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/*
* nsd-notify.c -- sends notify(rfc1996) message to a list of servers
*
* Copyright (c) 2001-2006, NLnet Labs. All rights reserved.
*
* See LICENSE for the license.
*
*/
#include <config.h>
#include <sys/types.h>
#ifdef HAVE_SYS_SELECT_H
#include <sys/select.h>
#endif
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <errno.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <tsig.h>
#include <unistd.h>
#include <netdb.h>
#include "query.h"
extern char *optarg;
extern int optind;
/*
* Check if two getaddrinfo result lists have records with matching
* ai_family fields.
*/
int check_matching_address_family(struct addrinfo *a, struct addrinfo *b);
/*
* Returns the first record with ai_family == FAMILY, or NULL if no
* such record is found.
*/
struct addrinfo *find_by_address_family(struct addrinfo *addrs, int family);
/*
* Assigns pointers to hostname and port and wipes out the optional delimiter.
*/
void get_hostname_port_frm_str(char* arg, const char** hostname,
const char** port);
/*
* Log a warning message.
*/
static void warning(const char *format, ...) ATTR_FORMAT(printf, 1, 2);
static void
warning(const char *format, ...)
{
va_list args;
va_start(args, format);
log_vmsg(LOG_WARNING, format, args);
va_end(args);
}
static void
usage(void)
{
fprintf(stderr, "usage: nsd-notify [-4] [-6] [-a src[@port] [-h] [-p \
port] [-y key:secret[:algo]] -z zone servers\n\n");
fprintf(stderr, "Send NOTIFY to secondary servers to force a zone \
update.\n");
fprintf(stderr, "Version %s. Report bugs to <%s>.\n\n",
PACKAGE_VERSION, PACKAGE_BUGREPORT);
fprintf(stderr, " -4 Send using IPv4.\n");
fprintf(stderr, " -6 Send using IPv6.\n");
fprintf(stderr, " -a src[@port] Local hostname/ip-address for "
"the connection, including optional source port.\n");
fprintf(stderr, " -h Print this help "
"information.\n");
fprintf(stderr, " -p port Port number of secondary "
"server.\n");
fprintf(stderr, " -y key:secret[:algo] TSIG keyname, base64 secret "
"blob and HMAC algorithm.\n"
" If algo is not provided, "
"HMAC-MD5 is assumed.\n");
fprintf(stderr, " -z zone Name of zone to be updated.\n");
fprintf(stderr, " servers IP addresses of the secondary "
"server(s).\n");
exit(1);
}
/*
* Send NOTIFY messages to the host, as in struct q,
* waiting for ack packet (received in buffer answer).
* Will retry transmission after a timeout.
* addrstr is the string describing the address of the host.
*/
static void
notify_host(int udp_s, struct query* q, struct query *answer,
struct addrinfo* res, const dname_type *zone, const char* addrstr)
{
int timeout_retry = 1; /* seconds */
int num_retry = 6; /* times to try */
fd_set rfds;
struct timeval tv;
int retval = 0;
ssize_t received = 0;
int got_ack = 0;
socklen_t addrlen = 0;
while(!got_ack) {
/* WE ARE READY SEND IT OUT */
if (sendto(udp_s,
buffer_current(q->packet),
buffer_remaining(q->packet), 0,
res->ai_addr, res->ai_addrlen) == -1) {
warning("send to %s failed: %s\n", addrstr,
strerror(errno));
close(udp_s);
return;
}
/* wait for ACK packet */
FD_ZERO(&rfds);
FD_SET(udp_s, &rfds);
tv.tv_sec = timeout_retry; /* seconds */
tv.tv_usec = 0; /* microseconds */
retval = select(udp_s + 1, &rfds, NULL, NULL, &tv);
if (retval == -1) {
warning("error waiting for reply from %s: %s\n",
addrstr, strerror(errno));
close(udp_s);
return;
}
if (retval == 0) {
num_retry--;
if(num_retry == 0) {
warning("error: failed to send notify to %s.\n",
addrstr);
exit(1);
}
