diff options
Diffstat (limited to 'toys/posix')
| -rw-r--r-- | toys/posix/cpio.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/toys/posix/cpio.c b/toys/posix/cpio.c new file mode 100644 index 00000000..900e5128 --- /dev/null +++ b/toys/posix/cpio.c @@ -0,0 +1,213 @@ +/* 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 y + 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 = -1; + ssize_t llen; + + len = getline(&name, &size, stdin); + if (len<1) break; + if (name[len-1] == '\n') name[--len] = 0; + if (lstat(name, &st) + || (S_ISREG(st.st_mode) && (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; + llen -= nlen; + // 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 (llen) 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)); + } +} |