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-rw-r--r--archival/tar.c513
1 files changed, 226 insertions, 287 deletions
diff --git a/archival/tar.c b/archival/tar.c
index 8f802de..8f83d04 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -68,57 +68,84 @@ static const char tar_usage[] =
#endif
-/*
- * Tar file constants.
- */
-#define TAR_BLOCK_SIZE 512
-#define TAR_NAME_SIZE 100
+/* Tar file constants */
-/*
- * The POSIX (and basic GNU) tar header format.
- * This structure is always embedded in a TAR_BLOCK_SIZE sized block
- * with zero padding. We only process this information minimally.
- */
-typedef struct {
- char name[TAR_NAME_SIZE];
- char mode[8];
- char uid[8];
- char gid[8];
- char size[12];
- char mtime[12];
- char checkSum[8];
- char typeFlag;
- char linkName[TAR_NAME_SIZE];
- char magic[6];
- char version[2];
- char uname[32];
- char gname[32];
- char devMajor[8];
- char devMinor[8];
- char prefix[155];
-} TarHeader;
-
-#define TAR_MAGIC "ustar"
-#define TAR_VERSION "00"
-
-#define TAR_TYPE_REGULAR '0'
-#define TAR_TYPE_HARD_LINK '1'
-#define TAR_TYPE_SOFT_LINK '2'
+/* POSIX tar Header Block, from POSIX 1003.1-1990 */
+struct TarHeader
+{
+ /* byte offset */
+ char name[100]; /* 0 */
+ char mode[8]; /* 100 */
+ char uid[8]; /* 108 */
+ char gid[8]; /* 116 */
+ char size[12]; /* 124 */
+ char mtime[12]; /* 136 */
+ char chksum[8]; /* 148 */
+ char typeflag; /* 156 */
+ char linkname[100]; /* 157 */
+ char magic[6]; /* 257 */
+ char version[2]; /* 263 */
+ char uname[32]; /* 265 */
+ char gname[32]; /* 297 */
+ char devmajor[8]; /* 329 */
+ char devminor[8]; /* 337 */
+ char prefix[155]; /* 345 */
+ /* padding 500 */
+};
+typedef struct TarHeader TarHeader;
+
+
+/* A few useful constants */
+#define TAR_MAGIC "ustar" /* ustar and a null */
+#define TAR_VERSION "00" /* 00 and no null */
+#define TAR_MAGIC_LEN 6
+#define TAR_VERSION_LEN 2
+#define TAR_NAME_LEN 100
+#define TAR_BLOCK_SIZE 512
+
+/* A nice enum with all the possible tar file content types */
+enum TarFileType
+{
+ REGTYPE = '0', /* regular file */
+ REGTYPE0 = '\0', /* regular file (ancient bug compat)*/
+ LNKTYPE = '1', /* hard link */
+ SYMTYPE = '2', /* symbolic link */
+ CHRTYPE = '3', /* character special */
+ BLKTYPE = '4', /* block special */
+ DIRTYPE = '5', /* directory */
+ FIFOTYPE = '6', /* FIFO special */
+ CONTTYPE = '7', /* reserved */
+};
+typedef enum TarFileType TarFileType;
+
+/* This struct ignores magic, non-numeric user name,
+ * non-numeric group name, and the checksum, since
+ * these are all ignored by BusyBox tar. */
+struct TarInfo
+{
+ int tarFd; /* An open file descriptor for reading from the tarball */
+ char * name; /* File name */
+ mode_t mode; /* Unix mode, including device bits. */
+ uid_t uid; /* Numeric UID */
+ gid_t gid; /* Numeric GID */
+ size_t size; /* Size of file */
+ time_t mtime; /* Last-modified time */
+ enum TarFileType type; /* Regular, directory, link, etc */
+ char * linkname; /* Name for symbolic and hard links */
+ dev_t device; /* Special device for mknod() */
+};
+typedef struct TarInfo TarInfo;
+
+/* Static data */
+static const unsigned long TarChecksumOffset = (const unsigned long)&(((TarHeader *)0)->chksum);
/*
* Static data.
*/
-static int listFlag;
-static int extractFlag;
-static int createFlag;
-static int verboseFlag;
-static int tostdoutFlag;
-
static int inHeader; // <- check me
static int badHeader;
-static int errorFlag;
static int skipFileFlag;
static int warnedRoot;
static int eofFlag;
@@ -134,7 +161,6 @@ static time_t mtime;
/*
* Static data associated with the tar file.