warning("timeout (%d s) expired, retry notify to %s.\n",
timeout_retry, addrstr);
}
if (retval == 1) {
got_ack = 1;
}
/* Exponential backoff */
timeout_retry *= 2;
}
/* receive reply */
addrlen = res->ai_addrlen;
received = recvfrom(udp_s, buffer_begin(answer->packet),
buffer_remaining(answer->packet), 0,
res->ai_addr, &addrlen);
res->ai_addrlen = addrlen;
if (received == -1) {
warning("recv %s failed: %s\n", addrstr, strerror(errno));
} else {
/* check the answer */
if ((ID(q->packet) == ID(answer->packet)) &&
(OPCODE(answer->packet) == OPCODE_NOTIFY) &&
AA(answer->packet) &&
QR(answer->packet) && (RCODE(answer->packet) == RCODE_OK)) {
/* no news is good news */
/* info("reply from: %s, acknowledges notify.\n",
addrstr); */
} else {
warning("bad reply from %s for zone %s, error response %s (%d).\n",
addrstr, dname_to_string(zone, NULL), rcode2str(RCODE(answer->packet)),
RCODE(answer->packet));
}
}
close(udp_s);
}
static tsig_key_type*
add_key(region_type* region, const char* opt, tsig_algorithm_type** algo)
{
/* parse -y key:secret_base64 format option */
char* delim = strchr(opt, ':');
char* delim2 = NULL;
tsig_key_type *key = (tsig_key_type*)region_alloc(
region, sizeof(tsig_key_type));
size_t len;
int sz;
if (delim) {
delim2 = strchr(delim+1, ':');
}
if(!key) {
log_msg(LOG_ERR, "region_alloc failed (add_key)");
return 0;
}
if(!delim) {
log_msg(LOG_ERR, "bad key syntax %s", opt);
return 0;
}
*delim = '\0';
key->name = dname_parse(region, opt);
if(!key->name) {
log_msg(LOG_ERR, "bad key name %s", opt);
return 0;
}
*delim = ':';
if (!delim2)
*algo = tsig_get_algorithm_by_name("hmac-md5");
else {
char* by_name = (char*) malloc(sizeof(char)*(5+strlen(delim2)));
snprintf(by_name, 5+strlen(delim2), "%s", delim2+1);
*algo = tsig_get_algorithm_by_name(by_name);
free(by_name);
*delim2 = '\0';
}
if (!(*algo)) {
*delim2 = ':';
log_msg(LOG_ERR, "bad tsig algorithm %s", opt);
return 0;
}
len = strlen(delim+1);
key->data = region_alloc(region, len+1);
if(!key->data) {
log_msg(LOG_ERR, "region_alloc failed (add_key, key->data)");
return 0;
}
sz= b64_pton(delim+1, (uint8_t*)key->data, len);
if(sz == -1) {
log_msg(LOG_ERR, "bad key syntax %s", opt);
return 0;
}
key->size = sz;
tsig_add_key(key);
return key;
}
int
main (int argc, char *argv[])
{
int c, udp_s;
struct query q;
struct query answer;
const dname_type *zone = NULL;
struct addrinfo hints, *res0, *res;
int error;
int default_family = DEFAULT_AI_FAMILY;
const char *local_hostname = NULL;
struct addrinfo *local_address, *local_addresses = NULL;
const char *port = UDP_PORT;
const char *local_port = NULL;
region_type *region = region_create(xalloc, free);
tsig_key_type *tsig_key = 0;
tsig_record_type tsig;
tsig_algorithm_type* algo = NULL;
log_init("nsd-notify");
if(!tsig_init(region)) {
log_msg(LOG_ERR, "could not init tsig\n");
exit(1);
}
srandom((unsigned long) getpid() * (unsigned long) time(NULL));
/* Parse the command line... */
while ((c = getopt(argc, argv, "46a:hp:y:z:")) != -1) {
switch (c) {
case '4':
default_family = AF_INET;
break;
case '6':
#ifdef INET6
default_family = AF_INET6;
break;
#else /* !INET6 */
log_msg(LOG_ERR, "IPv6 support not enabled\n");
exit(1);
#endif /* !INET6 */
case 'a':
get_hostname_port_frm_str((char *) optarg,
&local_hostname, &local_port);
break;
case 'p':
port = optarg;
break;
case 'y':
if (!(tsig_key = add_key(region, optarg, &algo)))
exit(1);
break;
case 'z':
zone = dname_parse(region, optarg);
if (!zone) {
log_msg(LOG_ERR,
"incorrect domain name '%s'",
optarg);
exit(1);
}
break;
