1 files changed, 226 insertions, 287 deletions

diff --git a/tar.c b/tar.c
index 8f802de64..8f83d04a6 100644
--- a/tar.c
+++ b/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