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- /*
- * This file is part of the UCB release of Plan 9. It is subject to the license
- * terms in the LICENSE file found in the top-level directory of this
- * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
- * part of the UCB release of Plan 9, including this file, may be copied,
- * modified, propagated, or distributed except according to the terms contained
- * in the LICENSE file.
- */
- /*
- * tar - `tape archiver', actually usable on any medium.
- * POSIX "ustar" compliant when extracting, and by default when creating.
- * this tar attempts to read and write multiple Tblock-byte blocks
- * at once to and from the filesystem, and does not copy blocks
- * around internally.
- */
- #include <u.h>
- #include <libc.h>
- #include <ctype.h>
- #include <fcall.h> /* for %M */
- #include <String.h>
- /*
- * modified versions of those in libc.h; scans only the first arg for
- * keyletters and options.
- */
- #define TARGBEGIN {\
- (argv0 || (argv0 = *argv)), argv++, argc--;\
- if (argv[0]) {\
- char *_args, *_argt;\
- Rune _argc;\
- _args = &argv[0][0];\
- _argc = 0;\
- while(*_args && (_args += chartorune(&_argc, _args)))\
- switch(_argc)
- #define TARGEND SET(_argt); USED(_argt);USED(_argc);USED(_args); \
- argc--, argv++; } \
- USED(argv); USED(argc); }
- #define TARGC() (_argc)
- #define HOWMANY(a, size) (((a) + (size) - 1) / (size))
- #define BYTES2TBLKS(bytes) HOWMANY(bytes, Tblock)
- /* read big-endian binary integers; args must be (unsigned char *) */
- #define G2BEBYTE(x) (((x)[0]<<8) | (x)[1])
- #define G3BEBYTE(x) (((x)[0]<<16) | ((x)[1]<<8) | (x)[2])
- #define G4BEBYTE(x) (((x)[0]<<24) | ((x)[1]<<16) | ((x)[2]<<8) | (x)[3])
- #define G8BEBYTE(x) (((int64_t)G4BEBYTE(x)<<32) | (uint32_t)G4BEBYTE((x)+4))
- typedef int64_t Off;
- typedef char *(*Refill)(int ar, char *bufs, int justhdr);
- enum { Stdin, Stdout, Stderr };
- enum { Rd, Wr }; /* pipe fd-array indices */
- enum { Output, Input };
- enum { None, Toc, Xtract, Replace };
- enum { Alldata, Justnxthdr };
- enum {
- Tblock = 512,
- Namsiz = 100,
- Maxpfx = 155, /* from POSIX */
- Maxname = Namsiz + 1 + Maxpfx,
- Binsize = 0x80, /* flag in size[0], from gnu: positive binary size */
- Binnegsz = 0xff, /* flag in size[0]: negative binary size */
- Nblock = 40, /* maximum blocksize */
- Dblock = 20, /* default blocksize */
- Debug = 0,
- };
- /* POSIX link flags */
- enum {
- LF_PLAIN1 = '\0',
- LF_PLAIN2 = '0',
- LF_LINK = '1',
- LF_SYMLINK1 = '2',
- LF_SYMLINK2 = 's', /* 4BSD used this */
- LF_CHR = '3',
- LF_BLK = '4',
- LF_DIR = '5',
- LF_FIFO = '6',
- LF_CONTIG = '7',
- /* 'A' - 'Z' are reserved for custom implementations */
- };
- #define islink(lf) (isreallink(lf) || issymlink(lf))
- #define isreallink(lf) ((lf) == LF_LINK)
- #define issymlink(lf) ((lf) == LF_SYMLINK1 || (lf) == LF_SYMLINK2)
- typedef union {
- unsigned char data[Tblock];
- struct {
- char name[Namsiz];
- char mode[8];
- char uid[8];
- char gid[8];
- char size[12];
- char mtime[12];
- char chksum[8];
- char linkflag;
- char linkname[Namsiz];
- /* rest are defined by POSIX's ustar format; see p1003.2b */
- char magic[6]; /* "ustar" */
- char version[2];
- char uname[32];
- char gname[32];
- char devmajor[8];
- char devminor[8];
- char prefix[Maxpfx]; /* if non-null, path= prefix "/" name */
- };
- } Hdr;
- typedef struct {
- char *comp;
- char *decomp;
- char *sfx[4];
- } Compress;
- static Compress comps[] = {
- "gzip", "gunzip", { ".tar.gz", ".tgz" }, /* default */
- "compress", "uncompress", { ".tar.Z", ".tz" },
- "bzip2", "bunzip2", { ".tar.bz", ".tbz",
- ".tar.bz2",".tbz2" },
- };
- typedef struct {
- int kid;
- int fd; /* original fd */
