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Tag: djb/1.00
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363 lines (323 sloc) 9.92 kB
#include "uint32.h"
#include "uint16.h"
#include "stralloc.h"
#include "error.h"
#include "strerr.h"
#include "getln.h"
#include "buffer.h"
#include "readwrite.h"
#include "exit.h"
#include "open.h"
#include "scan.h"
#include "byte.h"
#include "str.h"
#include "ip4.h"
#include "dns.h"
#define FATAL "axfr-get: fatal: "
void die_usage(void)
{
strerr_die1x(100,"axfr-get: usage: axfr-get zone fn fn.tmp");
}
void die_generate(void)
{
strerr_die2sys(111,FATAL,"unable to generate AXFR query: ");
}
void die_parse(void)
{
strerr_die2sys(111,FATAL,"unable to parse AXFR results: ");
}
unsigned int x_copy(char *buf,unsigned int len,unsigned int pos,char *out,unsigned int outlen)
{
pos = dns_packet_copy(buf,len,pos,out,outlen);
if (!pos) die_parse();
return pos;
}
unsigned int x_getname(char *buf,unsigned int len,unsigned int pos,char **out)
{
pos = dns_packet_getname(buf,len,pos,out);
if (!pos) die_parse();
return pos;
}
unsigned int x_skipname(char *buf,unsigned int len,unsigned int pos)
{
pos = dns_packet_skipname(buf,len,pos);
if (!pos) die_parse();
return pos;
}
static char *zone;
unsigned int zonelen;
char *fn;
char *fntmp;
void die_netread(void)
{
strerr_die2sys(111,FATAL,"unable to read from network: ");
}
void die_netwrite(void)
{
strerr_die2sys(111,FATAL,"unable to write to network: ");
}
void die_read(void)
{
strerr_die4sys(111,FATAL,"unable to read ",fn,": ");
}
void die_write(void)
{
strerr_die4sys(111,FATAL,"unable to write ",fntmp,": ");
}
int saferead(int fd,char *buf,unsigned int len)
{
int r;
r = timeoutread(60,fd,buf,len);
if (r == 0) { errno = error_proto; die_parse(); }
if (r <= 0) die_netread();
return r;
}
int safewrite(int fd,char *buf,unsigned int len)
{
int r;
r = timeoutwrite(60,fd,buf,len);
if (r <= 0) die_netwrite();
return r;
}
char netreadspace[1024];
buffer netread = BUFFER_INIT(saferead,6,netreadspace,sizeof netreadspace);
char netwritespace[1024];
buffer netwrite = BUFFER_INIT(safewrite,7,netwritespace,sizeof netwritespace);
void netget(char *buf,unsigned int len)
{
int r;
while (len > 0) {
r = buffer_get(&netread,buf,len);
buf += r; len -= r;
}
}
int fd;
buffer b;
char bspace[1024];
void put(char *buf,unsigned int len)
{
if (buffer_put(&b,buf,len) == -1) die_write();
}
int printable(char ch)
{
if (ch == '.') return 1;
if ((ch >= 'a') && (ch <= 'z')) return 1;
if ((ch >= '0') && (ch <= '9')) return 1;
if ((ch >= 'A') && (ch <= 'Z')) return 1;
if (ch == '-') return 1;
return 0;
}
static char *d1;
static char *d2;
static char *d3;
stralloc line;
int match;
int numsoa;
unsigned int doit(char *buf,unsigned int len,unsigned int pos)
{
char data[20];
uint32 ttl;
uint16 dlen;
uint16 typenum;
uint32 u32;
int i;
pos = x_getname(buf,len,pos,&d1);
pos = x_copy(buf,len,pos,data,10);
uint16_unpack_big(data,&typenum);
uint32_unpack_big(data + 4,&ttl);
uint16_unpack_big(data + 8,&dlen);
if (len - pos < dlen) { errno = error_proto; return 0; }
len = pos + dlen;
if (!dns_domain_suffix(d1,zone)) return len;
