Don't use getmntent_r from system's libc

Fix #5354

Co-authored-by: topjohnwu <topjohnwu@gmail.com>
This commit is contained in:
LoveSy
2022-02-05 15:19:12 +08:00
committed by GitHub
parent e9f562a8b7
commit d2c2456fbe
3 changed files with 57 additions and 49 deletions

View File

@@ -53,32 +53,6 @@ ssize_t 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 *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 *setmntent(const char *path, const char *mode) {
return fopen(path, mode);
}

View File

@@ -352,12 +352,39 @@ void parse_prop_file(const char *file, const function<bool(string_view, string_v
});
}
// Original source: https://android.googlesource.com/platform/bionic/+/master/libc/bionic/mntent.cpp
// License: AOSP, full copyright notice please check original source
static 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;
}
void parse_mnt(const char *file, const function<bool(mntent*)> &fn) {
auto fp = sFILE(setmntent(file, "re"), endmntent);
if (fp) {
mntent mentry{};
char buf[4096];
while (getmntent_r(fp.get(), &mentry, buf, sizeof(buf))) {
// getmntent_r from system's libc.so is broken on old platform
// use the compat one instead
while (compat_getmntent_r(fp.get(), &mentry, buf, sizeof(buf))) {
if (!fn(&mentry))
break;
}