- int rfd; /* replacement fd */
- int input;
- int open;
- } Pushstate;
- #define OTHER(rdwr) ((rdwr) == Rd? Wr: Rd)
- static int fixednblock;
- static int verb;
- static int posix = 1;
- static int docreate;
- static int aruid;
- static int argid;
- static int relative = 1;
- static int settime;
- static int verbose;
- static int docompress;
- static int keepexisting;
- static int ignerrs; /* flag: ignore i/o errors if possible */
- static Off blkoff; /* offset of the current archive block (not Tblock) */
- static Off nexthdr;
- static int nblock = Dblock;
- static int resync;
- static char *usefile, *arname = "archive";
- static char origdir[Maxname*2];
- static Hdr *tpblk, *endblk;
- static Hdr *curblk;
- static void
- usage(void)
- {
- fprint(2, "usage: %s {crtx}[PRTfgikmpsuvz] [archive] [file1 file2...]\n",
- argv0);
- exits("usage");
- }
- /* I/O, with error retry or exit */
- static int
- cope(char *name, int fd, void *buf, int32_t len, Off off)
- {
- fprint(2, "%s: %serror reading %s: %r\n", argv0,
- (ignerrs? "ignoring ": ""), name);
- if (!ignerrs)
- exits("read error");
- /* pretend we read len bytes of zeroes */
- memset(buf, 0, len);
- if (off >= 0) /* seekable? */
- seek(fd, off + len, 0);
- return len;
- }
- static int
- eread(char *name, int fd, void *buf, int32_t len)
- {
- int rd;
- Off off;
- off = seek(fd, 0, 1); /* for coping with errors */
- rd = read(fd, buf, len);
- if (rd < 0)
- rd = cope(name, fd, buf, len, off);
- return rd;
- }
- static int
- ereadn(char *name, int fd, void *buf, int32_t len)
- {
- int rd;
- Off off;
- off = seek(fd, 0, 1);
- rd = readn(fd, buf, len);
- if (rd < 0)
- rd = cope(name, fd, buf, len, off);
- return rd;
- }
- static int
- ewrite(char *name, int fd, void *buf, int32_t len)
- {
- int rd;
- werrstr("");
- rd = write(fd, buf, len);
- if (rd != len)
- sysfatal("error writing %s: %r", name);
- return rd;
- }
- /* compression */
- static Compress *
- compmethod(char *name)
- {
- int i, nmlen, sfxlen;
- Compress *cp;
- if (name != nil) {
- nmlen = strlen(name);
- for (cp = comps; cp < comps + nelem(comps); cp++)
- for (i = 0; i < nelem(cp->sfx) && cp->sfx[i]; i++) {
- sfxlen = strlen(cp->sfx[i]);
- if (nmlen > sfxlen &&
- strcmp(cp->sfx[i], name+nmlen-sfxlen) == 0)
- return cp;
- }
- }
- return docompress? comps: nil;
- }
- /*
- * push a filter, cmd, onto fd. if input, it's an input descriptor.
- * returns a descriptor to replace fd, or -1 on error.
- */
- static int
- push(int fd, char *cmd, int input, Pushstate *ps)
- {
- int nfd, pifds[2];
- String *s;
- ps->open = 0;
- ps->fd = fd;
- ps->input = input;
- if (fd < 0 || pipe(pifds) < 0)
- return -1;
- ps->kid = fork();
- switch (ps->kid) {
- case -1:
- return -1;
- case 0:
- if (input)
- dup(pifds[Wr], Stdout);
- else
- dup(pifds[Rd], Stdin);
- close(pifds[input? Rd: Wr]);
- dup(fd, (input? Stdin: Stdout));
- s = s_new();
- if (cmd[0] != '/')
- s_append(s, "/bin/");
- s_append(s, cmd);
- execl(s_to_c(s), cmd, nil);
- sysfatal("can't exec %s: %r", cmd);
- default:
- nfd = pifds[input? Rd: Wr];
- close(pifds[input? Wr: Rd]);
- break;
- }
- ps->rfd = nfd;
- ps->open = 1;
- return nfd;
- }
- static char *
- pushclose(Pushstate *ps)
- {
- Waitmsg *wm;
- if (ps->fd < 0 || ps->rfd < 0 || !ps->open)
- return "not open";
- close(ps->rfd);
- ps->rfd = -1;
- ps->open = 0;
- while ((wm = wait()) != nil && wm->pid != ps->kid)
- continue;
- return wm? wm->msg: nil;
- }
- /*
- * block-buffer management
- */
- static void
- initblks(void)
- {
- free(tpblk);
- tpblk = malloc(Tblock * nblock);
- assert(tpblk != nil);
- endblk = tpblk + nblock;
- }
- /*
- * (re)fill block buffers from archive. `justhdr' means we don't care
- * about the data before the next header block.
