Fixed segfault with 'cut -f 1 -d:' and added 'cut -s' suport.
[oweals/busybox.git] / tar.c
diff --git a/tar.c b/tar.c
index 91baa2ddba8deee891e3eef3cddad3fedb2d058f..836d127e7c2c3781704d011d25d1eeb84b8d6941 100644 (file)
--- a/tar.c
+++ b/tar.c
@@ -2,9 +2,9 @@
 /*
  * Mini tar implementation for busybox 
  *
- * Note, that as of BusyBox 0.43 tar has been completely rewritten from the
- * ground up.  It still has remnents of the old code lying about, but it pretty
- * different (i.e. cleaner, less global variables, etc)
+ * Note, that as of BusyBox-0.43, tar has been completely rewritten from the
+ * ground up.  It still has remnents of the old code lying about, but it is
+ * very different now (i.e. cleaner, less global variables, etc)
  *
  * Copyright (C) 2000 by Lineo, inc.
  * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
 #include <utime.h>
 #include <sys/types.h>
 #include <sys/sysmacros.h>
-#include <sys/param.h>                 /* for PATH_MAX */
 
 
-#ifdef BB_FEATURE_TAR_CREATE
-
 static const char tar_usage[] =
-       "tar -[cxtvOf] [tarFileName] [FILE] ...\n\n"
-       "Create, extract, or list files from a tar file.  Note that\n"
-       "this version of tar packs hard links as separate files.\n\n"
-       "Options:\n"
-
-       "\tc=create, x=extract, t=list contents, v=verbose,\n"
-       "\tO=extract to stdout, f=tarfile or \"-\" for stdin\n";
-
+#ifdef BB_FEATURE_TAR_CREATE
+       "tar -[cxtvO] "
 #else
-
-static const char tar_usage[] =
-       "tar -[xtvOf] [tarFileName] [FILE] ...\n\n"
-       "Extract, or list files stored in a tar file.  This\n"
-       "version of tar does not support creation of tar files.\n\n"
-       "Options:\n"
-
-       "\tx=extract, t=list contents, v=verbose,\n"
-       "\tO=extract to stdout, f=tarfile or \"-\" for stdin\n";
-
+       "tar -[xtvO] "
 #endif
-
+#if defined BB_FEATURE_TAR_EXCLUDE
+       "[--exclude File] "
+#endif
+       "[-f tarFile] [FILE] ...\n"
+#ifndef BB_FEATURE_TRIVIAL_HELP
+       "\nCreate, extract, or list files from a tar file.  Note that\n"
+       "this version of tar treats hard links as separate files.\n\n"
+       "Main operation mode:\n"
+#ifdef BB_FEATURE_TAR_CREATE
+       "\tc\t\tcreate\n"
+#endif
+       "\tx\t\textract\n"
+       "\tt\t\tlist\n"
+       "\nFile selection:\n"
+       "\tf\t\tname of tarfile or \"-\" for stdin\n"
+       "\tO\t\textract to stdout\n"
+#if defined BB_FEATURE_TAR_EXCLUDE
+       "\t--exclude\tfile to exclude\n"
+#endif
+       "\nInformative output:\n"
+       "\tv\t\tverbosely list files processed\n"
+#endif
+       ;
 
 /* Tar file constants  */
 #ifndef MAJOR
@@ -88,31 +92,30 @@ static const char tar_usage[] =
 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 */
+       char name[100];               /*   0-99 */
+       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 */
+       char chksum[8];               /* 148-155 */
+       char typeflag;                /* 156-156 */
+       char linkname[100];           /* 157-256 */
+       char magic[6];                /* 257-262 */
+       char version[2];              /* 263-264 */
+       char uname[32];               /* 265-296 */
+       char gname[32];               /* 297-328 */
+       char devmajor[8];             /* 329-336 */
+       char devminor[8];             /* 337-344 */
+       char prefix[155];             /* 345-499 */
+       char padding[12];             /* 500-512 (pad to exactly the TAR_BLOCK_SIZE) */
 };
 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_VERSION        "  "           /* Be compatable with old GNU format */
+#define TAR_VERSION        "  "           /* Be compatable with GNU tar format */
 #define TAR_MAGIC_LEN       6
 #define TAR_VERSION_LEN     2
 #define TAR_BLOCK_SIZE      512
@@ -151,94 +154,108 @@ struct TarInfo
 };
 typedef struct TarInfo TarInfo;
 
