#include <dirent.h>

#include <errno.h>

#include <fcntl.h>

#include <stddef.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <sys/sendfile.h>

#include <sys/stat.h>

#include <sys/xattr.h>

#include <time.h>

#include <unistd.h>

#include "alloc-util.h"

#include "btrfs-util.h"

#include "chattr-util.h"

#include "copy.h"

#include "dirent-util.h"

#include "fd-util.h"

#include "fileio.h"

#include "fs-util.h"

#include "io-util.h"

#include "macro.h"

#include "string-util.h"

#include "strv.h"

#include "time-util.h"

#include "umask-util.h"

#include "xattr-util.h"

#define COPY_BUFFER_SIZE (16*1024)

int copy_bytes(int fdf, int fdt, uint64_t max_bytes, bool try_reflink) {

bool try_sendfile = true, try_splice = true;

int r;

assert(fdf >= 0);

assert(fdt >= 0);

/* Try btrfs reflinks first. */

if (try_reflink &&

max_bytes == (uint64_t) -1 &&

lseek(fdf, 0, SEEK_CUR) == 0 &&

lseek(fdt, 0, SEEK_CUR) == 0) {

r = btrfs_reflink(fdf, fdt);

if (r >= 0)

return 0; /* we copied the whole thing, hence hit EOF, return 0 */

}

for (;;) {

size_t m = COPY_BUFFER_SIZE;

ssize_t n;

if (max_bytes != (uint64_t) -1) {

if (max_bytes <= 0)

return 1; /* return > 0 if we hit the max_bytes limit */

if ((uint64_t) m > max_bytes)

m = (size_t) max_bytes;

}

/* First try sendfile(), unless we already tried */

if (try_sendfile) {

n = sendfile(fdt, fdf, NULL, m);

if (n < 0) {

if (errno != EINVAL && errno != ENOSYS)

return -errno;

try_sendfile = false;

/* use fallback below */

} else if (n == 0) /* EOF */

break;

else if (n > 0)

/* Success! */

goto next;

}

/* The try splice, unless we already tried */

if (try_splice) {

n = splice(fdf, NULL, fdt, NULL, m, 0);

if (n < 0) {

if (errno != EINVAL && errno != ENOSYS)

return -errno;

try_splice = false;

/* use fallback below */

} else if (n == 0) /* EOF */

break;

else if (n > 0)

/* Success! */

goto next;

}

/* As a fallback just copy bits by hand */

{

uint8_t buf[m];

n = read(fdf, buf, m);

if (n < 0)

return -errno;

if (n == 0) /* EOF */

break;

r = loop_write(fdt, buf, (size_t) n, false);

if (r < 0)

return r;

}

next:

if (max_bytes != (uint64_t) -1) {

assert(max_bytes >= (uint64_t) n);

max_bytes -= n;

}

}

return 0; /* return 0 if we hit EOF earlier than the size limit */

}

static int fd_copy_symlink(int df, const char *from, const struct stat *st, int dt, const char *to) {

_cleanup_free_ char *target = NULL;

int r;

assert(from);

assert(st);

assert(to);

r = readlinkat_malloc(df, from, &target);

if (r < 0)

return r;

if (symlinkat(target, dt, to) < 0)

return -errno;

if (fchownat(dt, to, st->st_uid, st->st_gid, AT_SYMLINK_NOFOLLOW) < 0)

return -errno;

return 0;

}

static int fd_copy_regular(int df, const char *from, const struct stat *st, int dt, const char *to) {

_cleanup_close_ int fdf = -1, fdt = -1;

struct timespec ts[2];

int r, q;

assert(from);

assert(st);

assert(to);

fdf = openat(df, from, O_RDONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);

if (fdf < 0)

return -errno;

fdt = openat(dt, to, O_WRONLY|O_CREAT|O_EXCL|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, st->st_mode & 07777);

if (fdt < 0)

return -errno;

r = copy_bytes(fdf, fdt, (uint64_t) -1, true);

if (r < 0) {

unlinkat(dt, to, 0);

return r;

}

if (fchown(fdt, st->st_uid, st->st_gid) < 0)

r = -errno;

if (fchmod(fdt, st->st_mode & 07777) < 0)

r = -errno;

ts[0] = st->st_atim;

ts[1] = st->st_mtim;

(void) futimens(fdt, ts);