*/
-static const char *tarName;
static int tarFd;
static dev_t tarDev;
static ino_t tarInode;
@@ -143,35 +169,25 @@ static ino_t tarInode;
/*
* Local procedures to restore files from a tar file.
*/
-static void readTarFile(int fileCount, char **fileTable);
+static int readTarFile(const char* tarName, int extractFlag, int listFlag,
+ int tostdoutFlag, int verboseFlag);
static void readData(const char *cp, int count);
static long getOctal(const char *cp, int len);
-
-static void readHeader(const TarHeader * hp,
-
- int fileCount, char **fileTable);
-
+static int parseTarHeader(struct TarHeader *rawHeader, struct TarInfo *header);
static int wantFileName(const char *fileName,
-
- int fileCount, char **fileTable);
+ int argc, char **argv);
#ifdef BB_FEATURE_TAR_CREATE
/*
* Local procedures to save files into a tar file.
*/
static void saveFile(const char *fileName, int seeLinks);
-
static void saveRegularFile(const char *fileName,
-
const struct stat *statbuf);
-
static void saveDirectory(const char *fileName,
-
const struct stat *statbuf);
-
static void writeHeader(const char *fileName, const struct stat *statbuf);
-
-static void writeTarFile(int fileCount, char **fileTable);
+static void writeTarFile(int argc, char **argv);
static void writeTarBlock(const char *buf, int len);
static int putOctal(char *cp, int len, long value);
@@ -180,7 +196,13 @@ static int putOctal(char *cp, int len, long value);
extern int tar_main(int argc, char **argv)
{
+ const char *tarName=NULL;
const char *options;
+ int listFlag = FALSE;
+ int extractFlag = FALSE;
+ int createFlag = FALSE;
+ int verboseFlag = FALSE;
+ int tostdoutFlag = FALSE;
argc--;
argv++;
@@ -188,21 +210,7 @@ extern int tar_main(int argc, char **argv)
if (argc < 1)
usage(tar_usage);
-
- errorFlag = FALSE;
- extractFlag = FALSE;
- createFlag = FALSE;
- listFlag = FALSE;
- verboseFlag = FALSE;
- tostdoutFlag = FALSE;
- tarName = NULL;
- tarDev = 0;
- tarInode = 0;
- tarFd = -1;
-
- /*
- * Parse the options.
- */
+ /* Parse options */
if (**argv == '-')
options = (*argv++) + 1;
else
@@ -212,13 +220,12 @@ extern int tar_main(int argc, char **argv)
for (; *options; options++) {
switch (*options) {
case 'f':
- if (tarName != NULL) {
- fprintf(stderr, "Only one 'f' option allowed\n");
-
- exit(FALSE);
- }
+ if (tarName != NULL)
+ fatalError( "Only one 'f' option allowed\n");
tarName = *argv++;
+ if (tarName == NULL)
+ fatalError( "Option requires an argument: No file specified\n");
argc--;
break;
@@ -253,9 +260,8 @@ extern int tar_main(int argc, char **argv)
break;
default:
- fprintf(stderr, "Unknown tar flag '%c'\n"
+ fatalError( "Unknown tar flag '%c'\n"
"Try `tar --help' for more information\n", *options);
- exit(FALSE);
}
}
@@ -265,23 +271,22 @@ extern int tar_main(int argc, char **argv)
*/
if (createFlag == TRUE) {
#ifndef BB_FEATURE_TAR_CREATE
- fprintf(stderr,
- "This version of tar was not compiled with tar creation support.\n");
- exit(FALSE);
+ fatalError( "This version of tar was not compiled with tar creation support.\n");
#else
- writeTarFile(argc, argv);
+ exit(writeTarFile(argc, argv));
#endif
} else {
- readTarFile(argc, argv);
+ exit(readTarFile(tarName, extractFlag, listFlag, tostdoutFlag, verboseFlag));
}
- if (errorFlag == TRUE) {
- fprintf(stderr, "\n");
- }
- exit(!errorFlag);
flagError:
- fprintf(stderr, "Exactly one of 'c', 'x' or 't' must be specified\n");
- exit(FALSE);
+ fatalError( "Exactly one of 'c', 'x' or 't' must be specified\n");
+}
+
+static void
+tarExtractRegularFile(TarInfo *header, int extractFlag, int listFlag, int tostdoutFlag, int verboseFlag)
+{
+
}
@@ -289,178 +294,148 @@ extern int tar_main(int argc, char **argv)
* Read a tar file and extract or list the specified files within it.