-/* Static data  */
-static const unsigned long TarChecksumOffset = (const unsigned long)&(((TarHeader *)0)->chksum);
-
-
 /* Local procedures to restore files from a tar file.  */
 static int readTarFile(const char* tarName, int extractFlag, int listFlag, 
-               int tostdoutFlag, int verboseFlag);
+               int tostdoutFlag, int verboseFlag, char** excludeList);
 
 
 
 #ifdef BB_FEATURE_TAR_CREATE
 /* Local procedures to save files into a tar file.  */
 static int writeTarFile(const char* tarName, int tostdoutFlag, 
-               int verboseFlag, int argc, char **argv);
-static int putOctal(char *cp, int len, long value);
-
+               int verboseFlag, int argc, char **argv, char** excludeList);
 #endif
 
 
 extern int tar_main(int argc, char **argv)
 {
-       const char *tarName=NULL;
-       const char *options;
+       char** excludeList=NULL;
+#if defined BB_FEATURE_TAR_EXCLUDE
+       int excludeListSize=0;
+#endif
+       const char *tarName="-";
        int listFlag     = FALSE;
        int extractFlag  = FALSE;
        int createFlag   = FALSE;
        int verboseFlag  = FALSE;
        int tostdoutFlag = FALSE;
+       int stopIt;
 
-       argc--;
-       argv++;
-
-       if (argc < 1)
+       if (argc <= 1)
                usage(tar_usage);
 
-       /* Parse options  */
-       if (**argv == '-')
-               options = (*argv++) + 1;
-       else
-               options = (*argv++);
-       argc--;
-
-       for (; *options; options++) {
-               switch (*options) {
-               case 'f':
-                       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;
-
-               case 't':
-                       if (extractFlag == TRUE || createFlag == TRUE)
-                               goto flagError;
-                       listFlag = TRUE;
-                       break;
-
-               case 'x':
-                       if (listFlag == TRUE || createFlag == TRUE)
-                               goto flagError;
-                       extractFlag = TRUE;
-                       break;
-               case 'c':
-                       if (extractFlag == TRUE || listFlag == TRUE)
-                               goto flagError;
-                       createFlag = TRUE;
-                       break;
-
-               case 'v':
-                       verboseFlag = TRUE;
-                       break;
-
-               case 'O':
-                       tostdoutFlag = TRUE;
-                       tarName = "-";
-                       break;
-
-               case '-':
-                       usage(tar_usage);
-                       break;
-
-               default:
-                       fatalError( "Unknown tar flag '%c'\n" 
-                                       "Try `tar --help' for more information\n", *options);
+       /* Parse any options */
+       while (--argc > 0 && strspn(*(++argv), "-cxt") >0 ) {
+               stopIt=FALSE;
+               while (stopIt==FALSE && *argv && **argv) {
+                       switch (**argv) {
+                               case 'f':
+                                       if (--argc == 0) {
+                                               fatalError( "Option requires an argument: No file specified\n");
+                                       }
+                                       if (*tarName != '-')
+                                               fatalError( "Only one 'f' option allowed\n");
+                                       tarName = *(++argv);
+                                       if (tarName == NULL)
+                                               fatalError( "Option requires an argument: No file specified\n");
+                                       stopIt=TRUE;
+                                       break;
+
+                               case 't':
+                                       if (extractFlag == TRUE || createFlag == TRUE)
+                                               goto flagError;
+                                       listFlag = TRUE;
+                                       break;
+
+                               case 'x':
+                                       if (listFlag == TRUE || createFlag == TRUE)
+                                               goto flagError;
+                                       extractFlag = TRUE;
+                                       break;
+                               case 'c':
+                                       if (extractFlag == TRUE || listFlag == TRUE)
+                                               goto flagError;
+                                       createFlag = TRUE;
+                                       break;
+
+                               case 'v':
+                                       verboseFlag = TRUE;
+                                       break;
+
+                               case 'O':
+                                       tostdoutFlag = TRUE;
+                                       tarName = "-";
+                                       break;
+                               case '-':
+#if defined BB_FEATURE_TAR_EXCLUDE
+                                       if (strcmp(*argv, "-exclude")==0) {
+                                               if (--argc == 0) {
+                                                       fatalError( "Option requires an argument: No file specified\n");
+                                               }
+                                               excludeList=realloc( excludeList, sizeof(char**) * (excludeListSize+2));
+                                               excludeList[excludeListSize] = *(++argv);
+                                               /* Remove leading "/"s */
+                                               if (*excludeList[excludeListSize] =='/') {
+                                                       excludeList[excludeListSize] = (excludeList[excludeListSize])+1;
+                                               }
+                                               if (excludeList[excludeListSize++] == NULL)
+                                                       fatalError( "Option requires an argument: No file specified\n");
+                                               /* Tack a NULL onto the end of the list */
+                                               excludeList[excludeListSize] = NULL;
+                                               stopIt=TRUE;
+                                               break;
+                                       }
+#endif
+                                       if (strcmp(*argv, "-help")==0) {
+                                               usage(tar_usage);
+                                       }
+                                       break;
+
+                               default:
+                                       fatalError( "Unknown tar flag '%c'\n" 
+                                                       "Try `tar --help' for more information\n", **argv);
+                       }
+                       ++(*argv);
                }
        }
 
