LibC: Implement inet_aton

This is not POSIX but IMO it makes sense to have the counter part to
inet_ntoa
This commit is contained in:
Bananymous 2025-06-02 11:29:52 +03:00
parent be6da3e0db
commit 022bb69782
2 changed files with 31 additions and 21 deletions

View File

@ -27,28 +27,10 @@ uint16_t ntohs(uint16_t netshort)
in_addr_t inet_addr(const char* cp)
{
uint32_t a, b, c, d, n;
const int ret = sscanf(cp, "%i%n.%i%n.%i%n.%i%n",
&a, &n, &b, &n, &c, &n, &d, &n
);
if (ret < 1 || ret > 4 || cp[n] != '\0')
in_addr addr;
if (inet_aton(cp, &addr) == 0)
return INADDR_NONE;
if (ret == 1 && (a > 0xFFFFFFFF))
return INADDR_NONE;
if (ret == 2 && (a > 0xFF || b > 0xFFFFFF))
return INADDR_NONE;
if (ret == 3 && (a > 0xFF || b > 0xFF || c > 0xFFFF))
return INADDR_NONE;
if (ret == 4 && (a > 0xFF || b > 0xFF || c > 0xFF || d > 0xFF))
return INADDR_NONE;
uint32_t result = 0;
result |= (ret == 1) ? a : a << 24;
result |= (ret == 2) ? b : b << 16;
result |= (ret == 3) ? c : c << 8;
result |= (ret == 4) ? d : d << 0;
return htonl(result);
return addr.s_addr;
}
char* inet_ntoa(struct in_addr in)
@ -64,6 +46,33 @@ char* inet_ntoa(struct in_addr in)
return buffer;
}
int inet_aton(const char* cp, struct in_addr* inp)
{
uint32_t a, b, c, d, n;
const int ret = sscanf(cp, "%i%n.%i%n.%i%n.%i%n",
&a, &n, &b, &n, &c, &n, &d, &n
);
if (ret < 1 || ret > 4 || cp[n] != '\0')
return 0;
if (ret == 1 && (a > 0xFFFFFFFF))
return 0;
if (ret == 2 && (a > 0xFF || b > 0xFFFFFF))
return 0;
if (ret == 3 && (a > 0xFF || b > 0xFF || c > 0xFFFF))
return 0;
if (ret == 4 && (a > 0xFF || b > 0xFF || c > 0xFF || d > 0xFF))
return 0;
uint32_t result = 0;
result |= (ret == 1) ? a : a << 24;
result |= (ret == 2) ? b : b << 16;
result |= (ret == 3) ? c : c << 8;
result |= (ret == 4) ? d : d << 0;
inp->s_addr = htonl(result);
return 1;
}
const char* inet_ntop(int af, const void* __restrict src, char* __restrict dst, socklen_t size)
{
if (af == AF_INET)

View File

@ -11,6 +11,7 @@ __BEGIN_DECLS
#include <bits/types/socklen_t.h>
in_addr_t inet_addr(const char* cp);
int inet_aton(const char* cp, struct in_addr* inp);
char* inet_ntoa(struct in_addr in);
const char* inet_ntop(int af, const void* __restrict src, char* __restrict dst, socklen_t size);
int inet_pton(int af, const char* __restrict src, void* __restrict dst);