Magisk/native/jni/utils/missing.cpp
2020-11-03 01:12:33 -08:00

110 lines
2.8 KiB
C++

/*
* Host all missing/incomplete implementation in bionic
* Copied from various sources
* */
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <mntent.h>
#include "missing.hpp"
/* Original source: https://github.com/freebsd/freebsd/blob/master/contrib/file/src/getline.c
* License: BSD, full copyright notice please check original source */
ssize_t compat_getdelim(char **buf, size_t *bufsiz, int delimiter, FILE *fp) {
char *ptr, *eptr;
if (*buf == nullptr || *bufsiz == 0) {
*bufsiz = BUFSIZ;
if ((*buf = (char *) malloc(*bufsiz)) == nullptr)
return -1;
}
for (ptr = *buf, eptr = *buf + *bufsiz;;) {
int c = fgetc(fp);
if (c == -1) {
if (feof(fp))
return ptr == *buf ? -1 : ptr - *buf;
else
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 = (char *) realloc(*buf, nbufsiz)) == nullptr)
return -1;
*buf = nbuf;
*bufsiz = nbufsiz;
eptr = nbuf + nbufsiz;
ptr = nbuf + d;
}
}
}
ssize_t compat_getline(char **buf, size_t *bufsiz, FILE *fp) {
return getdelim(buf, bufsiz, '\n', fp);
}
/* Original source: https://android.googlesource.com/platform/bionic/+/master/libc/bionic/mntent.cpp
* License: AOSP, full copyright notice please check original source */
struct mntent *compat_getmntent_r(FILE* fp, struct mntent* e, char* buf, int buf_len) {
memset(e, 0, sizeof(*e));
while (fgets(buf, buf_len, fp) != nullptr) {
// Entries look like "proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0".
// That is: mnt_fsname mnt_dir mnt_type mnt_opts 0 0.
int fsname0, fsname1, dir0, dir1, type0, type1, opts0, opts1;
if (sscanf(buf, " %n%*s%n %n%*s%n %n%*s%n %n%*s%n %d %d",
&fsname0, &fsname1, &dir0, &dir1, &type0, &type1, &opts0, &opts1,
&e->mnt_freq, &e->mnt_passno) == 2) {
e->mnt_fsname = &buf[fsname0];
buf[fsname1] = '\0';
e->mnt_dir = &buf[dir0];
buf[dir1] = '\0';
e->mnt_type = &buf[type0];
buf[type1] = '\0';
e->mnt_opts = &buf[opts0];
buf[opts1] = '\0';
return e;
}
}
return nullptr;
}
FILE *compat_setmntent(const char* path, const char* mode) {
return fopen(path, mode);
}
int compat_endmntent(FILE* fp) {
if (fp != nullptr) {
fclose(fp);
}
return 1;
}
char *compat_hasmntopt(const struct mntent* mnt, const char* opt) {
char* token = mnt->mnt_opts;
char* const end = mnt->mnt_opts + strlen(mnt->mnt_opts);
const size_t optLen = strlen(opt);
while (token) {
char* const tokenEnd = token + optLen;
if (tokenEnd > end) break;
if (memcmp(token, opt, optLen) == 0 &&
(*tokenEnd == '\0' || *tokenEnd == ',' || *tokenEnd == '=')) {
return token;
}
token = strchr(token, ',');
if (token) token++;
}
return nullptr;
}