@@ -250,10 +267,11 @@ extern int tar_main(int argc, char **argv)
 #ifndef BB_FEATURE_TAR_CREATE
                fatalError( "This version of tar was not compiled with tar creation support.\n");
 #else
-               exit(writeTarFile(tarName, tostdoutFlag, verboseFlag, argc, argv));
+               exit(writeTarFile(tarName, tostdoutFlag, verboseFlag, argc, argv, excludeList));
 #endif
-       } else {
-               exit(readTarFile(tarName, extractFlag, listFlag, tostdoutFlag, verboseFlag));
+       }
+       if (listFlag == TRUE || extractFlag == TRUE) {
+               exit(readTarFile(tarName, extractFlag, listFlag, tostdoutFlag, verboseFlag, excludeList));
        }
 
   flagError:
@@ -285,11 +303,14 @@ tarExtractRegularFile(TarInfo *header, int extractFlag, int tostdoutFlag)
 
        /* Open the file to be written, if a file is supposed to be written */
        if (extractFlag==TRUE && tostdoutFlag==FALSE) {
-               if ((outFd=open(header->name, O_CREAT|O_TRUNC|O_WRONLY, header->mode & ~S_IFMT)) < 0)
-                       errorMsg(io_error, header->name, strerror(errno)); 
                /* Create the path to the file, just in case it isn't there...
                 * This should not screw up path permissions or anything. */
                createPath(header->name, 0777);
+               if ((outFd=open(header->name, O_CREAT|O_TRUNC|O_WRONLY, 
+                                               header->mode & ~S_IFMT)) < 0) {
+                       errorMsg(io_error, header->name, strerror(errno)); 
+                       return( FALSE);
+               }
        }
 
