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#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include "strerr.h"
#include "error.h"
#include "str.h"
#include "dns.h"
#include "cdb.h"
#include "ip4.h"
#include "buffer.h"
#include "seek.h"
#include "byte.h"
#include "open.h"
#include "env.h"
#include "scan.h"
#define USAGE " fqdn dynip"
#define FATAL "tinydyndns-update: fatal: "
#define INFO "tinydyndns-update: info: "
char *progname;
void usage () { strerr_die4x(1, "usage: ", progname, USAGE, "\n"); }
void die_nomem() { strerr_die2x(111, FATAL, "out of memory."); }
char *dynhost;
char *dynip;
unsigned long ttl =0;
unsigned long ttd =0;
char *loc;
static char *host;
char ip[4];
char data[21];
unsigned int l;
static struct cdb c;
int fdcdb;
int fdtmp;
int main (int argc, char ** argv) {
int i;
unsigned int dlen;
uint32 dpos;
buffer bcdb;
char bcdbspace[4096];
buffer btmp;
char btmpspace[4096];
char *s;
struct tai tt, plus;
progname =argv[0];
if (! (dynhost =argv[1])) usage();
if (! (dynip =argv[2])) usage();
if (! ip4_scan(dynip, ip)) usage();
if (! dns_domain_fromdot(&host, dynhost, str_len(dynhost))) die_nomem();
if ((s =env_get("TTL"))) scan_ulong(s, &ttl);
if ((s =env_get("TTD"))) scan_ulong(s, &ttd);
if ((loc =env_get("LOC"))) if (! loc[0] || ! loc[1]) loc =0;
/* setlock? */
/* open cdb */
if ((fdcdb =open_read("data.cdb")) == -1)
strerr_die2sys(100, FATAL, "unable to open data.cdb: ");
cdb_init(&c, fdcdb);
cdb_findstart(&c);
/* search host */
for (;;) {
if(! cdb_findnext(&c, host, dns_domain_length(host))) {
cdb_free(&c);
close(fdcdb);
strerr_die3x(114, FATAL, dynhost, ": not found in data.cdb.");
}
dpos =cdb_datapos(&c);
dlen =cdb_datalen(&c);
/* check data size */
if ((dlen != 19) && (dlen != 21)) continue;
/* read data */
if (cdb_read(&c, data, dlen, dpos) == -1) {
cdb_free(&c);
close(fdcdb);
strerr_die3sys(111, FATAL, dynhost, ": cdb_read: ");
}
if (dlen == 19) if (data[2] != '=') continue;
if (dlen == 21) {
if (data[2] != '>') continue;
if (! loc || ! byte_equal(&data[3], 2, loc)) continue;
}
l =dlen -19;
/* check record type */
if (byte_equal(data, 2, DNS_T_A)) break;
}
cdb_free(&c);
/* manipulate data */
if (! ttd) {
if (byte_equal(&data[15 +l], 4, ip))
if (byte_diff(&data[3 +l], 4, "\0\0\0\0"))
strerr_die3x(0, INFO, dynhost, ": IP address not changed.");
if (! ttl) ttl =5;
byte_zero(&data[7 +l], 8);
}
else {
tai_now(&tt);
tai_uint(&plus, ttd);
tai_add(&tt, &tt, &plus);
tai_pack(&data[7 +l], &tt);
}
uint32_pack_big(&data[3 +l], ttl);
byte_copy(&data[15 +l], 4, ip);
/* copy cdb cdb.tmp */
if (seek_begin(fdcdb) == -1)
strerr_die3sys(111, FATAL, dynhost, ": seek: ");
if ((fdtmp =open_trunc("data.cdb.tmp")) == -1)
strerr_die2sys(111, FATAL, "unable to create data.cdb.tmp: ");
buffer_init(&bcdb, buffer_unixread, fdcdb, bcdbspace, sizeof bcdbspace);
buffer_init(&btmp, buffer_unixwrite, fdtmp, btmpspace, sizeof btmpspace);
while ((i =buffer_feed(&bcdb)) > 0) {
if (buffer_put(&btmp, buffer_peek(&bcdb), i) == -1)
strerr_die2sys(111, FATAL, "unable to write data.cdb.tmp: ");
buffer_seek(&bcdb, i);
}
if (i == -1)
strerr_die2sys(111, FATAL, "unable to read data.cdb: ");
if (buffer_flush(&btmp) == -1)
strerr_die2sys(111, FATAL, "unable to write data.cdb.tmp: ");
/* manipulate cdb.tmp */
if (seek_set(fdtmp, dpos) == -1)
strerr_die3sys(111, FATAL, dynhost, ": seek: ");
if (write(fdtmp, data, 19 +l) != 19 +l)
strerr_die3sys(111, FATAL, dynhost, ": write: ");
if (fsync(fdtmp) == -1)
strerr_die2sys(111, FATAL, "unable to write data.cdb.tmp: ");
if (close(fdtmp) == -1)
strerr_die2sys(111, FATAL, "unable to write data.cdb.tmp: ");
close(fdcdb);
/* move cdb.tmp cdb */
if (rename("data.cdb.tmp", "data.cdb") == -1)
strerr_die2sys(111, FATAL, "unable to move data.cdb.tmp to data.cdb: ");
buffer_puts(buffer_1, INFO);
buffer_puts(buffer_1, "update: ");
buffer_puts(buffer_1, dynhost);
buffer_puts(buffer_1, " -> ");
buffer_puts(buffer_1, dynip);
buffer_putsflush(buffer_1, "\n");
_exit(0);
}
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