shadow/libmisc/inet_sockaddr2str.c
Alejandro Colomar bb3a89577c Add inet_sockaddr2str() to wrap inet_ntop(3)
Signed-off-by: Alejandro Colomar <alx@kernel.org>
2023-01-02 08:20:43 +01:00

79 lines
1.8 KiB
C

/*
* SPDX-FileCopyrightText: 2022, Alejandro Colomar <alx@kernel.org>
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <config.h>
#include <arpa/inet.h>
#include <errno.h>
#include <netinet/in.h>
#include <sys/param.h>
#include <sys/socket.h>
#ident "$Id$"
#include "defines.h"
#include "prototypes.h"
#if !defined(INET_ADDRSTRLENMAX)
#define INET_ADDRSTRLENMAX MAX(INET_ADDRSTRLEN, INET6_ADDRSTRLEN)
#endif
/*
* SYNOPSIS
* const char *inet_sockaddr2str(const struct sockaddr *sa);
*
* DESCRIPTION
* This function is similar to inet_ntop(3). It transforms an address
* in 'struct in_addr' or 'struct in6_addr' form into a human-readable
* string.
*
* It receives a sockaddr structure, which is simpler to pass after
* receiving it from getaddrinfo(3). However, this function is not
* reentrant, and like inet_ntoa(3), it uses an internal buffer, for
* simplicity; anyway we're not in a multithreaded program, and it
* doesn't contain any sensitive data, so it's fine to use static
* storage here.
*
* RETURN VALUE
* This function returns a pointer to a statically allocated buffer,
* which subsequent calls will overwrite.
*
* On error, it returns NULL.
*
* ERRORS
* EAFNOSUPPORT
* The address family in sa->sa_family is not AF_INET or AF_INET6.
*
* CAVEATS
* This function is not reentrant.
*/
const char *
inet_sockaddr2str(const struct sockaddr *sa)
{
struct sockaddr_in *sin;
struct sockaddr_in6 *sin6;
static char buf[INET_ADDRSTRLENMAX];
switch (sa->sa_family) {
case AF_INET:
sin = (struct sockaddr_in *) sa;
inet_ntop(AF_INET, &sin->sin_addr, buf, NITEMS(buf));
return buf;
case AF_INET6:
sin6 = (struct sockaddr_in6 *) sa;
inet_ntop(AF_INET6, &sin6->sin6_addr, buf, NITEMS(buf));
return buf;
default:
errno = EAFNOSUPPORT;
return NULL;
}
}