tar:

* unpack: handle tar header fields which are not NUL terminated
* pack: handle 4+GB files correctly
* pack: refuse to store 101+ softlinks (was truncating link
  target name)
* pack: mask mode with 07777



git-svn-id: svn://busybox.net/trunk/busybox@16650 69ca8d6d-28ef-0310-b511-8ec308f3f277

1 files changed, 127 insertions, 105 deletions

diff --git a/archival/tar.c b/archival/tar.c
index db812e0f4..911c2d35e 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -35,25 +35,26 @@
 #define TAR_BLOCK_SIZE          512
 
 /* POSIX tar Header Block, from POSIX 1003.1-1990  */
-#define NAME_SIZE                       100
-struct TarHeader {              /* byte offset */
-        char name[NAME_SIZE];   /*   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[NAME_SIZE];       /* 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) */
+#define NAME_SIZE      100
+#define NAME_SIZE_STR "100"
+struct TarHeader {                /* byte offset */
+        char name[NAME_SIZE];     /*   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[NAME_SIZE]; /* 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;
 
@@ -121,8 +122,8 @@ static void addHardLinkInfo(HardLinkInfo ** hlInfoHeadPtr,
 
 static void freeHardLinkInfo(HardLinkInfo ** hlInfoHeadPtr)
 {
-        HardLinkInfo *hlInfo = NULL;
-        HardLinkInfo *hlInfoNext = NULL;
+        HardLinkInfo *hlInfo;
+        HardLinkInfo *hlInfoNext;
 
         if (hlInfoHeadPtr) {
                 hlInfo = *hlInfoHeadPtr;
@@ -148,60 +149,70 @@ static HardLinkInfo *findHardLinkInfo(HardLinkInfo * hlInfo, struct stat *statbu
 }
 
 /* Put an octal string into the specified buffer.
- * The number is zero and space padded and possibly null padded.
- * Returns TRUE if successful.  */
-static int putOctal(char *cp, int len, long value)
+ * The number is zero padded and possibly null terminated.
+ * Returns TRUE if successful. - DISABLED (no caller ever checked)  */
+static void putOctal(char *cp, int len, long long value)
 {
         int tempLength;
-        char tempBuffer[32];
+        /* long long for the sake of storing lengths of 4Gb+ files */
+        /* (we are bust anyway after 64Gb: it doesn't fit into the field) */
+        char tempBuffer[sizeof(long long)*3+1];
         char *tempString = tempBuffer;
 
-        /* Create a string of the specified length with an initial space,
+        /* Create a string of the specified length with
          * leading zeroes and the octal number, and a trailing null.  */
-        sprintf(tempString, "%0*lo", len - 1, value);
-
-        /* If the string is too large, suppress the leading space.  */
-        tempLength = strlen(tempString) + 1;
-        if (tempLength > len) {
-                tempLength--;
-                tempString++;
+        tempLength = sprintf(tempBuffer, "%0*llo", len - 1, value);
+
+        /* If the string is too large, suppress leading 0's.  */
+        /* If that is not enough, drop trailing null.  */
+        tempLength -= len; /* easier to do checks */
+        while (tempLength >= 0) {
+                if (tempString[0] != '0') {
+                        if (!tempLength) {
+                                /* 1234 barely fits in 4 chars (w/o EOL '\0') */
+                                break;
+                        }
+                        /* 12345 doesn't fit into 4 chars */
+                        return /*FALSE*/;
+                }
+                tempLength--; /* still have leading '0', */
+                tempString++; /* can afford to drop it but retain EOL '\0' */
         }
 
-        /* If the string is still too large, suppress the trailing null.  */
-        if (tempLength > len)
-                tempLength--;
-
-        /* If the string is still too large, fail.  */
-        if (tempLength > len)
-                return FALSE;
-
         /* Copy the string to the field.  */
         memcpy(cp, tempString, len);
-
-        return TRUE;
+        /*return TRUE;*/
 }
 
 /* Write out a tar header for the specified file/directory/whatever */
+void BUG_tar_header_size(void);
 static int writeTarHeader(struct TarBallInfo *tbInfo,
                 const char *header_name, const char *fileName, struct stat *statbuf)
 {
-        long chksum = 0;
         struct TarHeader header;
-        const unsigned char *cp = (const unsigned char *) &header;
-        ssize_t size = sizeof(struct TarHeader);
+        const unsigned char *cp;
+        int chksum;
+        int size;
 