- */
- static char *
- refill(int ar, char *bufs, int justhdr)
- {
- int i, n;
- unsigned bytes = Tblock * nblock;
- static int done, first = 1, seekable;
- if (done)
- return nil;
- blkoff = seek(ar, 0, 1); /* note position for `tar r' */
- if (first)
- seekable = blkoff >= 0;
- /* try to size non-pipe input at first read */
- if (first && usefile && !fixednblock) {
- n = eread(arname, ar, bufs, bytes);
- if (n == 0)
- sysfatal("EOF reading archive %s: %r", arname);
- i = n;
- if (i % Tblock != 0)
- sysfatal("%s: archive block size (%d) error", arname, i);
- i /= Tblock;
- if (i != nblock) {
- nblock = i;
- fprint(2, "%s: blocking = %d\n", argv0, nblock);
- endblk = (Hdr *)bufs + nblock;
- bytes = n;
- }
- } else if (justhdr && seekable && nexthdr - blkoff >= bytes) {
- /* optimisation for huge archive members on seekable media */
- if (seek(ar, bytes, 1) < 0)
- sysfatal("can't seek on archive %s: %r", arname);
- n = bytes;
- } else
- n = ereadn(arname, ar, bufs, bytes);
- first = 0;
- if (n == 0)
- sysfatal("unexpected EOF reading archive %s", arname);
- if (n % Tblock != 0)
- sysfatal("partial block read from archive %s", arname);
- if (n != bytes) {
- done = 1;
- memset(bufs + n, 0, bytes - n);
- }
- return bufs;
- }
- static Hdr *
- getblk(int ar, Refill rfp, int justhdr)
- {
- if (curblk == nil || curblk >= endblk) { /* input block exhausted? */
- if (rfp != nil && (*rfp)(ar, (char *)tpblk, justhdr) == nil)
- return nil;
- curblk = tpblk;
- }
- return curblk++;
- }
- static Hdr *
- getblkrd(int ar, int justhdr)
- {
- return getblk(ar, refill, justhdr);
- }
- static Hdr *
- getblke(int ar)
- {
- return getblk(ar, nil, Alldata);
- }
- static Hdr *
- getblkz(int ar)
- {
- Hdr *hp = getblke(ar);
- if (hp != nil)
- memset(hp->data, 0, Tblock);
- return hp;
- }
- /*
- * how many block buffers are available, starting at the address
- * just returned by getblk*?
- */
- static int
- gothowmany(int max)
- {
- int n = endblk - (curblk - 1);
- return n > max? max: n;
- }
- /*
- * indicate that one is done with the last block obtained from getblke
- * and it is now available to be written into the archive.
- */
- static void
- putlastblk(int ar)
- {
- unsigned bytes = Tblock * nblock;
- /* if writing end-of-archive, aid compression (good hygiene too) */
- if (curblk < endblk)
- memset(curblk, 0, (char *)endblk - (char *)curblk);
- ewrite(arname, ar, tpblk, bytes);
- }
- static void
- putblk(int ar)
- {
- if (curblk >= endblk)
- putlastblk(ar);
- }
- static void
- putbackblk(int ar)
- {
- curblk--;
- USED(ar);
- }
- static void
- putreadblks(int ar, int blks)
- {
- curblk += blks - 1;
- USED(ar);
- }
- static void
- putblkmany(int ar, int blks)
- {
- assert(blks > 0);
- curblk += blks - 1;
- putblk(ar);
- }
- /*
- * common routines
- */
- /*
- * modifies hp->chksum but restores it; important for the last block of the
- * old archive when updating with `tar rf archive'
- */
- static int32_t
- chksum(Hdr *hp)
- {
- int n = Tblock;
- int32_t i = 0;
- unsigned char *cp = hp->data;
- char oldsum[sizeof hp->chksum];
- memmove(oldsum, hp->chksum, sizeof oldsum);
- memset(hp->chksum, ' ', sizeof hp->chksum);
- while (n-- > 0)
- i += *cp++;
- memmove(hp->chksum, oldsum, sizeof oldsum);
- return i;
- }
- static int
- isustar(Hdr *hp)
- {
- return strcmp(hp->magic, "ustar") == 0;
- }
- /*
- * s is at most n bytes int32_t, but need not be NUL-terminated.
- * if shorter than n bytes, all bytes after the first NUL must also
- * be NUL.
