->family = -1;
#ifdef IPV4_SUPPORT
if ((srvr->family == -1) && (inet_pton(AF_INET, targetserver, &srvr->addr.addr4) > 0))
srvr->family = AF_INET;
#endif
#ifdef IPV6_SUPPORT
if ((srvr->family == -1) && (inet_pton(AF_INET6, targetserver, &srvr->addr.addr6) > 0))
srvr->family = AF_INET6;
#endif
if (srvr->family == -1) {
errprintf("Unsupported IP family for DNS target IP %s, test %s\n", targetserver, rec->testspec);
return 0;
}
/* Create a new ARES request channel */
rec->dnschannel = malloc(sizeof(ares_channel));
/*
* The C-ARES timeout handling is a bit complicated. The timeout setting
* here in the options only determines the timeout for the first query;
* subsequent queries (up to the "tries" count) use a progressively
* higher timeout setting.
* So we cannot easily determine what combination of timeout/tries will
* result in the full query timing out after the desired number of seconds.
* Therefore, use a fixed set of values - the 2000 ms / 4 tries combination
* results in a timeout after 23-24 seconds.
*/
optmask = ARES_OPT_FLAGS | ARES_OPT_SERVERS | ARES_OPT_TIMEOUTMS | ARES_OPT_TRIES;
options.flags = ARES_FLAG_NOCHECKRESP;
options.servers = NULL;
options.nservers = 0;
options.timeout = 2000;
options.tries = 4;
status = ares_init_options(rec->dnschannel, &options, optmask);
if (status != ARES_SUCCESS) {
errprintf("Cannot create ARES channel for DNS target %s, test %s\n", targetserver, rec->testspec);
rec->dnsstatus = DNS_FINISHED;
return 0;
}
/* Point the channel at the target server */
status = ares_set_servers(*((ares_channel *)rec->dnschannel), servers);
destroy_addr_list(servers);
if (status != ARES_SUCCESS)
{
errprintf("Cannot select ARES target DNS server %s, test %s\n", targetserver, rec->testspec);
rec->dnsstatus = DNS_QUERY_COMPLETED; /* To reap the ARES channel later */
return 0;
}
/* Post the queries we want to perform */
tdup = strdup(rec->testspec);
tst = strtok(tdup, ",");
do {
char *p, *tlookup;
int atype = dns_atype;
p = strchr(tst, ':');
tlookup = (p ? p+1 : tst);
if (p) {
*p = '\0';
atype = dns_name_type(tst);
*p = ':';
}
/* Use ares_query() here, since we dont want to get results from hosts file or other odd stuff. */
ares_query(*((ares_channel *)rec->dnschannel), tlookup, dns_aclass, atype, dns_query_callback, rec);
tst = strtok(NULL, ",");
} while (tst);
xfree(tdup);
rec->textlog = newstrbuffer(0);
getntimer(&rec->dnsstarttime);
rec->dnsstatus = DNS_QUERY_ACTIVE;
return 1;
}