if (byte_diff(data + 2,2,DNS_C_IN)) return len;
if (byte_equal(data,2,DNS_T_SOA)) {
if (++numsoa >= 2) return len;
pos = x_getname(buf,len,pos,&d2);
pos = x_getname(buf,len,pos,&d3);
x_copy(buf,len,pos,data,20);
uint32_unpack_big(data,&u32);
if (!stralloc_copys(&line,"#")) return 0;
if (!stralloc_catulong0(&line,u32,0)) return 0;
if (!stralloc_cats(&line," auto axfr-get\n")) return 0;
if (!stralloc_cats(&line,"Z")) return 0;
if (!dns_domain_todot_cat(&line,d1)) return 0;
if (!stralloc_cats(&line,":")) return 0;
if (!dns_domain_todot_cat(&line,d2)) return 0;
if (!stralloc_cats(&line,".:")) return 0;
if (!dns_domain_todot_cat(&line,d3)) return 0;
if (!stralloc_cats(&line,".")) return 0;
for (i = 0;i < 5;++i) {
uint32_unpack_big(data + 4 * i,&u32);
if (!stralloc_cats(&line,":")) return 0;
if (!stralloc_catulong0(&line,u32,0)) return 0;
}
}
else if (byte_equal(data,2,DNS_T_NS)) {
if (!stralloc_copys(&line,"&")) return 0;
if (byte_equal(d1,2,"\1*")) { errno = error_proto; return 0; }
if (!dns_domain_todot_cat(&line,d1)) return 0;
if (!stralloc_cats(&line,"::")) return 0;
x_getname(buf,len,pos,&d1);
if (!dns_domain_todot_cat(&line,d1)) return 0;
if (!stralloc_cats(&line,".")) return 0;
}
else if (byte_equal(data,2,DNS_T_CNAME)) {
if (!stralloc_copys(&line,"C")) return 0;
if (!dns_domain_todot_cat(&line,d1)) return 0;
if (!stralloc_cats(&line,":")) return 0;
x_getname(buf,len,pos,&d1);
if (!dns_domain_todot_cat(&line,d1)) return 0;
if (!stralloc_cats(&line,".")) return 0;
}
else if (byte_equal(data,2,DNS_T_MX)) {
uint16 dist;
if (!stralloc_copys(&line,"@")) return 0;
if (!dns_domain_todot_cat(&line,d1)) return 0;
if (!stralloc_cats(&line,"::")) return 0;
pos = x_copy(buf,len,pos,data,2);
uint16_unpack_big(data,&dist);
x_getname(buf,len,pos,&d1);
if (!dns_domain_todot_cat(&line,d1)) return 0;
if (!stralloc_cats(&line,".:")) return 0;
if (!stralloc_catulong0(&line,dist,0)) return 0;
}
else if (byte_equal(data,2,DNS_T_A) && (dlen == 4)) {
char ipstr[IP4_FMT];
if (!stralloc_copys(&line,"+")) return 0;
if (!dns_domain_todot_cat(&line,d1)) return 0;
if (!stralloc_cats(&line,":")) return 0;
x_copy(buf,len,pos,data,4);
if (!stralloc_catb(&line,ipstr,ip4_fmt(ipstr,data))) return 0;
}
else {
unsigned char ch;
unsigned char ch2;
if (!stralloc_copys(&line,":")) return 0;
if (!dns_domain_todot_cat(&line,d1)) return 0;
if (!stralloc_cats(&line,":")) return 0;
if (!stralloc_catulong0(&line,typenum,0)) return 0;
if (!stralloc_cats(&line,":")) return 0;
for (i = 0;i < dlen;++i) {
pos = x_copy(buf,len,pos,data,1);
ch = data[0];
if (printable(ch)) {
if (!stralloc_catb(&line,&ch,1)) return 0;
}
else {
if (!stralloc_cats(&line,"\\")) return 0;
ch2 = '0' + ((ch >> 6) & 7);
if (!stralloc_catb(&line,&ch2,1)) return 0;
ch2 = '0' + ((ch >> 3) & 7);
if (!stralloc_catb(&line,&ch2,1)) return 0;
ch2 = '0' + (ch & 7);
if (!stralloc_catb(&line,&ch2,1)) return 0;
}
}
}
if (!stralloc_cats(&line,":")) return 0;
if (!stralloc_catulong0(&line,ttl,0)) return 0;
if (!stralloc_cats(&line,"\n")) return 0;
put(line.s,line.len);
return len;
}
stralloc packet;
main(int argc,char **argv)
{
char out[20];