        /* Write out the file, if we are supposed to be doing that */
@@ -321,6 +342,8 @@ tarExtractRegularFile(TarInfo *header, int extractFlag, int tostdoutFlag)
                                errorMsg(io_error, header->name, strerror(errno)); 
                                return( FALSE);
                        }
+               } else {
+                       actualWriteSz=writeSize;
                }
 
                size -= actualWriteSz;
@@ -453,10 +476,23 @@ static int
 readTarHeader(struct TarHeader *rawHeader, struct TarInfo *header)
 {
        int i;
-       long chksum, sum;
+       long chksum, sum=0;
        unsigned char *s = (unsigned char *)rawHeader;
 
        header->name  = rawHeader->name;
+       /* Check for and relativify any absolute paths */
+       if ( *(header->name) == '/' ) {
+               static int alreadyWarned=FALSE;
+
+               while (*(header->name) == '/')
+                       ++*(header->name);
+
+               if (alreadyWarned == FALSE) {
+                       errorMsg("tar: Removing leading '/' from member names\n");
+                       alreadyWarned = TRUE;
+               }
+       }
+
        header->mode  = getOctal(rawHeader->mode, sizeof(rawHeader->mode));
        header->uid   =  getOctal(rawHeader->uid, sizeof(rawHeader->uid));
        header->gid   =  getOctal(rawHeader->gid, sizeof(rawHeader->gid));
@@ -469,12 +505,16 @@ readTarHeader(struct TarHeader *rawHeader, struct TarInfo *header)
        header->devminor  = getOctal(rawHeader->devminor, sizeof(rawHeader->devminor));
 
        /* Check the checksum */
-       sum = ' ' * sizeof(rawHeader->chksum);
-       for ( i = TarChecksumOffset; i > 0; i-- )
-               sum += *s++;
-       s += sizeof(rawHeader->chksum);       
-       for ( i = (512 - TarChecksumOffset - sizeof(rawHeader->chksum)); i > 0; i-- )
+       for (i = sizeof(*rawHeader); i-- != 0;) {
                sum += *s++;
+       }
+       /* Remove the effects of the checksum field (replace 
+        * with blanks for the purposes of the checksum) */
+       s = rawHeader->chksum;
+       for (i = sizeof(rawHeader->chksum) ; i-- != 0;) {
+               sum -= *s++;
+       }
+       sum += ' ' * sizeof(rawHeader->chksum);
        if (sum == chksum )
                return ( TRUE);
        return( FALSE);
@@ -486,14 +526,15 @@ readTarHeader(struct TarHeader *rawHeader, struct TarInfo *header)
  * If the list is empty than all files are extracted or listed.
  */
 static int readTarFile(const char* tarName, int extractFlag, int listFlag, 
-               int tostdoutFlag, int verboseFlag)
+               int tostdoutFlag, int verboseFlag, char** excludeList)
 {
-       int status, tarFd=0;
+       int status, tarFd=-1;
        int errorFlag=FALSE;
        TarHeader rawHeader;
        TarInfo header;
-       int alreadyWarned=FALSE;
-       //int skipFileFlag=FALSE;
+#if defined BB_FEATURE_TAR_EXCLUDE
+       char** tmpList;
+#endif
 
        /* Open the tar file for reading.  */
        if (!strcmp(tarName, "-"))
@@ -514,7 +555,6 @@ static int readTarFile(const char* tarName, int extractFlag, int listFlag,
 
