wireguard-android/tunnel/tools/ndk-compat/compat.c

/* SPDX-License-Identifier: BSD
 *
 * Copyright © 2017-2023 WireGuard LLC. All Rights Reserved.
 *
 */

#define FILE_IS_EMPTY

#if defined(__ANDROID_API__) && __ANDROID_API__ < 18
#undef FILE_IS_EMPTY
#include <stdio.h>
#include <stdlib.h>

ssize_t getdelim(char **buf, size_t *bufsiz, int delimiter, FILE *fp)
{
	char *ptr, *eptr;

	if (*buf == NULL || *bufsiz == 0) {
		*bufsiz = BUFSIZ;
		if ((*buf = malloc(*bufsiz)) == NULL)
			return -1;
	}

	for (ptr = *buf, eptr = *buf + *bufsiz;;) {
		int c = fgetc(fp);
		if (c == -1) {
			if (feof(fp)) {
				ssize_t diff = (ssize_t)(ptr - *buf);
				if (diff != 0) {
					*ptr = '\0';
					return diff;
				}
			}
			return -1;
		}
		*ptr++ = c;
		if (c == delimiter) {
			*ptr = '\0';
			return ptr - *buf;
		}
		if (ptr + 2 >= eptr) {
			char *nbuf;
			size_t nbufsiz = *bufsiz * 2;
			ssize_t d = ptr - *buf;
			if ((nbuf = realloc(*buf, nbufsiz)) == NULL)
				return -1;
			*buf = nbuf;
			*bufsiz = nbufsiz;
			eptr = nbuf + nbufsiz;
			ptr = nbuf + d;
		}
	}
}

ssize_t getline(char **buf, size_t *bufsiz, FILE *fp)
{
	return getdelim(buf, bufsiz, '\n', fp);
}
#endif

#if defined(__ANDROID_API__) && __ANDROID_API__ < 24
#undef FILE_IS_EMPTY
#include <string.h>

char *strchrnul(const char *s, int c)
{
        char *x = strchr(s, c);
        if (!x)
                return (char *)s + strlen(s);
        return x;
}
#endif

#ifdef FILE_IS_EMPTY
#undef FILE_IS_EMPTY
static char ____x __attribute__((unused));
#endif