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#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <stdlib.h>
#include <arpa/inet.h>
#include <sys/poll.h>
#include <unistd.h>
#include <errno.h>
#include <arpa/nameser.h>
#include <resolv.h>
#include "dietfeatures.h"
#include "dietdns.h"
extern void __dns_readstartfiles(void);
extern int __dns_decodename(unsigned char *packet,unsigned int offset,unsigned char *dest,
unsigned int maxlen,unsigned char* behindpacket);
/* Oh boy, this interface sucks so badly, there are no words for it.
* Not one, not two, but _three_ error signalling methods! (*h_errnop
* nonzero? return value nonzero? *RESULT zero?) The glibc goons
* really outdid themselves with this one. */
#ifdef WANT_FULL_RESOLV_CONF
static int __dns_gethostbyx_r_inner(const char* name, struct hostent* result,
char *buf, size_t buflen,
struct hostent **RESULT, int *h_errnop, int lookfor);
static int __dns_gethostbyx_r_inner(const char* name, struct hostent* result,
char *buf, size_t buflen,
struct hostent **RESULT, int *h_errnop, int lookfor) {
#else
int __dns_gethostbyx_r(const char* name, struct hostent* result,
char *buf, size_t buflen,
struct hostent **RESULT, int *h_errnop, int lookfor) {
#endif
int names,ips;
unsigned char *cur;
unsigned char *max;
unsigned char inpkg[1500];
char* tmp;
int size;
if (lookfor==1) {
result->h_addrtype=AF_INET;
result->h_length=4;
} else {
result->h_addrtype=AF_INET6;
result->h_length=16;
}
result->h_aliases=(char**)(buf+8*sizeof(char*));
result->h_addr_list=(char**)buf;
result->h_aliases[0]=0;
cur=buf+16*sizeof(char*);
max=buf+buflen;
names=ips=0;
if ((size=res_query(name,C_IN,lookfor,inpkg,512))<0) {
invalidpacket:
*h_errnop=HOST_NOT_FOUND;
return -1;
}
{
tmp=inpkg+12;
{
char Name[257];
unsigned short q=((unsigned short)inpkg[4]<<8)+inpkg[5];
while (q>0) {
if (tmp>(char*)inpkg+size) goto invalidpacket;
while (*tmp) { tmp+=*tmp+1; if (tmp>(char*)inpkg+size) goto invalidpacket; }
tmp+=5;
--q;
}
if (tmp>(char*)inpkg+size) goto invalidpacket;
q=((unsigned short)inpkg[6]<<8)+inpkg[7];
if (q<1) goto nodata;
while (q>0) {
int decofs=__dns_decodename(inpkg,(size_t)(tmp-(char*)inpkg),Name,256,inpkg+size);
if (decofs<0) break;
tmp=inpkg+decofs;
--q;
if (tmp[0]!=0 || tmp[1]!=lookfor || /* TYPE != A */
tmp[2]!=0 || tmp[3]!=1) { /* CLASS != IN */
if (tmp[1]==5) { /* CNAME */
tmp+=10;
decofs=__dns_decodename(inpkg,(size_t)(tmp-(char*)inpkg),Name,256,inpkg+size);
if (decofs<0) break;
tmp=inpkg+decofs;
} else
break;
continue;
}
tmp+=10; /* skip type, class, TTL and length */
{
int slen;
if (lookfor==1 || lookfor==28) /* A or AAAA*/ {
slen=strlen(Name);
if (cur+slen+8+(lookfor==28?12:0)>=max) { *h_errnop=NO_RECOVERY; return -1; }
} else if (lookfor==12) /* PTR */ {
decofs=__dns_decodename(inpkg,(size_t)(tmp-(char*)inpkg),Name,256,inpkg+size);
if (decofs<0) break;
tmp=inpkg+decofs;
slen=strlen(Name);
} else
slen=strlen(Name);
strcpy(cur,Name);
if (names==0)
result->h_name=cur;
else
result->h_aliases[names-1]=cur;
result->h_aliases[names]=0;
if (names<8) ++names;
/* cur+=slen+1; */
cur+=(slen|3)+1;
result->h_addr_list[ips++] = cur;
if (lookfor==1) /* A */ {
*(int*)cur=*(int*)tmp;
cur+=4;
result->h_addr_list[ips]=0;
} else if (lookfor==28) /* AAAA */ {
{
int k;
for (k=0; k<16; ++k) cur[k]=tmp[k];
}
cur+=16;
result->h_addr_list[ips]=0;
}
}
/* puts(Name); */
}
}
}
if (!names) {
nodata:
*h_errnop=NO_DATA;
return -1;
}
*h_errnop=0;
*RESULT=result;
return 0;
}
#ifdef WANT_FULL_RESOLV_CONF
extern int __dns_search;
extern char *__dns_domains[];
int __dns_gethostbyx_r(const char* name, struct hostent* result,
char *buf, size_t buflen,
struct hostent **RESULT, int *h_errnop, int lookfor) {
const char *tmp=name;
char Buf[MAXDNAME+1];
int res;
size_t len=strlen(name);
int count=0;
__dns_readstartfiles();
memmove(Buf,name,len);
Buf[len]=Buf[MAXDNAME]=0;
// printf("appending %d: %p\n",count,__dns_domains[count]);
while ((res=__dns_gethostbyx_r_inner(tmp,result,buf,buflen,RESULT,h_errnop,lookfor))) {
if (res==-1 && *h_errnop!=HOST_NOT_FOUND) break;
if (count==__dns_search) break;
Buf[len]='.';
// printf("appending %d: %p (%s)\n",count,__dns_domains[count],__dns_domains[count]);
memccpy(Buf+len+1,__dns_domains[count],0,MAXDNAME-len-1);
tmp=Buf;
++count;
}
return res;
}
#endif
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