* If the list is empty than all files are extracted or listed.
*/
-static void readTarFile(int fileCount, char **fileTable)
+static int readTarFile(const char* tarName, int extractFlag, int listFlag,
+ int tostdoutFlag, int verboseFlag)
{
- const char *cp;
- int cc;
- int inCc;
- int blockSize;
- char buf[BUF_SIZE];
-
- skipFileFlag = FALSE;
- badHeader = FALSE;
- warnedRoot = FALSE;
- eofFlag = FALSE;
- inHeader = TRUE;
- inCc = 0;
- dataCc = 0;
- outFd = -1;
- blockSize = sizeof(buf);
- cp = buf;
+ int status, tarFd=0;
+ int errorFlag=FALSE;
+ TarHeader rawHeader;
+ TarInfo header;
- /*
- * Open the tar file for reading.
- */
- if ((tarName == NULL) || !strcmp(tarName, "-")) {
+ /* Open the tar file for reading. */
+ if (!strcmp(tarName, "-"))
tarFd = fileno(stdin);
- } else
+ else
tarFd = open(tarName, O_RDONLY);
-
if (tarFd < 0) {
- perror(tarName);
- errorFlag = TRUE;
- return;
+ errorMsg( "Error opening '%s': %s", tarName, strerror(errno));
+ return ( FALSE);
}
- /*
- * Read blocks from the file until an end of file header block
- * has been seen. (A real end of file from a read is an error.)
- */
- while (eofFlag == FALSE) {
- /*
- * Read the next block of data if necessary.
- * This will be a large block if possible, which we will
- * then process in the small tar blocks.
- */
- if (inCc <= 0) {
- cp = buf;
- inCc = fullRead(tarFd, buf, blockSize);
-
- if (inCc < 0) {
- perror(tarName);
- errorFlag = TRUE;
- goto done;
- }
-
- if (inCc == 0) {
- fprintf(stderr,
- "Unexpected end of file from \"%s\"", tarName);
- errorFlag = TRUE;
- goto done;
+ /* Read the tar file */
+ while ( (status = fullRead(tarFd, (char*)&rawHeader, TAR_BLOCK_SIZE)) == TAR_BLOCK_SIZE ) {
+ /* Now see if the header looks ok */
+ if ( parseTarHeader(&rawHeader, &header) == FALSE ) {
+ close( tarFd);
+ if ( *(header.name) == '\0' ) {
+ goto endgame;
+ } else {
+ errorFlag=TRUE;
+ errorMsg("Bad tar header, skipping\n");
+ continue;
}
}
-
- /*
- * If we are expecting a header block then examine it.
- */
- if (inHeader == TRUE) {
- readHeader((const TarHeader *) cp, fileCount, fileTable);
-
- cp += TAR_BLOCK_SIZE;
- inCc -= TAR_BLOCK_SIZE;
-
- continue;
+ if ( *(header.name) == '\0' )
+ goto endgame;
+
+ /* If we got here, we can be certain we have a legitimate
+ * header to work with. So work with it. */
+ switch ( header.type ) {
+ case REGTYPE:
+ case REGTYPE0:
+ /* If the name ends in a '/' then assume it is
+ * supposed to be a directory, and fall through */
+ if (header.name[strlen(header.name)-1] != '/') {
+ tarExtractRegularFile(&header, extractFlag, listFlag, tostdoutFlag, verboseFlag);
+ break;
+ }
+#if 0
+ case Directory:
+ tarExtractDirectory( &header, extractFlag, listFlag, tostdoutFlag, verboseFlag);
+ break;
+ case HardLink:
+ tarExtractHardLink( &header, extractFlag, listFlag, tostdoutFlag, verboseFlag);
+ break;
+ case SymbolicLink:
+ tarExtractSymLink( &header, extractFlag, listFlag, tostdoutFlag, verboseFlag);
+ break;
+ case CharacterDevice:
+ case BlockDevice:
+ case FIFO:
+ tarExtractSpecial( &header, extractFlag, listFlag, tostdoutFlag, verboseFlag);
+ break;
+#endif
+ default:
+ close( tarFd);
+ return( FALSE);
}
-
- /*
- * We are currently handling the data for a file.
- * Process the minimum of the amount of data we have available
- * and the amount left to be processed for the file.
- */
- cc = inCc;
-
- if (cc > dataCc)
- cc = dataCc;
-
- readData(cp, cc);
-
- /*
- * If the amount left isn't an exact multiple of the tar block
- * size then round it up to the next block boundary since there
- * is padding at the end of the file.
