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-rw-r--r--toys/posix/cpio.c213
1 files changed, 213 insertions, 0 deletions
diff --git a/toys/posix/cpio.c b/toys/posix/cpio.c
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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 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));
+ }
+}