case 'h':
default:
usage();
}
}
argc -= optind;
argv += optind;
if (argc == 0 || zone == NULL) {
usage();
}
/* Initialize the query */
memset(&q, 0, sizeof(struct query));
q.addrlen = sizeof(q.addr);
q.maxlen = 512;
q.packet = buffer_create(region, QIOBUFSZ);
memset(buffer_begin(q.packet), 0, buffer_remaining(q.packet));
/* Set up the header */
OPCODE_SET(q.packet, OPCODE_NOTIFY);
ID_SET(q.packet, qid_generate());
AA_SET(q.packet);
QDCOUNT_SET(q.packet, 1);
buffer_skip(q.packet, QHEADERSZ);
buffer_write(q.packet, dname_name(zone), zone->name_size);
buffer_write_u16(q.packet, TYPE_SOA);
buffer_write_u16(q.packet, CLASS_IN);
if(tsig_key) {
assert(algo);
tsig_create_record(&tsig, region);
tsig_init_record(&tsig, algo, tsig_key);
tsig_init_query(&tsig, ID(q.packet));
tsig_prepare(&tsig);
tsig_update(&tsig, q.packet, buffer_position(q.packet));
tsig_sign(&tsig);
tsig_append_rr(&tsig, q.packet);
ARCOUNT_SET(q.packet, ARCOUNT(q.packet) + 1);
}
buffer_flip(q.packet);
/* initialize buffer for ack */
memset(&answer, 0, sizeof(struct query));
answer.addrlen = sizeof(answer.addr);
answer.maxlen = 512;
answer.packet = buffer_create(region, QIOBUFSZ);
memset(buffer_begin(answer.packet), 0, buffer_remaining(answer.packet));
memset(&hints, 0, sizeof(hints));
hints.ai_family = default_family;
hints.ai_socktype = SOCK_DGRAM;
hints.ai_protocol = IPPROTO_UDP;
if (local_hostname) {
int rc = getaddrinfo(local_hostname, local_port,
&hints, &local_addresses);
if (rc) {
warning("local hostname '%s' not found: %s",
local_hostname, gai_strerror(rc));
}
}
for (/*empty*/; *argv; argv++) {
error = getaddrinfo(*argv, port, &hints, &res0);
if (error) {
warning("skipping bad address %s: %s\n", *argv,
gai_strerror(error));
continue;
}
if (local_addresses
&& !check_matching_address_family(res0, local_addresses))
{
warning("no local address family matches remote "
"address family, skipping server '%s'",
*argv);
continue;
}
for (res = res0; res; res = res->ai_next) {
if (res->ai_addrlen > (socklen_t)sizeof(q.addr)) {
continue;
}
/*
* If a local address is specified, use an
* address with the same family as the remote
* address.
*/
local_address = find_by_address_family(local_addresses,
res->ai_family);
if (local_addresses && !local_address) {
/* Continue with next remote address. */
continue;
}
udp_s = socket(res->ai_family, res->ai_socktype,
res->ai_protocol);
if (udp_s == -1) {
warning("cannot create socket: %s\n",
strerror(errno));
continue;
}
/* Bind socket to local address, if required. */
if (local_address && bind(udp_s,
local_address->ai_addr,
local_address->ai_addrlen) < 0)
{
warning("cannot bind to %s: %s\n",
local_hostname, strerror(errno));
}
memcpy(&q.addr, res->ai_addr, res->ai_addrlen);
notify_host(udp_s, &q, &answer, res, zone, *argv);
}
freeaddrinfo(res0);
}
exit(0);
}
void
get_hostname_port_frm_str(char* arg, const char** hostname,
const char** port)
{
/* parse -a src[@port] option */
char* delim = strchr(arg, '@');
if (delim) {
*delim = '\0';
*port = delim+1;
}
*hostname = arg;
}
int
check_matching_address_family(struct addrinfo *a0, struct addrinfo *b0)
{
struct addrinfo *a;
struct addrinfo *b;
for (a = a0; a; a = a->ai_next) {
for (b = b0; b; b = b->ai_next) {
if (a->ai_family == b->ai_family) {
return 1;
}
}
}
return 0;
}
struct addrinfo *
find_by_address_family(struct addrinfo *addrs, int family)
{
for (; addrs; addrs = addrs->ai_next) {
if (addrs->ai_family == family) {
return addrs;
}
}
return NULL;
}
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