-        bzero(&header, size);
+        if (sizeof(header) != 512)
+                BUG_tar_header_size();
+
+        bzero(&header, sizeof(struct TarHeader));
 
         safe_strncpy(header.name, header_name, sizeof(header.name));
 
-        putOctal(header.mode, sizeof(header.mode), statbuf->st_mode);
+        /* POSIX says to mask mode with 07777. */
+        putOctal(header.mode, sizeof(header.mode), statbuf->st_mode & 07777);
         putOctal(header.uid, sizeof(header.uid), statbuf->st_uid);
         putOctal(header.gid, sizeof(header.gid), statbuf->st_gid);
-        putOctal(header.size, sizeof(header.size), 0);  /* Regular file size is handled later */
+        if (sizeof(header.size) != sizeof("00000000000"))
+                BUG_tar_header_size();
+        strcpy(header.size, "00000000000"); /* Regular file size is handled later */
         putOctal(header.mtime, sizeof(header.mtime), statbuf->st_mtime);
         strcpy(header.magic, "ustar  ");
 
         /* Enter the user and group names (default to root if it fails) */
+//cache!!!
         if (bb_getpwuid(header.uname, statbuf->st_uid, sizeof(header.uname)) == NULL)
                 strcpy(header.uname, "root");
         if (bb_getgrgid(header.gname, statbuf->st_gid, sizeof(header.gname)) == NULL)
@@ -214,11 +225,18 @@ static int writeTarHeader(struct TarBallInfo *tbInfo,
                                 sizeof(header.linkname));
         } 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 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 */
+                ) {
+                        free(lpath);
+                        bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported");
+                        return FALSE;
+                }
                 free(lpath);
         } else if (S_ISDIR(statbuf->st_mode)) {
                 header.typeflag = DIRTYPE;
@@ -252,9 +270,10 @@ static int writeTarHeader(struct TarBallInfo *tbInfo,
          * digits, followed by a null like the other fields... */
         memset(header.chksum, ' ', sizeof(header.chksum));
         cp = (const unsigned char *) &header;
-        while (size-- > 0)
-                chksum += *cp++;
-        putOctal(header.chksum, 7, chksum);
+        chksum = 0;
+        size = sizeof(struct TarHeader);
+        do { chksum += *cp++; } while (--size);
+        putOctal(header.chksum, sizeof(header.chksum)-1, chksum);
 
         /* Now write the header out to disk */
         xwrite(tbInfo->tarFd, &header, sizeof(struct TarHeader));
@@ -348,22 +367,21 @@ static int writeFileToTarball(const char *fileName, struct stat *statbuf,
         }
 
         if (strlen(fileName) >= NAME_SIZE) {
-                bb_error_msg(bb_msg_name_longer_than_foo, NAME_SIZE);
+                bb_error_msg("names longer than "NAME_SIZE_STR" chars not supported");
                 return TRUE;
         }
 
         if (header_name[0] == '\0')
                 return TRUE;
 
-        if (ENABLE_FEATURE_TAR_FROM &&
-                        exclude_file(tbInfo->excludeList, header_name)) {
+        if (exclude_file(tbInfo->excludeList, header_name))
                 return SKIP;
-        }
 
         /* Is this a regular file? */
-        if ((tbInfo->hlInfo == NULL) && (S_ISREG(statbuf->st_mode))) {
+        if (tbInfo->hlInfo == NULL && S_ISREG(statbuf->st_mode)) {
                 /* open the file we want to archive, and make sure all is well */
-                if ((inputFileFd = open(fileName, O_RDONLY)) < 0) {
+                inputFileFd = open(fileName, O_RDONLY);
+                if (inputFileFd < 0) {
                         bb_perror_msg("%s: cannot open", fileName);
                         return FALSE;
                 }
@@ -383,7 +401,8 @@ static int writeFileToTarball(const char *fileName, struct stat *statbuf,
                 close(inputFileFd);
 
                 /* Pad the file up to the tar block size */
-                readSize = (TAR_BLOCK_SIZE - readSize) & (TAR_BLOCK_SIZE-1);
+                /* (a few tricks here in the name of code size) */
+                readSize = (-(int)readSize) & (TAR_BLOCK_SIZE-1);
                 bzero(bb_common_bufsiz1, readSize);
                 xwrite(tbInfo->tarFd, bb_common_bufsiz1, readSize);
         }
@@ -423,10 +442,10 @@ static int writeTarFile(const int tar_fd, const int verboseFlag,
                 signal(SIGPIPE, SIG_IGN);       /* we only want EPIPE on errors */
 