- */
- if (cc % TAR_BLOCK_SIZE)
- cc += TAR_BLOCK_SIZE - (cc % TAR_BLOCK_SIZE);
-
- cp += cc;
- inCc -= cc;
}
- done:
- /*
- * Close the tar file if needed.
- */
- if ((tarFd >= 0) && (close(tarFd) < 0))
- perror(tarName);
-
- /*
- * Close the output file if needed.
- * This is only done here on a previous error and so no
- * message is required on errors.
- */
- if (tostdoutFlag == FALSE) {
- if (outFd >= 0) {
- close(outFd);
- }
+ close(tarFd);
+ if (status > 0) {
+ /* Bummer - we read a partial header */
+ errorMsg( "Error reading '%s': %s", tarName, strerror(errno));
+ return ( FALSE);
}
+ else
+ return( status);
+
+ /* Stuff we do when we know we are done with the file */
+endgame:
+ close( tarFd);
+ if ( *(header.name) == '\0' ) {
+ if (errorFlag==FALSE)
+ return( TRUE);
+ }
+ return( FALSE);
}
-
/*
- * Examine the header block that was just read.
- * This can specify the information for another file, or it can mark
- * the end of the tar file.
+ * Read an octal value in a field of the specified width, with optional
+ * spaces on both sides of the number and with an optional null character
+ * at the end. Returns -1 on an illegal format.
*/
-static void
-readHeader(const TarHeader * hp, int fileCount, char **fileTable)
+static long getOctal(const char *cp, int size)
{
- int checkSum;
- int cc;
- int hardLink;
- int softLink;
- int devFileFlag;
- unsigned int major;
- unsigned int minor;
- long size;
- struct utimbuf utb;
-
- /*
- * If the block is completely empty, then this is the end of the
- * archive file. If the name is null, then just skip this header.
- */
- outName = hp->name;
-
- if (*outName == '\0') {
- for (cc = TAR_BLOCK_SIZE; cc > 0; cc--) {
- if (*outName++)
- return;
- }
+ long val = 0;
- eofFlag = TRUE;
-
- return;
+ for(;(size > 0) && (*cp == ' '); cp++, size--);
+ if ((size == 0) || !isOctal(*cp))
+ return -1;
+ for(; (size > 0) && isOctal(*cp); size--) {
+ val = val * 8 + *cp++ - '0';
}
+ for (;(size > 0) && (*cp == ' '); cp++, size--);
+ if ((size > 0) && *cp)
+ return -1;
+ return val;
+}
- /*
- * There is another file in the archive to examine.
- * Extract the encoded information and check it.
- */
- mode = getOctal(hp->mode, sizeof(hp->mode));
- uid = getOctal(hp->uid, sizeof(hp->uid));
- gid = getOctal(hp->gid, sizeof(hp->gid));
- size = getOctal(hp->size, sizeof(hp->size));
- mtime = getOctal(hp->mtime, sizeof(hp->mtime));
- checkSum = getOctal(hp->checkSum, sizeof(hp->checkSum));
- major = getOctal(hp->devMajor, sizeof(hp->devMajor));
- minor = getOctal(hp->devMinor, sizeof(hp->devMinor));
-
- if ((mode < 0) || (uid < 0) || (gid < 0) || (size < 0)) {
- if (badHeader == FALSE)
- fprintf(stderr, "Bad tar header, skipping\n");
-
- badHeader = TRUE;
+/* Parse the tar header and fill in the nice struct with the details */
+static int
+parseTarHeader(struct TarHeader *rawHeader, struct TarInfo *header)
+{
+ long major, minor, chksum, sum;
+
+ header->name = rawHeader->name;
+ header->mode = getOctal(rawHeader->mode, sizeof(rawHeader->mode));
+ header->uid = getOctal(rawHeader->uid, sizeof(rawHeader->uid));
+ header->gid = getOctal(rawHeader->gid, sizeof(rawHeader->gid));
+ header->size = getOctal(rawHeader->size, sizeof(rawHeader->size));
+ header->mtime = getOctal(rawHeader->mtime, sizeof(rawHeader->mtime));
+ chksum = getOctal(rawHeader->chksum, sizeof(rawHeader->chksum));
+ header->type = rawHeader->typeflag;
+ header->linkname = rawHeader->linkname;
+ header->device = MAJOR(getOctal(rawHeader->devmajor, sizeof(rawHeader->devmajor))) |
+ MINOR(getOctal(rawHeader->devminor, sizeof(rawHeader->devminor)));
+
+ /* Check the checksum */
+ sum = ' ' * sizeof(rawHeader->chksum);
+ for ( i = TarChecksumOffset; i > 0; i-- )
+ sum += *s++;
+ s += sizeof(h->chksum);
+ for ( i = (512 - TarChecksumOffset - sizeof(h->chksum)); i > 0; i-- )
+ sum += *s++;
+ if (sum == checksum )
+ return ( TRUE);
+ return( FALSE);
+}
- return;
+#if 0
+ if ((header->mode < 0) || (header->uid < 0) ||
+ (header->gid < 0) || (header->size < 0)) {
+ errorMsg(stderr, "Bad tar header, skipping\n");
+ return( FALSE);
}
badHeader = FALSE;
@@ -502,7 +477,7 @@ readHeader(const TarHeader * hp, int fileCount, char **fileTable)
* See if we want this file to be restored.