- */
- static int
- strnlen(char *s, int n)
- {
- return s[n - 1] != '\0'? n: strlen(s);
- }
- /* set fullname from header */
- static char *
- name(Hdr *hp)
- {
- int pfxlen, namlen;
- char *fullname;
- static char fullnamebuf[2+Maxname+1]; /* 2+ for ./ on relative names */
- fullname = fullnamebuf+2;
- namlen = strnlen(hp->name, sizeof hp->name);
- if (hp->prefix[0] == '\0' || !isustar(hp)) { /* old-style name? */
- memmove(fullname, hp->name, namlen);
- fullname[namlen] = '\0';
- return fullname;
- }
- /* name is in two pieces */
- pfxlen = strnlen(hp->prefix, sizeof hp->prefix);
- memmove(fullname, hp->prefix, pfxlen);
- fullname[pfxlen] = '/';
- memmove(fullname + pfxlen + 1, hp->name, namlen);
- fullname[pfxlen + 1 + namlen] = '\0';
- return fullname;
- }
- static int
- isdir(Hdr *hp)
- {
- /* the mode test is ugly but sometimes necessary */
- return hp->linkflag == LF_DIR ||
- strrchr(name(hp), '\0')[-1] == '/' ||
- (strtoul(hp->mode, nil, 8)&0170000) == 040000;
- }
- static int
- eotar(Hdr *hp)
- {
- return name(hp)[0] == '\0';
- }
- /*
- static uint64_t
- getbe(unsigned char *src, int size)
- {
- uint64_t vl = 0;
- while (size-- > 0) {
- vl <<= 8;
- vl |= *src++;
- }
- return vl;
- }
- */
- static void
- putbe(unsigned char *dest, uint64_t vl, int size)
- {
- for (dest += size; size-- > 0; vl >>= 8)
- *--dest = vl;
- }
- /*
- * cautious parsing of octal numbers as ascii strings in
- * a tar header block. this is particularly important for
- * trusting the checksum when trying to resync.
- */
- static uint64_t
- hdrotoull(char *st, char *end, uint64_t errval, char *name, char *field)
- {
- char *numb;
- for (numb = st; (*numb == ' ' || *numb == '\0') && numb < end; numb++)
- ;
- if (numb < end && isascii(*numb) && isdigit(*numb))
- return strtoull(numb, nil, 8);
- else if (numb >= end)
- fprint(2, "%s: %s: empty %s in header\n", argv0, name, field);
- else
- fprint(2, "%s: %s: %s: non-numeric %s in header\n",
- argv0, name, numb, field);
- return errval;
- }
- /*
- * return the nominal size from the header block, which is not always the
- * size in the archive (the archive size may be zero for some file types
- * regardless of the nominal size).
- *
- * gnu and freebsd tars are now recording int64_ts as big-endian binary
- * with a flag in byte 0 to indicate this, which permits file sizes up to
- * 2^64-1 (actually 2^80-1 but our file sizes are int64_ts) rather than 2^33-1.
- */
- static Off
- hdrsize(Hdr *hp)
- {
- unsigned char *p;
- if((unsigned char)hp->size[0] == Binnegsz) {
- fprint(2, "%s: %s: negative length, which is insane\n",
- argv0, name(hp));
- return 0;
- } else if((unsigned char)hp->size[0] == Binsize) {
- p = (unsigned char *)hp->size + sizeof hp->size - 1 -
- sizeof(int64_t); /* -1 for terminating space */
- return G8BEBYTE(p);
- }
- return hdrotoull(hp->size, hp->size + sizeof hp->size, 0,
- name(hp), "size");
- }
- /*
- * return the number of bytes recorded in the archive.
- */
- static Off
- arsize(Hdr *hp)
- {
- if(isdir(hp) || islink(hp->linkflag))
- return 0;
- return hdrsize(hp);
- }
- static int32_t
- parsecksum(char *cksum, char *name)
- {
- Hdr *hp;
- return hdrotoull(cksum, cksum + sizeof hp->chksum, (uint64_t)-1LL,
- name, "checksum");
- }
- static Hdr *
- readhdr(int ar)
- {
- int32_t hdrcksum;
- Hdr *hp;
- hp = getblkrd(ar, Alldata);
- if (hp == nil)
- sysfatal("unexpected EOF instead of archive header in %s",
- arname);
- if (eotar(hp)) /* end-of-archive block? */
- return nil;
- hdrcksum = parsecksum(hp->chksum, name(hp));
- if (hdrcksum == -1 || chksum(hp) != hdrcksum) {
- if (!resync)
- sysfatal("bad archive header checksum in %s: "
- "name %.100s...; expected %#luo got %#luo",
- arname, hp->name, hdrcksum, chksum(hp));
- fprint(2, "%s: skipping past archive header with bad checksum in %s...",
- argv0, arname);
- do {
- hp = getblkrd(ar, Alldata);
- if (hp == nil)
- sysfatal("unexpected EOF looking for archive header in %s",
- arname);
- hdrcksum = parsecksum(hp->chksum, name(hp));
- } while (hdrcksum == -1 || chksum(hp) != hdrcksum);
- fprint(2, "found %s\n", name(hp));
- }
- nexthdr += Tblock*(1 + BYTES2TBLKS(arsize(hp)));
- return hp;
- }
- /*
- * tar r[c]
- */
- /*
- * if name is int32_ter than Namsiz bytes, try to split it at a slash and fit the
- * pieces into hp->prefix and hp->name.