 # if __GNUC__
-                        /* Avoid vfork clobbering */
-                        (void) &include;
-                        (void) &errorFlag;
-                        (void) &zip_exec;
+                /* Avoid vfork clobbering */
+                (void) &include;
+                (void) &errorFlag;
+                (void) &zip_exec;
 # endif
 
                 gzipPid = vfork();
@@ -498,8 +517,8 @@ static int writeTarFile(const int tar_fd, const int verboseFlag,
         if (errorFlag)
                 bb_error_msg("error exit delayed from previous errors");
 
-        if (gzipPid && waitpid(gzipPid, NULL, 0)==-1)
-                bb_error_msg("cannot wait");
+        if (gzipPid && waitpid(gzipPid, NULL, 0) == -1)
+                bb_error_msg("waitpid failed");
 
         return !errorFlag;
 }
@@ -634,7 +653,7 @@ static char get_header_tar_Z(archive_handle_t *archive_handle)
 #define TAR_OPT_STR_NOPRESERVE            "\203\213"
 #define TAR_OPT_AFTER_NOPRESERVE          TAR_OPT_AFTER_COMPRESS + 2
 
-static const char tar_options[]="txC:f:Opvk" \
+static const char tar_options[] = "txC:f:Opvk" \
         TAR_OPT_STR_CREATE \
         TAR_OPT_STR_BZIP2 \
         TAR_OPT_STR_LZMA \
@@ -645,38 +664,38 @@ static const char tar_options[]="txC:f:Opvk" \
 
 #ifdef CONFIG_FEATURE_TAR_LONG_OPTIONS
 static const struct option tar_long_options[] = {
-        { "list",                               0,      NULL,   't' },
-        { "extract",                    0,      NULL,   'x' },
-        { "directory",                  1,      NULL,   'C' },
-        { "file",                               1,      NULL,   'f' },
-        { "to-stdout",                  0,      NULL,   'O' },
-        { "same-permissions",   0,      NULL,   'p' },
-        { "verbose",                    0,      NULL,   'v' },
-        { "keep-old",                   0,      NULL,   'k' },
-        { "no-same-owner",              0,      NULL,   '\203' },
-        { "no-same-permissions",0,      NULL,   '\213' },
+        { "list",               0,  NULL,   't' },
+        { "extract",            0,  NULL,   'x' },
+        { "directory",          1,  NULL,   'C' },
+        { "file",               1,  NULL,   'f' },
+        { "to-stdout",          0,  NULL,   'O' },
+        { "same-permissions",   0,  NULL,   'p' },
+        { "verbose",            0,  NULL,   'v' },
+        { "keep-old",           0,  NULL,   'k' },
+        { "no-same-owner",      0,  NULL,   '\203' },
+        { "no-same-permissions",0,  NULL,   '\213' },
 # ifdef CONFIG_FEATURE_TAR_CREATE
-        { "create",                             0,      NULL,   'c' },
-        { "dereference",                0,      NULL,   'h' },
+        { "create",             0,  NULL,   'c' },
+        { "dereference",        0,  NULL,   'h' },
 # endif
 # ifdef CONFIG_FEATURE_TAR_BZIP2
-        { "bzip2",                              0,      NULL,   'j' },
+        { "bzip2",              0,  NULL,   'j' },
 # endif
 # ifdef CONFIG_FEATURE_TAR_LZMA
-        { "lzma",                               0,      NULL,   'a' },
+        { "lzma",               0,  NULL,   'a' },
 # endif
 # ifdef CONFIG_FEATURE_TAR_FROM
-        { "files-from",                 1,      NULL,   'T' },
-        { "exclude-from",               1,      NULL,   'X' },
-        { "exclude",                    1,      NULL,   '\n' },
+        { "files-from",         1,  NULL,   'T' },
+        { "exclude-from",       1,  NULL,   'X' },
+        { "exclude",            1,  NULL,   '\n' },
 # endif
 # ifdef CONFIG_FEATURE_TAR_GZIP
-        { "gzip",                               0,      NULL,   'z' },
+        { "gzip",               0,  NULL,   'z' },
 # endif
 # ifdef CONFIG_FEATURE_TAR_COMPRESS
-        { "compress",                   0,      NULL,   'Z' },
+        { "compress",           0,  NULL,   'Z' },
 # endif
-        { 0,                                    0, 0, 0 }
+        { 0,                    0, 0, 0 }
 };
 #else
 #define tar_long_options        0
@@ -712,22 +731,23 @@ int tar_main(int argc, char **argv)
                                 );
 