                /* First, try to read the header */
                if ( readTarHeader(&rawHeader, &header) == FALSE ) {
-                       close( tarFd);
                        if ( *(header.name) == '\0' ) {
                                goto endgame;
                        } else {
@@ -525,19 +565,34 @@ static int readTarFile(const char* tarName, int extractFlag, int listFlag,
                }
                if ( *(header.name) == '\0' )
                                goto endgame;
-
-               /* Check for and relativify any absolute paths */
-               if ( *(header.name) == '/' ) {
-
-                       while (*(header.name) == '/')
-                               ++*(header.name);
-
-                       if (alreadyWarned == FALSE) {
-                               errorMsg("Absolute path detected, removing leading slashes\n");
-                               alreadyWarned = TRUE;
+               header.tarFd = tarFd;
+
+#if defined BB_FEATURE_TAR_EXCLUDE
+               {
+                       int skipFlag=FALSE;
+                       /* Check for excluded files....  */
+                       for (tmpList=excludeList; tmpList && *tmpList; tmpList++) {
+                               /* Do some extra hoop jumping for when directory names
+                                * end in '/' but the entry in tmpList doesn't */
+                               if (strncmp( *tmpList, header.name, strlen(*tmpList))==0 || (
+                                                       header.name[strlen(header.name)-1]=='/'
+                                                       && strncmp( *tmpList, header.name, 
+                                                               MIN(strlen(header.name)-1, strlen(*tmpList)))==0)) {
+                                       /* If it is a regular file, pretend to extract it with
+                                        * the extractFlag set to FALSE, so the junk in the tarball
+                                        * is properly skipped over */
+                                       if ( header.type==REGTYPE || header.type==REGTYPE0 ) {
+                                                       tarExtractRegularFile(&header, FALSE, FALSE);
+                                       }
+                                       skipFlag=TRUE;
+                                       break;
+                               }
                        }
+                       /* There are not the droids you're looking for, move along */
+                       if (skipFlag==TRUE)
+                               continue;
                }
-
+#endif
                /* Special treatment if the list (-t) flag is on */
                if (verboseFlag == TRUE && extractFlag == FALSE) {
                        int len, len1;
@@ -562,7 +617,7 @@ static int readTarFile(const char* tarName, int extractFlag, int listFlag,
                                len1=snprintf(buf, sizeof(buf), "%ld,%-ld ", 
                                                header.devmajor, header.devminor);
                        } else {
-                               len1=snprintf(buf, sizeof(buf), "%d ", header.size);
+                               len1=snprintf(buf, sizeof(buf), "%lu ", (long)header.size);
                        }
                        /* Jump through some hoops to make the columns match up */
                        for(;(len+len1)<31;len++)
@@ -592,13 +647,6 @@ static int readTarFile(const char* tarName, int extractFlag, int listFlag,
                        printf("\n");
                }
 
-#if 0
-               /* See if we want to restore this file or not */
-               skipFileFlag=FALSE;
-               if (wantFileName(outName) == FALSE) {
-                       skipFileFlag = TRUE;
-               }
-#endif
                /* Remove any clutter lying in our way */
                unlink( header.name);
 
@@ -675,6 +723,7 @@ struct TarBallInfo
                                                                         tarball lives, so we can avoid trying 
                                                                         to include the tarball into itself */
        int verboseFlag;              /* Whether to print extra stuff or not */
+       char** excludeList;           /* List of files to not include */
 };
 typedef struct TarBallInfo TarBallInfo;
 
@@ -719,6 +768,9 @@ writeTarHeader(struct TarBallInfo *tbInfo, const char *fileName, struct stat *st
 {
        long chksum=0;
        struct TarHeader header;
+#if defined BB_FEATURE_TAR_EXCLUDE
+       char** tmpList;
+#endif
        const unsigned char *cp = (const unsigned char *) &header;
        ssize_t size = sizeof(struct TarHeader);
 