- */
- static int
- putfullname(Hdr *hp, char *name)
- {
- int namlen, pfxlen;
- char *sl, *osl;
- String *slname = nil;
- if (isdir(hp)) {
- slname = s_new();
- s_append(slname, name);
- s_append(slname, "/"); /* posix requires this */
- name = s_to_c(slname);
- }
- namlen = strlen(name);
- if (namlen <= Namsiz) {
- strncpy(hp->name, name, Namsiz);
- hp->prefix[0] = '\0'; /* ustar paranoia */
- return 0;
- }
- if (!posix || namlen > Maxname) {
- fprint(2, "%s: name too int32_t for tar header: %s\n",
- argv0, name);
- return -1;
- }
- /*
- * try various splits until one results in pieces that fit into the
- * appropriate fields of the header. look for slashes from right
- * to left, in the hopes of putting the largest part of the name into
- * hp->prefix, which is larger than hp->name.
- */
- sl = strrchr(name, '/');
- while (sl != nil) {
- pfxlen = sl - name;
- if (pfxlen <= sizeof hp->prefix && namlen-1 - pfxlen <= Namsiz)
- break;
- osl = sl;
- *osl = '\0';
- sl = strrchr(name, '/');
- *osl = '/';
- }
- if (sl == nil) {
- fprint(2, "%s: name can't be split to fit tar header: %s\n",
- argv0, name);
- return -1;
- }
- *sl = '\0';
- strncpy(hp->prefix, name, sizeof hp->prefix);
- *sl++ = '/';
- strncpy(hp->name, sl, sizeof hp->name);
- if (slname)
- s_free(slname);
- return 0;
- }
- static int
- mkhdr(Hdr *hp, Dir *dir, char *file)
- {
- int r;
- /*
- * some of these fields run together, so we format them left-to-right
- * and don't use snprint.
- */
- sprint(hp->mode, "%6lo ", dir->mode & 0777);
- sprint(hp->uid, "%6o ", aruid);
- sprint(hp->gid, "%6o ", argid);
- if (dir->length >= (Off)1<<32) {
- static int printed;
- if (!printed) {
- printed = 1;
- fprint(2, "%s: storing large sizes in \"base 256\"\n", argv0);
- }
- hp->size[0] = Binsize;
- /* emit so-called `base 256' representation of size */
- putbe((unsigned char *)hp->size+1, dir->length, sizeof hp->size - 2);
- hp->size[sizeof hp->size - 1] = ' ';
- } else
- sprint(hp->size, "%11lluo ", dir->length);
- sprint(hp->mtime, "%11luo ", dir->mtime);
- hp->linkflag = (dir->mode&DMDIR? LF_DIR: LF_PLAIN1);
- r = putfullname(hp, file);
- if (posix) {
- strncpy(hp->magic, "ustar", sizeof hp->magic);
- strncpy(hp->version, "00", sizeof hp->version);
- strncpy(hp->uname, dir->uid, sizeof hp->uname);
- strncpy(hp->gname, dir->gid, sizeof hp->gname);
- }
- sprint(hp->chksum, "%6luo", chksum(hp));
- return r;
- }
- static void addtoar(int ar, char *file, char *shortf);
- static void
- addtreetoar(int ar, char *file, char *shortf, int fd)
- {
- int n;
- Dir *dent, *dirents;
- String *name = s_new();
- n = dirreadall(fd, &dirents);
- if (n < 0)
- fprint(2, "%s: dirreadall %s: %r\n", argv0, file);
- close(fd);
- if (n <= 0)
- return;
- if (chdir(shortf) < 0)
- sysfatal("chdir %s: %r", file);
- if (Debug)
- fprint(2, "chdir %s\t# %s\n", shortf, file);
- for (dent = dirents; dent < dirents + n; dent++) {
- s_reset(name);
- s_append(name, file);
- s_append(name, "/");
- s_append(name, dent->name);
- addtoar(ar, s_to_c(name), dent->name);
- }
- s_free(name);
- free(dirents);
- /*
- * this assumes that shortf is just one component, which is true
- * during directory descent, but not necessarily true of command-line
- * arguments. Our caller (or addtoar's) must reset the working
- * directory if necessary.
