diff options
| -rw-r--r-- | archival/tar.c | 77 |
1 files changed, 35 insertions, 42 deletions
diff --git a/archival/tar.c b/archival/tar.c index b326d1e..d875805 100644 --- a/archival/tar.c +++ b/archival/tar.c @@ -150,40 +150,29 @@ static HardLinkInfo *findHardLinkInfo(HardLinkInfo * hlInfo, struct stat *statbu /* Put an octal string into the specified buffer. * The number is zero padded and possibly null terminated. - * Returns TRUE if successful. - DISABLED (no caller ever checked) */ -/* FIXME: we leave field untouched if value doesn't fit. */ -/* This is not good - what will happen at untar time?? */ -static void putOctal(char *cp, int len, long long value) + * Stores low-order bits only if whole value does not fit. + * Returns FALSE if that happens. */ +static int putOctal(char *cp, int len, off_t value) { - int tempLength; - /* 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 tempBuffer[sizeof(off_t)*3+1]; char *tempString = tempBuffer; + int width; - /* Create a string of the specified length with - * leading zeroes and the octal number, and a trailing null. */ - 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' */ - } + width = sprintf(tempBuffer, "%0*"OFF_FMT"o", len, value); + tempString += (width - len); - /* Copy the string to the field. */ + /* If string has leading zeroes, we can drop one */ + /* and field will have trailing '\0' */ + /* (increases chances of compat with other tars) */ + if (tempString[0] == '0') + tempString++; + + /* Copy the string to the field */ memcpy(cp, tempString, len); - /*return TRUE;*/ + + /* If after shift we have zero - value did not overflow, */ + /* return 1 (TRUE) then */ + return (value >> (len*3)) == 0; } /* Write out a tar header for the specified file/directory/whatever */ @@ -203,12 +192,13 @@ static int writeTarHeader(struct TarBallInfo *tbInfo, safe_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. */ - 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); + 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 */ - putOctal(header.mtime, sizeof(header.mtime), statbuf->st_mtime); + PUT_OCTAL(header.mtime, statbuf->st_mtime); strcpy(header.magic, "ustar "); /* Enter the user and group names */ @@ -240,25 +230,28 @@ static int writeTarHeader(struct TarBallInfo *tbInfo, strncat(header.name, "/", sizeof(header.name)); } else if (S_ISCHR(statbuf->st_mode)) { header.typeflag = CHRTYPE; - putOctal(header.devmajor, sizeof(header.devmajor), - major(statbuf->st_rdev)); - putOctal(header.devminor, sizeof(header.devminor), - minor(statbuf->st_rdev)); + PUT_OCTAL(header.devmajor, major(statbuf->st_rdev)); + PUT_OCTAL(header.devminor, minor(statbuf->st_rdev)); } else if (S_ISBLK(statbuf->st_mode)) { header.typeflag = BLKTYPE; - putOctal(header.devmajor, sizeof(header.devmajor), - major(statbuf->st_rdev)); - putOctal(header.devminor, sizeof(header.devminor), - minor(statbuf->st_rdev)); + PUT_OCTAL(header.devmajor, major(statbuf->st_rdev)); + PUT_OCTAL(header.devminor, minor(statbuf->st_rdev)); } else if (S_ISFIFO(statbuf->st_mode)) { header.typeflag = FIFOTYPE; } else if (S_ISREG(statbuf->st_mode)) { header.typeflag = REGTYPE; - putOctal(header.size, sizeof(header.size), statbuf->st_size); + if ((PUT_OCTAL(header.size, statbuf->st_size) == FALSE) + && sizeof(statbuf->st_size) > 4 + ) { + bb_error_msg_and_die("cannot store file '%s' " + "of size %"OFF_FMT"d, aborting", + fileName, statbuf->st_size); + } } else { 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 |