// Copyright (c) Microsoft. All rights reserved.

// Licensed under the MIT license. See LICENSE file in the project root for full license information.

#include "pal_config.h"

#include "pal_mount.h"

#include "pal_utilities.h"

#include <assert.h>

#include <string.h>

#include <errno.h>

// Check if we should use getmntinfo or /proc/mounts

#if HAVE_MNTINFO

#include <sys/mount.h>

#else

#include <sys/statfs.h>

#include <mntent.h>

#define STRING_BUFFER_SIZE 8192

#endif

static int32_t GetMountInfo(MountPointFound onFound)

{

#if HAVE_MNTINFO

// getmntinfo returns pointers to OS-internal structs, so we don't need to worry about free'ing the object

struct statfs* mounts = nullptr;

int count = getmntinfo(&mounts, 0);

for (int32_t i = 0; i < count; i++)

{

onFound(mounts[i].f_mntonname);

}

return 0;

}

#else

int result = -1;

FILE* fp = setmntent("/proc/mounts", MNTOPT_RO);

if (fp != nullptr)

{

// The _r version of getmntent needs all buffers to be passed in; however, we don't know how big of a string

// buffer we will need, so pick something that seems like it will be big enough.

char buffer[STRING_BUFFER_SIZE] = {};

mntent entry;

while (getmntent_r(fp, &entry, buffer, STRING_BUFFER_SIZE) != nullptr)

{

onFound(entry.mnt_dir);

}

result = endmntent(fp);

assert(result == 1); // documented to always return 1

result =

0; // We need to standardize a success return code between our implementations, so settle on 0 for success

}

return result;

}

#endif

extern "C" int32_t GetAllMountPoints(MountPointFound onFound)

{

return GetMountInfo(onFound);

}

extern "C" int32_t GetSpaceInfoForMountPoint(const char* name, MountPointInformation* mpi)

{

assert(name != nullptr);

assert(mpi != nullptr);

struct statfs stats = {};

int result = statfs(name, &stats);

if (result == 0)

{

// Note that these have signed integer types on some platforms but musn't be negative.

// Also, upcast here (some platforms have smaller types) to 64-bit before multiplying to

// avoid overflow.

uint64_t bsize = UnsignedCast(stats.f_bsize);

uint64_t bavail = UnsignedCast(stats.f_bavail);

uint64_t bfree = UnsignedCast(stats.f_bfree);

uint64_t blocks = UnsignedCast(stats.f_blocks);

mpi->AvailableFreeSpace = bsize * bavail;

mpi->TotalFreeSpace = bsize * bfree;

mpi->TotalSize = bsize * blocks;

}

else

{

*mpi = {};

}

return result;

}

extern "C" int32_t

GetFormatInfoForMountPoint(const char* name, char* formatNameBuffer, int32_t bufferLength, int64_t* formatType)

{

assert((formatNameBuffer != nullptr) && (formatType != nullptr));

assert(bufferLength > 0);

struct statfs stats;

int result = statfs(name, &stats);

if (result == 0)

{

#if HAVE_STATFS_FSTYPENAME

if (bufferLength < MFSNAMELEN)

{

result = ERANGE;

*formatType = 0;

}

else

{

SafeStringCopy(formatNameBuffer, bufferLength, stats.f_fstypename);

*formatType = -1;

}

#else

assert(formatType != nullptr);

*formatType = stats.f_type;

SafeStringCopy(formatNameBuffer, bufferLength, "");

#endif

}

else

{

*formatType = 0;

}

return result;

}