- */
- if (chdir("..") < 0)
- sysfatal("chdir %s/..: %r", file);
- if (Debug)
- fprint(2, "chdir ..\n");
- }
- static void
- addtoar(int ar, char *file, char *shortf)
- {
- int n, fd, isdir;
- int32_t bytes, blksread;
- uint32_t blksleft;
- Hdr *hbp;
- Dir *dir;
- String *name = nil;
- if (shortf[0] == '#') {
- name = s_new();
- s_append(name, "./");
- s_append(name, shortf);
- shortf = s_to_c(name);
- }
- if (Debug)
- fprint(2, "opening %s # %s\n", shortf, file);
- fd = open(shortf, OREAD);
- if (fd < 0) {
- fprint(2, "%s: can't open %s: %r\n", argv0, file);
- if (name)
- s_free(name);
- return;
- }
- dir = dirfstat(fd);
- if (dir == nil)
- sysfatal("can't fstat %s: %r", file);
- hbp = getblkz(ar);
- isdir = (dir->qid.type & QTDIR) != 0;
- if (mkhdr(hbp, dir, file) < 0) {
- putbackblk(ar);
- free(dir);
- close(fd);
- if (name)
- s_free(name);
- return;
- }
- putblk(ar);
- blksleft = BYTES2TBLKS(dir->length);
- free(dir);
- if (isdir)
- addtreetoar(ar, file, shortf, fd);
- else {
- for (; blksleft > 0; blksleft -= blksread) {
- hbp = getblke(ar);
- blksread = gothowmany(blksleft);
- assert(blksread >= 0);
- bytes = blksread * Tblock;
- n = ereadn(file, fd, hbp->data, bytes);
- assert(n >= 0);
- /*
- * ignore EOF. zero any partial block to aid
- * compression and emergency recovery of data.
- */
- if (n < Tblock)
- memset(hbp->data + n, 0, bytes - n);
- putblkmany(ar, blksread);
- }
- close(fd);
- if (verbose)
- fprint(2, "%s\n", file);
- }
- if (name)
- s_free(name);
- }
- static void
- skip(int ar, Hdr *hp, char *msg)
- {
- uint32_t blksleft, blksread;
- Off bytes;
- bytes = arsize(hp);
- for (blksleft = BYTES2TBLKS(bytes); blksleft > 0; blksleft -= blksread) {
- if (getblkrd(ar, Justnxthdr) == nil)
- sysfatal("unexpected EOF on archive %s %s", arname, msg);
- blksread = gothowmany(blksleft);
- putreadblks(ar, blksread);
- }
- }
- static void
- skiptoend(int ar)
- {
- Hdr *hp;
- while ((hp = readhdr(ar)) != nil)
- skip(ar, hp, "skipping to end");
- /*
- * we have just read the end-of-archive Tblock.
- * now seek back over the (big) archive block containing it,
- * and back up curblk ptr over end-of-archive Tblock in memory.
- */
- if (seek(ar, blkoff, 0) < 0)
- sysfatal("can't seek back over end-of-archive in %s: %r", arname);
- curblk--;
- }
- static char *
- replace(char **argv)
- {
- int i, ar;
- char *arg;
- Compress *comp = nil;
- Pushstate ps;
- /* open archive to be updated */
- if (usefile && docreate)
- ar = create(usefile, OWRITE, 0666);
- else if (usefile) {
- if (docompress)
- sysfatal("cannot update compressed archive");
- ar = open(usefile, ORDWR);
- } else
- ar = Stdout;
- /* push compression filter, if requested */
- if (docompress) {
- comp = compmethod(usefile);
- if (comp)
- ar = push(ar, comp->comp, Output, &ps);
- }
- if (ar < 0)
- sysfatal("can't open archive %s: %r", usefile);
- if (usefile && !docreate)
- skiptoend(ar);
- for (i = 0; argv[i] != nil; i++) {
- arg = argv[i];
- cleanname(arg);
- if (strcmp(arg, "..") == 0 || strncmp(arg, "../", 3) == 0)
- fprint(2, "%s: name starting with .. is a bad idea\n",
- argv0);
- addtoar(ar, arg, arg);
- chdir(origdir); /* for correctness & profiling */
- }
- /* write end-of-archive marker */
- getblkz(ar);
- putblk(ar);
- getblkz(ar);
- putlastblk(ar);
- if (comp)
- return pushclose(&ps);
- if (ar > Stderr)
- close(ar);
- return nil;
- }
- /*
- * tar [xt]
- */
- /* is pfx a file-name prefix of name? */
- static int
- prefix(char *name, char *pfx)
- {
- int pfxlen = strlen(pfx);
- char clpfx[Maxname+1];
- if (pfxlen > Maxname)
- return 0;
- strcpy(clpfx, pfx);
- cleanname(clpfx);
- return strncmp(clpfx, name, pfxlen) == 0 &&
- (name[pfxlen] == '\0' || name[pfxlen] == '/');
- }
- static int
- match(char *name, char **argv)
- {
- int i;
- char clname[Maxname+1];
- if (argv[0] == nil)
- return 1;
- strcpy(clname, name);
- cleanname(clname);
- for (i = 0; argv[i] != nil; i++)
- if (prefix(clname, argv[i]))
- return 1;
- return 0;
- }
- static void
- cantcreate(char *s, int mode)
- {
- int len;
- static char *last;
- /*
- * Always print about files. Only print about directories
- * we haven't printed about. (Assumes archive is ordered
- * nicely.)