* If not, then set up to skip it.
*/
- if (wantFileName(outName, fileCount, fileTable) == FALSE) {
+ if (wantFileName(outName, argc, argv) == FALSE) {
if (!hardLink && !softLink && (S_ISREG(mode) || S_ISCHR(mode)
|| S_ISBLK(mode) || S_ISSOCK(mode)
|| S_ISFIFO(mode))) {
@@ -726,7 +701,7 @@ static void readData(const char *cp, int count)
* Returns TRUE if the file is selected.
*/
static int
-wantFileName(const char *fileName, int fileCount, char **fileTable)
+wantFileName(const char *fileName, int argc, char **argv)
{
const char *pathName;
int fileLength;
@@ -735,7 +710,7 @@ wantFileName(const char *fileName, int fileCount, char **fileTable)
/*
* If there are no files in the list, then the file is wanted.
*/
- if (fileCount == 0)
+ if (argc == 0)
return TRUE;
fileLength = strlen(fileName);
@@ -743,8 +718,8 @@ wantFileName(const char *fileName, int fileCount, char **fileTable)
/*
* Check each of the test paths.
*/
- while (fileCount-- > 0) {
- pathName = *fileTable++;
+ while (argc-- > 0) {
+ pathName = *argv++;
pathLength = strlen(pathName);
@@ -762,43 +737,6 @@ wantFileName(const char *fileName, int fileCount, char **fileTable)
return FALSE;
}
-/*
- * Read an octal value in a field of the specified width, with optional
- * spaces on both sides of the number and with an optional null character
- * at the end. Returns -1 on an illegal format.
- */
-static long getOctal(const char *cp, int len)
-{
- long val;
-
- while ((len > 0) && (*cp == ' ')) {
- cp++;
- len--;
- }
-
- if ((len == 0) || !isOctal(*cp))
- return -1;
-
- val = 0;
-
- while ((len > 0) && isOctal(*cp)) {
- val = val * 8 + *cp++ - '0';
- len--;
- }
-
- while ((len > 0) && (*cp == ' ')) {
- cp++;
- len--;
- }
-
- if ((len > 0) && *cp)
- return -1;
-
- return val;
-}
-
-
-
/* From here to the end of the file is the tar writing stuff.
* If you do not have BB_FEATURE_TAR_CREATE defined, this will
@@ -809,14 +747,14 @@ static long getOctal(const char *cp, int len)
/*
* Write a tar file containing the specified files.
*/
-static void writeTarFile(int fileCount, char **fileTable)
+static void writeTarFile(int argc, char **argv)
{
struct stat statbuf;
/*
* Make sure there is at least one file specified.
*/
- if (fileCount <= 0) {
+ if (argc <= 0) {
fprintf(stderr, "No files specified to be saved\n");
errorFlag = TRUE;
}
@@ -852,8 +790,8 @@ static void writeTarFile(int fileCount, char **fileTable)
* Append each file name into the archive file.
* Follow symbolic links for these top level file names.
*/
- while (errorFlag == FALSE && (fileCount-- > 0)) {
- saveFile(*fileTable++, FALSE);
+ while (errorFlag == FALSE && (argc-- > 0)) {
+ saveFile(*argv++, FALSE);
}
/*
@@ -1284,3 +1222,4 @@ static int putOctal(char *cp, int len, long value)
#endif
/* END CODE */
+#endif
generated by cgit v1.1 at 2024-12-25 17:06:51 +0000