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#include <netdb.h>
#include <limits.h>
#include <string.h>
#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <net/if.h>
#include <ctype.h>
#include "lookup.h"
#include "stdio_impl.h"
int __dns_parse(const unsigned char *, int, int (*)(void *, int, const void *, int, const void *), void *);
int __dn_expand(const unsigned char *, const unsigned char *, const unsigned char *, char *, int);
int __res_mkquery(int, const char *, int, int, const unsigned char *, int, const unsigned char*, unsigned char *, int);
int __res_send(const unsigned char *, int, unsigned char *, int);
#define PTR_MAX (64 + sizeof ".in-addr.arpa")
#define RR_PTR 12
static char *itoa(char *p, unsigned x) {
p += 3*sizeof(int);
*--p = 0;
do {
*--p = '0' + x % 10;
x /= 10;
} while (x);
return p;
}
static void mkptr4(char *s, const unsigned char *ip)
{
sprintf(s, "%d.%d.%d.%d.in-addr.arpa",
ip[3], ip[2], ip[1], ip[0]);
}
static void mkptr6(char *s, const unsigned char *ip)
{
static const char xdigits[] = "0123456789abcdef";
int i;
for (i=15; i>=0; i--) {
*s++ = xdigits[ip[i]&15]; *s++ = '.';
*s++ = xdigits[ip[i]>>4]; *s++ = '.';
}
strcpy(s, "ip6.arpa");
}
static void reverse_hosts(char *buf, const unsigned char *a, unsigned scopeid, int family)
{
char line[512], *p, *z;
unsigned char _buf[1032], atmp[16];
struct address iplit;
FILE _f, *f = __fopen_rb_ca("/etc/hosts", &_f, _buf, sizeof _buf);
if (!f) return;
if (family == AF_INET) {
memcpy(atmp+12, a, 4);
memcpy(atmp, "\0\0\0\0\0\0\0\0\0\0\xff\xff", 12);
a = atmp;
}
while (fgets(line, sizeof line, f)) {
if ((p=strchr(line, '#'))) *p++='\n', *p=0;
for (p=line; *p && !isspace(*p); p++);
*p++ = 0;
if (__lookup_ipliteral(&iplit, line, AF_UNSPEC)<=0)
continue;
if (iplit.family == AF_INET) {
memcpy(iplit.addr+12, iplit.addr, 4);
memcpy(iplit.addr, "\0\0\0\0\0\0\0\0\0\0\xff\xff", 12);
iplit.scopeid = 0;
}
if (memcmp(a, iplit.addr, 16) || iplit.scopeid != scopeid)
continue;
for (; *p && isspace(*p); p++);
for (z=p; *z && !isspace(*z); z++);
*z = 0;
if (z-p < 256) {
memcpy(buf, p, z-p+1);
break;
}
}
__fclose_ca(f);
}
static void reverse_services(char *buf, int port, int dgram)
{
unsigned long svport;
char line[128], *p, *z;
unsigned char _buf[1032];
FILE _f, *f = __fopen_rb_ca("/etc/services", &_f, _buf, sizeof _buf);
if (!f) return;
while (fgets(line, sizeof line, f)) {
if ((p=strchr(line, '#'))) *p++='\n', *p=0;
for (p=line; *p && !isspace(*p); p++);
if (!*p) continue;
*p++ = 0;
svport = strtoul(p, &z, 10);
if (svport != port || z==p) continue;
if (dgram && strncmp(z, "/udp", 4)) continue;
if (!dgram && strncmp(z, "/tcp", 4)) continue;
if (p-line > 32) continue;
memcpy(buf, line, p-line);
break;
}
__fclose_ca(f);
}
static int dns_parse_callback(void *c, int rr, const void *data, int len, const void *packet)
{
if (rr != RR_PTR) return 0;
if (__dn_expand(packet, (const unsigned char *)packet + 512,
data, c, 256) <= 0)
*(char *)c = 0;
return 0;
}
int getnameinfo(const struct sockaddr *restrict sa, socklen_t sl,
char *restrict node, socklen_t nodelen,
char *restrict serv, socklen_t servlen,
int flags)
{
char ptr[PTR_MAX];
char buf[256], num[3*sizeof(int)+1];
int af = sa->sa_family;
unsigned char *a;
unsigned scopeid;
switch (af) {
case AF_INET:
a = (void *)&((struct sockaddr_in *)sa)->sin_addr;
if (sl != sizeof(struct sockaddr_in)) return EAI_FAMILY;
mkptr4(ptr, a);
scopeid = 0;
break;
case AF_INET6:
a = (void *)&((struct sockaddr_in6 *)sa)->sin6_addr;
if (sl != sizeof(struct sockaddr_in6)) return EAI_FAMILY;
if (memcmp(a, "\0\0\0\0\0\0\0\0\0\0\xff\xff", 12))
mkptr6(ptr, a);
else
mkptr4(ptr, a+12);
scopeid = ((struct sockaddr_in6 *)sa)->sin6_scope_id;
break;
default:
return EAI_FAMILY;
}
if (node && nodelen) {
buf[0] = 0;
if (!(flags & NI_NUMERICHOST)) {
reverse_hosts(buf, a, scopeid, af);
}
if (!*buf && !(flags & NI_NUMERICHOST)) {
unsigned char query[18+PTR_MAX], reply[512];
int qlen = __res_mkquery(0, ptr, 1, RR_PTR,
0, 0, 0, query, sizeof query);
int rlen = __res_send(query, qlen, reply, sizeof reply);
buf[0] = 0;
if (rlen > 0)
__dns_parse(reply, rlen, dns_parse_callback, buf);
}
if (!*buf) {
if (flags & NI_NAMEREQD) return EAI_NONAME;
inet_ntop(af, a, buf, sizeof buf);
if (scopeid) {
char *p = 0, tmp[IF_NAMESIZE+1];
if (!(flags & NI_NUMERICSCOPE) &&
(IN6_IS_ADDR_LINKLOCAL(a) ||
IN6_IS_ADDR_MC_LINKLOCAL(a)))
p = if_indextoname(scopeid, tmp+1);
if (!p)
p = itoa(num, scopeid);
*--p = '%';
strcat(buf, p);
}
}
if (strlen(buf) >= nodelen) return EAI_OVERFLOW;
strcpy(node, buf);
}
if (serv && servlen) {
char *p = buf;
int port = ntohs(((struct sockaddr_in *)sa)->sin_port);
buf[0] = 0;
if (!(flags & NI_NUMERICSERV))
reverse_services(buf, port, flags & NI_DGRAM);
if (!*p)
p = itoa(num, port);
if (strlen(p) >= servlen)
return EAI_OVERFLOW;
strcpy(serv, p);
}
return 0;
}
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