- */
- if(mode&DMDIR){
- if(last){
- /* already printed this directory */
- if(strcmp(s, last) == 0)
- return;
- /* printed a higher directory, so printed this one */
- len = strlen(s);
- if(memcmp(s, last, len) == 0 && last[len] == '/')
- return;
- }
- /* save */
- free(last);
- last = strdup(s);
- }
- fprint(2, "%s: can't create %s: %r\n", argv0, s);
- }
- static int
- makedir(char *s)
- {
- int f;
- if (access(s, AEXIST) == 0)
- return -1;
- f = create(s, OREAD, DMDIR | 0777);
- if (f >= 0)
- close(f);
- else
- cantcreate(s, DMDIR);
- return f;
- }
- static int
- mkpdirs(char *s)
- {
- int err;
- char *p;
- p = s;
- err = 0;
- while (!err && (p = strchr(p+1, '/')) != nil) {
- *p = '\0';
- err = (access(s, AEXIST) < 0 && makedir(s) < 0);
- *p = '/';
- }
- return -err;
- }
- /* Call access but preserve the error string. */
- static int
- xaccess(char *name, int mode)
- {
- char err[ERRMAX];
- int rv;
- err[0] = 0;
- errstr(err, sizeof err);
- rv = access(name, mode);
- errstr(err, sizeof err);
- return rv;
- }
- static int
- openfname(Hdr *hp, char *fname, int dir, int mode)
- {
- int fd;
- fd = -1;
- cleanname(fname);
- switch (hp->linkflag) {
- case LF_LINK:
- case LF_SYMLINK1:
- case LF_SYMLINK2:
- fprint(2, "%s: can't make (sym)link %s\n",
- argv0, fname);
- break;
- case LF_FIFO:
- fprint(2, "%s: can't make fifo %s\n", argv0, fname);
- break;
- default:
- if (!keepexisting || access(fname, AEXIST) < 0) {
- int rw = (dir? OREAD: OWRITE);
- fd = create(fname, rw, mode);
- if (fd < 0) {
- mkpdirs(fname);
- fd = create(fname, rw, mode);
- }
- if (fd < 0 && (!dir || xaccess(fname, AEXIST) < 0))
- cantcreate(fname, mode);
- }
- if (fd >= 0 && verbose)
- fprint(2, "%s\n", fname);
- break;
- }
- return fd;
- }
- /* copy from archive to file system (or nowhere for table-of-contents) */
- static void
- copyfromar(int ar, int fd, char *fname, uint32_t blksleft, Off bytes)
- {
- int wrbytes;
- uint32_t blksread;
- Hdr *hbp;
- if (blksleft == 0 || bytes < 0)
- bytes = 0;
- for (; blksleft > 0; blksleft -= blksread) {
- hbp = getblkrd(ar, (fd >= 0? Alldata: Justnxthdr));
- if (hbp == nil)
- sysfatal("unexpected EOF on archive extracting %s from %s",
- fname, arname);
- blksread = gothowmany(blksleft);
- if (blksread <= 0) {
- fprint(2, "%s: got %ld blocks reading %s!\n",
- argv0, blksread, fname);
- blksread = 0;
- }
- wrbytes = Tblock*blksread;
- assert(bytes >= 0);
- if(wrbytes > bytes)
- wrbytes = bytes;
- assert(wrbytes >= 0);
- if (fd >= 0)
- ewrite(fname, fd, hbp->data, wrbytes);
- putreadblks(ar, blksread);
- bytes -= wrbytes;
- assert(bytes >= 0);
- }
- if (bytes > 0)
- fprint(2, "%s: %lld bytes uncopied at EOF on archive %s; "
- "%s not fully extracted\n", argv0, bytes, arname, fname);
- }
- static void
- wrmeta(int fd, Hdr *hp, int32_t mtime, int mode) /* update metadata */
- {
- Dir nd;
- nulldir(&nd);
- nd.mtime = mtime;
- nd.mode = mode;
- dirfwstat(fd, &nd);
- if (isustar(hp)) {
- nulldir(&nd);
- nd.gid = hp->gname;
- dirfwstat(fd, &nd);
- nulldir(&nd);
- nd.uid = hp->uname;
- dirfwstat(fd, &nd);
- }
- }
- /*
- * copy a file from the archive into the filesystem.