         if (opt & CTX_TEST) {
-                if ((tar_handle->action_header == header_list) ||
-                        (tar_handle->action_header == header_verbose_list))
-                {
+                if (tar_handle->action_header == header_list
+                 || tar_handle->action_header == header_verbose_list
+                ) {
                         tar_handle->action_header = header_verbose_list;
-                } else tar_handle->action_header = header_list;
+                } else
+                        tar_handle->action_header = header_list;
         }
-        if((opt & CTX_EXTRACT) && tar_handle->action_data != data_extract_to_stdout)
+        if ((opt & CTX_EXTRACT) && tar_handle->action_data != data_extract_to_stdout)
                 tar_handle->action_data = data_extract_all;
 
         if (opt & TAR_OPT_2STDOUT)
                 tar_handle->action_data = data_extract_to_stdout;
 
         if (opt & TAR_OPT_VERBOSE) {
-                if ((tar_handle->action_header == header_list) ||
-                        (tar_handle->action_header == header_verbose_list))
-                {
+                if (tar_handle->action_header == header_list
+                 || tar_handle->action_header == header_verbose_list
+                ) {
                         tar_handle->action_header = header_verbose_list;
                 } else
                         tar_handle->action_header = header_list;
@@ -782,7 +802,7 @@ int tar_main(int argc, char **argv)
                 optind++;
         }
 
-        if ((tar_handle->accept) || (tar_handle->reject))
+        if (tar_handle->accept || tar_handle->reject)
                 tar_handle->filter = filter_accept_reject_list;
 
         /* Open the tar file */
@@ -796,8 +816,9 @@ int tar_main(int argc, char **argv)
                                 bb_error_msg_and_die("empty archive");
 
                         tar_stream = stdout;
-                        flags = O_WRONLY | O_CREAT | O_EXCL;
-                        unlink(tar_filename);
+                        /* Mimicking GNU tar 1.15.1: */
+                        flags = O_WRONLY|O_CREAT|O_TRUNC;
+                /* was doing unlink; open(O_WRONLY|O_CREAT|O_EXCL); why? */
                 } else {
                         tar_stream = stdin;
                         flags = O_RDONLY;
@@ -824,9 +845,9 @@ int tar_main(int argc, char **argv)
                 if (ENABLE_FEATURE_TAR_BZIP2 && get_header_ptr == get_header_tar_bz2)
                         zipMode = 2;
 
-                if ((tar_handle->action_header == header_list) ||
-                                (tar_handle->action_header == header_verbose_list))
-                {
+                if (tar_handle->action_header == header_list
+                 || tar_handle->action_header == header_verbose_list
+                ) {
                         verboseFlag = TRUE;
                 }
                 writeTarFile(tar_handle->src_fd, verboseFlag, opt & TAR_OPT_DEREFERENCE,
@@ -839,9 +860,10 @@ int tar_main(int argc, char **argv)
                 /* Check that every file that should have been extracted was */
                 while (tar_handle->accept) {
                         if (!find_list_entry(tar_handle->reject, tar_handle->accept->data)
-                                && !find_list_entry(tar_handle->passed, tar_handle->accept->data))
-                        {
-                                bb_error_msg_and_die("%s: not found in archive", tar_handle->accept->data);
+                         && !find_list_entry(tar_handle->passed, tar_handle->accept->data)
+                        ) {
+                                bb_error_msg_and_die("%s: not found in archive",
+                                        tar_handle->accept->data);
                         }
                         tar_handle->accept = tar_handle->accept->link;
                 }
@@ -850,5 +872,5 @@ int tar_main(int argc, char **argv)
         if (ENABLE_FEATURE_CLEAN_UP && tar_handle->src_fd != STDIN_FILENO)
                 close(tar_handle->src_fd);
 
-        return(EXIT_SUCCESS);
+        return EXIT_SUCCESS;
 }