@@ -730,11 +782,30 @@ writeTarHeader(struct TarBallInfo *tbInfo, const char *fileName, struct stat *st
                        errorMsg("tar: Removing leading '/' from member names\n");
                        alreadyWarned=TRUE;
                }
-               strcpy(header.name, fileName+1); 
+               strncpy(header.name, fileName+1, sizeof(header.name)); 
        }
        else {
-               strcpy(header.name, fileName); 
+               strncpy(header.name, fileName, sizeof(header.name)); 
        }
+
+#if defined BB_FEATURE_TAR_EXCLUDE
+       /* Check for excluded files....  */
+       for (tmpList=tbInfo->excludeList; tmpList && *tmpList; tmpList++) {
+               /* Do some extra hoop jumping for when directory names
+                * end in '/' but the entry in tmpList doesn't */
+               if (strncmp( *tmpList, header.name, strlen(*tmpList))==0 || (
+                                       header.name[strlen(header.name)-1]=='/'
+                                       && strncmp( *tmpList, header.name, 
+                                               MIN(strlen(header.name)-1, strlen(*tmpList)))==0)) {
+                       /* Set the mode to something that is not a regular file, thereby
+                        * faking out writeTarFile into thinking that nothing further need
+                        * be done for this file.  Yes, I know this is ugly, but it works. */
+                       statbuf->st_mode = 0;
+                       return( TRUE);
+               }
+       }
+#endif
+
        putOctal(header.mode, sizeof(header.mode), statbuf->st_mode);
        putOctal(header.uid, sizeof(header.uid), statbuf->st_uid);
        putOctal(header.gid, sizeof(header.gid), statbuf->st_gid);
@@ -743,22 +814,25 @@ writeTarHeader(struct TarBallInfo *tbInfo, const char *fileName, struct stat *st
        strncpy(header.magic, TAR_MAGIC TAR_VERSION, 
                        TAR_MAGIC_LEN + TAR_VERSION_LEN );
 
+       /* Enter the user and group names (default to root if it fails) */
        my_getpwuid(header.uname, statbuf->st_uid);
-       /* Put some sort of sane fallback in place... */
        if (! *header.uname)
-               strncpy(header.uname, "root", 5);
+               strcpy(header.uname, "root");
        my_getgrgid(header.gname, statbuf->st_gid);
        if (! *header.uname)
-               strncpy(header.uname, "root", 5);
+               strcpy(header.uname, "root");
 
-       // FIXME: (or most likely not) I break Hard Links
+       /* WARNING/NOTICE: I break Hard Links */
        if (S_ISLNK(statbuf->st_mode)) {
+               int link_size=0;
                char buffer[BUFSIZ];
                header.typeflag  = SYMTYPE;
-               if ( readlink(fileName, buffer, sizeof(buffer) - 1) < 0) {
+               link_size = readlink(fileName, buffer, sizeof(buffer) - 1);
+               if ( link_size < 0) {
                        errorMsg("Error reading symlink '%s': %s\n", header.name, strerror(errno));
                        return ( FALSE);
                }
+               buffer[link_size] = '\0';
                strncpy(header.linkname, buffer, sizeof(header.linkname)); 
        } else if (S_ISDIR(statbuf->st_mode)) {
                header.typeflag  = DIRTYPE;
@@ -868,12 +942,11 @@ static int writeFileToTarball(const char *fileName, struct stat *statbuf, void*
 }
 
 static int writeTarFile(const char* tarName, int tostdoutFlag, 
-               int verboseFlag, int argc, char **argv)
+               int verboseFlag, int argc, char **argv, char** excludeList)
 {
        int tarFd=-1;
        int errorFlag=FALSE;
        ssize_t size;
-       //int skipFileFlag=FALSE;
        struct TarBallInfo tbInfo;
        tbInfo.verboseFlag = verboseFlag;
 
@@ -890,6 +963,7 @@ static int writeTarFile(const char* tarName, int tostdoutFlag,
                errorMsg( "tar: Error opening '%s': %s\n", tarName, strerror(errno));
                return ( FALSE);
        }
+       tbInfo.excludeList=excludeList;
        /* Store the stat info for the tarball's file, so
         * can avoid including the tarball into itself....  */
        if (fstat(tbInfo.tarFd, &tbInfo.statBuf) < 0)
@@ -911,6 +985,12 @@ static int writeTarFile(const char* tarName, int tostdoutFlag,
        for (size=0; size<(2*TAR_BLOCK_SIZE); size++) {
                write(tbInfo.tarFd, "\0", 1);
        }
+
+       /* To be pedantically correct, we would check if the tarball
+        * is smaller then 20 tar blocks, and pad it if it was smaller,
+        * but that isn't necessary for GNU tar interoperability, and
+        * so is considered a waste of space */
+
        /* Hang up the tools, close up shop, head home */
        close(tarFd);
        if (errorFlag == TRUE) {