- * fname is result of name(), so has two extra bytes at beginning.
- */
- static void
- extract1(int ar, Hdr *hp, char *fname)
- {
- int fd = -1, dir = 0;
- int32_t mtime = strtol(hp->mtime, nil, 8);
- uint32_t mode = strtoul(hp->mode, nil, 8) & 0777;
- Off bytes = hdrsize(hp); /* for printing */
- uint32_t blksleft = BYTES2TBLKS(arsize(hp));
- /* fiddle name, figure out mode and blocks */
- if (isdir(hp)) {
- mode |= DMDIR|0700;
- dir = 1;
- }
- switch (hp->linkflag) {
- case LF_LINK:
- case LF_SYMLINK1:
- case LF_SYMLINK2:
- case LF_FIFO:
- blksleft = 0;
- break;
- }
- if (relative)
- if(fname[0] == '/')
- *--fname = '.';
- else if(fname[0] == '#'){
- *--fname = '/';
- *--fname = '.';
- }
- if (verb == Xtract)
- fd = openfname(hp, fname, dir, mode);
- else if (verbose) {
- char *cp = ctime(mtime);
- print("%M %8lld %-12.12s %-4.4s %s\n",
- mode, bytes, cp+4, cp+24, fname);
- } else
- print("%s\n", fname);
- copyfromar(ar, fd, fname, blksleft, bytes);
- /* touch up meta data and close */
- if (fd >= 0) {
- /*
- * directories should be wstated *after* we're done
- * creating files in them, but we don't do that.
- */
- if (settime)
- wrmeta(fd, hp, mtime, mode);
- close(fd);
- }
- }
- static char *
- extract(char **argv)
- {
- int ar;
- char *int32_tname;
- char msg[Maxname + 40];
- Compress *comp;
- Hdr *hp;
- Pushstate ps;
- /* open archive to be read */
- if (usefile)
- ar = open(usefile, OREAD);
- else
- ar = Stdin;
- /* push decompression filter if requested or extension is known */
- comp = compmethod(usefile);
- if (comp)
- ar = push(ar, comp->decomp, Input, &ps);
- if (ar < 0)
- sysfatal("can't open archive %s: %r", usefile);
- while ((hp = readhdr(ar)) != nil) {
- int32_tname = name(hp);
- if (match(int32_tname, argv))
- extract1(ar, hp, int32_tname);
- else {
- snprint(msg, sizeof msg, "extracting %s", int32_tname);
- skip(ar, hp, msg);
- }
- }
- if (comp)
- return pushclose(&ps);
- if (ar > Stderr)
- close(ar);
- return nil;
- }
- void
- main(int argc, char *argv[])
- {
- int errflg = 0;
- char *ret = nil;
- fmtinstall('M', dirmodefmt);
- TARGBEGIN {
- case 'c':
- docreate++;
- verb = Replace;
- break;
- case 'f':
- usefile = arname = EARGF(usage());
- break;
- case 'g':
- argid = strtoul(EARGF(usage()), 0, 0);
- break;
- case 'i':
- ignerrs = 1;
- break;
- case 'k':
- keepexisting++;
- break;
- case 'm': /* compatibility */
- settime = 0;
- break;
- case 'p':
- posix++;
- break;
- case 'P':
- posix = 0;
- break;
- case 'r':
- verb = Replace;
- break;
- case 'R':
- relative = 0;
- break;
- case 's':
- resync++;
- break;
- case 't':
- verb = Toc;
- break;
- case 'T':
- settime++;
- break;
- case 'u':
- aruid = strtoul(EARGF(usage()), 0, 0);
- break;
- case 'v':
- verbose++;
- break;
- case 'x':
- verb = Xtract;
- break;
- case 'z':
- docompress++;
- break;
- case '-':
- break;
- default:
- fprint(2, "tar: unknown letter %C\n", TARGC());
- errflg++;
- break;
- } TARGEND
- if (argc < 0 || errflg)
- usage();
- initblks();
- switch (verb) {
- case Toc:
- case Xtract:
- ret = extract(argv);
- break;
- case Replace:
- if (getwd(origdir, sizeof origdir) == nil)
- strcpy(origdir, "/tmp");
- ret = replace(argv);
- break;
- default:
- usage();
- break;
- }
- exits(ret);
- }
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