(void) copy_xattr(fdf, fdt);

q = close(fdt);

fdt = -1;

if (q < 0) {

r = -errno;

unlinkat(dt, to, 0);

}

return r;

}

static int fd_copy_fifo(int df, const char *from, const struct stat *st, int dt, const char *to) {

int r;

assert(from);

assert(st);

assert(to);

r = mkfifoat(dt, to, st->st_mode & 07777);

if (r < 0)

return -errno;

if (fchownat(dt, to, st->st_uid, st->st_gid, AT_SYMLINK_NOFOLLOW) < 0)

r = -errno;

if (fchmodat(dt, to, st->st_mode & 07777, 0) < 0)

r = -errno;

return r;

}

static int fd_copy_node(int df, const char *from, const struct stat *st, int dt, const char *to) {

int r;

assert(from);

assert(st);

assert(to);

r = mknodat(dt, to, st->st_mode, st->st_rdev);

if (r < 0)

return -errno;

if (fchownat(dt, to, st->st_uid, st->st_gid, AT_SYMLINK_NOFOLLOW) < 0)

r = -errno;

if (fchmodat(dt, to, st->st_mode & 07777, 0) < 0)

r = -errno;

return r;

}

static int fd_copy_directory(

int df,

const char *from,

const struct stat *st,

int dt,

const char *to,

dev_t original_device,

bool merge) {

_cleanup_close_ int fdf = -1, fdt = -1;

_cleanup_closedir_ DIR *d = NULL;

struct dirent *de;

bool created;

int r;

assert(st);

assert(to);

if (from)

fdf = openat(df, from, O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);

else

fdf = fcntl(df, F_DUPFD_CLOEXEC, 3);

d = fdopendir(fdf);

if (!d)

return -errno;

fdf = -1;

r = mkdirat(dt, to, st->st_mode & 07777);

if (r >= 0)

created = true;

else if (errno == EEXIST && merge)

created = false;

else

return -errno;

fdt = openat(dt, to, O_RDONLY|O_DIRECTORY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW);

if (fdt < 0)

return -errno;

r = 0;

if (created) {

struct timespec ut[2] = {

st->st_atim,

st->st_mtim

};

if (fchown(fdt, st->st_uid, st->st_gid) < 0)

r = -errno;

if (fchmod(fdt, st->st_mode & 07777) < 0)

r = -errno;

(void) futimens(fdt, ut);

(void) copy_xattr(dirfd(d), fdt);

}

FOREACH_DIRENT_ALL(de, d, return -errno) {

struct stat buf;

int q;

if (STR_IN_SET(de->d_name, ".", ".."))

continue;

if (fstatat(dirfd(d), de->d_name, &buf, AT_SYMLINK_NOFOLLOW) < 0) {

r = -errno;

continue;

}

if (buf.st_dev != original_device)

continue;

if (S_ISREG(buf.st_mode))

q = fd_copy_regular(dirfd(d), de->d_name, &buf, fdt, de->d_name);

else if (S_ISDIR(buf.st_mode))

q = fd_copy_directory(dirfd(d), de->d_name, &buf, fdt, de->d_name, original_device, merge);

else if (S_ISLNK(buf.st_mode))

q = fd_copy_symlink(dirfd(d), de->d_name, &buf, fdt, de->d_name);

else if (S_ISFIFO(buf.st_mode))

q = fd_copy_fifo(dirfd(d), de->d_name, &buf, fdt, de->d_name);

else if (S_ISBLK(buf.st_mode) || S_ISCHR(buf.st_mode))

q = fd_copy_node(dirfd(d), de->d_name, &buf, fdt, de->d_name);

else

q = -EOPNOTSUPP;

if (q == -EEXIST && merge)

q = 0;

if (q < 0)

r = q;

}

return r;

}

int copy_tree_at(int fdf, const char *from, int fdt, const char *to, bool merge) {

struct stat st;

assert(from);

assert(to);

if (fstatat(fdf, from, &st, AT_SYMLINK_NOFOLLOW) < 0)

return -errno;

if (S_ISREG(st.st_mode))

return fd_copy_regular(fdf, from, &st, fdt, to);

else if (S_ISDIR(st.st_mode))

return fd_copy_directory(fdf, from, &st, fdt, to, st.st_dev, merge);

else if (S_ISLNK(st.st_mode))

return fd_copy_symlink(fdf, from, &st, fdt, to);

else if (S_ISFIFO(st.st_mode))

return fd_copy_fifo(fdf, from, &st, fdt, to);

else if (S_ISBLK(st.st_mode) || S_ISCHR(st.st_mode))

return fd_copy_node(fdf, from, &st, fdt, to);

else

return -EOPNOTSUPP;