unsigned long u;
uint16 dlen;
unsigned int pos;
uint32 oldserial = 0;
uint32 newserial = 0;
uint16 numqueries;
uint16 numanswers;
if (!*argv) die_usage();
if (!*++argv) die_usage();
if (!dns_domain_fromdot(&zone,*argv,str_len(*argv))) die_generate();
zonelen = dns_domain_length(zone);
if (!*++argv) die_usage();
fn = *argv;
if (!*++argv) die_usage();
fntmp = *argv;
fd = open_read(fn);
if (fd == -1) {
if (errno != error_noent) die_read();
}
else {
buffer_init(&b,read,fd,bspace,sizeof bspace);
if (getln(&b,&line,&match,'\n') == -1) die_read();
if (!stralloc_0(&line)) die_read();
if (line.s[0] == '#') {
scan_ulong(line.s + 1,&u);
oldserial = u;
}
close(fd);
}
if (!stralloc_copyb(&packet,"\0\0\0\0\0\1\0\0\0\0\0\0",12)) die_generate();
if (!stralloc_catb(&packet,zone,zonelen)) die_generate();
if (!stralloc_catb(&packet,DNS_T_SOA DNS_C_IN,4)) die_generate();
uint16_pack_big(out,packet.len);
buffer_put(&netwrite,out,2);
buffer_put(&netwrite,packet.s,packet.len);
buffer_flush(&netwrite);
netget(out,2);
uint16_unpack_big(out,&dlen);
if (!stralloc_ready(&packet,dlen)) die_parse();
netget(packet.s,dlen);
packet.len = dlen;
pos = x_copy(packet.s,packet.len,0,out,12);
uint16_unpack_big(out + 4,&numqueries);
uint16_unpack_big(out + 6,&numanswers);
while (numqueries) {
--numqueries;
pos = x_skipname(packet.s,packet.len,pos);
pos += 4;
}
if (!numanswers) { errno = error_proto; die_parse(); }
pos = x_getname(packet.s,packet.len,pos,&d1);
if (!dns_domain_equal(zone,d1)) { errno = error_proto; die_parse(); }
pos = x_copy(packet.s,packet.len,pos,out,10);
if (byte_diff(out,4,DNS_T_SOA DNS_C_IN)) { errno = error_proto; die_parse(); }
pos = x_skipname(packet.s,packet.len,pos);
pos = x_skipname(packet.s,packet.len,pos);
pos = x_copy(packet.s,packet.len,pos,out,4);
uint32_unpack_big(out,&newserial);
if (oldserial && newserial) /* allow 0 for very recently modified zones */
if (oldserial == newserial) /* allow serial numbers to move backwards */
_exit(0);
fd = open_trunc(fntmp);
if (fd == -1) die_write();
buffer_init(&b,write,fd,bspace,sizeof bspace);
if (!stralloc_copyb(&packet,"\0\0\0\0\0\1\0\0\0\0\0\0",12)) die_generate();
if (!stralloc_catb(&packet,zone,zonelen)) die_generate();
if (!stralloc_catb(&packet,DNS_T_AXFR DNS_C_IN,4)) die_generate();
uint16_pack_big(out,packet.len);
buffer_put(&netwrite,out,2);
buffer_put(&netwrite,packet.s,packet.len);
buffer_flush(&netwrite);
numsoa = 0;
while (numsoa < 2) {
netget(out,2);
uint16_unpack_big(out,&dlen);
if (!stralloc_ready(&packet,dlen)) die_parse();
netget(packet.s,dlen);
packet.len = dlen;
pos = x_copy(packet.s,packet.len,0,out,12);
uint16_unpack_big(out + 4,&numqueries);
while (numqueries) {
--numqueries;
pos = x_skipname(packet.s,packet.len,pos);
pos += 4;
}
while (pos < packet.len) {
pos = doit(packet.s,packet.len,pos);
if (!pos) die_parse();
}
}
if (buffer_flush(&b) == -1) die_write();
if (fsync(fd) == -1) die_write();
if (close(fd) == -1) die_write(); /* NFS dorks */
if (rename(fntmp,fn) == -1)
strerr_die6sys(111,FATAL,"unable to move ",fntmp," to ",fn,": ");
_exit(0);
}
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