diff options
| -rw-r--r-- | archival/tar.c | 123 |
1 files changed, 98 insertions, 25 deletions
diff --git a/archival/tar.c b/archival/tar.c index c870d53..bf6786f 100644 --- a/archival/tar.c +++ b/archival/tar.c @@ -169,6 +169,72 @@ static void putOctal(char *cp, int len, off_t value) /* Copy the string to the field */ memcpy(cp, tempString, len); } +#define PUT_OCTAL(a, b) putOctal((a), sizeof(a), (b)) + +static void chksum_and_xwrite(int fd, struct TarHeader* hp) +{ + const unsigned char *cp; + int chksum, size; + + strcpy(hp->magic, "ustar "); + + /* Calculate and store the checksum (i.e., the sum of all of the bytes of + * the header). The checksum field must be filled with blanks for the + * calculation. The checksum field is formatted differently from the + * other fields: it has 6 digits, a null, then a space -- rather than + * digits, followed by a null like the other fields... */ + memset(hp->chksum, ' ', sizeof(hp->chksum)); + cp = (const unsigned char *) hp; + chksum = 0; + size = sizeof(*hp); + do { chksum += *cp++; } while (--size); + putOctal(hp->chksum, sizeof(hp->chksum)-1, chksum); + + /* Now write the header out to disk */ + xwrite(fd, hp, sizeof(*hp)); +} + +#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS +static void writeLongname(int fd, int type, const char *name, int dir) +{ + static const struct { + char mode[8]; /* 100-107 */ + char uid[8]; /* 108-115 */ + char gid[8]; /* 116-123 */ + char size[12]; /* 124-135 */ + char mtime[12]; /* 136-147 */ + } prefilled = { + "0000000", + "0000000", + "0000000", + "00000000000", + "00000000000", + }; + struct TarHeader header; + int size; + + dir = !!dir; /* normalize: 0/1 */ + size = strlen(name) + 1 + dir; /* GNU tar uses strlen+1 */ + /* + dir: account for possible '/' */ + + bzero(&header, sizeof(header)); + strcpy(header.name, "././@LongLink"); + memcpy(header.mode, prefilled.mode, sizeof(prefilled)); + PUT_OCTAL(header.size, size); + header.typeflag = type; + chksum_and_xwrite(fd, &header); + + /* Write filename[/] and pad the block. */ + /* dir=0: writes 'name<NUL>', pads */ + /* dir=1: writes 'name', writes '/<NUL>', pads */ + dir *= 2; + xwrite(fd, name, size - dir); + xwrite(fd, "/", dir); + size = (-size) & (TAR_BLOCK_SIZE-1); + bzero(&header, size); + xwrite(fd, &header, size); +} +#endif /* Write out a tar header for the specified file/directory/whatever */ void BUG_tar_header_size(void); @@ -176,25 +242,20 @@ static int writeTarHeader(struct TarBallInfo *tbInfo, const char *header_name, const char *fileName, struct stat *statbuf) { struct TarHeader header; - const unsigned char *cp; - int chksum; - int size; if (sizeof(header) != 512) BUG_tar_header_size(); bzero(&header, sizeof(struct TarHeader)); - safe_strncpy(header.name, header_name, sizeof(header.name)); + strncpy(header.name, header_name, sizeof(header.name)); -#define PUT_OCTAL(a, b) putOctal((a), sizeof(a), (b)) /* POSIX says to mask mode with 07777. */ PUT_OCTAL(header.mode, statbuf->st_mode & 07777); PUT_OCTAL(header.uid, statbuf->st_uid); PUT_OCTAL(header.gid, statbuf->st_gid); memset(header.size, '0', sizeof(header.size)-1); /* Regular file size is handled later */ PUT_OCTAL(header.mtime, statbuf->st_mtime); - strcpy(header.magic, "ustar "); /* Enter the user and group names */ safe_strncpy(header.uname, get_cached_username(statbuf->st_uid), sizeof(header.uname)); @@ -205,24 +266,36 @@ static int writeTarHeader(struct TarBallInfo *tbInfo, header.typeflag = LNKTYPE; strncpy(header.linkname, tbInfo->hlInfo->name, sizeof(header.linkname)); +#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS + /* Write out long linkname if needed */ + if (header.linkname[sizeof(header.linkname)-1]) + writeLongname(tbInfo->tarFd, GNULONGLINK, + tbInfo->hlInfo->name, 0); +#endif } else if (S_ISLNK(statbuf->st_mode)) { char *lpath = xreadlink(fileName); if (!lpath) /* Already printed err msg inside xreadlink() */ return FALSE; header.typeflag = SYMTYPE; strncpy(header.linkname, lpath, sizeof(header.linkname)); +#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS + /* Write out long linkname if needed */ + if (header.linkname[sizeof(header.linkname)-1]) + writeLongname(tbInfo->tarFd, GNULONGLINK, lpath, 0); +#else /* If it is larger than 100 bytes, bail out */ - if (header.linkname[sizeof(header.linkname)-1] /* at least 100? */ - && lpath[sizeof(header.linkname)] /* and 101th is also not zero */ - ) { + if (header.linkname[sizeof(header.linkname)-1]) { free(lpath); bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported"); return FALSE; } +#endif free(lpath); } else if (S_ISDIR(statbuf->st_mode)) { header.typeflag = DIRTYPE; - strncat(header.name, "/", sizeof(header.name)); + /* Append '/' only if there is a space for it */ + if (!header.name[sizeof(header.name)-1]) + header.name[strlen(header.name)] = '/'; } else if (S_ISCHR(statbuf->st_mode)) { header.typeflag = CHRTYPE; PUT_OCTAL(header.devmajor, major(statbuf->st_rdev)); @@ -247,22 +320,17 @@ static int writeTarHeader(struct TarBallInfo *tbInfo, bb_error_msg("%s: unknown file type", fileName); return FALSE; } -#undef PUT_OCTAL - /* Calculate and store the checksum (i.e., the sum of all of the bytes of - * the header). The checksum field must be filled with blanks for the - * calculation. The checksum field is formatted differently from the - * other fields: it has [6] digits, a null, then a space -- rather than - * digits, followed by a null like the other fields... */ - memset(header.chksum, ' ', sizeof(header.chksum)); - cp = (const unsigned char *) &header; - chksum = 0; - size = sizeof(struct TarHeader); - do { chksum += *cp++; } while (--size); - putOctal(header.chksum, sizeof(header.chksum)-1, chksum); +#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS + /* Write out long name if needed */ + /* (we, like GNU tar, output long linkname *before* long name) */ + if (header.name[sizeof(header.name)-1]) + writeLongname(tbInfo->tarFd, GNULONGNAME, + header_name, S_ISDIR(statbuf->st_mode)); +#endif /* Now write the header out to disk */ - xwrite(tbInfo->tarFd, &header, sizeof(struct TarHeader)); + chksum_and_xwrite(tbInfo->tarFd, &header); /* Now do the verbose thing (or not) */ if (tbInfo->verboseFlag) { @@ -272,7 +340,9 @@ static int writeTarHeader(struct TarBallInfo *tbInfo, vbFd = stderr; /* GNU "tar cvvf" prints "extended" listing a-la "ls -l" */ /* We don't have such excesses here: for us "v" == "vv" */ - fprintf(vbFd, "%s\n", header.name); + /* '/' is probably a GNUism */ + fprintf(vbFd, "%s%s\n", header_name, + S_ISDIR(statbuf->st_mode) ? "/" : ""); } return TRUE; @@ -352,10 +422,12 @@ static int writeFileToTarball(const char *fileName, struct stat *statbuf, header_name++; } +#if !ENABLE_FEATURE_TAR_GNU_EXTENSIONS if (strlen(fileName) >= NAME_SIZE) { bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported"); return TRUE; } +#endif if (header_name[0] == '\0') return TRUE; @@ -384,7 +456,8 @@ static int writeFileToTarball(const char *fileName, struct stat *statbuf, /* write the file to the archive */ readSize = bb_copyfd_size(inputFileFd, tbInfo->tarFd, statbuf->st_size); - if (readSize != statbuf->st_size) { + /* readSize < 0 means that error was already reported */ + if (readSize != statbuf->st_size && readSize >= 0) { /* Deadly. We record size into header first, */ /* and then write out file. If file shrinks in between, */ /* tar will be corrupted. So bail out. */ |