}

int copy_tree(const char *from, const char *to, bool merge) {

return copy_tree_at(AT_FDCWD, from, AT_FDCWD, to, merge);

}

int copy_directory_fd(int dirfd, const char *to, bool merge) {

struct stat st;

assert(dirfd >= 0);

assert(to);

if (fstat(dirfd, &st) < 0)

return -errno;

if (!S_ISDIR(st.st_mode))

return -ENOTDIR;

return fd_copy_directory(dirfd, NULL, &st, AT_FDCWD, to, st.st_dev, merge);

}

int copy_file_fd(const char *from, int fdt, bool try_reflink) {

_cleanup_close_ int fdf = -1;

int r;

assert(from);

assert(fdt >= 0);

fdf = open(from, O_RDONLY|O_CLOEXEC|O_NOCTTY);

if (fdf < 0)

return -errno;

r = copy_bytes(fdf, fdt, (uint64_t) -1, try_reflink);

(void) copy_times(fdf, fdt);

(void) copy_xattr(fdf, fdt);

return r;

}

int copy_file(const char *from, const char *to, int flags, mode_t mode, unsigned chattr_flags) {

int fdt = -1, r;

assert(from);

assert(to);

RUN_WITH_UMASK(0000) {

fdt = open(to, flags|O_WRONLY|O_CREAT|O_CLOEXEC|O_NOCTTY, mode);

if (fdt < 0)

return -errno;

}

if (chattr_flags != 0)

(void) chattr_fd(fdt, chattr_flags, (unsigned) -1);

r = copy_file_fd(from, fdt, true);

if (r < 0) {

close(fdt);

unlink(to);

return r;

}

if (close(fdt) < 0) {

unlink_noerrno(to);

return -errno;

}

return 0;

}

int copy_file_atomic(const char *from, const char *to, mode_t mode, bool replace, unsigned chattr_flags) {

_cleanup_free_ char *t = NULL;

int r;

assert(from);

assert(to);

r = tempfn_random(to, NULL, &t);

if (r < 0)

return r;

r = copy_file(from, t, O_NOFOLLOW|O_EXCL, mode, chattr_flags);

if (r < 0)

return r;

if (replace) {

r = renameat(AT_FDCWD, t, AT_FDCWD, to);

if (r < 0)

r = -errno;

} else

r = rename_noreplace(AT_FDCWD, t, AT_FDCWD, to);

if (r < 0) {

(void) unlink_noerrno(t);

return r;

}

return 0;

}

int copy_times(int fdf, int fdt) {

struct timespec ut[2];

struct stat st;

usec_t crtime = 0;

assert(fdf >= 0);

assert(fdt >= 0);

if (fstat(fdf, &st) < 0)

return -errno;

ut[0] = st.st_atim;

ut[1] = st.st_mtim;

if (futimens(fdt, ut) < 0)

return -errno;

if (fd_getcrtime(fdf, &crtime) >= 0)

(void) fd_setcrtime(fdt, crtime);

return 0;

}

int copy_xattr(int fdf, int fdt) {

_cleanup_free_ char *bufa = NULL, *bufb = NULL;

size_t sza = 100, szb = 100;

ssize_t n;

int ret = 0;

const char *p;

for (;;) {

bufa = malloc(sza);

if (!bufa)

return -ENOMEM;

n = flistxattr(fdf, bufa, sza);

if (n == 0)

return 0;

if (n > 0)

break;

if (errno != ERANGE)

return -errno;

sza *= 2;

bufa = mfree(bufa);

}

p = bufa;

while (n > 0) {

size_t l;

l = strlen(p);

assert(l < (size_t) n);

if (startswith(p, "user.")) {

ssize_t m;

if (!bufb) {

bufb = malloc(szb);

if (!bufb)

return -ENOMEM;

}

m = fgetxattr(fdf, p, bufb, szb);

if (m < 0) {

if (errno == ERANGE) {

szb *= 2;

bufb = mfree(bufb);

continue;

}

return -errno;

}

if (fsetxattr(fdt, p, bufb, m, 0) < 0)

ret = -errno;

}

p += l + 1;

n -= l + 1;

}

return ret;

}