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/* cpio.c - a basic cpio
*
* Written 2013 AD by Isaac Dunham; this code is placed under the
* same license as toybox or as CC0, at your option.
*
* http://refspecs.linuxfoundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/cpio.html
* and http://pubs.opengroup.org/onlinepubs/7908799/xcu/cpio.html
*
* Yes, that's SUSv2, the newer standards removed it around the time RPM
* and initramfs started heavily using this archive format.
*
* Modern cpio expanded header to 110 bytes (first field 6 bytes, rest are 8).
* In order: magic ino mode uid gid nlink mtime filesize devmajor devminor
* rdevmajor rdevminor namesize check
USE_CPIO(NEWTOY(cpio, "duH:i|t|F:o|v(verbose)[!io][!ot]", TOYFLAG_BIN))
config CPIO
bool "cpio"
default n
help
usage: cpio -{o|t|i} [-v] [--verbose] [-F FILE] [ignored: -du -H newc]
copy files into and out of a "newc" format cpio archive
-F FILE use archive FILE instead of stdin/stdout
-i extract from archive into file system (stdin=archive)
-o create archive (stdin=list of files, stdout=archive)
-t test files (list only, stdin=archive, stdout=list of files)
-v verbose (list files during create/extract)
*/
#define FOR_cpio
#include "toys.h"
GLOBALS(
char *archive;
char *fmt;
)
// Read strings, tail padded to 4 byte alignment. Argument "align" is amount
// by which start of string isn't aligned (usually 0).
static char *strpad(int fd, unsigned len, unsigned align)
{
char *str;
align = (align + len) & 3;
if (align) len += (4-align);
xreadall(fd, str = xmalloc(len+1), len);
str[len]=0; // redundant, in case archive is bad
return str;
}
//convert hex to uint; mostly to allow using bits of non-terminated strings
unsigned x8u(char *hex)
{
unsigned val, inpos = 8, outpos;
char pattern[6];
while (*hex == '0') {
hex++;
if (!--inpos) return 0;
}
// Because scanf gratuitously treats %*X differently than printf does.
sprintf(pattern, "%%%dX%%n", inpos);
sscanf(hex, pattern, &val, &outpos);
if (inpos != outpos) error_exit("bad header");
return val;
}
void cpio_main(void)
{
int afd;
// Subtle bit: FLAG_o is 1 so we can just use it to select stdin/stdout.
afd = toys.optflags & FLAG_o;
if (TT.archive) {
int perm = (toys.optflags & FLAG_o) ? O_CREAT|O_WRONLY|O_TRUNC : O_RDONLY;
afd = xcreate(TT.archive, perm, 0644);
}
// read cpio archive
if (toys.optflags & (FLAG_i|FLAG_t)) for (;;) {
char *name, *tofree, *data;
unsigned size, mode;
int test = toys.optflags & FLAG_t, err = 0;
// Read header and name.
xreadall(afd, toybuf, 110);
tofree = name = strpad(afd, x8u(toybuf+94), 110);
if (!strcmp("TRAILER!!!", name)) break;
// If you want to extract absolute paths, "cd /" and run cpio.
while (*name == '/') name++;
// Align to 4 bytes. Note header is 110 bytes which is 2 bytes over.
size = x8u(toybuf+54);
mode = x8u(toybuf+14);
if (toys.optflags & (FLAG_t|FLAG_v)) puts(name);
if (!test && strrchr(name, '/') && mkpathat(AT_FDCWD, name, 0, 2)) {
perror_msg("mkpath '%s'", name);
test++;
}
// Consume entire record even if it couldn't create file, so we're
// properly aligned with next file.
if (S_ISDIR(mode)) {
if (!test) err = mkdir(name, mode);
} else if (S_ISLNK(mode)) {
data = strpad(afd, size, 0);
if (!test) err = symlink(data, name);
} else if (S_ISREG(mode)) {
int fd;
// If write fails, we still need to read/discard data to continue with
// archive. Since doing so overwrites errno, report error now
fd = test ? 0 : open(name, O_CREAT|O_WRONLY|O_TRUNC|O_NOFOLLOW, mode);
if (fd < 0) {
perror_msg("create %s", name);
test++;
}
data = toybuf;
while (size) {
if (size < sizeof(toybuf)) data = strpad(afd, size, 0);
else xreadall(afd, toybuf, sizeof(toybuf));
if (!test) xwrite(fd, data, data == toybuf ? sizeof(toybuf) : size);
if (data != toybuf) {
free(data);
break;
}
size -= sizeof(toybuf);
}
close(fd);
} else if (!test)
err = mknod(name, mode, makedev(x8u(toybuf+62), x8u(toybuf+70)));
if (err<0) perror_msg("create '%s'", name);
free(tofree);
// Output cpio archive
} else {
char *name = 0;
size_t size = 0;
for (;;) {
struct stat st;
unsigned nlen = strlen(name)+1, error = 0, zero = 0;
int len, fd;
ssize_t llen;
len = getline(&name, &size, stdin);
if (len<1) break;
if (name[len-1] == '\n') name[--len] = 0;
if (lstat(name, &st) || (fd = open(name, O_RDONLY))<0) {
perror_msg("%s", name);
continue;
}
if (!S_ISREG(st.st_mode) && !S_ISLNK(st.st_mode)) st.st_size = 0;
if (st.st_size >> 32) perror_msg("skipping >2G file '%s'", name);
else {
llen = sprintf(toybuf,
"070701%08X%08X%08X%08X%08X%08X%08X%08X%08X%08X%08X%08X%08X",
(int)st.st_ino, st.st_mode, st.st_uid, st.st_gid, (int)st.st_nlink,
(int)st.st_mtime, (int)st.st_size, major(st.st_dev),
minor(st.st_dev), major(st.st_rdev), minor(st.st_rdev), nlen, 0);
xwrite(afd, toybuf, llen);
xwrite(afd, name, nlen);
// NUL Pad header up to 4 multiple bytes.
llen = (llen + nlen) & 3;
if (llen) xwrite(afd, &zero, 4-llen);
// Write out body for symlink or regular file
llen = st.st_size;
if (S_ISLNK(st.st_mode)) {
if (readlink(name, toybuf, sizeof(toybuf)-1) == llen)
xwrite(afd, toybuf, llen);
else perror_msg("readlink '%s'", name);
} else while (llen) {
nlen = llen > sizeof(toybuf) ? sizeof(toybuf) : llen;
// If read fails, write anyway (already wrote size in header)
if (nlen != readall(fd, toybuf, nlen))
if (!error++) perror_msg("bad read from file '%s'", name);
xwrite(afd, toybuf, nlen);
}
llen = st.st_size & 3;
if (nlen) write(afd, &zero, 4-llen);
}
close(fd);
}
free(name);
xwrite(afd, toybuf,
sprintf(toybuf, "070701%040X%056X%08XTRAILER!!!%c%c%c",
1, 0x0b, 0, 0, 0, 0));
}
}
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